TWI737578B - Film roll and its storage method - Google Patents

Abstract

The subject of the present invention is to provide a film roll that is less likely to be affected by condensation even when condensation occurs on the inner wall of a cylindrical core.

The solution of the present invention is a film roll, which is a film roll formed by winding a film (not shown) around a cylindrical core 1 and having a water absorbing member 3 on the inner wall 2 of the core 1. It is better to have a water-absorbing member 3 on the inner wall 2 of both ends 5 of the core 1; it is better to have a water-absorbing member 3 at the lower part of the inner wall 2 of the core 1; from the end 4 of the core 1 to the water-absorbing member The distance of 3 is preferably 10 cm or more; the water absorbing member 3 preferably contains at least one selected from the group consisting of cellulose-based synthetic fibers and polyester-based fibers.

Description

Film roll and its storage method

The present invention relates to a film roll formed by winding a film on a cylindrical core (cylindrical core).

Plastic films such as polyvinyl alcohol used as a raw material for polarizing films (hereinafter, "polyvinyl alcohol" will be abbreviated as "PVA") films are usually made of film rolls wound around a cylindrical core. Form to be stored or transported. Recently, among PVA films used as raw materials for polarizing films for liquid crystal displays, as liquid crystal displays increase in size, PVA films with wider widths are required, and in order to improve the processability and productivity of polarizing films, winding is also required. Long-length PVA film. With the widening and long rolls of this kind of PVA film, the weight of the film roll will increase. When loading and unloading or moving the film roll to a stand or processing device, most of the methods are used to put a support rod inside the core to operate. . Therefore, in order to make it easy for the support rod to be inserted into the core, it is an opportunity to transport or store the film roll in a state where the inside of the core is exposed to the outside air without covering both ends of the cylindrical core with a cover or the like. Increase. In addition, with regard to the material of the cylindrical core, metals with high strength (flexural rigidity, etc.), carbon fiber reinforced plastics, or composite materials of these have gradually begun to be used.

Incidentally, in cold places such as in winter, if the film roll is moved from a storage place without air conditioning to an air-conditioned processing place, condensation may form on the inner wall of the cylindrical core. Particularly recently, as the weight of the film roll has increased as described above, the heat capacity of the film roll has increased, and the accompanying temperature change rate of the entire film roll has decreased, making condensation more likely to occur. And as mentioned above, as the weight of film rolls increases, metal cores or carbon fiber reinforced plastic cores are used, but metal or plastic cores are easier than paper cores. Condensation has occurred.

In order to solve the problem of condensation as described above, for example, a method of setting the packaging form of a film roll to a specific form (refer to Patent Document 1) is known.

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] International Publication No. 2012/147665

However, the method of Patent Document 1 must adopt a special packaging form. Therefore, there is room for further improvement in terms of providing a method that can solve the condensation problem even without adopting this packaging form.

Therefore, the object of the present invention is to provide a film roll that is less susceptible to dew condensation even when condensation occurs on the inner wall of the cylindrical core.

In order to achieve the above purpose, the inventors have painstakingly researched As a result, it was discovered that by installing a water-absorbing member on the inner wall of the cylindrical core, even if condensation occurs on the inner wall of the core, it becomes a film roll that is not easily affected by the condensation. Based on this insight, further studies have been carried out. , Then completed the present invention.

That is, the present invention relates to: [1] A film roll, which is a film roll formed by winding a film on a cylindrical core, and having a water-absorbing member on the inner wall of the core, [2] as described in [1] The film roll described herein has water absorbing members on the inner walls of both ends of the core. [3] The film roll described in [1] or [2] has water absorbing members on the lower part of the inner wall of the core. [4] The film roll as described in any one of [1] to [3], wherein the distance from the end of the core body to the water-absorbing member is 10 cm or more, [5] such as any one of [1] to [4] The film roll described in item 1, wherein the water-absorbing member includes at least one selected from the group consisting of cellulose-based synthetic fibers and polyester-based fibers, [6] such as any one of [1] to [5] The film roll described, in which a plurality of water absorbing members are laminated, [7] the film roll described in 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 described in [7], wherein the adhesive tape is made of polyethylene or polypropylene, [9] the film roll described in any one of [1] to [8], wherein the core It is made of metal or plastic, [10] The film roll as described in any one of [1] to [9], wherein the core The length in the axial direction of [11] is the film roll described in any one of [1] to [10], wherein the film is a PVA film, and [12] is any of [1] to [11] The film roll described in item 1, wherein the mass is 500 kg or more, [13] the film roll described in any one of [1] to [12], wherein the length of the film is 2,000 m or more.

According to the present invention, it is possible to provide a film roll that is less susceptible to the influence of condensation even when condensation occurs on the inner wall of the cylindrical core.

1‧‧‧Cylindrical core

2‧‧‧The inner wall of the core

3‧‧‧Water absorbing member

4‧‧‧One end of the core

5‧‧‧One end of the core

Figure 1 shows a schematic view of the shape of one end of the core in the film roll of Example 1 (but the film is not shown), (a) is a schematic view viewed from the axial direction of the core, and (b) is A schematic view viewed from a direction on a horizontal plane perpendicular to the axial direction of the core body.

[The form of implementing the invention]

The present invention will be described in detail below.

[Core]

The film roll of the present invention is formed by winding a film on a cylindrical core. The type of the cylindrical core is not particularly limited, and examples thereof include those made of metal, plastic, paper, and wood. In addition, a core in the form of a composite body such as a core using both metal and plastic, a core using both metal and paper, and a core using both plastic and paper can also be used. From strength In terms of high and more significant effects of the present invention, among them, metal and/or plastic cores are preferred. In terms of being less susceptible to abrasion and the like even in repeated use, metal The prepared core is preferred. The ratio of the mass of metal and plastic relative to the total mass of the cylindrical core is preferably 50% by mass or more, more preferably 80% by mass, more preferably 95% by mass, and 100% by mass. good.

Examples of the above metals include iron, stainless steel, aluminum, etc., and one of these may be used alone, or two or more of them may be used in combination. From the viewpoint of strength, lightness, price, etc., aluminum is preferred among them.

In addition, the above-mentioned plastics include, for example, polyvinyl chloride, polyvinylidene chloride, polyester, polycarbonate, polyamide, epoxy resin, polyurethane, polyurea, polysiloxane resin, etc. , One of these may be used alone, or two or more of them may be used in combination. Among these, polyvinyl chloride is preferred. From the standpoint of strength, etc., the plastic is preferably a fiber reinforced plastic (FRP) such as carbon fiber reinforced plastic.

In the present invention, even when the material of at least a part of the surface of the cylindrical core body is a core body that is prone to condensation such as metal and/or plastic, it is not easily affected by condensation. Therefore, in the case of using such a core, the effect of the present invention can be more remarkably exhibited. From the viewpoint that the effect of the present invention can be more remarkably exhibited, at least a part of the inner peripheral surface of the cylindrical core (preferably 50% or more of the area of the inner peripheral surface, more preferably 80% or more of the area of the inner peripheral surface ) Is preferably made of metal and/or plastic, more preferably all of the inner peripheral surface is made of metal and/or plastic, and more preferably, the entire surface of the cylindrical core is made of metal and/or plastic.

The length of the cylindrical core in the axial direction can be appropriately selected in accordance with the width of the film wound on it, etc. From the viewpoint of more remarkably exerting the effect of the present invention, the length is preferably 2.5 m or more, more preferably 3 m or more, 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 standpoints of strength, handleability, etc., its outer diameter is preferably in the range of 50 to 800 mm, more preferably in the range of 80 to 500 mm, and further It is preferably in the range of 100 to 300 mm, particularly preferably in the range of 150 to 250 mm.

In addition, from the viewpoints of strength, handleability, etc., 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 still more preferably in the range of 4 to 50 mm. Within 10mm.

[film]

The type of the above-mentioned film is not particularly limited, and examples include polyethylene film, polypropylene film, polymethylpentene film, alicyclic olefin polymer film, polystyrene film, polycarbonate film, and polyvinyl chloride film. , Methacrylic resin film, polyamide film, polyethylene terephthalate film, PVA film, etc., especially from the aspect of significant deterioration in quality caused by moisture absorption, and more significant performance of the effects of the present invention Look, PVA film is better.

The PVA constituting the PVA film can be produced by saponifying a polyvinyl ester obtained by polymerizing a vinyl ester monomer. The vinyl ester monomers include, for example, vinyl formic acid, vinyl acetate, vinyl propionate, vinyl valerate, and vinyl laurate. Ester, vinyl stearate, vinyl benzoate, trimethyl vinyl acetate, vinyl versatate, etc. Among them, vinyl acetate is preferred.

Although the degree of polymerization of the PVA constituting the PVA film depends on the use of the PVA film, etc., it is preferably in the range of 500 to 9,000, more preferably in the range of 1,500 to 7,000, and still more preferably in the range of 1,800 to 5,000 Within the range, it is particularly preferable to be in the range of 2,000 to 3,000. In addition, the degree of polymerization of PVA in this specification means the average degree of polymerization measured in accordance with the description of JIS K6726-1994.

In addition, although the degree of saponification of the PVA constituting the PVA film depends on the use of the PVA film, etc., it is preferably 75 mol% or more, more preferably 85 mol% or more, and still more preferably 95 mol% or more. Preferably, it is 99 mol% or more. In addition, the degree of saponification of PVA in this specification refers to the total number of moles of structural units (typically vinyl ester units) and vinyl alcohol units that can be converted into vinyl alcohol units by saponification. The ratio of the number of moles of the vinyl alcohol unit (mole%). The degree of saponification can be measured in accordance with the description of JIS K6726-1994.

The PVA film can also contain plasticizers, surfactants, dichroic dyes, etc. as needed. The manufacturing method of the PVA film is not particularly limited, and a PVA film formed by a known method such as a solution film forming method and 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 still more preferably in the range of 15 to 100 μm.

The width of the film is not particularly limited, but it is preferably 2.1m Above, it is more preferably 2.3 m or more, still more preferably 2.6 m or more, particularly preferably 3 m or more, and most preferably 3.3 m or more. When a film having such a width is used, water from condensation is likely to be generated in a larger amount. However, in the present invention, since it is not easily affected by condensation, when a film having such a width is used, the present invention The effect can be more significant.

On the other hand, if the width of the film is too wide, the operability may decrease, so 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, and particularly preferably 11,000 m or more. In the case of less than 2,000 m, due to reasons such as the increase in the ratio of the loss at the beginning/end of winding of the film roll to the whole, etc., it may not be economical. On the other hand, the upper limit of the length of the film is not particularly limited, but if it is too long, the mass or diameter of the film roll becomes too large, and handling tends to be difficult when loading and unloading or moving to a stand or processing device. Therefore, the film The length of is preferably 20,000m 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, still more preferably 1,800 kg or more, and particularly preferably 3,300 kg or more. In the present invention, even if it is a film roll whose mass is larger and is prone to condensation, it is not susceptible to the influence of condensation. Therefore, in the case of the film roll as described above, the effect of the present invention can be more remarkably exhibited. However, if the mass of the film roll is too large, workability and the like may be reduced. Therefore, the mass of the film roll is preferably 5,000 kg or less.

[Water absorbing member]

The film roll of the present invention has a water-absorbing member on the inner wall of the core body. The position where the water absorbing member is arranged in the inner wall of the core is not particularly limited, but from the point of view that the effect of the present invention can be more remarkably exhibited, it is preferably arranged on the inner wall of the end of the core. From the point of view of not causing obstruction when moving the film roll, the specific arrangement position of the water absorbing member is such that the distance from the end of the core to the water absorbing member (the shortest distance) is preferably 10 cm or more, and 15 cm or more. . On the other hand, if it is too far away from the end, there will be problems such as the tendency of the water-absorbing member to be difficult to install, so the above-mentioned distance is preferably 50 cm or less. When the water-absorbing member is arranged on the inner wall of the end of the core, it can be arranged only on the inner wall of one end of the core in the axial direction. However, the effect of the present invention can be more prominently displayed. It is preferable that the inner walls of both ends have water absorbing members.

In addition, the water-absorbing member may be continuously arranged in a ring shape along the inner wall of the core, but from the viewpoint of ease of arrangement and cost reduction, it is preferable to arrange only a part of the inner wall of the core, especially It is more preferable to arrange a water-absorbing member at the lower part of the inner wall of the core.

The material of the water absorbing member is not particularly limited, and any one can be used as long as it is a member having water absorption. Specific examples of the material of the water-absorbing member include cellulose-based synthetic fibers, cellulose-based natural fibers, and polyester-based fibers. From the viewpoint of the difficulty of occurrence of problems such as the attachment of fragments of the water-absorbing member to the film and the deterioration of the film quality, among these, at least one selected from the group consisting of cellulose-based synthetic fibers and polyester-based fibers is used as Preferably, cellulosic synthetic fibers are more preferable. From the standpoints of low price or temporal stability of water absorbing performance, the water absorbing member is preferably made of fibers such as those mentioned above, but when higher water absorbing performance is required In addition, it is also preferable to use a desiccant such as silica colloid as the water-absorbing member.

The form of the water-absorbing member is not particularly limited, but from the viewpoints of ease of handling and availability, a sheet form is preferred, and a sheet-like nonwoven fabric is particularly preferred. In the case of using a sheet-like water-absorbing member, one sheet may be separately arranged on the inner wall of the core. However, from the viewpoint of ensuring sufficient water-absorbing capacity, etc., it is preferable to laminate a plurality of water-absorbing members. In this case, the number of laminated water-absorbing members is not particularly limited, but for example, two or more are preferable, three or more are more preferable, four or more are more preferable, and 10 or less are more preferable.

There is no particular limitation on the arrangement means when the water absorbing member is arranged on the inner wall of the core. Examples include adhesive tape, adhesive, magnet, etc. However, from the viewpoint of being able to be sufficiently fixed and relatively easy to remove, the water absorbing member is It is better to fix it with adhesive tape.

The type of the adhesive tape is not particularly limited. Examples include paper adhesive tape, cloth adhesive tape, film adhesive tape, special adhesive tape, etc. Specifically, cellophane tape, kraft paper tape, cloth adhesive tape, OPP Adhesive tape, aluminum tape, vinyl tape, polyester tape, polyethylene tape, polypropylene tape, polyimide tape, gum tape, or a composite processed by combining two or more of these Tape etc. From the point of view that it is difficult to cause problems such as adhesion of the broken pieces of the adhesive tape to the film, which reduces the quality of the film, and the waterproofness is also excellent, among these, the adhesive tape made of polyethylene or polypropylene is preferred.

The film roll of the present invention can be transported in its original form or Storage, or transport or storage in the form of a package packaged with packaging materials. The use of the film in the film roll of the present invention is not particularly limited, but according to the present invention, since the influence of condensation is small and excellent film quality can be maintained, it is preferably used as a raw material film for the production of optical films such as polarizing films .

[Example]

Hereinafter, the present invention will be described in more detail with examples and the like, but the present invention is not limited by these examples. In addition, the dew condensation on the inner wall of the core body, the condensation flowing out of the core body, the dust observed on the inner wall of the core body, and the evaluation of the fixability of the water-absorbing member used in the following examples and comparative examples The method is revealed as follows.

[Condensation on the inner wall of the core]

Evaluate the occurrence of condensation on the inner wall of the core according to the following criteria.

○: Less condensation.

×: There is much condensation.

[Condensation flows out from the core]

The flow of condensation from the core is evaluated according to the following criteria.

○: No condensation was observed to flow out from the end of the core body at all.

×: Condensation is observed to flow out from the end of the core.

[Dust confirmed on the inner wall of the core]

The dust found on the inner wall of the core is evaluated based on the following criteria.

○: Dust cannot be confirmed visually.

×: Dust can be confirmed visually.

[Fixability of water-absorbing member]

The fixability of the water-absorbing member on the inner wall of the core was evaluated in accordance with the following criteria.

○: Fixed.

×: Will move and become unstable.

[Example 1]

A PVA film with a film width of 3.3m, a thickness of 60μm, and a length of 12,500m (the degree of polymerization of PVA is 2,450, the degree of saponification of PVA is 99.3 mol%) is wound on an aluminum cylinder with a length of 3.5m, an outer diameter of 215mm, and a wall thickness of 6mm. The central part of the shaped core. Then, prepare two sheets of non-woven fabrics ("Dust Tackle" Wiper, manufactured by KURARAY Co., Ltd., length 33 cm × width 33 cm) composed of 4 cellulose-based synthetic fibers, as shown in the outline of Figure 1. As shown in the figure, these are respectively fixed to the lower part of the inner wall of the both ends of the core with adhesive tape. In addition, the fixed position of the non-woven fabric was set to a position at a distance of 20 cm in the axial direction from each end (the shortest distance from the end of the core body to the water-absorbing member is 20 cm). In addition, the adhesive tape is made of polyethylene. The mass of the film roll obtained in this way is 3,600 kg.

After storing the above-mentioned film roll at 10°C or less for 10 hours or more, then leave it in a gas environment where condensation occurs at 20°C or higher for a predetermined period of time to perform the above-mentioned evaluations. The results are shown in Table 1.

[Example 2]

Two sheets of cellulose-based natural fibers (wool, length 30 cm × width 30 cm) were used instead of four sheets of cellulose synthetic fiber laminated non-woven fabric, except that it was the same as Example 1 Obtain film rolls. For this film roll, the various items were carried out in the same way as in Example 1. Evaluate. The results are shown in Table 1.

[Example 3]

Except having changed the length of the PVA film from 12,500 m to 1,000 m, the same procedure as in Example 1 was carried out to obtain a film roll. In addition, the mass of the film roll is 300 kg. With respect to this film roll, various evaluations were performed in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 1]

The film roll was obtained in the same manner as in Example 1 except that the nonwoven fabric was not used. With respect to this film roll, various evaluations were performed in the same manner as in Example 1. The results are shown in Table 1.

1‧‧‧Cylindrical core

2‧‧‧The inner wall of the core

3‧‧‧Water absorbing member

4‧‧‧One end of the core

5‧‧‧One end of the core

Claims (10)

A film roll, which is a film roll formed by winding a polyvinyl alcohol film on a cylindrical core body, wherein the core body is made of metal or plastic, and the axial length of the core body is 2.5m or more. The quality of the film roll It is 500 kg or more, and the inner wall of the core has at least one water-absorbing member selected from the group consisting of cellulose-based synthetic fibers and polyester-based fibers. Such as the film roll of claim 1, which has water absorbing members on the inner walls of both ends of the core body. Such as the film roll of claim 1 or 2, which has a water absorbing member at the lower part of the inner wall of the core body. The film roll of claim 1 or 2, wherein the distance from the end of the core to the water-absorbing member is 10 cm or more. For example, the film roll of claim 1 or 2, in which a plurality of water-absorbing members are laminated. Such as the film roll of claim 1 or 2, wherein the water-absorbing member is fixed to the inner wall of the core by an adhesive tape. Such as the film roll of claim 6, wherein the adhesive tape is made of polyethylene or polypropylene. Such as the film roll of claim 1 or 2, wherein the length of the film is 2,000m or more. For example, the film roll of claim 1 or 2 is not packaged with packaging materials. A method for storing film rolls, which is to roll the film rolls of any one of claims 1 to 9 in a state where the two ends of the core body are opened and the inside of the core body is exposed to outside air at a temperature below 10°C Keep for more than 10 hours.

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