TWI791124B - laminate - Google Patents

Abstract

The laminate (101) of the present invention comprises: an adhesive optical film (10) with an adhesive layer (12) fixed and laminated on the optical film (11), and a release film temporarily attached to the surface of the adhesive layer (12). 70), and the surface protective film (50) temporarily adhered to the optical film (11). The release film (70) and the surface protection film (50) exist to protrude to the area outside the periphery of the adhesive optical film (10), the adhesive layer (52) of the surface protection film (50) and the release film ( 70) Connect. The adhesive force of the adhesive optical film (10) and the surface protection film (50) to the acrylic resin plate are respectively in specific ranges, and the three-point bending loads of the release film (70) and the surface protection film (50) are respectively in specific ranges.

Description

laminate

The present invention relates to a laminate with a release film temporarily adhered to the surface of an adhesive optical film and a surface protection film.

Optical devices such as displays include optical films such as polarizing plates, retardation films, antireflection films, and hard coat films. These optical films are bonded to an image display unit or the like as an adhesive optical film having an adhesive layer layered on one surface. Before the adhesive optical film is attached to an adherend such as an image display unit, a release film is temporarily attached to the surface of the adhesive layer. In addition, a surface protection film is temporarily attached to the surface of the optical film in order to prevent damage to the optical film. When attaching the adhesive optical film to an adherend, the release film is peeled off from the surface of the adhesive layer, and the exposed adhesive layer is attached to an adherend such as an image display unit. Thereafter, the surface protection film was peeled off from the optical film.

Usually, the adhesive optical film is cut into a single piece having a shape and a size conforming to the image size of an image display device. If a laminate with a release film and a surface protection film temporarily attached to an adhesive optical film is punched using a Thomson blade, etc., the surface protection film, adhesive optical film, and release film will be cut into the same The shape and size of each end face are aligned. If the end faces of the adhesive optical film are aligned with the end faces of the surface protection film and the release film, the adhesive layer will be exposed to the end faces, which may cause contamination of the paste or chipping of the paste. In addition, there are cases where the laminate is blocked due to seepage of the adhesive from the end surface, or the peeling operation of the release film or the surface protection film becomes difficult.

Patent Document 1 discloses a laminate of the following design: a release film and a surface protection film having a size larger than the adhesive optical film are attached to the adhesive optical film, so that the release film and the surface protection film protrude to the adhesive optical film Outside the outer perimeter. By locating the end faces of the release film and the surface protection film on the outer side than the end faces to which the optical film is adhered, the problem caused by the seepage of the adhesive from the end faces can be solved. [Prior Art Literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open No. 2002-303730

[Problem to be solved by the invention]

The surface protection film bonded to the adhesive optical film has an adhesive layer fixedly laminated on the surface of the film substrate, and is bonded to the optical film through the adhesive layer. If the surface protection film is designed to protrude to the outside of the adhesive optical film, the adhesive layer of the surface protection film will be exposed. If the adhesive layer of the surface protection film is exposed, the following problems may occur: contamination caused by foreign matter deposited on the adhesive layer, or adhesion of the adhesive layer to other components or conveying equipment, etc. Paste pollution or peeling of the surface protective film, etc. Therefore, in Patent Document 1, the protrusion amount of the surface protection film is set to 5 mm or less.

Even when the protruding amount of the surface protection film is small, it is difficult to completely eliminate the problem of contamination or peeling due to the exposure of the adhesive layer of the surface protection film. On the other hand, if contrary to the disclosure of Patent Document 1, the protruding amount of the surface protection film and the release film is increased intentionally, then in the area protruding from the outer periphery of the adhesive optical film, the adhesive of the surface protection film The layer will be in close contact with the release film, so the exposure of the adhesive layer can be prevented.

However, if the pressure-sensitive adhesive layer of the surface protection film is in close contact with the release film, it may be difficult to selectively peel the release film when peeling the release film from the adhesive optical film. Specifically, there is a case where peeling at the interface between the adhesive layer and the release film that adheres the optical film becomes difficult, or peeling occurs at the interface between the surface protection film and the optical film, and there is a case where the optical film is attached to the adherend. Tendency to reduce the efficiency of cooperative business.

In view of the above circumstances, an object of the present invention is to provide a laminate in which a release film can be easily peeled off in a state where a surface protective film is temporarily attached to an optical film. [Technical means to solve the problem]

The inventors of the present invention conducted research and found that by setting the adhesive force of the adhesive layer on the optical film, the adhesive force of the adhesive layer on the surface protection film, the mechanical properties of the surface protection film, and the mechanical properties of the release film, respectively For a specific range, the above-mentioned problems can be solved.

The laminate of the present invention includes: an adhesive optical film in which the first adhesive layer is fixedly laminated on the optical film, a release film temporarily adhered to the surface of the first adhesive layer, and a surface protection film temporarily adhered to the optical film. The surface protection film has a film substrate and a second adhesive layer fixedly laminated on the film substrate, and the second adhesive layer of the surface protection film is temporarily adhered to the second main surface of the optical film. The release film and the surface protection film have a region protruding outside the outer periphery of the adhesive optical film, and the adhesive layer of the surface protection film is in contact with the release film.

Regarding the laminate, it is preferable that the release film and the surface protection film protrude outside the outer periphery of the adhesive optical film over the entire periphery of the adhesive optical film. The surface protection film preferably protrudes outward by more than 5 mm from the outer periphery of the adhesive optical film. The release film may have a region protruding outside the outer periphery of the surface protection film.

The 180° peel force of the first adhesive layer adhering the optical film to the acrylic resin plate at a tensile speed of 0.3 m/min is 3 N/25 mm or more. The 180° peel force of the second adhesive layer of the surface protection film relative to the acrylic resin plate at a tensile speed of 0.3 m/min is 1 N/25 mm or less. The adhesive force of the first adhesive layer of the optical film to the acrylic resin plate is preferably more than 20 times the adhesive force of the second adhesive layer of the surface protection film to the acrylic resin plate.

The three-point bending load of the release film is 1 g or less. The three-point bending load of the surface protection film is 1.2 g or more. The three-point bending load of the surface protection film is preferably more than three times the three-point bending load of the release film. The thickness of the film substrate of the surface protection film is preferably 60 μm or more. [Effect of Invention]

In the laminated body of the present invention, since the release film and the surface protection film are provided in such a manner as to protrude to the outside of the outer periphery of the adhesive optical film, it is possible to suppress leakage of the adhesive from the end surface of the adhesive optical film. bad situation. Also, in the area where the release film and the surface protection film protrude outside the outer periphery of the adhesive optical film, since the release film is in contact with the adhesive layer of the surface protection film, exposure of the adhesive is suppressed. The adhesive strength of the adhesive optical film and the surface protection film to the acrylic resin board is within a specific range, and the three-point bending load of the release film and the surface protection film is within a specific range. Therefore, when the optical film is temporarily adhered to the surface protection In the state of the film, the peeling operation of the release film can be easily performed.

[Layered composition of laminated body] FIG. 1 is a cross-sectional view of a laminate 101 in which a surface protection film 50 and a release film 70 are temporarily bonded and laminated on an adhesive optical film 10 . The adhesive optical film 10 has an adhesive layer 12 fixedly laminated on the first main surface of the optical film 11 . A release film 70 is temporarily attached to the first adhesive layer 12 . The surface protection film 50 has a second adhesive layer 52 fixedly laminated on the surface of the film substrate 51 , and the second adhesive layer 52 is attached to the second main surface of the optical film 11 .

Furthermore, "adhesion" refers to a state in which two layers of a laminate are firmly bonded, and peeling at the interface between the two is impossible or difficult to occur. "Temporary adhesion" refers to the state in which the adhesive force between the two layers of the laminate is relatively small and can be easily peeled off at the interface between the two.

FIG. 2 is a plan view of the laminate 101 viewed from the surface protection film 50 side, and the cross-sectional view at line I-I in FIG. 2 corresponds to FIG. 1 . The size of the surface protection film 50 and the size of the release film 70 are larger than the size of the adhesive optical film 10 . In the laminated body 101, the surface protection film 50 and the release film 70 are provided so that the whole periphery may protrude from the end surface of the adhesive optical film 10.

In the area where the surface protection film 50 and the release film 70 protrude to the outside of the end surface to which the optical film 10 is adhered, the adhesive layer 52 of the surface protection film 50 is in contact with the release film 70 and bonded. Therefore, the end surface of the adhesive optical film 10 is covered by the surface protection film 50 and the release film 70 , which can prevent the adhesive layer 12 from protruding from the end surface of the optical film 11 to cause paste defects or paste contamination.

In the laminate of the present invention, it is only necessary that the surface protection film 50 and the release film 70 protrude outside the outer periphery of the adhesive optical film 10 on at least a part of the outer periphery of the adhesive optical film 10 . In order to reduce the exposure of the adhesive layer 12 on the end face of the optical film 11, preferably in the area of more than 1/3 of the outer circumference of the adhesive optical film 10, the surface protection film 50 and the release film 70 protrude farther than the adhesive optical film 10. The outer periphery is more lateral. The area where the surface protection film 50 and the release film 70 protrude outside the outer periphery of the adhesive optical film 10 is preferably more than 1/2, preferably more than 2/3 of the outer periphery of the adhesive optical film 10 . Preferably, as shown in FIG. 2 , on the entire periphery of the adhesive optical film 10 , the surface protection film 50 and the release film 70 protrude outside the outer periphery of the adhesive optical film 10 .

The protrusion amount L ₁ of the surface protection film 50 from the end surface to which the optical film 10 is adhered is preferably at least 5 mm, more preferably at least 8 mm, and still more preferably at least 10 mm. L ₁ may be greater than 15 mm or greater than 20 mm. The protruding amount L ₂ of the release film 70 from the end surface of the adhesive optical film 10 is preferably greater than the protruding amount L ₁ of the surface protection film 50 .

By making the protruding amount of the surface protection film 50 and the release film 70 larger from the end surface of the adhesive optical film 10, the bonding area of the adhesive layer 52 of the surface protection film 50 and the release film 70 can be ensured, and can be properly maintained. Bonding state of the release film 70 and the surface protection film. By making the protruding amount _L2 of the release film 70 equal to or greater than the protruding amount _L1 of the surface protection film 50, the release film is temporarily attached to the adhesive layer 52 over the entire area protruding from the adhesive optical film 10. 70, therefore, it is possible to suppress the disadvantages caused by the exposure of the adhesive layer 52.

When the protruding amount _L2 of the release film 70 is greater than the protruding amount _L1 of the surface protection film 50, the release film 70 can be selectively pinched, so it is easy to peel the release film 70 from the laminate Operation. When L ₂ is greater than L ₁ , L ₂ - L ₁ is preferably at least 2 mm, more preferably at least 3 mm, and still more preferably at least 5 mm. L ₂ -L ₁ may be more than 7 mm or more than 10 mm.

The upper limit of the protrusion amount L ₁ of the surface protection film 50 and the protrusion amount L ₂ of the release film 70 is not particularly limited. In consideration of workability, area efficiency, etc., L ₁ and L ₂ are preferably 150 mm or less, more preferably 100 mm or less, further preferably 70 mm or less. L ₁ and L ₂ may be less than 50 mm, less than 40 mm, less than 30 mm, or less than 20 mm.

In order to improve the peeling workability of the release film, when the part where the protruding amount L ₂ of the release film 70 is larger than the protruding amount L ₁ of the surface protection film 50 is set, the pinch of the release film during peeling can be reduced. A portion selectively protrudes from the outer periphery of the adhesive layer. For example, the laminate 103 shown in the sectional view of FIG. 3 and the top view of FIG. 4 can be partially provided with a protruding part 77 on the outer periphery of the release film 70, and the release film can be peeled off by pinching the protruding part.

[Adhesion of optical film to adherend] 5A to 5F are conceptual diagrams showing a state in which the adhesive optical film 10 is bonded to the adherend 30 . First, the release film 70 is peeled off from the laminate 101 to expose the adhesive layer 12 adhering the optical film 10 ( FIGS. 5A to 5C ). Thereafter, the optical film 11 is bonded to the adherend 30 via the adhesive layer 12 ( FIG. 5D ). As an example of the to-be-adhered body 30, image display units, such as a liquid crystal cell and an organic EL cell, are mentioned. The adherend 30 may also be an image display device in which various optical films, cover glass, etc. are bonded to the surface of the image display unit. After bonding the adhesive optical film 10 to the adherend, the surface protection film 50 is peeled and removed from the optical film 11 ( FIGS. 5E to 5F ). Since the release film 70 and the surface protection film 50 are flexible, when these films are peeled off, tensile stress is applied to the bonding surface at a specific angle, and the films are peeled in a bent state.

When the release film 70 is peeled off and removed, at first, the peeling of the interface between the adhesive layer 52 of the surface protection film 50 and the release film 70 is carried out in the area protruding from the outer periphery of the adhesive optical film 10 ( FIG. 5A ), Thereafter, the peeling at the interface between the adhesive layer 12 and the release film 70 adhering the optical film 10 is performed ( FIG. 5B ). In the industrial process, it is required to be able to successfully implement both the peeling of the release film 70 from the surface protection film 50 and the peeling of the release film 70 from the adhesive optical film 10, and the ability to selectively peel the release film 70 from the laminate peel off.

When peeling at the interface of the adhesive layer 52 of the surface protection film 50 and the release film 70, as shown in FIG. 5A, the peeling is performed by bending the release film 70 and applying tensile stress. At this time, if the surface protection film 50 bends following the release film 70, the angle (peeling angle) between the interface and the release film 70 cannot be formed, and an appropriate peeling force is not given, so it is difficult to realize the separation of the release film 70 from the surface. Peeling of the protective film 50 .

When the release film 70 is bent, it is preferable that the three-point bending load of the surface protection film 50 be larger than the three-point bending load of the release film 70 in order to prevent the surface protection film 50 from following and bending. The three-point bending load is measured in accordance with JIS K7171 under the conditions of a distance between fulcrums of 25 mm, an indentation speed of 0.5 mm/min, and an indentation amount of 5 mm.

The bending load is an indicator of the bending difficulty of the material, which is proportional to the bending stiffness. Bending stiffness is expressed by the product of longitudinal elastic modulus (Young's modulus) E and section secondary moment I, ie E×I. When the section is rectangular like a film, the secondary moment I of the section is proportional to the cube of the thickness d of the film. Therefore, the three-point bending load of the film is proportional to the cube of the thickness of the film.

From the standpoint of bending the release film 70 to facilitate peeling, the three-point bending load of the release film 70 is preferably 1 g or less, more preferably 0.7 g or less, further preferably 0.5 g or less, especially preferably 0.5 g or less. 0.4 g or less. On the other hand, if the bending load is too small, the film tends to be difficult to handle. Therefore, the three-point bending load of the release film 70 is preferably at least 0.005 g, more preferably at least 0.01 g, and still more preferably at least 0.02 g.

When the release film 70 is bent, the three-point bending load of the surface protection film 50 is preferably 1.2 g or more, more preferably 1.5 g or more, in order to suppress the surface protection film 50 from following and bending. From the same point of view, the three-point bending load of the surface protection film 50 is preferably 3 times or more, more preferably 6 times or more, further preferably 8 times or more, and especially preferably 3 times or more, the three-point bending load of the release film 70 more than 10 times.

In order to make the peeling of the release film 70 easier, the three-point bending load of the surface protection film 50 should be larger and heavier. On the other hand, when the bending load of the surface protection film 50 is too large, it may become difficult to peel off the surface protection film from the surface of the optical film 11. Therefore, the three-point bending load of the surface protection film 50 is preferably 60 g or less, more preferably 50 g or less. The three-point bending load of the surface protection film 50 may be 1.8 g or more or 2 g or more. The three-point bending load of the surface protection film 50 may be 40 g or less, 30 g or less, 20 g or less, 15 g or less, 10 g or less, 7 g or less, or 5 g or less.

When peeling off the release film 70 from the adhesive layer 12 of the adhesive optical film 10, as shown in FIG. The interface between the adhesive layer 12 and the release film 70 is peeled off. On the other hand, when peeling the surface protection film 50 from the optical film 11, as shown in FIG. Peeling is performed at the interface between the adhesive layer 52 and the optical film 11 .

In order to easily realize the peeling at the interface between the adhesive layer 12 and the release film 70 , the release film 70 is preferably subjected to a release treatment on the contact surface with the adhesive layer 12 . Examples of the release agent used in the release treatment include silicone-based release agents, fluorine-based, long-chain alkyl-based release agents, fatty acid amide-based release agents, and silica powder.

In order to easily realize the peeling at the interface between the adhesive layer 52 and the optical film 11 , it is preferable that the adhesive force of the adhesive layer 12 is smaller than that of the adhesive layer 52 . Adhesive strength can be evaluated by the peeling force when the sample is pasted on the acrylic resin plate and the tensile speed is 0.3 m/min when the 180° peeling test is performed. Hereinafter, unless otherwise specified, the peel force with respect to the 180° peel test at a tensile speed of 0.3 m/min of the acrylic resin plate is described as "adhesive force".

The adhesive force of the surface protection film 50 (second adhesive layer 52) is preferably 1 N/25 mm or less. The adhesive force of adhering the optical film 10 (the first adhesive layer 12 ) is preferably 3 N/25 mm or more. When peeling off the surface protection film 50, in order to suppress the peeling of the adhesive optical film 10 from the adherend 30, the adhesive force of the first adhesive layer 12 is preferably more than 20 times that of the second adhesive layer 52, more preferably 25 times or more, and more preferably 30 times or more. The adhesive force of the first adhesive layer 12 may be 40 times or more, 50 times or more, 60 times or more, 70 times or more, 80 times or more, 90 times or more, or 100 times or more of the adhesive force of the second adhesive agent layer 52 .

From the viewpoint that the surface protection film 50 exhibits suitable adhesiveness to the optical film 11 and the release film 70 and is easy to peel off, the adhesive force of the adhesive layer 52 of the surface protection film 50 is preferably 0.01 to 1 N/ 25 mm, more preferably 0.03-0.6 N/25 mm, still more preferably 0.05-0.4 N/25 mm.

In order to firmly adhere the adhesive optical film 10 to the adherend 30, the adhesive force of the adhesive layer 12 of the adhesive optical film 10 is preferably 3 N/25 mm or more, more preferably 6 N/25 mm or more, and even more preferably 8 N/25 mm or more. The upper limit of the adhesive force of the adhesive layer 12 for adhering the optical film 10 is not particularly limited. When secondary processability is required, the adhesive force is preferably 80 N/25 mm or less, more preferably 60 N/25 mm or less , and more preferably 50 N/25 mm or less. The adhesive strength of the adhesive layer 12 adhering the optical film 10 may be greater than 10 N/25 mm, greater than 13 N/25 mm, or greater than 15 N/25 mm. The adhesive force of the adhesive layer 12 adhering the optical film 10 may be 40 N/25 mm or less, 35 N/25 mm or less, or 30 N/25 mm or less.

[Optical film] Examples of the optical film 11 include polarizing plates, retardation plates, viewing angle expansion films, viewing angle limiting (peep prevention) films, brightness enhancement films, antireflection films, reflective sheets, transparent conductive films, prism sheets, light guide plates, and the like. The optical film 11 may be formed by laminating a plurality of optical films through an appropriate adhesive layer or adhesive layer as needed.

As a polarizing plate, it is usually used on one or both sides of a polarizing element, and a suitable transparent protective film is attached as needed. Examples of polarizing elements include polyvinyl alcohol-based films, partially formalized polyvinyl alcohol-based films, ethylene-vinyl acetate copolymer-based partially saponified films, etc. Hydrophilic polymer film uniaxially stretched, polyene-based oriented film such as dehydration treatment of polyvinyl alcohol or dehydrochlorination treatment of polyvinyl chloride, etc.

Regarding the transparent protective film as a polarizing element protective film, it is preferable to use: cellulose-based resins such as cellulose triacetate, polyester-based resins, polyether-based resins, poly-based resins, polycarbonate-based resins, polyacrylic resins, etc. Amine resins, polyimide resins, polyolefin resins, (meth)acrylic resins, cyclic polyolefin resins (northylene resins), polyarylate resins, polystyrene resins, Transparent resins such as polyvinyl alcohol-based resins. The thickness of the polarizing element protective film is not particularly limited, but it is preferably about 5 to 100 μm, more preferably 10 to 80 μm, in terms of workability such as strength and handleability, and thin film properties.

When the polarizing element protective film is provided on both sides of the polarizing element, a film made of the same resin material or a film made of different resin materials may be used for the front and back. In addition, in order to achieve optical compensation of the liquid crystal cell, expansion of the viewing angle, etc., an optically anisotropic film such as a retardation plate (stretched film) can also be used as a polarizing element protective film. The polarizing element protective film may be a λ/4 plate, and the circular polarizing plate may be constituted by the polarizing element and the polarizing element protective film. For example, by arranging a circular polarizing plate on the viewing side surface of the organic EL element, the reflection of external light caused by metal electrodes and the like can be shielded to improve the visibility of the display.

The polarizer and the protective film for the polarizer are preferably bonded via an appropriate adhesive layer. The material of the adhesive used in laminating the PVA-based polarizer and the polarizer protective film is not particularly limited as long as it is optically transparent. Examples include epoxy-based resins, silicone-based resins, acrylic-based resins, and polyurethanes. Ester, polyamide, polyether, polyvinyl alcohol, etc. The thickness of the adhesive is preferably 5 μm or less, more preferably 0.01-3 μm, and still more preferably 0.05-2 μm.

As the adhesive, various forms such as water-based adhesives, solvent-based adhesives, hot-melt adhesives, and active energy ray-curable adhesives can be used. Among them, a water-based adhesive or an active energy ray-curable adhesive is preferable because the thickness of the adhesive layer can be reduced.

Examples of water-based adhesives include vinyl polymer-based, gelatin-based, vinyl-based latex-based, polyurethane-based, isocyanate-based, polyester-based, epoxy-based, etc., including water-soluble or water-dispersible polymers. Adhesives. The adhesive layer containing such a water-based adhesive is formed by applying an aqueous solution on a film and drying it. When preparing the aqueous solution, catalysts such as cross-linking agents or other additives and acids may also be formulated as needed.

The active energy ray-curable adhesive is an adhesive capable of radical polymerization, cationic polymerization, or anionic polymerization by irradiating active energy rays such as electron beams or ultraviolet rays. Among them, photoradically polymerizable adhesives that start radical polymerization by ultraviolet irradiation are preferred because they can be cured with low energy. As a monomer of a radically polymerizable adhesive agent, the compound which has a (meth)acryl group, or the compound which has a vinyl group is mentioned.

On the surface of the optical film 11, functional imparting layers such as an antireflection layer, an antifouling layer, a light diffusion layer, an easy-adhesive layer, an antistatic layer, a hard coat layer, and an anti-adhesion layer can be provided. Examples of the antireflection layer include a thin-layer type that prevents reflection by utilizing the canceling effect of reflected light due to multiple interference of light, or a type that reduces reflectivity by imparting a fine structure to the surface. Examples of materials for the antifouling layer include silane compounds containing fluorine groups, organic compounds containing fluorine groups, and the like. In addition, diamond-like carbon and the like can also be used as a material for the antifouling layer. The thickness of the antifouling layer is, for example, about 0.01-2 μm, preferably 0.05-1.5 μm.

In order to improve the wettability or adhesion of the adhesive agent or the adhesive agent, etc., an easy-adhesive layer may be provided on the surface of the optical film. Examples of materials for the easy-adhesive layer include epoxy-based resins, isocyanate-based resins, polyurethane-based resins, polyester-based resins, polymers containing amino groups in their molecules, and ester-based urethanes. resins, acrylic resins with oxazoline groups, etc. The thickness of the easily adhesive layer is, for example, 0.05-3 μm, preferably 0.1-1 μm.

As an antistatic layer, what added an antistatic agent to binder resin can be used preferably. Examples of the antistatic agent include ionic surfactants, conductive polymers such as polyaniline, polythiophene, polypyrrole, and polyquinoline; metal oxides such as tin oxide, antimony oxide, and indium oxide; and the like.

[Film base material of surface protection film] As the film base material 51 of the surface protection film 50, a plastic film can be used. When the surface protection film 50 is bonded to the optical film 11 and inspected visually or with an inspection device, the film base material 51 is preferably transparent. The total light transmittance of the film substrate 51 is preferably at least 80%, more preferably at least 85%, and still more preferably at least 90%. The haze of the film substrate 51 is preferably 10% or less, more preferably 5% or less, and still more preferably 2% or less. The resin material constituting the film substrate is not particularly limited. As the transparent resin material, acrylic resins, polyolefins, cyclic polyolefins, polyesters, and the like are preferably used.

The thickness of the film substrate 51 is not particularly limited. In order to make the three-point bending load of the surface protection film 50 fall within the above-mentioned range, the thickness of the film substrate 51 is preferably 60 μm or more, more preferably 65 μm or more, and even more preferably 70 μm or more. The bending load of the surface protection film 50 depends on the Young's modulus and thickness of the film base material 51 and the Young's modulus and thickness of the adhesive layer 52, but since the Young's modulus of the adhesive layer is much smaller than the film base material, Therefore, the bending load of the surface protection film 50 is substantially equal to the bending load of the film base material 51 . Since the bending load is proportional to the cube of the thickness of the film substrate, the thickness of the film substrate becomes the main factor governing the bending stiffness of the surface protection film 50 . Therefore, in order to make the bending rigidity of the surface protection film 50 into the said range, it is preferable to increase the thickness of the film base material 51.

The film substrate 51 may be formed by laminating two or more resin films via an adhesive layer or an adhesive layer. By laminating a plurality of films and increasing the thickness, the bending rigidity of the surface protection film can be increased. When the film base material 51 is a laminated body of two or more resin films, it is preferable that the total thickness of each resin film is in the said range. Adhesives or bonding agents used to laminate a plurality of films are not particularly limited. The adhesive used for laminating a plurality of films may be the same adhesive as that of the second adhesive layer 52 of the surface protection film 50 . When the film base material 51 is a laminate of two or more resin films, the total thickness of each resin film does not include the thickness of the adhesive or adhesive used for laminating the films.

The upper limit of the thickness of the film substrate 51 is not particularly limited. From the viewpoint of easy peeling of the surface protection film 50 from the flexible optical film 11, the thickness of the film substrate 51 is preferably 300 μm or less, more preferably Preferably, it is 250 μm or less, and more preferably 220 μm or less.

When optical inspection is performed with the surface protection film 50 bonded to the optical film 11, the phase difference of the film base material 51 may cause the inspection light to be colored. From the viewpoint of preventing light leakage, coloring, and rainbow unevenness during optical inspection, the front retardation Re of the film base material 51 is preferably 100 nm or less, more preferably 50 nm or less, further preferably 30 nm or less, and most preferably below 20 nm. By making the retardation Rth in the thickness direction of the film base material 51 small, light leakage, coloring, rainbow unevenness, and the like can be prevented even when viewed from an oblique direction. Therefore, the difference in color or brightness between the vicinity of the center (in the frontal direction) and the peripheral portion (in the oblique direction) becomes smaller in a wide-range photographed image with a fixed camera, and data processing becomes easier. The retardation Rth in the thickness direction of the film substrate 51 is preferably 100 nm or less, more preferably 50 nm or less, further preferably 30 nm or less.

The front retardation Re and the thickness direction retardation Rth are defined as follows, and these are measured values at a wavelength of 590 nm. Re=(nx－ny)×d Rth=(nx－nz)×d nx is the refractive index in the direction of the slow axis in the plane, ny is the refractive index in the direction of the advancing axis in the plane, nz is the refractive index in the thickness direction, and d is the thickness.

In order to make the Re and Rth of the film base material 51 fall within the above-mentioned ranges, it is preferable to use a low-birefringence material film, a film without stretching or a film with a low stretching ratio as the film base material 51 . Examples of materials capable of achieving both high transparency and low birefringence include cycloolefin resins and acrylic resins.

Examples of cycloolefin-based resins include polynorthene. Examples of commercially available cycloolefin-based resins include Zeonor and Zeonex manufactured by Zeon Japan, Arton manufactured by JSR, APPEL manufactured by Mitsui Chemicals, and TOPAS manufactured by TOPAS ADVANCED POLYMERS. The cycloolefin-based film preferably contains 50% by weight or more of cycloolefin-based resin.

Examples of acrylic resins include poly(meth)acrylates such as polymethyl methacrylate, methyl methacrylate-(meth)acrylic acid copolymers, methyl methacrylate-(meth)acrylate copolymers, Polymers, methyl methacrylate-acrylate-(meth)acrylic acid copolymers, (meth)acrylate-styrene copolymers (MS resins, etc.), polymers with alicyclic hydrocarbon groups (for example, methyl methyl acrylate-cyclohexyl methacrylate copolymer, methyl methacrylate-northyl (meth)acrylate copolymer, etc.). As a commercial item of an acrylic resin, ACRYPET manufactured by Mitsubishi Chemical Corporation is mentioned. A (meth)acrylic resin having an inner alicyclic structure or a (meth)acrylic resin having an unsaturated alkyl carboxylate unit and a glutarimide unit can also be used as a constituent material of the film substrate 51 . It is preferable that an acrylic film contains 50 weight% or more of acrylic resin.

[adhesive layer] The composition of the adhesive constituting the first adhesive layer 12 for adhering the optical film 10 and the second adhesive layer 52 of the surface protection film 50 is not particularly limited, and acrylic polymers and silicone polymers can be suitably selected and used. , polyester, polyurethane, polyamide, polyvinyl ether, vinyl acetate/vinyl chloride copolymer, modified polyolefin, epoxy, fluorine, natural rubber, synthetic rubber, etc. polymer as the base polymer. In particular, it is preferable to use an acrylic adhesive having an acrylic polymer as a base polymer from the viewpoint of excellent optical transparency.

As the acrylic base polymer, one having an alkyl (meth)acrylate monomer unit as the main skeleton can be suitably used. In addition, in this specification, "(meth)acrylic acid" means acrylic acid and/or methacrylic acid.

As the alkyl (meth)acrylate, an alkyl (meth)acrylate having 1 to 20 carbon atoms in the alkyl group can be suitably used. For example, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, second butyl (meth)acrylate, (meth)acrylate ) tertiary butyl acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, neopentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, ( 2-ethylhexyl methacrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, (meth)acrylic acid Decyl ester, Isodecyl (meth)acrylate, Undecyl (meth)acrylate, Lauryl (meth)acrylate, Isotridecyl (meth)acrylate, (Meth) Myristyl acrylate, Isotetradecyl (meth)acrylate, Pentadecyl (meth)acrylate, Cetyl (meth)acrylate, Heptadecyl (meth)acrylate, Octadecyl (meth)acrylate, isostearyl (meth)acrylate, nonadecyl (meth)acrylate, aralkyl (meth)acrylate, etc.

The content of the alkyl (meth)acrylate is preferably at least 40% by weight, more preferably at least 50% by weight, and still more preferably at least 60% by weight, based on the total amount of monomer components constituting the base polymer. The acrylic polymer can be a copolymer of several kinds of alkyl (meth)acrylates. The arrangement of the constituent monomer units may be random or block.

The acrylic polymer preferably contains a monomer component having a crosslinkable functional group as a copolymerization component. As a monomer which has a crosslinkable functional group, a hydroxyl group containing monomer or a carboxyl group containing monomer is mentioned. Among them, it is preferable to contain a hydroxyl group-containing monomer as a copolymerization component of the base polymer. The hydroxyl group or carboxyl group of the base polymer becomes a reaction point with the crosslinking agent described below. By introducing a cross-linked structure into the base polymer, the cohesive force of the adhesive is improved, and moderate adhesion to the adherend is exhibited.

Examples of hydroxyl-containing monomers include: 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxy (meth)acrylate Hexyl ester, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, (4-hydroxymethylcyclohexyl)methyl acrylate. Examples of the carboxyl group-containing monomer include: (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, etc. .

Regarding the acrylic polymer, in addition to the above, as comonomer components, acid anhydride group-containing monomers, caprolactone adducts of acrylic acid, sulfonic acid group-containing monomers, phosphoric acid group-containing monomers, and the like can also be used. Also, as a modifying monomer, vinyl acetate, vinyl propionate, N-vinylpyrrolidone, methylvinylpyrrolidone, vinylpyridine, vinylpiperidone, vinylpyrimidine can also be used , vinylpyrrole, vinylpyrrole, vinylpyrrole, vinylimidazole, vinyloxazole, vinylmorpholine, N-vinylcarboxamides, styrene, α-methylstyrene, N- Vinyl-based monomers such as vinyl caprolactam; cyanoacrylate-based monomers such as acrylonitrile and methacrylonitrile; epoxy-containing acrylic monomers such as glycidyl (meth)acrylate; (meth) ) glycol-based acrylate monomers such as polyethylene glycol acrylate, polypropylene glycol (meth)acrylate, methoxyethylene glycol (meth)acrylate, and methoxypolypropylene glycol (meth)acrylate; Acrylate-based monomers such as tetrahydrofurfuryl (meth)acrylate, fluoro(meth)acrylate, silicone (meth)acrylate, or 2-methoxyethyl acrylate.

The ratio of the comonomer component in the acrylic polymer is not particularly limited. For example, when a hydroxyl-containing monomer or a carboxyl-containing monomer is used as the comonomer component in order to introduce crosslinking points, the ratio of the hydroxyl-containing monomer and the The total content of carboxyl group monomers is preferably about 1 to 20%, more preferably about 2 to 15%, based on the total amount of monomer components constituting the base polymer.

The acrylic polymer as the base polymer is obtained by polymerizing the above-mentioned monomer components by various known methods such as solution polymerization, photopolymerization, emulsion polymerization, block polymerization, and suspension polymerization. As a solvent for solution polymerization, ethyl acetate, toluene and the like can be used. The solution concentration is usually about 20 to 80% by weight. As a polymerization initiator, various well-known ones, such as an azo type and a peroxide type, can be used. In order to adjust the molecular weight, chain transfer agents can also be used. The reaction temperature is usually about 50 to 80°C, and the reaction time is usually about 1 to 8 hours.

The molecular weight of the base polymer is appropriately adjusted so that the adhesive layer 52 has a desired adhesive force. For example, the weight average molecular weight in terms of polystyrene is about 50,000 to 2 million, preferably about 70,000 to 1.8 million. , more preferably about 100,000 to 1.5 million, and more preferably about 200,000 to 1 million. Furthermore, when introducing a crosslinked structure into a base polymer, it is preferable that the molecular weight of the base polymer before introducing a crosslinked structure is the said range.

In order to obtain the adhesive layer 52 having suitable adhesiveness to the adherend under a normal temperature environment, the glass transition temperature (Tg) of the base polymer in terms of Fox's formula is preferably 0° C. or lower. The Tg of the base polymer is preferably -10 to -80°C, more preferably -15 to -75°C, still more preferably -20 to -70°C.

In order to adjust the adhesion of the adhesive layer, etc., a cross-linked structure can also be introduced into the base polymer. For example, a crosslinking agent is added to a solution after polymerizing a base polymer, and heating is performed as necessary to introduce a crosslinked structure. Examples of the cross-linking agent include: isocyanate-based cross-linking agents, epoxy-based cross-linking agents, oxazoline-based cross-linking agents, aziridine-based cross-linking agents, carbodiimide-based cross-linking agents, metal chelate Cross-linking agent, etc. Among these, isocyanate-based crosslinking agents and epoxy-based crosslinking agents are preferred from the viewpoint of high reactivity with the hydroxyl group or carboxyl group of the base polymer and ease of introduction of a crosslinked structure. These crosslinking agents react with functional groups such as hydroxyl or carboxyl introduced into the base polymer to form a crosslinking structure.

As the isocyanate-based crosslinking agent, a polyisocyanate having two or more isocyanate groups in one molecule is used. Examples of isocyanate-based crosslinking agents include lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate; cyclopentyl diisocyanate, cyclohexylene diisocyanate, and isophorone diisocyanate; Cycloaliphatic isocyanates such as 2,4-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate and other aromatic isocyanates; trimethylolpropane/toluene diisocyanate trimethylolpropane/toluene diisocyanate Polymer adducts (for example, "CORONATE L" manufactured by Tosoh), trimethylolpropane/hexamethylene diisocyanate trimer adducts (for example, "CORONATE HL" manufactured by Tosoh), benzene Trimethylolpropane adducts of dimethylene diisocyanate (for example, "TAKENATE D110N" manufactured by Mitsui Chemicals), isocyanurates of hexamethylene diisocyanate (for example, "CORONATE" manufactured by Tosoh HX") and other isocyanate adducts, etc.

As an epoxy-type crosslinking agent, the polyfunctional epoxy compound which has 2 or more epoxy groups in 1 molecule can be used. The epoxy group of the epoxy-based crosslinking agent may be a glycidyl group. Examples of epoxy-based crosslinking agents include N,N,N',N'-tetraglycidyl-m-xylylenediamine, diglycidylaniline, 1,3-bis(N,N-di Glycidylaminomethyl) cyclohexane, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polyethylene glycol Alcohol diglycidyl ether, polypropylene glycol diglycidyl ether, sorbitol polyglycidyl ether, glycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitan polyglycidyl ether, three Methylolpropane Polyglycidyl Ether, Diglycidyl Adipate, Diglycidyl Phthalate, Tris(2-Hydroxyethyl) Isocyanurate Triglycidyl Ether, Resorcinol Diglycidyl Ether , Bisphenol S-diglycidyl ether, etc. As the epoxy-based crosslinking agent, commercial items such as "DENACOL" manufactured by Nagase ChemteX Corporation, "TETRAD X" and "TETRAD C" manufactured by Mitsubishi Gas Chemical can also be used.

By adding a crosslinking agent to the polymerized base polymer, a crosslinked structure is introduced into the base polymer. The amount of cross-linking agent can be appropriately adjusted according to the composition, molecular weight, and target adhesive properties of the base polymer.

By roll coating, contact roll coating, gravure coating, reverse coating, roll brush, spray coating, dip roll coating, rod coating, knife coating, air knife coating, curtain coating , lip coating, die coating, etc. The adhesive composition is applied on the substrate, and the solvent is dried and removed as necessary to form an adhesive layer. As a drying method, an appropriate method can be suitably adopted. The heating and drying temperature is preferably from 40°C to 200°C, more preferably from 50°C to 180°C, and still more preferably from 70 to 170°C. The drying time is preferably from 5 seconds to 20 minutes, more preferably from 5 seconds to 15 minutes, further preferably from 10 seconds to 10 minutes, particularly preferably from 10 seconds to 5 minutes.

When the adhesive composition contains a crosslinking agent, it is preferable to advance the crosslinking by heating or aging simultaneously with drying of the solvent or after drying of the solvent. The heating temperature or heating time is appropriately set according to the type of cross-linking agent used, and cross-linking is usually performed by heating in the range of 20° C. to 160° C. for 1 minute to about 7 days. The heating used for drying to remove the solvent can also be used as the heating for crosslinking.

The thickness of the adhesive layer 12, 52 is not particularly limited. The thickness of the adhesive layer is usually about 2-200 μm. There is a tendency that the adhesive force to the adherend increases as the thickness of the adhesive layer increases. The thickness of the first adhesive layer 12 for adhering the optical film 10 is preferably 5-200 μm, more preferably 10-150 μm. The thickness of the second adhesive layer 52 of the surface protection film 50 is preferably 1-30 μm, more preferably 3-25 μm.

As mentioned above, the adhesive strength of the first adhesive layer 12 for adhering the optical film 10 to the acrylic resin plate is preferably 3 N/25 mm or more, and the second adhesive layer 52 of the surface protection film 50 is preferably relatively Adhesion to acrylic resin plate is below 1 N/25 mm. When the adhesive strength of the first adhesive layer 12 to the acrylic resin plate is 3 N/25 mm or more, the durability of adhesion to adherends such as image display units is improved. If the adhesive force of the second adhesive layer 52 to the acrylic resin plate is 1 N/25 mm or less, the surface protection film can be easily peeled off from the surface of the adherend or the optical film.

The adhesion of the adhesive layer can be adjusted to a desired range by the composition and molecular weight of the base polymer, the type of crosslinking agent and the amount of crosslinking structure introduced, the thickness of the adhesive layer, and the like.

[Release film] The release film 70 temporarily adhered to the surface of the first adhesive layer 12 is preferably a resin film obtained by performing a release treatment on the bonding surface with the adhesive layer 12 . As a constituent material of the resin film, acrylic resin, polyolefin, cyclic polyolefin, polyester, etc. are preferable.

As described above, in order to easily peel the release film 70 from the bonding surface with the protective film 50, the three-point bending load of the release film 70 is preferably 0.01 to 1 g. In order to make the three-point bending load into the above-mentioned range, the thickness of the release film 70 is preferably 15-55 μm, more preferably 20-50 μm. Also, in order to make the ratio of the three-point bending load of the surface protection film 50 to the three-point bending load of the release film 70 in an appropriate range, the thickness of the release film 70 is preferably the thickness of the film substrate 51 of the surface protection film 50 70% or less, more preferably 60% or less, and more preferably 50% or less.

[Production of monolithic laminate] A laminate can be obtained by layering the first adhesive layer 12 and the release film 70 on the first main surface of the optical film 11 and layering the surface protection film 50 on the second main surface of the optical film 11 . The stacking sequence is not particularly limited.

The formation and lamination of each layer are preferably carried out in a roll-to-roll manner. In the roll-to-roll method, the long flexible substrate is conveyed along the side of the field, and the adhesive composition is coated on the other side, and the solvent is dried or the polymer is hardened as necessary to form an adhesive layer. The lamination of the film and the adhesive layer, the attachment or replacement of the release film can also be implemented by roll-to-roll.

After fabricating a large-area laminate (mother substrate) by roll-to-roll, a single-sheet laminate can be obtained by cutting into a specific size that matches the size of the adherend. This method can improve productivity because a plurality of individual sheets can be obtained from the mother substrate.

The shape or size of a single adhesive optical film is set according to the shape or size of the adherend. For example, when the optical film is placed on the front of an image display device and used, the size of the adhesive optical film is approximately equal to the size of the image. The area of the adhesive optical film is usually about 5 to 25000 cm ² . The area of a single adhesive optical film can be less than 10000 cm ² , less than 5000 cm ² , less than 3000 cm ² , less than 1000 cm ² or less than 500 cm ² . When the adhesive sheet is rectangular, the length of the diagonal is about 2 to 250 cm. The length of the diagonal of the adhesive optical film may be less than 100 cm, less than 50 cm, less than 30 cm, or less than 20 cm. When the adhesive optical film is rectangular, it may be a rectangle having a long side and a short side, or may be a square having four sides of equal length. The length of the long side of the rectangle can usually be less than 10 times, less than 5 times, less than 3 times or less than 2 times the length of the short side.

The laminate in which the surface protection film 50 and the release film 70 protrude from the outer periphery of the adhesive optical film 10 can be obtained by cutting the adhesive optical film 10 into individual pieces of a specific size, and The cutting line on the outside of the outer periphery of 10 cuts the surface protection film 50 and the release film 70 .

6A to 6G are conceptual diagrams showing a series of steps for cutting out a plurality of monolithic laminates from a mother substrate. In this embodiment, a laminate 161 in which a long release film 7 is temporarily bonded to the surface of an adhesive layer of a long sticky optical film 1 is used as a motherboard ( FIG. 6A ).

First, the optical film 1 side of the laminated body 161 is cut (half-cut) at a depth reaching the surface of the release film 7 to form cutting lines 61a and 61b ( FIG. 6B ). The cutting lines 61a and 61b become the outer periphery of the adhesive optical film 10 in the single-piece laminate.

The cutting method is not particularly limited, and suitable cutting methods such as a rotary cutter, a creasing knife (such as a Thomson blade), and a laser cutter can be used. In each of the following embodiments, the cutting method is also not particularly limited.

Cutting lines 61a and 61b are formed in the entire thickness direction of the optical film and the adhesive layer to which the optical film is bonded. It is also possible to form a notch at a depth not reaching the back surface in the release film 7 . The depth of the slit formed in the release film 7 by half cutting is not particularly limited as long as it does not reach the back surface of the release film 7 . From the viewpoint of preventing cracking or breakage of the release film when the release film 70 is peeled off from the adhesive layer 12, the depth of the incision is preferably 1/2 or less of the thickness of the release film, more preferably 1/3 or less .

After the cut lines 61a and 61b are formed, the cut pieces of the adhesive optical film outside the area of the product are peeled off from the surface of the release film 7 to obtain an adhesive film with a plurality of single pieces on the elongated release film 7. The laminated body 162 of the optical film 10 (FIG. 6C). A long surface protection film 5 is bonded to the adhesive optical film 10 so as to cover the entire laminated body 162 ( FIG. 6D ). In FIG. 6D , it is shown that the release film 7 and the surface protection film 5 are separated in the region where the adhesive optical film 10 is not provided, but the surface protection film 5 can also be closely bonded to the surface of the release film 7 . Two adhesive layers. The same applies to FIGS. 7D and 8E described below.

In the layered body 163 after the surface protection film 5 is attached, the cutting lines 62a and 62b are formed on the surface protection film 5 in the region where the adhesive optical film 10 is not provided ( FIG. 6E ). Cutting lines 62a and 62b form the outer periphery of surface protection film 50 in a single-sheet laminate. At this time, a cut can be formed on the release film 7 by half-cutting.

In the laminated body 164 after removing the cut sheet of the surface protection film, cutting lines 63a and 63b are formed on the release film 7 in the region where the adhesive optical film 10 and the surface protection film 50 are not provided (FIG. 6F). Thereby, the release film is cut, and a single-sheet laminate is obtained from a long laminate ( FIG. 6G ). The surface protection film 50 and release film 70 of the obtained laminate protrude outside the outer periphery of the adhesive optical film 10 , and the release film 70 protrudes outside the surface protection film 50 .

After bonding the elongated surface protection film 5 on the adhesive optical film 10 to form a laminate 163 (FIG. 6D), it is also possible to cut the surface protection film 5 and the release film 7 as a whole as shown in FIG. 6H Cutting lines 64a, 64b are formed. Thus, by simultaneously cutting the surface protection film and the release film, a laminate in which the end faces of the surface protection film 50 and the end faces of the release film 70 are aligned as shown in FIG. 6I can be obtained.

6A to 6I show an example of cutting the adhesive optical film by half-cutting the long release film 7 as the carrier substrate, but it is also possible to half-cut the long surface protection film 5 as the carrier substrate. . For example, in the embodiment shown in FIGS. 7A to 7D , as a mother substrate, a long strip of release film 9 is temporarily adhered to the surface of the adhesive layer of the long adhesive optical film 1, and the optical film is temporarily adhered. Laminated body 181 with elongated surface protection film 5 (FIG. 7A). The release film 9 is temporarily bonded to protect the surface of the first adhesive layer that adheres to the optical film, and will be replaced and attached to the release film 7 after the adhesive optical film is cut off. Therefore, the release film 9 in the laminate 181 is not particularly limited as long as it can protect the surface of the adhesive layer adhering to the optical film. The film 70 may be of the same kind, but may be of a different thickness, material, and the like.

First, half cutting is performed from the release film 9 side of the laminate 181 to a depth reaching the surface of the surface protection film 5 to form cutting lines 81a and 81b ( FIG. 7B ). The cutting lines 81a and 81b become the outer peripheral edges of the adhesive optical film 10 in the single-piece laminate. By this cutting step, the cutting lines 81a and 81b are formed in the entire thickness direction of the release film 9 and the optical film and the adhesive layer to which the optical film is bonded. It is also possible to form a notch in the surface protection film 5 to a depth not reaching the back surface.

After the cutting lines 81a and 81b are formed, the cut pieces of the adhesive optical film outside the area of the product are peeled off together with the release film 9, thereby obtaining an adhesive film with a plurality of single pieces on the elongated surface protection film 5. The laminated body 182 of the optical film 10 (FIG. 7C). A long release film 7 is bonded to the adhesive layer for adhering the optical film 10 so as to cover the entire laminated body 182 ( FIG. 7D ). Thereafter, the surface protection film 5 and the release film 7 are cut in the same manner as in FIGS. 6E to 6G or FIGS. 6H to I, whereby the surface protection film 50 and the release film 70 protrude to the outer periphery of the adhesive optical film 10. The layered body on the outer side of the edge.

It is also possible to cut the adhesive optical film by half-cutting using a carrier substrate different from the release film and the surface protection film. 8A to 8G are schematic cross-sectional views showing a series of steps of cutting the mother substrate on the carrier sheet 3 to form a single-piece laminate. As the motherboard, use the same laminated body 181 as shown in FIG. A laminate of the surface protection film 5 of the strip.

First, the carrier sheet 3 is bonded to the surface on the surface protection film 5 side of the motherboard ( FIG. 8A ). The constituent material of the carrier sheet 3 is preferably a plastic film. The carrier sheet 3 is preferably such that the dimensional change caused by the conveying tension during the roll-to-roll conveying is small. When cutting the adhesive optical film, when cutting (half-cut) in such a way as to reach the surface of the carrier sheet 3 (interface with the surface protection film 5), it is necessary to prevent the cutting knife from reaching the back of the carrier sheet 3 . Therefore, the thickness of the carrier sheet 3 is preferably at least 10 μm, more preferably at least 20 μm.

An adhesive layer (not shown) for fixing the motherboard is preferably provided on the surface of the carrier sheet 3 . As the carrier sheet 3, a self-adhesive film in which an adhesive layer is integrally formed on the surface of a film base material can also be used.

From the side of the release film 9 of the laminated body 191 of the mother substrate bonded on the carrier sheet 3, cut (half-cut) at a depth reaching the surface of the carrier sheet 3 to form cutting lines 91a, 91b (FIG. 8B ). By this cutting step, cutting lines 91 a and 91 b are formed in the entire thickness direction of the release film 9 , the adhesive optical film 1 , and the surface protection film 5 . It is also possible to form a notch in the carrier sheet 3 to a depth not reaching the back surface.

Half cutting is performed from the release film 9 side to a depth reaching the surface of the surface protection film 5 to form cutting lines 92 a and 92 b ( FIG. 8C ). By this cutting process, the cutting lines 92a and 92b are formed in the entire thickness direction of the release film 9 and the adhesive optical film 1 . It is also possible to form a notch in the surface protection film 5 to a depth not reaching the back surface.

The cutting lines 91a and 91b form the outer periphery of the surface protection film 50 in the single-sheet laminate. Cutting lines 92a and 92b become the outer periphery of the adhesive optical film 10 . By providing the cutting lines 91a, 91b outside the cutting lines 92a, 92b, a laminate in which the surface protection film 50 is provided so as to protrude from the end surface of the adhesive optical film 10 can be obtained. The formation of the cutting lines 91a and 91b reaching the carrier sheet 3 and the forming of the cutting lines 92a and 92b reaching the surface protection film 5 may be performed first, or both may be performed simultaneously.

After cutting the adhesive optical film 1 and the surface protection film 5 from the release film 9 side, the release film 9 is peeled off. At this time, in the area between the cutting line 91a and the cutting line 91b, in addition to the release film 9, the cut piece of the adhesive optical film 1 and the surface protection film 5 is peeled off from the carrier sheet 3 and removed. In the region between the cutting line 92a and the cutting line 92b, in addition to the release film 9, the cut piece of the adhesive optical film 1 is peeled off from the surface protection film 5 and removed. In this way, in addition to the release film 9, the adhesive optical film 1 and the surface protection film 5 in the area surrounded by the cutting line are also peeled off, thereby obtaining an island-like surface on the carrier sheet 3 as shown in FIG. 8D. A laminate 192 of a laminate of the surface protection film 50 and the adhesive optical film 10 is provided.

A long release film 7 is bonded to the adhesive layer for adhering the optical film so as to cover the entire laminated body 192 ( FIG. 8E ). Cut off the release film 7 along the cutting lines 93a, 93b (FIG. 6F), and peel off the carrier sheet 3 temporarily adhered to the surface protection film 50, so that the surface protection film 50 and the release film 70 can be stretched out to It is a single-piece laminate that is outside the outer periphery of the adhesive optical film 10 and where the release film 70 protrudes outside the surface protection film 50 ( FIG. 8G ).

In forming the cutting lines 93a and 93b, only the release film 7 may be cut, or the carrier sheet 3 may also be cut in addition to the release film 7 . Cutting of the release film 7 may be performed after peeling the carrier sheet 3 from the surface protection film 50 .

As explained above, by cutting the adhesive optical film into a specific shape by half cutting on the carrier substrate, and then cutting the surface protection film and the release film, multiple single-piece laminates can be obtained from the mother substrate . In this method, the position of each cutting line can be set arbitrarily, so the planar shape of the adhesive optical film 10, the planar shape of the surface protection film 50, and the planar shape of the release film 70 can be set arbitrarily. Therefore, it is possible to obtain a laminate in which the protrusion amount _L1 of the surface protection film 50 from the outer periphery of the adhesive optical film 10 and the protrusion amount _L2 of the release film 70 from the outer periphery of the adhesive optical film 10 are different. [Example]

Examples are shown below to further illustrate the present invention, but the present invention is not limited to these examples.

[Preparation of Adhesive Sheet] <Adhesive Sheet 1> (Preparation of Polymer Slurry A) 86 parts by weight of acrylic acid-2- Ethylhexyl ester (2EHA) and 14 parts by weight of N-vinyl-2-pyrrolidone (NVP), and 0.05 parts by weight of Irgacure 184 (manufactured by BASF) and 0.05 parts by weight of Irgacure 651 ( manufactured by BASF), and nitrogen gas was blown in, and nitrogen replacement was performed for about 1 hour while stirring. Then, under a nitrogen atmosphere, ultraviolet rays of 5 mW/cm ² were irradiated to obtain a partial polymer (acrylic polymer syrup A) with a polymerization rate of about 11% by weight.

(Preparation of Acrylic Oligomer) 100 parts by weight of dicyclopentanyl methacrylate ("FA-513M" manufactured by Hitachi Chemical Industry Co., Ltd.) 3 parts by weight of thioglycolic acid as a transfer agent and 100 parts by weight of toluene were stirred at 70° C. for 1 hour under a nitrogen atmosphere. Thereafter, 0.2 parts by weight of 2,2'-azobisisobutyronitrile (AIBN) was charged as a thermal polymerization initiator, and reacted at 70° C. for 2 hours, and then reacted at 80° C. for 2 hours. Thereafter, the reaction solution was heated to 130° C., and the toluene, the chain transfer agent, and the unreacted monomer were distilled off to obtain a solid acrylic oligomer (weight average molecular weight: 4,500).

(Preparation of Adhesive Composition) An adhesive composition was prepared by adding 20 parts by weight of an acrylic oligomer and 0.085 parts by weight of trimethylolpropane triacrylate to 100 parts by weight of acrylic polymer slurry A and stirring.

Apply the above-mentioned adhesive composition to the peeling surface of a separator (polyester film with a thickness of 38 μm obtained by peeling one side with silicone; “Diafoil MRF#38” manufactured by Mitsubishi Chemical) to form a thickness of 25 μm The coating layer. On the coating layer of the adhesive composition, another release film ("Diafoil MRN#38" manufactured by Mitsubishi Chemical) was laminated so that the release-treated surface was in contact with the coating layer of the adhesive composition. The laminate was photocured by irradiating ultraviolet light with an illuminance of 5 mW/cm ² for 360 seconds using a black light lamp, and an adhesive sheet with a thickness of 25 μm was obtained.

＜Adhesive sheet 2＞ (Preparation of Base Polymer B) In a reaction vessel equipped with a thermometer, a stirrer, a condenser and a nitrogen gas introduction pipe, 81.9 parts by weight of butyl acrylate (BA), 13.0 parts by weight of benzyl acrylate (BzA), 5 parts by weight of Acrylic acid (AA) and 0.1 part by weight of 4-hydroxybutyl acrylate (4HBA), 0.1 part of AIBN as a polymerization initiator, and 100 parts by weight of ethyl acetate, while slowly stirring at 23 ° C, while Nitrogen gas was introduced to perform nitrogen substitution. Thereafter, the liquid temperature was maintained at around 55° C. and the polymerization reaction was carried out for 8 hours to prepare a solution (concentration: 50% by weight) of the base polymer B having a weight average molecular weight of 2.01 million.

(Preparation of adhesive composition and production of adhesive sheet) 0.45 parts by weight of an isocyanate-based crosslinking agent (trimethylolpropane adduct of toluene diisocyanate) was added to a solution of 200 parts by weight of the base polymer B (100 parts by weight of solid content). 75% solution; "Coronate L" manufactured by Tosoh), 0.1 part by weight of a peroxide-based crosslinking agent ("Nyper BMT" manufactured by NOF), 1 part by weight of a polyether compound ("SILYL SAT10 manufactured by Kaneka ", the number average molecular weight is 5000) and stirred to prepare an acrylic adhesive solution. The acrylic adhesive solution was coated on the release surface of the release film (MRF#38), and heated at 130°C for 20 seconds to form an adhesive sheet with a thickness of 20 μm.

＜Adhesive sheet 3＞ (Preparation of Base Polymer C) In a reaction vessel equipped with a thermometer, a stirrer, a condenser and a nitrogen gas introduction pipe, 96.2 parts by weight of 2-ethylhexyl acrylate (2EHA) and 3.8 parts by weight of hydroxyethyl acrylate (HEA ), and 0.2 parts by weight of AIBN as a polymerization initiator, and 150 parts by weight of ethyl acetate, while slowly stirring at 23° C., introducing nitrogen gas for nitrogen replacement. Thereafter, the temperature of the liquid was kept at around 60°C and the polymerization reaction was carried out for 6 hours. After cooling to room temperature, it was diluted with ethyl acetate to prepare a solution of the base polymer C with a weight average molecular weight of 540,000 (concentration 25 weight%).

(Preparation of adhesive composition and production of adhesive sheet) To a solution of 400 parts by weight of the base polymer C (100 parts by weight of solid content), 0.5 parts by weight of an isocyanate-based crosslinking agent ("CORONATE L" manufactured by Tosoh) was added in terms of solid content, and as The cross-linking catalyst was an ethyl acetate solution of 0.02 parts by weight of dioctyltin dilaurate ("Envilizer OL-1" manufactured by Tokyo Fine Chemical) in terms of solid content and stirred to prepare an acrylic adhesive solution. The acrylic adhesive solution was coated on the release surface of the release film (MRF#38), and heated at 130°C for 20 seconds to form an adhesive sheet with a thickness of 20 μm.

＜Adhesive sheet 4＞ In a solution of 400 parts by weight of the base polymer C (100 parts by weight of solid content), 4.0 parts by weight of an isocyanate-based crosslinking agent (isocyanurate of hexamethylene diisocyanate) was added in terms of solid content. body; "CORONATE HX" manufactured by Tosoh), and as a crosslinking catalyst, an ethyl acetate solution of dioctyltin dilaurate ("Envilizer OL -1") to prepare an acrylic adhesive solution. The acrylic adhesive solution was coated on the release surface of the release film (MRF#38), and heated at 130°C for 20 seconds to form an adhesive sheet with a thickness of 10 μm.

[Production of surface protection film] ＜Surface Protection Film 1＞ Corona treatment is performed on one side of a cycloolefin film with a thickness of 100 μm (“ZEONORFILM ZF-14-100” manufactured by ZEON, Japan), and an adhesive sheet 3 is attached to the corona-treated surface, and a thickness of 20 is set on the film with a thickness of 100 μm. The adhesive layer of μm is obtained by temporarily adhering the surface protection film of the isolation film on the surface of the adhesive layer.

＜Surface Protection Film 2＞ Corona treatment is performed on one side of a cycloolefin film with a thickness of 40 μm (“ZEONORFILM ZF-14-40” manufactured by ZEON, Japan), and an adhesive sheet 3 is attached to the corona-treated surface, and a thickness of 20 is set on the film with a thickness of 40 μm. The adhesive layer of μm is obtained by temporarily adhering the surface protection film of the isolation film on the surface of the adhesive layer.

＜Surface Protection Film 3＞ Laminate 2 sheets of the above-mentioned surface protection film 2, and sequentially laminate a film with a thickness of 40 μm, an adhesive layer with a thickness of 20 μm, a film with a thickness of 40 μm, and an adhesive layer with a thickness of 20 μm to obtain temporary adhesion on the surface of the adhesive layer. Surface protective film with isolation film.

＜Surface Protection Film 4＞ Attach the surface protection film 2 on the above surface protection film 1, and sequentially laminate a film with a thickness of 40 μm, an adhesive layer with a thickness of 20 μm, a film with a thickness of 100 μm, and an adhesive layer with a thickness of 20 μm to obtain the adhesive layer The surface of the isolation film is temporarily adhered to the surface protective film.

＜Surface Protection Film 5＞ Laminate 2 pieces of the above-mentioned surface protection film 1, and sequentially laminate a film with a thickness of 100 μm, an adhesive layer with a thickness of 20 μm, a film with a thickness of 100 μm, and an adhesive layer with a thickness of 20 μm to obtain a temporary adhesion on the surface of the adhesive layer. The surface protection film of the isolation film.

＜Surface protection film 6＞ Corona treatment is performed on one side of a cycloolefin film with a thickness of 100 μm (“ZEONORFILM ZF-14-100” manufactured by ZEON, Japan), and an adhesive sheet 4 is attached to the corona-treated surface, and a thickness of 10 is set on a film with a thickness of 100 μm. The adhesive layer of μm is obtained by temporarily adhering the surface protection film of the isolation film on the surface of the adhesive layer.

＜Surface Protection Film 7＞ Corona treatment is performed on one side of a biaxially stretched polyester film ("Diafoil T100-100" manufactured by Mitsubishi Chemical) with a thickness of 100 μm, and an adhesive sheet 3 is attached to the corona-treated surface, and the thickness is set on the film with a thickness of 100 μm. Adhesive layer of 20 μm to obtain a surface protection film with a release film temporarily attached to the surface of the adhesive layer.

＜Surface protection film 8＞ Corona treatment was performed on one side of a biaxially stretched polyester film ("Diafoil T100C38" manufactured by Mitsubishi Chemical) with a thickness of 38 μm, and an adhesive sheet 3 was attached to the corona-treated surface, and a thickness of 20 was set on a film with a thickness of 100 μm. The adhesive layer of μm is obtained by temporarily adhering the surface protection film of the isolation film on the surface of the adhesive layer. Laminate 2 pieces of the surface protection film, and sequentially laminate a film with a thickness of 38 μm, an adhesive layer with a thickness of 20 μm, a film with a thickness of 38 μm, and an adhesive layer with a thickness of 20 μm to obtain a temporary adhesive barrier on the surface of the adhesive layer. The surface protection film of the film.

[Example 1] ＜Production of Adhesive Polarizer＞ (polarizer) Corona treatment is performed on one side of an amorphous polyester film (polyethylene terephthalate/isophthalate; glass transition temperature 75°C) with a thickness of 100 μm, and the corona-treated surface is treated at 25°C The coating contains polyvinyl alcohol (polymerization degree 4200, saponification degree 99.2 mole%) and acetoacetyl-modified polyvinyl alcohol ("Gosefimer Z200" manufactured by Japan Synthetic Chemical Industry Co., Ltd.; polymerization degree) at a weight ratio of 9:1. 1200, the degree of modification of acetoacetyl group is 4.6%, and the degree of saponification is more than 99.0 mole%), and dry it to make a laminate with a PVA-based resin layer with a thickness of 11 μm on an amorphous polyester film substrate. body.

By auxiliary stretching in the air in an oven at 120°C, the laminate is stretched to 2.0 times in the longitudinal direction in the form of uniaxial stretching at the free end, and then it is conveyed by rollers while being sequentially placed in 4% boric acid aqueous solution at 30°C. Soak for 30 seconds in the staining solution at 30°C (0.2% iodine, 1.0% potassium iodide aqueous solution) for 60 seconds. Then, while transporting the laminated body by roller transport, it was immersed in a cross-linking solution (potassium iodide 3%, boric acid 3% aqueous solution) at 30°C for 30 seconds to carry out cross-linking treatment, and at 70°C with 4% boric acid, Immerse in a 5% potassium iodide aqueous solution, and perform free-end uniaxial stretching in the elongation direction on one side so that the total elongation ratio becomes 5.5 times. Thereafter, the laminate was immersed in a cleaning solution (4% potassium iodide aqueous solution) at 30° C. to obtain a laminate in which a PVA-based polarizing element with a thickness of 5 μm was provided on an amorphous polyester film substrate.

(Lamination of polarizing element protective film) The following ultraviolet curable adhesive was prepared, which contained 40 parts by weight of N-hydroxyethylacrylamide and 60 parts by weight of N-acryloylmorpholine as hardening components, and further contained as 3 parts by weight of 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one (“Irgacure 819” manufactured by BASF) as a polymerization initiator. Apply this adhesive to the surface of the polarizing element of the above-mentioned laminate with a thickness of about 1 μm, and attach an acrylic film with a thickness of 40 μm as a protective film of the polarizing element on it, and irradiate with a cumulative light intensity of 1000 mJ/cm ² UV rays harden the adhesive. As the acrylic film, a biaxially stretched film made of imidized MS resin produced in the same manner as "transparent protective film 1A" described in Example of JP-A-2017-26939 was used.

(lamination of adhesive layer) The amorphous polyester film substrate was peeled off from the surface of the PVA-based polarizing element. The release film (MRN#38) temporarily attached to one side of the adhesive sheet 1 was peeled off, and the adhesive sheet was attached to the surface of the PVA-based polarizer to obtain a polarizing plate with an adhesive.

＜Lamination of surface protection film＞ The release film temporarily attached to the surface of the adhesive layer of the surface protection film 1 was peeled off, and the surface protection film was attached to the acrylic film (polarizer protective film) of the polarizing plate with the adhesive. Through the above steps, a laminate (mother substrate) is obtained in which a release film is temporarily attached to the adhesive layer of a polarizing plate with an adhesive, and a surface protection film is temporarily attached to the polarizing plate.

＜Cutting＞ Attach a micro-adhesive film on the surface protection film side of the laminate as a carrier sheet, cut the laminate according to the process shown in Figures 8A to 8C, peel off the separator (MRF#38) and the cut piece. Afterwards, attach a release film (MRF#38) to the surface of the adhesive layer (adhesive sheet 1) on which the optical film is attached, punch out the size of the product, and obtain a laminated film on one side of the polarizer (the side of the polarizer) A laminate comprising an adhesive sheet 1 and a release film with a thickness of 38 μm, and a surface protective film 1 attached to the other side of the polarizer (acrylic protective film).

[Examples 2-11 and Comparative Examples 1-3] As shown in Table 1, the type of adhesive sheet provided on one side of the polarizing plate, the type of release film temporarily attached to the adhesive sheet, and the type of surface protection film attached to the other side of the polarizing plate were changed. Other than that, it carried out similarly to Example 1, and obtained the adhesive polarizing plate to which the release film and the surface protection film were temporarily adhered. In addition, the release film of each Example was the polyester film obtained by peeling off one side with silicone, and the following commercially available products were used. Release film with a thickness of 25 μm: "Diafoil MRF#25" manufactured by Mitsubishi Chemical Release film with a thickness of 38 μm: "Diafoil MRF#38" manufactured by Mitsubishi Chemical Release film with a thickness of 50 μm: "Diafoil MRF#50" manufactured by Mitsubishi Chemical

[evaluate] ＜Adhesion＞ Cut the adhesive polarizing plate and surface protection film into a size of 25 mm in width and 100 mm in length, peel off the separator, and place it on an acrylic resin plate ("Acrylite" manufactured by Mitsubishi Chemical, thickness: 2 mm, width: 70 mm) , Length: 100 mm), roll crimping at a pressure of 0.25 MPa and a conveying speed of 0.3 m/min. After the sample was left to stand for 30 minutes at 23°C and a relative humidity of 50%, a peeling test was performed at a peeling angle of 180° and a tensile speed of 0.3 m/min in the same environment, and the peeling test at each tensile speed was measured. 180°peel force.

＜Three-point bending load＞ Cut the surface protection film and release film to a size of 6 mm in width and 50 mm in length. Place the sample on a three-point bending jig with a distance of 25 mm between fulcrums, and obtain the dynamic viscoelasticity measurement device ("RSA-III" manufactured by TA Instruments) in an environment of 23°C and a relative humidity of 50%. The load when the indenter is pressed into the sample to a depth of 5 mm at a pressing speed of 0.5 mm/s.

＜Peelability of Release Film＞ Hold the release film protruding to the outer periphery of the laminate and peel off the release film. Also, the release film protruding to the outer periphery of the laminate is held and peeled off while the surface of the laminate on the surface protective film side is bonded via the double-sided adhesive tape on the horizontal platform. Those that can be easily peeled off at any level are marked as ◎, those that can be easily peeled off in a state fixed on a horizontal table but difficult to peel off in normal operations are marked as 0, and the surface protection film is rated at any level Those that could follow the release film and could not be peeled off were rated as x.

＜Surface Protection Film Peelability＞ Peel the release film from the laminate, and place it on an acrylic resin plate ("Acrylite" manufactured by Mitsubishi Chemical, thickness: 2 mm, width: 70 mm, length: 100 mm) at a pressure of 0.25 MPa and a conveying speed of 0.3 m/min. The speed of roller crimping. In the area where the surface protection film protrudes from the outer periphery of the adhesive polarizing plate (the area where the surface protection film is adhered to the acrylic resin plate), the area where the surface protection film can be easily peeled off from the acrylic resin plate is marked as 0, and the area where the surface protection film is easily peeled off is marked as 0. Those who were recorded as ×.

＜Optical Film Adhesion Durability＞ The sample after the peeling test of the surface protective film (the sample with an adhesive polarizer attached to the surface of the acrylic resin plate) was taken out after standing in a constant temperature bath at a temperature of 85°C for 5 days, and at 23°C with a relative humidity of 50 % environment for 30 minutes, by visually observing the uplift state of the adhesive layer. The case where no air bubbles were seen at the interface was marked as 0, and the case where air bubbles were formed at the interface was marked as ×.

The composition of the laminates of the above-mentioned examples and comparative examples (the thickness of the release film, the type of adhesive provided on the surface of the polarizing plate, the composition of the surface protection film (the material of the film base material and the total thickness of the film, the adhesive The type and thickness)) and evaluation results are shown in Table 1.

[Table 1]

As shown in Table 1, the peelability of the release film, the peelability of the surface protection film, and the adhesion reliability of the polarizing plate of the laminates of Examples 1 to 11 were all good. In Comparative Example 2 in which the adhesive sheet 3 having a small adhesive force was used as the adhesive layer in contact with the polarizing element, the adhesion durability of the polarizing plate was insufficient. In Comparative Example 3 in which the adhesive sheet 3 was used as the adhesive layer of the surface protection film, the peeling of the surface protection film was difficult.

In Comparative Example 1 in which the thickness of the film substrate of the surface protection film was small, since the bending load of the surface protection film was small (that is, the surface protection film was easily bent), if the release film was bent, the surface protection film would be damaged. The following bending makes it difficult to peel off the release film from the laminate. In Example 8 and Example 11 using a release film with a thickness of 50 μm, the peelability of the release film was inferior compared to other Examples. The reason for this is considered to be that the difference between the bending load of the release film and the bending load of the surface protection film is small, and the surface protection film tends to bend following the bending of the release film.

From the above results, it can be seen that by setting the bending load of the release film and the surface protection film to a specific range, and making the difference between the bending loads of the two larger, it is possible to suppress the tracking of the surface protection film when the release film is peeled off. Bending occurs to obtain a laminate that can easily achieve peeling at the bonding interface between the release film and the surface protection film.

1: Adhesive optical film 3: Carrier sheet 5: Surface protective film 7: Release film 9: Release film 10: Adhesive optical film 11: Optical film 12: Adhesive layer 30: Adhered body 50: Surface protective film 51 : film substrate 52 : adhesive layer 61 a : cutting line 61 b : cutting line 62 a : cutting line 62 b : cutting line 63 a : cutting line 63 b : cutting line 64 a : cutting line 64 b : cutting line 70 : Release film 77: Extending portion 81a: Cutting line 81b: Cutting line 91a: Cutting line 91b: Cutting line 92a: Cutting line 92b: Cutting line 93a: Cutting line 93b: Cutting line 101 : laminate 103: laminate 161: laminate 162: laminate 163: laminate 164: laminate 181: laminate 182: laminate 183: laminate 191: laminate 192: laminate 193: laminate L ₁ : Protrusion amount L ₂ : Protrusion amount

Fig. 1 is a cross-sectional view showing an example of a laminate structure of a laminate in which a surface protection film and a release film are temporarily adhered to an optical film. Fig. 2 is a top view of the laminated body in Fig. 1 . Fig. 3 is a cross-sectional view showing an example of a laminate structure of a laminate in which a surface protection film and a release film are temporarily adhered to an optical film. Fig. 4 is a top view of the laminated body in Fig. 3 . Fig. 5A is a schematic cross-sectional view showing a state where a release film is peeled off from a laminate. Fig. 5B is a schematic cross-sectional view showing a state where the release film is peeled off from the laminate. Fig. 5C is a schematic cross-sectional view of the laminate after peeling off the release film. Fig. 5D is a schematic cross-sectional view showing a state in which an optical film is bonded to an adherend. 5E is a schematic cross-sectional view showing a state where the surface protection film is peeled off from the optical film. FIG. 5F is a schematic cross-sectional view of a laminate of an adherend and an optical film after peeling off the surface protective film. Fig. 6A is a cross-sectional view of a laminate (mother substrate) for manufacturing a monolithic laminate. Fig. 6B is a cross-sectional view showing a state where a cutting line is formed in the laminate. Fig. 6C is a cross-sectional view of the laminate after the cut piece is removed. Fig. 6D is a cross-sectional view of the laminate after the surface protection film is attached. FIG. 6E is a cross-sectional view showing a state where a cutting line is formed on the surface protection film. FIG. 6F is a cross-sectional view showing a state where a cutting line is formed on the release film. Fig. 6G is a cross-sectional view of a monolithic laminate obtained by dicing from a mother substrate. FIG. 6H is a cross-sectional view showing a state where cutting lines are formed on the surface protection film and the release film. FIG. 6I is a cross-sectional view of a monolithic laminate obtained by dicing from a mother substrate. Fig. 7A is a cross-sectional view of a laminate (mother substrate) for manufacturing a monolithic laminate. Fig. 7B is a cross-sectional view showing a state where a cutting line is formed in the laminate. Fig. 7C is a cross-sectional view of the laminate after removing the release film and the cut sheet. Fig. 7D is a cross-sectional view of the laminate after the release film is pasted. Fig. 8A is a cross-sectional view of a laminate (mother substrate) for manufacturing a monolithic laminate. Fig. 8B is a cross-sectional view showing a state where a cutting line is formed in the laminate. Fig. 8C is a cross-sectional view showing a state where a cutting line is formed in the laminate. Fig. 8D is a cross-sectional view of the laminate after removing the release film and the cut sheet. Fig. 8E is a cross-sectional view of the laminate after the release film is bonded. FIG. 8F is a cross-sectional view showing a state where a cutting line is formed on the release film. 8G is a cross-sectional view of a monolithic laminate obtained by dicing from a mother substrate.

10: Adhesive optical film

11: Optical film

12: Adhesive layer

50: surface protection film

51: Membrane substrate

52: Adhesive layer

70: Release film

101: laminated body

L ₁ : Overhang

L ₂ : Overhang

Claims (7)

A laminate comprising: an adhesive optical film with a first adhesive layer fixedly laminated on the first main surface of the optical film, a release film temporarily adhered to the surface of the first adhesive layer, and a release film temporarily adhered to the above-mentioned A surface protection film on the second main surface of the optical film, wherein the surface protection film has a film substrate and a second adhesive layer fixedly laminated on the film substrate, and the second adhesive layer is temporarily adhered to the optical film The second main surface of the above-mentioned release film and the above-mentioned surface protection film has a region that protrudes to the outside of the outer periphery of the above-mentioned adhesive optical film. In the area outside the outer periphery, the second adhesive layer of the surface protection film is in contact with the release film, and the tensile speed of the first adhesive layer of the above-mentioned adhesive optical film relative to the acrylic resin plate is 0.3m The 180° peel force per minute is 3N/25mm or more, and the 180° peel force of the second adhesive layer of the surface protection film relative to the acrylic resin plate at a tensile speed of 0.3m/min is 1N/25mm or less , the three-point bending load of the above-mentioned release film is 1g or less, and the three-point bending load of the above-mentioned surface protection film is more than 1.2g, wherein the above-mentioned three-point bending load is based on JIS K7171, the distance between the fulcrums is 25mm, and the pressing speed is 0.5 The value measured under the conditions of mm/min and indentation amount of 5mm. The laminate according to claim 1, wherein the three-point bending load of the above-mentioned surface protection film is more than three times the three-point bending load of the above-mentioned release film. The laminate according to Claim 1 or 2, wherein the 180° peeling force of the first adhesive layer of the above-mentioned adhesive optical film relative to the acrylic resin plate at a tensile speed of 0.3 m/min is equal to the above-mentioned first adhesive layer of the above-mentioned surface protection film. The second adhesive layer is more than 20 times the 180° peeling force of the acrylic resin plate at a tensile speed of 0.3m/min. The laminate according to claim 1 or 2, wherein the release film and the surface protection film protrude outside the outer periphery of the adhesive optical film over the entire periphery of the adhesive optical film. The laminate according to claim 1 or 2, wherein the release film has a region protruding outside the outer periphery of the surface protection film. The laminate according to claim 1 or 2, wherein the surface protection film protrudes outward by more than 5 mm from the outer periphery of the adhesive optical film. The laminate according to claim 1 or 2, wherein the thickness of the film substrate of the above-mentioned surface protection film is 60 μm or more.

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