JP6913295B2 - Glass plate and manufacturing method of glass plate - Google Patents

Description

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

In recent years, in order to meet the demand for improvement in the production efficiency of liquid crystal displays and the like, the demand for improvement in the manufacturing efficiency of the glass substrate used for the display and the like has been increasing. Here, in the manufacture of a glass substrate, one or a plurality of glass substrates are cut out from a large glass original plate (molded original plate). This makes it possible to obtain a glass substrate having desired dimensions.

On the other hand, since the end surface of the glass substrate cut out from the glass original plate is usually a cut surface or a folded surface, there are often minute scratches (defects). If there is a scratch on the end face of the glass substrate, cracks will occur from the scratch. To prevent this, grinding (rough polishing) and polishing (finish polishing) are applied to the end face of the glass substrate. (See, for example, Patent Document 1).

International release WO2013 / 187400

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

When the end face is subjected to, for example, grinding using the above-mentioned grindstone, the finished end face is flattened. However, if the positioning pin is made of rubber or plastic with a hardness of about 60 degrees and the positioning pin is elastically deformed, the end face after processing becomes too flat, and the contact area between the positioning pin and the end face increases. do. As a result, there is a problem that glass powder is likely to be generated.

In view of the above circumstances, it is a technical problem to be solved by the present invention to prevent the generation of glass powder from the end face as much as possible by forming a predetermined minute waviness on the end face of the glass plate.

The solution to the above problems is achieved by the glass plate according to the present invention. That is, this glass plate is a glass plate in which the end face has been subjected to a predetermined process, and is characterized in that the arithmetic mean 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 mean swell Wa of the end face, and the minimum value that the value of the arithmetic mean swell Wa should satisfy is defined. If the end face has such a shape, for example, when a positioning member such as a pin comes into contact with the end face of the glass plate during each manufacturing process of a glass plate or a product having a glass plate as an element or during interprocess transportation, the end face becomes Since it mainly comes into contact with the peak portion of the minute undulation (details will be described later), the contact area with the positioning member can be reduced. This makes it possible to suppress the generation of glass powder.

Further, in the glass plate according to 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 face in this way, the height difference between the peak and the valley of the minute undulations of the end face becomes large, and it becomes difficult for the positioning member and the valley of the minute undulations to come into contact with each other. As a result, the contact area with the positioning member can be further reduced, and the generation of glass powder can be suppressed more effectively.

Further, in the glass plate according to 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 minute undulations becomes long. Therefore, since the number of ridges of minute undulations that come into contact with the positioning member is reduced, the contact area with the positioning member can be further reduced, and the generation of glass powder can be suppressed more effectively.

Further, in the glass plate according to the present invention, the skewness Wsk of the end face may be larger than 0.

By defining the skewness Wsk of the end face in this way, the shape of the minute undulation can be indirectly defined. That is, when the skewness Wsk takes a positive value, the mountainous portion of the minute swell tends to have a sharp shape. Therefore, by defining the skewness Wsk to 0 or more, it is possible to reduce the contact area between the positioning member and the peak portion of the minute waviness of the end face. As a result, the contact area with the positioning member can be further reduced, and the generation of glass powder can be suppressed more effectively.

Further, the glass plate according to the present invention satisfies the relationship of the following formula 1 when one cycle of minute waviness appearing on the end face is A [mm] and the height difference between the peak and the valley is B [mm]. It may be.

ここで、位置決めピン６の半径ｒと周期Ａ、及び距離Ｃとの間には数式３に示す関係が成り立つ。なお、数式３における変数Ａは、微小うねり３の隣り合う山部４，４間の距離［ｍｍ］である。

数式３を変形すると、距離Ｃは、数式４の如く半径ｒと周期Ａの関数として表される。

数式４を数式２に代入して整理すると、数式５が得られる。

ここで、位置決めピン６の外径寸法（半径ｒの二倍）の代表的な大きさを例えば４００ｍｍとした場合、数式１が得られる。 The above specification is made by paying attention to the relationship between the shape of the minute waviness appearing on the end face of the glass plate and the contact state with the positioning pin. That is, when the end face of the glass plate is processed with an axially rotatable grindstone, as shown in FIG. 3, minute waviness 3 having a period of unevenness longer than the roughness curve such as surface roughness Ra may appear on the end face 2. be. The minute waviness 3 appears in the same order as the waviness curve of the arithmetic mean waviness Wa, and the uneven shape (the shape of the peak 4 and the valley 5) forms a substantially arc shape following the outer shape of the grindstone. Often. Therefore, for example, when considering a state in which the positioning pin 6 having a radius r [mm] is in contact with the adjacent peaks 4 and 4 of the minute undulations 3 forming a substantially arc shape, as long as the relationship specified in the following mathematical formula 2 is satisfied. , The positioning pin 6 does not come into contact with the valley portion 5 of the minute swell 3. The variable B in Equation 2 is the height difference [mm] between the peak 4 and the valley 5, and the variable C is the midpoint P2 to the positioning pin 6 between the contact points P1 and P1 between the positioning pin 6 and the peak 4. The distance [mm] to the center point P3 of.

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 the mathematical formula 3 is the distance [mm] between the adjacent peaks 4 and 4 of the minute swell 3.

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

By substituting the formula 4 into the formula 2 and rearranging it, the formula 5 is obtained.

Here, when the typical size of the outer diameter dimension (twice the radius r) of the positioning pin 6 is set to, for example, 400 mm, Equation 1 can be obtained.

In this way, by considering the specific contact mode with the positioning pin and shaping the minute undulation into an optimum shape, it is possible to prevent the positioning pin from coming into contact with the valley portion of the minute undulation as much as possible. Therefore, it is possible to more effectively suppress the generation of glass powder.

Further, the solution of the above problems is also achieved by the method for manufacturing a glass plate according to the present invention. That is, in this manufacturing method, a glass plate is manufactured including an end face processing step of performing a predetermined processing on the end face by moving a rotating processing tool relative to the end face while making contact with the end face of the glass plate. The method is characterized in that the end face is subjected to a predetermined process with a grindstone so that the arithmetic mean waviness Wa of the end face is 2.7 μm or more.

In the present invention, attention is paid to the arithmetic mean swell Wa of the end face, and the end face is subjected to predetermined processing by a rotating processing tool so that the value of the arithmetic mean swell Wa is a value to be satisfied. According to this method, as in the case of the glass plate according to the present invention, when the positioning member such as a pin comes into contact with the end face of the glass plate during each manufacturing process or during interprocess transportation of the glass plate or the product having the glass plate as an element. Since the peaks of the minute waviness of the end face mainly come into contact with each other, the contact area with the positioning member can be reduced. This makes it possible to suppress the generation of glass powder.

As described above, according to the present invention, it is possible to prevent the generation of glass powder from the end face as much as possible by forming a predetermined minute waviness on the end face of the glass plate.

It is a schematic plan view of the end face processing apparatus of the glass plate which concerns on one Embodiment of this invention. It is a side view of the main part of the grindstone rotating system shown in FIG. It is a figure for demonstrating the contact mode in the swell curve order of an end face of a glass plate and a positioning pin. It is a figure which shows the contact mode in the waviness curve order between the end face of a glass plate which concerns on another form, and a positioning pin. It is a figure which shows the contact mode in the waviness curve order between the end face of the glass plate which concerns on this invention, and a positioning pin.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 5. First, an outline of the end face processing apparatus used in the manufacturing method according to the present embodiment will be described with reference to FIGS. 1 and 2.

As shown in FIGS. 1 and 2, the end face processing apparatus 10 performs predetermined processing on the end surface 2 of the glass plate 1, and includes a motor 13 for rotationally driving the grindstones 11 and 12 as end face processing portions. Mainly includes a spindle 14. The spindle 14 is connected to the motor 13. In this embodiment, the motor 13 and the spindle 14 have a common rotation axis Y. The spindle 14 may be connected to the spindle of the motor 13 via a belt or the like.

The end face processing device 10 having such a configuration may include a device for controlling the pressing force of the grindstone 11 (12) as described in Patent Document 1. Alternatively, the end face processing device 10 may be of a method of fixing the position of the grindstone 11 (12) at the time of processing. Alternatively, an end face processing device 10 other than these methods may be used.

As shown in FIG. 2, the grindstone 11 (12) is attached to the spindle 14 via the grindstone mounting flange 20. More specifically, the grindstone 11 (12) is provided with a fitting hole 21, and the grindstone mounting flange 20 is provided with a fitting convex portion 22. By fitting the fitting convex portion 22 of the grindstone mounting flange 20 into the fitting hole 21 of the grindstone 11 (12), the grindstone 11 (12) is connected to the grindstone mounting flange 20 and the grindstone mounting flange 20. Positioning including centering of the grindstone 11 (12) with respect to the whetstone 11 (12) is performed.

Further, the grindstone mounting flange 20 is provided with a fitting recess 23 on the side opposite to the fitting convex portion 22. The fitting recess 23 has a tapered shape, and can be tapered and fitted to the tip portion 24 of the spindle 14 which also has a tapered shape. Therefore, for example, after preparing the sub-assembly 25 of the grindstone 11 (12) described later and the flange 20 for mounting the grindstone, the sub-assembly 25 is attached to the tip 24 of the spindle 14 to automatically mount the grindstone 11 (12). Centering and positioning with respect to the spindle 14 of the above.

Further, in the present embodiment, the end surface 2 of the glass plate 1 is subjected to two types of processing (here, a grinding process whose main purpose is chamfering the end surface 2 and a main purpose of smoothing the minute irregularities of the end surface 2). The grindstones 11 and 12 corresponding to each of the grindstones 11 and 12 can be used in order to perform the polishing process. That is, the particle size of the abrasive grains in the second grindstone 12 for polishing is the same as or larger than the particle size of the abrasive grains in the first grindstone 11 for grinding. The particle size of the abrasive grains in the first grindstone 11 for grinding can be, for example, # 100 to # 1000, and the particle size of the abrasive grains in the second grindstone 12 for polishing can be, for example, # 200 to # 2000. be able to. The diameters of the grindstones 11 and 12 are, for example, 100 to 200 mm.

The glass plate 1 has a rectangular plate shape, for example, as shown in FIG. The thickness dimension of the glass plate 1 is preferably, for example, 0.05 mm to 10 mm, more preferably 0.2 mm to 0.7 mm. Of course, the glass plate 1 to which the present invention can be applied is not limited to the above form. 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) and a glass plate having a thickness dimension of more than 0.05 mm to 10 mm.

It is preferable that the main surface (front surface and back surface) of the glass 1 is a fire-made surface, that is, a state in which the glass 1 is not processed by a grindstone or the like and has no polishing marks. The arithmetic average roughness Ra (JIS R 1683: 2014) of the main surface of the glass 1 is preferably 10 nm or less, and more preferably 2 nm or less.

The glass plate 1 can move relative to the grindstones 11 and 12 along a predetermined feed direction X. Note that FIG. 1 shows a case where the glass plate 1 moves in the feed direction X and the grindstones 11 and 12 are fixed, but of course, the glass plate 1 is fixed and the grindstones 11 and 12 are in the feed direction X. May move in the opposite direction. Further, at this time, either one of the glass plate 1 and the grindstones 11 and 12 may move, the other may be fixed, or both may move.

The rotation direction of the grindstones 11 and 12 is arbitrary, but it is preferable to determine the rotation direction of the grindstones 11 and 12 so as to rotate in a direction facing the feed direction X of the glass plate 1, for example. In FIG. 1, it is preferable to determine the rotation direction of the grindstones 11 and 12 so that the upper grindstones 11 and 12 are counterclockwise and the lower grindstones 11 and 12 are clockwise.

Subsequently, an example of a method for manufacturing a glass sheet when the end face processing device 10 described above is used will be described.

That is, in the manufacturing method according to the present embodiment, the rotating grindstones 11 and 12 are brought into contact with the end face 2 of the glass plate 1 and the grindstones 11 and 12 are relatively moved along the end face 2. The end face 2 is provided with an end face processing step of performing a predetermined process. This manufacturing method may further include a step of preparing the glass plate 1 (glass plate preparation step). In the step of preparing the glass plate 1, for example, a molded original plate is obtained by a down draw method such as an overflow down draw method, a float method, or the like, and the glass plate 1 is cut out from the molded original plate. If necessary, after the end face 2 is processed, the glass plate 1 is inspected, packed, and the like. From the viewpoint that the main surfaces (front surface and back surface) of the glass 1 are fire-made surfaces and the arithmetic average roughness Ra is 10 nm or less, it is preferable to use the overflow down draw method in the step of preparing the glass plate 1.

In the step of performing a predetermined process on the end face 2 of the glass plate 1 (end face machining step), the subassembly 25 of the grindstone 11 (12) and the flange for mounting the grindstone 20 is prepared so as to have a predetermined static runout and dynamic balance. The subassembly preparation step S1 to be performed and the end face processing step S2 for carrying out the above-mentioned end face processing using the prepared subassembly 25 are provided. Further, 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 mean waviness Wa of the end face 2 after the end face processing is 2.7 μm or more.

(S1) Subassembly preparation step In this step, the subassembly 25 of the grindstone 11 (12) and the grindstone mounting flange 20 is prepared so that the dynamic balance is equal to or more than a predetermined value, for example, 60 g · mm or more. The dynamic balance can be measured using a predetermined dynamic balance measuring device.

At this time, the individual dynamic balances of the grindstone 11 (12) and the grindstone mounting flange 20 are not particularly limited. As long as the dynamic balance of the subassembly 25 is 60 g · mm or more, it is possible to use the grindstone 11 (12) showing an arbitrary dynamic balance and the grindstone mounting flange 20.

(S2) End Face Processing Step In this step, the subassembly 25 prepared in the preparation step S1 is attached to, for example, the spindle 14 (see FIG. 2) of the end face processing apparatus 10 shown in FIG. Perform predetermined end face processing (grinding and polishing).

Here, FIG. 4 shows an example of the waviness curve of the end face 2'of the glass plate 1'obtained when the subassembly 25 having the dynamic balance of 10 g · mm is used, and FIG. 5 shows the dynamic balance of 80 g · mm. An example of the waviness curve of the end face 2 of the glass plate 1 obtained when the subassembly 25 is used is shown. Both of these glass plates 1, 1'have a rectangular shape of 2250 mm × 2500 mm and have a thickness of 0.5 mm. The end face processing was performed on the end faces of the long sides of the glass plates 1, 1'using the end face processing device 10 shown in FIG. In the end face processing, one set of the first grindstone 11 for grinding was arranged, and one set of the second grindstone 12 for polishing was arranged. The dynamic balance of the subassembly 25 between the grindstone 11 (12) and the flange for mounting the grindstone 20 was the same for all (the first grindstone 11 for grinding and the second grindstone 12 for polishing).

As shown in FIG. 4, when the subassembly 25 having a dynamic balance of 10 g · mm is used, the height difference between the mountain portion 4'and the valley portion 5'is very large in the undulation curve of the obtained end face 2'. A small swell 3'appeared in. In this case, the arithmetic mean waviness Wa of the end face 2'was 2.5 μm, the average height Wc was 5 μm, and the average length Wsm was 2500 μm.

On the other hand, when the subassembly 25 having a dynamic balance of 80 g · mm was used, the undulation curve of the obtained end face 2 followed the outer shape of the grindstone 11 (12) as shown in FIG. A minute swell 3 that clearly reflected the substantially arc shape appeared. In this case, the arithmetic mean waviness Wa of the end face 2 was 2.8 μm, the average height Wc was 10 μm, and the average length Wsm was 4000 μm. The skewness Wsk of the end face 2 was larger than 0.

Therefore, when considering the contact state between these end faces 2 and 2'and the positioning pin 6 having a perfect circular cross section, for example, the probability that the minute waviness 3'shown in FIG. 4 comes into contact with the positioning pin 6 at the valley portion 5'. However, in the case of the minute undulation 3 shown in FIG. 5, that is, the minute undulation 3 according to the present invention, the peak portion 4 comes into contact with the positioning pin 6 with high probability.

At this time, from the viewpoint of minimizing the contact area with the positioning pin 6, each parameter (period A, height difference B between the peak portion 4 and the valley portion 5) indicating the shape and size of the minute undulation 3 is described above. It is desirable to satisfy the relationship of Equation 1.

When the arithmetic mean waviness Wa of the end face 2 is 2.7 μm or more, 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. Is desirable.

As described above, in the present invention, attention is paid to the arithmetic mean swell Wa of the end face 2, and the end face 2 of the glass plate 1 is brought into rotational contact with the grindstones 11 and 12 so that the value of the arithmetic mean swell Wa is 2.7 μm or more. Predetermined end face processing (grinding processing, polishing processing) was performed. With the end face 2 having such a form, for example, the positioning member such as the positioning pin 6 is a glass plate during each manufacturing process or during inter-process transportation of a glass plate 1 or a product (liquid crystal display or the like) having the glass plate 1 as an element. When it comes into contact with the end face 2 of 1, the mountain portion 4 of the minute undulation 3 of the end face 2 mainly comes into contact. Therefore, the contact area between the end surface 2 of the glass plate 1 and the positioning member can be reduced, and the generation of glass powder can be suppressed.

Further, in consideration of a specific contact mode with the positioning pin 6, the minute waviness 3 of the end face 2 is formed into a shape satisfying the relationship of the mathematical formula 1, so that the positioning pin 6 comes into contact with the valley portion 5 of the minute waviness 3. The situation can be prevented as much as possible. Therefore, it is possible to more effectively suppress the generation of glass powder.

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 mean 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 surface 2 of the glass plate 1 and the positioning member is too small, excessive stress is generated in the mountain portion 4 of the minute waviness 3 of the end surface 2, and the glass plate 1 may be damaged. Therefore, the arithmetic mean 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 mean waviness Wa, the average height Wc, and the average length Wsm of the end face 2 shall be measured in accordance with JIS B 0601: 2013. Further, in the measurement of the arithmetic mean swell Wa, the average height Wc, and the average length Wsm, the end faces of the glass plate are measured at 10 points at equal intervals along one side of the glass plate. For the arithmetic mean swell Wa, the average value of the measurement results at 10 points shall be used, and for the average height Wc and the average length Wsm, the minimum value of the measurement results at 10 points shall be used.

Further, in the present invention, the average length Wsm measured by the above method is used for one cycle A in the minute swell, and the height difference B between the peak and the valley is the average height measured by the above method. Wc shall be used.

Although one embodiment of the present invention has been described above, of course, the glass plate and the method for producing the same according to the present invention are not limited to this form, and various forms can be taken within the scope of the present invention. ..

For example, in the above embodiment, the subassembly 25 of the grindstone 11 (12) and the grindstone mounting flange 20 having a dynamic balance of a predetermined value or more, for example, 60 g · mm or more is used, and is shown in FIGS. 1 and 2. An example is illustrated in which a glass plate 1 having an arithmetic mean waviness Wa of the end face 2 of 2.7 μm or more is obtained by performing the end face processing, but of course, the end face processing method according to the present invention is not limited to this. For example, by performing the above-mentioned end face processing on the grindstones 11 and 12 by means other than adjusting the dynamic balance, the glass plate 1 having an arithmetic mean waviness Wa of the end face 2 of 2.7 μm or more can be obtained. Obtainable. Alternatively, by performing the above-mentioned end face processing in a state where the glass plate 1 is subjected to a predetermined vibration, the glass plate 1 having an arithmetic mean waviness Wa of the end face 2 of 2.7 μm or more can be obtained.

Further, in the above embodiment, two sets of grindstones 11 (12) are arranged at positions facing each other across the glass plate 1, and two types (two sets) of grindstones 11 and 12 having different particle sizes are conveyed. Although the case of arranging them side by side in the direction has been illustrated, it is of course possible to take other arrangement modes. For example, it is possible to arrange two or three or more sets of the grindstone 11 for grinding and the grindstone 12 for polishing, respectively. Further, as long as the required quality including the shape can be ensured for the end face 2 after the end face processing, for example, one set or a plurality of sets of grindstones 11 (12) having one type of shape can be arranged.

Further, in the above description, the case where the present invention is applied when the end face 2 is subjected to the predetermined end face processing by the rotational contact of the grindstone 11 (12) has been illustrated, but the end face processing method according to the present invention is limited to this. Not done. By moving the rotating processing tool relative to the end face 2 while contacting the end face 2 of the glass plate 1, an arbitrary end face machining method can be adopted as long as the end face 2 is subjected to a predetermined machining. Is possible.

Furthermore, further, the glass plate according to the present invention is not limited to the one by the above-mentioned end face processing method. As long as the arithmetic mean waviness Wa of the end face 2 is 2.7 μm or more, any end face processing method can be applied to obtain the glass plate according to the present invention.

1 Glass plate 2, 2'End face 3, 3'Micro waviness 4, 4'Mountain part 5, 5'Tani part 6 Pin 10 End face processing device 11, 12 Grindstone 13 Motor 14 Spindle 20 Grindstone mounting flange 21 Fitting hole 22 Fitting convex part 23 Fitting concave part 24 Tip part 25 Subassembly X Feeding direction Y Rotating shaft

Claims (6)

A glass plate in which the end face has been subjected to a predetermined process.
A glass plate having an arithmetic mean waviness Wa of the end face of 2.7 μm or more and 4.0 μm or less. The glass plate according to claim 1, wherein the average height Wc of the end face is 5.0 μm or more. The glass plate according to claim 1 or 2, wherein the average length Wsm of the end face is 2000 μm or more. The glass plate according to any one of claims 1 to 3, wherein the skewness Wsk of the end face is larger than 0. Any one of claims 1 to 4 that satisfies the relationship of the following formula 1 when one cycle of the minute swell appearing on the end face is A [mm] and the height difference between the peak and the valley is B [mm]. The glass plate described in.

A method for manufacturing a glass plate, which comprises an end face processing step of performing a predetermined process on the end face by moving a rotating processing tool relative to the end face while making contact with the end face of the glass plate.
A method for manufacturing a glass plate, in which the end face is subjected to the predetermined processing by the processing tool so that the arithmetic mean waviness Wa of the end face is 2.7 μm or more and 4.0 μm or less in the end face processing step. ..

Images