TWI576295B - Fabricating method of glass roll and glass roll - Google Patents

Description

Glass roll manufacturing method and glass roll

The present invention relates to an improvement in a manufacturing technique of a glass roll in which a glass film formed by a down-draw method is wound into a roll.

As is well known, in recent years, flat panel displays (FPDs) represented by liquid crystal displays, plasma displays, and organic electroluminescence (EL) displays have become mainstream. In these FPD substrates, in order to ensure airtightness. Flatness. Heat resistance. Light transmission. A glass substrate is used for various required characteristics such as insulation. From the viewpoint of weight reduction, the actual situation is that the glass substrate used in the FPD is becoming thinner. In particular, in an FPD such as an organic EL display, since the display screen is bent and used, it is required to thin the glass substrate in order to impart flexibility.

Further, the organic EL is not a flat light source in which a thin three-primary color is flickered by a thin film transistor (TFT) as in a display, and is emitted only in a single color (for example, white) to be used as a light source for indoor illumination. In the organic EL illumination device, as long as the glass substrate has flexibility, the light-emitting surface can be freely deformed, and the use of the glass can be greatly expanded. Therefore, from the viewpoint of ensuring sufficient flexibility, the glass substrate used in the above illumination device is also promoted to be thinned.

Further, since the touch panel is operated by rubbing the surface with a human finger or the like, the glass substrate is often used in order to secure the surface of the touch panel. With the spread of mobile terminals equipped with such touch panels, touch panels are used. The glass substrate is also required to be thinned to achieve weight reduction.

Further, in response to the demand for such a thin plate, a glass film which has been thinned to a film shape (for example, having a thickness of 300 μm or less) has been developed. Since the glass film has a moderate degree of flexibility, it may be wound around a winding core in a roll shape, and may be accommodated in a state of a so-called glass roll (for example, see Patent Document 1). . Thus, the storage space of the glass film is greatly reduced, and thus the transportation efficiency can be improved. In addition, various processes such as cutting or film formation can be continuously performed on the glass film wound from the glass roll on the upstream side by the roll-to-roll apparatus, and the production efficiency can be greatly improved.

Prior technical literature

Patent literature

Patent Document 1: Japanese Patent Laid-Open Publication No. 2010-132350

However, most of the glass film is formed by a down-draw method. Therefore, when it is intended to be accommodated in a state of being wrapped in a glass roll, it is necessary to wind the glass film continuously formed by the molded body which performs the down-draw method directly around the winding core.

However, in this case, if tension is excessively applied to the glass film at the time of winding (for example, about 100 N is applied to the glass film having a width of 1 m), excessive tension acts on the softened glass film in the vicinity of the molded body, so that the glass The thickness of the film becomes unstable, or warpage or undulation occurs, so that there is a fatal problem of fracture of the lower portion of the formed body as the case may be.

Therefore, it is difficult to apply sufficient tension to the glass film and winding it in practical use. For example, the wound glass film is likely to undergo winding deviation after moving in the width direction afterwards. Moreover, if a moderate tension is not applied to the glass film When it is wound, in the state of the glass roll, the glass film floats from the core, which may cause an improper gap between the glass films. Further, when the winding deviation or the floating (diameter gap) occurs in the glass film as described above, the glass film is easily broken and the operation becomes very troublesome. Further, in this case, since the glass film is in an irregularly wound state, the appearance of the glass roll is also extremely poor, which may cause a decrease in product value.

In view of the above facts, the technical problem of the present invention is to reduce the occurrence of the glass film contained in the glass roll as much as possible when the glass film continuously formed by the down-draw method is housed in a glass roll state. Winding offset or float.

According to a first aspect of the invention, the present invention is directed to a molding step of conveying a glass film while continuously forming a glass film by a molding device that performs a down-draw method, and a first winding step in the forming step. a downstream end of the transport path is formed by laminating a first protective film on the glass film and winding it into a roll shape to produce a raw material glass roll, and a second winding step of winding the glass film from the raw material glass roll The downstream side is conveyed, and the second protective film is superposed on the glass film at the downstream end of the transport path, and is re-wound into a roll shape to produce a glass roll; and the second winding step acts on the glass film. The tension in the winding direction is larger than the tension acting on the glass film in the first winding step.

According to the above-described method, in the second winding step, the glass film wound in the first winding step is applied to the winding direction (the conveying direction of the glass film) by the tension larger than the first winding step. Rewind. Thus, in In the first winding step of directly winding the glass film formed by the molding apparatus, it is not necessary to apply excessive tension to the glass film to perform winding. Incidentally, in the first winding step, the tension is applied to the glass film in a range that does not cause an adverse effect such as an abnormal thickness of the glass film formed by the molding apparatus, and as a result, even if it is produced on the glass film. The winding offset or float can also be corrected in the second winding step. In other words, in the second winding step, even if a large tension is applied to the glass film, the glass film is not adversely affected, so that the glass film can be applied without causing winding deviation or floating. With a sufficient degree of tension, the glass film can be re-wound to produce a glass roll.

In the above method, preferably, in the first winding step, the tension acting in the winding direction of the first protective film is larger than the tension acting in the winding direction of the glass film.

Thus, even if a large tension is not directly applied to the glass film, the movement of the glass film can be suppressed by the first protective film. That is, an effect equivalent to the case where the tension acts directly on the glass film can be obtained. Therefore, it is possible to suppress the winding deviation or floating of the glass film generated in the first winding step to a minimum. Further, since the glass film is reliably pressed by the first protective film in the state of the raw material glass roll, when the glass film is taken out from the raw material glass roll in the second winding step, it is less likely to occur in the raw material glass roll. The situation in which the glass film is improperly wound up. Further, when the glass film is wound up, since the glass film and the protective film are rubbed against each other, minute damage is formed on the surface of the glass film.

In the above method, in the second winding step, the above-described second winding step can be applied to the above The tension in the winding direction of the glass film is larger than the tension acting in the winding direction of the second protective film.

In the glass roll produced in the second winding step, that is, in the glass roll of the product, it is possible to surely prevent the occurrence of winding deviation or floating on the glass film after the tension acting on the glass film itself. State of affairs. Incidentally, the second protective film is forcibly pressed and the glass film is not corrected, so that the improper stress does not easily act on the glass film, and the stable packing state can be maintained.

In the above method, it is preferable that the surface of one side of the glass film is conveyed while being contact-supported in the second winding step.

Thus, the surface on the other side of the glass film is a non-contact surface. Therefore, the surface of the glass film which becomes this non-contact surface is hard to form the micro damage by the conveyance. Therefore, when a glass substrate for FPD such as an organic EL display is produced from the glass film, if components or wirings are formed on the non-contact surface of the glass film, components or wirings caused by minute damage are less likely to occur. The formation is poor, so that a highly reliable FPD can be provided.

In the above-described second winding step, it is preferable that the contact supporting surface of the glass film is wound on the inner peripheral surface side of the glass roll.

In this way, even if minute damage is caused to the contact supporting surface of the glass film, the contact supporting surface is wound on the inner peripheral surface side of the glass roll, so that only the compressive stress acts on the contact supporting surface. Therefore, even if a minute damage occurs on the contact support surface, the force for developing the minute damage is less likely to function. In other words, the non-contact surface which is substantially free from minute damage is located on the outer peripheral surface side of the glass film which acts to force the micro-damage to develop, and thus it is confirmed Really reduce the damage of the glass film.

In the above method, in at least one of the first winding step and the second winding step, the glass film may be wound by cutting into a predetermined width by laser cutting. Here, laser cuts include laser cuts and laser blows. The laser cutting is a method in which the initial crack is developed to cut the glass film by utilizing the thermal stress generated by the expansion caused by the heating action of the laser and the contraction caused by the cooling action of the refrigerant. On the other hand, the laser fusing is a method in which a part which is softened and melted by heating by a laser energy is injected and a high-pressure gas is injected and cut.

In the case of forming by the overflow down-draw method, for example, the ineffective portion (ear portion) which is formed to be relatively thick at both end portions in the width direction of the glass film can be cut and removed, and then wound. Further, the glass film can be wound after being changed to a desired width. Further, since the glass films are cut by laser cutting, there is an advantage that it is difficult to form microcracks which are a cause of breakage at the cut end faces of the glass film.

In the above method, it is preferable that the pull-down method is an overflow down-draw method.

In this manner, even if the surface of the glass film is not separately processed after the molding, the surface of the glass film can be provided with excellent smoothness with a small surface roughness.

In the above method, the thickness of the glass film is preferably 1 μm or more and 300 μm or less.

In this way, since sufficient flexibility can be imparted to the glass film, when the glass film is wound, the situation in which the undue stress acts on the glass film can be reduced, and the breakage of the glass film can be prevented.

A second invention for solving the above problems is a method for producing a glass roll, wherein a glass film is formed by a down-draw method, and the formed glass film is superposed on a protective film and wound into a roll shape; In the manufacturing method, the glass film and the protective film are wound while applying a tension in the winding direction larger than the glass film to the protective film.

According to the above method, even if the glass film is not subjected to a large tension in the winding direction, the glass film can be bundled by the tension applied to the relatively large winding direction of the protective film, so that it can be manufactured without winding. A loose glass roll appears. In addition, since the tension in the winding direction is not imparted to the glass film during the winding of the glass film or the tension is small, even in the case where the curved region is bent in a substantially horizontal direction in the curved region, The curvature of the curved region can be prevented from changing, so that the formation of the glass film is stabilized, and a glass film having no warpage or undulation and no change in thickness can be wound.

In the above method, the ineffective portion (ear portion) formed at both end portions in the width direction of the glass film may be laser-cut at a stage until the glass film is wound into a roll shape. Here, laser cutting and laser fusing are included in the laser cutting. The laser cutting is a method in which the initial crack is developed to cut the glass film by utilizing the thermal stress generated by the expansion caused by the heating action of the laser and the contraction caused by the cooling action of the refrigerant. On the other hand, the laser fusing is a method in which a part which is softened and melted by heating by a laser energy is injected and a high-pressure gas is injected and cut.

In this way, it is possible to easily impart appropriate smoothness to the cut surfaces of the both end faces in the width direction of the glass film without performing post-processing such as polishing. Moreover, since the protective film is given a relatively large tension in the winding direction, The end surface of the glass film is in easy contact with the protective film, but even in the case of contact, the end face is not caught on the protective film due to the smoothing of the end surface of the glass film, and the separation of the glass film and the protective film can be favorably maintained. Sex. Further, when the glass film is wound into a roll shape, fine damage is less likely to occur on both end faces of the glass film. Thereby, it is possible to reduce the glass frit generated by the fine particles due to the fine damage of the end surface of the glass film, and it is very advantageous in terms of ensuring the cleanness of the front and back surfaces of the glass film.

In the above method, the protective film is wound on the outer peripheral surface side of the glass film so that the protective film is placed on the outermost surface of the glass film, and the protective film is wound.

In this way, the glass film can be easily bundled by the protective film, and the glass roll without slack can be reliably produced.

In the above method, it is preferable that the pull-down method is an overflow down-draw method.

In this manner, it is possible to form a glass film having excellent surface smoothness without separately performing processing after molding, and thus it is possible to easily produce a glass roll having excellent surface precision.

According to a third aspect of the invention, the glass film is formed by laminating a glass film formed by a down-draw method on a protective film and winding it into a roll shape, wherein the protective film is provided. The tension in the winding direction larger than the above glass film.

According to such a configuration, it is possible to produce a glass roll in which a glass film having no warpage or undulation and no change in thickness is wound without being loosely wound.

In the above configuration, the thickness of the glass film is preferably 1 μm or more and 300 μm or less.

In this way, appropriate flexibility can be imparted to the glass film. Therefore, it is possible to reduce the undue stress acting on the glass film when the glass film is wound, and it is possible to prevent breakage.

In the above configuration, it is preferable that the arithmetic mean roughness Ra of both end faces in the width direction of the glass film is 0.1 μm or less.

In this way, appropriate smoothness can be imparted to both end faces of the glass film in the width direction. Since the protective film is given a relatively large tension in the winding direction, the end surface of the glass film is easily in contact with the protective film, but even in the case of contact, the end face is not stuck due to the smoothing of the end surface of the glass film. On the film, the separation between the glass film and the protective film can be favorably maintained.

In the above configuration, it is preferable that the protective film is extended from both sides in the width direction of the glass film.

In this manner, the protective film can protect both end faces in the width direction of the glass film. Further, since both ends in the width direction of the glass film are covered by the protective film, entry of foreign matter from the outside can be prevented.

According to the first aspect of the invention, the glass film continuously formed by the down-draw method is wound in the first winding step, and in the second winding step, the glass film is wound in the first winding step. The large tension of the step acts on the state of the winding direction to be re-wound. Therefore, even when the glass film is continuously formed by the down-draw method, it is possible to impart a moderate tension to the glass film by the first winding step and the second winding step, thereby making it difficult to produce a winding. Offset or floating glass roll.

Further, according to the second invention and the third invention described above, the glass film can be applied to the protective film without applying a large tension in the winding direction. The relatively large tension in the winding direction binds the glass film, and thus it is possible to manufacture a glass roll which is less likely to cause winding deviation or floating.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Fig. 1 is a flow chart showing a method of manufacturing a glass roll according to a first embodiment of the present invention. The method for producing the glass roll includes a molding step S1, a cutting step S2, a temporary winding step (first winding step) S3, and a final winding step (second winding step) S4.

In the present embodiment, the molding step S1 is performed by the molding apparatus 1 that performs the overflow down-draw method as shown in Fig. 2 . The forming apparatus 1 has a forming zone 2, a slow cooling (annealing) zone 3, and a cooling zone 4 in this order from the top. Further, the forming apparatus 1 can perform other down-draw methods such as a down hole drawing method or a re-drawing method.

In the forming zone 2, the molten glass Gm is supplied to the molded body 5 having a wedge-shaped cross-sectional shape, and the molten glass Gm overflowing from the top of the molded body 5 to the both sides is fused and flows down at the lower end portion thereof. A plate-shaped glass film G is formed from the molten glass Gm. The glass film G gradually increases in viscosity as it moves downward, and after the sufficient viscosity of the shape can be maintained, the strain is removed in the slow cooling zone 3, and further cooled to a temperature near the room temperature in the cooling zone 4.

In the slow cooling zone 3 and the cooling zone 4, a roller group 6 having a pair of rollers is disposed at a plurality of portions from the upstream side to the downstream side of the conveying path of the glass film G, and both ends of the glass film G in the width direction are disposed. Guide to the lower side. In the present embodiment, the roller disposed at the uppermost portion of the molding region 2 in the molding apparatus 1 serves as a cooling roller that cools both end portions of the glass film G in the width direction. The function also functions as a drive roller for extracting the glass film G downward. On the other hand, the remaining roller in the molding apparatus 1 functions as an idle roller, a stretching roller, or the like to guide the glass film G downward.

The glass film G formed in the forming step S1 is a strip having a thickness of 1 μm to 600 μm (preferably 1 μm to 300 μm, more preferably 10 μm to 200 μm), for example, for a liquid crystal display. Plasma display. Glass substrates such as FPDs for organic EL displays, solar cells, lithium ion batteries, digital signage, touch panels, electronic paper, etc., or cover glass for organic EL illumination, glass containers for medical products, window glass, laminated Lightweight window glass, etc.

Further, the width of the glass film G is preferably 100 mm or more, more preferably 300 mm or more, and still more preferably 500 mm or more. Further, the glass film G can be used in a variety of devices ranging from small-screen displays for small mobile phones to large-screen displays such as large-sized television receivers. Therefore, the width of the glass film G is preferably appropriately selected depending on the size of the substrate of the apparatus to be used.

Further, as the glass composition of the glass film G, various glass compositions such as silicate glass such as alumina glass or borosilicate glass can be used, but alkali-free glass is preferable. This is because when the glass film G contains an alkali component, a phenomenon called so-called sodium precipitation occurs, and the structure becomes rough. When the glass film G is bent, the structure is deteriorated due to deterioration over the years. The roughened part is damaged. In addition, the alkali-free glass referred to herein means a glass which does not substantially contain an alkali component, and specifically means an alkali metal oxide of 1000 ppm or less (preferably 500 ppm or less, more preferably 300 ppm or less). As a glass which satisfies this condition, for example, Nippon Electric Glass OA-10G manufactured by the company.

In addition, the glass film G formed in the above-described forming step S1 is bent in a substantially horizontal direction by the posture changing roller group 7 having a plurality of rollers supporting the glass film G from below, and is maintained in the posture. And it is sent to the cutting step S2. Further, the posture changing roller group 7 may be omitted as appropriate.

In the cutting step S2, the ineffective portion (ear portion) Gx formed at both end portions in the width direction of the glass film G in the forming step S1 is cut and removed by the cutting device 8. The ineffective portion Gx is relatively thicker than the effective portion Ga at the central portion in the width direction of the glass film G.

Specifically, the cutting device 8 performs laser cutting, and includes a conveying unit 9 that conveys the glass film G continuously formed in the molding device 1 in a substantially horizontal posture and conveys it to the downstream side; the local heating unit 10 is placed on the side. The glass film G on the transport unit 9 irradiates the laser beam L from the surface side to perform local heating, and the cooling unit 11 sprays the cooling water W from the surface side to the heating region heated by the local heating unit 10. By cutting the glass film G by the laser cutting, it is possible to easily impart appropriate smoothness to the cut surface of the both end faces in the width direction of the glass film G without performing post-processing such as polishing. Therefore, the end surface having the glass film G does not get stuck on the protective film F1, so that the separation property of the glass film G and the protective film F1 can be favorably maintained. Further, there is an advantage that when the glass film G is wound into a roll shape, the both end faces of the glass film G are less likely to cause chips due to fine damage. Here, the arithmetic mean roughness Ra of both end faces in the width direction of the glass film G is preferably 0.1 from the viewpoint that the above advantages can be more reliably obtained. Below μm, more preferably 0.05 μm or less.

In the present embodiment, a carbon dioxide gas laser is used as the local heating unit 10, but it may be a unit that can perform other local heating such as a heating wire or a hot air jet. Further, the cooling unit 11 sprays the cooling water W as a refrigerant by air pressure or the like, and the refrigerant may be a coolant other than the cooling water, a gas such as air or an inert gas, or a mixture of a gas and a liquid, and further A substance obtained by mixing a solid such as dry ice or ice with the above gas and/or the above liquid. Further, the cutting device 8 can perform cutting or performing laser fusing along the scribe line using a diamond cutter.

The glass film G is transported to the downstream side by the transport unit 9, whereby the heating region of the local heating unit 10 is cut along the longitudinal direction of the glass film G before the cooling region of the cooling unit 11 (the effective portion Ga and the ineffective portion) The boundary portion of Gx is scanned from the one end side. Thereby, thermal stress is generated by the expansion caused by the heating action and the contraction caused by the cooling action of the refrigerant, and an initial crack (not shown) formed in advance at the front end portion of the planned cutting line is developed along the planned cutting line, thereby forming a glass film. G is continuously cut off in its entirety.

Further, the ineffective portion Gx of the cut glass film G is bent downward and separated from the effective portion Ga, and then discarded. On the other hand, the effective portion Ga of the glass film G is sent to the temporary winding step S3.

In the temporary winding step S3, the protective film F1 is wound in the outer peripheral surface side of the glass film G (specifically, the effective portion Ga) so that the protective film F1 is maintained in the outermost layer, and the protective film is wound up from the protective roller 12. F1 is wound around the winding core 13 to a predetermined length while being overlapped, and then the glass is cut by a cutting device (not shown). The glass film G and the protective film F1 are cut in the width direction to produce a raw material glass roll 14. At this time, when tension is excessively applied to the glass film G, excessive tension acts on the softened glass film G in the vicinity of the molded body 5, and the thickness of the glass film G becomes unstable or may occur depending on the situation. A fatal problem of fracture of the lower portion of the formed body 5. Therefore, in the temporary winding step S3, the tension is applied within a range that does not adversely affect the molding of the glass film G (for example, the glass film G is given 0 N/m to 20 (less than) N/ along the width direction. m) Winding around the winding core 13 while acting on the glass film G in the winding direction. Here, in the temporary winding step S3, it is not necessary to cause the tension to actively act on the glass film G, and it is only necessary to apply a minimum tension which naturally acts when the glass film G is wound to the glass film G.

Further, in this embodiment, in the temporary winding step S3, the tension in the winding direction larger than the glass film G is applied to the protective film F1. Specifically, for example, a tension of 0.8 N/m to 400 N/m in the width direction is applied to the protective film F1. The tension of the protective film F1 is imparted, for example, by providing a difference in rotational speed between the raw material glass roll 14 and the protective roller 12, or by inserting the tension roller 15 shown between the raw material glass roll 14 and the protective roll 12. Thus, even if a large tension is not directly applied to the glass film G, the movement of the glass film G can be suppressed by the protective film F1. That is, an effect equivalent to the case where the tensile force acts directly on the glass film G can be obtained. Therefore, the winding deviation or floating of the glass film G generated in the temporary winding step S3 can be suppressed to the minimum. Further, in the state of the raw material glass roll 14, the glass film G is reliably pressed by the protective film F1, and therefore, when the glass film G is unwound from the raw material glass roll 14 in the main winding step S4 to be described later, it is less likely to be generated. Glass in raw glass roll 14 The situation in which the membrane G is improperly wound up.

The thickness of the protective film F1 for the raw material glass roll 14 is preferably 20 μm to 1000 μm (more preferably 25 μm to 500 μm). Further, the width of the protective film F1 is preferably larger than the width of the effective portion Ga of the glass film G, so that the both end faces in the width direction of the protective glass film G are not damaged by various contacts. In other words, it is preferable that the protective film F1 is extended to both sides in the width direction of the effective portion Ga of the glass film G.

Further, in the stage in which the temporary winding step S3 is performed, the temperature of the glass film G may be 50° C. or more. Therefore, it is preferable that the protective film F1 does not undergo softening or the like before and after 100° C.

The protective film F1 is preferably an elastic film. Thereby, it is possible to produce the raw material glass roll 14 which is free from slack while imparting a suitable tension in the winding direction to the protective film F1. Here, the tensile modulus of the protective film F1 is preferably from 1 GPa to 5 GPa.

It is preferable to impart conductivity to the protective film F1. As described above, when the glass film G is taken out from the raw material glass roll 14, peeling electrification is less likely to occur between the glass film G and the protective film F1, and the advantage of easily peeling off the protective film F1 from the glass film G can be enjoyed. In the case where the protective film F1 is made of a resin, for example, a conductive element such as polyethylene glycol is added to the protective film F1. Further, in the case where the protective film F1 is a spacer paper, a conductive fiber is incorporated in the spacer paper. Further, even when a conductive film such as ITO is formed on the surface of the protective film F1, conductivity can be imparted to the protective film F1.

Specifically, as the protective film F1, for example, an ionomer can be used. (ionomer) film, polyethylene film, polypropylene film, polyvinyl chloride film, polyvinylidene chloride film, polyvinyl alcohol film, polyester ( Polyester) film, polycarbonate film, polystyrene film, polyacrylonitrile film, ethylene-vinyl acetate copolymer film, ethylene-vinyl alcohol copolymer film, ethylene-methacrylic acid copolymer film, polyfluorene A resin film such as an organic resin film (synthetic resin film) such as a polyamide film, a polyimide film, or a cellophane. In addition, as the protective film F1, a foamed resin film such as a polyethylene foamed resin film or a composite material obtained by laminating a foamed resin film on the above resin film can be used. Further, a lubricant such as alumina which is excellent in slidability between the resin film and the glass film G can be dispersed in the resin film. As described above, the variation in the winding length of both of the glass film G and the protective film F1 due to the difference in the fine winding diameter of the protective film F1 can be absorbed by the lubricity of the protective film F1. The same applies to the protective film F2 for the glass roll 16 to be described later.

In addition, about the matter of the said protective film F1, the protective film F2 for the glass roll 16 mentioned later is also similar.

Then, the raw material glass roll 14 produced in the above temporary winding step S3 is sent to the main winding step S4 and re-wound.

In the main winding step S4, as shown in FIG. 3, the glass film G (specifically, the effective portion Ga) that is unwound from the raw material glass roll 14 is wound again by a roll-to-roll apparatus. Thereby, the glass roll 16 which becomes a product is manufactured.

Specifically, in the present embodiment, the glass film G rolled up from the raw material glass roll 14 at the unwinding position P1 is guided to a substantially circumferential shape around the far side by the roll group 17 including a plurality of rolls. The winding core 18 is wound again at the winding position P2, thereby manufacturing the glass roll 16. When the glass film G is guided in this manner, an appropriate tension can be easily applied to the glass film G between the rolls of the roll group 17.

At this time, at the unwinding position P1, the protective film F1 is peeled off from the glass film G, and the protective film F1 is wound as the protective roller 19. On the other hand, at the winding position P2, the protective film F2 is wound in the outermost surface side, and the protective film F2 wound from the other protective roller 20 is newly overlapped on the outer peripheral surface side of the glass film G. The core 18 is wound. After the protective film F1 is placed on the glass film G and wound around the winding core 18 by a predetermined length, the protective film F2 (or the glass film G and the protective film F2) is cut in the width direction by a cutting device (not shown). Thus, the glass roll 16 is manufactured. In the present embodiment, the type of the protective film F2 is the same as that of the protective film F1 used in the temporary winding step S3.

Further, in the main winding step S4, as shown in FIG. 1, the tension b acting in the winding direction of the glass film G is made larger than the tension a acting on the glass film G in the temporary winding step S3. Specifically, for example, a tension in the width direction of 10 N/m to 500 N/m is applied to the glass film G. The tension of the glass film G is imparted, for example, by providing a difference in rotational speed between the raw material glass roll 14 and the glass roll 16. In this way, even if a winding deviation or floating occurs on the glass film G contained in the raw material glass roll 14 produced in the temporary winding step S3, sufficient tension can be applied to the glass film in the main winding step S4. G, so that the winding offsets and the like can be corrected and re-wound.

Further, in the main winding step S4, a tension in the winding direction larger than the protective film F2 may be applied to the glass film G. Specifically, for example, it is preferable to apply a tension of 0.8 N/m to 400 N/m in the width direction to the protective film F2. The tension of the protective film F2 is imparted, for example, by providing a difference in rotational speed between the glass roll 16 and the protective roll 20, or by inserting the tension roller 21 shown between the glass roll 16 and the protective roll 20. In this case, the magnitude relationship between the tension acting in the winding direction of the protective film F2 in the main winding step S4 and the tension acting on the winding direction of the protective film F1 in the temporary winding step S3 is not particularly limited, and various requirements may be considered. The setting is appropriately set (tension of F1 < tension of F2, tension of F1 = tension of F2, tension of F1 > tension of F2).

In the main winding step S4, as shown in FIG. 3, the surface of one side of the glass film G is conveyed while being contact-supported, and the contact supporting surface is located on the inner peripheral surface side of the glass roll 16 The glass film G is wound. In this manner, even if minute damage is caused to the contact support surface of the glass film G, the contact support surface may be wound on the inner peripheral surface side of the glass roll 16. In the glass roll 16, only the compressive stress acts on the surface on the inner peripheral surface side of the glass film G. Therefore, even if a fine flaw is caused on the contact support surface, it is difficult to exert a force for developing the minute damage. In other words, the non-contact surface which is substantially free from minute damage is located on the outer peripheral surface side of the glass film G which acts to cause the development of the minute damage, and thus the damage of the glass film G can be surely reduced. Further, in this embodiment, in the temporary winding step S3, only the surface of one side of the glass film G is contact-supported, and the contact supporting surface is set to the same side as the contact supporting surface of the main winding step S4.

Furthermore, the present invention is not limited to the first embodiment described above, and may be Various forms are implemented. For example, as shown in FIG. 4, in the main winding step S4, a cutting step may also be performed. Specifically, the glass film G (specifically, the effective portion Ga) wound from the raw material glass roll 14 may be cut in the width direction and divided into a plurality of desired widths (in the illustrated example, The two glass films G are formed by superposing the protective film F2 on each of the glass films G and winding around the winding core 18, whereby a plurality of glass rolls 16 can be simultaneously produced.

In the above-described embodiment, the surface on the inner circumferential surface side in the state of the raw material glass roll 14 is described as the contact support surface of the glass film G at the time of conveyance. However, as shown in FIG. The surface on the outer peripheral surface side in the state of the raw material glass roll 14 is the contact support surface of the glass film G at the time of conveyance. In the above-described embodiment, the case where the contact supporting surface is wound on the inner peripheral surface side of the glass roll 16 has been described. However, the contact supporting surface may be wound around the outer peripheral surface side of the glass roll 16.

Further, in the above-described embodiment, in the case where the glass film G wound from the raw material glass roll 14 is guided in a substantially circumferential shape and then wound in the main winding step S4, it may be as shown in the figure. As shown in Fig. 5, the glass film G wound from the raw material glass roll 14 is guided in a straight line and then wound.

Further, in the above-described embodiment, the case where the main winding step S4 is performed only once after the temporary winding step S3 has been described, and the step of rewinding the glass film G after the main winding step S4 may be performed. Contains 1 to many times.

Next, a method of producing a glass roll according to a second embodiment of the present invention will be described. Furthermore, the second embodiment can be the same as that shown in FIG. The aspect is implemented, except that the temporary winding step S3 is performed as a formal winding step of the glass roll for manufacturing the final product.

Specifically, in the second embodiment, as shown in FIG. 1, the glass film G is formed by a down-draw method, and the protective film F1 is placed on the outer peripheral side of the formed glass film G, and the roll larger than the glass film G is formed. The tension in the winding direction is applied to the protective film F1 while being wound into a roll shape, thereby producing a glass roll which becomes a final product. Further, in the wound state of the glass roll thus produced, the protective film F1 is given a tension in the winding direction larger than the glass film G.

Here, the tension applied to the protective film F1 and the tension applied to the glass film G are the tensions described in the temporary winding step S3 described in the first embodiment (for example, the width direction of the glass film G is 0 N/m). ~20 (less than) N/m, the same applies to the protective film F1 in the width direction of 0.8 N/m to 400 N/m.

[Industrial availability]

The present invention can be suitably used for a glass substrate used in a flat panel display such as a liquid crystal display or an organic EL display, a solar cell, or the like, and a cover glass such as an organic EL illumination.

1‧‧‧Forming device

2‧‧‧ Forming area

3‧‧‧ Slow cooling zone

4‧‧‧Cooling area

5‧‧‧Formed body

6, 17‧‧ ‧ roll group

7‧‧‧ posture shifting roller group

8‧‧‧cutting device

9‧‧‧Transport unit

10‧‧‧Local heating unit

11‧‧‧Cooling unit

12,19,20‧‧‧protection roller

13, 18 ‧ ‧ core

14‧‧‧Material glass roll

15, 21‧‧‧ Tension roller

16‧‧‧ glass roll

F1, F2‧‧‧ protective film

G‧‧‧glass film

Ga‧‧‧ effective department

Gm‧‧‧ molten glass

Gx‧‧‧Inactive (ear)

L‧‧‧Laser beam

P1‧‧‧ roll out position

P2‧‧‧ winding position

S1~S4‧‧‧ steps

W‧‧‧Cooling water

Fig. 1 is a flow chart showing a method of manufacturing a glass roll according to an embodiment of the present invention.

FIG. 2 is a view for explaining an implementation state of a molding step, a cutting step, and a temporary winding step included in the method for producing a glass roll according to the embodiment.

Fig. 3 is a view for explaining the method of manufacturing the glass roll of the embodiment; A diagram showing the implementation status of the formal winding step.

4 is a view for explaining another embodiment of the main winding step included in the method for producing a glass roll according to the embodiment.

Fig. 5 is a view for explaining another embodiment of the main winding step included in the method for producing a glass roll of the embodiment.

S1~S4‧‧‧ steps

Claims (12)

A method for producing a glass roll, comprising: a molding step of conveying a glass film while continuously forming a glass film by a molding device that performs a down-draw method; and a first winding step downstream of a conveying path of the forming step At the end, the first protective film is superimposed on the glass film and wound into a roll to produce a raw material glass roll, and the second winding step is carried out while the glass film is wound from the raw material glass roll to the downstream side. At the downstream end of the transport path, the second protective film is superposed on the glass film and re-wound into a roll shape to produce a glass roll, and the roll acting on the glass film in the second winding step is produced. The tension in the winding direction is larger than the tension acting on the glass film in the first winding step. The method for producing a glass roll according to the first aspect of the invention, wherein, in the first winding step, a tension acting in a winding direction of the first protective film is greater than a winding direction acting on the glass film The tension is large. The method for producing a glass roll according to the first or second aspect of the invention, wherein in the second winding step, a tension acting in a winding direction of the glass film is applied to the second protective film. The tension in the winding direction is large. The method for manufacturing a glass roll according to claim 1 or 2, wherein In the second winding step, the surface of one side of the glass film is conveyed while being contact-supported. The method for producing a glass roll according to the fourth aspect of the invention, wherein the contact-supporting surface of the glass film is wound on the inner peripheral surface side of the glass roll. The method for producing a glass roll according to claim 1 or 2, wherein in the at least one of the first winding step and the second winding step, the glass film is cut by laser After being cut to a predetermined width, the winding is performed. The method for producing a glass roll according to claim 1 or 2, wherein the pull-down method is an overflow down-draw method. The method for producing a glass roll according to the first or second aspect of the invention, wherein the glass film has a thickness of from 1 μm to 300 μm. A method for producing a glass roll, wherein a glass film is formed by a down-draw method, and the formed glass film is superposed on a protective film and wound into a roll shape; and the method for producing the glass roll is characterized in that the protective film is provided The glass film and the protective film are wound while applying a tension in a winding direction larger than that of the glass film. The method for manufacturing a glass roll according to claim 9, wherein The ineffective portion formed at both end portions in the width direction of the glass film is subjected to laser cutting at a stage until the glass film is wound into a roll shape. The method for producing a glass roll according to the invention of claim 9, wherein the protective film is superposed on the outer peripheral surface side of the glass film so that the protective film is placed in the outermost layer. The glass film and the protective film are wound while being wound. The method for producing a glass roll according to claim 9 or claim 10, wherein the pull-down method is an overflow down-draw method.