TWI645221B - Laminated body and manufacturing method of polarizing film - Google Patents

Laminated body and manufacturing method of polarizing film Download PDF

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TWI645221B
TWI645221B TW102127781A TW102127781A TWI645221B TW I645221 B TWI645221 B TW I645221B TW 102127781 A TW102127781 A TW 102127781A TW 102127781 A TW102127781 A TW 102127781A TW I645221 B TWI645221 B TW I645221B
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pva
polarizing film
laminated body
layer
stretching
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TW201411203A (en
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Masahiro Takafuji
高藤勝啓
Takanori Isozaki
磯崎孝德
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Kuraray Co., Ltd.
可樂麗股份有限公司
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C55/00—Shaping by stretching, e.g. drawing through a die; Apparatus therefor
    • B29C55/02—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets
    • B29C55/023—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets using multilayered plates or sheets
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C55/00—Shaping by stretching, e.g. drawing through a die; Apparatus therefor
    • B29C55/02—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets
    • B29C55/04—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets uniaxial, e.g. oblique
    • 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
    • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
    • B32B27/08—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
    • 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
    • B32B27/18—Layered products comprising a layer of synthetic resin characterised by the use of special additives
    • B32B27/22—Layered products comprising a layer of synthetic resin characterised by the use of special additives using plasticisers
    • 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
    • B32B27/30—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
    • B32B27/306—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers comprising vinyl acetate or vinyl alcohol (co)polymers
    • 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
    • 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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2029/00—Use of polyvinylalcohols, polyvinylethers, polyvinylaldehydes, polyvinylketones or polyvinylketals or derivatives thereof as moulding material
    • B29K2029/04—PVOH, i.e. polyvinyl alcohol
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2995/00—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds
    • B29K2995/0018—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds having particular optical properties, e.g. fluorescent or phosphorescent
    • B29K2995/0034—Polarising
    • 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
    • B32B2250/00—Layers arrangement
    • B32B2250/24—All layers being polymeric
    • 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
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/40—Properties of the layers or laminate having particular optical properties
    • B32B2307/402—Coloured
    • B32B2307/4026—Coloured within the layer by addition of a colorant, e.g. pigments, dyes
    • 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
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/40—Properties of the layers or laminate having particular optical properties
    • B32B2307/42—Polarizing, birefringent, filtering
    • 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
    • B32B2457/00—Electrical equipment
    • B32B2457/20—Displays, e.g. liquid crystal displays, plasma displays
    • 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
    • B32B2457/00—Electrical equipment
    • B32B2457/20—Displays, e.g. liquid crystal displays, plasma displays
    • B32B2457/202—LCD, i.e. liquid crystal displays

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Nonlinear Science (AREA)
  • Mathematical Physics (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Polarising Elements (AREA)
  • Laminated Bodies (AREA)

Abstract

本發明係提供一種即使沒有預先進行不溶化處理，在與水接觸的步驟中也可抑制PVA之溶出，且可使用通用的偏光膜製造設備簡便地製造偏光性能佳之偏光膜的積層體、及使用其之偏光膜之製造方法；以及提供一種偏光性能佳，同時在正交偏光(crossed nicol)狀態的紅色光之洩漏少的偏光膜、及其製造方法。 The present invention provides a laminated body that can suppress the dissolution of PVA in the step of contact with water and can easily manufacture a polarizing film with excellent polarizing performance using a universal polarizing film manufacturing equipment even without insolubilizing treatment in advance, and using the same A method for manufacturing a polarizing film; and a polarizing film with excellent polarization performance and a small leakage of red light in a crossed nicol state, and a method for manufacturing the same.

一種製造方法，其係包含具有熱可塑性樹脂膜層與膨潤度為180%以上260%以下的PVA層之積層體、及將該積層體拉伸的步驟之偏光膜之製造方法；以及包含在雙折射率為45×10-3以上之基體吸附有二色性色素的偏光膜、及將具有熱可塑性樹脂膜層與PVA層的積層體拉伸為5.7倍以上的步驟之偏光膜之製造方法，PVA層所包含之PVA的平均聚合度為2,800以上9,500以下。 A manufacturing method comprising a laminated body comprising a thermoplastic resin film layer and a PVA layer having a swelling degree of 180% to 260%, and a manufacturing method of a polarizing film including the step of stretching the laminated body; and A method for producing a polarizing film having a refractive index of 45 × 10 -3 or more on which a dichroic pigment is adsorbed, and a step of stretching a laminated body having a thermoplastic resin film layer and a PVA layer by 5.7 times or more, The average degree of polymerization of the PVA contained in the PVA layer is from 2,800 to 9,500.

Description

積層體、及偏光膜之製造方法 Laminated body and manufacturing method of polarizing film

本發明係關於一種具有熱可塑性樹脂膜層與聚乙烯醇層的積層體及使用其之偏光膜之製造方法。又，本發明係關於一種在基體吸附有二色性色素(dichroic dye)的偏光膜及其製造方法。 The present invention relates to a laminated body having a thermoplastic resin film layer and a polyvinyl alcohol layer, and a method for manufacturing a polarizing film using the same. The present invention also relates to a polarizing film having a dichroic dye adsorbed on a substrate and a method for producing the same.

具有光之透射及遮蔽機能的偏光板，與使光之偏光狀態變化的液晶同時為液晶顯示器(LCD)之基本的構成要素。大多的偏光板，在偏光膜之表面具有三醋酸纖維素(TAC)膜等之保護膜貼合的結構，作為構成偏光板的偏光膜，在將聚乙烯醇膜(以下有時將「聚乙烯醇」簡稱為「PVA」)單軸拉伸而組成的基體(單軸拉伸而配向的拉伸膜)吸附有碘系色素(I3 -或I5 -等)或二色性有機染料之二色性色素者係成為主流。如前述的偏光膜，係進行將預先含有二色性色素的PVA膜單軸拉伸，與PVA膜的單軸拉伸同時吸附二色性色素，在將PVA膜單軸拉伸後吸附二色性色素等而製造。 A polarizing plate having a function of transmitting and shielding light is a basic constituent element of a liquid crystal display (LCD) at the same time as a liquid crystal that changes a polarization state of the light. Most polarizing plates have a structure in which a protective film such as a cellulose triacetate (TAC) film is bonded on the surface of the polarizing film. As a polarizing film constituting the polarizing plate, a polyvinyl alcohol film (hereinafter sometimes referred to as "polyethylene Alcohol "(abbreviated as" PVA ") is a uniaxially stretched substrate (uniaxially stretched and oriented stretched film) that adsorbs iodine-based pigments (I 3 - or I 5 - etc.) or dichroic organic dyes. Those with dichroic pigments have become mainstream. As described above, the polarizing film is subjected to uniaxial stretching of a PVA film containing a dichroic pigment in advance, and simultaneously adsorbs the dichroic pigment with the uniaxial stretching of the PVA film. After the PVA film is uniaxially stretched, the dichroic pigment is adsorbed. Sex pigments.

LCD，係於計算機及腕時計等之小型機器、筆記型電腦、液晶監視器、液晶彩色投影機、液晶電視、車載用導航系統、行動電話、屋內外所使用的計測機器等之廣泛範圍中被使用，但近年來特別多用於小型之筆 記型電腦或行動電話等之行動用途，且對於偏光板之薄型化的要求變強。特別是使構成偏光板之偏光膜的厚度成為10μm以下的要求高漲。 LCD is used in a wide range of small devices such as computers and wristwatches, notebook computers, LCD monitors, LCD color projectors, LCD TVs, car navigation systems, mobile phones, and measurement equipment used indoors and outdoors. , But in recent years it has been used more for small pens For mobile applications such as notebook computers and mobile phones, thinner polarizers are required. In particular, there is an increasing demand for the thickness of the polarizing film constituting the polarizing plate to be 10 μm or less.

作為將構成偏光板之偏光膜薄型化的方法，已知有將在熱可塑性樹脂膜之單面形成PVA層而成的積層體拉伸、染色、乾燥，之後視需要將拉伸的熱可塑性樹脂膜之層剝離除去的方法(參照專利文獻1及2等)。 As a method for reducing the thickness of a polarizing film constituting a polarizing plate, a laminated body formed by forming a PVA layer on one side of a thermoplastic resin film is known to be stretched, dyed, and dried, and the stretched thermoplastic resin is then stretched as necessary. A method of peeling and removing a layer of a film (see Patent Documents 1 and 2 and the like).

在利用前述的方法製造偏光膜之際，在染色等之偏光膜製造時之與水接觸的步驟中，PVA層所包含的PVA不會溶出係為重要。因此，以往的方法中，需要在染色等之與水接觸的步驟之前預先進行PVA層之不溶化處理。 When the polarizing film is manufactured by the method described above, it is important that the PVA contained in the PVA layer does not dissolve during the step of contacting with water during the production of the polarizing film such as dyeing. Therefore, in the conventional method, it is necessary to perform insolubilization treatment of the PVA layer before the step of contacting with water, such as dyeing.

具體而言，專利文獻1中，記載有在具有至少20μm之厚度的樹脂基材生成PVA層，且吸附二色性物質後，在硼酸水溶液中，使總拉伸倍率成為原長的5倍以上而拉伸以製作偏光膜的方法。專利文獻1中，記載有為了防止染色中之PVA對水溶液之溶出，在將生成於樹脂基材的PVA層浸漬於染色液之前，預先對PVA層施加不溶化處理，具體而言，記載有浸漬於常溫的硼酸水溶液之方法。又，專利文獻1中，記載有關於拉伸倍率，更佳為5.5倍以上、使用聚合度為1,000~10,000的PVA、以及最大拉伸倍率為4.0~5.5倍。 Specifically, Patent Document 1 describes that a PVA layer is formed on a resin substrate having a thickness of at least 20 μm, and a dichroic substance is adsorbed. Then, in a boric acid aqueous solution, the total stretching ratio is 5 times or more the original length. The method of stretching to produce a polarizing film. Patent Document 1 describes that in order to prevent the dissolution of PVA from an aqueous solution during dyeing, an insolubilization treatment is applied to the PVA layer in advance before the PVA layer formed on the resin substrate is immersed in the dyeing solution. Specifically, it is described that the PVA layer is immersed in Method of boric acid aqueous solution at room temperature. In addition, Patent Document 1 describes a stretching ratio of more than 5.5 times, a PVA having a polymerization degree of 1,000 to 10,000, and a maximum stretching ratio of 4.0 to 5.5 times.

另一方面，專利文獻2中，有記載將在非晶質酯系熱可塑性樹脂基材製膜PVA層而成的積層體於95~150℃的烘箱中空中高溫拉伸後，並吸附二色性物 質，之後，在硼酸水溶液中進一步拉伸以製作偏光膜的方法。專利文獻2中，記載有作為實施例1之未經由利用硼酸水溶液的不溶化處理而製作偏光膜的方法，但實際上，藉由實施例1之於130℃的空中高溫拉伸之結晶化，PVA層係成為不溶化。又，專利文獻2中，記載有使用聚合度1,000以上的PVA。 On the other hand, in Patent Document 2, it is described that a laminated body formed by forming a PVA layer on an amorphous ester-based thermoplastic resin base material is subjected to high-temperature stretching in the air at an oven of 95 to 150 ° C. and adsorbs two colors. Sex Method, and then further stretching in a boric acid aqueous solution to make a polarizing film. Patent Document 2 describes a method for producing a polarizing film without insolubilization with an aqueous solution of boric acid as Example 1, but in fact, the crystallization of the high-temperature air stretching at 130 ° C in Example 1 resulted in PVA The layer system becomes insoluble. Further, Patent Document 2 describes the use of PVA having a polymerization degree of 1,000 or more.

先前技術文獻 Prior art literature 專利文獻 Patent literature

專利文獻1 國際公開第2010/100917號 Patent Document 1 International Publication No. 2010/100917

專利文獻2 日本專利第4691205號說明書 Patent Document 2 Japanese Patent No. 4691205

然而，有以下問題：習知技術之對於前述的硼酸水溶液之浸漬或空中高溫拉伸，其操作係為繁雜、或是並未使用至今為止實用化之通用的偏光膜製造設備，需要特別的製造設備等。因此本發明之目的在於提供一種即使沒有預先進行對於硼酸水溶液之浸漬或空中高溫拉伸的不溶化處理，也可在與水接觸的步驟中抑制PVA之溶出，且可使用通用的偏光膜製造設備簡便地製造偏光性能佳之偏光膜的積層體、及使用其之偏光膜之製造方法。 However, there are the following problems: the conventional technique for dipping the boric acid aqueous solution or stretching at high temperature in the air is complicated or does not use the conventional polarizing film manufacturing equipment which has been put into practical use until now, and requires special manufacturing Equipment, etc. Therefore, an object of the present invention is to provide a method for suppressing the dissolution of PVA in the step of contact with water even if the boric acid aqueous solution is not immersed in advance or the insolubilization treatment of high-temperature stretching in the air is carried out in advance, and a general-purpose polarizing film manufacturing facility is simple A laminated body of a polarizing film with excellent polarizing performance is produced therefrom, and a method for producing a polarizing film using the same.

又，習知方法所製造的偏光膜，有正交偏光(crossed nicol)狀態之紅色光之洩漏多的問題。因此，本發明之另一目在於提供一種偏光性能佳，同時在正交偏光狀態的紅色光之洩漏少的偏光膜、及其製造方法。 In addition, the polarizing film produced by the conventional method has a problem in that a large amount of red light leaks in a crossed nicol state. Therefore, another object of the present invention is to provide a polarizing film with excellent polarization performance and a small leakage of red light in the orthogonal polarization state, and a method for manufacturing the same.

本案發明人等為了達成前述目的重複仔細探討的結果發現：在拉伸具有熱可塑性樹脂膜層與PVA層之積層體以製造偏光膜時，若將未拉伸之積層體所具有的PVA層之澎潤度調整成180%以上260%以下，則即使不預先進行對於硼酸水溶液之浸漬或空中高溫拉伸的不溶化處理，也可在與水接觸的步驟中抑制PVA之溶出，因此，可省略操作繁雜、需要特別的製造設備之前述不溶化處理，可使用通用的偏光膜製造設備簡便地製造偏光性能佳之偏光膜。 In order to achieve the foregoing object, the inventors of the present invention have repeatedly and carefully discussed the results. It has been found that when a laminate having a thermoplastic resin film layer and a PVA layer is stretched to manufacture a polarizing film, if the PVA layer of the unstretched laminate is When the degree of swelling is adjusted to 180% or more and 260% or less, the dissolution of PVA can be suppressed in the step of contact with water even if the insolubilization treatment of the boric acid aqueous solution or the in-air high temperature stretching is not performed in advance. Therefore, the operation can be omitted The aforementioned insolubilization process, which is complicated and requires special manufacturing equipment, can be easily manufactured using a general-purpose polarizing film manufacturing equipment with a good polarizing performance.

又，本案發明人發現：在基體吸附有二色性色素的偏光膜中，使基體的雙折射率成為較習知高45×10-3以上的話，可成為偏光性能佳，同時在正交偏光狀態的紅色光之洩漏少的偏光膜。 In addition, the inventors of the present invention found that in a polarizing film in which a dichroic dye is adsorbed on a substrate, if the birefringence of the substrate is 45 × 10 -3 or more higher than the conventional one, the polarizing performance can be improved, and at the same time, orthogonal polarization can be achieved. Polarizing film with little leakage of red light in the state.

再者，在將PVA層形成於熱可塑性樹脂膜上作為積層體，並對其實施單軸拉伸等而得到在熱可塑性樹脂膜上形成的偏光膜時，使用平均聚合度為2,800以上9,500以下之PVA的話，可提升單軸拉伸之際的極限拉伸倍率。一般認為，PVA的平均聚合度越高拉伸時之張力越高，且極限拉伸倍率會下降，但在以前述的方法得到偏光膜時，出乎預料的是使用具有前述之平均聚合度的PVA的話，例如，與使用平均聚合度為2,600之PVA的情況比較，極限拉伸倍率未下降反而上升。 In addition, when a PVA layer is formed on a thermoplastic resin film as a laminate, and uniaxial stretching is performed thereon to obtain a polarizing film formed on the thermoplastic resin film, the average degree of polymerization is 2,800 or more and 9,500 or less. With PVA, the ultimate draw ratio can be increased during uniaxial stretching. It is generally believed that the higher the average degree of polymerization of PVA is, the higher the tension is during stretching, and the ultimate stretching ratio will decrease. However, when a polarizing film is obtained by the aforementioned method, it is unexpected to use a polymer having the aforementioned average degree of polymerization. In the case of PVA, for example, compared with the case of using PVA having an average degree of polymerization of 2,600, the ultimate stretch ratio does not decrease but instead increases.

然後發現：使用平均聚合度為2,800以上9,500以下之PVA，在熱可塑性樹脂膜上形成PVA層作為積層體， 並將其拉伸為5.7倍以上，製造在熱可塑性樹脂膜上形成的偏光膜時，可順利且簡便地得到基體的雙折射率較習知高45×10-3以上的偏光膜。 Then, it was found that when a PVA layer having an average degree of polymerization of 2,800 or more and 9,500 or less was used to form a PVA layer on a thermoplastic resin film as a laminate, and it was stretched to 5.7 times or more, a polarizing film formed on the thermoplastic resin film was manufactured. It is possible to smoothly and easily obtain a polarizing film having a birefringence of 45 × 10 -3 or more higher than that of a conventional substrate.

本案發明人等根據該等知識，進一步重複探討而完成本發明。 Based on such knowledge, the inventors of the present case further repeated the discussion to complete the present invention.

亦即，本發明關於下述者： That is, the present invention relates to the following:

[1]一種積層體(以下有時將其稱為「積層體(1)」)，其係具有熱可塑性樹脂膜層與膨潤度為180%以上260%以下的PVA層。 [1] A laminated body (hereinafter sometimes referred to as "laminated body (1)"), which is a thermoplastic resin film layer and a PVA layer having a swelling degree of 180% to 260%.

[2]如前述[1]之積層體，其中PVA層所包含之PVA的乙烯含量為1莫耳%以上12莫耳%以下。 [2] The laminated body according to the aforementioned [1], wherein the ethylene content of the PVA contained in the PVA layer is 1 mol% or more and 12 mol% or less.

[3]如前述[1]或[2]之積層體，其中PVA層所包含之PVA的1,2-二醇鍵結量為0.4莫耳%以上1.5莫耳%以下。 [3] The laminated body according to the above [1] or [2], wherein the 1,2-diol bonding amount of PVA contained in the PVA layer is 0.4 mol% or more and 1.5 mol% or less.

[4]如前述[1]至[3]中任一項之積層體，其中PVA層所包含之PVA的平均聚合度為1,000以上9,500以下。 [4] The laminated body according to any one of the above [1] to [3], wherein the average degree of polymerization of the PVA contained in the PVA layer is 1,000 or more and 9,500 or less.

[5]如前述[1]至[4]中任一項之積層體，其中PVA層所包含之PVA的皂化度為98莫耳%以上。 [5] The laminated body according to any one of the aforementioned [1] to [4], wherein the saponification degree of the PVA contained in the PVA layer is 98 mol% or more.

[6]如前述[1]至[5]中任一項之積層體，其中PVA層相對於PVA100質量份，係含有可塑劑1質量份以上15質量份以下。 [6] The laminated body according to any one of the above [1] to [5], wherein the PVA layer contains 100 parts by mass of PVA and contains 1 to 15 parts by mass of a plasticizer.

[7]如前述[6]之積層體，其中可塑劑為甘油。 [7] The laminated body according to the aforementioned [6], wherein the plasticizer is glycerin.

[8]一種偏光膜之製造方法(以下有時將其稱為「偏光膜之製造方法(1)」)，其係包含將如前述[1]至[7]中任一項之積層體拉伸的步驟。 [8] A method for manufacturing a polarizing film (hereinafter sometimes referred to as a "method for manufacturing a polarizing film (1)"), which includes pulling a multilayer body as described in any one of the above [1] to [7] Stretching steps.

[9]如前述[8]之製造方法，其係包含對於拉伸前之積層體的PVA層；在積層體的拉伸中之拉伸途中的PVA層；及、由拉伸積層體後之PVA層形成的拉伸膜層；中之任一者，使二色性色素接觸的步驟。 [9] The manufacturing method according to the aforementioned [8], which comprises a PVA layer for the laminated body before stretching; a PVA layer in the middle of stretching during stretching of the laminated body; and, after stretching the laminated body A stretched film layer formed of a PVA layer; any one of the steps of contacting a dichroic pigment.

[10]如前述[9]之製造方法，其中在使二色性色素接觸的步驟之前，並未包含與含有硼化合物之水溶液接觸的步驟。 [10] The method according to the aforementioned [9], wherein the step of bringing into contact with an aqueous solution containing a boron compound is not included before the step of bringing the dichroic pigment into contact.

[11]如前述[9]或[10]之製造方法，其中在使二色性色素接觸的步驟之前，並未包含在95℃以上之溫度拉伸的步驟。 [11] The method according to the aforementioned [9] or [10], wherein the step of stretching at a temperature of 95 ° C. or higher is not included before the step of contacting the dichroic pigment.

又，本發明關於下述者： In addition, the present invention relates to the following:

[12]一種偏光膜(以下有時將其稱為「偏光膜(2)」)，其係於雙折射率為45×10-3以上的基體吸附有二色性色素。 [12] A polarizing film (hereinafter sometimes referred to as a "polarizing film (2)"), which is a substrate having a birefringence of 45 × 10 -3 or higher, to which a dichroic dye is adsorbed.

[13]如前述[12]之偏光膜，其中基體含有PVA，且其平均聚合度為2,800以上9,500以下。 [13] The polarizing film according to the above [12], wherein the matrix contains PVA, and the average degree of polymerization is 2,800 or more and 9,500 or less.

[14]如前述[12]之偏光膜，其中基體含有PVA，且其平均聚合度為4,100以上9,500以下。 [14] The polarizing film according to the aforementioned [12], wherein the matrix contains PVA, and the average degree of polymerization is 4,100 or more and 9,500 or less.

[15]如前述[12]至[14]中任一項之偏光膜，其厚度為10μm以下。 [15] The polarizing film according to any one of [12] to [14], which has a thickness of 10 μm or less.

[16]一種製造方法(以下有時將其稱為「偏光膜之製造方法(2)」)，其係包含將具有熱可塑性樹脂膜層與PVA層之積層體拉伸為5.7倍以上的步驟之偏光膜之製造方法，PVA層所包含之PVA的平均聚合度為2,800以上9,500以下。 [16] A manufacturing method (hereinafter sometimes referred to as "the manufacturing method of a polarizing film (2)"), which includes a step of stretching a laminated body having a thermoplastic resin film layer and a PVA layer by 5.7 times or more In the method for manufacturing a polarizing film, the average degree of polymerization of PVA contained in the PVA layer is 2,800 or more and 9,500 or less.

[17]如前述[16]之製造方法，其中PVA的平均聚合度為4,100以上9,500以下。 [17] The method according to the aforementioned [16], wherein the average degree of polymerization of PVA is 4,100 or more and 9,500 or less.

[18]如前述[16]或[17]之製造方法，其中PVA層相對於PVA100質量份，係含有可塑劑1質量份以上15質量份以下。 [18] The method according to the aforementioned [16] or [17], wherein the PVA layer contains 100 parts by mass of PVA and contains 1 to 15 parts by mass of a plasticizer.

[19]如前述[16]或[17]之製造方法，其中PVA層相對於PVA100質量份，係含有可塑劑4質量份以上12質量份以下。 [19] The method according to the aforementioned [16] or [17], wherein the PVA layer contains 100 parts by mass of PVA and contains 4 to 12 parts by mass of a plasticizer.

[20]如前述[18]或[19]之製造方法，其中可塑劑為甘油。 [20] The method according to the aforementioned [18] or [19], wherein the plasticizer is glycerin.

根據本發明的積層體(1)及使用其之偏光膜之製造方法(1)，即使不預先進行對於硼酸水溶液之浸漬或空中高溫拉伸的不溶化處理，也可在與水接觸的步驟中抑制PVA之溶出，且可使用通用的偏光膜製造設備簡便地製造偏光性能佳之偏光膜。 According to the laminated body (1) and the manufacturing method (1) of the polarizing film using the same according to the present invention, it is possible to suppress the step of contact with water even if the insolubilization treatment of the boric acid aqueous solution or the high-temperature stretching in the air is not performed in advance. The dissolution of PVA, and the use of general-purpose polarizing film manufacturing equipment can easily produce polarizing films with good polarizing performance.

又，本發明的偏光膜(2)，其偏光性能佳，同時在正交偏光狀態的紅色光之洩漏少。再者，根據本發明的偏光膜之製造方法(2)，可順利且簡便地製造偏光性能佳，同時在正交偏光狀態的紅色光之洩漏少的前述偏光膜(2)。 In addition, the polarizing film (2) of the present invention has good polarizing performance and has a small leakage of red light in a cross-polarized state. Furthermore, according to the method (2) for manufacturing a polarizing film of the present invention, the aforementioned polarizing film (2) with good polarization performance and low leakage of red light in the orthogonal polarization state can be smoothly and easily manufactured.

以下對於本發明詳細地說明。 The present invention will be described in detail below.

《積層體(1)》 `` Laminate (1) ''

本發明的積層體(1)，係具有熱可塑性樹脂膜層與PVA層。作為構成熱可塑性樹脂膜層的熱可塑性樹脂，例如，可舉出聚乙烯、聚丙烯、聚甲基戊烯、聚苯乙烯、聚碳酸酯、聚氯乙烯、甲基丙烯酸樹脂、耐綸、聚對苯二甲酸乙二酯等之各種熱可塑性樹脂、及具有多種構成該等之熱可塑性樹脂的單體單元之共聚物等。在熱可塑性樹脂膜層中，可僅含有1種熱可塑性樹脂，亦可含有2種以上，兩者均可。該等之中，從具備高耐熱性與拉伸性的觀點，聚對苯二甲酸乙二酯較佳，非晶質聚對苯二甲酸乙二酯更佳。 The laminated body (1) of the present invention includes a thermoplastic resin film layer and a PVA layer. Examples of the thermoplastic resin constituting the thermoplastic resin film layer include polyethylene, polypropylene, polymethylpentene, polystyrene, polycarbonate, polyvinyl chloride, methacrylic resin, nylon, and poly Various thermoplastic resins such as ethylene terephthalate, and copolymers having a plurality of monomer units constituting the thermoplastic resins. The thermoplastic resin film layer may contain only one type of thermoplastic resin, or may contain two or more types, both of which are acceptable. Among these, polyethylene terephthalate is preferable, and amorphous polyethylene terephthalate is more preferable from the viewpoint of having high heat resistance and stretchability.

熱可塑性樹脂膜層的厚度，在20~250μm的範圍內較佳，在30~230μm的範圍內更佳，在50~200μm的範圍內特佳。藉由熱可塑性樹脂膜層的厚度為20μm以上，可有效地防止在形成PVA層之際造成皺紋。另一方面，藉由熱可塑性樹脂膜層的厚度為250μm以下，可抑制拉伸積層體(1)之際的張力過度變高。 The thickness of the thermoplastic resin film layer is preferably within a range of 20 to 250 μm, more preferably within a range of 30 to 230 μm, and particularly preferably within a range of 50 to 200 μm. When the thickness of the thermoplastic resin film layer is 20 μm or more, it is possible to effectively prevent wrinkles from being formed when the PVA layer is formed. On the other hand, when the thickness of the thermoplastic resin film layer is 250 μm or less, it is possible to suppress an excessively high tension when the laminated body (1) is stretched.

本發明之積層體(1)具有的PVA層之膨潤度需為180%以上260%以下，185%以上較佳，190%以上更佳，而且，255%以下較佳，250%以下更佳。膨潤度高於260%的話，在沒有預先進行對於硼酸水溶液之浸漬或空中高溫拉伸的不溶化處理時，在偏光膜製造時之與水接觸的步驟中PVA層所包含的PVA會溶出，偏光膜之製造變困難。另一方面，膨潤度低於180%的話，PVA層之染色變困難，容易產生斑，難以得到偏光性能佳的偏光 膜。再者，本發明的PVA層之膨潤度，係指將在30℃之蒸餾水浸漬PVA層30分鐘後的該PVA層之質量，除以在浸漬後以105℃乾燥16小時後的PVA層之質量而得到的值之百分率。該PVA層的膨潤度，因以積層體的狀態測定也可得到與以PVA層單獨測定時實質上相同的值，故考慮到操作性的話，以積層體的狀態測定較為理想。作為PVA層的膨潤度之具體的測定方法，可在實施例中舉出後述之方法。 The PVA layer of the laminated body (1) of the present invention needs to have a swelling degree of 180% or more and 260% or less, more preferably 185% or more, more preferably 190% or more, and more preferably 255% or less and 250% or less. If the swelling degree is higher than 260%, the PVA contained in the PVA layer will dissolve during the step of contacting with water during the production of the polarizing film without performing insolubilization of the boric acid aqueous solution or in-air high temperature stretching beforehand, and the polarizing film Manufacturing becomes difficult. On the other hand, if the swelling degree is less than 180%, the dyeing of the PVA layer becomes difficult, and it is easy to generate spots, and it is difficult to obtain polarized light with good polarization performance. membrane. In addition, the swelling degree of the PVA layer of the present invention refers to the mass of the PVA layer after the PVA layer is immersed in distilled water at 30 ° C for 30 minutes, divided by the mass of the PVA layer after being dipped at 105 ° C for 16 hours And the percentage of the value obtained. Since the degree of swelling of the PVA layer can be measured in the state of the laminated body, it can obtain substantially the same value as in the case of the PVA layer alone. Therefore, it is preferable to measure the state of the laminated body in consideration of workability. As a specific measurement method of the swelling degree of a PVA layer, the method mentioned later is mentioned in an Example.

PVA層的膨潤度之調整方法並沒有特別限制，例如可使用一般的PVA(乙酸乙烯酯之單獨聚合物的皂化物)，以製造具有熱可塑性樹脂膜層與PVA層的積層體為前提，藉由將其於100℃以上的溫度適當熱處理而進行。在此，越提高熱處理溫度，又，越加長熱處理時間，可降低膨潤度的值。然而，對於具有熱可塑性樹脂膜層與PVA層的積層體以100℃以上的溫度實施熱處理的話，伴隨熱可塑性樹脂膜層之尺寸變化，有造成皺紋的傾向。因此，藉由使用後述之容易降低膨潤度的PVA調整PVA層之膨潤度的方法較為理想。根據前述，即使在不會為100℃以上的條件製備具有熱可塑性樹脂膜層與PVA層的積層體，也可輕易地將該PVA層的膨潤度調整為前述範圍。 The method for adjusting the swelling degree of the PVA layer is not particularly limited. For example, a general PVA (saponified product of a separate polymer of vinyl acetate) can be used. The premise is to produce a laminate having a thermoplastic resin film layer and a PVA layer. This is performed by appropriately heat-treating at a temperature of 100 ° C or higher. Here, the higher the heat treatment temperature and the longer the heat treatment time, the lower the swelling value. However, when a laminated body having a thermoplastic resin film layer and a PVA layer is subjected to a heat treatment at a temperature of 100 ° C. or higher, wrinkles tend to occur due to a change in the size of the thermoplastic resin film layer. Therefore, a method of adjusting the degree of swelling of the PVA layer by using PVA which can easily reduce the degree of swelling described later is preferable. According to the foregoing, even if a laminated body having a thermoplastic resin film layer and a PVA layer is prepared under a condition where the temperature is not higher than 100 ° C, the swelling degree of the PVA layer can be easily adjusted to the aforementioned range.

作為PVA層的PVA，可使用藉由將聚合乙酸乙烯酯、甲酸乙烯酯、丙酸乙烯酯、酪酸乙烯酯、三甲基乙酸乙烯酯、新癸酸(versatic acid)乙烯酯、月桂酸乙烯酯、硬脂酸乙烯酯、苯甲酸乙烯酯、乙酸異丙烯酯等 之乙烯酯之1種或2種以上而得到的聚乙烯酯皂化而得者。前述乙烯酯中，從PVA的製造之容易性、取得容易性、成本等之觀點，以乙酸乙烯酯為佳。 As the PVA of the PVA layer, polymerized vinyl acetate, vinyl formate, vinyl propionate, vinyl caseinate, trimethyl vinyl acetate, versatic acid vinyl ester, and vinyl laurate can be used. , Vinyl stearate, vinyl benzoate, isopropenyl acetate, etc. A polyvinyl ester obtained by saponifying one or more vinyl esters. Among the vinyl esters, vinyl acetate is preferred from the viewpoints of ease of production, availability, and cost of PVA.

前述聚乙烯酯，可為僅使用作為單體之1種或2種以上的乙烯酯而得者，但只要在不損及本發明之效果的範圍內，亦可為1種或2種以上的乙烯酯、與可與其共聚合的其他單體之共聚物。 The polyvinyl ester may be obtained by using only one or two or more vinyl esters as a monomer, but may be one or two or more as long as the effect of the present invention is not impaired. Copolymers of vinyl esters and other monomers copolymerizable therewith.

作為可與前述乙烯酯共聚合的其他單體，例如，可舉出乙烯、丙烯、1-丁烯、異丁烯等之碳數2~30之α-烯烴；(甲基)丙烯酸或其鹽；(甲基)丙烯酸甲酯、(甲基)丙烯酸乙酯、(甲基)丙烯酸正丙酯、(甲基)丙烯酸異丙酯、(甲基)丙烯酸正丁酯、(甲基)丙烯酸異丁酯、(甲基)丙烯酸三級丁酯、(甲基)丙烯酸2-乙基己酯、(甲基)丙烯酸十二烷酯、(甲基)丙烯酸十八烷酯等之(甲基)丙烯酸酯；(甲基)丙烯醯胺、N-甲基(甲基)丙烯醯胺、N-乙基(甲基)丙烯醯胺、N,N-二甲基(甲基)丙烯醯胺、二丙酮(甲基)丙烯醯胺、(甲基)丙烯醯胺丙磺酸或其鹽、(甲基)丙烯醯胺丙基二甲胺或其鹽、N-羥甲基(甲基)丙烯醯胺或其衍生物等之(甲基)丙烯醯胺衍生物；N-乙烯甲醯胺、N-乙烯乙醯胺、N-乙烯吡咯啶酮等之N-乙烯醯胺；甲基乙烯醚、乙基乙烯醚、正丙基乙烯醚、異丙基乙烯醚、正丁基乙烯醚、異丁基乙烯醚、三級丁基乙烯醚、十二烷基乙烯醚、十八烷基乙烯醚等之乙烯醚；(甲基)丙烯腈等之氰乙烯；氯乙烯、偏二氯乙烯、氟乙烯、偏二氟乙烯等之鹵乙烯；乙酸烯丙酯、烯丙氯等之烯丙基化合 物；馬來酸或其鹽、酯或酸酐；衣康酸或其鹽、酯或酸酐；乙烯三甲氧矽烷等之乙烯矽基化合物；不飽和磺酸等。前述的聚乙烯酯，可具有源自於前述之其他的單體之1種或2種以上的結構單元。 Examples of other monomers copolymerizable with the vinyl ester include α-olefins having 2 to 30 carbon atoms, such as ethylene, propylene, 1-butene, and isobutylene; (meth) acrylic acid or a salt thereof; Methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate (Meth) acrylates such as tert-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, etc. ; (Meth) acrylamide, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, diacetone (Meth) acrylamide, (meth) acrylamide propanesulfonic acid or a salt thereof, (meth) acrylamide propyldimethylamine or a salt thereof, N-methylol (meth) acrylamide (Meth) acrylamidonium derivatives such as or its derivatives; N-vinylmethylamine, N-vinylacetamide, N-vinylpyrrolidone, etc .; methyl vinyl ether, ethylamine Vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether Isobutyl vinyl ether, tertiary butyl vinyl ether, dodecyl vinyl ether, octadecyl vinyl ether and other vinyl ethers; (meth) acrylonitrile and other vinyl cyanide; vinyl chloride, vinylidene chloride, Ethylene halides such as vinyl fluoride and vinylidene fluoride; allyl compounds such as allyl acetate and allyl chloride Substances; maleic acid or its salt, ester or anhydride; itaconic acid or its salt, ester or anhydride; ethylene silicon compounds such as ethylene trimethoxysilane; unsaturated sulfonic acid and the like. The polyvinyl ester may have one or more structural units derived from the other monomers.

前述之聚乙烯酯所佔的源自於前述之其他的單體之結構單元的比例，基於構成聚乙烯酯之全結構單元的莫耳數，以15莫耳%以下為佳，亦可為10莫耳%以下，甚至為5莫耳%以下。 The proportion of the structural units derived from the other monomers mentioned above based on the polyvinyl ester is preferably 15 mol% or less based on the molar number of the entire structural unit constituting the polyvinyl ester, and may also be 10 Molar% or less, or even 5 Molar% or less.

特別是前述之其他的單體，如(甲基)丙烯酸、不飽和磺酸等，係有促進所得到之PVA之水溶性的可能性之單體時，為了防止PVA在偏光膜之製造過程中溶解，聚乙烯酯之源自於該等單體的結構單元之比例，基於構成聚乙烯酯之全結構單元的莫耳數，以5莫耳%以下為佳，3莫耳%以下較佳。 In particular, when other monomers such as (meth) acrylic acid and unsaturated sulfonic acid are monomers that have the possibility of promoting the water solubility of the obtained PVA, in order to prevent PVA from being used in the manufacturing process of polarizing films Dissolved, the proportion of the structural units derived from these monomers of the polyvinyl ester, based on the molar number of the entire structural unit constituting the polyvinyl ester, is preferably 5 mol% or less, and more preferably 3 mol% or less.

前述的PVA，只要在不損及本發明之效果的範圍內，亦可為藉由1種或2種以上之可接枝共聚合的單體而改質者。作為該可接枝共聚合的單體，例如，可舉出不飽和羧酸或其衍生物；不飽和磺酸或其衍生物；碳數2~30之α-烯烴等。PVA之源自於可接枝共聚合的單體之結構單元(接枝改質部分之結構單元)的比例，基於構成PVA之全結構單元的莫耳數，以5莫耳%以下為佳。 The aforementioned PVA may be modified by using one or more types of graft copolymerizable monomers, as long as the effect of the present invention is not impaired. Examples of the graft copolymerizable monomer include an unsaturated carboxylic acid or a derivative thereof; an unsaturated sulfonic acid or a derivative thereof; an α-olefin having 2 to 30 carbon atoms; and the like. The proportion of the structural units (structural units of the graft-modified portion) derived from the graft copolymerizable monomer of PVA is preferably 5 mol% or less based on the number of moles of the entire structural unit constituting the PVA.

前述之PVA，其羥基之一部分可進行交聯，亦可不進行交聯。又，前述的PVA，其羥基之一部分可與乙醛、丁醛等之醛化合物等反應而形成縮醛結構，亦可未與該等化合物反應而形成縮醛結構。 In the aforementioned PVA, a part of the hydroxyl group may or may not be crosslinked. Moreover, a part of the hydroxyl groups of the aforementioned PVA may react with aldehyde compounds such as acetaldehyde and butyraldehyde to form an acetal structure, or may form an acetal structure without reacting with these compounds.

如前述使用容易使膨潤度下降的PVA時，即使在不會為100℃以上的條件製備具有熱可塑性樹脂膜層與PVA層的積層體，也可輕易地將該PVA層的膨潤度調整為前述範圍。作為如此容易使膨潤度下降的PVA，例如，可舉出乙烯含量為1莫耳%以上12莫耳%以下的PVA。在此之乙烯含量係指相對於構成PVA之全結構單元的莫耳數，源自於乙烯的結構單元之莫耳數佔的比例(莫耳%)。藉由乙烯含量為1莫耳%以上，即使將如後述的原液塗布後之乾燥或熱處理於低溫進行，也可輕易地使膨潤度為前述上限以下。另一方面，藉由乙烯含量為12莫耳%以下，可輕易地使膨潤度成為前述下限以上。從可輕易地將膨潤度調整為在本發明中規定的範圍之觀點，乙烯含量係1.5莫耳%以上為佳，2.0莫耳%以上較佳，又，11.5莫耳%以下為佳，11莫耳%以下較佳。 When using PVA that is easy to reduce the swelling degree as described above, the swelling degree of the PVA layer can be easily adjusted to the aforementioned value even if a laminated body having a thermoplastic resin film layer and a PVA layer is prepared under conditions that do not exceed 100 ° C. range. Examples of the PVA that can easily reduce the swelling degree include PVA having an ethylene content of 1 mol% or more and 12 mol% or less. The ethylene content herein refers to the mole ratio (mole%) of the molar number of the structural unit derived from ethylene with respect to the molar number of the entire structural unit constituting the PVA. With an ethylene content of 1 mol% or more, even if drying or heat treatment is performed at a low temperature after coating a stock solution as described below, the degree of swelling can be easily made below the aforementioned upper limit. On the other hand, when the ethylene content is 12 mol% or less, the degree of swelling can be easily made to be the above lower limit. From the viewpoint that the swelling degree can be easily adjusted to the range specified in the present invention, the ethylene content is preferably 1.5 mol% or more, more preferably 2.0 mol% or more, and further preferably 11.5 mol% or less, and 11 mol. Below ear% is preferred.

又，作為容易使膨潤度下降的PVA另一例，可舉出1,2-二醇鍵結量為0.4莫耳%以上1.5莫耳%以下的PVA。在此之1,2-二醇鍵結量，可指相對於隣接的乙烯醇單元間之鍵結的總莫耳數，1,2-二醇鍵所鍵結之隣接的乙烯醇單元間之鍵結的莫耳數佔的比例(莫耳%)，亦可藉由NMR測定法求得。藉由1,2-二醇鍵結量為1.5莫耳%以下，即使將如後述的原液塗布後之乾燥或熱處理於低溫進行，也可輕易地使膨潤度為前述上限以下。另一方面，藉由1,2-二醇鍵結量為0.4莫耳%以上，可輕易地使膨潤度為前述下限以上。從可輕易地將膨潤度調整 為在本發明中規定的範圍之觀點，1,2-二醇鍵結量係0.5莫耳%以上為佳，0.6莫耳%以上較佳，又，1.4莫耳%以下為佳，1.3莫耳%以下較佳。1,2-二醇鍵結量之值小的PVA，可將藉由在低溫聚合乙烯酯而得到的聚乙烯酯作為原料製造。具體而言，1,2-二醇鍵結量為0.4莫耳%以上1.5莫耳%以下的PVA，可將藉由在約-50℃以上+50℃以下的範圍內聚合乙烯酯而得到的聚乙烯酯作為原料製造。 In addition, as another example of the PVA that is liable to decrease the degree of swelling, PVA having a 1,2-diol bonding amount of 0.4 mol% or more and 1.5 mol% or less can be mentioned. Here, the amount of 1,2-diol bonds may refer to the total number of moles of bonds between adjacent vinyl alcohol units, and the number of bonds between adjacent vinyl alcohol units to which 1,2-diol bonds are bonded. The ratio (Mole%) of the Mohr number of the bond can also be determined by an NMR measurement method. With a 1,2-diol bond amount of 1.5 mol% or less, even if drying or heat treatment is performed at a low temperature after coating a stock solution as described below, the degree of swelling can be easily made below the aforementioned upper limit. On the other hand, when the amount of 1,2-diol bonding is 0.4 mol% or more, the degree of swelling can be easily made to the aforementioned lower limit or more. Easy adjustment of swelling From the viewpoint of the range specified in the present invention, the 1,2-diol bonding amount is preferably 0.5 mol% or more, more preferably 0.6 mol% or more, and more preferably 1.4 mol% or less, and 1.3 mol. % Or less is preferred. PVA having a small amount of 1,2-diol bond can be produced using a polyvinyl ester obtained by polymerizing a vinyl ester at a low temperature as a raw material. Specifically, PVA having a 1,2-diol bond content of 0.4 mol% or more and 1.5 mol% or less can be obtained by polymerizing vinyl esters in a range of about -50 ° C to + 50 ° C. Polyvinyl ester is manufactured as a raw material.

前述的PVA，可僅滿足前述之乙烯含量的範圍及1,2-二醇鍵結量的範圍中之任一方，亦可同時滿足雙方，兩者均可。亦即，任何乙烯含量在前述範圍內，同時1,2-二醇鍵結量超過1.5莫耳%的PVA；乙烯含量未滿1莫耳%，同時1,2-二醇鍵結量在前述範圍的PVA；及乙烯含量與1,2-二醇鍵結量同時在前述範圍的PVA均可作為容易使膨潤度下降的PVA使用。但是，乙烯含量與1,2-二醇鍵結量同時在前述範圍的PVA，特別是在乙烯含量相較高的情況中及/或1,2-二醇鍵結量相較低的情況中等，有使PVA層的膨潤度過度下降的情況。因此，使用乙烯含量與1,2-二醇鍵結量同時在前述範圍的PVA時，在相較低溫度進行PVA層形成後之乾燥處理或熱處理、或是使乙烯含量變低及/或使1,2-二醇鍵結量變高較為理想。 The aforementioned PVA may satisfy only one of the aforementioned range of ethylene content and the range of 1,2-diol bonding amount, or both, or both. That is, any PVA with an ethylene content within the aforementioned range and a 1,2-diol bond amount exceeding 1.5 mol%; an ethylene content of less than 1 mol%, and a 1,2-diol bond amount within the foregoing PVA in the range; and PVA in which the ethylene content and the 1,2-diol bond amount are both in the aforementioned range can be used as PVA that is liable to decrease the swelling degree. However, PVA in which the ethylene content and the 1,2-diol bonding amount are both in the aforementioned range, especially in the case where the ethylene content is relatively high and / or when the 1,2-diol bonding amount is relatively low In some cases, the degree of swelling of the PVA layer may be excessively reduced. Therefore, when using PVA having an ethylene content and a 1,2-diol bond amount in the aforementioned range, the drying or heat treatment after the formation of the PVA layer is performed at a relatively low temperature, or the ethylene content is lowered and / or It is desirable to increase the amount of 1,2-diol bonds.

前述的PVA之平均聚合度在1,000以上9,500以下的範圍內為佳，該平均聚合度為1,500以上較佳，2,000以上更佳，又，9,200以下較佳，6,000以下 更佳。藉由平均聚合度為1,000以上，可提升得到的偏光膜之偏光性能。另一方面，藉由平均聚合度為9,500以下，可提升PVA的生產性。再者，在PVA層之形成所使用的PVA(PVA層所包含的PVA)之平均聚合度，可依據JIS K6726-1994之記載測定。 The average degree of polymerization of the aforementioned PVA is preferably in the range of 1,000 to 9,500. The average degree of polymerization is preferably 1,500 or more, more preferably 2,000 or more, and more preferably 9,200 or less, and 6,000 or less. Better. With an average degree of polymerization of 1,000 or more, the polarization performance of the obtained polarizing film can be improved. On the other hand, when the average degree of polymerization is 9,500 or less, the productivity of PVA can be improved. The average degree of polymerization of PVA (PVA included in the PVA layer) used for forming the PVA layer can be measured in accordance with the description of JIS K6726-1994.

從得到之偏光膜的偏光性能等之觀點，前述PVA的皂化度係98莫耳%以上為佳，98.5莫耳%以上較佳，99莫耳%以上更佳。皂化度未滿98莫耳%時，PVA變得容易在偏光膜之製造過程溶出，且有溶出的PVA附著於膜，使偏光膜之偏光性能下降的情況。再者，本說明書的PVA之皂化度，係指PVA具有之相對於藉由皂化轉變為乙烯醇單元而得到的結構單元(典型而言為乙烯酯單元)與乙烯醇單元之合計莫耳數，該乙烯醇單元之莫耳數佔的比例(莫耳%)。皂化度，可依據JIS K6726-1994之記載測定。 From the viewpoint of the polarization performance of the obtained polarizing film, the saponification degree of the PVA is preferably 98 mol% or more, more preferably 98.5 mol% or more, and more preferably 99 mol% or more. When the saponification degree is less than 98 mol%, PVA becomes easy to dissolve in the manufacturing process of the polarizing film, and the dissolved PVA may adhere to the film, which may reduce the polarizing performance of the polarizing film. In addition, the saponification degree of PVA in this specification refers to the total mole number of the structural unit (typically, a vinyl ester unit) and a vinyl alcohol unit which PVA has with respect to a vinyl alcohol unit obtained by saponification. The mole ratio (mole%) of the vinyl alcohol unit. The degree of saponification can be measured in accordance with JIS K6726-1994.

PVA層，從提升拉伸積層體(1)之際的拉伸性之觀點，包含可塑劑較為理想。作為該可塑劑，例如，可舉出乙二醇、甘油、丙二醇、二乙二醇、二甘油、三乙二醇、四乙二醇、三羥甲基丙烷等之多元醇等，PVA層可包含該等可塑劑之1種或2種以上。該等之中，從拉伸性之提升效果的觀點，以甘油較為理想。 The PVA layer preferably contains a plasticizer from the viewpoint of improving the stretchability when the laminated laminate (1) is stretched. Examples of the plasticizer include polyhydric alcohols such as ethylene glycol, glycerol, propylene glycol, diethylene glycol, diglycerin, triethylene glycol, tetraethylene glycol, and trimethylolpropane. The PVA layer may be Contains one or more of these plasticizers. Among these, glycerin is preferred from the viewpoint of improving the stretchability.

PVA之可塑劑的含量，相對於其所含的PVA100質量份，在1質量份以上15質量份以下的範圍內為佳。藉由該含量為1質量份以上，可進一步提升積層體(1)之拉伸性。另一方面，藉由該含量為15質量份 以下，可防止PVA層變得過於柔軟而處理性下降，並防止PVA層自熱可塑性樹脂膜層剝離。PVA層之可塑劑的含量，相對於PVA100質量份為2質量份以上更佳，4質量份以上特佳，5質量份以上最佳，而且，13質量份以下更佳，12質量份以下特佳，8質量份以下最佳。 The content of the plasticizer of PVA is preferably within a range of 1 part by mass to 15 parts by mass with respect to 100 parts by mass of PVA contained therein. When the content is 1 part by mass or more, the stretchability of the laminated body (1) can be further improved. On the other hand, when the content is 15 parts by mass In the following, it is possible to prevent the PVA layer from becoming too soft and lowering the handleability, and to prevent the PVA layer from peeling from the thermoplastic resin film layer. The content of the plasticizer in the PVA layer is preferably 2 parts by mass or more, more preferably 4 parts by mass or more, 5 parts by mass or more is preferable, and 13 parts by mass or less is preferable, and 12 parts by mass or less is particularly preferable. , 8 mass parts or less is the best.

再者，在使用本發明的積層體(1)製造偏光膜的情況中，也根據其製造條件等，但因為PVA層所包含的可塑劑會在製造偏光膜之際溶出等，所以其總量並沒有限於殘留在偏光膜。 In addition, in the case where a polarizing film is produced using the multilayer body (1) of the present invention, depending on the production conditions and the like, the plasticizer contained in the PVA layer will dissolve during the production of the polarizing film, etc., so its total amount It is not limited to remaining in a polarizing film.

PVA層，視需要亦可進一步包含抗氧化劑、抗凍劑、pH調整劑、遮蔽劑、抗著色劑、油劑、界面活性劑等之成分。 The PVA layer may further include components such as an antioxidant, an antifreezing agent, a pH adjuster, a masking agent, an anti-staining agent, an oil agent, and a surfactant, if necessary.

PVA層之PVA的含有率，從成為所需的偏光膜之製備的容易度等之觀點，在50質量%以上99質量%以下的範圍內為佳，該含有率為75質量%以上較佳，80質量%以上更佳，85質量%以上特佳，又，98質量%以下較佳，96質量%以下更佳，95質量%以下特佳。 The content of PVA in the PVA layer is preferably in the range of 50% by mass or more and 99% by mass or less from the viewpoint of ease of preparation of a desired polarizing film, etc., and the content rate is preferably 75% by mass or more. 80% by mass or more is preferable, 85% by mass or more is particularly preferable, 98% by mass or less is preferable, 96% by mass or less is more preferable, and 95% by mass or less is particularly preferable.

PVA層的厚度並沒有特別限制，例如，可定為100μm以下，但從可輕易地製備薄型的偏光膜等之觀點，使PVA層變薄較為理想，具體而言，PVA層的厚度係20μm以下為佳，15μm以下較佳，10μm以下更佳。本發明的積層體(1)中，因為PVA層具有如前述之特定的構成，所以即使將PVA層之厚度如前述變薄，在與水接觸的步驟中也可抑制PVA之溶出，並可簡便地製造偏光性能佳之薄型的偏光膜。又，在PVA層的厚度如前述一 樣薄的情況中，也可能將拉伸積層體(1)之際的張力減低。再者，由於PVA層的厚度過薄的話，有於積層體(1)之拉伸時容易產生拉伸斷裂的傾向，故PVA層的厚度，例如為3μm以上。 The thickness of the PVA layer is not particularly limited. For example, it can be set to 100 μm or less, but from the viewpoint that a thin polarizing film can be easily prepared, it is desirable to make the PVA layer thin. Specifically, the thickness of the PVA layer is 20 μm or less. Preferably, 15 μm or less is more preferred, and 10 μm or less is more preferred. In the laminated body (1) of the present invention, since the PVA layer has a specific structure as described above, even if the thickness of the PVA layer is reduced as described above, the dissolution of PVA can be suppressed in the step in contact with water, and can be simplified. In order to manufacture a thin polarizing film with excellent polarizing performance. In addition, the thickness of the PVA layer is as described above. In such a thin case, it is possible to reduce the tension at the time of stretching the laminated body (1). In addition, if the thickness of the PVA layer is too thin, tensile fracture tends to easily occur during stretching of the laminated body (1). Therefore, the thickness of the PVA layer is, for example, 3 μm or more.

本發明的積層體(1)之層構成並沒有特別限制，但從更簡便地得到偏光性能佳的偏光膜之觀點，熱可塑性樹脂膜層1層與PVA層1層之2層結構較為理想。 The layer structure of the laminated body (1) of the present invention is not particularly limited, but from the viewpoint of more easily obtaining a polarizing film with excellent polarizing performance, a two-layer structure of a single layer of a thermoplastic resin film and a single layer of a PVA layer is preferable.

積層體(1)的形狀並沒有特別限制，但從可連續且輕易地製造更均勻的積層體，同時在使用其製造偏光膜之際也可連續使用的觀點，長條的積層體較為理想。長條的積層體之長度(長條方向的長度)並沒有特別限制，可因應製造的偏光膜之用途等適當設定，例如，可定為5m以上20,000m以下的範圍內。 The shape of the laminated body (1) is not particularly limited, but a long laminated body is preferable from the viewpoint that a more uniform laminated body can be continuously and easily manufactured, and can also be used continuously when a polarizing film is produced using the laminated body. The length of the long laminated body (length in the longitudinal direction) is not particularly limited, and it can be appropriately set according to the use of the polarizing film to be manufactured, for example, it can be set within a range of 5 m to 20,000 m.

積層體(1)的寬並沒有特別限制，可因應製造的偏光膜之用途等適當設定，但近年來從進行液晶電視或液晶監視器之大畫面化的觀點，使積層體(1)的寬成為0.5m以上，較佳為成為1.0m以上的話，較適合於該等用途。另一方面，積層體(1)的寬過廣的話，由於以實用化的裝置製造偏光膜時有難以均勻地拉伸的傾向，故積層體(1)的寬係7m以下為佳。 The width of the laminated body (1) is not particularly limited, and can be appropriately set according to the use of the polarizing film to be manufactured, but in recent years, the width of the laminated body (1) has been increased from the viewpoint of increasing the screen size of liquid crystal televisions or liquid crystal monitors. When it is 0.5 m or more, and preferably 1.0 m or more, it is more suitable for these applications. On the other hand, if the laminated body (1) is too wide, it is difficult to stretch uniformly when the polarizing film is produced by a practical device, so the width of the laminated body (1) is preferably 7 m or less.

作為製造積層體(1)的方法，例如，可舉出在熱可塑性樹脂膜上形成PVA層的方法，具體而言，可舉出將溶解有PVA及視需要進一步溶解前述可塑劑等之PVA以外的成分至液體媒體中的原液塗布於熱可塑性樹脂膜上並進行乾燥的方法；將熔融混練PVA、液體媒體 及視需要進一步熔融混練其他成分而成的原液擠製於熱可塑性樹脂膜上，且視需要進一步乾燥的方法；將包含PVA及視需要進一步包含其他成分的PVA膜以周知的方法製作之後，與熱可塑性樹脂膜貼合的方法等。該等之中，從可輕易地製備薄的PVA層之觀點及所得到的PVA層之厚度的均勻性之觀點，將溶解有PVA及視需要進一步溶解其他的成分至液體媒體中的原液塗布於熱可塑性樹脂膜上並進行乾燥的方法較佳。 Examples of the method for producing the laminated body (1) include a method of forming a PVA layer on a thermoplastic resin film, and specifically, other than PVA in which PVA is dissolved and the plasticizer and the like are further dissolved as necessary The method of coating the raw material of the ingredients into the liquid medium on a thermoplastic resin film and drying it; kneading the melted PVA and liquid medium And a method of further melting and kneading other ingredients as needed, extruding the raw material on a thermoplastic resin film, and further drying if necessary; after the PVA film containing PVA and if necessary further containing other components is produced by a known method, and A method of laminating a thermoplastic resin film. Among these, from the viewpoint that a thin PVA layer can be easily prepared and the uniformity of the thickness of the obtained PVA layer, a stock solution in which PVA is dissolved and other components are further dissolved in a liquid medium as necessary is applied to A method of drying the thermoplastic resin film is preferred.

作為前述的液體媒體，例如，可舉出水、二甲亞碸、二甲基甲醯胺、二甲基乙醯胺、N-甲基吡咯啶酮、乙二醇、甘油、丙二醇、二乙二醇、三乙二醇、四乙二醇、三羥甲基丙烷、乙二胺、二乙三胺等，且可使用該等之中的1種或2種以上。其中，從給予環境負荷或回收性的觀點，以水為佳。 Examples of the liquid medium include water, dimethylmethylene, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, ethylene glycol, glycerol, propylene glycol, and diethyl ether. Diol, triethylene glycol, tetraethylene glycol, trimethylolpropane, ethylenediamine, diethylenetriamine, and the like, and one or more of these may be used. Among them, water is preferred from the viewpoint of giving an environmental load or recyclability.

原液的揮發分率(在PVA層之形成時藉由揮發或乾燥去除的液體媒體等之揮發性成分的原液中之含有比例)，根據PVA層之形成方法或形成條件等也有不同，但在50質量%以上98質量%以下的範圍內為佳，在55質量%以上95質量%以下的範圍內較佳。藉由原液的揮發分率為50質量%以上，其黏度不會變得過高，而原液製備時之過濾或脫泡係順利地進行，容易形成異物或缺點少的PVA層，同時也提升塗布性。另一方面，藉由原液的揮發分率為98質量%以下，原液的濃度不會變得過低，而積層體之工業上的製造變容易。 The volatile content of the original solution (the content ratio of the original solution of volatile components such as liquid media removed by volatilization or drying during the formation of the PVA layer) varies depending on the method of forming the PVA layer or the forming conditions, but it is within 50%. It is preferably within a range of from mass% to 98% by mass, and more preferably within a range of from 55% by mass to 95% by mass. With the volatile content of the stock solution above 50% by mass, its viscosity will not become too high, and the filtration or defoaming during the preparation of the stock solution will proceed smoothly, and it is easy to form a PVA layer with few foreign matter or defects, and also improve coating. Sex. On the other hand, when the volatile content of the stock solution is 98% by mass or less, the concentration of the stock solution does not become too low, and the industrial production of the laminated body becomes easy.

作為將原液塗布於熱可塑性樹脂膜上之際的塗布方法，例如，可舉出模塗法、點塗法、浸塗法等。該等之中，從所得到的PVA層之厚度的均勻性之觀點，模塗法較為理想。 Examples of the coating method when the stock solution is applied onto the thermoplastic resin film include a die coating method, a spot coating method, and a dip coating method. Among these, the die coating method is preferable from the viewpoint of the uniformity of the thickness of the obtained PVA layer.

使用於積層體(1)之製造的熱可塑性樹脂膜，預先將至少一方的表面進行親水化處理為佳。藉由與經過如前述的親水化處理的表面接觸形成PVA層，可提升熱可塑性樹脂膜層與PVA層之接著性。作為親水化處理，例如，可舉出電暈處理、電漿處理、結合層處理等。該等之中，從容易調整親水性的觀點，以電暈處理為佳。 It is preferable that the thermoplastic resin film used for the production of the laminated body (1) be subjected to a hydrophilization treatment on at least one surface in advance. By forming the PVA layer in contact with the surface subjected to the hydrophilization treatment as described above, the adhesion between the thermoplastic resin film layer and the PVA layer can be improved. Examples of the hydrophilization treatment include a corona treatment, a plasma treatment, and a bonding layer treatment. Among these, corona treatment is preferred from the viewpoint of easy adjustment of hydrophilicity.

藉由前述之親水化處理將熱可塑性樹脂膜的表面之接觸角調整為55°以上70°以下為佳，將該接觸角調整為57°以上較佳，調整為59°以上更佳，又，調整為69°以下較佳，調整為68°以下更佳。該接觸角低於55°時，熱可塑性樹脂膜層與PVA層之接著強度有變得過強的傾向，在積層體(1)之拉伸後將拉伸的熱可塑性樹脂膜層剝離的情況，剝離會變困難。另一方面，該接觸角高於70°時，在積層體(1)之拉伸中PVA層變得容易自熱可塑性樹脂膜層剝離、裂開，有變得難以以高拉伸倍率拉伸之傾向。再者，熱可塑性樹脂膜的表面之接觸角，係可指水的自由表面與熱可塑性樹脂膜接觸處之水面與熱可塑性樹脂膜之表面所形成之角(取在水的內部之角)，可在實施例中藉由後述的方法測定。 It is better to adjust the contact angle of the surface of the thermoplastic resin film to 55 ° or more and 70 ° or less by the aforementioned hydrophilization treatment. It is better to adjust the contact angle to 57 ° or more, and 59 ° or more. It is preferably adjusted to 69 ° or less, and more preferably adjusted to 68 ° or less. When the contact angle is less than 55 °, the bonding strength between the thermoplastic resin film layer and the PVA layer tends to be too strong, and the stretched thermoplastic resin film layer may be peeled off after the laminate (1) is stretched. , Peeling will become difficult. On the other hand, when the contact angle is higher than 70 °, the PVA layer is easily peeled from the thermoplastic resin film layer and cracked during stretching of the laminate (1), making it difficult to stretch at a high stretching ratio. The tendency. Furthermore, the contact angle of the surface of the thermoplastic resin film refers to the angle formed by the water surface where the free surface of water contacts the thermoplastic resin film and the surface of the thermoplastic resin film (taken from the angle inside the water), It can be measured in the examples by the method described later.

藉由電暈處理將熱可塑性樹脂膜的表面之接觸角調整為前述範圍時之電暈處理的條件並沒有特別限制，但從可將熱可塑性樹脂膜的表面之接觸角輕易地調整為前述範圍的觀點，以下述式(1)所示之放電量為180~350W．分鐘/m2的範圍內為佳，190~320W．分鐘/m2的範圍內較佳，200~300W．分鐘/m2的範圍內更佳。 The conditions of the corona treatment when the contact angle of the surface of the thermoplastic resin film is adjusted to the aforementioned range by corona treatment are not particularly limited, but the contact angle of the surface of the thermoplastic resin film can be easily adjusted to the aforementioned range From the viewpoint, the discharge capacity shown by the following formula (1) is 180 ~ 350W. It is better in the range of minutes / m 2 , 190 ~ 320W. The range of minutes / m 2 is better, 200 ~ 300W. It is more preferably in the range of minutes / m 2 .

放電量(W．分/m2)=輸出(W/m)/處理速度(m/分) (1) Discharge (W.min / m 2 ) = Output (W / m) / Processing speed (m / min) (1)

將原液塗布、擠製於熱可塑性樹脂膜上後的乾燥之條件並沒有特別限制，但為了防止對熱可塑性樹脂膜造成皺紋，以熱可塑性樹脂膜之玻璃轉化溫度以下的溫度乾燥較為理想。此時，以使用作為PVA之前述容易使膨潤度下降的PVA等為前提，以不會為100℃以上的條件乾燥為佳。具體的乾燥溫度並沒有特別限制，但考慮到容易將PVA層之膨潤度調整為前述範圍的觀點或乾燥效率等，以20℃以上95℃以下的範圍內為佳，該乾燥溫度為係50℃以上較佳，65℃以上更佳，又，90℃以下較佳，85℃以下更佳。藉此，可輕易地得到在熱可塑性樹脂膜層積層膨潤度為180%以上260%以下之未拉伸PVA層的積層體(1)。 The drying conditions after coating and extruding the original solution on the thermoplastic resin film are not particularly limited, but in order to prevent wrinkles on the thermoplastic resin film, it is preferable to dry at a temperature lower than the glass transition temperature of the thermoplastic resin film. In this case, it is premised that the PVA or the like which is easy to reduce the swelling degree as the PVA is used, and it is preferably not dried under the conditions of 100 ° C or higher. The specific drying temperature is not particularly limited, but considering the viewpoint that it is easy to adjust the swelling degree of the PVA layer to the aforementioned range, drying efficiency, etc., it is preferably in the range of 20 ° C to 95 ° C. The drying temperature is 50 ° C. The above is preferable, more preferably 65 ° C or more, and more preferably 90 ° C or less, and more preferably 85 ° C or less. Thereby, a laminate (1) of an unstretched PVA layer having a swelling degree of a thermoplastic resin film laminated layer of 180% or more and 260% or less can be easily obtained.

《偏光膜之製造方法(1)》 "Manufacturing method of polarizing film (1)"

本發明的偏光膜之製造方法(1)係包含將前述積層體(1)拉伸的步驟。 The manufacturing method (1) of the polarizing film of this invention includes the process of extending | stretching the said laminated body (1).

在此，使PVA層預先含有二色性色素的話，藉由將積層體(1)拉伸可得到吸附有二色性色素的偏光膜。在該情況中，使PVA層含有二色性色素的方法並沒有特別限 制，例如，可適當採用使積層體(1)的PVA層接觸二色性色素的方法、使用於形成PVA層之使前述原液預先含有二色性色素的方法等。又，在未使PVA層預先含有二色性色素的情況中，藉由在積層體(1)之拉伸中使拉伸途中的PVA層與二色性色素接觸、或是在將積層體(1)拉伸後使由(拉伸前的)PVA層形成的拉伸膜層與二色性色素接觸，可得到吸附有二色性色素的偏光膜。該等之中，從更顯著地發揮本發明的效果之觀點，以藉由包含對於拉伸前之積層體(1)的PVA層；在積層體(1)的拉伸中之拉伸途中的PVA層；及、由拉伸積層體(1)後之PVA層形成的拉伸膜層；中之任一者，使二色性色素接觸的步驟之製造方法而得到吸附有二色性色素的偏光膜為佳。 When the dichroic dye is contained in the PVA layer in advance, the polarizing film to which the dichroic dye is adsorbed can be obtained by stretching the laminate (1). In this case, the method of making the PVA layer contain a dichroic pigment is not particularly limited. For example, a method in which the PVA layer of the multilayer body (1) is brought into contact with a dichroic dye, a method for forming a PVA layer, and the undiluted solution containing the dichroic dye in advance can be suitably used. When the dichroic dye is not contained in the PVA layer in advance, the PVA layer in the middle of stretching is brought into contact with the dichroic dye during the stretching of the laminate (1), or the laminated body ( 1) After stretching, a stretched film layer formed of a PVA layer (before stretching) is brought into contact with a dichroic dye, and a polarizing film having a dichroic dye adsorbed thereon can be obtained. Among these, from the viewpoint of more prominently exerting the effects of the present invention, the PVA layer for the laminated body (1) before stretching is included; A PVA layer; and a stretched film layer formed of the PVA layer after stretching the laminated body (1); any one of the manufacturing methods of the step of contacting a dichroic dye to obtain a dichroic dye adsorbed A polarizing film is preferred.

在前述之任一方法中，除了拉伸及使二色性色素接觸的處理(染色)以外，視需要可進一步實施膨潤處理、交聯處理、固定處理、乾燥等。各處理的順序可視需要而適當變更，又可實施各處理2次以上，甚至可同時實施不同的處理。又，根據前述的製造方法，可得到在拉伸後的熱可塑性樹脂膜層上形成的偏光膜，但視需要亦可包含將該拉伸後的熱可塑性樹脂膜層剝離的步驟。 In any of the aforementioned methods, in addition to the stretching (contact dyeing) and the treatment (dyeing) for bringing the dichroic pigment into contact, if necessary, a swelling treatment, a crosslinking treatment, a fixing treatment, drying, and the like may be performed. The order of each process can be appropriately changed as required, and each process can be performed more than two times, and even different processes can be performed at the same time. Moreover, according to the aforementioned manufacturing method, a polarizing film formed on the stretched thermoplastic resin film layer can be obtained, but if necessary, a step of peeling the stretched thermoplastic resin film layer may be included.

如前述，本發明的偏光膜之製造方法(1)中，積層體(1)具有的PVA層之膨潤度為180%以上260%以下的範圍內，因此即使沒有預先進行對於硼酸水溶液之浸漬或空中高溫拉伸的不溶化處理，也可在染色等之偏光膜製造時之與水接觸的步驟中抑制PVA之溶出。因此， 在如前述之沒有預先進行不溶化處理而製造偏光膜的情況中，可更顯著地發揮本發明的效果。具體而言，在藉由包含對於拉伸前之積層體(1)的PVA層；在積層體(1)的拉伸中之拉伸途中的PVA層；及、由拉伸積層體(1)後之PVA層形成的拉伸膜層；中之任一者，使二色性色素接觸的步驟之製造方法製造吸附有二色性色素的偏光膜之際，在由準備本發明的積層體(1)至使前述二色性色素接觸的步驟之前的期間，未包含與含有硼酸、硼砂等之硼酸鹽等之硼化合物的水溶液接觸之步驟、及/或未包含在95℃以上的溫度拉伸的步驟(較佳為未包含在50℃以上的溫度拉伸的步驟)為佳。 As described above, in the method (1) for producing a polarizing film of the present invention, the swelling degree of the PVA layer included in the laminated body (1) is within a range of 180% to 260%. The insolubilization treatment of high-temperature stretching in the air can also suppress the elution of PVA in the step of contact with water during the production of polarizing films such as dyeing. therefore, In the case where a polarizing film is produced without performing insolubilization in advance as described above, the effect of the present invention can be more significantly exhibited. Specifically, the PVA layer in the middle of stretching by stretching the laminated body (1) before stretching; the PVA layer in the middle of stretching in the stretching of the laminated body (1); and, by stretching the laminated body (1) When the polarizing film to which the dichroic dye is adsorbed is produced by any one of the production methods of the step of bringing the dichroic dye into contact with the stretched film layer formed by the subsequent PVA layer, the laminated body of the present invention ( 1) The period before the step of contacting the dichroic dye is not included in the step of contacting with an aqueous solution containing a boron compound such as a borate such as boric acid and borax, and / or is not stretched at a temperature of 95 ° C or higher The step (preferably a step which does not include stretching at a temperature of 50 ° C or higher) is preferred.

作為本發明的偏光膜之製造方法(1)的一例，可舉出首先對於具有未包含二色性色素之PVA層的積層體(1)實施膨潤處理，接著藉由與二色性色素接觸而使PVA層含有二色性色素，且視需要進一步施以交聯處理，將得到的積層體拉伸，並視需要進一步施以固定處理，且進行乾燥，藉由該等一連串的處理，得到在拉伸的熱可塑性樹脂膜層上形成的偏光膜，將該拉伸的熱可塑性樹脂膜層剝離的方法。 As an example of the manufacturing method (1) of the polarizing film of this invention, the laminated body (1) which has a PVA layer which does not contain a dichroic pigment is swelled first, and it contacts with a dichroic pigment, and The PVA layer contains a dichroic pigment, and if necessary, further cross-linking treatment is applied, the obtained laminated body is stretched, and if necessary, further fixed treatment is applied, and drying is performed. A method of peeling a polarizing film formed on a stretched thermoplastic resin film layer and peeling the stretched thermoplastic resin film layer.

膨潤處理，可藉由將積層體(1)浸漬於水而進行。作為浸漬於水之際的水之溫度，在20℃以上40℃以下的範圍內為佳，該溫度為22℃以上較佳，25℃以上更佳，又，38℃以下較佳，35℃以下更佳。藉由使該溫度為20℃以上40℃以下的範圍內，可有效地使PVA層膨潤。又，作為浸漬於水的時間，以0.1分鐘以上5分鐘 以下的範圍內為佳，0.5分鐘以上3分鐘以下的範圍內較佳。藉由在0.1分鐘以上5分鐘以下的範圍內，可有效地使PVA層膨潤。再者，浸漬於水之際的水並沒有限定於純水，亦可為溶解有各種成分的水溶液，也可為水與水性媒體之混合物。 The swelling treatment can be performed by immersing the laminate (1) in water. The temperature of water when immersed in water is preferably in the range of 20 ° C to 40 ° C. The temperature is preferably 22 ° C or higher, 25 ° C or higher, or 38 ° C or lower, or 35 ° C or lower. Better. When the temperature is in the range of 20 ° C to 40 ° C, the PVA layer can be effectively swelled. The time for immersion in water is 0.1 minute or more and 5 minutes. The following range is preferable, and the range of 0.5 minute to 3 minutes is preferable. Within a range of 0.1 minutes to 5 minutes, the PVA layer can be effectively swelled. The water to be immersed in the water is not limited to pure water, and may be an aqueous solution in which various components are dissolved, or a mixture of water and an aqueous medium.

如前述，藉由對於拉伸前之積層體(1)的PVA層；在積層體(1)的拉伸中之拉伸途中的PVA層；及、由拉伸積層體(1)後之PVA層形成的拉伸膜層等，使其與二色性色素接觸而染色，可得到在基體吸附有二色性色素的偏光膜。二色性色素之接觸，可藉由將拉伸前、拉伸中、或拉伸後之積層體浸漬於包含二色性色素的溶液(特別是水溶液)而進行。包含二色性色素的溶液中之二色性色素的濃度，可因應所使用的二色性色素之種類等而適當設定，例如，可定為0.001質量%以上1質量%以下，但在使用碘-碘化鉀溶液(特別是水溶液)作為含有二色性色素的溶液時，從可使基體有效地吸附碘系色素之觀點，使用的碘(I2)之濃度在0.01質量%以上1.0質量%以下的範圍內為佳，使用的碘化鉀(KI)之濃度在0.01質量%以上10質量%以下的範圍內較佳。從可使基體有效地吸附碘系色素之觀點，包含二色性色素的溶液之溫度定為20℃以上50℃以下的範圍內，特別是25℃以上40℃以下的範圍內為佳。 As mentioned above, the PVA layer for the laminated body (1) before stretching; the PVA layer in the middle of stretching during the stretching of the laminated body (1); and the PVA after stretching the laminated body (1) A polarizing film in which a stretched film layer formed by a layer is dyed in contact with a dichroic dye, and a dichroic dye is adsorbed on a substrate can be obtained. The contact of the dichroic pigment can be performed by immersing the laminated body before, during, or after stretching in a solution (particularly an aqueous solution) containing the dichroic pigment. The concentration of the dichroic pigment in the solution containing the dichroic pigment can be appropriately set according to the type of the dichroic pigment used, for example, it can be set to 0.001% by mass or more and 1% by mass or less, but when using iodine -When a potassium iodide solution (especially an aqueous solution) is used as a solution containing a dichroic pigment, the concentration of iodine (I 2 ) used is 0.01 mass% or more and 1.0 mass% or less from the viewpoint that the substrate can efficiently adsorb iodine-based pigments The range is preferably, and the concentration of potassium iodide (KI) used is more preferably within a range of 0.01% by mass to 10% by mass. From the viewpoint of enabling the substrate to efficiently adsorb iodine-based dyes, the temperature of the solution containing the dichroic dye is preferably within a range of 20 ° C to 50 ° C, and particularly preferably within a range of 25 ° C to 40 ° C.

作為前述的二色性色素，可舉出碘系色素(I3 -或I5 -等)、二色性有機染料等。碘系色素，例如，可藉由使碘(I2)與碘化鉀接觸而得到。又，作為二色性有機染 料，可舉出直接黑17、19、154；直接棕44、106、195、210、223；直接紅2、23、28、31、37、39、79、81、240、242、247；直接藍1、15、22、78、90、98、151、168、202、236、249、270；直接紫9、12、51、98；直接綠1、85；直接黃8、12、44、86、87；直接橘26、39、106、107等。該等之二色性色素之中，從處理性、取得性、偏光性能等之觀點，以碘系色素為佳。再者，二色性色素可為單獨1種，亦可為2種以上，兩者均可，例如，亦可為如I3 -及I5 -之平衡混合物。 Examples of the dichroic dye include iodine-based dyes (I 3 - or I 5- , etc.), and dichroic organic dyes. The iodine-based pigment can be obtained, for example, by contacting iodine (I 2 ) with potassium iodide. Examples of the dichroic organic dye include direct black 17, 19, 154; direct brown 44, 106, 195, 210, 223; direct red 2, 23, 28, 31, 37, 39, 79, 81, 240, 242, 247; direct blue 1, 15, 22, 78, 90, 98, 151, 168, 202, 236, 249, 270; direct purple 9, 12, 51, 98; direct green 1, 85; direct yellow 8, 12, 44, 86, 87; direct orange 26, 39, 106, 107, etc. Among these dichroic pigments, iodine-based pigments are preferred from the viewpoints of handleability, availability, and polarization performance. Further, the dichroic dye may be alone, or two or more may also be, both of which can, for example, may also be such as I 3 - and I 5 - the equilibrium mixture.

藉由對於PVA層施以交聯處理，在高溫進行濕式拉伸之際可更有效地防止PVA對於水溶出。從該觀點，交聯處理係於使二色性色素接觸之處理之後，且在拉伸之前進行為佳。交聯處理，可藉由將積層體(1)浸漬於包含交聯劑的水溶液而進行。作為該交聯劑，可使用硼酸、硼砂等之硼酸鹽等之硼化合物的1種或2種以上。包含交聯劑的水溶液之交聯劑的濃度在1質量%以上15質量%以下的範圍內為佳，2質量%以上較佳，3質量%以上更佳，又，7質量%以下較佳，6質量%以下更佳。藉由使交聯劑的濃度在1質量%以上15質量%以下的範圍內，可維持足夠的拉伸性。包含交聯劑的水溶液亦可含有碘化鉀等之輔助劑。包含交聯劑的水溶液之溫度定為20℃以上50℃以下的範圍內，特別是25℃以上40℃以下的範圍內為佳。藉由使該溫度為20℃以上50℃以下的範圍內，可有效地進行交聯。 By applying a crosslinking treatment to the PVA layer, it is possible to more effectively prevent PVA from leaching out of water when wet stretching is performed at a high temperature. From this viewpoint, the crosslinking treatment is preferably performed after the treatment of bringing the dichroic pigment into contact and before stretching. The crosslinking treatment can be performed by immersing the laminated body (1) in an aqueous solution containing a crosslinking agent. As this crosslinking agent, one or two or more kinds of boron compounds such as boric acid such as boric acid and borax can be used. The concentration of the cross-linking agent in the aqueous solution containing the cross-linking agent is preferably within a range of 1% by mass to 15% by mass, more preferably 2% by mass or more, more preferably 3% by mass, and even more preferably 7% by mass or less. 6 mass% or less is more preferable. When the concentration of the crosslinking agent is in the range of 1% by mass to 15% by mass, sufficient stretchability can be maintained. The aqueous solution containing a crosslinking agent may contain auxiliary agents, such as potassium iodide. The temperature of the aqueous solution containing a cross-linking agent is preferably in a range of 20 ° C to 50 ° C, and particularly preferably in a range of 25 ° C to 40 ° C. When the temperature is in the range of 20 ° C to 50 ° C, crosslinking can be effectively performed.

將積層體(1)拉伸之際的拉伸方法並沒有特別限制，可以濕式拉伸法及乾式拉伸法中之任一者進行。濕式拉伸法的情況中，亦可在包含硼酸、硼砂等之硼酸鹽等之硼化合物的1種或2種以上之水溶液中進行，也可在前述之包含二色性色素的溶液中或後述之固定處理浴中進行。又，乾式拉伸法的情況中，可直接以室溫進行拉伸，亦可一邊加熱一邊進行拉伸，也可在吸水後拉伸。該等之中，從得到的偏光膜之寬方向的厚度之均勻性的觀點，以濕式拉伸法為佳，在硼酸水溶液中拉伸較佳。硼酸水溶液中之硼酸的濃度在0.5質量%以上6.0質量%以下的範圍內為佳，該濃度為1.0質量%以上較佳，1.5質量%以上更佳，又，5.0質量%以下較佳，4.0質量%以下更佳。藉由使硼酸的濃度在0.5質量%以上6.0質量%以下的範圍內，可得到寬方向的厚度之均勻性佳的偏光膜。前述之包含硼化合物的水溶液亦可含有碘化鉀，其濃度在0.01質量%以上10質量%以下的範圍內為佳。藉由使碘化鉀的濃度在0.01質量%以上10質量%以下的範圍內，可得到偏光性能更為良好的偏光膜。 The stretching method in the case of stretching the laminated body (1) is not particularly limited, and it can be performed by either of a wet stretching method and a dry stretching method. In the case of the wet stretching method, it may be performed in an aqueous solution containing one or two or more kinds of boron compounds such as boric acid such as boric acid and borax, or in a solution containing a dichroic pigment as described above or Performed in a fixed treatment bath described later. In the case of the dry stretching method, stretching may be performed at room temperature as it is, stretching may be performed while heating, or stretching may be performed after absorbing water. Among these, from the viewpoint of the uniformity of the thickness in the width direction of the obtained polarizing film, a wet stretching method is preferred, and stretching in a boric acid aqueous solution is preferred. The concentration of boric acid in the boric acid aqueous solution is preferably within a range of 0.5% by mass to 6.0% by mass. The concentration is preferably 1.0% by mass or more, more preferably 1.5% by mass or more, and preferably 5.0% by mass or less, and 4.0% by mass. % Is better. When the concentration of the boric acid is in the range of 0.5% by mass to 6.0% by mass, a polarizing film having excellent thickness uniformity in a wide direction can be obtained. The aforementioned boron compound-containing aqueous solution may also contain potassium iodide, and its concentration is preferably within a range of 0.01% by mass to 10% by mass. When the concentration of potassium iodide is in the range of 0.01% by mass or more and 10% by mass or less, a polarizing film having better polarizing performance can be obtained.

積層體(1)拉伸之際的溫度在30℃以上90℃以下的範圍內為佳，該溫度為40℃以上較佳，50℃以上更佳，又，80℃以下較佳，70℃以下更佳。藉由使該溫度在30℃以上90℃以下的範圍內，可得到寬方向的厚度之均勻性佳的偏光膜。 The temperature of the laminated body (1) during stretching is preferably within a range of 30 ° C to 90 ° C. The temperature is preferably 40 ° C or higher, more preferably 50 ° C or higher, and preferably 80 ° C or lower, and 70 ° C or lower. Better. By setting the temperature in a range of 30 ° C. to 90 ° C., a polarizing film having excellent thickness uniformity in a wide direction can be obtained.

積層體(1)拉伸之際的拉伸倍率為5.7倍以上為佳，5.8倍以上較佳，5.9倍以上更佳。藉由使積層體 (1)的拉伸倍率在前述的範圍內，可得到偏光性能更佳的偏光膜。積層體(1)之拉伸倍率的上限並沒有特別限制，但8倍以下為佳。積層體(1)之拉伸可進行一次，亦可分成多次進行，兩者均可，但在分成多次進行時，只要各拉伸之拉伸倍率相乘的總拉伸倍率在前述範圍內即可。再者，本說明書的拉伸倍率係基於拉伸前之積層體(1)的長度者，未進行拉伸的狀態相當於拉伸倍率1倍。 The stretch ratio when the laminate (1) is stretched is preferably 5.7 times or more, more preferably 5.8 times or more, and even more preferably 5.9 times or more. Laminated body The stretching ratio of (1) is in the aforementioned range, and a polarizing film having better polarizing performance can be obtained. The upper limit of the draw ratio of the laminated body (1) is not particularly limited, but it is preferably 8 times or less. The stretching of the laminated body (1) can be performed once or divided into multiple times, both of which can be performed, but when divided into multiple times, as long as the total stretching ratio multiplied by the stretching ratio of each stretching is within the aforementioned range Within. In addition, the stretching ratio in this specification is based on the length of the laminated body (1) before stretching, and a state in which stretching is not performed corresponds to a stretching ratio of 1 time.

積層體(1)之拉伸，從得到的偏光膜之性能的觀點，以單軸拉伸為佳。在將長條的積層體(1)拉伸時之單軸拉伸的方向並沒有特別限制，可採用對於長條方向之單軸拉伸或橫單軸拉伸，但從可得到偏光性能更佳的偏光膜之觀點，以對於長條方向的單軸拉伸為佳。對於長條方向的單軸拉伸，可藉由使用具備相互平行的多個輥之拉伸裝置，並改變各輥間之周速而進行。另一方面，橫單軸拉伸可使用拉幅型拉伸機進行。 The stretching of the laminated body (1) is preferably uniaxial stretching from the viewpoint of the performance of the obtained polarizing film. The direction of uniaxial stretching when stretching the long laminated body (1) is not particularly limited. Uniaxial stretching in the longitudinal direction or uniaxial stretching in the transverse direction can be adopted, but the polarization performance can be obtained more. From the viewpoint of a good polarizing film, uniaxial stretching in the longitudinal direction is preferred. Uniaxial stretching in the longitudinal direction can be performed by using a stretching device having a plurality of rolls parallel to each other and changing the peripheral speed between the rolls. On the other hand, transverse uniaxial stretching can be performed using a tenter-type stretching machine.

固定處理，主要係為了強化對於PVA層或拉伸膜(基體)的二色性色素之吸附而進行。固定處理，可藉由將拉伸前、拉伸中或拉伸後之積層體浸漬於固定處理浴而進行。作為固定處理浴。作為固定處理浴，可使用包含硼酸、硼砂等之硼酸鹽等之硼化合物的1種或2種以上之水溶液。又，視需要亦可在固定處理浴中添加碘化合物或金屬化合物。作為固定處理浴使用之包含硼化合物的水溶液中之硼化合物的濃度，一般為2質量%以上15質量%以下的範圍內，特別是3質量%以上10質量%以下的範圍內為佳。藉由使該濃度在2質量%以上 15質量%以下的範圍內，可更強化二色性色素之吸附。固定處理浴的溫度在15℃以上60℃以下的範圍內，特別是25℃以上40℃以下的範圍內為佳。藉由使該溫度在15℃以上60℃以下的範圍內，可更強化二色性色素之吸附。 The fixation treatment is mainly performed in order to enhance the adsorption of the dichroic dye to the PVA layer or the stretched film (substrate). The fixing treatment can be performed by immersing the laminated body before, during or after stretching in a fixing treatment bath. As a fixed treatment bath. As the fixed treatment bath, an aqueous solution containing one or two or more boron compounds such as boric acid such as boric acid and borax can be used. If necessary, an iodine compound or a metal compound may be added to the fixed treatment bath. The concentration of the boron compound in the boron compound-containing aqueous solution used as the fixed treatment bath is generally within a range of 2% by mass or more and 15% by mass or less, and particularly preferably within a range of 3% by mass or more and 10% by mass or less. By setting the concentration to 2% by mass or more Within the range of 15% by mass or less, the adsorption of the dichroic pigment can be further enhanced. The temperature of the fixed treatment bath is preferably in a range of 15 ° C to 60 ° C, and particularly preferably in a range of 25 ° C to 40 ° C. When the temperature is within a range of 15 ° C to 60 ° C, the adsorption of the dichroic dye can be further enhanced.

乾燥的條件並沒有特別限制，但在30℃以上150℃以下的範圍內，特別是在50℃以上130℃以下的範圍內之溫度進行為佳。藉由在30℃以上150℃以下的範圍內之溫度進行乾燥，容易得到尺寸穩定性佳的偏光膜。 The drying conditions are not particularly limited, but it is preferably performed at a temperature in a range of 30 ° C to 150 ° C, particularly in a range of 50 ° C to 130 ° C. By drying at a temperature in the range of 30 ° C to 150 ° C, a polarizing film having good dimensional stability is easily obtained.

藉由如前述進行，可得到在拉伸的熱可塑性樹脂膜層上形成的偏光膜。如前述之形態的偏光膜之使用方法並沒有特別限制，例如，亦可不將拉伸的熱可塑性樹脂膜層剝離，將其直接或根據所需在偏光膜側貼合光學上為透明且具有機械強度的保護膜而作為偏光板，亦可在與拉伸的熱可塑性樹脂膜層所在側為相反之側貼合保護膜後，將該拉伸的熱可塑性樹脂膜層剝離，將其直接或根據所需在剝離面貼合另一保護膜而作為偏光板。作為保護膜，可使用三醋酸纖維素(TAC)膜、乙酸．丁酸纖維素(CAB)膜、丙烯酸系膜、聚酯系膜等。又，作為用以貼合的黏著劑，可舉出PVA系黏著劑或胺基甲酸酯系黏著劑等，但PVA系黏著劑較佳。 By proceeding as described above, a polarizing film formed on the stretched thermoplastic resin film layer can be obtained. The method of using the polarizing film in the aforementioned form is not particularly limited. For example, the stretched thermoplastic resin film layer may not be peeled off, and it may be bonded directly or as required on the polarizing film side to be optically transparent and mechanical. Strength protective film as a polarizing plate, after the protective film is pasted on the side opposite to the stretched thermoplastic resin film layer side, the stretched thermoplastic resin film layer is peeled off, and it can be directly or based on It is necessary to stick another protective film on the peeling surface as a polarizing plate. As the protective film, cellulose triacetate (TAC) film, acetic acid can be used. Cellulose butyrate (CAB) film, acrylic film, polyester film, etc. Examples of the adhesive used for bonding include PVA-based adhesives and urethane-based adhesives. PVA-based adhesives are preferred.

利用本發明的偏光膜之製造方法(1)得到的偏光膜之厚度係10μm以下為佳，8μm以下較佳。藉由偏光膜具有如前述的厚度，可適當用於行動電話等之對薄型化之要求高的領域。再者，厚度過薄的偏光膜，其製備有困難，因此偏光膜的厚度，例如為1μm以上。 The thickness of the polarizing film obtained by the method (1) for producing a polarizing film of the present invention is preferably 10 μm or less, and more preferably 8 μm or less. Since the polarizing film has the thickness as described above, it can be suitably used in a field requiring high thickness reduction such as a mobile phone. Furthermore, since a polarizing film having an excessively thin thickness is difficult to prepare, the thickness of the polarizing film is, for example, 1 μm or more.

《偏光膜(2)》 "Polarizing Film (2)"

本發明的偏光膜(2)中，係於雙折射率為45×10-3以上的基體吸附有二色性色素。在此之二色性色素，可吸附於基體的內部，亦可吸附於基體的表面，兩者均可，但從偏光性能之觀點，以二色性色素吸附於基體的內部為佳。在基體吸附有二色性色素的偏光膜，可進行將預先含有二色性色素的初始膜拉伸、與初始膜之拉伸同時使二色性色素吸附、在將初始膜拉伸並形成基體後使二色性色素吸附等而製造。 In the polarizing film (2) of the present invention, a dichroic dye is adsorbed on a substrate having a birefringence of 45 × 10 -3 or more. Here, the dichroic pigment can be adsorbed on the inside of the substrate or on the surface of the substrate, both of which can be used, but from the viewpoint of polarizing performance, it is preferable that the dichroic pigment is adsorbed on the inside of the substrate. For a polarizing film having a dichroic dye adsorbed on a substrate, stretching the initial film containing the dichroic pigment in advance, and adsorbing the dichroic dye simultaneously with stretching of the initial film, and stretching the initial film to form a substrate can be performed. It is then manufactured by adsorbing a dichroic dye or the like.

作為偏光膜(2)及後述的偏光膜之製造方法(2)的二色性色素之說明，因為可直接採用偏光膜之製造方法(1)的說明欄中前述二色性色素的說明，所以在此省略重複的記載。 As the description of the dichroic pigment in the polarizing film (2) and the method (2) for manufacturing the polarizing film described later, the description of the dichroic pigment in the description column of the method (1) for manufacturing the polarizing film can be directly used. Duplicate descriptions are omitted here.

本發明的偏光膜(2)中，具有構成其之基體的雙折射率為45×10-3以上之習知沒有的構成。基體的雙折射率未滿45×10-3的話，在將其偏光膜2片配置為正交偏光狀態之際紅色光之洩漏變多且偏光性能也下降。從提升偏光性能，並使正交偏光狀態之紅色光之洩漏下降的觀點，構成偏光膜(2)之基體的雙折射率以46×10-3以上為佳，47×10-3以上較佳，48×10-3以上更佳，49×10-3以上特佳，50×10-3以上最佳。再者，從雙折射率過高的基體，其製備困難的觀點，基體的雙折射率，例如為60×10-3以下。 The polarizing film (2) of the present invention has a conventional structure having a birefringence of 45 × 10 -3 or more. If the birefringence of the substrate is less than 45 × 10 -3 , when two polarizing films are arranged in a cross-polarized state, the leakage of red light increases and the polarization performance decreases. From the viewpoint of improving the polarization performance and reducing the leakage of red light in the orthogonal polarization state, the birefringence of the matrix constituting the polarizing film (2) is preferably 46 × 10 -3 or more, and more preferably 47 × 10 -3 or more , 48 × 10 -3 or more is preferred, 49 × 10 -3 or more is particularly preferred, and 50 × 10 -3 or more is most preferred. In addition, from the viewpoint of making a substrate having an excessively high birefringence difficult to prepare, the birefringence of the substrate is, for example, 60 × 10 -3 or less.

構成偏光膜(2)之基體的雙折射率，係相當於由偏光膜(2)的雙折射率減去基於二色性色素的雙折射 率者。又，一般膜的雙折射率，可藉由將膜的阻滯值(藉由平行於膜的厚度方向之光測定的面內阻滯值)除以膜的厚度而求得。因此，在偏光膜(2)中規定之基體的雙折射率，可在求得相當於由偏光膜(2)的阻滯值減去基於二色性色素的阻滯值者之基體的阻滯值後，藉由將其除以基體的厚度(此通常與偏光膜(2)的厚度相同)而求得。 The birefringence of the matrix constituting the polarizing film (2) is equivalent to subtracting the birefringence based on a dichroic pigment from the birefringence of the polarizing film (2). Rater. The birefringence of a general film can be obtained by dividing the film's retardation value (in-plane retardation value measured by light parallel to the thickness direction of the film) by the thickness of the film. Therefore, the birefringence of the substrate specified in the polarizing film (2) can be obtained by subtracting the retardation value of the dichroic pigment from the retardation value of the polarizing film (2). The value is obtained by dividing it by the thickness of the substrate (this is usually the same as the thickness of the polarizing film (2)).

具體而言，在測定膜的阻滯值之際一般所使用的光之波長域中，通常基體的雙折射率幾乎沒有波長相依性，另一方面，利用基於二色性色素的雙折射率之波長相依性高，可藉由以下的方法求得基體的雙折射率。 Specifically, when measuring the retardation value of a film, the birefringence of a substrate generally has almost no wavelength dependence, and the birefringence of a dichroic pigment is used. The wavelength dependence is high, and the birefringence of the substrate can be obtained by the following method.

即，在將利用波長λnm的光測定的偏光膜(2)之阻滯值(單位：nm)作為Rλ，將基體的阻滯值(單位：nm)作為A，將利用波長λ的光之基於二色性色素的阻滯值(單位：nm)作為Bλ之際，將下述式(2)及(3)之關係看作成立，Rλ=A+Bλ (2) In other words, when the retardation value (unit: nm) of the polarizing film (2) measured by light having a wavelength of λ nm is used as R λ , the retardation value (unit: nm) of the substrate is used as A, and When the retardation value (unit: nm) of a dichroic pigment is B λ , the relationship between the following formulas (2) and (3) is considered to be true, and R λ = A + B λ (2)

Bλ=B’/(λ2-6002) (3) B λ = B '/ (λ 2 -600 2 ) (3)

且將藉由在該等式之λ各別代入測定波長之800nm及1000nm而得到的下述式(2’)、(3’)、(2”)及(3”)之聯立方程式，R800=A+B800 (2’) And the following simultaneous equations (2 '), (3'), (2 "), and (3") obtained by substituting 800nm and 1000nm of the measurement wavelength at λ of this equation, respectively, R 800 = A + B 800 (2 ')

B800=B’/(8002-6002) (3’) B 800 = B '/ (800 2 -600 2 ) (3')

R1000=A+B1000 (2”) R 1000 = A + B 1000 (2 ”)

B1000=B’/(10002-6002) (3”) B 1000 = B '/ (1000 2 -600 2 ) (3 ”)

使用測定的R800及R1000之值並解出求得作為基體的阻滯值之A，並藉由將其除以偏光膜(2)的厚度(單位：nm)而求得。在此，B’為在測定的偏光膜中固有的值。 The measured values of R 800 and R 1000 were used to solve for A, which was the retardation value of the matrix, and was obtained by dividing it by the thickness (unit: nm) of the polarizing film (2). Here, B 'is a value inherent in the measured polarizing film.

構成基體的成分並沒有特別限制，但基體包含PVA，而且該基體所含的PVA之平均聚合度為2,800以上9,500以下的範圍內為佳。藉由使用如前述的平均聚合度之PVA，且採用後述的方法可輕易地製造本發明的偏光膜(2)，如前述的偏光膜，作為其結果，基體所包含之PVA的平均聚合度係進入到前述範圍。從基體之製備的容易度之觀點，基體所包含之PVA的平均聚合度為3,000以上較佳，4,000以上更佳，4,100以上特佳，亦可為4,500以上，甚至為5,000以上，又，9,200以下較佳，8,000以下更佳，6,000以下特佳。再者，基體所包含之PVA的平均聚合度，可將偏光膜(2)浸漬於山梨糖醇水溶液等，且視需要進一步進行水洗等而將基體包含之PVA以外的成分萃取．去除，並使用作為殘留物而得到的PVA，根據JIS K6726-1994之記載而求得，具體而言，可在實施例中藉由後述的方法求得。 The components constituting the matrix are not particularly limited, but the matrix contains PVA, and the average degree of polymerization of the PVA contained in the matrix is preferably within a range of 2,800 or more and 9,500 or less. The polarizing film (2) of the present invention can be easily manufactured by using the PVA of the average degree of polymerization as described above and the method described later. As a result, the average degree of polymerization of the PVA contained in the matrix is as a result. Enter the aforementioned range. From the viewpoint of the ease of preparation of the substrate, the average polymerization degree of the PVA contained in the substrate is preferably 3,000 or more, more preferably 4,000 or more, particularly preferably 4,100 or more, or 4,500 or more, or even 5,000 or more, and 9,200 or less Better, below 8,000, especially below 6,000. In addition, for the average degree of polymerization of PVA contained in the matrix, the polarizing film (2) can be immersed in an aqueous sorbitol solution and the like, and further washed with water as necessary to extract components other than PVA contained in the matrix. The PVA obtained by removing it and using it as a residue is obtained in accordance with the description of JIS K6726-1994. Specifically, it can be obtained by a method described later in Examples.

基體之PVA的含有率並沒有特別限制，但從本發明之偏光膜(2)的製備之容易度等觀點，在50質量%以上100質量%以下的範圍內為佳，該含有率為80質量%以上較佳，90質量%以上更佳，又，99質量%以下較佳，98質量%以下更佳。再者，基體的質量係由偏光膜(2)的質量減去二色性色素的質量而求得。 The content of PVA of the substrate is not particularly limited, but from the standpoint of ease of preparation of the polarizing film (2) of the present invention, it is preferably in a range of 50% by mass or more and 100% by mass or less, and the content is 80% by mass % Or more is preferable, 90% by mass or more is preferable, 99% by mass or less is preferable, and 98% by mass or less is more preferable. The mass of the substrate is obtained by subtracting the mass of the dichroic pigment from the mass of the polarizing film (2).

偏光膜(2)及後述的偏光膜之製造方法(2)中，作為前述平均聚合度之說明以外的PVA之說明(包含皂化度之說明)，因為可直接採用在積層體(1)之說明的欄中前述PVA之說明，所以在此省略重複的記載。再者， 作為偏光膜(2)及後述的偏光膜之製造方法(2)的PVA，並不需要特別使用在積層體(1)之說明的欄中為較佳PVA之前述容易使澎潤度下降的PVA。 In the polarizing film (2) and the manufacturing method (2) of the polarizing film described later, the description of the PVA (including the description of the degree of saponification) other than the description of the average degree of polymerization described above can be directly used in the description of the laminated body (1) The description of the PVA in the above column is omitted here. Furthermore, As the PVA for the polarizing film (2) and the method (2) for manufacturing the polarizing film described later, it is not necessary to use the PVA which is a preferable PVA in the column of the laminated body (1), which is easy to reduce the degree of wetness. .

本發明的偏光膜(2)之厚度，以10μm以下為佳，8μm以下較佳。藉由偏光膜(2)具有如前述的厚度，可適當使用於行動電話等之對薄型化之要求高的領域。再者，厚度過薄的偏光膜，其製備有困難，因此偏光膜(2)的厚度，例如為1μm以上。 The thickness of the polarizing film (2) of the present invention is preferably 10 μm or less, and more preferably 8 μm or less. Since the polarizing film (2) has the thickness as described above, the polarizing film (2) can be suitably used in a field such as a mobile phone, where thinning is required. Furthermore, since a polarizing film having an excessively thin thickness is difficult to prepare, the thickness of the polarizing film (2) is, for example, 1 μm or more.

《偏光膜之製造方法(2)》 "Manufacturing method of polarizing film (2)"

用於製造本發明之偏光膜(2)的方法並沒有特別限定，但若藉由包含將具有熱可塑性樹脂膜層與PVA層的積層體拉伸為5.7倍以上之步驟的偏光膜之製造方法，且PVA層所包含之PVA的平均聚合度為2,800以上9,500以下之本發明的偏光膜之製造方法(2)，可順利且簡便地製造基體的雙折射率在特定的範圍、偏光性能佳、同時在正交偏光狀態的紅色光之洩漏少的本發明之偏光膜(2)。 The method for producing the polarizing film (2) of the present invention is not particularly limited, but if the method includes a method for producing a polarizing film including a step of stretching a laminate having a thermoplastic resin film layer and a PVA layer by 5.7 times or more And the method (2) of the polarizing film of the present invention in which the average polymerization degree of PVA contained in the PVA layer is 2,800 or more and 9,500 or less, the birefringence of the substrate can be smoothly and easily manufactured in a specific range, the polarizing performance is good, The polarizing film (2) of the present invention has little leakage of red light in the orthogonal polarization state.

作為偏光膜之製造方法(2)中使用的前述積層體具有的熱可塑性樹脂膜層之說明，因為可直接採用積層體(1)的說明欄中前述熱可塑性樹脂膜層的說明，所以在此省略重複的記載。 As the description of the thermoplastic resin film layer of the laminated body used in the method (2) for manufacturing a polarizing film, the description of the aforementioned thermoplastic resin film layer in the description column of the laminated body (1) can be directly used, so here Omit duplicate descriptions.

偏光膜之製造方法(2)中使用的前述積層體具有的PVA層所包含之PVA的平均聚合度為2,800以上9,500以下的範圍內，該平均聚合度以3,000以上為佳，4,000以上較佳，4,100以上更佳，4,500以上特佳，5,000 以上最佳，又，以9,200以下為佳，8,000以下較佳，6,000以下更佳。一般認為，PVA的平均聚合度越高拉伸時之張力越高而極限拉伸倍率會下降，但本案發明人等發現：將具有熱可塑性樹脂膜層與PVA層的積層體拉伸而得到偏光膜時，使用具有前述平均聚合度之PVA的話，例如，與使用平均聚合度為2,600之PVA的情況比較，極限拉伸倍率未下降反而上升，及將具有熱可塑性樹脂膜層與PVA層，且PVA層所包含之PVA的平均聚合度在前述範圍內的積層體拉伸為5.7倍以上，製造在熱可塑性樹脂膜上形成的偏光膜時，可順利且簡便地得到基體的雙折射率較習知高、為45×10-3以上的偏光膜。 The average polymerization degree of the PVA contained in the PVA layer included in the aforementioned laminated body used in the method (2) for producing a polarizing film is in a range of 2,800 or more and 9,500 or less. The average polymerization degree is preferably 3,000 or more, and 4,000 or more is preferable. More than 4,100 is preferred, more than 4,500 is particularly preferred, more than 5,000 is most preferred, and less than 9,200 is preferred, less than 8,000 is preferred, and less than 6,000 is more preferred. It is generally believed that the higher the average degree of polymerization of PVA, the higher the tension during stretching and the ultimate stretch ratio will decrease. When a PVA having the aforementioned average degree of polymerization is used in a film, for example, compared with a case where PVA having an average degree of polymerization of 2,600 is used, the ultimate stretch ratio is increased without decreasing, and a thermoplastic resin film layer and a PVA layer are provided, and The laminated body having an average degree of polymerization of PVA included in the PVA layer is stretched by 5.7 times or more. When manufacturing a polarizing film formed on a thermoplastic resin film, the birefringence of the substrate can be smoothly and easily obtained. Known as a polarizing film of 45 × 10 -3 or more.

再者，PVA層之形成所使用的PVA(PVA層所含的PVA)之平均聚合度，可根據JIS K6726-1994之記載求得，具體而言，可在實施例中藉由後述的方法求得。 The average degree of polymerization of PVA (PVA contained in the PVA layer) used to form the PVA layer can be obtained in accordance with JIS K6726-1994. Specifically, it can be obtained in the Examples by a method described later. Got.

從提升拉伸積層體之際的拉伸性之觀點，在偏光膜之製造方法(2)中使用之前述積層體具有的PVA層，包含可塑劑為佳。作為該可塑劑，例如，可舉出乙二醇、甘油、丙二醇、二乙二醇、二甘油、三乙二醇、四乙二醇、三羥甲基丙烷等之多元醇等，PVA層可包含該等之可塑劑的1種或2種以上。該等之中，從拉伸性之提升效果的觀點，以甘油為佳。 From the viewpoint of improving the stretchability when stretching the laminated body, it is preferable that the PVA layer included in the laminated body used in the method (2) for producing a polarizing film contains a plasticizer. Examples of the plasticizer include polyhydric alcohols such as ethylene glycol, glycerol, propylene glycol, diethylene glycol, diglycerin, triethylene glycol, tetraethylene glycol, and trimethylolpropane. The PVA layer may be One or two or more of these plasticizers are included. Among these, glycerin is preferred from the viewpoint of improving the stretchability.

在偏光膜之製造方法(2)中使用之前述積層體具有的PVA層之可塑劑的含量，相對於其所包含的PVA100質量份，係1質量份以上15質量份以下的範圍內為佳。藉由該含量為1質量份以上，可進一步提升積 層體之拉伸性。另一方面，藉由該含量為15質量份以下，可防止PVA層變得過於柔軟而處理性下降，並可防止PVA層自熱可塑性樹脂膜層剝離。又，PVA層所包含之PVA的平均聚合度在前述範圍之本發明的偏光膜之製造方法(2)中，PVA層的可塑劑之含量，相對於PVA100質量份為2質量份以上13質量份以下的範圍內，甚至為4質量份以上12質量份以下的範圍內，特別是為5質量份以上8質量份以下的範圍內時，理由尚未清楚，但根據極限拉伸倍率進一步提升，如前述的含量為佳。 The content of the plasticizer of the PVA layer in the laminated body used in the method (2) for producing a polarizing film is preferably within a range of 1 part by mass to 15 parts by mass with respect to 100 parts by mass of the PVA contained therein. When the content is 1 part by mass or more, the product can be further increased. Stretchability of the layer. On the other hand, when the content is 15 parts by mass or less, it is possible to prevent the PVA layer from becoming too soft and lowering the handleability, and to prevent the PVA layer from peeling from the thermoplastic resin film layer. In addition, in the method (2) for producing a polarizing film of the present invention in which the average polymerization degree of PVA contained in the PVA layer is in the aforementioned range, the content of the plasticizer in the PVA layer is 2 parts by mass or more and 13 parts by mass based on 100 parts by mass of PVA. In the following range, even in the range of 4 parts by mass or more and 12 parts by mass or less, especially in the range of 5 parts by mass or more and 8 parts by mass or less, the reason is not yet clear, but the limit stretching ratio is further increased, as described above. The content is better.

再者，雖亦依據偏光膜的製造條件等，但因為PVA層所包含的可塑劑會在製造偏光膜之際溶出等，所以沒有限制其需全量殘留在偏光膜中。 In addition, although it depends on the manufacturing conditions of the polarizing film, etc., the plasticizer contained in the PVA layer will be dissolved out during the production of the polarizing film, etc., so there is no limitation that the plasticizer should remain in the polarizing film in its entirety.

在偏光膜之製造方法(2)中使用之前述積層體具有的PVA層，視需要亦可進一步包含抗氧化劑、抗凍劑、pH調整劑、遮蔽劑、抗著色劑、油劑、界面活性劑等之成分。 The PVA layer of the aforementioned laminated body used in the method (2) for producing a polarizing film may further include an antioxidant, an antifreeze agent, a pH adjuster, a masking agent, an anti-colorant, an oil agent, and a surfactant, if necessary. And other ingredients.

在偏光膜之製造方法(2)中使用之前述積層體具有的PVA層之PVA的含有率，從成為所需的偏光膜之製備的容易度等之觀點，在50質量%以上99質量%以下的範圍內為佳，該含有率為75質量%以上較佳，80質量%以上更佳，85質量%以上特佳，又，98質量%以下較佳，96質量%以下更佳，95質量%以下特佳。 The PVA content of the PVA layer in the laminated body used in the method (2) for producing a polarizing film is 50% by mass or more and 99% by mass or less from the viewpoint of ease of preparation of a desired polarizing film, and the like. The content is preferably within the range of 75% by mass or more, more preferably 80% by mass or more, particularly preferably 85% by mass or more, 98% by mass or less, 96% by mass or less, and 95% by mass. The following is particularly good.

在偏光膜之製造方法(2)中使用之前述積層體具有的PVA層之厚度並沒有特別限制，例如，可定為100μm以下，但從可輕易地製備薄型的偏光膜等之觀 點，使PVA層變薄為佳，具體而言，PVA層的厚度係20μm以下為佳，15μm以下較佳，10μm以下更佳。本發明的偏光膜之製造方法(2)中，因為PVA層具有如前述之特定的構成，所以即使將PVA層之厚度如前述變薄，也可以高極限拉伸倍率拉伸，作為其結果，可得到偏光性能佳，同時在正交偏光狀態的紅色光之洩漏少的薄型之偏光膜。又，在PVA層的厚度如前述一樣薄的情況中，也可將拉伸積層體之際的張力減低。再者，由於PVA層的厚度過薄的話，有於積層體之拉伸時容易產生拉伸斷裂的傾向，故PVA層的厚度，例如為3μm以上。 The thickness of the PVA layer in the aforementioned laminated body used in the method (2) for manufacturing a polarizing film is not particularly limited. For example, it can be set to 100 μm or less, but from the viewpoint that a thin polarizing film can be easily prepared. It is preferable to make the PVA layer thinner. Specifically, the thickness of the PVA layer is preferably 20 μm or less, more preferably 15 μm or less, and more preferably 10 μm or less. In the manufacturing method (2) of the polarizing film of the present invention, since the PVA layer has a specific structure as described above, even if the thickness of the PVA layer is reduced as described above, it can be stretched at a high limit stretch ratio. As a result, It is possible to obtain a thin polarizing film with excellent polarization performance and little leakage of red light in the orthogonal polarization state. When the thickness of the PVA layer is as thin as described above, the tension at the time of stretching the laminated body can be reduced. Furthermore, if the thickness of the PVA layer is too thin, tensile fracture tends to easily occur during stretching of the laminated body, so the thickness of the PVA layer is, for example, 3 μm or more.

作為關於偏光膜之製造方法(2)中使用的前述積層體之其他說明(包含製造也含有熱可塑性樹脂膜之表面的接觸角之調整等的積層體之方法的說明)，因為可直接採用在積層體(1)的說明欄中關於前述積層體的說明，所以在此省略重複的記載。 As other explanations of the aforementioned laminated body used in the manufacturing method (2) of the polarizing film (including the explanation of the method of manufacturing the laminated body including the adjustment of the contact angle of the surface also containing the thermoplastic resin film), it can be directly used in The description of the laminated body described in the description column of the laminated body (1) will not be repeated here.

本發明的偏光膜之製造方法(2)中，係將前述積層體拉伸為5.7倍以上。在此，使PVA層預先含有二色性色素的話，藉由拉伸積層體可得到在基體吸附有二色性色素的偏光膜(2)。該情況中，使PVA層含有二色性色素的方法並沒有特別限制，例如，可適當採用使積層體的PVA層接觸二色性色素的方法、或使用於形成PVA層之前述原液預先含有二色性色素的方法等。又，在未使PVA層預先含有二色性色素的情況中，藉由在積層體之拉伸中使拉伸途中的PVA層與二色性色素接觸、或是在將積層體拉伸後使由(拉伸前的)PVA層形成的拉伸膜 層與二色性色素接觸，可得到在基體吸附有二色性色素的偏光膜(2)。 In the manufacturing method (2) of the polarizing film of this invention, the said laminated body is stretched 5.7 times or more. Here, if the PVA layer contains a dichroic dye in advance, a polarizing film (2) having a dichroic dye adsorbed on a substrate can be obtained by stretching the laminate. In this case, the method of making the PVA layer contain a dichroic pigment is not particularly limited. For example, a method of bringing the PVA layer of the laminate into contact with a dichroic pigment, or the aforementioned stock solution for forming the PVA layer may contain two in advance. Chromogenic pigments, etc. When the dichroic dye is not previously contained in the PVA layer, the PVA layer in the middle of stretching is brought into contact with the dichroic dye during the stretching of the laminate, or the laminated body is stretched after being stretched. Stretched film formed from (before stretching) PVA layer The layer is in contact with the dichroic dye, and a polarizing film (2) having a dichroic dye adsorbed on the substrate can be obtained.

在前述之任一方法中，除了拉伸及使二色性色素接觸的處理(染色)以外，視需要可進一步實施PVA層之不溶化處理、膨潤處理、交聯處理、固定處理、乾燥等。各處理的順序可視需要而適當變更，或可實施各處理2次以上，甚至可同時實施不同的處理。又，根據前述的製造方法，可得到在拉伸後的熱可塑性樹脂膜層上形成的偏光膜，但亦可含有視需要將該拉伸後的熱可塑性樹脂膜層剝離的步驟。 In any one of the methods described above, in addition to the stretching (dyeing) treatment and contacting the dichroic pigment, if necessary, an insolubilization treatment, a swelling treatment, a crosslinking treatment, a fixing treatment, and a drying treatment of the PVA layer may be performed. The order of each process can be appropriately changed as required, or each process can be performed more than two times, and even different processes can be performed at the same time. In addition, according to the aforementioned manufacturing method, a polarizing film formed on the stretched thermoplastic resin film layer can be obtained, but may include a step of peeling the stretched thermoplastic resin film layer if necessary.

作為本發明的偏光膜之製造方法(2)的一例，可舉出首先對於具有未包含二色性色素之PVA層的積層體實施不溶化處理，且視需要進一步實施膨潤處理，接著藉由與二色性色素接觸而使PVA層含有二色性色素，且視需要進一步施以交聯處理，將得到的積層體拉伸為5.7倍以上，並視需要進一步施以固定處理，且進行乾燥，藉由該等一連串的處理，得到在拉伸的熱可塑性樹脂膜層上形成的偏光膜，將該拉伸的熱可塑性樹脂膜層剝離的方法。 As an example of the method (2) for producing a polarizing film of the present invention, first, an insolubilization treatment is performed on a laminate having a PVA layer not containing a dichroic pigment, and a swelling treatment is further performed if necessary, and then, by Contact the chromatic pigments to make the PVA layer contain dichroic pigments, and further apply a cross-linking treatment if necessary, stretch the obtained laminate to be 5.7 times or more, and further apply a fixed treatment if necessary, and dry. A method of obtaining a polarizing film formed on the stretched thermoplastic resin film layer by such a series of processes, and peeling the stretched thermoplastic resin film layer.

PVA層之不溶化處理，主要係為了防止PVA層所包含的PVA對水之溶出而進行。作為該不溶化處理，例如，可舉出對於積層體實施熱處理的方法、或將積層體浸漬於包含硼酸、硼砂等之硼酸鹽等之硼化合物的1種或2種以上之水溶液的方法。該等之中，因為對於積層體實施熱處理的話，伴隨熱可塑性樹脂膜層之尺 寸變化，有造成皺紋的情況，所以使用包含硼化合物之水溶液的方法為佳。前述熱處理，例如，可在80℃以上200℃以下之範圍內的溫度進行。從防止皺紋的觀點，熱處理係一邊對積層體施加張力一邊進行為佳。又，在使用包含硼化合物之水溶液的方法中，其水溶液的溫度在20℃以上40℃以下的範圍內為佳，22℃以上較佳，25℃以上更佳，又，38℃以下較佳，35℃以下更佳。藉由使該溫度成為20℃以上40℃以下的範圍內，可防止PVA之溶解並有效地不溶化。作為浸漬於包含硼化合物之水溶液的時間，例如為0.1分鐘以上5分鐘以下的範圍內。藉由在0.1分鐘以上5分鐘以下的範圍內，可有效地不溶化。包含硼化合物之水溶液中的硼化合物之濃度係0.5質量%以上為佳，1.0質量%以上較佳，1.5質量%以上更佳，又，6.0質量%以下為佳，5.0質量%以下較佳，4.0質量%以下更佳。藉由使該濃度在0.5質量%以上6.0質量%以下的範圍內，可防止PVA之溶解並有效地不溶化。 The insolubilization treatment of the PVA layer is mainly performed in order to prevent the PVA contained in the PVA layer from leaching out of water. Examples of the insolubilization treatment include a method of heat-treating the laminate, or a method of immersing the laminate in an aqueous solution of one or two or more kinds of boron compounds such as boric acid such as boric acid and borax. Among these, if the laminated body is heat-treated, the size of the thermoplastic resin film layer is accompanied. In order to change the size and cause wrinkles, it is better to use an aqueous solution containing a boron compound. The heat treatment may be performed at a temperature in a range of 80 ° C. to 200 ° C., for example. From the viewpoint of preventing wrinkles, the heat treatment is preferably performed while applying tension to the laminated body. In the method using an aqueous solution containing a boron compound, the temperature of the aqueous solution is preferably in a range of 20 ° C to 40 ° C, more preferably 22 ° C or higher, more preferably 25 ° C or higher, and further preferably 38 ° C or lower. More preferably below 35 ° C. By setting the temperature in the range of 20 ° C to 40 ° C, the dissolution of PVA can be prevented and effectively insolubilized. The time of immersion in an aqueous solution containing a boron compound is, for example, in a range of 0.1 minutes to 5 minutes. When it is in the range of 0.1 minutes to 5 minutes, it can effectively be insoluble. The concentration of the boron compound in the aqueous solution containing the boron compound is preferably 0.5% by mass or more, more preferably 1.0% by mass or more, more preferably 1.5% by mass or more, more preferably 6.0% by mass or less, preferably 5.0% by mass or less, 4.0 It is more preferably less than mass%. When the concentration is in the range of 0.5% by mass to 6.0% by mass, the dissolution of PVA can be prevented and effectively insolubilized.

PVA層之不溶化處理，係在使二色性色素接觸的處理之前，進一步在膨潤處理之前進行為佳。 The insolubilization treatment of the PVA layer is preferably performed before the treatment for contacting the dichroic pigment and before the swelling treatment.

作為偏光膜之製造方法(2)的膨潤處理、使二色性色素接觸的處理(染色)、及交聯處理之各說明，因為可直接採用在偏光膜之製造方法(1)的說明欄中前述膨潤處理、使二色性色素接觸的處理(染色)、及交聯處理之各說明，所以在此省略重複的記載。 The descriptions of the swelling process, the process of contacting the dichroic pigment (dyeing), and the cross-linking process as the manufacturing method (2) of the polarizing film can be directly used in the description column of the manufacturing method (1) of the polarizing film. Each of the swelling treatment, the treatment (dyeing) for bringing the dichroic dye into contact, and the cross-linking treatment will be described, and therefore redundant descriptions are omitted here.

在偏光膜之製造方法(2)中，將積層體拉伸之際的拉伸方法並沒有特別限制，亦可以濕式拉伸法及乾 式拉伸法中之任一者進行。濕式拉伸法的情況中，亦可在包含硼酸、硼砂等之硼酸鹽等之硼化合物的1種或2種以上之水溶液中進行，也可在前述之包含二色性色素的溶液中或後述之固定處理浴中進行。又，乾式拉伸法的情況中，可直接在室溫進行拉伸，亦可一邊加熱一邊進行拉伸，也可在吸水後拉伸。該等之中，從得到的偏光膜之寬方向的厚度之均勻性的觀點，以濕式拉伸法為佳，在硼酸水溶液中拉伸較佳。硼酸水溶液中之硼酸的濃度在0.5質量%以上6.0質量%以下的範圍內為佳，該濃度為1.0質量%以上較佳，1.5質量%以上更佳，又，5.0質量%以下較佳，4.0質量%以下更佳。藉由使硼酸的濃度在0.5質量%以上6.0質量%以下的範圍內，可得到寬方向的厚度之均勻性佳的偏光膜。前述之包含硼化合物的水溶液可含有碘化鉀，其濃度在0.01質量%以上10質量%以下的範圍內為佳。藉由使碘化鉀的濃度在0.01質量%以上10質量%以下的範圍內，可得到偏光性能更為良好的偏光膜。 In the manufacturing method (2) of the polarizing film, the stretching method when the laminated body is stretched is not particularly limited, and a wet stretching method and a dry method may be used. It is performed by any one of the stretching methods. In the case of the wet stretching method, it may be performed in an aqueous solution containing one or two or more kinds of boron compounds such as boric acid such as boric acid and borax, or in a solution containing a dichroic pigment as described above or Performed in a fixed treatment bath described later. In the case of the dry stretching method, stretching may be performed directly at room temperature, stretching may be performed while heating, or stretching may be performed after absorbing water. Among these, from the viewpoint of the uniformity of the thickness in the width direction of the obtained polarizing film, a wet stretching method is preferred, and stretching in a boric acid aqueous solution is preferred. The concentration of boric acid in the boric acid aqueous solution is preferably within a range of 0.5% by mass to 6.0% by mass. The concentration is preferably 1.0% by mass or more, more preferably 1.5% by mass or more, and preferably 5.0% by mass or less, and 4.0% by mass. % Is better. When the concentration of the boric acid is in the range of 0.5% by mass to 6.0% by mass, a polarizing film having excellent thickness uniformity in a wide direction can be obtained. The aforementioned boron compound-containing aqueous solution may contain potassium iodide, and its concentration is preferably within a range of 0.01% by mass to 10% by mass. When the concentration of potassium iodide is in the range of 0.01% by mass or more and 10% by mass or less, a polarizing film having better polarizing performance can be obtained.

將積層體拉伸之際的溫度在30℃以上90℃以下的範圍內為佳，該溫度為40℃以上較佳，50℃以上更佳，又，80℃以下較佳，70℃以下更佳。藉由使該溫度在30℃以上90℃以下的範圍內，可得到寬方向的厚度之均勻性佳的偏光膜。 The temperature when the laminate is stretched is preferably within a range of 30 ° C to 90 ° C. The temperature is preferably 40 ° C or higher, more preferably 50 ° C or higher, more preferably 80 ° C or lower, and more preferably 70 ° C or lower. . By setting the temperature in a range of 30 ° C. to 90 ° C., a polarizing film having excellent thickness uniformity in a wide direction can be obtained.

本發明的偏光膜之製造方法(2)中，需要將積層體拉伸為5.7倍以上，拉伸為5.8倍以上為佳，拉伸為5.9倍以上較佳。藉由使積層體的拉伸倍率在前述的範圍 內，可順利且簡便地製造基體之雙折射率較習知高且偏光性能佳，同時在正交偏光狀態的紅色光之洩漏少的偏光膜(2)。積層體之拉伸倍率的上限並沒有特別限制，但8倍以下為佳。積層體之拉伸可進行一次，亦可分成多次進行，兩者均可，但在分成多次進行時，只要各拉伸之拉伸倍率相乘的總拉伸倍率在前述範圍內即可。再者，本說明書的拉伸倍率係基於拉伸前之積層體的長度者，且未進行拉伸的狀態相當於拉伸倍率1倍。 In the manufacturing method (2) of the polarizing film of the present invention, the laminated body needs to be stretched at least 5.7 times, preferably at least 5.8 times, and more preferably at least 5.9 times. By setting the stretch ratio of the laminate to the aforementioned range In addition, a polarizing film (2) having a higher birefringence than conventional and good polarization performance and a small leakage of red light in the orthogonal polarization state can be manufactured smoothly and simply. The upper limit of the stretch ratio of the laminated body is not particularly limited, but it is preferably 8 times or less. The stretching of the laminated body can be performed once or divided into multiple times, both of which can be performed, but when divided into multiple times, as long as the total stretching ratio multiplied by the stretching ratio of each stretching is within the foregoing range . In addition, the stretching ratio in this specification is based on the length of the laminated body before stretching, and the state in which stretching is not performed is equivalent to 1 times the stretching ratio.

積層體之拉伸，從得到的偏光膜之性能的觀點，單軸拉伸較為理想。在將長條的積層體拉伸時之單軸拉伸的方向並沒有特別限制，可採用對於長條方向之單軸拉伸或橫單軸拉伸，但從可得到偏光性能更佳的偏光膜之觀點，對於長條方向的單軸拉伸較為理想。對於長條方向的單軸拉伸，可藉由使用具備相互平行的多個輥之拉伸裝置，並改變各輥間之周速而進行。另一方面，橫單軸拉伸可使用拉幅型拉伸機進行。 The stretching of the laminated body is preferably uniaxial stretching from the viewpoint of the performance of the obtained polarizing film. The direction of uniaxial stretching when stretching the long laminated body is not particularly limited. Uniaxial stretching in the longitudinal direction or transverse uniaxial stretching can be used, but polarized light with better polarization performance can be obtained from The viewpoint of a film is ideal for uniaxial stretching in a long direction. Uniaxial stretching in the longitudinal direction can be performed by using a stretching device having a plurality of rolls parallel to each other and changing the peripheral speed between the rolls. On the other hand, transverse uniaxial stretching can be performed using a tenter-type stretching machine.

作為偏光膜之製造方法(2)的固定處理、及乾燥之各說明，因為可直接採用在偏光膜之製造方法(1)的說明欄中前述固定處理、及乾燥之各說明，所以在此省略重複的記載。 The descriptions of the fixing process and drying of the polarizing film manufacturing method (2) can be directly used in the description column of the manufacturing method (1) of the polarizing film, and the respective descriptions of the fixing processing and drying can be directly omitted. Duplicate record.

藉由如前述進行，可得到在拉伸的熱可塑性樹脂膜層上形成的偏光膜(2)。如前述之形態的偏光膜之使用方法並沒有特別限制，例如，亦可不將拉伸的熱可塑性樹脂膜層剝離，將其直接或根據所需在偏光膜側貼合光學上為透明且具有機械強度的保護膜而作為偏光 板，亦可在與拉伸的熱可塑性樹脂膜層所在側為相反之側貼合保護膜後，將該拉伸的熱可塑性樹脂膜層剝離，將其直接或根據所需在剝離面貼合另一保護膜而作為偏光板。作為保護膜，可使用三醋酸纖維素(TAC)膜、乙酸．丁酸纖維素(CAB)膜、丙烯酸系膜、聚酯系膜等。又，作為用以貼合的黏著劑，可舉出PVA系黏著劑或胺基甲酸酯系黏著劑等，但PVA系黏著劑較佳。 By performing as described above, a polarizing film (2) formed on the stretched thermoplastic resin film layer can be obtained. The method of using the polarizing film in the aforementioned form is not particularly limited. For example, the stretched thermoplastic resin film layer may not be peeled off, and it may be bonded directly or as required on the polarizing film side to be optically transparent and mechanical. Strong protective film as polarized light Sheet, the protective film may be pasted on the side opposite to the stretched thermoplastic resin film layer, and then the stretched thermoplastic resin film layer may be peeled off, and the peeled surface may be bonded directly or as required The other protective film functions as a polarizing plate. As the protective film, cellulose triacetate (TAC) film, acetic acid can be used. Cellulose butyrate (CAB) film, acrylic film, polyester film, etc. Examples of the adhesive used for bonding include PVA-based adhesives and urethane-based adhesives. PVA-based adhesives are preferred.

[實施例] [Example]

根據以下的實施例進一步具體地說明本發明，但本發明並沒有限定於該等之實施例。再者，在以下參考例、實施例及比較例中採用的各測定或評價方法係示於下述。 The present invention will be described more specifically based on the following examples, but the present invention is not limited to these examples. The measurement or evaluation methods used in the following Reference Examples, Examples, and Comparative Examples are shown below.

[熱可塑性樹脂膜之表面的接觸角之測定] [Measurement of the contact angle on the surface of a thermoplastic resin film]

使用協和界面科學股份有限公司製「DropMaster500」，在20℃、65%RH之環境下，自內徑0.4mm的針將2μL的純水擠出至熱可塑性樹脂膜的表面，並測定接觸角。 "DropMaster500" manufactured by Kyowa Interface Science Co., Ltd. was used to extrude 2 μL of pure water from a needle with an inner diameter of 0.4 mm to the surface of a thermoplastic resin film under an environment of 20 ° C and 65% RH, and the contact angle was measured.

[PVA層的膨潤度之測定] [Measurement of swelling degree of PVA layer]

將以下的實施例或比較例所得到的積層體切為適當的大小(例如300cm2左右)，並浸漬於30℃之1,000g的蒸餾水30分鐘。之後，取出積層體，以濾紙擦取表面的水，並測定質量(將其質量作為A)。接著，將該積層體於105℃乾燥16小時，測定質量(將其質量作為B)。再者，將乾燥後的積層體於95℃的熱水煮沸6小時使PVA層溶解，將殘留的熱可塑性樹脂膜層於105℃乾 燥16小時，並測定質量(將其質量作為C)。PVA層的膨潤度S(%)，係以下述式(4)算出。 The laminates obtained in the following examples or comparative examples were cut to an appropriate size (for example, about 300 cm 2 ), and immersed in 1,000 g of distilled water at 30 ° C. for 30 minutes. After that, the laminated body was taken out, and the surface water was wiped with a filter paper, and the mass was measured (the mass was taken as A). Next, this laminated body was dried at 105 degreeC for 16 hours, and the mass was measured (the mass was made into B). Furthermore, the dried laminated body was boiled in hot water at 95 ° C for 6 hours to dissolve the PVA layer, and the remaining thermoplastic resin film layer was dried at 105 ° C for 16 hours, and the mass was measured (the mass was taken as C). The swelling degree S (%) of the PVA layer is calculated by the following formula (4).

S=100×(A-C)/(B-C) (4) S = 100 × (A-C) / (B-C) (4)

[PVA的平均聚合度之測定] [Measurement of average polymerization degree of PVA]

依據JIS K6726-1994之記載測定。但是，作為試驗溶液，係使用藉由將PVA0.28g、蒸餾水70g、及攪拌子投入100mL的可互換磨口接頭三角燒瓶並塞住，浸漬於95℃的恆溫槽，一邊以攪拌子攪拌一邊溶解PVA，成為濃度約0.4質量%的PVA水溶液，將其以布赫納漏斗形玻璃過濾器3G過濾，且於30℃的恆溫水槽中冷卻者。 Measured according to JIS K6726-1994. However, as a test solution, 0.28 g of PVA, 70 g of distilled water, and a stirrer were put into a 100 mL interchangeable mill-mouthed conical flask and stoppered. The test solution was immersed in a 95 ° C thermostat and dissolved while stirring with a stirrer PVA is a PVA aqueous solution having a concentration of about 0.4% by mass, which is filtered by a Buchner funnel-shaped glass filter 3G and cooled in a constant-temperature water tank at 30 ° C.

[偏光膜的厚度之測定(1)] [Measurement of thickness of polarizing film (1)]

使用Digital Gauge(Magnescale公司製「DE12BR」)，測定在偏光膜之任意位置(5處)的厚度，並將其平均值作為偏光膜的厚度(1)。 Digital Gauge ("DE12BR" manufactured by Magnescale) was used to measure the thickness at any position (5 places) of the polarizing film, and the average value was used as the thickness of the polarizing film (1).

[基體的雙折射率之測定] [Measurement of the birefringence of the substrate]

關於以下參考例、實施例或比較例所得到的偏光膜，使用晶胞間隙檢查裝置(大塚電子股份有限公司製「RETS-1100」)，利用波長800nm及1,000nm之光測定阻滯值。測定位置，定為通過偏光膜之寬方向(相對於單軸拉伸的方向，垂直的膜面內之方向)的中央部之長度方向(單軸拉伸的方向)的直線上之任意5點。然後，將利用波長800nm之光測定的5個阻滯值的平均值作為前述式(2’)的R800，將利用波長1,000nm之光測定的5個阻滯值的平均值作為前述式(2”)的R1000，解出前述式 (2’)、(3’)、(2”)及(3”)的聯立方程式，求出為基體的阻滯值之A(單位：nm)，藉由將其除以後述的「偏光膜的厚度之測定(2)」所測定之偏光膜的厚度(5處的平均值，將單位換算為nm者)，求得基體的雙折射率。 Regarding the polarizing films obtained in the following reference examples, examples, or comparative examples, a cell gap inspection device ("RETS-1100" manufactured by Otsuka Electronics Co., Ltd.) was used to measure the retardation value using light having a wavelength of 800 nm and 1,000 nm. The measurement position is set to any five points on a straight line passing through the central portion of the polarizing film in the width direction (the direction in which the film is uniaxially stretched, and the direction perpendicular to the film surface). . Then, an average value of five retardation values measured by light with a wavelength of 800 nm is used as R 800 in the aforementioned formula (2 ′), and an average value of five retardation values measured by light with a wavelength of 1,000 nm is used as the aforementioned formula ( 2 ”) of R 1000 , solve the simultaneous equations of the aforementioned formulae (2 ′), (3 ′), (2”), and (3 ”), and find A (unit: nm) as the retardation value of the matrix The birefringence of the substrate was determined by dividing the thickness of the polarizing film (average of 5 places, the unit is converted to nm) measured by "Measurement of the thickness of the polarizing film (2)" described later.

[偏光膜的厚度之測定(2)] [Determination of thickness of polarizing film (2)]

使用D igital Gauge(Magnescale公司製「DE12BR」)，測定在前述基體的雙折射率之測定的阻滯值之測定位置(5處)的偏光膜之厚度，並將其平均值作為偏光膜的厚度(2)。 Using Digi Gauge ("DE12BR" by Magnescale), the thickness of the polarizing film at the measurement position (5 places) of the retardation value of the birefringence of the substrate was measured, and the average value was used as the thickness of the polarizing film. (2).

[偏光性能之評價] [Evaluation of Polarization Performance] (a)透射率Ts之測定 (a) Measurement of transmittance Ts

由以下實施例或比較例所得到的偏光膜之寬方向的中央部，採取偏光膜的寬方向2cm×長度方向2cm之正方形的樣本2片，使用附有積分球的分光光度計(日本分光股份有限公司製「V7100」)，依據JIS Z 8722(物體色的測定方法)，進行C光源、2°視野之可見光領域的視感度補正，對於1片的樣本，測定相對於長度方向傾斜45°時的光之透射率與傾斜-45°時的光之透射率，並求得該等之平均值Ts1(%)。對於另1片的樣本也同樣進行，測定傾斜45°時的光之透射率與傾斜-45°時的光之透射率，並求得該等之平均值Ts2(%)。根據下述式(5)平均Ts1與Ts2，作為偏光膜的透射率Ts(%)。 In the central part of the polarizing film obtained in the following examples or comparative examples, two samples of a square of the polarizing film in a width direction of 2 cm × a length direction of 2 cm were used, and a spectrophotometer with an integrating sphere (Japan Spectroscopy Corporation) was used. "V7100" manufactured by Co., Ltd.), in accordance with JIS Z 8722 (method for measuring the color of an object), the visual sensitivity of the C light source and visible light in a 2 ° field of view is corrected. The transmittance of light and the transmittance of light at an inclination of -45 °, and the average value Ts1 (%) of these was obtained. The same was done for the other sample, and the transmittance of light at a tilt of 45 ° and the transmittance of light at a tilt of -45 ° were measured, and the average Ts2 (%) of these was obtained. The average Ts1 and Ts2 according to the following formula (5) was taken as the transmittance Ts (%) of the polarizing film.

Ts=(Ts1+Ts2)/2 (5) Ts = (Ts1 + Ts2) / 2 (5)

(b)偏光度V之測定 (b) Measurement of polarization degree V

將前述透射率Ts之測定所採取的2片之樣本，將使其長度方向成為平行而重疊時的光之透射率T ∥(%)、使長度方向為正交而重疊時的光之透射率T ⊥(%)，與前述「(a)透射率Ts之測定」時同樣進行而測定，並根據下述式(6)求得偏光度V(%)。 The two samples taken for the measurement of the transmittance Ts described above were made such that the longitudinal directions of the light transmittance T ∥ (%) were parallel and overlapping, and the transmittances of the light when the longitudinal directions were orthogonal and overlapped. T ⊥ (%) was measured in the same manner as in the above-mentioned "(a) Measurement of transmittance Ts", and the degree of polarization V (%) was obtained according to the following formula (6).

V={(T ∥-T ⊥)/(T ∥+T ⊥)}1/2×100 (6) V = ((T ∥-T ⊥) / (T ∥ + T ⊥)) 1/2 × 100 (6)

(c)透射率44%時的二色性比之算出 (c) Calculation of dichroism ratio at 44% transmittance

在以下的各實施例及比較例中，將對含有碘系色素的水溶液之浸漬時間在1~2分鐘的範圍內，由1分鐘開始變更4次，並進行同樣的操作，製造與各實施例或比較例所製造的偏光膜之二色性色素的吸附量不同的4片之偏光膜。針對該等4片之偏光膜，各自以前述的方法求出透射率Ts(%)及偏光度V(%)，且每個實施例及比較例，係將透射率Ts(%)作為橫軸、偏光度V(%)作為縱軸，並將基於各實施例或比較例所得到的偏光膜之透射率Ts(%)及偏光度V(%)為1點，將其包含在內合計5點作圖為圖表求出近似曲線，並從該近似曲線求得透射率Ts(%)為44%時的偏光度V44(%)。 In each of the following examples and comparative examples, the immersion time of an iodine-based pigment-containing aqueous solution was in the range of 1 to 2 minutes, and the change was performed 4 times from 1 minute, and the same operation was performed to produce and each example. Or the polarizing film of the four polarizing films of the polarizing film manufactured by the comparative example which differed in the adsorption amount of the dichroic dye. For the four polarizing films, the transmittance Ts (%) and the polarization degree V (%) were obtained by the methods described above, and the transmittance Ts (%) was used as the horizontal axis in each of the examples and comparative examples. And the degree of polarization V (%) is taken as the vertical axis, and the transmittance Ts (%) and the degree of polarization V (%) of the polarizing films obtained based on the respective examples or comparative examples are taken as one point, including them in total 5 The point plot is a graph to obtain an approximate curve, and the degree of polarization V 44 (%) when the transmittance Ts (%) is 44% is obtained from the approximate curve.

由得到的偏光度V44(%)，根據下述式(7)求出透射率44%時的二色性比，並作為偏光性能的指標。 From the obtained polarization degree V 44 (%), a dichroism ratio at a transmittance of 44% was obtained according to the following formula (7), and used as an index of polarization performance.

透射率44%時之二色性比=log(44/100-44/100×V44/100)/log(44/100+44/100×V44/100) (7) 44% of the transmittance of the dichroic ratio = log (44 / 100-44 / 100 × V 44/100) / log (44/100 + 44/100 × V 44/100) (7)

[正交偏光狀態之紅色光的洩漏之評價] [Evaluation of Red Light Leakage in Cross Polarized State]

以下之每個實施例及比較例中，針對各實施例或比較例所得到的偏光膜1片、與前述偏光性能之評價的「(c)透射率44%時的二色性比之算出」所得到的偏光膜4片之合計5片的偏光膜，測定波長700nm的光之正交透射率T700 ⊥(%)。亦即，針對前述偏光性能的評價所得到之5組的樣本，各自使2片的樣本以長度方向正交而重疊，使用附有積分球的分光光度計(日本分光股份有限公司製「V7100」)，測定相對於一方的樣本之長度方向傾斜45。時之波長700nm的光之透射率與傾斜-45°時之波長700nm的光之透射率，並將該等之平均值作為T700 ⊥(%)。 In each of the following examples and comparative examples, "(c) Calculation of dichroic ratio at 44% transmittance" for one polarizing film obtained in each of the examples or comparative examples and the aforementioned evaluation of polarizing performance A total of 5 polarizing films of 4 polarizing films were obtained, and the orthogonal transmittance T 700 ⊥ (%) of light having a wavelength of 700 nm was measured. That is, for the five groups of samples obtained from the evaluation of the polarization performance, two samples of each were orthogonally overlapped in the longitudinal direction, and a spectrophotometer with an integrating sphere ("V7100", manufactured by JASCO Corporation) was used. ), And measure 45 with respect to the longitudinal direction of one sample. The transmittance of light at a wavelength of 700 nm at time and the transmittance of light at a wavelength of 700 nm at a slope of -45 ° are taken as the average value of T 700 ⊥ (%).

然後，將前述偏光性能的評價所求得之透射率Ts(%)作為橫軸、波長700nm的光之正交透射率T700 ⊥(%)作為縱軸，並將合計5點作圖為圖表求出近似曲線，並從該近似曲線求得透射率Ts(%)為44%時之波長700nm的光之正交透射率T700 ⊥ 44(%)。該T700 ⊥ 44(%)低時，係評價為紅色光之洩漏少。 Then, the transmittance Ts (%) obtained by the evaluation of the polarization performance is taken as the horizontal axis and the orthogonal transmittance T 700 ⊥ (%) of light with a wavelength of 700 nm is taken as the vertical axis, and a total of 5 points are plotted as a graph. An approximate curve was obtained, and the orthogonal transmittance T 700 ⊥ 44 (%) of light having a wavelength of 700 nm when the transmittance Ts (%) was 44% was obtained from the approximate curve. When the T 700 ⊥ 44 (%) is low, it is evaluated that there is little leakage of red light.

[實施例1] [Example 1] (1)熱可塑性樹脂膜之親水化處理 (1) Hydrophilic treatment of thermoplastic resin film

使用非晶質聚對苯二甲酸乙二酯膜(帝人化成股份有限公司製A-PET薄片FR厚度150μm)作為熱可塑性樹脂膜，在熱可塑性樹脂膜之單面以放電量280W．分鐘/m2(輸出280W/m、處理速度1.0m/分鐘)進行電暈處理。電暈處理後的熱可塑性樹脂膜之表面的接觸角為60°(電暈處理前的接觸角為79°)。 An amorphous polyethylene terephthalate film (A-PET sheet FR thickness 150 μm made by Teijin Chemicals Co., Ltd.) was used as a thermoplastic resin film, and the discharge capacity was 280 W on one side of the thermoplastic resin film. Corona treatment was performed per minute / m 2 (output of 280 W / m and processing speed of 1.0 m / minute). The contact angle on the surface of the thermoplastic resin film after the corona treatment was 60 ° (the contact angle before the corona treatment was 79 °).

(2)原液之製備 (2) Preparation of stock solution

製備含有平均聚合度2,400、皂化度99.8莫耳%、乙烯含量2.5莫耳%、1,2-二醇鍵結量1.6莫耳%之PVA(乙酸乙烯酯與乙烯的共聚物之皂化物)100質量份、作為可塑劑之甘油6質量份及水的PVA濃度為10質量%之水溶液，並作為用於形成PVA層的原液。 Preparation of PVA (Saponification of copolymer of vinyl acetate and ethylene) containing an average degree of polymerization of 2,400, a degree of saponification of 99.8 mole%, an ethylene content of 2.5 mole%, and a 1,2-diol bond amount of 1.6 mole% An aqueous solution of 6 parts by mass of glycerin as a plasticizer and a PVA concentration of 10% by mass of water was used as a stock solution for forming a PVA layer.

(3)積層體之製作 (3) Production of laminated body

藉由在(1)進行親水化處理之熱可塑性樹脂膜的電暈處理面，使用模塗機將(2)所製備的原液塗布後，於80℃乾燥240秒鐘，製作含有非晶質聚對苯二甲酸乙二酯膜層與厚度為6μm之PVA層的2層結構之積層體(寬0.5m之長條的積層體)。關於得到的積層體，係進行PVA層的膨潤度之測定。結果係示於表1。 The corona-treated surface of the thermoplastic resin film (1) subjected to a hydrophilization treatment was coated with a stock solution prepared in (2) using a die coater and dried at 80 ° C. for 240 seconds to prepare an amorphous polymer. A laminate of a two-layer structure of a film of ethylene terephthalate and a PVA layer having a thickness of 6 μm (a long laminate of 0.5 m in width). About the obtained laminated body, the swelling degree of the PVA layer was measured. The results are shown in Table 1.

(4)偏光膜之製造 (4) Manufacturing of polarizing film

相對於(3)製作的積層體，係將膨潤處理、染色、單軸拉伸、乾燥處理依照該順序實施而製造偏光膜。亦即，將積層體浸漬於蒸餾水1分鐘作為膨潤處理。接著，浸漬於含有碘系色素的水溶液(使用的碘之濃度：0.3質量%、使用的碘化鉀之濃度：2.1質量%、溫度：30℃)1分鐘並使PVA層含有碘系色素。其次，在硼酸水溶液(硼酸濃度：4質量%、碘化鉀濃度：6質量%、溫度：65℃)中朝長條方向單軸拉伸直到極限。再者，預先以同樣的方法拉伸，並確定斷裂的倍率，將低於其斷裂的倍率0.20倍的倍率作為前述的極限。之後，在60℃乾燥1分鐘，得到在拉伸的非晶質聚對苯二甲酸乙二酯膜層上形成的 偏光膜。由此將拉伸的非晶質聚對苯二甲酸乙二酯層剝離，對於得到的偏光膜，進行厚度(1)及偏光性能的各測定或評價。將結果與採用的拉伸倍率一起示於表1。 With respect to the multilayer body produced in (3), a swelling treatment, dyeing, uniaxial stretching, and drying treatment are performed in this order to produce a polarizing film. That is, the laminated body was immersed in distilled water for 1 minute as a swelling treatment. Next, it was immersed in an aqueous solution containing iodine-based pigment (concentration of iodine used: 0.3% by mass, concentration of potassium iodide used: 2.1% by mass, temperature: 30 ° C.) for 1 minute, and the PVA layer contained the iodine-based pigment. Next, it was uniaxially stretched in a long direction to the limit in an aqueous boric acid solution (boric acid concentration: 4% by mass, potassium iodide concentration: 6% by mass, temperature: 65 ° C). Furthermore, the same method was used to stretch beforehand, and the breaking magnification was determined, and a magnification of 0.20 times lower than the breaking magnification was taken as the aforementioned limit. Thereafter, it was dried at 60 ° C for 1 minute to obtain a film formed on the stretched amorphous polyethylene terephthalate film layer. Polarizing film. Thereby, the stretched amorphous polyethylene terephthalate layer was peeled off, and each of the obtained polarizing films was subjected to each measurement or evaluation of thickness (1) and polarization performance. The results are shown in Table 1 together with the draw ratio used.

[實施例2~4] [Examples 2 to 4]

使PVA之乙烯含量及1,2-二醇鍵結量成為如表1所示，此外係與實施例1同樣進行，得到積層體，並進行PVA層的膨潤度之測定，同時由其積層體得到偏光膜(將拉伸的非晶質聚對苯二甲酸乙二酯層剝離者)，進行厚度(1)及偏光性能之各測定或評價。將結果與採用的拉伸倍率一起示於表1。 The ethylene content and the 1,2-diol bond amount of PVA were as shown in Table 1. The laminate was obtained in the same manner as in Example 1, and the swelling degree of the PVA layer was measured. A polarizing film (a peeled amorphous polyethylene terephthalate layer was obtained) was obtained, and each measurement or evaluation of thickness (1) and polarizing performance was performed. The results are shown in Table 1 together with the draw ratio used.

[比較例1] [Comparative Example 1]

使PVA之乙烯含量為如表1所示，此外係與實施例1同樣進行，得到積層體，並進行PVA層的膨潤度之測定。又，與實施例1同樣進行，欲由其積層體製作偏光膜時，因為在膨潤處理時PVA層所含的PVA溶出，所以無法製作偏光膜。結果係示於表1。 The ethylene content of PVA was as shown in Table 1. The procedure was the same as in Example 1 to obtain a laminate, and the swelling degree of the PVA layer was measured. Further, it was carried out in the same manner as in Example 1. When a polarizing film was to be produced from the laminated body, the PVA contained in the PVA layer was eluted during the swelling treatment, so that a polarizing film could not be produced. The results are shown in Table 1.

[比較例2] [Comparative Example 2]

使PVA之乙烯含量為如表1所示，此外係與實施例1同樣進行，得到積層體，並進行PVA層的膨潤度之測定。又，與實施例1同樣進行，由其積層體製作偏光膜時，因為染色性不佳，且有斑，所以僅進行厚度(1)之測定，沒有進行偏光性能之評價。將結果與採用的拉伸倍率一起示於表1。 The ethylene content of PVA was as shown in Table 1. The procedure was the same as in Example 1 to obtain a laminate, and the swelling degree of the PVA layer was measured. In addition, it was carried out in the same manner as in Example 1. When the polarizing film was produced from the laminated body, because the dyeability was poor and there were spots, only the measurement of the thickness (1) was performed, and the polarization performance was not evaluated. The results are shown in Table 1 together with the draw ratio used.

實施例1~4中，PVA層的膨潤度在180%以上260%以下的範圍內，因此不論是否預先進行對硼酸水溶液之浸漬或空中高溫拉伸之不溶化處理，均可製造偏光性能佳的偏光膜。另一方面，比較例1中，PVA層的膨潤度高於260%，因此在偏光膜製造時PVA層所含的PVA溶出，無法製作偏光膜，又，比較例2中，PVA層的膨潤度低於180%，因此成為有斑的偏光膜。 In Examples 1 to 4, the swelling degree of the PVA layer is in the range of 180% to 260%. Therefore, regardless of whether the dilute aqueous solution of boric acid or the insolubilization treatment at high temperature in the air is performed in advance, polarized light with good polarization performance can be produced. membrane. On the other hand, in Comparative Example 1, the degree of swelling of the PVA layer was higher than 260%. Therefore, the PVA contained in the PVA layer was eluted during the manufacture of the polarizing film, and a polarizing film could not be produced. In Comparative Example 2, the degree of swelling of the PVA layer Below 180%, it becomes a speckled polarizing film.

[參考例1] [Reference Example 1]

將含有平均聚合度2,400、皂化度99.8莫耳%之PVA(乙酸乙烯酯的單獨聚合物之皂化物)100質量份、作為可塑劑之甘油12質量份及水之揮發分率66質量%之水溶液作為原液，將其由T型模在95℃之第1乾燥輥上吐出為膜狀，於第1乾燥輥上乾燥直到揮發分率成為22質量%，並自第1乾燥輥剝離，藉由後續的多個80℃的乾燥輥進一步進行乾燥後，藉由110℃的熱處理輥進行熱處理，得到厚度60μm之單層的PVA膜(寬0.5m之長條的膜) An aqueous solution containing 100 parts by mass of PVA (saponification of a separate polymer of vinyl acetate) having an average degree of polymerization of 2,400 and a degree of saponification of 99.8 mol%, 12 parts by mass of glycerin as a plasticizer, and 66% by mass of volatile matter in water As a raw solution, it was discharged into a film form from a T-die on a first drying roll at 95 ° C., and dried on the first drying roll until the volatile matter ratio became 22% by mass, and was peeled off from the first drying roll. A plurality of 80 ° C drying rollers were further dried and then heat-treated by a 110 ° C heat treatment roller to obtain a single-layer PVA film (a long film having a width of 0.5m) having a thickness of 60 μm.

相對於該PVA膜，將膨潤處理、染色、單軸拉伸、乾燥處理依該順序實施而製造偏光膜。亦即，將PVA膜浸漬於30℃的水1分鐘。接著，浸漬於含有碘系色素的水溶液(使用的碘之濃度：0.3質量%、使用的碘化鉀之濃度：2.1質量%、溫度：30℃)1分鐘，使PVA層含有碘系色素。其次，在硼酸水溶液(硼酸濃度：4質量%、碘化鉀濃度：6質量%、溫度：55℃)中朝長條方向單軸拉伸直到極限。再者，預先以同樣的方法拉伸，並確定斷裂的倍率，將低於其斷裂的倍率0.20倍的倍率作為前述的極限。之後，在60℃乾燥4分鐘，得到偏光膜。對於該偏光膜，進行基體的雙折射率及厚度(2)之各測定。將結果與採用的拉伸倍率一起示於表2。 A polarizing film was produced by performing a swelling treatment, dyeing, uniaxial stretching, and drying treatment in this order on the PVA film. That is, the PVA film was immersed in water at 30 ° C for 1 minute. Next, it was immersed in an aqueous solution containing iodine-based pigment (concentration of iodine used: 0.3% by mass, concentration of potassium iodide used: 2.1% by mass, temperature: 30 ° C.) for 1 minute, so that the PVA layer contained the iodine-based pigment. Next, it was uniaxially stretched in a long direction in a boric acid aqueous solution (boric acid concentration: 4% by mass, potassium iodide concentration: 6% by mass, and temperature: 55 ° C) to the limit. Furthermore, the same method was used to stretch beforehand, and the breaking magnification was determined, and a magnification of 0.20 times lower than the breaking magnification was taken as the aforementioned limit. Then, it dried at 60 degreeC for 4 minutes, and obtained the polarizing film. About this polarizing film, each measurement of the birefringence and thickness (2) of a base body was performed. The results are shown in Table 2 together with the used draw ratio.

[參考例2~4] [Reference Examples 2 to 4]

使用具有表2所示之平均聚合度的PVA(皂化度99.8莫耳%、乙酸乙烯酯的單獨聚合物之皂化物)，除此之外係與參考例1同樣進行，得到偏光膜，並進行基體的雙折射率及厚度(2)之各測定。將結果與採用的拉伸倍率一起示於表2。 A polarizing film was obtained in the same manner as in Reference Example 1 except that PVA (Saponification degree of 99.8 mol%, saponified polymer of vinyl acetate alone) having an average polymerization degree shown in Table 2 was used. The birefringence and thickness (2) of the substrate were measured. The results are shown in Table 2 together with the used draw ratio.

由參考例1~4可明顯得知：在由單層之PVA膜製造偏光膜時，依據PVA的平均聚合度變高，可知極限拉伸倍率下降。又，藉由參考例1~4所得到的偏光膜中，基體的雙折射率低。 It is obvious from Reference Examples 1 to 4 that when a polarizing film is manufactured from a single-layer PVA film, the average degree of polymerization of PVA becomes higher, and it can be seen that the ultimate stretching ratio decreases. In the polarizing films obtained in Reference Examples 1 to 4, the birefringence of the substrate was low.

[實施例5] [Example 5] (1)熱可塑性樹脂膜之親水化處理 (1) Hydrophilic treatment of thermoplastic resin film

使用非晶質聚對苯二甲酸乙二酯膜(帝人化成股份有限公司製A-PET薄片FR厚度150μm)作為熱可塑性樹脂膜，在熱可塑性樹脂膜之單面以放電量280W．分鐘/m2(輸出280W/m、處理速度1.0m/分鐘)進行電暈處理。電暈處理後的熱可塑性樹脂膜之表面的接觸角為60°(電暈處理前的接觸角為79°)。 An amorphous polyethylene terephthalate film (A-PET sheet FR thickness 150 μm made by Teijin Chemicals Co., Ltd.) was used as a thermoplastic resin film, and the discharge capacity was 280 W on one side of the thermoplastic resin film. Corona treatment was performed per minute / m 2 (output of 280 W / m and processing speed of 1.0 m / minute). The contact angle on the surface of the thermoplastic resin film after the corona treatment was 60 ° (the contact angle before the corona treatment was 79 °).

(2)原液之製備 (2) Preparation of stock solution

製備含有平均聚合度5,500、皂化度99.8莫耳%的PVA(乙酸乙烯酯的單獨聚合物之皂化物)100質量份、作為可塑劑之甘油12質量份及水之PVA濃度為5質量%之水溶液，並作為用於形成PVA層的原液。 An aqueous solution containing 100 parts by mass of PVA (saponified product of a separate polymer of vinyl acetate) having an average polymerization degree of 5,500 and a saponification degree of 99.8 mol%, 12 parts by mass of glycerin as a plasticizer, and an aqueous solution having a PVA concentration of 5% by mass And as a stock solution for forming a PVA layer.

(3)積層體之製作 (3) Production of laminated body

藉由在(1)進行親水化處理之熱可塑性樹脂膜的電暈處理面，使用模塗機將(2)所製備的原液塗布後，於80℃乾燥240秒鐘，製作含有非晶質聚對苯二甲酸乙二酯膜層與厚度為6μm之PVA層的2層結構之積層體(寬0.5m之長條的積層體)。 The corona-treated surface of the thermoplastic resin film (1) subjected to a hydrophilization treatment was coated with a stock solution prepared in (2) using a die coater and dried at 80 ° C. for 240 seconds to prepare an amorphous polymer. A laminate of a two-layer structure of a film of ethylene terephthalate and a PVA layer having a thickness of 6 μm (a long laminate of 0.5 m in width).

(4)偏光膜之製造 (4) Manufacturing of polarizing film

對於(3)製作的積層體，係將PVA層之不溶化處理、染色、單軸拉伸、乾燥處理依照該順序實施而製造偏光膜。亦即，將積層體浸漬於硼酸水溶液(濃度：3質量%、溫度：30℃)1分鐘作為PVA層之不溶化處理。接著，浸漬於含有碘系色素的水溶液(使用的碘之濃度：0.3質量%、使用的碘化鉀之濃度：2.1質量%、溫度：30℃)1分鐘，使PVA層含有碘系色素。其次，在硼酸水溶液(硼酸濃度：4質量%、碘化鉀濃度：6質量%、溫度：65℃)中朝長條方向單軸拉伸直到極限。再者，預先以同樣的方法拉伸，並確定斷裂的倍率，將低於其斷裂的倍率0.20倍的倍率作為前述的極限。之後，在60℃乾燥1分鐘，得到在拉伸的非晶質聚對苯二甲酸乙二酯膜層上形成的偏光膜。由此將拉伸的非晶質聚對苯二甲酸乙二酯層剝離，對於得到的偏光膜，進行基體的雙折射率、厚度(2)、偏光性能及正交偏光狀態的紅色光之洩漏的各測定或評價。將結果與採用的拉伸倍率一起示於表3。 The laminated body prepared in (3) was subjected to insolubilization treatment, dyeing, uniaxial stretching, and drying treatment of the PVA layer in this order to produce a polarizing film. That is, the laminate was immersed in an aqueous boric acid solution (concentration: 3% by mass, temperature: 30 ° C) for 1 minute as an insolubilization treatment of the PVA layer. Next, it was immersed in an aqueous solution containing iodine-based pigment (concentration of iodine used: 0.3% by mass, concentration of potassium iodide used: 2.1% by mass, temperature: 30 ° C.) for 1 minute, so that the PVA layer contained the iodine-based pigment. Next, it was uniaxially stretched in a long direction to the limit in an aqueous boric acid solution (boric acid concentration: 4% by mass, potassium iodide concentration: 6% by mass, temperature: 65 ° C). Furthermore, the same method was used to stretch beforehand, and the breaking magnification was determined, and a magnification of 0.20 times lower than the breaking magnification was taken as the aforementioned limit. Then, it dried at 60 degreeC for 1 minute, and obtained the polarizing film formed on the stretched amorphous polyethylene terephthalate film layer. As a result, the stretched amorphous polyethylene terephthalate layer was peeled off, and the obtained polarizing film was subjected to leakage of red light of the substrate's birefringence, thickness (2), polarization performance, and orthogonal polarization state. Of each measurement or evaluation. The results are shown in Table 3 together with the draw ratio used.

[實施例6~14及比較例3~7] [Examples 6 to 14 and Comparative Examples 3 to 7]

使PVA(皂化度99.8莫耳%、乙酸乙烯酯的單獨聚合物之皂化物)的平均聚合度及甘油的含量為如表3所示，除此之外係與實施例5同樣進行，得到偏光膜(將拉伸的非晶質聚對苯二甲酸乙二酯層剝離者)，並進行基體的雙折射率、厚度(2)、偏光性能及正交偏光狀態的紅色光之洩漏的各測定或評價。將結果與採用的拉伸倍率一起示於表3。 The average degree of polymerization of PVA (saponification degree of 99.8 mol%, saponified polymer of vinyl acetate alone) and glycerol content were as shown in Table 3, except that the same procedure was performed as in Example 5 to obtain polarized light. Film (when the stretched amorphous polyethylene terephthalate layer is peeled off), and the birefringence, thickness (2), polarization performance, and red light leakage of the orthogonal polarization state of the substrate are measured Or evaluation. The results are shown in Table 3 together with the draw ratio used.

[比較例8及9] [Comparative Examples 8 and 9]

使PVA(皂化度99.8莫耳%、乙酸乙烯酯的單獨聚合物之皂化物)的平均聚合度及甘油的含量為如表3所示，同時將積層體的拉伸倍率定為5.00倍，除此之外係與實施例5同樣進行，得到偏光膜(將拉伸的非晶質聚對苯二甲酸乙二酯層剝離者)，並進行基體的雙折射率、厚度(2)、偏光性能及正交偏光狀態的紅色光之洩漏的各測定或評價。將結果與採用的拉伸倍率一起示於表3。 The average polymerization degree and glycerol content of PVA (saponification degree of 99.8 mol%, saponified polymer of vinyl acetate alone) were set as shown in Table 3, and the stretch ratio of the laminate was set to 5.00 times, except that Except for this, the same procedure as in Example 5 was performed to obtain a polarizing film (a peeled stretched amorphous polyethylene terephthalate layer), and the birefringence, thickness (2), and polarization performance of the substrate were obtained. And each measurement or evaluation of the leakage of red light in the crossed polarization state. The results are shown in Table 3 together with the draw ratio used.

藉由實施例5~14所得到的偏光膜中，基體的雙折射率高，如前述的偏光膜，可知其二色性比的值大且偏光性能佳，而且T700 ⊥ 44的值小且正交偏光狀態的 紅色光之洩漏少。另一方面，藉由比較例3~9得到的偏光膜中，可知基體的雙折射率低，二色性比的值小且偏光性能差，又，T700 ⊥ 44的值大且正交偏光狀態的紅色光之洩漏多。 According to the polarizing films obtained in Examples 5 to 14, the birefringence of the substrate is high. As in the aforementioned polarizing film, it can be seen that the value of the dichroic ratio is large and the polarization performance is good, and the value of T 700 ⊥ 44 is small and Leakage of red light in the cross-polarized state is small. On the other hand, in the polarizing films obtained in Comparative Examples 3 to 9, it was found that the substrate had a low birefringence, a small value of dichroism ratio, and poor polarization performance, and a large value of T 700 ⊥ 44 and orthogonal polarization. The state of red light leaks a lot.

[產業上利用性] [Industrial availability]

根據本發明的積層體(1)及使用其之偏光膜之製造方法(1)，即使沒有預先進行對於硼酸水溶液之浸漬或空中高溫拉伸的不溶化處理，在染色等之偏光膜製造時之與水接觸的步驟中，也可抑制PVA層所含的PVA之溶出，因此，可省略操作繁雜、需要特別的製造設備之前述不溶化處理，藉此，可使用通用的偏光膜製造設備簡便地製造偏光性能佳之偏光膜。又，本發明的偏光膜(2)，偏光性能佳，同時在正交偏光狀態的紅色光之洩漏少。再者，藉由本發明的偏光膜之製造方法(2)，可順利且簡便地製造偏光性能佳，同時在正交偏光狀態的紅色光之洩漏少的前述偏光膜(2)。 According to the laminated body (1) of the present invention and the manufacturing method (1) of the polarizing film using the same, even if the boric acid aqueous solution is not impregnated or the insolubilization treatment of high-temperature stretching in the air is not performed in advance, it is used in the manufacture of polarizing films such as dyeing, In the step of water contact, the dissolution of PVA contained in the PVA layer can also be suppressed. Therefore, the aforementioned insolubilization process, which is complicated in operation and requires special manufacturing equipment, can be omitted, thereby making it possible to easily manufacture polarized light using general-purpose polarizing film manufacturing equipment High performance polarizing film. In addition, the polarizing film (2) of the present invention has good polarization performance, and at the same time, there is less leakage of red light in the orthogonal polarization state. In addition, by the method (2) for manufacturing a polarizing film of the present invention, the aforementioned polarizing film (2) with good polarization performance and low leakage of red light in the orthogonal polarization state can be smoothly and easily manufactured.

Claims (10)

一種積層體，其具有熱可塑性樹脂膜層、與膨潤度為180%以上260%以下且厚度為3~10μm的聚乙烯醇層，該聚乙烯醇層所包含之聚乙烯醇的乙烯含量為1莫耳%以上12莫耳%以下。A laminated body comprising a thermoplastic resin film layer and a polyvinyl alcohol layer having a swelling degree of 180% or more and 260% or less and a thickness of 3 to 10 μm. The polyvinyl content of the polyvinyl alcohol layer is 1 More than 12 mole%. 如請求項1之積層體，其中該聚乙烯醇層所包含之聚乙烯醇的1,2-二醇鍵結量為0.4莫耳%以上1.5莫耳%以下。For example, the laminated body of claim 1, wherein the 1,2-diol bond of polyvinyl alcohol contained in the polyvinyl alcohol layer is 0.4 mol% or more and 1.5 mol% or less. 如請求項1之積層體，其中該聚乙烯醇層所包含之聚乙烯醇的平均聚合度為1,000以上9,500以下。The laminated body according to claim 1, wherein the polyvinyl alcohol contained in the polyvinyl alcohol layer has an average degree of polymerization of 1,000 or more and 9,500 or less. 如請求項1之積層體，其中該聚乙烯醇層所包含之聚乙烯醇的皂化度為98莫耳%以上。For example, the laminated body of claim 1, wherein the saponification degree of the polyvinyl alcohol contained in the polyvinyl alcohol layer is 98 mol% or more. 如請求項1之積層體，其中該聚乙烯醇層相對於聚乙烯醇100質量份，係含有可塑劑1質量份以上15質量份以下。For example, the laminated body according to claim 1, wherein the polyvinyl alcohol layer contains 1 to 15 parts by mass of a plasticizer with respect to 100 parts by mass of the polyvinyl alcohol. 如請求項5之積層體，其中該可塑劑為甘油。The laminated body according to claim 5, wherein the plasticizer is glycerin. 一種偏光膜之製造方法，其包含將如請求項1至6中任一項之積層體拉伸的步驟。A method for manufacturing a polarizing film, comprising the step of stretching the laminated body according to any one of claims 1 to 6. 如請求項7之製造方法，其包含：對於拉伸前之該積層體的該聚乙烯醇層、在該積層體的拉伸中之拉伸途中的該聚乙烯醇層、或由拉伸該積層體後之該聚乙烯醇層形成的拉伸膜層，使二色性色素接觸的步驟。The manufacturing method according to claim 7, comprising: for the polyvinyl alcohol layer of the laminated body before stretching, the polyvinyl alcohol layer in the middle of stretching in the stretching of the laminated body, or stretching the A step of contacting a dichroic dye with a stretched film layer formed by the polyvinyl alcohol layer after the laminate. 如請求項8之製造方法，其中在該使二色性色素接觸的步驟之前，未包含與含有硼化合物之水溶液接觸的步驟。The method according to claim 8, wherein the step of bringing into contact with an aqueous solution containing a boron compound is not included before the step of contacting the dichroic pigment. 如請求項8之製造方法，其中在該使二色性色素接觸的步驟之前，未包含在95℃以上之溫度拉伸的步驟。The method according to claim 8, wherein the step of stretching at a temperature of 95 ° C or higher is not included before the step of contacting the dichroic pigment.
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