TW201714936A - Packaging body, method for storing or transporting polyvinyl alcohol-based film, polyvinyl alcohol-based film, and polarizing film - Google Patents

Abstract

The present invention provides a packaging body for a polyvinyl alcohol-based film, the packaging body being capable of suppressing deformation or degradation in the optical performance during storage or transportation. A packaging body 11 is formed by preparing a film roll 3 by wrapping a belt-like polyvinyl alcohol-based film around a core tube 2, attaching protection pads 7 to both ends of the film roll 3, and packaging the protection pads 7 and the film roll 3 in a water vapor barrier film 4. Humidity conditioning sheets 8 are attached to the surfaces of the protection pads 7 contacting the film roll 3, and, hence, the film roll 3 is packaged in the water vapor barrier film 4 together with the protection pads 7, to which the humidity conditioning sheets 8 are attached. By packaging the humidity conditioning sheets 8 with the film roll 3, the humidity of an internal space where the film roll 3 is disposed is conditioned to 20 to 80 % RH.

Description

Method for preserving or transporting package, polyvinyl alcohol film, polyvinyl alcohol film and polarizing film

The present invention relates to a package, a method for preserving or transporting a polyvinyl alcohol-based film, a polyvinyl alcohol-based film, and a polarizing film. More specifically, the present invention relates to a package which is suitable for storage and transportation of a polyvinyl alcohol-based film which is excellent in appearance, has no optical unevenness, and is useful as a raw roll for obtaining a polarizing film; A method for preserving or transporting a polyvinyl alcohol-based film of a package, a polyvinyl alcohol-based film stored and/or transported in this manner, and a polarizing film obtained by using the polyvinyl alcohol-based film.

Conventionally, a polyvinyl alcohol-based film is formed by dissolving a polyvinyl alcohol-based resin in a solvent such as water and forming a film by a solution casting method (casting method), and then using a metal heating roll (hereinafter referred to as a metal heating roll). .) etc. are dried and manufactured. The polyvinyl alcohol-based film obtained in this manner is used as a film having excellent transparency and dyeability in various applications, and one of useful uses thereof is a polarizing film.

The polarizing film is a film obtained by dyeing the above polyvinyl alcohol-based film with a dye, and is used as a basic component of a liquid crystal display. In recent years, in the use of displays requiring high quality and high reliability, particularly liquid crystal television receivers used in large screens, it is required to further reduce the in-plane uniformity of the degree of polarization and the stain.

In order to improve the physical properties of the polyvinyl alcohol-based film itself, it is necessary, but the packaging form at the time of storage and transportation of the polyvinyl alcohol-based film after production is also important. The reason is that if the water content of the polyvinyl alcohol-based film is greatly changed during storage and transportation, or if the moisture content in the film surface is uneven, not only the film is deformed, but also the optical properties in the film surface are changed, and the polarized light is obtained. The film produces uneven polarization (in-plane unevenness of polarization) and color spots.

As a technique for solving such a problem, for example, Patent Document 1 proposes a technique in which a roll of a polyvinyl alcohol-based film is packaged by a water vapor barrier resin packaging film and a packaging film made of an aluminum material, and is stored or transported. (Refer to paragraphs 0044 to 0044). Further, for example, Patent Document 2 proposes a package in which both ends of the packaging material are fixed to the core tube, and the remaining portions of the both end portions are further pushed into the core (see paragraphs 0014 and 3). . [Patent Literature]

[Patent Document 1] JP-A-2005-306483 [Patent Document 2] JP-A-2013-227073

[Problems to be Solved by the Invention] However, even in the above-described disclosed technique, deformation of the polyvinyl alcohol-based film and reduction in optical properties during transportation cannot be sufficiently suppressed. In general, a polyvinyl alcohol-based film is packaged in a state where the water content is several %. Even if moisture is infiltrated from the outside by the water vapor barrier resin packaging film, if moisture intrudes into the inside of the package from the gap between the packaging film and the core tube, deformation may occur or optical unevenness may occur. Further, in the inside of the package, if moisture absorption and desorption are repeated due to moisture of the film itself, deformation or occurrence of optical unevenness may occur. With regard to these phenomena, the wider the polyvinyl alcohol-based film, the more easily it is produced, and the thinner the more. Therefore, an object of the present invention is to provide a package of a polyvinyl alcohol-based film which can reduce deformation and optical unevenness even during storage and transportation. [Means for solving the problem]

As a result of intensive studies to solve the above problems, the inventors of the present invention have found that the above problems can be solved by adjusting the humidity of the internal space of the package to 20 to 80% RH, and have completed the present invention.

That is, the present invention is a package in which a film roll obtained by winding a strip-shaped polyvinyl alcohol-based film on a core tube is packaged by a water vapor barrier film, and is characterized in that the inner space of the package is Humidity is adjusted to 20-80% RH.

Further, in the case of the above package, it is preferable to package the humidity-conditioning sheet together with the film roll.

Further, the humidity-conditioning sheet is preferably a nonwoven fabric having a thickness of 0.1 to 2 mm.

Further, the humidity-conditioning sheet preferably has a moisture absorption rate of 50% by weight or more at 30 ° C and 90% RH.

Preferably, the axial length of the core tube is longer than the width of the film, and the end portion of the core tube on the axial direction side of the water vapor barrier film is folded into the inside of the core tube protruding from the film roll to wrap Preferably, the end portion of the core tube is wound in a manner of being wound; further, it is preferable to dispose the water absorbing material inside the core tube.

Further, in the case of the above package, it is preferable to package a humidity indicator together with the film roll.

The polyvinyl alcohol-based film is preferably a width of 4 m or more and a length of 4 km or more.

The thickness of the polyvinyl alcohol-based film is preferably 5 to 40 μm.

The polyvinyl alcohol-based film is preferably a polyvinyl alcohol-based film for a polarizing film.

Moreover, the present invention relates to a method for preserving or transporting a polyvinyl alcohol-based film, which is used for storage and/or transport of the polyvinyl alcohol-based film.

Further, the present invention is a polyvinyl alcohol-based film which is stored and/or transported using the above-described package.

Further, the present invention is a polarizing film obtained by using the above polyvinyl alcohol-based film. [Effects of the Invention]

According to the present invention, it is possible to suppress deformation and optical performance of the belt-shaped polyvinyl alcohol-based film during storage and/or transportation, and at the same time, prevent winding deviation or scratch of the film roll, and deterioration of the film due to adhesion. . Further, the quality of the film roll in the width direction and the longitudinal direction (from the outer peripheral portion of the roll to the core portion) can be kept constant. Further, not only a polarizing film having excellent in-plane uniformity but also a roll-out during the production of the polarizing film can be easily obtained, and productivity can be improved.

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. In the following, the same or corresponding elements are designated by the same reference numerals, and the repeated description is omitted.

In the packaging system of the present invention, a film roll obtained by winding a strip-shaped polyvinyl alcohol-based film on a core tube is packaged by a water vapor barrier film, and is characterized in that the humidity of the inner space of the package body in which the film roll is disposed Adjust to 20 to 80% RH. The humidity of the inner space of the package is preferably 30 to 70% RH, and particularly preferably 35 to 65% RH. When the humidity is too low or too high, the polyvinyl alcohol-based film on the surface layer of the film roll tends to be dried/moisture-sensitive and deformed. When the humidity is too low or too high, there is a polyvinyl alcohol-based film. The tendency to reduce the appearance and optical performance. Specifically, white turbidity may occur, or optical unevenness may increase.

1 is a schematic cross-sectional view showing a part of the package 11 according to the first embodiment of the present invention, and FIG. 2 is a perspective view showing a packaging step of the film roll 3 in the package 11.

As for the package 11, as shown in FIG. 2, a strip-shaped polyvinyl alcohol-based film is wound around a core tube 2 having a longer axial length than a film to form a film roll 3, and is formed on a film roll. After the protective pads 7 are respectively attached to the both ends of the 3, the film roll 3 and the protective pad 7 are packaged together with the water vapor barrier film 4.

More specifically, first, as shown in FIG. 2(a), one end of the rectangular water vapor barrier film 4 is fixed to a predetermined start winding position of the outer peripheral portion of the film roll 3. At this time, one side of the water vapor barrier film 4 is disposed and fixed so as to be parallel to the axial direction of the core tube 2.

Then, as shown in Fig. 2(b), after the water vapor barrier film 4 is wound at least one circumference along the outer circumference of the film roll 3, the other end of the water vapor barrier film 4 is fixed by, for example, an adhesive tape 5. At this stage, the water vapor barrier film 4 is formed into a cylindrical shape. Then, as shown in Fig. 2(c), the two end portions on the axial direction side of the core tube 2 of the water vapor barrier film 4 are respectively fixed to the film roll 3 (strictly speaking, as shown in Fig. 1) The package body 11 of this embodiment is completed from the outer peripheral portion of the core tube 2 which protrudes from the protective pad 7).

The method of fixing the end portion of the water vapor barrier film 4 to the outer peripheral portion of the core tube 2 may, for example, be a method of fixing the tape on the outer side of the water vapor barrier film 4 and fixing it by a double-sided adhesive tape, or A method of fixing the end portion of the water vapor barrier film 4 by heat sealing to the outer surface of the adhesive tape attached to the outer peripheral portion of the core tube 2, a method using a rubber band, a method using a surface fastener, and the like. Among them, a method of fixing the tape on the outer side of the water vapor barrier film 4 and fixing it by a double-sided adhesive tape, and fixing the water vapor barrier film by heat sealing on the outer surface of the adhesive tape attached to the outer periphery of the core tube 2 The method of the end portion of 4 is preferable in that the humidity of the internal space of the package 11 is stably maintained. In addition, in FIG. 1, for easy understanding, it is drawn between the water vapor barrier film 4 and the film roll 3, and between the water vapor barrier film 4 and the core tube 2, but actually the water vapor barrier film 4 The film reel 3 and the core tube 2 are wound around the outer circumference of the core tube 2 and fixed, and the film reel 3 is sealed by the water vapor barrier film 4.

As described above, in the package 11, the film roll 3 is disposed in the internal space formed by the core tube 2 and the water vapor barrier film 4. In the present invention, the humidity in the internal space in which the film roll 3 is disposed is appropriately adjusted, thereby suppressing the deformation of the belt-shaped polyvinyl alcohol-based film during storage, the deformation during transportation, and the deterioration of optical performance.

As shown in Fig. 1, a protective pad 7 is attached to the end of the film roll 3 before packaging. The protective pad 7 is attached with the humidity-conditioning sheet 8 on the side of the contact surface with the film roll 3, so that the film roll 3 is packaged with the water vapor barrier film 4 together with the protective pad 7 to which the humidity-conditioning sheet 8 is attached. . As described above, by packing the humidity-conditioning sheet 8 together with the film roll 3, the humidity of the internal space of the package 11 in which the film roll 3 is disposed can be adjusted to 20 to 80% RH.

The tape-shaped polyvinyl alcohol-based film in the present invention is not particularly limited, and for example, a polyvinyl alcohol-based film obtained by the method described later can be used. The width of the film, in consideration of the large area, is preferably 4 m or more, and the aspect of further large-area is considered to be particularly good at 4.5 m or more, and the aspect of avoiding fracture is considered to be 4.5 to 6 m.

The core tube 2 in which the strip-shaped polyvinyl alcohol-based film is wound may have a cylindrical shape, and in view of light weight, it is preferably a hollow cylinder. Further, when the core tube 2 has a cylindrical shape, a support rod can be inserted into the core tube 2, and the film roll 3 can be mounted on a gantry or a processing apparatus. The material of the core tube 2 is, for example, metal or plastic, and is not particularly limited. Examples of the metal include carbon steel, high tensile steel, stainless steel, aluminum, aluminum alloy such as duralumin, copper, brass, bronze, and the like. A resin layer such as soft polyvinyl chloride or low-density polyethylene may be laminated on the surface or the inner surface of the metal core tube 2, or may be plated with nickel, chromium, zinc or tin. Examples of the plastics include rigid polyvinyl chloride, polypropylene, high density polyethylene, ultrahigh molecular weight polyethylene, polycarbonate, and polyester. The outer diameter of the core tube 2 is preferably 7.5 cm or more, more preferably 8.5 cm or more. When the outer diameter of the core tube 2 is too small, wrinkles tend to occur in the film. When the core tube 2 is cylindrical, the thickness of the core tube 2 is preferably 1.5 to 20 mm, more preferably 2 to 15 mm, and still more preferably 3 to 10 mm. The size of the core tube 2 is generally 11 to 31 cm in outer diameter and 10 to 30 cm in inner diameter.

The axial length of the core tube 2 (that is, the length in the axial direction) is longer than the width of the strip-shaped polyvinyl alcohol-based film, and it is preferable to protrude from the both ends of the axial direction side of the film roll 3 by 10 cm or more. good. Specifically, the axial length of the core tube 2 is preferably 4.1 m or more, and in view of further large area, it is particularly preferable to be 4.6 m or more, and it is preferable to avoid the fracture of the polyvinyl alcohol-based film, and it is more preferably 4.6 to 6.1 m. By having the protruding portion of the core tube 2, a bracket may be provided at both ends of the protruding portion, or both ends of the protruding portion may be placed on the gantry so that the film reel 3 does not contact the ground or other film reel or the like. In a state of being suspended, it is possible to prevent the entire load of the package 11 from being applied to the entire film roll 3, and to prevent adhesion and deterioration of the films. Further, the water vapor barrier film 4 and the packaging film can be fixed to both ends of the protruding portion.

The water vapor barrier film 4 used in the present invention is not particularly limited, and the moisture permeability measured in accordance with JIS Z 0208 can be 10 g/m ² ·day or less, preferably 1 g/m ² ·day or less. Specific examples include a single layer film of high density polyethylene, low density polyethylene, polypropylene, polyester, polyvinylidene chloride coated polypropylene, glass vapor deposited polyester, or the like, or a laminated film thereof. Or laminated film with patchwork, paper, and non-woven fabric. The laminated film may, for example, be a laminated film of glass or aluminum vapor-deposited polyester and polyethylene, a laminated film of polyvinylidene chloride-coated polypropylene and polyethylene, or the like.

When the water vapor barrier film 4 is subjected to antistatic treatment in advance, it is also preferable in terms of preventing foreign matter from being mixed in. The antistatic agent can be kneaded into the film or applied to the surface. In the case of kneading, it is preferably used in an amount of about 0.01 to 5% by weight based on the resin, and in the case of surface coating, an antistatic agent of about 0.01 to 1 g/m ² is preferably used. The antistatic agent is not particularly limited as long as it does not adversely affect the optical properties, and examples thereof include alkyl diethanolamine, polyoxyethylene alkylamine, higher fatty acid alkanolamine, and sorbitan fatty acid ester.

In the case where the water vapor barrier film 4 is laminated on a water vapor barrier film in which a moisture absorbing film is laminated, it is also preferable to adjust the humidity of the internal space of the package 11. As the moisture absorbing film, for example, an inorganic or organic drying agent such as calcium chloride, cerium oxide gel, zeolite, saccharide or water-absorbent resin is dispersed, impregnated, coated on a synthetic resin, or natural cellulose. a moisture absorbing layer prepared by synthesizing a formable material such as cellulose, glass cloth or non-woven fabric, and drying the inorganic or organic desiccant into a polyester film, a polyethylene film, a polypropylene film, and Teflon (registered trademark) A thermoplastic resin film such as a film. When these laminates are used, the moisture absorbing film side is packaged so as to be inside the package 11.

Before the film roll 3 is packaged by the water vapor barrier film 4, the film film 3 can be wound around the film roll 3 as an inner film. By winding the inner film, stains and scratches of the film roll 3 can be prevented. The interior film is not particularly limited, and it is preferably an inexpensive polyethylene film.

After the film roll 3 is packaged by the water vapor barrier film 4, it can be further packaged in a packaging film made of an aluminum material. The packaging film may be a laminated film of an aluminum foil, an aluminum foil and a moisture-resistant plastic film (for example, a laminated film of an aluminum foil and a polyolefin film), a laminated film of an aluminum vapor-deposited film and a moisture-resistant plastic film (for example, aluminum steaming) A laminated film of a coating film and a polyolefin film, a laminated film of an aluminum vapor-deposited film and a moisture-resistant plastic film (for example, a laminated film of an aluminum vapor-deposited polyester film and a polyethylene film). In the present invention, in particular, a laminated film of an aluminum foil and a polyolefin film (for example, a laminated film of an aluminum foil and a polyethylene film), an aluminum deposited film and a polyolefin film laminated film (for example, an aluminum evaporated polyester film and polyethylene) A laminated film of a film is useful, in particular, a laminated film formed of a stretched polypropylene film/polyethylene film/aluminum foil/polyethylene film, formed of an extended polypropylene film/low density polyethylene film/aluminum foil. A laminated film or the like is useful.

Further, in the package 11 of the present embodiment, the entire heat insulating material can be packed and stored and/or transported. Of course, the humidity of the internal space of the package 11 depends on the temperature. In recent years, the temperature during storage and/or during transportation has been continuously managed from the viewpoint of quality assurance, but in practice, it is often varied within the range of 0 to 80 °C. In order to adjust the humidity of the internal space of the package 11 to the above range, temperature management of the package 11 is also important. The heat insulating material used in the present invention is not particularly limited, and in view of heat insulating property, aluminum vapor deposited sheet is preferred, and aluminum vapor deposited felt is particularly preferable in terms of impact resistance. In addition, the heat insulating material should preferably be reused.

The method of adjusting the humidity of the internal space of the package 11 to the above range includes a dried sheet and a film roll 3 in which a desiccant such as cerium oxide gel, calcium chloride or zeolite is sandwiched between a thermoplastic film and paper. In the present invention, it is preferable to package the humidity-conditioning sheet 8 together with the film roll 3 in the present invention. The humidity-conditioning sheet 8 maintains the humidity of the inner space of the package 11 by suction and release. The drying of the dried sheet alone cannot be said to be the adjustment of the humidity, and if the internal space of the package 11 is too dry, the polyvinyl alcohol-based film is deformed. Further, when the dried sheet absorbs moisture, the moisture release rate is slow, so that it is difficult to cope with repeated changes in humidity. Further, since the dried sheet has a small moisture absorption amount and a slow moisture absorption rate, there is a problem that it is impossible to cope with a sudden environmental change.

The humidity-conditioning sheet 8 used in the present invention is preferably a non-woven fabric in terms of environmental considerations. In general, inorganic desiccants are industrial waste, but non-woven fabrics can be incinerated. Considering the moisture absorption rate and the moisture absorption rate, it is preferable that the non-woven fabric composed of the highly hygroscopic fiber is better, and the non-woven fabric composed of the acrylic high-absorbent fiber is particularly preferable in terms of the repeated durability, and the sodium polymer is partially sodium. A non-woven fabric composed of a salt crosslinked fiber or an acrylic polymer crosslinked fiber is particularly preferred. For example, "Bellsunny" manufactured by Teijin Co., Ltd., and an acrylic polymer crosslinked product fiber, for example, "Mois fine" manufactured by Toyobo Co., Ltd., may be mentioned. Further, polyethylene fibers, polyester fibers, and the like may be added to the nonwoven fabric to the extent that moisture absorption is not impaired.

The thickness of the humidity-conditioning sheet 8 is preferably 0.1 to 2 mm, more preferably 0.2 to 1.5 mm, and more preferably 0.3 to 1.0 mm. If the thickness is too small, the moisture absorption amount tends to be insufficient, and if it is too large, processing and handling tend to be difficult.

The moisture absorption rate of the humidity-conditioning sheet 8 is preferably 50% by weight or more with respect to the self-weight (weight in a dry state) at 30 ° C and 90% RH, more preferably 70% by weight or more, and still more preferably 80% by weight or more. If the moisture absorption rate is too low, the moisture absorption amount tends to be insufficient.

The installation position of the humidity-conditioning sheet 8 is not particularly limited as long as it is in the internal space of the package 11, and it is preferable to attach it to the protective pads 7 provided at both end portions of the film roll 3. The protective pad 7 is a disc-shaped plastic sheet in which a core tube through-hole is formed in the center portion, and is provided to suppress the winding deviation or to protect the end portion of the film roll 3 from impact. Further, it is preferable that the protective pad 7 and the humidity-conditioning sheet 8 have substantially the same size as the end surface of the spool 3.

3 is a schematic cross-sectional view showing a part of the package 21 according to the second embodiment of the present invention, and FIG. 4 is a perspective view showing a packaging step of the film roll 3 in the package 21.

In the present embodiment, as shown in Fig. 4(c), the two end portions on the axial direction side of the core tube 2 of the water vapor barrier film 4 are each folded at the end portion of the core tube 2 projecting from the film roll 3. The inner side is thereby wound and fixed to the core tube 2 so that the end portion of the core tube 2 is surrounded by the water vapor barrier film 4. Further, the water absorbing material 6 is disposed inside the core tube 2, and the package body 21 of the present embodiment is completed. In addition, in FIG. 3, for easy understanding, it is drawn between the water vapor barrier film 4 and the film roll 3 and between the water vapor barrier film 4 and the core tube 2, but actually the water vapor barrier film 4 The film is wound in such a manner as to be in close contact with the film roll 3 and the core tube 2.

By arranging the water absorbing material 6 inside the core tube 2 and sucking the moisture deposited on the inner peripheral portion of the core tube 2 with the water absorbing material 6, it is possible to suppress the intrusion of moisture from the inside of the core tube 2 into the core tube 2 and the water vapor barrier film. 4 inside the internal space formed. Further, by folding the end portion of the water vapor barrier film 4 into the inside of the core tube 2 and winding it so as to wrap the end portion of the core tube 2, moisture can be suppressed from the inner peripheral surface of the core tube 2 and water vapor. The gap between the barrier films 4 intrudes into the above internal space. According to the above configuration, the humidity in the internal space in which the film roll 3 is disposed can be adjusted to 20 to 80% RH.

Fig. 5 is a schematic cross-sectional view showing a part of the package body 101 when the water absorbing material 6 in the second embodiment is not disposed. Since the water absorbing material 6 is not disposed in the package 101 shown in FIG. 5, the end portion of the water vapor barrier film 4 is separated from the inner circumferential surface of the core tube 2 and floats to generate a gap, and moisture is passed through the inner side of the core tube 2. The gap is invaded.

However, in the present embodiment, as shown in FIG. 3, the water absorbing material 6 is disposed inside the core tube 2 so as to be in close contact with the inner peripheral portion of the core tube 2, so that the end portion of the water vapor barrier membrane 4 and the core tube 2 are The inner peripheral surface is in close contact with each other, and it is more difficult to create a gap between the inner peripheral surface of the core tube 2 and the water vapor barrier film 4, and it is possible to further surely prevent moisture from entering the inner space.

The water absorbing material 6 used in the present embodiment is preferably a cylindrical shape or a cylindrical shape having an outer diameter of 10 to 30 cm, and is adapted to be in close contact with the inner peripheral portion of the core tube 2 to correspond to the inner diameter of the core tube 2. The water absorbing material 6 having an appropriate outer diameter is selected. Preferably, the outer diameter is 13 to 25 cm, and the outer diameter is preferably 15 to 22 cm. If the outer diameter is too small, the water absorbing effect tends to be insufficient, and if the outer diameter is too large, the weight of the package 21 tends to increase. Of course, the size of the water absorbing material 6 is preferably such that it can be smoothly inserted during storage and transportation, and can be smoothly taken out at the time of storage or transportation. The water absorbing material 6 may be provided only at both ends of the inside of the core tube 2, or may be provided in the entire axial direction of the core tube 2, and the number of the water absorbing materials 6 may be one or more. When the water absorbing material 6 is provided at both ends of the inside of the core tube 2, the length of the water absorbing material 6 in the axial direction is preferably from the both ends of the core tube 2 to the front end portion of the water vapor barrier film 4 folded into the core tube 2. It is preferably longer than the length, and is particularly excellent in exceeding the length.

The material of the water absorbing material 6 is preferably made of a resin in consideration of strength, and in consideration of weight reduction of the package 21, the weight is preferably 20 kg or less. Further, in view of further reducing the weight and not damaging the inner peripheral portion of the core tube 2, it is preferable that the sponge has a pore size of a micron unit, and a polyvinyl alcohol sponge or an urethane sponge is particularly preferable. Examples of the sponge having micropores in the order of micrometers include those having an apparent density of 0.01 to 0.5 g/cm ³ .

The humidity of the internal space of the packages 11 and 21 of the first and second embodiments can be measured by using a hygrometer in the vapor barrier film 4, and in the present invention, it is possible to easily confirm the humidity history during transportation. In terms of aspect, it is preferable to use an electronic record type card type or a sticker type humidity indicator.

For example, "Ondotori" manufactured by T&D Corporation, "WATCH LOGGER" manufactured by Fujita Electric Co., Ltd., "midi LOGGER" manufactured by GRAPHTEC Co., Ltd., and the like are exemplified.

Further, the sticker type humidity indicator may be a compound such as cobalt bromide which is irreversibly colored when exposed to high humidity or low humidity for a predetermined period of time. For example, a plurality of labels having a diameter of about 5 mm are arranged on the surface of the film, and the labels are a 50% RH detection label, a 60% RH detection label, a 70% RH detection label, an 80% RH detection label, and a 90% RH detection label, corresponding to The label of the humidity reached changes from blue to pink, or from white to blue, or blue to blur, thereby confirming the highest reaching humidity. A humidity indicator with a low humidity side starting from 5% RH and a high humidity side to 90% RH is commercially available. The measurement accuracy is about ±5% RH.

In the present invention, the humidity indicator can be packaged together with the film roll 3, and specifically, a humidity indicator can be attached to the outermost layer of the film roll 3 and the inside of the water vapor barrier film 4 to be packaged.

Hereinafter, the polyvinyl alcohol-based film used in the present invention will be described. The polyvinyl alcohol-based film of the present invention is obtained by casting an aqueous solution of a polyvinyl alcohol-based resin into a casting mold to form a film, and continuously drying the film by a metal heating roll.

In the above polyvinyl alcohol-based resin, an unmodified polyvinyl alcohol-based resin, that is, a resin obtained by saponifying a polyvinyl acetate obtained by polymerizing vinyl acetate, is usually used. If necessary, a resin obtained by saponifying a copolymer of vinyl acetate and a small amount (usually 10 mol% or less, preferably 5 mol% or less) copolymerizable with the vinyl acetate may be used. The component copolymerizable with vinyl acetate may, for example, be an unsaturated carboxylic acid (for example, a salt, an ester, a guanamine, a nitrile or the like) or an olefin having 2 to 30 carbon atoms (for example, ethylene, propylene, n-butene). , isobutylene, etc.), vinyl ethers, unsaturated sulfonates, and the like. Further, a modified polyvinyl alcohol-based resin obtained by chemically modifying a saponified hydroxyl group can also be used.

Further, as the polyvinyl alcohol-based resin, a polyvinyl alcohol-based resin having a 1,2-diol structure in its side chain can also be used. The polyvinyl alcohol-based resin having a 1,2-diol structure in a side chain, for example, by (i) copolymerizing vinyl acetate with 3,4-diethyloxy-1-butene a method of saponification, (ii) a method of saponifying and decarboxylating a copolymer of vinyl acetate and vinyl ethylene carbonate, and (iii) a vinyl acetate and 2,2-dialkyl-4-vinyl-1 A method of saponifying and deketalizing a copolymer of 3-dioxycyclopentane, (iv) a method of saponifying a copolymer of vinyl acetate and glycerol monoallyl ether, or the like.

The weight average molecular weight of the polyvinyl alcohol-based resin is preferably from 100,000 to 300,000, more preferably from 110,000 to 280,000, and more preferably from 120,000 to 260,000. When the weight average molecular weight is too small, it may be difficult to obtain sufficient optical performance when the optical film is produced from a polyvinyl alcohol-based resin; if it is too large, stretching may be difficult when the polyvinyl alcohol-based film is stretched to form a polarizing film. Industrial production has become a tendency to become difficult. Further, the weight average molecular weight of the polyvinyl alcohol-based resin is a weight average molecular weight measured by a GPC-MALS method.

The average saponification degree of the polyvinyl alcohol-based resin used in the present invention is preferably 98 mol% or more, more preferably 99 mol% or more, more preferably 99.5 mol% or more, and still more preferably 99.8 mol% or more. When the average degree of saponification is too small, sufficient optical performance may not be obtained when a polarizing film is formed of a polyvinyl alcohol-based film. Here, the average degree of saponification in the present invention is measured in accordance with JIS K 6726.

In the polyvinyl alcohol-based resin to be used in the present invention, two or more kinds of modified substances, modified amounts, weight average molecular weight, and average saponification degree may be used.

A polyvinyl alcohol-based resin aqueous solution is produced using the polyvinyl alcohol-based resin. The polyvinyl alcohol-based resin is preferably washed with water and dehydrated by a centrifugal separator or the like to obtain a polyvinyl alcohol-based resin wet cake having a water content of 50% by weight or less. If the moisture content of the wet cake is too large, it tends to be difficult to adjust to the desired aqueous solution concentration. The polyvinyl alcohol-based resin wet cake was dissolved in warm water or hot water to prepare a polyvinyl alcohol-based resin aqueous solution.

The method for preparing the polyvinyl alcohol-based resin aqueous solution is not particularly limited. For example, it may be prepared by using a heated multi-axis extruder, or may be added to the dissolution tank having a stirring flow-producing type stirring blade. The resin is wet cake, and water vapor is blown into the tank to dissolve and prepare an aqueous solution of a desired concentration.

The polyvinyl alcohol-based resin aqueous solution contains, in addition to the polyvinyl alcohol-based resin, glycerin, diglycerin, triglycerin, ethylene glycol, triethylene glycol, polyethylene glycol, trimethylolpropane, and the like. In the case of at least one of the nonionic, anionic, and cationic surfactants, the film forming property of the polyvinyl alcohol film is preferred.

The resin concentration of the polyvinyl alcohol-based resin aqueous solution thus obtained is preferably from 15 to 60% by weight, particularly preferably from 17 to 55% by weight, more preferably from 20 to 50% by weight. When the resin concentration of the aqueous solution is too low, the drying load tends to be poor, and the productivity tends to be poor. When the viscosity is too high, the viscosity tends to be too high, and it tends to be difficult to uniformly dissolve.

In the polyvinyl alcohol-based film of the present invention, a polyvinyl alcohol-based resin aqueous solution can be prepared by using the polyvinyl alcohol-based resin, and the aqueous solution can be discharged and cast into a casting mold, and the film can be formed by a casting method. Drying and continuous production can be carried out, for example, by the following steps (A) to (D). (A) Film forming film by casting method (B) Heating and drying the film formed film (C) After cutting the dried film, winding it into a roll shape to obtain a film roll (D) The cylinder is packaged in a water vapor barrier film (and further wrapped in a packaging film if necessary)

Here, the casting mold may, for example, be a casting drum (roller type roller) or an endless belt, and it is preferable that the casting drum is preferable in terms of widening or lengthening and excellent uniformity of film thickness. . Hereinafter, a case where the casting mold is a casting drum will be described. Hereinafter, the above steps (A) to (D) will be described in order.

[Step (A)] In the step (A), first, the polyvinyl alcohol-based resin aqueous solution is usually subjected to a defoaming treatment. Examples of the defoaming method include a method of static defoaming, and defoaming by a multi-axis extruder having a vent hole. A multi-axis extruder having a vent hole generally uses a twin-shaft extruder having a vent hole.

After the defoaming treatment, the polyvinyl alcohol-based resin aqueous solution was quantitatively introduced into the T-slot die in this order, and cast into a casting mold to form a film.

The temperature of the polyvinyl alcohol-based resin aqueous solution at the outlet of the T-slot die is preferably from 80 to 100 ° C, particularly preferably from 85 to 98 ° C. When the temperature of the aqueous solution of the polyvinyl alcohol-based resin is too low, the flow tends to be poor, and if it is too high, foaming tends to occur.

The viscosity of the polyvinyl alcohol-based resin aqueous solution is preferably 50 to 200 Pa·s at the time of discharge, and particularly preferably 70 to 150 Pa·s. If the viscosity of the aqueous solution is too low, flow tends to be poor, and if it is too high, casting tends to be difficult.

The discharge rate of the polyvinyl alcohol-based resin aqueous solution discharged from the T-slot die to the casting drum is preferably 0.1 to 5 m/min, more preferably 0.2 to 4 m/min, and more preferably 0.3 to 3 m/min. If the discharge speed is too slow, the productivity tends to decrease, and if it is too fast, the casting tends to be difficult.

The diameter of the casting drum is preferably 2 to 5 m, more preferably 2.4 to 4.5 m, and even more preferably 2.8 to 4 m. When the diameter is too small, the drying speed is insufficient, and the transport speed of the film formed on the drum tends to be slow. When the diameter is too large, the transportability tends to be lowered.

The width of the casting drum is preferably 4 m or more, more preferably 4.5 m or more, more preferably 5 m or more, and particularly preferably 5 to 7 m. If the width of the casting drum is too small, the productivity tends to be lowered.

The casting drum preferably has a rotational speed of 3 to 50 m/min, preferably 4 to 40 m/min, and more preferably 5 to 35 m/min.

The surface temperature of the casting drum is preferably from 40 to 99 ° C, more preferably from 60 to 95 ° C. If the surface temperature is too low, drying tends to be poor, and if it is too high, foaming tends to occur.

[Step (B)] Next, the above step (B) will be described. The step (B) is a step of heating and drying the film-formed polyvinyl alcohol-based film.

The drying of the film formed in the casting drum is carried out by alternately contacting the surface and the back surface of the film with a plurality of metal heating rolls. The surface temperature of the metal heating roller is usually 40 to 150 ° C, preferably 50 to 140 ° C. If the surface temperature is too low, drying tends to be poor, and if it is too high, there is a tendency that the drying is excessive and the appearance is unfavorable such as undulation. Further, the metal heating roller is, for example, a roller having a diameter of 0.2 to 2 m which has been hard-chromed or mirror-finished on the surface, and usually 2 to 30, preferably 10 to 25, may be used for drying.

In the present invention, after drying by a metal heating roll, it is preferred to heat-treat the film. The heat treatment temperature is preferably 60 to 150 ° C, more preferably 70 to 140 ° C. When the heat treatment temperature is too low, the water resistance of the polyvinyl alcohol-based film is insufficient, which tends to cause a phase difference swing. When the temperature is too high, the elongation at the time of production of the polarizing film tends to decrease. The heat treatment method includes, for example, a method using a floating dryer, a method of temporarily cooling to a high temperature metal heating roller after drying to a normal temperature, and a method of irradiating the both surfaces of the film with near infrared rays using an infrared lamp.

In addition, the above method for preparing a polyvinyl alcohol-based resin aqueous solution, casting the aqueous solution into a casting mold, forming a film by a casting method, and drying to produce a polyvinyl alcohol-based film has been described, and a polyvinyl alcohol-based resin may be used. The solution is cast onto a resin film or a metal belt, and formed into a film and dried to produce a polyvinyl alcohol-based film.

[Step (C)] The film obtained by the heat treatment in the step (B) is further subjected to heat treatment as needed, and the product (the polyvinyl alcohol-based film of the present invention) is produced through the step (C). In the step (C), after the two ends of the dried film are cut, the core tube (hereinafter, also referred to as a roll) having a longer axial length than the film is taken up, and the strip-shaped polyvinyl alcohol film is taken up. The step of rolling into a roll.

A film roll obtained by winding a polyvinyl alcohol film on a roll was obtained by the above method. The length of the polyvinyl alcohol-based film is preferably 4 km or more in consideration of the large-area area, and it is preferable to further increase the area by 4.5 km or more, and it is more preferable to measure the weight by 5 to 50 km.

In addition, the thickness of the polyvinyl alcohol-based film of the present invention is preferably 60 μm or less in consideration of the thickness reduction of the polarizing film, and is preferably 50 μm or less in consideration of further reduction in thickness, and is considered to be 5 to 40 μm in consideration of avoiding breakage. Better.

The polyvinyl alcohol-based film can be suitably used as a polyvinyl alcohol-based film for optics, and is further preferably used as a raw roll for a polarizing film.

[Step (D)] The obtained film roll is formed into a package via the aforementioned step (D). Regarding the step (D), as described above, the film roll is packaged with a water vapor barrier film, and if necessary, further packaged by a packaging film to form a package. The obtained package is stored, shipped to a shipping destination, and used for, for example, the manufacture of a polarizing film.

[Storage and/or transport] The packaged film reel is provided with a bracket (support plate) at the protruding ends of the core tube, or the protrusions at both ends are placed on the gantry for support. It is stored and transported in a so-called suspended state without touching the ground. When the width of the film is relatively small, a bracket is usually used, and when the width of the film is relatively large, a gantry is usually used.

In the case of a wide film roll, a stand is usually used. A pair of support platforms on both sides of the gantry are connected by a connecting plate. The support platform is formed by horizontally erecting a frame portion between the pillars at both ends of the base, and the protruding portion of the core tube is placed on the frame portion of the support base.

When storing and/or transporting the packaged film roll, it is preferable to avoid extreme high temperature or low temperature, low humidity, high humidity conditions, and specifically, it is preferably a temperature of 10 to 30 ° C and a humidity of 40 to 75% RH. However, the package of the present invention does not have to worry about the winding deviation of the film roll even if it is subjected to a severe environment other than these conditions for a long period of time, and can exhibit a remarkable effect as a major feature.

Hereinafter, a method for producing a polarizing film obtained by using the polyvinyl alcohol-based film of the present invention will be described.

In the polarizing film of the present invention, the polyvinyl alcohol-based film is taken up from a roll and transferred in the horizontal direction, and is produced by a step of swelling, dyeing, boric acid crosslinking, stretching, washing, and drying.

The swelling step is carried out prior to the dyeing step. In addition, the swelling of the surface of the polyvinyl alcohol-based film can be washed by the swelling step, and the polyvinyl alcohol-based film can be swollen to have an effect of preventing uneven dyeing. In the swelling step, water is usually used in terms of the treatment liquid. The treatment liquid may be a main component as water, or a small amount of an iodine compound, an additive such as a surfactant, or an alcohol may be added. The temperature of the swelling bath is usually about 10 to 45 ° C, and the immersion time in the swelling bath is usually about 0.1 to 10 minutes.

The dyeing step is carried out by contacting the film with a liquid containing iodine or a dichroic dye. An aqueous solution of iodine-potassium iodide is usually used, and the concentration of iodine is 0.1 to 2 g/L, and the concentration of potassium iodide is preferably 1 to 100 g/L. The dyeing time is about 30 to 500 seconds, which is more practical. The temperature of the treatment bath is preferably from 5 to 50 ° C. The aqueous solution may contain a small amount of an organic solvent compatible with water in addition to the aqueous solvent.

The boric acid crosslinking step is carried out using a boron compound such as boric acid or borax. When the boron compound is used in the form of an aqueous solution or a water-organic solvent mixture and a concentration of about 10 to 100 g/L, and potassium iodide is allowed to coexist in the liquid, it is preferable in terms of stabilizing the polarization performance. The temperature during the treatment is preferably about 30 to 70 ° C, and the treatment time is preferably about 0.1 to 20 minutes. Further, if necessary, the stretching operation can be carried out during the treatment.

The stretching step is performed in a uniaxial direction by 3 to 10 times, preferably 3.5 to 6 times. At this time, it is possible to carry out a slight extension in the direction perpendicular to the extending direction (preventing the degree of contraction in the width direction or the extension of the degree or more). The temperature at the time of stretching is preferably from 30 to 170 ° C. Further, as long as the stretching ratio is finally set to the above range, the stretching operation is carried out not only in a single stage but also in a stage of any range of the manufacturing steps.

The washing step is carried out, for example, by immersing the polyvinyl alcohol-based film in an aqueous solution of an iodide such as water or potassium iodide, and the precipitate generated on the surface of the film can be removed by this step. The potassium iodide concentration in the case of using an aqueous potassium iodide solution is preferably from about 1 to 80 g/L. The temperature at the time of the washing treatment is usually 5 to 50 ° C, preferably 10 to 45 ° C. The treatment time is usually from 1 to 300 seconds, preferably from 10 to 240 seconds. Further, the washing with water and the washing with an aqueous solution of potassium iodide are preferably carried out in an appropriate combination.

The drying step may be carried out at 40 to 80 ° C for 1 to 10 minutes in the air.

Further, the degree of polarization of the polarizing film is preferably 99.8% or more, more preferably 99.9% or more. If the degree of polarization is too low, there is a tendency that the contrast of the liquid crystal display cannot be ensured. Further, the degree of polarization is generally a light transmittance (H ₁₁ ) measured at a wavelength λ in a state in which two polarizing films are superposed such that their alignment directions are in the same direction, and two polarizing films are superposed so that The light transmittance (H ₁ ) measured at the wavelength λ in a state in which the alignment direction is perpendicular to each other is calculated by the following equation. [(H ₁₁ -H ₁ )/(H ₁₁ +H ₁ )] ^1/2

Further, the transmittance of the polarizing film of the present invention is preferably 42% or more, more preferably 43% or more. If the transmittance of the monomer is too low, there is a tendency that the luminance of the liquid crystal display cannot be increased. The monomer transmittance is a value obtained by measuring the light transmittance of the polarizing film monomer using a spectrophotometer.

The polarizing film thus obtained is formed into a polarizing plate by laminating an optically isotropic resin film as a protective film on one surface or both sides thereof via an adhesive. Examples of the protective film include cellulose triacetate, cellulose diacetate, polycarbonate, polymethyl methacrylate, cycloolefin polymer, cyclic olefin copolymer, polystyrene, polyether oxime, and poly stretch aryl. A film or sheet of ester, poly-4-methylpentene, polyphenylene oxide or the like.

The bonding can be carried out by a known method. For example, after the liquid adhesive composition is uniformly applied to the polarizing film, the protective film, or both, the two are attached and pressure-bonded, and heated or irradiated. The energy ray is carried out.

Further, in order to reduce the thickness, a curable resin such as an urethane resin, an acrylic resin or a urea resin may be applied to one surface or both surfaces of the polarizing film instead of the protective film, and cured to form a polarizing plate.

The polarizing film obtained according to the invention has few disadvantages and excellent in-plane uniformity of polarizing performance, and can be ideally used in portable information terminal, personal computer, television, projector, nameplate, electronic desktop computer. Liquid crystal display devices such as electronic clocks, word processors, measuring instruments for automobiles or machinery, sunglasses, anti-glare glasses, stereo glasses, wearable displays, display elements (CRT, LCD, organic EL, electronic paper, etc.) Use reflection reduction layers, optical communication equipment, medical equipment, building materials, toys, etc. [Examples]

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to the following examples as long as the invention is not exceeded.

<Measurement conditions> (1) Optical unevenness of polyvinyl alcohol-based film A test piece of a polyvinyl alcohol-based film having a length of 30 cm × a width of 30 cm was cut at a 45-degree angle in a crossed nicol state. Between the two polarizing plates (having a single transmittance of 43.5% and a degree of polarization of 99.9%), optical unevenness was observed in a transmission mode using a light box having a surface illuminance of 14,000 lx in a dark room, and evaluated according to the following criteria. ○・・・No shading was observed in the surface. ×・・・ I confirm the shading on the whole surface.

(2) Polarization degree (%) of the polarizing film, and monomer transmittance (%) The center piece of the longitudinal direction of the polarizing film was taken as the center, and the test piece of the length of 4 cm and the width of 4 cm was cut out by 3 points in the longitudinal direction. And cut out 3 points in the width direction, and cut out 9 points in total, and measured the degree of polarization and the transmittance of the monomer using an automatic polarizing film measuring device (manufactured by JASCO Corporation: VAP-7070), and took the average value as a polarizing film. Polarization and monomer transmittance.

(3) The color spot of the polarizing film was cut out from the obtained polarizing film by a test piece having a length of 30 cm × a width of 13 cm, and two polarizing plates were sandwiched in a crossed Nicols at a 45-degree angle (single transmittance 43.5%, Between 99.9% of the degree of polarization, the stain was observed in a transmission mode using a light box having a surface illuminance of 14,000 lx in a dark room, and evaluated according to the following criteria. ○・・・No color spots △・・・Invisible color spots ×・・・Color spots

<Example 1> (Production of film roll) 1,000 kg of a polyvinyl alcohol-based resin having a weight average molecular weight of 142,000 and a saponification degree of 99.8 mol%, 2,500 kg of water, and 100 kg of glycerin as a plasticizer were added, and the temperature was raised while stirring. At 140 ° C, the concentration was adjusted to a resin concentration of 25% to obtain a polyvinyl alcohol-based resin aqueous solution which was uniformly dissolved. Then, the polyvinyl alcohol-based resin aqueous solution was supplied to a biaxial extruder for defoaming, and then the aqueous solution temperature was 95° C., and the casting drum was discharged from the T-slot die discharge port and cast to a surface temperature of 90° C. and was carried out. Film making. Then, the obtained film was dried by a plurality of metal heating rolls, heat-treated using a floating dryer, and cut into a width of 4 m. Finally, it was taken up in an aluminum core tube having an outer diameter of 17 cm, an inner diameter of 16 cm, and a length of 4.4 m, and a strip-shaped polyvinyl alcohol-based film having a water content of 4% by weight (width: 4 m, length: 5 km, thickness: 40 μm) was wound. A film reel made of a core tube. A test piece of a polyvinyl alcohol-based film was cut out from the front end of the obtained film roll, and optical unevenness was observed. The results are shown in Table 1.

(Manufacturing of package) First, two disk-shaped polystyrene foams (diameter 18 cm in diameter) having a diameter of 60 cm and a thickness of 4 mm were prepared as a protective pad at the end of the protective pad at the end of the film roll. In the face-to-face cooperation, "Bellsunny F" (60 cm in diameter, 0.8 mm in thickness, and 18 cm in diameter of the through hole) made by Teijin Co., Ltd., the protective pad was placed through the core tube and attached to both ends of the film roll. . The humidity-conditioning sheet had a moisture absorption rate of 100% by weight at 30 ° C and 90% RH. Then, a laminated film of an aluminum vapor-deposited polyester film (a polyethylene vapor-deposited polyethylene terephthalate film of 50 nm, 12 μm thick) and a polyethylene film (25 μm thick) was prepared as a water vapor barrier film, and The polyethylene side of the package is attached with a humidity indicator ("WATCH LOGGER KT-275", manufactured by Fujita Electric Manufacturing Co., Ltd.). Finally, the water vapor barrier film is double-wound on the obtained film roll in an environment of 23 ° C and 50% RH, and the remaining portion of the axial direction side of the core tube is taped around the core tube, and The film roll is sealed to obtain a package.

(storage) The protruding portion of the core tube protruding from the film roll is placed on the gantry, so that the obtained package body is suspended from the ground, and is stored at 60 ° C, 90% RH for 10 days, and then at 10 ° C, 10%. RH was stored for 10 days and then stored at 25 ° C, 50% RH for 10 days. Unpack the preserved package and confirm the humidity history of the internal space of the package with a humidity indicator. The minimum humidity is 40% RH and the highest humidity is 60% RH. The film roll after storage did not undergo a winding deviation. Further, a film of 20 m was taken out from the film roll, and deformation and optical unevenness of the film were observed, and it was not confirmed that it was different from that before storage.

(Production of Polarizing Film) A test piece of a polyvinyl alcohol-based film having a width (TD direction) of 30 cm × a length (MD direction) of 30 cm was cut out from the front end portion of the film roll (the portion from the film end portion of 20 m), and impregnated. At a water temperature of 25 ° C sink and extended to 1.7 times. Then, it was immersed in an aqueous solution of 28 ° C composed of iodine 0.5 g / L and potassium iodide 30 g / L, and was extended to 1.6 times while dyeing, and continuously immersed in an aqueous solution of boric acid 40 g / L and potassium iodide 30 g / L (55 ° C ), uniaxially extended to 2.1 times and subjected to boric acid treatment. Thereafter, the solution was washed with an aqueous solution of potassium iodide, and dried to obtain a polarizing film having a total stretching ratio of 5.8. The polarizing characteristics of the obtained polarizing film are shown in Table 2.

<Example 2> A laminate in which a moisture absorbing film was laminated (NS-APP, manufactured by Nissin Seal Industry Co., Ltd.) was used as a water vapor barrier film, and a package was produced in the same manner as in Example 1 except that a humidity control sheet was not used. Manufacturing, storage, and manufacturing of polarizing films. The results are shown in Tables 1 and 2.

<Example 3> A laminated film of an aluminum vapor-deposited polyester film (a polyethylene-evaporated polyethylene terephthalate film of 50 nm, 12 μm thick) and a polyethylene film (25 μm thick) was prepared as a water vapor barrier film. The humidity indicator ("WATCH LOGGER KT-275", manufactured by Fujita Electric Co., Ltd.) is attached to the polyethylene side of the inside of the package. Then, the water vapor barrier film was double-wound around the film roll of Example 1 under an environment of 23 ° C and 50% RH, and the polyethylene film was made inside. The axial end side end portion of the core tube of the water vapor barrier film is fixed to the outer periphery of the end portion of the core tube projecting portion (0.2 m at both ends) by a rubber band, and the water vapor is further blocked by enclosing the end portion of the core tube. The remainder of the membrane is folded into the interior of the core tube. Further, the length of the water vapor barrier film portion folded in from the one-side end portion of the core tube was 0.4 m. Finally, two cylindrical polyvinyl alcohol sponges (PVA sponges made by AION Co., Ltd.) having an outer diameter of 16 cm, an inner diameter of 10 cm, and a length of 0.5 m as the water absorbing material were respectively inserted into the inside of the core tube from both ends of the core tube to make the end face of the water absorbing material. Align with the end of the core tube to obtain the package. The weight of one of the water absorbing materials was 1.4 kg. The obtained package was stored in the same manner as in Example 1 and the polarizing film was produced. The results are shown in Tables 1 and 2.

<Example 4> The same procedure as in Example 3 was carried out except that a cylindrical urethane sponge (polyurethane sponge manufactured by AION Co., Ltd.) having an outer diameter of 16 cm, an inner diameter of 10 cm, and a length of 0.5 m was used as the water absorbing material. Manufacturing, storage, and production of polarizing film. The weight of one of the water absorbing materials was 1.3 kg. The results are shown in Tables 1 and 2.

<Comparative Example 1> The production, storage, and production of a polarizing film of the package were carried out in the same manner as in Example 3 except that the water absorbing material was not used. The results are shown in Tables 1 and 2.

[Table 1]

[Table 2]

From the results of Examples 1 to 4, it is understood that the polyvinyl alcohol-based film stored in the package of the present invention has a humidity of 20 to 80% RH in the internal space in which the film roll is disposed during storage, so the storage process It is not easy to be deformed in the middle, and the optical unevenness is also the same as the initial one after storage. Moreover, the polarizing film obtained by the packaging system of the present invention is suppressed in deformation and optical performance of the polyvinyl alcohol-based film used for production, so that the degree of polarization and the transmittance of the monomer are high, and color unevenness is less likely to occur. [Industrial use]

The polarizing film obtained by the packaging system of the invention has excellent polarizing performance and can be ideally used in a portable information terminal, a personal computer, a television, a projector, a signboard, an electronic desktop computer, an electronic clock, a word processor, Liquid crystal display devices such as electronic paper, game machines, cameras, cameras, photo albums, thermometers, stereos, automobile or mechanical measuring instruments, sunglasses, anti-glare glasses, stereo glasses, wearable displays, display elements (CRT, LCD, organic EL, electronic paper, etc.) use reflection reduction layer, optical communication equipment, medical equipment, building materials, toys, and the like.

11, 21, 101‧‧‧ package
2‧‧‧ core tube
3‧‧‧ film reel
4‧‧‧Water vapor barrier film
5‧‧‧Adhesive tape
6‧‧‧Water absorption material
7‧‧‧Protection mat
8‧‧‧Wetting tablets

Fig. 1 is a schematic cross-sectional view showing a part of a package 11 according to a first embodiment of the present invention in an enlarged manner. 2(a) to 2(c) are perspective views showing a packaging step of the film roll 3 in the package 11. Fig. 3 is a schematic cross-sectional view showing a part of a package 21 according to a second embodiment of the present invention in an enlarged manner. 4(a) to 4(c) are perspective views showing a packaging step of the film roll 3 in the package 21. [ Fig. 5] Fig. 5 is a schematic cross-sectional view showing a part of the package 101 when the water absorbing material 6 of the second embodiment is not disposed.

11‧‧‧Package

2‧‧‧ core tube

3‧‧‧ film reel

4‧‧‧Water vapor barrier film

7‧‧‧Protection mat

8‧‧‧Wetting tablets

Claims (12)

The invention relates to a package film obtained by winding a strip-shaped polyvinyl alcohol-based film on a core tube and packaging the film roll with a water vapor barrier film; the characteristic is: the humidity of the inner space of the package is adjusted to 20~ 80% RH. The package of claim 1, wherein the film roll is packaged with a humidity control sheet. The package according to claim 2, wherein the humidity-conditioning sheet is a non-woven fabric having a thickness of 0.1 to 2 mm. The package according to claim 2 or 3, wherein the humidity-conditioning sheet has a moisture absorption rate of 50% by weight or more at 30 ° C and 90% RH. The package according to claim 1, wherein the core tube has a longer axial length than the film width, and the end portion of the water vapor barrier film on the axial direction side of the core tube is folded into the film. The inside of the core tube protruding from the reel is wound to wrap the end of the core tube; further, a water absorbing material is disposed inside the core tube. A package according to any one of claims 1 to 3, wherein a humidity indicator is packaged with the film roll. The package according to any one of claims 1 to 3, wherein the polyvinyl alcohol-based film has a width of 4 m or more and a length of 4 km or more. The package according to any one of claims 1 to 3, wherein the polyvinyl alcohol-based film has a thickness of 5 to 40 μm. The package according to any one of claims 1 to 3, wherein the polyvinyl alcohol-based film is a polyvinyl alcohol-based film for a polarizing film. A method of preserving or transporting a polyvinyl alcohol-based film by using the package according to any one of claims 1 to 9 for storage and/or transport of the polyvinyl alcohol-based film. A polyvinyl alcohol-based film which is stored and/or transported using a package according to any one of claims 1 to 9. A polarizing film obtained by using a polyvinyl alcohol-based film as in claim 11 of the patent application.