200931080 九、發明說明： 【發明所屬之技術領域】 本發明大致上係關於一種偏光板，更特別地，係關於一種 可控制翹曲程度之偏光板及其製造方法。 【先前技術】 近年來由於液晶螢幕的可視面積變大，所要求之對比增 ❹ 加’其所需要之偏光板也需較高的品質。而不管是小尺寸或大 尺寸之液晶螢幕均需要厚度較薄之偏光板來達成其品質輕、薄 之要求。 然而偏光板變薄後，當面板廠進行液晶玻璃上之偏光板片 貼時’常會發生一些問題，例如翹曲、剥離(peeling)、產生氣 泡或重工性差等問題’尤其以具有兩片不同厚度之三醋酸纖維 膜(TAC)之偏光板的翹曲問題更為嚴重。以32吋以上的τν面 ❿ 板來說，在後段面板製造時，若要使用薄型化偏光板常合導致 翹曲或重工性不佳。這些問題大都是因為偏光板薄型/匕所導 致，而針對大尺寸偏光板而言，如何在其厚度與重工性達成巧 妙平衡是目前一重要的課題。 習知改善翹曲的方法有利用傅立葉轉換紅外光譜儀 (FTIR) ’針對偏光板關之三醋__巾塑化躺含量二例 監測’藉以控制不易麵曲之偏光板的生產狀況。然而，此量測 手法會因為取樣位置的差異與儀器誤差範圍之精確度上的困 200931080 擾’使得此方法並不可行。糾’習知亦有彻具有不同魅曲 方向之TAC _偏光層貼合，较控觸鄉度及貼合前之 滾輪與貼合輪之絲成-錄且㈣此比值小於6G，藉以抑 制所製造之偏光板的翹曲，然而此法因機台作動機制的不同， 於不同廠牌之機台無法獲得較佳的再現性。 因此，需要可在不增加製程困難度下，較佳是不變動機台 设備下’提供一種可生產不易發生翹曲或不易發生負翹之偏光 板及其形成的方法。 【發明内容】 本發明之一方面在提供一種製造偏光板的方法，以在不增 加製程困難度下，使所生產之偏光板可有效降低翹曲變形現 象。 於一實施例中，未發明提供一種製造楱光板的方法，包 Ο 含：提供偏光層；形成第一透光層於偏光層之一侧，第一透光 層具有第一張力(T1);形成第二透光層於偏光層之另一侧，以 形成偏光膜’其中第二透光層具有一第二張力(T2);乾燥偏光 膜；以及形成保護層於偏光膜之第二透光層上，保護層具有第 三張力(丁3)。其中’第一張力、第二張力及第三張力係於上述 步驟中加以控制’以使一張力比值(tensi〇n rati〇, TR)不大於一 預定值以控制偏光板之翹曲程度，張力比值與第一張力、第二 張力及第三張力之關係為：TR=(T1/T2)/T3。 200931080 前述實施例中，當第二透光層之厚度對第一透光層之厚度 比值係約0.882至約1.16時，張力比值(TR)不大於〇 〇132。且 藉由控制張力比值(TR)不大於_32，使得偏光·幅寬方向 之翹曲值小於張力比值(TR)大於_32時之偏光板於幅寬方 向之翹曲值。 前述實施例中，當第二透光層之厚度對第一透光層之厚度 比值係約1施至約2.486時，張力比值⑽不大於〇曰〇〇56Γ ❹ 且藉由控制張力比值(TR)不大於〇施6，使得偏光板於一延伸 方向之翹曲值不小於〇。 本發日騰h方面係祕—顏歧，尤其是齡離麵 後不易發生負翹現象的偏光板。 於-實施例令，本發明提供一種偏光板，包含：偏光層、 第-透光層、第二透光層及保護層。第一透光層係位於偏光層 〇 之一側，而第二透光層係位於偏光層之另一側，其中第一透光 層及第二透光層形成於偏光層之前，第一透光層具有第一張力 (τι)且第二透光層具有第二張力(T2)。保護層係位於第二透光 層上，其中保護層形成於第二透光層之前，保護層且有第三張 力(Τ3)。其中，第-張力、第二張力與第三張力具有一張力比 值(TR)，其_式為：TR=(T1/T2)/T3，且偏光板係藉由控制 張力比值(TR)不大於一預定值以控制翹曲程度。 8 200931080 【實施方式】 本發明較佳實施例之製造及使用將於下詳細描述。然而， 可以了解的是本發明提供多種適當的新穎觀念，可以特定内容 的廣泛變化予以具體化。在此所討論的特定實施例僅為製造及 使用本發明的特定方式之說明，但並非用以限定本發明之範 圍。 參考圖一，顯示本發明於一實施例中製造一偏光板的方法 ° 之流程圖。魏參考步驟⑽，提供-偏光層。此處提供-偏 光層之步驟係包含提供一親水性高分子臈(步驟112)，然後染 ^此親水性高分子膜(步驟114)，接著延伸此染色後的親水性 面分子膜(步驟116) ’最後再將染色延伸後的親水性高分子膜 烘乾以形成一偏光層。在此需注意的是，步驟112、114和116 較佳係連續進行而不分開完成。於此實施例中，親水性高分子 膜較佳地為聚乙烯醇(Polyvinyl alcohol)膜，更佳地為聚合度 • 2400的聚乙烯醇膜，而且經步驟112至116所形成之偏光層 〇 厚度一般係在20至35Mm之間，偏光度較佳地為99.9%以上， 且單體穿透率在41%以上。 此外，步驟114中，染色親水性高分子膜之步驟更包含浸 泡聚乙烯醇膜於溫度在25-35°C之間的水溶液中，接著浸泡於 含續與硼酸水溶液中，以形成含填之聚乙婦醇膜。此處浸泡聚 乙烯醇膜於一水溶液中係藉由水溶液膨潤聚乙烯醇膜，因此當 膨潤後的聚乙烯醇膜浸泡於含碘與硼酸水溶液中，可快速的進 行碘染色並固定碘離子於聚乙烯醇膜中。於此實施例中，含碘 200931080 與硼酸水溶液可為含有硼酸和碘化鉀之水溶液，其中硼酸之濃 度在約3.0%-5.5 wt%之間’埃化鉀之濃度在2.0-6.0 wt°/〇之間。 然而，本發明並不以此為限，熟悉此技藝者當知，本發明亦可 將膨潤後的聚乙烯醇膜浸泡於含有染料和硼酸等藥劑的水溶 液中，以形成含染料之聚乙烯醇膜。 接著，參考步驟120及圖二，圖二係依據本發明之一實施 例所形成之一偏光板20的剖面示意圖。如圖所示，在上述步 〇 驟所形成的偏光層21〇(如含碘之聚乙烯醇膜)上，接著形成第 一透光層220於偏光層210之一侧，以及形成第二透光層23〇 於偏光層210之另一侧，以形成一偏光膜2〇〇。然而，熟此技 藝者應該了解，形成第一透光層220及第二透光層23〇之步驟 亦可顛倒，較佳地為同時形成於偏光層21〇之兩侧。一般而 言，透光層係用以保護偏光層，避免其斷裂破損造成生產上的 困擾，故一般又稱透光層為保護層或保護膜等。其中第一透光 層220和第二透光層23〇之材質包含三醋酸纖維素 _CetylCellulose，TAC)、聚對苯二甲酸乙二酯⑽卿㈣咖 terephthalate，PET)或聚碳酸酯(p〇iyCarb〇nate，pc)等。於此實施 例中，第一透光層220和第二透光層230係以分別具有第一張 f(Tl)和第二張力(T2)的三醋酸纖維膜為例進行說明，然而， 第透光層和第二透光層之數量、材質及厚度亦可視實際設計 需求而變化，並不限於本實施例所例示。 形成偏光膜200後，將此偏光膜200進行乾燥(步驟13〇)， 此乾燥步驟-般係利用紅外線烘烤或熱風乾 乾燥步驟-般會造成偏光層(如聚乙__二二= 200931080BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to a polarizing plate, and more particularly to a polarizing plate which can control the degree of warpage and a method of manufacturing the same. [Prior Art] In recent years, as the visible area of the liquid crystal screen has become larger, the required contrast is increased, and the required polarizing plate also requires higher quality. Regardless of whether it is a small-sized or large-sized LCD screen, a thinner polarizing plate is required to achieve the requirements of light weight and thinness. However, after the polarizing plate is thinned, when the panel factory performs the polarizing plate on the liquid crystal glass, some problems often occur, such as warping, peeling, bubble generation, or poor workability, especially with two different thicknesses. The warpage problem of the polarizing plate of the triacetate film (TAC) is more serious. For the τν surface 吋 plate of 32 吋 or more, in the manufacture of the rear panel, if the thinned polarizing plate is used in common, the warpage or the reworkability is poor. These problems are mostly caused by the thin polarizer/匕, and for large-size polarizers, how to achieve a delicate balance between thickness and reworkability is an important issue at present. Conventional methods for improving warpage include the use of Fourier Transform Infrared Spectrometer (FTIR) to monitor the production of polarizing plates that are not easily embossed by the two vinegars for polarizing plates. However, this measurement method makes this method infeasible because of the difference in sampling position and the accuracy of the instrument error range. Correction 'Knowledge also has a TAC _ polarized layer fit with different enchantment directions, compared with the touch of the touch and the front of the roll and the fit wheel is recorded - and (4) the ratio is less than 6G, so as to suppress the The warpage of the manufactured polarizing plate, however, this method cannot obtain better reproducibility on the machine of different brands due to the different mechanism of the machine. Therefore, it is desirable to provide a method for producing a polarizing plate which is less prone to warpage or which is less prone to negative warpage and which is formed without increasing the difficulty of the process, preferably under the constant engine table apparatus. SUMMARY OF THE INVENTION One aspect of the present invention provides a method of manufacturing a polarizing plate to effectively reduce warpage deformation of the produced polarizing plate without increasing the difficulty of the process. In one embodiment, a method for manufacturing a calender is provided, comprising: providing a polarizing layer; forming a first light transmissive layer on one side of the polarizing layer, the first light transmissive layer having a first tension (T1); Forming a second light transmissive layer on the other side of the polarizing layer to form a polarizing film 'where the second light transmissive layer has a second tension (T2); drying the polarizing film; and forming a second light transmissive layer of the protective layer on the polarizing film On the layer, the protective layer has a third tension (D 3). Wherein the 'first tension, the second tension and the third tension are controlled in the above steps' such that a force ratio (tensi〇n rati〇, TR) is not greater than a predetermined value to control the degree of warpage of the polarizing plate, the tension The relationship between the ratio and the first tension, the second tension, and the third tension is: TR = (T1/T2) / T3. In the foregoing embodiment, when the thickness ratio of the thickness of the second light-transmitting layer to the first light-transmitting layer is about 0.882 to about 1.16, the tension ratio (TR) is not larger than 〇 132. And by controlling the tension ratio (TR) to be no more than _32, the warpage value in the polarization/width direction is smaller than the warpage value of the polarizing plate in the width direction when the tension ratio (TR) is larger than _32. In the foregoing embodiment, when the thickness ratio of the thickness of the second light transmissive layer to the first light transmissive layer is about 1 to about 2.486, the tension ratio (10) is not more than 〇曰〇〇56Γ 且 and by controlling the tension ratio (TR) ) is not greater than the application 6, so that the warpage value of the polarizing plate in an extending direction is not less than 〇. This is the secret of the face of the hair--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- In an embodiment, the present invention provides a polarizing plate comprising: a polarizing layer, a first light transmitting layer, a second light transmitting layer, and a protective layer. The first light transmissive layer is located on one side of the polarizing layer ,, and the second light transmissive layer is located on the other side of the polarizing layer, wherein the first light transmissive layer and the second light transmissive layer are formed before the polarizing layer, and the first translucent layer is formed. The light layer has a first tension (τι) and the second light transmissive layer has a second tension (T2). The protective layer is on the second light transmissive layer, wherein the protective layer is formed before the second light transmissive layer and has a third tensile force (Τ3). Wherein, the first tension, the second tension and the third tension have a force ratio (TR), wherein the formula is: TR=(T1/T2)/T3, and the polarizing plate is controlled by the tension ratio (TR) is not greater than A predetermined value to control the degree of warpage. 8 200931080 [Embodiment] The manufacture and use of the preferred embodiments of the present invention will be described in detail below. However, it will be appreciated that the present invention provides a variety of appropriate novel concepts that can be embodied in a wide variety of specifics. The specific embodiments discussed herein are merely illustrative of specific ways of making and using the invention, but are not intended to limit the scope of the invention. Referring to Figure 1, there is shown a flow chart of a method of fabricating a polarizing plate in accordance with one embodiment of the present invention. Referring to step (10), a polarizing layer is provided. The step of providing a polarizing layer includes providing a hydrophilic polymer enthalpy (step 112), then dyeing the hydrophilic polymer film (step 114), and then extending the dyed hydrophilic surface molecular film (step 116). ) Finally, the hydrophilic polymer film after dyeing extension is dried to form a polarizing layer. It should be noted here that steps 112, 114 and 116 are preferably performed continuously without being separated. In this embodiment, the hydrophilic polymer film is preferably a polyvinyl alcohol film, more preferably a polyvinyl alcohol film having a polymerization degree of 2400, and the polarizing layer formed by the steps 112 to 116. The thickness is generally between 20 and 35 Mm, the degree of polarization is preferably 99.9% or more, and the monomer transmittance is 41% or more. In addition, in step 114, the step of dyeing the hydrophilic polymer film further comprises soaking the polyvinyl alcohol film in an aqueous solution at a temperature between 25 and 35 ° C, and then immersing in the aqueous solution containing the boric acid to form a filling. Polyethylene glycol film. Here, the polyvinyl alcohol film is immersed in an aqueous solution to swell the polyvinyl alcohol film by an aqueous solution. Therefore, when the swelled polyvinyl alcohol film is immersed in an aqueous solution containing iodine and boric acid, iodine dyeing and immobilization of iodide ions can be quickly performed. In the polyvinyl alcohol film. In this embodiment, the iodine containing 200931080 and the aqueous boric acid solution may be an aqueous solution containing boric acid and potassium iodide, wherein the concentration of boric acid is between about 3.0% and 5.5 wt%, and the concentration of potassium ethoxide is between 2.0 and 6.0 wt. between. However, the present invention is not limited thereto, and it is known to those skilled in the art that the present invention can also immerse a swollen polyvinyl alcohol film in an aqueous solution containing a dye and a boric acid to form a dye-containing polyvinyl alcohol. membrane. Next, referring to step 120 and FIG. 2, FIG. 2 is a schematic cross-sectional view of a polarizing plate 20 formed in accordance with an embodiment of the present invention. As shown in the figure, on the polarizing layer 21 (such as the iodine-containing polyvinyl alcohol film) formed in the above step, the first light transmitting layer 220 is formed on one side of the polarizing layer 210, and a second transparent layer is formed. The light layer 23 is disposed on the other side of the polarizing layer 210 to form a polarizing film 2〇〇. However, it should be understood by those skilled in the art that the steps of forming the first light transmissive layer 220 and the second light transmissive layer 23 can also be reversed, preferably simultaneously formed on both sides of the polarizing layer 21〇. In general, the light-transmitting layer is used to protect the polarizing layer from the breakage and damage caused by the production of the polarizing layer. Therefore, the light-transmitting layer is generally referred to as a protective layer or a protective film. The material of the first light transmissive layer 220 and the second light transmissive layer 23 includes cellulose triacetate (Cetyl Cellulose, TAC), polyethylene terephthalate (10), teephthalate (PET) or polycarbonate (p). 〇iyCarb〇nate, pc) and so on. In this embodiment, the first light transmissive layer 220 and the second light transmissive layer 230 are exemplified by a triacetate membrane having a first sheet f(T1) and a second tension (T2), respectively, however, The number, material and thickness of the light transmissive layer and the second light transmissive layer may also vary depending on actual design requirements, and are not limited to the examples. After the polarizing film 200 is formed, the polarizing film 200 is dried (step 13A), and the drying step is generally performed by an infrared baking or a hot air drying step to cause a polarizing layer (for example, polyethylene__二二=200931080)
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張力(T3)的保護層240於偏光膜2〇〇之第二透光層23〇上，^ ,護第二透光層23G於後續的生產流程中不會產生刮傷、壓傷 等的缺點。保護層24CM系為習知具有易撕型黏著劑的對苯二甲 酸乙二酯（polyethylene terephthalate，PET)或聚乙婦 (polyethylene，PE)等’於此不再贅述。另外於一實施例中亦 可接著形成感壓膠層及離型層於偏光膜2〇〇之第一透光層22〇 上，以形成偏光板20，如步驟15〇所示。其中在後續將偏光 板片貼在液晶玻璃上時’將會撕除離型層，以使感壓膠層有效 的片貼在顯示裝置中之液晶玻璃上。 參考圖三’依據本發明之一較佳具體實施例進一步提供製 造偏光板20之方法的生產製程示意圖。於一實施例中，本發 明提供偏光層210、第一透光層220、第二透光層230及保護 層240使形成如圖二所示之偏光板2〇結構。於另一實施例中， 本發明另提供第一滚輪310、第二滚輪320、第一壓合滾輪組 330、第三滾輪340、第二壓合滾輪組350及烘箱360以連續 式生產偏光板20。如圖所示，本發明藉由第一滾輪31〇以捲 出第一透光層220’及藉由第二滾輪320以捲出第二透光層 230，並以第一壓合滾輪組330貼合第一透光層220和第二透 光層230在偏光層210之兩側上，以形成多層堆疊之偏光膜 11 200931080 200。於另一實施例中’在第一壓合滾輪組wo貼合第一透光 層220和第二透光層230於偏光層210之兩側時，亦可同時在 第一透光層220與偏光層210之間加入以一水膠層(例如，pVA 水膠）’以增加兩層間的黏著性。同理，亦可於第二透光層23〇 和偏光層210之間加入相同或不同的一水膠層，以增加兩層間 的黏著性。The protective layer 240 of the tension (T3) is on the second light transmissive layer 23 of the polarizing film 2, and the second light transmissive layer 23G does not have the disadvantages of scratching, crushing, etc. in the subsequent production process. . The protective layer 24CM is a polyethylene terephthalate (PET) or a polyethylene (PE) which is known to have a tear-off adhesive, and will not be described herein. In addition, in an embodiment, a pressure sensitive adhesive layer and a release layer may be formed on the first light transmissive layer 22 of the polarizing film 2 to form the polarizing plate 20, as shown in step 15A. When the polarizing plate is subsequently attached to the liquid crystal glass, the release layer will be peeled off so that the effective pressure-sensitive adhesive layer is attached to the liquid crystal glass in the display device. Referring to Figure 3, a schematic diagram of a production process for fabricating a polarizing plate 20 is further provided in accordance with a preferred embodiment of the present invention. In one embodiment, the present invention provides a polarizing layer 210, a first light transmissive layer 220, a second light transmissive layer 230, and a protective layer 240 to form a polarizing plate structure as shown in FIG. In another embodiment, the present invention further provides a first roller 310, a second roller 320, a first pressing roller set 330, a third roller 340, a second pressing roller set 350, and an oven 360 for continuously producing a polarizing plate. 20. As shown in the figure, the first roller 31 is used to roll out the first light transmissive layer 220' and the second roller 320 is used to roll out the second light transmissive layer 230, and the first press roller group 330 is used. The first light transmissive layer 220 and the second light transmissive layer 230 are bonded on both sides of the polarizing layer 210 to form a multi-layer stacked polarizing film 11 200931080 200. In another embodiment, when the first pressing roller group and the second light transmitting layer 220 are attached to both sides of the polarizing layer 210, the first light transmitting layer 220 may be simultaneously A water-repellent layer (for example, pVA water gel) is added between the polarizing layers 210 to increase the adhesion between the two layers. Similarly, the same or different water-repellent layer may be added between the second light-transmissive layer 23A and the polarizing layer 210 to increase the adhesion between the two layers.
接著’將此多層堆疊的偏光膜2〇〇(可含有水膠層)於50-80 C的烘箱360中烘烤約3-5分鐘’用以乾燥偏光膜2〇〇。然而， 熟此技藝者當知’偏光膜2〇〇於烘箱360中之烘烤溫度及時間 等條件，皆可依實際的烘箱長度、生產機速、進風量、乾燥程 度等而有所調整，且此烘烤溫度條件較佳地係多段式溫度梯 度:例如5段式烘箱溫度變化。其後，利用第三滾輪34〇捲出 保護層240，並以第二壓合滚輪組35〇貼合保護層24〇於第二 透光層230上，以形成如圖二所示之偏光板2〇。Next, the multilayer laminated polarizing film 2 (which may contain a water-repellent layer) is baked in an oven 360 of 50-80 C for about 3-5 minutes to dry the polarizing film 2 〇〇. However, those skilled in the art know that the conditions such as the baking temperature and time of the polarizing film 2 in the oven 360 can be adjusted according to the actual oven length, the production speed, the air intake amount, the drying degree, and the like. And the baking temperature condition is preferably a multi-stage temperature gradient: for example, a 5-stage oven temperature change. Thereafter, the protective layer 240 is rolled out by the third roller 34, and the protective layer 24 is attached to the second transparent layer 230 by the second pressing roller set 35 to form a polarizing plate as shown in FIG. 2〇.
其中，藉由調整第一滚輪31〇的捲出速度及第一壓合滾輪 組330的轉動速度與滾輪間隙大小，使貼合前的第一透光層 ϋ具有一第一張力(T1)°同樣的，藉由調整第二滾輪320的 速度及第-壓合滚輪組33〇的轉動速度與滾輪間隙大 小，使貼^前的第二透光層23〇具有一第二張力(τ2)。另一方 =貼合前的保護層亦可藉由調整第三滾輪的捲出速 壓合滚輪組’的轉動速度與滾輪組的壓合間隙，使 具Ϊ —第三張力(Τ3)。由實驗結果可知，偏光板2〇 αΐ力以壬 =错由對第一張力(Τ1)、第二張力(Τ2)及第三張力 (Τ3)加以控制，使一張力比值(TR)不大於一預定值，以達馳 12 200931080 曲程度的控制。其中’張力比值(TR)與第—張力(T1)、第二張 力(Τ2)及第二張力(丁3)之關係為：。 如鈿所述，藉由控制張力比值(TR)不大於一預定值時，可 對偏光板之翹曲程度進行控制。其中由實驗結果得知，當第二 透光層230之厚度對第一透光層22〇之厚度比值係約〇 882至 約1.16時，張力比值(TR)較佳地係不大於〇 〇132。當第二透 光層230之厚度對第-透光層mo之厚度比值係約1 666至約 ❹ 2.486時，張力比值(TR)不大於0.0056。舉例說明，當第一透 光層220與第二透光層23〇皆為厚度約8〇仰的三醋酸纖維膜 (TAC)時，較佳地係控制張力比值(TR)不大於〇 〇132，使得連 續式生產之偏光板20於一幅寬方向扣狀沉记directi〇n，TD)之 翹曲值小於張力比值(TR)大於0.0132時之偏光板2〇於一幅寬 方向(TD)之翹曲值。於另一範例說明中，第一透光層22〇與第 一透光層230可分別為厚度不同之三醋酸纖維膜(TAC)，例如 分別為約牝从111與約80μηι，其中藉由控制張力比值(TR)不大 於0.0056時，使得偏光板2〇於一延伸方向(machine a—， md)之翹曲值不小於〇，即沒有負翹。 為使本發明之敘述更加詳盡與完備，參考圖四，本發明定 義沿著參考標號490之箭頭指示之收捲方向為延伸方向 (MD) ’且此方向與偏光層21〇之延伸方向相同；並定義垂直 延伸方向之方向為幅寬方向(TD)’即偏光膜2〇〇兩側之寬度方 向。另定義偏光膜200或偏光板20朝保護層240方向的翹曲 為正翹(即翹曲值大於0)，而朝第一透光層22〇方向的翹曲為 負翹(即翹曲值小於⑺。 13 200931080 參考圖五顯示依據本發明之方法所形成之偏光板50的剖 面示意圖。於本發明之另一實施例中，如圖五所示，本發明之 第二透光層530可包含一基材532及一光學鍍層534於基材 532上。基材532可為前述之三醋酸纖維膜(TAC)，而光學鏡 層534通常為厚度3-8/rni的硬鑛膜(hard-coating film)、抗反射 膜(anti-reflection film)、低反射膜(low reflection film)、抗眩膜 (anti-glare film)或抗靜電膜(anti-static film)等，以塗佈的方式形 成於透明基材532上’用以做為一般偏光板的表面處理，可加 強偏光板硬度以防止日常生活無意的刮傷或避免光線被過度 集中讓使用者觀看時感覺不適。此外，熟此技藝者當知，一般 具有光學鍍層534之偏光膜’接續可形成感壓膠層55〇和離型 層560於第一透光層220上，以形成一偏光板50。由實驗結 果得知’具有光學鍍層534之第二透光層530所形成之偏光板 5〇 ’同樣可藉由在生產製程中控制張力比值(TR)不大於一預定 值，以控制偏光板50的翹曲程度，如前所述，第二透光層530 和第一透光層220之厚度比值將決定此張力比值(TR)的適用 範圍，於此不再贅述。 圖六係本發明於再一實施例中之一種偏光板6〇的剖面示 意圖。如圖六所示，偏光板60，例如大尺寸偏光板，包含偏 光層210’以及第一透光層220和第二透光層230於偏光層210 之兩侧。其中，介於偏光層210和第一透光層22〇及/或第二 透光層230之間可包含厚度非常薄之黏著層615(一般係小於 Ιμηι)。而且’當第一透光層220和第二透光層230為三醋酸纖 維臈時，一般可先經由皂化處理程序，以改變三醋酸纖維膜表 面之親水性(接觸角），以便黏著層615形成於上。於此實施例 14 200931080 中’黏著層615係由親水性之聚乙烯醇樹脂所形成，一般稱為 水膠(hydrogel)，用以接著偏光層210和第一透光層22〇及/或 第二透光層230使其不會分離。由於此黏著層615相對於偏光 板60整體厚度而言屬於非常的薄，一般對偏光板6〇之翹曲程 度影響不大’故偏光板60同樣可經由控制第一透光層220、 第二透光層230及保護層240之第一張力、第二張力及第三張 力之張力比值’以控制魅曲值，於此不再贅述。 Ο 此外偏光板60可選擇性地包含光學層655於第一透光層 220上。如圖六所示，於此實施例中，光學層655係形成於^ 一透光層220上，且光學層655可視需求設計為反射膜、半穿 透反射膜、相位差膜、視角補償膜、增亮膜或其組合。換句話 說’當光學層655為視角補償膜時，則偏光板6〇可為視角補 償之偏光板；當光學層65S為反射膜時，則偏光板6〇可為反 射型之偏光板。 ❹ 另外，為使本發明之目的、特徵能更明顯易懂，下列 實例做詳細說明如下： 、 實例說明 提供聚乙烯麵’在溫度約25〜35°C之水射進行膨潤， 然後將膨織的聚乙烯醇藏進具有3q〜55 wt%之爛_ 2.0〜6.0wt%之视_水溶財，3〜7倍岐伸= 行延伸’以形成-偏光層21〇。且所形成之偏光層2ω _ 厚度20〜35/m $含蛾之聚乙烯醇膜，其單體穿透率達43〇/。以 200931080 上’且偏光度達99.9%以上 接下來，將經過皂化處理的第一透光層no及第二透光層 230(例如’二醋酸纖維膜），藉由水轉沖。㈣貼合於偏光層 ^3之ϋ = 烤過程後貼合保護層240於第二透光 230 曰 下列表係提供第一透光層220及第二透朵展 之厚度條似柳麵力_(TR)貼合嶋件。^ ❹ 表一The first light transmissive layer 贴 before the bonding has a first tension (T1) by adjusting the winding speed of the first roller 31〇 and the rotation speed of the first pressing roller group 330 and the roller gap size. Similarly, by adjusting the speed of the second roller 320 and the rotational speed of the first-pressing roller set 33〇 and the roller gap size, the second light-transmitting layer 23A before the bonding has a second tension (τ2). The other side = the protective layer before the bonding can also be adjusted to the third tension (Τ3) by adjusting the rotational speed of the roll-out speed of the third roller and the pressing gap of the roller set. It can be seen from the experimental results that the polarizing plate 2〇αΐ force is controlled by the first tension (Τ1), the second tension (Τ2) and the third tension (Τ3) by a 壬=error, so that a force ratio (TR) is not more than one. The predetermined value is controlled by the degree of Dach 12 200931080. The relationship between the 'tension ratio (TR) and the first tension (T1), the second tension (Τ2), and the second tension (D) is: As described above, the degree of warpage of the polarizing plate can be controlled by controlling the tension ratio (TR) to be not more than a predetermined value. It is known from the experimental results that when the thickness ratio of the thickness of the second light transmissive layer 230 to the first light transmissive layer 22 is about 882 to about 1.16, the tension ratio (TR) is preferably not more than 〇〇132. . When the thickness ratio of the thickness of the second light-transmitting layer 230 to the first-light-transmitting layer mo is about 1 666 to about 486 2.486, the tension ratio (TR) is not more than 0.0056. For example, when the first light transmissive layer 220 and the second light transmissive layer 23 are both a triacetate film (TAC) having a thickness of about 8 angstroms, it is preferred that the control tension ratio (TR) is not greater than 〇〇132. Therefore, the polarizing plate 2 of the continuously produced polarizing plate 20 in a wide direction buckle shape is less than the tension ratio (TR) greater than 0.0132, and the polarizing plate 2 is in a width direction (TD). Warpage value. In another example, the first light transmissive layer 22 and the first light transmissive layer 230 may be respectively different thicknesses of triacetate film (TAC), for example, about 111 and about 80 μm, respectively, by controlling When the tension ratio (TR) is not more than 0.0056, the warpage value of the polarizing plate 2 in a direction of extension (machine a-, md) is not less than 〇, that is, there is no negative warp. In order to make the description of the present invention more detailed and complete, with reference to FIG. 4, the present invention defines that the winding direction indicated by the arrow of reference numeral 490 is the extending direction (MD)' and this direction is the same as the extending direction of the polarizing layer 21〇; And defining the direction of the vertical extension direction is the width direction (TD)', that is, the width direction of both sides of the polarizing film 2 。. Further, the warpage of the polarizing film 200 or the polarizing plate 20 in the direction of the protective layer 240 is defined as positive warpage (that is, the warpage value is greater than 0), and the warp direction toward the first light transmitting layer 22 is negative warp (ie, warpage value). It is less than (7). 13 200931080 Referring to FIG. 5, a cross-sectional view of a polarizing plate 50 formed by the method of the present invention is shown. In another embodiment of the present invention, as shown in FIG. 5, the second transparent layer 530 of the present invention may be A substrate 532 and an optical coating 534 are included on the substrate 532. The substrate 532 can be the aforementioned triacetate film (TAC), and the optical mirror layer 534 is typically a hard ore film having a thickness of 3-8/rni (hard -coating film), anti-reflection film, low reflection film, anti-glare film or anti-static film, etc. Formed on the transparent substrate 532' as a general surface treatment of the polarizing plate, the hardness of the polarizing plate can be strengthened to prevent unintentional scratching of daily life or to prevent the light from being excessively concentrated to make the user feel uncomfortable to watch. As the skilled person knows, a polarizing film generally having an optical coating 534 can be formed continuously. The pressure sensitive adhesive layer 55A and the release layer 560 are on the first light transmissive layer 220 to form a polarizing plate 50. From the experimental results, the polarizing plate 5 formed by the second light transmissive layer 530 having the optical plating layer 534 is known. 〇' can also control the degree of warpage of the polarizing plate 50 by controlling the tension ratio (TR) not greater than a predetermined value in the production process, as described above, the second light transmitting layer 530 and the first light transmitting layer 220 The thickness ratio will determine the applicable range of the tension ratio (TR), and will not be further described herein. Fig. 6 is a schematic cross-sectional view of a polarizing plate 6A according to still another embodiment of the present invention. 60, for example, a large-sized polarizing plate, comprising a polarizing layer 210' and first and second light-transmitting layers 220 and 230 on opposite sides of the polarizing layer 210. The polarizing layer 210 and the first light-transmitting layer 22 And/or the second light transmissive layer 230 may include a very thin adhesive layer 615 (generally less than Ιμηι). And 'when the first light transmissive layer 220 and the second light transmissive layer 230 are triacetate, Generally, the saponification treatment procedure can be used to change the hydrophilicity of the surface of the triacetate membrane (contact The adhesive layer 615 is formed thereon. In the embodiment 14 200931080, the adhesive layer 615 is formed of a hydrophilic polyvinyl alcohol resin, generally referred to as a hydrogel, for the subsequent polarizing layer 210 and the first A light transmissive layer 22 and/or a second light transmissive layer 230 is not separated. Since the adhesive layer 615 is very thin relative to the overall thickness of the polarizing plate 60, generally the degree of warpage of the polarizing plate 6 The effect of the polarizing plate 60 can also control the charm value by controlling the tension ratios of the first tension, the second tension, and the third tension of the first light transmissive layer 220, the second light transmissive layer 230, and the protective layer 240. This will not be repeated here. Further, the polarizing plate 60 may optionally include an optical layer 655 on the first light transmissive layer 220. As shown in FIG. 6, in this embodiment, the optical layer 655 is formed on the transparent layer 220, and the optical layer 655 can be designed as a reflective film, a semi-transmissive reflective film, a retardation film, and a viewing angle compensation film. , brightness enhancing film or a combination thereof. In other words, when the optical layer 655 is a viewing angle compensation film, the polarizing plate 6A can be a viewing angle-compensated polarizing plate; when the optical layer 65S is a reflecting film, the polarizing plate 6A can be a reflective polarizing plate. ❹ In addition, in order to make the object and features of the present invention more obvious and easy to understand, the following examples are described in detail as follows: Example provides a polyethylene surface which is swelled by water at a temperature of about 25 to 35 ° C, and then woven. The polyvinyl alcohol is stored in a crystallization of 3q to 55 wt% _ 2.0 to 6.0 wt% _ water-soluble, 3 to 7 times 岐 extension = row extension 'to form - polarizing layer 21 〇. And the polarizing layer formed 2ω_thickness 20~35/m $polyphenol-containing polyvinyl alcohol film has a monomer transmittance of 43 〇/. The upper side of 200931080 and the degree of polarization are 99.9% or more. Next, the saponified first light-transmitting layer no and the second light-transmitting layer 230 (for example, 'diacetate film) are transferred by water. (4) affixing to the polarizing layer ^3 贴 = after the baking process, the protective layer 240 is attached to the second light-transmissive 230 曰 list to provide the first light-transmissive layer 220 and the thickness of the second transparent layer is like a willow force _ (TR) fitting conditions. ^ ❹ Table 1
將上述編號1〜H)所完成之偏光板，參考圖四的方气、八 16 200931080 著幅寬方向(TD)進行偏光板取樣，樣品之長寬各約300mm及 230mm ’並先以尺規量測偏光板四個角落的翹曲值。量測時將 樣品置於平板玻璃上，量測其MD(1，3)和TD(2,4)方向的趣曲 值並取其平均值，量測結果如表二所示。The polarizing plates completed by the above Nos. 1 to H) are sampled with reference to the square gas of FIG. 4 and the width direction (TD) of the August 16 200931080. The length and width of the samples are about 300 mm and 230 mm respectively. Measure the warpage value of the four corners of the polarizer. During the measurement, the sample was placed on a flat glass, and the interesting values in the MD (1, 3) and TD (2, 4) directions were measured and averaged. The measurement results are shown in Table 2.
表二 編號 張力比值 (TR) MD(1，3)翹曲 平均值(mm) TD(2, 4)翹曲 平均值(mm) 1 0.0072 -6.50 4.80 2 0.0052 1.0 6.02 3 0.0042 5.9 6.8 4 0.0042 19.5 ........ 11.8 5 0.0040 7.35 8.65 6 0.0136 -1.4 106.5 7 0.0109 6.2 84 8 0.090 9.2 31.5 9 0.0079 8.6 4.15 10 0.0040 7.35 8.65 —----- 由上述實驗結果及實驗趨勢線得知，當第一透光層及第二 透光層的厚度不均時(例如約1:2)，藉由控制張力比值(TR)不大 於約0.0056，使得偏光板於延伸方向(MD)之翹曲值不小於〇。 當第一透光層及第二透光層的厚度接近(例如約1:1)時，藉由 控制張力比值(TR)不大於約0.0132，可使偏光板於幅寬方向 200931080 (=之魅曲值小於張力比值㈣大於約_2時之偏光板於 二2向(TD)之翹曲值。且第二透光層是否具有光學 影響實驗結果。 本發明於此m光層及第二透光層之厚度比值為 、”、U和約1:2作為例示說明，賴此技藝者應該瞭解，本發 明於其他的厚度比值條件下(例如約1:3、Η等），亦可藉由控 制張力比值(TR)不大於一預定值，以控制偏光板的翹曲程度。 〇 、上所述本發明之較佳實施例❿£»，並非帛以限定本 發明之申請專利範圍；凡其他未脫離本發明所揭示之精神下所 完成之等效改變或修飾’均應包含在下述之申請範圍内。 【圖式簡單說明】 圖-顯示本發明於-實施例之形成—偏紐的方法之流 程圖。 ❹ 圖二顯示依據本發明之-實施例之偏光板_面示意圖。 圖二係根據本發明於另一實施例中，以捲料方式連續生產 偏光板的示意圖。 圖四係根據本發明之-實___生產偏光板之方 向性及樣品取樣方式的示意圖。 18 200931080 圖五顯示依據本發明之方法所形成之一偏光板的剖面示 意圖。 圖六顯示本發明於再一實施例中之一偏光板的剖面示意 圖。Table 2 Number tension ratio (TR) MD (1,3) warpage average (mm) TD (2, 4) warpage average (mm) 1 0.0072 -6.50 4.80 2 0.0052 1.0 6.02 3 0.0042 5.9 6.8 4 0.0042 19.5 ........ 11.8 5 0.0040 7.35 8.65 6 0.0136 -1.4 106.5 7 0.0109 6.2 84 8 0.090 9.2 31.5 9 0.0079 8.6 4.15 10 0.0040 7.35 8.65 —----- From the above experimental results and experimental trend line When the thicknesses of the first light transmissive layer and the second light transmissive layer are not uniform (for example, about 1:2), the polarizing plate is tilted in the extending direction (MD) by controlling the tension ratio (TR) to be no more than about 0.0056. The mean value is not less than 〇. When the thicknesses of the first light transmissive layer and the second light transmissive layer are close to each other (for example, about 1:1), by controlling the tension ratio (TR) to be no more than about 0.0132, the polarizing plate can be made in the width direction of 200931080 (=the charm) The curvature value is less than the warp value of the polarizing plate in the two-direction (TD) when the tension ratio (4) is greater than about _2, and whether the second light-transmitting layer has an optical influence test result. The present invention is in the m-light layer and the second through-layer. The thickness ratio of the optical layer is ", U, and about 1:2 as an illustration. It should be understood by those skilled in the art that the present invention can be used under other thickness ratio conditions (e.g., about 1:3, Η, etc.). The control tension ratio (TR) is not greater than a predetermined value to control the degree of warpage of the polarizing plate. The preferred embodiment of the present invention described above is not intended to limit the scope of the patent application of the present invention; Equivalent changes or modifications made without departing from the spirit of the invention shall be included in the scope of the application below. [Simplified illustration of the drawings] Figure - shows the method of forming - partial conjugates of the present invention Flowchart ❹ Figure 2 shows a polarizing plate according to an embodiment of the present invention_ Fig. 2 is a schematic view showing the continuous production of a polarizing plate by a coiling method according to another embodiment of the present invention. Fig. 4 is a schematic view showing the directivity of a polarizing plate and a sample sampling mode according to the present invention. 18 200931080 Figure 5 shows a schematic cross-sectional view of a polarizing plate formed in accordance with the method of the present invention. Figure 6 is a cross-sectional view showing a polarizing plate in accordance with still another embodiment of the present invention.
【主要元件符號說明】 20, 50, 60 偏光板 200 偏光膜 210 偏光層 220 第一透光層 230 第二透光層 240 保護層 310 第一滾輪 320 第二滾輪 330 第一壓合滾輪組 340 第三滾輪 350 第二壓合滾輪組 360 烘箱 530 第二透光層 532 基材 534 光學鑛層 550 感壓膠層 19 200931080 560 離型層 615 黏著層 655 光學層[Main component symbol description] 20, 50, 60 polarizing plate 200 polarizing film 210 polarizing layer 220 first light transmitting layer 230 second light transmitting layer 240 protective layer 310 first roller 320 second roller 330 first pressing roller group 340 Third roller 350 second pressing roller set 360 oven 530 second light transmitting layer 532 substrate 534 optical ore layer 550 pressure sensitive adhesive layer 19 200931080 560 release layer 615 adhesive layer 655 optical layer