TW202200377A - Optical multilayer body - Google Patents

Abstract

The present invention provides an optical multilayer body which is capable of suppressing the occurrence of a crack even in cases where the optical multilayer body is bent. This optical multilayer body is sequentially provided with a circularly polarizing plate 60 and a second adhesive layer 70 in this order. In a cross section of the optical multilayer body along the stacking direction, if [Theta] is the angle between the interface L between the circularly polarizing plate 60 and the second adhesive layer 70 and the tangent line P at the interface L in the end face EF of the circularly polarizing plate 60, [Theta] ≥ 80 DEG is satisfied.

Description

Optical laminate

The present invention relates to an optical laminate.

Conventionally, there has been known an optical laminate including a front plate, a first adhesive layer, a circularly polarizing plate, and a second adhesive layer in this order. Such an optical laminate is cut from a blank to a desired size by a knife or a laser. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2019-218513

[The problem to be solved by the invention] The inventors have studied and found that when a conventional optical layered body is used for a flexible display, cracks sometimes occur at the end of the optical layered body when it is bent. [Means of Solving Problems]

The present invention has been made in view of the above-mentioned problems, and an object thereof is to provide an optical layered body capable of suppressing the occurrence of cracks even when bent.

An optical layered product according to one aspect of the present invention is an optical layered product including a circularly polarizing plate and a second adhesive layer, in a cross section of the optical layered product along the layering direction, when the circularly polarizing plate and the When the angle formed by the tangent at the interface between the interface of the second adhesive layer and the end face of the circularly polarizing plate is set to θ, θ≧80° is satisfied.

An optical layered product according to another aspect of the present invention is an optical layered product including a front surface plate, a first adhesive layer, a circularly polarizing plate, and a second adhesive layer in this order in a direction along the layering direction of the optical layered product. In the cross section of , when the angle between the interface between the circular polarizer and the second adhesive layer and the tangent at the interface of the end face of the circular polarizer is set as θ, θ≧80° is satisfied .

Here, in the cross section of the optical layered product along the lamination direction, when the thickness of the central portion of the circularly polarizing plate is T1, the end portions of the circularly polarizing plate with the T1 as a reference T2/T1 is 10% or more when the increase in the thickness of the T2 is assumed to be T2.

In addition, the circular polarizing plate may include a linear polarizing plate and a retardation plate.

In addition, the retardation plate may include a λ/4 plate. [Effect of invention]

ADVANTAGE OF THE INVENTION According to this invention, the optical laminated body which can suppress generation|occurence|production of a crack even when it bends is provided.

(first embodiment) As shown in FIG. 1 , the optical laminate 100 according to the first embodiment of the present invention mainly includes a front surface plate 10 , a first adhesive layer 20 , a circular polarizer 60 , and a second adhesive layer 70 in sequence. In addition, the Z direction is the stacking direction, +Z is the visual recognition side, and a person captures the light emitted in the +Z direction. In addition, the X direction is the bending axis, and the Y direction is the direction perpendicular to the bending axis.

(front panel) The material and thickness of the front plate 10 are not limited as long as it is a plate-shaped body that can transmit light and can be bent, and may include only one layer or two or more layers. Examples thereof include resin-made plate-shaped bodies (eg, resin plates, resin sheets, resin films, etc.), glass-made plate-shaped bodies (eg, glass plates, glass films, etc.), resin-made plate-shaped bodies, and glass-made laminated bodies of plate-like bodies. The front panel may be the outermost layer constituting the display device.

The thickness of the front surface plate 10 may be, for example, 30 μm or more and 1,000 μm or less, preferably 50 μm or more and 1,000 μm or less, and more preferably 50 μm or more and 500 μm or less.

When the front panel 10 is a resin-made plate-shaped body, the resin-made plate-shaped body is not limited as long as it can transmit light. Examples of resins include films containing the following polymers: triacetyl cellulose, acetyl cellulose butyrate, ethylene-vinyl acetate copolymer, acyl cellulose, butyl cellulose, and acetyl acrylate fibers plain, polyester, polystyrene, polyamide, polyetherimide, poly(meth)acrylic acid, polyimide, polyether, polystyrene, polyethylene, polypropylene, polymethylpentene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl acetal, polyether ketone, polyether ether ketone, polyether dust, polymethyl methacrylate, polyethylene terephthalate, poly Butylene terephthalate, polyethylene naphthalate, polycarbonate, polyamide imide, etc. The polymers may be used alone or in combination of two or more. From the viewpoint of improving strength and transparency, a resin film formed of a polymer such as polyimide, polyamide, and polyamideimide is preferred. The thickness of the resin-made plate-like body may be, for example, 30 μm or more and 2,000 μm or less, preferably 50 μm or more and 1,000 μm or less, more preferably 50 μm or more and 500 μm or less, and may be 100 μm or less.

As shown in FIG. 2 , the front surface plate 10 may have a structure in which the hard coat layer 12 is provided on at least one side of the base film 14 to further increase the hardness. As the base film 14, the above-mentioned resin-made plate-shaped body can be used. The hard coat layer 12 may be formed on one side of the base film 14 (for example, the side that is visually recognized, that is, the side opposite to the first adhesive layer), or may be formed on both sides. By providing the hard coat layer 12, the front panel 10 with improved hardness and scratch resistance can be produced. The hard coat layer 12 is, for example, a hardened layer of an ultraviolet curable resin. As an ultraviolet curable resin, an acrylic resin, a silicone type resin, a polyester type resin, a urethane type resin, an amide type resin, an epoxy type resin, etc. are mentioned, for example. In order to increase hardness, the hard coat layer 12 may contain additives. The additive is not limited, and examples thereof include inorganic fine particles, organic fine particles, or a mixture thereof.

It is also preferable to form an abrasion-resistant layer on the visible side of the hard coat layer 12 in order to improve abrasion resistance or prevent contamination by sebum or the like. The front surface plate may have a wear-resistant layer, and the wear-resistant layer may be a layer that constitutes a visually recognizable side surface of the front surface plate. The wear-resistant layer contains a structure derived from a fluorine compound. The fluorine compound is preferably a compound having a silicon atom and having a hydrolyzable group such as an alkoxy group or a halogen in the silicon atom. A coating film can be formed by the dehydration condensation reaction of the hydrolyzable group, and the adhesion of the wear-resistant layer can be improved by the reaction with the active hydrogen on the surface of the substrate. In addition, when the fluorine compound has a perfluoroalkyl group or a perfluoropolyether structure, water repellency can be imparted, which is preferable. Particularly preferred is a fluorine-containing polyorganosiloxane compound having a perfluoropolyether structure and a long-chain alkyl group having 4 or more carbon atoms. It is also preferable to use two or more kinds of compounds as the fluorine compound. The fluorine compound preferably contained is a fluorine-containing organosiloxane compound containing an alkylene group having 2 or more carbon atoms and a perfluoroalkylene group.

The thickness of the wear-resistant layer is, for example, 1 nm to 20 nm. In addition, the wear-resistant layer has water resistance, and the water contact angle is, for example, about 110° to 125°. The contact angle hysteresis and the slip angle measured by the slip-off method are about 3° to 20° and about 2° to 55°, respectively. Furthermore, the wear-resistant layer may contain a silanol condensation catalyst, an antioxidant, a rust inhibitor, an ultraviolet absorber, a light stabilizer, an antifungal agent, an antibacterial agent, or a biofouling agent within a range that does not inhibit the effects of the present invention. Various additives such as inhibitors, deodorants, pigments, flame retardants, antistatic agents, etc.

A primer layer may also be provided between the wear-resistant layer and the hard coat layer 12 . As the primer, for example, there are primers such as an ultraviolet curing type, a thermosetting type, a moisture curing agent, or a two-component curing type epoxy-based compound. In addition, as a primer, a polyamic acid can be used, and a silane coupling agent is also preferably used. The thickness of the undercoat layer is, for example, 0.001 μm to 2 μm.

As a method of obtaining a laminate including the wear-resistant layer and the hard coat layer 12, a primer layer can be formed by applying a primer agent on the hard coat layer 12 as needed, and drying and hardening to form a primer layer. After that, a composition containing a fluorine compound (a composition for coating an anti-wear layer) is applied and dried. As a coating method, a dip coating method, a roll coating method, a bar coating method, a spin coating method, a spray coating method, a die coating method, a gravure coater method, etc. are mentioned, for example. In addition, it is also preferable to perform a hydrophilization treatment such as plasma treatment, corona treatment, or ultraviolet treatment on the coated surface before coating the primer or the composition for coating an anti-wear layer. The laminated body may be directly laminated on the front surface plate, or the laminated body may be laminated on another transparent base material by using an adhesive or an adhesive, so that the laminated body can be laminated on the front surface plate.

When the front panel 10 is a glass plate, tempered glass for display is preferably used as the glass plate. The thickness of the glass plate may be, for example, 10 μm or more and 1,000 μm or less. By using the glass plate, the front panel 10 having excellent mechanical strength and surface hardness can be constructed.

When the optical laminate 100 is used for a display device, the front surface plate 10 may have a function as a window film in the display device. The front panel 10 may also have a function as a touch sensor, a blue light blocking function, a viewing angle adjustment function, and the like.

(first adhesive layer) As shown in FIG. 1 , the first adhesive layer 20 is disposed between the front panel 10 and the circular polarizer 60 to fix them.

The so-called adhesive is a pressure-sensitive adhesive, which is in the state of a soft solid (viscoelastic body) in a temperature range around room temperature (for example, 25°C), and has the ability to easily adhere to the adherend by pressure. the nature of the material.

The main component of the first adhesive layer 20 is not particularly limited, for example, it can be (meth)acrylic polymer, urethane polymer, polyester polymer, silicone polymer, polyvinyl ether polymers, rubber-based polymers, etc. In this specification, a main component means the component which contains 50 mass % or more in the total solid content of a layer. In addition, "(meth)acrylic-type resin" in this specification means at least 1 sort(s) chosen from the group which consists of an acrylic-type resin and a methacrylic-type resin.

As the (meth)acrylic polymer, for example, butyl (meth)acrylate, ethyl (meth)acrylate, hexyl (meth)acrylate, octyl (meth)acrylate, and (meth)acrylate are preferably used. (methyl) lauryl acrylate, isooctyl (meth)acrylate, isodecyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isobornyl (meth)acrylate, etc. ) A polymer or copolymer of one or more of acrylates as monomers. The base polymer is preferably a polar monomer copolymerized. Examples of polar monomers include (meth)acrylic acid, 4-hydroxybutyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, hydroxyethyl (meth)acrylate, (meth)acrylate Monomers having a carboxyl group, a hydroxyl group, an amide group, an amino group, an epoxy group, etc., such as acrylamide, N,N-dimethylaminoethyl (meth)acrylate, and glycidyl (meth)acrylate body.

Adhesives may contain only the base polymer, but typically more contain a crosslinking agent. Examples of the crosslinking agent include: a metal ion having a valence of two or more, and a metal carboxylate salt is formed with a carboxyl group; a polyamine compound, and an amide bond is formed with a carboxyl group; a polyepoxy compound or A polyhydric alcohol that forms an ester bond with a carboxyl group; a polyisocyanate compound that forms an amide bond with a carboxyl group. Among them, polyisocyanate compounds are preferred.

The first adhesive layer 20 may be an active energy ray hardening type hardened by active energy rays such as ultraviolet rays or electron rays, or a thermosetting type hardened by heating. In this case, it has adhesiveness before active energy ray irradiation and can adhere to adherends such as films, and is cured by active energy ray irradiation, and the adhesive force can be adjusted. The active energy ray curable adhesive contains an active energy ray polymerizable compound in addition to the base polymer and the crosslinking agent. Moreover, a photopolymerization initiator, a photosensitizer, etc. are also contained as needed.

In addition to polymers, the first adhesive layer 20 may also contain solvents; adhesion imparting agents, softeners, fillers (metal powder or other inorganic powders, etc.), antioxidants, ultraviolet absorbers, dyes, pigments, colorants, Additives such as foaming agents, preservatives, photopolymerization initiators, etc.

The thickness of the first adhesive layer 20 is not particularly limited, and is preferably 2 μm or more, may be 15 μm or more, may be 20 μm or more, or 25 μm or more, and is usually 200 μm or less, and may be 100 μm or more. μm or less, and may be 50 μm or less.

The storage elastic modulus of the first adhesive layer 20 at 25° C. is preferably 1×10 ⁶ Pa (1 MPa) or less, more preferably 5×10 ⁵ Pa (0.5 MPa) or less, and still more preferably 3×10 ⁵ Pa (0.3 MPa) or less. It is preferable that the storage elastic modulus is 1×10 ⁶ Pa (1 MPa) or less, since it is difficult to generate air bubbles or display unevenness due to bending. In addition, the storage elastic modulus is preferably 1×10 ⁴ Pa (0.01 MPa) or more, more preferably 2×10 ⁴ Pa (0.02 MPa) or more, and still more preferably 3×10 ⁴ Pa (0.03 Mpa) or more. When the storage elastic modulus is 1×10 ⁴ Pa (0.01 MPa) or more, the adhesive tends to be less likely to adhere to other parts during the manufacturing operation, which is preferable. In addition, the storage elastic modulus of the adhesive at 80°C is preferably 5×10 ⁵ Pa (0.5 MPa) or less, more preferably 3×10 ⁵ Pa (0.3 MPa) or less, and still more preferably 1×10 ⁵ Pa (0.1 MPa) or less, particularly preferably 5×10 ⁴ Pa (0.05 MPa) or less, particularly preferably 3×10 ⁴ Pa (0.03 MPa) or less. When the storage elastic modulus at 80° C. is 5×10 ⁵ Pa (0.5 MPa) or less, the fluidity during the heating operation is good, and thus the generation of air bubbles and the like tends to be suppressed, which is preferable.

The storage elastic coefficient can be measured using a viscoelasticity measuring device (MCR-301, Anton Paar). After laminating a plurality of adhesive layers with a thickness of 150 μm and bonding to a glass plate, in the state of being attached to the measurement wafer, in the temperature range of -20°C to 100°C, at a frequency of 1.0 Hz, a deformation amount of 1%, The measurement was performed under the condition of a temperature increase rate of 5°C/min.

The loss tangent of the first adhesive layer 20 may be, for example, 0.7 or less, preferably less than 0.5, and more preferably 0.3 or less.

(circular polarizer) The circularly polarizing plate 60 includes the linear polarizing plate 30 , the retardation plate 50 , and the bonding layer 40 arranged between them and fixing them. The linear polarizing plate 30 is arranged closer to the front surface plate 10 than the retardation plate 50 is. That is, the linear polarizing plate 30 , the bonding layer 40 , and the retardation plate 50 are arranged in this order from the front plate 10 side (visibility side). The circular polarizer may not have the bonding layer 40 .

(Linear polarizer) The linear polarizer 30 has a function of selectively transmitting linearly polarized light in one direction from non-polarized light such as natural light. As shown in FIG. 3 , the linear polarizer 30 has a polarizer layer 34 , and may further have a protective layer 32 and a protective layer 36 provided on one side or both sides of the polarizer layer 34 .

The polarizer layer 34 may be a stretched film to which a dichroic dye is adsorbed, or may be a cured product containing a polymerizable liquid crystal compound and a dichroic dye, and the dichroic dye may be dispersed in the cured product of the polymerizable liquid crystal compound Aligned liquid crystal layer. A dichroic dye refers to a dye having a property that the absorbance in the long axis direction of the molecule is different from the absorbance in the short axis direction.

(When the polarizer layer is a stretched film) A stretched film to which a dichroic dye is adsorbed is usually produced through the following steps: a step of uniaxially stretching a polyvinyl alcohol-based resin film; and by dyeing the polyvinyl alcohol-based resin film with a dichroic dye such as iodine A step of adsorbing the dichroic dye; a step of treating the dichroic dye-adsorbed polyvinyl alcohol-based resin film with an aqueous boric acid solution; and a step of washing with water after the treatment with an aqueous boric acid solution. The polarizer layer of the obtained stretched film can be used directly as a linear polarizing plate, or can also be used as a linear polarizing plate in which a protective layer is formed on one side or both sides. The thickness of the polarizer layer thus obtained is preferably 2 μm to 40 μm.

The polyvinyl alcohol-based resin is 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, copolymers of vinyl acetate and other monomers copolymerizable therewith are used. Examples of other monomers that can be copolymerized with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, (meth)acrylamides having an ammonium group, and the like.

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

The film thickness of the polyvinyl alcohol-based resin film before stretching can be, for example, about 10 μm to 150 μm.

The uniaxial stretching of the polyvinyl alcohol-based resin film can be performed before, simultaneously with, or after dyeing with a dichroic dye. When performing uniaxial stretching after dyeing, the uniaxial stretching may be performed before the boric acid treatment or during the boric acid treatment. In addition, uniaxial stretching may be performed in the above-mentioned plural stages. In the case of uniaxial stretching, uniaxial stretching may be performed between rolls having different circumferential speeds, or uniaxial stretching may be performed using hot rolls. In addition, the uniaxial stretching may be either dry stretching or wet stretching, in which dry stretching is performed in the atmosphere, and wet stretching is performed in a state where a polyvinyl alcohol-based resin film is swelled with a solvent stretch down. The draw ratio is usually about 3 to 8 times.

The thickness of a linear polarizer having a stretched film as a polarizer layer and including a protective layer on one side or both sides thereof may be, for example, 1 μm or more and 100 μm or less, 5 μm or more, or 7 μm or more. , may be 70 μm or less, or 50 μm or less.

The material of the protective layer 32 and the protective layer 36 provided on one or both surfaces of the polarizer layer 34 is not particularly limited, and examples include cyclic polyolefin-based resins; cellulose acetate-based resins such as resins; polyester-based resins including resins such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate; Carbonate-based resins; (meth)acrylic-based resins; polypropylene-based resins and other known resins in the art. From the viewpoint of thinning, the thickness of the protective layer is usually 100 μm or less, preferably 50 μm or less, more preferably 30 μm or less, and usually 5 μm or more, preferably 10 μm or more. The protective layer may be a film, and the film-shaped protective layer may have a retardation. When the protective layer is a film, the polarizer layer and the protective layer may be laminated via an adhesive layer or an adhesive layer. The adhesive layer or the adhesive layer can be formed using the above-described adhesive composition or adhesive composition.

(When the polarizer layer is a liquid crystal layer) The polymerizable liquid crystal compound used for forming the liquid crystal layer is a compound that has a polymerizable reactive group and exhibits liquid crystallinity. The polymerizable reactive group is a group that participates in a polymerization reaction, and is preferably a photopolymerizable reactive group. The photopolymerizable reactive group refers to a group capable of participating in a polymerization reaction by an active radical generated from a photopolymerization initiator, an acid, or the like. Examples of the photopolymerizable functional group include vinyl, vinyloxy, 1-chlorovinyl, isopropenyl, 4-vinylphenyl, acryloxy, methacryloyloxy, and oxirane. base, oxetanyl, etc. Among them, acryloxy, methacryloyloxy, vinyloxy, oxetanyl, and oxetanyl are preferred, and acryloxy is more preferred. The type of the polymerizable liquid crystal compound is not particularly limited, and rod-like liquid crystal compounds, discotic liquid crystal compounds, and mixtures thereof can be used. The liquid crystallinity of the polymerizable liquid crystal compound may be a thermotropic liquid crystal or a lyotropic liquid crystal, and the phase sequence structure may be a nematic liquid crystal or a smectic liquid crystal.

As a dichroic dye used for the polarizer layer using a liquid crystal layer, what has an absorption maximum wavelength (λMAX) in the range of 300 nm - 700 nm is preferable. Examples of such dichroic dyes include acridine dyes, oxazine dyes, cyanine dyes, naphthalene dyes, azo dyes, and anthraquinone dyes, among which azo dyes are preferred. The azo dyes include monoazo dyes, disazo dyes, trisazo dyes, tetrazo dyes, and stilbene azo dyes, and preferred are disazo dyes and trisazo dyes. The dichroic dyes may be alone or in combination of two or more, preferably three or more. In particular, it is more preferable to combine three or more azo compounds. A part of the dichroic dye may have a reactive group, and may have liquid crystallinity.

The polarizer layer using the liquid crystal layer can be obtained by, for example, applying a composition for forming a polarizing layer containing a polymerizable liquid crystal compound and a dichroic dye on an alignment layer formed on a substrate, and polymerizing the polymerizable liquid crystal compound. formed by hardening. Alternatively, a polarizer layer may be formed by applying the composition for forming a polarizer layer on a base material to form a coating film, and stretching the coating film together with the base material layer. The base material for forming the polarizer layer can also be used as a protective layer for the polarizer layer. As a base material, a resin film is mentioned, for example, the film shape|molded using the material which forms the said protective layer is mentioned.

As a composition for forming a polarizer layer containing a polymerizable liquid crystal compound and a dichroic dye, and a method for producing a polarizer layer using the composition, Japanese Patent Laid-Open No. 2013-37353 and Japanese Patent Laid-Open No. 2013 can be exemplified - Those described in Gazette No. 33249, Japanese Patent Laid-Open No. 2017-83843, etc. In addition to the polymerizable liquid crystal compound and the dichroic dye, the polarizer layer-forming composition may further contain additives such as a solvent, a polymerization initiator, a crosslinking agent, a leveling agent, an antioxidant, a plasticizer, and a sensitizer. Only one of these components may be used, respectively, or two or more of them may be used in combination.

The polymerization initiator which may be contained in the composition for forming a polarizer layer is a compound which can initiate the polymerization reaction of the polymerizable liquid crystal compound, and is preferably a photopolymerizable initiator in terms of initiating the polymerization reaction under lower temperature conditions. Specifically, a photopolymerization initiator that can generate an active radical or an acid by the action of light is mentioned, and among them, a photopolymerization initiator that generates a radical by the action of light is preferable. The content of the polymerization initiator is preferably 1 to 10 parts by mass, more preferably 3 to 8 parts by mass, with respect to 100 parts by mass of the total amount of the polymerizable liquid crystal compound. Within this range, the reaction of the polymerizable group proceeds sufficiently, and the alignment state of the liquid crystal compound is easily stabilized.

The thickness of the polarizer layer using the liquid crystal layer is not particularly limited, but is preferably 20 μm or less, more preferably 10 μm or less, still more preferably 5 μm or less, and may be 3 μm or less. Although there is no lower limit of the thickness, it may be 0.5 μm or more.

As shown in FIG. 3 , the polarizer layer 34 using the liquid crystal layer may have a protective layer 32 and a protective layer 36 called overcoat layers on one or both surfaces of the polarizer layer 34 . The overcoat layer may be provided for the purpose of protecting the linearly polarizing layer or the like. The protective layer can be formed by, for example, applying a protective layer-forming material (composition) on the linearly polarizing layer. As a material for protective layer formation, a photocurable resin, a water-soluble polymer, etc. are mentioned, for example, (meth)acrylic-type resin or a polyvinyl alcohol-type resin can be used. The thickness of the protective layer can be set to 0.5 μm to 5 μm. The thickness of the polarizer layer 34 using the liquid crystal layer and the linear polarizer including the protective layer on one side or both sides thereof can be set to 10 μm to 40 μm.

(adhering layer 40) The bonding layer 40 is not particularly limited, and may be the same adhesive layer as the first adhesive layer, or may be an adhesive layer. The thickness can be set to 2 μm to 50 μm. When the bonding layer is an adhesive layer, the adhesive composition for forming the adhesive layer is not particularly limited, and examples thereof include a water-based adhesive, an active energy ray-curable adhesive, and the like.

As an aqueous adhesive, a polyvinyl alcohol-type resin aqueous solution, an aqueous two-component urethane emulsion adhesive, etc. are mentioned, for example. The active energy ray-curable adhesive is one that is cured by irradiation with active energy rays such as ultraviolet rays, and examples thereof include adhesives containing a polymerizable compound and a photopolymerizable initiator, adhesives containing a photoreactive resin, Adhesives containing binder resins and photoreactive crosslinking agents, etc. Examples of the polymerizable compound include photopolymerizable monomers such as photocurable epoxy-based monomers, photocurable (meth)acrylic monomers, and photocurable urethane-based monomers, or sources. Oligomers and the like from these monomers. Examples of the photopolymerization initiator include those containing active species such as neutral radicals, anionic radicals, and cationic radicals by irradiation with active energy rays such as ultraviolet rays.

(Phase plate) The retardation plate 50 includes at least a λ/4 plate. The λ/4 plate is a film that imparts a retardation of λ/4 in the direction orthogonal to the advancing direction of the incident light (the in-plane direction of the film). The angle formed by the retardation axis of the λ/4 plate and the absorption axis of the linear polarizer 30 may be 45°±10°. The λ/4 plate may also have reverse wavelength dispersion.

The λ/4 plate may be a stretched retardation plate produced by stretching a polymer film such as a cellulose-based film, an olefin-based film, and a polycarbonate-based film. As required, retardation adjusters, plasticizers, ultraviolet absorbers, infrared absorbers, colorants such as pigments or dyes, optical brighteners, dispersants, heat stabilizers, light stabilizers, anti- Static agents, antioxidants, lubricants, solvents, etc. The thickness of the stretched λ/4 bit plate may be 100 μm or less, preferably 1 μm to 50 μm. When the thickness exceeds 100 μm, the flexibility may decrease.

Moreover, as another example of a λ/4 plate, a liquid crystal coating type λ/4 plate formed by applying a liquid crystal composition may be used. The liquid crystal composition contains a liquid crystal compound having a property of exhibiting a liquid crystal state such as nematic, cholesteric, and smectic. Any compound including a liquid crystal compound in the liquid crystal composition has a polymerizable functional group. The liquid crystal coating type λ/4 plate may further include initiator, solvent, dispersant, leveling agent, stabilizer, surfactant, cross-linking agent, silane coupling agent and the like. The liquid crystal coating type λ/4 plate can be produced by coating a liquid crystal composition on an alignment film provided on a substrate and curing to form a liquid crystal retardation layer. The liquid crystal coating type λ/4 plate can be thinner than the stretched type λ/4 plate. The thickness of the liquid crystal coating type λ/4 plate is 0.5 μm to 10 μm, preferably 1 μm to 5 μm. The liquid crystal coating type λ/4 plate can also be peeled off from the base material and transferred to the laminate, or the base material can be directly laminated. The base material is also preferably used as a transparent base material for a protective film, a retardation plate, and a front surface plate.

In general, there are many materials that exhibit larger birefringence as the wavelength is shorter, and smaller birefringence as the wavelength increases. In this case, the retardation of λ/4 cannot be achieved in the entire visible light region. Therefore, in many cases, the in-plane retardation is designed to be 100 nm to 180 nm with a retardation value of λ/4 in the vicinity of 560 nm with high visual sensitivity. , preferably 130 nm to 150 nm. It is preferable to use an inverse dispersion λ/4 plate using a material having birefringence wavelength dispersion characteristics opposite to those of usual because visibility can be improved. As such a material, in the case of a stretched stencil, Japanese Patent Laid-Open No. 2007-232873 or the like is preferably used, and in the case of a liquid crystal coating stencil, the description in Japanese Patent Laid-Open No. 2010-30979 is preferably used s material.

As shown in (a) of FIG. 4 , the retardation plate 50 may include only the λ/4 plate 52 .

As shown in FIGS. 4( b ) to 4 ( d ), in addition to the λ/4 plate 52 , the retardation plate 50 may have one or more plates for imparting other retardation. Examples of plates to which other retardation is imparted are λ/2 plates and positive C plates.

The λ/2 plate is a film that imparts a retardation of λ/2 in the direction orthogonal to the advancing direction of the incident light (the in-plane direction of the film). The λ/2 plate can also be manufactured by the same material method as the λ/4 plate. A technique of obtaining a wide-band λ/4 retardation plate by combining a λ/2 plate with a λ/4 plate is known (Japanese Patent Laid-Open No. 10-90521). The thickness of the λ/2 plate is 0.5 μm to 10 μm, preferably 1 μm to 5 μm.

The positive C plate is a film satisfying nx≒ny<nz. "≒" includes not only the exact same situation, but also the substantially same situation. The term "substantially the same", for example, (nx-ny)×d (where d is the thickness of the film) is 0 nm to 10 nm, preferably 0 nm to 5 nm, is also included in "nx≒ny".

When a positive C plate is added to the λ/4 plate, the visibility in the oblique direction can be improved (see Japanese Patent Laid-Open No. 2014-224837). The positive C plate can be a liquid crystal coating type retardation plate or a stretched type retardation plate. The retardation in the thickness direction is -200 nm to 20 nm, preferably -140 nm to -40 nm. The thickness of the positive C plate is 0.5 μm to 10 μm, preferably 1 μm to 5 μm.

When the retardation plate 50 has two or more plates for imparting retardation, the retardation plate 50 may have a bonding layer 54 for laminating the plates (for example, a λ/4 plate and a positive C plate) to each other for imparting a retardation. As the bonding layer, the above-mentioned adhesive may be used, or an adhesive may be used. The thickness of the bonding layer can be set to 0.5 μm to 10 μm.

When the retardation plate 50 includes a positive C plate, as shown in FIG. 4( b ), it may include a λ/4 plate 52 , a bonding layer 54 , and a positive C plate 56 in this order from the linear polarizer 30 side. As shown in FIG. 4( c ), the positive C plate 56 , the bonding layer 54 , and the λ/4 plate 52 may be included in this order from the linear polarizer 30 side.

When the retardation plate 50 includes a λ/4 plate and a λ/2 plate, as shown in FIG. 4( d ), a λ/2 plate 58 and a bonding layer 54 may be included in this order from the linear polarizer 30 side. , and λ/4 plate 52 . The angle formed by the retardation axis of the λ/4 plate 52 and the retardation axis of the λ/2 plate 58 may be 60°±10°.

As described above, the plate for imparting each retardation may include a stretched film or a layer in which the polymerizable liquid crystal compound is cured. The retardation-imparting plate may further include an alignment film or a base film.

In addition, the retardation plate 50 may have an overcoat layer that protects the surface of the plate to which each retardation is imparted.

The thickness of the retardation plate 50 is not particularly limited, and may be, for example, 1 μm or more and 50 μm or less.

The circularly polarizing plate 60 can suppress the outgoing of reflected light of external light incident from the front plate 10 , and thus can provide the optical layered body 100 with a function as an antireflection film.

(Second Adhesive Layer) The second adhesive layer 70 is provided on the surface opposite to the first adhesive layer 20 in the circular polarizer 60 , that is, on the surface of the retardation plate 50 . The second adhesive layer 70 may be an adhesive layer for attaching the optical laminate to the touch sensor panel or the organic EL display element.

The material of the second adhesive layer 70 is not particularly limited, and the same material as the first adhesive layer 20 can be used, and the thickness can be appropriately set within the same range.

(Partition plate) Preferably, there is a separator 80 under the second adhesive layer 70 . The material of the partition plate 80 is not particularly limited as long as it can be peeled off from the second adhesive layer 70 . Although the thickness of a spacer is not specifically limited, For example, it can be 10 micrometers or more and 50 micrometers or less.

(protective film) A protective film 90 may be provided on the front surface plate 10 . In addition, a protective film may be provided under the partition plate 80 . The material of the protective film is not particularly limited as long as it can be peeled off from the front panel 10 or the like, and may have an adhesive layer. In the case where the protective film has an adhesive layer, the protective film can be peeled off from the front surface plate or the like together with the adhesive layer. Although the thickness of a protective film is not specifically limited, For example, it can be 20 micrometers or more and 200 micrometers or less.

(Second Embodiment) Next, the layered structure of the optical layered body 100 according to the second embodiment of the present invention will be described. The description of the same matters as those of the first embodiment is omitted. As shown in FIG. 5 , the optical laminate 100 of the present embodiment mainly includes a circular polarizer 60 and a second adhesive layer 70 . That is, the optical layered body 100 of the present embodiment does not include the front plate 10 and the first adhesive layer 20 . A protective film 90 may be provided on the circular polarizing plate 60 . A separator 80 may be provided under the second adhesive layer 70 . The circular polarizing plate 60 , the second adhesive layer 70 , the protective film 90 , and the partition plate 80 are the same as in the first embodiment.

(Angle of the circular polarizer at the end face of the optical laminate) Next, the angle of the circularly polarizing plate of the end surface of the optical layered body 100 of 1st Embodiment and 2nd Embodiment is demonstrated. As shown in FIG. 6 , in the cross section of the optical laminate 100 along the lamination direction (Z direction), when the interface L between the circular polarizer 60 and the second adhesive layer 70 and the interface between the end face EF of the circular polarizer 60 are compared When the angle formed by the tangent P at L is θ, θ≧80° is satisfied. θ is preferably 82° or more, more preferably 84° or more, and still more preferably 85° or more. The upper limit of θ may be 120°. The upper limit may also be 110˚. The interface L may be an interface of a site where the projections EP described later are not generated.

When θ is 80° or more, the occurrence of cracks in the optical layered body 100 during the bending test can be suppressed. Although the reason for this is not clear, the following mechanism of action is presumed. Cracks are often generated on the retardation plate. When the optical layered body has the above-mentioned angle θ, the second adhesive layer 70 is present directly under the retardation plate 50 . In this way, the area of the end of the retardation plate 50 exposed to the outside can be reduced, and the area of the second adhesive layer 70 to support the retardation plate 50 can be increased. Therefore, it is considered that cracks are less likely to occur in the retardation plate 50 during bending.

The above-mentioned relational expression may be satisfied over the entire circumference of the end face of the optical layered body 100, or only a part of the end face may satisfy the above-mentioned relation. The problem can be solved if the portion of the end face that is subjected to bending satisfies the above-mentioned relational expression. For example, when the planar shape of the optical layered body is a rectangle and is curved so that the short sides face each other, it is preferable that both end surfaces corresponding to the pair of long sides satisfy the relational expression.

As shown in FIG. 6 , in the cross section of the optical layered body 100 along the lamination direction (Z direction), the thickness of the central portion of the circularly polarizing plate 60 is T1, and the end of the circularly polarizing plate 60 is based on T1 When the increase in the thickness of the portion is assumed to be T2, T2 may be 10% or more of T1, in other words, T2/T1×100 may be 10% or more. T2/T1×100 may be 11% or more, 12% or more, 13% or more, 15% or more, 17% or more, and 18% or more. Although there is no upper limit for T2/T1×100, it may be, for example, 20% or less.

When cut by a laser or the like, protrusions EP tend to be formed at the ends of the circular polarizer 60 , and the thickness of the ends of the circular polarizer 60 tends to be larger than that of the center. The protrusion EP can also be formed on the side of the first adhesive layer 20 of the circular polarizing plate (in the case where the optical laminate 100 does not have the first adhesive layer 20, the circular polarizing plate 60 and the second adhesive layer 70 are provided on the side of the circular polarizing plate 60 ). the opposite side of the surface), the second adhesive layer 70 side, or both sides. When the thickness of the end portion of the circularly polarizing plate 60 is increased, the generation of cracks tends to be further suppressed by the effect of dispersing the stress applied to the retardation plate 50 .

The optical laminate 100 can be bent. Bendable means that when the front panel 10 side (the circular polarizer 60 side in the case where the optical layered body 100 does not have the first adhesive layer 20 , the circular polarizer 60 side) becomes the inner side, the bendable radius is Bend at 1 mm. In the optical layered body 100, it is preferable that the number of times of bending when the inner surface of the optical layered body 100 has a bending radius of 1 mm is 10,000 times, so that cracks are not generated.

The thickness of the optical layered body 100 is not particularly limited because it varies depending on the function required of the optical layered body and the application of the optical layered body, but is, for example, 50 μm or more and 1,000 μm or less, preferably 100 μm or more and 500 μm or less. .

The planar shape of the optical layered body 100 may be, for example, a square, preferably a square having long sides and short sides, and more preferably a rectangle. When the shape of the optical layered body 100 in the plane direction is a rectangle, the length of the long side may be, for example, 10 mm or more and 1400 mm or less, or preferably 50 mm or more and 600 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 optical layered body 100 can be used for, for example, a display device or the like. The display device is not particularly limited, and examples thereof include organic electroluminescence (electroluminescence (EL)) display devices, inorganic electroluminescence (inorganic EL) display devices, liquid crystal display devices, and electroluminescence display devices. The display device may have a touch panel function. The optical laminate 100 is suitable for a display device having flexibility, such as a flexible display.

In addition, in this specification, when there is no particular description about the measurement wavelength, the measurement wavelength is 550 nm.

Next, the manufacturing method of the said optical laminated body is demonstrated.

First, a blank of the optical layered body is prepared. The blanks can be produced by previously known methods. For example, it can be manufactured by laminating layers sequentially, or in the case of the first embodiment, laminating the front plate 10 and the circularly polarizing plate 60 with the second adhesive layer 70 using the first adhesive layer 20 .

Next, the blank is cut into the desired planar shape. Specifically, the blank is cut into a desired shape by a laser. At this time, as shown in FIG. 7 , by adjusting the position of the focal point FP of the laser beam in the thickness direction of the optical layered body 100 , the angle θ of the circular polarizer 60 on the end face can be controlled. Here, from the front plate 10 side of the optical layered body 100 (in the case where the optical layered body 100 does not have the front plate 10 , from the side of the circular polarizer 60 of the optical layered body 100 , that is, from the side of the optical layered body 100 ) The visual recognition side) irradiates the laser LB vertically toward the second adhesive layer 70 side, with the interface L between the circular polarizer 60 and the second adhesive layer 70 as the reference, as long as the position of the focal point FP of the laser is not on the front panel It is sufficient to be too far apart in the direction of the 10 side (circular polarizing plate 60 side). In this specification, the position of the focal point FP of the laser beam LB is expressed as the distance between the interface L and the focal point FP, and the focal point FP of the laser beam is located closer to the circular polarizer 60 than the interface L ( FIG. 7( d ) ) is set to a positive (+) sign, the case where the focal point FP of the laser coincides with the interface L ( FIG. 7( c )) is set to zero, and the focal point FP of the laser is located in the second adhesive layer 70 that is closer to the interface L In the case of the side ( FIG. 7( a ) and ( b )), the sign is negative (−). If the position of the focal point FP of the laser is too far away from the interface L between the circular polarizer 60 and the second adhesive layer 70 in the direction (positive direction) of the front panel 10 (the side of the circular polarizer 60 ), there is an angle θ lower than 80˚ inclination. For example, if the position of the focal point FP of the laser is within 320 μm from the interface L between the circular polarizer 60 and the second adhesive layer 70 in the direction of the front panel 10 (the side of the circular polarizer 60 ), that is, When cutting so that the distance between the interface L and the focal point FP is +320 μm or less, the angle θ tends to exceed 80°.

A preferable laser is a CO ₂ laser, which can be cut with a minimum output capable of cutting the optical laminate at a cutting speed of 320 mm/sec, for example. That is, the closer the focal position of the laser is to the interface between the circular polarizer 60 and the second adhesive layer 70 , the more the output of the laser can be reduced. When the interface L between the circular polarizer 60 and the second adhesive layer 70 is the reference position (the distance is 0) and the direction on the front plate 10 side is +, the focal position of the laser is -500 μm or more In the case of +1000 μm or less, the output of the laser can be set to 5 W or more and 20 W or less. When the focal position of the laser is less than -500 μm or more than +1000 μm, the output of the laser can be set to It is more than 20 W and less than 50 W. The moving speed (cutting speed) of the laser can be set to 10 mm/s or more and 1000 mm/s or less, and can be set to 100 mm/s or more and 500 mm/s or less.

The energy of the laser beam irradiated by the scan per unit length (hereinafter, sometimes referred to as irradiation energy.) is preferably 1 mJ/mm or more, more preferably 10 mJ/mm or more, and still more preferably 25 mJ/mm or more. The upper limit of the irradiation energy is not particularly limited, but may be, for example, 1000 mJ/mm or less, 500 mJ/mm or less, or 100 mJ/mm or less.

The optical laminate can be cut by full cutting. It is also possible to temporarily cut the optical layered body by half cutting to a depth where the optical layered body is not cut, and then irradiate the laser light one or more times again to completely cut the optical layered body. Full cutting means that all layers in the lamination direction are cut off by one laser irradiation. Preferably, the cutting step is performed by full cutting. [Example]

The optical layered body 100 having the structure shown in FIG. 8 was produced. Protective film 90/hard coat layer 12/substrate film 14/first adhesive layer 20/protective layer (TAC) 32/polarizer layer 34/protective layer 36/bonding layer 40/λ/4 plate 52/bonding Layer 54 / Positive C Plate 56 / Second Adhesive Layer 70 / Separator Plate 80

(Production of Front Panel A with Adhesive Layer) A front surface plate (window film) 10 having a thickness of 60 μm and a hard coat layer 12 having a thickness of 10 μm formed on one surface of a base film 14 having a thickness of 50 μm and an acrylic adhesive serving as the first adhesive layer 20 are prepared layer (thickness 25 μm). The base film 14 of the front panel is a polyimide-based resin film, and the hard coat layer 12 is a layer formed of a composition containing a dendrimer compound having a polyfunctional acrylic group at the terminal. After that, after corona treatment is performed on the surface of the base film 14 of the front panel 10 and the surface of the first adhesive layer 20 , the base film 14 and the first adhesive layer 20 are bonded together to obtain an adhesive layer with an adhesive. front panel A. The corona treatment was carried out under the conditions of frequency: 20 kHz/voltage: 8.6 kV/power: 2.5 kW/speed: 6 m/min.

(Production of Circular Polarizing Plate B with Adhesive Layer) A photo-alignment film was formed on a triacetyl cellulose (TAC) film having a thickness of 25 μm as the protective layer 32 . The composition containing the dichroic dye and the polymerizable liquid crystal compound was coated on the photo-alignment film, oriented, and hardened to obtain a polarizer layer 34 with a thickness of 2.5 μm. The linear polarizer 30 was obtained by applying an acrylic resin composition on the polarizer layer 34 and irradiating it with ultraviolet rays to cure it to obtain an overcoat layer having a thickness of 1 μm as the protective layer 36 .

On this protective layer 36 (overcoat layer), a retardation plate 50 including a layer in which a liquid crystal compound is polymerized and hardened is bonded via a bonding layer (adhesive layer) 40 having a thickness of 5 μm. The layer structure of the retardation plate 50 is as follows from the linear polarizer 30 side: a λ/4 plate 52 (thickness 3 μm) including a layer formed by curing a liquid crystal compound and an alignment film, a bonding layer (adhesive layer) 54 ( thickness 5 μm), a positive C plate 56 (thickness 3 μm) including a layer formed by curing a liquid crystal compound and an alignment film. The circular polarizing plate 60 (thickness 44.5 μm) was thus obtained.

Then, the second adhesive layer 70 with the partition plate 80 (acrylic adhesive layer: thickness 25 μm) was prepared. Corona treatment is performed on the surface of the positive C plate 56 of the retardation plate 50 and the surface of the second adhesive layer 70 , and the second adhesive layer 70 with the separator 80 is laminated on the retardation plate 50 . Furthermore, the separator 80 can be peeled off from the second adhesive layer 70 .

(Production of Optical Laminate) The surface of the first adhesive layer 20 of the front panel A with an adhesive layer and the surface of the protective layer 32 (TAC) of the circularly polarizing plate B with an adhesive layer are subjected to corona treatment, and are bonded together using a roller The corona-treated surfaces of the machine were attached to each other. A protective film 90 having a thickness of 135 μm is laminated on the surface of the front panel 10 . The protective film 90 includes a PET film and an acrylic adhesive layer, and can be peeled off from the front surface plate 10 . Furthermore, a protective film for a process is layered on both surface areas of the obtained optical layered body 100 . The process protective film can also be peeled off from the protective film 90 and the separator 80 .

In this way, the optical layered body 100 of FIG. 8 is obtained.

Next, the optical layered body 100 of the structure shown in FIG. 9 was produced. Protective film 90/protective layer (TAC) 32/polarizer layer 34/protective layer 36/lamination layer 40/λ/4 plate 52/lamination layer 54/positive C plate 56/second adhesive layer 70/separation Plate 80 Specifically, except that the protective film 90 described above is laminated on the protective layer 32 of the circularly polarizing plate B with an adhesive layer prepared as described above without sticking the front surface plate A with an adhesive layer, as shown in FIG. The optical layered body 100 of 8 was produced in the same manner.

Using a laser cutting machine (LPTSLC-M, manufactured by LPTech), a laser is irradiated vertically from the front surface plate 10 side or the circular polarizing plate 60 side of the optical laminate 100 toward the second adhesive layer 70 side, The obtained optical layered body of FIG. 8 or FIG. 9 was cut into a rectangular shape having a size of 20 mm×110 mm. Severing is performed as a full cut. In each of the Examples and Comparative Examples, the interface L between the circular polarizer 60 and the second adhesive layer 70 was set as the reference position (the distance was zero), and the direction on the front plate 10 side (the circular polarizer 60 side) was set as the reference position (the distance was zero). When it is +, the focal position of the laser is set as shown in the table. In addition, the laser output, moving speed, and irradiation energy are also set as shown in the table. In addition, Table 1 also shows the optical layered body used in each Example and each comparative example.

(Evaluation of Optical Laminates) [Determination of angle and bulge] Angle θ: The optical layered body cut into a rectangular shape by laser is cut with a diamond cutter in the thickness direction to obtain a cross section, and electron microscope is used: manufactured by Hitachi High-Technologies Co., Ltd. The SU8010 takes a cross-sectional photo of the tip. In the cross-sectional photograph, as shown in FIG. 6 , the angle formed by the interface L between the circular polarizer 60 and the second adhesive layer 70 and the tangent P at the interface L of the end face EF of the circular polarizer 60 is measured.

Expansion of the edge portion of the circularly polarizing plate: In the cross-sectional photograph, the maximum thickness of the end portion EP of the circularly polarizing plate 60 was measured, and the thickness T1 (40 μm) of the central portion was subtracted from the maximum thickness to obtain the relative end portion relative to each other. The thickness increase amount T2 of the center part was divided by T1, and the thickness increase rate (T2/T1*100) of the edge part was calculated|required.

(Bending test) (Preparation of Substitute Film for Organic EL Panel) An organic EL panel substitute laminate having two sheets of polyimide-based resin films and an adhesive layer disposed between them and having a thickness of 95 μm as a whole was obtained. The obtained substitute laminate was cut into a size of 22 mm×112 mm using a laser cutting machine (LPTSLC-M, manufactured by LPTech). Laser cutting was cut at speed: 240 mm/sec, output: 24 W.

(Preparation of bending test pieces) A pair of process protective films are peeled off from the optical laminated body 100, and the separator 80 is peeled further. The exposed 2nd adhesive bond layer 70 and the substitute laminated body are bonded together using a roll laminator. In addition, corona treatment is performed on the surface of the 2nd adhesive bond layer 70 and a substitute laminated body before bonding. A bending test piece was thus obtained.

(Bending test) The bend test was carried out at a temperature of 25°C. In a bending tester (F1-2SV, manufactured by Forehu Co., Ltd.), the bending test pieces obtained in the respective Examples and Comparative Examples were set in a flat state (unbent state), and the front panel side (circularly polarized light) was placed. The bending test piece was bent 180° so that the distance between the opposing front surface plates or between the circular polarizers was 2.0 mm (bending radius 1.0 mm). After that, it returned to the original flat state. When a series of operations were performed once, the number of times of bending was calculated as one, and the bending operation was repeated. The bending speed was set to 1 time/1 sec. The number of bends at which cracks occurred in the area that was bent during the bending operation or the adhesive layer was lifted was recorded as the limit number of bends. The conditions and results are shown in Table 1. In Table 1, 1 k means 1000 times.

[Table 1] Table 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Example 1 Example 2 Example 3 Example 4 Example 5 Optical laminate Figure 8 Figure 8 Figure 9 Figure 8 Figure 8 Figure 8 Figure 8 Figure 9 Laser exposure conditions The focal position of the laser based on the interface μm +1320 +820 +1320 +320 +70 -180 -680 +320 output W 29 11 13 10 9 14 29 6 Moving speed mm/s 320 320 320 320 320 320 320 320 Irradiation energy mJ/mm 91 34 41 31 28 44 91 19 Evaluation angle theta ˚ 64 74 70 86 87 85 103 87 Thickness T1 of the central part of the circular polarizer μm 40 40 40 40 40 40 40 40 Thickness increase amount T2 at the end of the circular polarizer μm 0 4 3 5 5 8 6 10 T2/T1 % 0.0 10.0 7.5 12.5 12.5 20.0 15.0 25.0 Limit bending times Second-rate Below 1k Below 1k Below 1k 115k 121k 167k 142k 102k

10: Front panel 12: Hard coating 14: substrate film 20: The first adhesive layer 30: Linear polarizer 32: protective layer 34: polarizer layer 36: Protective layer 40: Lamination layer 50: Phase difference plate 52: λ/4 board 54: Lamination layer 56: Positive C board 58: λ/2 board 60: Circular polarizer 70: Second Adhesive Layer 80: Divider 90: Protective film 100: Optical Laminate EP: Protrusion EF: end face FP: Focus L: interface LB: Laser T1: Thickness of the central part T2: Thickness increase P: Tangent θ: angle

FIG. 1 is a schematic cross-sectional view showing a laminated structure of an optical laminated body 100 according to the first embodiment of the present invention. FIG. 2 is a schematic end view of the front panel 10 according to the embodiment of the present invention. FIG. 3 is a schematic end view of the linear polarizing plate 30 according to the embodiment of the present invention. FIG. 4 is a schematic end view of the retardation plate 50 according to the embodiment of the present invention. FIG. 5 is a schematic cross-sectional view showing the laminated structure of the optical laminated body 100 according to the second embodiment of the present invention. FIG. 6 is an enlarged view of the end surfaces of the circularly polarizing plate 60 and the second adhesive layer 70 of the optical laminate 100 of FIGS. 1 and 5 . FIG. 7 is a schematic diagram illustrating the focal position of the laser beam in the manufacturing process of the optical layered body of the present invention. FIG. 8 is a schematic end view showing the layered structure of the optical layered bodies of Examples and Comparative Examples. FIG. 9 is a schematic end view showing the laminate structure of another optical laminate of Examples and Comparative Examples.

10: Front panel

20: The first adhesive layer

30: Linear polarizer

40: Lamination layer

50: Phase difference plate

60: Circular polarizer

70: Second Adhesive Layer

80: Divider

90: Protective film

100: Optical Laminate

Claims (4)

An optical laminate, comprising a circular polarizer and a second adhesive layer, wherein, In the cross section along the lamination direction of the optical layered product, when the interface between the circularly polarizing plate and the second adhesive layer and the tangent at the interface of the end face of the circularly polarizing plate are shown When the angle is θ, θ≧80° is satisfied. The optical layered product according to claim 1, wherein in the cross section of the optical layered product along the layering direction, when the thickness of the central portion of the circularly polarizing plate is T1, the T1 is used as a reference When the increase in the thickness of the end portion of the circularly polarizing plate is set as T2, T2/T1×100 is 10% or more. The optical laminate according to claim 1 or claim 2, wherein the circularly polarizing plate includes a linear polarizing plate and a retardation plate. The optical laminate of claim 3, wherein the retardation plate comprises a λ/4 plate.

Images