JP2015105206A - Manufacturing method of glass plate, and glass plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a glass plate capable of cutting a thin glass plate formed by a down-draw process without causing a cutting defect.SOLUTION: A manufacturing method of a glass plate includes a forming step for forming a glass plate from molten glass by a down-draw process and a slow-cooling step. The glass plate has end parts in the width direction and a central region in the width direction between the end parts. In the slow-cooling step, the end parts are drawn downward along the conveying direction of the glass plate while being held by a plurality of pairs of rollers, the pairs of rollers being installed so as to cover the end parts at the position opposite to the end parts having a specific thickness corresponding to a thickness of the central region in the width direction.

Description

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

  In the glass substrate manufacturing method using the downdraw method, first, in the forming step, the molten glass overflows from the formed body to form a sheet-like glass plate. In the subsequent slow cooling step, the glass plate is drawn downward while being sandwiched by a plurality of pairs of rollers, so that the glass plate is stretched to a desired thickness and no distortion occurs inside. The glass plate is cooled so as not to warp. Both ends of the glass plate in the widthwise direction in the slow cooling process are referred to as “ears” or “ears”, and a plurality of pairs of rollers sandwich the portion on the inner side in the width direction than the ears to convey the glass plate. I do. Usually, the ear portion is 2 to 5 times thicker than a region (hereinafter also referred to as a center region in the width direction) that can be used as a product (glass substrate). Here, since the thickness of the ear portion does not change so much even if the thickness of the product changes, the difference between the thickness of the central region in the width direction used as the product is thin. It gets bigger.

  Patent Document 1 discloses a method for reducing warpage and distortion of a glass plate by cooling the ears faster than the central region in the width direction of the glass plate, thereby applying tension in the width direction of the glass plate. . However, when the thickness of the central region in the width direction used as a product is reduced, the amount of heat retained varies depending on the thickness between the ear portion and the central region in the width direction, so that a difference occurs in the amount of shrinkage of the glass. For this reason, a stress is generated between the ear portion and the central region in the width direction, warping the glass plate and causing distortion.

  In addition, since the roller sandwiches the inner part in the width direction from the ear part and conveys the glass plate, the difference between the heat amount due to the difference in thickness between the ear part and the inner part in the width direction than the ear part. The glass plate warped and was distorted.

Special table 2011-502099 gazette

  The glass plate is drawn with a scribe line, bent along the scribe line, and cut. However, if the glass plate is warped and distorted, the force applied to the scribe line becomes non-uniform. There may be a cutting failure that the glass plate breaks from the uniform part.

  Then, an object of this invention is to provide the manufacturing method and glass plate of a glass plate which can be cut | disconnected so that a cutting defect may not arise when the thin glass plate shape | molded by the down draw method is cut | disconnected.

One aspect of the present invention is a method of manufacturing a glass substrate,
A molding step of molding a glass plate from molten glass using the downdraw method;
The glass plate has an end portion in the width direction and a center region in the width direction sandwiched between the end portions, at a position facing the end portion having a predetermined thickness with respect to the plate thickness of the center region in the width direction. And a slow cooling step of performing slow cooling by pulling downward along the conveying direction of the glass plate while sandwiching the end with a plurality of pairs of rollers provided so as to cover the end. ,
It is characterized by that.

  In the slow cooling step, the pair of rollers preferably rolls the end portions so as to reduce the thickness of the end portions.

  In the slow cooling step, it is preferable that the pair of rollers sandwich a part of the central area in the width direction in addition to the end parts, and cool the end parts from a part of the central area in the width direction.

  It is preferable that an area where the pair of rollers abut on the end portion is larger than an area abutted on a part of the central region in the width direction.

One aspect of the present invention is a glass plate obtained by the above method for producing a glass plate,
The amount of strain at the end is 20 nm / cm or less,
The glass plate has a thickness of 0.05 to 0.4 mm.
It is characterized by that.

  According to the said aspect, when cut | disconnecting the thin glass ribbon shape | molded by the down draw method, it can cut | disconnect so that a cutting defect may not arise.

It is a schematic front view of the manufacturing apparatus of the glass plate concerning this embodiment. It is a schematic longitudinal cross-sectional view along the II-II line of the manufacturing apparatus of the glass plate shown in FIG. It is a figure which shows one shape which planarly viewed the glass plate shape | molded with a glass plate shaping | molding apparatus. It is the figure which showed the roller concerning this embodiment by planar view. It is a figure which shows the state which shape | molded the edge part of the glass plate using the roller concerning this embodiment. It is a figure which shows one shape which planarly viewed the roller concerning this embodiment. It is a figure which shows the modification 1 of a roller. It is a figure which shows the modification 2 of a roller. It is a figure which shows the modification 3 of a roller.

Hereinafter, with reference to drawings, the manufacturing method of the glass plate of this embodiment is demonstrated.
FIG. 1 is a schematic front view of a glass plate manufacturing apparatus used in the glass plate manufacturing method according to the present embodiment, and FIG. 2 is a schematic view taken along line II-II of the glass plate manufacturing apparatus shown in FIG. It is a longitudinal cross-sectional view. The glass plate manufacturing apparatus 100 includes a furnace 2, a glass plate forming apparatus (molded body) 4 disposed in the upper portion of the furnace 2, and a plurality of pairs of rollers 6 disposed below the glass plate forming apparatus 4. The partition member 8 and the temperature control device 10 are provided. According to this apparatus 100, after the glass raw material supplied in the melting tank is heated and melted, the molten glass obtained by clarification in the clarification tank and stirring in the stirring tank is a glass plate forming apparatus. The glass plate can be manufactured by a down draw method in which molten glass overflowing from the glass plate forming apparatus 4 is fused at the lower end 4e to form a sheet-like glass plate 9. Here, as for the thickness of the glass plate 9 shape | molded by the down draw method, 0.05-0.4 mm is mentioned.

  The furnace 2 is made of, for example, refractory bricks and is installed so as to surround and cover the glass plate forming apparatus 4. A plurality of temperature control devices 10 are arranged on the inner wall of the furnace 2 along the vertical direction, and the temperature of the glass plate 9 is controlled so that the glass plate 9 has a desired thickness and does not warp or distort.

  The partition member 8 is a heat insulating material arrange | positioned at the thickness direction both sides of the molten glass (glass plate 9) merged at the merge point 4e of the glass plate shaping | molding apparatus 4 mentioned later. The partition member 8 blocks the movement of heat from the upper side to the lower side of the partition member 8 by partitioning the upper atmosphere and the lower atmosphere at the meeting point of the molten glass.

  The temperature control device 10 includes a temperature raising device and a temperature lowering device provided along the width direction of the glass plate 9 so as to control the temperature profile of the glass plate 9 in the width direction. The heating amount of each of the temperature raising device and the temperature lowering device can be adjusted. Further, a plurality of temperature control devices 10 are arranged at predetermined intervals in the vertical direction, and are heated so that the glass plate 9 has a temperature distribution corresponding to a temperature profile designed so that the glass plate 9 is not warped or distorted. ,Cooling. The temperature control device 10 heats and cools the glass plate 9 so that a central region used as a product of the glass plate 9 is formed to a predetermined thickness in accordance with the rotational speed of a roller 6 described later.

  The glass plate forming apparatus 4 is made of fire brick, for example, and shows a wedge shape in a cross section perpendicular to the longitudinal direction LD of the glass plate forming apparatus 4. The longitudinal direction LD of the glass plate forming apparatus 4 coincides with the width direction of the glass plate 9. A groove 4k for holding the molten glass is formed in the upper part of the glass plate forming apparatus 4 so as to extend in the longitudinal direction LD. A supply pipe 11 is connected to the groove 4k so that the molten glass can be continuously supplied to the groove 4k from one side in the longitudinal direction LD. The glass plate forming apparatus 4 has a pair of side walls 4j with respect to the longitudinal direction LD and the direction perpendicular to the vertical direction. The side wall 4j forms a flow path of the molten glass overflowing from the groove 4k. These side walls 4j form a ridge line at the lower end 4e so that the molten glass flowing through the side walls 4j is fused at the lower end 4e. Guides 7 that prevent the molten glass from protruding from the side wall 4j are attached to both ends of the glass plate forming apparatus 4 in the longitudinal direction LD. The guide 7 has a wedge shape in plan view, and is made of a plate material having a size capable of covering the entire end surface of the glass plate forming apparatus 4. With respect to the vertical direction, the position of the tip of the guide 7 coincides with the lower end 4 e of the glass plate forming apparatus 4. By the action of the guide 7, it is possible to flow all of the molten glass along the side wall 4j.

  FIG. 3 is a diagram showing a shape of the glass plate 9 formed by the glass plate forming apparatus 4 in plan view. The glass plate 9 is formed by fusing molten glass at the lower end 4e. However, since the molten glass is dammed by the guide 7, the molten glass is formed near the guide 7, that is, at both ends of the glass plate forming apparatus 4 in the longitudinal direction LD. Accumulates. For this reason, the end 91 in the width direction of the glass plate 9 fused at the lower end 4e has a bulbous shape as shown in FIG. Here, the end portion 91 refers to a portion having a predetermined thickness with respect to the plate thickness at the center in the width direction of the glass plate 9. A region in the width direction sandwiched between the end portions 91 is referred to as a central region 92. Since the end portion 91 is thicker than the central region 92 having a substantially uniform thickness that can be used as a product (glass substrate) sandwiched between the end portions 91, the retained heat amount is larger than that of the central region 92. When there is a difference in the amount of retained heat, a difference occurs in the amount of shrinkage of the glass, so that stress is generated between the end portion 91 and the central region 92, warping the glass plate 9 and causing distortion. In particular, when the thickness of the final product of the glass plate 9 is 0.05 to 0.4 mm, the crease lines necessary for cutting the glass plate 9 are not uniformly formed, and the crease lines are not uniform. If it is attempted to cut along the line, it will not be cut along the ruled line, and a cutting failure tends to occur.

  A plurality of rollers 6 are arranged at predetermined intervals in the vertical direction, and serve to cool the end 91 of the glass plate 9 while conveying the glass plate 9 below the glass plate forming apparatus 4. Moreover, the roller 6 is arrange | positioned symmetrically regarding the perpendicular | vertical surface containing the lower end 4e of the glass plate shaping | molding apparatus 4 so that the glass plate 9 may be pinched | interposed in the thickness direction. FIG. 4 is a diagram showing the roller 6 according to the present embodiment in plan view. FIG. 5 is a view showing a state in which the end portion 91 of the glass plate 9 is formed using the roller 6. As shown in FIG. 4, the roller 6 includes a roller shaft 61 and a roller head 62, and the roller head 62 is fitted and attached to the roller shaft 61. The roller head 62 covers the entire end 91 from both sides of the glass plate 9 in the thickness direction, that is, the position facing the end 91, and is part of the end 91 and the central region 92. The end adjacent portion 93 located at the center in the width direction from 91 is sandwiched and rolled so as to reduce the thickness of the end 91 as shown in FIG. The length of the roller head 62 in contact with the end 91 from the head front end side 62a to the roller shaft side 62b is longer than the length d of the end 91 from the end front end side 91a to the end central region side 91b. The head 62 has a shape that can cover the entire end portion 91. The roller head 62 is a cylinder or tube that is fitted to the roller shaft 61 and attached thereto, and rotates with the rotation of the roller shaft 61. The roller shaft 61 is cooled by an air-cooled tube or a water-cooled tube that is passed through the roller shaft 61. The cold air that has cooled the roller shaft 61 is transmitted to the roller head 62, and the glass plate 9 that contacts the roller head 62 is cooled. Since the roller shaft 61 is uniformly cooled from the tip to the root, the portion where the roller shaft 61 and the roller head 62 are in contact is uniformly cooled from the tip to the root.

  The surface of the roller head 62 has, for example, a mesh structure or a notch structure so that the end 91 is sandwiched and conveyed downward against the influence of the surface tension of the glass plate 9. Since the end portion 91 of the glass plate 9 is in a cooling stage and has an appropriate viscosity, when rolled by the roller head 62, a part of the end portion 91 enters a recess having a mesh structure or a notch structure. Therefore, when the roller head 62 rotates in a state where the end portion 91 is sandwiched between the pair of roller heads 62, the roller head 62 and the end portion 91 do not slide with each other, based on the rotation amount of the roller head 62. The glass plate 9 is conveyed downward.

  FIG. 6 is a diagram showing a shape of the roller 6 according to the present embodiment when viewed in plan. In the roller 6, the contact area between the roller head 62 and the end 91 is larger than the contact area between the roller head 62 and the end adjacent portion 93. Specifically, the mesh on the head tip side 62a is coarse and the mesh on the roller shaft side 62b is fine. In the portion where the roller shaft 61 and the roller head 62 are in contact with each other, the cooling is uniformly performed from the tip to the root. However, on the surface of the roller head 62, the roller shaft side from the contact area between the head tip side 62 a and the glass plate 9. Since the contact area between 62 b and the glass plate 9 is large, the cooling amount of the end portion 91 is larger than the end portion adjacent portion 93. For this reason, the end 91 is cooled earlier than the end adjacent portion 93 in the region cooled while being rolled by the roller 6. By cooling the end portion 91 quickly, the glass plate 9 can be prevented from shrinking in the width direction, and the width of the central region 91 used as a product can be increased. Moreover, since the temperature difference between the end 91 and the end adjacent portion 93 is reduced by cooling the end 91 having a larger amount of heat than the end adjacent portion 93 earlier, the end 91 and the end adjacent portion 93 And the stress generated at the end 91 is small. For this reason, the warp and distortion generated in the glass plate 9 are suppressed, the force for scoring the glass plate 9 becomes uniform, and when the glass plate 9 is cut, it can be cut so as not to cause a cutting failure.

  When the plate | board thickness of the glass plate 9 is 0.05-0.4mm, since the difference of thickness with the edge part 91 and the center area | region 92 becomes large, a difference arises in retained heat amount. And when stress generate | occur | produces between the edge part 91 and the edge part adjacent part 93, it will warp to the glass plate 9 and a distortion will generate | occur | produce. Since the glass plate 9 manufactured by the glass plate manufacturing method according to the present embodiment is formed so that the thickness of the end portion 91 is reduced as shown in FIG. In addition, the strain amount in the end portion 91 and / or the region between the end portion 91 and the end adjacent portion 93 is 20 nm / cm or less.

  As described above, according to the method for manufacturing a glass plate of the present embodiment, stress generated between the end portion and the end adjacent portion can be suppressed, and thus warpage and distortion generated in the glass plate are suppressed. be able to. In addition, since the warpage and distortion that occur in the glass plate can be suppressed, the force for marking the glass plate becomes uniform, and even when it is a thin glass plate, it can be cut so as not to cause cutting defects. it can. Further, since the roll 6 is clamped from the end portion 91 to the end adjacent portion 93, the glass plate is based on the rotation amount of the roller 6 (roller head 62) without sliding between the roller head 62 and the end portion 91. 9 can be conveyed downward.

(Modification 1)
FIG. 7 is a diagram illustrating a first modification of the roller 6. Note that the description of the configuration common to the above is omitted.
The roller 6 of Modification 1 can also include a groove 63 between the head tip side 62a and the roller shaft side 62b. When the end 91 is pressure-contacted by the roller head 62, a part of the end 91 enters the groove 63, so that the catch between the roller 6 and the glass plate 9 can be increased. Thereby, conveyance of the glass plate 9 suitable for rotation of the roller 6 is realizable. Further, the mesh pattern on the surface of the roller head 62 can be formed in an oblique direction with respect to the conveying direction of the glass plate 9. By doing so, the roller head 62 and the end 91 can be caught.

(Modification 2)
FIG. 8 is a diagram illustrating a second modification of the roller 6. Note that the description of the configuration common to the above is omitted.
In the roller 6 of the second modification, the head tip side 62a of the roller shaft 61 is thinner than the roller shaft side 62b. Since the roller shaft 61 is cooled by an air cooling tube or a water cooling tube passed through the roller shaft 61, the roller shaft side 62b has a larger cooling amount than the head tip side 62a. As a result, the end 91 having a larger amount of retained heat than the end adjacent portion 93 can be cooled quickly.

(Modification 3)
FIG. 9 is a diagram showing a third modification of the roller 6. Note that the description of the configuration common to the above is omitted.
The roller 6 of Modification 3 has irregularities on the surface of the roller head 62, and the roller shaft side 62b has a larger irregularity shape than the head tip side 62a. Therefore, the contact area where the roller shaft side 62b of the roller head 62 is in contact with the glass plate 9 is larger than the contact area where the head tip side 62a of the roller head 62 is in contact with the glass plate 9, so The large end portion 91 can be cooled quickly.

  The glass plate 9 manufactured in the present embodiment is suitably used for, for example, a glass substrate for liquid crystal display, a glass substrate for organic EL display, a cover glass, and a glass substrate for polysilicon TFT liquid crystal display. In addition, the glass plate 9 can also be used as a display for a portable terminal device, a cover glass for a housing, a touch panel plate, a glass substrate of a solar cell, or a cover glass.

  Moreover, the length of the width direction of the glass plate 9 is 500 mm-3500 mm, 1000 mm-3500 mm, and 2000 mm-3500 mm, for example. Moreover, the length of the vertical direction (conveyance direction) of the glass plate 9 is also 500 mm-3500 mm, 1000 mm-3500 mm, 2000 mm-3500 mm, for example.

  As the glass used for the glass plate 9, for example, borosilicate glass, aluminosilicate glass, aluminoborosilicate glass, soda lime glass, alkali silicate glass, alkali aluminosilicate glass, alkali aluminogermanate glass, and the like can be applied. The glass applicable to the present invention is not limited to the above.

  The force with which the roller 6 presses the glass plate 9 and the speed at which the roller 6 rotates can be appropriately changed depending on the viscosity of the glass plate 9, the thickness of the central region 92 of the glass plate 9, and the like.

  As mentioned above, although the manufacturing method of the glass plate of this invention and the glass plate were demonstrated in detail, this invention is not limited to the said embodiment, Even if it is variously improved and changed in the range which does not deviate from the main point of this invention. Of course it is good.

6 Roller 61 Roller shaft 62 Roller head 9 Glass plate 91 End 92 Central region 93 End adjacent

Claims (5)

A molding step of molding a glass plate from molten glass using the downdraw method;
The glass plate has an end portion in the width direction and a center region in the width direction sandwiched between the end portions, at a position facing the end portion having a predetermined thickness with respect to the plate thickness of the center region in the width direction. And a slow cooling step of performing slow cooling by pulling downward along the conveying direction of the glass plate while sandwiching the end with a plurality of pairs of rollers provided so as to cover the end. ,
The manufacturing method of the glass plate characterized by the above-mentioned. In the slow cooling step, the pair of rollers rolls the end portion so as to reduce the thickness of the end portion,
The manufacturing method of the glass plate of Claim 1 characterized by the above-mentioned. In the slow cooling step, the pair of rollers sandwiches a part of the central region in the width direction in addition to the end portions, and cools the end portions from a part of the central region in the width direction.
The manufacturing method of the glass plate of Claim 1 or 2 characterized by the above-mentioned. The area where the pair of rollers abut on the end is larger than the area abutted on a part of the central region in the width direction,
The manufacturing method of the glass plate of Claim 3 characterized by the above-mentioned. A glass plate obtained by the method for producing a glass plate according to claim 1,
The amount of strain at the end is 20 nm / cm or less,
The glass plate has a thickness of 0.05 to 0.4 mm.
A glass plate characterized by that.

Images