Film roll package, method for manufacturing same, and method for storing or transporting film roll

Abstract

Provided is an excellent film roll package which is capable of suppressing damage to a film roll during storage and transport and of suppressing adhesion of dust, chips, and the like. A film roll package is provided with: a film roll (13) obtained by winding a polyvinyl alcohol film (11) around a core tube (12); a packaging material (14) for packaging the film roll (13); and protective pads (16) disposed on both end surfaces of the film roll (13). Furthermore, the packaging material (14) is composed of a film containing an aluminum raw material, and the protective pad (16) has a base material (17) containing a foamed member, and a non-foamed resin layer (18) provided at least on the surface on the end surface side of the film roll.

Description

Technical Field

[0001] The present invention relates to a film roll package obtained by winding a polyvinyl alcohol-based film around a core tube, a method for manufacturing the same, and a method for storing or transporting the film roll. Background Art

[0002] Conventionally, a polyvinyl alcohol-based film has been manufactured as follows: a polyvinyl alcohol-based resin is dissolved in a solvent, defoamed to prepare a stock solution, and then a film is formed by a solution casting method (casting method), and the film is dried using a metal heating roll or the like. The polyvinyl alcohol-based film obtained by such an operation is used for many applications as a film having excellent shape stability, and one of its useful applications is an optical film, particularly a polarizing film.

[0003] The polarizing film is a film obtained by uniaxially stretching and dyeing the above-mentioned polyvinyl alcohol-based film, and is used as a basic component of a liquid crystal display. In recent years, there has been a need for high-quality and highly reliable devices, particularly for applications such as large-sized liquid crystal displays, and there has been a strong need to improve the quality such as enlargement and in-plane uniformity of required physical properties accompanying this.

[0004] In order to meet the improvement requirements for the polarizing film, it is also necessary to improve the physical properties of the polyvinyl alcohol-based film itself as a blank, but most of the physical properties and optical properties are greatly affected by the deformation of the film roll, the generation of wrinkles, and the adhesion of dust and dirt during the storage and transportation of the polyvinyl alcohol-based film.

[0005] Therefore, when storing or transporting a polyvinyl alcohol-based film, the film is usually wound around a core tube to form a film roll, and the film roll is processed in a state of being packaged with a packaging film.

[0006] For example, it has been proposed to package a film roll obtained by winding a polyvinyl alcohol film around a core tube longer than the film width with a water vapor barrier resin packaging film, and package it from above with a packaging film made of an aluminum raw material, thereby preventing winding deviation of the film roll during storage or transportation, damage to the film, and deterioration of the film due to adhesion, and obtaining a polarizing film with less deviation in optical performance from the winding outer peripheral portion to the winding core portion of the film roll (see Patent Document 1).

[0007] In addition, as Figure 3As shown, it is proposed that: in order to buffer impacts, after installing protective pads 3 made of foamed members having core tube through-holes at both ends of a film roll formed by winding a polyvinyl alcohol film 2 around a core tube 1, the film roll is packaged with a packaging film, and further, second protective pads are installed at both ends of the film roll from above, thereby preventing damage to the film roll during storage and transportation, and even when using the film roll in a clean room, damage to the film roll can be suppressed, and breakage during uniaxial stretching of the polyvinyl alcohol film 2 can be reduced (see Patent Document 2).

[0008] Prior Art Documents

[0009] Patent Documents

[0010] Patent Document 1: Japanese Patent Application Laid-Open No. 2005-306483

[0011] Patent Document 2: International Publication No. 2013 / 103074 Summary of the Invention

[0012] Problems to be Solved by the Invention

[0013] According to such a conventional packaging form, there is a certain degree of effect of preventing damage and the occurrence of breakage during stretching can be reduced, but the occurrence of breakage has not been completely suppressed and there is still room for further improvement.

[0014] In addition, in recent years, the required performance for cleanliness in the manufacture of polarizing films and polarizing plates has been further improved, and the use of polyvinyl alcohol-based films in clean rooms has also increased. At this time, when bringing a polyvinyl alcohol-based film into a clean room, it is necessary to suppress the attachment of dust, dirt, etc. as much as possible. However, in the conventional packaging form, since it is impossible to sufficiently suppress the dust and dirt generated from the packaged materials, such as foamed members, in the packaging material, and the contamination of each aqueous solution tank during the cleaning, crosslinking, dyeing, stretching, color compensation, etc. in the manufacture of polarizing members using wet stretching processing, there are the following problems: there is a concern that foreign matter may attach to the polarizing film or the polyvinyl alcohol-based film may break during stretching processing, resulting in a decrease in optical properties.

[0015] Furthermore, due to the thinning of liquid crystal displays, there is an increasing expectation for further thinning of polyvinyl alcohol-based films. If the thickness of the polyvinyl alcohol-based film becomes thinner, there are the following problems: breakage may occur even for damage that has not been a problem so far, or the winding length of the film roll for winding the polyvinyl alcohol-based film becomes longer, so that the frequency of foreign matter attachment and breakage each time the film roll is used further increases.

[0016] Solutions to the Problems

[0017] However, the inventors of the present invention conducted in-depth research to solve the above-mentioned problems and found that: in a film roll package in which a polyvinyl alcohol-based film is wound around a core tube, a film containing an aluminum raw material is disposed, and protective pads are disposed on both end faces of the film roll, by setting the structure of the protective pad to include a base material containing a foaming member and setting the surface on the film roll end face side of the foaming member to a non-foaming resin layer, the above-mentioned problems can be solved.

[0018] That is, the present invention has the following aspects.

[0019] [1] A film roll package, comprising:

[0020] A film roll formed by winding a polyvinyl alcohol-based film around a core tube,

[0021] A packaging material for packaging the film roll, and

[0022] Protective pads disposed on both end faces of the film roll,

[0023] The packaging material is at least composed of a film containing an aluminum raw material,

[0024] The protective pad has: a base material containing a foaming member, and a non-foaming resin layer provided on at least the surface on the film roll end face side of the base material.

[0025] [2] The film roll package according to [1], wherein the film containing an aluminum raw material is a laminated film of a polyolefin film and an aluminum foil.

[0026] [3] The film roll package according to [1] or [2], wherein the film containing an aluminum raw material is a laminated film having at least a laminated structure of a polyethylene film / aluminum foil / polyethylene film.

[0027] [4] The film roll package according to any one of [1] to [3], further comprising a second packaging material made of a water vapor barrier film.

[0028] [5] The film roll package according to any one of [1] to [4], wherein the base material containing a foaming member is made of a foamed polyethylene-based resin.

[0029] [6] The film roll package according to any one of [1] to [5], wherein the thickness of the non-foaming resin layer is 5 μm or more.

[0030] [7] The film roll package according to any one of [1] to [6], wherein the thickness of the non-foaming resin layer is 500 μm or less.

[0031] [8] A method for manufacturing a thin film roll package, which is the method for manufacturing the thin film roll package according to any one of [1] to [7], comprising:

[0032] A step of installing protective pads on both end faces of the thin film roll, and

[0033] A step of packaging the thin film roll with the protective pads installed using a packaging material composed of a thin film containing an aluminum raw material.

[0034] [9] A method for storing or transporting a thin film roll, which stores or transports the thin film roll in the form of the thin film roll package according to any one of [1] to [7].

[0035] Effects of the Invention

[0036] The thin film roll package of the present invention includes: a thin film roll formed by winding a polyvinyl alcohol-based thin film around a core tube, a packaging material composed of a thin film containing an aluminum raw material, and protective pads disposed on both end faces of the aforementioned thin film roll. The aforementioned protective pads have a base material containing a foaming member and a non-foaming resin layer provided on the surface of the foaming member on the end face side of the thin film roll. Therefore, it is possible to sufficiently prevent damage to the thin film roll during storage and transportation, and when using the thin film roll in a clean room, it is possible to suppress dust and dirt adhering to the thin film roll, and further suppress chips generated from the packaging material.

[0037] In addition, according to the method for manufacturing the thin film roll package of the present invention, the aforementioned thin film roll package can be efficiently manufactured.

[0038] Moreover, according to the method for storing or transporting the thin film roll of the present invention, it is possible to store and transport the thin film roll in a good state without damage or contamination. Description of the Drawings

[0039] Figure 1 It is a schematic cross-sectional view of a thin film roll package according to an embodiment of the present invention.

[0040] Figure 2 (a) is a schematic cross-sectional view of the protective pad used in the aforementioned embodiment, and (b) is a schematic cross-sectional view of a modified example thereof.

[0041] Figure 3 It is an explanatory diagram showing an example of the packaging form of a conventional thin film roll. Detailed Embodiments

[0042] Hereinafter, the present invention will be described in detail based on the embodiments of the present invention, but the present invention is not limited to the following embodiments.

[0043] It should be noted that in the present invention, when expressed as "X to Y" (X and Y are arbitrary numbers), unless otherwise specified, it includes the meaning of "X or more and Y or less", as well as the meaning of "preferably greater than X" or "preferably less than Y".

[0044] In addition, when expressed as "X or more" (X is an arbitrary number) or "Y or less" (Y is an arbitrary number), it also includes the meaning of "preferably greater than X" or "preferably less than Y".

[0045] Moreover, "X and / or Y (X and Y are arbitrary components)" means at least one of X and Y, that is, it means the following three cases: only X, only Y, and X and Y.

[0046] The film roll package of the present invention mainly relates to a film roll package used in the process before manufacturing a polarizing film and a polarizing plate, and it exerts an effect during the storage and transmission of the film roll package.

[0047] As shown in the Figure 1 schematic cross-sectional view of one of its embodiments, the aforementioned film roll package includes: a film roll 13 formed by winding a polyvinyl alcohol-based film 11 before stretching processing or the like for use in a polarizing film or the like around a core tube 12, a packaging material 14 composed of at least a film containing an aluminum raw material, a second packaging material 15 composed of a water vapor barrier film, and protective pads 16 disposed on both end faces of the aforementioned film roll 13. It should be noted that Figure 1 in, the component member represented by the symbol 20 is a fixing member (such as a rubber band) for fixing the aforementioned second packaging material 15 to the core tube 12.

[0048] Hereinafter, each component member of the aforementioned film roll package will be described.

[0049] <Film roll 13>

[0050] First, the polyvinyl alcohol-based film 11 constituting the film roll 13 and the core tube 12 around which it is wound will be described.

[0051] (1) Polyvinyl alcohol-based film 11

[0052] First, the polyvinyl alcohol-based film 11 used in the present embodiment will be described.

[0053] The polyvinyl alcohol-based resin used in the manufacture of the aforementioned polyvinyl alcohol-based film 11 is usually obtained by saponifying polyvinyl acetate obtained by polymerizing vinyl acetate, but it is not limited thereto, and it may also be a modified polyvinyl alcohol-based resin containing a small amount of unsaturated carboxylic acids (including salts, esters, amides, nitriles, etc.), olefins having 2 to 30 carbon atoms (ethylene, propylene, n-butene, isobutene, etc.), vinyl ethers, unsaturated sulfonates, and other components that can copolymerize with vinyl acetate.

[0054] In addition, besides this modification, it may also be a polyvinyl alcohol-based resin containing a silyl group. Examples thereof also include methods such as subjecting polyvinyl alcohol to post-modification using a silylating agent, and saponifying a copolymer obtained by copolymerizing an ethylenically unsaturated monomer containing a silyl group and vinyl acetate. Examples of the ethylenically unsaturated monomer containing a silyl group include vinyl silane, (meth)acrylamide-alkyl silane, etc.

[0055] The weight-average molecular weight of the polyvinyl alcohol-based resin is not particularly limited, and is preferably set to 60,000 to 300,000, more preferably set to 100,000 to 260,000. If the weight-average molecular weight is less than 60,000, sufficient optical properties as an optical film cannot be obtained. If it exceeds 300,000, stretching becomes difficult, and industrial production is difficult and not preferred. It should be noted that the weight-average molecular weight is measured by the GPC-MALS method.

[0056] Furthermore, the saponification degree of the polyvinyl alcohol-based resin is preferably 80 mol% or more, more preferably 85 to 100 mol%, and further preferably 98 to 100 mol%. By setting the saponification degree as described above, sufficient optical properties as an optical film can be obtained. It should be noted that the aforementioned saponification degree is measured according to JIS K 6726:1994 method.

[0057] In the aforementioned polyvinyl alcohol-based resin, if necessary, per 100 parts by mass of the polyvinyl alcohol-based resin, it is preferably to contain 1 kind or 2 or more kinds of commonly used plasticizers such as glycerol, diglycerol, triglycerol, ethylene glycol, triethylene glycol, polyethylene glycol, etc. in an amount of 30 parts by mass or less, more preferably to contain 3 to 25 parts by mass, and further preferably to contain 5 to 20 parts by mass. By setting the content of the plasticizer within the aforementioned range, a decrease in film strength can be suppressed.

[0058] In addition, in order to improve the peelability of the film, per 100 parts by mass of the polyvinyl alcohol-based resin, it is preferably to contain 1 kind or 2 or more kinds of various peeling agents in an amount of 5 parts by mass or less, more preferably to contain 0.001 to 3 parts by mass, and further preferably to contain 0.001 to 2 parts by mass. By setting the peeling agent within the aforementioned range, appearance defects on the film surface can be suppressed, and adhesion between films can be suppressed.

[0059] Using the aforementioned polyvinyl alcohol-based resin to prepare an aqueous solution of the polyvinyl alcohol-based resin, and casting this aqueous solution onto a drum-shaped roller using a T-shaped slot die head, followed by film formation and drying, the polyvinyl alcohol-based film 11 used in the present embodiment can thus be obtained.

[0060] It should be noted that when preparing the aforementioned aqueous solution of polyvinyl alcohol resin, water, dimethyl sulfoxide (DMSO), N-methylpyrrolidone, glycerin, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyhydric alcohols such as trimethylolpropane, amines such as ethylenediamine and diethylenetriamine, and mixtures thereof are used as solvents. It is practical to set the concentration of the polyvinyl alcohol resin in the aqueous solution of polyvinyl alcohol resin to 5 to 50% by mass.

[0061] Then, the aforementioned aqueous solution of polyvinyl alcohol resin is cast onto a drum roll using a T-slot die and film is formed at a temperature of about 80 to 100 °C.

[0062] The material of the drum roll is not particularly limited, and stainless steel is usually suitably used. In order to prevent damage, it is preferably metal-plated on the surface of the roll. As the type of metal plating, for example, chromium plating, nickel plating, zinc plating, etc. can be suitably used, and they can be used alone or in the form of a multi-layer combination of two or more. Particularly from the viewpoints of ease of surface smoothing and its durability, chromium plating is preferably applied to the outermost surface, and the surface roughness (according to JIS B 0031:1994 method) is preferably 3S or less, more preferably 0.5S or less. The lower limit value is usually 0S.

[0063] The heating method of the aforementioned drum roll can adopt steam, heat medium, warm water, electric heater, etc. In addition, an auxiliary device for blowing hot air, cold air, etc. or sucking the air and steam around the device can also be used. The diameter of the drum roll is suitably 2,000 to 5,000 mm, and the width is suitably 2 to 8 m. The film will peel off from the drum roll when the moisture content of the film reaches 5 to 30% by mass.

[0064] Then, after peeling the film obtained by casting and forming from the drum roll, the aforementioned film is passed between a plurality of drying metal rolls, preferably in such a way that the front and back surfaces of the film alternately pass along the circumferential surface of the roll, to dry it. A plurality of drying metal rolls are used, preferably 3 to 30, and particularly preferably 3 to 26.

[0065] The material of the aforementioned drying metal roll is not particularly limited in the same way as the drum roll. From the viewpoints of ease of surface smoothing and its durability, chromium plating is preferably applied to the outermost surface and the surface roughness is 3S or less, more preferably 0.5S or less. The lower limit value is usually 0S. Moreover, the diameter of the aforementioned drying metal roll is suitably 100 to 1,000 mm, and the width is suitably 2 to 8 m. The temperature of the aforementioned drying metal roll is practically 50 to 150 °C, and a temperature gradient and a rotational speed difference can also be appropriately applied between the rolls.

[0066] The heating method of the aforementioned metal roll for drying can also adopt steam, heat medium, warm water, electric heater, etc. in the same way as the drum roll. In addition, an auxiliary device for blowing hot air, cold air, etc. or sucking the air and steam around the suction device can also be provided.

[0067] When manufacturing a film, if the wetting tension on the surface of the aforementioned drum roll and / or the metal roll for drying is adjusted to 25 to 50 mN / m, the film can be manufactured with good productivity. The wetting tension is measured according to JIS K 6768:1999 method. The method for setting the wetting tension within the aforementioned range is not particularly limited. (A) A roll with a chromium surface treated with a mirror finish can be used, and the surface can be treated with an acid aqueous solution with a pH of 1 to 3 (measured at 20 °C, the same hereinafter). As the acid aqueous solution with a pH of 1 to 3, aqueous solutions of acetic acid, sulfuric acid, hydrochloric acid, nitric acid, etc. can be cited, and aqueous solutions of acetic acid and nitric acid are particularly preferred. Acid aqueous solutions with a pH outside the aforementioned range are not likely to obtain the wetting tension within the aforementioned range.

[0068] In addition, in addition to treating the roll surface with an acid aqueous solution as in the aforementioned (A), as a method for adjusting the wetting tension, it is also possible to (B) add a surfactant to the aqueous solution of the polyvinyl alcohol-based resin in advance under the condition that the wetting tension on the roll surface becomes within the aforementioned range, cast the aqueous solution onto the drum roll to form a film and / or dry the obtained film with the metal roll for drying. From the viewpoint of further improving the long-term film-forming property in addition to the uniformity of the film thickness and the appearance characteristics of the film, it is preferable to adjust the wetting tension in this way.

[0069] There is no particular limitation on the addition amount of the aforementioned surfactant. Relative to 100 parts by mass of the polyvinyl alcohol-based resin, it is preferably set to 0.001 to 5 parts by mass, more preferably set to 0.01 to 2 parts by mass, and further preferably set to 0.01 to 1 part by mass. By setting the addition amount within the aforementioned range, problems such as difficulty in adjusting the wetting tension or adhesion of the film can be suppressed.

[0070] As the aforementioned surfactant, the following can be cited: carboxylate types such as fatty acid soaps, N-acyl amino acids and their salts, polyoxyethylene alkyl ester carboxylates, and acylated peptides; sulfonate types such as alkylbenzene sulfonates, alkylnaphthalene sulfonates, formaldehyde condensate salts of naphthalene sulfonic acid, formaldehyde condensate salts of melamine sulfonic acid, dialkyl sulfosuccinate salts, alkyl disulfosuccinate salts, polyoxyethylene alkyl sulfosuccinate disalts, alkyl sulfonacetates, α-olefin sulfonates, N-acyl methyl taurate salts, and sodium salt of dimethyl isophthalate-5-sulfonate; sulfate ester type salts such as sulfated oils, higher alkyl sulfate esters, polyoxyethylene alkyl ether sulfates, higher alcohol ethoxysulfates, polyoxyethylene alkyl phenyl ether sulfates, and monoglyceride sulfates; phosphate ester type salts such as polyoxyethylene alkyl ether phosphates, polyoxyethylene alkyl phenyl ether phosphates, and alkyl phosphates, etc. anion surfactants.

[0071] In addition, as the aforementioned surfactant, the following can also be used: polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, ethylene oxide derivatives of alkylphenol formaldehyde condensates, polyoxyethylene-polyoxypropylene block polymers, polyoxyethylene glycerol fatty acid esters, polyoxyethylene castor oil and hydrogenated castor oil, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitol fatty acid esters and other ether ester type nonionic surfactants, polyethylene glycol fatty acid esters, sorbitan fatty acid esters, fatty acid monoglycerides, propylene glycol fatty acid esters, sucrose fatty acid esters and other ester type surfactants, higher fatty acid alkanolamides, higher fatty acid amides, polyoxyethylene alkylamines and other nitrogen-containing nonionic surfactants. One of them can be used or two or more of them can be used in combination. When implementing the method of the present invention, of course, the aforementioned methods (A) and (B) can be used in combination for film formation.

[0072] Then, after forming an unstretched polyvinyl alcohol-based film by drying, if necessary, heat treatment and humidity adjustment are further performed. In this way, the polyvinyl alcohol-based film 11 used in this embodiment can be obtained.

[0073] By winding the obtained polyvinyl alcohol-based film 11 around a core tube 12 described later, the film roll 13 in this embodiment can be obtained.

[0074] The width of the aforementioned polyvinyl alcohol-based film 11 is preferably set to 1 m or more, more preferably set to 2 m or more, further preferably set to 3 m or more, and particularly preferably set to 4 m or more. In addition, it is preferably 7 m or less, more preferably 6 m or less. By setting the width of the polyvinyl alcohol-based film 11 within the aforementioned range, during uniaxial stretching in the manufacture of optical films such as polarizing films, the influence of film shrinkage is likely to reach the central part of the film, and a good optical film can be obtained.

[0075] In addition, if the length of the aforementioned polyvinyl alcohol-based film 11 is 4,000 m or more, the effects of the present invention can be significantly obtained. It should be noted that if the length is less than 1,000 m, there will be more joints in the obtained polarizing film and the loss will increase. In addition, the thickness of the aforementioned polyvinyl alcohol-based film 11 is practically 10 to 100 μm, preferably 10 to 70 μm, more preferably 10 to 50 μm, and further preferably 10 to 40 μm. By setting the thickness within the aforementioned range, it is possible to suppress the difficulty of stretching at high magnification.

[0076] (2) Regarding the core tube 12

[0077] The core tube 12 around which the aforementioned polyvinyl alcohol-based film 11 is wound is cylindrical, and any material such as metal, plastic, paper, etc. can be used as its material. As metals, examples include: carbon steel, high-tensile steel, stainless steel, aluminum, aluminum alloys such as duralumin, copper, brass, bronze, etc. For such a metal core tube 12, soft polyvinyl chloride or low-density polyethylene can also be laminated or subjected to plating treatment using nickel, chromium, zinc, tin, etc. In addition, as plastics, examples include: rigid polyvinyl chloride, polypropylene, high-density polyethylene, ultra-high molecular weight polyethylene, polycarbonate, polyester, fiber-reinforced plastic, carbon fiber-reinforced plastic, aramid fiber-reinforced plastic, etc.

[0078] The outer diameter of the aforementioned core tube 12 is preferably 7.5 cm or more, more preferably 8.5 cm or more. By setting the outer diameter of the core tube 12 as described above, wrinkles generated in the film can be suppressed. The length of the core tube 12 needs to be longer than the width of the polyvinyl alcohol-based film 11, and it is preferably set to protrude 1 to 50 cm from the end of the film roll 13.

[0079] Brackets are provided at both ends of the protruding portion or both ends of the protruding portion are placed on a bracket or the like, so that the film roll 13 is in a state of floating in the air without contacting the ground or other film rolls, etc., thereby preventing the load of the film roll 13 from being applied to the wound polyvinyl alcohol-based film 11, and adhesion and deterioration between the polyvinyl alcohol-based films 11 can be suppressed. The wall thickness of the core tube 12 is preferably 1.5 to 20 mm, more preferably 2 to 15 mm, and further preferably 3 to 10 mm.

[0080] <Protective pad 16>

[0081] Regarding the protective pads 16 arranged on both end faces of the film roll 13 formed by winding the aforementioned polyvinyl alcohol-based film 11 around the core tube 12, as shown in (a) of Figure 2 which is a schematic enlarged cross-sectional view thereof, it has a layer structure including a base material 17 containing a foamed member and a non-foamed resin layer 18. Moreover, the aforementioned non-foamed resin layer 18 is provided on the surface of the base material 17 on the side opposite to the end face of the polyvinyl alcohol-based film 11 (i.e., the end face of the film roll 13).

[0082] (1) Regarding the base material 17

[0083] The foamed member constituting the base material 17 used in the aforementioned protective pad 16 is not particularly limited as long as it has a foamed structure, and it can be formed of a foamed plastic with closed cells or a foamed plastic with open cells.

[0084] However, the water content rate in the PVA-based film 11 in the film roll package may be controlled such that it falls within a specified range. If a foamed member made of a foamed plastic with continuous air bubbles is used, the water content rate in the PVA-based film 11 will change due to the water absorption rate of the foamed member. Therefore, in this case, it is preferable to use a foamed plastic with independent air bubbles as the foamed member.

[0085] The material of the aforementioned foamed member is not particularly limited, and a foamed member formed of a foamed plastic resin such as a foamed polyethylene-based resin, a foamed polystyrene-based resin, a foamed polyurethane-based resin, or a foamed polyvinyl chloride-based resin can be used. However, if a foamed member made of a material with a high water absorption rate as described above is used, from the perspective that it becomes difficult to suppress the change in the water content rate in the PVA-based film 11 in the package, when such suppression is required, it is preferable to use a foamed member formed of a foamed polyethylene-based resin that can easily suppress the water absorption rate to a low level.

[0086] Furthermore, the water absorption rate of the aforementioned foamed member is preferably 0.05 g / cm 2 Hereinafter, it is more preferably 0.03 g / cm 2 Hereinafter, it is further preferably 0.015 g / cm 2 Hereinafter. By setting the water absorption rate within the aforementioned range, it is possible to suppress the occurrence of uneven water content rate in the PVA-based film due to the foamed member absorbing water in the PVA-based film and the occurrence of breakage during uniaxial stretching of the PVA-based film. In addition, the lower limit of the water absorption rate is not particularly limited, but there is a tendency that the lower the water absorption rate, the harder it becomes and the buffering function decreases. Therefore, the water absorption rate is preferably 0.0002 g / cm 2 or more. It should be noted that the water absorption rate in this specification refers to the water absorption rate obtained by the measurement method described in JIS A9511:2006R, Method A.

[0087] The thickness of the aforementioned foamed member is preferably 3 mm or more, more preferably 7 mm or more, and further preferably 9 mm or more. By setting the thickness within the aforementioned range, it is possible to more effectively prevent damage to the end face of the film roll. The upper limit of the thickness of the foamed member is not particularly limited, and from the perspective of handleability, the thickness is preferably 30 mm or less, more preferably 25 mm or less, and further preferably set to 20 mm or less. It should be noted that when it is difficult to ensure that a single foamed member has the aforementioned thickness, multiple foamed members can be overlapped to ensure the aforementioned thickness in terms of the total thickness.

[0088] The 25% compression stress of the aforementioned foamed member is not particularly limited, preferably 5 kPa or more, more preferably 7 kPa or more, and further preferably 10 kPa or more. In addition, it is preferably less than 50 kPa, more preferably 47 kPa or less, further preferably 45 kPa or less, and particularly preferably 42 kPa or less. By setting the 25% compression stress of the foamed member within the aforementioned range, damage to the end face of the film roll can be more effectively suppressed.

[0089] It should be noted that the 25% compression stress of the aforementioned foamed member can be measured according to the JIS K 7220:2006 method.

[0090] (2) Regarding the non-foamed resin layer 18

[0091] On the other hand, the material of the non-foamed resin layer 18 used in the protective pad 16 is not particularly limited, and ordinary resins can be used, such as polyethylene resins, polypropylene resins, polyvinyl chloride resins, polycarbonate resins, polyester resins, acrylic resins, polyvinyl alcohol resins, polyacrylamide resins, polyamide resins, fluorine resins, etc. Among them, from the viewpoints of excellent strength and flexibility, a polyolefin resin is preferably used, and a polyethylene resin is more preferably used.

[0092] The thickness of the aforementioned non-foamed resin layer 18 is preferably 5 μm or more, more preferably 8 μm or more, and further preferably 12 μm or more. By setting the thickness of the non-foamed resin layer 18 as described above, it is possible to suppress the transfer of the surface shape of the foamed member used in the aforementioned base material 17 and generate fine irregularities on the surface of the non-foamed resin layer 18, and it is possible to suppress dust, chips, etc. adhering to the irregularities. Furthermore, it is also possible to suppress the generation of chips due to friction with the end face of the film roll.

[0093] In addition, the thickness of the aforementioned non-foamed resin layer 18 is preferably 500 μm or less, more preferably 300 μm or less, further preferably 100 μm or less, still more preferably 80 μm or less, particularly preferably 60 μm or less, and especially preferably 50 μm or less. By setting the thickness of the non-foamed resin layer 18 as described above, the tensile strength of the non-foamed resin layer 18 can be made appropriate, and it is possible to suppress damage to the end face of the film roll 13, bending of the film near the end face of the wound polyvinyl alcohol-based film 11, and film thickness variation when transmitting external loads, impacts, etc. from the foamed member to the film roll 13.

[0094] The thickness of the aforementioned non-foamed resin layer 18 is measured by observing the cross-section using a microscope, and the average value obtained by measuring the thickness at any 10 locations is set as the thickness value.

[0095] The surface roughness Ra (arithmetic mean roughness, measured by the method of JIS B 0601:1994) of the aforementioned non-foamed resin layer 18 is preferably 0.01 μm or more, more preferably 0.05 μm or more, and further preferably 0.1 μm or more. Additionally, it is preferably 5 μm or less, more preferably 3 μm or less, and further preferably 1 μm or less. By setting the surface roughness Ra of the non-foamed resin layer 18 as described above, the situation where dust, chips, etc. easily adhere to the surface irregularities or attachments and enter between the irregularities and become difficult to remove can be suppressed.

[0096] It should be noted that the measurement conditions for the surface roughness of the present invention are a measurement length of 1 mm, stylus shape: tip radius 2 μm, and cone angle 60 μm.

[0097] The surface roughness Ry (maximum height, measured by the method of JIS B 0601:1994) of the aforementioned non-foamed resin layer 18 is preferably 0.1 μm or more, more preferably 0.5 μm or more, and further preferably 1 μm or more. Additionally, it is preferably 8 μm or less, more preferably 6 μm or less, and further preferably 4 μm or less. By setting the surface roughness Ry of the non-foamed resin layer 18 as described above, the situation where dust, chips, etc. easily adhere to the surface irregularities or attachments and enter between the irregularities and become difficult to remove can be suppressed.

[0098] The surface roughness Rz (ten-point mean roughness, measured by the method of JIS B 0601:1994) of the aforementioned non-foamed resin layer 18 is preferably 0.1 μm or more, more preferably 0.5 μm or more, and further preferably 1 μm or more. Additionally, it is preferably 8 μm or less, more preferably 6 μm or less, and further preferably 4 μm or less. By setting the surface roughness Rz of the non-foamed resin layer 18 as described above, the situation where dust, chips, etc. easily adhere to the surface irregularities or attachments and enter between the irregularities and become difficult to remove can be suppressed.

[0099] The bonding method of the aforementioned non-foamed resin layer 18 and the aforementioned substrate 17 containing a foamed member is not particularly limited, and an appropriate method is adopted according to their materials. For example, the two can be bonded using an adhesive, or the two can be melt-bonded through a heating roller in a state where the foamed sheet as the substrate 17 and the resin sheet as the non-foamed resin layer 18 are overlapped with each other. Additionally, when obtaining the substrate 17 using a foamed sheet, a non-foamed surface layer can also be formed by pressing the surface layer portion of the foamed sheet with a heating roller, and the substrate 17 and the non-foamed resin layer 18 can be integrally formed. By performing such operations, the protective pad 16 can be obtained.

[0100] Regarding the protective pad 16, the abrasion amount measured by the method described in the following embodiments is preferably 15 mg or less, more preferably 12 mg or less, and even more preferably 10 mg or less. By setting the abrasion amount of the protective pad 16 as described above, it is possible to effectively suppress the generation of chips due to friction with the end face of the film roll during storage and transportation.

[0101] It should be noted that for the protective pad 16 in this embodiment, in Figure 2 (a), the non-foamed resin layer 18 is provided only on the surface of the base material 17 on the side opposite to the end face of the film roll 13, but it is not limited thereto. For example, as shown in Figure 2 (b), from the viewpoint of preventing contamination and damage to the film roll 13, it is more preferable to also provide the non-foamed resin layer 18 on the surface of the base material 17 on the side opposite to the end face side of the film roll 13.

[0102] <Packaging material 14>

[0103] The packaging material 14 used in this embodiment is composed of a film containing an aluminum raw material. Examples of such a film include: aluminum foil, a laminated film of aluminum foil and a moisture-resistant plastic film (for example, a laminated film of aluminum foil and polyethylene 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 polyethylene film), a laminated film of an aluminum oxide vapor-deposited film and a moisture-resistant plastic film (for example, a laminated film of an aluminum oxide vapor-deposited polyester film and polyethylene film), etc. In particular, a laminated film of aluminum foil and a polyolefin film, a laminated film of an aluminum vapor-deposited film and a polyolefin film are preferred, and a laminated film formed by the composition of a stretched polypropylene film / polyethylene film / aluminum foil / polyethylene film, a laminated film formed by the composition of a stretched polypropylene film / low-density polyethylene film / aluminum foil, etc. are particularly preferred.

[0104] By using such a packaging film containing an aluminum raw material as the aforementioned packaging material 14, it is possible to suppress the generation of pinholes in the aluminum raw material layer, making it less likely to reduce the water vapor barrier property. And after packaging the film roll 13 at the time of packaging with this packaging material 14, it is possible to seal the film roll in a substantially tubular shape by methods such as heat sealing, and it is possible to more effectively suppress water from seeping into the interior of the film roll package.

[0105] In the above-mentioned packaging material 14, when aluminum foil is used as the above-mentioned aluminum raw material, the thickness of the aluminum foil is preferably set to 30 μm or less, more preferably set to 20 μm or less, further preferably set to 15 μm or less, particularly preferably set to 10 μm or less, and especially preferably set to 8 μm or less. In addition, it is preferably set to 1 μm or more, more preferably set to 3 μm or more, and further preferably set to 5 μm or more. By setting the thickness of the aluminum foil as described above, the generation of pinholes can be suppressed, and furthermore, flexibility can be imparted to the packaging material 14, making it easier to handle the packaging material 14 during packaging and improving the packaging workability. Furthermore, for the load and impact applied from the outside of the film roll package, it releases them with an appropriate strength to exert a buffering effect, so the generation of scratches and damages to the polyvinyl alcohol-based film 11 as the content can be suppressed.

[0106] <Second packaging material 15>

[0107] In this embodiment, the second packaging material 15 used together with the above-mentioned packaging material 14 is composed of a water vapor barrier film. In this example, the above-mentioned second packaging material 15 is disposed on the inner side (film roll 13 side) than the above-mentioned packaging material 14.

[0108] As the water vapor barrier film constituting the above-mentioned second packaging material 15, as long as it has the property of blocking water vapor, there is no particular limitation, and those with a suitable moisture permeability of 10 g / m 2 / day (measured according to JIS Z 0208:1976) or less are suitable. As specific examples, single-layer films such as high-density polyethylene-based resins, low-density polyethylene-based resins, polypropylene-based resins, polyester-based resins, polyvinyl chloride-based resins, glass-evaporated polyester-based resins, or laminated films thereof, or laminated films with rags, paper, non-woven fabrics, etc. can be cited. As the laminated film, a laminated film of glass-evaporated polyester and polyethylene can be cited.

[0109] The thickness of the above-mentioned water vapor barrier film is not particularly limited, and is preferably set to 100 μm or less, more preferably set to 70 μm or less, further preferably set to 50 μm or less, and particularly preferably set to 40 μm or less. In addition, it is preferably set to 5 μm or more, more preferably set to 10 μm or more, and further preferably set to 15 μm or more. By setting the thickness of the water vapor barrier film as described above, water vapor barrier properties can be imparted, and the generation of tearing and the like caused by impact can also be suppressed. Moreover, the flexibility becomes excellent, and the processability during packaging becomes preferable.

[0110] In addition, it is also suitable to perform antistatic treatment on the aforementioned water vapor barrier film. That is, if antistatic treatment is carried out in advance, foreign substances that cause fracture can be prevented from mixing in when the polarizing film is manufactured by stretching the polyvinyl alcohol-based film 11. As a method of antistatic treatment, it can be a method of kneading an antistatic agent in the aforementioned water vapor barrier film or coating the film surface with a film containing an antistatic agent. When kneading, about 0.01 to 5% by mass of the antistatic agent is used relative to the resin, and about 0.01 to 1 g / m 2 of the antistatic agent is used for surface coating. As the antistatic agent, there is no particular limitation as long as it does not have an adverse effect on the optical properties, and for example, alkyl diethanolamine, polyoxyethylene alkylamine, higher fatty acid alkanolamide, sorbitan fatty acid ester, etc. can be used.

[0111] <Film roll package>

[0112] When obtaining the film roll package of the present embodiment using the aforementioned respective constituent members, for example, first, for the film roll 13 formed by winding the polyvinyl alcohol-based film 11 around the core tube 12, protective pads 16 having core tube through holes are respectively installed at both end faces in a state where the non-foaming resin layer 18 faces the end faces of the film roll 13. Then, the film roll 13 is packaged with the second packaging material 15 made of a water vapor barrier film, and the excess ends in the width direction are squeezed along the core tube 12 and tied up with a rubber band 20. Then, the whole is packaged with a packaging material 14 made of a film containing an aluminum raw material (hereinafter, also referred to as an "aluminum-based film"), and the excess ends in the width direction are sealed along the core part 12. In this way, a form arranged in the order of "film roll 13 / protective pad 16 / second packaging material 15 (water vapor barrier film) / packaging material 14 (aluminum-based film) / outside of the package" can be obtained (refer to Figure 1 ).

[0113] It should be noted that the packaging order is not limited to this example, and in addition, for example, the following arrangements can also be cited: from the inside of the package (film roll 13 side) towards the outside of the package.

[0114] · A form arranged in the order of film roll 13 / protective pad 16 / packaging material 14 (aluminum-based film) / second packaging material 15 (water vapor barrier film) / outside of the package

[0115] · A form arranged in the order of film roll 13 / packaging material 14 (aluminum-based film) / protective pad 16 / second packaging material 15 (water vapor barrier film) / outside of the package

[0116] ·The arrangement in the order of the film roll 13 / the packaging material 14 (aluminum-based film) / the second packaging material 15 (water vapor barrier film) / the protective pad 16 / the outside of the package

[0117] ·The arrangement in the order of the film roll 13 / the second packaging material 15 (water vapor barrier film) / the packaging material 14 (aluminum-based film) / the protective pad 16 / the outside of the package

[0118] In addition, in addition to these arrangements, it is also possible to adopt an arrangement in which a second protective pad (which may be the same as the protective pad 16 in the present embodiment or another protective pad with a different structure) is installed on the outermost side of the package.

[0119] Furthermore, in the foregoing embodiment, the packaging material 14 made of an aluminum-based film and the second packaging material 15 made of a water vapor barrier film are used in combination, but it is not necessary to use the foregoing second packaging material 15 (water vapor barrier film). In this case, as the arrangement of the package, the following arrangements can be cited as examples.

[0120] ·The arrangement in the order of the film roll 13 / the protective pad 16 / the packaging material 14 (aluminum-based film) / the outside of the package

[0121] ·The arrangement in the order of the film roll 13 / the packaging material 14 (aluminum-based film) / the protective pad 16 / the outside of the package

[0122] ·Among these arrangements, an arrangement in which the aforementioned second protective pad is further installed on the outside thereof

[0123] It should be noted that in each of the foregoing arrangements, the packaging material 14 (aluminum-based film), the second packaging material 15 (water vapor barrier film), and the protective pad 16 may each have a multilayer structure. For example, " / the packaging material 14 (aluminum-based film) / " means that it can be any one of a single layer of a single packaging material 14 (aluminum-based film), a single packaging material 14 with two or more layers, or two or more packaging materials 14 each having one or two or more layers.

[0124] Moreover, among these specific ways of the film roll package, particularly from the viewpoints of ease of manufacturing the package and protecting the end faces of the film roll 13 up to the equipment for the process of setting on the polarizing film, etc., the ways arranged in the order of "film roll 13 / protective pad 16 / packaging material 14 (aluminum-based film) / outside of the package" from the inside of the package toward the outside, the way arranged in the order of "film roll 13 / protective pad 16 / second packaging material 15 (water vapor barrier film) / packaging material 14 (aluminum-based film) / outside of the package", and the way arranged in the order of "film roll 13 / protective pad 16 / packaging material 14 (aluminum-based film) / second packaging material 15 (water vapor barrier film) / outside of the package" are particularly preferred.

[0125] In addition, in the aforementioned film roll package, in order to adjust the humidity inside the package, a desiccant or a moisture absorbent can be additionally sealed. Examples of the aforementioned desiccant or moisture absorbent include: a moisture absorption layer formed by dispersing, impregnating, or coating and drying a desiccant or a water absorbent such as calcium chloride, silica gel, molecular sieve, saccharides, particularly saccharides with high osmotic pressure, and a water-absorbing resin in a moldable material such as natural cellulose, synthetic cellulose, glass cloth, or non-woven fabric. In addition, examples include those formed by sandwiching these moisture absorbents or water-absorbing materials with these moldable materials, thermoplastic resin films such as polyester film, polyethylene film, polypropylene film, and Teflon (registered trademark) film. Examples of commercially available sheet desiccants include: "ID Sheet" manufactured by I.D.CO., LTD., "Arrow Sheet", "Zeo Sheet" manufactured by Shinagawa Kasei Co., Ltd., and "Hi Sheet Dry" manufactured by Hi Sheet Industry Co., Ltd.

[0126] Moreover, the manufacturing method of the aforementioned film roll package is not particularly limited, and it can be manufactured by any manufacturing method. However, from the viewpoint of being able to efficiently and smoothly package the film roll 13, a method having the following processes can be adopted: a process of installing the protective pad 16 at both end portions of the film roll 13, a process of packaging the film roll 13 with the protective pad 16 installed using the packaging material 14 (aluminum-based film) and / or the second packaging material 15 (water vapor barrier film), and preferably a process of further installing the second protective pad at both end portions of the packaged film roll 13, etc.

[0127] The aforementioned film roll package obtained by such an operation can sufficiently prevent damage to the film roll 13 during storage and transportation, and can still suppress damage to the film roll 13 even when the film roll 13 is used in a clean room.

[0128] When storing the aforementioned film roll 13 in the form of a film roll package, there are no particular restrictions on the storage conditions. It is preferable to avoid extreme high temperature, low temperature, low humidity, and high humidity conditions. Specifically, as the storage temperature, it is preferably in the range of -20 to 50 °C, more preferably in the range of -10 to 40 °C, and further preferably in the range of -5 to 30 °C. In addition, as the storage humidity, it is preferably 90% RH or less, more preferably 45 to 80% RH.

[0129] There are also no particular restrictions on the storage time when storing the aforementioned film roll package. For example, it is preferably in the range of 1 day to 1 year, more preferably in the range of 2 days to 6 months.

[0130] Thus, according to the film roll package of the present invention, it is possible to sufficiently prevent damage to the film roll during storage and transportation, and even when using the film roll in a clean room, it is possible to suppress damage to the film roll, and it is possible to suppress dust and dirt adhering to the film roll, and furthermore, to suppress chips generated from the packaging material. Therefore, the present invention includes the method for storing or transporting the film roll 13 in the form of the package of the present invention as described above.

[0131] Moreover, the film roll stored or transported in the form of the film roll package of the present invention can reduce breakage or suppress the generation and adhesion of dust when uniaxially stretching the polyvinyl alcohol-based film of the film roll. Therefore, it can be preferably used as a polarizing film or a polarizer having excellent optical properties.

[0132] Thus, the polyvinyl alcohol-based film in the film roll package of the present invention is effectively used as a blank film for optical use, particularly for polarizing films. Therefore, the manufacturing method of polarizing films will be described below.

[0133] As the manufacturing method of the polarizing film, there can be mentioned: a method of stretching the polyvinyl alcohol-based film and immersing it in a solution of iodine or a dichroic dye for dyeing, simultaneously performing stretching and dyeing, dyeing with iodine or a dichroic dye and then performing a boron compound treatment after stretching. In addition, there is also a method of performing stretching in a solution of a boron compound after dyeing, etc., which can be appropriately selected and used.

[0134] As the film thickness of the polyvinyl alcohol-based film used in the polarizing film, it is preferably 10 to 100 μm, more preferably 10 to 70 μm, further preferably 15 to 50 μm, and particularly preferably 15 to 40 μm. By setting the film thickness within the aforementioned range, it is possible to suppress a decrease in film forming accuracy.

[0135] When stretching, dyeing, and treating with a boron compound for the polyvinyl alcohol-based film (unstretched film), stretching, dyeing, and treating with a boron compound can be carried out separately or simultaneously, but it is preferable to perform uniaxial stretching in at least one of the dyeing process and the boron compound treatment process.

[0136] For stretching, it is preferable to stretch 3 to 10 times, preferably 3.5 to 6 times, in the uniaxial direction. At this time, it is also okay to perform a little stretching in the direction perpendicular to the above (stretching to prevent shrinkage in the width direction or more). The temperature condition during stretching is preferably selected from 40 to 170 °C. Furthermore, the stretching ratio can be finally set within the above range, and the stretching operation is not limited to one stage, and can be carried out at any stage in the manufacturing process.

[0137] The dyeing of the film is carried out by bringing a liquid containing iodine or a dichroic dye into contact with the film. Usually, an aqueous solution of iodine-potassium iodide is used, and the concentration of iodine is 0.1 to 20 g / L, the concentration of potassium iodide is 10 to 70 g / L, and the mass ratio of potassium iodide / iodine is 10 to 100 is suitable. The dyeing time of about 30 to 500 seconds is practical. The temperature of the treatment bath is preferably 5 to 60 °C. In addition to water solvents, a small amount of organic solvents compatible with water may also be contained. As the contact method, any method such as dipping, coating, and spraying can be applied.

[0138] The dyed film is then treated with a boron compound. As the boron compound, boric acid and borax are practical. The boron compound is used in the form of an aqueous solution or a water-organic solvent mixture at a concentration of about 0.3 to 2 mol / L, and it is preferably practical to have a small amount of potassium iodide coexisting in the liquid. The treatment method is preferably the dipping method, and of course, the coating method and the spraying method can also be implemented. The temperature during treatment is preferably about 40 to 70 °C, the treatment time is preferably about 2 to 20 minutes, and in addition, a stretching operation can also be carried out during treatment as needed.

[0139] For the polarizing film obtained by such operations, an optically isotropic polymer film or sheet can also be used as a protective film and laminated and bonded on one or both sides. As the protective film, for example, films or sheets of triacetyl cellulose, diacetyl cellulose, polycarbonate, polymethyl methacrylate, polystyrene, polyethersulfone, polyarylate, poly-4-methylpentene, polyphenylene oxide, etc. can be cited.

[0140] In addition, in this polarizing film, for the purpose of forming a film, a curable resin such as a urethane-based resin, an acrylic-based resin, or a urea resin can be coated or laminated on one or both sides instead of the above-mentioned protective film.

[0141] For this polarizing film (or a film obtained by laminating a protective film or a curable resin on at least one of its surfaces), sometimes, if necessary, a transparent pressure-sensitive adhesive layer is formed on one of its surfaces by a generally known method for practical use. As the aforementioned pressure-sensitive adhesive layer, a copolymer of an acrylate such as butyl acrylate, ethyl acrylate, methyl acrylate, 2-ethylhexyl acrylate, etc. and an α-monoolefin carboxylic acid such as acrylic acid, maleic acid, itaconic acid, methacrylic acid, crotonic acid, etc. (including those to which vinyl monomers such as acrylonitrile, vinyl acetate, and styrene are added) as the main component is particularly preferred because it does not hinder the polarization characteristics of the polarizing film, but it is not limited thereto, and any pressure-sensitive adhesive having transparency can be used. For example, it can also be a polyvinyl ether-based substance, a rubber-based substance, etc.

[0142] In addition, various functional layers can be further provided on one side (the side where the aforementioned pressure-sensitive adhesive is not provided) of the polarizing plate (provided with the aforementioned pressure-sensitive adhesive). As the functional layers, for example, an antiglare layer, a hard coat layer, an antireflection layer, a semireflection layer, a reflection layer, a phosphorescent layer, a diffusion layer, an electroluminescent layer, a viewing angle widening layer, a brightness enhancing layer, etc. can be cited. Furthermore, various combinations of two or more layers can also be made, for example, combinations of an antiglare layer and an antireflection layer, a phosphorescent layer and a reflection layer, a phosphorescent layer and a semireflection layer, a phosphorescent layer and a light diffusion layer, a phosphorescent layer and an electroluminescent layer, a semireflection layer and an electroluminescent layer, etc. can be cited. However, it is not limited to these.

[0143] Examples

[0144] Hereinafter, examples are given to further specifically illustrate the present invention. The present invention is not limited to the following examples as long as it does not exceed its gist.

[0145] It should be noted that "%" in the examples refers to the mass basis.

[0146] <Example 1>

[0147] (Production of polyvinyl alcohol-based film)

[0148] In a 5,000 L dissolution kettle, 1,000 kg of a polyvinyl alcohol-based resin having a weight average molecular weight of 123,000 and a saponification degree of 99.8 mol%, 3,000 kg of water, 115 kg of glycerol as a plasticizer, and 0.25 kg of sodium dodecylsulfonate as a surfactant were added, and the mixture was heated to 150 °C with stirring and pressurized for dissolution to obtain a polyvinyl alcohol-based resin aqueous solution adjusted to a resin concentration of 29%.

[0149] Next, the aqueous solution of the polyvinyl alcohol-based resin is supplied to a twin-screw extruder having air vents and defoamed, and then the temperature of the aqueous solution is brought to 95°C. It is discharged from the die orifice of a T-shaped slit die and cast and extruded onto a casting mold rotating at 12 m / min to form a film. Next, the surface and the back surface of the film are alternately brought into contact with a total of 15 hot rollers for drying, and hot air at 95°C is blown from both sides of the film for heat treatment.

[0150] (Production of film roll)

[0151] The obtained film is wound around a cylindrical aluminum core tube with a length of 340 cm and a diameter of 6 inches to obtain a film roll (film thickness: 45 μm, width: 3 m, length: 5 km). At this time, the end face and the outer peripheral face of the film roll are visually observed, and as a result, no attachment of dust, chips, etc. is observed.

[0152] (Production of protective pad)

[0153] A foamed member (made of polyethylene) with a thickness of 10 mm, a foaming ratio of 10 times (closed cells), and a 25% compressive stress of 35 kPa is bonded to a non-foamed resin sheet (made of polyethylene) with a thickness of 15 μm (the surface roughness Ra of the non-foamed resin sheet after bonding is 0.6 μm, the surface roughness Ry is 2.1 μm, and the surface roughness Rz is 2.0 μm), and it is cut out according to the shape of the end face of the roller, whereby two protective pads are prepared. Each of these protective pads has a base material including the foamed member and non-foamed resin layers on both sides thereof.

[0154] (Production of film roll package)

[0155] After installing the two aforementioned protective pads in such a configuration that the non-foamed resin layer sides thereof face the end face of the film roll, the outer periphery of the film roll is wound with a water vapor barrier film (made of polyethylene, thickness: 30 μm, water vapor transmission rate: 7 g / m 2 / day) as the second packaging material for packaging. Then, the excess portion in the width direction of the film roll of the water vapor barrier film is fixed to the core tube with a rubber band.

[0156] Next, from above the film roll packaged with the water vapor barrier film, double-layer winding packaging is performed using an aluminum-based film (stretched polypropylene film / polyethylene film / aluminum foil (thickness: 7 μm) / polyethylene film) as the packaging material, and the excess portion in the width direction of the film roll of the aluminum-based film is fixed to the core tube with an adhesive tape to complete the packaging (refer to Figure 1 ).

[0157] Then, the protruding portion of the core tube is placed on a bracket to make a state in which the film roll floats in the air without being grounded.

[0158] After storing the obtained film roll package for 7 days, after 10 days of land and sea transportation along the specified route, the packaging material of the film roll was removed and the appearance of the polyvinyl alcohol-based film was visually confirmed. As a result, almost no adhesion of dust, chips, etc. to the end face and outer peripheral face of the film roll was confirmed.

[0159] <Example 2>

[0160] A foamed member with a thickness of 10 mm, a foaming ratio of 10 times (closed cells), and a 25% compression stress of 35 kPa and a non-foamed resin sheet (made of polyethylene) with a thickness of 7 μm were used as the protective pad (the surface roughness Ra of the non-foamed resin sheet after lamination was 1.4 μm, the surface roughness Ry was 5.8 μm, and the surface roughness Rz was 5.1 μm). Other than this, the same operations as in Example 1 were performed, and after storing and transporting on land and sea in a state where the protruding portion of the core tube was placed on the support and the film roll was floating in the air without being grounded, the packaging material of the film roll was removed, and the appearance of the polyvinyl alcohol-based film was visually confirmed. As a result, very slight adhesion of dust, chips, etc. considered to be derived from the protective pad was confirmed on the end face of the film roll.

[0161] <Comparative Example 1>

[0162] A protective pad composed of a foamed member with a thickness of 10 mm, a foaming ratio of 10 times (closed cells), and a 25% compression stress of 35 kPa and without a non-foamed resin layer was used. Other than this, the same operations as in Example 1 were performed to obtain a film roll package. Then, in the same manner as in Example 1, after storing and transporting on land and sea in a state where the protruding portion of the core tube was placed on the support and the film roll was floating in the air without being grounded, the packaging material of the film roll was removed, and the appearance of the polyvinyl alcohol-based film was visually confirmed. As a result, a large amount of adhesion of dust, chips, etc. considered to be derived from the protective pad was confirmed on the end face of the film roll.

[0163] <Abrasion Evaluation>

[0164] In order to evaluate the ease of cutting of the surface of the protective pad, a Taber abrasion test (in accordance with JIS K 7204:1999 method, test conditions: abrasion wheel CS-17, test load 4.9 N, number of revolutions 1000 times) was performed on the protective pads used in Example 1 and Comparative Example 1 above. The results are shown in Table 1 below.

[0165] [Table 1]

[0166]

[0167] <Study>

[0168] Based on the foregoing results, it was confirmed that the film roll package defined in the present invention also inhibits the adhesion of dust, chips, etc. to the polyvinyl alcohol-based film during storage and transportation. Furthermore, it was confirmed that chips that are likely to be generated due to friction with the end face of the film roll during storage and transportation are not easily generated according to the protective pad defined in the present invention.

[0169] Therefore, the polyvinyl alcohol-based film can also be used in a cleaner room of a higher grade, and the breakage during uniaxial stretching of the polyvinyl alcohol-based film can be reduced. In addition, it is known that when the polyvinyl alcohol-based film is processed into a polarizing film or a polarizing plate, a reduction in optical properties can also be suppressed.

[0170] In the foregoing embodiments, specific modes in the present invention are shown, but the foregoing embodiments are merely illustrative and not to be construed in a limiting sense. Various modifications obvious to those skilled in the art are contemplated to be included within the scope of the present invention.

[0171] Industrial Applicability

[0172] The film roll package of the present invention sufficiently prevents damage and contamination of the film roll during storage and transportation. Even when the film roll is used in a clean room, damage and contamination of the film roll can still be suppressed. Therefore, the quality of the polyvinyl alcohol-based film wound in the form of a film roll is not impaired, and it is useful as a technology for maintaining it well.

[0173] Explanation of Reference Numerals

[0174] 11: Polyvinyl alcohol-based film

[0175] 12: Core tube

[0176] 13: Film roll

[0177] 14: Packaging material

[0178] 16: Protective pad

[0179] 17: Substrate

[0180] 18: Non-foamed resin layer

Claims

1. A thin film roll package, comprising: A thin film roll formed by winding a polyvinyl alcohol-based thin film around a core tube, A packaging material for packaging the thin film roll, and Protective pads disposed on both end faces of the thin film roll, The packaging material is at least composed of a thin film containing an aluminum raw material, The protective pad has: a base material containing a foaming member, and a non-foaming resin layer provided on at least the surface on the thin film roll end face side of the base material.

2. The thin film roll package according to claim 1, wherein, The thin film containing an aluminum raw material is a laminated film of a polyolefin film and an aluminum foil.

3. The thin film roll package according to claim 1 or 2, wherein, The thin film containing an aluminum raw material is a laminated film having at least a laminated structure of a polyethylene film / aluminum foil / polyethylene film.

4. The thin film roll package according to claim 1 or 2, further comprising a second packaging material composed of a water vapor barrier film.

5. The thin film roll package according to claim 1 or 2, wherein, The base material containing a foaming member is composed of a foamed polyethylene-based resin.

6. The thin film roll package according to claim 1 or 2, wherein, The thickness of the non-foaming resin layer is 5 μm or more.

7. The thin film roll package according to claim 1 or 2, wherein, The thickness of the non-foaming resin layer is 500 μm or less.

8. A method for manufacturing a thin film roll package, which is a method for manufacturing the thin film roll package according to claim 1 or 2, comprising: A step of installing protective pads on both end faces of the thin film roll, and A step of packaging the thin film roll with the protective pads installed using a packaging material composed of a thin film containing an aluminum raw material.

9. A method for storing or transporting a thin film roll, which stores or transports a thin film roll in the form of the thin film roll package according to claim 1 or 2.

Images