TWI729040B - Optical laminate and image display device - Google Patents

Optical laminate and image display device Download PDF

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Publication number
TWI729040B
TWI729040B TW105139854A TW105139854A TWI729040B TW I729040 B TWI729040 B TW I729040B TW 105139854 A TW105139854 A TW 105139854A TW 105139854 A TW105139854 A TW 105139854A TW I729040 B TWI729040 B TW I729040B
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Taiwan
Prior art keywords
layer
substrate
retardation
optical laminate
polarizing element
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TW105139854A
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Chinese (zh)
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TW201730601A (en
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角村浩
武田健太郎
飯田敏行
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日商日東電工股份有限公司
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
    • B32B7/02—Physical, chemical or physicochemical properties
    • B32B7/023—Optical properties
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/30—Polarising elements
    • G02B5/3025—Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state
    • G02B5/3033—Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state in the form of a thin sheet or foil, e.g. Polaroid
    • G02B5/3041—Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state in the form of a thin sheet or foil, e.g. Polaroid comprising multiple thin layers, e.g. multilayer stacks
    • G02B5/305—Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state in the form of a thin sheet or foil, e.g. Polaroid comprising multiple thin layers, e.g. multilayer stacks including organic materials, e.g. polymeric layers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/36—Layered products comprising a layer of synthetic resin comprising polyesters
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/30—Polarising elements
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/13363—Birefringent elements, e.g. for optical compensation
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
    • G09F9/00—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements
    • G09F9/30—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the desired character or characters are formed by combining individual elements
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B33/00—Electroluminescent light sources
    • H05B33/02—Details
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
    • H10K59/80—Constructional details
    • H10K59/8791—Arrangements for improving contrast, e.g. preventing reflection of ambient light

Abstract

本發明提供一種儘管具備具有光學各向異性之基材(以下亦稱為各向異性基材)但抗反射功能仍優異之光學積層體。 本發明之光學積層體依序具有包含偏光元件及配置於該偏光元件之至少單側之保護層之偏光板、相位差層、導電層、及基材，該基材之面內相位差Re(550)大於0 nm，該基材之遲相軸與該相位差層之遲相軸所成之角度為-40°～-50°或40°～50°。The present invention provides an optical laminate that has an optically anisotropic substrate (hereinafter also referred to as an anisotropic substrate) but has excellent anti-reflection function. The optical laminate of the present invention has in this order a polarizing plate including a polarizing element and a protective layer disposed on at least one side of the polarizing element, a retardation layer, a conductive layer, and a substrate. The in-plane retardation Re( 550) greater than 0 nm, the angle formed by the late axis of the substrate and the late axis of the retardation layer is -40°～-50° or 40°～50°.

Description

光學積層體及圖像顯示裝置Optical laminate and image display device

本發明係關於一種光學積層體及使用其之圖像顯示裝置。The present invention relates to an optical laminate and an image display device using the same.

近年來，薄型顯示器普及，與此同時提出有搭載有有機EL(Electroluminescence，電致發光)面板之顯示器(有機EL顯示裝置)。有機EL面板由於具有反射性較高之金屬層，故而容易產生外部光反射或背景之映入等問題。因此，已知有藉由將圓偏光板設置於視認側以防止該等問題。另一方面，於顯示單元(例如有機EL單元)與偏光板之間組入有觸控感測器之所謂之內置觸控面板型輸入顯示裝置之需求高漲。此種構成之輸入顯示裝置由於圖像顯示單元與觸控感測器之距離較近，因而能夠對使用者賦予自然之輸入操作感。又，上述構成之輸入顯示裝置可降低起因於形成於觸控感測器之導電圖案之反射光之影響。 一般而言，上述構成之輸入顯示裝置中之觸控感測器具備感測器膜，該感測器膜具備基材及形成於該基材上之導電層。上述基材大量使用各向同性基材。該各向同性基材只要於光學上完全地各向同性，則充分地發揮藉由圓偏光板所形成之抗反射功能。然而，實際上，因導電層形成步驟、提高基材之韌性之處理等之影響，即便於實現了各向同性之基材中，亦會表現出若干之各向異性。其結果，即便配置圓偏光板，亦存在產生外部光反射或背景之映入等問題尚未解決之問題之情況。 [先前技術文獻] [專利文獻] [專利文獻1]日本專利特開2003-311239號公報 [專利文獻2]日本專利特開2002-372622號公報 [專利文獻3]日本專利第3325560號公報 [專利文獻4]日本專利特開2003-036143號公報In recent years, thin displays have become popular, and at the same time, displays (organic EL display devices) equipped with organic EL (Electroluminescence) panels have been proposed. The organic EL panel has a highly reflective metal layer, so it is prone to problems such as reflection of external light or reflection of the background. Therefore, it is known to prevent these problems by arranging a circular polarizing plate on the viewing side. On the other hand, there is an increasing demand for so-called built-in touch panel type input display devices in which a touch sensor is incorporated between a display unit (such as an organic EL unit) and a polarizer. The input display device with such a structure can give the user a natural sense of input operation due to the short distance between the image display unit and the touch sensor. In addition, the input display device with the above-mentioned structure can reduce the influence of the reflected light caused by the conductive pattern formed on the touch sensor. Generally speaking, the touch sensor in the input display device of the above-mentioned configuration includes a sensor film, and the sensor film includes a substrate and a conductive layer formed on the substrate. The above-mentioned base material uses a large amount of isotropic base material. As long as the isotropic substrate is completely optically isotropic, it can fully exhibit the anti-reflection function formed by the circular polarizing plate. However, in fact, due to the influence of the conductive layer forming step, the treatment to improve the toughness of the substrate, etc., even in a substrate that has achieved isotropy, a certain amount of anisotropy will be exhibited. As a result, even if the circular polarizing plate is arranged, there are still unsolved problems such as reflection of external light or reflection of the background. [Prior Art Document] [Patent Document] [Patent Document 1] Japanese Patent Laid-Open No. 2003-311239 [Patent Document 2] Japanese Patent Laid-Open No. 2002-372622 [Patent Document 3] Japanese Patent No. 3325560 [Patent Document 4] Japanese Patent Laid-Open No. 2003-036143

[發明所欲解決之問題] 本發明係為了解決上述先前之課題而成者，其主要目的在於提供一種儘管具備具有光學各向異性之基材(以下亦稱為各向異性基材)但抗反射功能仍優異之光學積層體。 [解決問題之技術手段] 本發明之光學積層體依序具有包含偏光元件及配置於該偏光元件之至少單側之保護層之偏光板、相位差層、導電層、及基材，該基材之面內相位差Re(550)大於0 nm，該基材之遲相軸與該相位差層之遲相軸所成之角度為-40°～-50°或40°～50°。 於一實施形態中，上述偏光元件之吸收軸與上述相位差層之遲相軸所成之角度為38°～52°。 於一實施形態中，上述相位差層之Re(450)/Re(550)為0.8以上且未達1。 於一實施形態中，上述相位差層之Re(650)/Re(550)大於1且為1.2以下。 於一實施形態中，上述相位差層係由聚碳酸酯系構成。 根據本發明之另一形態，提供一種圖像顯示裝置。該圖像顯示裝置具備上述光學積層體。 [發明之效果] 根據本發明，可提供一種藉由將各向異性基材之遲相軸角度最佳化，儘管具備各向異性基材，抗反射功能仍優異之光學積層體。[Problems to be Solved by the Invention] The present invention was made in order to solve the above-mentioned previous problems, and its main purpose is to provide a substrate with optical anisotropy (hereinafter also referred to as anisotropic substrate) that is resistant to Optical laminate with excellent reflection function. [Technical Means for Solving the Problem] The optical laminate of the present invention sequentially has a polarizing plate including a polarizing element and a protective layer disposed on at least one side of the polarizing element, a retardation layer, a conductive layer, and a substrate, the substrate The in-plane retardation Re(550) is greater than 0 nm, and the angle formed by the late axis of the substrate and the late axis of the retardation layer is -40°～-50° or 40°～50°. In one embodiment, the angle formed by the absorption axis of the polarizing element and the retardation axis of the retardation layer is 38° to 52°. In one embodiment, Re(450)/Re(550) of the retardation layer is 0.8 or more and less than 1. In one embodiment, Re(650)/Re(550) of the retardation layer is greater than 1 and 1.2 or less. In one embodiment, the retardation layer is made of polycarbonate. According to another aspect of the present invention, an image display device is provided. This image display device includes the above-mentioned optical laminate. [Effects of the Invention] According to the present invention, it is possible to provide an optical laminate having an excellent anti-reflection function despite having an anisotropic substrate by optimizing the retardation axis angle of an anisotropic substrate.

以下，對本發明之實施形態進行說明，但本發明並不限定於該等實施形態。 (用語及符號之定義) 本說明書中之用語及符號之定義如下所述。 (1)折射率(nx、ny、nz) 「nx」係面內之折射率成為最大之方向(即遲相軸方向)之折射率，「ny」係於面內與遲相軸正交之方向(即進相軸方向)之折射率，「nz」係厚度方向之折射率。 (2)面內相位差(Re) 「Re(λ)」係利用23℃下之波長λnm之光進行測定所得之面內相位差。例如，「Re(550)」係利用23℃下之波長550 nm之光進行測定所得之面內相位差。於將層(膜)之厚度設為d(nm)時，Re(λ)係藉由式：Re(λ)＝(nx－ny)×d而求出。 (3)厚度方向之相位差(Rth) 「Rth(λ)」係利用23℃下之波長λnm之光進行測定所得之厚度方向之相位差。例如，「Rth(550)」係利用23℃下之波長550 nm之光進行測定所得之厚度方向之相位差。於將層(膜)之厚度設為d(nm)時，Rth(λ)係藉由式：Rth(λ)＝(nx－nz)×d而求出。 (4)Nz係數 Nz係數係藉由Nz＝Rth/Re而求出。 A.光學積層體之整體構成 圖1係本發明之一實施形態之光學積層體之概略剖視圖。本實施形態之光學積層體100依序具有偏光板11、相位差層12、導電層21、及基材22。偏光板11包含偏光元件1、配置於偏光元件1之一側之第1保護層2、及配置於偏光元件1之另一側之第2保護層3。亦可根據目的省略第1保護層2及第2保護層3之一者。例如，於相位差層12亦可作為偏光元件1之保護層發揮功能之情形時，亦可省略第2保護層3。導電層21及基材22既可分別作為單一層設為光學積層體100之構成要素，亦可作為基材22與導電層21之積層體導入至光學積層體100。基材22與導電層21之積層體例如可作為觸控感測器之感測器膜20發揮功能。再者，為了便於觀察，圖式中之各層之厚度之比率與實物不同。又，構成光學積層體之各層亦可經由任意適當之接著層(接著劑層或黏著劑層：未圖示)而積層。另一方面，基材22亦可密接積層於導電層21。於本說明書中，所謂「密接積層」，意指2層不介存接著層(例如接著劑層、黏著劑層)而直接且固接地積層。 偏光板11與相位差層12之積層體10可作為圓偏光板發揮功能。又，基材22可為光學各向異性。於本發明中，可提供一種即便具備各向異性基材22，藉由將該基材22之遲相軸與相位差層12所成之角度設為特定之範圍(如下所述為-40°～-50°或40°～50°)，亦可充分地發揮圓偏光板之抗反射功能，從而有效地防止外部光反射或背景之映入等之光學積層體。基材22具有面內相位差(例如，面內相位差Re(550)大於0 nm且為10 nm以下)。詳細內容如下所述。 光學積層體之總厚度較佳為220 μm以下，更佳為40 μm～180 μm。 光學積層體既可為長條狀(例如輥狀)，亦可為單片狀。 以下，對構成光學積層體之各層及光學膜更詳細地進行說明。 B.偏光板 B-1.偏光元件 作為偏光元件1，可採用任意適當之偏光元件。例如，形成偏光元件之樹脂膜既可為單層之樹脂膜，亦可為兩層以上之積層體。 作為由單層之樹脂膜構成之偏光元件之具體例，可列舉：對聚乙烯醇(PVA)系膜、局部縮甲醛化PVA系膜、乙烯-乙酸乙烯酯共聚物系局部皂化膜等親水性高分子膜實施有利用碘或二色性染料等二色性物質而進行之染色處理及延伸處理而成者，PVA之脫水處理物或聚氯乙烯之脫鹽酸處理物等多烯系配向膜等。就光學特性優異之方面而言，較佳為使用利用碘對PVA系膜進行染色並使之單軸延伸而獲得之偏光元件。 利用上述碘進行之染色例如係藉由將PVA系膜浸漬於碘水溶液中而進行。上述單軸延伸之延伸倍率較佳為3～7倍。延伸可於染色處理後進行，亦可一面進行染色一面進行延伸。又，亦可於延伸後進行染色。視需要對PVA系膜實施膨潤處理、交聯處理、洗淨處理、乾燥處理等。例如，於染色之前將PVA系膜浸漬於水中進行水洗，藉此不僅可將PVA系膜表面之污漬及抗黏連劑洗淨，亦可使PVA系膜膨潤而防止染色不均等。 作為使用積層體而獲得之偏光元件之具體例，可列舉使用樹脂基材與積層於該樹脂基材之PVA系樹脂層(PVA系樹脂膜)之積層體或者樹脂基材與塗佈形成於該樹脂基材之PVA系樹脂層之積層體而獲得之偏光元件。使用樹脂基材與塗佈形成於該樹脂基材之PVA系樹脂層之積層體而獲得之偏光元件例如可藉由如下方式而製作：將PVA系樹脂溶液塗佈於樹脂基材並使之乾燥而於樹脂基材上形成PVA系樹脂層，獲得樹脂基材與PVA系樹脂層之積層體；對該積層體進行延伸及染色而將PVA系樹脂層製成偏光元件。於本實施形態中，代表性而言，延伸包含使積層體浸漬於硼酸水溶液中並使之延伸。進而，延伸可進而包含視需要於在硼酸水溶液中進行延伸之前將積層體於高溫(例如95℃以上)下進行空中延伸。所獲得之樹脂基材/偏光元件之積層體既可直接使用(即亦可將樹脂基材作為偏光元件之保護層)，亦可將樹脂基材自樹脂基材/偏光元件之積層體剝離，並於該剝離面積層與目的相對應之任意適當之保護層後使用。此種偏光元件之製造方法之詳細內容例如記載於日本專利特開2012-73580號公報。該公報之整體之記載係作為參考而被引用至本說明書中。 偏光元件之厚度較佳為15 μm以下，更佳為1 μm～12 μm，進而較佳為3 μm～12 μm，尤佳為5 μm～12 μm。 偏光元件之硼酸含量較佳為18重量%以上，更佳為18重量%～25重量%。若偏光元件之硼酸含量為此種範圍，則藉由與下述碘含量之協同效應，可良好地維持貼合時之捲曲調整之容易性，且可良好地抑制加熱時之捲曲，並且可改善加熱時之外觀耐久性。硼酸含量例如可根據中和法並使用下述式，作為每單位重量之偏光元件所包含之硼酸量而算出。 [數1]

Figure 02_image001
偏光元件之碘含量較佳為2.1重量%以上，更佳為2.1重量%～3.5重量%。若偏光元件之碘含量為此種範圍，則藉由與上述硼酸含量之協同效應，可良好地維持貼合時之捲曲調整之容易性，且可良好地抑制加熱時之捲曲，並且可改善加熱時之外觀耐久性。於本說明書中，所謂「碘含量」，意指偏光元件(PVA系樹脂膜)中所包含之所有碘之量。更具體而言，於偏光元件中，碘係以碘離子(I- )、碘分子(I2 )、多碘離子(I3 - 、I5 - )等形態存在，本說明書中之碘含量意指包含所有該等形態之碘之量。碘含量例如可藉由螢光X射線分析之校準曲線法而算出。再者，多碘離子係以於偏光元件中形成有PVA-碘錯合物之狀態存在。藉由形成此種錯合物，可於可見光之波長範圍內表現出吸收二色性。具體而言，PVA與三碘化物離子之錯合物(PVA・I3 - )於470 nm附近具有吸光波峰，PVA與五碘化物離子之錯合物(PVA・I5 - )於600 nm附近具有吸光波峰。作為結果，多碘離子可根據其形態於可見光之較寬之範圍內吸收光。另一方面，碘離子(I- )於230 nm附近具有吸光波峰，實質上與可見光之吸收並不相關。因此，以與PVA之錯合物之狀態存在之多碘離子能夠主要關係到偏光元件之吸收性能。 偏光元件較佳為於波長380 nm～780 nm之任一波長下顯示出吸收二色性。偏光元件之單質透過率如上所述為43.0%～46.0%，較佳為44.5%～46.0%。偏光元件之偏光度較佳為97.0%以上，更佳為99.0%以上，進而較佳為99.9%以上。 B-2.第1保護層 第1保護層2係由可用作偏光元件之保護層之任意適當之膜形成。作為成為該膜之主成分之材料之具體例，可列舉：三乙醯纖維素(TAC)等纖維素系樹脂或聚酯系、聚乙烯醇系、聚碳酸酯系、聚醯胺系、聚醯亞胺系、聚醚碸系、聚碸系、聚苯乙烯系、聚降
Figure 105139854-A0304-03-0013-01
烯系、聚烯烴系、(甲基)丙烯酸系、乙酸酯系等之透明樹脂等。又，亦可列舉：(甲基)丙烯酸系、胺基甲酸酯系、(甲基)丙烯酸胺基甲酸酯系、環氧系、聚矽氧系等熱硬化型樹脂或紫外線硬化型樹脂等。此外，例如亦可列舉矽氧烷系聚合物等玻璃質系聚合物。又，亦可使用日本專利特開2001-343529號公報(WO01/37007)所記載之聚合物膜。作為該膜之材料，例如可使用含有於側鏈具有經取代或未經取代之醯亞胺基之熱塑性樹脂及於側鏈具有經取代或未經取代之苯基以及腈基之熱塑性樹脂之樹脂組合物，例如可列舉具有包含異丁烯與N-甲基馬來醯亞胺之交替共聚物及丙烯腈-苯乙烯共聚物之樹脂組合物。該聚合物膜例如可為上述樹脂組合物之擠出成形物。 如下所述，本發明之光學積層體代表性而言配置於圖像顯示裝置之視認側，第1保護層2代表性而言配置於其視認側。因此，亦可視需要對第1保護層2實施硬塗處理、抗反射處理、抗黏處理、防眩處理等表面處理。進而/或者亦可視需要對第1保護層2實施改善隔著偏光太陽眼鏡視認之情形時之視認性之處理(代表性而言，賦予(橢)圓偏光功能、賦予超高相位差)。藉由實施此種處理，即便於隔著偏光太陽眼鏡等偏光透鏡視認顯示畫面之情形時，亦可實現優異之視認性。因此，光學積層體亦可較佳地應用於可於屋外使用之圖像顯示裝置。 第1保護層之厚度可採用任意適當之厚度。第1保護層之厚度例如為10 μm～50 μm，較佳為15 μm～40 μm。再者，於實施有表面處理之情形時，第1保護層之厚度係包含表面處理層厚度之厚度。 B-3.第2保護層 又，第2保護層3亦由可用作偏光元件之保護層之任意適當之膜形成。成為該膜之主成分之材料如關於第1保護層而於上述B-2項中說明所述。第2保護層3較佳為光學上大致各向同性。於本說明書中，所謂「光學上大致各向同性」，係指面內相位差Re(550)為0 nm～10 nm且厚度方向之相位差Rth(550)為-10 nm～+10 nm。 第2保護層之厚度例如為15 μm～35 μm，較佳為20 μm～30 μm。第1保護層之厚度與第2保護層之厚度之差較佳為15 μm以下，更佳為10 μm以下。若厚度之差為此種範圍，則可良好地抑制貼合時之捲曲。第1保護層之厚度與第2保護層之厚度既可相同，亦可為第1保護層較厚，亦可為第2保護層較厚。代表性而言，第1保護層厚於第2保護層。 C.相位差層 相位差層12可根據目的而具有任意適當之光學特性及/或機械特性。代表性而言，相位差層12具有遲相軸。於一實施形態中，相位差層12之遲相軸與偏光元件1之吸收軸所成之角度θ較佳為38°～52°，更佳為42°～48°，進而較佳為約45°。若角度θ為此種範圍，則藉由如下所述般將相位差層製成λ/4板，可獲得具有非常優異之圓偏光特性(作為結果為非常優異之抗反射特性)之光學積層體。 相位差層較佳為折射率特性顯示nx＞ny≧nz之關係。代表性而言，相位差層係為了對偏光板賦予抗反射特性而設置，於一實施形態中，可作為λ/4板發揮功能。於此情形時，相位差層之面內相位差Re(550)較佳為80 nm～200 nm，更佳為100 nm～180 nm，進而較佳為110 nm～170 nm。再者，此處，「ny＝nz」不僅包含ny與nz完全相等之情形，亦包含實質上相等之情形。因此，可於無損本發明之效果之範圍內存在ny＜nz之情形。 相位差層之Nz係數較佳為0.1～3，更佳為0.2～1.5，進而較佳為0.3～1.3。藉由滿足此種關係，於將所獲得之光學積層體用於圖像顯示裝置之情形時，可達成非常優異之反射色相。 相位差層既可顯示出相位差值對應於測定光之波長而增大之逆分散波長特性，亦可顯示出相位差值對應於測定光之波長而縮小之正的波長分散特性，亦可顯示出相位差值幾乎不會因測定光之波長而變化之平坦之波長分散特性。於一實施形態中，相位差層顯示出逆分散波長特性。於此情形時，相位差層之Re(450)/Re(550)較佳為0.8以上且未達1，更佳為0.8以上且0.95以下。又，相位差層之Re(650)/Re(550)較佳為大於1且為1.2以下，更佳為1.05以上且1.2以下。若為此種構成，則可實現非常優異之抗反射特性。又，藉由以如上方式將具有逆波長分散特性之相位差層與適當調整了遲相軸角度之基材(下述)進行組合而使該效果變得顯著。再者，相位差層之波長分散特性之控制例如可如下所述般使用聚碳酸酯系樹脂膜作為樹脂膜，並調整構成該聚碳酸酯系樹脂之結構單元之含有比率後進行。 相位差層包含光彈性係數之絕對值較佳為2×10-11 m2 /N以下、更佳為2.0×10-13 m2 /N～1.5×10-11 m2 /N、進而較佳為1.0×10-12 m2 /N～1.2×10-11 m2 /N之樹脂。若光彈性係數之絕對值為此種範圍，則於產生加熱時之收縮應力之情形時不易產生相位差變化。其結果，可良好地防止所獲得之圖像顯示裝置之熱不均。 相位差層之厚度較佳為60 μm以下，較佳為30 μm～55 μm。若相位差層之厚度為此種範圍，則可良好地抑制加熱時之捲曲，並且良好地調整貼合時之捲曲。 相位差層可包含可滿足上述特性之任意適當之樹脂膜。作為此種樹脂之代表例，可列舉：環狀烯烴系樹脂、聚碳酸酯系樹脂、纖維素系樹脂、聚酯系樹脂、聚乙烯醇系樹脂、聚醯胺系樹脂、聚醯亞胺系樹脂、聚醚系樹脂、聚苯乙烯系樹脂、丙烯酸系樹脂。於相位差層係由顯示出逆分散波長特性之樹脂膜構成之情形時，可較佳地使用聚碳酸酯系樹脂。 作為上述聚碳酸酯樹脂，只要可獲得本發明之效果，則可使用任意適當之聚碳酸酯樹脂。較佳為聚碳酸酯樹脂包含源自茀系二羥基化合物之結構單元、源自異山梨酯系二羥基化合物之結構單元、及源自選自由脂環式二醇、脂環式二甲醇、二、三或聚乙二醇、以及伸烷基二醇或螺二醇所組成之群中之至少1種二羥基化合物之結構單元。較佳為聚碳酸酯樹脂包含源自茀系二羥基化合物之結構單元、源自異山梨酯系二羥基化合物之結構單元、源自脂環式二甲醇之結構單元以及/或者源自二、三或聚乙二醇之結構單元；進而較佳為包含源自茀系二羥基化合物之結構單元、源自異山梨酯系二羥基化合物之結構單元及源自二、三或聚乙二醇之結構單元。聚碳酸酯樹脂亦可視需要包含源自其他二羥基化合物之結構單元。再者，可較佳地用於本發明之聚碳酸酯樹脂之詳細內容例如記載於日本專利特開2014-10291號公報、日本專利特開2014-26266號公報中，且該記載係作為參考而引用至本說明書中。 上述聚碳酸酯樹脂之玻璃轉移溫度較佳為120℃以上且190℃以下，更佳為130℃以上且180℃以下。若玻璃轉移溫度過低，則有耐熱性變差之傾向，可能會於膜成形後引起尺寸變化，又，存在會降低所獲得之圖像顯示裝置之圖像品質之情形。若玻璃轉移溫度過高，則存在膜成形時之成形穩定性變差之情形，又，存在會損害膜之透明性之情況。再者，玻璃轉移溫度係基於JIS K 7121(1987)而求出。 上述聚碳酸酯樹脂之分子量可以還原黏度表示。還原黏度係使用二氯甲烷作為溶劑，將聚碳酸酯濃度精密地製備成0.6 g/dL，並於溫度20.0℃±0.1℃下使用烏氏黏度管進行測定。還原黏度之下限通常較佳為0.30 dL/g，更佳為0.35 dL/g以上。還原黏度之上限通常較佳為1.20 dL/g，更佳為1.00 dL/g，進而較佳為0.80 dL/g。若還原黏度小於上述下限值，則存在會產生成形品之機械強度降低之問題之情形。另一方面，若還原黏度大於上述上限值，則存在會產生成形時之流動性降低、生產性或成形性降低之問題之情形。 作為聚碳酸酯系樹脂膜，亦可使用市售之膜。作為市售品之具體例，可列舉：帝人公司製造之商品名「PURE-ACE WR-S」、「PURE-ACE WR-W」、「PURE-ACE WR-M」、日東電工公司製造之商品名「NRF」。 相位差層例如可藉由使利用上述聚碳酸酯系樹脂形成之膜延伸而獲得。作為利用聚碳酸酯系樹脂形成膜之方法，可採用任意適當之成形加工法。作為具體例，可列舉：壓縮成形法、轉移成形法、射出成形法、擠出成形法、吹塑成形法、粉末成形法、FRP(Fiber Reinforced Plastics，纖維增強塑膠)成形法、澆鑄塗佈法(例如流延法)、軋光成形法、熱壓製法等。較佳為擠出成形法或澆鑄塗佈法。其原因在於，可提高所獲得之膜之平滑性而獲得良好之光學均勻性。成形條件可根據所使用之樹脂之組成或種類、相位差層所需之特性等適當設定。再者，如上所述，關於聚碳酸酯系樹脂，由於市售有大量膜製品，因而亦可將該市售膜直接供於延伸處理。 樹脂膜(未延伸膜)之厚度可根據相位差層之所需之厚度、所需之光學特性、下述延伸條件等設定為任意適當之值。較佳為50 μm～300 μm。 上述延伸可採用任意適當之延伸方法、延伸條件(例如延伸溫度、延伸倍率、延伸方向)。具體而言，可將自由端延伸、固定端延伸、自由端收縮、固定端收縮等各種延伸方法單獨使用，亦可同時或者逐次使用。關於延伸方向，亦可於長度方向、寬度方向、厚度方向、斜方向等各種方向或維度進行。延伸之溫度相對於樹脂膜之玻璃轉移溫度(Tg)，較佳為Tg－30℃～Tg＋60℃，更佳為Tg－30℃～Tg＋50℃，進而較佳為Tg－15℃～Tg＋30℃。 藉由適當選擇上述延伸方法、延伸條件，可獲得具有上述所需之光學特性(例如折射率特性、面內相位差、Nz係數)之相位差膜。 於一實施形態中，相位差膜係藉由使樹脂膜單軸延伸或者固定端單軸延伸而製作。作為固定端單軸延伸之具體例，可列舉一面使樹脂膜沿長邊方向移動，一面使之沿寬度方向(橫向)延伸之方法。延伸倍率較佳為1.1倍～3.5倍。 於另一實施形態中，相位差膜可藉由使長條狀之樹脂膜相對於長邊方向沿上述角度θ之方向連續地傾斜延伸而製作。藉由採用傾斜延伸，可獲得相對於膜之長邊方向具有角度θ之配向角(角度θ之方向上為遲相軸)之長條狀之延伸膜，例如於與偏光元件積層時，可實現輥對輥而使製造步驟簡略化。再者，角度θ於附相位差層之偏光板中可為偏光元件之吸收軸與相位差層之遲相軸所成之角度。如上所述，角度θ較佳為38°～52°，更佳為42°～48°，進而較佳為約45°。 作為用於傾斜延伸之延伸機，例如可列舉可於橫向及/或縱向上賦予左右不同速度之傳送力或者牽引力或拉取力之拉幅式延伸機。拉幅式延伸機有橫向單軸延伸機、同時雙軸延伸機等，只要可使長條狀之樹脂膜連續地傾斜延伸，則可使用任意適當之延伸機。 於上述延伸機中，分別適當地控制左右之速度，藉此可獲得具有上述所需之面內相位差且於上述所需之方向上具有遲相軸之相位差層(實質上為長條狀之相位差膜)。 上述膜之延伸溫度可根據相位差層所需之面內相位差值及厚度、所使用之樹脂之種類、所使用之膜之厚度、延伸倍率等而變化。具體而言，延伸溫度較佳為Tg－30℃～Tg＋60℃，更佳為Tg－30℃～Tg＋50℃，進而較佳為Tg－15℃～Tg＋30℃。藉由於此種溫度下進行延伸，於本發明中，可獲得具有適當之特性之相位差層。再者，Tg係膜之構成材料之玻璃轉移溫度。 D.導電層 導電層可藉由任意適當之成膜方法(例如真空蒸鍍法、濺鍍法、CVD(Chemical Vapor Deposition，化學氣相沈積)法、離子鍍敷法、噴霧法等)於任意適當之基材上成膜金屬氧化物膜而形成。成膜後，亦可視需要進行加熱處理(例如100℃～200℃)。藉由進行加熱處理，可使非晶質膜結晶化。作為金屬氧化物，例如可列舉：氧化銦、氧化錫、氧化鋅、銦-錫複合氧化物、錫-銻複合氧化物、鋅-鋁複合氧化物、銦-鋅複合氧化物。氧化銦中亦可摻雜二價金屬離子或四價金屬離子。較佳為銦系複合氧化物，更佳為銦-錫複合氧化物(ITO)。銦系複合氧化物具有如下特徵：於可見光區域(380 nm～780 nm)中具有較高之透過率(例如80%以上)，且每單位面積之表面電阻值較低。 於導電層包含金屬氧化物之情形時，該導電層之厚度較佳為50 nm以下，更佳為35 nm以下。導電層之厚度之下限較佳為10 nm。 導電層之表面電阻值較佳為300 Ω/□以下，更佳為150 Ω/□以下，進而較佳為100 Ω/□以下。導電層可視需要進行圖案化。藉由進行圖案化，可形成導通部與絕緣部。作為圖案化方法，可採用任意適當之方法。作為圖案化方法之具體例，可列舉濕式蝕刻法、網版印刷法。 E.基材 基材具有遲相軸。於本發明中，可提供一種即便使用具有遲相軸之基材、即各向異性基材，亦可充分地發揮圓偏光板之抗反射功能，從而有效地防止外部光反射或背景之映入等之光學積層體。因此，根據本發明，無需如先前般重視光學各向同性來選擇構成基材之材料，可根據所需之特性選擇多種多樣之材料。 又，上述基材雖係以光學各向同性(面內相位差Re(550)為0 nm)為目標而製作，但亦可為不可避免地具有遲相軸之基材。於基材上使導電層成膜而形成之情形(即藉由密接積層將基材與導電層積層之情形)時，存在因成膜步驟中之加熱等而導致基材產生不需要之遲相軸之情形。以如上方式而產生之遲相軸會抑制藉由圓偏光板所致之抗反射功能，並且通常難以控制其方向，從而亦會導致生產穩定性降低。於本發明中，即便為產生了上述遲相軸之基材，亦會充分地發揮圓偏光板之抗反射功能。於此種本發明中，可容許產生遲相軸，並形成導電層，從而可減少導電層成膜條件之限制。 上述效果可藉由使基材之遲相軸與相位差層之遲相軸之角度最佳化而獲得。本發明於不論基材之遲相軸於何種方向上產生均充分地發揮圓偏光板之抗反射功能之方面特別有用。 基材之遲相軸與相位差層之遲相軸所成之角度為-40°～-50°或40°～50°，較佳為-42°～-48°或42°～48°，更佳為-44°～-46°或44°～46°，尤佳為-45°或45°。若為此種範圍，則可提供一種可充分地發揮圓偏光板之抗反射功能，從而有效地防止外部光反射或背景之映入等之光學積層體。再者，於本說明書中，以基材之遲相軸為基準而將順時針方向之角度設為正之角度，將逆時針方向之角度設為負之角度。 基材較佳為折射率特性顯示出nx＞ny≧nz之關係。基材之面內相位差Re(550)大於0 nm。根據本發明，即便使用具有面內相位差Re之基材，如上所述，亦可獲得充分地發揮圓偏光板之抗反射功能之光學積層體。於一實施形態中，基材之面內相位差Re(550)為3 nm以上。於另一實施形態中，基材之面內相位差Re(550)為5 nm以上。基材之面內相位差Re(550)之上限例如為10 nm。若基材之面內相位差Re(550)為10 nm以下(更佳為8 nm以下，進而較佳為6 nm以下)，則圓偏光板之抗反射功能進一步增高。 作為基材，可使用任意適當之樹脂膜。作為構成材料之具體例，可列舉：環狀烯烴系樹脂、聚碳酸酯系樹脂、纖維素系樹脂、聚酯系樹脂、丙烯酸系樹脂。 基材之厚度較佳為10 μm～200 μm，更佳為20 μm～60 μm。 亦可視需要於導電層21與基材22之間設置硬塗層(未圖示)。作為硬塗層，可使用具有任意適當之構成之硬塗層。硬塗層之厚度例如為0.5 μm～2 μm。只要霧度為容許範圍，則亦可於硬塗層中添加用以降低牛頓環之微粒子。進而，亦可視需要於導電層21與基材22(於存在之情形時為硬塗層)之間設置用以提高導電層之密接性之增黏塗層、及/或用以調整反射率之折射率調整層。作為增黏塗層及折射率調整層，可採用任意適當之構成。增黏塗層及折射率調整層可為數nm～數十nm之薄層。 亦可視需要於基材22之與導電層21相反之側(光學積層體之最外側)設置另一硬塗層。代表性而言，該硬塗層包含黏合劑樹脂層與球狀粒子，球狀粒子自黏合劑樹脂層突出而形成凸部。此種硬塗層之詳細內容記載於日本專利特開2013-145547號公報中，該公報之記載係作為參考而引用至本說明書中。 F.其他 本發明之實施形態之光學積層體亦可進而包含其他層。於實際使用上，於基材22之表面設置有用以貼合於顯示單元之黏著劑層(未圖示)。較佳為於將光學積層體供於使用之前將剝離膜貼合於該黏著劑層之表面。 G.圖像顯示裝置 上述A項至F項中所記載之光學積層體可應用於圖像顯示裝置。因此，本發明包含使用此種光學積層體之圖像顯示裝置。作為圖像顯示裝置之代表例，可列舉：液晶顯示裝置、有機EL顯示裝置。本發明之實施形態之圖像顯示裝置於其視認側具備上述A項至G項中所記載之光學積層體。光學積層體係以導電層成為顯示單元(例如液晶單元、有機EL單元)側之方式(偏光元件成為視認側之方式)進行積層。即，本發明之實施形態之圖像顯示裝置可為於顯示單元(例如液晶單元、有機EL單元)與偏光板之間組入有觸控感測器之所謂之內置觸控面板型輸入顯示裝置。於此情形時，觸控感測器可配置於導電層(或附基材之導電層)與顯示單元之間。觸控感測器之構成可採用業界眾所周知之構成，因此省略詳細之說明。 [實施例] 以下，藉由實施例對本發明具體地進行說明，但本發明不受該等實施例限定。 [實施例1] 關於下述表1所示之構成之光學積層體，使用光學模擬器(Shintec公司製造，商品名「LCD Master V8」)，並根據正面色相a、b對該光學積層體之反射特性進行評價。 再者，設為於偏光板之與相位差層相反之側配置光源(於「LCD Master V8」中註冊之D65光源)，於基材之與相位差層相反之側配置反射板(於「LCD Master V8」中註冊之理想反射板Idea-Reflector)之構成。 又，以除不包含基材以外與表1相同之構成算出正面色相a、b，並將其結果作為參考。 本評價係如下所述般改變基材之遲相軸角度進行模擬，並藉由與參考進行比較而對光學積層體之反射特性進行評價。 [表1]
Figure 105139854-A0304-0001
 [實施例1-1] 將基材之遲相軸與偏光板之偏光元件之吸收軸所成之角度設為90°。即，將基材之遲相軸與相位差層之遲相軸所成之角度設為45°。 [實施例1-2] 將基材之遲相軸與偏光板之偏光元件之吸收軸所成之角度設為0°。即，將基材之遲相軸與相位差層之遲相軸所成之角度設為-45°。 [實施例1-3] 將基材之遲相軸與偏光板之偏光元件之吸收軸所成之角度設為85°。即，將基材之遲相軸與相位差層之遲相軸所成之角度設為40°。 [實施例1-4] 將基材之遲相軸與偏光板之偏光元件之吸收軸所成之角度設為95°。即，將基材之遲相軸與相位差層之遲相軸所成之角度設為50°。 [實施例1-5] 將基材之遲相軸與偏光板之偏光元件之吸收軸所成之角度設為-5°。即，將基材之遲相軸與相位差層之遲相軸所成之角度設為-50°。 [實施例1-6] 將基材之遲相軸與偏光板之偏光元件之吸收軸所成之角度設為5°。即，將基材之遲相軸與相位差層之遲相軸所成之角度設為-40°。 [比較例1] 於10°～80°及100°～170°之範圍內變更基材之遲相軸與偏光板之偏光元件之吸收軸所成之角度，對各角度下之反射特性進行評價。 關於實施例1及比較例1之結果，將正面色相a、b之繪圖示於圖2。又，將表示Δab之軸角度依存性之圖表示於圖3。Δab係藉由Δab＝{(正面色相a－參考之正面色相a)2 ＋(正面色相b－參考之正面色相b)2 }1/2 而算出。Δab越低，表示各向同性基材之影響越少而抗反射特性越優異。 根據圖2及圖3明確本發明之光學積層體具有優異之抗反射功能。 [實施例2] 將相位差層之Re(550)設為139 nm，將相位差層之波長分散特性Re(550)/Re(450)設為0.85，將波長分散特性Re(650)/Re(550)設為1.06，除此以外，以實施例1(實施例1-1～1-6)相同之方式對光學積層體之反射特性進行評價。 [比較例2] 將相位差層之Re(550)設為139 nm，將相位差層之波長分散特性Re(550)/Re(450)設為0.85，將波長分散特性Re(650)/Re(550)設為1.06，除此以外，以與比較例2相同之方式對光學積層體之反射特性進行評價。 關於實施例2及比較例2之結果，將表示Δab之軸角度依存性之圖表示於圖4。 [實施例3] 將相位差層之波長分散特性Re(550)/Re(450)設為0.82，將波長分散特性Re(650)/Re(550)設為1.08，除此以外，以與實施例1(實施例1-1～1-6)相同之方式對光學積層體之反射特性進行評價。 [比較例3] 將相位差層之波長分散特性Re(550)/Re(450)設為0.82，將波長分散特性Re(650)/Re(550)設為1.08，除此以外，以與比較例2相同之方式對光學積層體之反射特性進行評價。 關於實施例3及比較例3之結果，將表示Δab之軸角度依存性之圖表示於圖5。 [產業上之可利用性] 本發明之光學積層體可較佳地用於液晶顯示裝置及有機EL顯示裝置之類之圖像顯示裝置，尤其可較佳地用作有機EL顯示裝置之抗反射膜。進而，本發明之光學積層體可較佳地用於內置觸控面板型輸入顯示裝置。Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to these embodiments. (Definition of terms and symbols) The definitions of terms and symbols in this manual are as follows. (1) Refractive index (nx, ny, nz) "nx" refers to the refractive index in the direction in which the in-plane refractive index becomes the largest (ie the direction of the late axis), and "ny" refers to the in-plane perpendicular to the late axis The refractive index in the direction (that is, the direction of the advancing axis), "nz" is the refractive index in the thickness direction. (2) In-plane retardation (Re) "Re(λ)" is the in-plane retardation measured using light with a wavelength of λnm at 23°C. For example, "Re(550)" is the in-plane phase difference measured using light with a wavelength of 550 nm at 23°C. When the thickness of the layer (film) is d (nm), Re(λ) is obtained by the formula: Re(λ)=(nx-ny)×d. (3) Thickness direction retardation (Rth) "Rth(λ)" is the thickness direction retardation obtained by measuring light with a wavelength of λnm at 23°C. For example, "Rth(550)" uses light with a wavelength of 550 nm at 23°C to measure the retardation in the thickness direction. When the thickness of the layer (film) is d (nm), Rth(λ) is obtained by the formula: Rth(λ)=(nx-nz)×d. (4) Nz coefficient The Nz coefficient is obtained by Nz=Rth/Re. A. Overall structure of optical laminate FIG. 1 is a schematic cross-sectional view of an optical laminate according to an embodiment of the present invention. The optical laminate 100 of this embodiment has a polarizing plate 11, a retardation layer 12, a conductive layer 21, and a base material 22 in this order. The polarizing plate 11 includes a polarizing element 1, a first protective layer 2 arranged on one side of the polarizing element 1, and a second protective layer 3 arranged on the other side of the polarizing element 1. One of the first protective layer 2 and the second protective layer 3 may be omitted according to the purpose. For example, when the retardation layer 12 can also function as a protective layer of the polarizing element 1, the second protective layer 3 may be omitted. The conductive layer 21 and the base material 22 may each be used as a single layer as a constituent element of the optical laminate 100, or may be introduced into the optical laminate 100 as a laminate of the base material 22 and the conductive layer 21. The laminated body of the base material 22 and the conductive layer 21 can function as a sensor film 20 of a touch sensor, for example. Furthermore, in order to facilitate observation, the ratio of the thickness of each layer in the drawing is different from the actual product. In addition, each layer constituting the optical laminate may be laminated via any appropriate adhesive layer (adhesive layer or adhesive layer: not shown). On the other hand, the base material 22 may be laminated on the conductive layer 21 in close contact. In this specification, the so-called "adhesive build-up layer" means two layers that do not intervene with an adhesive layer (for example, an adhesive layer, an adhesive layer), but a direct and solid build-up layer. The laminated body 10 of the polarizing plate 11 and the retardation layer 12 can function as a circular polarizing plate. In addition, the substrate 22 may be optically anisotropic. In the present invention, it is possible to provide an anisotropic substrate 22 by setting the angle between the slow axis of the substrate 22 and the retardation layer 12 in a specific range (-40° as described below). ～-50° or 40°～50°), it can also give full play to the anti-reflection function of the circular polarizing plate, thus effectively preventing the reflection of external light or the reflection of the background and other optical laminates. The substrate 22 has an in-plane retardation (for example, the in-plane retardation Re(550) is greater than 0 nm and 10 nm or less). The details are as follows. The total thickness of the optical laminate is preferably 220 μm or less, more preferably 40 μm to 180 μm. The optical layered body may have a long strip shape (for example, a roll shape) or a single sheet shape. Hereinafter, each layer and optical film constituting the optical laminate will be described in more detail. B. Polarizing plate B-1. Polarizing element As the polarizing element 1, any suitable polarizing element can be used. For example, the resin film forming the polarizing element may be a single-layer resin film or a laminate of two or more layers. Specific examples of the polarizing element composed of a single-layer resin film include: PVA-based films, partially formalized PVA-based films, ethylene-vinyl acetate copolymer-based partially saponified films, etc. The polymer film is formed by dyeing and stretching using dichroic substances such as iodine or dichroic dyes, and polyene-based alignment films such as dehydrated PVA or dehydrated polyvinyl chloride. . In terms of excellent optical properties, it is preferable to use a polarizing element obtained by dyeing a PVA-based film with iodine and uniaxially stretching it. The dyeing with the above-mentioned iodine is performed, for example, by immersing the PVA-based film in an iodine aqueous solution. The stretching magnification of the above-mentioned uniaxial stretching is preferably 3 to 7 times. Stretching can be done after dyeing, or it can be stretched while dyeing. Also, dyeing may be performed after stretching. If necessary, the PVA-based film is subjected to swelling treatment, cross-linking treatment, washing treatment, drying treatment, etc. For example, immersing the PVA-based film in water for washing before dyeing can not only clean the stains and anti-blocking agent on the surface of the PVA-based film, but also swell the PVA-based film to prevent uneven dyeing. As a specific example of a polarizing element obtained by using a laminate, a laminate of a resin substrate and a PVA-based resin layer (PVA-based resin film) laminated on the resin substrate or a laminate of a resin substrate and a coating formed on the resin substrate can be cited. A polarizing element obtained by a laminate of PVA-based resin layers of a resin base material. A polarizing element obtained by using a laminate of a resin substrate and a PVA-based resin layer formed on the resin substrate by coating can be produced, for example, by applying a PVA-based resin solution to the resin substrate and drying it A PVA-based resin layer is formed on the resin substrate to obtain a laminate of the resin substrate and the PVA-based resin layer; the laminate is extended and dyed to form the PVA-based resin layer into a polarizing element. In this embodiment, the stretching typically includes immersing the layered body in a boric acid aqueous solution and stretching it. Furthermore, stretching may further include stretching the laminated body in the air at a high temperature (for example, 95° C. or higher) before stretching in a boric acid aqueous solution, if necessary. The obtained resin substrate/polarizing element laminate can be used directly (that is, the resin substrate can also be used as a protective layer for the polarizing element), or the resin substrate can be peeled from the resin substrate/polarizing element laminate. And use it after peeling off any suitable protective layer corresponding to the purpose of the area layer. The details of the manufacturing method of such a polarizing element are described in, for example, Japanese Patent Laid-Open No. 2012-73580. The entire description of this gazette is incorporated into this specification as a reference. The thickness of the polarizing element is preferably 15 μm or less, more preferably 1 μm-12 μm, still more preferably 3 μm-12 μm, and particularly preferably 5 μm-12 μm. The boric acid content of the polarizing element is preferably 18% by weight or more, more preferably 18% by weight to 25% by weight. If the boric acid content of the polarizing element is in this range, the synergistic effect with the following iodine content can maintain the ease of curl adjustment during bonding, and suppress curl during heating, and improve Appearance durability when heated. The boric acid content can be calculated as the amount of boric acid contained in the polarizing element per unit weight by using the following formula according to the neutralization method, for example. [Number 1]
Figure 02_image001
The iodine content of the polarizing element is preferably 2.1% by weight or more, and more preferably 2.1% to 3.5% by weight. If the iodine content of the polarizing element is in this range, the synergistic effect with the above-mentioned boric acid content can maintain the ease of curl adjustment during bonding, and suppress curl during heating, and improve heating The appearance and durability of time. In this specification, the "iodine content" means the total amount of iodine contained in the polarizing element (PVA-based resin film). More specifically, the polarizing element, an iodine to iodide ion (I -), molecular iodine (I 2), polyiodide ions (I 3 -, I 5 - ) and the like existing form, the iodine content of the present specification is intended to Refers to the amount of iodine containing all of these forms. The iodine content can be calculated by, for example, a calibration curve method of fluorescent X-ray analysis. Furthermore, polyiodide ions exist in a state where PVA-iodide complexes are formed in the polarizing element. By forming such a complex, it can exhibit absorption dichroism in the wavelength range of visible light. Specifically, PVA and complexes (PVA · I 3 -) triiodide ions having light absorption peaks in the vicinity of 470 nm, and the five complexes iodide ions PVA (PVA · I 5 -) in the vicinity of 600 nm Has a light absorption peak. As a result, polyiodide ions can absorb light in a wider range of visible light according to their form. On the other hand, an iodide ion (I -) in the vicinity of 230 nm having a light absorption peak, does not substantially absorb visible light associated with it. Therefore, the presence of multiple iodide ions in the state of a complex with PVA can mainly affect the absorption performance of the polarizing element. The polarizing element preferably exhibits absorption dichroism at any wavelength from 380 nm to 780 nm. The elemental transmittance of the polarizing element is 43.0%-46.0% as described above, preferably 44.5%-46.0%. The degree of polarization of the polarizing element is preferably 97.0% or more, more preferably 99.0% or more, and still more preferably 99.9% or more. B-2. The first protective layer The first protective layer 2 is formed of any suitable film that can be used as a protective layer of a polarizing element. Specific examples of the material that becomes the main component of the film include: cellulose resins such as triacetyl cellulose (TAC) or polyester, polyvinyl alcohol, polycarbonate, polyamide, polyamide, etc. Imide series, polyether series, poly series, polystyrene series, polyether series
Figure 105139854-A0304-03-0013-01
Transparent resins such as olefin-based, polyolefin-based, (meth)acrylic-based, acetate-based, etc. Also, examples may be: (meth)acrylic, urethane, (meth)acrylate urethane, epoxy, silicone, or other thermosetting resins or ultraviolet curing resins Wait. In addition, for example, glassy polymers such as silicone polymers can also be cited. In addition, the polymer film described in Japanese Patent Laid-Open No. 2001-343529 (WO01/37007) can also be used. As the material of the film, for example, a resin containing a thermoplastic resin having a substituted or unsubstituted amide group in the side chain and a thermoplastic resin having a substituted or unsubstituted phenyl group and a nitrile group in the side chain can be used The composition includes, for example, a resin composition having an alternating copolymer containing isobutylene and N-methylmaleimide and an acrylonitrile-styrene copolymer. The polymer film may be, for example, an extrusion molded product of the above-mentioned resin composition. As described below, the optical laminate of the present invention is typically arranged on the visible side of an image display device, and the first protective layer 2 is typically arranged on the visible side. Therefore, if necessary, the first protective layer 2 may be subjected to surface treatments such as hard coating treatment, anti-reflection treatment, anti-sticking treatment, and anti-glare treatment. Furthermore/or, if necessary, the first protective layer 2 may be subjected to processing to improve visibility when viewed through polarized sunglasses (typically, imparting (elliptical) circular polarization function and imparting ultra-high retardation). By performing such processing, even when viewing the display screen through a polarizing lens such as polarized sunglasses, excellent visibility can be achieved. Therefore, the optical laminate can also be preferably applied to image display devices that can be used outdoors. The thickness of the first protective layer can be any appropriate thickness. The thickness of the first protective layer is, for example, 10 μm to 50 μm, preferably 15 μm to 40 μm. Furthermore, when the surface treatment is performed, the thickness of the first protective layer includes the thickness of the surface treatment layer. B-3. Second protective layer In addition, the second protective layer 3 is also formed of any suitable film that can be used as a protective layer of a polarizing element. The material that becomes the main component of the film is as described in the above section B-2 regarding the first protective layer. The second protective layer 3 is preferably approximately optically isotropic. In this specification, "substantially optically isotropic" means that the in-plane retardation Re (550) is 0 nm to 10 nm and the thickness direction retardation Rth (550) is -10 nm to +10 nm. The thickness of the second protective layer is, for example, 15 μm to 35 μm, preferably 20 μm to 30 μm. The difference between the thickness of the first protective layer and the thickness of the second protective layer is preferably 15 μm or less, more preferably 10 μm or less. If the difference in thickness is in such a range, curling at the time of bonding can be suppressed well. The thickness of the first protective layer and the thickness of the second protective layer may be the same, the first protective layer may be thicker, or the second protective layer may be thicker. Typically, the first protective layer is thicker than the second protective layer. C. Retardation layer The retardation layer 12 may have any appropriate optical properties and/or mechanical properties according to the purpose. Typically, the retardation layer 12 has a slow axis. In one embodiment, the angle θ formed by the slow axis of the retardation layer 12 and the absorption axis of the polarizing element 1 is preferably 38°-52°, more preferably 42°-48°, and still more preferably about 45° °. If the angle θ is in this range, by making the retardation layer into a λ/4 plate as described below, an optical laminate having very excellent circular polarization characteristics (and as a result, very excellent anti-reflection characteristics) can be obtained . The retardation layer preferably exhibits a relationship of nx>ny≧nz in refractive index characteristics. Typically, the retardation layer is provided to impart anti-reflection properties to the polarizing plate, and in one embodiment, it can function as a λ/4 plate. In this case, the in-plane retardation Re(550) of the retardation layer is preferably 80 nm to 200 nm, more preferably 100 nm to 180 nm, and still more preferably 110 nm to 170 nm. Furthermore, here, "ny=nz" includes not only the case where ny and nz are completely equal, but also the case where they are substantially equal. Therefore, the situation of ny<nz can exist in the range which does not impair the effect of the present invention. The Nz coefficient of the retardation layer is preferably 0.1 to 3, more preferably 0.2 to 1.5, and still more preferably 0.3 to 1.3. By satisfying this relationship, when the obtained optical laminate is used in an image display device, a very excellent reflection hue can be achieved. The retardation layer can show both the reverse dispersion wavelength characteristic that the retardation value increases corresponding to the wavelength of the measurement light, or the positive wavelength dispersion characteristic that the retardation value decreases corresponding to the wavelength of the measurement light. It has a flat wavelength dispersion characteristic that the retardation value hardly changes due to the wavelength of the measured light. In one embodiment, the retardation layer exhibits reverse dispersion wavelength characteristics. In this case, the Re(450)/Re(550) of the retardation layer is preferably 0.8 or more and less than 1, more preferably 0.8 or more and 0.95 or less. In addition, Re(650)/Re(550) of the retardation layer is preferably greater than 1 and 1.2 or less, more preferably 1.05 or more and 1.2 or less. With this structure, very excellent anti-reflection characteristics can be achieved. In addition, this effect becomes remarkable by combining a retardation layer having reverse wavelength dispersion characteristics and a base material (described below) whose lag axis angle is appropriately adjusted as described above. In addition, the wavelength dispersion characteristics of the retardation layer can be controlled, for example, by using a polycarbonate-based resin film as the resin film as described below, and adjusting the content ratio of the structural units constituting the polycarbonate-based resin. The absolute value of the retardation layer including the photoelastic coefficient is preferably 2×10 -11 m 2 /N or less, more preferably 2.0×10 -13 m 2 /N to 1.5×10 -11 m 2 /N, and more preferably of 1.0 × 10 -12 m 2 /N~1.2×10 -11 m 2 / N of the resin. If the absolute value of the photoelastic coefficient is in this range, the phase difference will not change easily when the shrinkage stress during heating occurs. As a result, the thermal unevenness of the obtained image display device can be prevented well. The thickness of the retardation layer is preferably 60 μm or less, preferably 30 μm to 55 μm. If the thickness of the retardation layer is in this range, curling during heating can be well suppressed, and curling during bonding can be adjusted well. The retardation layer may include any appropriate resin film that can satisfy the above-mentioned characteristics. Representative examples of such resins include: cyclic olefin resins, polycarbonate resins, cellulose resins, polyester resins, polyvinyl alcohol resins, polyamide resins, and polyimide resins. Resin, polyether resin, polystyrene resin, acrylic resin. When the retardation layer is composed of a resin film exhibiting reverse wavelength dispersion characteristics, a polycarbonate resin can be preferably used. As the aforementioned polycarbonate resin, any appropriate polycarbonate resin can be used as long as the effects of the present invention can be obtained. Preferably, the polycarbonate resin contains a structural unit derived from a stilbene-based dihydroxy compound, a structural unit derived from an isosorbide-based dihydroxy compound, and a structural unit derived from alicyclic diol, alicyclic dimethanol, two A structural unit of at least one dihydroxy compound in the group consisting of, tri- or polyethylene glycol, and alkylene glycol or spirodiol. Preferably, the polycarbonate resin contains a structural unit derived from a stilbene-based dihydroxy compound, a structural unit derived from an isosorbide-based dihydroxy compound, a structural unit derived from alicyclic dimethanol, and/or a structural unit derived from two, three Or a structural unit of polyethylene glycol; further preferably includes a structural unit derived from a stilbene-based dihydroxy compound, a structural unit derived from an isosorbide-based dihydroxy compound, and a structure derived from di-, tri-, or polyethylene glycol unit. The polycarbonate resin may optionally contain structural units derived from other dihydroxy compounds. Furthermore, the details of the polycarbonate resin that can be preferably used in the present invention are described in, for example, Japanese Patent Laid-Open No. 2014-10291 and Japanese Patent Laid-Open No. 2014-26266, and this description is incorporated by reference. Quoted in this manual. The glass transition temperature of the polycarbonate resin is preferably 120°C or higher and 190°C or lower, more preferably 130°C or higher and 180°C or lower. If the glass transition temperature is too low, the heat resistance tends to deteriorate, which may cause dimensional changes after the film is formed, and in addition, it may reduce the image quality of the obtained image display device. If the glass transition temperature is too high, the forming stability during film forming may deteriorate, and the transparency of the film may be impaired. In addition, the glass transition temperature is calculated based on JIS K 7121 (1987). The molecular weight of the above polycarbonate resin can be expressed by reduced viscosity. The reduced viscosity is determined by using dichloromethane as the solvent to precisely prepare the polycarbonate concentration to 0.6 g/dL and using a Ubbelohde viscosity tube at a temperature of 20.0℃±0.1℃. The lower limit of the reduction viscosity is usually preferably 0.30 dL/g, more preferably 0.35 dL/g or more. The upper limit of the reduction viscosity is generally preferably 1.20 dL/g, more preferably 1.00 dL/g, and still more preferably 0.80 dL/g. If the reduction viscosity is less than the above lower limit, there may be a problem that the mechanical strength of the molded product decreases. On the other hand, if the reduction viscosity is greater than the above upper limit, there may be a problem of decreased fluidity during molding, and decreased productivity or moldability. As the polycarbonate resin film, a commercially available film may also be used. Specific examples of commercially available products include: "PURE-ACE WR-S", "PURE-ACE WR-W", "PURE-ACE WR-M" manufactured by Teijin, and products manufactured by Nitto Denko Corporation The name is "NRF". The retardation layer can be obtained, for example, by stretching a film formed of the above-mentioned polycarbonate resin. As a method of forming a film using a polycarbonate-based resin, any appropriate forming method can be adopted. Specific examples include: compression molding method, transfer molding method, injection molding method, extrusion molding method, blow molding method, powder molding method, FRP (Fiber Reinforced Plastics) molding method, casting coating method (For example, casting method), calender forming method, hot pressing method, etc. Preferably, it is an extrusion molding method or a cast coating method. The reason is that the smoothness of the obtained film can be improved to obtain good optical uniformity. The molding conditions can be appropriately set according to the composition or type of the resin used, the required characteristics of the retardation layer, and the like. Furthermore, as described above, regarding polycarbonate-based resins, since a large number of film products are commercially available, the commercially available film can also be directly used for the stretching treatment. The thickness of the resin film (unstretched film) can be set to any appropriate value according to the required thickness of the retardation layer, the required optical properties, the following stretching conditions, etc. It is preferably 50 μm to 300 μm. Any appropriate stretching method and stretching conditions (e.g. stretching temperature, stretching magnification, stretching direction) can be used for the above-mentioned stretching. Specifically, various extension methods such as free end extension, fixed end extension, free end contraction, and fixed end contraction can be used alone, or simultaneously or successively. Regarding the extension direction, it may be performed in various directions or dimensions such as the length direction, the width direction, the thickness direction, and the oblique direction. The temperature of stretching relative to the glass transition temperature (Tg) of the resin film is preferably Tg-30°C to Tg+60°C, more preferably Tg-30°C to Tg+50°C, and still more preferably Tg-15°C to Tg+30°C. By appropriately selecting the above-mentioned stretching method and stretching conditions, a retardation film having the above-mentioned required optical properties (for example, refractive index characteristics, in-plane retardation, and Nz coefficient) can be obtained. In one embodiment, the retardation film is produced by uniaxially extending a resin film or uniaxially extending a fixed end. As a specific example of uniaxial extension of the fixed end, a method of moving the resin film in the longitudinal direction on one side and extending it in the width direction (lateral direction) on the other side can be cited. The stretching ratio is preferably 1.1 to 3.5 times. In another embodiment, the retardation film can be produced by continuously extending and obliquely extending a long resin film in the direction of the above-mentioned angle θ with respect to the longitudinal direction. By adopting oblique stretching, a long stretched film with an alignment angle θ (the direction of the angle θ is the slow phase axis) with respect to the longitudinal direction of the film can be obtained. For example, when laminated with a polarizing element, it can be realized Roll to roll simplifies the manufacturing process. Furthermore, the angle θ in the polarizing plate with retardation layer may be the angle formed by the absorption axis of the polarizing element and the retardation axis of the retardation layer. As described above, the angle θ is preferably 38° to 52°, more preferably 42° to 48°, and still more preferably about 45°. As the stretching machine used for oblique stretching, for example, a tenter stretching machine that can impart a transmission force or a traction force or a take-off force at different speeds in the lateral direction and/or the longitudinal direction can be exemplified. Tenter stretching machines include horizontal uniaxial stretching machines, simultaneous biaxial stretching machines, etc. Any suitable stretching machine can be used as long as the long resin film can be stretched continuously and obliquely. In the above-mentioned stretching machine, the left and right speeds are appropriately controlled respectively, thereby obtaining the phase difference layer (substantially long strip) with the required in-plane phase difference and the delayed phase axis in the required direction. The retardation film). The stretching temperature of the above-mentioned film can be changed according to the required in-plane retardation value and thickness of the retardation layer, the type of resin used, the thickness of the film used, the stretching ratio, and the like. Specifically, the stretching temperature is preferably Tg-30°C to Tg+60°C, more preferably Tg-30°C to Tg+50°C, and still more preferably Tg-15°C to Tg+30°C. By stretching at such a temperature, in the present invention, a retardation layer with appropriate characteristics can be obtained. Furthermore, Tg is the glass transition temperature of the constituent material of the film. D. Conductive layer The conductive layer can be formed by any appropriate film forming method (for example, vacuum evaporation method, sputtering method, CVD (Chemical Vapor Deposition) method, ion plating method, spray method, etc.) A metal oxide film is formed on a suitable substrate. After film formation, heat treatment (for example, 100°C to 200°C) may be performed as necessary. By performing heat treatment, the amorphous film can be crystallized. Examples of metal oxides include indium oxide, tin oxide, zinc oxide, indium-tin composite oxide, tin-antimony composite oxide, zinc-aluminum composite oxide, and indium-zinc composite oxide. Indium oxide can also be doped with divalent metal ions or tetravalent metal ions. It is preferably an indium-based composite oxide, and more preferably an indium-tin composite oxide (ITO). Indium-based composite oxides have the following characteristics: they have a high transmittance (for example, more than 80%) in the visible light region (380 nm to 780 nm), and a low surface resistance value per unit area. When the conductive layer contains a metal oxide, the thickness of the conductive layer is preferably 50 nm or less, more preferably 35 nm or less. The lower limit of the thickness of the conductive layer is preferably 10 nm. The surface resistance of the conductive layer is preferably 300 Ω/□ or less, more preferably 150 Ω/□ or less, and still more preferably 100 Ω/□ or less. The conductive layer can be patterned as needed. By patterning, the conductive portion and the insulating portion can be formed. As the patterning method, any appropriate method can be adopted. Specific examples of the patterning method include wet etching and screen printing. E. Substrate The substrate has a slow axis. In the present invention, it is possible to provide an anti-reflection function of a circular polarizing plate even if a substrate with a delayed phase axis, that is, an anisotropic substrate is used, thereby effectively preventing external light reflection or background reflection And other optical laminates. Therefore, according to the present invention, it is not necessary to select the material constituting the substrate with the emphasis on optical isotropy as before, and a variety of materials can be selected according to the required characteristics. In addition, although the above-mentioned base material is produced with the objective of optical isotropy (in-plane retardation Re(550) is 0 nm), it may be a base material that inevitably has a late axis. In the case of forming a conductive layer on a substrate (that is, a case where the substrate and the conductive layer are laminated by adhesion lamination), there is an unnecessary late phase of the substrate due to heating in the film forming step, etc. The situation of the shaft. The lag axis generated in the above manner inhibits the anti-reflection function caused by the circular polarizer, and it is usually difficult to control its direction, which also leads to a decrease in production stability. In the present invention, even if it is a base material that generates the aforementioned late axis, it will fully exhibit the anti-reflection function of the circular polarizer. In this invention, it is possible to allow the generation of a slow phase axis and to form a conductive layer, thereby reducing the restriction on the film forming conditions of the conductive layer. The above effect can be obtained by optimizing the angle between the late axis of the substrate and the late axis of the retardation layer. The present invention is particularly useful for fully exerting the anti-reflection function of the circular polarizer regardless of the direction in which the slow axis of the substrate is generated. The angle formed by the late axis of the substrate and the late axis of the retardation layer is -40°～-50° or 40°～50°, preferably -42°～-48° or 42°～48°, It is more preferably -44° to -46° or 44° to 46°, and particularly preferably -45° or 45°. If it is in this range, it is possible to provide an optical laminate that can fully exert the anti-reflection function of the circular polarizing plate, thereby effectively preventing the reflection of external light or the reflection of the background. Furthermore, in this specification, the angle in the clockwise direction is set as a positive angle, and the angle in the counterclockwise direction is set as a negative angle based on the slow axis of the substrate. The substrate preferably has a refractive index characteristic showing a relationship of nx>ny≧nz. The in-plane phase difference Re(550) of the substrate is greater than 0 nm. According to the present invention, even if a substrate having an in-plane retardation Re is used, as described above, an optical laminate that sufficiently exhibits the antireflection function of the circular polarizing plate can be obtained. In one embodiment, the in-plane retardation Re(550) of the substrate is 3 nm or more. In another embodiment, the in-plane retardation Re(550) of the substrate is 5 nm or more. The upper limit of the in-plane retardation Re(550) of the substrate is, for example, 10 nm. If the in-plane retardation Re(550) of the substrate is 10 nm or less (more preferably 8 nm or less, and more preferably 6 nm or less), the anti-reflection function of the circular polarizer is further enhanced. As the substrate, any appropriate resin film can be used. Specific examples of constituent materials include cyclic olefin resins, polycarbonate resins, cellulose resins, polyester resins, and acrylic resins. The thickness of the substrate is preferably 10 μm to 200 μm, more preferably 20 μm to 60 μm. Optionally, a hard coat layer (not shown) may be provided between the conductive layer 21 and the substrate 22 as needed. As the hard coat layer, a hard coat layer having any suitable configuration can be used. The thickness of the hard coat layer is, for example, 0.5 μm to 2 μm. As long as the haze is within the allowable range, fine particles for reducing Newton's rings can also be added to the hard coat layer. Furthermore, if necessary, an adhesion-promoting coating to improve the adhesion of the conductive layer and/or to adjust the reflectivity may be provided between the conductive layer 21 and the substrate 22 (the hard coating when it exists). Refractive index adjustment layer. As the adhesion-promoting coating and the refractive index adjustment layer, any appropriate structure can be adopted. The adhesion-promoting coating and the refractive index adjustment layer can be a thin layer of several nm to several tens of nm. Optionally, another hard coat layer may be provided on the side of the substrate 22 opposite to the conductive layer 21 (the outermost side of the optical laminate). Typically, the hard coat layer includes a binder resin layer and spherical particles, and the spherical particles protrude from the binder resin layer to form convex portions. The details of such a hard coat layer are described in Japanese Patent Application Laid-Open No. 2013-145547, and the description of the publication is incorporated into this specification as a reference. F. The optical laminate of other embodiments of the present invention may further include other layers. In actual use, an adhesive layer (not shown) for bonding to the display unit is provided on the surface of the substrate 22. It is preferable to attach a release film to the surface of the adhesive layer before using the optical laminate. G. Image display device The optical laminate described in the above items A to F can be applied to an image display device. Therefore, the present invention includes an image display device using such an optical laminate. Representative examples of image display devices include liquid crystal display devices and organic EL display devices. The image display device of the embodiment of the present invention is provided with the optical laminate described in the above items A to G on the viewing side. The optical laminated system is laminated so that the conductive layer is on the display unit (for example, liquid crystal cell, organic EL unit) side (the polarizing element is on the visible side). That is, the image display device of the embodiment of the present invention may be a so-called built-in touch panel type input display device in which a touch sensor is integrated between the display unit (for example, a liquid crystal unit, an organic EL unit) and a polarizing plate. In this case, the touch sensor can be disposed between the conductive layer (or the conductive layer with the substrate) and the display unit. The structure of the touch sensor can be a structure well-known in the industry, so a detailed description is omitted. [Examples] Hereinafter, the present invention will be specifically described with examples, but the present invention is not limited by these examples. [Example 1] Regarding the optical laminate with the configuration shown in Table 1 below, an optical simulator (manufactured by Shintec, trade name "LCD Master V8") was used, and the optical laminate was measured according to the front hues a and b. The reflection characteristics are evaluated. Furthermore, set the light source (the D65 light source registered in "LCD Master V8") on the opposite side of the polarizing plate to the retardation layer, and arrange the reflector on the side opposite to the retardation layer of the substrate (in the "LCD The composition of the ideal reflector (Idea-Reflector) registered in "Master V8". In addition, the front hues a and b were calculated with the same configuration as in Table 1 except that the base material was not included, and the result was used as a reference. In this evaluation, the angle of the slow axis of the substrate was changed as described below to simulate, and the reflection characteristics of the optical laminate were evaluated by comparison with a reference. [Table 1]
Figure 105139854-A0304-0001
 [Example 1-1] The angle formed by the slow axis of the substrate and the absorption axis of the polarizing element of the polarizing plate was set to 90°. That is, the angle formed by the late axis of the substrate and the late axis of the retardation layer is 45°. [Example 1-2] The angle formed by the slow axis of the substrate and the absorption axis of the polarizing element of the polarizer was set to 0°. That is, the angle formed by the late axis of the substrate and the late axis of the retardation layer is -45°. [Example 1-3] The angle formed by the slow axis of the substrate and the absorption axis of the polarizing element of the polarizer was set to 85°. That is, the angle formed by the late axis of the substrate and the late axis of the retardation layer is set to 40°. [Example 1-4] The angle formed by the slow axis of the substrate and the absorption axis of the polarizing element of the polarizer was set to 95°. That is, the angle formed by the late axis of the substrate and the late axis of the retardation layer is 50°. [Example 1-5] The angle formed by the slow axis of the substrate and the absorption axis of the polarizing element of the polarizer was set to -5°. That is, the angle formed by the late axis of the substrate and the late axis of the retardation layer is set to -50°. [Example 1-6] The angle formed by the slow axis of the substrate and the absorption axis of the polarizing element of the polarizer was set to 5°. That is, the angle formed by the late axis of the substrate and the late axis of the retardation layer is -40°. [Comparative Example 1] The angle between the slow axis of the substrate and the absorption axis of the polarizing element of the polarizer was changed within the range of 10°～80° and 100°～170°, and the reflection characteristics at each angle were evaluated . Regarding the results of Example 1 and Comparative Example 1, the plots of the front hues a and b are shown in FIG. 2. In addition, a graph showing the axis angle dependence of Δab is shown in FIG. 3. Δab is calculated by Δab={(front hue a-reference front hue a) 2 + (front hue b-reference front hue b) 2 } 1/2 . The lower the Δab, the less the influence of the isotropic substrate and the better the anti-reflection properties. According to Figs. 2 and 3, it is clear that the optical laminate of the present invention has an excellent anti-reflection function. [Example 2] The Re(550) of the retardation layer was set to 139 nm, the wavelength dispersion characteristic Re(550)/Re(450) of the retardation layer was set to 0.85, and the wavelength dispersion characteristic Re(650)/Re Except that (550) was set to 1.06, the reflection characteristics of the optical laminate were evaluated in the same manner as in Example 1 (Examples 1-1 to 1-6). [Comparative Example 2] The Re(550) of the retardation layer was set to 139 nm, the wavelength dispersion characteristic Re(550)/Re(450) of the retardation layer was set to 0.85, and the wavelength dispersion characteristic Re(650)/Re Except that (550) was set to 1.06, the reflection characteristics of the optical laminate were evaluated in the same manner as in Comparative Example 2. Regarding the results of Example 2 and Comparative Example 2, a graph showing the axis angle dependence of Δab is shown in FIG. 4. [Example 3] The wavelength dispersion characteristic Re(550)/Re(450) of the retardation layer was set to 0.82, and the wavelength dispersion characteristic Re(650)/Re(550) was set to 1.08. The reflection characteristics of the optical laminate were evaluated in the same manner as in Example 1 (Examples 1-1 to 1-6). [Comparative Example 3] The wavelength dispersion characteristic Re(550)/Re(450) of the retardation layer was set to 0.82, and the wavelength dispersion characteristic Re(650)/Re(550) was set to 1.08. Other than that, for comparison The reflection characteristics of the optical laminate were evaluated in the same manner as in Example 2. Regarding the results of Example 3 and Comparative Example 3, a graph showing the axis angle dependence of Δab is shown in FIG. 5. [Industrial Applicability] The optical laminate of the present invention can be preferably used for image display devices such as liquid crystal display devices and organic EL display devices, and can be particularly preferably used as antireflection for organic EL display devices. membrane. Furthermore, the optical laminate of the present invention can be preferably used for a built-in touch panel type input display device.

1‧‧‧偏光元件 2‧‧‧第1保護層 3‧‧‧第2保護層 10‧‧‧積層體 11‧‧‧偏光板 12‧‧‧相位差層 20‧‧‧感測器膜 21‧‧‧導電層 22‧‧‧基材 100‧‧‧光學積層體1‧‧‧Polarizing element 2‧‧‧The first protective layer 3‧‧‧Second protection layer 10‧‧‧Layered body 11‧‧‧Polarizer 12‧‧‧Phase Difference Layer 20‧‧‧Sensor film 21‧‧‧Conductive layer 22‧‧‧Substrate 100‧‧‧Optical laminate

圖1係本發明之一實施形態之光學積層體之概略剖視圖。 圖2係表示實施例及比較例之結果之圖表。 圖3係表示實施例及比較例之結果之圖表。 圖4係表示實施例及比較例之結果之圖表。 圖5係表示實施例及比較例之結果之圖表。Fig. 1 is a schematic cross-sectional view of an optical laminate according to an embodiment of the present invention. Fig. 2 is a graph showing the results of Examples and Comparative Examples. Fig. 3 is a graph showing the results of Examples and Comparative Examples. Fig. 4 is a graph showing the results of Examples and Comparative Examples. Fig. 5 is a graph showing the results of Examples and Comparative Examples.

1‧‧‧偏光元件 1‧‧‧Polarizing element

2‧‧‧第1保護層 2‧‧‧The first protective layer

3‧‧‧第2保護層 3‧‧‧Second protection layer

10‧‧‧積層體 10‧‧‧Layered body

11‧‧‧偏光板 11‧‧‧Polarizer

12‧‧‧相位差層 12‧‧‧Phase Difference Layer

20‧‧‧感測器膜 20‧‧‧Sensor film

21‧‧‧導電層 21‧‧‧Conductive layer

22‧‧‧基材 22‧‧‧Substrate

100‧‧‧光學積層體 100‧‧‧Optical laminate

Claims (6)

一種光學積層體，其依序具有包含偏光元件及配置於該偏光元件之至少單側之保護層之偏光板、相位差層、導電層、及基材，該基材之面內相位差Re(550)大於0nm且為10nm以下，該基材之遲相軸與該相位差層之遲相軸所成之角度為-40°~-50°或40°~50°。 An optical laminate having, in sequence, a polarizing plate including a polarizing element and a protective layer disposed on at least one side of the polarizing element, a retardation layer, a conductive layer, and a substrate. The in-plane retardation Re( 550) greater than 0nm and less than 10nm, the angle formed by the late axis of the substrate and the retardation axis of the retardation layer is -40°~-50° or 40°~50°. 如請求項1之光學積層體，其中上述偏光元件之吸收軸與上述相位差層之遲相軸所成之角度為38°~52°。 The optical laminate of claim 1, wherein the angle formed by the absorption axis of the polarizing element and the late axis of the retardation layer is 38° to 52°. 如請求項1之光學積層體，其中上述相位差層之Re(450)/Re(550)為0.8以上且未達1。 Such as the optical laminate of claim 1, wherein the Re(450)/Re(550) of the retardation layer is 0.8 or more and less than 1. 如請求項1之光學積層體，其中上述相位差層之Re(650)/Re(550)大於1且為1.2以下。 The optical laminate of claim 1, wherein Re(650)/Re(550) of the retardation layer is greater than 1 and less than 1.2. 如請求項1之光學積層體，其中上述相位差層係由聚碳酸酯系構成。 The optical laminate of claim 1, wherein the retardation layer is made of polycarbonate. 一種圖像顯示裝置，其具備如請求項1之光學積層體。 An image display device including the optical laminate as claimed in claim 1.
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Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP7044468B2 (en) * 2016-02-05 2022-03-30 三菱ケミカル株式会社 An optical laminate and an image display device using the optical laminate
US11411206B2 (en) 2017-07-10 2022-08-09 Lg Chem, Ltd. Circularly polarizing plate
JP2019095604A (en) * 2017-11-22 2019-06-20 日東電工株式会社 Image display device
KR102466770B1 (en) * 2019-07-23 2022-11-14 주식회사 엘지화학 Optical Laminate

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001201632A (en) * 2000-01-17 2001-07-27 Kanegafuchi Chem Ind Co Ltd Liquid crystal display device with touch panel and touch panel
JP2009109996A (en) * 2007-10-09 2009-05-21 Toray Ind Inc Retardation film
US20140168768A1 (en) * 2012-12-14 2014-06-19 Cheil Industries Inc. Polarizing plate and optical display apparatus including the same
TW201508597A (en) * 2013-08-23 2015-03-01 Miracletouch Technology Inc Polarized capacitive touch panel and display using the same

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002372622A (en) 2001-06-14 2002-12-26 Nitto Denko Corp Composite optical retardation plate, circularly polarizing plate and liquid crystal display, organic el display device
JP2003036143A (en) 2001-07-25 2003-02-07 Sumitomo Chem Co Ltd Inner touch panel
JP2003311239A (en) 2002-04-23 2003-11-05 Matsushita Electric Works Ltd Apparatus for treating garbage
CN100472287C (en) * 2005-03-30 2009-03-25 卡西欧计算机株式会社 Vertical orientation type liquid crystal display device
SG183550A1 (en) * 2010-03-03 2012-10-30 3M Innovative Properties Co Composite with nano-structured layer and method of making the same
CN103052489B (en) * 2010-08-02 2015-03-11 株式会社日本触媒 Method of manufacturing phase difference film and phase difference film roll
JP5528606B2 (en) * 2012-06-21 2014-06-25 日東電工株式会社 Polarizing plate and organic EL panel
JP2014112510A (en) * 2012-11-02 2014-06-19 Nitto Denko Corp Transparent conductive film
TWI636285B (en) * 2013-08-09 2018-09-21 住友化學股份有限公司 Optical film
JP2015069158A (en) * 2013-09-30 2015-04-13 大日本印刷株式会社 Optical film, image display device, and method for manufacturing the optical film
JP6483811B2 (en) * 2015-04-13 2019-03-13 富士フイルム株式会社 Transparent substrate film laminate, sensor film for touch panel, touch panel, image display device, and method for improving visibility of image display device

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001201632A (en) * 2000-01-17 2001-07-27 Kanegafuchi Chem Ind Co Ltd Liquid crystal display device with touch panel and touch panel
JP2009109996A (en) * 2007-10-09 2009-05-21 Toray Ind Inc Retardation film
US20140168768A1 (en) * 2012-12-14 2014-06-19 Cheil Industries Inc. Polarizing plate and optical display apparatus including the same
TW201508597A (en) * 2013-08-23 2015-03-01 Miracletouch Technology Inc Polarized capacitive touch panel and display using the same

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