KR20130138819A - Production method for glass plate, production method for glass substrate for display, and glass plate - Google Patents

Abstract

The manufacturing method of a glass plate includes the process of grinding the end surface of a glass plate, and the process of grinding the end surface of the said glass plate after grinding. The step of grinding the end face of the glass plate comprises a first grinding step of grinding the end face of the glass plate using a first grinding wheel in which the abrasive grain is hardened with the first binder, and after the first grinding step, the abrasive is ground. It has a 2nd grinding process which grinds the end surface of the said glass plate using the 2nd grinding wheel hardened by the 2nd binder with hardness and rigidity lower than the said 1st binder.

Description

TECHNICAL METHOD FOR GLASS SUBSTRATE FOR DISPLAY, AND GLASS PLATE}

This invention relates to the manufacturing method of the glass plate, the manufacturing method of the glass substrate for a display, and the glass plate including the process of grinding the end surface of the molded glass plate.

When manufacturing glass plates, such as a flat panel display, a molded glass plate is cut | disconnected to predetermined size. In cutting of a glass plate, the mechanical cutting using a cutter and the cutting using a laser are common. In the cutting of the glass plate using the cutter, since the cutting line is mechanically formed and cut on the glass plate, the cut end surface has a crack having a depth of about several to 100 μm, for example, from 7% of the thickness of the glass plate. Cracks extending inwardly from the surface by 10% have been produced. This crack causes the mechanical strength of the glass plate to deteriorate. Moreover, in the cutting using a laser, since a perforated line is formed and cut | disconnected on a glass plate using a thermal stress, the end surface of the cut glass plate becomes sharp and it is easy to be fragmented or peeled off. Therefore, the crack and the sharp part of the end surface of the cut glass plate are removed by grinding and grinding | polishing. That is, in order to improve the mechanical strength of a glass plate, to prevent a crack and a crack of a glass plate, and to make it easy to handle in a post process, grinding and grinding of the end surface of a glass plate are performed.

As the processing of the end face of the glass plate, the end face of the glass plate is ground by a metal bond diamond wheel, and then polished by the polishing wheel having flexibility and elasticity disclosed in Japanese Patent Application Laid-Open No. 2001-259978. Chamfering methods are known. However, in conventional end face processing, even if polishing is performed by the above-described polishing wheel, removal of minute unevenness of the end face of the glass plate may be insufficient. In such a case, when particles such as glass powder accumulate on the minute unevenness of the end face of the glass plate, the particles accumulated in the unevenness in the later step adhere to the main surface, which is the front and back surface of the glass plate, during the processing in the later step. This will cause deterioration of the glass plate quality. Moreover, when the unevenness | corrugation of the end surface of a glass plate is not fully reduced, the mechanical strength of a glass plate may fall. Moreover, in the manufacturing method of a glass plate, in order to improve the productivity of a glass plate, it is also necessary to raise a grinding speed.

The present invention provides a manufacturing method of a glass plate, a manufacturing method of a glass substrate for display, and a glass plate, which reduce unevenness of the end face of the glass plate than before while ensuring the production amount of the glass plate.

One aspect of the present invention is a method for producing a glass plate. In the above manufacturing method,

Grinding the end face of the glass plate,

And grinding | polishing the end surface of the said glass plate after grinding.

The step of grinding the end face of the glass plate,

A first grinding step of grinding the end face of the glass plate using a first grinding wheel having hardened abrasive grains as a first binder,

After the said 1st grinding process, it has a 2nd grinding process of grinding the end surface of the said glass plate using the 2nd grinding wheel which hardened the abrasive grain to the 2nd binder with hardness and rigidity lower than the said 1st binder.

Preferably, the first binder is a metal binder and the second binder is a resin binder.

In the first grinding step, the end face of the glass plate is ground so that the maximum height Rmax specified in JIS B 0601-1982 becomes 10 µm or more and 18 µm or less, and in the second grinding process, The end face is preferably ground such that the maximum height Rmax is 4 µm or more and 8 µm or less.

In the process of polishing the glass plate, the end face of the glass plate is preferably polished so that the maximum height Rmax is less than 4 µm.

Preferably, the grinding amount of the end surface of the glass plate in the first grinding step is 40 µm or more and 60 µm or less, and the grinding amount of the end surface of the glass plate in the second grinding step is 10 µm or more. Moreover, it is 30 micrometers or less.

In that case, it is preferable to grind | polish the said grinding | polishing process without changing a shape of the end surface of the said glass substrate ground by the said grinding process substantially.

Moreover, it is preferable that the said grinding | polishing process mirror-processes the end surface ground by the said grinding process.

Preferably, the first grinding step, the second grinding step and the step of polishing the glass plate are carried out while conveying the glass plate,

The conveyance direction of the said glass plate in a said 2nd grinding process is a reverse direction to the conveyance direction of the said glass plate in a said 1st grinding process.

In that case, the rotation direction of the said 1st grinding wheel in the point which the said 1st grinding wheel contact | connects the said glass plate is a direction opposite to the conveyance direction of the said glass plate, and the said 2nd grinding wheel contact | connects the said glass plate It is preferable that the rotation direction of the said 2nd grinding wheel in the point is the same direction as the conveyance direction of the said glass plate.

The conveyance speed of the said glass plate is 10 m / min or more, for example.

The conveyance speed of the said glass plate in a said 2nd grinding process is 15 m / min or more, for example.

The abrasive grains of the first grinding wheel and the second grinding wheel are diamond abrasive grains,

It is preferable that the particle size of the abrasive grain of the said 1st grinding wheel is equal to or larger than the particle size of the abrasive grain of the said 2nd grinding wheel.

Further, in the process of polishing the glass plate, the binder of the polishing wheel for polishing the end face of the glass plate is a foamed elastomer material, and the abrasive is one or more materials selected from SiC, Al ₂ O ₃ , or CeO ₂ . It is preferable that it is formed by.

It is preferable that the said glass plate is used for the board | substrate of the display apparatus of a flat panel display, or the cover glass of the display screen of an electronic device, and the said glass plate is shape | molded by the down-draw method or the float method.

Moreover, another aspect of this invention is the glass plate manufactured by the manufacturing method of the said glass plate. The glass plate,

The cross-sectional shape of the end face of the glass plate is formed in a convex shape with a curvature, the maximum height Rmax defined in JIS B 0601-1982 of the end face of the glass plate is less than 4 μm, and JIS B 0601-1982 Arithmetic mean roughness Ra prescribed | regulated by is 0.06 micrometer or less.

Moreover, another one aspect of this invention is a manufacturing method of the glass substrate for a display. In the above manufacturing method,

Grinding the end face of the glass substrate and grinding the end face into a convex shape given curvature;

And a step of polishing the end face of the glass substrate after grinding without substantially changing the shape.

The step of grinding the end surface of the glass substrate,

1st grinding which grinds the end surface of the said glass substrate so that the maximum height Rmax prescribed | regulated by JIS B 0601-1982 may be 10 micrometers or more and 18 micrometers or less using the 1st grinding wheel which hardened an abrasive grain with the 1st binder. Fair,

After the said 1st grinding process, the grinding amount by the said 2nd grinding wheel was measured as said Rmax using the 2nd grinding wheel which hardened the abrasive grain to the 2nd binder with hardness and rigidity lower than the said 1st binder. It has a 2nd grinding process to make it more than a numerical value.

In that case, it is preferable that the grinding amount of the end surface of the said glass plate in a said 2nd grinding process is 10 micrometers or more and 30 micrometers or less.

Moreover, it is preferable that the thickness of the said glass substrate is 0.25 mm-0.7 mm.

According to the manufacturing method and glass plate of the said glass aspect, the unevenness | corrugation of the end surface of a glass plate can be reduced compared with the past, ensuring the manufacturing amount of a glass plate.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the flow of the processing of the end surface of the glass plate in 1 line in the manufacturing process of a glass plate.
FIG. 2: is a perspective view which shows the 1st grinding wheel and the 2nd grinding wheel in this embodiment. FIG.

Hereinafter, the manufacturing method of the glass plate of this invention, the manufacturing method of a glass substrate for a display, and a glass plate are demonstrated in detail based on this embodiment.

Although the glass plate manufactured by this embodiment is not specifically limited, For example, it uses suitably for the cover glass used for the display screen of electronic apparatuses, such as a portable electronic apparatus, the glass substrate for display of display apparatuses, such as a flat panel display, etc. do.

Although the composition of a glass plate is not specifically limited, For example, it can apply to the glass plate of the following composition ratios.

(a) SiO ₂ : 50-70 mass%,

(b) B ₂ O ₃ : 5-18 mass%,

(c) Al ₂ O ₃ : 10-25 mass%,

(d) MgO: 0-10 mass%,

(e) CaO: 0-20 mass%,

(f) SrO: 0-20 mass%,

(o) BaO: 0-10 mass%,

(p) RO: 5-20 mass% (R is at least 1 sort (s) chosen from Mg, Ca, Sr, and Ba, and is total of RO content.),

(q) R _'2 O: less than 0.20% by weight and 2.0% by weight (where R' is the total content of Li, and at least one member selected from Na and K, R _'2 O),

(r) 0.05-1.5 mass% in total of at least 1 sort (s) of metal oxide chosen from tin oxide, iron oxide, and cerium oxide.

In this embodiment, after melt | dissolving glass is shape | molded by the down-draw method, grinding and polishing of the end surface of a glass plate are carried out, conveying the glass plate cut | disconnected to predetermined length at the conveyance speed of 10 m / min or more. The shaping | molding method of glass is not limited to the down-draw method, You may shape | mold by other methods, such as a float method.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the flow of the processing of the end surface of the glass plate in one line in the manufacturing process of the manufacturing method of the glass plate of this embodiment or the manufacturing method of the glass substrate for display. Hereinafter, a glass plate and a glass substrate are called glass plate, unless there is particular notice. In the end surface processing line 10 of the glass plate, the 1st chamfer 12, the 2nd chamfer 14, the corner cut machine 16, and the inverter 18 are provided. The 1st chamfer 12, the inverter 18, the 2nd chamfer 14, and the corner cut machine 16 are arrange | positioned in order from the upstream of a conveyance path | route. FIG. 2: is a perspective view which shows the 1st grinding wheel and the 2nd grinding wheel in the 1st chamfer 12 and the 2nd chamfer 14. As shown in FIG.

As shown in FIG. 1, the diamond wheel for grinding provided in the both sides of a conveyance path | route with respect to the end surface of the short side of the rectangular glass plate G in the 1st chamfering machine 12, conveying glass plate G. As shown in FIG. Grinding is performed using (12a). As shown in FIG. 2, the diamond wheel 12a is composed of two stages of the first grinding wheel 12a ₁ and the second grinding wheel 12a _{2 in} the direction of the rotation axis Z. As shown in FIG.

The 1st grinding wheel 12a ₁ is a grinding wheel which hardened diamond abrasive grains with the metallic binder containing iron. A first binding agent of the grinding wheel (12a ₁₎ is used to the second higher hardness and rigidity than the binder of the grinding wheel (12a _2). Hardness here is Shore hardness, and rigidity means Young's modulus. The first is to use another metal binder, such as metal-based coupling agent is, for example, cobalt, bronze series of grinding wheels (12a _1). Further, the second higher hardness and rigidity than the binder of the grinding wheel (12a _2), the query is also possible to use a ceramic binder as the binder of the first grinding wheel (12a _1). As the first grinding wheel 12a ₁ , for example, diamond abrasive grains having a particle size of about # 300 to # 400 defined in JIS R6001-1987 can be used. In the present embodiment, the first grinding wheel 12a ₁ uses diamond abrasive grains having a particle size of # 400. The abrasive grain is not limited to diamond, but may be CBN (borazone). The particle size of the first grinding wheel 12a ₁ may be equal to or larger than the particle size of the diamond abrasive grains of the second grinding wheel 12a ₂ .

The second grinding wheel 12a ₂ is a grinding wheel in which diamond abrasive grains are hardened with a resin-based binder containing epoxy. The second binder of the diamond abrasive grains of the grinding wheel (12a ₂₎ is used that the first binding agent is lower than the hardness and rigidity of the grinding wheel (12a _1). If the binder of the second grinding wheel 12a ₂ is lower in hardness and rigidity than the binder of the first grinding wheel 12a ₁ , a ceramic binder may be used. The second binding agent of the grinding wheel (12a ₂₎ is, for example, may be a material of the polyimide-based resin is. The abrasive grains of the second grinding wheel 12a ₂ are not limited to diamond but may be CBN. In this embodiment, the second grinding wheel (12a ₂₎ is used the particle size of the diamond abrasive grains of # 400, which is defined in JIS R6001-1987.

The grain size of the abrasive grains of the first grinding wheel 12a ₁ is preferably equal to or larger than the grain size of the abrasive grains of the second grinding wheel 12a ₂ in order to efficiently perform grinding.

In the first grinding step, in the first side odor 12, the glass sheet G is also conveyed in the conveying direction indicated by the arrow of Figure 1, the first grinding wheel (12a _1), also indicated by a broken line in 2 The end face of the glass plate G is ground by the grinding groove W. A first grinding wheel (12a ₁₎ is an end face of the glass sheet G, and grinding a predetermined amount of grinding. Thereby, the end surface of glass plate G retreats to the center side of a glass plate rather than an original end surface, and the cross-sectional shape of an end surface curvature corresponding to the cross-sectional shape of the grinding groove W of the 1st grinding wheel 12a ₁ . It is ground in the convex shape provided. Here, a grinding amount is the distance from the position of the original end surface before grinding to the position of the apex of the convex end surface after grinding which grind | pulverized and retracted. In other words, the end face of the glass plate G is an amount ground in a direction parallel to the main surface of the glass plate G. The amount of grinding of the glass plate G by the 1st grinding wheel 12a ₁ exists in 40 micrometers-60 micrometers, for example. It is preferable that the conveyance speed of glass plate G in a 1st grinding process is 10 m / min or more from a viewpoint of ensuring productivity. In this embodiment, the conveyance speed of glass plate G is 10 m / min.

In the 1st grinding process, glass is made so that the maximum height Rmax prescribed | regulated by JIS B 0601-1982 of the end surface of glass plate G may be at least 10 micrometers or more and 18 micrometers or less, More preferably, 13 micrometers or more and 14 micrometers or less. The end face of the plate G is ground. In addition, the arithmetic mean roughness Ra prescribed | regulated by JIS B 0601-1982 of the end surface of glass plate G becomes about 0.5 micrometer, for example.

Thereafter, as shown in FIG. 2, the diamond wheel 12a moves in the direction of the rotation axis Z so that the grinding groove W of the second grinding wheel 12a ₂ corresponds to the position of the end face of the glass plate G. As shown in FIG. . In a second grinding process, the glass sheet G is also being conveyed in the arrow a direction opposite the first, of the conveying path, the second end surface by the grinding groove W of the second grinding wheel (12a ₂₎ is ground. As a result, only the cross-sectional shape of the face of the glass sheet G is, the second corresponding to the cross-section of the grinding groove W of the grinding wheel (12a ₂₎ is ground with a curvature is given a convex shape.

The grinding amount of the glass plate G by the second grinding wheel (12a _2), for example in the range of from 10㎛ to 30㎛. It is preferable that it is 10 m / min or more from a viewpoint of securing productivity, and, as for the conveyance speed of the glass plate G in a 2nd grinding process, it is more preferable that it is 15 m / min or more. In this embodiment, the conveyance speed of glass plate G is 15 m / min. It is preferable that the conveyance speed of the glass plate G in a 2nd grinding process is larger than the conveyance speed of the glass plate G in a 1st grinding process.

In the second grinding step, the end face of the glass plate G such that the maximum height Rmax defined in JIS B 0601-1982 of the end face of the glass plate G is at least 4 μm or more and 8 μm or less, more preferably about 6 μm. Grind In addition, the said arithmetic mean roughness Ra of the end surface of glass plate G becomes about 0.1 micrometer-about 0.2 micrometer, for example.

In addition, about the rotation direction of the grinding wheel 12a, the rotation direction of the outer peripheral surface of the grinding wheel 12a in the point which contacts glass plate G may be set so that it may become the same as the conveyance direction of glass plate G, and it is reversed. It may be set in the direction of. In this embodiment, the rotation direction of the outer peripheral surface of the grinding wheel 12a in the point which contacts glass plate G in a 1st grinding process becomes a direction opposite to the conveyance direction of glass plate G, and is 2nd grinding process The grinding wheel 12a is rotated in one direction so as to be in the same direction as the conveying direction of the glass plate G.

In the grinding | polishing process, the end surface of the glass G ground by the 2nd grinding process is polished by the grinding wheel 12b provided in the both sides of a conveyance path | route. As the polishing wheel 12b, for example, a resin-bonded polishing wheel having flexibility and elasticity, as disclosed in Japanese Patent Application Laid-Open No. 2001-259978, can be used. In this case, since the resin-bonded abrasive wheel ensures flexibility and elasticity, the elastic modulus of the resin-bonded abrasive wheel is preferably 50 to 10000 kg / cm 2 or 500 to 7000 kg / cm 2, for example. The Shore D hardness of the resin-bonded polishing wheel is preferably 10 to 95 or 40 to 80, and the density of the resin-bonded polishing wheel is preferably 0.4 to 2.5 g / cm 3, for example. This application refers to Unexamined-Japanese-Patent No. 2001-259978.

The abrasive wheel 12b, which is a resin bonded abrasive wheel, hardens abrasive grains commonly used in abrasive materials such as SiC, Al ₂ O ₃ and CeO ₂ with a resin binder having flexibility and elasticity. As the particle size of the abrasive grain of the polishing wheel 12b, for example, about # 300 to # 500 defined in JIS R6001-1987 can be used. In this embodiment, the particle size of the grinding wheel 12b is # 400. As the resin binder, for example, a binder of polyurethane or polyimide can be used.

It is preferable that the conveyance speed of glass plate G in a grinding | polishing process is 15 m / min or more from a viewpoint of ensuring productivity. In this embodiment, the conveyance speed of glass plate G is 20 m / min, for example. In addition, about the rotation direction of the grinding wheel 12b, the rotation direction of the outer peripheral surface of the grinding wheel 12b in the point which contacts glass plate G may be set so that it may become the same as the conveyance direction of glass plate G, and it is reversed. It may be set in the direction of. In this embodiment, the rotation direction of the polishing wheel 12b is set so that the rotation direction of the outer peripheral surface of the polishing wheel 12b at the point of contact with the glass plate G may be the direction opposite to the conveying direction of the glass plate G. It is.

In the grinding | polishing process, the end surface of glass plate G is polished so that the said maximum height Rmax of the end surface of glass plate G may be less than 4 micrometers, Preferably it is 3.5 micrometers or less. In addition, the said average roughness Ra of the end surface of glass plate G becomes about 0.03 micrometer-0.06 micrometer, for example.

In addition, in this embodiment, grinding and polishing of the end surface of glass plate G are distinguished clearly. That is, grinding | polishing is the process of shape | molding the cross-sectional shape of the end surface of glass plate G to a desired shape by shaving glass, and it is accompanied by the grinding amount of at least several micrometers. Therefore, by grinding, the above-mentioned surface quality of the end surface of plate glass G used as a final product cannot be obtained.

On the other hand, grinding | polishing is a process which reduces or removes fine unevenness | corrugation by leveling the unevenness | corrugation of the end surface of glass plate G, and improves the surface quality of the end surface of glass plate G. Therefore, the polishing hardly changes the cross-sectional shape of the end face of the glass plate G, and is a processing including surface treatment as so-called mirror surface processing. That is, the polishing step polishes the end face of the glass plate G while maintaining the shape of the end face of the glass plate G, in other words, without substantially changing the shape of the end face of the glass plate G ground by the grinding step. .

In addition, in this embodiment, although polishing is performed using the polishing wheel 12b, polishing is performed using a known tape polishing technique, a pad polishing technique, a brush polishing technique, or a magnetic fluid finishing technique in place of the polishing wheel 12b. You can also do it.

In addition, in this embodiment, although the diamond wheel 12a and the grinding wheel 12b are ground and grind | polished without moving to the conveyance direction of glass plate G, glass plate G is stopped or glass plate G is stopped. The diamond wheel 12a and / or the polishing wheel 12b may be moved to grind and polish the end face of the glass plate G while conveying.

After polishing, the inverter 18 rotates the glass plate G in a direction of 90 degrees, and conveys the glass plate G to the second chamfering machine 14 along the conveyance path. The second chamfer 14 has a diamond wheel 14a similar to the diamond wheel 12a of the first chamfer 12. As shown in FIG. 2, the diamond wheel 14a is the first grinding wheel 14a ₁ similar to the first grinding wheel 12a ₁ and the second grinding wheel 12a ₂ of the first chamfer _12. ) And second grinding wheel 14a ₂ .

In the 2nd chamfering machine 14, the 1st surface by the 1st grinding wheel 14a ₁ of the diamond wheel 14a provided in the both sides of the conveyance path | route with respect to the end surface of the long side of the rectangular glass plate G. The first grinding step similar to the odor 12 is performed. Then, with respect to the long side end surface of a rectangular glass plate G, the first subjected to a second grinding process similar to that of the first surface odor 12 by the grinding wheel (14a _2).

Thereafter, in the polishing step, polishing of the end face of the glass plate G ground using the polishing wheels 14b provided on both sides of the conveyance path is performed. The polishing wheel 14b is configured similarly to the polishing wheel 12b of the first chamfer 12. Thereafter, the glass plate G is conveyed to the corner cut machine 16, and the corner of the glass plate G is ground and polished using the diamond wheel 16a for corner cuts. Then, glass plate G is shipped as a product through a washing | cleaning process and an inspection process.

In this embodiment, grinding of the end surface of glass plate G is performed by grinding by the 1st grinding wheels 12a ₁ and 14a ₁ which are metal bond diamond wheels which hardened the diamond abrasive grain with the metal binder, and a diamond abrasive grain of thermosetting The grinding is performed in two stages of grinding by the second grinding wheels 12a ₂ and 14a ₂ , which are resin bond diamond wheels hardened with a resin binder.

The metal bond diamond wheel, that is, the grinding wheel using a metal binder, can grind with a focus on the grinding quality depending on the particle size and the specification of the binder, and can also perform high-speed grinding with a focus on the grinding ability. All grinding specifications can be set. In the wheel specification focused on the grinding processing ability, the damage to the glass plate is increased as the processing capacity for grinding the glass plate is improved, and the quality of the end face of the glass plate such as surface roughness and chipping may be sacrificed. . Therefore, in order to maintain the quality of the end surface of a glass plate, the metal bond diamond wheel of the specification which focused on grinding quality is used. However, if the grinding speed is increased by using a wheel with a focus on grinding quality, the frequency of glazing and clogging of the abrasive grains increases, and the grinding processing ability is insufficient, causing defects such as grinding burns and shell cracks. Risk arises. Therefore, when using the metal bond diamond wheel of the specification which focused on grinding quality, it is difficult to maintain and improve productivity. In addition, in order to grind | roughen the unevenness | corrugation of the end surface of glass plate G in the state grind | polished with the grinding wheel using the metal binder, in order to fully reduce the unevenness | corrugation of the end surface of glass plate G, and to improve product quality, the polishing time is excessively excessive. As it gets longer, you have to sacrifice productivity.

Resin bond diamond wheels, that is, grinding wheels using a thermosetting resin binder, are rich in cushioning properties and have high flexibility as compared with the grinding wheels using a metal binder. Therefore, the damage to the end surface of glass plate G is suppressed as much as possible, and delicate grinding is possible. Therefore, compared with the grinding wheel using a metal binder, the surface roughness of the end surface of glass plate G becomes small.

In this embodiment, the grinding | polishing force is centered on the grinding force as grinding by a metal bond diamond wheel, and the shape required for the end surface of a glass plate is formed in a short time by high speed grinding. After that, the end surface of the glass plate G is ground by the resin bonded diamond wheel as fast as possible so as to have a predetermined surface roughness that can realize the surface roughness targeted in the polishing of the next step. And final polishing is performed on the end surface of the glass plate of higher quality than the conventional grinding obtained by the grinding of this embodiment, and the high quality end surface, such as surface roughness of the target glass plate G, can be obtained. In addition, it can be processed in a short time. In addition, in this embodiment, the above-mentioned grinding can suppress the glass particle which generate | occur | produces over time from the end surface of glass plate G, and can reduce the adhesion amount of the glass particle to the surface. This makes it possible to use a wiring / electrode material having low adhesion in a panel of a thin film transistor (TFT) panel display for organic EL (Elector-Luminescence) or a TFT panel display for high-precision liquid crystal. For example, although the adhesiveness is low compared with Al type electrode, Cr, Mo electrode, etc., a low resistance Cu type electrode material can be used. In other words, the wider selection of the electrode material makes it possible to solve the problem of RC delay (wiring delay), which tends to be a problem in large panel displays. In addition, it is possible to provide a glass substrate that can solve the problem of RC delay that may occur in a small panel display which is further refined in the future.

In the present embodiment, the maximum height Rmax described above is used as an index of surface roughness. In the grinding and polishing of the end face of the glass plate G, minute irregularities are formed on the end face of the glass plate G, but the concave portion is considered to be more dominant than the convex portion. Therefore, by using the maximum height Rmax as an index of surface roughness, it is possible to prevent an extremely deep recess from being formed. As a result, the amount of particles accumulated in the concave portion of the end face of the glass plate G can be reduced, the amount of particles adhering to the surface of the glass plate G can be reduced, and the quality of the glass plate G can be improved. In addition, the strength of the glass plate can be improved by preventing an extremely deep recess from being formed in the end face of the glass plate G.

In addition, the conveyance direction of the glass plate G in a 2nd grinding process is opposite to the conveyance direction of the glass plate G in a 1st grinding process. Therefore, compared with the case where glass plate G is conveyed in one direction, a conveyance line can be shortened and grinding apparatuses, such as the 1st chamfer 12 and the 2nd chamfer 14, can be made compact.

Further, the first grinding wheel (12a ₁₎ is the direction of the rotational direction, the glass plate G opposite to the conveying direction of the first grinding wheel (12a ₁₎ at the point in contact with the glass sheet G. As a result, the speed difference between the glass plate G and the first grinding wheel 12a ₁ is increased, and the end face shape can be processed more quickly.

Further, the second grinding wheel (12a ₂₎ is the same direction as the transport direction of the rotational direction, the glass plate G in the second grinding wheel (12a ₂₎ in a point which contacts the glass sheet G. As a result, while maintaining the productivity, to reduce the difference in speed of the glass plate G and the second grinding wheel (12a _2), it is possible to process than the end surface of high quality.

The thickness of the glass plate used for this embodiment is 0.25-0.7 mm, Preferably it is 0.3-0.5 mm.

As explained above, according to the manufacturing method of the glass plate of this embodiment, the unevenness | corrugation of the end surface of glass plate G can fully be reduced, and the product quality can be improved, ensuring productivity.

In addition, the end surface processing line 10 of glass plate G is not limited to said structure. For example, the corner cut machine 16 and the inverter 18 can be omitted by giving the function of the corner cut machine 16 and the inverter 18 to the 1st chamfer 12. FIG. In this case, following (1)-(5) can be performed in one chamfering machine.

(1) After conveying glass plate G to a conveyance direction and performing corner cut, the 1st grinding process of the long side of glass plate G is performed, and corner cut is again performed.

(2) Glass plate G is conveyed in the reverse direction to a conveyance direction, and the 2nd grinding process of the long side of glass plate G is performed.

(3) Rotate glass plate G by 90 °.

(4) After conveying glass plate G to a conveyance direction and performing corner cut, the 1st grinding process of the short side of a glass plate is performed, and corner cut is again performed.

(5) Glass plate G is conveyed in the reverse direction to a conveyance direction, and the 2nd grinding process of the short side of glass plate G is performed.

In addition, the corner cut of the process of (4) is performed only when the dimension to cut is large. About corner cut, the 1st grinding wheel 12a ₁ used at the 1st grinding process can be used. In addition, the chamfer to grind and the grinder to grind may be used as a separate apparatus.

(Example, Comparative Example)

Hereinafter, the Example based on said embodiment and the comparative example different from this embodiment are demonstrated.

In the Example, as mentioned above, the 1st grinding process, the 2nd grinding process, and the grinding | polishing process were performed to the end surface of the glass plate G of thickness 0.5mm. In the comparative example to be compared with Examples, it was subjected to grinding using only the first grinding wheel a diamond wheel (12a ₁₎ and using the metal binder of the same in the embodiment described above, were subjected to the above-described polishing process.

The outer diameter of the diamond wheel 12a used for the Example and the comparative example was all 250 mm, and the outer diameter of the grinding wheel 14b was all 150 mm. In addition, all the rotation speeds of the grinding wheel 12a in a 1st grinding process are 2298 rpm, and the rotation speed of the grinding wheel 12a in a 2nd grinding process is 3000 rpm, and the grinding wheel ( All rotation speeds of 14b) were 2500 rpm. The particle size of the diamond abrasive grains of the diamond wheel used in a 1st grinding process was set to # 400 in the Example and # 500 in the comparative example, and the metal binder used the iron-type binder all. The particle size of the diamond abrasive grain of the diamond wheel used in a 2nd grinding process was set to # 400, and the resin binder used the epoxy binder. The abrasive grain used in the grinding | polishing process used SiC, the particle size was # 400, and the resin binder which has flexibility and elasticity used the polyurethane binder. Under these conditions, the end face of the glass plate was ground and polished. In addition, in the Example, the conveyance speed of the glass plate was 10 m / min in the 1st grinding process, 15 m / min in the 2nd grinding process, and 20 m / min in the grinding | polishing process. In the comparative example, the conveyance speed of the glass plate was 7 m / min in the grinding process, and 20 m / min in the grinding | polishing process.

At this time, the grinding amount of the end surface of a glass plate was 90 micrometers-110 micrometers in the 40 micrometers-60 micrometers, and the grinding process of a comparative example in the 1st grinding process of an Example. Then, in the 2nd grinding process performed in the Example, the grinding amount of the end surface of the glass plate was 10 micrometers-30 micrometers.

In the Example and the comparative example, it grind | polished after that using the grinding | polishing wheel similar to the grinding wheel 14b in said embodiment.

That is, in the said Example, after performing the grinding | polishing of the end surface of a glass plate in two steps of grinding with a metal bond diamond wheel and grinding with a resin bond diamond wheel, the end surface of the glass plate after grinding was polished. On the other hand, in the said comparative example, after grinding the end surface of plate glass only by the grinding | polishing by a metal bond diamond wheel, it differs from the said Example by the point which grind | polished the end surface of the glass plate after grinding.

In the comparative example, the crack was seen in the photograph of the side view which image | photographed the end surface from the direction perpendicular | vertical to the front and back surface (main surface) of a glass plate. Moreover, in the photograph of Front View which image | photographed the end surface by 5 times and 20 times magnification from the direction parallel to the front and back surface of a glass plate, the comparatively large recessed part was formed.

In the Example, the crack was not seen in the photograph of the side view which image | photographed the end surface from the direction perpendicular | vertical to the front and back surface of a glass plate. Moreover, in Front View which image | photographed the end surface by 5 times and 20 times magnification from the direction parallel to the front and back surface of a glass plate, the recessed part was shallow and small compared with the comparative example, and the smoothness of the end surface improved.

The amount of particles on the end face of the glass plate subjected to the grinding and polishing based on the above-described example and the amount of particles on the end face of the glass plate subjected to the grinding and polishing based on the Comparative Example were measured and compared. The measurement of the amount of particles was performed by sucking the end face of the glass plate using a particle counter having an aspirator. Specifically, by sliding the end face of the glass plate while pressing the scrape member that is softer than the glass plate, friction is applied to the end face of the glass plate to scrape the particles of the end face, and suction the scraped particles. The particle of the glass plate end surface was measured by counting the number by the particle counter. Such a measuring method is described in detail in Japanese Patent Application Laid-Open No. 2010-230646, for example. In the sample of the said Example, the quantity of particle fell about 30% compared with the sample of the said comparative example.

Arithmetic mean roughness Ra defined in JIS B 0601-1982 of the end face of the ground and ground glass plate based on the said Example, and arithmetic mean of the end face of the glass plate which ground and ground based on the said comparative example Roughness Ra was compared. In the sample of the said Example, Ra fell about 0.05 micrometer, and Ra fell about 37% compared with the sample of the said comparative example. In addition, arithmetic mean roughness Ra is a result measured using the Co., Ltd. product made by Tokyo Semitsu, a roughness measuring instrument, and a surfcom (brand name). The maximum height Rmax is also measured by the same method.

The bending strength of the glass plate which performed the grinding and polishing based on the said Example, and the glass plate which performed the grinding and polishing based on the said comparative example was compared. In the sample of the glass plate of the Example, 0.1% damage rate improved about 5-10 Mpa compared with the sample of the glass plate of the comparative example, and it was confirmed that the mechanical strength of the glass plate improved. The bending strength of the glass plate was measured by the four point bending test.

As mentioned above, although the manufacturing method of the glass plate of this invention was demonstrated in detail, this invention is not limited to the said embodiment, A various improvement and change may be carried out in the range which does not deviate from the main point of this invention.

As mentioned above, although the manufacturing method and glass plate of the glass plate of this invention were demonstrated in detail, this invention is not limited to the said embodiment, A various improvement and change may be carried out in the range which does not deviate from the main point of this invention. Of course.

10: end face processing line
12: first chamfering machine
12a: second chamfering machine
12a ₁ , 14a ₁ : First grinding wheel
12a ₂ , 14a ₂ : second grinding wheel
12b, 14b: Polishing Wheel
14: second chamfering machine
14a: diamond wheel
16: corner cut
16a: diamond wheel for corner cut
18: inverter

Claims (18)

As a manufacturing method of the glass plate,
Grinding the end face of the glass plate,
Including an end surface of the glass plate after grinding,
The step of grinding the end face of the glass plate,
A first grinding step of grinding the end face of the glass plate using a first grinding wheel having hardened abrasive grains as a first binder,
After the said 1st grinding process, the glass plate which has a 2nd grinding process of grinding the end surface of the said glass plate using the 2nd grinding wheel which hardened the abrasive grain to the 2nd binder with hardness and rigidity lower than the said 1st binder. Method of preparation. The method of claim 1,
The first binder is a metal binder, and the second binder is a resin binder manufacturing method. 3. The method according to claim 1 or 2,
In the first grinding step, the end face of the glass plate is ground so that the maximum height Rmax specified in JIS B 0601-1982 is 10 µm or more and 18 µm or less,
In the second grinding step, the end face of the glass plate is ground so that the maximum height Rmax is 4 µm or more and 8 µm or less. 4. The method according to any one of claims 1 to 3,
In the step of polishing the glass plate, the end face of the glass plate is polished so that the maximum height Rmax is less than 4㎛. 5. The method according to any one of claims 1 to 4,
The grinding amount of the end surface of the said glass plate in a said 1st grinding process is 40 micrometers or more and 60 micrometers or less,
The grinding | polishing amount of the end surface of the said glass plate in a said 2nd grinding process is 10 micrometers or more and 30 micrometers or less. The method of claim 5,
The said grinding | polishing process is a manufacturing method of the glass plate which grinds without changing the shape of the end surface of the said glass substrate ground by the grinding process substantially. The method according to claim 5 or 6,
The said grinding | polishing process is a manufacturing method of the glass plate which mirror-processes the end surface ground by the said grinding process. 8. The method according to any one of claims 1 to 7,
Carrying out the process of grinding the said 1st grinding process, the said 2nd grinding process, and the said glass plate, conveying the said glass plate,
The conveyance direction of the said glass plate in a said 2nd grinding process is a manufacturing method of the glass plate opposite to the conveyance direction of the said glass plate in a said 1st grinding process. 9. The method of claim 8,
The rotation direction of the said 1st grinding wheel in the point which the said 1st grinding wheel contact | connects the said glass plate is a direction opposite to the conveyance direction of the said glass plate,
The rotation direction of the said 2nd grinding wheel in the point which the said 2nd grinding wheel contacts with the said glass plate is a manufacturing method of the glass plate which is the same direction as the conveyance direction of the said glass plate. 10. The method according to claim 8 or 9,
The conveyance speed of the said glass plate is 10 m / min or more, The manufacturing method of the glass plate. The method of claim 10,
The conveyance speed of the said glass plate in a said 2nd grinding process is a manufacturing method of the glass plate which is 15 m / min or more. 12. The method according to any one of claims 1 to 11,
The abrasive grains of the first grinding wheel and the second grinding wheel are diamond abrasive grains,
A method for producing a glass plate, wherein the grain size of the abrasive grains of the first grinding wheel is equal to or larger than the grain size of the abrasive grains of the second grinding wheel. 13. The method according to any one of claims 1 to 12,
In the process of polishing the glass plate, the binder of the polishing wheel for polishing the end face of the glass plate is a foamed elastomer material, and the abrasive is formed by at least one material selected from SiC, Al ₂ O ₃ , or CeO ₂ . The manufacturing method of the glass plate. The method according to any one of claims 1 to 13,
The said glass plate is used for the board | substrate of the display apparatus of a flat panel display, or the cover glass of the display screen of an electronic device,
The said glass plate is a manufacturing method of the glass plate shape | molded by the down draw method or the float method. As a glass plate manufactured by the manufacturing method of the glass plate of any one of Claims 1-14,
The cross-sectional shape of the end face of the glass plate is formed in a convex shape given a curvature,
The glass plate of the end surface of the said glass plate whose maximum height Rmax prescribed | regulated by JIS B 0601-1982 is less than 4 micrometers, and the arithmetic mean roughness Ra prescribed | regulated by JIS B 0601-1982 is 0.06 micrometer or less. As a manufacturing method of a glass substrate for a display,
Grinding the end face of the glass substrate and grinding the end face into a convex shape given curvature;
A step of polishing the end face of the glass substrate after grinding without substantially changing the shape,
The step of grinding the end surface of the glass substrate,
1st grinding which grinds the end surface of the said glass substrate so that the maximum height Rmax prescribed | regulated by JIS B 0601-1982 may be 10 micrometers or more and 18 micrometers or less using the 1st grinding wheel which hardened an abrasive grain with the 1st binder. Fair,
After the said 1st grinding process, the grinding amount by the said 2nd grinding wheel was measured as said Rmax using the 2nd grinding wheel which hardened the abrasive grain to the 2nd binder with hardness and rigidity lower than the said 1st binder. The manufacturing method of the glass substrate for a display which has a 2nd grinding process made into a numerical value or more. 17. The method of claim 16,
The grinding amount of the end surface of the said glass plate in a said 2nd grinding process is 10 micrometers or more and 30 micrometers or less, The manufacturing method of the glass substrate for displays. 18. The method according to claim 16 or 17,
The thickness of the said glass substrate is 0.25 mm-0.7 mm, The manufacturing method of the glass substrate for a display.

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