JP2021011390A - Film roll and method of storing the same - Google Patents

Abstract

To provide a film roll that is hard to be affected by condensation even when condensation occurs on an inner wall of a cylindrical core thereof.SOLUTION: The film roll is formed by a film (not illustrated) being wound on a cylindrical core 1, with an inner wall 2 of the core 1 having a fiber-made water absorption member 3. The inner wall 2 of both ends 5 of the core 1 preferably has the water absorption member 3, and a bottom part of the inner wall 2 of the core 1 preferably has the water absorption member 3. A distance from an end 4 of the core 1 to the water absorption member 3 is preferably 10 cm or over. The water absorption member 3 preferably contains at least one kind selected from a group formed by cellulosic synthetic fiber and polyester fiber.SELECTED DRAWING: Figure 1

Description

The present invention relates to a film roll in which a film is wound around a cylindrical core.

A plastic film such as a polyvinyl alcohol (hereinafter, “polyvinyl alcohol” may be abbreviated as “PVA”) film which is a raw material of a polarizing film is usually in the form of a film roll formed by winding around a cylindrical core. Stored or shipped in. Recently, in PVA film which is a raw material of a polarizing film for a liquid crystal display, a wider PVA film is required as the size of the liquid crystal display increases, and the winding length is improved in order to improve the processability and productivity of the polarizing film. Long PVA film is also required. As the width and length of the PVA film have increased, the weight of the film roll has increased, so that a support rod is inserted inside the core when the film roll is loaded or unloaded or moved to a gantry or processing device. Handling methods have become popular. Therefore, in order to facilitate the insertion of the support rod into the core, both ends of the cylindrical core are opened without being blocked by a cap or the like, and the film roll is transported or stored with the inside of the core exposed to the outside air. Opportunities have increased. Further, as the material of the cylindrical core, a metal having high strength (flexural rigidity, etc.), a carbon fiber reinforced plastic, or a composite material thereof has come to be used.

By the way, when a film roll is carried from an unair-conditioned storage place to an air-conditioned processing plant in a cold region in winter, dew condensation may occur on the inner wall of the cylindrical core. In particular, recently, as the weight of the film roll has increased as described above, dew condensation is more likely to occur due to the increase in the heat capacity of the film roll and the accompanying decrease in the temperature change rate of the entire film roll. There is. In addition, as described above, as the weight of the film roll increases, metal cores and carbon fiber reinforced plastic cores have come to be used, but metal and plastic cores include paper cores. Condensation is more likely to occur than in.

In order to solve the above-mentioned problem of dew condensation, for example, a method of specifying a specific packaging form of a film roll is known (see Patent Document 1).

International Publication No. 2012/147665

However, since the method of Patent Document 1 needs to adopt a special packaging form, there is room for further improvement in providing a method capable of solving the problem of dew condensation without adopting such a packaging form. there were.

Therefore, an object of the present invention is to provide a film roll that is not easily affected by dew condensation even when dew condensation occurs on the inner wall of the cylindrical core.

As a result of diligent studies to achieve the above object, the present inventors have attached a fiber water absorbing member to the inner wall of the cylindrical core, so that even if dew condensation occurs on the inner wall of the core. , It was found that the film roll is not easily affected by dew condensation, and further studies were carried out based on the findings to complete the present invention.

That is, the present invention
[1] A film roll in which a film is wound around a cylindrical core and has a water absorbing member made of fiber on the inner wall of the core.
[2] The film roll according to [1], which has water absorbing members on the inner walls of both ends of the core.
[3] The film roll according to [1] or [2], which has a water absorbing member at the lower part of the inner wall of the core.
[4] The film roll according to any one of [1] to [3], wherein the distance from the end of the core to the water absorbing member is 10 cm or more.
[5] The film roll according to any one of [1] to [4], wherein the water absorbing member contains at least one selected from the group consisting of cellulosic synthetic fibers and polyester fibers.
[6] The film roll according to any one of [1] to [5], wherein a plurality of water absorbing members are laminated.
[7] The film roll according to any one of [1] to [6], wherein the water absorbing member is fixed to the inner wall of the core by an adhesive tape.
[8] The film roll according to [7], wherein the adhesive tape is made of polyethylene or polypropylene.
[9] The film roll according to any one of [1] to [8], wherein the core is made of metal or plastic.
[10] The film roll according to any one of [1] to [9], wherein the axial length of the core is 2.5 m or more.
[11] The film roll according to any one of [1] to [10], wherein the film is a PVA film.
[12] The film roll according to any one of [1] to [11], which has a mass of 500 kg or more.
[13] The film roll according to any one of [1] to [12], wherein the length of the film is 2,000 m or more.
Regarding.

According to the present invention, there is provided a film roll that is not easily affected by dew condensation even when dew condensation occurs on the inner wall of the cylindrical core.

It is the schematic which shows the state of one end part of the core in the film roll of Example 1 (however, the film is not shown), (a) is the schematic view seen from the axial direction of the core, and (b) is It is a schematic view from the direction on the horizontal plane which is perpendicular to the axial direction of a core.

Hereinafter, the present invention will be described in detail.
〔core〕
The film roll of the present invention is formed by winding a film around a cylindrical core. The type of the cylindrical core is not particularly limited, and examples thereof include metal ones, plastic ones, paper ones, and wooden ones. Cores in the form of composites can also be used, such as those in which both metal and plastic are used, those in which both metal and paper are used, and those in which both plastic and paper are used. Among these, a metal and / or plastic core is preferable because it has high strength and the effect of the present invention is more remarkable, and it is not easily affected by wear even after repeated use. Therefore, it is made of metal. Core is more preferred. The ratio of the mass of the metal and the plastic to the total mass of the cylindrical core is preferably 50% by mass or more, more preferably 80% by mass or more, and further preferably 95% by mass or more. It is preferably 100% by mass, and particularly preferably 100% by mass.

Examples of the above-mentioned metal include iron, stainless steel, aluminum, and the like, and one of these metals may be used alone or two or more thereof may be used in combination. Among these, aluminum is preferable from the viewpoint of strength, light weight, price and the like.

In addition, examples of the above-mentioned plastics include polyvinyl chloride, polyvinylidene chloride, polyester, polycarbonate, polyamide, epoxy resin, polyurethane, polyurea, silicone resin, and the like, and one of these may be used alone. Also, two or more types may be used in combination. Of these, polyvinyl chloride is preferred. It is also preferable that the plastic is a fiber reinforced plastic (FRP) such as carbon fiber reinforced plastic from the viewpoint of strength and the like.

In the present invention, even when a core that is prone to dew condensation is used, such that at least a part of the surface of the cylindrical core is made of metal and / or plastic, it is not easily affected by dew condensation. Therefore, the effect of the present invention is more remarkable when such a core is used. Since the effect of the present invention is more pronounced, the cylindrical core has at least a part of its inner peripheral surface (preferably 50% or more of the area of the inner peripheral surface, more preferably the area of the inner peripheral surface). The material of 80% or more) is preferably metal and / or plastic, more preferably all the material of the inner peripheral surface thereof is metal and / or plastic, and the material of the entire surface of the cylindrical core is metal. And / or plastic is more preferred.

The axial length of the cylindrical core can be appropriately selected according to the width of the film wound around the core, etc., but the length is 2 because the effect of the present invention is more remarkable. It is preferably .5 m or more, more preferably 3 m or more, and even more preferably 3.5 m or more. The upper limit of the length is not particularly limited, but the length is, for example, 8.5 m or less.

The diameter of the cylindrical core is not particularly limited, but from the viewpoint of strength, handleability, etc., the outer diameter thereof is preferably in the range of 50 to 800 mm, more preferably in the range of 80 to 500 mm. It is more preferably in the range of 100 to 300 mm, and particularly preferably in the range of 150 to 250 mm.
The wall thickness of the cylindrical core is preferably in the range of 2 to 50 mm, more preferably in the range of 3 to 20 mm, and in the range of 4 to 10 mm from the viewpoint of strength, handleability, and the like. It is more preferable to be inside.

〔the film〕
The types of the above films are not particularly limited, and for example, polyethylene film, polypropylene film, polymethylpentene film, alicyclic olefin polymer film, polystyrene film, polycarbonate film, polyvinyl chloride film, methacrylic resin film, polyamide film, etc. Examples thereof include polyethylene terephthalate film and PVA film, and PVA film is preferable because the quality of the film is significantly deteriorated due to moisture absorption and the effect of the present invention is more remarkable.

As the PVA constituting the PVA film, one produced by saponifying a polyvinyl ester obtained by polymerizing a vinyl ester-based monomer can be used. Examples of the vinyl ester-based monomer include vinyl formate, vinyl acetate, vinyl propionate, vinyl valerate, vinyl laurate, vinyl stearate, vinyl benzoate, vinyl pivalate, vinyl versatic acid and the like. Of these, vinyl acetate is preferable.

The degree of polymerization of PVA constituting the PVA film is preferably in the range of 500 to 9,000, and more preferably in the range of 1,500 to 7,000, although it depends on the use of the PVA film and the like. It is more preferably in the range of 1,800 to 5,000, and particularly preferably in the range of 2,000 to 3,000. The degree of polymerization of PVA referred to in the present specification means the average degree of polymerization measured according to the description of JIS K6726-1994.

The saponification degree of PVA constituting the PVA film is preferably 75 mol% or more, more preferably 85 mol% or more, and 95 mol% or more, although it depends on the use of the PVA film and the like. It is more preferable, and 99 mol% or more is particularly preferable. The degree of saponification of PVA in the present specification refers to the total number of moles of structural units (typically vinyl ester units) and vinyl alcohol units of PVA that can be converted into vinyl alcohol units by saponification. The ratio (mol%) of the number of moles of vinyl alcohol units. The degree of saponification can be measured according to the description of JIS K6726-1994.

The PVA film may contain a plasticizer, a surfactant, a dichroic dye, or the like, if necessary. The method for producing the PVA film is not particularly limited, and a PVA film formed by a known method such as a solution film forming method or a melt film forming method can be preferably used.

The thickness of the film is not particularly limited, but is preferably in the range of 5 to 500 μm, more preferably in the range of 10 to 300 μm, and further preferably in the range of 15 to 100 μm.

The width of the film is not particularly limited, but is preferably 2.1 m or more, more preferably 2.3 m or more, further preferably 2.6 m or more, and particularly preferably 3 m or more. Most preferably, it is 3.3 m or more. When a film having such a width is used, a large amount of water derived from dew condensation is likely to be generated, but in the present invention, since it is not easily affected by dew condensation, a film having the above width is used. When used, the effect of the present invention is more pronounced.
On the other hand, if the width of the film is too wide, the handleability may be deteriorated. Therefore, the width of the film is preferably 8 m or less.

The length of the film wound around the cylindrical core is not particularly limited, but is preferably 2,000 m or more, more preferably 4,000 m or more, still more preferably 7,000 m or more. It is particularly preferable that the length is 11,000 m or more. If it is less than 2,000 m, it may not be economical because the ratio of the loss generated at the start / end of winding of the film roll to the whole becomes large. On the other hand, the upper limit of the length of the film is not particularly limited. Therefore, the length of the film is preferably 20,000 m or less.

The mass of the film roll of the present invention is preferably 500 kg or more, more preferably 1,000 kg or more, further preferably 1,800 kg or more, and particularly preferably 3,300 kg or more. In the present invention, even a film roll having a larger mass and prone to dew condensation is less susceptible to dew condensation. Therefore, the effect of the present invention is more remarkable in the case of the film roll as described above. However, if the mass of the film roll is too large, the handleability may be deteriorated. Therefore, the mass of the film roll is preferably 5,000 kg or less.

[Water absorption member]
The film roll of the present invention has a water absorbing member made of fiber on the inner wall of the core. There is no particular limitation on the position of the water absorbing member on the inner wall of the core, but it is preferable to place the water absorbing member on the inner wall at the end of the core because the effect of the present invention is more remarkable. As a specific arrangement position of the water absorbing member, the distance (shortest distance) from the end of the core to the water absorbing member is preferably 10 cm or more from the viewpoint of not getting in the way when moving the film roll. , 15 cm or more is more preferable. On the other hand, if it is too far from the end, it tends to be difficult to attach the water absorbing member, so that the above distance is preferably 50 cm or less. When the water absorbing member is arranged on the inner wall of the end portion of the core, it may be arranged only on the inner wall of one end portion in the axial direction of the core, but since the effect of the present invention is more remarkable, the core It is preferable to have water absorbing members on the inner walls of both ends.

Further, the water absorbing member may be arranged in an annular shape so as to be continuously along the peripheral surface of the inner wall of the core, but from the viewpoint of ease of arrangement and cost reduction, it is arranged only on a part of the peripheral surface of the inner wall of the core. It is more preferable to arrange the water absorbing member in the lower part of the inner wall of the core.

Specific examples of the material of the water absorbing member include cellulose-based synthetic fibers, cell-roll-based natural fibers, polyester-based fibers, and the like. Among these, at least one selected from the group consisting of cellulosic synthetic fibers and polyester fibers is unlikely to cause problems such as debris of the water absorbing member adhering to the film and deteriorating the quality of the film. It is preferable, and it is more preferable that it is a cellulosic synthetic fiber. The water-absorbing member is made of the above-mentioned fibers from the viewpoints of low cost and stability of water-absorbing performance over time.

The form of the water absorbing member is not particularly limited, but from the viewpoint of ease of handling and availability, it is preferably in the form of a sheet, and more preferably in the form of a non-woven fabric in the form of a sheet. When a sheet-shaped water absorbing member is used, one sheet may be individually arranged on the inner wall of the core, but it is preferable to stack a plurality of water absorbing members from the viewpoint of ensuring sufficient water absorption capacity. .. In this case, the number of water absorbing members to be laminated is not particularly limited, but for example, it is preferably 2 or more, more preferably 3 or more, further preferably 4 or more, and 10 or more. The following is preferable.

There are no particular restrictions on the means of arranging the water absorbing member on the inner wall of the core, such as adhesive tape, adhesive, magnet, etc., but in addition to being sufficiently fixed, it is relatively easy to remove. Therefore, it is preferable that the water absorbing member is fixed by the adhesive tape.

The types of the above adhesive tapes are not particularly limited, and examples thereof include paper adhesive tapes, cloth adhesive tapes, film adhesive tapes, special adhesive tapes, and specifically, cellophane tapes, kraft adhesive tapes, cloth adhesive tapes, and OPP. Examples thereof include adhesive tapes, aluminum tapes, vinyl tapes, polyester tapes, polyethylene tapes, polypropylene tapes, polyimide tapes, gum tapes, or composite tapes processed by combining two or more kinds thereof. Of these, polyethylene or polypropylene adhesive tapes are preferable because they are less likely to cause problems such as debris of the adhesive tape adhering to the film and degrading the quality of the film, and are also excellent in waterproofness. ..

The film roll of the present invention may be transported or stored as it is, or may be transported or stored in the form of a package packaged with a packaging material. The use of the film in the film roll of the present invention is not particularly limited, but according to the present invention, the influence of dew condensation is small and excellent film quality can be maintained. Therefore, in order to manufacture an optical film such as a polarizing film. It is preferable to use it as a raw film.

Hereinafter, the present invention will be specifically described with reference to Examples and the like, but the present invention is not limited to these Examples. The methods for evaluating the dew condensation on the inner wall of the core, the outflow of dew condensation from the core, the dust confirmed on the inner wall of the core, and the fixing property of the water absorbing member, which were adopted in the following examples and comparative examples, are as follows. Shown.

Condensation on the inner wall of the core The state of dew condensation on the inner wall of the core was evaluated according to the following criteria.
◯: Condensation is relatively small.
X: Condensation is relatively large.

Outflow of condensation from the core The outflow of condensation from the core was evaluated according to the following criteria.
◯: No outflow of dew condensation is observed from the end of the core.
X: Condensation outflow is observed from the end of the core.

Dust found on the inner wall of the core Dust found on the inner wall of the core was evaluated according to the following criteria.
◯: Dust cannot be visually confirmed.
X: Dust can be visually confirmed.

Fixability of water-absorbing member The fixability of the water-absorbing member on the inner wall of the core was evaluated according to the following criteria.
◯: It is fixed and does not move.
×: Moving and unstable.

[Example 1]
A PVA film with a film width of 3.3 m, a thickness of 60 μm, and a length of 12,500 m (PVA degree of polymerization 2,450, PVA saponification degree 99.3 mol%) is made of aluminum, length 3.5 m, outer diameter. It was wound around the center of a cylindrical core having a thickness of 215 mm and a wall thickness of 6 mm. After that, two sheets of non-woven fabric (“Dust Tackle” wiper, manufactured by Kuraray Co., Ltd., length 33 cm × width 33 cm) made of cellulosic synthetic fibers were prepared and two sheets were prepared, and FIG. 1 shows a schematic diagram. These were fixed to the lower part of the inner wall at both ends of the core with adhesive tape. The non-woven fabric was fixed at a position 20 cm away from each end in the axial direction (the shortest distance from the end of the core to the water absorbing member was 20 cm). Moreover, as the adhesive tape, the one made of polyethylene was used. The mass of the film roll thus obtained was 3,600 kg.

After storing the above film roll at 10 ° C. or lower for 10 hours or more, it was left for a predetermined time in an atmosphere where dew condensation occurred at 20 ° C. or higher, and each of the above evaluations was performed. The results are shown in Table 1.

[Example 2]
Examples except that two sheets of natural cellulosic fibers (wool, 30 cm in length × 30 cm in width) were used instead of four sheets of non-woven fabric in the form of sheets made of synthetic cellulose fibers. A film roll was obtained in the same manner as in 1. Each evaluation of this film roll was carried out in the same manner as in Example 1. The results are shown in Table 1.

[Example 3]
A film roll was obtained in the same manner as in Example 1 except that the length of the PVA film was changed from 12,500 m to 1,000 m. The mass of the film roll was 300 kg. Each evaluation of this film roll was carried out in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 1]
A film roll was obtained in the same manner as in Example 1 except that the non-woven fabric was not used. Each evaluation of this film roll was carried out in the same manner as in Example 1. The results are shown in Table 1.

1. 1. Cylindrical core, 2. Inner wall of core, 3. Water absorption member, 4. One end of the core, 5. One end of the core.

That is, the present invention
[1] A film roll in which a polyvinyl alcohol film is wound around a cylindrical core, the core is made of metal or plastic, the axial length of the core is 2.5 m or more, and the film roll. and the mass is 500kg or more, a state in which the core interior is both ends of the core opening is exposed to the outside air, have a fiber made of water-absorbing member at the bottom of the inner wall of the core, and from the end of the core to water-absorbing member Film rolls with a distance of 10 cm or more ,
[2] The film roll according to [1], which has water absorbing members on the inner walls of both ends of the core.
[3] The film roll according to [1] or [2] , wherein the water absorbing member contains at least one selected from the group consisting of cellulosic synthetic fibers and polyester fibers.
[4] The film roll according to any one of [1] to [3], wherein a plurality of water absorbing members are laminated.
[5] The film roll according to any one of [1] to [4] , wherein the water absorbing member is fixed to the inner wall of the core by an adhesive tape.
[6] The film roll according to [5] , wherein the adhesive tape is made of polyethylene or polypropylene.
[7] The film roll according to any one of [1] to [6] , wherein the length of the film is 2,000 m or more.
[8] The film roll according to any one of [1] to [7] is stored at 10 ° C. or lower for 10 hours or more with both ends of the core open and the inside of the core exposed to the outside air. , How to store film rolls ,
Regarding.

Claims (13)

A film roll in which a film is wound around a cylindrical core, and has a water-absorbing member made of fiber on the inner wall of the core. The film roll according to claim 1, which has water absorbing members on the inner walls of both ends of the core. The film roll according to claim 1 or 2, which has a water absorbing member at the lower part of the inner wall of the core. The film roll according to any one of claims 1 to 3, wherein the distance from the end of the core to the water absorbing member is 10 cm or more. The film roll according to any one of claims 1 to 4, wherein the water absorbing member comprises at least one selected from the group consisting of cellulosic synthetic fibers and polyester fibers. The film roll according to any one of claims 1 to 5, wherein a plurality of water absorbing members are laminated. The film roll according to any one of claims 1 to 6, wherein the water absorbing member is fixed to the inner wall of the core by an adhesive tape. The film roll according to claim 7, wherein the adhesive tape is made of polyethylene or polypropylene. The film roll according to any one of claims 1 to 8, wherein the core is made of metal or plastic. The film roll according to any one of claims 1 to 9, wherein the axial length of the core is 2.5 m or more. The film roll according to any one of claims 1 to 10, wherein the film is a polyvinyl alcohol film. The film roll according to any one of claims 1 to 11, which has a mass of 500 kg or more. The film roll according to any one of claims 1 to 12, wherein the length of the film is 2,000 m or more.