JP6648054B2 - Touch panel - Google Patents

Description

The present invention relates to a resin laminate and a touch panel.

Conventionally, a touch panel member manufactured using an optical laminate in which a metal oxide layer such as ITO is directly laminated as a conductive layer on a light-transmitting base material has been widely known. A touch panel using this touch panel member is arranged on a display panel such as a liquid crystal display panel, and is used as an input means in, for example, a PDA (Personal Digital Assistants), a portable information terminal, a car navigation system, and the like.

Here, the touch panel is disposed on, for example, a liquid crystal display panel and is directly contacted by a finger of a person or the like.Therefore, a surface protection plate for protecting the outermost surface portion is provided. A glass plate was used.
However, the glass plate has a problem that it becomes heavier when the thickness is increased in order to impart a certain degree of impact resistance, while there is a problem that the glass plate is easily broken when the thickness is reduced. To overcome these problems, for example, chemically strengthened thin glass has been put on the market, but there has been a problem that such a glass plate is difficult to process. For this reason, in recent years, various studies have been made to use a resin plate instead of a glass plate as a surface protection plate for a touch panel.
However, a liquid crystal display having such a resin plate as a surface protection plate of a touch panel has a polarization axis of light emitted from the display screen and a transmission axis of the polarized sunglasses when the display screen is viewed with polarized sunglasses. The display screen becomes darker (hereinafter, also referred to as "blackout") or unevenness of different colors on the display screen (hereinafter, also referred to as "smoothness") depending on the angle, especially when the display screen is observed obliquely. And the display quality of the liquid crystal display is impaired.

To solve such a problem, for example, Patent Document 1 discloses a laminate for a protective layer in which a polycarbonate resin layer is laminated on both surfaces of an acrylic resin layer and the in-plane retardation value is 50 nm or less. .
However, in such a laminate for a protective layer, generation of rainbow-like irregularities can be suppressed to some extent, but there is a problem that the problem of blackout cannot be sufficiently solved.

In recent years, thin and flexible displays of flexible type have been developed. In order to apply to such a flexible type display, when a laminate for a protective layer in which a polycarbonate resin layer is laminated on both sides of a conventional acrylic resin layer is bent by molding or the like, only the bent portion has birefringence. Therefore, when viewing the display screen with polarized sunglasses, there is a problem in that unevenness of different colors occurs at places having birefringence.

JP 2011-232504 A

In view of the above circumstances, the present invention is used as a surface protection plate of a touch panel of an image display device, and highly suppresses occurrence of blackout and rainbow-colored even when a display screen is viewed through a polarizing filter such as polarized sunglasses. It is another object of the present invention to provide a resin laminate and a touch panel including the resin laminate, which can highly suppress the occurrence of unevenness and unevenness in different colors even when used in a bent state. .

The present invention is a touch panel including a resin laminate provided with a resin plate on one surface of a transparent substrate having in-plane birefringence, the transparent substrate having in-plane birefringence, Having a retardation of 8000 nm or more, the resin plate has a multilayer structure having a configuration in which a polycarbonate resin layer and an acrylic resin layer are directly laminated, is used as a surface protection plate of a touch panel, and has birefringence in the plane. Both the transparent substrate and the resin plate are disposed on the surface of the touch panel, and the resin used by being disposed on the touch panel such that the transparent substrate having birefringence in the surface is the outermost surface side A touch panel comprising a laminate .

In the touch panel of the present invention, the transparent base material having birefringence in the plane has a refractive index (nx) in a slow axis direction in which the refractive index is large, and a refractive index (nx) in a direction orthogonal to the slow axis direction. The difference (nx-ny) from the refractive index (ny) in the phase axis direction is preferably 0.05 to 0.20.
Further, the transparent substrate having birefringence in the plane is preferably a polyester substrate.
Further, the touch panel of the present invention is preferably further provided with at least one kind of optical functional layer selected from the group consisting of a hard coat layer, an antiglare layer and a low refractive index layer.

The present invention is also a touch panel including the resin laminate of the present invention.
Hereinafter, the present invention will be described in detail.
In the present invention, unless otherwise specified, curable resin precursors such as monomers, oligomers, and prepolymers are also described as “resins”.

The present invention is a resin laminate in which a resin plate is provided on one surface of a transparent substrate having in-plane birefringence.
The present inventors have conducted intensive studies in view of the conventional problems described above, and as a result, in a resin laminated plate in which a transparent substrate and a resin plate are laminated, a transparent substrate having in-plane birefringence as the transparent substrate. Has a predetermined retardation value, and when used as a surface protection plate for a touch panel, has found that blackout and occurrence of rainbow-like unevenness in a display image can be effectively suppressed, and the present invention has been completed. .

In the resin laminate of the present invention, a resin plate is provided on one surface of a transparent substrate having in-plane birefringence.
The transparent substrate having in-plane birefringence has a retardation of 8000 nm or more. If the retardation is less than 8000 nm, blackouts and unevenness appear on the display image of a liquid crystal display device equipped with a touch panel using the resin laminate of the present invention as a surface protection plate. On the other hand, the upper limit of the retardation of the transparent substrate is not particularly limited, but is preferably about 30,000 nm. If the thickness exceeds 30,000 nm, no further improvement in the effect of improving the blackout and rainbow-like unevenness of the displayed image is not observed, and the film thickness becomes considerably large, and the film is weak against impact and easily cracked.
The retardation of the transparent substrate is preferably from 8000 to 25000 nm from the viewpoints of blackout prevention properties, rainbow-like prevention properties, and thinning.

The retardation is defined as the refractive index (nx) in the direction of the largest refractive index (slow axis direction) and the refraction in the direction perpendicular to the slow axis direction (fast axis direction) in the plane of the transparent substrate. The ratio is expressed by the following equation, based on the ratio (ny) and the thickness (d) of the transparent substrate.
Retardation (Re) = (nx−ny) × d
The above-mentioned retardation can be measured (measurement angle 0 °, measurement wavelength 548.2 nm) by, for example, KOBRA-WR manufactured by Oji Scientific Instruments.
In addition, the refractive index measured the average reflectance (R) of wavelength 380-780 nm using the spectrophotometer (UV-3100PC made by Shimadzu Corporation), and obtained the following average reflectance (R) from the obtained average reflectance (R). Was used to determine the value of the refractive index (n).
The average reflectance (R) of the transparent base material was determined by coating the raw material composition of the transparent base material on 50 μm PET having no easy adhesion treatment to form a cured film having a thickness of 1 to 3 μm, and the surface on which PET was not applied ( A black vinyl tape (for example, Yamato vinyl tape NO200-38-21 38 mm width) having a width larger than the measured spot area was applied to the back surface to prevent back surface reflection, and then the average reflectance of the cured film was measured. The refractive index of the transparent substrate was measured after similarly attaching a black vinyl tape to the surface opposite to the measurement surface.
R (%) = (1-n) ² / (1 + n) ²
Further, as a method of measuring the refractive index of the transparent base material after forming the resin laminate, the transparent base material is scraped with a cutter or the like to prepare a sample in a powder state, and the JIS K7142 (2008) B method (powder or The powdered sample is placed on a slide glass or the like using a Cargill reagent having a known refractive index according to the Becke method (for a granular transparent material), the reagent is dropped on the sample, and the sample is immersed in the reagent. Observing the appearance with a microscope, and using a method in which the refractive index of the sample is determined by the difference in refractive index between the sample and the reagent; Can be.
When the transparent substrate is a polyester substrate described later, the refractive index varies depending on the direction. Therefore, instead of the Becke method, the average reflectance is measured and determined by attaching the above-mentioned black vinyl tape to the resin plate laminated surface.
In the present invention, the nx-ny (hereinafter also referred to as Δn) is preferably 0.05 to 0.20. If the above-mentioned Δn is less than 0.05, a sufficient effect of suppressing rainbow-like unevenness may not be obtained, and the film thickness necessary for obtaining the above-mentioned retardation value may be large. On the other hand, when the above Δn exceeds 0.20, the transparent substrate is likely to be torn, torn or the like, and the practicality as an industrial material may be significantly reduced.
A more preferred lower limit of Δn is 0.07, and a more preferred upper limit is 0.15. If Δn is smaller than 0.07, the effect of preventing rainbow-like unevenness when the slow axis is set to 0 ° or 90 ° with respect to the absorption axis of the polarizing plate of the image display device becomes difficult. If the above Δn exceeds 0.15, the durability of the transparent substrate in the wet heat resistance test may be poor. The upper limit of Δn is more preferably 0. 12 because of its excellent durability in a wet heat resistance test.
In addition, (nx) is preferably from 1.67 to 1.78, more preferably a lower limit is 1.69, and a more preferable upper limit is 1.73. Further, (ny) is preferably from 1.55 to 1.65, more preferably 1.57, and more preferably 1.62.
When nx and ny are in the above-mentioned range and satisfy the above-mentioned relationship of Δn, a suitable effect of suppressing rainbow-like unevenness can be obtained.

The transparent substrate having birefringence in the plane is not particularly limited, and includes, for example, a substrate made of polycarbonate, cycloolefin polymer, acryl, polyester, or the like. Among them, it is advantageous in cost and mechanical strength. Preferably, it is a polyester substrate. In the following description, a transparent substrate having an in-plane birefringence will be described as a polyester substrate.

The material constituting the polyester substrate is not particularly limited as long as it satisfies the above-mentioned retardation, and is synthesized from an aromatic dibasic acid or an ester-forming derivative thereof, and a diol or an ester-forming derivative thereof. Linear saturated polyester. Specific examples of the polyester include polyethylene terephthalate, polyethylene isophthalate, polybutylene terephthalate, poly (1,4-cyclohexylene dimethylene terephthalate), and polyethylene-2,6-naphthalate.
The polyester used for the polyester substrate may be a copolymer of the above polyesters. The polyester is mainly used (for example, a component of 80 mol% or more) and a small proportion (for example, 20 mol% or less) of the polyester is used. It may be blended with another kind of resin.
Polyethylene terephthalate or polyethylene-2,6-naphthalate is particularly preferred as the polyester because of its good balance of mechanical properties and optical properties. In particular, it is preferable to be made of polyethylene terephthalate (PET). This is because polyethylene terephthalate has high versatility and is easily available. In the present invention, it is possible to obtain a resin laminate capable of producing an image display device having high display quality even with a very versatile film such as PET. Further, PET is excellent in transparency, heat or mechanical properties, can control retardation by stretching, has a large intrinsic birefringence, and can obtain large retardation relatively easily even with a small film thickness.

The method for obtaining the polyester base material is not particularly limited as long as the method satisfies the above-mentioned retardation. After the transverse stretching using a tenter or the like at a temperature equal to or higher than the transition temperature, a heat treatment is performed.
The horizontal stretching temperature is preferably from 80 to 130 ° C, more preferably from 90 to 120 ° C. Further, the transverse stretching ratio is preferably 2.5 to 6.0 times, more preferably 3.0 to 5.5 times. When the transverse stretching ratio exceeds 6.0 times, the transparency of the obtained polyester base material is liable to decrease, and when the stretching ratio is less than 2.5 times, the stretching tension becomes small. The birefringence of the material may be small, and the retardation may not be 8000 nm or more.
Further, in the present invention, after the transverse stretching of the unstretched polyester is performed under the above conditions using a biaxial stretching test apparatus, stretching in the flow direction with respect to the transverse stretching (hereinafter, also referred to as longitudinal stretching) is performed. Is also good. In this case, the stretching ratio in the longitudinal stretching is preferably 2 times or less. If the stretching ratio of the longitudinal stretching exceeds 2 times, the value of Δn may not be able to be in the above-mentioned preferable range.
Further, the treatment temperature during the heat treatment is preferably 100 to 250 ° C, more preferably 180 to 245 ° C.

As a method of controlling the retardation of the polyester substrate produced by the above-described method to 8000 nm or more, a method of appropriately setting a stretching ratio, a stretching temperature, and a film thickness of the produced polyester substrate is exemplified. Specifically, for example, the higher the draw ratio, the lower the draw temperature, the thicker the film, the easier it is to obtain high retardation, the lower the draw ratio, the higher the draw temperature, The thinner the film, the easier it is to obtain low retardation.

The thickness of the polyester base is preferably 40 μm or more and less than 500 μm. When it is less than 40 μm, the retardation of the polyester base material cannot be made 8000 nm or more, and the anisotropy of the mechanical properties becomes remarkable, so that tearing, tearing and the like are likely to occur, and the practicality as an industrial material is significantly reduced. Sometimes. On the other hand, when the thickness is 500 μm or more, the polyester substrate is weak to impact and easily cracked.
Here, a polyester base material having a thickness of 500 μm or more and satisfying the retardation has the same effect as the resin laminate of the present invention when the polyester base material alone is used as a surface protective plate of a touch panel. It is thought that it can be demonstrated. However, the polyester base material that satisfies the above-mentioned retardation has a breaking elongation and a breaking strength in the MD direction, which is a film forming direction, as compared with a known biaxially stretched polyester base material (PET base material) that does not satisfy the above-mentioned retardation. Small. For this reason, a polyester base material that satisfies the retardation having a large thickness is vulnerable to impact and is easily broken, and cannot be used as a surface protection plate of a touch panel. On the other hand, in the resin laminate of the present invention, the polyester base has a laminated structure with a resin plate described later, so that it can be used as a surface protection plate of a touch panel. A more preferred lower limit of the thickness of the polyester substrate is 50 μm, a more preferred upper limit is 400 μm, and a still more preferred upper limit is 300 μm.

Further, the polyester base material preferably has a transmittance in the visible light region of 80% or more, more preferably 84% or more. In addition, the said transmittance | permeability can be measured by JISK7361-1 (the test method of the total light transmittance of a plastic-transparent material).

In the present invention, the polyester substrate may be subjected to a surface treatment such as a saponification treatment, a glow discharge treatment, a corona discharge treatment, an ultraviolet (UV) treatment, and a flame treatment without departing from the spirit of the present invention. Good.
Further, an easily-adhesive primer treatment layer for performing a hard coat treatment or the like may be provided on the polyester base material.

In the resin laminate of the present invention, a resin plate is provided on one surface of the transparent base material.
The material used for the resin plate is not particularly limited, and examples thereof include a thermoplastic resin such as a polycarbonate resin and a polymethyl methacrylate resin. It is known that an optical laminate having a resin layer such as a hard coat layer provided on the above-described polyester base material is used as a surface protective plate of a touch panel. The resin layer is made of a curable resin that is cured by heat, electron beam, ultraviolet light, or the like.

In the present invention, the resin plate preferably has a multilayer structure having a polycarbonate resin layer and an acrylic resin layer. With such a multilayer structure, various additional functions such as hard coat performance and printing performance can be added to the resin plate of the present invention.

Examples of the polycarbonate resin constituting the polycarbonate resin layer include, for example, a resin obtained by reacting a dihydric phenol and a carbonylating agent with an interfacial polycondensation method or a melt transesterification method, or a solid phase ester of a carbonate prepolymer. Examples thereof include a resin obtained by polymerizing by an exchange method or the like, a resin obtained by polymerizing a cyclic carbonate compound by a ring-opening polymerization method, and the like.

Examples of the dihydric phenol include hydroquinone, resorcinol, 4,4′-dihydroxydiphenyl, bis (4-hydroxyphenyl) methane, bis {(4-hydroxy-3,5-dimethyl) phenyl} methane, 1,1 -Bis (4-hydroxyphenyl) ethane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, 2,2-bis (4-hydroxyphenyl) propane (commonly known as bisphenol A), 2,2-bis {(4-hydroxy-3-methyl) phenyl} propane, 2,2-bis {(4-hydroxy-3,5-dimethyl) phenyl} propane, 2,2-bis} (4-hydroxy-3,5- Dibromo) phenyl {propane, 2,2-bis {(3-isopropyl-4-hydroxy) phenyl} propane, 2,2-bis} 4-hydroxy-3-phenyl) phenyl} propane, 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) -3-methylbutane, 2,2-bis (4-hydroxy Phenyl) -3,3-dimethylbutane, 2,4-bis (4-hydroxyphenyl) -2-methylbutane, 2,2-bis (4-hydroxyphenyl) pentane, 2,2-bis (4-hydroxyphenyl) -4-methylpentane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -4-isopropylcyclohexane, 1,1-bis (4-hydroxyphenyl) -3, 3,5-trimethylcyclohexane, 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis {(4-hydro (C-3-methyl) phenyl} fluorene, α, α′-bis (4-hydroxyphenyl) -o-diisopropylbenzene, α, α′-bis (4-hydroxyphenyl) -m-diisopropylbenzene, α, α ′ -Bis (4-hydroxyphenyl) -p-diisopropylbenzene, 1,3-bis (4-hydroxyphenyl) -5,7-dimethyladamantane, 4,4'-dihydroxydiphenylsulfone, 4,4'-dihydroxydiphenylsulfoxide , 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl ketone, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl ester and the like. These dihydric phenols may be used alone or in combination of two or more.

Among the above dihydric phenols, bisphenol A, 2,2-bis {(4-hydroxy-3-methyl) phenyl} propane, 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (4- (Hydroxyphenyl) -3-methylbutane, 2,2-bis (4-hydroxyphenyl) -3,3-dimethylbutane, 2,2-bis (4-hydroxyphenyl) -4-methylpentane, 1,1-bis ( It is preferable to use at least one selected from the group consisting of 4-hydroxyphenyl) -3,3,5-trimethylcyclohexane and α, α′-bis (4-hydroxyphenyl) -m-diisopropylbenzene. Use of bisphenol A alone, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, At least one selected from the group consisting of phenol A, 2,2-bis {(4-hydroxy-3-methyl) phenyl} propane and α, α′-bis (4-hydroxyphenyl) -m-diisopropylbenzene; Are preferably used in combination.

Examples of the carbonylating agent include carbonyl halides such as phosgene, carbonate esters such as diphenyl carbonate, and haloformates such as dihaloformate of dihydric phenol. These carbonylating agents may be used alone or in combination of two or more.

It is preferable that the polycarbonate resin layer contains an acrylic resin. By containing the acrylic resin, the adhesiveness with the acrylic resin layer described later can be made excellent. Specifically, the polycarbonate resin layer is preferably made of a polycarbonate resin composition containing 0.01 to 1 part by mass of an acrylic resin based on 100 parts by mass of the polycarbonate resin.
As the acrylic resin, a resin similar to an acrylic resin used for an acrylic resin layer described later can be used, and among them, a resin having a low molecular weight is preferably used.
The molecular weight (mass average molecular weight) of the acrylic resin is preferably, for example, 1,000 to 100,000. If it is less than 1,000, the acrylic resin may be volatilized when the polycarbonate resin composition is extruded to form a polycarbonate resin layer, and if it exceeds 100,000, the acrylic resin in the polycarbonate resin layer May cause phase separation with the polycarbonate resin, and may reduce the light transmittance of the resin plate.

As the acrylic resin constituting the acrylic resin layer, methacrylic resin having excellent transparency and high rigidity is preferable. Examples of the methacrylic resin include those having a methyl methacrylate unit as a main component. The methacrylic resin is specifically a methyl methacrylate resin containing usually 50% by mass or more, preferably 70% by mass or more of methyl methacrylate units, and is a methyl methacrylate homopolymer having 100% by mass of methyl methacrylate units. It may be a copolymer of methyl methacrylate and another monomer copolymerizable with the methyl methacrylate.

Examples of the other monomer that can be copolymerized with the methyl methacrylate include, for example, ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, 2-ethylhexyl methacrylate, and 2-methyl methacrylate. Methacrylates other than methyl methacrylate such as hydroxyethyl, methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, 2-ethylhexyl acrylate, 2-hydroxy acrylate And acrylates such as ethyl.
Further, as the other monomer, for example, as styrene and substituted styrenes, for example, halogenated styrenes such as chlorostyrene and bromostyrene, vinyl toluene, alkylstyrenes such as α-methylstyrene, and the like. And unsaturated acids such as methacrylic acid and acrylic acid, acrylonitrile, methacrylonitrile, maleic anhydride, phenylmaleimide, and cyclohexylmaleimide.
These other monomers copolymerizable with methyl methacrylate may be used alone or in combination of two or more.

Further, the acrylic resin may contain rubber particles.
By containing the rubber particles, the impact resistance of the resin laminate of the present invention can be improved.
Examples of the rubber particles include, for example, graft polymerization of 20 to 95 parts by mass of an ethylenically unsaturated monomer such as an acrylic unsaturated monomer to 5 to 80 parts by mass of a rubbery polymer having an acrylic multilayer structure. And the like.

The acrylic multi-layer structure polymer preferably contains an elastomer layer in an amount of about 20 to 60% by mass, preferably has a hard layer as the outermost layer, and more preferably has a hard layer as the innermost layer.

The layer of the elastomer is preferably a layer of an acrylic polymer having a glass transition point (Tg) of less than 25 ° C. Specifically, lower alkyl acrylate, lower alkyl methacrylate, lower alkoxyalkyl acrylate, cyanoethyl acrylate, A polymer obtained by crosslinking at least one monofunctional monomer selected from the group consisting of acrylamide, hydroxy lower alkyl acrylate, hydroxy lower alkyl methacrylate, acrylic acid and methacrylic acid with a polyfunctional monomer such as allyl methacrylate. It is preferred that it is a united layer.

Examples of the lower alkyl group in the lower alkyl acrylate and the like include a linear or branched alkyl group having 1 to 6 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, t-butyl, pentyl, and hexyl. Examples of the lower alkoxy group in the lower alkoxyalkyl acrylate include, for example, methoxy, ethoxy, propoxy, isopropoxy, butoxy, t-butoxy, pentyloxy, hexyloxy and other straight-chain or branched alkoxy having 1 to 6 carbon atoms. Groups. In the case where the above-mentioned monofunctional monomer is used as a main component to form a copolymer, another monofunctional monomer such as styrene or substituted styrene may be copolymerized as a copolymer component.

The hard layer is preferably a layer of an acrylic polymer having a Tg of 25 ° C. or higher, specifically, an alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms alone or polymerized as a main component. It is preferred that it is.
Examples of the alkyl group having 1 to 4 carbon atoms include linear or branched alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, and t-butyl.

In the case where the above-mentioned alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms is used as a main component to form a copolymer, as a copolymer component, other alkyl methacrylates and alkyl acrylates, styrene, substituted styrene, acrylonitrile, methacrylonitrile and the like A monofunctional monomer may be used, or a polyfunctional monomer such as allyl methacrylate may be added to form a crosslinked polymer.
Examples of the alkyl group in the above alkyl methacrylate and the like include the same linear or branched alkyl group having 1 to 6 carbon atoms as exemplified in the above lower alkyl group.

Examples of the acrylic multilayer polymer include those described in JP-B-55-27576, JP-A-6-80739, and JP-A-49-23292.

In the above graft copolymer obtained by graft-polymerizing 20 to 95 parts by mass of the ethylenically unsaturated monomer to the rubbery polymer of 5 to 80 parts by mass, as the rubbery polymer, for example, polybutadiene rubber, Diene rubbers such as acrylonitrile / butadiene copolymer rubber, styrene / butadiene copolymer rubber, acrylic rubbers such as polybutyl acrylate, polypropyl acrylate and poly-2-ethylhexyl acrylate, ethylene / propylene / non-conjugated diene rubber And the like.
Examples of the ethylenic monomer used for graft copolymerization with the rubbery polymer include styrene, acrylonitrile, alkyl (meth) acrylate, and the like. Examples of these graft copolymers include those described in JP-A-55-147514 and JP-B-47-9740.

The amount of the rubber particles to be used is preferably 3 to 150 parts by mass, more preferably 4 to 50 parts by mass, and still more preferably 5 to 30 parts by mass with respect to 100 parts by mass of the acrylic resin. If the amount is less than 3 parts by mass, the above-mentioned effects due to the addition of rubber particles may not be sufficiently obtained. On the other hand, the larger the amount of rubber particles used, the more the impact resistance of the acrylic resin layer is improved, and there is a tendency for the acrylic resin layer to be hardly cracked when pressed. Is too large, and the surface hardness of the acrylic resin layer is undesirably reduced.

In the resin laminate of the present invention, the polycarbonate resin layer and the acrylic resin layer each include, as necessary, for example, an additive such as a light stabilizer, an ultraviolet absorber, an antioxidant, a flame retardant, and an antistatic agent. One type or two or more types may be added.

The resin plate having a multilayer structure having the polycarbonate resin layer and the acrylic resin layer may have, for example, a two-layer structure in which a polycarbonate resin layer is laminated on the acrylic resin layer described above, and may be formed on both surfaces of the polycarbonate resin layer. It may have a three-layer structure in which the acrylic resin layer is laminated.
In the case of the two-layer structure, the resin laminate of the present invention preferably has a structure in which the polycarbonate resin layer is laminated on the transparent substrate, and an acrylic resin layer is provided on the outermost surface. With such a structure, the hard coat property can be improved and printing performance can be imparted.

Further, a primer layer may be formed between the resin plate and the transparent substrate.
The primer layer can be formed, for example, by applying a reactive varnish composed of polyester polyol or polyether polyol and polyisocyanate at 0.5 to 2 g / m2.

Further, the resin plate having a multilayer structure having the polycarbonate resin layer and the acrylic resin layer can be suitably manufactured by, for example, a co-extrusion molding method.
As a method of manufacturing a resin plate by the above-mentioned coextrusion molding method, specifically, first, using two or three uniaxial or twin-screw extruders, a material for an acrylic resin layer and a material for a polycarbonate resin layer are used. Are melt-kneaded, and then a molten resin laminate is formed by laminating and integrating through a feed block die, a multi-manifold die, and the like. Next, a method of cooling and solidifying the laminated and integrated molten laminated resin body using, for example, a roll unit or the like is given. The resin plate manufactured by this co-extrusion molding method is preferable in that it is easier to perform secondary molding than a resin plate manufactured by bonding using an adhesive or an adhesive.

In the resin laminate of the present invention, the resin plate is usually in the form of a sheet or a film, and the thickness thereof is preferably 0.1 to 2 mm, more preferably 0.1 to 1.5 mm.
When the resin plate has a multilayer structure having an acrylic resin layer and a polycarbonate resin layer, the thickness of each of the acrylic resin layer and the polycarbonate resin layer is preferably 1.0 mm or less, more preferably 0 mm or less. 0.01 to 0.5 mm. If it exceeds 1.0 mm, it may not be applicable to a flexible type display.
The thickness of the acrylic resin layer is preferably 70 to 99% of the total thickness of the resin laminate of the present invention.

In the resin laminate of the present invention, it is preferable that a touch sensor function is provided on the side opposite to the transparent substrate having birefringence in the plane of the transparent substrate of the resin plate. In the resin laminate of the present invention having such a configuration, the above-described resin plate and transparent substrate function as a protection plate for the touch sensor function portion.
The touch sensor function is not particularly limited, and includes a conventionally known one.

The resin laminate of the present invention having the transparent substrate and the resin plate is suitably used as a surface protection plate for a touch panel.
As described above, since the resin laminate of the present invention has a transparent base material having a predetermined retardation, when used as a surface protection plate of a touch panel, the occurrence of blackout and blemishes on a display screen is highly suppressed. be able to. The blackout problem is caused by the angle between the polarization axis of the light emitted from the display screen and the transmission axis of the polarized sunglasses. Specifically, the blackout problem is caused by the absorption of the polarizer on the display screen side of the image display device. This is a problem that occurs in a crossed Nicol state in which the axis is perpendicular to the absorption axis of the polarized sunglasses. When the resin laminate of the present invention is used as a surface protection plate of a touch panel, the slow axis of the transparent substrate having the predetermined retardation and the absorption axis of the polarizer are arranged to be shifted to some extent, The blackout problem can be suitably solved.
Incidentally, the angle between the slow axis of the transparent substrate having the predetermined retardation and the absorption axis of the polarizer is preferably 45 ° ± 40 °, more preferably 45 ° ± 30 °, More preferably, it is 45 ° ± 20 °.
The touch panel is not particularly limited. For example, a known capacitive touch panel is preferably used.

When the resin laminate of the present invention is used as a surface protection plate of a touch panel, it is preferable that the resin laminate of the present invention be used by being arranged on a touch panel such that the transparent substrate is the outermost surface side. By arranging the transparent base material so as to be the outermost surface, it is possible to extremely suppress the occurrence of blackouts and uneven stripes on the display screen.

When the resin laminate of the present invention is used as a surface protection plate of a touch panel, the resin laminate of the present invention may be used by being arranged on a touch panel such that the resin plate is located on the outermost surface side. For example, by arranging the above-mentioned acrylic resin layer so as to be the outermost surface, it is possible to improve the hard coat property and to impart printing performance.

The resin laminate of the present invention further comprises a hard coat layer, an anti-glare layer, and at least one optical functional layer selected from the group consisting of a low refractive index layer, wherein the at least one optical functional layer is formed on the resin plate or the transparent substrate. It is preferable that the coating is provided via the primer layer.
The hard coat layer refers to a layer showing a hardness of H or more in a pencil hardness test specified in JIS K5600-5-4 (1999).
The thickness (when cured) of the hard coat layer is 0.1 to 100 μm, preferably 0.8 to 20 μm.

As the hard coat layer, any layer having the above hardness and transparency may be used, and usually, various types of curing such as an ionizing radiation curable resin cured by ultraviolet rays or electron beams, and a thermosetting resin cured by heat. A composition formed as a cured resin layer of a composition for a hard coat layer containing a conductive resin is used. Further, a thermoplastic resin or the like is appropriately added to these curable resins in order to appropriately add flexibility and other physical properties. Among curable resins, an ionizing radiation curable resin is preferable because a typical and excellent hard coating film can be obtained.

Examples of the ionizing radiation-curable resin include compounds having one or more unsaturated bonds, such as compounds having an acrylate-based functional group. Examples of the compound having one unsaturated bond include ethyl (meth) acrylate, ethylhexyl (meth) acrylate, styrene, methylstyrene, and N-vinylpyrrolidone. As the compound having two or more unsaturated bonds, for example, polymethylolpropane tri (meth) acrylate, hexanediol (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, pentaerythritol tri ( Polyfunctional compounds such as (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, or the above polyfunctional compound and (meth) acrylate And the like (for example, poly (meth) acrylate esters of polyhydric alcohols). In this specification, "(meth) acrylate" refers to methacrylate and acrylate.

In addition to the above compounds, relatively low molecular weight polyester resin having an unsaturated double bond, polyether resin, acrylic resin, epoxy resin, urethane resin, alkyd resin, spiroacetal resin, polybutadiene resin, polythiol polyene resin, etc. It can be used as an ionizing radiation-curable resin.

The ionizing radiation-curable resin is used in combination with a solvent-drying resin (such as a thermoplastic resin, which becomes a film by simply drying a solvent added to adjust the solid content during coating). You can also. By using a solvent-drying resin in combination, it is possible to effectively prevent film defects on the coated surface. The solvent drying type resin that can be used in combination with the ionizing radiation curing type resin is not particularly limited, and generally, a thermoplastic resin can be used.
The thermoplastic resin is not particularly limited and includes, for example, a styrene resin, a (meth) acrylic resin, a vinyl acetate resin, a vinyl ether resin, a halogen-containing resin, an alicyclic olefin resin, a polycarbonate resin, and a polyester resin. Resins, polyamide resins, cellulose derivatives, silicone resins and rubbers or elastomers can be mentioned. The thermoplastic resin is preferably non-crystalline and soluble in an organic solvent (particularly a common solvent capable of dissolving a plurality of polymers and curable compounds). In particular, from the viewpoints of film forming properties, transparency and weather resistance, styrene-based resins, (meth) acrylic resins, alicyclic olefin-based resins, polyester-based resins, cellulose derivatives (such as cellulose esters), and the like are preferable.

The thermosetting resin is not particularly limited. For example, phenol resin, urea resin, diallyl phthalate resin, melamine resin, guanamine resin, unsaturated polyester resin, polyurethane resin, epoxy resin, amino alkyd resin, melamine-urea Co-condensation resins, silicon resins, polysiloxane resins and the like can be mentioned.

When the ionizing radiation-curable resin is cured with an electron beam, a photopolymerization initiator is not necessary. However, when the resin is cured with ultraviolet rays, it is preferable that a photopolymerization initiator be contained.
The photopolymerization initiator is not particularly limited, and known photopolymerization initiators can be used.Examples include acetophenones, benzophenones, Michler benzoyl benzoate, α-amyloxime esters, thioxanthones, propiophenones, and benzyls. Benzoins and acylphosphine oxides. Further, it is preferable to use a mixture of photosensitizers, and specific examples thereof include n-butylamine, triethylamine, and poly-n-butylphosphine.

As the photopolymerization initiator, when the ionizing radiation-curable resin is a resin having a radically polymerizable unsaturated group, acetophenones, benzophenones, thioxanthones, benzoin, benzoin methyl ether or the like alone or as a mixture. Preferably, it is used. When the ionizing radiation-curable resin is a resin having a cationically polymerizable functional group, the photopolymerization initiator may be an aromatic diazonium salt, an aromatic sulfonium salt, an aromatic iodonium salt, a metallocene compound, or a benzoin sulfone. It is preferable to use an acid ester or the like alone or as a mixture.

The content of the photopolymerization initiator in the composition for a hard coat layer is preferably 1 to 10 parts by mass based on 100 parts by mass of the ionizing radiation-curable resin. If the amount is less than 1 part by mass, the hardness of the hard coat layer may be insufficient. If the amount exceeds 10 parts by mass, the unreacted photopolymerization initiator acts as a plasticizer and reduces the hardness of the coating film. There is fear.
The more preferable lower limit of the content of the photopolymerization initiator is 2 parts by mass, and the more preferable upper limit is 8 parts by mass. When the content of the photopolymerization initiator is in this range, curing failure does not occur, and unreacted substances are hardly generated.

The composition for a hard coat layer may contain a solvent.
The solvent can be selected and used according to the type of the resin component to be used. Examples of the solvent include ketones (eg, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone), ethers (eg, dioxane, tetrahydrofuran), and fats. Aromatic hydrocarbons (such as hexane), alicyclic hydrocarbons (such as cyclohexane), aromatic hydrocarbons (such as toluene and xylene), halogenated carbons (such as dichloromethane and dichloroethane), and esters (such as methyl acetate and acetic acid) Ethyl, butyl acetate, etc.), water, alcohols (ethanol, isopropanol, butanol, cyclohexanol, etc.), cellosolves (methyl cellosolve, ethyl cellosolve, etc.), cellosolve acetates, sulfoxides (dimethylsulfoxide, etc.), amides (dimethyl Holmua De, dimethylacetamide, etc.) and the like can be exemplified, it may be a mixed solvent thereof.

The composition for forming a hard coat layer can be obtained by mixing and dispersing the various components described above. For the mixing and dispersion, a known method such as a paint shaker or a bead mill can be used.

The hard coat layer is formed from the composition for a hard coat layer.
The hard coat layer is formed by applying the composition for the hard coat layer on the resin plate or the transparent substrate to form a coating, and drying the coating as necessary, and then irradiating with an active energy ray. It is preferable to form by curing.
Examples of the method for applying the composition for forming a hard coat layer include a coating method such as a roll coating method, a miller coating method, and a gravure coating method.

Examples of the active energy ray irradiation include irradiation with an ultraviolet ray or an electron beam. Specific examples of the ultraviolet light source include light sources such as an ultra-high pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc lamp, a black light fluorescent lamp, and a metal halide lamp. As the wavelength of the ultraviolet light, a wavelength range of 190 to 380 nm can be used. Specific examples of the electron beam source include various electron beam accelerators such as Cockcroft-Wald type, Van degraft type, resonance transformer type, insulating core transformer type, linear type, dynamitron type, and high frequency type.

The anti-glare layer is a layer having an irregular shape on its surface or a layer having an internal scattering property by an included anti-glare agent, or a layer having only an internal scattering property without an irregular shape, and the present invention It has a function of reducing external light reflection on the surface of the resin laminate, and a function of diffusing transmitted light from inside and reflected light from outside.
The antiglare layer is not particularly limited, and includes, for example, a layer formed of an antiglare phase composition containing a resin and an antiglare agent.

The anti-glare layer, when the average interval of the unevenness of the surface is Sm, the average inclination angle of the uneven portion is θa, the arithmetic average roughness of the unevenness is Ra, and the ten-point average roughness of the unevenness is Rz, An image that has glare by ensuring that only the edge of the projected image is not clearly visible, as well as preventing glare by eliminating large diffusion and preventing the occurrence of stray light and having a moderately transparent portion. From the viewpoint of obtaining an antiglare film having excellent contrast in a bright room and a dark room, it is preferable that the following formula is satisfied. If θa, Ra, and Rz are less than the lower limits, reflection of external light may not be able to be suppressed. If the values of θa, Ra, and Rz exceed the upper limits, the brightness of the image decreases due to the decrease in the specular component, the bright room contrast decreases due to the increase in diffuse reflection of external light, and the stray light from the transmitted image light increases. By doing so, the dark room contrast may be reduced. In the configuration of the present invention, if Sm is less than the lower limit, control of aggregation may be difficult. On the other hand, when Sm exceeds the upper limit, there may be a problem that fineness of the image cannot be reproduced and a large image is obtained.
50 μm <Sm <600 μm
0.1 ° <θa <1.5 °
0.02 μm <Ra <0.25 μm
0.30 μm <Rz <2.00 μm

In addition, the unevenness of the antiglare layer more preferably satisfies the following formula from the above viewpoint.
100 μm <Sm <400 μm
0.1 ° <θa <1.2 °
0.02 μm <Ra <0.15 μm
0.30 μm <Rz <1.20 μm
The uneven shape of the antiglare layer more preferably satisfies the following expression.
120 μm <Sm <300 μm
0.1 ° <θa <0.5 °
0.02 μm <Ra <0.12 μm
0.30 μm <Rz <0.80 μm
In the present specification, Sm, Ra and Rz are values obtained by a method based on JIS B 0601-1994, and θa is a surface roughness measuring instrument: SE-3400 instruction manual (1995.07) .20 revision) (Kosaka Laboratory Co., Ltd.), and as shown in FIG. 1, as shown in FIG. 1, the sum of the heights of the convex portions existing in the reference length L (h ₁ + h ₂ + h ₃ + ··· + _{h n)} can be determined by the arc tangent .theta.a ⁼ tan _-1 of _{{(h 1 + h 2 +} h 3 + ··· + h n) / L}.
Such Sm, θa, Ra, and Rz can be determined, for example, by measuring with a surface roughness measuring device: SE-3400 / manufactured by Kosaka Laboratory Co., Ltd.

The antiglare layer satisfies Δn = | n1-n2 | <0.1, where n1 and n2 are the refractive indexes of the antiglare agent and the resin, respectively, and the haze inside the antiglare layer. Preferably, the value is 55% or less.
The thickness (when cured) of the antiglare layer is preferably from 0.1 to 100 μm, more preferably 0.8 μm, and more preferably 10 μm. When the film thickness is in this range, the function as an antiglare layer can be sufficiently exhibited.

Fine particles are mentioned as the antiglare agent. The shape is not particularly limited, such as a true sphere or an ellipse, but a true sphere is preferably used.

When the anti-glare agent is fine particles, it may be made of an inorganic material or an organic material. Further, the fine particles exhibit antiglare properties, and are preferably transparent. The particle diameter of the fine particles is about 0.1 to 20 μm as measured by a coal counter method.
Specific examples of the fine particles made of the inorganic material include amorphous and spherical silica beads.
Specific examples of the fine particles made of an organic material include, for example, styrene beads (refractive index: 1.59), melamine beads (refractive index: 1.57), acrylic beads (refractive index: 1.49), acryl-styrene Beads (refractive index 1.53 to 1.58), benzoguanamine-formaldehyde condensate beads (refractive index 1.66), melamine-formaldehyde condensate beads (refractive index 1.66), polycarbonate beads (refractive index 1.57) , Polyethylene beads (refractive index 1.50), polyvinyl chloride beads (refractive index 1.60), and the like. The fine particles made of the organic material may have a hydrophobic group on the surface.

The content of the antiglare agent in the antiglare layer is preferably 0.1 to 30 parts by mass, more preferably 1 part by mass, based on 100 parts by mass of the resin in the antiglare layer. A more preferred upper limit is 25 parts by mass.

The resin in the antiglare layer is not particularly limited. For example, an ionizing radiation-curable resin, an ionizing radiation-curable resin, which is a resin curable by ultraviolet rays or electron beams similar to the resin described in the hard coat layer described above, and a solvent Examples thereof include a mixture with a dry resin, and a thermosetting resin.

The hard coat layer and the anti-glare layer described above may further contain a known antistatic agent, a high refractive index agent, and a high hardness / low curl material such as colloidal silica.

The low-refractive-index layer is a layer that plays a role in lowering the reflectance when external light (for example, a fluorescent lamp or natural light) is reflected on the surface of the optical laminate. The low-refractive-index layer preferably contains 1) a resin containing low-refractive-index particles such as silica and magnesium fluoride, 2) a fluororesin that is a low-refractive-index resin, and 3) silica or magnesium fluoride. It is composed of any one of a fluorine resin, 4) a thin film of a low refractive index substance such as silica, magnesium fluoride and the like. As the resin other than the fluorine-based resin, the same resin as the resin described in the hard coat layer can be used.
Further, the above-mentioned silica is preferably hollow silica fine particles, and such hollow silica fine particles can be produced, for example, by the production method described in the example of JP-A-2005-097778.
These low refractive index layers preferably have a refractive index of 1.45 or less, particularly preferably 1.42 or less.
In addition, the thickness of the low refractive index layer is not limited, but usually may be appropriately set within a range of about 30 nm to 1 μm.
In addition, although the effect of the single layer of the low refractive index layer can be obtained, it is also possible to appropriately provide two or more low refractive index layers for the purpose of adjusting a lower minimum reflectance or a higher minimum reflectance. . When two or more low refractive index layers are provided, it is preferable to provide a difference in the refractive index and the thickness of each low refractive index layer.

As the fluorine-based resin, a polymerizable compound containing at least a fluorine atom in a molecule or a polymer thereof can be used. The polymerizable compound is not particularly limited, but is preferably a compound having a curing reactive group such as a functional group curable by ionizing radiation and a polar group curable by heat. Further, a compound having these reactive groups simultaneously may be used. In contrast to this polymerizable compound, a polymer does not have any reactive group or the like as described above.

As the polymerizable compound having a functional group which is cured by ionizing radiation, a fluorine-containing monomer having an ethylenically unsaturated bond can be widely used. More specifically, examples thereof include fluoroolefins (for example, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, perfluorobutadiene, perfluoro-2,2-dimethyl-1,3-dioxole, etc.). Can be. Examples of those having a (meth) acryloyloxy group include 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3,3-pentafluoropropyl (meth) acrylate, and 2- (perfluorobutyl) ) Ethyl (meth) acrylate, 2- (perfluorohexyl) ethyl (meth) acrylate, 2- (perfluorooctyl) ethyl (meth) acrylate, 2- (perfluorodecyl) ethyl (meth) acrylate, α-trifluoro (Meth) acrylate compounds having a fluorine atom in the molecule, such as methyl methacrylate and α-trifluoroethyl methacrylate; a fluoroalkyl group having 1 to 14 carbon atoms and having at least 3 fluorine atoms in the molecule; A cycloalkyl or fluoroalkylene group and at least two (T) A fluorine-containing polyfunctional (meth) acrylate compound having an acryloyloxy group is also available.

Preferred as the thermosetting polar group are, for example, a hydrogen bond-forming group such as a hydroxyl group, a carboxyl group, an amino group, and an epoxy group. These are excellent not only in adhesion to the coating film but also in affinity with inorganic ultrafine particles such as silica. Examples of the polymerizable compound having a thermosetting polar group include 4-fluoroethylene-perfluoroalkyl vinyl ether copolymer; fluoroethylene-hydrocarbon vinyl ether copolymer; epoxy, polyurethane, cellulose, phenol, polyimide, and the like. Examples include fluorine-modified products of each resin.
Examples of the polymerizable compound having both the functional group curable by ionizing radiation and the polar group curable by heat include acrylic or methacrylic acid portions and fully fluorinated alkyl, alkenyl, aryl esters, fully or partially fluorinated vinyl ethers, Or, partially fluorinated vinyl esters, fully or partially fluorinated vinyl ketones and the like can be exemplified.

Examples of the fluorine-based resin include the following.
A polymer of a monomer or a monomer mixture containing at least one fluorine-containing (meth) acrylate compound of a polymerizable compound having an ionizing radiation-curable group; at least one fluorine-containing (meth) acrylate compound, and methyl (meth) Copolymers with (meth) acrylate compounds containing no fluorine atom in the molecule, such as acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate; fluoroethylene Fluorine-containing compounds such as vinylidene fluoride, trifluoroethylene, chlorotrifluoroethylene, 3,3,3-trifluoropropylene, 1,1,2-trichloro-3,3,3-trifluoropropylene and hexafluoropropylene Homopolymer of monomer or Copolymer such as. A silicone-containing vinylidene fluoride copolymer containing a silicone component in these copolymers can also be used. As the silicone component in this case, (poly) dimethylsiloxane, (poly) diethylsiloxane, (poly) diphenylsiloxane, (poly) methylphenylsiloxane, alkyl-modified (poly) dimethylsiloxane, azo group-containing (poly) dimethylsiloxane, Dimethyl silicone, phenylmethyl silicone, alkyl / aralkyl-modified silicone, fluorosilicone, polyether-modified silicone, fatty acid ester-modified silicone, methyl hydrogen silicone, silanol-containing silicone, alkoxy-containing silicone, phenol-containing silicone, methacryl-modified silicone, acrylic Modified silicone, amino-modified silicone, carboxylic acid-modified silicone, carbinol-modified silicone, epoxy-modified silicone, mercapto-modified silicone Over emissions, fluorine-modified silicones, polyether-modified silicone and the like. Among them, those having a dimethylsiloxane structure are preferred.

Furthermore, non-polymers or polymers comprising the following compounds can also be used as the fluorine-based resin. That is, a fluorine-containing compound having at least one isocyanato group in a molecule is reacted with a compound having at least one functional group that reacts with an isocyanato group such as an amino group, a hydroxyl group, and a carboxyl group in the molecule. Compounds obtained by reacting a fluorine-containing polyol such as a fluorine-containing polyether polyol, a fluorine-containing alkyl polyol, a fluorine-containing polyester polyol, a fluorine-containing ε-caprolactone-modified polyol with a compound having an isocyanato group, and the like. Can be used.

Further, together with the above-mentioned polymerizable compound or polymer having a fluorine atom, each resin as described in the above-mentioned hard coat layer can be used in combination. Further, a curing agent for curing a reactive group or the like, and various additives and solvents can be appropriately used for improving coating properties and imparting antifouling properties.

In the formation of the low refractive index layer, the viscosity of the composition for a low refractive index layer obtained by adding a low refractive index agent and a resin is 0.5 to 5 mPa · s (25 ° C.) at which favorable coating properties are obtained. Preferably, it is in the range of 0.7 to 3 mPa · s (25 ° C.). An antireflection layer excellent in visible light can be realized, a uniform thin film without coating unevenness can be formed, and a low refractive index layer particularly excellent in adhesion can be formed.

The means for curing the resin may be the same as that described for the hard coat layer described above. When a heating means is used for the curing treatment, it is preferable that a thermal polymerization initiator which generates radicals by heating to start polymerization of the polymerizable compound is added to the fluorine-based resin composition.

The layer thickness (nm) d _A of the low refractive index layer is represented by the following formula (1):
d _A = mλ / (4n _A ) (1)
(In the above formula,
n _A represents the refractive index of the low refractive index layer,
m represents a positive odd number, preferably 1;
λ is a wavelength, preferably a value in the range of 480 to 580 nm)
Those satisfying the following are preferable.

In the present invention, the low refractive index layer has the following formula (2):
_{120 <n A d A <145} (2)
Is preferable in terms of lowering the reflectance.

The resin laminate of the present invention may further include another layer (an antistatic layer, an antifouling layer, an adhesive layer, another hard coat layer, or the like), if necessary, as long as the effects of the present invention are not impaired. One layer or two or more layers can be appropriately formed. Especially, it is preferable to have at least one of an antistatic layer and an antifouling layer. As these layers, those similar to known layers can be employed.
Here, in the case where a hard coat layer is formed on the surface opposite to the outermost surface of the resin laminate of the present invention, the above resin plate is bonded via an optical adhesive layer (OCA or liquid OCA) (so-called bonding type). In some cases), low contact with the surface of the hard coat layer is performed in order to secure adhesion to the optical adhesive layer and to make the surface of the hard coat layer spread well when the liquid OCA is filled. There is a need to be a corner. For this reason, it is preferable that the contact angle of water on the surface of the hard coat layer is 30 to 80 °.

The resin laminate of the present invention preferably has a total light transmittance of 90% or more. If it is less than 90%, color reproducibility and visibility may be impaired when mounted on the display surface. The total light transmittance is more preferably at least 95%, even more preferably at least 98%.
The total light transmittance can be measured by a method based on JIS K-7361 using a haze meter (manufactured by Murakami Color Research Laboratory, product number: HM-150).

The haze of the resin laminate of the present invention is preferably less than 1%, more preferably less than 0.5%.
When the resin laminate of the present invention has the antiglare layer, the haze may be less than 80% in the entire laminate. The antiglare layer may be composed of haze due to internal diffusion and haze due to unevenness of the outermost surface, and the haze due to internal diffusion is preferably 3.0% or more and less than 79%, and more preferably 10% or more and less than 50%. Is more preferable. The haze on the outermost surface is preferably 1% or more and less than 35%, more preferably 1% or more and less than 20%, further preferably 1% or more and less than 10%.
The haze can be measured using a haze meter (manufactured by Murakami Color Research Laboratory, product number: HM-150) in accordance with JIS K-7136.

The hardness of the resin laminate of the present invention is preferably 2H or more, more preferably 3H or more, and more preferably 4H or more in a pencil hardness test (load: 4.9N) according to JIS K5600-5-4 (1999). Is more preferable. In a Taber test according to JIS K5400, it is preferable that the amount of wear of the test piece before and after the test is small.

The resin laminate of the present invention can be manufactured by laminating the resin plate on the transparent substrate.
As a method of laminating the resin plate on the transparent substrate, for example, a method by the above-described co-extrusion molding method is preferably exemplified.

The resin laminate of the present invention is suitably used as a surface protective plate for a touch panel as described above, but a touch panel including such a resin laminate of the present invention is also one of the present invention. is there.

Since the resin laminate of the present invention has the above-described configuration, it is used as a surface protection plate of a touch panel of an image display device, and even when a display screen is viewed through a polarizing filter such as polarized sunglasses, blackout is prevented. In addition, the generation of rainbow-like irregularities can be highly suppressed.
For this reason, the resin laminate of the present invention can be suitably applied as a surface protection plate of a touch panel.

FIG. 4 is an explanatory diagram of a method of measuring θa. It is a schematic diagram which shows the extrusion laminating apparatus which manufactures the resin laminated board of this invention. 4 is a graph showing a backlight light source spectrum of a liquid crystal monitor used in Examples and the like.

The contents of the present invention will be described with reference to the following examples, but the contents of the present invention should not be construed as being limited to these embodiments. Unless otherwise specified, “parts” and “%” are based on mass.

(Reference Example 1)
(Preparation of transparent substrate and optical function layer)
The polyethylene terephthalate material was melted at 290 ° C., extruded into a sheet through a film forming die, brought into close contact with a water-cooled rotary quenching drum, and cooled to produce an unstretched film. This unstretched film was preheated at 120 ° C. for 1 minute in a biaxial stretching test apparatus (manufactured by Toyo Seiki Co., Ltd.), and then stretched at 120 ° C. to a stretch ratio of 4.5 times. A primer layer resin composition comprising 28.0 parts by mass of an aqueous dispersion and 72.0 parts by mass of water was uniformly applied with a roll coater to prepare a coated film.
Next, the coated film is dried at 95 ° C. and stretched at a stretch ratio of 1.5 times in a direction 90 ° from the previous stretching direction, and nx = 1.70, ny = 1.60, (nx− ny) = 0.10, a film thickness of 80 μm, and a retardation = 8000 nm to obtain a transparent substrate provided with a primer layer having a refractive index of 1.56 and a film thickness of 100 nm.

Next, as an optical functional layer, dipentaerythritol hexaacrylate (DPHA) was dissolved in MIBK solvent so that the solid content concentration was 30% by mass, and a photopolymerization initiator (Irg184, manufactured by BASF) was further added to the solid content. 5% by mass of the composition for an optical functional layer was prepared. The composition for an optical functional layer was coated on a primer layer of a transparent substrate obtained by a bar coater so that the film thickness after drying was 5 μm to form a coating film.
Next, the formed coating film was heated at 70 ° C. for 1 minute to remove the solvent, and fixed by irradiating the coated surface with ultraviolet rays, and an optical functional layer having a refractive index (nf) of 1.53 (hard coat layer, HC) was formed on one surface of the transparent substrate.

(Production of resin laminate)
The resin laminate was obtained by a so-called extrusion lamination method in which a material for a resin plate was melt-extruded onto the transparent substrate, and the transparent substrate was pressed and adhered.
Specifically, as shown in FIG. 2, an extrusion laminating apparatus including two extruders 21a and 21b, a die 22, a substrate feeding unit 30, a belt pressure feeding unit 40, and a resin laminate winding unit 50. 20 was used to produce a resin laminate. FIG. 2 is a schematic diagram showing an extrusion laminating apparatus for producing the resin laminate of the present invention.

As the extruders 21a and 21b, single-screw vented extruders (manufactured by Toshiba Machine Co., Ltd.) having a screw diameter of 65 mm and 45 mm are used, respectively, and the following two types of resin A and resin B are melt-kneaded, respectively, and then fed. A resin plate was obtained by being supplied to the block and performing coextrusion.
Resin A: Polycarbonate resin “Calibur” manufactured by Sumitomo Dow
Resin B: Sumitomo Chemical Co., Ltd., methacrylic resin "SUMIPEX EX"

In addition, the resin plate is provided with the first feed roll 41 and the second feed roll of the belt pressure feed unit 40 on the side of the transparent base material supplied from the base material feed unit 30 where the optical functional layer is not formed. By pressing between the rolls 32, a resin laminate is obtained.

(Evaluation of Nijimura)
In the obtained resin laminate, the optical functional layer is on the outermost surface side, and the slow axis of the transparent base material and the absorption axis of the polarizer of the installed liquid crystal monitor (FLATORON IPS226V (manufactured by LG Electronics Japan)) are parallel. The display image was observed obliquely (about 50 degrees) from a position 50 to 60 cm away from the polarized sunglasses, and rainbow-like was evaluated according to the following criteria. The results are shown in Table 1. FIG. 3 shows a backlight light source spectrum of the liquid crystal monitor used.
◎: No imperfections are observed at all ×: Impairments are strongly observed

(Evaluation of color change and blackout)
The obtained resin laminate was placed in the same manner as in the evaluation of rainbow-like irregularities, and the resin laminate was subjected to a sensory evaluation for a change in tint when rotated on a liquid crystal monitor and for the presence or absence of blackout. The results are shown in Table 1.

(Falling ball test)
A resin laminated plate was placed on a plate having a void of φ40 mm so that the optical functional layer surface was on the upper surface, and the appearance change after dropping a 36 g steel ball from a height of 50 cm was observed. The results are shown in Table 1.

(Pencil hardness)
After conditioning the obtained resin laminate at a temperature of 25 ° C. and a relative humidity of 60% for 2 hours, using a test pencil specified by JIS S-6006, the stipulated in JIS K5600-5-4 (1999). A pencil hardness test (4.9 N load) was performed. The results are shown in Table 1.

(Example 1)
Using the same resin laminate as in Reference Example 1, the same method as in Reference Example 1 was used except that the slow axis of the transparent substrate and the absorption axis of the polarizer of the liquid crystal monitor were set to 45 degrees in the evaluation of rainbow-color. Was evaluated.

(Example 2)
In the production of the resin laminate, a resin laminate was produced in the same manner as in Reference Example 1 except that only the resin B was used, and the same evaluation as in Reference Example 1 was performed.

(Example 3)
The resin A and the resin B in Reference Example 1 were exchanged, and the resin A and the resin B were co-extruded so that the resin A was in contact with the transparent base material side, and a resin plate was provided on the transparent base material. Thereafter, the same optical functional layer as in Reference Example 1 was provided on the obtained resin plate (on the resin layer made of resin B), and the same evaluation as in Reference Example 1 was performed.

(Comparative Example 1)
A resin laminate was prepared in the same manner as in Reference Example 1 except that a polycarbonate base material (Pure Ace, manufactured by Teijin Limited) was used instead of the transparent substrate in Reference Example 1, and the evaluation was performed in the same manner as in Reference Example 1. went.

(Comparative Example 2)
A resin laminate was prepared in the same manner as in Reference Example 1 except that a transparent base material having a retardation of 5000 nm and a thickness of 50 μm was prepared by adjusting the stretching ratio and the film thickness of the unstretched film, and evaluated in the same manner as in Reference Example 1. Was done.

(Reference Example 2)
A resin plate was produced in the same manner as in Reference Example 1, except that the transparent substrate was not supplied from the substrate feeding section 30. Thereafter, an adhesive layer was formed on the surface of the primer layer of the transparent substrate obtained in Reference Example 1 using an acrylic adhesive (25 μm thick), and a resin laminate was prepared by laminating the obtained resin plates. Evaluation was performed in the same manner as in Reference Example 1.

(Reference Example 3)
A resin laminate was prepared in the same manner as in Reference Example 1 except that the stretching ratio and the film thickness of the unstretched film were adjusted to produce a transparent substrate having a retardation of 50,000 nm and a thickness of 500 μm, and the same as in Reference Example 1. Was evaluated.

As shown in Table 1, the resin laminate according to the example was able to sufficiently suppress the occurrence of blackout and rainbow-like unevenness.
On the other hand, the resin laminate according to Comparative Example 1 had a large amount of color change and was inferior in pencil hardness. In addition, the resin laminate according to Comparative Example 2 was unable to suppress the occurrence of black spots and blackouts. Further, in the resin laminate according to Reference Example 1, blackout could not be suppressed because the slow axis of the transparent substrate was parallel to the absorption axis of the polarizer. Further, in the resin laminate according to Reference Example 2, since the transparent substrate and the resin layer were bonded via the adhesive layer, blackout was not suppressed, and the pencil hardness was poor.
Further, the resin laminate according to Reference Example 3 could not suppress the occurrence of blackout, and was inferior to the ball drop test.
In addition, assuming applicability to a flexible type display by bending the resin laminate according to the example, a sample of 5 cm × 10 cm in the long side direction is set so that the viewing side, that is, the optical functional layer surface is outside. When bent and fixed at a radius of curvature of 5 cm and observed from the optical functional layer side in the same manner as in the examples, no unevenness or unevenness in color was observed in any of the resin laminates at the bent portions.

The resin laminate of the present invention can be suitably applied as a surface protection plate for a touch panel.

REFERENCE SIGNS LIST 20 extrusion laminating devices 21 a and 21 b extruder 22 dice 30 substrate feed unit 32 second feed roll 40 belt pressure feed unit 41 first feed roll 50 resin laminate board winding unit

Claims (4)

A touch panel including a resin laminate provided with a resin plate on one surface of a transparent substrate having birefringence in a plane,
The transparent substrate having birefringence in the plane has a retardation of 8000 nm or more,
The resin plate has a multilayer structure having a configuration in which a polycarbonate resin layer and an acrylic resin layer are directly laminated,
A transparent base material used as a surface protection plate of a touch panel, wherein both the transparent substrate having birefringence in the plane and the resin plate are arranged on the front side of the touch panel, and having birefringence in the plane. Provided with a resin laminate used by being arranged on the touch panel so that is the outermost surface side
A touch panel, characterized in that: The transparent substrate having in-plane birefringence has a refractive index (nx) in a slow axis direction in which the refractive index is large and a refractive index (fast index direction in a direction orthogonal to the slow axis direction). 2. The touch panel according to claim 1, wherein a difference (nx−ny) with respect to (ny) is 0.05 to 0.20. The touch panel according to claim 1, wherein the transparent substrate having in-plane birefringence is a polyester substrate. 4. The touch panel according to claim 1, further comprising at least one optical functional layer selected from the group consisting of a hard coat layer, an antiglare layer, and a low refractive index layer.

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