KR102153288B1 - Support roller, method for molding glass plate, method for manufacturing glass plate, and device for manufacturing glass plate - Google Patents

Abstract

(Solution means) A support roll for supporting a strip-shaped glass ribbon, comprising a rotating member in contact with the glass ribbon, a shaft member having a coolant flow path therein, rotating together with the rotating member, and branching from the coolant flow path. Has a branching path, has a protruding member protruding from the outer circumference of the shaft member, the rotating member is formed of ceramics, between the protruding member and the rotating member, a heat transfer member having a higher thermal conductivity than the rotating member is formed Supported roll.

Description

A support roll, a method for forming a glass plate, a method for manufacturing a glass plate, and a manufacturing apparatus for a glass plate TECHNICAL FIELD [SUPPORT ROLLER, METHOD FOR MOLDING GLASS PLATE, METHOD FOR MANUFACTURING GLASS PLATE, AND DEVICE FOR MANUFACTURING GLASS PLATE}

The present invention relates to a support roll, a method for forming a glass plate, a method for manufacturing a glass plate, and an apparatus for manufacturing a glass plate.

The molding method of a glass plate has a process of molding molten glass into a strip-shaped glass ribbon. Glass ribbons thinner than the equilibrium thickness try to shrink in the width direction. Therefore, in order to maintain the thickness of the glass ribbon at a desired thickness, a support roll that applies tension in the width direction to the glass ribbon is used (see, for example, Patent Document 1). The support rolls are used in pairs and press the edges on both sides of the glass ribbon. A plurality of pairs of support rolls are arranged and formed at intervals along the moving direction of the glass ribbon. The support roll has a rotating member in contact with the glass ribbon at its tip, and the glass ribbon is delivered in a predetermined direction by rotating the rotating member. The glass ribbon gradually cools and becomes hard while moving in a predetermined direction.

Japanese Patent Laid-Open Publication No. 2011-225386

The conventional rotating member is made of a metal material and has low heat resistance. On the other hand, there is a problem that the rotating member formed of ceramics is liable to crack due to the temperature gradient.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a support roll capable of suppressing cracks in a rotating member made of ceramics.

In order to solve the above problem, according to one aspect of the present invention,

As a support roll for supporting a strip-shaped glass ribbon,

A rotating member in contact with the glass ribbon,

A shaft member having a refrigerant flow path therein and rotating together with the rotating member;

And a protruding member protruding from the outer periphery of the shaft member,

The rotating member is formed of ceramics,

A support roll is provided between the protruding member and the rotating member, in which a heat transfer member having a higher thermal conductivity than the rotating member is disposed.

According to one aspect of the present invention, it is possible to provide a support roll capable of suppressing cracks in a rotating member made of ceramics.

1 is a partial cross-sectional view showing an apparatus for forming a glass plate according to an embodiment of the present invention.
FIG. 2 is a plan view showing a lower structure of the apparatus for forming a glass plate of FIG. 1.
3 is a cross-sectional view showing a support roll according to an embodiment of the present invention.
4 is a graph showing a time change in wettability of a molten glass with respect to the sintered body according to Examples 1 to 4;
5 is a cross-sectional view showing a rotating member according to a modified example.
6 is a view showing the convex dimension of the rotating member of FIG. 5.
Fig. 7 is another view showing the convex dimension of the rotating member of Fig. 5.
8 is a cross-sectional view showing a rotating member according to another modified example.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding reference numerals are assigned to the same or corresponding configurations, and description thereof is omitted.

1 is a partial cross-sectional view showing an apparatus for forming a glass plate according to an embodiment of the present invention. FIG. 2 is a plan view showing a lower structure of the apparatus for forming a glass plate of FIG. 1.

The molding apparatus 10 molds molten glass into a strip-shaped glass ribbon 14. The molding apparatus 10 includes a bath 20 containing a molten metal (for example, molten tin) 16, and a molten glass continuously supplied onto the molten metal 16 is formed by using the molten metal 16 It flows in a predetermined direction (X direction in FIG. 2) on the top, and it is formed into a strip plate shape. After the glass ribbon 14 is cooled in the process of flowing in a predetermined direction (X direction in FIG. 2), it is pulled up from the molten metal by a lift-out roll, slowly cooled in a slow cooling furnace, and then taken out from the slow cooling furnace, It is cut into a predetermined dimensional shape by a cutter to form a glass plate as a product.

The molding apparatus 10 includes a bathtub 20 for accommodating the molten metal 16, a ceiling 22 formed above the bathtub 20, and a side wall that blocks a gap between the bathtub 20 and the ceiling 22 (24) and the like. A gas supply path 32 is formed in the ceiling 22, and a heater 34 as a heating source is inserted through the gas supply path 32.

The gas supply path 32 supplies a reducing gas to the space above the molten metal 16 to prevent oxidation of the molten metal 16. The reducing gas contains, for example, 1 to 15 vol% of hydrogen gas and 85 to 99 vol% of nitrogen gas.

A plurality of heaters 34 are formed above the molten metal 16 and the glass ribbon 14 at intervals in the moving direction and the width direction of the glass ribbon 14. The output of the heater 34 is controlled so that the temperature of the glass ribbon 14 decreases as it goes from the upstream side to the downstream side. In addition, the output of the heater 34 is controlled so that the thickness of the glass ribbon 14 becomes uniform in the width direction (Y direction).

The molding apparatus 10 has a support roll 40 used for suppressing the shrinkage in the width direction of the strip-shaped glass ribbon 14. The support rolls 40 are used in pairs, and press both edge portions of the glass ribbon 14. A plurality of pairs of support rolls 40 are arranged and formed at intervals along the moving direction of the glass ribbon 14. The support roll 40 has a rotating member 42 in contact with the glass ribbon 14 at its tip, and when the rotating member 42 rotates, the glass ribbon 14 is delivered in a predetermined direction. The glass ribbon 14 gradually cools and becomes hard while moving in a predetermined direction.

3 is a cross-sectional view showing a support roll according to an embodiment of the present invention. The support roll 40 is a rotating member 42, a shaft member 44, a flange 46 as a protruding member, a heat transfer member 48, a pressing member 50, a first elastic body 54, a heat insulating member 60 ), a shim abutting member 64, a second elastic body 66, and the like.

In order to suppress the slip with respect to the glass ribbon 14, the rotating member 42 just needs to have the cogwheel-shaped irregularities 43 in contact with the glass ribbon 14 on the outer periphery, as shown in FIG. 1, for example. . The shape of the convex portion of the cogwheel-shaped irregularities 43 is not particularly limited, but may be formed in a tapered shape (for example, a square pyramid shape) as shown in FIG. 3, for example. The cogwheel-shaped irregularities 43 are formed in a row in the thickness direction of the outer periphery of the rotating member 42 (Y direction in FIG. 1) as shown in FIG. 1, but may be formed in multiple rows.

The rotating member 42 does not have a coolant flow path therein. In addition, since the shaft member 44 inserted into the through hole of the rotating member 42 is a member different from the rotating member 42, the coolant flow path 45 formed in the shaft member 44 is It is a refrigerant flow path formed outside.

The rotating member 42 is formed of ceramics having higher heat resistance than a metal material. Although it does not specifically limit as ceramics of the rotating member 42, For example, silicon carbide (SiC) quality ceramics, silicon nitride (Si ₃ N ₄ ) quality ceramics, etc. are used. Silicon carbide and silicon nitride have high resistance to droplets of molten metal 16 and vapor of molten metal 16, and are excellent in high temperature strength and creep properties.

The type of ceramics of the rotating member 42 is selected according to the type of glass or the like. For example, in the case of an alkali-free glass, since the molding temperature of the glass is high, silicon nitride ceramics having excellent thermal shock resistance are preferable. Silicon nitride ceramics are also excellent in terms of low reactivity with alkali-free glass. Meanwhile, in the case of soda-lime glass, in addition to silicon nitride ceramics, silicon carbide ceramics or alumina-based ceramics may be used.

In the case of alkali-free glass, at least a portion of the rotating member 42 in contact with the glass ribbon 14 may be silicon nitride ceramics, and the entire rotating member 42 may not be silicon nitride ceramics. For example, a layer of silicon nitride ceramics may be formed on a substrate made of ceramics other than silicon nitride ceramics.

The silicon nitride ceramics may be a sintered body obtained by sintering a molded body made of a mixed powder containing a powder of silicon nitride and a powder of a sintering aid. Examples of the sintering method include atmospheric pressure sintering and pressure sintering (including hot press sintering and gas pressure sintering). As the sintering aid, for example, at least one type selected from alumina (Al ₂ O ₃ ), magnesia (MgO), titania (TiO ₂ ), zirconia (ZrO ₂ ) and yttria (Y ₂ O ₃ ) is used. do.

In the silicon nitride ceramics, the content of aluminum (Al) is 0.1% by mass or less, preferably less than 0.1% by mass, and the content of magnesium (Mg) is 0.7% by mass or less, preferably less than 0.7% by mass, of titanium (Ti). The content should just be 0.9 mass% or less, preferably less than 0.9 mass%. When the Al content, Mg content, and Ti content are in the above ranges, the reactivity between the rotating member 42 and the glass ribbon 14 is low, and the rotating member 42 and the glass ribbon 14 are not easily adhered to each other, resulting in good durability. Lose. The Al content, the Mg content, and the Ti content may each be 0 mass%.

The silicon nitride ceramics have a zirconium (Zr) content of 3.5 mass% or less, preferably less than 3.5 mass%, and a yttrium (Y) content of 0.5 mass% or more, preferably more than 0.5 mass%, 10 mass% or less, Preferably, it may be less than 10 mass%. Zr and Y are components that do not diffuse with each other well with the glass ribbon 14 compared to Al, Mg, and Ti, so they may be contained within the above range. By being contained in the above range, sintering of the silicon nitride powder can be promoted. Zr is an optional component, and the Zr content may be 0% by mass.

In addition, although the silicon nitride ceramics of this embodiment was said to be a sintered body obtained by an atmospheric pressure sintering method or a pressure sintering method, a sintered body obtained by a reaction sintering method may be used. The reaction sintering method is a method of heating a molded article formed from a powder of metallic silicon (Si) in a nitrogen atmosphere. Since the reaction sintering method does not use a sintering aid, a sintered compact of high purity can be obtained, and durability of the sintered compact to the glass ribbon 14 can be improved.

The glass plate which is a product is not particularly limited, but may be, for example, a flat panel display (FPD) such as a liquid crystal display (LCD), a plasma display (PDP), or an organic EL display. In recent years, thinning of the FPD is in progress, and thinning of the glass plate for FPD is in progress. In particular, in the case of a glass plate for display substrates, a glass plate of preferably 0.7 mm or less, more preferably 0.3 mm or less, still more preferably 0.2 mm or less, and particularly preferably 0.1 mm or less is desired. Therefore, the thickness of the glass ribbon 14 becomes thin, the contraction force in the width direction of the glass ribbon 14 becomes strong, and the molding temperature of the glass ribbon 14 increases. In the support roll 40 of this embodiment, as will be described later in detail, a heat transfer member 48 having a higher thermal conductivity than the rotation member 42 is disposed between the rotating member 42 and the flange 46 as a protruding member. Since it is formed, the crack of the rotating member 42 can be suppressed, and it is suitable for the molding of the glass plate for FPD.

The kind of glass plate which is a product is not specifically limited. The composition of the glass plate is, for example, in terms of oxide-based mass%, SiO ₂ : 50 to 75%, Al ₂ O ₃ : 0.1 to 24%, B ₂ O ₃ : 0 to 12%, MgO: 0 to 10 %, CaO: 0 to 14.5%, SrO: 0 to 24%, BaO: 0 to 13.5%, Na ₂ O: 0 to 20%, K ₂ O: 0 to 20%, ZrO ₂ : 0 to 5%, MgO + CaO + SrO + BaO: 5 to 29.5%, Na ₂ O + K ₂ O: 0 to 20% is contained.

The glass plate may be formed of, for example, alkali-free glass. The alkali-free glass is a glass that does not contain an alkali metal oxide (Na ₂ O, K ₂ O, Li ₂ O, etc.) substantially. As for the alkali-free glass, the total amount of the content of the alkali metal oxide should be 0.1 mass% or less.

The alkali-free glass is, for example, in terms of oxide-based mass%, SiO ₂ : 50 to 70% (preferably 50 to 66%), Al ₂ O ₃ : 10.5 to 24%, B ₂ O ₃ :0 -12%, MgO: 0-10% (preferably 0-8%), CaO: 0-14.5%, SrO: 0-24%, BaO: 0-13.5%, ZrO ₂ : 0-5%, MgO + CaO + SrO + BaO: 8 to 29.5% (preferably 9 to 29.5%) is contained.

When the alkali-free glass is compatible with a high distortion point and high solubility, it is preferably expressed by mass% based on oxide, SiO ₂ : 58 to 66 %, Al ₂ O ₃ : 15 to 22 %, B ₂ O ₃ : 5 to 12%, MgO: 0 to 8%, CaO: 0 to 9%, SrO: 3 to 12.5%, BaO: 0 to 2%, MgO + CaO + SrO + BaO: 9 to 18%.

Alkali-free glass, particularly in the case of obtaining a high distortion point, is preferably expressed in terms of mass% based on oxide, SiO ₂ : 54 to 73%, Al ₂ O ₃ : 10.5 to 22.5%, B ₂ O ₃ :0 -5.5%, MgO:0-10%, CaO:0-9%, SrO:0-16%, BaO:0-2.5%, MgO+CaO+SrO+BaO: 8-26%.

As shown in FIG. 1, the shaft member 44 passes through the side wall 24 and is connected to a drive device 36 disposed outside the side wall 24. The drive device 36 is constituted by a motor, a speed reducer, or the like, and rotates the shaft member 44 about the center line of the shaft member 44. The shaft member 44 is inserted through a through hole formed in the central portion of the rotating member 42 and rotates together with the rotating member 42.

The shaft member 44 may be formed of, for example, a metal material in a cylindrical shape, and has a refrigerant flow path 45 through which a refrigerant such as water passes. The refrigerant may be a fluid, and may be air or the like.

The flange 46 may be formed integrally with the shaft member 44. The flange 46 protrudes from the outer periphery of the shaft member 44 in the radial direction of the rotation member 42 in the middle of the shaft member 44. In the inner periphery of the flange 46, a branch passage 47 branching from the coolant passage 45 of the shaft member 44 is formed, and the branch passage 47 extends to the vicinity of the outer periphery of the flange 46. The flange 46 is cooled by the refrigerant passing through the branch passage 47.

The heat transfer member 48 is formed in a ring shape, for example. The inner diameter of the heat transfer member 48 is larger than the outer diameter of the shaft member 44, and the heat transfer member 48 does not contact the shaft member 44. The heat transfer member 48 is positioned by a positioning groove 49 formed on a side surface of the flange 46 on the side of the rotating member 42.

The heat transfer member 48 is formed between the flange 46 and the rotation member 42, has a higher thermal conductivity than the rotation member 42, and flanges the heat of the rotation member 42 transmitted from the glass ribbon 14. (46) to exit. The outer periphery of the rotating member 42 is maintained at a temperature such that it does not stick to the glass ribbon 14, so that the rotation torque can be reduced.

Here, the thermal conductivity of the heat transfer member 48 and the thermal conductivity of the rotating member 42 are measured at the use temperature of the support roll 40. In the use temperature of the support roll 40, the thermal conductivity of the heat transfer member 48 is preferably 30 to 200 W/(m·°C).

Since the flange 46 cools the heat transfer member 48 and the heat transfer member 48 cools the rotation member 42 from the side, compared to the case where the rotation member 42 is cooled from the inner circumference, the rotation member 42 The temperature gradient in the radial direction of is gentle, and breakage of the rotating member 42 due to thermal stress can be suppressed.

The heat transfer member 48 should just have a higher thermal conductivity than the rotation member 42, and is formed of, for example, metal or carbon. Metal and carbon are softer than ceramics, and the heat transfer member 48 and the rotating member 42 are likely to come into close contact with each other. Therefore, the contact heat resistance is low, and the heat transfer efficiency is good. Carbon is particularly preferred from the viewpoint of heat resistance.

When the heat transfer member 48 is formed of the same material as the flange 46, the heat transfer member 48 and the flange 46 may be integrally formed.

The pressing member 50 presses the rotation member 42 against the heat transfer member 48 to lower the contact heat resistance between the heat transfer member 48 and the rotation member 42. The pressing member 50 is disposed on the side opposite to the heat transfer member 48 based on the rotation member 42.

The pressing member 50 is constituted by, for example, a pressing member main body 51 and a contact portion 52. The pressing member main body 51 is formed of, for example, metal, and the shaft member 44 is inserted through a through hole formed in the central portion of the pressing member main body 51. The contact portion 52 may be formed in a ring shape similar to the heat transfer member 48. The outer diameter of the contact portion 52 is larger than the inner diameter of the shaft member 44, and the contact portion 52 does not contact the shaft member 44, and the opposite side of the contact portion of the heat transfer member 48 in the rotating member 42 Press intensively. The contact portion 52 is formed of metal or carbon. Carbon is particularly preferred from the viewpoint of heat resistance. The contact portion 52 is positioned by a positioning groove 53 formed on a side surface of the pressing member main body 51 on the side of the rotating member 42. When the contact portion 52 is formed of the same material as the pressing member main body 51, the contact portion 52 and the pressing member main body 51 may be formed integrally.

The first elastic body 54 elastically supports the pressing member 50 which can be freely displaced in the axial direction of the shaft member 44 toward the rotating member 42. The first elastic body 54 is constituted by, for example, a disc spring, and the shaft member 44 is inserted through a through hole formed in the first elastic body 54. The shaft member 44 has a screw shaft portion 44a, and the first elastic body 54 between the rotating member 42 and the first nut 58 screwed to the screw shaft portion 44a is reduced from its natural state. Batch is formed. When a dimensional change occurs due to temperature change or the like, the rotation member 42 is always pressed against the heat transfer member 48 by the pressing member 50.

In addition, although the 1st elastic body 54 of this embodiment is comprised by a disc spring, it may be comprised by a coil spring, and the structure of the 1st elastic body 54 is not specifically limited. In addition, the first elastic body 54 may not be required. In this case, by tightening the first nut 58, the first nut 58 presses the pressing member 50, and the pressing member 50 is rotated by the rotating member 42. ) Is pressed against the heat transfer member 48.

The heat insulating member 60 is formed normally, for example. From the viewpoint of workability and cost, the heat insulating member 60 may be divided into a plurality of divided bodies (for example, two semi-divided bodies) in the circumferential direction.

The heat insulating member 60 is disposed between the inner periphery of the rotating member 42 and the outer periphery of the shaft member 44, has a lower thermal conductivity than the rotating member 42, and the heat of the rotating member 42 is transferred to the shaft member ( 44) to suppress the exit. The temperature gradient in the radial direction of the rotating member 42 becomes more gentle, and damage of the rotating member 42 due to thermal stress can be suppressed.

Here, the thermal conductivity of the heat insulating member 60 and the thermal conductivity of the rotating member 42 are measured at the use temperature of the support roll 40. In the use temperature of the support roll 40, the thermal conductivity of the heat insulating member 60 is preferably 0.01 to 30 W/(m·° C.).

The material of the heat insulating member 60 is not particularly limited as long as it has a lower thermal conductivity than the material of the rotating member 42, but, for example, a slate or the like is used. The slate may be either a natural slate made of rocks such as slate or an artificial slate in which a fiber material is mixed with cement.

The outer circumferential surface of the heat insulating member 60 is a contact surface in contact with the inner circumferential surface of the rotating member 42 and has a tapered shape whose diameter decreases toward the flange 46 along the center line of the rotating member 42. Similarly, the inner circumferential surface of the rotating member 42 is a contact surface in contact with the outer circumferential surface of the heat insulating member 60 and has a tapered shape whose diameter decreases toward the flange 46 along the center line of the rotating member 42. If at least one of the contact surfaces of the heat insulating member 60 and the rotating member 42 in contact with each other is tapered, the vibration between the heat insulating member 60 and the rotating member 42 can be reduced. In addition, the direction of the taper may be a reverse direction, and each contact surface may be a tapered shape whose diameter increases along the center line of the rotation member 42 toward the flange 46.

The shim abutting member 64 is formed by abutting the center line of the heat insulating member 60 and the center line of the shaft member 44, and is formed normally, for example, and the inner circumference of the heat insulating member 60 and the shaft member 44 It is arranged and formed between the outer peripheries. Like the shaft member 44, the shim abutting member 64 may be formed of metal. Since the difference in thermal expansion between the shim abutting member 64 and the shaft member 44 is small, the clearance between the shim abutting member 64 and the shaft member 44 can be set narrowly, and the shim abutting member 64 and the shaft member 44 Vibration can be reduced.

The shim abutting member 64 serves to butt the positions of the plurality of divided bodies when the heat insulating member 60 is divided into a plurality of divided bodies in the circumferential direction.

The outer circumferential surface of the shim abutting member 64 is a contact surface in contact with the inner circumferential surface of the heat insulating member 60 and has a tapered shape whose diameter decreases toward the flange 46 along the center line of the rotating member 42. Similarly, the inner circumferential surface of the heat insulating member 60 is a contact surface in contact with the outer circumferential surface of the shim abutting member 64 and has a tapered shape whose diameter becomes smaller as it moves toward the flange 46 along the center line of the rotating member 42. If at least one of the contact surfaces of the seam abutting member 64 and the heat insulating member 60 in contact with each other is tapered, it is possible to reduce the shaking of the shim abutting member 64 and the heat insulating member 60. In addition, the direction of the taper may be a reverse direction, and each contact surface may be a tapered shape whose diameter increases along the center line of the rotation member 42 toward the flange 46.

In addition, in this embodiment, the shim abutting member 64 is disposed between the inner circumference of the heat insulating member 60 and the outer circumference of the shaft member 44, but the shim abutting member 64 may not be required, and the heat insulating member 60 There may be a slight clearance between the inner periphery of the shaft member and the outer periphery of the shaft member 44.

The second elastic body 66 is a heat-insulating member 60 that can be freely displaced in the axial direction of the shaft member 44 via a shim abutting member 64 that can be freely displaced in the axial direction of the shaft member 44. ) Is elastically supported toward the flange (46). The second elastic body 66 is constituted by, for example, a disc spring, and the shaft member 44 is inserted through a through hole formed in the second elastic body 66. Between the second nut 68 and the shim abutting member 64 screwed to the screw shaft portion 44a of the shaft member 44, the second elastic body 66 is disposed in a reduced state than in the natural state. When a dimensional change occurs due to temperature change or the like, it is possible to prevent the separation between the shim abutting member 64 and the heat insulating member 60, and also prevent the separation between the heat insulating member 60 and the rotating member 42. .

In addition, although the 2nd elastic body 66 of this embodiment is comprised with a disc spring, it may comprise a coil spring, and the structure of the 2nd elastic body 66 is not specifically limited. In the absence of the shim abutting member 64, the second elastic body 66 contacts the heat insulating member 60 and elastically supports the heat insulating member 60 toward the flange 46. Further, the second elastic body 66 may not be required, and in this case, by tightening the second nut 68, the shim abutting member 64 and the heat insulating member 60 are in close contact, and the heat insulating member 60 and the rotating member ( 42) is close.

In the support roll 40 of this embodiment, considering the moldability of the glass ribbon 14, the molding range of the molding apparatus 10 (the viscosity range of the glass ribbon 14 is 10 ^4.5 to 10 ^7.5 dPa·s) It is preferable to use in the region) and the first low-temperature region (a region in which the glass ribbon 14 is in a viscosity range of 10 ^6.7 to 10 ^7.65 dPa·s), and the molding region (the glass ribbon 14 is 10 ^4.5 to 10 It is more preferable to use in the region of the viscosity range of ^7.5 dPa·s) and the second low temperature region (the region of the viscosity range of the glass ribbon 14 exceeding 10 ^7.5 to 10 ^7.65 dPa·s). In the case of alkali-free glass, the viscosity range in which the glass ribbon 14 is 10 ^4.5 to 10 ^7.5 dPa·s corresponds to the temperature range in which the glass ribbon 14 is 946 to 1200°C, and the glass ribbon 14 is 10 ^The viscosity range of ^6.7 to 10 ^7.65 dPa·s corresponds to the temperature range in which the glass ribbon 14 is 937 to 1000°C, and the viscosity range of the glass ribbon 14 exceeds 10 ^7.5 to 10 ^7.65 dPa·s is The glass ribbon 14 corresponds to a temperature range of 937°C or more and less than 946°C.

Further, the support roll 40 may be used in combination with a support roll having a general configuration, or may be used in a part such as a molding area, a first low temperature region, and a second low temperature region.

Example

In Examples 1 to 4, the relationship between the wettability of the sintered body to the molten glass and the impurities contained in the sintered body was investigated.

The test piece and test plate for evaluation were manufactured by processing a sintered body of silicon nitride (Si ₃ N ₄ ) quality ceramics different from each other.

The content of impurities in the sintered body was measured by analyzing a test piece cut out from the sintered body into individual phases by glow discharge mass spectrometry. Impurities to be measured are those contained as a sintering aid, and are aluminum (Al), magnesium (Mg), titanium (Ti), zirconium (Zr), and yttrium (Y).

The wettability of the sintered body with respect to the molten glass was measured with a high-temperature wettability tester (manufactured by RBAC, WET1200). Specifically, each glass piece of alkali-free glass (manufactured by Asahi Glass, AN100) was placed on a test plate processed to a thickness of 1 mm, and the temperature was raised to 1150°C for 10 minutes in a nitrogen atmosphere, and maintained at 1150°C for 10 minutes. After the molten glass was produced, the temperature was lowered from 1150°C to 1050°C for 90 seconds and maintained at 1050°C, and the contact angle of the droplets was measured. The measurement was carried out at the time when it was lowered to 1050°C, and 2 hours, 4 hours, 6 hours, and 8 hours from the time point. A larger contact angle means that the molten glass is less likely to get wet with the sintered body, and thus the reactivity between the molten glass and the sintered body is low. In addition, the smaller the time change of the contact angle is, the more likely it is that it is easier to keep wet.

The results of the evaluation are shown in Table 1 and Fig. 4. In FIG. 4, the vertical axis represents the contact angle (°), and the horizontal axis represents the elapsed time (h: hours). In addition, 10000 mass ppm is 1 mass %.

As is clear from Table 1 and Fig. 4, the Al content is 0.1% by mass or less, preferably less than 0.1% by mass, the Mg content is 0.7% by mass or less, preferably less than 0.7% by mass, and the Ti content is 0.9% by mass or less, Preferably less than 0.9 mass%, Zr content is 3.5 mass% or less, preferably 3.5 mass% or less, Y content is 0.5 mass% or more, 10 mass% or less, preferably more than 0.5 mass% and less than 10 mass% , Since the time change of the contact angle is small and the contact angle after 8 hours is large, it can be seen that good durability is obtained.

In the above, the support roll, the manufacturing method of a glass plate, and the embodiment of the manufacturing apparatus of a glass plate were demonstrated, but this invention is not limited to the said embodiment. The present invention can be modified or improved within the scope of the scope of the claims.

For example, the support roll 40 of the above embodiment is used in the float method of forming the glass ribbon 14 on the molten metal 16, but may be used in other forming methods, for example, used in the fusion method. May be.

The rotating member 42 of the above embodiment has cogwheel-like irregularities on its outer circumference, but does not have to have cogwheel-like irregularities on its outer circumference. Since the refrigerant does not flow inside the rotating member, the glass ribbon is not strongly cooled in the vicinity of the rotating member, and it is difficult to become hard. Therefore, even if there are no cogwheel-shaped irregularities, the rotating member can easily press the glass ribbon and shrinkage of the glass ribbon in the width direction can be suppressed.

5 is a cross-sectional view showing a rotating member according to a modified example. 6 is a view showing the convex dimension of the rotating member of FIG. 5. Fig. 7 is another view showing the convex dimension of the rotating member of Fig. 5.

The rotation member 242 shown in FIG. 5 is used instead of the rotation member 42 shown in FIG. 3. The outer circumferential surface of the rotating member 242 has a curved shape in which the cross-sectional shape is convex radially outward over the entire circumference, and the central portion in the axial direction protrudes radially outward from both ends in the axial direction. The outer peripheral surface of the rotating member 242 has the same cross-sectional shape over the entire circumference. Since there are no cogwheel-shaped irregularities, it is not easily damaged, thereby reducing molding and processing costs.

For example, as shown in FIG. 6, the radius of curvature Ra of the convex curved shape is preferably R1 to R100 mm, more preferably R3 to R50 mm, and R5 in consideration of the grip force with the glass ribbon 14. -R30 mm is more preferable, and R10-R20 mm is particularly preferable. In the convex curved phase, for example, as shown in FIG. 7, the radius of curvature Rb of the central portion in the axial direction and the radius of curvature Rc of both ends in the axial direction may be a composite R. At this time, both the radius of curvature Rb and Rc are preferably R1 to R100 mm, more preferably R3 to R50 mm, still more preferably R5 to R30 mm, and particularly preferably R10 to R20 mm. Further, in the convex curved phase, a part may have a flat portion, but it is preferable not to have a flat portion because the grip force with the glass ribbon 14 is stabilized.

Considering the grip force with the glass ribbon 14, the width d of the rotating member 242 in the convex curved shape shown in FIG. 6 in the radial direction is preferably 0.5 mm or more, and more preferably 1 mm or more. , 2 mm or more is more preferable. Similarly, the width d of the rotating member 242 in the convex curved shape in the radial direction is preferably 5 mm or less, and more preferably 4 mm or less.

The radius r of the rotating member 242 shown in FIG. 6 is preferably 100 mm or more, and 150 mm or more in consideration of contact prevention between the flange 46 and the glass ribbon 14 and the horizontality of the shaft member 44. This is more preferable, 180 mm or more is more preferable, and 350 mm or less is preferable in consideration of position adjustment of the rotation member 242 and the glass ribbon 14 and fine adjustment of the rotation speed of the rotation member 242, 300 mm or less is more preferable, and 270 mm or less is still more preferable.

The thickness w of the rotating member 242 is preferably 5 mm or more, more preferably 10 mm or more, even more preferably 15 mm or more, and particularly 30 mm or more in consideration of the grip force with the glass ribbon 14 Preferably, in consideration of improving the flatness of the glass ribbon 14 and preventing unnecessary enlargement of the grip width, 120 mm or less is preferable, 100 mm or less is more preferable, 80 mm or less is still more preferable, and 60 mm or less is more It is more preferable, and 40 mm or less is especially preferable.

8 is a cross-sectional view showing a rotating member according to another modified example. The rotation member 342 shown in FIG. 8 is used instead of the rotation member 42 shown in FIG. 3. The cross-sectional shape of the outer circumferential surface of the rotating member 342 is flat, and the rotating member 342 has a rounded boundary portion between the outer circumferential surface and the side surface. The boundary is formed by chamfering or the like.

In the modified example shown in Fig. 5 or the modified example shown in Fig. 8, a plurality of protrusions having a height of 0.1 to 10 mm may be formed on the outer peripheral surface of the rotating member, or a plurality of grooves having a depth of 0.1 to 10 mm may be formed on the outer peripheral surface of the rotating member. . Further, both protrusions and grooves may be formed on the outer peripheral surface of the rotating member. The height of the protrusion and the depth of the groove are measured using the outer peripheral surface of the rotating member as a reference surface. The height of the protrusion and the depth of the groove are smaller than the radius r shown in FIG. 6, the radius of curvature Ra shown in FIG. 6, and the radius of curvature Rb and Rc shown in FIG. 7.

This application claims priority based on Japanese Patent Application No. 2013-104378 for which it applied to the Japan Patent Office on May 16, 2013, and the entire contents of Japanese Patent Application No. 2013-104378 are incorporated herein by reference.

10: molding device
40: support roll
42: rotating member
43: irregularities
44: shaft member
46: flange (protruding member)
48: heat transfer member
50: pressing member
51: pressing member main body
52: contact
54: first elastic body
60: insulation member
64: shim abutting member
66: second elastic body

Claims (15)

As a support roll for supporting a strip-shaped glass ribbon,
A rotating member in contact with the glass ribbon,
A shaft member having a refrigerant flow path therein and rotating together with the rotating member;
And a protruding member protruding from the outer periphery of the shaft member,
The rotating member is formed of ceramics,
A support roll in which a heat transfer member having a higher thermal conductivity than the rotation member is disposed between the protruding member and the rotation member. The method of claim 1,
A support roll having a pressing member for pressing the rotating member against the heat transfer member. The method of claim 2,
A support roll having a first elastic body elastically supporting the pressing member, which can be freely displaced in the axial direction of the shaft member, toward the rotation member. The method of claim 1,
The shaft member is inserted through a through hole formed in the rotating member,
A support roll in which a heat insulating member having a lower thermal conductivity than the rotating member is disposed between the inner periphery of the rotating member and the outer periphery of the shaft member. The method of claim 4,
A support roll in which a contact surface of the rotating member with the heat insulating member is tapered. The method of claim 4,
A support roll in which a contact surface of the heat insulating member with the rotating member is tapered. The method of claim 5,
A support roll having a second elastic body elastically supporting the heat insulating member, which can be freely displaced in the axial direction of the shaft member, toward the protruding member. The method of claim 1,
At least a portion of the rotating member in contact with the glass ribbon is formed of silicon nitride ceramics. The method of claim 8,
The silicon nitride ceramics is a sintered body, the support roll having an aluminum (Al) content of 0.1 mass% or less, a magnesium (Mg) content of 0.7 mass% or less, and a titanium (Ti) content of 0.9 mass% or less. The method of claim 9,
The silicon nitride ceramics have a zirconium (Zr) content of 3.5 mass% or less, and a yttrium (Y) content of 0.5 mass% or more and 10 mass% or less. The method of claim 1,
A support roll in which an outer peripheral surface of the rotating member is formed in a curved shape in which a cross-sectional shape is convex radially outwardly over the entire circumference. The method of claim 1,
The rotation member is a support roll having a toothed-wheel-shaped irregularities on the outer periphery. A method for forming a glass plate having a step of supporting a strip-shaped glass ribbon using the support roll according to any one of claims 1 to 12. A method for manufacturing a glass plate having a step of supporting a strip-shaped glass ribbon using the support roll according to any one of claims 1 to 12, and then slowly cooling the glass ribbon and cutting it. . An apparatus for forming a glass plate having a support roll according to any one of claims 1 to 12.

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