TW201947778A - Laminate body is difficult to generate reduced adhesion force between the adhesive agent layer and the peeling film layer and contamination at the area of the optical film layer inside the plane of the laminate body - Google Patents

Abstract

The invention provides a laminate body, which is a bendable laminate body, difficult to generate reduced adhesion force between the adhesive agent layer and the peeling film layer and contamination at the area of the optical film layer inside the plane of the laminate body even if the end portion of the laminate body is impacted from outside. According to the laminate body of the invention, the first film layer, the optical film layer, the adhesive layer, and the second film layer are laminated in this order to obtain a flexible laminate body. All position of the end portions of the first film layer and the second film layer are equivalent to the position of the end portion of the adhesive agent layer or are located more outermost than the position of the end portion of the adhesive agent layer, and at least a partial position of the end portion of the adhesive agent layer is located more outermost than the position of the end portion of the optical film layer.

Description

Laminated body

The present invention relates to a laminated body.

In an adhesive optical film in which an adhesive layer is provided on one or both sides of an optical film, an adhesive optical film having a portion where the adhesive layer is located more inward than the end edge of the optical film is proposed (Patent Document 1).
[Prior technical literature]
[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2004-170907

[Problems to be solved by the invention]

When the above-mentioned adhesive optical film is subjected to an impact from the outside at the end portion, a decrease in adhesion caused by the lack of the adhesive layer between the adhesive layer and the release film layer, or a decent layer due to the adhesion of a foreign substance, is generated. Contamination of the inner optical film area.

An object of the present invention is to provide a laminated body, which is difficult to reduce the adhesion between the adhesive layer and the release film layer and the in-plane optics even when the end of the laminated body is impacted from the outside. Contaminated flexible laminates in the membrane area.
[Technical means to solve the problem]

The present invention provides a laminated body shown below.

[1] A laminated body, which is a flexible laminated body obtained by laminating a first film layer, an optical film layer, an adhesive layer, and a second film layer in this order,
The position of the end portion of the adhesive layer is at least partially outside the position of the end portion of the optical film layer.
[2] The laminated body according to [1], wherein the positions of the end portions of the adhesive layer are all located outside the positions of the end portions of the optical film layer.
[3] The laminated body according to [2], wherein the adhesive layer is in contact with the first film layer at a position more than 0.4 mm outward from a position of an end portion of the optical film layer.
[4] The laminated body according to [1] or [2], wherein the positions of the ends of the first film layer and the second film layer are all the same as the positions of the ends of the adhesive layer or are located more than the adhesive The ends of the layers are positioned further outside.
[5] The laminated body according to [4], wherein the positions of the ends of the first film layer and / or the second film layer are at least partly located outside the positions of the ends of the adhesive layer.
[6] The laminated body according to any one of [1] to [3], wherein the optical film layer includes a substrate film and a coating layer disposed on one side thereof.
[Effect of the invention]

According to the present invention, it is possible to provide a laminated body, which is difficult to reduce the adhesion between the adhesive layer and the release film layer and the optical in the plane of the laminated body even when the end of the laminated body is impacted from the outside. Contaminated flexible laminates in the membrane area.

＜ Laminated body ＞
The flexible laminated body (hereinafter, also referred to as a laminated body) of the present invention is a laminated body obtained by laminating the first film layer, the optical film layer, the adhesive layer, and the second film layer in this order, and the adhesive layer. The position of at least a part of the end portion is located outside the position of the end portion of the optical film layer.

An optical film having an optical film layer and an adhesive layer as described in Patent Document 1 is generally used to prevent contamination (paste contamination) caused by overflow of the adhesive at the ends during transportation, processing, or manufacturing and processing steps, The adhesive-containing layer is located on the inner side of the optical film. However, when such an optical film is subjected to an impact from the outside of the laminated body during transportation, the optical film in the laminated body is liable to decrease in adhesion caused by the lack of an adhesive layer or caused by foreign matter adhesion. Layer area pollution. In contrast, according to the present invention, the position of the end portion of the adhesive layer is located at least partially outside the position of the end portion of the optical film layer. That is, when the end of the laminated body is impacted from the outside and the adhesive layer is missing or foreign matter is attached, the optical film layer may not be cut, but the adhesive layer with missing or foreign matter is cut, and only the first film and And / or the second film. This makes it possible to obtain a flexible laminated body between the adhesive layer and the second film layer (equivalent to the release film layer) without causing a decrease in adhesion and contamination of the optical film layer region in the plane of the laminated body.

Bendable means bending with a radius of curvature of 2.5 mm. It is preferable that the laminated body does not generate cracks even if the curvature radius of the inner surface of the structure is 2.5 mm and the number of bending times is 50,000.

The laminated body may be a monolithic body or a long body. When the laminated body is a monolithic body, the monolithic body can be obtained by laminating a monolithic film, or can be made into a monolithic shape by cutting out a laminated body of a long body.

In the case where the laminated body is a single piece, the shape of the laminated body and / or the faces of the layers is preferably a quadrangle, more preferably a rectangle or a square, and further preferably a rectangle. Particularly preferably, the shape of the laminated body and each layer is rectangle. At least one of the layers constituting the laminated body may be chamfered by corners or processed by openings.

At least a part of the position of the above-mentioned end means that in the case where the laminated body is a quadrangular monolith, the position of the end of each layer of at least one of the four sides of the quadrilateral means that the laminated body is a long body In this case, the positions of the ends of each layer of at least one of the two ends in the width direction of the strip and the two ends in the transport direction of the strip. At least a portion of the position of the ends may be opposite ends.

From the viewpoint that it is difficult to reduce the adhesion between the adhesive layer and the second film layer and contamination, it is preferable that the positions of the end portions of the adhesive layer are all located outside the positions of the end portions of the optical film layer. .

All of the positions of the above-mentioned ends means that in the case where the laminated body is a quadrilateral monolith, the positions of the ends of the layers on all sides of the four sides of the quadrilateral means that in the case where the laminated body is a long body, Both ends of the strip in the width direction and positions of the ends of the layers of all the ends of the both ends in the transport direction of the strip.

The laminated body is preferably from the viewpoint of preventing contamination caused by the adhesive in the manufacturing step and the conveying step of the laminated body, and it is preferable that the positions of the ends of the first film layer and the second film layer are all the ends of the adhesive layer. The positions of the parts are the same or located more outward than the positions of the ends of the adhesive layer.

From the viewpoint of preventing the contamination caused by the adhesive in the manufacturing step and the conveying step of the laminated body, it is more preferable that at least a part of the end portion of the first film layer and / or the second film layer is located more than The positions of the ends of the adhesive layer are further outside.

The adhesive layer may be in contact with the first film layer in all or a part of the area located outside the end portion of the optical film layer, or may not be in contact. It is preferably located in all areas located outside the end portion of the optical film layer It is in contact with the first film layer. In the case where the adhesive layer is in contact with the first film layer in the entire area located outside the end portion of the optical film layer, even when the laminated body is impacted during transportation, the optical film layer is damaged or damaged. Foreign matter tends to be suppressed.

The position of the end of the adhesive layer, which is further outside than the position of the end of the optical film layer, may be 1 mm or more from the end of the optical film layer, preferably 2 mm or more, and more preferably 5 mm. the above. In this case, there is a tendency that a decrease in adhesion between the adhesive layer and the release film layer and the contamination of the optical film layer region in the plane of the laminated body are difficult to occur.
On the one hand, the position of the end of the adhesive layer, which is further outside than the position of the end of the optical film layer, may be 50 mm or less from the end of the optical film layer, preferably 30 mm or less, and more preferably The distance is less than 10 mm. In this case, when the laminated body is cut before being used by attaching the laminated body to, for example, a display device or the like, there is a tendency that the amount of the end portion of the laminated body to be cut can be reduced.

The adhesive layer may be in contact with the first film layer at a position more than 0.4 mm outward from the position of the end portion of the optical film layer. The adhesive layer may not be in contact with the first film layer at a position more inward than the portion where the adhesive layer is in contact with the first film layer. In other words, the laminated body may have a non-contact portion at the outer edge of the optical film layer where the adhesive layer and the first film layer are not in contact. The adhesive layer and the first film layer may be in contact with each other on the outer edge of the non-contact portion.

When the laminated body is monolithic and the shape of the laminated body is rectangular, the length of the long side is, for example, 10 mm or more and 1400 mm or less, preferably 50 mm or more and 600 mm or less, more preferably 100 mm or more and 500 mm or less. The length of the short side is, for example, 5 mm or more and 800 mm or less, preferably 30 mm or more and 500 mm or less, and more preferably 50 mm or more and 300 mm or less.

The thickness of the laminated body varies depending on the function pursued by the laminated body, the use of the laminated body, and the like, so it is not particularly limited, and is, for example, 20 μm or more and 1000 μm or less, and preferably 50 μm or more and 500 μm or less.

The laminated body can be adhered to, for example, a display device, a polarizing plate, a touch sensor, etc. via the adhesive layer after the second film layer is peeled off to expose the adhesive layer. The display device is not particularly limited, and examples thereof include an organic electroluminescence (organic EL) display device, an inorganic electroluminescence (inorganic EL) display device, a liquid crystal display device, a touch panel display device, and an electroluminescence display device. The optical laminated body can be preferably used for a bendable display device.

Before being laminated to a display device or the like, the laminated body can be used by cutting the adhesive layer, the first film layer, and the end portions of the second film layer that are located outside the end portion of the optical film layer. At this time, while cutting the end portions of the adhesive layer, the first film layer, and the second film layer, the end portions of the optical film layer can be cut.

The embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiments.

(First Embodiment)
FIG. 1 is a schematic cross-sectional view of a laminated body according to a first embodiment of the present invention. The laminated body 100 includes a first film layer 101, an optical film layer 102, an adhesive layer 103, and a second film layer 104 in this order. The positions of the end portions of the first film layer 101, the adhesive layer 103, and the second film layer 104 are the same as each other, and are located outside the positions of the end portions of the optical film layer 102.

(Second Embodiment)
Fig. 2 is a schematic sectional view of a laminated body according to a second embodiment of the present invention. The laminated body 200 includes a first film layer 101, an optical film layer 102, an adhesive layer 103, and a second film layer 104 in this order. The positions of the ends of the first film layer 101, the adhesive layer 103, and the second film layer 104 are located more outward than the positions of the ends of the optical film layer 102, and the positions of the ends of the first film layer 101 and the second film layer 104. The position is further outside than the position of the end portion of the adhesive layer 103.

(Third Embodiment)
Fig. 3 is a schematic cross-sectional view of a laminated body according to a third embodiment of the present invention. The laminated body 300 includes a first film layer 101, an optical film layer 102, an adhesive layer 103, and a second film layer 104 in this order. The positions of the ends of the first film layer 101, the adhesive layer 103, and the second film layer 104 are located outside the ends of the optical film layer 102, and the positions of the ends of the second film layer 104 are located on the more adhesive layer. The positions of the ends of 103 and the first film layer 104 are further outside.

(Fourth Embodiment)
Fig. 4 is a schematic sectional view of a laminated body according to a fourth embodiment of the present invention. The laminated body 400 includes a first film layer 101, an optical film layer 102, an adhesive layer 103, and a second film layer 104 in this order. The positions of the ends of the first film layer 101, the adhesive layer 103, and the second film layer 104 are located more outward than the positions of the ends of the optical film layer 102, and the positions of the ends of the first film layer 101 are located in the more adhesive layer. The positions of the end portions of 103 and the second film layer 104 are further outside.

(Fifth Embodiment)
Fig. 8 is a schematic cross-sectional view of a laminated body according to a fifth embodiment of the present invention. The laminated body 500 includes a first film layer 101, an optical film layer 102, an adhesive layer 103, and a second film layer 104 in this order. The positions of the end portions of the first film layer 101, the adhesive layer 103, and the second film layer 104 are located outside the positions of the end portions of the optical film layer 102. The adhesive layer 103 is in contact with the first film layer 101 at a distance of 0.4 mm or more from the end of the optical film layer 102 to the outside. The adhesive layer 103 is not in contact with the first film layer 101 at a position more inward than the portion where the adhesive layer 103 is in contact with the first film layer 101.

(1st film layer)
The first film layer 101 can function as a protective film used to protect the surface of the optical film layer from damage or contamination. The protective film is, for example, peeled off after the laminated body is attached to a display device or the like.

The first film layer 101 may include, for example, a resin film from the viewpoint of making the display device bendable, and preferably includes a transparent resin film. The material of the resin film is not particularly limited, and examples thereof include a cyclic polyolefin-based resin film, a cellulose acetate-based resin film containing a resin such as triethylammonium cellulose and diethylammonium cellulose, Polyester resin film, polycarbonate resin film, (meth) acrylic resin film, polypropylene resin of polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate resin Equal to the film known in the art.

The thickness of the first film layer 101 may be, for example, 5 μm or more and 200 μm or less. From the viewpoint of thinning the laminated body, it is preferably 10 μm or more and 150 μm or less, and more preferably 20 μm or more and 100 μm or less. .

The first film layer 101 may have an adhesive layer on one surface of the resin film for bonding to an optical film layer 102 described later. The first film layer 101 may not include an adhesive layer. That is, the first film layer 101 may be a self-adhesive film.

(Optical film layer)
The optical film layer 102 may be a window film including a substrate film and a coating layer disposed on one side of the substrate film. Examples of the optical film layer 102 include a film formed with a hard coat layer or a liquid crystal layer, a polarizing element, a polarizing element protective film, a reflective film, a transflective reflective film, a brightness enhancement film, an optical compensation film, and Anti-glare film. The optical film may be used singly or in combination of two or more kinds. The optical film may also be a window film, a polarizing plate, a laminated body of a window film and a polarizing plate. The thickness of the optical film layer 102 may be, for example, 0.5 μm or more and 500 μm or less, and preferably 5 μm or more and 100 μm or less.

(Base film)
If the substrate film is a plate-like body that can transmit light, the material and thickness are not limited, and may be a single layer or a multilayer, and may be a film made of glass or resin. The base film is preferably a resin film from the viewpoint of making the laminated body bendable. The resin film is not limited as long as it is a resin film that can transmit light. Examples of the resin constituting the resin film include polyolefins such as polyethylene, polypropylene, and norbornene polymers; cyclic olefin resins; polyvinyl alcohol; polyethylene terephthalate; polymethacrylate Polyacrylates; cellulose esters such as triethyl cellulose, diethyl cellulose and cellulose acetate propionate; polyethylene naphthalate; polycarbonate; polyfluorene; polyether fluorene; polyether ketone; Polyphenylene sulfide; polyphenylene ether; polyimide, polyimide and other plastics. Among them, a cyclic olefin resin, a cellulose ester substrate, and a polyimide are preferred. These polymers can be used alone or in combination of two or more. (Meth) acrylic acid means either methacrylic acid or acrylic acid. (Meth) such as (meth) acrylate has the same meaning.

(Hard coating)
The hard coat layer may be formed on one side of the base film, or may be formed on both sides. By providing a hard coat layer, hardness and scratch resistance can be improved. The hard coat layer is, for example, a hardened layer of an ultraviolet curable resin. Examples of the ultraviolet-curable resin include acrylic resins, silicone resins, polyester resins, polyurethane resins, amido resins, and epoxy resins. The hard coat layer may contain additives in order to increase strength. The additives are not limited, and examples thereof include inorganic fine particles, organic fine particles, and mixtures thereof.

(Liquid crystal layer)
The liquid crystal layer is a layer containing a cured film of a composition (hereinafter, also referred to as a composition for forming a liquid crystal layer) containing a polymerizable liquid crystal compound, and may be a retardation layer. The polarizing layer can also be formed by including a dichroic dye in the composition for forming a liquid crystal layer. The composition for forming a liquid crystal layer may further contain a solvent, a polymerization initiator, a photosensitizer, a polymerization inhibitor, a leveling agent, an adhesiveness improving agent, and the like.

The polymerizable liquid crystal compound refers to a compound having a polymerizable group and having liquid crystallinity. The polymerizable group means a group participating in a polymerization reaction, and is preferably a photopolymerizable group. The photopolymerizable group refers to a group that can participate in the polymerization reaction by living radicals or acids generated from a photopolymerization initiator. Examples of the polymerizable group include a vinyl group, a vinyloxy group, a 1-chlorovinyl group, an isopropenyl group, a 4-vinylphenyl group, a propenyloxy group, a methacryloxy group, an ethylene oxide group, Oxetanyl and the like. Among them, acryloxy, methacryloxy, vinyloxy, ethylene oxide, and oxetanyl are preferred, and acryloxy is more preferred. The liquid crystallinity may be either a thermotropic liquid crystal or a liquid crystalline liquid crystal. When mixed with a dichroic dye, a thermotropic liquid crystal is preferred.

Examples of the dichroic pigment include an acridine pigment, a perylene pigment, a cyanine pigment, a naphthalene pigment, an azo pigment, and an anthraquinone pigment. Among these, an azo pigment is preferred. Examples of the azo pigment include a monoazo pigment, a diazo pigment, a triazo pigment, a tetraazo pigment, and a triazo pigment, and the diazo pigment and the triazo pigment are preferred. The dichroic pigment may be used alone or in combination. In order to obtain absorption in the entire visible light range, it is preferable to combine three or more dichroic pigments, and it is more preferable to combine three or more azo pigments.

The polymerization initiator is a compound capable of starting a polymerization reaction of a polymerizable liquid crystal or the like. As the polymerization initiator, a photopolymerization initiator that generates a living radical by the action of light is preferred from the viewpoint of not depending on the phase state of the thermotropic liquid crystal.

Examples of the polymerization initiator include a benzoin compound, a benzophenone compound, a benzophenone compound, a fluorenylphosphine oxide compound, a tertiary compound, a sulfonium salt, and a sulfonium salt.

By transferring the cured film of the polymer of the polymerizable liquid crystal compound by peeling off the base film, a further thinning effect can be obtained. The thickness of the cured film of the polymer of the polymerizable liquid crystal compound is preferably small. However, if the thickness is too thin, the strength tends to decrease and the workability tends to be poor. The thickness of the cured film may be, for example, 0.5 μm or more and 20 μm or less, and preferably 1 μm or more and 5 μm or less.

An alignment film may be formed between the substrate film and the liquid crystal layer. As the alignment film, a solvent used when forming a polarizing film on the alignment film is preferred, and it has heat resistance in the removal of the solvent or the heat treatment of the alignment of the liquid crystal. Examples of the alignment film include an alignment film containing an alignment polymer, a photo-alignment film, and a groove alignment film. The thickness of the alignment film is usually in a range of 10 nm to 5000 nm, preferably in a range of 10 nm to 1,000 nm, more preferably in a range of 30 nm to 300 nm.

(Polarizing element)
It is also possible to use a polarizing element as the optical film. A polarizing element generally passes through a step of uniaxially stretching a polyvinyl alcohol-based resin film, a step of adsorbing the dichroic dye by dyeing the polyvinyl alcohol-based resin film with a dichroic dye, and adsorbing a dichroic dye The polyvinyl alcohol-based resin film is produced by a step of treating with a boric acid aqueous solution, and a step of washing with water after treating with a boric acid aqueous solution. This polarizing element can be used directly as a polarizing plate, or one obtained by laminating a transparent protective film on one or both sides can be used as a polarizing plate. The thickness of the polarizing element thus obtained is preferably 2 μm or more and 40 μm or less.

A dichroic pigment is a pigment having properties in which the absorbance in the long axis direction of the molecule and the absorbance in the short axis direction are different. As a dichroic pigment, it is preferable to have a characteristic which has the characteristic of absorbing visible light, and it is more preferable that it has the absorption maximum wavelength ((lambda) MAX) in the range of 380 nm or more and 680 nm or less. As a dichroic dye used for a polarizing element, an iodine or a dichroic organic dye can be used, for example. The dichroic organic dye contains a dichroic direct dye containing a diazo compound such as C.I.DIRECT RED 39, and a dichroic direct dye containing a compound such as triazo or tetraazo.

The polyvinyl alcohol-based resin can be obtained by saponifying a polyvinyl acetate-based resin. As the polyvinyl acetate-based resin, in addition to polyvinyl acetate, which is a homopolymer of vinyl acetate, a copolymer of vinyl acetate and other monomers copolymerizable therewith can be used. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamides having an ammonium group.

The saponification degree of the polyvinyl alcohol-based resin is usually about 85 to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol-based resin may be modified. For example, polyvinyl formal or polyvinyl acetal modified with aldehydes may be used. The degree of polymerization of the polyvinyl alcohol-based resin is usually from about 1,000 to about 10,000, and preferably from 1,500 to 5,000.

This polyvinyl alcohol resin is formed into a film that can be used as a blank film for a polarizing plate. The method of forming a polyvinyl alcohol-type resin into a film is not specifically limited, A film can be formed by a well-known method. The film thickness of the polyvinyl alcohol-based blank film can be, for example, about 10 μm to about 150 μm.

The uniaxial stretching of the polyvinyl alcohol-based resin film may be performed before dyeing with a dichroic pigment, simultaneously with dyeing, or after dyeing. When uniaxial stretching is performed after dyeing, the uniaxial stretching may be performed before the boric acid treatment, or may be performed during the boric acid treatment. Also, uniaxial extension may be performed in these plural stages. When uniaxial stretching, it can be uniaxially extended between rollers with different peripheral speeds, or hot roller uniaxially extended. The uniaxial stretching may be dry stretching in the air, or wet stretching using a solvent in a state where the polyvinyl alcohol resin film is swollen. The stretching ratio is usually about 3 to 8 times.

(Polarizer protection film)
The protective film for a polarizing element may be laminated on one or both sides of the polarizing element, and may be a film made of a light-transmitting (preferably optically transparent) thermoplastic resin. Examples of the thermoplastic resin include polyolefin resins such as chain polyolefin resins (such as polypropylene resins) and cyclic polyolefin resins (such as norbornene resins); such as triethyl cellulose, and Cellulose resins of ethyl acetate; such as polyester resins of polyethylene terephthalate and polybutylene terephthalate; polycarbonate resins; such as those of methyl methacrylate resins ( (Meth) acrylic resins; polystyrene resins; polyvinyl chloride resins; acrylonitrile-butadiene-styrene resins; acrylonitrile-styrene resins; polyvinyl acetate resins; polyvinylidene chloride Vinyl resin; Polyamine resin; Polyacetal resin; Modified polyphenylene ether resin; Polyfluorene resin; Polyether resin; Polyarylate resin; Polyamide resin; Polyimide-based resins and the like. Among them, polyolefin resins and cellulose resins are preferred. In addition, in this specification, "(meth) acrylic resin" means at least 1 sort (s) chosen from the group which consists of an acrylic resin and a methacrylic resin. The same applies to other terms with "(methyl)".

The thickness of the protective film is usually 1 to 100 μm, and from the viewpoint of strength, workability, etc., it is preferably 5 to 60 μm, and more preferably 5 to 50 μm.

At least one of the protective films may be provided on its outer surface (the surface opposite to the polarizing element) with, for example, a hard coat layer, an anti-glare layer, a light diffusion layer, and a retardation layer (having a retardation value of 1/4 wavelength). Retardation layer, etc.), anti-reflection layer, antistatic layer, antifouling layer, surface treatment layer (coating) or optical layer.

The protective film can be bonded to a polarizing element via an adhesive layer, for example. As the adhesive for forming the adhesive layer, a water-based adhesive, an active energy ray-curable adhesive, or a thermosetting adhesive can be used, and a water-based adhesive or an active energy-ray-curable adhesive is preferable.

(Adhesive layer)
The adhesive layer 103 can play a role of bonding a laminated body to, for example, an image display element of a display device.

The adhesive layer 103 refers to a layer containing an adhesive. The adhesive is a soft rubbery, and it is called a pressure-sensitive adhesive by sticking itself to an adherend such as an optical film or a liquid crystal layer. In addition, an active energy ray-curable adhesive described later can adjust the degree of crosslinking or adhesion by irradiating energy rays.

As the adhesive, a conventionally known adhesive having excellent optical transparency can be used without particular limitation. For example, an adhesive having a base polymer such as acrylic, polyurethane, silicone, and polyvinyl ether can be used. . In addition, it may be an active energy ray-curable adhesive, a thermosetting adhesive, or the like. Among these, an acrylic resin excellent in transparency, adhesion, re-peelability (hereinafter, also referred to as reworkability), weather resistance, and heat resistance is preferably used as an adhesive for the base polymer. The adhesive layer is preferably a reaction product of an adhesive composition containing a (meth) acrylic resin, a crosslinking agent, and a silane compound.

An active energy ray-curable adhesive is prepared by blending a UV-curable compound such as a polyfunctional acrylate in the adhesive composition to form an adhesive layer of the active energy ray-curable adhesive. Then, it is irradiated with ultraviolet rays to harden the adhesive. This situation is also useful for harder adhesive layers. Active energy ray-curable adhesives have the property of being hardened by irradiation with energy rays such as ultraviolet rays or electron beams.
The activated energy ray hardening adhesive has adhesiveness before energy ray irradiation, so it is in close contact with an adherend such as an optical film or a liquid crystal layer, and has the property that it can be hardened by irradiation with energy rays to adjust the adhesion. Adhesive.

The active energy ray-curable adhesive generally includes an acrylic adhesive and an energy ray polymerizable compound as main components. Usually, a cross-linking agent is further formulated, and a photopolymerization initiator, a photosensitizer, or the like may also be formulated as necessary.

The thickness of the adhesive layer 103 may be, for example, 3 μm or more and 100 μm or less, and preferably 20 μm or more and 50 μm or less.

(2nd film layer)
The second film layer 104 can be peeled off from the adhesive layer 103 and can function as a film that supports the adhesive layer 103 and protects the adhesive layer 103 formed on the second film layer 104. The film constituting the second film layer 104 may be a known release film, release paper, or the like, or may be the resin film used for the first film layer 101 described above. It may also be obtained by subjecting a resin film to a release treatment such as silicone coating.

(Manufacturing method of laminated body)
The manufacturing method of the laminated body 100 may have the following steps: a first preparation step (FIG. 5 (a)), that is, preparing an optical film 110 with a protective film including an optical film 102 and a protective film 106; a first bonding step (FIG. 5 (b)), that is, attaching the first film 101 to the optical film with a protective film such that at least a part of the end portion of the first film 101 is positioned outside the position of the end portion of the optical film layer 102 The surface of the optical film layer 102 side of 110 obtains the first laminated body 111; the second preparation step (FIG. 5 (c)), that is, preparing the adhesive layer 103 to sandwich the first isolation film 107 and the second film layer 104 ( The second adhesive film 112); and the second bonding step (FIG. 5 (d)), that is, the protective film 106 is peeled off from the optical film 110 with the protective film, and the release film 107 is peeled off from the adhesive film 112. The lamination body 100 is obtained by laminating so that at least a part of the position of the end portion of the adhesive layer 103 is more outward than the position of the end portion of the optical film layer 102.

In the first bonding step and the second bonding step, each film can be bonded using, for example, a unit bonding machine.

The method for manufacturing the laminated body 100 may further include a first cutting step of cutting the optical film 110 and / or the first film layer 101 with a protective film into a desired size between the first preparation step and the first lamination step.

The method for manufacturing the laminated body 100 may further include a second cutting step of cutting the adhesive film 112 and / or the second film layer 104 into a desired size between the second preparation step and the second lamination step.

Examples of the cutting method used in the first cutting step and the second cutting step include cutting with a knife, laser cutting, and the like.

After the second bonding step, the manufacturing method of the laminated body 100 may have the first or second layer of the laminated body 101 obtained in order to make all or a part of the adhesive layer located outside the end portion of the optical film layer contact the first film. 1 film and / or 2nd film side is a step of applying a squeeze. As a method of applying a squeeze, the method of passing between nip rolls, etc. are mentioned, for example.

The present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited by these examples.
[Example]

[Production of test piece]
As shown in FIG. 6, an acrylic plate 201 (having a thickness of 5 mm) is provided so that the thickness direction of the acrylic plate 201 is perpendicular to the wall surface 202. On both sides of the laminated body 203 obtained in each of the examples and comparative examples, a reinforcing bar 204 (thickness 1 mm, width 25 mm) was abutted and fixed at a position 20 mm from the end of the laminated body 203. The end of the laminated body 203 was brought into contact with the surface of the acrylic plate 201, and reciprocated 10 times (at a speed of 1 second per second, and the moving distance was 10 mm) to prepare a test piece.

[Number of foreign bodies]
The test piece prepared as described above was observed using an optical microscope (manufactured by Olympus Co., Ltd.).
The area to be observed is an area between the end of the optical film and a position 20 mm inward from the end of the self-laminated body. The number of foreign objects existing between the adhesive layer and the second film layer as measured in the optical film layer region within the laminated body surface was measured as the number of foreign objects in the optical film layer.

[Adhesiveness]
Each laminated body after the measurement of the number of foreign objects was cut, and the portion from the end in contact with the surface of the acrylic plate to the end of the optical film was removed by a laser cutter (manufactured by LPTech). Thereafter, the protective film 2, the protective film 2 ′, or the protective film 2 ″ (first film layer) on the upper part of the window film is peeled off. A second optically transparent adhesive layer (thickness: 25 μm, LINTEC Co., Ltd.) was formed on the peeled area of the first film layer. Next, the laminated body was cut into a size of 2.54 cm × 220 mm, and then adhered to a glass plate (thickness: 0.7 mm) through a second optically transparent adhesive layer, and this was made into a sample for evaluating adhesion. The sample for adhesion evaluation includes a glass plate, a second optically transparent adhesive layer, an optical film, a first optically transparent adhesive layer, and a second release film in this order.
For each sample for adhesion evaluation, a 180-degree peel test was performed using CA-210 manufactured by Shimadzu Corporation to measure the adhesion between the first optically transparent adhesive layer and the second release film.

[Flexibility]
About the optical laminated body obtained by each Example and the comparative example, the evaluation test which confirmed the durability of bending was performed using the bending evaluation equipment (STS-VRT-500 by Science Town Corporation). FIG. 7 is a diagram schematically showing a method of the evaluation test. As shown in FIG. 7, two mounting tables 501 and 502 that can be individually moved are arranged so that the gap C is 5.0 mm (2.5R), and the laminated body 100 is fixedly arranged so that the center in the width direction is located in the center of the gap C ( Figure 7 (a)). At this time, the laminated body 100 is arrange | positioned so that a window film (front panel 10) may be upper. Then, the two mounting tables 501 and 502 are rotated 90 degrees above with the positions P1 and P2 as the centers of the rotation axes, and a bending force is applied to the area of the laminated body 100 corresponding to the gap C of the mounting table (Fig. 7 (b )). Thereafter, the two mounting tables 501 and 502 are returned to their original positions (FIG. 7 (a)). Complete one of the above series of operations and count the number of times the bending force is applied as one. Accumulate the number of times the bending force is applied, and confirm whether bubbles or cracks have occurred in the area of the laminated body 100 corresponding to the gap C of the mounting tables 501 and 502. Stop the application of the bending force at the time when the bubbles or cracks occur. Evaluation. The evaluation results are shown in Table 1. The moving speeds of the mounting tables 501 and 502 and the speed of the bending force application were set to the same conditions in the evaluation test of any of the optical laminates.
A: Even if the bending force is applied 10,000 times, bubbles and cracks are not generated.
B: The number of times the bending force is applied is not less than 7,000 and less than 10,000, and bubbles or cracks are generated.
C: The number of times the bending force is applied is more than 5,000 to less than 70,000, and bubbles or cracks are generated.
D: The number of times the bending force is applied is more than 0.2 million and less than 50 thousand, and bubbles or cracks are generated.
E: The number of times the bending force is applied is less than 0.2 million, and bubbles or cracks are generated.

Example 1 (the first embodiment described above)
Prepare a protective film 1 (a film having a thickness of 75 μm with an adhesive layer formed on one side of a resin film made of PET (polyethylene terephthalate), manufactured by Fujimori Industry Co., Ltd.), and A window film (thickness: 70 μm) including a hard coat layer and a substrate layer was prepared as an optical film layer. The surface of the adhesive layer side of the protective film 1 and the surface of the base film layer side of the window film were laminated by a roll-to-roll method, and a laser cutter (manufactured by LPTech) was used to unit units (280 mm). × 220 mm).

Next, a protective film 2 (75 μm thick, 284 mm × 224 mm, Fujimori Industry Co., Ltd.) 4 mm larger than the length of each side of the unit was prepared as the first film layer. That is, the distance from the position of the end portion of the optical film layer to the position of the end portion of the first film layer is 2 mm. The protective film 2 was bonded to the surface of the hard-coat side of the window film using a unit bonding machine (promis. Company) so that the center of each surface of the window film and the protective film 2 was aligned.

Next, a first optically transparent adhesive layer (acrylic adhesive, thickness 25 μm) is prepared as an adhesive layer, and a first release film (resin film made of PET) and a second 2 An optically transparent adhesive film sandwiched between a release film (a resin film made of PET). Use a laser cutter (manufactured by LPTech) to cut the length of each side of the first release film, the second release film, and the first optically transparent adhesive layer by 4 mm larger than the length of each side of the unit. . That is, the distance from the position of the end portion of the optical film layer to the position of the end portion of each of the second film layer and the adhesive layer is 2 mm.

The protective film 1 is peeled from the window film. The first release film was peeled from the optically transparent adhesive film cut as described above. The peeled surface of the protective film 1 of the window film and the peeled surface of the first release film of the optically clear adhesive film were bonded together using a unit bonding machine (promis) to obtain a laminated body 1.

Example 2 (the second embodiment described above)
Instead of using the protective film 2 in Example 1, a protective film 2 'larger than the length of each side of the unit unit by 10 mm was used. The length of each side of the second insulation film is 10 mm larger than the length of each side of the unit unit, and the length of each side of the first insulation film and the first optically transparent adhesive layer is longer than each of the unit unit. Cut the side with a length of 4 mm. Except for these changes, a laminated body was produced in the same manner as in Example 1, whereby a laminated body 2 was obtained. The distances from the positions of the end portions of the optical film layer to the positions of the end portions of the first film layer, the second film layer, and the adhesive layer were 5 mm, 5 mm, and 2 mm, respectively.

Example 3 (the third embodiment described above)
In Example 1, the length of each side of the second insulation film is 10 mm greater than the length of each side of the unit unit, and the length of each side of the first insulation film and the first optically transparent adhesive layer is longer than the unit. The four sides of the unit are cut to a length of 4 mm. Except for this modification, a laminated body was produced in the same manner as in Example 1, whereby a laminated body 3 was obtained. The distances from the positions of the end portions of the optical film layer to the positions of the end portions of the first film layer, the second film layer, and the adhesive layer were 2 mm, 5 mm, and 2 mm, respectively.

Example 4 (the fourth embodiment described above)
Instead of using the protective film 2 in Example 1, a protective film 2 'larger than the length of each side of the unit unit by 10 mm was used. Except for this modification, a laminated body was produced in the same manner as in Example 1, whereby a laminated body 4 was obtained. The distances from the positions of the end portions of the optical film layer to the positions of the end portions of the first film layer, the second film layer, and the adhesive layer were 5 mm, 2 mm, and 2 mm, respectively.

Example 5
In Example 1, cutting was performed in such a manner that the length of each side of the first release film, the second release film, and the first optically transparent adhesive layer was larger than the length of each side of the unit unit by 1 mm. Except this change, it carried out similarly to Example 1, and produced the laminated body, and obtained the laminated body 6 by this. The distances from the positions of the end portions of the optical film layer to the positions of the end portions of the first film layer, the second film layer, and the adhesive layer were 2 mm, 0.5 mm, and 0.5 mm, respectively.

Comparative Example 1
Prepare protective film 1 (a film with an adhesive layer thickness of 75 μm formed on one side of a resin film made of PET, manufactured by Fujimori Industry Co., Ltd.), and prepare a window film including a hard coat layer and a substrate layer (Thickness: 70 μm) as an optical film layer. The protective film 1 is laminated by a roll-to-roll method so that the adhesive layer side of the protective film 1 is in contact with the surface of the base film layer side of the window film.

Next, a protective film 2 "(75 μm thick, 285 mm × 225 mm, purchased from Fujimori Industry Co., Ltd.) was prepared as the first film layer. The protective film 2 '' was bonded to the surface of the hard-coat side of a window film using the unit bonding machine (made by Promis) so that the center of each surface of a window film and the protective film 2 '' may be aligned.

Next, an optically transparent adhesive film (the thickness of the adhesive layer is 25) is prepared as a first optically transparent adhesive layer sandwiched by a first release film and a second release film as a second film layer. μm). A laser cutter (manufactured by LPTech) was used to cut the length of each side of the first release film, the second release film, and the optically transparent adhesive layer with the length of each side of the window film.

The protective film 1 is peeled from the window film. The first release film was peeled from the optically transparent adhesive film cut as described above. The peeled surface of the protective film 1 of the window film and the peeled surface of the first release film of the optically transparent adhesive film were in contact with each other using a cell bonding machine (promis). Next, a laser cutter (manufactured by LPTech) was used to cut the unit (280 mm × 220 mm) to obtain a laminated body 5. The distances from the positions of the end portions of the optical film layer to the positions of the end portions of the first film layer, the second film layer, and the adhesive layer are all 0 mm.

The multilayer bodies 1 to 6 obtained in Examples 1 to 5 and Comparative Example 1 were tested for the number of foreign materials and adhesion. The results are shown in Table 1.

[Table 1]

100, 200, 300, 400‧‧‧ laminated bodies

101‧‧‧The first layer

102‧‧‧Optical film

103‧‧‧Adhesive layer

104‧‧‧Second film layer

106‧‧‧ protective film

107‧‧‧The first insulation film

110‧‧‧ Optical film with protective film

111‧‧‧The first laminated body

112‧‧‧Adhesive film

201‧‧‧ acrylic board

202‧‧‧wall

203‧‧‧layer

204‧‧‧ Rebar

500‧‧‧layer

501, 502‧‧‧ mounting table

P1‧‧‧Location

P2‧‧‧Location

Fig. 1 is a schematic cross-sectional view showing a laminated body according to a first embodiment of the present invention.

Fig. 2 is a schematic cross-sectional view showing a laminated body according to a second embodiment of the present invention.

Fig. 3 is a schematic cross-sectional view showing a laminated body according to a third embodiment of the present invention.

Fig. 4 is a schematic cross-sectional view showing a laminated body according to a fourth embodiment of the present invention.

5 (a) to 5 (d) are schematic cross-sectional views of a laminated body schematically showing a method for producing a laminated body of the present invention.

6 (a) and 6 (b) are schematic cross-sectional views schematically showing a method for producing a test piece used in the examples.

7 (a) and 7 (b) are diagrams schematically showing a method of an evaluation test in Examples.

Fig. 8 is a schematic cross-sectional view showing a laminated body according to a fifth embodiment of the present invention.

Claims (6)

A laminated body is a flexible laminated body obtained by laminating a first film layer, an optical film layer, an adhesive layer, and a second film layer in this order, The position of the end portion of the adhesive layer is at least partially outside the position of the end portion of the optical film layer. For example, the laminated body of claim 1, wherein the positions of the end portions of the adhesive layer are all located outside the positions of the end portions of the optical film layer. For example, the laminated body of claim 2, wherein the adhesive layer is in contact with the first film layer at a position more than 0.4 mm outward from the position of the end of the optical film layer. For example, the laminated body of claim 1 or 2, wherein the positions of the ends of the first film layer and the second film layer are all the same as the positions of the ends of the adhesive layer or are located more than the ends of the adhesive layer. The position is more outboard. For example, the laminated body according to claim 4, wherein the positions of the end portions of the first film layer and / or the second film layer are located at least partly outside the positions of the end portions of the adhesive layer. The laminated body according to any one of claims 1 to 3, wherein the optical film layer includes a substrate film and a coating layer disposed on one side thereof.