TWI652512B - Method for manufacturing polarizing plate with double-sided protective film - Google Patents

Abstract

本發明係提供一種雙面附有保護膜之偏光板之製造方法，其係包含：從依序包含基材膜、碘系偏光片及第1保護膜之多層膜，將基材膜剝離去除之步驟，以及將第2保護膜貼合於碘系偏光片的外面之步驟；第1及第2保護膜為透濕度150g/m²/24hr以下之熱塑性樹脂膜；貼合第2保護膜時之碘系偏光片的水分率未達8重量%；並且提供一種雙面附有保護膜之偏光板，其係於水分率未達8重量%之碘系偏光片的雙面積層有透濕度150g/m²/24hr以下之熱塑性樹脂膜。 The present invention provides a method for manufacturing a polarizing plate with a protective film on both sides, which includes: peeling off a base film from a multilayer film including a base film, an iodine polarizer and a first protective film in sequence Steps, and the step of attaching the second protective film to the outer surface of the iodine-based polarizer; the first and second protective films are thermoplastic resin films with a moisture permeability of 150 g / m ² / 24hr or less; when the second protective film is applied The moisture content of the iodine-based polarizer is less than 8% by weight; and a polarizing plate with a protective film on both sides is provided. The double-area layer of the iodine-based polarizer with a moisture content of less than 8% by weight has a moisture permeability of 150g / m ² / 24hr or less thermoplastic resin film.

Description

雙面附有保護膜之偏光板之製造方法 Method for manufacturing polarizing plate with protective film on both sides

本發明係關於將保護膜貼合於碘系偏光片的雙面之雙面附有保護膜之偏光板之製造方法，詳細而言，係關於將透濕度低的保護膜逐次地貼合於碘系偏光片的雙面而製造雙面附有保護膜之偏光板之方法。 The present invention relates to a method for manufacturing a polarizing plate with a protective film attached to a double-sided double-sided protective film of an iodine-based polarizer. Specifically, it relates to sequentially attaching a protective film with low moisture permeability to iodine A method of manufacturing a polarizing plate with a protective film on both sides of the polarizer on both sides.

偏光板係廣泛使用在液晶顯示裝置等之顯示裝置，尤其近年來廣泛使用在如智慧型手機般之各種可攜式機器。偏光板一般是使用接著劑將保護膜貼合於偏光片的單面或雙面而構成者。 Polarizing plates are widely used in display devices such as liquid crystal display devices, especially in recent years, they are widely used in various portable devices like smart phones. The polarizing plate is generally formed by attaching a protective film to one side or both sides of the polarizer using an adhesive.

偏光片本身係耐濕熱性低，偏光特性於濕熱環境下容易劣化。以往，用以保護偏光片之保護膜係可使用三乙醯纖維素膜，但由於三乙醯纖維素膜的透濕度高，使用此作為保護膜之偏光板，尤其當使用碘系偏光片作為偏光片時，會有耐濕熱性變得更不足之問題。 The polarizer itself has low moisture and heat resistance, and the polarization characteristics are easily degraded in a hot and humid environment. In the past, the protective film used to protect the polarizer can be triacetyl cellulose film, but due to the high moisture permeability of the triethyl cellulose film, the polarizer used as the protective film, especially when using iodine polarizer as In the case of polarizers, there is a problem that the resistance to heat and humidity becomes more insufficient.

因此，為了改善偏光板的耐濕熱性，係有人提出將例如降莰烯系樹脂膜般之透濕度低的保護膜，取代三乙醯纖維素膜而貼合於碘系偏光片[例如日本特開 2004-245925號公報(專利文獻1)的段落[0005]]。 Therefore, in order to improve the moisture and heat resistance of polarizing plates, it has been proposed to replace a triacetyl cellulose film with a low moisture permeability protective film such as a norbornene-based resin film and attach it to an iodine-based polarizer [such as Japan Special open Paragraph [0005] of 2004-245925 (Patent Document 1)].

[先前技術文獻] [Prior Technical Literature]

[專利文獻] [Patent Literature]

[專利文獻1]日本特開2004-245925號公報 [Patent Document 1] Japanese Patent Laid-Open No. 2004-245925

若將透濕度低的保護膜貼合於碘系偏光片的雙面，則可降低水分從外部之侵入，故可提高偏光板的耐濕熱性。然而，另一方面，經過本發明者的探討，可得知將透濕度低的保護膜使用在雙面之以往之雙面附有保護膜之偏光板，在實施較一般的耐濕熱性試驗更高的溫度環境下之耐熱性試驗時，會產生正交偏光下的光漏(產生褪色，使紅色區域的光從偏光板漏出而使偏光板看起來變紅之現象，亦稱為紅變)，或是使偏光特性降低。該耐熱性不良之問題，係碘系偏光片的厚度愈小愈顯著。 If a protective film with low moisture permeability is attached to both sides of the iodine-based polarizer, the intrusion of moisture from the outside can be reduced, so the humidity resistance of the polarizing plate can be improved. However, on the other hand, after discussion by the present inventors, it can be known that the use of a protective film with a low moisture permeability on both sides of the conventional polarizing plate with a protective film on both sides is more effective in carrying out more general humidity and heat resistance tests. In the heat resistance test under a high temperature environment, light leakage under orthogonal polarized light will occur (fading will cause light in the red area to leak out from the polarizing plate and make the polarizing plate look red, also known as redness) , Or to reduce the polarization characteristics. This problem of poor heat resistance is more pronounced as the thickness of the iodine-based polarizer is smaller.

因此，本發明之目的在於提供一種用以製造將透濕性低的保護膜貼合於碘系偏光片的雙面之偏光板，且兼具耐濕熱性及耐熱性之雙面附有保護膜之偏光板之方法，以及提供一種兼具耐濕熱性及耐熱性之雙面附有保護膜之偏光板。 Therefore, an object of the present invention is to provide a double-sided polarizing plate for manufacturing a protective film with low moisture permeability bonded to an iodine-based polarizer, and a double-sided protective film with both moisture resistance and heat resistance The method of polarizing plate and providing a polarizing plate with protective film on both sides which have both heat and humidity resistance and heat resistance.

本發明係提供以下所示之雙面附有保護膜之偏光板之製造方法，以及雙面附有保護膜之偏光板。 The present invention provides a manufacturing method of a polarizing plate with a protective film on both sides shown below, and a polarizing plate with a protective film on both sides.

[1]一種雙面附有保護膜之偏光板之製造方法，其係包含：從依序包含基材膜、碘系偏光片及第1保護膜之多層膜，將基材膜剝離去除而得到單面附有保護膜之偏光板之步驟，以及將第2保護膜貼合於前述單面附有保護膜之偏光板之碘系偏光片的外面，而得到雙面附有保護膜之偏光板之步驟；前述第1保護膜及前述第2保護膜為透濕度150g/m²/24hr以下之熱塑性樹脂膜；貼合前述第2保護膜時之前述碘系偏光片的水分率未達8重量%。 [1] A method for manufacturing a polarizing plate with a protective film on both sides, comprising: a multilayer film including a base film, an iodine-based polarizer, and a first protective film in sequence, and the base film is peeled off and obtained The step of polarizing plate with protective film on one side, and attaching the second protective film to the outside of the iodine polarizer of the polarizing plate with protective film on one side, to obtain the polarizing plate with protective film on both sides Steps; the first protective film and the second protective film are thermoplastic resin films with a moisture permeability of 150 g / m ² / 24hr or less; the moisture content of the iodine-based polarizer when the second protective film is laminated is less than 8 weight %.

[2]如[1]所述之製造方法，其中使用活化能射線硬化性接著劑，將前述第2保護膜貼合於前述碘系偏光片的外面。 [2] The production method according to [1], wherein the second protective film is bonded to the outer surface of the iodine-based polarizer using an active energy ray-curable adhesive.

[3]如[1]或[2]所述之製造方法，其中前述碘系偏光片之厚度為10μm以下。 [3] The manufacturing method according to [1] or [2], wherein the thickness of the iodine-based polarizer is 10 μm or less.

[4]一種雙面附有保護膜之偏光板之製造方法，其係包含：將第2保護膜貼合於包含碘系偏光片及積層於該碘系偏光片的單面之第1保護膜之單面附有保護膜之偏光板中之碘系偏光片的外面，而得到雙面附有保護膜之偏光板之步驟；前述第1保護膜及前述第2保護膜為透濕度150g/m²/24hr以下之熱塑性樹脂膜；貼合前述第2保護膜時之前述碘系偏光片的水分率未達8重量%。 [4] A method for manufacturing a polarizing plate with a protective film on both sides, comprising: bonding a second protective film to a single protective film including an iodine-based polarizer and a single layer laminated on the iodine-based polarizer The step of obtaining a polarizing plate with a protective film on both sides of the polarizing plate with a protective film on one side and obtaining a polarizing plate with a protective film on both sides; the first protective film and the second protective film have a moisture permeability of 150 g / m ² / 24hr or less thermoplastic resin film; the moisture content of the iodine-based polarizer when the second protective film is bonded is less than 8% by weight.

[5]如[4]所述之製造方法，其中使用活化能射線硬化性接著劑，將前述第2保護膜貼合於前述碘系偏光片的外面。 [5] The production method according to [4], wherein the second protective film is bonded to the outer surface of the iodine-based polarizer using an active energy ray-curable adhesive.

[6]如[4]或[5]所述之製造方法，其中前述碘系偏光片之厚度為10μm以下。 [6] The manufacturing method according to [4] or [5], wherein the thickness of the iodine-based polarizer is 10 μm or less.

[7]一種雙面附有保護膜之偏光板，其係包含：碘系偏光片及積層於該雙面之保護膜；積層於雙面之保護膜均為透濕度150g/m²/24hr以下之熱塑性樹脂膜；前述碘系偏光片的水分率未達8重量%。 [7] A polarizing plate with a protective film on both sides, which includes: an iodine-based polarizer and a protective film laminated on the double side; the protective films laminated on both sides are all less than 150g / m ² / 24hr The thermoplastic resin film; the moisture content of the aforementioned iodine-based polarizer is less than 8% by weight.

[8]如[7]所述之雙面附有保護膜之偏光板，其中前述碘系偏光片之厚度為10μm以下。 [8] The polarizing plate with a protective film on both sides as described in [7], wherein the thickness of the iodine-based polarizer is 10 μm or less.

根據本發明，可提供一種用以製造將透濕性低的保護膜貼合於碘系偏光片的雙面之偏光板，且兼具耐濕熱性及耐熱性之雙面附有保護膜之偏光板之方法，以及提供一種將透濕性低的保護膜貼合於碘系偏光片的雙面之偏光板，且兼具耐濕熱性及耐熱性之雙面附有保護膜之偏光板。 According to the present invention, it is possible to provide a double-sided polarizing plate for manufacturing a double-sided polarizing plate in which a protective film with low moisture permeability is bonded to an iodine-based polarizer, and a double-sided polarizing plate with protective film that has both moisture resistance and heat resistance A method of providing a plate, and a double-sided polarizing plate in which a protective film with low moisture permeability is attached to an iodine-based polarizer, and a double-sided polarizing plate with a protective film having both moisture resistance and heat resistance.

5‧‧‧碘系偏光片 5‧‧‧Iodine polarizer

6‧‧‧聚乙烯醇系樹脂層 6‧‧‧Polyvinyl alcohol resin layer

6'‧‧‧經拉伸之聚乙烯醇系樹脂層 6'‧‧‧Stretched polyvinyl alcohol resin layer

10‧‧‧第1保護膜 10‧‧‧The first protective film

15‧‧‧第1接著劑層 15‧‧‧The first adhesive layer

20‧‧‧第2保護膜 20‧‧‧Second protective film

25‧‧‧第2接著劑層 25‧‧‧ 2nd adhesive layer

30‧‧‧基材膜 30‧‧‧ Base film

30'‧‧‧經拉伸之基材膜 30'‧‧‧Stretched base film

100‧‧‧單面附有保護膜之偏光板 100‧‧‧Polarized plate with protective film on one side

200‧‧‧積層膜 200‧‧‧Lamination film

300‧‧‧拉伸膜 300‧‧‧Stretched film

400‧‧‧偏光性積層膜 400‧‧‧ Polarized laminated film

500‧‧‧多層膜 500‧‧‧Multilayer film

600‧‧‧雙面附有保護膜之偏光板 600‧‧‧ Polarizer with protective film on both sides

第1圖係顯示本發明之雙面附有保護膜之偏光板之製造方法的較佳一例之流程圖。 FIG. 1 is a flow chart showing a preferred example of the method for manufacturing a polarizing plate with a protective film on both sides of the present invention.

第2圖係顯示單面附有保護膜之偏光板之層構成的一例之概略剖面圖。 FIG. 2 is a schematic cross-sectional view showing an example of the layer configuration of a polarizing plate with a protective film on one side.

第3圖係顯示單面附有保護膜之偏光板之製備步驟的較佳一例之流程圖。 FIG. 3 is a flowchart showing a preferred example of the preparation steps of a polarizing plate with a protective film on one side.

第4圖係顯示於樹脂層形成步驟所得之積層膜之層構成的一例之概略剖面圖。 FIG. 4 is a schematic cross-sectional view showing an example of the layer structure of the laminated film obtained in the resin layer forming step.

第5圖係顯示於拉伸步驟所得之拉伸膜之層構成的一例之概略剖面圖。 Fig. 5 is a schematic cross-sectional view showing an example of the layer structure of the stretched film obtained in the stretching step.

第6圖係顯示於染色步驟所得之偏光性積層膜之層構成的一例之概略剖面圖。 Fig. 6 is a schematic cross-sectional view showing an example of the layer configuration of the polarizing laminate film obtained in the dyeing step.

第7圖係顯示於貼合步驟所得之多層膜之層構成的一例之概略剖面圖。 FIG. 7 is a schematic cross-sectional view showing an example of the layer structure of the multilayer film obtained in the bonding step.

第8圖係顯示本發明之雙面附有保護膜之偏光板之層構成的一例之概略剖面圖。 Fig. 8 is a schematic cross-sectional view showing an example of the layer configuration of a polarizing plate with a protective film on both sides of the present invention.

<雙面附有保護膜之偏光板之製造方法> <Manufacturing method of polarizing plate with protective film on both sides>

本發明之雙面附有保護膜之偏光板之製造方法，如第1圖所示，可包含下述步驟。 The method for manufacturing a polarizing plate with a protective film on both sides of the present invention, as shown in FIG. 1, may include the following steps.

(1)製備：包含碘系偏光片及積層於該碘系偏光片的單面之第1保護膜之單面附有保護膜之偏光板之步驟S10(以下亦稱為「單面附有保護膜之偏光板的製備步驟S10」)，以及(2)將第2保護膜貼合於單面附有保護膜之偏光板之碘系偏光片的外面，而得到雙面附有保護膜之偏光板之步驟S20(以下亦稱為「雙面附有保護膜之偏光板的製作步驟S20」)。 (1) Preparation: Step S10 including an iodine-based polarizer and a polarizing plate with a protective film on one side of the first protective film laminated on one side of the iodine-based polarizer (hereinafter also referred to as "single side with protection Preparation step of film polarizing plate S10 "), and (2) The second protective film is attached to the outside of the iodine polarizer of the polarizing plate with protective film on one side to obtain polarized light with protective film on both sides Step S20 of the board (hereinafter also referred to as "step S20 of manufacturing a polarizing plate with a protective film on both sides").

如上述般，本發明中，第1保護膜及第2保護膜係逐次地貼合於碘系偏光片。此時，為了提升所得之雙面附有保護膜之偏光板的耐濕熱性，貼合於碘系偏光片之一方的面之第1保護膜及貼合於另一方的面之第2保護膜，係使用透濕度150g/m²/24hr以下之低透濕度的熱塑性樹脂膜。 As described above, in the present invention, the first protective film and the second protective film are successively bonded to the iodine-based polarizer. At this time, in order to improve the moisture and heat resistance of the obtained polarizing plate with a protective film on both sides, the first protective film attached to one side of the iodine-based polarizer and the second protective film attached to the other side , Use a low moisture permeability thermoplastic resin film with a moisture permeability of 150 g / m ² / 24hr or less.

此外，為了提升所得之雙面附有保護膜之偏光板的耐熱性，將第2保護膜貼合於碘系偏光片時之碘系偏光片的水分率設為未達8重量%。本發明中，為了提升耐濕熱性，而將透濕度低的保護膜貼合於碘系偏光片的雙面而設為偏光板者，但從以下狀況來看：a)若將透濕度低的保護膜適用於雙面，碘系偏光片中的水分不易被釋放至外部，水分會累積於碘系偏光片中，以及b)耐熱性試驗中之紅變或偏光特性的降低，是由殘留於該碘系偏光片中之水分所引起；如上述般，對貼合第2保護膜時之碘系偏光片的水分率進行管理者乃為有效。碘系偏光片的水分率係依據實施例的項目所記載之方法來測定。 In addition, in order to improve the heat resistance of the obtained polarizing plate with a protective film on both sides, the moisture content of the iodine-based polarizer when the second protective film was bonded to the iodine-based polarizer was not more than 8% by weight. In the present invention, in order to improve the heat and humidity resistance, a protective film with low moisture permeability is attached to the double-sided of the iodine-based polarizer and used as a polarizer, but from the following situation: a) If the moisture permeability is low The protective film is suitable for both sides, the moisture in the iodine-based polarizer is not easily released to the outside, the moisture will accumulate in the iodine-based polarizer, and b) the redness in the heat resistance test or the degradation of the polarization characteristics are caused by the residual Caused by moisture in the iodine-based polarizer; as described above, it is effective to manage the moisture content of the iodine-based polarizer when the second protective film is attached. The moisture content of the iodine-based polarizer is measured according to the method described in the item of the example.

碘系偏光片的水分率係可藉由設置下述步驟S30來達成，亦即於製造雙面附有保護膜之偏光板之步驟中，在將第2保護膜貼合於碘系偏光片之前的任意階段中，設置：(3)對包含碘系偏光片之膜施以水分率降低處理之步驟S30(以下亦稱為「水分率降低步驟S30」)(參考第1 圖)。 The moisture content of the iodine-based polarizer can be achieved by setting the following step S30, that is, before the step of manufacturing a polarizing plate with a protective film on both sides, before attaching the second protective film to the iodine-based polarizer At any stage of the process, set: (3) Step S30 of applying a moisture content reduction process to the film containing the iodine-based polarizer (hereinafter also referred to as "moisture content reduction step S30") (Figure).

以下參考第2圖~第8圖來說明各步驟。 The following describes each step with reference to FIGS. 2 to 8.

(1)單面附有保護膜之偏光板的製備步驟S10 (1) Preparation step of polarizing plate with protective film on one side S10

本步驟為製備(準備)例如第2圖所示之單面附有保護膜之偏光板100之步驟，該單面附有保護膜之偏光板100包含碘系偏光片5及積層於該碘系偏光片5之第1保護膜10。如第2圖所示，第1保護膜10通常介於第1接著劑層15貼合(接著固定)於碘系偏光片5的單面。 This step is a step of preparing (preparing), for example, the polarizing plate 100 with a protective film on one side shown in FIG. The first protective film 10 of the polarizer 5. As shown in FIG. 2, the first protective film 10 is usually bonded (adhered) to the single side of the iodine-based polarizer 5 through the first adhesive layer 15.

[碘系偏光片] [Iodine Polarizer]

碘系偏光片5為使碘作為雙色性色素而吸附配向之偏光片，具體而言，可為使碘吸附配向於經單軸拉伸之聚乙烯醇系樹脂層(或膜)者。碘系偏光片5的厚度例如為30μm以下，更可為20μm以下，尤其在可攜式機器用途中，從雙面附有保護膜之偏光板的薄型化之觀點來看，較佳為10μm以下，尤佳為8μm以下。碘系偏光片5的厚度通常為2μm以上。 The iodine-based polarizer 5 is a polarizer in which iodine is adsorbed and aligned as a dichromatic dye, and specifically, it may be one in which iodine is adsorbed and aligned to a uniaxially stretched polyvinyl alcohol-based resin layer (or film). The thickness of the iodine-based polarizer 5 is, for example, 30 μm or less, and more preferably 20 μm or less. In particular, in portable applications, from the viewpoint of thinning the polarizing plate with a protective film on both sides, it is preferably 10 μm or less. , Particularly preferably 8 μm or less. The thickness of the iodine-based polarizer 5 is usually 2 μm or more.

若碘系偏光片5的厚度變小，碘的濃度更提高，存在於積層在雙面上之保護膜的界面附近之碘錯合物的濃度亦變高，因而容易受到從外部侵入之水分的影響。因此，碘系偏光片5的厚度愈小，耐濕熱性愈容易降低。此外，碘系偏光片5的厚度變小而碘的濃度更提高時，容易受到殘存於碘系偏光片中之水分的影響，耐熱性亦容易降低。如此，碘系偏光片5的厚度愈小，耐濕熱性及耐 熱性愈容易降低，如此，本發明於碘系偏光片5的厚度較小時，特別有利。 If the thickness of the iodine-based polarizer 5 is reduced, the concentration of iodine is further increased, and the concentration of the iodine complex existing near the interface of the protective film laminated on both sides also becomes high, so it is susceptible to moisture entering from the outside influences. Therefore, the smaller the thickness of the iodine-based polarizer 5 is, the easier it is to reduce the resistance to moisture and heat. In addition, when the thickness of the iodine-based polarizer 5 is reduced and the concentration of iodine is further increased, it is easily affected by the moisture remaining in the iodine-based polarizer, and the heat resistance is also easily reduced. In this way, the smaller the thickness of the iodine-based polarizer 5, the resistance to moisture and heat and the resistance The more easily the thermal property is reduced, the present invention is particularly advantageous when the thickness of the iodine-based polarizer 5 is small.

構成聚乙烯醇系樹脂層之聚乙烯醇系樹脂，可使用使聚乙酸乙烯酯系樹脂皂化者。聚乙酸乙烯酯系樹脂，除了乙酸乙烯酯的均聚物之聚乙酸乙烯酯之外，可例示出乙酸乙烯酯及可與該乙酸乙烯酯共聚合之其他單體的共聚物。可與乙酸乙烯酯共聚合之其他單體，例如可列舉出不飽和羧酸類、烯烴類、乙烯醚類、不飽和磺酸類、具有銨基之丙烯醯胺類等。 As the polyvinyl alcohol resin constituting the polyvinyl alcohol resin layer, one that saponifies the polyvinyl acetate resin can be used. Polyvinyl acetate-based resins can be exemplified by copolymers of vinyl acetate and other monomers copolymerizable with the vinyl acetate, in addition to polyvinyl acetate, which is a homopolymer of vinyl acetate. Other monomers copolymerizable with vinyl acetate include, for example, unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamides having ammonium groups.

本說明書中所謂「(甲基)丙烯酸」，意指選自丙烯酸及甲基丙烯酸之至少一方。在稱為「(甲基)丙烯醯基」等之情形時亦同。 In this specification, "(meth) acrylic acid" means at least one selected from acrylic acid and methacrylic acid. It is the same when it is called "(meth) acryloyl".

將上述聚乙烯醇系樹脂製膜而成者，係構成碘系偏光片5。製膜聚乙烯醇系樹脂之方法並無特別限定，可藉由一般所知的方法來製膜，由於容易得到厚度小的碘系偏光片5，且步驟中之薄膜的碘系偏光片5的處理性亦優異，故較佳為後述般之將聚乙烯醇系樹脂的溶液塗布於基材膜上而製膜之方法。 The film formed of the polyvinyl alcohol-based resin constitutes the iodine-based polarizer 5. The method of forming the polyvinyl alcohol-based resin is not particularly limited, and the film can be formed by a generally known method, since it is easy to obtain the iodine-based polarizer 5 with a small thickness, and The handleability is also excellent, so it is preferable to apply a solution of a polyvinyl alcohol-based resin to a base film as described later to form a film.

聚乙烯醇系樹脂的皂化度，可設為80.0~100.0莫耳%的範圍，較佳為90.0~99.5莫耳%的範圍，尤佳為94.0~99.0莫耳%的範圍。當皂化度未達80.0莫耳%時，所得之雙面附有保護膜之偏光板的耐水性及耐濕熱性降低。當皂化度超過99.5莫耳%時，使用聚乙烯醇系樹脂時，碘的染色速度會變慢，且生產性降低，有時無法得到 具有充分的偏光性能之碘系偏光片5。 The saponification degree of the polyvinyl alcohol-based resin can be set in the range of 80.0 to 100.0 mol%, preferably in the range of 90.0 to 99.5 mol%, and particularly preferably in the range of 94.0 to 99.0 mol%. When the degree of saponification is less than 80.0 mol%, the resulting polarizing plate with a protective film on both sides has reduced water resistance and moisture and heat resistance. When the degree of saponification exceeds 99.5 mol%, when a polyvinyl alcohol-based resin is used, the dyeing speed of iodine becomes slow, and the productivity decreases, and sometimes it is not available Iodine polarizer 5 with sufficient polarizing performance.

所謂皂化度，意指以單位比(莫耳%)表示藉由皂化步驟使作為聚乙烯醇系樹脂的原料之聚乙酸乙烯酯系樹脂中所包含之乙酸基(乙醯氧基：-OCOCH₃)轉化為羥基之比率，且由下列式所定義。 The saponification degree means that the unit ratio (mol%) represents the acetate group (ethoxyl group: -OCOCH ₃ ) contained in the polyvinyl acetate resin as the raw material of the polyvinyl alcohol resin through the saponification step. ) The ratio of conversion to hydroxyl groups, and is defined by the following formula.

皂化度(莫耳%)=100×(羥基的數目)÷(羥基的數目+乙酸基的數目) Saponification degree (mol%) = 100 × (number of hydroxyl groups) ÷ (number of hydroxyl groups + number of acetate groups)

皂化度可依據JIS K 6726-1994來求取。皂化度愈高，表示羥基的比率愈高，因而表示阻礙結晶化之乙酸基的比率低。 The degree of saponification can be determined in accordance with JIS K 6726-1994. The higher the degree of saponification, the higher the ratio of hydroxyl groups, and therefore the lower the ratio of acetic acid groups that hinder crystallization.

聚乙烯醇系樹脂係可為一部分經改質之改質聚乙烯醇系樹脂。例如可列舉出以乙烯、丙烯等之烯烴類；以丙烯酸、甲基丙烯酸、巴豆酸等之不飽和羧酸類；以不飽和羧酸的烷酯、(甲基)丙烯醯胺等，將聚乙烯醇系樹脂予以改質者。改質的比率，較佳未達30莫耳%，尤佳未達10莫耳%。當進行超過30莫耳%之改質時，難以吸附碘，有難以得到具有充分的偏光性能之碘系偏光片5之傾向。 The polyvinyl alcohol-based resin system may be a part of the modified modified polyvinyl alcohol-based resin. For example, olefins such as ethylene and propylene; unsaturated carboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid; alkyl esters of unsaturated carboxylic acids, (meth) acrylamide, etc. The alcohol-based resin is modified. The rate of modification is preferably less than 30 mol%, and particularly preferably less than 10 mol%. When the modification of more than 30 mol% is performed, it is difficult to adsorb iodine, and there is a tendency that it is difficult to obtain an iodine-based polarizer 5 having sufficient polarizing performance.

聚乙烯醇系樹脂的平均聚合度，較佳為100~10000，尤佳為1500~8000，更佳為2000~5000。聚乙烯醇系樹脂的平均聚合度，亦可依據JIS K 6726-1994來求取。 The average degree of polymerization of the polyvinyl alcohol-based resin is preferably 100 to 10,000, particularly preferably 1500 to 8000, and more preferably 2000 to 5000. The average degree of polymerization of the polyvinyl alcohol-based resin can also be determined in accordance with JIS K 6726-1994.

[第1保護膜] [1st protective film]

第1保護膜10係可由具有透光性(較佳為光學透明性)之熱塑性樹脂所構成，且透濕度為150g/m²/24hr以下之膜。透濕度係包含後述之第2保護膜的透濕度，為依據JIS Z 0208-1976「防濕包裝材料的透濕度試驗方法(杯法)」所測得之溫度40℃、相對濕度90%之透濕度。透濕度較佳為100g/m²/24hr以下。 The first protective film 10 may be a film made of a thermoplastic resin having translucency (preferably optical transparency) and having a moisture permeability of 150 g / m ² / 24hr or less. The moisture permeability includes the moisture permeability of the second protective film described later, which is the permeability at a temperature of 40 ° C and a relative humidity of 90% measured in accordance with JIS Z 0208-1976 "Moisture permeability test method for moisture-proof packaging materials (cup method)" humidity. The moisture permeability is preferably 100 g / m ² / 24hr or less.

將第1保護膜10的透濕度設為150g/m²/24hr以下之手段，可列舉出：使用透濕性低者作為構成膜之熱塑性樹脂，或是增加膜的厚度，或是在膜上設置透濕性低的阻障層之手段。 Means for setting the moisture permeability of the first protective film 10 to 150 g / m ² / 24hr or less include: using a film with a low moisture permeability as the thermoplastic resin constituting the film, or increasing the thickness of the film, or on the film Means to provide a barrier layer with low moisture permeability.

構成第1保護膜10之熱塑性樹脂，只要可達成上述透濕度者即可，並無特別限制，由於透濕性低且可減少第1保護膜10的厚度，故可較佳地使用鏈狀聚烯烴系樹脂(聚丙烯系樹脂等)、環狀聚烯烴系樹脂(降莰烯系樹脂等)般之聚烯烴系樹脂；聚對苯二甲酸乙二酯系樹脂般之聚酯系樹脂；聚碳酸酯系樹脂；(甲基)丙烯酸系樹脂；聚苯乙烯系樹脂；或此等之混合物、共聚物等。 The thermoplastic resin constituting the first protective film 10 is not particularly limited as long as it can achieve the above moisture permeability. Since the moisture permeability is low and the thickness of the first protective film 10 can be reduced, a chain-shaped polymer can be preferably used Polyolefin resins such as olefin resins (polypropylene resins, etc.) and cyclic polyolefin resins (norbornene resins, etc.); polyester resins such as polyethylene terephthalate resins; poly Carbonate resin; (meth) acrylic resin; polystyrene resin; or mixtures, copolymers, etc. of these.

第1保護膜10亦可為相位差膜、增亮膜般之兼具光學功能之保護膜。例如，可藉由對由上述熱塑性樹脂所構成之膜進行拉伸(單軸拉伸或雙軸拉伸)，或是於該膜上形成液晶層等，以形成為賦予任意的相位差值之相位差膜。 The first protective film 10 may also be a protective film having optical functions like a phase difference film and a brightness enhancement film. For example, the film composed of the above thermoplastic resin can be stretched (uniaxially stretched or biaxially stretched), or a liquid crystal layer is formed on the film to form an arbitrary phase difference value. Retardation film.

鏈狀聚烯烴系樹脂係除了聚乙烯樹脂、聚丙烯樹脂般之鏈狀烯烴的均聚物之外，亦可列舉出由2種 以上的鏈狀烯烴所構成之共聚物。 In addition to the homopolymers of chain olefins such as polyethylene resins and polypropylene resins, the chain polyolefin resins can also be exemplified by two types Copolymers composed of the above chain olefins.

環狀聚烯烴系樹脂為以環狀烯烴為聚合單元所聚合之樹脂的總稱。列舉出環狀聚烯烴系樹脂的具體例，為環狀烯烴的開環(共)聚合物、環狀烯烴的加成聚合物、環狀烯烴與乙烯、丙烯般的鏈狀烯烴之共聚物(代表性為隨機共聚物)、以及以不飽和羧酸或該衍生物將此等予以改質之接枝聚合物、以及此等之氫化物等。當中，可較佳地使用：使用降莰烯或多環降莰烯系單體等之降莰烯系單體作為環狀烯烴之降莰烯系樹脂。 The cyclic polyolefin resin is a general term for resins polymerized using cyclic olefin as a polymerization unit. Specific examples of cyclic polyolefin-based resins include ring-opening (co) polymers of cyclic olefins, addition polymers of cyclic olefins, and copolymers of cyclic olefins and chain olefins such as ethylene and propylene ( (Representatives are random copolymers), graft polymers modified with unsaturated carboxylic acids or the derivatives, and these hydrides. Among them, it can be preferably used as a norbornene-based resin using a norbornene-based monomer such as norbornene or a polycyclic norbornene-based monomer as a cyclic olefin.

聚酯系樹脂為具有酯鍵之樹脂，一般是由多元羧酸或該衍生物與多元醇之聚縮合物所構成者。多元羧酸或該衍生物，可使用二羧酸或該衍生物，例如可列舉出對苯二甲酸、間苯二甲酸、對苯二甲酸二甲酯、萘二羧酸二甲酯等。多元醇可使用二醇，例如可列舉出乙二醇、丙二醇、丁二醇、新戊二醇、環己烷二甲醇等。 The polyester resin is a resin having an ester bond, and is generally composed of a polycondensate of a polycarboxylic acid or the derivative and a polyhydric alcohol. As the polycarboxylic acid or the derivative, dicarboxylic acid or the derivative can be used, and examples thereof include terephthalic acid, isophthalic acid, dimethyl terephthalate, and dimethyl naphthalene dicarboxylate. Polyols can use diols, and examples thereof include ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, and cyclohexane dimethanol.

聚酯系樹脂之具體例，包含聚對苯二甲酸乙二酯、聚對苯二甲酸丁二酯、聚萘二甲酸乙二酯、聚萘二甲酸丁二酯、聚對苯二甲酸丙二酯、聚萘二甲酸丙二酯、聚對苯二甲酸環己烷二甲酯、聚萘二甲酸環己烷二甲酯。 Specific examples of polyester resins include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, and polypropylene terephthalate Ester, polytrimethylene naphthalate, polycyclohexane dimethyl terephthalate, polycyclohexane naphthalate.

聚碳酸酯系樹脂，係由單體單元介於碳酸酯基而鍵結之聚合物所構成。聚碳酸酯系樹脂，亦可為將聚合物骨架改質之稱為改質聚碳酸酯之樹脂，或是共聚合聚碳酸酯等。 The polycarbonate-based resin is composed of a polymer in which monomer units are bonded through carbonate groups. The polycarbonate resin may also be a resin called modified polycarbonate whose polymer skeleton is modified, or a copolymerized polycarbonate.

(甲基)丙烯酸系樹脂是以具有(甲基)丙烯 醯基之化合物作為主要構成單體之樹脂。(甲基)丙烯酸系樹脂的具體例，例如包含：聚甲基丙烯酸甲酯般之聚(甲基)丙烯酸酯；甲基丙烯酸甲酯-(甲基)丙烯酸共聚物；甲基丙烯酸甲酯-(甲基)丙烯酸酯共聚物；甲基丙烯酸甲酯-丙烯酸酯-(甲基)丙烯酸共聚物；甲基丙烯酸甲酯-苯乙烯共聚物(MS樹脂等)；甲基丙烯酸甲酯與具有脂環族烴基之化合物之共聚物(例如甲基丙烯酸甲酯-甲基丙烯酸環己酯共聚物、甲基丙烯酸甲酯-甲基丙烯酸降莰酯共聚物等)。較佳係使用以聚(甲基)丙烯酸甲酯般之聚(甲基)丙烯酸C_1-6烷酯為主成分之聚合物，尤佳為使用以甲基丙烯酸甲酯為主成分(50~100重量%，較佳為70~100重量%)之甲基丙烯酸甲酯系樹脂。 The (meth) acrylic resin is a resin having a (meth) acryloyl group as the main constituent monomer. Specific examples of (meth) acrylic resins include, for example, poly (meth) acrylates like polymethyl methacrylate; methyl methacrylate- (meth) acrylic acid copolymer; methyl methacrylate- (Meth) acrylate copolymer; methyl methacrylate-acrylate- (meth) acrylic copolymer; methyl methacrylate-styrene copolymer (MS resin, etc.); methyl methacrylate and resin Copolymers of cyclic hydrocarbon-based compounds (such as methyl methacrylate-cyclohexyl methacrylate copolymer, methyl methacrylate-norbornyl methacrylate copolymer, etc.). Preferably, a polymer containing poly (meth) acrylate C _1-6 alkyl (meth) acrylate as the main component is used, and it is particularly preferred to use methyl methacrylate as the main component (50 ~ 100% by weight, preferably 70 to 100% by weight) methyl methacrylate resin.

於第1保護膜10之與碘系偏光片5相反側的表面上，亦可形成硬塗層、防眩層、抗反射層、抗靜電層、防污層般之表面處理層(塗布層)。形成表面處理層之方法並無特別限定，可使用一般所知的方法。 On the surface of the first protective film 10 opposite to the iodine-based polarizer 5, a surface treatment layer (coating layer) like a hard coat layer, an anti-glare layer, an anti-reflection layer, an antistatic layer, an anti-fouling layer can also be formed . The method of forming the surface treatment layer is not particularly limited, and generally known methods can be used.

第1保護膜10可含有1種或2種以上之潤滑劑、可塑劑、分散劑、熱穩定劑、紫外線吸收劑、紅外線吸收劑、抗靜電劑、抗氧化劑般之添加劑。 The first protective film 10 may contain one or more kinds of lubricants, plasticizers, dispersants, heat stabilizers, ultraviolet absorbers, infrared absorbers, antistatic agents, antioxidant-like additives.

第1保護膜10的厚度，從雙面附有保護膜之偏光板的薄膜化之觀點來看，較佳為90μm以下，尤佳為50μm以下，更佳為30μm以下。第1保護膜10的厚度，從強度及處理性之觀點來看，通常為5μm以上。 The thickness of the first protective film 10 is preferably 90 μm or less, particularly preferably 50 μm or less, and more preferably 30 μm or less from the viewpoint of thinning the polarizing plate with protective films on both sides. The thickness of the first protective film 10 is usually 5 μm or more from the viewpoint of strength and handleability.

[第1接著劑層] [1st adhesive layer]

第1接著劑層15係用以將第1保護膜10接著固定於碘系偏光片5之一方的面之層。形成第1接著劑層15之接著劑，可為含有藉由紫外線、可見光、電子束、X射線般之活化能射線的照射而使接著劑硬化之硬化性化合物之活化能射線硬化性接著劑(較佳為紫外線硬化性接著劑)，或是將聚乙烯醇系樹脂般之接著劑成分溶解或分散於水之水系接著劑。 The first adhesive layer 15 is a layer for fixing the first protective film 10 to one side of the iodine-based polarizer 5. The adhesive forming the first adhesive layer 15 may be an activation energy ray-curable adhesive containing a curing compound that hardens the adhesive by irradiation with ultraviolet, visible, electron beam, or X-ray activation energy rays ( (Ultraviolet-curable adhesive is preferred), or an aqueous adhesive in which an adhesive component like a polyvinyl alcohol-based resin is dissolved or dispersed in water.

上述硬化性化合物可為陽離子聚合性的硬化性化合物或自由基聚合性的硬化性化合物。陽離子聚合性的硬化性化合物，例如可列舉出環氧系化合物(於分子內具有1個或2個以上的環氧基之化合物)，或氧呾(oxetane)系化合物(於分子內具有1個或2個以上的氧呾環之化合物)，或此等之組合。自由基聚合性的硬化性化合物例如可列舉出(甲基)丙烯酸系化合物(於分子內具有1個或2個以上的(甲基)丙烯醯氧基之化合物)、或具有自由基聚合性的雙鍵之其他乙烯基系化合物，或此等之組合。亦可併用陽離子聚合性的硬化性化合物與自由基聚合性的硬化性化合物。活化能射線硬化性接著劑通常更包含用以使上述硬化性化合物的硬化反應開始進行之陽離子聚合起始劑及/或自由基聚合起始劑。 The curable compound may be a cation polymerizable curable compound or a radical polymerizable curable compound. Examples of the cationic polymerizable hardenable compound include epoxy compounds (compounds having one or more epoxy groups in the molecule), or oxetane compounds (having one in the molecule) Or more than two oxygen and ring compounds), or a combination of these. Examples of the radically polymerizable curable compound include (meth) acrylic compounds (compounds having one or more (meth) acryloyloxy groups in the molecule) or radically polymerizable compounds Other vinyl compounds with double bonds, or a combination of these. A cationically polymerizable hardening compound and a radically polymerizable hardening compound may be used together. The active energy ray-curable adhesive agent usually further includes a cationic polymerization initiator and / or a radical polymerization initiator for starting the hardening reaction of the above-mentioned curable compound.

單面附有保護膜之偏光板100可預先製備，或是藉由任意之方法所製造者。製造方法可列舉出以下所示者。 The polarizing plate 100 with a protective film on one side may be prepared in advance, or manufactured by any method. The manufacturing method includes the following.

(i)將第1保護膜10貼合於由以一般所知的方法製造出之單體(單獨)膜所構成之碘系偏光片5的單面之方法，以及(ii)包含如第3圖所示之下述步驟之製造方法。 (i) A method of bonding the first protective film 10 to one side of the iodine-based polarizer 5 composed of a single (separate) film manufactured by a generally known method, and (ii) including the third The manufacturing method of the following steps shown in the figure.

於基材膜之至少一方的面塗布包含聚乙烯醇系樹脂之塗布液後，藉由乾燥來形成聚乙烯醇系樹脂層而得到積層膜之樹脂層形成步驟S10-1；將積層膜拉伸而得到拉伸膜之拉伸步驟S10-2；以碘將拉伸膜的聚乙烯醇系樹脂層染色而形成碘系偏光片，得到偏光性積層膜之染色步驟S10-3；將第1保護膜10貼合於偏光性積層膜的碘系偏光片上而得到多層膜之貼合步驟S10-4；以及從多層膜將基材膜剝離去除而得到單面附有保護膜之偏光板100之剝離步驟S10-5。 After coating the coating liquid containing the polyvinyl alcohol-based resin on at least one surface of the base film, the resin layer forming step S10-1 of forming the laminated film by drying to form the polyvinyl alcohol-based resin layer; stretching the laminated film The stretching step S10-2 for obtaining a stretched film; the polyvinyl alcohol-based resin layer of the stretched film is dyed with iodine to form an iodine-based polarizer, and the dyeing step S10-3 for obtaining a polarizing laminate film; the first protection The film 10 is bonded to the polarizing laminate film iodine-based polarizer to obtain a multilayer film bonding step S10-4; and the base film is peeled off from the multilayer film to obtain a single-sided polarizer 100 with a protective film peeled off Step S10-5.

[樹脂層形成步驟S10-1] [Resin layer forming step S10-1]

參考第4圖，本步驟為於基材膜30之至少一方的面形成聚乙烯醇系樹脂層6而得到積層膜200之步驟。此聚乙烯醇系樹脂層6為經過拉伸步驟S10-2及染色步驟S10-3而成為碘系偏光片5之層。聚乙烯醇系樹脂層6可藉由將包含聚乙烯醇系樹脂之塗布液塗布於基材膜30的單面或雙面並乾燥而形成。藉由如此之塗布來形成聚乙烯醇系樹脂層之方法，就容易得到薄膜的碘系偏光片5之方面來看，較為有利。 Referring to FIG. 4, this step is a step of forming a polyvinyl alcohol-based resin layer 6 on at least one surface of the base film 30 to obtain a laminated film 200. This polyvinyl alcohol-based resin layer 6 is a layer that becomes the iodine-based polarizer 5 through the stretching step S10-2 and the dyeing step S10-3. The polyvinyl alcohol-based resin layer 6 can be formed by applying a coating liquid containing a polyvinyl alcohol-based resin to one side or both sides of the base film 30 and drying. The method of forming a polyvinyl alcohol-based resin layer by such coating is more advantageous in that the thin film iodine-based polarizer 5 is easily obtained.

基材膜30可由熱塑性樹脂所構成，當中，較佳是由透明性、機械強度、熱穩定性、拉伸性等優異之熱塑性樹脂所構成。如此之熱塑性樹脂的具體例，例如包含：鏈狀聚烯烴系樹脂、環狀聚烯烴系樹脂(降莰烯系樹脂等)般之聚烯烴系樹脂；聚酯系樹脂；(甲基)丙烯酸系樹脂；纖維素三乙酸酯、纖維素二乙酸酯般之纖維素酯系樹脂；聚碳酸酯系樹脂；聚乙烯醇系樹脂；聚乙酸乙烯酯系樹脂；聚芳酸酯系樹脂；聚苯乙烯系樹脂；聚醚碸系樹脂；聚碸系樹脂；聚醯胺系樹脂；聚醯亞胺系樹脂；及此等之混合物、共聚物。 The base film 30 may be composed of a thermoplastic resin, and among them, it is preferably composed of a thermoplastic resin excellent in transparency, mechanical strength, thermal stability, and stretchability. Specific examples of such thermoplastic resins include, for example, polyolefin resins such as chain polyolefin resins and cyclic polyolefin resins (norbornene resins, etc.); polyester resins; (meth) acrylic resins Resin; cellulose triacetate, cellulose diacetate-like cellulose ester resin; polycarbonate resin; polyvinyl alcohol resin; polyvinyl acetate resin; polyarylate resin; poly Styrene-based resin; Polyether-based resin; Poly-based resin; Polyamide-based resin; Polyimide-based resin; and mixtures and copolymers of these.

基材膜30可為由1種或2種以上的熱塑性樹脂所構成之1層樹脂層所形成之單層構造，或是積層複數層之由1種或2種以上的熱塑性樹脂所構成之樹脂層之多層構造。基材膜30在後述之拉伸步驟S10-2中將聚乙烯醇系樹脂層6拉伸時，較佳係以可在適合的拉伸溫度下進行拉伸之樹脂來構成。 The base film 30 may be a single-layer structure formed by one resin layer composed of one or two or more thermoplastic resins, or a resin composed of one or more thermoplastic resins laminated in multiple layers Multi-layer structure. When the base film 30 stretches the polyvinyl alcohol-based resin layer 6 in the stretching step S10-2 described later, it is preferably formed of a resin that can be stretched at a suitable stretching temperature.

基材膜30可含有添加劑。添加劑的具體例，包含紫外線吸收劑、抗氧化劑、潤滑劑、可塑劑、脫模劑、抗著色劑、難燃劑、成核劑、抗靜電劑、顏料、及著色劑。 The base film 30 may contain additives. Specific examples of additives include ultraviolet absorbers, antioxidants, lubricants, plasticizers, mold release agents, colorants, flame retardants, nucleating agents, antistatic agents, pigments, and coloring agents.

基材膜30的厚度，一般從強度和處理性等觀點來看，為1~500μm，較佳為1~300μm，尤佳為5~200μm，更佳為5~150μm。 The thickness of the base film 30 is generally 1 to 500 μm, preferably 1 to 300 μm, particularly preferably 5 to 200 μm, and more preferably 5 to 150 μm from the viewpoint of strength and handleability.

塗布於基材膜30之塗布液，較佳為使聚乙 烯醇系樹脂的粉末溶解於良溶劑(例如水)所得之聚乙烯醇系樹脂溶液。聚乙烯醇系樹脂的詳細內容如上所述。塗布液可因應必要而包含可塑劑、界面活性劑等之添加劑。 The coating liquid applied to the base film 30 is preferably made of polyethylene The solution of the polyvinyl alcohol resin obtained by dissolving the powder of the enol resin in a good solvent (for example, water). The details of the polyvinyl alcohol-based resin are as described above. The coating liquid may contain additives such as plasticizers and surfactants as necessary.

將上述塗布液塗布於基材膜30之方法，可適當地選自線棒塗布法；反轉塗布、凹版塗布般之輥塗布法；壓鑄模塗布法；逗號輪塗布法；唇板塗布法；旋轉塗布法；網版塗布法；噴泉式塗布法；浸漬法；噴霧法等之方法。 The method of applying the above coating liquid to the base film 30 can be appropriately selected from wire bar coating method; roll coating method like reverse coating and gravure coating; die casting die coating method; comma wheel coating method; lip coating method; Spin coating method; screen coating method; fountain coating method; dipping method; spray method and other methods.

塗布層(乾燥前的聚乙烯醇系樹脂層)的乾燥溫度及乾燥時間，可因應塗布液所包含之溶劑的種類來設定。乾燥溫度例如為50~200℃，較佳為60~150℃。當溶劑包含水時，乾燥溫度較佳為80℃以上。 The drying temperature and drying time of the coating layer (the polyvinyl alcohol-based resin layer before drying) can be set according to the type of solvent contained in the coating liquid. The drying temperature is, for example, 50 to 200 ° C, preferably 60 to 150 ° C. When the solvent contains water, the drying temperature is preferably 80 ° C or higher.

聚乙烯醇系樹脂層6係可僅形成於基材膜30之一方的面，或是形成於雙面。若形成於雙面時，可抑制偏光性積層膜400(參考第6圖)的製造時所可能產生之膜的捲曲，並且可從1片偏光性積層膜400得到2片偏光板，就偏光板的生產效率之方面來看，亦有利。11 The polyvinyl alcohol-based resin layer 6 may be formed only on one side of the base film 30 or on both sides. If it is formed on both sides, curling of the film that may be generated during the manufacture of the polarizing laminate film 400 (refer to FIG. 6) can be suppressed, and two polarizing plates can be obtained from one polarizing laminate film 400. In terms of production efficiency, it is also advantageous. 11

積層膜200中之聚乙烯醇系樹脂層6的厚度，較佳為3~30μm，尤佳為5~20μm。若是具有此範圍內的厚度之聚乙烯醇系樹脂層6，則經過後述之拉伸步驟S10-2及染色步驟S10-3，可得到碘的染色性良好且偏光性能優異，並且厚度極薄(例如厚度10μm以下)之碘系偏光片5。 The thickness of the polyvinyl alcohol-based resin layer 6 in the laminated film 200 is preferably 3 to 30 μm, and particularly preferably 5 to 20 μm. If it is a polyvinyl alcohol-based resin layer 6 having a thickness within this range, through the stretching step S10-2 and the dyeing step S10-3 to be described later, it is possible to obtain good dyeability of iodine and excellent polarizing performance, and an extremely thin thickness ( For example, an iodine-based polarizer 5 with a thickness of 10 μm or less).

在塗布液的塗布之前，為了提升基材膜30 與聚乙烯醇系樹脂層6之密合性，可至少對形成有聚乙烯醇系樹脂層6之側的基材膜30表面，施以電暈處理、電漿處理、火焰(火炎)處理等。此外，以同樣理由，可介於底漆層等將聚乙烯醇系樹脂層6形成於基材膜30上。 Before applying the coating liquid, in order to lift the base film 30 For adhesion to the polyvinyl alcohol-based resin layer 6, at least the surface of the base film 30 on the side where the polyvinyl alcohol-based resin layer 6 is formed may be subjected to corona treatment, plasma treatment, flame (fire) treatment, etc. . In addition, for the same reason, the polyvinyl alcohol-based resin layer 6 may be formed on the base film 30 between the primer layer and the like.

底漆層係可藉由將底漆層形成用塗布液塗布於基材膜30表面後，進行乾燥而形成。該塗布液係包含可發揮對於基材膜30與聚乙烯醇系樹脂層6之兩者具有某種程度的強密合力之成分，通常包含可賦予該密合力之樹脂成分以及溶劑。樹脂成分較佳係使用透明性、熱穩定性、拉伸性等為優異之熱塑性樹脂，例如可列舉出(甲基)丙烯酸系樹脂、聚乙烯醇系樹脂等。當中，較佳為使用可賦予良好的密合力之聚乙烯醇系樹脂。尤佳為使用聚乙烯醇樹脂。溶劑通常使用可溶解上述樹脂成分之一般的有機溶劑或水系溶劑，較佳是由以水為溶劑之塗布液來形成底漆層。 The primer layer can be formed by applying the coating liquid for forming a primer layer on the surface of the base film 30 and then drying it. This coating liquid contains a component that can exert a certain degree of strong adhesion to both the base film 30 and the polyvinyl alcohol-based resin layer 6, and usually contains a resin component and a solvent that can give the adhesion. As the resin component, a thermoplastic resin excellent in transparency, thermal stability, stretchability, etc. is preferably used, and examples thereof include (meth) acrylic resins and polyvinyl alcohol resins. Among them, it is preferable to use a polyvinyl alcohol-based resin that can impart good adhesion. It is particularly preferable to use polyvinyl alcohol resin. As the solvent, a general organic solvent or an aqueous solvent that can dissolve the above resin components is generally used, and it is preferable to form the primer layer from a coating liquid using water as a solvent.

為了提升底漆層的強度，可於底漆層形成用塗布液添加交聯劑。交聯劑的具體例，包含環氧系、異氰酸酯系、二醛系、金屬系(例如金屬鹽、金屬氧化物、金屬氫氧化物、有機金屬化合物)、高分子系的交聯劑。當使用聚乙烯醇系樹脂作為形成底漆層之樹脂成分時，可較佳地使用聚醯胺環氧樹脂、羥甲基化三聚氰胺樹脂、二醛系交聯劑、金屬螯合化合物系交聯劑等。 In order to increase the strength of the primer layer, a crosslinking agent may be added to the coating liquid for forming the primer layer. Specific examples of the crosslinking agent include epoxy-based, isocyanate-based, dialdehyde-based, metal-based (for example, metal salts, metal oxides, metal hydroxides, organometallic compounds), and polymer-based crosslinking agents. When using a polyvinyl alcohol-based resin as the resin component for forming the primer layer, it is preferable to use a polyamide epoxy resin, a methylolated melamine resin, a dialdehyde-based crosslinking agent, and a metal chelate compound-based crosslinking Agent.

底漆層的厚度，較佳為0.05~1μm，尤佳為0.1~0.4μm。較0.05μm更薄時，基材膜30與聚乙烯醇系樹脂層6之密合力提升的效果小，較1μm更厚時，不利 於雙面附有保護膜之偏光板的薄型化。 The thickness of the primer layer is preferably 0.05 to 1 μm, and particularly preferably 0.1 to 0.4 μm. When it is thinner than 0.05 μm, the effect of improving the adhesion force between the base film 30 and the polyvinyl alcohol-based resin layer 6 is small, but thicker than 1 μm is unfavorable. Thinner polarizer with protective film on both sides.

將底漆層形成用塗布液塗布於基材膜30之方法，係可與聚乙烯醇系樹脂層形成用塗布液之情形時相同。由底漆層形成用塗布液所構成之塗布層的乾燥溫度，例如為50~200℃，較佳為60~150℃。當溶劑包含水時，乾燥溫度較佳為80℃以上。 The method of applying the coating liquid for forming a primer layer to the base film 30 may be the same as in the case of the coating liquid for forming a polyvinyl alcohol-based resin layer. The drying temperature of the coating layer composed of the coating liquid for forming a primer layer is, for example, 50 to 200 ° C, preferably 60 to 150 ° C. When the solvent contains water, the drying temperature is preferably 80 ° C or higher.

[拉伸步驟S10-2] [Stretching Step S10-2]

參考第5圖，本步驟為對積層膜200進行拉伸，而得到由經拉伸之基材膜30'及聚乙烯醇系樹脂層6'所構成之拉伸膜300之步驟。拉伸處理通常為單軸拉伸。 Referring to FIG. 5, this step is a step of stretching the laminated film 200 to obtain a stretched film 300 composed of the stretched base film 30 ′ and the polyvinyl alcohol-based resin layer 6 ′. The stretching treatment is usually uniaxial stretching.

積層膜200的拉伸倍率，可因應期望的偏光特性而適當地選擇，較佳係相對於積層膜200的原長度為超過5倍且為17倍以下，尤佳為超過5倍且為8倍以下。當拉伸倍率為5倍以下時，聚乙烯醇系樹脂層6'未充分地配向，故碘系偏光片5的偏光度有時未充分地提高。另一方面，當拉伸倍率超過17倍時，拉伸時容易產生膜的斷裂，並且拉伸膜300的厚度被薄化至所需程度以上，而有在後續步驟中的加工性及處理性降低之虞。 The stretching magnification of the laminated film 200 can be appropriately selected according to the desired polarization characteristics, and it is preferably more than 5 times and less than 17 times relative to the original length of the laminated film 200, particularly preferably more than 5 times and 8 times the following. When the stretching magnification is 5 times or less, the polyvinyl alcohol-based resin layer 6 'is not sufficiently aligned, so the polarization degree of the iodine-based polarizer 5 may not be sufficiently improved. On the other hand, when the stretching magnification exceeds 17 times, the film is likely to break during stretching, and the thickness of the stretched film 300 is thinned to a required degree or more, and there is workability and handleability in subsequent steps Lower the risk.

拉伸處理並不限定於單段的拉伸，亦可多段地進行。此時，可在染色步驟S10-3之前連續地進行多階段的拉伸處理之全部，亦可與染色步驟S10-3中的染色處理及/或交聯處理同時地進行第二階段以後的拉伸處理。當如此多段地進行拉伸處理時，較佳係以拉伸處理的 全段合計成為超過5倍的拉伸倍率之方式進行拉伸處理。 The stretching treatment is not limited to single-stage stretching, and may be performed in multiple stages. At this time, all of the multi-stage stretching treatment may be continuously performed before the dyeing step S10-3, or the second and subsequent stretching may be performed simultaneously with the dyeing treatment and / or cross-linking treatment in the dyeing step S10-3. Extend treatment. When stretch treatment is performed in so many stages, it is preferable to use stretch treatment The stretching process is carried out so that the total ratio of all stages becomes more than 5 times.

拉伸處理係除了可為在膜長度方向(膜運送方向)上進行拉伸之縱向拉伸之外，亦可為在膜寬度方向上進行拉伸之橫向拉伸或斜向拉伸等。縱向拉伸方式，可列舉出：使用輥進行拉伸之輥間拉伸、壓縮拉伸、使用吸附盤(夾鉗)之拉伸等，橫向拉伸方式可列舉出拉幅法等。拉伸處理係濕潤式拉伸方法及乾式拉伸方法均可採用。 The stretching treatment may be longitudinal stretching that stretches in the film length direction (film transport direction), lateral stretching or diagonal stretching that stretches in the film width direction. The longitudinal stretching method can be exemplified by inter-roll stretching using rollers, compression stretching, stretching using suction discs (clamps), etc., and the transverse stretching method can be tentered. Both the wet stretching method and the dry stretching method of the stretching treatment system can be used.

拉伸溫度係被設定在聚乙烯醇系樹脂層6及基材膜30全體顯示出可拉伸程度的流動性之溫度以上，較佳為基材膜30的相轉移溫度(熔點或玻璃轉移溫度)之-30℃至+30℃的範圍，尤佳為-30℃至+5℃的範圍，更佳-25℃至+0℃的範圍。當基材膜30由複數層樹脂層所構成時，上述相轉移溫度意指該複數層樹脂層所顯示之相轉移溫度中之最高的相轉移溫度。 The stretching temperature is set to a temperature higher than the temperature at which the polyvinyl alcohol-based resin layer 6 and the base film 30 as a whole exhibit stretchability, and preferably the phase transition temperature (melting point or glass transition temperature) of the base film 30 ), The range of -30 ° C to + 30 ° C, particularly preferably the range of -30 ° C to + 5 ° C, more preferably the range of -25 ° C to + 0 ° C. When the base film 30 is composed of a plurality of resin layers, the above-mentioned phase transition temperature means the highest phase transition temperature among the phase transition temperatures exhibited by the plurality of resin layers.

若拉伸溫度低於相轉移溫度的-30℃，難以達成超過5倍的高倍率拉伸，或是基材膜30的流動性過低，而有難以進行拉伸處理之傾向。當拉伸溫度超過相轉移溫度的+30℃時，基材膜30的流動性過大，而有難以拉伸之傾向。為了更容易達成超過5倍的高倍率拉伸，拉伸溫度較佳位於上述範圍內，更佳為120℃以上。 If the stretching temperature is lower than -30 ° C of the phase transition temperature, it is difficult to achieve high-magnification stretching over 5 times, or the fluidity of the base film 30 is too low, and there is a tendency that stretching treatment is difficult. When the stretching temperature exceeds + 30 ° C of the phase transition temperature, the fluidity of the base film 30 is too large, and it tends to be difficult to stretch. In order to more easily achieve a high-magnification stretch of more than 5 times, the stretching temperature is preferably within the above range, more preferably 120 ° C. or higher.

拉伸處理中之積層膜200的加熱方法，係有：熱區加熱法(例如在藉由吹送熱風而調整至既定溫度之加熱爐般的拉伸熱區內加熱之方法)；在使用輥來進行拉伸時，加熱輥本身之方法；加熱器加熱法(將紅外線加熱器、 鹵素加熱器、平板加熱器等設置在積層膜200的上下方並以輻射熱進行加熱之方法)等。於輥間拉伸方式中，從拉伸溫度的均一性之觀點來看，較佳為熱區加熱法。 The heating method of the laminated film 200 in the stretching process includes: a hot zone heating method (for example, a method of heating in a stretching hot zone like a heating furnace adjusted to a predetermined temperature by blowing hot air); When stretching, the method of heating the roller itself; heater heating method (the infrared heater, A halogen heater, a flat panel heater, etc. are provided above and below the laminated film 200 and are heated by radiant heat) or the like. In the roll-to-roll stretching method, the hot zone heating method is preferred from the viewpoint of the uniformity of the stretching temperature.

在拉伸步驟S10-2之前，可設置將積層膜200預熱之預熱處理步驟。預熱方法可使用與拉伸處理中的加熱方法相同之方法。預熱溫度較佳為拉伸溫度的-50℃至±0℃的範圍，尤佳為拉伸溫度的-40℃至拉伸溫度的-10℃的範圍。 Before the stretching step S10-2, a pre-heat treatment step for pre-heating the laminated film 200 may be provided. The preheating method can use the same method as the heating method in the stretching process. The preheating temperature is preferably in the range of -50 ° C to ± 0 ° C of the stretching temperature, and particularly preferably in the range of -40 ° C to -10 ° C.

此外，於拉伸步驟S10-2的拉伸處理後，可設置熱固處理步驟。熱固處理係在以夾鉗握持拉伸膜300的端部之狀態下，一邊維持拉緊狀態一邊以結晶化以上的溫度進行熱處理之處理。藉由該熱固處理，可促進聚乙烯醇系樹脂層6'的結晶化。熱固處理的溫度，較佳為拉伸溫度的-0℃~-80℃的範圍，尤佳為拉伸溫度的-0℃~-50℃的範圍。 In addition, after the stretching treatment in the stretching step S10-2, a thermosetting treatment step may be provided. The thermosetting treatment is a treatment in which the end of the stretched film 300 is gripped with a clamp, and heat treatment is performed at a temperature equal to or higher than the temperature of crystallization while maintaining the tensioned state. By this thermosetting treatment, the crystallization of the polyvinyl alcohol-based resin layer 6 'can be promoted. The temperature of the thermosetting treatment is preferably in the range of -0 ° C to -80 ° C of the stretching temperature, and particularly preferably in the range of -0 ° C to -50 ° C of the stretching temperature.

[染色步驟S10-3] [Dyeing Step S10-3]

參考第6圖，本步驟為以碘將拉伸膜300的聚乙烯醇系樹脂層6'染色並使其吸附配向，而形成碘系偏光片5之步驟。經過本步驟，可得到在基材膜30'的單面或雙面積層有碘系偏光片5之偏光性積層膜400。 Referring to FIG. 6, this step is a step of forming the iodine-based polarizer 5 by dyeing the polyvinyl alcohol-based resin layer 6 ′ of the stretched film 300 with iodine and aligning it with adsorption. Through this step, a polarizing laminate film 400 having the iodine-based polarizer 5 on one side or double area of the base film 30 'can be obtained.

染色步驟係可藉由將拉伸膜300浸漬在含有碘之溶液(染色溶液)來進行。染色溶液係可使用將碘溶解於溶劑之溶液。溶劑一般係使用水，亦可進一步添加與 水具有相溶性之有機溶劑。染色溶液中之碘的濃度，較佳為0.01~10重量%，尤佳為0.02~7重量%。 The dyeing step can be performed by immersing the stretched film 300 in a solution containing iodine (dyeing solution). As the dyeing solution, a solution in which iodine is dissolved in a solvent can be used. The solvent generally uses water, which can be further added with Water is a miscible organic solvent. The concentration of iodine in the dyeing solution is preferably 0.01-10% by weight, particularly preferably 0.02-7% by weight.

由於可提升染色效率，故較佳更將碘化物添加於染色溶液。碘化物例如可列舉出碘化鉀、碘化鋰、碘化鈉、碘化鋅、碘化鋁、碘化鉛、碘化銅、碘化鋇、碘化鈣、碘化錫、碘化鈦等。染色溶液中之碘化物的濃度，較佳為0.01~20重量%。碘化物中，較佳係添加碘化鉀。添加碘化鉀時，碘與碘化鉀之比率，以重量比計較佳為1：5~1：100，尤佳為1：6~1：80。染色溶液的溫度，較佳為10~60℃，尤佳為20~40℃。 Since the dyeing efficiency can be improved, it is better to add iodide to the dyeing solution. Examples of the iodide include potassium iodide, lithium iodide, sodium iodide, zinc iodide, aluminum iodide, lead iodide, copper iodide, barium iodide, calcium iodide, tin iodide, and titanium iodide. The concentration of iodide in the dyeing solution is preferably 0.01 to 20% by weight. Among the iodide, potassium iodide is preferably added. When potassium iodide is added, the ratio of iodine to potassium iodide is preferably 1: 5 to 1: 100 in terms of weight ratio, and particularly preferably 1: 6 to 1:80. The temperature of the dyeing solution is preferably 10 to 60 ° C, and particularly preferably 20 to 40 ° C.

亦可在拉伸步驟S10-2之前進行染色步驟S10-3，或是同時進行此等步驟，但較佳係以使吸附於聚乙烯醇系樹脂層之碘可良好地配向之方式，對積層膜200至少施以某種程度的拉伸處理後再實施染色步驟S10-3。 It is also possible to perform the dyeing step S10-3 before the stretching step S10-2, or to perform these steps at the same time, but it is preferable that the iodine adsorbed on the polyvinyl alcohol-based resin layer can be aligned well in After the film 200 is subjected to at least a certain degree of stretching treatment, the dyeing step S10-3 is performed.

染色步驟S10-3係可包含：在接續於染色處理後所實施之交聯處理步驟。交聯處理係可藉由將染色後之膜浸漬在使交聯劑溶解於溶劑之溶液(交聯溶液)中而進行。交聯劑例如可列舉出硼酸、硼砂般的硼化物、乙二醛、戊二醛等。交聯劑可僅單獨使用1種或併用2種以上。交聯溶液的溶劑可使用水，亦可進一步包含與水具有相溶性之有機溶劑。交聯溶液中之交聯劑的濃度，較佳為1~20重量%，尤佳為6~15重量%。 The dyeing step S10-3 may include: a cross-linking treatment step performed after the dyeing treatment. The crosslinking treatment can be performed by immersing the dyed film in a solution (crosslinking solution) in which the crosslinking agent is dissolved in a solvent. Examples of the crosslinking agent include boric acid, borax-like boride, glyoxal, glutaraldehyde and the like. The crosslinking agent may be used alone or in combination of two or more. The solvent of the cross-linking solution may use water, and may further contain an organic solvent having compatibility with water. The concentration of the cross-linking agent in the cross-linking solution is preferably from 1 to 20% by weight, particularly preferably from 6 to 15% by weight.

交聯溶液更可包含碘化物。藉由碘化物的添加，可使碘系偏光片5之面內的偏光性能更達到均一 化。碘化物的具體例係與上述相同。交聯溶液中之碘化物的濃度，較佳為0.05~15重量%，尤佳為0.5~8重量%。交聯溶液的溫度，較佳為10~90℃。 The cross-linking solution may further contain iodide. By adding iodide, the polarization performance in the plane of the iodine polarizer 5 can be more uniform Change. Specific examples of iodide are the same as described above. The concentration of iodide in the cross-linking solution is preferably 0.05 to 15% by weight, particularly preferably 0.5 to 8% by weight. The temperature of the cross-linking solution is preferably 10 to 90 ° C.

交聯處理亦可藉由將交聯劑調配於染色溶液中而與染色處理同時處理。此外，亦可使用組成不同之2種以上的交聯溶液，並進行2次以上之浸漬在交聯溶液之處理。 The cross-linking treatment can also be processed simultaneously with the dyeing treatment by blending the cross-linking agent in the dyeing solution. In addition, two or more cross-linking solutions with different compositions may be used, and the treatment of immersing in the cross-linking solution more than twice.

於染色步驟S10-3後，後述貼合步驟S10-4之前，較佳係進行洗淨步驟及乾燥步驟。洗淨步驟通常包含水洗淨步驟。水洗淨步驟係可藉由將染色處理後或交聯處理後的膜浸漬在離子交換水、蒸餾水般之純水中進行。水洗淨溫度通常為3~50℃，較佳為4~20℃。洗淨步驟亦可為水洗淨步驟與依據碘化物溶液所進行的洗淨步驟之組合。於洗淨步驟後所進行之乾燥步驟，可採用自然乾燥、送風乾燥、加熱乾燥等之任意的適當方法。例如加熱乾燥時，乾燥溫度通常為20~95℃。 After the dyeing step S10-3 and before the bonding step S10-4 described later, it is preferable to perform a washing step and a drying step. The washing step usually includes a water washing step. The water washing step can be performed by immersing the membrane after dyeing treatment or cross-linking treatment in pure water such as ion-exchanged water or distilled water. The water washing temperature is usually 3 to 50 ° C, preferably 4 to 20 ° C. The washing step may also be a combination of a water washing step and a washing step based on an iodide solution. For the drying step performed after the washing step, any suitable method such as natural drying, air drying, and heating drying can be used. For example, when heating and drying, the drying temperature is usually 20 to 95 ° C.

[貼合步驟S10-4] [Fit Step S10-4]

參考第7圖，本步驟為隔著第1接著劑層15將第1保護膜10貼合於偏光性積層膜400的碘系偏光片5上，亦即碘系偏光片5之與基材膜30'側為相反側的面上，而得到多層膜500之步驟。關於形成第1接著劑層15之接著劑，係如上所述。 Referring to FIG. 7, this step is to attach the first protective film 10 to the iodine-based polarizer 5 of the polarizing laminate film 400 via the first adhesive layer 15, that is, the iodine-based polarizer 5 and the base film The 30 'side is the opposite side, and the step of obtaining the multilayer film 500. The adhesive for forming the first adhesive layer 15 is as described above.

當偏光性積層膜400於基材膜30'的雙面上 具有碘系偏光片5時，通常於雙面的碘系偏光片5上分別貼合第1保護膜10。此時，此等第1保護膜可為同種類的保護膜，或不同種類的保護膜。 When the polarizing laminate film 400 is on both sides of the base film 30 ' When the iodine-based polarizer 5 is provided, the first protective film 10 is usually bonded to the double-sided iodine-based polarizer 5 respectively. At this time, the first protective films may be the same type of protective films or different types of protective films.

使用活化能射線硬化性接著劑來貼合第1保護膜10時，在透過成為第1接著劑層15之活化能射線硬化性接著劑將第1保護膜10積層於碘系偏光片5上之後，照射紫外線、可見光、電子束、X射線般之活化能射線使接著劑層硬化。當中，較佳為紫外線，此時的光源可使用低壓汞燈、中壓汞燈、高壓汞燈、超高壓汞燈、化學燈、黑光燈、微波激發汞燈、金屬鹵化物燈等。使用水系接著劑時，只要透過水系接著劑將第1保護膜10積層於碘系偏光片5上後進行加熱乾燥即可。 When the first protective film 10 is bonded using an active energy ray-curable adhesive, after the first protective film 10 is laminated on the iodine-based polarizer 5 through the active energy ray-curable adhesive that becomes the first adhesive layer 15 , Irradiate ultraviolet, visible light, electron beam, X-ray-like activation energy rays to harden the adhesive layer. Among them, ultraviolet light is preferred, and the light source at this time may be a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a chemical lamp, a black light lamp, a microwave-excited mercury lamp, a metal halide lamp, or the like. When an aqueous adhesive is used, the first protective film 10 may be laminated on the iodine polarizer 5 through the aqueous adhesive, and then heated and dried.

將第1保護膜10貼合於碘系偏光片5時，於第1保護膜10及/或碘系偏光片5的貼合面，為了提升與碘系偏光片5之接著性，可進行電漿處理、電暈處理、紫外線照射處理、火焰(火炎)處理、皂化處理等之表面處理(易接著處理)，當中，較佳係進行電漿處理、電暈處理或皂化處理。 When bonding the first protective film 10 to the iodine-based polarizer 5, on the bonding surface of the first protective film 10 and / or the iodine-based polarizer 5, in order to improve the adhesion with the iodine-based polarizer 5, electrical Among the surface treatment (easy adhesion treatment) such as plasma treatment, corona treatment, ultraviolet irradiation treatment, flame (fire) treatment, saponification treatment, etc., preferably plasma treatment, corona treatment or saponification treatment is performed.

[剝離步驟S10-5] [Stripping Step S10-5]

本步驟為從多層膜500中將基材膜30'剝離去除之步驟。經過此步驟，可得到與第2圖相同之單面附有保護膜之偏光板100。當偏光性積層膜400於基材膜30'的雙面具有碘系偏光片5，且在將第1保護膜10貼合於此等兩者的 碘系偏光片5時，藉由此剝離步驟S10-5，可從1片偏光性積層膜400得到2片之單面附有保護膜之偏光板100。 This step is a step of peeling and removing the base film 30 'from the multilayer film 500. Through this step, the polarizing plate 100 with a protective film on one side as in FIG. 2 can be obtained. When the polarizing laminate film 400 has the iodine-based polarizer 5 on both sides of the base film 30 ', and the first protective film 10 is bonded to the two When the iodine-based polarizer 5 is peeled off by this step S10-5, two polarizing plates 100 with a protective film on one side can be obtained from one polarizing laminate film 400.

將基材膜30'剝離去除之方法並無特別限定，通常可藉由與附有黏著劑之偏光板所進行之分隔片(剝離膜)的剝離步驟相同之方法來剝離。基材膜30'係可於貼合步驟S10-4後，直接剝離，或是於貼合步驟S10-4後，先捲取為輥狀，並於後續步驟一邊捲出一邊剝離。 The method of peeling and removing the base film 30 'is not particularly limited, and it can usually be peeled by the same method as the peeling step of the separator (peeling film) by the polarizer with an adhesive. The base film 30 'can be peeled directly after the laminating step S10-4, or after the laminating step S10-4, it is first rolled into a roll shape and peeled while being rolled out in the subsequent steps.

(2)雙面附有保護膜之偏光板的製作步驟S20 (2) Production step of polarizing plate with protective film on both sides S20

本步驟中，將第2保護膜20貼合於單面附有保護膜之偏光板100的碘系偏光片5的外面，藉此得到雙面附有保護膜之偏光板。雙面附有保護膜之偏光板之層構成的一例，如第8圖所示。如第8圖所示之雙面附有保護膜之偏光板600般，第2保護膜20通常透過第2接著劑層25貼合(接著固定)於碘系偏光片5。所謂碘系偏光片5的外面，意指碘系偏光片5之與第1保護膜10為相反側的面，當經過將基材膜30'剝離去除之步驟來製作單面附有保護膜之偏光板100時，意指藉由基材膜30'的剝離去除所暴露出之碘系偏光片5的表面。 In this step, the second protective film 20 is bonded to the outer surface of the iodine-based polarizer 5 of the polarizing plate 100 with a protective film on one side, thereby obtaining a polarizing plate with a protective film on both sides. An example of the layer configuration of a polarizing plate with a protective film on both sides is shown in Figure 8. Like the polarizing plate 600 with a protective film on both sides shown in FIG. 8, the second protective film 20 is usually bonded (and then fixed) to the iodine-based polarizer 5 through the second adhesive layer 25. The outer surface of the iodine-based polarizer 5 means the surface of the iodine-based polarizer 5 on the side opposite to the first protective film 10, and after the step of peeling and removing the base film 30 'to produce a single-sided protective film In the case of the polarizing plate 100, it means that the surface of the exposed iodine-based polarizer 5 is removed by peeling off the base film 30 '.

此外，第2保護膜20係與第1保護膜10相同，可由具有透光性(較佳為光學透明)之熱塑性樹脂所構成，且透濕度為150g/m²/24hr以下之膜。亦可為相位差膜、增亮膜般之兼具光學功能之保護膜。第2保護膜20能夠具有之表面處理層及膜的厚度、材質等，可援引第1 保護膜10中所說明之上述記載內容。第1保護膜10與第2保護膜20，可互為由同種類的樹脂所構成之保護膜，或是由不同種類的樹脂所構成之保護膜。 In addition, the second protective film 20 is the same as the first protective film 10, and can be made of a thermoplastic resin having translucency (preferably optically transparent) and having a moisture permeability of 150 g / m ² / 24hr or less. It can also be a protective film with optical functions like phase difference film and brightness enhancement film. The surface treatment layer and the thickness, material, etc. of the film that the second protective film 20 can have can be cited as described above in the first protective film 10. The first protective film 10 and the second protective film 20 may be a protective film made of the same type of resin, or a protective film made of different types of resin.

形成第2接著劑層25之接著劑，與第1接著劑層15相同，可為活化能射線硬化性接著劑或水系接著劑，但較佳為紫外線硬化性接著劑般之活化能射線硬化性接著劑。使用水系接著劑時，由於會將水分供給至碘系偏光片5，所以有時貼合第2保護膜20時之碘系偏光片5的水分率無法成為未達8重量%。形成第2接著劑層25之接著劑，可具有與形成第1接著劑層15之接著劑為相同之組成，亦可具有相異之組成。 The adhesive forming the second adhesive layer 25 is the same as the first adhesive layer 15 and may be an active energy ray-curable adhesive or an aqueous adhesive, but is preferably an active energy ray-curable like an ultraviolet-curable adhesive Then agent. When an aqueous adhesive is used, moisture is supplied to the iodine-based polarizer 5, so the moisture content of the iodine-based polarizer 5 when the second protective film 20 is bonded may not be less than 8% by weight. The adhesive forming the second adhesive layer 25 may have the same composition as the adhesive forming the first adhesive layer 15 or may have a different composition.

(3)水分率降低步驟S30 (3) Moisture rate reduction step S30

本發明之雙面附有保護膜之偏光板之製造方法，為了使貼合第2保護膜20時之碘系偏光片5的水分率未達8重量%，於製造上述所說明之雙面附有保護膜之偏光板之步驟中，係包含：於雙面附有保護膜之偏光板的製作步驟S20之前之任意1個以上的階段中所實施之水分率降低步驟S30。水分率降低步驟S30，為對於包含碘系偏光片5之膜施以降低碘系偏光片5的水分率之處理之步驟。 In the method for manufacturing a polarizing plate with a protective film on both sides of the present invention, in order to make the moisture content of the iodine-based polarizer 5 when the second protective film 20 is attached less than 8 wt%, The step of the polarizing plate with a protective film includes a step S30 of reducing the moisture content at any one or more stages before the step S20 of the polarizing plate with a protective film on both sides. The moisture content reduction step S30 is a step of applying a process of reducing the moisture content of the iodine-based polarizer 5 to the film containing the iodine-based polarizer 5.

列舉出實施水分率降低步驟S30之時機的例子，如下所述。 An example of the timing of implementing the moisture content reduction step S30 is as follows.

1)在將第1保護膜10貼合於由單體(單獨)膜所構成之碘系偏光片5的單面，得到單面附有保護膜之偏光板100 後，貼合第2保護膜20之方法中，於第1保護膜10的貼合前、貼合後(包含即將實施雙面附有保護膜之偏光板的製作步驟S20前)或此等之兩者。惟在單體(單獨)膜的狀態下降低水分率時，碘系偏光片5容易裂開或斷裂，故較佳係於第1保護膜10的貼合後。 1) The first protective film 10 is bonded to one side of an iodine-based polarizer 5 composed of a single (separate) film to obtain a polarizing plate 100 with a protective film on one side Then, in the method of bonding the second protective film 20, before the bonding of the first protective film 10, after the bonding (including the step S20 immediately before the implementation of the polarizing plate with a protective film on both sides) or the like Both. However, when the moisture content is reduced in the state of a single (single) film, the iodine-based polarizer 5 is likely to crack or break, so it is preferably after the first protective film 10 is bonded.

2)依據第3圖所示之方法而得到單面附有保護膜之偏光板100後，貼合第2保護膜20之方法，係於染色步驟S10-3後、貼合步驟S10-4後、剝離步驟S10-5後(包含即將實施雙面附有保護膜之偏光板的製作步驟S20前)或此等之2個以上的階段。從容易降低水分率來看，水分率降低步驟S30較佳是在碘系偏光片5的表面暴露出之階段，例如在貼合步驟S10-4前或剝離步驟S10-5後進行。 2) After obtaining the polarizing plate 100 with a protective film on one side according to the method shown in FIG. 3, the method of bonding the second protective film 20 is after the dyeing step S10-3 and after the bonding step S10-4 2. After the peeling step S10-5 (including the step S20 immediately before the implementation of the polarizing plate with a protective film on both sides) or two or more of these stages. From the viewpoint of easily reducing the moisture content, the moisture content reduction step S30 is preferably performed at a stage where the surface of the iodine-based polarizer 5 is exposed, for example, before the bonding step S10-4 or after the peeling step S10-5.

例如於上述2)中，在貼合步驟S10-4前實施水分率降低步驟S30般，不論上述1)或2)，於水分率降低步驟S30與雙面附有保護膜之偏光板的製作步驟S20之間具有相對較長的區間時，以不會因該區間中的吸濕而在第2保護膜20的貼合時使水分率成為8重量%以上之方式，設置吸濕抑制手段，或是於該區間中再次實施水分率降低步驟S30。 For example, in the above 2), the moisture reduction step S30 is performed before the bonding step S10-4, regardless of the above 1) or 2), the moisture reduction step S30 and the manufacturing step of the polarizing plate with a protective film on both sides When there is a relatively long interval between S20, a moisture absorption suppression means is provided so that the moisture content does not become 8% by weight or more when the second protective film 20 is bonded due to moisture absorption in the interval, or In this interval, the step S30 of reducing the moisture content is performed again.

吸濕抑制手段係可列舉出：將可剝離的防濕性膜暫貼合於碘系偏光片5的暴露面之方法；在用以形成包含具有暴露表面之碘系偏光片5之膜之步驟結束後，盡可能迅速將膜捲繞為輥狀以抑制水分從外部侵入之方法；以鋁積層膜般的防濕性膜更將輥狀的膜捆包之方法 等。捲繞為輥狀之方法，在所捲繞之膜具有基材膜，且該基材膜為透濕性低者時特別有利。或者是不須特別設置如以上之吸濕抑制手段，而是考量到碘系偏光片5的吸濕速度，以在因吸濕而使水分率成為8重量%以上之前，可實施雙面附有保護膜之偏光板的製作步驟S20之方式來設計步驟。 The means for suppressing moisture absorption may include: a method of temporarily attaching a peelable moisture-proof film to the exposed surface of the iodine-based polarizer 5; a step for forming a film including the iodine-based polarizer 5 having an exposed surface After the end, as soon as possible to wind the film into a roll to prevent moisture from invading from outside; a method of wrapping the roll-shaped film with a moisture-proof film like an aluminum laminate film Wait. The method of winding into a roll shape is particularly advantageous when the wound film has a base film and the base film is one having low moisture permeability. Or, it is not necessary to provide a moisture absorption suppression means as described above, but the moisture absorption rate of the iodine-based polarizer 5 is taken into consideration, so that before the moisture content becomes 8% by weight or more due to moisture absorption, double-sided The design step is performed in the manner of the manufacturing step S20 of the polarizing plate of the protective film.

此外，例如於水分率降低步驟S30與雙面附有保護膜之偏光板的製作步驟S20之間具有相對較長的區間時，考量碘系偏光片5的吸濕速度，於水分率降低步驟S30中，預先將水分率降低至較8重量%充分地低。藉由此方法，於水分率降低步驟S30與雙面附有保護膜之偏光板的製作步驟S20之間不須設置特別手段，可使貼合第2保護膜20時之水分率設為未達8重量%。 In addition, for example, when there is a relatively long interval between the moisture reduction step S30 and the manufacturing step S20 of the polarizing plate with a double-sided protective film, the moisture absorption rate of the iodine-based polarizer 5 is considered, and the moisture percentage reduction step S30 In the middle, the moisture content is reduced to be sufficiently lower than 8% by weight in advance. By this method, no special means is required between the step S30 of reducing the moisture content and the step S20 of manufacturing a polarizing plate with a protective film on both sides, and the moisture rate when the second protective film 20 is bonded can be set to less 8% by weight.

如上述般，於碘系偏光片5與第1保護膜10之貼合可使用水系接著劑，但若使用水系接著劑，由於會將水分供給至碘系偏光片5，所以較佳是在貼合第1保護膜10之後至貼合第2保護膜20為止之間進行水分率降低步驟S30。該水分率降低步驟S30不須為最初的水分率降低步驟S30。 As described above, the water-based adhesive can be used for bonding the iodine-based polarizer 5 and the first protective film 10, but if the water-based adhesive is used, water is supplied to the iodine-based polarizer 5, so it is preferable to stick After the first protective film 10 is closed until the second protective film 20 is bonded, the moisture content reduction step S30 is performed. This water content reduction step S30 need not be the first water content reduction step S30.

從耐熱性之觀點來看，貼合第2保護膜20時之碘系偏光片5的水分率，較佳為未達6重量%，尤佳為5重量%以下。用以降低水分率之具體方法並無特別限制，例如可列舉出吹送乾燥空氣之方法、通過調整為低濕度之調濕區之方法、通過熱風乾燥爐之方法、使用紅外線 加熱器般之加熱裝置而進行加熱之方法、以及此等之組合。 From the viewpoint of heat resistance, the moisture content of the iodine-based polarizer 5 when the second protective film 20 is bonded is preferably less than 6% by weight, and particularly preferably 5% by weight or less. The specific method for reducing the moisture content is not particularly limited, and examples include a method of blowing dry air, a method of adjusting the humidity adjustment zone to low humidity, a method of using a hot air drying furnace, and the use of infrared rays Heater-like heating means for heating, and combinations of these.

〈雙面附有保護膜之偏光板〉 <Polarizing plate with protective film on both sides>

本發明之雙面附有保護膜之偏光板，如第8圖所示，係包含：碘系偏光片5、積層於該一方的面之第1保護膜10、以及積層於另一方的面之第2保護膜20。通常，第1保護膜10、第2保護膜20分別隔著第1接著劑層15、第2接著劑層25貼合(接著固定)於碘系偏光片5。 As shown in FIG. 8, the polarizing plate with a protective film on both sides of the present invention includes: an iodine-based polarizer 5, a first protective film 10 laminated on one side, and a polarizing plate laminated on the other side The second protective film 20. Generally, the first protective film 10 and the second protective film 20 are bonded (adhered to) to the iodine-based polarizer 5 via the first adhesive layer 15 and the second adhesive layer 25, respectively.

本發明之雙面附有保護膜之偏光板中，碘系偏光片5的水分率為未達8重量%，較佳係未達6重量%，尤佳為5重量%以下。此外，第1保護膜10及第2保護膜20均使用透濕度150g/m²/24hr以下，較佳為100g/m²/24hr以下之熱塑性樹脂膜。關於碘系偏光片5、第1保護膜10及第2保護膜20的具體構成，係援引上述記載內容。 In the polarizing plate with a protective film on both sides of the present invention, the moisture content of the iodine-based polarizer 5 is less than 8% by weight, preferably less than 6% by weight, and particularly preferably less than 5% by weight. In addition, for both the first protective film 10 and the second protective film 20, a thermoplastic resin film having a moisture permeability of 150 g / m ² / 24hr or less, preferably 100 g / m ² / 24hr or less is used. The specific structures of the iodine-based polarizer 5, the first protective film 10, and the second protective film 20 are cited above.

本發明之雙面附有保護膜之偏光板，可藉由以上所說明之方法而適合地製造。本發明之雙面附有保護膜之偏光板，由於碘系偏光片5的水分率為未達8重量%，且將低透濕度的保護膜積層於雙面，故即使碘系偏光片5的厚度薄(例如厚度10μm以下)，亦可兼具耐濕熱性及耐熱性。雙面附有保護膜之偏光板可適合地適用在液晶顯示裝置或有機電激發光裝置般之影像顯示裝置。適用在液晶顯示裝置時，本發明之雙面附有保護膜之偏光板可為配置在液晶單元的前面(觀看)側之偏光板，或是配置在背 面(背光)側之偏光板。 The polarizing plate with a protective film on both sides of the present invention can be suitably manufactured by the method described above. In the polarizing plate with a protective film on both sides of the present invention, since the moisture content of the iodine-based polarizer 5 is less than 8% by weight, and a protective film with low moisture permeability is laminated on both sides, even the iodine-based polarizer 5 The thickness is thin (for example, the thickness is 10 μm or less), and may have both moisture resistance and heat resistance. The polarizing plate with a protective film on both sides can be suitably applied to an image display device like a liquid crystal display device or an organic electroluminescence device. When applied to a liquid crystal display device, the polarizing plate with a protective film on both sides of the present invention may be a polarizing plate arranged on the front (viewing) side of the liquid crystal cell, or arranged on the back Polarizer on the side (backlight) side.

雙面附有保護膜之偏光板，亦可具備：貼合於在第1保護膜10或第2保護膜20上所積層之其他構件(例如當適用於液晶顯示裝置時為液晶單元)之黏著劑層。形成黏著劑層之黏著劑，通常是由以(甲基)丙烯酸系樹脂、苯乙烯系樹脂、聚矽氧系樹脂等作為基質聚合物，且將異氰酸酯化合物、環氧化合物、氮丙啶化合物般之交聯劑添加於此之黏著劑組成物所構成。此外，亦可構成為更含有微粒而顯現出光散射性之黏著劑層。黏著劑層的厚度通常為1~40μm，較佳為3~25μm。 A polarizing plate with a protective film on both sides may also be provided with: adhesion to other members laminated on the first protective film 10 or the second protective film 20 (for example, a liquid crystal cell when applied to a liquid crystal display device)剂 层。 Agent layer. The adhesive that forms the adhesive layer is usually made of (meth) acrylic resin, styrene resin, polysiloxane resin, etc. as the matrix polymer, and the isocyanate compound, epoxy compound, aziridine compound The crosslinking agent is added to the adhesive composition. In addition, it may be configured as an adhesive layer that further contains fine particles and exhibits light scattering properties. The thickness of the adhesive layer is usually 1-40 μm, preferably 3-25 μm.

此外，雙面附有保護膜之偏光板，可更具備積層於第1保護膜10或第2保護膜20上之其他光學層。其他光學層，可列舉出：可使某種偏光之光穿透並且使顯現出與其相反性質的偏光之光進行反射之反射型偏光膜；於表面具有凹凸形狀之附有防眩功能之膜；表面附有抗反射功能之膜；於表面具有反射功能之反射膜；兼具反射功能及穿透功能之半穿透半反射膜；視角補償膜等。 In addition, the polarizing plate with a protective film on both sides may further include another optical layer laminated on the first protective film 10 or the second protective film 20. Other optical layers may include: a reflective polarizing film that can penetrate a certain polarized light and reflect the polarized light that exhibits the opposite properties; a film with an anti-glare function that has a concave and convex shape on the surface; A film with anti-reflection function is attached to the surface; a reflection film with reflection function on the surface; a semi-transmissive semi-reflection film with both reflection function and transmission function; viewing angle compensation film, etc.

[實施例] [Example]

以下，係顯示實施例及比較例而更具體地說明本發明，但本發明並不限定於此等例。 Hereinafter, the present invention will be described more specifically by showing examples and comparative examples, but the present invention is not limited to these examples.

〈實施例1〉 <Example 1>

(1)底漆層形成步驟 (1) Step of forming primer layer

將聚乙烯醇粉末(日本合成化學工業股份有限公司製的「Z-200」、平均聚合度1100、皂化度99.5莫耳%)溶解於95℃的熱水，調製出濃度3重量%的聚乙烯醇水溶液。以相對於聚乙烯醇粉末6重量份為5重量份之比率，將交聯劑(田岡化學工業股份有限公司製的「Sumirez Resin 650」)混合於所得之水溶液中，而得到底漆層形成用塗布液。 Polyvinyl alcohol powder ("Z-200" manufactured by Nippon Synthetic Chemical Industry Co., Ltd., average polymerization degree 1100, saponification degree 99.5 mol%) was dissolved in hot water at 95 ° C to prepare polyethylene with a concentration of 3% by weight Alcohol solution. A crosslinking agent ("Sumirez Resin 650" manufactured by Taoka Chemical Industry Co., Ltd.) was mixed with the obtained aqueous solution at a ratio of 5 parts by weight relative to 6 parts by weight of the polyvinyl alcohol powder to obtain a primer layer. Coating liquid.

接著，對由聚丙烯所構成之厚度90μm的基材膜(熔點：163℃、透濕度：15g/m²/24hr)的單面施以電暈處理後，使用小徑微凹版塗布機將上述底漆層形成用塗布液塗布於該電暈處理面，於80℃下使其乾燥10分鐘，藉此得到厚度0.2μm的底漆層。 Next, after corona treatment was applied to one side of a base film composed of polypropylene and having a thickness of 90 μm (melting point: 163 ° C., moisture permeability: 15 g / m ² / 24hr), the above was applied using a small-diameter microgravure coater The coating liquid for forming a primer layer was applied to this corona-treated surface, and dried at 80 ° C. for 10 minutes, thereby obtaining a primer layer with a thickness of 0.2 μm.

(2)積層膜的製作(樹脂層形成步驟) (2) Production of laminated film (resin layer forming step)

將聚乙烯醇粉末(Kuraray股份有限公司製的「PVA124」、平均聚合度2400、皂化度98.0~99.0莫耳%)溶解於95℃的熱水，調製出濃度8重量%的聚乙烯醇水溶液，並以此作為聚乙烯醇系樹脂層形成用塗布液。 Polyvinyl alcohol powder ("PVA124" manufactured by Kuraray Co., Ltd., average degree of polymerization 2400, saponification degree 98.0-99.0 mol%) was dissolved in hot water at 95 ° C to prepare a polyvinyl alcohol aqueous solution with a concentration of 8% by weight This was used as a coating liquid for forming a polyvinyl alcohol-based resin layer.

使用壓鑄模塗布機，將上述聚乙烯醇系樹脂層形成用塗布液塗布於上述(1)中所製作之具有底漆層之基材膜的底漆層表面後，於80℃乾燥20分鐘，藉此於底漆層上形成聚乙烯醇系樹脂層，而得到由基材膜/底漆層/聚乙烯醇系樹脂層所構成之積層膜。 Using a die-casting die coater, apply the coating solution for forming a polyvinyl alcohol-based resin layer to the surface of the primer layer of the base film with a primer layer prepared in (1) above, and dry at 80 ° C for 20 minutes. In this way, a polyvinyl alcohol-based resin layer is formed on the primer layer to obtain a laminate film composed of the base film / primer layer / polyvinyl alcohol-based resin layer.

(3)拉伸膜的製作(拉伸步驟) (3) Production of stretched film (stretching step)

使用浮動的縱向單軸拉伸裝置，於160℃對上述(2)中所製作之積層膜實施自由端單軸拉伸至5.3倍為止，而得到拉伸膜。拉伸後之聚乙烯醇系樹脂層的厚度為5.1μm。 Using a floating longitudinal uniaxial stretching device, the laminated film produced in (2) above was subjected to free end uniaxial stretching up to 5.3 times at 160 ° C to obtain a stretched film. The thickness of the polyvinyl alcohol-based resin layer after stretching was 5.1 μm.

(4)偏光性積層膜的製作(染色步驟) (4) Preparation of polarizing laminated film (dyeing step)

將上述(3)中所製作之拉伸膜，浸漬在含有碘及碘化鉀之30℃的染色水溶液(水每100重量份，含有0.6重量份的碘及10重量份的碘化鉀)約180秒，以進行聚乙烯醇系樹脂層的染色處理後，以10℃的純水洗去多餘的染色水溶液。 The stretched film prepared in (3) above is immersed in a 30 ° C dyeing aqueous solution (water containing 100 parts by weight of water, containing 0.6 parts by weight of iodine and 10 parts by weight of potassium iodide) for about 180 seconds, After the dyeing treatment of the polyvinyl alcohol-based resin layer, the excess dyeing aqueous solution was washed away with pure water at 10 ° C.

接著，浸漬在含有硼酸之78℃的第1交聯水溶液(水每100重量份，含有10.4重量份的硼酸)120秒，然後浸漬在含有硼酸及碘化鉀之70℃的第2交聯水溶液(水每100重量份，含有5.7重量份的硼酸及12重量份的碘化鉀)60秒，以進行交聯處理。然後，以80℃之純水洗淨10秒。最後，以50℃乾燥60秒，於80℃乾燥60秒(水分率降低步驟)，藉此，得到由基材膜/碘系偏光片所構成之偏光性積層膜。於乾燥結束時點之偏光性積層膜所具有之碘系偏光片的水分率為0.4重量%。此外，碘系偏光片的厚度為5.6μm。 Next, it was immersed in a 78 ° C first crosslinking aqueous solution containing boric acid (for every 100 parts by weight of water, containing 10.4 parts by weight of boric acid) for 120 seconds, and then immersed in a 70 ° C second crosslinking aqueous solution containing boric acid and potassium iodide (water Each 100 parts by weight contains 5.7 parts by weight of boric acid and 12 parts by weight of potassium iodide) for 60 seconds for cross-linking treatment. Then, it was washed with pure water at 80 ° C for 10 seconds. Finally, it was dried at 50 ° C. for 60 seconds and at 80 ° C. for 60 seconds (moisture content reduction step), whereby a polarizing laminated film composed of a base film / iodine-based polarizer was obtained. The moisture content of the iodine-based polarizer included in the polarizing laminate film at the end of drying was 0.4% by weight. In addition, the thickness of the iodine-based polarizer is 5.6 μm.

以可將空氣中的水分吸濕而抑制碘系偏光片的水分率上升之方式，於碘系偏光片之與基材膜相反側的面上，於乾燥後立即貼合具有再剝離性且透濕度低之防濕性膜(透濕度30g/m²/24hr的聚烯烴系樹脂膜)。藉此，由 於碘系偏光片被低透濕度的基材膜與防濕性膜所夾持，所以可維持低水分率。 In order to absorb moisture in the air and suppress the increase in the moisture content of the iodine-based polarizer, the surface of the iodine-based polarizer on the side opposite to the base film is immediately re-peelable and transparent after drying. A moisture-proof film with low humidity (polyolefin resin film with a moisture permeability of 30 g / m ² / 24hr). Thereby, since the iodine-based polarizer is sandwiched between the base film and the moisture-proof film with low moisture permeability, the low moisture content can be maintained.

(5)多層膜的製作(貼合步驟) (5) Fabrication of multilayer film (lamination step)

從上述(4)中所製作之附有防濕性膜之偏光性積層膜剝離防濕性膜，並立即(1分鐘以內)將第1保護膜貼合於該剝離面。第1保護膜係使用透濕度為16g/m²/24hr且由環狀聚烯烴系樹脂所構成之厚度23μm的熱塑性樹脂膜(Zeon Japan股份有限公司製的「ZF14」)。第1保護膜的貼合係以使硬化後的厚度成為1.0μm之方式，使用小徑微凹版塗布機將將紫外線硬化性接著劑(ADEKA股份有限公司製的「KR-75T」)塗布於其單面後，使用貼合輥將此貼合於上述剝離面，然後，使用高壓汞燈，以200mJ/cm²的積算光量從基材膜側照射紫外線使接著劑層硬化而進行。 Peel off the moisture-proof film from the polarizing laminate film with moisture-proof film prepared in (4) above, and immediately (within 1 minute) apply the first protective film to the peeling surface. As the first protective film, a thermoplastic resin film (“ZF14” manufactured by Zeon Japan Co., Ltd.) having a moisture permeability of 16 g / m ² / 24hr and a thickness of 23 μm composed of a cyclic polyolefin resin was used. The bonding of the first protective film was to apply an ultraviolet curable adhesive ("KR-75T" manufactured by ADEKA Co., Ltd.) using a small-diameter microgravure coater so that the thickness after curing became 1.0 μm. After one side, this was bonded to the peeling surface using a bonding roller, and then, using a high-pressure mercury lamp, ultraviolet light was irradiated from the base film side with an integrated light amount of 200 mJ / cm ² to harden the adhesive layer.

(6)雙面附有保護膜之偏光板的製作(剝離步驟及雙面附有保護膜之偏光板的製作步驟) (6) Manufacture of polarizing plate with protective film on both sides (peeling step and manufacturing process of polarizing plate with protective film on both sides)

從上述(5)中所製作之多層膜中剝離基材膜，並立即將第2保護膜貼合於該剝離面，而得到由第1保護膜/接著劑層/碘系偏光片/接著劑層/第2保護膜所構成之雙面附有保護膜之偏光板。第2保護膜係使用透濕度為16g/m²/24hr且由環狀聚烯烴系樹脂所構成之厚度23μm的熱塑性樹脂膜(Zeon Japan股份有限公司製的「ZF14」)。第2保護膜的貼合係以使硬化後的厚度成為1.0μm之方式，使用小徑微凹 版塗布機將紫外線硬化性接著劑(ADEKA股份有限公司製的「KR-75T」)塗布於其單面後，使用貼合輥將此貼合於上述剝離面，然後使用高壓汞燈，以200mJ/cm²的積算光量從第2保護膜側照射紫外線使接著劑層硬化而進行。貼合第2保護膜時之碘系偏光片的水分率為0.5重量%。 The base film was peeled from the multilayer film produced in (5) above, and the second protective film was immediately attached to the peeling surface to obtain the first protective film / adhesive layer / iodine-based polarizer / adhesive layer / A polarizing plate with a protective film on both sides composed of a second protective film. As the second protective film, a thermoplastic resin film (“ZF14” manufactured by Zeon Japan Co., Ltd.) having a moisture permeability of 16 g / m ² / 24hr and a thickness of 23 μm composed of a cyclic polyolefin resin was used. The bonding of the second protective film was performed by applying a UV curable adhesive ("KR-75T" manufactured by ADEKA Co., Ltd.) using a small-diameter microgravure coater so that the thickness after curing became 1.0 μm. After the surface, this was adhered to the peeling surface using a bonding roller, and then a high-pressure mercury lamp was used to irradiate ultraviolet rays from the second protective film side with an integrated light amount of 200 mJ / cm ² to harden the adhesive layer. The moisture content of the iodine-based polarizer when bonding the second protective film was 0.5% by weight.

〈實施例2〉 <Example 2>

將染色步驟最後之乾燥處理(水分率降低步驟)的條件，設為於50℃進行60秒，然後於65℃進行60秒，除此之外，其他與實施例1相同而製作出雙面附有保護膜之偏光板。貼合第2保護膜時之碘系偏光片的水分率為4.6重量%。 The conditions of the last drying process (moisture content reduction step) of the dyeing step were set at 50 ° C for 60 seconds, and then at 65 ° C for 60 seconds, except that the other steps were the same as in Example 1 to produce a double-sided adhesive. Polarizer with protective film. The moisture content of the iodine-based polarizer when bonding the second protective film was 4.6% by weight.

〈實施例3〉 <Example 3>

與實施例2相同地，製作出雙面附有保護膜之偏光板。貼合第2保護膜時之碘系偏光片的水分率為4.4重量%，雙面附有保護膜之偏光板的視感度修正偏光度Py為99.995%，視感度修正單體穿透率Ty為40.9%。 In the same manner as in Example 2, a polarizing plate with protective films on both sides was produced. The moisture content of the iodine-based polarizer when the second protective film is attached is 4.4% by weight, the polarizing plate with a protective film on both sides has a visual sensitivity correction polarization degree Py of 99.995%, and a visual sensitivity correction monomer transmission rate Ty is 40.9%.

〈實施例4〉 <Example 4>

第1保護膜及第2保護膜，係使用透濕度為63g/m²/24hr且由丙烯酸系樹脂所構成之厚度80μm的熱塑性樹脂膜，並使用紫外線硬化性接著劑(ADEKA股份有限公司製的「KR-15P」)，除此之外，其他與實施例2相同，而製作出 雙面附有保護膜之偏光板。貼合第2保護膜時之碘系偏光片的水分率為4.2重量%，雙面附有保護膜之偏光板的視感度修正偏光度Py為99.994%，視感度修正單體穿透率Ty為41.4%。 For the first protective film and the second protective film, a thermoplastic resin film with a moisture permeability of 63 g / m ² / 24hr and a thickness of 80 μm made of acrylic resin was used, and an ultraviolet curing adhesive (manufactured by ADEKA Co., Ltd.) was used. "KR-15P"), except for the others, the same as in Example 2, a polarizing plate with a protective film on both sides was produced. The moisture content of the iodine-based polarizer when the second protective film is attached is 4.2% by weight, the polarizing plate with a protective film on both sides has a visual sensitivity correction polarization degree Py of 99.994%, and a visual sensitivity correction monomer transmission rate Ty 41.4%.

〈實施例5〉 <Example 5>

第1保護膜係使用透濕度為63g/m²/24hr且由丙烯酸系樹脂所構成之厚度80μm的熱塑性樹脂膜，第2保護膜係使用透濕度為16g/m²/24hr且由環狀聚烯烴系樹脂所構成之厚度23μm的熱塑性樹脂膜(Zeon Japan股份有限公司製的「ZF14」)。第1保護膜係使用紫外線硬化性接著劑(ADEKA股份有限公司製的「KR-15P」)，第2保護膜係使用紫外線硬化性接著劑(ADEKA股份有限公司製的「KR-75T」)，除此之外，其他與實施例2相同，而製作出雙面附有保護膜之偏光板。貼合第2保護膜時之碘系偏光片的水分率為4.8重量%，雙面附有保護膜之偏光板的視感度修正偏光度Py為99.994%，視感度修正單體穿透率Ty為41.4%。 The first protective film uses a thermoplastic resin film with a moisture permeability of 63 g / m ² / 24hr and a thickness of 80 μm made of acrylic resin, and the second protective film uses a ring-shaped polymer with a moisture permeability of 16 g / m ² / 24hr. A 23 μm-thick thermoplastic resin film (“ZF14” manufactured by Zeon Japan Co., Ltd.) composed of an olefin resin. The first protective film system uses an ultraviolet curing adhesive ("KR-15P" manufactured by ADEKA Corporation), and the second protective film system uses an ultraviolet curing adhesive ("KR-75T" manufactured by ADEKA Corporation), Other than that, the same as in Example 2, a polarizing plate with a protective film on both sides was produced. The moisture content of the iodine-based polarizer when the second protective film is attached is 4.8% by weight. The polarizing plate with a protective film on both sides has a visual sensitivity correction polarization degree Py of 99.994% and a visual sensitivity correction monomer transmission rate Ty 41.4%.

〈比較例1〉 <Comparative Example 1>

將染色步驟最後之乾燥處理(水分率降低步驟)的條件，設為於40℃進行60秒，然後於50℃進行60秒，除此之外，其他與實施例1相同，而製作出雙面附有保護膜之偏光板。貼合第2保護膜時之碘系偏光片的水分率為10.7 重量%。 The conditions of the last drying process (moisture content reduction step) of the dyeing step were set at 40 ° C for 60 seconds, and then at 50 ° C for 60 seconds, except that the other steps were the same as in Example 1 to produce a double-sided Polarizing plate with protective film. The moisture content of the iodine polarizer when the second protective film is attached is 10.7 weight%.

〈比較例2〉 <Comparative Example 2>

將染色步驟最後之乾燥處理(水分率降低步驟)的條件，設為於40℃進行120秒，除此之外，其他與實施例1相同，而製作出雙面附有保護膜之偏光板。貼合第2保護膜時之碘系偏光片的水分率為12.5重量%。 The conditions of the drying process (moisture content reduction step) at the end of the dyeing step were set at 40 ° C. for 120 seconds, except that the polarizing plates with protective films on both sides were produced in the same manner as in Example 1. The moisture content of the iodine-based polarizer when bonding the second protective film was 12.5% by weight.

〈比較例3〉 <Comparative Example 3>

於染色步驟最後的乾燥處理(水分率降低步驟)後，不貼合防濕性膜，並於25℃、55%RH的環境下保管約2天，使碘系偏光片的水分率上升至平衡含水率附近，然後，貼合第1及第2保護膜，除此之外，其他與實施例2相同，而製作出雙面附有保護膜之偏光板。貼合第2保護膜時之碘系偏光片的水分率為15.3重量%。 After the final drying process in the dyeing step (moisture content reduction step), the moisture-proof film is not attached and stored at 25 ° C and 55% RH for about 2 days to increase the moisture content of the iodine-based polarizer to equilibrium After the moisture content was near, the first and second protective films were laminated, and otherwise, the same as in Example 2, a polarizing plate with protective films on both sides was produced. The moisture content of the iodine-based polarizer when bonding the second protective film was 15.3% by weight.

各實施例及比較例之膜的透濕度及碘系偏光片的水分率，係以下述方法來測定。 The moisture permeability of the films of each Example and Comparative Example and the moisture content of the iodine-based polarizer were measured by the following methods.

(1)透濕度 (1) Moisture permeability

依據JIS Z 0208-1976「防濕包裝材料的透濕度試驗方法(杯法)」，測定溫度40℃、相對濕度90%時之透濕度。 According to JIS Z 0208-1976 "Moisture permeability test method for moisture-proof packaging materials (cup method)", the moisture permeability at a temperature of 40 ° C and a relative humidity of 90% is measured.

(2)碘系偏光片的水分率 (2) Moisture content of iodine polarizer

對於水分率相異之複數個碘系偏光片樣本，求取藉由 近紅外線水分率計(Chino股份有限公司製的「IRMA1100S」)所測得之水分率與藉由乾燥重量法所測得之水分率，並從所得之兩水分率，預先求取以一次式來表示兩水分率的關係之檢量線，使用上述檢量線，將藉由近紅外線水分率計所測得之水分率換算為依據乾燥重量法之水分率，並將此設為碘系偏光片的水分率。依據乾燥重量法之水分率，以乾燥前之試樣的重量設為W0，以於105℃、1小時的條件下使同一試樣乾燥後之重量設為W1時，係以下述式來定義。 For multiple samples of iodine-based polarizers with different moisture rates, find The moisture rate measured by the near-infrared moisture meter ("IRMA1100S" manufactured by Chino Co., Ltd.) and the moisture rate measured by the dry weight method, and the two moisture rates obtained in advance are obtained in one-shot formula A calibration line representing the relationship between the two moisture rates. Using the above calibration line, convert the moisture rate measured by the near-infrared moisture meter to the moisture rate according to the dry weight method, and set this to the iodine polarizer Of moisture. According to the moisture content of the dry weight method, when the weight of the sample before drying is W0 and the weight after drying the same sample at 105 ° C. for 1 hour is W1, it is defined by the following formula.

水分率(重量%)=100×(W0-W1)/W0 Moisture rate (wt%) = 100 × (W0-W1) / W0

[雙面附有保護膜之偏光板之耐濕熱性及耐熱性的評估] [Evaluation of Moisture Heat Resistance and Heat Resistance of Polarizing Plate with Protective Film on Both Sides]

(1)耐濕熱性的評估 (1) Evaluation of heat and humidity resistance

對於實施例1及2、比較例1~3中所製作之雙面附有保護膜之偏光板，使用吸光光度計(日本分光股份有限公司製的「V7100」)，測定於65℃、90%RH的環境下靜置500小時之耐濕熱性試驗後的視感度修正偏光度Py與試驗前的Py，並從兩者的差△Py(試驗前的Py-試驗後的Py)評估耐濕熱性。△Py的絕對值愈小，耐濕熱性愈高。結果如第1表所示。於Py的測定時，以使入射光照射於第2保護膜側之方式設置雙面附有保護膜之偏光板。耐濕熱性試驗後的視感度修正偏光度Py，係在耐濕熱性試驗後，於23℃、55%RH的環境下靜置約12小時後測定。 The polarizing plates with protective films on both sides produced in Examples 1 and 2 and Comparative Examples 1 to 3 were measured at 65 ° C and 90% using an absorbance photometer ("V7100" manufactured by Japan Spectroscopy Co., Ltd.) The visual sensitivity correction Py and the Py before the test of the humidity sensitivity after standing for 500 hours under the RH environment are evaluated from the difference between the two △ Py (Py before the test-Py after the test) . The smaller the absolute value of ΔPy, the higher the resistance to moisture and heat. The results are shown in Table 1. In the measurement of Py, a polarizing plate with a protective film on both sides was provided so that incident light was irradiated to the second protective film side. The visual sensitivity correction polarization degree Py after the moist heat resistance test was measured after standing for about 12 hours in an environment of 23 ° C. and 55% RH after the moist heat resistance test.

耐濕熱性試驗(及下述耐熱性試驗)前的 Py，各實施例及比較例均為99.995%。此外，使用同一吸光光度計所測得之視感度修正單體穿透率Ty，各實施例及比較例均為41.6%。 Before the humidity and heat resistance test (and the following heat resistance test) Py, each example and comparative example are 99.995%. In addition, the visual acuity measured by the same absorbance photometer corrects the monomer transmission rate Ty, and is 41.6% in each of the Examples and Comparative Examples.

(2)耐熱性的評估 (2) Evaluation of heat resistance

對於實施例1及2、比較例1~3中所製作之雙面附有保護膜之偏光板，進行於85℃、乾燥的環境下靜置500小時之耐熱性試驗，藉此，與上述耐濕熱性的評估相同，從△Py(試驗前的Py-試驗後的Py)評估耐熱性。△Py的絕對值愈小，耐熱性愈高。結果如第1表所示。 The polarizing plates with protective films on both sides produced in Examples 1 and 2 and Comparative Examples 1 to 3 were subjected to a heat resistance test of standing at 85 ° C in a dry environment for 500 hours. The evaluation of the damp heat property is the same, and the heat resistance is evaluated from ΔPy (Py before the test-Py after the test). The smaller the absolute value of ΔPy, the higher the heat resistance. The results are shown in Table 1.

(3)促進條件下之耐濕熱性的評估 (3) Evaluation of the heat and humidity resistance under accelerated conditions

對於實施例3~5中所製作之雙面附有保護膜之偏光板，藉由與前述(1)耐濕熱性的評估相同之方法來進行於80℃、90%RH的環境下靜置48小時之耐濕熱性試驗。結果如第2表所示。 The polarizing plates with protective films on both sides produced in Examples 3 to 5 were allowed to stand in an environment of 80 ° C. and 90% RH by the same method as the above (1) evaluation of moisture and heat resistance. Hours of heat and humidity resistance test. The results are shown in Table 2.

(4)促進條件下之耐熱性的評估 (4) Evaluation of heat resistance under accelerated conditions

對於實施例3~5中所製作之雙面附有保護膜之偏光板，藉由與前述(2)耐熱性的評估相同之方法來進行於105℃、乾燥的環境下靜置48小時之耐熱性試驗。結果如第2表所示。 The polarizing plates with protective films on both sides produced in Examples 3 to 5 were subjected to heat resistance at 105 ° C in a dry environment for 48 hours by the same method as the aforementioned (2) evaluation of heat resistance Sex test. The results are shown in Table 2.

此外，對於耐熱性試驗後之雙面附有保護膜之偏光板，以目視確認光洩漏(紅變)的程度。具體而言， 從耐熱性試驗後之雙面附有保護膜之偏光板裁切出2片10cm×20cm的試樣片，使用黏著劑將此等試樣貼合於玻璃板的雙面。此時，係使第2保護膜側成為玻璃板側，並且配置在雙面之試樣片成為正交偏光的位置關係。然後，於暗房內，從一方的偏光板側照射背光，並依據下述評估基準進行紅變的目視評估。結果如第1表及第2表所示。 In addition, for the polarizing plate with a protective film on both sides after the heat resistance test, the degree of light leakage (reddening) was visually confirmed. in particular, From the polarizing plate with protective film on both sides after the heat resistance test, two 10 cm × 20 cm sample pieces were cut out, and these samples were attached to both sides of the glass plate using an adhesive. At this time, the second protective film side is set to the glass plate side, and the sample pieces arranged on both sides have a positional relationship of orthogonal polarized light. Then, in a dark room, the backlight is irradiated from one side of the polarizing plate, and a visual evaluation of redness is performed according to the following evaluation criteria. The results are shown in Table 1 and Table 2.

A：保持全黑的狀態，以目視無法辨識出紅變。 A: Maintain the black state, and the red change cannot be recognized visually.

B：觀察到明顯的紅變。 B: Obvious redness was observed.

Claims (8)

一種雙面附有保護膜之偏光板之製造方法，其係包含：從依序包含基材膜、碘系偏光片及第1保護膜之多層膜，將基材膜剝離去除而得到單面附有保護膜之偏光板之步驟，以及將第2保護膜貼合於前述單面附有保護膜之偏光板之碘系偏光片的外面，而得到雙面附有保護膜之偏光板之步驟；前述第1保護膜及前述第2保護膜，為透濕度150g/m²/24hr以下之熱塑性樹脂膜；貼合前述第2保護膜時之前述碘系偏光片的水分率為未達8重量%。A method for manufacturing a polarizing plate with a protective film on both sides, which comprises: peeling off and removing a base film from a multilayer film including a base film, an iodine-based polarizer and a first protective film in sequence to obtain a single-sided film The steps of a polarizing plate with a protective film, and the step of attaching the second protective film to the outside of the iodine polarizer of the polarizing plate with a protective film on one side, to obtain a polarizing plate with a protective film on both sides; The first protective film and the second protective film are thermoplastic resin films with a moisture permeability of 150 g / m ² / 24hr or less; the moisture content of the iodine-based polarizer when the second protective film is laminated is less than 8% by weight . 如申請專利範圍第1項所述之製造方法，其中使用活化能射線硬化性接著劑，將前述第2保護膜貼合於前述碘系偏光片的外面。The manufacturing method as described in item 1 of the patent application range, wherein the second protective film is attached to the outer surface of the iodine-based polarizer using an active energy ray-curable adhesive. 如申請專利範圍第1或2項所述之製造方法，其中前述碘系偏光片之厚度為10μm以下。The manufacturing method as described in item 1 or 2 of the patent application, wherein the thickness of the iodine-based polarizer is 10 μm or less. 一種雙面附有保護膜之偏光板之製造方法，其係包含：將第2保護膜貼合於包含碘系偏光片及積層於該碘系偏光片的單面之第1保護膜之單面附有保護膜之偏光板中之碘系偏光片的外面，而得到雙面附有保護膜之偏光板之步驟；前述第1保護膜及前述第2保護膜，為透濕度150g/m²/24hr以下之熱塑性樹脂膜；貼合前述第2保護膜時之前述碘系偏光片的水分率為未達8重量%。A method for manufacturing a polarizing plate with a protective film on both sides, comprising: bonding a second protective film to a single side of a first protective film including an iodine-based polarizer and a single side laminated on the iodine-based polarizer The step of obtaining a polarizing plate with a protective film on both sides of the polarizing plate with a protective film on the outside of the iodine-based polarizer; the first protective film and the second protective film have a moisture permeability of 150 g / m ² / The thermoplastic resin film of 24 hours or less; the moisture content of the iodine-based polarizer when the second protective film is bonded is less than 8% by weight. 如申請專利範圍第4項所述之製造方法，其中使用活化能射線硬化性接著劑，將前述第2保護膜貼合於前述碘系偏光片的外面。The manufacturing method as described in item 4 of the patent application range, wherein the second protective film is attached to the outer surface of the iodine-based polarizer using an active energy ray-curable adhesive. 如申請專利範圍第4或5項所述之製造方法，其中前述碘系偏光片之厚度為10μm以下。The manufacturing method as described in item 4 or 5 of the patent application, wherein the thickness of the iodine-based polarizer is 10 μm or less. 一種雙面附有保護膜之偏光板，其係包含：碘系偏光片及積層於該雙面之保護膜；積層於雙面之保護膜均為透濕度150g/m²/24hr以下之熱塑性樹脂膜；前述碘系偏光片的水分率為未達8重量%，前述碘系偏光片之厚度為10μm以下。A polarizing plate with a protective film on both sides, comprising: an iodine-based polarizer and a protective film laminated on the both sides; the protective films laminated on both sides are thermoplastic resins with a moisture permeability of 150g / m ² / 24hr or less Film; the moisture content of the iodine-based polarizer is less than 8% by weight, and the thickness of the iodine-based polarizer is 10 μm or less. 如申請專利範圍第7頂所述之雙面附有保護膜之偏光板，其中前述碘系偏光片及積層於該碘系偏光片之雙面之前述保護膜係隔著由活化能射線硬化性接著劑所形成的接著劑層而積層。The polarizing plate with a protective film on both sides as described in the seventh top of the patent scope, wherein the iodine-based polarizer and the protective film laminated on both sides of the iodine-based polarizer are hardened by active energy rays The adhesive layer formed by the adhesive is laminated.