TW201809762A - Polarizing plate - Google Patents

Abstract

The present invention provides a polarizing film and a polarizing plate comprising the polarizing film and a protect film which is laminated on at least one surface of the polarizing film, wherein the polarizing film has a ratio WI/Ty of iodine content WI [weight%] to a luminosity correction unit transmittance Ty[%] of 0.145 or more. The WI/Ty is preferably 0.5 or less.

Description

偏光板 Polarizer

本發明係關於一種偏光膜及含有該偏光膜之偏光板。 The invention relates to a polarizing film and a polarizing plate containing the polarizing film.

偏光板係被廣泛地使用在以液晶顯示裝置為代表之圖像顯示裝置等。作為偏光板，通常的結構係將保護膜貼合在偏光膜的一面或兩面，而前述偏光膜係使碘等二色性色素吸附定向在聚乙烯醇系樹脂膜而成。近年來，隨著圖像顯示裝置在可攜式機器、薄型電視等的應用，而日益對偏光板、以及偏光膜的薄膜化有所要求。 Polarizing plates are widely used in image display devices and the like typified by liquid crystal display devices. As a polarizing plate, a protective film is generally bonded to one or both sides of a polarizing film, and the polarizing film is formed by adsorbing and orienting a dichroic dye such as iodine on a polyvinyl alcohol resin film. In recent years, with the application of image display devices in portable devices, thin televisions, and the like, there has been an increasing demand for thinning of polarizing plates and polarizing films.

在日本特開2013-182162號公報中，係記載一種偏光膜(偏光子層)的厚度為10μm以下之偏光板的製造方法。 Japanese Patent Application Laid-Open No. 2013-182162 describes a method for manufacturing a polarizing plate with a thickness of 10 μm or less of a polarizing film (polarizing layer).

先前技術文獻 Prior art literature

專利文獻 Patent literature

[專利文獻1]日本特開2013-182162號公報 [Patent Document 1] Japanese Patent Application Publication No. 2013-182162

就偏光膜而言，其厚度越小，則從表面侵入 的水分之影響變得越大，而在放置於濕熱環境下時、暴露或浸漬在溫水時，會有容易產生偏光特性降低、色偏等特性劣化之傾向。又，在本說明書中，係將對於被放置在濕熱環境下而引起的特性劣化之抗性稱為「耐濕熱性」，將對於暴露或浸漬在溫水而引起的特性劣化之抗性稱為「耐溫水性」，而且將該等統稱為「耐水性」。 For a polarizing film, the smaller its thickness, the more it penetrates from the surface The influence of the moisture content becomes larger, and when placed in a hot and humid environment, exposed or immersed in warm water, there is a tendency that characteristics such as a reduction in polarization characteristics and a deterioration in color deviation tend to occur. In addition, in this specification, resistance to property deterioration caused by being placed in a hot and humid environment is referred to as "damp heat resistance", and resistance to property deterioration caused by exposure or immersion in warm water is referred to as "damp heat resistance". "Water resistance", and these are collectively referred to as "water resistance."

在日本特開2013-182162號公報所記載之發明，係於被貼合在偏光膜的保護膜使用透濕度較低者，藉此使偏光板的耐濕熱性提升。但是，使用該手段時，所使用的保護膜之材質、厚度會受到限制。 The invention described in Japanese Patent Application Laid-Open No. 2013-182162 relates to a protective film to be attached to a polarizing film, which uses a lower moisture permeability, thereby improving the humidity and heat resistance of the polarizing plate. However, when using this method, the material and thickness of the protective film used are limited.

本發明之目的在於使偏光膜本身的耐水性提升。而且，本發明之另一目的在於提供一種耐水性優異之偏光板。 The object of the present invention is to improve the water resistance of the polarizing film itself. Another object of the present invention is to provide a polarizing plate having excellent water resistance.

本發明係提供以下所示之偏光膜及偏光板。 The present invention provides a polarizing film and a polarizing plate described below.

[1]一種偏光膜，其係碘元素含有率W_I[重量%]相對於光度校正單體透射率Ty[%]之比W_I/Ty為0.145以上。 [1] A polarizing film which contains iodine-based ratio W _I [wt%] with respect to the transmittance Ty photometric correction monomer [%] ratio W _I / Ty is 0.145 or more.

[2]如[1]所述之偏光膜，其中，前述W_I/Ty為0.5以下。 [2] The polarizing film according to [1], wherein the W _I / Ty is 0.5 or less.

[3]如[1]或[2]所述之偏光膜，其中，厚度為10μm以下。 [3] The polarizing film according to [1] or [2], wherein the thickness is 10 μm or less.

[4]如[1]至[3]項中任一項所述之偏光膜，其中，含有 聚乙烯醇系樹脂。 [4] The polarizing film according to any one of [1] to [3], which contains Polyvinyl alcohol resin.

[5]如[1]至[4]項中任一項所述之偏光膜，其中，前述Ty為40至47%。 [5] The polarizing film according to any one of [1] to [4], wherein the Ty is 40 to 47%.

[6]一種偏光板，其係包含如[1]至[5]項中任一項所述之偏光膜、及層積在前述偏光膜的至少一面上的保護膜。 [6] A polarizing plate comprising the polarizing film according to any one of [1] to [5], and a protective film laminated on at least one side of the polarizing film.

依據本發明，可提供一種具有優異的耐水性之偏光膜及偏光板。 According to the present invention, a polarizing film and a polarizing plate having excellent water resistance can be provided.

1、2‧‧‧偏光板 1, 2‧‧‧ polarizing plates

5‧‧‧偏光膜 5‧‧‧ polarizing film

6、6’‧‧‧聚乙烯醇系樹脂層 6, 6’‧‧‧ 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‧‧‧The second adhesive layer

30、30’‧‧‧基材膜 30, 30’‧‧‧ substrate film

100‧‧‧積層膜 100‧‧‧ laminated film

200‧‧‧延伸膜 200‧‧‧ stretch film

300‧‧‧偏光性積層膜 300‧‧‧Polarized laminated film

400‧‧‧貼合膜 400‧‧‧ laminated film

第1圖係表示本發明之偏光板的層結構的一個例子之示意剖面圖。 FIG. 1 is a schematic cross-sectional view showing an example of a layer structure of a polarizing plate of the present invention.

第2圖係表示本發明之偏光板的層結構之另一個例子之示意剖面圖。 Fig. 2 is a schematic cross-sectional view showing another example of the layer structure of the polarizing plate of the present invention.

第3圖係表示本發明之偏光板的製造方法的一個較佳例之流程圖。 Fig. 3 is a flowchart showing a preferred example of a method for manufacturing a polarizing plate of the present invention.

第4圖係表示在樹脂層形成步驟所得到的積層膜之層結構的一個例子之示意剖面圖。 FIG. 4 is a schematic cross-sectional view showing an example of a layer structure of a laminated film obtained in a resin layer forming step.

第5圖係表示在延伸步驟所得到的延伸膜之層結構的一個例子之示意剖面圖。 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圖係表示在染色步驟所得到的偏光性積層膜之層結構的一個例子之示意剖面圖。 Fig. 6 is a schematic cross-sectional view showing an example of a layer structure of a polarizing laminated film obtained in a dyeing step.

第7圖係表示在第1貼合步驟所得到的貼合膜之層結構的一個例子之示意剖面圖。 FIG. 7 is a schematic cross-sectional view showing an example of the layer structure of the bonding film obtained in the first bonding step.

<偏光膜> <Polarizing film>

本發明之偏光膜，其特徵在於：碘元素含有率W_I相對於光度校正單體透射率Ty之比W_I/Ty為0.145以上。W_I/Ty為0.145以上之本發明的偏光膜係耐水性(耐濕熱性及耐溫水性)優異，即便是在放置於濕熱環境下時、暴露或浸漬於溫水時，亦不容易產生偏光特性降低、色偏等特性劣化。若使用本發明之偏光膜，則因為係其本身具有優異的耐水性，所以不會受到使用透濕度低的薄膜等限制與其貼合之保護膜的材質和厚度，而能夠提供具有優異的耐水性之偏光板。 The polarizing film of the present invention is characterized in that the ratio W _I / Ty of the iodine element content ratio W _I to the photometric correction monomer transmittance Ty is 0.145 or more. The polarizing film of the present invention having a W _I / Ty of 0.145 or more is excellent in water resistance (damp heat resistance and temperature resistance), and even when placed in a humid and hot environment, exposed or immersed in warm water, polarized light is not easily generated Deterioration of characteristics and deterioration of characteristics such as color shift. If the polarizing film of the present invention is used, since it has excellent water resistance, it will not be restricted by the material and thickness of the protective film to which the low-permeability film and the like are attached, and can provide excellent water resistance. Of polarizing plate.

以下說明將W_I/Ty設為0.145以上之技術上的意義。在使碘吸附定向在聚乙烯醇系樹脂膜而成之偏光膜，聚乙烯醇系樹脂與碘係形成錯合物(以下，稱為「PVA-碘錯合物」)，以往已知藉由該錯合物顯示吸收二色性而表現偏光性能。雖然在偏光膜亦存在不形成PVA-碘錯合物之碘，惟因此種碘在可見區域不具有太多吸收，所以對於偏光性能不太有所助益。尤其是以碘化物離子(I^-)的狀態存在之碘，在可見區域為不吸收，所以其本身係對偏光膜的偏光性能完全沒有幫助，而且對偏光膜的外觀(色相)亦完全沒有幫助。 The technical significance of setting W _I / Ty to 0.145 or more will be described below. In a polarizing film formed by orienting iodine adsorption on a polyvinyl alcohol-based resin film, a polyvinyl alcohol-based resin and an iodine-based complex (hereinafter, referred to as a "PVA-iodine complex") are known. This complex shows absorption dichroism and exhibits polarizing performance. Although iodine that does not form a PVA-iodine complex is also present in the polarizing film, this kind of iodine does not have much absorption in the visible region, so it is not very helpful for polarizing performance. Especially in iodide ion (I ^-) in the presence of iodine state, it does not absorb in the visible region, so that its polarization performance of the polarizing film, which in itself is no help, but the appearance of the polarizing film (hue) also did not help .

更詳細地說明偏光膜的偏光性能時，偏光性能通常係由稱為「光度校正單體透射率(luminosity correction unit transmittance)Ty」、「光度校正偏光度(luminosity correction degree of polarization)Py」之二個參數來進行評估。該等參數，是分別以人類肉眼敏感度最高的550nm附近之加權值成為最大的方式進行校正而成之可見區域(波長380至780nm)之透射率、偏光度。因為人類肉眼係無法視認波長未達380nm的光線，所以在Ty及Py係不考慮。因而，例如在大約200至230nm的波長區域具有吸收帶之碘化物離子(I^-)，其本身係不會對偏光膜的Ty及Py、亦即偏光性能造成影響。 When describing the polarization performance of a polarizing film in more detail, the polarization performance is usually referred to as "luminosity correction unit transmittance Ty" and "luminosity correction degree of polarization Py". Parameters for evaluation. These parameters are the transmittance and polarization of the visible region (wavelength 380 to 780 nm), which are corrected in such a manner that the weighted value around 550 nm, which is the highest sensitivity of the human eye, is maximized. Because the human eye cannot recognize light with a wavelength of less than 380 nm, it is not considered in the Ty and Py systems. Thus, for example, having a wavelength region of about 200 to 230nm of the iodide ion (I ^-) of the absorption band, based not on their own and Py polarizing Ty, i.e. affect polarization performance.

基於如上所述的理由，先前在進行評估/解析偏光膜及使用其之偏光板的偏光性能時，對於未形成PVA-碘錯合物之碘、尤其碘化物離子(I^-)並沒有進行討論。然而，儘管此種先前的技術常識，但是本發明者等專心研究，結果發現為了使偏光膜及使用該偏光膜之偏光板的耐水性提升，不僅是PVA-碘錯合物，考慮在Ty及Py未出現的碘化物離子(I^-)係屬重要，更具體而言，係發現了以下的事項。 Based on the reasons described above, during the previous evaluation / resolved when the polarizing film and polarizing properties of the polarizing plate which, for the iodine iodide complexes of PVA- not formed, in particular iodide ion (I ^-), and are not discussed . However, despite this prior technical knowledge, the present inventors and others have made intensive studies and found that in order to improve the water resistance of polarizing films and polarizing plates using the polarizing films, it is not only PVA-iodine complexes that are considered in Ty and iodide ion (I ^-) Py does not appear in the Department is important, and more specifically, the Department found the following matters.

a)在偏光膜中之碘化物離子，係大為影響PVA-碘錯合物的形成，就經驗而言，在偏光膜中，係成立下述式(1)的平衡：I^-+PVA-I₅錯合物n PVA-I₃錯合物+(2-n)I₃ ^- (1)。 a) In the polarizing film of iodide ion, iodine PVA- based greatly affect the formation of the complexes, to experience, in the polarizing film, the establishment of balanced lines following formula (1): I ^- + PVA- I ₅ complex n PVA-I ₃ complexes _{+ (2-n) I 3} - (1).

b)將偏光膜和偏光板放置在濕熱環境下時、暴露或浸漬在溫水時，當碘化物離子(I^-)係容易從偏光膜脫離時，由於碘化物離子(I^-)的脫離，上述式(1)的平衡係傾向左側且PVA-I₃錯合物容易減少。因此，由於形成短波長(藍色)側的吸收帶之PVA-I₃錯合物變少，所以偏光膜和偏光板變得不容易吸收藍色而產生色偏(藍色色偏)。而且，因PVA-I₃錯合物變少而產生藍色色偏時，則偏光度亦會伴隨著此種情形而降低。又，上述式(1)的平衡傾向左側時，形成長波長(紅色)側的吸收帶之PVA-I₅錯合物有增加之傾向。 b) When the polarizing film and a polarizing plate disposed in a hot and humid environment, exposed to or immersed in hot water, when the iodide ion (I ^- time) based polarizing film is easily detached from, since the iodide ion (I ^- off) of The balance system of the above formula (1) tends to the left and the PVA-I ₃ complex is liable to decrease. Therefore, the PVA-I ₃ complex that forms the absorption band on the short-wavelength (blue) side is reduced, so that the polarizing film and the polarizing plate do not easily absorb blue and cause color shift (blue color shift). In addition, when the PVA-I ₃ complex is reduced and the blue color shift occurs, the degree of polarization decreases with this situation. When the balance of the above formula (1) tends to the left, the PVA-I ₅ complex that forms an absorption band on the long wavelength (red) side tends to increase.

c)在偏光膜，藉因為由先使得相對於「PVA-碘錯合物的含量」的「碘化物離子的含量」成為過剩，能夠使上述式(1)的平衡預先成為傾向右側的狀態，所以即使稍微產生碘化物離子(I^-)的脫離，上述式(1)的平衡也不會輕易而簡單地傾向左側，可藉由充分的量使PVA-I₃錯合物的含量安定化。藉此，可抑制藍色色偏及偏光度降低。 c) In the polarizing film, since the "content of iodide ion" relative to the "content of PVA-iodine complex" is made excessive, the balance of the above-mentioned formula (1) can be brought to the right side in advance, even if very slight iodide ion (I ^-) disengaged, the above balance formula (1) will not easily and simply left tends to be by a sufficient amount so that the content of PVA-I complex compound ₃ stabilization. This can suppress the reduction of blue color cast and polarization.

碘元素含有率W_I相對於光度校正單體透射率Ty之亦即W_I/Ty的參數之導出，係基於如以上的研討結果。亦即，首先，上述c)所記載之「PVA-碘錯合物的含量」係可對應「Ty」。這是因為形成可見區域的吸收帶之PVA-碘錯合物的含量係與Ty成正比。而且，為了使上述c)所記載之使「碘化物離子的含量」相對於「PVA-碘錯合物的含量」為過剩地存在，只要使在偏光膜所含有的「總碘原子量」相對於「PVA-碘錯合物的含量」增多即可，所以「碘 化物離子的含量」係能夠對應「總碘原子量」。在此，所謂「總碘原子量」，係與上述的「碘元素含有率W_I」同義。因此，「碘化物離子的含量」相對於「PVA-碘錯合物的含量」係能夠替換成為「碘元素含有率W_I」相對於「Ty」，亦即W_I/Ty。 The derivation of the parameter of the iodine content rate W _I with respect to the photometric correction monomer transmittance Ty, that is, W _I / Ty, is based on the results of the above discussion. That is, first, the "content of PVA-iodine complex" described in c) above may correspond to "Ty". This is because the content of the PVA-iodine complex forming the absorption band in the visible region is directly proportional to Ty. Furthermore, in order to make the "content of iodide ion" relative to the "content of PVA-iodine complex" described in c) excessively present, the "total iodine atomic amount" contained in the polarizing film should be relative to The "content of PVA-iodine complex" can be increased, so the "content of iodide ion" can correspond to "total iodine atomic weight". Here, the "total iodine atomic weight" is synonymous with the above-mentioned "iodine element content rate W _I ". Therefore, the "content of iodide ion" with respect to "content of PVA-iodine complex" can be replaced with "iodine element content rate W _I " with respect to "Ty", that is, W _I / Ty.

如以上所述，為了使偏光膜及偏光板的耐水性提升，不是需增大「碘元素含有率W_I」本身，而是需增大W_I/Ty。由研討的結果，明瞭到為了使偏光膜及偏光板的耐水性提高，需將W_I/Ty增大至0.145以上。未達0.145時，無法確認到耐水性的提升效果。從提升耐水性的觀點來看，W_I/Ty較佳為0.150以上。 As described above, in order to improve the water resistance of the polarizing film and the polarizing plate, it is not necessary to increase the "iodine element content rate W _I " itself, but to increase W _I / Ty. From the results of the research, it became clear that in order to improve the water resistance of the polarizing film and the polarizing plate, it is necessary to increase W _I / Ty to 0.145 or more. When it is less than 0.145, the improvement effect of water resistance cannot be confirmed. From the viewpoint of improving water resistance, W _I / Ty is preferably 0.150 or more.

另一方面，W_I/Ty的上限值係沒有特別限制，該值太大時，就其結果而言，碘化物離子(I^-)含量變地過大，則PVA-I₃錯合物與PVA-I₅錯合物之量的平衡會偏掉(亦即，上述式(1)的平衡過於傾向右側，致使形成長波長(紅色)側的吸收帶之PVA-I₅錯合物的量不足)，而無法將偏光膜及偏光板的初始色相保持為中性色。因而，W_I/Ty係以0.5以下為佳，以0.4以下為更佳。 On the other hand, the upper limit line W _I / Ty not particularly limited, when it is too large, in terms of its result, iodide ions (I ^-) to the content becomes too large, the PVA-I ₃ complexes with The balance of the amount of the PVA-I ₅ complex is off (that is, the balance of the above formula (1) is too much to the right, causing the amount of the PVA-I ₅ complex to form an absorption band on the long wavelength (red) side. Insufficient), and the initial hue of the polarizing film and the polarizing plate cannot be maintained at a neutral color. Therefore, W _I / Ty is preferably 0.5 or less, and more preferably 0.4 or less.

偏光膜的碘元素含有率W_I，係定義為在每重量單位的偏光膜所含有的碘元素之總重量，具體而言係能夠依照下述式(2)求取：W_I[重量%]={碘元素的總重量[mg]/偏光膜的重量[mg]}×100。 在偏光膜所含有的碘元素之總重量，係能夠依據JIS K 0127：2013之燃燒-離子層析法而求取。該方法，係藉由使偏光膜試料在含有氧的燃燒氣體中燃燒，將所產生的氣體捕集在吸收液之後，使用離子層析法進行定量之方法。偏光膜(測定試樣)的燃料前處理，係依照同JIS規格之6.3.5。又，在上述式之「偏光膜的重量」，當碘元素含有率W_I為1%以上時，係設為10至20mg，未達1%時係設為100mg以上。 The iodine element content rate W _{I of} a polarizing film is defined as the total weight of the iodine element contained in the polarizing film per weight unit, and can be specifically calculated according to the following formula (2): W _I [wt%] = {Total weight of iodine element [mg] / weight of polarizing film [mg]} × 100. The total weight of the iodine element contained in the polarizing film can be obtained in accordance with the combustion-ion chromatography method of JIS K 0127: 2013. This method is a method in which a polarizing film sample is burned in a combustion gas containing oxygen, and the generated gas is captured in an absorption liquid, and then quantified by ion chromatography. The fuel pretreatment of the polarizing film (measurement sample) is in accordance with 6.3.5 of the same JIS standard. In the "weight of the polarizing film" in the above formula, when the content of iodine element W _I is 1% or more, it is 10 to 20 mg, and when it is less than 1%, it is 100 mg or more.

為了使W_I/Ty成為0.145至0.5的範圍，偏光膜的碘元素含有率W_I係以5至15為佳，以6至10為更佳。 In order to make W _I / Ty in the range of 0.145 to 0.5, the content of iodine element W _{I in the} polarizing film is preferably 5 to 15, and more preferably 6 to 10.

又，在後述的偏光膜之波長217nm的吸光度，係以2.5以上為佳，以3.0以上為更佳，上限值通常係以4.2以下為佳，以4.0以下為更佳。 The absorbance at a wavelength of 217 nm of the polarizing film described later is preferably 2.5 or more, more preferably 3.0 or more, and the upper limit value is usually preferably 4.2 or less, and more preferably 4.0 or less.

偏光膜的光度校正單體透射率Ty，可為在應用該偏光膜和包含該偏光膜的偏光板之液晶顯示裝置等圖像顯示裝置中所通常被要求的值，具體而言，係以40至47%的範圍內為佳。Ty更佳為41至45%的範圍內，此時，Ty與Py的平衡係變為更良好。Ty太高時，則Py會降低而圖像顯示裝置的顯示品質降低。Ty太低時，則圖像顯示裝置的亮度降低而顯示品質降低、或為了充分地提高亮度而需增大投入電力。 The photometric correction unit transmittance Ty of the polarizing film may be a value generally required in image display devices such as a liquid crystal display device in which the polarizing film and a polarizing plate including the polarizing film are applied. Specifically, the value is 40. It is preferably in the range of 47%. Ty is more preferably in the range of 41 to 45%, and at this time, the balance between Ty and Py becomes better. When Ty is too high, Py decreases and the display quality of the image display device decreases. When Ty is too low, the brightness of the image display device is lowered and the display quality is lowered, or in order to sufficiently increase the brightness, it is necessary to increase the input power.

又，作為用以提升偏光膜的耐水性之其它手段，例如能夠考慮提高碘的吸附量來減小Ty。但是該方法係如上述，會使亮度降低。另一方面，依據本發明，可維持充分高的Ty，同時使偏光膜的耐水性提升。 Further, as another means for improving the water resistance of the polarizing film, for example, it is possible to consider increasing the adsorption amount of iodine to reduce Ty. However, this method is as described above, and the brightness is reduced. On the other hand, according to the present invention, while maintaining a sufficiently high Ty, the water resistance of the polarizing film can be improved.

偏光膜的光度校正偏光度Py，係以99.9%以上為佳，以99.95%以上為更佳。從即使在耐水性試驗(耐濕熱性試驗或耐溫水性試驗)後也維持圖像顯示裝置的顯示品質之觀點來看，該試驗後的Py係以98.0%以上為佳。 The photometric correction polarization degree Py of the polarizing film is preferably 99.9% or more, and more preferably 99.95% or more. From the viewpoint of maintaining the display quality of the image display device even after the water resistance test (humidity heat resistance test or temperature water resistance test), the Py after the test is preferably 98.0% or more.

偏光膜的Ty及Py，在偏光膜係以單體存在時，能夠將其本身作為測定試樣而測定。另一方面，以在偏光膜上貼合有保護膜之偏光板的方式存在時，係將保護膜及接著劑層從偏光板除去，而將偏光板所含有的偏光膜單離並將其作為測定試樣，或是將偏光板本身作為測定試樣，測定Ty及Py，且將所測得的Ty及Py設作偏光膜的Ty及Py。將偏光板作為測定試樣而測定之Ty及Py，實質上係與將單離後的偏光膜作為測定試樣而測定之Ty及Py相同。 Ty and Py of a polarizing film can be measured as a measurement sample when a polarizing film exists as a monomer. On the other hand, when a polarizing plate having a protective film bonded to the polarizing film exists, the protective film and the adhesive layer are removed from the polarizing plate, and the polarizing film contained in the polarizing plate is isolated and used as The measurement sample or the polarizing plate itself is used as a measurement sample to measure Ty and Py, and the measured Ty and Py are set to Ty and Py of the polarizing film. The Ty and Py measured using a polarizing plate as a measurement sample are substantially the same as the Ty and Py measured using a polarized film as a measurement sample.

本發明之偏光膜，係使碘作為二色性色素吸附定向而成者，較佳是含有聚乙烯醇系樹脂者，更具體而言，係使碘吸附定向在由經單軸延伸的聚乙烯醇系樹脂所構成之膜(聚乙烯醇系樹脂膜)而成者。 The polarizing film of the present invention is formed by orienting iodine as a dichroic dye, preferably one containing a polyvinyl alcohol-based resin, and more specifically, orienting iodine on polyethylene that is uniaxially stretched. A film made of an alcohol-based resin (polyvinyl alcohol-based resin film).

偏光膜的厚度係例如30μm以下，可進一步為20μm以下，惟從偏光板的薄型化之觀點來看，係以10μm以下為佳，以8μm以下為更佳。偏光膜的厚度係通常2μm以上。厚度越小，則耐水性越容易降低，惟依劇本發明，能夠提供一種即使厚度為10μm以下耐水性亦良好的偏光膜。 The thickness of the polarizing film is, for example, 30 μm or less, and may further be 20 μm or less. From the viewpoint of thinning the polarizing plate, the thickness is preferably 10 μm or less, and more preferably 8 μm or less. The thickness of the polarizing film is usually 2 μm or more. The smaller the thickness, the more easily the water resistance is reduced. However, according to the present invention, it is possible to provide a polarizing film having good water resistance even if the thickness is 10 μm or less.

作為構成偏光膜之聚乙烯醇系樹脂，可使用 將聚乙酸乙烯系樹脂皂化而成者。作為聚乙酸乙烯系樹脂，在乙酸乙烯酯的同元聚合物之聚乙酸乙烯酯之外，可例示乙酸乙烯酯和能夠與乙酸乙烯酯共聚合的其它單體之共聚物。作為能夠與乙酸乙烯酯共聚合之其它單體，例如可舉出：不飽和羧酸類、烯烴類、乙烯醚類、不飽和磺酸類及具有銨基之(甲基)丙烯醯胺類等。 As a polyvinyl alcohol resin constituting a polarizing film, it can be used A product obtained by saponifying a polyvinyl acetate resin. Examples of the polyvinyl acetate-based resin include copolymers of vinyl acetate and other monomers capable of copolymerizing with vinyl acetate in addition to polyvinyl acetate, which is a homopolymer of vinyl acetate. Examples of other monomers that can be copolymerized with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, (meth) acrylamidoamines having an ammonium group, and the like.

將上述聚乙烯醇系樹脂製膜而成者係構成偏光膜。將聚乙烯醇系樹脂製膜之方法沒有特別限定，能夠使用周知的方法來製膜，惟就容易得到厚度較小的偏光膜、在步驟中為薄膜的偏光膜之處理性優異而言，以在基材膜上塗佈聚乙烯醇系樹脂的溶液而製膜之方法為佳。 A polarizing film is formed by forming the polyvinyl alcohol-based resin into a film. The method of forming a polyvinyl alcohol-based resin into a film is not particularly limited, and a well-known method can be used for forming a film. However, a polarizing film having a small thickness and a polarizing film that is a thin film in the step are excellent in reason. A method of applying a solution of a polyvinyl alcohol-based resin to a base film to form a film is preferred.

聚乙烯醇系樹脂的皂化度，可於80.0至100.0莫耳%的範圍，以90.0至99.5莫耳%的範圍為佳，以94.0至99.0莫耳%的範圍為更佳。皂化度未達80.0莫耳%時，所得到的偏光膜之耐水性容易降低。使用皂化度超過99.5莫耳%之聚乙烯醇系樹脂時，則會有染色速度變慢、生產性降低，同時無法得到具有充分的偏光性能之偏光膜之情形。 The degree of saponification of the polyvinyl alcohol resin may be in the range of 80.0 to 100.0 mol%, preferably in the range of 90.0 to 99.5 mol%, and more preferably in the range of 94.0 to 99.0 mol%. When the degree of saponification is less than 80.0 mol%, the water resistance of the obtained polarizing film tends to decrease. When a polyvinyl alcohol-based resin having a saponification degree of more than 99.5 mol% is used, there may be a case where the dyeing speed becomes slow, productivity decreases, and a polarizing film having sufficient polarizing performance cannot be obtained.

所謂皂化度，係將在聚乙烯醇系樹脂的原料之聚乙酸乙烯系樹脂所含有的乙酸基(乙醯氧基：-OCOCH₃)藉由皂化步驟而變化成為羥基之比率以單位比(莫耳%)表示者，係能以下述式定義：皂化度(莫耳%)=100×(羥基的數目)÷(羥基的數目+乙酸基的數目)。 皂化度係能夠依據JIS K 6726(1994)而求取。皂化度越高，則表示羥基的比率越高，因此表示阻礙結晶化之乙酸基的比率低。 The so-called saponification degree refers to the ratio of the acetic acid group (acetoxy: -OCOCH ₃ ) contained in the polyvinyl acetate resin which is the raw material of the polyvinyl alcohol resin to the hydroxyl group by the saponification step. It can be defined by the following formula: degree of saponification (mol%) = 100 × (number of hydroxyl groups) ÷ (number of hydroxyl groups + number of acetate groups). 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 the hydroxyl groups, and therefore the lower the ratio of the acetic acid groups that inhibit crystallization.

聚乙烯醇系樹脂亦可以是一部分經改性之改性聚乙烯醇。例如可舉出：將聚乙烯醇系樹脂以乙烯、丙烯等烯烴；丙烯酸、甲基丙烯酸、巴豆酸等不飽和羧酸；不飽和羧酸的烷酯、(甲基)丙烯醯胺等改性而成者。改性的比率係以未達30莫耳%為佳，以未達10%為更佳。進行大於30莫耳%之改性時，有變得不易吸附二色性色素、不易得到具有充分的偏光性能之偏光膜5之傾向。又，在本說明書，所謂「(甲基)丙烯醯基」，係意指選自由丙烯醯基及甲基丙烯醯基所組成群組之至少一者。對於「(甲基)丙烯醯基」等亦同理。 The polyvinyl alcohol-based resin may be a partially modified modified polyvinyl alcohol. Examples include modification of polyvinyl alcohol-based resins with 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; Become. The modification ratio is preferably less than 30 mol%, and more preferably less than 10%. When the modification is performed at more than 30 mol%, there is a tendency that it becomes difficult to adsorb a dichroic dye and it is difficult to obtain a polarizing film 5 having sufficient polarizing performance. In the present specification, the "(meth) acrylfluorenyl group" means at least one selected from the group consisting of acrylamyl and methacrylfluorenyl. The same applies to "(meth) acrylfluorenyl" and the like.

聚乙烯醇系樹脂的平均聚合度，係以100至10000為佳，較佳為1500至8000，更佳是2000至5000。聚乙烯醇系樹脂的平均聚合度亦能夠依據JIS K 6726(1994)求取。 The average degree of polymerization of the polyvinyl alcohol-based resin is preferably 100 to 10,000, more preferably 1500 to 8000, and even more preferably 2,000 to 5000. The average degree of polymerization of the polyvinyl alcohol-based resin can also be obtained in accordance with JIS K 6726 (1994).

<偏光板> <Polarizer>

(1)偏光板的層結構 (1) Layer structure of polarizing plate

第1圖係表示本發明之偏光板的層結構的一個例子之示意剖面圖。如在第1圖所表示的偏光板1，本發明的偏光板可為具備偏光膜5及層積在偏光膜5的一面上的第1保護膜10之單面附保護膜的偏光板。第1保護膜10係可 經由第1接著劑層15而層積在偏光膜5上。 FIG. 1 is a schematic cross-sectional view showing an example of a layer structure of a polarizing plate of the present invention. As the polarizing plate 1 shown in FIG. 1, the polarizing plate of the present invention may be a single-sided polarizing plate with a protective film including a polarizing film 5 and a first protective film 10 laminated on one surface of the polarizing film 5. The first protective film 10 is possible It is laminated on the polarizing film 5 via the first adhesive layer 15.

而且，本發明之偏光板，亦可在偏光膜5的另一面進一步貼合保護膜，具體而言，係如第2圖表示之偏光板2，為具備偏光膜5、層積在偏光膜5的一面上之第1保護膜10及層積在偏光膜5的另一面上之第2保護膜20之兩面附保護膜的偏光板。第2保護膜20係可經由第2接著劑層25而層積在偏光膜5上。 In addition, the polarizing plate of the present invention may further be bonded with a protective film on the other side of the polarizing film 5. Specifically, the polarizing plate 2 shown in FIG. 2 includes the polarizing film 5 and is laminated on the polarizing film 5. A polarizing plate with a protective film is attached to both sides of the first protective film 10 on one side and the second protective film 20 laminated on the other side of the polarizing film 5. The second protective film 20 can be laminated on the polarizing film 5 via the second adhesive layer 25.

本發明之偏光板被組入如液晶顯示裝置的圖像顯示裝置時，可以是配置在如液晶單元的圖像顯示元件的視認(前面)側之偏光板，亦可以是配置在圖像顯示元件的背面側(例如液晶顯示裝置的背光側)之偏光板。 When the polarizing plate of the present invention is incorporated into an image display device such as a liquid crystal display device, the polarizing plate may be a polarizing plate disposed on the visual (front) side of an image display element such as a liquid crystal cell, or may be an image display element. Polarizer on the rear side (for example, the backlight side of a liquid crystal display device).

(2)偏光膜 (2) Polarizing film

本發明之偏光板，係包含上述之本發明的偏光膜作為偏光膜5。因此，偏光膜5的詳細內容係引用上述的記載。在偏光板所包含之偏光膜5的碘元素含有率W_I，係能夠藉由將保護膜及接著劑層從偏光板除去而針對單離後的偏光膜5進行測定。 The polarizing plate of the present invention includes the polarizing film of the present invention described above as the polarizing film 5. Therefore, the details of the polarizing film 5 refer to the above description. The iodine element content rate W _I of the polarizing film 5 included in the polarizing plate can be measured for the polarized film 5 after isolation by removing the protective film and the adhesive layer from the polarizing plate.

(3)第1保護膜 (3) The first protective film

第1保護膜10可以是包含具有透光性(較佳是光學上透明)之熱可塑性樹脂的膜，前述熱可塑性樹脂例如：如鏈狀聚烯烴系樹脂(聚丙烯系樹脂等)、環狀聚烯烴系樹脂(降莰烯系樹脂等)之聚烯烴系樹脂；如纖維素三乙酸酯、纖維 素二乙酸酯之纖維素酯系樹脂；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；或該等之混合物、共聚物等。為進一步使偏光板的耐水性提升，作為第1保護膜10，亦宜選擇如包含聚烯烴系樹脂、聚酯系樹脂、(甲基)丙烯酸系樹脂、聚苯乙烯系樹脂等的保護膜之透濕度較低的保護膜。 The first protective film 10 may be a film containing a thermoplastic resin having translucency (preferably optically transparent). The thermoplastic resin may be, for example, a chain polyolefin resin (such as a polypropylene resin), or a ring. Polyolefin-based resins (norbornene-based resins, etc.); polyolefin-based resins; such as cellulose triacetate, fiber Polyester resin; Polycarbonate resin; (Meth) acrylic resin; Polystyrene resin; or mixtures and copolymers of these. In order to further improve the water resistance of the polarizing plate, as the first protective film 10, it is also preferable to select a protective film such as a polyolefin resin, a polyester resin, a (meth) acrylic resin, a polystyrene resin, or the like Protective film with low moisture permeability.

第1保護膜10亦可為兼具如相位差膜、增亮膜的光學功能之保護膜。可為例如：藉由將包含上述熱可塑性樹脂之膜延伸(單軸延伸或雙軸延伸等)、或是在該膜上形成液晶層等，而經賦予任意的相位差值之相位差膜。 The first protective film 10 may be a protective film having both optical functions such as a retardation film and a brightness enhancement film. For example, a retardation film having an arbitrary retardation value may be obtained by extending a film (such as uniaxial extension or biaxial extension) containing the thermoplastic resin, or forming a liquid crystal layer on the film.

作為鏈狀聚烯烴系樹脂，除了聚乙烯樹脂、聚丙烯樹脂之鏈狀烯烴的同元聚合物之外，可列舉包含2種以上的鏈狀烯烴之共聚物。 Examples of the chain polyolefin resin include copolymers of two or more kinds of chain olefins in addition to homopolymers of chain olefins of polyethylene resins and polypropylene resins.

環狀聚烯烴系樹脂，係以環狀烯烴作為聚合單元而聚合之樹脂的統稱。環狀聚烯烴系樹脂的具體例，可舉出有：環狀烯烴的開環(共)聚合物；環狀烯烴的加成聚合物；環狀烯烴與如乙烯、丙烯的鏈狀烯烴之共聚物(代表性者為無規共聚物)；及將該等以不飽和羧酸和其衍生物改性而成之接枝聚合物；以及該等的氫化物等。其中，尤其適合使用將降莰烯、多環降莰烯系單體等降莰烯系單體使用作為環狀烯烴之降莰烯系樹脂。 Cyclic polyolefin resins are collectively referred to as resins polymerized with cyclic olefins as the polymerization unit. Specific examples of the cyclic polyolefin resin include a ring-opened (co) polymer of a cyclic olefin; an addition polymer of a cyclic olefin; and a copolymerization of a cyclic olefin and a chain olefin such as ethylene and propylene. Polymers (typically random copolymers); graft polymers modified with unsaturated carboxylic acids and derivatives thereof; and hydrides of these. Among them, a norbornene-based resin using a norbornene-based monomer such as norbornene or a polycyclic norbornene-based monomer as a cyclic olefin is particularly suitable.

纖維素酯系樹脂，係纖維素與脂肪酸之酯。纖維素酯系樹脂的具體例，係包含：纖維素三乙酸酯、纖維素二乙酸酯、纖維素三丙酸酯、纖維素二丙酸酯。而且， 亦能夠使用該等之共聚物、和羥基的一部分經其它取代基修飾而成者。該等之中，係以纖維素三乙酸酯(三乙酸纖維素：TAC)為特佳。 Cellulose ester resin is an ester of cellulose and fatty acid. Specific examples of the cellulose ester-based resin include cellulose triacetate, cellulose diacetate, cellulose tripropionate, and cellulose dipropionate. and, Copolymers of this type and those in which a part of the hydroxyl group is modified with other substituents can also be used. Among these, cellulose triacetate (cellulose triacetate: TAC) is particularly preferred.

聚酯系樹脂，係具有酯鍵之上述纖維素酯系樹脂以外的樹脂，通常係包含多元羧酸或其衍生物與多元醇之聚縮合物者。作為多元羧酸或其衍生物，可使用二羧酸或其衍生物，例如可舉出：對酞酸、異酞酸、二甲基對酞酸酯、萘二羧酸二甲酯等。作為多元醇，可使用二醇，例如可舉出：乙二醇、丙二醇、丁二醇、新戊二醇、環己烷二甲醇等。 Polyester-based resins are resins other than the above-mentioned cellulose ester-based resins having an ester bond, and generally include a polycondensate of a polycarboxylic acid or a derivative thereof and a polyhydric alcohol. As the polycarboxylic acid or a derivative thereof, a dicarboxylic acid or a derivative thereof can be used, and examples thereof include terephthalic acid, isophthalic acid, dimethyl terephthalate, and dimethyl naphthalate. As the polyhydric alcohol, a diol can be used, and examples thereof include ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, and cyclohexanedimethanol.

聚酯系樹脂的具體例，係包含聚對酞酸乙二酯、聚對酞酸丁二酯、聚萘二甲酸乙二酯、聚萘二甲酸丁二酯、聚對酞酸丙二酯、聚萘二甲酸丙二酯、聚對酞酸環已烷二甲酯、聚萘二甲酸環己烷二甲酯。 Specific examples of the polyester-based resin include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polytrimethylene terephthalate, Polypropylene naphthalate, cyclohexane dimethyl terephthalate, cyclohexane dimethyl polynaphthalate.

聚碳酸酯系樹脂，係包含經由碳酸酯基鍵結單體單元而成之聚合物。聚碳酸酯系樹脂亦可為聚合物骨架經修飾之被稱為改性聚碳酸酯之樹脂、共聚合聚碳酸酯等。 The polycarbonate-based resin is a polymer including monomer units bonded via a carbonate group. The polycarbonate-based resin may also be a resin called a modified polycarbonate with a modified polymer skeleton, a copolymerized polycarbonate, and the like.

(甲基)丙烯酸系樹脂，係以具有(甲基)丙烯醯基的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：如聚甲基丙烯酸甲酯的聚(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的化合物之共聚物(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)丙烯酸降莰基共聚物等)。以使用如聚(甲基)丙烯酸甲酯之以聚(甲基)丙烯酸C_1-6烷酯作為主成分之聚合物為佳，較佳為使用以甲基丙烯酸甲酯作為主成分(50至100重量%，更佳為70至100重量%)之甲基丙烯酸甲酯系樹脂。 The (meth) acrylic resin is a resin mainly composed of a compound having a (meth) acrylfluorenyl group as a monomer. Specific examples of the (meth) acrylic resin include, for example, poly (meth) acrylate such as polymethyl methacrylate; methyl methacrylate- (meth) acrylic copolymer; and methyl methacrylate- (Meth) acrylate copolymer; methyl methacrylate-acrylate- (meth) acrylate copolymer; methyl (meth) acrylate-styrene copolymer (MS resin, etc.); methyl methacrylate and A copolymer of a compound having an alicyclic hydrocarbon group (for example, a methyl methacrylate-cyclohexyl methacrylate copolymer, a methyl methacrylate- (meth) acrylic norbornyl copolymer, etc.). It is preferable to use a polymer containing poly (meth) acrylate C _1-6 alkyl as a main component such as poly (meth) acrylate, and it is more preferable to use a polymer containing methyl methacrylate as a main component (50 to 100% by weight, more preferably 70 to 100% by weight) of a methyl methacrylate resin.

在與第1保護膜10之偏光膜5為相反側的表面，亦能夠形成如硬塗層、防眩層、抗反射層、抗靜電層、防污層的表面處理層(塗佈層)。而且，第1保護膜10可含有1種或2種以上之如光滑劑、塑化劑、分散劑、熱安定劑、紫外線吸收劑、紅外線吸收劑、抗靜電劑、抗氧化劑的添加劑。 A surface treatment layer (coating layer) such as a hard coat layer, an anti-glare layer, an anti-reflection layer, an antistatic layer, and an antifouling layer can also be formed on a surface opposite to the polarizing film 5 of the first protective film 10. In addition, the first protective film 10 may contain one or two or more additives such as a smoothing agent, a plasticizer, a dispersant, a heat stabilizer, an ultraviolet absorber, an infrared absorber, an antistatic agent, and an antioxidant.

從偏光板的薄型化之觀點來看，第1保護膜10的厚度係以90μm以下為佳，更佳為50μm以下，又更佳為30μm以下。從強度及處理性的觀點來看，第1保護膜10的厚度通常為5μm以上。 From the viewpoint of reducing the thickness of the polarizing plate, the thickness of the first protective film 10 is preferably 90 μm or less, more preferably 50 μm or less, and still more preferably 30 μm or less. From the viewpoints of strength and handleability, the thickness of the first protective film 10 is usually 5 μm or more.

(4)第1接著劑層 (4) The first adhesive layer

第1接著劑層15，係用以將第1保護膜10接著固定在偏光膜5的一面之層。形成第1接著劑層15之接著劑，可為含有藉由照射如紫外線、可見光、電子射線、X射線之活性能量射線而硬化的硬化性化合物之活性能量射線硬化性接著劑；和使如聚乙烯醇系樹脂的接著劑成分溶解或 分散在水中而成之水系接著劑。其中，尤其是從使偏光板的耐水性提升的觀點來看，係以使用活性能量射線硬化性接著劑為佳。活性能量射線硬化性接著劑的較佳例子係紫外線硬化性接著劑。 The first adhesive layer 15 is a layer for fixing the first protective film 10 to one side of the polarizing film 5. The adhesive for forming the first adhesive layer 15 may be an active energy ray-curable adhesive containing a hardening compound that is hardened by irradiating active energy rays such as ultraviolet rays, visible light, electron rays, and X-rays; The adhesive component of the vinyl alcohol resin is dissolved or An aqueous adhesive made by dispersing in water. Among them, it is particularly preferable to use an active energy ray-curable adhesive from the viewpoint of improving the water resistance of the polarizing plate. A preferable example of the active energy ray-curable adhesive is an ultraviolet-curable adhesive.

作為形成第1接著劑層15之活性能量射線硬化性接著劑，因為顯示良好的接著性，故可適合使用含有陽離子聚合性的硬化性化合物及/或自由基聚合性的硬化性化合物之活性能量射線硬化性接著劑組成物。活性能量射線硬化性接著劑能夠進一步含有用以使上述硬化性化合物開始硬化反應之陽離子聚合起始劑及/或自由基聚合起始劑。 As the active-energy-ray-curable adhesive that forms the first adhesive layer 15, since it exhibits good adhesiveness, it is suitable to use the active energy of a cationically polymerizable curable compound and / or a radical polymerizable curable compound. Radiocurable adhesive composition. The active energy ray-curable adhesive may further contain a cationic polymerization initiator and / or a radical polymerization initiator for starting a curing reaction of the curable compound.

作為陽離子聚合性的硬化性化合物，例如可列舉在環氧系化合物(在分子內具有1個或2個以上的環氧基之化合物)和氧雜環丁烷系化合物(在分子內具有1個或2個以上的氧雜環丁烷環之化合物)、或該等之組合。作為自由基聚合性的硬化性化合物，例如可列舉：(甲基)丙烯酸系化合物(在分子內具有1個或2個以上的(甲基)丙烯醯基或(甲基)丙烯醯基氧基之化合物)、具有自由基聚合性的雙鍵之其它的乙烯系化合物、或該等之組合。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。 Examples of the cationically polymerizable curable compound include epoxy compounds (compounds having one or two or more epoxy groups in the molecule) and oxetane compounds (having one in the molecule). Or two or more oxetane rings), or a combination of these. Examples of the radically polymerizable sclerosing compound include (meth) acrylic compounds (having one or two or more (meth) acrylfluorenyl groups or (meth) acrylfluorenyloxy groups in the molecule). Compound), another vinyl compound having a radical polymerizable double bond, or a combination thereof. A cationically polymerizable curable compound and a radical polymerizable curable compound may be used in combination.

活性能量射線硬化性接著劑，視所需係可含有陽離子聚合促進劑、離子捕集劑、抗氧化劑、鏈轉移劑、賦黏劑、熱可塑性樹脂、填充劑、流動調整劑、塑化劑、 消泡劑、抗靜電劑、調平劑、溶劑等添加劑。 Active energy ray hardening adhesive, if necessary, may contain a cationic polymerization accelerator, an ion trapping agent, an antioxidant, a chain transfer agent, a tackifier, a thermoplastic resin, a filler, a flow modifier, a plasticizer, Antifoaming agent, antistatic agent, leveling agent, solvent and other additives.

第1接著劑層15的厚度通常為0.001至5μm左右，較佳為0.01至3μm。 The thickness of the first adhesive layer 15 is usually about 0.001 to 5 μm, and preferably 0.01 to 3 μm.

(5)第2保護膜 (5) The second protective film

在第2圖所示之兩面附保護膜的偏光板2所具有的第2保護膜20，係與第1保護膜10相同，可為包含上面所例示之熱可塑性樹脂之膜，亦可為兼具如相位差膜、增亮膜的光學功能之保護膜。針對第2保護膜20所能具有的表面處理層及膜的厚度等，係能夠引用在第1保護膜10處已有所敘述之記載。第1保護膜10與第2保護膜20，係可以是包含互為同種的樹脂之保護膜，亦可以是包含不同種的樹脂之保護膜。為了使偏光板的耐水性進一步提升，係以選擇包含如聚烯烴系樹脂、聚酯系樹脂、(甲基)丙烯酸系樹脂、聚苯乙烯系樹脂等的保護膜之透濕度較低的保護膜作為第2保護膜20亦佳。 The second protective film 20 included in the polarizing plate 2 with protective films on both sides shown in FIG. 2 is the same as the first protective film 10, and may be a film including the thermoplastic resin exemplified above, or Protective film with optical functions such as retardation film and brightness enhancement film. Regarding the surface treatment layer, the thickness of the film, and the like that the second protective film 20 can have, the descriptions already described in the first protective film 10 can be cited. The first protective film 10 and the second protective film 20 may be protective films including resins of the same type, or may be protective films including resins of different types. In order to further improve the water resistance of the polarizing plate, a protective film having a low moisture permeability is selected to include a protective film such as polyolefin resin, polyester resin, (meth) acrylic resin, and polystyrene resin. It is also preferable as the second protective film 20.

(6)第2接著劑層 (6) The second adhesive layer

第2接著劑層25，係用以將第2保護膜20接著固定在偏光膜5的另一面之層。針對第2接著劑層25的詳細內容，係可引用上述的第1接著劑層15之記載。從使偏光板的耐水性提升的觀點來看，第2接著劑層25係以由活性能量射線硬化性接著劑形成為佳。形成第2接著劑層25之接著劑，係可具有與形成第1接著劑層15之接著劑相同的組 成，亦可具有不同的組成。 The second adhesive layer 25 is a layer for further fixing the second protective film 20 on the other surface of the polarizing film 5. The details of the second adhesive layer 25 can be referred to the description of the first adhesive layer 15 described above. From the viewpoint of improving the water resistance of the polarizing plate, the second adhesive layer 25 is preferably formed of an active energy ray-curable adhesive. The adhesive for forming the second adhesive layer 25 may have the same composition as the adhesive for forming the first adhesive layer 15. Can also have different compositions.

(7)黏著劑層 (7) Adhesive layer

用以將偏光板貼合在其它構件(例如應用在液晶顯示裝置時之液晶單元)之黏著劑層，可層積在第1圖所示之單面附保護膜的偏光板1之偏光膜5上，或第2圖所示之兩面附保護膜的偏光板2之第1保護膜10或是第2保護膜20上。形成黏著劑層之黏著劑，通常包含黏著劑組成物，該黏著劑組成物係以(甲基)丙烯酸系樹脂、苯乙烯系樹脂、矽酮系樹脂等作為基質聚合物，且在其中添加有如異氰酸酯化合物、環氧化合物、氮丙啶化合物的交聯劑者。亦能夠使之進一步含有微粒子而成為顯示光散射性之黏著劑層。黏著劑層的厚度通常為1至40μm，較佳為3至25μm。 An adhesive layer for attaching a polarizing plate to other components (such as a liquid crystal cell used in a liquid crystal display device), and can be laminated on the polarizing film 5 of the polarizing plate 1 with a protective film on one side as shown in FIG. 1 On the first protective film 10 or the second protective film 20 of the polarizing plate 2 with protective films on both sides shown in FIG. 2. The adhesive forming the adhesive layer usually includes an adhesive composition. The adhesive composition uses (meth) acrylic resin, styrene resin, silicone resin, etc. as a matrix polymer, and is added to the polymer such as Cross-linking agents for isocyanate compounds, epoxy compounds, and aziridine compounds. It can also be made into an adhesive layer which further contains a fine particle and shows light-scattering property. The thickness of the adhesive layer is usually 1 to 40 μm, and preferably 3 to 25 μm.

(8)其它的光學層 (8) Other optical layers

本發明之偏光板，係可進一步含有被層積在其第1及/或第2保護膜10,20和偏光膜5上之其它光學層。作為其它光學層，可舉出：透射某種偏光且反射與該種偏光顯示相反的性質之偏光之反射型偏光膜；在表面具有凹凸形狀之附防眩功能的膜；附表面抗反射功能的膜；在表面具有反射功能之反射膜；兼具反射功能及透射功能之半透射反射膜；視角補償膜等。 The polarizing plate of the present invention may further include other optical layers laminated on the first and / or second protective films 10 and 20 and the polarizing film 5. Examples of other optical layers include: reflective polarizing films that transmit a certain type of polarized light and reflect polarized light having properties opposite to that of the polarized light; films having an uneven shape on the surface with anti-glare function; and those with anti-reflection function on the surface Film; reflective film with reflective function on the surface; semi-transmissive reflective film with both reflective and transmissive functions; viewing angle compensation film, etc.

<偏光膜及偏光板之製造方法> <Manufacturing method of polarizing film and polarizing plate>

本發明的偏光膜及偏光板，係可使用第3圖所表示的方法來製造。第3圖所表示的製造方法係依序包含下述步驟：(1)樹脂層形成步驟S10，其係將含有聚乙烯醇系樹脂之塗佈液塗佈在基材膜的至少一面後使其乾燥，藉此形成聚乙烯醇系樹脂層而得到積層膜；(2)延伸步驟S20，其係將積層膜延伸而得到延伸膜；(3)染色步驟S30，其係使用碘將延伸膜的聚乙烯醇系樹脂層染色而形成偏光膜(偏光子層)，藉此得到偏光性積層膜；(4)第1貼合步驟S40，其係將保護膜貼合在偏光性積層膜的偏光膜上，而得到貼合膜；(5)剝離步驟S50，其係將基材膜從貼合膜剝離除去，而得到單面附保護膜的偏光板。 The polarizing film and polarizing plate of the present invention can be manufactured by using the method shown in FIG. 3. The manufacturing method shown in FIG. 3 includes the following steps in order: (1) a resin layer forming step S10, in which a coating liquid containing a polyvinyl alcohol resin is applied to at least one side of a base film and then Drying, thereby forming a polyvinyl alcohol-based resin layer to obtain a laminated film; (2) an extension step S20, which is to extend the laminated film to obtain an extended film; (3) a dyeing step S30, which uses iodine to polymerize the extended film. The vinyl alcohol-based resin layer is dyed to form a polarizing film (polarizing layer), thereby obtaining a polarizing laminated film; (4) a first bonding step S40, in which a protective film is attached to the polarizing film of the polarizing laminated film (5) A peeling step S50, which removes and removes the base film from the adhesive film to obtain a single-sided polarizing plate with a protective film.

製造如第2圖所示之兩面附保護膜的偏光板2時，係在剝離步驟S50後，進一步含有：(6)第2貼合步驟S60，其係在單面附保護膜的偏光板的偏光膜面貼合保護膜。 When manufacturing the polarizing plate 2 with a protective film on both sides as shown in FIG. 2, after the peeling step S50, it further includes: (6) a second bonding step S60, which is based on the polarizing plate with a protective film on one side. A protective film is attached to the polarizing film surface.

以下，係於參照第4圖至第7圖同時說明個步驟。又，在樹脂層形成步驟S10，亦可係在基材膜的兩面形成聚乙烯醇系樹脂層，惟以下主要是說明在單面形成之情況。 Hereinafter, each step will be described with reference to FIGS. 4 to 7. In the resin layer forming step S10, a polyvinyl alcohol-based resin layer may be formed on both sides of the base film. However, the case where the polyvinyl alcohol-based resin layer is formed on one side is mainly described below.

(1)樹脂層形成步驟S10 (1) Resin layer forming step S10

參照第4圖，本步驟係在基材膜30的至少一面形成聚乙烯醇系樹脂層6而得到積層膜100之步驟。該聚乙烯醇系樹脂層6，係經過延伸步驟S20及染色步驟S30而成為偏光膜5之層。聚乙烯醇系樹脂層6係可藉由在基材膜30的一面或兩面塗佈含有聚乙烯醇系樹脂之塗佈液，並使塗佈層乾燥而形成。就容易得到薄膜的偏光膜5而言，藉由此種塗佈來形成聚乙烯醇系樹脂層之方法乃是有利的。 Referring to FIG. 4, this step is a step of forming a polyvinyl alcohol-based resin layer 6 on at least one side of the base film 30 to obtain a laminated film 100. The polyvinyl alcohol-based resin layer 6 is a layer that becomes the polarizing film 5 after the stretching step S20 and the dyeing step S30. The polyvinyl alcohol-based resin layer 6 can be formed by applying a coating liquid containing a polyvinyl alcohol-based resin to one or both sides of the base film 30 and drying the coating layer. A method of forming a polyvinyl alcohol-based resin layer by such a coating is advantageous for the polarizing film 5 in which a thin film can be easily obtained.

基材膜30係可由熱可塑性樹脂構成，其中尤其是以由具有優異的透明性、機械強度、熱安定性、延伸性等之熱可塑性樹脂所構成為佳。此種熱可塑性樹脂的具體例，係包含例如：如鏈狀聚烯烴系樹脂、環狀聚烯烴系樹脂(降莰烯系樹脂等)的聚烯烴系樹脂；聚酯系樹脂；(甲基)丙烯酸系樹脂；如纖維素三乙酸酯、纖維素二乙酸酯的纖維素酯系樹脂；聚碳酸酯系樹脂；聚乙烯醇系樹脂；聚乙酸乙烯酯系樹脂；聚芳香酯系樹脂；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；及該等之混合物、共聚物。 The base film 30 may be made of a thermoplastic resin, and particularly preferably a thermoplastic resin having excellent transparency, mechanical strength, thermal stability, elongation, and the like. Specific examples of such thermoplastic resins are, for example, polyolefin resins such as chain polyolefin resins and cyclic polyolefin resins (norbornene resins); polyester resins; (meth) Acrylic resins; cellulose ester resins such as cellulose triacetate and cellulose diacetate; polycarbonate resins; polyvinyl alcohol resins; polyvinyl acetate resins; polyaromatic resins; Polystyrene resin; polyether fluorene resin; polyfluorene resin; polyamine resin; polyimide resin; and mixtures and copolymers thereof.

基材膜30係可以是包含1種或2種以上的熱可塑性樹脂之1層的樹脂層所成之單層結構，亦可以是積層複數層之包含1種或2種以上的熱可塑性樹脂的樹脂層所成之多層結構。在後述的延伸步驟S20而將積層膜100延伸時，基材膜30係以由可在適合將聚乙烯醇系樹脂層6 延伸的延伸溫度進行延伸之樹脂所構成為佳。 The base film 30 may be a single-layer structure formed of one layer of a resin layer containing one or two or more thermoplastic resins, or may be a laminate of a plurality of layers including one or two or more thermoplastic resins. Multilayer structure made of resin layer. When the laminated film 100 is stretched in the stretching step S20 described later, the base film 30 is made of a polyvinyl alcohol resin layer 6 suitable for The resin formed by stretching at the stretching temperature is preferred.

基材膜30可含有添加劑。添加劑的具體例係包含：紫外線吸收劑、抗氧化劑、光滑劑、塑化劑、脫模劑、防著色劑、阻燃劑、成核劑、抗靜電劑、顏料及著色劑。 The base film 30 may contain an additive. Specific examples of the additives include ultraviolet absorbers, antioxidants, smoothing agents, plasticizers, release agents, anti-colorants, flame retardants, nucleating agents, antistatic agents, pigments, and coloring agents.

就強度、處理性等之點而言，基材膜30的厚度通常為1至500μm，較佳為1至300μm，更佳為5至200μm，又更佳為5至150μm。 In terms of strength, handleability, and the like, the thickness of the base film 30 is usually 1 to 500 μm, preferably 1 to 300 μm, more preferably 5 to 200 μm, and still more preferably 5 to 150 μm.

塗佈在基材膜30之塗佈液，較佳是使聚乙烯醇系樹脂的粉末溶解於良溶劑(例如水)而得到之聚乙烯醇系樹脂溶液。聚乙烯醇系樹脂的詳細係如上述。塗佈液亦可視所需而含有塑化劑、界面活性劑等添加劑。 The coating liquid applied to the base film 30 is preferably a polyvinyl alcohol-based resin solution obtained by dissolving a powder of a polyvinyl alcohol-based 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 a plasticizer and a surfactant, as required.

將上述塗佈液塗佈在基材膜30之方法，可由下述方法適當地選擇：線棒塗佈法；如反向塗佈、凹版塗佈的輥塗佈法；模塗佈法；點式塗佈法；唇式塗佈法；旋轉塗佈法；網版塗佈法；噴流式塗佈(fountain coating)法；浸漬法；噴霧法等。 The method of applying the coating liquid to the substrate film 30 may be appropriately selected from the following methods: wire rod coating method; roll coating method such as reverse coating and gravure coating; die coating method; dot Coating method; lip coating method; spin coating method; screen coating method; fountain coating method; dipping method; spray method and the like.

塗佈層(乾燥前的聚乙烯醇系樹脂層)的乾燥溫度及乾燥時間，係可視在塗佈液所含有的溶劑之種類而設定。乾燥溫度係例如50至200℃，較佳為60至150℃。溶劑係含有水時，乾燥溫度以80℃以上為佳。 The drying temperature and drying time of the coating layer (the polyvinyl alcohol-based resin layer before drying) can be set depending on the type of the solvent contained in the coating liquid. The drying temperature is, for example, 50 to 200 ° C, and 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可以只在基材膜30的一面形成，亦可在兩面形成。在兩面形成時，因為能夠抑制在製造偏光性積層膜300(參照第6圖)時可能產生的薄膜卷 曲，同時能夠從1片偏光性積層膜300得到2片偏光板，所以就偏光板的生產效率方面而言亦是有利的。 The polyvinyl alcohol-based resin layer 6 may be formed on only one side of the base film 30 or may be formed on both sides. When formed on both sides, it is possible to suppress a film roll that may occur during the production of the polarizing laminated film 300 (see FIG. 6). At the same time, since two polarizing plates can be obtained from one polarizing laminated film 300, it is also advantageous in terms of production efficiency of the polarizing plate.

在積層膜100之聚乙烯醇系樹脂層6的厚度，係以3至30μm為佳，較佳為5至20μm。只要為具有該範圍內的厚度之聚乙烯醇系樹脂層6，則經過後述的延伸步驟S20及染色步驟S30，可得到碘的染色性良好、具有優異的偏光性能，而且充分薄的(例如厚度10μm以下的)偏光膜5。 The thickness of the polyvinyl alcohol-based resin layer 6 in the laminated film 100 is preferably 3 to 30 μm, and more preferably 5 to 20 μm. As long as it is a polyvinyl alcohol-based resin layer 6 having a thickness within this range, after the stretching step S20 and the dyeing step S30 described later, the iodine has good dyeability, excellent polarizing performance, and is sufficiently thin (for example, thick 10 μm or less) polarizing film 5.

在塗佈液的塗佈之前，為了使基材膜30與聚乙烯醇系樹脂層6之密著性提升，亦可至少在基材膜30之要形成聚乙烯醇系樹脂層6之側的表面施行電暈處理、電漿處理、火焰(flame)處理等。而且，基於同樣的理由，亦可經由底漆層等而在基材膜30上形成聚乙烯醇系樹脂層6。 Prior to the application of the coating liquid, in order to improve the adhesion between the base film 30 and the polyvinyl alcohol-based resin layer 6, it is also possible to place at least the side of the base film 30 where the polyvinyl alcohol-based resin layer 6 is to be formed. The surface is subjected to corona treatment, plasma treatment, flame treatment, and the like. For the same reason, the polyvinyl alcohol-based resin layer 6 may be formed on the base film 30 via a primer layer or the like.

底漆層係可藉由將底漆層形成用塗佈液塗佈在基材膜30表面之後，使其乾燥來形成。該塗佈液係含有對基材膜30及聚乙烯醇系樹脂層6之雙方發揮某種程度的較強密著力之成分，通常係含有賦予此種密著力之樹脂成分及溶劑。作為樹脂成分，較佳是使用透明性、熱安定性、延伸性等為優異之熱可塑樹脂，例如可舉出(甲基)丙烯酸系樹脂、聚乙烯醇系樹脂等。其中尤其適合使用可賦予良好的密著力之聚乙烯醇系樹脂。較佳為聚乙烯醇樹脂。作為溶劑，通常能夠使用可將上述樹脂成分溶解之一般的有機溶劑和水系溶劑，惟以由水作為溶劑之塗佈液形成底漆 層為佳。 The primer layer can be formed by applying a 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 exhibiting 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 impart such adhesion. As the resin component, a thermoplastic resin which is excellent in transparency, heat stability, elongation, and the like is preferably used, and examples thereof include (meth) acrylic resin, polyvinyl alcohol resin, and the like. Among them, a polyvinyl alcohol-based resin that can impart good adhesion is particularly suitable. Preferred is a polyvinyl alcohol resin. As the solvent, a general organic solvent and an aqueous solvent that can dissolve the resin component can be generally used, but a primer is formed by using a coating liquid containing water as a solvent. The layers are better.

為了提升底漆層的強度，亦可在底漆層形成用塗佈液添加交聯劑。交聯劑的具體例，係包含：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。使用聚乙烯醇系樹脂作為形成底漆層之樹脂成分時，能夠適合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、金屬螫合物化合物系交聯劑等。 In order to increase the strength of the primer layer, a crosslinking agent may be added to the coating liquid for forming a 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 a polyvinyl alcohol-based resin is used as a resin component for forming the primer layer, polyamine epoxy resin, methylolated melamine resin, dialdehyde-based crosslinking agent, metal adduct compound-based crosslinking agent, etc. can be suitably used. .

底漆層的厚度，係以0.05至1μm左右為佳，以0.1至0.4μm為更佳。比0.05μm薄時，提升基材膜30與聚乙烯醇系樹脂層6的密著力之效果較小，比1μm厚時，不利於偏光板的薄膜化。 The thickness of the primer layer is preferably about 0.05 to 1 μm, and more preferably 0.1 to 0.4 μm. When it is thinner than 0.05 μm, the effect of increasing the adhesion between the base film 30 and the polyvinyl alcohol-based resin layer 6 is small, and when it is thicker than 1 μm, it is not conducive to thinning the polarizing plate.

將底漆層形成用塗佈液塗佈在基材膜30之方法，可與聚乙烯醇系樹脂層形成用塗佈液相同。由底漆層形成用塗佈液所成之塗佈層的乾燥溫度，係例如50至200℃，較佳為60至150℃。溶劑含有水時，乾燥溫度係以80℃以上為佳。 The method for applying the coating liquid for forming a primer layer to the base film 30 may be the same as the coating liquid for forming a polyvinyl alcohol-based resin layer. The drying temperature of the coating layer formed of the coating liquid for forming a primer layer is, for example, 50 to 200 ° C, and preferably 60 to 150 ° C. When the solvent contains water, the drying temperature is preferably 80 ° C or higher.

(2)延伸步驟S20 (2) Extending step S20

參照第5圖，本步驟係將包含基材膜30及聚乙烯醇系樹脂層6之積層膜100進行延伸，而得到包含經延伸的基材膜30’及聚乙烯醇系樹脂層6’的延伸膜200之步驟。延伸處理通常為單軸延伸。 Referring to FIG. 5, in this step, the laminated film 100 including the base film 30 and the polyvinyl alcohol-based resin layer 6 is extended to obtain an extended base film 30 ′ and the polyvinyl alcohol-based resin layer 6 ′. Step of stretching the film 200. The stretching process is usually uniaxial.

積層膜100的延伸倍率，可視所期望的偏光 特性而適當地選擇，相對於積層膜100的原長，以超過5倍、17倍以下為佳，以超過5倍、8倍以下為更佳。延伸倍率為5倍以下時，因為聚乙烯醇系樹脂層6’未充分地定向，所以有偏光膜5的偏光度無法充分地變高之情形。另一方面，延伸倍率超過17倍時，則在延伸時膜容易產生斷裂，同時延伸膜200變薄至所需以上的厚度，而有在後步驟的加工性及處理性降低之虞。 Stretching ratio of laminated film 100, depending on desired polarization The characteristics are appropriately selected, and the original length of the laminated film 100 is preferably more than 5 times and 17 times or less, and more preferably more than 5 times and 8 times or less. When the stretching magnification is 5 times or less, the polyvinyl alcohol-based resin layer 6 'is not sufficiently aligned, so that the degree of polarization of the polarizing film 5 may not be sufficiently high. On the other hand, when the stretching ratio exceeds 17 times, the film is likely to be broken during stretching, and at the same time, the stretched film 200 is thinned to a desired thickness or more, and there is a possibility that the workability and handleability in the subsequent steps are reduced.

延伸處理係不限定為一階段的延伸，亦可以多階段進行。此時，可以在染色步驟S30之前連續地進行全部之多階段的延伸處理，亦可將第二階段以後的延伸處理與染色步驟S30之染色處理及/或交聯處理同時進行。採用如此多階段進行延伸處理時，係以將延伸處理的全部階段合計成為大於5倍的延伸倍率之方式進行延伸處理為佳。 The extension treatment is not limited to one-stage extension, and may be performed in multiple stages. At this time, all of the multi-stage stretching treatment may be performed continuously before the dyeing step S30, or the stretching treatment after the second stage and the dyeing treatment and / or the crosslinking treatment of the dyeing step S30 may be performed simultaneously. When the stretching process is performed in so many stages, the stretching process is preferably performed in such a manner that all stages of the stretching process are collectively increased to a stretching ratio greater than 5 times.

延伸處理，除了可為朝薄膜長度方向(薄膜搬運方向)延伸之縱向延伸以外，亦可為朝薄膜寬度方向延伸之橫向延伸或斜向延伸等。作為縱向延伸方式，可舉出：使用輥進行延伸之輥間延伸、壓縮延伸、使用固定具(夾具)之延伸等，作為橫向延伸方式，可舉出拉幅機法等。延伸處理係可採用濕潤式延伸法、乾式延伸法的任一種，惟就可從廣闊範圍選擇延伸溫度之點而言，係以使用乾式延伸法為佳。 The stretching treatment may be a longitudinal extension extending in the film length direction (film transport direction), or a lateral extension or oblique extension in the film width direction. Examples of the longitudinal stretching method include roll-to-roll stretching, compression stretching, and stretching using a fixture (clamp). Examples of the transverse stretching method include a tenter method. As the stretching treatment, either a wet stretching method or a dry stretching method can be adopted. However, in terms of selecting a stretching temperature from a wide range, it is preferable to use the dry stretching method.

延伸溫度，係能夠設定於聚乙烯醇系樹脂層6及基材膜30整體表現可延伸的程度之流動性之溫度以上，較佳為從基材膜30的相轉移溫度(熔點或玻璃轉移溫 度)的-30℃至+30℃的範圍，更佳是從-30℃至+5℃的範圍，又更佳是從-25℃至+0℃的範圍。基材膜30包含複數層的樹脂層時，上述相轉移溫度係意指該複數層的樹脂層表現之相轉移溫度之中，最高的相轉移溫度。 The elongation temperature is higher than the temperature at which the polyvinyl alcohol-based resin layer 6 and the base film 30 can be stretched as a whole, and is preferably a phase transition temperature (melting point or glass transition temperature) from the base film 30. Degrees) from -30 ° C to + 30 ° C, more preferably from -30 ° C to + 5 ° C, and even more preferably from -25 ° C to + 0 ° C. When the base film 30 includes a plurality of resin layers, the phase transition temperature means the highest phase transition temperature among the phase transition temperatures exhibited by the resin layers of the plurality of layers.

若使延伸溫度低於相轉移溫度的-30℃，則會有難以達成超過5倍的高倍率延伸、或是基材膜30的流動性太低致使延伸處理變得困難之傾向。若延伸溫度超過相轉移溫度的+30℃，則會有基材膜30的流動性太大而延伸變得困難之傾向。因為更容易達成大於5倍的高延伸倍率，故延伸溫度係於上述範圍內，而更佳為120℃以上。 If the elongation temperature is lower than -30 ° C of the phase transition temperature, it is difficult to achieve high-rate elongation exceeding 5 times, or the fluidity of the base film 30 is too low, which tends to make the elongation process difficult. If the elongation temperature exceeds + 30 ° C. of the phase transition temperature, the fluidity of the base film 30 tends to be too large, and the elongation tends to be difficult. Since it is easier to achieve a high elongation ratio of more than 5 times, the elongation temperature is within the above range, and more preferably 120 ° C or higher.

作為在延伸處理之積層膜100的加熱方法，有：區域加熱法(例如，在吹入熱風而調整成為預定溫度之加熱爐的延伸區內進行加熱之方法)；使用輥進行延伸時，將輥本身加熱之方法；及加熱器加熱法(在積層膜100的上下設置紅外線加熱器、鹵素加熱器、平板加熱器等，且藉由輻射熱進行加熱之方法)等。從延伸溫度的均勻性之觀點來看，輥間延伸方式係以區域加熱法為佳。 As a heating method for the stretched laminated film 100, there are a zone heating method (for example, a method of heating in an extension area of a heating furnace adjusted to a predetermined temperature by blowing hot air); A method for heating itself; and a heater heating method (a method in which an infrared heater, a halogen heater, a flat plate heater, and the like are provided above and below the laminated film 100, and heating is performed by radiant heat) and the like. From the viewpoint of the uniformity of the stretching temperature, the zone-to-roll stretching method is preferably the zone heating method.

又，所謂延伸溫度，在區域加熱法時，係意指區域內(例如加熱爐內)的氣體環境溫度；在加熱器加熱法時，亦是意指在爐內進行加熱時之爐內的氣體環境溫度。而且，在將輥本身加熱之方法時，係意指輥的表面溫度。 Also, the so-called extension temperature means the ambient temperature of the gas in the area (for example, in a heating furnace) in the area heating method; and also means the gas in the furnace when heating in the furnace in the heating method. Ambient temperature. In addition, the method of heating the roll itself means the surface temperature of the roll.

在延伸步驟S20之前，亦可設置將積層膜100預熱之預熱處理步驟。作為預熱方法，可使用與延伸處理 之加熱方法相同的方法。預熱溫度係以從延伸溫度的-50℃至±0℃的範圍為佳，以從延伸溫度的-40℃至-10℃的範圍為更佳。 Before the extending step S20, a preheating step for preheating the laminated film 100 may be provided. As a preheating method, it can be used and extended The heating method is the same. The preheating temperature is preferably in a range from -50 ° C to ± 0 ° C, and more preferably in a range from -40 ° C to -10 ° C, which is the extension temperature.

而且，在延伸步驟S20之延伸處理後，亦可設置熱固定處理步驟。熱固定處理係在使用夾具抓持延伸膜200的端部的狀態下，維持緊繃狀態，同時在結晶化溫度以上進行熱處理。藉由該熱固定處理，能夠促進聚乙烯醇系樹脂層6’的結晶化。熱固定處理的溫度，係以延伸溫度的-0℃至-80℃之範圍為佳，以延伸溫度的-0℃至-50℃之範圍為更佳。 Moreover, after the stretching process of the stretching step S20, a heat fixing process step may be provided. The heat-fixing treatment is performed while holding the end portion of the stretched film 200 with a jig, while maintaining a tight state, and performing a heat treatment at a temperature above the crystallization temperature. By this heat-setting treatment, crystallization of the polyvinyl alcohol-based resin layer 6 'can be promoted. The temperature of the heat-fixing treatment is preferably in the range of -0 ° C to -80 ° C, and more preferably in the range of -0 ° C to -50 ° C.

(3)染色步驟S30 (3) Dyeing step S30

參照第6圖，本步驟係將延伸膜200的聚乙烯醇系樹脂層6’以碘染色且使其吸附定向，而成為偏光膜5之步驟。經本步驟，能夠得到在基材膜30’的一面或兩面層積有偏光膜5之偏光性積層膜300。 Referring to FIG. 6, this step is a step of dyeing the polyvinyl alcohol-based resin layer 6 'of the stretched film 200 with iodine and aligning it to be adsorbed and oriented, thereby becoming a polarizing film 5. Through this step, a polarizing laminated film 300 in which the polarizing film 5 is laminated on one or both sides of the base film 30 'can be obtained.

染色步驟，係可藉由將延伸膜200整體浸漬在含碘的溶液(染色溶液)來進行。作為染色溶液，可使用於溶劑溶解有碘之溶液。作為溶劑，通常係使用水，亦可進一步添加與水具有相溶性之有機溶劑。在染色溶液之碘的濃度，係以0.01至10重量%為佳，較佳為0.02至7重量%。 The dyeing step can be performed by immersing the entire stretched film 200 in a solution (dyeing solution) containing iodine. As the dyeing solution, a solvent in which iodine is dissolved can be used. As a solvent, water is usually used, and an organic solvent compatible with water may be further added. The concentration of iodine in the dyeing solution is preferably 0.01 to 10% by weight, and more preferably 0.02 to 7% by weight.

因為能夠提升染色效率，故以在染色溶液進一步添加碘化物為佳。作為碘化物，例如可舉出：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。在染色溶液中之碘化物的濃度，較佳為0.01至20重量%。碘化物之中，以添加碘化鉀為佳。添加碘化鉀時，碘與碘化鉀的比率以重量比計，係以1：5至1：100為佳，1：6至1：80為更佳。染色溶液的溫度，係以10至60℃為佳，20至40℃為更佳。 Since the dyeing efficiency can be improved, it is preferable to further 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, titanium iodide, and the like. The concentration of the iodide in the dyeing solution is preferably 0.01 to 20% by weight. Among the iodides, potassium iodide is preferably added. When potassium iodide is added, the ratio of iodine to potassium iodide is based on a weight ratio, preferably 1: 5 to 1: 100, and more preferably 1: 6 to 1:80. The temperature of the dyeing solution is preferably 10 to 60 ° C, and more preferably 20 to 40 ° C.

又，雖可在延伸步驟S20前進行染色步驟S30，亦能夠同時進行該等步驟，惟較佳是以使吸附在聚乙烯醇系樹脂層之碘能夠良好地定向之方式，對積層膜100施行至少某種程度的延伸處理之後，實施染色步驟S30。 Also, although the dyeing step S30 can be performed before the extending step S20, these steps can also be performed at the same time, but it is preferable to perform the lamination film 100 in such a manner that the iodine adsorbed on the polyvinyl alcohol resin layer can be well oriented. After at least a certain degree of elongation treatment, a dyeing step S30 is performed.

染色步驟S30，係可包含接續染色處理而實施之交聯處理步驟。交聯處理係可藉由將經染色的薄膜浸漬在在溶劑溶解有交聯劑而成之溶液(交聯溶液)中來進行。作為交聯劑，例如可舉出：如硼酸、硼砂的硼化合物；乙二醛、戊二醛等。交聯劑可只使用1種，亦可併用2種以上。作為交聯溶液的溶劑，可使用水，惟亦可進一步含有與水具有相溶性之有機溶劑。交聯溶液中之交聯劑的濃度，係以0.2至20重量%為佳，較佳為0.5至10重量%。 The dyeing step S30 may include a cross-linking treatment step followed by a dyeing treatment. The crosslinking treatment can be performed by immersing the dyed film in a solution (crosslinking solution) in which a crosslinking agent is dissolved in a solvent. Examples of the crosslinking agent include boron compounds such as boric acid and borax; glyoxal and glutaraldehyde. The crosslinking agent may be used singly or in combination of two or more kinds. As the solvent of the crosslinking solution, water may be used, but it may further contain an organic solvent compatible with water. The concentration of the crosslinking agent in the crosslinking solution is preferably 0.2 to 20% by weight, and more preferably 0.5 to 10% by weight.

交聯溶液可進一步含有碘化物。藉由添加碘化物，可使在偏光膜5的面內之偏光性進一步均勻化。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，係以0.05至15重量%為佳，0.5至8重量%為更佳。交聯溶液的溫度係以1至90℃為佳。 The crosslinking solution may further contain iodide. By adding an iodide, the polarizing property in the plane of the polarizing film 5 can be made more uniform. Specific examples of the iodide are the same as described above. The concentration of iodide in the crosslinking solution is preferably 0.05 to 15% by weight, and more preferably 0.5 to 8% by weight. The temperature of the crosslinking solution is preferably from 1 to 90 ° C.

又，交聯處理亦可藉由在染色溶液中調配交 聯劑，而與染色處理同時進行。而且，亦可使用不同組成之2種以上的交聯溶液，進行2次以上之浸漬在交聯溶液之處理。 In addition, the cross-linking treatment can also be performed by blending in a dyeing solution. The agent is used simultaneously with the dyeing treatment. In addition, two or more types of cross-linking solutions having different compositions may be used to perform two or more immersions in the cross-linking solution.

染色步驟S30之後，係以在後述的第1貼合步驟S40之前進行洗淨步驟及乾燥步驟為佳。洗淨步驟通常包含水洗淨步驟。水洗淨處理，係可藉由將染色處理後或交聯處理後的薄膜浸漬在如離子交換水、蒸餾水的純水中而進行。水洗淨溫度係通常為3至50℃，較佳為4至20℃。洗淨步驟亦可為水洗淨步驟與使用碘化物溶液的洗淨步驟之組合。作為於洗淨步驟後進行之乾燥步驟，係能夠採用自然乾燥、送風乾燥、加熱乾燥等任意之適當的方法。例如加熱乾燥時，乾燥溫度通常係20至95℃。 After the dyeing step S30, it is preferable to perform a washing step and a drying step before the first bonding step S40 described later. The washing step usually includes a water washing step. The water washing treatment can be performed by immersing the film after the dyeing treatment or the 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 be a combination of a water washing step and a washing step using an iodide solution. As a drying step performed after the washing step, any appropriate method such as natural drying, air drying, and heating drying can be adopted. For example, when heating and drying, the drying temperature is usually 20 to 95 ° C.

(4)第1貼合步驟S40 (4) First bonding step S40

參照第7圖，本步驟係經由接著劑層將保護膜貼合在偏光性積層膜300的偏光膜5上，亦即貼合在在偏光膜5之與基材膜30’側為相反側之面，藉此得到貼合膜400之步驟。第7圖係表示經由第1接著劑層15而貼合第1保護膜10之例子，惟製造兩面附保護膜的偏光板2時，亦可經由第2接著劑層25而貼合第2保護膜20。針對形成第1接著劑層15和第2接著劑層25之接著劑係如上述。 Referring to FIG. 7, in this step, the protective film is bonded to the polarizing film 5 of the polarizing laminated film 300 through the adhesive layer, that is, the polarizing film 5 is bonded to the polarizing film 5 on the side opposite to the substrate film 30 ′ side. Surface, thereby obtaining the bonding film 400 step. FIG. 7 shows an example in which the first protective film 10 is bonded via the first adhesive layer 15. However, when the polarizing plate 2 with a protective film on both sides is manufactured, the second protection can also be bonded via the second adhesive layer 25.膜 20。 The film 20. The adhesives for forming the first adhesive layer 15 and the second adhesive layer 25 are as described above.

又，偏光性積層膜300係在基材膜30’的兩面具有偏光膜5時，通常係在兩面的偏光膜5上分別貼合保護膜。此時，該等保護膜可為同種的保護膜，亦可為不 同種的保護膜。 When the polarizing laminated film 300 is provided with the polarizing films 5 on both sides of the base film 30 ', a protective film is usually attached to the polarizing films 5 on both sides. At this time, these protective films may be the same kind of protective film, The same kind of protective film.

將使用活性能量射線硬化性接著劑而貼合第1保護膜10之情形作為例子，來說明保護膜的貼合接著方法，係經由作為第1接著劑層15之活性能量射線硬化性接著劑將第1保護膜10層積在偏光膜5上之後，照射如紫外線、可見光、電子射線、X射線的活性能量射線而使接著劑層硬化。其中尤以紫外線為佳，作為此時的光源，可使用低壓水銀燈、中壓水銀燈、高壓水銀燈、超高壓水銀燈、螢光燈、黑光燈、微波激發水銀燈、金屬鹵素燈等。 A case where the first protective film 10 is bonded using an active energy ray-curable adhesive is used as an example to explain the method of bonding the protective film. The active energy ray-curable adhesive is used as the first adhesive layer 15 to After the first protective film 10 is laminated on the polarizing film 5, it is irradiated with active energy rays such as ultraviolet rays, visible light, electron rays, and X-rays to harden the adhesive layer. Among them, ultraviolet rays are particularly preferable. As the light source at this time, low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, fluorescent lamps, black light lamps, microwave-excited mercury lamps, and metal halogen lamps can be used.

於將保護膜貼合在偏光膜5時，在保護膜及/或偏光膜5的貼合面，為了使與偏光膜5接著性提升，可進行如電漿處理、電暈處理、紫外線照射處理、火焰處理、皂化處理的表面處理(易接著處理)，其中尤以進行電漿處理、電暈處理或皂化處理為佳。 When the protective film is bonded to the polarizing film 5, on the bonding surface of the protective film and / or the polarizing film 5, in order to improve the adhesion with the polarizing film 5, for example, plasma treatment, corona treatment, and ultraviolet irradiation treatment may be performed. , Flame treatment, saponification treatment surface treatment (easy to follow treatment), especially plasma treatment, corona treatment or saponification treatment is preferred.

(5)剝離步驟S50 (5) Stripping step S50

本步驟，係將基材膜30’從貼合膜400剝離除去之步驟。經過該步驟，可得到與第1圖相同之單面附保護膜的偏光板。偏光性積層膜300係在基材膜30’的兩面具有偏光膜5且將保護膜貼合在該等偏光膜5的雙方時，藉由該剝離步驟S50，可從1片偏光性積層膜300得到2片之單面附保護膜的偏光板。 This step is a step of peeling and removing the base film 30 'from the bonding film 400. After this step, the same polarizing plate with a protective film on one side as in FIG. 1 can be obtained. When the polarizing laminated film 300 is provided with polarizing films 5 on both sides of the base film 30 ′ and a protective film is attached to both of the polarizing films 5, the peeling step S50 can be performed from one polarizing laminated film 300. Two polarizing plates with a protective film on one side were obtained.

將基材膜30’剝離除去之方法係沒有特別限定，可使用與通常在附黏著劑的偏光板進行之隔離膜(剝離 膜)的剝離步驟相同的方法來剝離。基材膜30’係可在第1貼合步驟S40後直接立即剝離，亦可在第1貼合步驟S40後，暫時捲取成為卷軸狀，而在之後的步驟捲出同時進行剝離。 The method of peeling and removing the base film 30 'is not particularly limited, and a release film (peeling) that is usually performed with a polarizing plate with an adhesive can be used. Film). The base film 30 'may be peeled immediately after the first bonding step S40, or may be temporarily wound into a reel shape after the first bonding step S40, and peeled off at the same time in the subsequent steps.

(6)第2貼合步驟S60 (6) Second bonding step S60

本步驟，係在單面附保護膜的偏光板之偏光膜5上，亦即在與於第1貼合步驟S40所貼合的保護膜為相反側之面，進一步貼合保護膜，而得到在第2圖所表示的構成之兩面附保護膜的偏光板2之步驟。當在第1貼合步驟S40貼合第1保護膜10時，係在本步驟貼合第2保護膜20；當在第1貼合步驟S40貼合第2保護膜20時，係在本步驟貼合第1保護膜10。經由第2接著劑層25進行之第2保護膜20的貼合，係可與第1保護膜10的貼合以相同方式進行。 In this step, the protective film is attached to the polarizing film 5 of the polarizing plate with a protective film on one side, that is, on the opposite side to the protective film bonded in the first bonding step S40, and the protective film is further bonded to obtain The process of polarizing plate 2 with a protective film on both surfaces of the structure shown in FIG. 2. When the first protective film 10 is bonded in the first bonding step S40, the second protective film 20 is bonded in this step; when the second protective film 20 is bonded in the first bonding step S40, it is in this step. The first protective film 10 was bonded. The bonding of the second protective film 20 through the second adhesive layer 25 can be performed in the same manner as the bonding of the first protective film 10.

以上，係詳述了由塗佈在基材膜上之聚乙烯醇系樹脂層形成偏光膜，繼而製造偏光板之方法，惟並不以此為限，亦可在包含單體(單獨)膜之偏光膜5貼合第1保護膜10、或第1及第2保護膜10,20而製造偏光板。 Above, the method of forming a polarizing film from a polyvinyl alcohol-based resin layer coated on a substrate film and then manufacturing a polarizing plate is described in detail, but it is not limited thereto, and a monomer (individual) film may be included. The polarizing film 5 is bonded to the first protective film 10 or the first and second protective films 10 and 20 to produce a polarizing plate.

由包含單體(單獨)膜之偏光膜5，係可藉由包括以下步驟之方法來製造：例如以如熔融擠出法、溶劑澆注法之周知的方法製造聚乙烯醇系樹脂膜之步驟；將聚乙烯醇系樹脂膜進行單軸延伸之步驟；使用碘將聚乙烯醇系樹脂膜染色且使其吸附之步驟；使用硼酸水溶液處理吸附 有碘之聚乙烯醇系樹脂膜之步驟；及在以硼酸水溶液處理後進行水洗之步驟。單軸延伸，係可在碘的染色前進行、與染色同時進行或於染色後進行。於染色之後進行單軸延伸時，該單軸延伸可在硼酸處理之前或在硼酸處理中進行。而且，亦可在該等之複數個階段進行單軸延伸。 The polarizing film 5 containing a monomer (separate) film can be manufactured by a method including the following steps: for example, a step of manufacturing a polyvinyl alcohol-based resin film by a well-known method such as a melt extrusion method and a solvent casting method; The step of uniaxially stretching the polyvinyl alcohol-based resin film; the step of dyeing and adsorbing the polyvinyl alcohol-based resin film with iodine; treating the adsorption with an aqueous boric acid solution A step of polyvinyl alcohol-based resin film with iodine; and a step of washing with water after treatment with an aqueous solution of boric acid. Uniaxial extension can be carried out before dyeing with iodine, simultaneously with dyeing or after dyeing. When uniaxial extension is performed after dyeing, the uniaxial extension may be performed before or during the boric acid treatment. Furthermore, uniaxial extension may be performed in a plurality of stages.

在將第1及第2保護膜10,20之雙方貼合而製造兩面附保護膜的偏光板時，該等保護膜係可經由接著劑層而依序貼合，亦可同時貼合。 When both of the first and second protective films 10 and 20 are bonded to produce a polarizing plate with a protective film on both sides, these protective films may be sequentially bonded via an adhesive layer, or may be bonded simultaneously.

(7)W_I/Ty的調控 (7) Regulation of W _I / Ty

提高碘元素含有率W_I相對於光度校正單體透射率Ty而使W_I/Ty成為上述預定範圍內之方法係沒有特別限制，例如可列舉以下的方法。 The method for increasing the content of iodine element W _I with respect to the photometrically corrected monomer transmittance Ty so that W _I / Ty falls within the predetermined range is not particularly limited, and examples thereof include the following methods.

a)在染色步驟，係將膜浸漬在含有相較於通常所採用的量為較大量的碘化物(包括碘和碘化物離子)之染色溶液之方法。此時，能夠藉由調整染色溶液中的碘化物濃度、染色溶液的溫度、薄膜的滯留時間等而調控W_I/Ty。 a) In the dyeing step, a method of dipping a film in a dyeing solution containing a larger amount of iodide (including iodine and iodide ions) than that usually used. At this time, W _I / Ty can be adjusted by adjusting the iodide concentration in the dyeing solution, the temperature of the dyeing solution, and the residence time of the film.

b)在交聯處理步驟，係將膜浸漬在含有相較於通常所採用的量為較大量地的碘化物離子之交聯溶液之方法。此時，亦可藉由調整交聯溶液中的碘化物離子的濃度、交聯溶液的溫度、薄膜的滯留時間等而調控W_I/Ty。 b) In the cross-linking treatment step, a method of immersing the film in a cross-linking solution containing a larger amount of iodide ions than the amount generally used. At this time, W _I / Ty can also be adjusted by adjusting the concentration of iodide ions in the crosslinking solution, the temperature of the crosslinking solution, and the residence time of the film.

c)使膜所含有的碘化物離子不脫離之方法。曾含有的碘化物離子較容易因以水洗淨而被沖洗掉。因 而，作為碘化物離子不脫離的方法，可列舉提高交聯溶液中的交聯劑濃度之方法。提高交聯劑濃度時，交聯劑的交聯量會變多，所以在進行水洗時可以使碘化物離子不易被沖洗掉。為了更有效地抑制碘化物離子脫離，交聯溶液的溫度係以盡可能設為低溫為佳。而且，作為使碘化物離子不脫離的之其它方法，使用氣動刮刀、鼓風機將附著在膜表面之液體吹掉、以吸水輥等進行除去來取代水洗之方法亦屬有效。藉由不進行水洗，可避免碘化物離子脫離。 c) A method for preventing the iodide ions contained in the film from detaching. Once contained iodide ions are easily washed away by washing with water. because As a method for preventing the iodide ion from detaching, a method of increasing the concentration of the crosslinking agent in the crosslinking solution is mentioned. When the concentration of the cross-linking agent is increased, the cross-linking amount of the cross-linking agent will increase, so that the iodide ions can not be easily washed out when washing with water. In order to more effectively suppress the detachment of iodide ions, the temperature of the crosslinking solution is preferably as low as possible. In addition, as another method for preventing the iodide ions from detaching, a method of using a pneumatic blade or a blower to blow off the liquid adhering to the surface of the film and remove it with a suction roller or the like instead of washing with water is also effective. By not washing with water, iodide ion detachment can be avoided.

d)上述a)至c)之2種以上的組合。 d) a combination of two or more of the above a) to c).

上述之中，以b)、c)的方法尤為有效，以c)的方法最為有效。 Among the above, the methods of b) and c) are particularly effective, and the method of c) is the most effective.

為了得到W_I/Ty為0.145以上之偏光膜，較佳實施形態之一係包括交聯處理步驟之方法，該交聯處理步驟係將膜浸漬在盡可能為低溫且含有交聯劑及碘化物離子的交聯溶液中。較佳的實施形態之一，係包括交聯處理步驟之方法，該交聯處理步驟係將膜浸漬在液溫為3至30℃、較佳為5至15℃，且含有交聯劑0.5至10重量%、較佳為1至5重量%，而且過剩地含有碘化物離子的交聯溶液中。在使用2槽以上的交聯溶液而實施交聯處理步驟時，該交聯溶液可為至少1種的交聯溶液。 In order to obtain a polarizing film having a W _I / Ty of 0.145 or more, one of the preferred embodiments is a method including a cross-linking treatment step in which the film is dipped in as low a temperature as possible and contains a crosslinking agent and an iodide. Ionic cross-linking solution. One of the preferred embodiments is a method including a cross-linking treatment step in which the film is immersed in a liquid temperature of 3 to 30 ° C, preferably 5 to 15 ° C, and contains a crosslinking agent of 0.5 to 10% by weight, preferably 1 to 5% by weight, and excessively contained in a crosslinking solution containing iodide ions. When a cross-linking treatment step is performed using a cross-linking solution having two or more tanks, the cross-linking solution may be at least one type of cross-linking solution.

更佳是在實施上述較佳實施形態之交聯處理步驟之後，不進行水洗，而是使用氣動刮刀、鼓風機、吸水輥等而將附著於膜表面的液體除去。又，之後的乾燥步驟之條件係沒有特別限制，即便在較高溫進行，碘化物離 子亦不容易產生脫離。 It is more preferable that after performing the cross-linking treatment step of the above-mentioned preferred embodiment, the liquid adhered to the surface of the film is removed without using water washing, but using a pneumatic blade, a blower, a suction roll, or the like. In addition, the conditions of the subsequent drying step are not particularly limited, and even if performed at a higher temperature, the iodide ionization The child is not prone to detachment.

[實施例] [Example]

以下，揭示實施例及比較例而更具體地說明本發明，但是本發明係不被該等例子限定。 Hereinafter, the present invention will be described more specifically with reference to 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) Primer layer forming step

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%)溶解在95℃的熱水，調製濃度3重量%的聚乙烯醇水溶液。在所得到的水溶液中，以相對於聚乙烯醇粉末6重量份為5重量份的比率混合交聯劑(田岡化學工業(股份有限公司)製的「Sumirez Resin 650」)而得到底漆層形成用塗佈液。 Polyvinyl alcohol powder ("Z-200" manufactured by Nippon Synthetic Chemical Industry Co., Ltd., average degree of polymerization 1100, degree of saponification 99.5 mole%) was dissolved in hot water at 95 ° C to prepare a polymer having a concentration of 3% by weight. Vinyl alcohol aqueous solution. In the obtained aqueous solution, a crosslinking agent ("Sumirez Resin 650" manufactured by Taoka Chemical Industry Co., Ltd.) was mixed at a ratio of 5 parts by weight to 6 parts by weight of the polyvinyl alcohol powder to obtain a primer layer. Use coating solution.

其次，準備厚度90μm之未延伸的聚丙烯(PP)膜(熔點：163℃)作為基材膜，在其一面施行電暈處理後，使用小徑凹版塗佈機將上述底漆層形成用塗佈液塗佈在其電暈處理面，使其在80℃乾燥10分鐘，藉此形成厚度0.2μm的底漆層。 Next, an unstretched polypropylene (PP) film (melting point: 163 ° C.) having a thickness of 90 μm was prepared as a base film, and one side was subjected to a corona treatment, and then the primer layer forming coating was applied using a small-diameter gravure coater. The cloth liquid was applied to the corona-treated surface and dried at 80 ° C. for 10 minutes, thereby forming a primer layer having a thickness of 0.2 μm.

(2)積層膜的製造(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至99.0莫耳%)溶解在95℃的熱水，來調製濃度8重量%的聚乙烯醇水溶液，將其作為聚乙烯醇系樹脂層形成用塗佈液。 Polyvinyl alcohol powder ("PVA124" manufactured by KURARAY (Co., Ltd.), average degree of polymerization 2400, degree of saponification 98.0 to 99.0 mole%) was dissolved in hot water at 95 ° C to prepare a polyvinyl alcohol having a concentration of 8% by weight. An aqueous solution was used as a coating liquid for forming a polyvinyl alcohol-based resin layer.

使用模塗機將上述聚乙烯醇系樹脂層形成用塗佈液塗佈在上述(1)所製作之具有底漆層的基材膜之底漆層表面後，在70℃使其乾燥4分鐘，藉此在底漆層上形成聚乙烯醇系樹脂層，而得到包含基材膜/底漆層/聚乙烯醇系樹脂層之積層膜。 The coating liquid for forming a polyvinyl alcohol-based resin layer was coated on the surface of the primer layer of the base film with the primer layer prepared in (1) above using a die coater, and then dried at 70 ° C. for 4 minutes. Thus, a polyvinyl alcohol-based resin layer is formed on the primer layer, and a laminated film including a base film / primer layer / polyvinyl alcohol-based resin layer is obtained.

(3)延伸膜的製作(延伸步驟) (3) Production of stretch film (stretching step)

使用非固定式縱向單軸延伸裝置，對上述(2)所製成的積層膜在160℃實施5.3倍的自由端單軸延伸而得到延伸膜。延伸後的聚乙烯醇系樹脂層之厚度為5.1μm。 A non-fixed longitudinal uniaxial stretching device was used to uniaxially stretch the free end of the laminated film prepared in (2) above at 5.3 times at 160 ° C to obtain a stretched film. The thickness of the stretched polyvinyl alcohol-based resin layer was 5.1 μm.

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

將在上述(3)所製作的延伸膜浸漬在含有碘及碘化鉀之30℃的染色水溶液(每100重量份水含有碘0.6重量份、碘化鉀10.0重量份)約180秒而進行聚乙烯醇系樹脂層的染色處理之後，使用10℃的純水沖洗多餘的染色水溶液。 The stretched film prepared in the above (3) was immersed in a dyeing aqueous solution containing 30% of iodine and potassium iodide (0.6 parts by weight of iodine per 100 parts by weight of water and 10.0 parts by weight of potassium iodide) for about 180 seconds to perform a polyvinyl alcohol resin After the layer was dyed, the excess dyeing aqueous solution was rinsed with pure water at 10 ° C.

其次，浸漬在含有硼酸之78℃的第1交聯水溶液(每100重量份水含有硼酸10.4重量份)120秒鐘，其次，浸漬在含有硼酸及碘化鉀之70℃的第2交聯水溶液(每100重量份水含有硼酸5.7重量份、碘化鉀12.0重量份)60秒，再浸漬在含有硼酸及碘化鉀之10℃的第3交聯水溶液(每100重量份水含有硼酸3.0重量份、碘化鉀15.0重量份)約10秒鐘而進行交聯處理。隨後立即使用鼓風機，將附著在兩面之液體去除，得到包含偏光膜之偏光性積層膜。 Next, it was immersed in a first cross-linked aqueous solution containing boric acid at 78 ° C (10.4 parts by weight of boric acid per 100 parts by weight of water) for 120 seconds, and secondly, it was immersed in a second cross-linked aqueous solution at 70 ° C containing boric acid and potassium iodide (each 100 parts by weight of water contains 5.7 parts by weight of boric acid and 12.0 parts by weight of potassium iodide) for 60 seconds, and then immersed in a third cross-linked aqueous solution containing boric acid and potassium iodide at 10 ° C (containing 3.0 parts by weight of boric acid and 15.0 parts by weight of potassium iodide per 100 parts by weight of water). ) Cross-linking is performed for about 10 seconds. Immediately afterwards, the liquid adhering to both sides was removed using a blower to obtain a polarizing laminated film including a polarizing film.

(5)單面附保護膜的偏光板之製造(第1貼合步驟、剝離步驟) (5) Manufacturing of a polarizing plate with a protective film on one side (first bonding step, peeling step)

在上述(4)所製作之偏光性積層膜的偏光膜上，經由包含紫外線硬化性接著劑(ADEKA(股份有限公司)製的「KR-75T」)之接著劑層貼合保護膜[包含三乙酸纖維素(TAC)之透明保護膜(Konica Minolta Opto(股份有限公司)製的「KC-2UAW」)]。其次，藉由使用高壓水銀燈進行照射紫外線來使接著劑層硬化，而得到包含保護膜/接著劑層/偏光膜/基材膜的層結構之貼合膜(第1貼合步驟)。之後，將基材膜從所得到的貼合膜剝離除去，而得到單面附保護膜的偏光板(剝離步驟)。 On the polarizing film of the polarizing laminated film produced in the above (4), a protective film is attached via an adhesive layer containing an ultraviolet curable adhesive ("KR-75T" manufactured by ADEKA (Co., Ltd.)) [including three Transparent protective film of cellulose acetate (TAC) ("KC-2UAW" by Konica Minolta Opto (Co., Ltd.))]. Next, the adhesive layer is hardened by irradiating ultraviolet rays using a high-pressure mercury lamp to obtain a bonding film including a layer structure of a protective film / adhesive layer / polarizing film / base film (first bonding step). Then, the base film was peeled and removed from the obtained bonding film, and the single-sided polarizing plate with a protective film was obtained (peeling process).

(6)評估用試樣的製造 (6) Manufacturing of evaluation samples

對所得到之單面附保護膜的偏光板的偏光膜側之面進行電暈處理，同時貼合(甲基)丙烯酸樹脂系的黏著劑(LINTEC(股份有限公司)製的「P-3132」)。將所得到之附黏著劑層的偏光板用其黏著劑層貼合於玻璃，得到評估用試樣。 The surface of the polarizing film side of the obtained single-sided polarizing plate with a protective film was corona-treated, and a (meth) acrylic resin-based adhesive ("P-3132" manufactured by LINTEC (Co., Ltd.) was bonded together. ). The obtained polarizing plate with an adhesive layer was bonded to glass with the adhesive layer, and the sample for evaluation was obtained.

<實施例2> <Example 2>

除了將在第3交聯水溶液之碘化鉀的含量設為每100重量份水含有6重量份，而且，使用吸水輥取代鼓風機而將兩面的液體除去以外，係與實施例1進行相同操作而製 成單面附保護膜的偏光板，其次製成評估用試樣。 It was prepared in the same manner as in Example 1 except that the content of potassium iodide in the third crosslinked aqueous solution was set to 6 parts by weight per 100 parts by weight of water, and the liquid on both sides was removed by using a suction roller instead of a blower. A single-sided polarizing plate with a protective film was formed, and then a sample for evaluation was produced.

<比較例1> <Comparative example 1>

除了將在第3交聯水溶液之碘化鉀的含量設為每100重量份水含有4重量份以外，係與實施例1進行相同操作而製成單面附保護膜的偏光板，其次製成評估用試樣。 A polarizing plate with a single-sided protective film was prepared in the same manner as in Example 1 except that the content of potassium iodide in the third cross-linked aqueous solution was 4 parts by weight per 100 parts by weight of water, followed by evaluation. Sample.

<比較例2> <Comparative example 2>

除了以浸漬在10℃的水取代浸漬在第3交聯水溶液以外，係與實施例1進行相同操作而製成單面附保護膜的偏光板，其次製成評估用試樣。 A polarizing plate with a single-sided protective film was prepared in the same manner as in Example 1 except that the third cross-linked aqueous solution was immersed in water immersed in 10 ° C, and then a sample for evaluation was prepared.

[Ty、Py及單體色相b的測定] [Determination of Ty, Py and monomer hue b]

針對所得到的評估用試樣之偏光板，使用附積分球之吸光光度計(日本分光(股份有限公司)製的「V7100」)，藉由JIS Z 8701的2度視野(C光源)對所得到的透射率、偏光度進行光度校正，來測定光度校正單體透射率Ty及光度校正偏光度Py。而且，使用相同的吸光光度計測定單體色相b。在測定時，係將評估用試樣以能夠照射入射光之方式安裝在玻璃側。將所得到的光度校正單體透射率Ty、光度校正偏光度Py及單體色相b，分別設為偏光膜的光度校正單體透射率Ty、光度校正偏光度Py及單體色相b。將結果表示在表1。 The polarizing plate of the obtained evaluation sample was measured with a 2 degree field of view (C light source) of JIS Z 8701 using a spectrophotometer with an integrating sphere ("V7100" manufactured by JASCO Corporation). The obtained transmittance and polarization degree are subjected to photometric correction, and the photometric correction unit transmittance Ty and the photometric corrected polarization degree Py are measured. The monomer hue b was measured using the same absorbance photometer. During the measurement, the evaluation sample is mounted on the glass side so as to be able to irradiate incident light. The obtained photometrically corrected monomer transmittance Ty, photometrically corrected polarization degree Py, and monochromatic hue b are respectively set as the photometrically corrected monomer transmittance Ty, photometrically corrected polarized light degree Py, and individual hue b of the polarizing film. The results are shown in Table 1.

[碘元素含有率W_I及W_I/Ty的測定] [Determination of Iodine Element Content W _I and W _I / Ty]

將保護膜及接著劑層從所得到之單面附保護膜的偏光板除去而將偏光膜單離，將其設作測定試樣，並藉由依據JIS K 0127：2013之燃燒-離子層析法而求取碘元素含有率W_I[重量%]。在燃燒-離子層析儀，係使用三菱化學Analytech公司製的氯/硫分析裝置「TOX-100」作為燃燒裝置，而且，使用Thermo Fisher Scientific公司製的「DX-500」作為離子層析裝置。使用12.2mg的偏光膜作為測定試樣，測定試樣的燃料前處理，係依照同JIS規格的6.3.5。而且，使用上述所得到的Ty而算出W_I/Ty。將結果表示在表1。 The protective film and the adhesive layer were removed from the obtained single-sided polarizing plate with a protective film, and the polarizing film was isolated. The polarizing film was set as a measurement sample and subjected to combustion-ion chromatography in accordance with JIS K 0127: 2013. The iodine content W _I [% by weight] was determined by the method. In the combustion-ion chromatography, a chlorine / sulfur analyzer "TOX-100" manufactured by Mitsubishi Chemical Analytech was used as a combustion device, and "DX-500" manufactured by Thermo Fisher Scientific was used as an ion chromatography device. A 12.2 mg polarizing film was used as a measurement sample, and the fuel pretreatment of the measurement sample was in accordance with 6.3.5 of the same JIS standard. Then, W _I / Ty is calculated using the obtained Ty. The results are shown in Table 1.

[在波長217nm之吸光度的測定] [Determination of absorbance at a wavelength of 217 nm]

將保護膜及接著劑層從所得到之單面附保護膜的偏光板除去而將偏光膜單離，且將其設作測定試樣，使用吸光光度計(島津製作所(股份有限公司)製：UV2450)測定於190至800nm的波長區域之吸光度。為了避免裝置所造成之偏光的影響，係採用使測定試樣的吸收軸相對於裝置呈水平而測得的吸光光譜及旋轉90度而測得的吸光光譜之平均值來作為偏光膜的吸光光譜。從該吸光光譜，求取源自碘化物離子(I^-)之在波長217nm的吸光度。將結果表示在表1。 The protective film and the adhesive layer were removed from the obtained single-sided polarizing plate with a protective film, and the polarizing film was isolated. The polarizing film was set as a measurement sample, and an absorbance meter (manufactured by Shimadzu Corporation, Ltd.) was used: UV2450) The absorbance was measured in a wavelength region of 190 to 800 nm. In order to avoid the influence of polarized light caused by the device, the average value of the light absorption spectrum measured by making the absorption axis of the measurement sample horizontal to the device and the light absorption spectrum measured by rotating 90 degrees is used as the light absorption spectrum of the polarizing film. . The absorption spectrum from the light, is obtained from an iodide ion (I ^-) is the absorbance at a wavelength of 217nm. The results are shown in Table 1.

在實施例1至2及比較例1至2之4種偏光膜，所得到的吸光度係與以燃燒-離子層析法求取的碘元素含有率W_I成正比關係。咸認此係因為為了使Ty成為相同 一致，與PVA形成錯合物之聚碘的量在4種偏光膜之間為大致相等，而且使用燃燒-離子層析法所測定的碘元素含有率W_I之大小會反映碘化物離子(I^-)量的大小之故。從該結果，得知從燃燒-離子層析法求取的碘元素含有率W_I係反映碘化物離子(I^-)量。 In the four types of polarizing films of Examples 1 to 2 and Comparative Examples 1 to 2, the absorbance obtained was directly proportional to the content ratio W _I of the iodine element obtained by the combustion-ion chromatography method. It is believed that this is because the amount of polyiodide that forms a complex with PVA is approximately the same among the four polarizing films in order to make Ty the same, and the content of iodine element W measured by combustion-ion chromatography _I reflect the size of the iodide ion (I ^-) so that the size of the volume. From this result, it is known from combustion - iodide ion (the I ^-) is obtained containing iodine ion chromatography based reflection amount of W _I.

[偏光板的耐水性評估] [Water resistance evaluation of polarizing plate]

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

將4cm×4cm的評估用試樣投入經調溫、調濕成為80℃、90%RH的烘箱中48小時之後，將試樣取出，在23℃、55%RH的環境下靜置約12小時之後，使用與上述相同的方法測定光度校正偏光度Py。將結果表示在表1。 The 4cm × 4cm sample for evaluation was placed in an oven that was adjusted to 80 ° C and 90% RH for 48 hours, and then the sample was taken out and left to stand in an environment of 23 ° C and 55% RH for about 12 hours. After that, the photometric correction polarization degree Py is measured using the same method as described above. The results are shown in Table 1.

(2)耐溫水性的評估 (2) Evaluation of temperature resistance

將4cm×4cm的評估用試樣浸漬在60℃的水中30分鐘之後，將試樣拉起且在23℃、55%RH的環境下靜置約12小時之後，使用與上述相同的方法測定單體色相b。而且，目視確認試驗後的試樣之色相，將試驗後亦能夠維持中性灰色時判定為A，將產生藍色色偏時評定為B。將結果表示在表1。 After immersing a 4 cm × 4 cm sample for evaluation in water at 60 ° C. for 30 minutes, the sample was pulled up and left to stand in an environment of 23 ° C. and 55% RH for about 12 hours. Body Hue b. In addition, the hue of the sample after the test was visually confirmed, and when the neutral gray was maintained after the test, it was judged as A, and when the blue color shift occurred, it was evaluated as B. The results are shown in Table 1.

1‧‧‧偏光板 1‧‧‧ polarizing plate

5‧‧‧偏光膜 5‧‧‧ polarizing film

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

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

Claims (4)

一種偏光板，其係包含：偏光膜，其光度校正單體透射率Ty[%]為40至47%，碘元素含有率W_I[重量%]相對於前述光度校正單體透射率Ty[%]之比W_I/Ty為0.145以上；保護膜，其係經由活性能量射線硬化性接著劑接著固定在前述偏光膜的至少一面上；前述保護膜之厚度為30μm以下。 A polarizing plate comprising: a polarizing film having a photometric correction monomer transmittance Ty [%] of 40 to 47%, and an iodine content rate W _I [wt%] relative to the aforementioned photometric correction monomer transmittance Ty [% ] Ratio W _I / Ty is 0.145 or more; a protective film is fixed to at least one side of the polarizing film via an active energy ray-curable adhesive; the thickness of the protective film is 30 μm or less. 如申請專利範圍第1項所述之偏光板，其中，前述W_I/Ty為0.5以下。 The polarizing plate according to item 1 of the scope of patent application, wherein the aforementioned W _I / Ty is 0.5 or less. 如申請專利範圍第1項所述之偏光板，其中，前述偏光膜之厚度為10μm以下。 The polarizing plate according to item 1 of the scope of patent application, wherein the thickness of the polarizing film is 10 μm or less. 如申請專利範圍第1至3項中任一項所述之偏光板，其中，前述偏光膜含有聚乙烯醇系樹脂。 The polarizing plate according to any one of claims 1 to 3, wherein the polarizing film contains a polyvinyl alcohol-based resin.