TW201903437A - Optical film, peeling method, and method of manufacturing optical display panel - Google Patents

Abstract

The present invention is a sheet-form film laminate in which a first release film having a first base-material film and a second release film having a functional film and a second base-material film are laminated, wherein the first release film is detached prior to the second release film, the functional film has a thickness of 110 [mu]m or less, and a first bending resistance (mm) in a bending test of the first release film is greater than a second bending resistance (mm) in a bending test of the second release film. In this laminate, the first release film (the release film on the side that is released first) can be easily released even when a thin functional film is used.

Description

Optical film, peeling method and manufacturing method of optical display panel

The present invention relates to a monolithic film laminate formed by sequentially laminating a first release film, a functional film, and a second release film.

Moreover, this invention relates to the peeling method of the 1st peeling film of the said film laminated body. Furthermore, this invention relates to the manufacturing method of the optical display panel using the said film laminated body.

The functional film may be protected by a release film on both sides until it is used for various applications. For example, when an optical film such as a polarizing film is used as an optical film provided with an adhesive layer on one side of the adhesive layer for bonding an optical unit such as a liquid crystal cell, a release film is usually temporarily adhered to the adhesive layer (Release film) until application. On the other hand, another release film (surface protection film) is temporarily adhered to the other side of the optical film. Such an optical film having an adhesive layer with a release film and a surface protective film can be applied to an optical display panel, but at this time, the adhesive layer exposed from the above-mentioned optical film with an adhesive layer is peeled off to expose the adhesive layer. Close the optical unit. The surface protective film is directly adhered on the attached optical film with the adhesive layer.

The above-mentioned bonding includes, for example, a method of bonding an optical layer with an adhesive layer rolled out of a wound body and being transported to the surface of an optical unit through peeling of a release film (hereinafter, also referred to as " "Roll-to-panel method"; Patent Document 1). In addition, there is a method (hereinafter, also referred to as a "sheet-to-panel method") for bonding an optical film with an adhesive layer in a single-sheet state to an optical unit by exposing the adhesive layer exposed through a release film.

On the other hand, image display devices such as liquid crystal display devices are becoming thinner, and thinner polarizing films are also required. Therefore, the thickness of the polarizing element is also reduced (Patent Document 2). The thinning of the polarizing film can be performed by using a single-sided protective polarizing film in which a protective film is provided only on one side of the polarizing element and a protective film is not provided on the other side. Compared with the two-sided protective polarizing film provided with the protective film on both sides of the polarizing element, the single-sided protective polarizing film has one less protective film, so that it can be made thinner. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 4404043 [Patent Document 2] Japanese Patent No. 4751481

[Problems to be solved by the invention]

When peeling the release film from the optical film with an adhesive layer having a release film and a surface protective film (for example, a polarizing film with an adhesive layer), the surface protection of the optical film with an adhesive layer is usually performed. The release film is peeled off with the film side fixed. However, in recent years, expectations for a state in which the surface protective film can be easily peeled without leaving a paste, have increased, and the peeling force of the surface protective film has been continuously reduced. If it is the previous one, from the viewpoint of the peeling order, it is more desirable to design it so that the peeling force of the previously peeled release film is sufficiently reduced (easy to peel off) than the surface protective film that is peeled off later. However, it has been newly clarified that in recent years, an optical film with an adhesive layer is designed in which the peeling force of the surface protective film is insufficiently larger than the peeling force of the release film, or the peeling force of the surface protective film is designed to be small. Therefore, the following problem arises: when the release film is peeled off, not at the interface between the release film and the adhesive layer, but at the interface between the optical film (such as a polarizing film) and the surface protective film. The above problem can be solved, for example, by setting the peeling force of the surface protective film and the peeling force of the release film to be approximately the same. However, regarding the release film, in order to ensure the adhesion between the optical film and the optical unit, a specific peeling force is required. Therefore, when the release force of the release film is designed to be approximately the same as that of the surface protective film, it cannot be It is required to reduce the adhesion between the optical film and the optical unit, or reduce the peeling force of the surface protective film. It can be seen that the above-mentioned problems are particularly noticeable when the release film is peeled from a single-layer polarizing film with an adhesive layer, which has a thin polarizing film having a specific thickness (for example, a thickness of 60 μm or less) in the sheet-to-panel method.

An object of the present invention is to provide a film laminate which is a single sheet having a first release film and a second release film on both sides of a functional film, and can be easily used even when a thin functional film is used. The first release film (the release film on the side where the release was performed first) was peeled.

Another object of the present invention is to provide a method for peeling the first release film of the film laminate, and an object of the present invention is to provide a method for manufacturing an optical display panel using the film laminate. [Technical means to solve the problem]

The inventors of the present invention and others have worked hard and found that the above-mentioned problems can be solved by the following film laminates and the like, and the present invention has been completed.

That is, the present invention relates to a film laminate, which is characterized in that it is a unit formed by sequentially laminating a first release film having a first base film, a functional film, and a second release film having a second base film. Sheet, and the thickness of the functional film is 110 μm or less, and the first bending stiffness (mm) of the first peeling film in the bending rigidity test is greater than the second bending stiffness (mm) of the second peeling film in the bending rigidity test. ).

In the film laminate, it is preferable that a difference between the first bending stiffness (mm) and the second bending stiffness (mm) is 10 mm or more.

In the said film laminated body, when the peeling force (1) of the said 1st peeling film is more than the peeling force (2) of the said 2nd peeling film, this invention is preferable.

In the film laminate, the thickness of the first base film is preferably greater than the thickness of the second base film.

In the film laminate, the thickness of the first base film is preferably 40 μm or more.

In the said film laminated body, it is preferable that the thickness of the said 2nd base material film is 35 micrometers or less.

In the film laminate, an optical film can be used as the functional film.

As the optical film, a polarizing film can be used. The above-mentioned polarizing film can be preferably used when a polarizing element having a thickness of 10 μm or less is used. In addition, the above-mentioned polarizing film can be preferably used in the case of a single-sided protective polarizing film having a protective film only on one side of a polarizing element.

The optical film is preferably one having a surface-treated layer on one or both sides.

In the said film laminated body, it is preferable to use a surface protection film for both the said 1st release film and the 2nd release film.

In the film laminate, when a functional film adhesive layer is provided on the side of the functional film where the first release film is provided, a surface protective film can be preferably used as the second release film.

In the film laminate, the surface protective film may be an adhesive layer having a surface protective film, and the surface protective film may be laminated on the functional film through the adhesive layer. As the surface protective film, a self-adhesive film can be used.

Moreover, this invention is a peeling method of the 1st peeling film characterized by peeling a 1st peeling film from the said film laminated body.

In addition, the present invention relates to a method for manufacturing an optical display panel, comprising: step (1) of preparing the film laminate; step (2) of peeling a first release film from the film laminate; and peeling the first (1) A step (3) of attaching the side of the adhesive layer for the functional film of the film laminate of the release film to one surface of the optical unit.

In the manufacturing method of the optical display panel, a liquid crystal cell or an organic EL cell can be used as the optical unit. [Effect of the invention]

The film lamination system of the present invention uses a first release film (a release film that is initially peeled off from the film laminate) and a second release film (a release film that is peeled off after the first release film is peeled off) on both sides of the functional film, The flexural rigidity (mm) of the first release film in the flexural rigidity test was greater than that of the second release film. It is considered that the shear force in the cross-sectional direction of the functional film when the first release film is peeled by the design of the film laminate is larger than that of the interface between the functional film and the second release film. As a result, when the thickness of the functional film is 110 μm or less and the toughness (elastic modulus) is weak (and the peeling force of the second peeling film is smaller than that of the first peeling film), In the case where the interface between the functional film and the second release film does not occur, the first release film can be easily peeled from the single-layer film laminate in the sheet-to-panel method.

Hereinafter, the film laminated body F of this invention is demonstrated, referring drawings. FIG. 1 to FIG. 5 are schematic sectional views of the film laminated body F. FIG. The laminated body F is a structure in which a first release film 1, a functional film A, and a second release film 2 are laminated in this order.

2 and 3 are on one side of the functional film A with an adhesive layer B for a functional film. A first release film 1 is provided on the adhesive layer B for a functional film. A first release film 1 is provided on the other side of the functional film A. 2 The appearance of peeling film 2. The first release film 1 has a first base film, and the second release film 2 has a second base film.

In the state of FIGS. 2 and 3, the first release film 1 is used as an adhesive layer B for protecting a functional film until it is used as a practical release film. In addition to the first release film 1 having a first base film, for example, in order to improve the peelability of the adhesive layer B for a functional film, the first release film 1 may be bonded to the adhesive layer B for a functional film of the first base film. A peeling treatment layer or the like (not shown) is provided on the side. When the first base film is not provided with a release treatment layer or the like, the thickness of the first base film corresponds to the thickness of the first release film 1.

On the other hand, in the aspect of FIGS. 2 and 3, the second release film 2 can be used as a surface protection film. The second release film 2 (surface protection film) described in FIG. 2 and FIG. 3 can be exemplified as having a second base film 21 and an adhesive layer 22 for a surface protection film. In FIG. 2 and FIG. 3, the surface protective film adhesive layer 22 side of the second release film 2 is bonded to the functional film A. Note that FIG. 1 conceptually shows a case where the second release film 2 is a self-adhesive film. When the second release film 2 is a self-adhesive film, the thickness of the self-adhesive film corresponds to the thickness of the second base film.

FIG. 3 shows a case where the functional film A is a single-sided protective polarizing film having a protective film a2 only on one side of the polarizing element a1. In addition, FIG. 3 illustrates the case where the side of the polarizing element a1 in the single-sided protective polarizing film has an adhesive layer B for a functional film, but the single-sided protective polarizing film can also have the side of the protective film a2 having an adhesive for a functional film. Agent B configuration. In addition, as the functional film A in FIG. 2, for example, various optical films can be used, and both sides of the polarizing element a1 can be provided with a two-sided protective polarizing film having a protective film a2.

4 and 5 show a state in which a first release film 1 is provided on one side of the functional film A as a surface protection film, and a second release film 2 is provided on the other side as a surface protection film.

In the aspect of FIGS. 4 and 5, the case where the first release film 1 includes the first base film 11 and the adhesive layer 12 for a surface protection film is exemplified. In FIGS. 4 and 5, the surface protective film adhesive layer 12 side of the first release film 1 is bonded to the functional film A. On the other hand, in the aspect of FIG. 4 and FIG. 5, the case where the 2nd peeling film 2 has the 2nd base material film 21 and the adhesive layer 22 for surface protection films like FIG. 2 and FIG. 3 is illustrated.

In FIG. 5, a case where the functional film A is provided with a surface treatment layer a4 on both sides of the functional base film a3 is exemplified. In addition, as the functional film A in FIG. 5, for example, various optical films can be used, and those having a surface treatment layer a4 only on one side of the functional base film a3 can be used.

The film lamination system of the present invention is selected in such a way that the first bending stiffness (mm) in the bending rigidity test of the first release film 1 is greater than the second bending stiffness (mm) in the bending rigidity test of the second release film 2. A release film and a second release film. The difference between the first bending stiffness (mm) and the second bending stiffness (mm) in terms of stability of the peeling accuracy (in the pick-up test) is preferably 10 mm or more, and more preferably 20 mm. The above is more preferably 30 mm or more.

The first peeling film 1 and the second peeling film 2 are the ones to be finally peeled off. The peeling force (1) of the first peeling film 1 and the peeling force (2) of the second peeling film 2 are preferably designed as Better peeling force. For example, in the state of FIGS. 2 and 3, the peeling force (1) is the peeling force of the first peeling film 1 to the adhesive layer B for a functional film. In the state of FIGS. 4 and 5, the peeling force (1) 1) The peeling force of the first release film 1 from the functional film A. The peeling force (2) is a peeling force of the second peeling film 2 from the functional film A.

The peeling force (1) is preferably 0.03 N / 25 mm or more from the viewpoint of preventing the end portion from floating during processing. It is more preferably 0.05 to 0.5 N / 25 mm, and still more preferably 0.1 to 0.3 N / 25 mm. The peeling force (2) is preferably 0.2 N / 25 mm or less, more preferably 0.01 to 0.1 N / 25 mm, and still more preferably 0.01 to 0.05 N / 25 from the viewpoint of easy peeling. mm.

The film laminate F of the present invention can be preferably used when the peeling force (1) of the first peeling film 1 is equal to or higher than the peeling force (2) of the second peeling film 2 described above. Particularly, it can be preferably used in a case where the above-mentioned peeling force (1) is larger than the above-mentioned peeling force (2). In the case where the value of the peeling force (1) relative to the peeling force (2) of the film laminate F of the present invention is [the peeling force (1) / peeling force (2)] is 1.1 times or more, and further 1.5 times or more The situation is better.

The film laminate F of the present invention is preferably such that the thickness of the first substrate film of the first release film 1 is greater than the thickness of the second substrate film of the second release film 2. The bending rigidity of the film substrate may be affected by the thickness of the film, but the larger the film thickness, the larger the bending stiffness. Therefore, by designing the thickness of the first base film to be greater than the thickness of the second base film, the first bending stiffness of the first release film can be adjusted to be greater than the second bending stiffness of the second release film. In particular, when the first base film and the second base film are the same forming material, it is easy to adjust the bending rigidity by the thickness.

In addition, the surface protective film adhesive layer or the like used as various treatment layers such as a release treatment layer in the first and second release films, or a surface protective film hardly affects the bending rigidity. Therefore, the first bending stiffness of the first release film depends on the material and thickness of the first base film, and the second bending stiffness of the second release film depends on the material and thickness of the second base film.

The thickness of the first base film of the first release film is usually preferably 40 to 240 μm, more preferably 45 to 230 μm, and still more preferably 50 to 220 μm. On the other hand, the thickness of the second base film of the second release film is usually preferably 5 to 150 μm, and more preferably 10 to 100 μm.

<Functional film> Functional films are various films that can be used in various fields depending on the field. For example, in the optical field, polarizing films, transparent protective films, retardation films, anti-reflection films, brightness enhancement films, diffusion films, etc. can be used. Optical film.

The functional film uses a thickness (total thickness) of 110 μm or less. The thickness of the functional film is preferably 95 μm or less, and more preferably 80 μm or less. When the thickness of the functional film is 110 μm or less, in the sheet-to-panel method, when the first peeling film is peeled off, it is not the interface between the first peeling film and the functional film, but the functional film and the second peeling. The interface of the film is prone to peeling, and the present invention can be preferably applied to a functional film of this thickness.

<Polarizing film> As said optical film, a polarizing film can be used suitably. When a polarizing film is used, it is preferable to use a polarizing film having a thickness (total thickness) of 60 μm or less. Regarding the thickness of the above-mentioned polarizing film, from the viewpoint of thinning, a thickness of 55 μm or less, and further 50 μm or less can be used. Furthermore, as the structure of the polarizing film, for example, (1) a structure in which a protective film is sequentially laminated on both sides of the polarizing element (two-sided protective polarizing film), and (2) a protective film is provided only in a single area layer of the polarizing element. Structure (single-sided protective polarizing film), etc.

≪Polarizing element≫ As the polarizing element, a polyvinyl alcohol resin can be used. Examples of polarizing elements include those that adsorb iodine or dichroic dyes to hydrophilic polymer films such as polyvinyl alcohol-based films, partially formalized polyvinyl alcohol-based films, and ethylene-vinyl acetate copolymer-based saponified films. Polyisotropic alignment films such as those obtained by uniaxially stretching a dichroic material, such as a dehydrated product of polyvinyl alcohol or a dehydrochlorinated product of polyvinyl chloride. Among these, a polarizing element containing a polyvinyl alcohol-based film and a dichroic substance such as iodine is preferred.

A polarizing element obtained by dyeing a polyvinyl alcohol-based film with iodine and uniaxially stretching it can be produced, for example, by immersing a polyvinyl alcohol in an aqueous solution of iodine for dyeing, and extending it to 3 to the original length. 7 times. If necessary, it may contain boric acid, zinc sulfate, zinc chloride, or the like, or may be immersed in an aqueous solution such as potassium iodide. Further, if necessary, the polyvinyl alcohol-based film may be immersed in water and washed with water before dyeing. The polyvinyl alcohol-based film can be washed with water to clean dirt or anti-blocking agents on the surface of the polyvinyl alcohol-based film. In addition, it can prevent uneven dyeing by swelling the polyvinyl alcohol-based film. Uneven effect. The stretching may be performed after dyeing with iodine, or may be extended while dyeing, or may be dyed with iodine after stretching. It can also be extended in an aqueous solution such as boric acid or potassium iodide or in a water bath.

The thickness of the polarizing element is preferably 10 μm or less, more preferably 8 μm or less, still more preferably 7 μm or less, and still more preferably 6 μm or less in terms of thickness reduction. On the other hand, the thickness of the polarizing element is preferably 2 μm or more, and more preferably 3 μm or more. Such a thin polarizing element has less thickness unevenness, excellent visibility, and less dimensional change, so it has excellent durability against thermal shock. On the other hand, a polarizing film including a polarizing element having a thickness of 10 μm or less significantly reduces the toughness (elastic modulus) of the film. Therefore, in the sheet-to-panel method, when the release film is peeled off, it is not the same as the release film and the The interface between the adhesive layer, but the interface between the polarizing film and the surface protective film, is particularly prone to peeling, and the present invention is particularly suitable for the polarizing film.

Representative examples of thin polarizers include: Japanese Patent No. 4751486, Japanese Patent No. 4751481, Japanese Patent No. 4815544, Japanese Patent No. 5048120, and International Publication No. 2014/077599. , A thin polarizing element described in International Publication No. 2014/077636, etc., or a thin polarizing element obtained by the manufacturing method described in these.

The above-mentioned polarizing element preferably satisfies the following formula P>-(10 ^0.929T-42.4 -1) × 100 (where T <42.3) with optical characteristics represented by single transmittance T and polarization degree P. Or P ≧ 99.9 (where T ≧ 42.3). Regarding a polarizing element configured to satisfy the above conditions, it is clear that it has the performance required as a display for a liquid crystal television using a large display element. Specifically, the contrast ratio is 1000: 1 or more and the maximum brightness is 500 cd / m ² or more. For other uses, for example, it is bonded to the visible side of an organic EL (Electroluminescence) unit.

As the above-mentioned thin polarizing element, in a manufacturing method including a step of stretching in a state of a laminated body and a step of dyeing, also in terms of being able to stretch at a high magnification and improving polarizing performance, it is preferable to use, for example, a Japanese patent It is particularly preferred to obtain the method described in Japanese Patent No. 4751486, Japanese Patent No. 4751481, and Japanese Patent No. 4815544, including a method for performing an extension step in an aqueous boric acid solution, and it is particularly preferable to use Japanese Patent No. 4751481 and Japanese Patent 4815544 The description in the specification includes those obtained by a manufacturing method in which an aerial stretching step is performed in advance in an aqueous solution of boric acid. These thin polarizing elements can be obtained by a production method including a step of stretching a polyvinyl alcohol resin (hereinafter, also referred to as a PVA resin) layer and a stretching resin substrate in a state of a laminate, and a dyeing step. According to this manufacturing method, even if a PVA (Polyvinyl Alcohol, polyvinyl alcohol) -based resin layer is thin, it can be stretched by being supported by a resin base material for stretching, without defects such as breakage due to stretching.

≪Protective film≫ As a material constituting the protective film, one having excellent transparency, mechanical strength, thermal stability, moisture blocking property, isotropy, and the like is preferable. Examples include polyester polymers such as polyethylene terephthalate or polyethylene naphthalate, cellulose polymers such as diacetyl cellulose or triethyl cellulose, and polymethyl methacrylate. Acrylic polymers such as esters, styrene polymers such as polystyrene or acrylonitrile-styrene copolymer (AS (Acrylonitrile-Styrene) resin), polycarbonate polymers, and the like. Examples of the polymer forming the protective film include polyethylene, polypropylene, a ring-based or polyolefin having a olefin-reducing structure, a polyolefin-based polymer such as an ethylene-propylene copolymer, and a vinyl chloride-based polymer. Polymers, fluorene-based polymers such as nylon, aromatic polyamines, fluorene-based polymers, fluorene-based polymers, polyether fluorene-based polymers, polyetheretherketone polymers, polyphenylene sulfide-based polymers Polymers, vinyl alcohol polymers, vinylidene chloride polymers, ethylene butyraldehyde polymers, aryl ester polymers, polyoxymethylene polymers, epoxy polymers, or blends of the above polymers, etc. . These protective films are usually bonded to a polarizing element using an adhesive layer.

Furthermore, one or more of any suitable additives may be contained in the protective film. Examples of the additives include ultraviolet absorbers, antioxidants, lubricants, plasticizers, release agents, anti-colorants, flame retardants, nucleating agents, antistatic agents, pigments, and colorants. The content of the thermoplastic resin in the protective film is preferably 50 to 100% by weight, more preferably 50 to 99% by weight, still more preferably 60 to 98% by weight, and even more preferably 70 to 97% by weight. When the content of the above-mentioned thermoplastic resin in the protective film is 50% by weight or less, there is a possibility that the high transparency originally possessed by the thermoplastic resin may not be sufficiently expressed.

As the protective film, a retardation film, a brightness enhancement film, a diffusion film, and the like can also be used.

The thickness of the protective film can be determined as appropriate. Generally, it is preferably 5 to 50 μm, and more preferably 5 to 45 μm in terms of workability such as strength and workability, and thin layer property.

A functional layer such as a hard coat layer, an anti-reflection layer, an anti-adhesion layer, a diffusion layer, or an anti-glare layer may be provided on the surface of the protective film not adjoining the polarizing element. In addition, the functional layers such as the hard coating layer, the anti-reflection layer, the anti-adhesion layer, the diffusion layer, or the anti-glare layer may be provided on the protective film itself, and may also be provided separately from the other forms of the protective film.

<Intermediate layer> The protective film and the polarizing element are laminated via an intervening layer such as an adhesive layer, an adhesive layer, and an undercoat layer (undercoat layer). At this time, it is preferable to laminate both of them by an intervening layer without an air gap. Moreover, the interposing layers of the polarizing element a1 and the protective film a2 are not shown in FIG. 2.

The adhesive layer is formed by an adhesive. The type of the adhesive is not particularly limited, and various types can be used. The above-mentioned adhesive layer is not particularly limited as long as it is optically transparent. As the adhesive, various forms such as water-based, solvent-based, hot-melt-based, and active energy ray hardening types can be used. An aqueous adhesive or active energy ray is preferred Hardening type adhesive.

Examples of the water-based adhesive include an isocyanate-based adhesive, a polyvinyl alcohol-based adhesive, a gelatin-based adhesive, an ethylene-based latex, and a water-based polyester. The water-based adhesive is usually used in the form of an adhesive containing an aqueous solution, and usually contains 0.5 to 60% by weight of a solid content component.

The active energy ray-curable adhesive is an adhesive that is hardened by active energy rays such as electron beam and ultraviolet (radical-curable and cation-curable). For example, it can be used in the form of electron beam-curable or ultraviolet-curable. As the active energy ray-curable adhesive, for example, a photoradical-curable adhesive can be used. When a photoradical-curable active energy ray-curable adhesive is used as the UV-curable adhesive, the adhesive contains a radical polymerizable compound and a photopolymerization initiator.

The coating method of the adhesive can be appropriately selected according to the viscosity of the adhesive or the target thickness. Examples of the coating method include a reverse coater, a gravure coater (direct, reverse, or offset), a bar reverse coater, a roll coater, a die coater, Bar coater, rod coater, etc. In addition, a method such as a dipping method may be suitably used for the application.

The application of the above-mentioned adhesive is preferably performed when a water-based adhesive or the like is used so that the thickness of the finally formed adhesive layer becomes 30 to 300 nm. The thickness of the adhesive layer is more preferably 60 to 150 nm. On the other hand, when using an active energy ray hardening type adhesive, it is preferable to perform it so that the thickness of the said adhesive layer may become 0.2-20 micrometers.

When the polarizing element and the protective film are laminated, an easy-adhesion layer may be provided between the protective film and the adhesive layer. The easy-adhesion layer can have, for example, a polyester skeleton, a polyether skeleton, a polycarbonate skeleton, a polyurethane skeleton, a polysiloxane, a polyamine skeleton, a polyimide skeleton, or a polyvinyl alcohol skeleton. Various resins. These polymer resins may be used singly or in combination of two or more kinds. In addition, other additives may be added during the formation of the easy-adhesive layer. Specifically, stabilizers such as an adhesion-imparting agent, an ultraviolet absorber, an antioxidant, and a heat-resistant stabilizer can also be used.

The adhesive layer is formed of an adhesive. As the adhesive, various adhesives can be used, and examples thereof include a rubber-based adhesive, an acrylic-based adhesive, a polysiloxane-based adhesive, a urethane-based adhesive, a vinyl alkyl ether-based adhesive, and a polymer. Vinyl pyrrolidone-based adhesives, polypropylene amidamine-based adhesives, cellulose-based adhesives, and the like. The adhesive base polymer can be selected according to the type of the adhesive. Among the above-mentioned adhesives, acrylic adhesives can be preferably used in terms of excellent optical transparency, exhibiting suitable wettability and adhesion characteristics of cohesiveness and adhesiveness, and excellent weather resistance or heat resistance.

The undercoat layer (undercoat layer) is formed in order to improve the adhesion between the polarizing element and the protective film. The material constituting the undercoat layer is not particularly limited as long as it exhibits a certain degree of strong adhesion to both the base film and the polyvinyl alcohol-based resin layer. For example, a thermoplastic resin excellent in transparency, thermal stability, and elongation can be used. Examples of the thermoplastic resin include an acrylic resin, a polyolefin resin, a polyester resin, a polyvinyl alcohol resin, or a mixture thereof.

<Other functional film> As the functional film of the present invention, the same protective film as exemplified in the above-mentioned item of polarizing film can be used. As the functional film, the film (functional substrate film) may be used alone, or a surface treatment layer may be provided on one or both sides of the functional substrate film as shown in FIG. 5. Examples of the surface treatment layer include functional layers such as a hard coat layer, an anti-reflection layer, an anti-adhesion layer, a diffusion layer, or an anti-glare layer which can be applied to the protective film of the polarizing film. The thickness of the functional base film can be appropriately determined within a range of 110 μm or less. Generally, in terms of workability such as strength and operability, and thinness, it is preferably 10 to 110 μm, and more preferably 25 to 105 μm. The surface treatment layer is preferably 25 μm or less, and more preferably 15 μm or less.

<Adhesive layer for functional films> In forming the adhesive layer for functional films, a suitable adhesive can be used, and the type is not particularly limited. Examples of the adhesive include a rubber-based adhesive, an acrylic-based adhesive, a polysiloxane-based adhesive, a urethane-based adhesive, a vinyl alkyl ether-based adhesive, a polyvinyl alcohol-based adhesive, and a polymer. Vinyl pyrrolidone-based adhesives, polypropylene amidamine-based adhesives, cellulose-based adhesives, and the like.

Among these adhesives, those which are excellent in optical transparency, exhibit suitable adhesion characteristics such as wettability, cohesiveness, and adhesion, and are excellent in weather resistance or heat resistance can be preferably used. As such a characteristic, it is preferable to use an acrylic adhesive.

As a method for forming an adhesive layer for a functional film, for example, it can be produced by applying the above-mentioned adhesive to a release film (release film, etc.) subjected to a peeling treatment, drying and removing a polymerization solvent, etc. to form an adhesive. A method for transferring the polarizing film to the polarizing film after the agent layer; or a method for coating the polarizing film with the above-mentioned adhesive, drying and removing the polymerization solvent, etc. to form an adhesive layer on the polarizing element. In addition, when the adhesive is applied, one or more solvents other than the polymerization solvent may be appropriately added.

As the release film after the release treatment, a silicone release liner can be preferably used. In the step of applying the adhesive of the present invention to such a gasket and drying it to form an adhesive layer, as a method of drying the adhesive, an appropriate method may be appropriately adopted according to the purpose. It is preferred to use a method in which the coating film is dried by heat. The heating and drying temperature is preferably 40 ° C to 200 ° C, more preferably 50 ° C to 180 ° C, and particularly preferably 70 ° C to 170 ° C. An adhesive having excellent adhesive properties can be obtained by setting the heating temperature to the above range.

The drying time may be appropriately adopted. The drying time is preferably 5 seconds to 20 minutes, more preferably 5 seconds to 10 minutes, and even more preferably 10 seconds to 5 minutes.

As a method for forming the adhesive layer, various methods can be used. Specific examples include: roll coating, contact roll coating, gravure coating, reverse coating, roll brush coating, spray coating, dip roll coating, bar coating, blade coating, air knife Coating, curtain coating, die lip coating, extrusion coating using a die coater, etc.

The thickness of the adhesive layer is not particularly limited, and is, for example, about 1 to 100 μm. It is preferably 2 to 50 μm, more preferably 2 to 40 μm, and still more preferably 5 to 35 μm.

<1st peeling film: case for protecting the adhesive layer for functional films> The 1st peeling film is, for example, holding the adhesive layer for functional films until it is put to practical use (refer FIG. 2, FIG. 3). As the first release film, the above-mentioned release film (such as a release film) for forming an adhesive layer for a functional film can be used as the first release film as it is. The first release film (release film) has a first base film. Examples of the constituent material of the first base film include plastic films such as polyethylene, polypropylene, polyethylene terephthalate, and polyester films, porous materials such as paper, cloth, and non-woven cloth, and meshes. Suitable foams, foamed sheets, metal foils, and laminates such as these are preferably plastic films in terms of excellent surface smoothness.

The plastic film is not particularly limited as long as it can protect the adhesive layer for the functional film, and examples thereof include polyethylene films, polypropylene films, polybutene films, polybutadiene films, and polymethyl Pentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polybutylene terephthalate film, polyurethane film, ethylene-vinyl acetate copolymer Film, etc.

On the first base film of the first release film, a polysiloxane-based, fluorine-based, long-chain alkyl-based or fatty ammonium-based release agent, silicon dioxide, etc. may be used as necessary. Mold release and antifouling treatment, or antistatic treatment of coating type, kneading type, evaporation type, etc. In particular, the surface of the release film may be suitably subjected to a peeling treatment such as a polysiloxane treatment, a long-chain alkyl treatment, or a fluorine treatment to further improve the peelability from the adhesive layer for the functional film. The thickness of the first base film of the first release film (release film) is designed so that the first bending stiffness of the first release film is greater than the second bending stiffness of the second release film.

<First peeling film, second peeling film: when used as a surface protective film> The first peeling film and the second peeling film can be used, for example, as a surface protective film. Regarding the surface protective film, when the functional film has an adhesive layer for a functional film on one side, it can be used as a second release film on the other side (see FIGS. 2 and 3). The surface protective film can be used as a first release film and a second release film on both sides of the functional film (see FIGS. 4 and 5).

The first and second release films (surface protection films) each have a first and a second base film. As the first and second base film for the surface protective film, a film material having isotropy or near isotropy is selected from the viewpoints of inspection and management. Examples of the film material include polyester resins such as polyethylene terephthalate films, cellulose resins, acetate resins, polyether fluorene resins, polycarbonate resins, and polyamides. Transparent polymers such as resins, polyimide resins, polyolefin resins such as polyethylene and polypropylene, and acrylic resins. Among these, a polyester resin is preferable. The first and second substrate films may be used in the form of a laminate of one or two or more film materials, and an extension of the above-mentioned film may also be used. The thicknesses of the first and second substrate films of the first and second release films (surface protection films) are designed so that the first bending stiffness of the first release film is greater than the second bending stiffness of the second release film.

As the surface protective film, those using the first and second substrate films as self-adhesive films, and those having the substrate film and the adhesive layer for a surface protective film can be used. From the viewpoint of protecting the functional film, the surface protective film is preferably one having an adhesive layer for a surface protective film.

The surface protective film adhesive layer used for the surface protective film laminate can be appropriately selected from, for example, (meth) acrylic polymers, silicone polymers, polyesters, polyurethanes, polyamides, Polyether, fluorine-based or rubber-based polymers are used as adhesives for base polymers. From the viewpoints of transparency, weather resistance, and heat resistance, an acrylic adhesive using an acrylic polymer as a base polymer is preferred. The thickness (dry film thickness) of the adhesive layer for a surface protection film can be determined according to the required adhesive force. It is usually about 1 to 100 μm, and preferably 5 to 50 μm.

In addition, for the surface protective film (the opposite side when the above-mentioned adhesive layer for a surface protective film is provided), low adhesion materials such as polysiloxane treatment, long-chain alkyl treatment, and fluorine treatment can be used. Instead, a peeling treatment layer is provided.

<Peeling of the 1st peeling film> The film laminated system of this invention laminated | stacked the functional film, and the 1st peeling film and the 2nd peeling film located on the both surfaces, and prepared it as the single piece state of a specific shape (step (1)). Examples of the specific shape include a rectangular shape. Then, the first release film is peeled from the film laminate (step (2)). When the first release film is peeled off, the film laminate can be fixed to the second release film side by, for example, adsorption, and the first release film can be peeled off using a peeling roller or the like (for example, refer to Japanese Patent Laid-Open No. 9-114384). Bulletin, etc.).

<Manufacture of optical display panel> When a film having an adhesive layer for a functional film is used as the film laminate of the present invention (for example, refer to FIG. 2 and FIG. 3), the above steps (1) and subsequent steps are used. (2) A film laminate (for example, a functional film having a surface protection film as an adhesive layer with a second release film) from which the first release film is peeled is bonded to one surface of the optical unit through step (3). In step (3), the side of the functional film adhesive layer for the functional film is bonded to the optical unit to manufacture an optical display panel.

<Other Optical Layers> When an optical film is used as the functional film of the present invention, the optical film can be laminated and used on other optical layers when practical. The optical layer is not particularly limited. For example, when a polarizing film is used as the optical film, for example, one or two or more reflective plates, transflective plates, and retardation plates (including 1/2 or 1/4) can be used. Wavelength plates, etc.), viewing angle compensation films, brightness enhancement films, etc. can be used to form optical layers for liquid crystal display devices and the like.

The optical film laminated with the above-mentioned optical layer can also be formed by sequentially and individually laminating in the manufacturing process of a liquid crystal display device and the like. Those who have been laminated in advance to make an optical film have excellent quality stability or assembly operations and are excellent and can be used. The advantages of manufacturing steps of a liquid crystal display device and the like are improved. For the lamination, a suitable bonding method such as an adhesive layer can be used. When adhering the above-mentioned polarizing film with an adhesive layer or other optical films, these optical axes can be set to an appropriate arrangement angle according to the target phase difference characteristics and the like.

<Optical unit> (Liquid crystal unit, liquid crystal display panel) The liquid crystal unit has a structure in which a liquid crystal layer is sealed between a pair of substrates (a first substrate (viewable side) Pa and a second substrate (back surface) Pb) disposed opposite to each other. Any type of liquid crystal cell may be used, but in order to achieve high contrast, a liquid crystal cell using a vertical alignment (VA) mode and a lateral electric field effect (IPS) mode is preferred. The liquid crystal display panel is a polarizing film bonded to one or both sides of the liquid crystal cell, and a driving circuit is installed as required.

Suitable liquid crystal display devices can be formed on one or both sides of the liquid crystal cell, with a liquid crystal display device having an optical film disposed thereon, or a backlight device or a reflector used in a lighting system. In this case, the optical film of the present invention may be provided on one or both sides of the liquid crystal cell. When the optical film of the present invention is provided on both sides, these may be the same or different. Further, when forming a liquid crystal display device, for example, one or two or more layers of a diffuser plate, an anti-glare layer, an anti-reflection film, a protective plate, a fluorene array, a lens array plate, a light diffusion plate, and a backlight device can be arranged. At the right place.

(Organic EL Unit, Organic EL Display Panel) An organic EL unit as another optical unit has a structure in which an electric field light-emitting layer is sandwiched between a pair of electrodes. As the organic EL unit, any type such as a top emission method, a bottom emission method, and a double-sided emission method can be used. In the organic EL display panel, the optical film (polarizing film) and the retardation film of the present invention are bonded to an organic EL unit together, and a driving circuit is installed as necessary. [Example]

Hereinafter, the present invention will be described with examples, but the present invention is not limited to the examples shown below. In addition, parts and% in each case are a basis of weight. Below, the room temperature storage conditions without special regulations are 23 ° C and 65% RH.

＜ Production of polarizing film ＞ (Production of polarizing element) Copolymerized with polyethylene terephthalate (IPA (Isophtalic Acid, isophthalic acid)) One side of the substrate of a copolymerized PET (Polyethylene terephthalate) film (thickness: 100 μm) is corona treated, and the corona treated surface is coated at 25 ° C. with 9: The ratio of 1 includes polyvinyl alcohol (degree of polymerization 4200, degree of saponification 99.2 mole%) and ethyl acetate modified with PVA (degree of polymerization 1200, degree of modification of ethyl acetate 4.6%, degree of saponification 99.0 mole%) Above, an aqueous solution of a trade name "GOHSEFIMER Z200" manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) was dried to form a PVA-based resin layer having a thickness of 11 μm, and a laminated body was produced. The obtained laminated body was uniaxially extended to 2.0 times along the free end in the longitudinal direction (long side direction) between rollers with different peripheral speeds in an oven at 120 ° C (air-assisted extension treatment). Next, the laminate was immersed in an insoluble bath (aqueous boric acid solution prepared by mixing 4 parts by weight of boric acid with 100 parts by weight of water) at a liquid temperature of 30 ° C. (insoluble treatment). Then, in a dyeing bath at a liquid temperature of 30 ° C., immersion was performed while adjusting the iodine concentration and the immersion time so that the polarizing plate had a specific transmittance. In this example, 0.2 part by weight of iodine and 1.0 part by weight of potassium iodide were mixed in 100 parts by weight of water for immersion in an iodine aqueous solution for 60 seconds (dyeing treatment). Then, immerse for 30 seconds (crosslinking treatment) in a crosslinking bath at a liquid temperature of 30 ° C. (3 parts by weight of potassium iodide was prepared for 100 parts by weight of water, and 3 parts by weight of boric acid was prepared as the boric acid aqueous solution). After that, the laminate was immersed in a boric acid aqueous solution at a liquid temperature of 70 ° C. (aqueous solution prepared by mixing 4 parts by weight of boric acid with 100 parts by weight of water and 5 parts by weight of potassium iodide) while walking between rollers having different peripheral speeds. The longitudinal direction (long-side direction) is uniaxially stretched so that the total stretching ratio becomes 5.5 times (water stretching treatment). Thereafter, the laminated body was immersed in a washing bath (aqueous solution obtained by mixing 4 parts by weight of potassium iodide with 100 parts by weight of water) at a liquid temperature of 30 ° C (washing treatment). Thus, an optical film laminate including a polarizing element having a thickness of 5 μm was obtained.

(Protective film) Protective film 1: A film having a total thickness of 50 μm was applied to one side of a triacetin cellulose film having a thickness of 40 μm and a low-reflection surface treatment with a thickness of 10 μm was applied. Protective film 2: A triethyl cellulose film with a thickness of 40 μm is used.

(Adhesive for protective films 1 and 2) 40 parts by weight of N-hydroxyethyl acrylamide (HEAA) and 60 parts by weight of acrylmorpholine (ACMO) and a photoinitiator "IRGACURE 819" (BASF Corporation) (Production) 3 parts by weight are mixed to prepare an ultraviolet curing adhesive.

<Production of single-sided protective polarizing film A1> On the surface of the polarizing element of the optical film laminate, while applying the ultraviolet-curing adhesive so that the thickness of the cured adhesive layer becomes 1 μm, the adhesive The protective film 1 (the surface on which the low-reflection surface treatment is not performed) is irradiated with ultraviolet rays as active energy rays to harden the adhesive. For ultraviolet irradiation, a gallium-encapsulated metal halide lamp was used (irradiation device: Light HAMMER10 manufactured by Fusion UV Systems, Inc., lamp: V lamp, peak illuminance: 1600 mW / cm ² , cumulative exposure 1000 / mJ / cm ² ( (Wavelength: 380 to 440 nm)), the illuminance of ultraviolet rays was measured using the Sola-Check system manufactured by Solatell. Next, the amorphous PET base material was peeled off, and a single-sided protective polarizing film A using a thin polarizing element was produced. Regarding the optical characteristics of the obtained single-sided protective polarizing film A1, the monomer transmittance was 42.8% and the polarization degree was 99.99%. The thickness of the obtained single-sided protective polarizing film was 56 μm.

＜ Production of polarizing film A2 with double-sided protection ＞ (Production of polarizing element with a thickness of 23 μm) A polyvinyl alcohol film with an average polymerization degree of 2400 and a saponification degree of 99.9 mol% and a thickness of 75 μm is immersed in warm water at 30 ° C for 60 seconds. Make it swollen. Then, the film was dyed while being immersed in an aqueous solution containing 0.3% of iodine / potassium iodide (weight ratio = 0.5 / 8) and being stretched to 3.5 times. Thereafter, it was stretched in a boric acid ester aqueous solution at 65 ° C. so that the total stretch ratio became 6 times. After stretching, it was dried in an oven at 40 ° C. for 3 minutes to obtain a PVA-based polarizing element (thickness: 23 μm). The protective film 1 is bonded to one side of the polarizing element via an ultraviolet curable adhesive in the same manner as described above, and then the protective film 2 is bonded to the other side via the ultraviolet curable adhesive in the same manner as described above. Regarding the optical characteristics of the obtained double-sided protective polarizing film A2, the transmittance was 42.8%, and the polarization degree was 99.99%. The thickness of the double-sided protective polarizing film A2 is 115 μm.

<Monomer transmittance T and polarization degree P of polarizing element> The monochromatic transmittance T and polarization degree of the obtained polarizing film were measured using a spectroscopic transmittance measuring device (Dot-3c of Murakami Color Research Institute) with an integrating sphere P was measured. In addition, the polarization degree P is a transmittance (parallel transmittance: Tp) when two identical polarizing films are superimposed so that their transmission axes become parallel, and the transmission axes of both The transmittance (orthogonal transmittance: Tc) when overlapping in an orthogonal manner is obtained by substituting the following equation. Polarization P (%) = {(Tp－Tc) / (Tp ＋ Tc)} ^1/2 × 100 Each transmittance is set to 100% of the complete polarized light obtained through the Glan-Taylor 稜鏡 polarizing element. JIS Z8701 shows the Y value of 2 degree visual field (C light source) for visibility compensation.

<Preparation of Adhesive> 100 parts of butyl acrylate, 3 parts of acrylic acid, 0.1 part of 2-hydroxyethyl acrylate, and 2,2'-coupling were placed in a reaction vessel equipped with a cooling pipe, a nitrogen introduction pipe, a thermometer, and a stirring device. 0.3 part of azabisisobutyronitrile was added together with ethyl acetate to prepare a solution. Then, the solution was stirred while blowing nitrogen gas into the solution, and reacted at 55 ° C. for 8 hours to obtain a solution containing an acrylic polymer having a weight average molecular weight of 2.2 million. Furthermore, ethyl acetate was added to the solution containing this acrylic polymer, and the acrylic polymer solution which adjusted the solid content concentration to 30% was obtained.

For 100 parts of the solid content of the acrylic polymer solution, 0.5 part of a cross-linking agent and a cross-linking agent containing a compound having an isocyanate group as a main component (manufactured by Nippon Polyurethane (shares), and the trade name "Coronate" L ") and 0.075 parts of γ-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name" KMB-403 ") as a silane coupling agent to prepare an adhesive solution.

<Functional film: TAC film> A3: A triacetyl cellulose film having a thickness of 80 μm is prepared. A4: Prepare a triacetin cellulose film with a thickness of 25 μm.

<Functional film: a film having a low-reflection surface treatment layer on both sides> A5: Prepare two pieces of the low-reflection surface treatment film (thickness 50 μm) of the above-mentioned protective film 1 and prepare the non-implementation of the film in the same manner as above The reflective surface-treated surfaces were bonded to each other with a UV-curable adhesive (thickness: 5 μm) on a film (a double-sided AR film) provided with a low-reflective surface-treated layer on both sides. The thickness of the two-sided AR (Anti-Reflection) film is 105 μm.

Example 1 <Laminate of a surface protective film> A surface protective film (second peeling film, trade name RP108C manufactured by Nitto Denko Corporation) was provided on the protective film 1 side of the single-sided protective polarizing film A1. The surface protective film is a polyester resin film (second substrate film) having a thickness of 25 μm and has an adhesive layer (equivalent to an adhesive layer for surface protective film) having a thickness of 15 μm.

<Formation of an adhesive layer with a release film (first release film)> The above-mentioned adhesive solution was applied so that the thickness after drying became 20 μm to a polyethylene terephthalate film containing a release treatment. (The thickness of the first base film is 50 μm: the trade name of DIAFOIL MRF manufactured by Mitsubishi Resin Co., Ltd.) The surface of the release film (isolation film) is dried to form an adhesive layer (equivalent to a polarizing film (functional film)) With an adhesive layer). Then, the above-mentioned adhesive layer is laminated on the side of the polarizing element of the single-sided protective polarizing film A having a surface protective film to produce the film laminate of the present invention (refer to FIG. 3: Adhesive with a release film and a surface protective film). Polarizing film of the agent layer).

Comparative Examples 1, 2, and Reference Examples 1 to 3 In Example 1, the type of polarizing film, the thickness of the second substrate film used as the surface protective film of the second release film, and the release of the first release film were used. Except that the thickness of the first base film of the mold film was changed as shown in Table 1, a film laminate was produced in the same manner as in Example 1.

Example 2 <Laminated surface protection film> A surface protection film (first and second release films) was provided on both sides of the functional film A3 (a TAC film having a thickness of 80 μm). For the first release film, a polyester resin film (first base film) having a thickness of 100 μm (having an adhesive layer for a surface protective film) having a thickness of 15 μm (manufactured by Nitto Denko Corporation) is used. Trade name RP108C) as a surface protection film. For the second release film, a 25 μm-thick polyester resin film (second substrate film) having an adhesive layer (equivalent to an adhesive layer for surface protection film) having a thickness of 15 μm (manufactured by Nitto Denko Corporation) is used. Trade name RP108C) as a surface protection film.

Examples 3 to 5 and Comparative Examples 3 to 6 In Example 2, the types of functional films, the thicknesses of the first and second substrate films used as the surface protective films of the first and second release films, and the material changes Except for having shown in Table 1, it carried out similarly to Example 2, and produced the film laminated body. Further, in Example 5 and Comparative Example 6, an adhesive layer (having a thickness of 15 μm on a polyethylene resin film (first base film or second base film) having a thickness of 240 μm or 60 μm ( (Equivalent to an adhesive layer for a surface protection film) (trade name HR6010 manufactured by Nitto Denko Corporation) is used as a surface protection film.

The film laminates obtained in the above Examples, Comparative Examples, and Reference Examples and their constituent materials were evaluated as follows. The results are shown in Table 1.

<Bending rigidity test> The bending rigidity of the 1st, 2nd, and 2nd peeling films was measured by the following method. A cantilever-type softness tester manufactured by Yasuda Seiki Co., Ltd. was used. In addition, in this test, in order to eliminate the influence of static electricity, the samples used in the test were appropriately destaticized and carried out. For each film laminate, a rectangular object F (sample) of 20 mm × 150 mm was prepared. It is set to be accommodated on the top surface of the smooth SUS plate stage 41. The top of the SUS plate stage 41 is a flat surface (20 mm × 150 mm: the same size as the sample), and one end of the long side has a 45 ° bevel. The cross section is trapezoidal (see Fig. 6). The above-mentioned sample was smoothly slid to the inclined surface side (1) at a pressing speed of 10 mm / sec. Stop the movement of the sample at the part where the front end of the sample initially contacts the bevel (2). The distance L (mm) of the sample moving on the plane of the top was measured. As for the bending stiffness (mm), for each sample, the shortest straight line distance L (mm) was measured three times for each of the two patterns when the first surface was set to the upper side and when the second surface was set to the upper side (total 12 Samples), and calculate the arithmetic mean of these.

<Measurement of Peeling Force> The film laminates obtained in Examples, Comparative Examples, and Reference Examples were cut to 25 mm × 100 mm, and the film on the side where the peeling force was not measured among the first peeling film and the second peeling film was applied. After peeling, each was bonded to an alkali-free glass having a thickness of 0.5 mm using a double-sided tape (manufactured by Nitto Denko Corporation, double-sided tape No. 511). Attach the transparent tape to the short-side end of the polarizing film with the adhesive layer attached on the alkali-free glass. After peeling off only the starting part in advance, use a tensile machine to pull the first release film or the second release film to 180 ° Peeling, peeling was performed parallel to the longitudinal direction of the film at a speed of 0.3 m / min. The peeling force of the 1st peeling film and the 2nd peeling film was measured separately. The results are shown in Table 1.

<Pickup test> The film laminates obtained in the examples, comparative examples, and reference examples were cut into a single sheet state (sample) by cutting to 150 mm × 150 mm. The first release film side of the sample was set to the upper side, the second release film side was set to the lower side, and the second release film of the sample was used with a double-sided tape (manufactured by Nitto Denko Corporation, double-sided tape No. 511). The sides (all) are fixed to the glass. On the other hand, a double-sided adhesive tape (manufactured by Nitto Denko Corporation, double-sided adhesive tape No. 511) having a width of 5 mm is prepared to be picked up by a pickup roller having a diameter of 45 mm. Next, using a pickup roller, the above-mentioned roller having a diameter of 45 mm was moved in parallel with the diagonal direction of the sample from the edge end of the sample fixed on the glass. The above-mentioned operation was performed 10 times, and the number of peelings from the first release film is shown in Table 1 in the form of "number of times / 10".

<Hanging Test> The film laminates obtained in the examples, comparative examples, and reference examples were cut to a single sheet state (sample) of 25 mm × 100 mm. The first release film side of the sample was set to the upper side, the second release film side was set to the upper side, and the second release film side of the sample was used with a double-sided tape (Double-sided tape No. 511 manufactured by Nitto Denko Corporation). (Only 20 to 100 mm from the end in the long side direction) is attached to the glass and fixed to the glass. That is, a portion of 0 to 20 mm from the end in the longitudinal direction of the sample is suspended. Then, at the end of the sample fixed on the glass (the side in the suspended state), a transparent tape with a width of 25 mm was attached to the test piece, and the sample was 300 mm / min along the long side of the sample at an angle of 30 °. The stretching speed stretches the transparent tape. When the said operation was performed, if the 1st peeling film was not peeled, it will show as "OK" in Table 1. When the first release film is peeled off, the distance (mm) in which it is stretched is shown in Table 1.

[Table 1] In Table 1, PET represents polyethylene terephthalate, and PE represents polyethylene.

1‧‧‧ the first release film

2‧‧‧ The second release film

11‧‧‧The first substrate film

12‧‧‧ Adhesive layer for surface protection film

21‧‧‧Second base film

22‧‧‧ Adhesive layer for surface protection film

41‧‧‧SUS pallet

A‧‧‧Functional film

A'‧‧‧ polarizing film

a1‧‧‧polarizing element

a2‧‧‧ protective film

B‧‧‧ Adhesive layer for functional film

F‧‧‧ Monolithic Film Laminated Optical Film

L‧‧‧ Distance

FIG. 1 is a schematic cross-sectional view of a film laminate in a monolithic state according to the present invention. FIG. 2 is a schematic cross-sectional view of a monolithic film laminate in another embodiment of the present invention. FIG. 3 is a schematic cross-sectional view of a single-layer film laminate in another embodiment of the present invention. FIG. 4 is a schematic cross-sectional view of a single-layer film laminate in another embodiment of the present invention. FIG. 5 is a schematic cross-sectional view of a single-layer film laminate in another embodiment of the present invention. FIG. 6 is a schematic diagram showing bending stiffness in a bending rigidity test.

Claims (18)

A film-laminated body, characterized in that it is a monolithic sheet formed by sequentially laminating a first release film having a first base film, a functional film, and a second release film having a second base film, and The first release film is the one which is released earlier than the second release film. The thickness of the functional film is 110 μm or less, and the first release rigidity (mm) of the first release film in the bending rigidity test is greater than that of the second release film. The second bending stiffness (mm) in the bending rigidity test. For example, the laminated body of claim 1, wherein the difference between the first bending stiffness (mm) and the second bending stiffness (mm) is 10 mm or more. For example, the film laminate of claim 1 or 2, wherein the peeling force (1) of the first peeling film is equal to or higher than the peeling force (2) of the second peeling film. The film laminate according to any one of claims 1 to 3, wherein the thickness of the first substrate film is greater than the thickness of the second substrate film. The film laminate according to any one of claims 1 to 4, wherein the thickness of the first substrate film is 40 μm or more. The optical film according to any one of claims 1 to 5, wherein the thickness of the second substrate film is 35 μm or less. The film laminate according to any one of claims 1 to 6, wherein the functional film is an optical film. The film laminate according to claim 7, wherein the optical film has a polarizing film. The multilayered film according to claim 8, wherein the polarizing film has a polarizing element having a thickness of 10 μm or less. For example, the film laminate of claim 8 or 9, wherein the polarizing film is a single-sided protective polarizing film having a protective film only on one side of the polarizing element. The film laminate according to any one of claims 7 to 10, wherein the optical film has a surface treatment layer on one side or both sides. The film laminate according to any one of claims 1 to 11, wherein the first release film and the second release film are both surface protection films. The film laminate according to any one of claims 1 to 12, wherein the functional film has an adhesive layer for a functional film on a side where the first release film is provided, and the second release film is a surface protective film. For example, the film laminate of claim 12 or 13, wherein the surface protective film has an adhesive layer for a surface protective film, and is laminated on the functional film through the adhesive layer. For example, the film laminate of claim 12 or 13, wherein the surface protection film is a self-adhesive film. A peeling method of a first peeling film, which is capable of peeling the first peeling film from the film laminate of any one of claims 1 to 15. A method for manufacturing an optical display panel, comprising: a step (1) of preparing a film laminate according to any one of claims 13 to 15; a step (2) of peeling a first release film from the film laminate; A step (3) of bonding the side of the adhesive layer for a functional film of the film laminate of the first release film to the first surface of the optical unit. The method for manufacturing an optical display panel according to claim 17, wherein the optical unit is a liquid crystal unit or an organic EL unit.