TW202238184A

TW202238184A - Polarizing plate production method and polarizing plate

Info

Publication number: TW202238184A
Application number: TW111101490A
Authority: TW
Inventors: 松山裕紀; 村永佳奈子; 安德友里; 中市誠
Original assignee: 日商日東電工股份有限公司
Priority date: 2021-03-25
Filing date: 2022-01-13
Publication date: 2022-10-01
Also published as: JP7203879B2; WO2022201708A1; CN117063098A; KR20230158475A; JP2022149242A

Abstract

Provided is a method that enables efficient production of a polarizing plate in which the occurrence of cracking is suppressed, even in harsh environments such as that of a heat shock test. A polarizing plate production method according to an embodiment of the present invention comprises: stacking a plurality of polarizing plates to form a workpiece; and using a twist file to process the outer peripheral surface of the workpiece such that a polarizer end surface of the polarizing plates has a surface roughness Sdr of not less than 11% as found according to ISO 25178.

Description

偏光板之製造方法及偏光板Manufacturing method of polarizing plate and polarizing plate

本發明涉及偏光板之製造方法及偏光板。The invention relates to a method for manufacturing a polarizing plate and the polarizing plate.

在液晶顯示裝置、有機電致發光(EL)顯示裝置等影像顯示裝置中，由於其影像形成方式，多數情況下，會於影像顯示單元之至少一側配置有偏光板。影像顯示裝置被使用在以電視機、智慧型手機、個人電腦、數位相機為首之廣泛用途上，並且其用途還在進一步擴展。所述用途可舉例如車載用途。具體而言，影像顯示裝置可用於汽車之儀表盤、配設於控台之各種儀表或導航系統等之顯示部。在所述車載用途中，對偏光板係要求在高溫、高濕等嚴酷環境下之耐久性。且，隨著影像顯示裝置之使用形態的多樣化，就連車載以外之用途，亦逐漸對偏光板要求提升在高溫、高濕等嚴酷環境下之耐久性。然而，偏光板(實質上為偏光板所含之偏光件)有在嚴酷環境下容易產生裂痕之問題。In image display devices such as liquid crystal display devices and organic electroluminescence (EL) display devices, due to the image forming method, in most cases, a polarizer is disposed on at least one side of the image display unit. Image display devices are used in a wide range of applications including televisions, smartphones, personal computers, and digital cameras, and their applications are still expanding. Such use may, for example, be used in vehicles. Specifically, the image display device can be used in the display part of the instrument panel of an automobile, various instruments arranged on the console, or a navigation system. In such automotive applications, durability in severe environments such as high temperature and high humidity is required for polarizing plates. Moreover, with the diversification of the use forms of image display devices, even applications other than automotive applications gradually require polarizers to be more durable in harsh environments such as high temperature and high humidity. However, the polarizer (essentially, the polarizer included in the polarizer) has the problem that it is prone to cracks under harsh environments.

先前技術文獻專利文獻專利文獻1：日本專利特開2014-102353號公報 prior art literature Patent Document Patent Document 1: Japanese Patent Laid-Open No. 2014-102353

發明欲解決之課題本發明係為了解決上述以往課題而成者，其主要目的在於提供一種可有效率地製造偏光板之方法，該偏光板係即使在如熱震試驗這種嚴酷環境下仍抑制得住裂痕發生者。 The problem to be solved by the invention The present invention is made to solve the above-mentioned conventional problems, and its main purpose is to provide a method for efficiently manufacturing a polarizing plate that suppresses the occurrence of cracks even in severe environments such as thermal shock tests. .

用以解決課題之手段本發明實施形態之偏光板之製造方法，包含以下步驟：將複數片偏光板疊合而形成工件；及，使用螺旋銼刀來加工該工件之外周面，使該偏光板之偏光件端面依循ISO 25178所得之面粗度Sdr為11%以上。在一實施形態中，其在將上述螺旋銼刀之旋轉數設為S(rpm)、將進給速度設為F(mm/分鐘)時，S/F為14以上。在一實施形態中，上述螺旋銼刀不具有餘隙角，且刀尖之寬度為0.1mm以上。在一實施形態中，上述製造方法包含一切削之步驟，其係以上述螺旋銼刀之刀的背面側在旋轉方向上游側之方式進行。在一實施形態中，上述偏光板更具有：表面保護薄膜，其係以可剝離之方式暫時黏附於其中一側；黏著劑層，其係配置於另一側；及分離件，其係以可剝離之方式暫時黏附於該黏著劑層；該製造方法係使該表面保護薄膜位於上述螺旋銼刀之切削屑的排出方向來疊合該偏光板而形成上述工件。在一實施形態中，上述製造方法包含一以上述螺旋銼刀加工上述工件之外周面的步驟，所述外周面位在與上述偏光板所含偏光件之吸收軸方向相交之方向。在一實施形態中，上述製造方法包含一以端銑刀加工上述工件之外周面的步驟，所述位周面位在與上述偏光板所含偏光件之吸收軸方向實質上平行之方向。在一實施形態中，上述利用螺旋銼刀進行之加工包含形成異形之步驟；並且，該螺旋銼刀形成該異形時之進給速度小於該螺旋銼刀加工該異形以外之部分時的進給速度。根據本發明另一面向，提供一種偏光板。該偏光板具有偏光件與配置於該偏光件之至少一側的保護層；在該偏光板之一對規定外緣且互相對向之邊中，其中一邊的該偏光件端面依循ISO 25178所得之面粗度Sdr(S)為11%以上，且該Sdr(S)與另一邊的該偏光件端面之面粗度Sdr(E)滿足下述關係： Sdr(S)-Sdr(E)≦3%。 means to solve problems The manufacturing method of the polarizing plate according to the embodiment of the present invention includes the following steps: stacking a plurality of polarizing plates to form a workpiece; and using a spiral file to process the outer peripheral surface of the workpiece so that the end surface of the polarizer of the polarizing plate complies with ISO 25178 The obtained surface roughness Sdr was 11% or more. In one embodiment, S/F is 14 or more when the rotation speed of the said helical file is S (rpm) and the feed rate is F (mm/min). In one embodiment, the spiral file does not have a clearance angle, and the width of the cutting edge is 0.1 mm or more. In one embodiment, the above-mentioned manufacturing method includes a cutting step, which is carried out so that the back side of the blade of the above-mentioned spiral file is on the upstream side in the direction of rotation. In one embodiment, the above-mentioned polarizing plate further has: a surface protection film, which is temporarily attached to one side in a peelable manner; an adhesive layer, which is arranged on the other side; and a separator, which is detachable The method of peeling is temporarily adhered to the adhesive layer; the manufacturing method is to position the surface protection film in the discharge direction of the cutting chips of the above-mentioned spiral file to laminate the polarizing plate to form the above-mentioned workpiece. In one embodiment, the manufacturing method includes a step of processing the outer peripheral surface of the workpiece with the spiral file, and the outer peripheral surface is located in a direction intersecting with the direction of the absorption axis of the polarizer contained in the polarizer. In one embodiment, the manufacturing method includes a step of machining the outer peripheral surface of the workpiece with an end mill, and the peripheral surface is located in a direction substantially parallel to the direction of the absorption axis of the polarizer included in the polarizer. In one embodiment, the above-mentioned processing with the spiral file includes a step of forming a special shape; and, the feed speed of the spiral file when forming the special shape is lower than the feed speed of the spiral file when processing the part other than the special shape. According to another aspect of the present invention, a polarizer is provided. The polarizer has a polarizer and a protective layer disposed on at least one side of the polarizer; among a pair of sides facing each other at the outer edges of the polarizer, the end face of the polarizer on one side complies with ISO 25178 The surface roughness Sdr(S) is more than 11%, and the surface roughness Sdr(E) of the Sdr(S) and the end surface of the polarizer on the other side satisfies the following relationship: Sdr(S)-Sdr(E)≦3%.

發明效果根據本發明實施形態，藉由使用螺旋銼刀加工偏光件端面，可有效率地製造一種偏光板，該偏光板係即便在如熱震試驗這種嚴酷環境下仍抑制得住裂痕發生者。並且，可縮小在最初階段加工之偏光件端面的Sdr與在最後階段加工之偏光件端面的Sdr之差。 Invention effect According to an embodiment of the present invention, by processing the end face of the polarizer with a spiral file, it is possible to efficiently manufacture a polarizing plate that suppresses the occurrence of cracks even in severe environments such as thermal shock tests. Also, the difference between the Sdr of the end face of the polarizer processed at the first stage and the end face of the polarizer processed at the last stage can be reduced.

以下說明本發明之實施形態，惟本發明不受該等實施形態所限。Embodiments of the present invention will be described below, but the present invention is not limited to these embodiments.

A.偏光板之製造方法本發明實施形態之偏光板之製造方法，包含以下步驟：將複數片偏光板疊合而形成工件；及使用螺旋銼刀來加工該工件之外周面，使該偏光板之偏光件端面依循ISO 25178所得之面粗度Sdr為11%以上。以下依序說明各步驟。 A. Manufacturing method of polarizing plate The method of manufacturing a polarizing plate according to the embodiment of the present invention includes the following steps: stacking a plurality of polarizing plates to form a workpiece; and using a spiral file to process the outer peripheral surface of the workpiece so that the end surface of the polarizer of the polarizing plate complies with ISO 25178 Surface roughness Sdr is 11% or more. Each step is described in order below.

A-1.工件之形成首先，形成工件。圖1係概略立體圖，用以說明本發明實施形態之偏光板之製造方法中之端面加工的概略，本圖中顯示有工件W。如圖1所示，形成已將複數片偏光板疊合而成的工件W。在形成工件時，偏光板在代表上係切斷成任意適當之形狀。具體而言，偏光板可切斷成矩形形狀，可切斷成類似矩形形狀之形狀(例如，形成一矩形形狀，其在俯視時於長邊中央部呈凹部之形狀)，亦可切斷成符合目的之適當形狀(例如圓形)。工件W在一實施形態中，具有互相對向之外周面1a、1b及與其等正交之外周面1c、1d。工件W宜被鉗夾機構(未圖示)從上下鉗著。工件之總厚度例如為10mm~60mm。偏光板係以工件會成為所述總厚度的方式來疊合。構成工件之偏光板的片數會因偏光板之厚度而變化。偏光板之片數例如為50片~300片。鉗夾機構(例如夾具)可藉由軟質材料構成、亦可藉由硬質材料構成。以軟質材料構成時，其硬度(JIS A)宜為60°~80°。若硬度過高，會有鉗夾機構所造成壓痕殘留的情形。若硬度過低，則因夾具之變形，會造成位置偏移，而有切削精度不足之情形。 A-1. Formation of workpiece First, a workpiece is formed. Fig. 1 is a schematic perspective view for explaining the outline of end surface processing in the method of manufacturing a polarizing plate according to an embodiment of the present invention, and a workpiece W is shown in this figure. As shown in FIG. 1 , a work W obtained by laminating a plurality of polarizing plates is formed. When forming a workpiece, the polarizer is typically cut into any appropriate shape. Specifically, the polarizing plate can be cut into a rectangular shape, can be cut into a shape similar to a rectangular shape (for example, a rectangular shape with a concave shape in the center of the long side when viewed from above), or can be cut into a rectangular shape. Appropriate shape for the purpose (e.g. round). In one embodiment, the workpiece W has outer peripheral surfaces 1a, 1b that face each other and outer peripheral surfaces 1c, 1d that are perpendicular thereto. The workpiece W should be clamped from top to bottom by a clamp mechanism (not shown). The total thickness of the workpiece is, for example, 10 mm to 60 mm. Polarizers are laminated in such a way that the workpiece will be the overall thickness. The number of polarizers constituting the workpiece will vary depending on the thickness of the polarizers. The number of polarizing plates is, for example, 50 to 300 sheets. The clamping mechanism (such as a clamp) can be made of soft material or hard material. When made of soft materials, the hardness (JIS A) should be 60°~80°. If the hardness is too high, the indentation caused by the clamping mechanism may remain. If the hardness is too low, the position will be shifted due to the deformation of the jig, and the cutting accuracy may be insufficient.

A-2.端面加工接著，為了可獲得預定之面粗度Sdr(ISO 25178)，對工件(實質上為偏光板)之外周面進行端面加工。本發明實施形態中，所得Sdr為11%以上，宜為12%以上，較宜為13%以上，更宜為14%以上，尤宜為18%以上。所得Sdr之上限無特別限定，例如可為100%、80%、60%或40%。端面加工代表上係使用螺旋銼刀來進行及因應需求而使用端銑刀來進行。藉由使用螺旋銼刀進行端面加工，便可實現上述所期望範圍的Sdr，結果，可實現一種即使在如熱震試驗這種嚴酷環境下仍抑制得住裂痕之偏光板，且可縮小在最初階段加工之偏光件端面的Sdr與在最後階段加工之偏光件端面的Sdr之差。此外，面粗度Sdr係依循ISO 25178所得之界面的展開面積比。面粗度Sdr係令平坦面為100%時之表面積的增加率，例如可藉由使用雷射顯微鏡之非接觸式(光探針)方法來測定。以下，先說明可用於端面加工之螺旋銼刀及端銑刀，接著說明端面加工之具體程序。 A-2. End processing Next, in order to obtain a predetermined surface roughness Sdr (ISO 25178), the outer peripheral surface of the workpiece (essentially a polarizing plate) is end-face processed. In the embodiment of the present invention, the obtained Sdr is more than 11%, preferably more than 12%, more preferably more than 13%, more preferably more than 14%, especially more than 18%. The upper limit of the obtained Sdr is not particularly limited, for example, it may be 100%, 80%, 60% or 40%. End processing means using a spiral file and an end mill according to requirements. By processing the end face with a spiral file, the Sdr in the desired range above can be realized. As a result, a polarizing plate that suppresses cracks even in a severe environment such as a thermal shock test can be realized, and can be shrunk at the initial stage The difference between the Sdr of the processed polarizer end face and the Sdr of the polarizer end face processed in the final stage. In addition, the surface roughness Sdr is the developed area ratio of the interface obtained in accordance with ISO 25178. The surface roughness Sdr is the rate of increase of the surface area when the flat surface is 100%, and can be measured, for example, by a non-contact (optical probe) method using a laser microscope. In the following, the spiral files and end mills that can be used for end face processing will be described first, and then the specific procedures for end face processing will be described.

A-2-1.螺旋銼刀之構成螺旋銼刀70代表上如圖2所示，係使鑽石粒子附著於具有螺旋刃之端銑刀而構成。具體而言，螺旋銼刀70具有：旋轉軸71，其係朝工件W之積層方向(鉛直方向)延伸；及切削刃72，其係構成為以旋轉軸71為中心而旋轉之本體的最外徑。切削刃72上附著有鑽石粒子，而形成銼身部73。在圖式例中，切削刃72係構成為沿旋轉軸71扭轉之最外徑，顯示為右刃右螺旋。切削刃72包含刀尖72a、前刀面72b及後刀面72c。切削刃72的刃數可因應目的適當設定。圖示例中之切削刃為3片構成，但刃數可為連續的1片，可為2片，可為4片，亦可為5片以上。螺旋角θ宜為10°~70°，較宜為30°~60°。斜角宜為1°~25°，較宜為3°~20°，更宜為3°~10°。本發明實施形態中，螺旋銼刀70(實質上為切削刃72)宜如圖3所示不具有餘隙角。亦即，刀尖72a具有平坦面，而可實現刀尖72a與工件之被加工(切削)面以面相接之狀態。若為所述構成，便可實現一種即使在如熱震試驗這種嚴酷環境下仍抑制得住裂痕發生之偏光板，且可縮小在最初階段加工之偏光件端面的Sdr與在最後階段加工之偏光件端面的Sdr之差。刀尖72a之平坦面的寬度B宜為0.1mm以上，較宜為0.2mm~1.4mm，更宜為0.4mm~1.0mm。若該寬度過小，有抑制裂痕之效果不充分之情形。若該寬度過大，實質上會與棒銼刀同等，而有在最初階段加工之偏光件端面的Sdr與在最後階段加工之偏光件端面的Sdr之差變大之情形。此外，圖3係為了方便觀看之示意圖，而不對應圖2之螺旋銼刀。 A-2-1. Composition of the spiral file The spiral file 70 is typically shown in FIG. 2, and is constructed by attaching diamond particles to an end mill having a spiral edge. Specifically, the spiral file 70 has: a rotating shaft 71 extending toward the stacking direction (vertical direction) of the workpiece W; . Diamond particles are attached to the cutting edge 72 to form the file body 73 . In the example shown in the figure, the cutting edge 72 is formed with an outermost diameter twisted along the rotation axis 71, and is shown as a right-handed right-hand helix. The cutting edge 72 includes a cutting edge 72a, a rake face 72b, and a flank face 72c. The number of cutting edges 72 can be appropriately set according to the purpose. The cutting edge in the illustration example is composed of 3 pieces, but the number of cutting edges can be 1 continuous piece, 2 pieces, 4 pieces, or 5 or more pieces. The helix angle θ is preferably 10°~70°, more preferably 30°~60°. The bevel angle should be 1°~25°, more preferably 3°~20°, more preferably 3°~10°. In the embodiment of the present invention, the helical file 70 (essentially the cutting edge 72 ) preferably does not have a clearance angle as shown in FIG. 3 . That is, the cutting edge 72a has a flat surface, and a state in which the cutting edge 72a is in contact with the machined (cut) surface of the workpiece can be realized. According to the above structure, it is possible to realize a polarizing plate that suppresses the occurrence of cracks even in a severe environment such as a thermal shock test, and it is possible to reduce the Sdr of the end face of the polarizer processed in the initial stage and that in the final stage. The difference in Sdr of the end face of the polarizer. The width B of the flat surface of the blade tip 72a is preferably at least 0.1mm, more preferably 0.2mm~1.4mm, more preferably 0.4mm~1.0mm. If the width is too small, the effect of suppressing cracks may not be sufficient. If the width is too large, it becomes substantially equivalent to a rod file, and the difference between the Sdr of the end surface of the polarizer processed at the first stage and the end surface of the polarizer processed at the last stage may become large. In addition, FIG. 3 is a schematic diagram for easy viewing, and does not correspond to the spiral file in FIG. 2 .

圖4係用以說明銼身部73之凹凸形狀的主要部分概略截面圖。銼身部73之凹凸的深度D例如為5µm~120µm。深度D之下限宜為8µm以上，較宜為15µm以上。深度D之上限宜為50µm以下，較宜為35µm以下。銼身部73之凹凸的間距P例如為5µm~250µm。間距P之下限宜為10µm以上，較宜為25µm以上。間距P之上限宜為100µm以下，較宜為60µm以下。螺旋銼刀70(實質上為切削刃72)之直徑(外徑)例如可為2mm~12mm。銼身部73之長度L例如可為10mm~100mm。此外，本說明書中所謂「螺旋銼刀之直徑」係指從旋轉軸71至刀尖72a的距離乘以2倍而得者。後述之「端銑刀之直徑」亦同。銼身部73之面的算術平均高度(Sa)宜為1µm~15µm，較宜為3µm~10µm。銼身部73之面的最大高度(Sz)宜為10µm~100µm，較宜為25µm~80µm。該等之面粗度可依循ISO 25178之「非接觸式(光探針)」評估方法來測定。具體上，可藉由雷射顯微鏡(Keyence公司製造，製品名「VK-X1000」)來測定。又，鑽石粒子之粒徑為例如1µm~100µm。FIG. 4 is a schematic cross-sectional view of main parts for explaining the concave-convex shape of the file body portion 73. As shown in FIG. The depth D of the concavities and convexities of the file body 73 is, for example, 5 µm to 120 µm. The lower limit of the depth D is preferably not less than 8 µm, more preferably not less than 15 µm. The upper limit of the depth D is preferably not more than 50 µm, more preferably not more than 35 µm. The pitch P of the concavities and convexities of the file body 73 is, for example, 5 µm to 250 µm. The lower limit of the pitch P is preferably not less than 10 µm, more preferably not less than 25 µm. The upper limit of the pitch P is preferably not more than 100 µm, more preferably not more than 60 µm. The diameter (outer diameter) of the spiral file 70 (substantially the cutting edge 72) can be, for example, 2 mm to 12 mm. The length L of the file body portion 73 may be, for example, 10 mm to 100 mm. In addition, the "diameter of the spiral file" in this specification refers to the product obtained by multiplying the distance from the rotating shaft 71 to the blade tip 72a by 2 times. The same applies to the "diameter of the end mill" described later. The arithmetic mean height (Sa) of the surface of the file body 73 is preferably 1 µm-15 µm, more preferably 3 µm-10 µm. The maximum height (Sz) of the surface of the file body 73 is preferably 10µm~100µm, more preferably 25µm~80µm. These surface roughness can be measured according to the "non-contact (optical probe)" evaluation method of ISO 25178. Specifically, it can be measured with a laser microscope (manufactured by Keyence, product name "VK-X1000"). In addition, the particle size of the diamond particles is, for example, 1 µm to 100 µm.

螺旋銼刀之銼身部之粒度例如可為#100以上，宜為#200以上，較宜為#500以上。銼刀之粒度例如可為#3000以下，宜為#2500以下，較宜為#2200以下。螺旋銼刀若粒度小(銼齒粗)，便可容易增大Sdr。另一方面，若粒度大(銼齒細)，則幾乎可自動實現預定值以上之Sdr，因此控制其他條件(例如旋轉數)之必要性便變小。由可容易增大Sdr之觀點與不易發生裂痕之觀點來看，銼刀之粒度宜為#500~#2000之範圍。粒度可藉由鑽石粒子之大小等來調整。The particle size of the file body of the spiral file can be, for example, above #100, preferably above #200, more preferably above #500. The particle size of the file can be below #3000, preferably below #2500, more preferably below #2200. If the particle size of the spiral file is small (coarse teeth), the Sdr can be easily increased. On the other hand, if the grain size is large (fine teeth), Sdr above a predetermined value can be achieved almost automatically, so the necessity of controlling other conditions (such as the number of revolutions) becomes less. From the point of view that the Sdr can be easily increased and cracks are not easy to occur, the particle size of the file should be in the range of #500~#2000. The particle size can be adjusted by the size of diamond particles, etc.

A-2-2.端銑刀之構成除了螺旋銼刀，還使用端銑刀來進行端面加工時，端銑刀除了切削刃上未附著有鑽石粒子及具有餘隙角外，其餘與螺旋銼刀相同。具體而言，端銑刀60如圖5所示，具有：旋轉軸61，其係朝工件W之積層方向(鉛直方向)延伸；及切削刃62，其係構成為以旋轉軸61為中心而旋轉之本體的最外徑。在圖式例中，切削刃62係構成為沿旋轉軸61扭轉之最外徑，顯示為右刃右螺旋。切削刃62包含刀尖62a、前刀面62b及後刀面62c。切削刃62的刃數可因應目的適當設定。圖示例中之切削刃為3片構成，但刃數可為連續的1片，可為2片，可為4片，亦可為5片以上。端銑刀的刃角度(圖式例中的切削刃之螺旋角θ)宜為10°~70°，較宜為30°~60°。斜角宜為1°~25°，較宜為3°~20°，更宜為3°~10°。切削刃之後刀面宜經粗面化處理。粗面化處理可採用任意適當之處理。代表例可舉噴砂處理。藉由對後刀面施行粗面化處理，可抑制黏著劑附著至切削刃，結果可抑制黏結。端銑刀之直徑(外徑)例如為6mm以上，又例如為6mm~20mm。端銑刀之切削刃的有效長度例如為10mm~60mm。 A-2-2. Composition of end mill When using an end mill in addition to a spiral file for face machining, the end mill is the same as the spiral file except that no diamond particles are attached to the cutting edge and it has a clearance angle. Specifically, as shown in FIG. 5 , the end mill 60 has: a rotating shaft 61 extending toward the stacking direction (vertical direction) of the workpiece W; The outermost diameter of the rotating body. In the example shown in the drawing, the cutting edge 62 is configured as the outermost diameter twisted along the rotation axis 61, and is shown as a right-handed right-hand helix. The cutting edge 62 includes a cutting edge 62a, a rake face 62b, and a flank face 62c. The number of cutting edges 62 can be appropriately set according to the purpose. The cutting edge in the illustration example is composed of 3 pieces, but the number of cutting edges can be 1 continuous piece, 2 pieces, 4 pieces, or 5 or more pieces. The edge angle of the end mill (the helix angle θ of the cutting edge in the example shown in the figure) should be 10°~70°, more preferably 30°~60°. The bevel angle should be 1°~25°, more preferably 3°~20°, more preferably 3°~10°. After the cutting edge, the knife face should be roughened. Any appropriate treatment may be used for the roughening treatment. A representative example is sandblasting. By roughening the flank, it is possible to suppress adhesion of the adhesive to the cutting edge, and as a result, it is possible to suppress sticking. The diameter (outer diameter) of the end mill is, for example, 6 mm or more, and for example, 6 mm to 20 mm. The effective length of the cutting edge of the end mill is, for example, 10 mm to 60 mm.

A-2-3.端面加工之具體程序端面加工代表上可藉由一邊使螺旋銼刀之銼身部抵接工件W之外周面，一邊使螺旋銼刀與工件相對地移動來進行。可僅使螺旋銼刀移動，也可僅使工件移動，亦可使螺旋銼刀與工件兩者移動。藉由抵接工件之外周面的銼身部旋轉來進行摩擦，結果，該外周面會被粗化而可形成具有預定之面粗度Sdr的端面。藉由所述端面加工，可將偏光板之偏光件端面依循ISO 25178所得之面粗度Sdr設為11%以上。結果，可實現一種即使在如熱震試驗這種嚴酷環境下仍抑制得住裂痕發生之偏光板。螺旋銼刀之旋轉數S例如為800rpm~20000rpm，宜為4000rpm~15000rpm，較宜為5000rpm~10000rpm，更宜為5000rpm~8000rpm。螺旋銼刀之進給速度F會因應螺旋銼刀之直徑、旋轉數、所期望之面粗度Sdr而變化。螺旋銼刀之進給速度例如為200mm/分鐘~5000mm/分鐘，宜為300mm/分鐘~3000mm/分鐘，較宜為300mm/分鐘~1000mm/分鐘。旋轉數與進給速度之比S/F例如為10以上，宜為14以上，較宜為15以上，更宜為16以上。S/F若在所述範圍內，便可獲得一種即使在如熱震試驗這種嚴酷環境下仍更加抑制得住裂痕發生之偏光板。S/F之上限例如可為35。S/F若過大，切削時間會變長及/或會產生熱，故有發生黏結及/或端面變色(黃帶)之情形。此外，如後述，在形成異形時，有使螺旋銼刀形成異形時之進給速度為螺旋銼刀加工異形以外之部分(實質上為直線部)時之進給速度以下之情形，惟即便在所述情況下，藉由將S/F設為上述範圍，仍可於異形加工部獲得相同之效果。利用螺旋銼刀之端面加工可使螺旋銼刀以單端固定狀態來進行，亦可使螺旋銼刀以兩端固定狀態來進行。 A-2-3. Specific procedures for end face processing Typically, end surface processing can be performed by moving the spiral file relative to the workpiece while the shank of the spiral file is in contact with the outer peripheral surface of the workpiece W. Only the spiral file may be moved, only the workpiece may be moved, or both the spiral file and the workpiece may be moved. The friction is performed by the rotation of the shank portion abutting against the outer peripheral surface of the workpiece. As a result, the outer peripheral surface is roughened to form an end surface having a predetermined surface roughness Sdr. Through the end surface processing, the surface roughness Sdr of the polarizer end surface of the polarizing plate in accordance with ISO 25178 can be set to 11% or more. As a result, it is possible to realize a polarizing plate that suppresses the occurrence of cracks even under severe environments such as thermal shock tests. The rotation speed S of the spiral file is, for example, 800rpm~20000rpm, preferably 4000rpm~15000rpm, more preferably 5000rpm~10000rpm, more preferably 5000rpm~8000rpm. The feed speed F of the spiral file will vary according to the diameter of the spiral file, the number of rotations, and the desired surface roughness Sdr. The feed speed of the spiral file is, for example, 200 mm/min to 5000 mm/min, preferably 300 mm/min to 3000 mm/min, more preferably 300 mm/min to 1000 mm/min. The ratio S/F of the number of revolutions to the feed rate is, for example, 10 or more, preferably 14 or more, more preferably 15 or more, more preferably 16 or more. If the S/F is within the above range, a polarizing plate that is more resistant to cracking even in a severe environment such as a thermal shock test can be obtained. The upper limit of S/F may be 35, for example. If the S/F is too large, the cutting time will be longer and/or heat will be generated, so sticking and/or end surface discoloration (yellow band) may occur. In addition, as described later, when forming a special shape, the feed speed of the spiral file for forming the special shape may be lower than the feed speed of the spiral file for processing the part other than the special shape (substantially a straight part), but even in the above-mentioned In this case, by setting S/F within the above-mentioned range, the same effect can be obtained in the special-shaped processed part. The end surface processing of the spiral file can be carried out with the single-end fixed state of the spiral file, or can be carried out with the two-end fixed state of the spiral file.

利用螺旋銼刀之加工可藉由將前刀面72b側作為旋轉方向上游側之「一般加工」來進行，亦可藉由將後刀面72c側(刀的背面側)作為旋轉方向上游側之「刀背加工」來進行。若為「刀背加工」，即便在具有餘隙角之情況(刀尖72a之平坦面的寬度B為0時：餘隙角可為例如2°~25°)下，刀尖72a與工件之被加工(切削)面仍會成為以面相接之狀態，故即便在具有餘隙角之情況下，仍可獲得充分之裂痕抑制效果。「刀背加工」可藉由以下方式等來實現：例如將螺旋銼刀之旋轉方向反轉；或是使螺旋銼刀之旋轉方向與一般加工之情況相同，並將其安裝成與一般加工之情況相反。Machining with a spiral file can be performed by "general machining" in which the side of the rake face 72b is the upstream side in the direction of rotation, or by "processing" in which the side of the flank 72c (the back side of the knife) is the upstream side in the direction of rotation. tool back processing". In the case of "tool back machining", even if there is a clearance angle (when the width B of the flat surface of the tool nose 72a is 0: the clearance angle can be, for example, 2°~25°), the distance between the tool nose 72a and the workpiece is The machined (cut) surface will still be in a state of contact, so even in the case of a clearance angle, sufficient crack suppression effect can still be obtained. "Back processing" can be realized by the following methods: for example, reversing the rotation direction of the spiral file; or making the rotation direction of the spiral file the same as that of general processing, and installing it opposite to that of general processing.

利用螺旋銼刀之端面加工可對工件之外周面的全周進行，亦可對工件之外周面的一部分進行。圖6(a)及圖6(b)係概略俯視圖，係例示說明利用螺旋銼刀對工件之外周面的一部分進行端面加工時的加工部分。如圖所示，在一實施形態中，利用螺旋銼刀之端面加工可對工件W之外周面進行，所述外周面位在與偏光板所含偏光件之吸收軸方向A相交之方向。利用螺旋銼刀對工件之的外周面進行端面加工，且所述外周面係位在與偏光件之吸收軸方向相交之方向，便能具有以下優點：可抑制因熱震試驗等耐久性試驗而於偏光件發生裂痕之問題，同時可抑制偏光板在加工開始側與結束側之外觀變化(Sdr變化)。藉由抑制偏光板在加工開始側與結束側之外觀變化(Sdr變化)，便能抑制偏光件以外之保護層的變色或破裂(尤其是以環狀烯烴系樹脂構成之保護層之破裂)。例如，在保護層為薄膜型相位差板時，可抑制在熱震試驗中於相位差板發生裂痕。利用螺旋銼刀對工件之外周面的一部分進行端面加工時，關於工件之外周面之其以外之部分(代表上為與吸收軸方向A實質上平行之方向)，例如，可利用端銑刀進行端面加工。藉由組合利用螺旋銼刀之端面加工與利用端銑刀之端面加工，便可抑制偏光板中之保護層(尤其是以環狀烯烴系樹脂構成之保護層)之破裂。例如，在保護層為薄膜型相位差板且偏光件之吸收軸與相位差板之慢軸相交(例如正交)時，利用端銑刀對工件之外周面之其以外的部分(代表上為與吸收軸方向實質上平行之方向)進行端面加工，便可在熱震試驗等之耐久性試驗中抑制於相位差板發生裂痕。The end face processing with a spiral file can be performed on the entire circumference of the outer peripheral surface of the workpiece, or on a part of the outer peripheral surface of the workpiece. 6( a ) and FIG. 6( b ) are schematic plan views and illustrate the processed portion when the end surface processing is performed on a part of the outer peripheral surface of the workpiece with a helical file. As shown in the figure, in one embodiment, the end surface processing with a spiral file can be performed on the outer peripheral surface of the workpiece W, and the outer peripheral surface is located in a direction intersecting the absorption axis direction A of the polarizer included in the polarizer. Using a spiral file to process the outer peripheral surface of the workpiece, and the outer peripheral surface is located in a direction intersecting with the absorption axis direction of the polarizer can have the following advantages: it can suppress the damage caused by durability tests such as thermal shock tests. The problem of cracks in the polarizer can be solved, and at the same time, the appearance change (Sdr change) of the polarizer between the processing start side and the end side can be suppressed. By suppressing the change in appearance (Sdr change) between the processing start side and the end side of the polarizing plate, it is possible to suppress discoloration or cracking of the protective layer other than the polarizer (especially cracking of the protective layer made of cyclic olefin resin). For example, when the protective layer is a film-type retardation film, it is possible to suppress the occurrence of cracks in the retardation film in a thermal shock test. When using a helical file to process a part of the outer peripheral surface of the workpiece, for the other part of the outer peripheral surface of the workpiece (typically, a direction substantially parallel to the absorption axis direction A), for example, an end mill can be used for end facing processing. By combining the end surface processing using a spiral file and the end surface processing using an end mill, it is possible to suppress cracking of a protective layer (especially a protective layer made of a cyclic olefin resin) in a polarizing plate. For example, when the protective layer is a film-type retardation plate and the absorption axis of the polarizer intersects (for example, is perpendicular to) the slow axis of the retardation plate, the other parts of the outer peripheral surface of the workpiece (represented as The end surface processing in a direction substantially parallel to the absorption axis direction can suppress the occurrence of cracks in the phase difference plate in durability tests such as thermal shock tests.

在一實施形態中，如圖6(a)所示，利用螺旋銼刀之端面加工包含形成異形之步驟。異形之形狀可舉出可形成於外周面(外緣)之任意適當之形狀。具體例可舉將隅部去角成R形狀者、於俯視時呈凹部之形狀。凹部之代表例可舉近似船形之形狀、近似浴缸形狀之R形狀、V字缺口、U字缺口。形成異形時，螺旋銼刀形成異形時之進給速度為螺旋銼刀加工異形以外之部分(實質上為直線部)時之進給速度以下。藉由如此地調整進給速度，可抑制異形部分之裂痕。螺旋銼刀形成異形時之進給速度例如為，上述進給速度的10%~100%，宜為10%~80%，較宜為30%~75%，更宜為45%~65%。具體而言，螺旋銼刀形成異形時之進給速度例如為100mm/分鐘~3000mm/分鐘，宜為100mm/分鐘~1000mm/分鐘，較宜為300mm/分鐘~700mm/分鐘。In one embodiment, as shown in FIG. 6( a ), the end surface processing using a spiral file includes a step of forming a different shape. As the shape of the irregular shape, any appropriate shape that can be formed on the outer peripheral surface (outer edge) can be mentioned. A specific example may be a shape in which the corners are chamfered into an R shape, which is a concave shape when viewed from above. Representative examples of the concave portion include a boat-like shape, an R-shaped bathtub-like shape, a V-shaped notch, and a U-shaped notch. When forming a special shape, the feed speed of the spiral file when forming the special shape is lower than the feed speed when the spiral file processes the part other than the special shape (essentially a straight part). By adjusting the feed rate in this way, it is possible to suppress cracks in the irregular-shaped portion. The feed rate when the helical file forms the irregular shape is, for example, 10%~100% of the above feed rate, preferably 10%~80%, more preferably 30%~75%, more preferably 45%~65%. Specifically, the feed speed of the helical file when forming the irregular shape is, for example, 100 mm/min to 3000 mm/min, preferably 100 mm/min to 1000 mm/min, more preferably 300 mm/min to 700 mm/min.

在組合利用螺旋銼刀之端面加工與利用端銑刀之端面加工時，利用端銑刀進行之端面加工代表上係藉由一邊使端銑刀之切削刃抵接工件W之外周面，一邊使端銑刀與工件相對地移動來進行。可僅使端銑刀移動，也可僅使工件移動，亦可使端銑刀與工件兩者移動。藉由抵接工件之外周面的端銑刀旋轉來進行切削，結果該外周面會被粗化而可形成具有預定之面粗度Sdr的端面。利用端銑刀進行之端面加工代表上係在高旋轉數及低進給速度下進行。端銑刀之旋轉數例如為25000rpm以上。藉由使具有大直徑(例如如上述之6mm以上)之端銑刀以高旋轉數旋轉來切削，可形成具有預定之面粗度Sdr的端面。端銑刀之進給速度會因應端銑刀之直徑、旋轉數、所期望之面粗度Sdr而變化。端銑刀之進給速度例如可為300mm/分鐘~1000mm/分鐘。利用端銑刀進行之端面加工可令端銑刀以單端固定狀態來進行，亦可以兩端固定狀態來進行。When face machining using a helical file and face machining using an end mill are combined, the end mill using an end mill represents that the cutting edge of the end mill is brought into contact with the outer peripheral surface of the workpiece W while the end mill is brought into contact with the end mill. The milling cutter moves relative to the workpiece. Only the end mill may be moved, only the workpiece may be moved, or both the end mill and the workpiece may be moved. Cutting is performed by rotating the end mill that abuts on the outer peripheral surface of the workpiece, and as a result the outer peripheral surface is roughened to form an end surface having a predetermined surface roughness Sdr. Face machining with end mills typically takes place at high rotation speeds and low feed rates. The rotation speed of the end mill is, for example, 25000 rpm or more. By turning an end mill having a large diameter (for example, 6 mm or more as described above) at a high number of revolutions for cutting, an end face having a predetermined surface roughness Sdr can be formed. The feed rate of the end mill will vary according to the diameter of the end mill, the number of rotations, and the desired surface roughness Sdr. The feed speed of the end mill can be, for example, 300 mm/min to 1000 mm/min. The end face processing using the end mill can be carried out with the end mill fixed at one end or fixed at both ends.

利用螺旋銼刀(及因應需求利用端銑刀)進行端面加工前，亦可進行粗加工。粗加工代表上可使用端銑刀來進行。粗加工之條件如以上關於利用端銑刀進行端面加工之說明所述。粗加工代表上可對工件之外周面的全周進行。在有進行粗加工之情況下，可省略上述利用端銑刀進行之端面加工。Rough machining can also be performed before end machining with a helical file (and, if required, an end mill). Rough machining can be performed on behalf of end mills. The conditions for rough machining are as described above in the description of end face machining with an end mill. Rough machining can be performed on the entire circumference of the outer peripheral surface of the workpiece. In the case of rough machining, the above-mentioned end milling with an end mill can be omitted.

在一實施形態中，構成工件之偏光板之狀態為：於其中一側以可剝離之方式暫時黏附有表面保護薄膜，於另一側配置有黏著劑層，且於該黏著劑層上以可剝離之方式暫時黏附有分離件。此時，較宜為以使表面保護薄膜位於螺旋銼刀(及使用端銑刀時為端銑刀)之切削屑的排出方向來疊合偏光板而形成工件。亦即，當螺旋銼刀(及使用端銑刀時為端銑刀)為右刃右螺旋及左刃左螺旋時，可使表面保護薄膜位於上側來疊合偏光板而形成工件；當螺旋銼刀(及使用端銑刀時為端銑刀)為右刃左螺旋及左刃右螺旋時，可使表面保護薄膜位於下側來疊合偏光板而形成工件。若為所述構成，便可抑制表面保護薄膜之浮凸。結果可維持優異之外觀品質。此外，所謂右刃係指從上側(柄側)看去可在順時針旋轉時切削的構成；所謂左刃則係指從上側(柄側)看去可在逆時針旋轉時切削的構成。並且，所謂右螺旋係指刀尖從側邊看去沿右斜上方延伸的構成；所謂左螺旋則係指刀尖從側邊看去沿左斜上方延伸的構成。右刃右螺旋及左刃左螺旋之切削屑的排出方向為上方；右刃左螺旋及左刃右螺旋之切削屑的排出方向為下方。In one embodiment, the state of the polarizing plate constituting the workpiece is: a surface protection film is temporarily attached in a peelable manner on one side, an adhesive layer is arranged on the other side, and a detachable film is placed on the adhesive layer. The peeling method temporarily adheres the separator. At this time, it is preferable to form the workpiece by laminating the polarizing plate so that the surface protection film is positioned in the discharge direction of the cutting chips of the spiral file (and the end mill when the end mill is used). That is, when the spiral file (and the end mill when using the end mill) is a right-blade right-helix and a left-blade left-helix, the surface protection film can be placed on the upper side to laminate the polarizer to form a workpiece; when the spiral file ( And when using an end mill, it is an end mill) When the right blade is left helical and the left blade is right helical, the surface protection film can be placed on the lower side to laminate the polarizing plate to form a workpiece. According to such a structure, the embossing of a surface protection film can be suppressed. As a result, excellent appearance quality can be maintained. In addition, the so-called right edge refers to the configuration that can be cut when viewed from the upper side (shank side), and the so-called left edge refers to the configuration that can be cut when viewed from the upper side (shank side) when rotated counterclockwise. And, the so-called right-hand helix means that the blade tip extends obliquely upward and right when viewed from the side; The chip discharge direction of the right-handed and left-handed helix is upward; the discharge direction of the right-handed left-handed and left-handed helical chips is downward.

本發明實施形態中，藉由利用螺旋銼刀進行端面加工，相較於利用棒銼刀之端面加工，可縮小在最初階段加工之偏光件端面的Sdr(S)與在最後階段加工之偏光件端面的Sdr(E)之差。推測是因為螺旋銼刀會比棒銼刀能更顯著抑制加工最後階段的阻塞。差「Sdr(S)-Sdr(E)」代表上為3%以下，宜為2%以下，較宜為1%以下，更宜為0。例如圖6(a)及圖6(b)所示之例中，Sdr(S)係偏光板之一對規定外緣且互相對向之邊中，包含加工開始地點「S」之一邊的偏光件端面的面粗度；而Sdr(S)係偏光板之一對規定外緣且互相對向之邊中，包含加工結束地點「E」之一邊的偏光件端面的面粗度。在對外周面整體進行端面加工時，可令包含加工開始地點「S」之一邊的偏光件端面的面粗度為Sdr(S)，並令與包含加工開始地點「S」之一邊為對向的一邊，其偏光件端面的面粗度為Sdr(E)。此外，藉由利用螺旋銼刀的端面加工，偏光件端面之Sdr在整個外周(外緣)整體會實質上相同。In the embodiment of the present invention, by processing the end surface with a spiral file, it is possible to reduce the Sdr(S) of the end surface of the polarizer processed at the initial stage and that of the end surface of the polarizer processed at the last stage compared to the end surface processing with a rod file. Sdr(E) difference. This is presumed to be because helical files inhibit clogging in the final stages of processing significantly more than rod files. The difference "Sdr(S)-Sdr(E)" is generally less than 3%, preferably less than 2%, more preferably less than 1%, and more preferably 0. For example, in the example shown in Fig. 6(a) and Fig. 6(b), Sdr(S) is the polarized light of the side that includes the processing start point "S" among a pair of predetermined outer edges of the polarizer and facing each other. The surface roughness of the end surface of the component; and Sdr (S) is the surface roughness of the end surface of the polarizer on the side that includes the processing end point "E" among the sides facing each other at the specified outer edge of one of the polarizers. When processing the end surface of the entire outer peripheral surface, the surface roughness of the end surface of the polarizer on the side including the processing start point "S" can be set to Sdr(S), and the side including the processing start point "S" can be opposite On one side, the surface roughness of the end face of the polarizer is Sdr(E). In addition, the Sdr of the end surface of the polarizer is substantially the same over the entire outer circumference (outer edge) by processing the end surface with a spiral file.

B.偏光板 B-1.偏光板之整體構成本發明實施形態亦包含藉由上述A項所載之製造方法來獲得之偏光板。圖7係藉由本發明實施形態之製造方法所獲得之偏光板的概略截面圖。圖式例之偏光板100具有：偏光件10；與配置於偏光件10之一側(圖式例中為與影像顯示面板相反側)的保護層(外側保護層)20。因應目的，亦可於偏光件10之與保護層20相反側設置另一保護層(內側保護層：未圖示)。又，因應目的，亦可僅設置內側保護層。就實際應用而言，於偏光板100上，可設置黏著劑層(未圖示)來作為與保護層20相反側之最外層，且可貼合於影像顯示面板。偏光板可作為影像顯示裝置之視辨側偏光板來使用，亦可作為背面側偏光板來使用。 B. Polarizer B-1. Overall composition of polarizing plate Embodiments of the present invention also include polarizing plates obtained by the manufacturing method described in item A above. Fig. 7 is a schematic cross-sectional view of a polarizing plate obtained by the manufacturing method according to the embodiment of the present invention. The polarizing plate 100 of the illustrated example has: a polarizer 10 ; and a protective layer (outer protective layer) 20 disposed on one side of the polarizer 10 (in the illustrated example, the side opposite to the image display panel). Depending on the purpose, another protective layer (inner protective layer: not shown) may also be disposed on the opposite side of the polarizer 10 to the protective layer 20 . Also, depending on the purpose, only the inner protective layer may be provided. In terms of practical application, an adhesive layer (not shown) can be provided on the polarizing plate 100 as the outermost layer opposite to the protective layer 20 , and can be attached to the image display panel. The polarizing plate can be used as a viewing-side polarizing plate of an image display device, and can also be used as a back-side polarizing plate.

本發明實施形態中，如上述A-2項所說明，偏光件10端面之面粗度Sdr為11%以上，宜為12%以上，較宜為13%以上，更宜為14%以上。Sdr之上限如上述例如可為40%。面粗度Sdr若在所述範圍內，便可獲得一種即使在如熱震試驗這種嚴酷環境下(代表上為溫度變化劇烈之環境下)仍抑制得住裂痕發生之偏光板。本發明實施形態中，進而，在偏光板之一對規定外緣且互相對向之邊中，其中一邊的偏光件端面之Sdr(S)與另一邊的偏光件端面之面粗度Sdr(E)代表上係滿足下述關係。 Sdr(S)-Sdr(E)≦3% 亦即，如上述A-2-3項所說明，藉由利用螺旋銼刀進行端面加工，可縮小最初階段加工之偏光件端面的Sdr(S)與最後階段加工之偏光件端面的Sdr(E)之差。差「Sdr(S)-Sdr(E)」宜為2%以下，較宜為1%以下，更宜為0。 In the embodiment of the present invention, as described in item A-2 above, the surface roughness Sdr of the end surface of the polarizer 10 is at least 11%, preferably at least 12%, more preferably at least 13%, and more preferably at least 14%. The upper limit of Sdr may be 40% as mentioned above, for example. If the surface roughness Sdr is within the above-mentioned range, a polarizing plate that suppresses the occurrence of cracks can be obtained even in a severe environment such as a thermal shock test (typically, an environment where the temperature changes rapidly). In the embodiment of the present invention, furthermore, in one pair of predetermined outer edges of the polarizer facing each other, the Sdr(S) of the end surface of the polarizer on one side and the surface roughness Sdr(E) of the end surface of the polarizer on the other side ) means that the upper line satisfies the following relationship. Sdr(S)-Sdr(E)≦3% That is, as described in the above item A-2-3, by processing the end surface with a spiral file, the Sdr(S) of the end surface of the polarizer processed in the initial stage and the Sdr(E) of the end surface of the polarizer processed in the final stage can be reduced Difference. The difference "Sdr(S)-Sdr(E)" is preferably 2% or less, more preferably 1% or less, and more preferably 0.

偏光板在一實施形態中，於偏光件端面附近形成有消偏光區域。消偏光區域宜形成在偏光件端面起算並往面方向內側8µm~500µm為止之位置。消偏光區域係形成在偏光件端面起算並往面方向內側較宜35µm以上之位置為止、更宜50µm以上之位置為止、尤宜70µm以上之位置為止。另一方面，消偏光區域係形成在偏光件端面起算並往面方向內側較宜400µm以下之位置為止、更宜250µm以下之位置為止、更宜110µm以下之位置為止。藉由將消偏光區域形成在偏光件端面起算並往面方向內側8µm以上(較宜為35µm以上)之位置為止，可更抑制偏光件在嚴酷環境下之裂痕。另一方面，消偏光區域之形成位置若是偏光件端面起算並往面方向內側500µm為止，則將偏光板應用於影像顯示裝置時，並不會對顯示特性帶來實質上不良的影響。形成所述消偏光區域所帶來之效果乃是為了實現上述預定面粗度Sdr而粗化偏光件端面後所獲得之見解，而為不可預期之優異效果。In one embodiment of the polarizer, a depolarization region is formed near the end face of the polarizer. The depolarization area should be formed at the position from the end face of the polarizer to 8µm~500µm inward in the plane direction. The depolarization area is formed from the end face of the polarizer to a position more than 35 µm inward in the plane direction, more preferably 50 µm or more, especially 70 µm or more. On the other hand, the depolarization region is formed from the end face of the polarizer to a position preferably less than 400 µm, more preferably less than 250 µm, and more preferably less than 110 µm inward in the plane direction. By forming the depolarization region from the end face of the polarizer to a position of more than 8 µm (preferably more than 35 µm) inward in the plane direction, cracks of the polarizer in harsh environments can be further suppressed. On the other hand, if the formation position of the depolarization region is 500 μm inward from the end surface of the polarizer, the display characteristics will not be substantially affected when the polarizer is applied to an image display device. The effect brought by the formation of the depolarization region is the insight obtained by roughening the end face of the polarizer in order to realize the above-mentioned predetermined surface roughness Sdr, and it is an unexpected excellent effect.

偏光板在熱震試驗中發生之裂痕的平均長度宜為400µm以下，較宜為300µm以下，更宜為200µm以下，尤宜為150µm以下，該熱震試驗係例如在-40℃下保持30分鐘後在85℃下保持30分鐘，並反覆前述操作100個循環者。該裂痕的平均長度越小越好，例如可為零。當然不發生裂痕本身為理想，但假設發生了裂痕，則相較於發生多個短裂痕，發生預定比率之預定長度以上之裂痕大多會造成偏光板整體之破裂、缺口等情況。理論上雖尚不明確，但根據本發明之實施形態，藉由將偏光件端面之面粗度Sdr設為預定值以上，可抑制裂痕本身之發生，而即便在發生了裂痕之情況下，仍可縮小預定長度以上之裂痕之比率，使平均長度落在上述範圍內。結果，可抑制偏光板整體之破裂、缺口等。The average length of the cracks in the polarizing plate during the thermal shock test is preferably less than 400µm, more preferably less than 300µm, more preferably less than 200µm, and especially preferably less than 150µm. The thermal shock test is maintained at -40°C for 30 minutes Then keep it at 85°C for 30 minutes, and repeat the above operation for 100 cycles. The average length of the cracks is preferably as small as possible, and may be zero, for example. Of course, it is ideal that no cracks occur, but if cracks occur, cracks with a predetermined ratio of a predetermined length or more often cause cracks or chipping of the entire polarizing plate than a plurality of short cracks. Although it is not clear in theory, according to the embodiment of the present invention, by setting the surface roughness Sdr of the end surface of the polarizer to be more than a predetermined value, the occurrence of the crack itself can be suppressed, and even when a crack occurs, it is still The ratio of cracks with a predetermined length or more can be reduced so that the average length falls within the above-mentioned range. As a result, cracks, chipping, etc. of the entire polarizing plate can be suppressed.

偏光板之長邊的長度宜為200mm以上，較宜為250mm以上。長邊的長度之上限無特別限定，例如為2000mm以下，且例如為1500mm以下，且例如為1000mm以下。本說明書中所謂「偏光板之長邊」，在偏光板為矩形時如文字所述係指長邊，例如為橢圓形時係指長徑，而在不定形(例如對應於汽車之儀表盤之形狀)時，係指最長部分之長度。偏光板為矩形時，短邊的長度宜為50mm以上，較宜為100mm以上。短邊的長度之上限無特別限定，例如為1500mm以下，且例如為1000mm以下，且例如為500mm以下。本發明人等發現預定尺寸以上之偏光板在熱震試驗時容易發生裂痕一事，並藉由本發明實施形態之構成解決了該課題。The length of the long side of the polarizing plate is preferably at least 200 mm, more preferably at least 250 mm. The upper limit of the length of the long side is not particularly limited, and is, for example, 2000 mm or less, for example, 1500 mm or less, and for example, 1000 mm or less. The so-called "long side of the polarizer" in this specification refers to the long side as described in the text when the polarizer is rectangular, for example, it refers to the long diameter when it is elliptical, and when it is indeterminate (such as corresponding to the dashboard of a car) shape), it refers to the length of the longest part. When the polarizing plate is rectangular, the length of the short side is preferably not less than 50 mm, more preferably not less than 100 mm. The upper limit of the length of the short side is not particularly limited, and is, for example, 1500 mm or less, and for example, 1000 mm or less, and for example, 500 mm or less. The inventors of the present invention have found that cracks are likely to occur in a polarizing plate having a predetermined size or more during a thermal shock test, and solved this problem by the constitution of an embodiment of the present invention.

在一實施形態中，偏光板如上述A-2-3項所說明(如圖6(a)及圖6(b)所示)具有矩形以外之異形。就異形的形狀而言，如上述，可舉能形成於外周面(外緣)之任意適當之形狀(例如，去角形狀、俯視時成為凹部之形狀)。以偏光板來說，容易於所述異形(異形加工部)發生裂痕，但根據本發明實施形態，可抑制所述裂痕。偏光板除了於外周面(外緣)具有利用螺旋銼刀之端面加工所形成之異形外，亦可於任意適當之位置具有例如貫通孔。In one embodiment, the polarizing plate has a shape other than a rectangle as described in item A-2-3 above (as shown in FIG. 6( a ) and FIG. 6( b ). As the irregular shape, as mentioned above, any appropriate shape (for example, a chamfered shape, a shape that becomes a concave portion in plan view) that can be formed on the outer peripheral surface (outer edge) can be mentioned. In the case of a polarizing plate, cracks are likely to occur in the irregular shape (deformation processed part), but according to the embodiment of the present invention, the cracks can be suppressed. In addition to having a special shape formed by end surface processing with a spiral file on the outer peripheral surface (outer edge), the polarizing plate may also have, for example, a through hole at any appropriate position.

偏光板如同上述，即使在如熱震試驗這種嚴酷環境下(代表上為溫度變化劇烈之環境下)仍抑制得住裂痕發生。因此，偏光板可適宜用於容易被放置於嚴酷環境下之車載用途的影像顯示裝置。此外，上述記載並不會妨礙偏光板用於車載用途以外之用途自是不言而喻。As mentioned above, the polarizer can suppress the occurrence of cracks even in severe environments such as thermal shock tests (typically, environments with severe temperature changes). Therefore, the polarizing plate can be suitably used for an in-vehicle image display device that is easily placed in a harsh environment. In addition, it is self-evident that the above description does not prevent the use of the polarizing plate in applications other than automotive applications.

B-2.偏光件偏光件代表上係以包含二色性物質之PVA系樹脂薄膜構成。例如，形成偏光件之樹脂薄膜可為單層樹脂薄膜、亦可為二層以上之積層體。 B-2. Polarizer The polarizer is typically composed of a PVA-based resin film containing a dichroic material. For example, the resin film forming the polarizer may be a single-layer resin film or a laminate of two or more layers.

由單層樹脂薄膜構成之偏光件的具體例，可舉：利用碘或二色性染料等二色性物質對聚乙烯醇(PVA)系薄膜、部分縮甲醛化PVA系薄膜、乙烯-乙酸乙烯酯共聚物系部分皂化薄膜等親水性高分子薄膜進行染色處理及延伸處理而成者；PVA之脫水處理物或聚氯乙烯之脫鹽酸處理物等多烯系定向薄膜等。由光學特性優異來看，宜使用將PVA系薄膜以碘染色並進行單軸延伸所得之偏光件。Specific examples of polarizers composed of a single-layer resin film include polyvinyl alcohol (PVA)-based films, partially formalized PVA-based films, ethylene-vinyl acetate Ester copolymers are partially saponified films and other hydrophilic polymer films that are dyed and stretched; polyene-based oriented films such as dehydrated PVA or dehydrochlorinated polyvinyl chloride. In view of excellent optical properties, it is preferable to use a polarizer obtained by dyeing a PVA film with iodine and uniaxially stretching it.

上述利用碘進行之染色，例如可藉由將PVA系薄膜浸漬於碘水溶液中來進行。上述單軸延伸之延伸倍率宜為3~7倍。延伸可在染色處理後進行，亦可邊染色邊進行。又，亦可延伸後再染色。可視需要，對PVA系薄膜施行膨潤處理、交聯處理、洗淨處理、乾燥處理等。例如，在染色前將PVA系薄膜浸漬於水中進行水洗，藉此，不僅可洗淨PVA系薄膜表面之污垢或抗黏結劑，還可使PVA系薄膜膨潤，從而防止染色不均等情況。The above-mentioned dyeing with iodine can be performed, for example, by immersing a PVA-based film in an iodine aqueous solution. The elongation ratio of the above-mentioned uniaxial stretching is preferably 3 to 7 times. Elongation can be performed after dyeing or while dyeing. In addition, dyeing after stretching is also possible. Swelling treatment, crosslinking treatment, washing treatment, drying treatment, etc. may be performed on the PVA-based film as necessary. For example, before dyeing, the PVA-based film is immersed in water for washing. In this way, not only the dirt and anti-adhesive agent on the surface of the PVA-based film can be cleaned, but also the PVA-based film can be swelled to prevent uneven dyeing.

作為使用積層體而得之偏光件的具體例可舉：使用樹脂基材與積層在該樹脂基材之PVA系樹脂層(PVA系樹脂薄膜)之積層體、或者是使用樹脂基材與塗佈形成於該樹脂基材之PVA系樹脂層之積層體而得之偏光件。使用樹脂基材與塗佈形成於該樹脂基材之PVA系樹脂層之積層體而得之偏光件，例如可藉由以下步驟來製作：將PVA系樹脂溶液塗佈於樹脂基材並使其乾燥，於樹脂基材上形成PVA系樹脂層，而獲得樹脂基材與PVA系樹脂層之積層體；及，將該積層體延伸及染色，以將PVA系樹脂層製成偏光件。本實施形態中，宜於樹脂基材之單側形成含鹵化物與聚乙烯醇系樹脂之聚乙烯醇系樹脂層。延伸在代表上包含使積層體浸漬於硼酸水溶液中來延伸。並且視需要，延伸可更包含在硼酸水溶液中進行延伸前，在高溫(例如95℃以上)下將積層體進行空中延伸。並且，在本實施形態中，宜將積層體供於乾燥收縮處理，該乾燥收縮處理係將積層體一邊往長邊方向輸送一邊加熱，藉此使其於寬度方向收縮2%以上。代表上，本實施形態之製造方法包含對積層體依序施行空中輔助延伸處理、染色處理、水中延伸處理及乾燥收縮處理。藉由導入輔助延伸，即便是在將PVA塗佈於熱塑性樹脂上之情況下仍可提高PVA之結晶性，而可達成高光學特性。又，同時事先提高PVA之定向性，可在後續的染色步驟或延伸步驟中浸漬於水中時，防止PVA之定向性降低或溶解等問題，而可達成高光學特性。並且，將PVA系樹脂層浸漬於液體中時，相較於PVA系樹脂層不含鹵化物之情況，更可抑制聚乙烯醇分子之定向紊亂及定向性降低。藉此，可提升經由染色處理及水中延伸處理等將積層體浸漬於液體中來進行的處理步驟而得之偏光件的光學特性。並且，透過乾燥收縮處理使積層體於寬度方向收縮，可提升光學特性。所得樹脂基材/偏光件之積層體可直接使用(即，亦可將樹脂基材作為偏光件之保護層)，亦可從樹脂基材/偏光件之積層體剝離樹脂基材並於該剝離面積層符合目的之任意適當的保護層後來使用。所述偏光件之製造方法之詳細內容記載於例如日本專利特開2012-73580號公報、日本專利第6470455號中。本說明書中即引用該等公報整體之記載作為參考。Specific examples of a polarizer using a laminate include a laminate using a resin substrate and a PVA-based resin layer (PVA-based resin film) laminated on the resin substrate, or a laminate using a resin substrate and a coating. A polarizer obtained by a laminate of PVA-based resin layers formed on the resin substrate. A polarizer obtained by using a laminate of a resin base material and a PVA-based resin layer coated and formed on the resin base material can be produced, for example, by the following steps: apply a PVA-based resin solution to the resin base material and make it drying, forming a PVA-based resin layer on the resin substrate to obtain a laminate of the resin substrate and the PVA-based resin layer; and stretching and dyeing the laminate to make the PVA-based resin layer into a polarizer. In this embodiment, it is preferable to form a polyvinyl alcohol-based resin layer containing a halide and a polyvinyl alcohol-based resin on one side of the resin substrate. Extending typically includes extending the laminate by immersing it in an aqueous solution of boric acid. If necessary, the stretching may further include stretching the laminate in air at a high temperature (for example, 95° C. or higher) before stretching in a boric acid aqueous solution. In addition, in this embodiment, it is preferable to subject the laminated body to drying shrinkage treatment in which the laminated body is heated while being transported in the longitudinal direction, thereby shrinking the laminated body by 2% or more in the width direction. Typically, the manufacturing method of this embodiment includes sequentially performing aerial assisted stretching, dyeing, underwater stretching, and drying shrinkage on the laminate. By introducing auxiliary stretching, even when PVA is coated on a thermoplastic resin, the crystallinity of PVA can be improved, and high optical characteristics can be achieved. Also, at the same time, by improving the orientation of PVA in advance, it is possible to prevent problems such as decrease in orientation or dissolution of PVA when immersed in water in the subsequent dyeing step or stretching step, and achieve high optical characteristics. In addition, when the PVA-based resin layer is immersed in a liquid, the disorder of the polyvinyl alcohol molecules and the decrease in orientation can be suppressed more than when the PVA-based resin layer does not contain a halide. Thereby, the optical characteristic of the polarizer obtained through the process step of immersing a laminate in liquid, such as dyeing process and underwater stretching process, can be improved. In addition, the optical properties can be improved by shrinking the laminate in the width direction through drying shrinkage treatment. The laminate of the obtained resin base material/polarizer can be used directly (that is, the resin base material can also be used as a protective layer of the polarizer), or the resin base material can be peeled off from the laminate of the resin base material/polarizer. Any suitable protective layer suitable for the purpose of the surface layer is subsequently used. The details of the manufacturing method of the polarizer are described in, for example, Japanese Patent Laid-Open No. 2012-73580 and Japanese Patent No. 6470455. The entire contents of these publications are incorporated herein by reference.

偏光件之厚度宜為20µm以下，較宜為1µm~15µm，更宜為3µm~12µm，尤宜為3µm~10µm。偏光件之厚度若在所述範圍內，便可良好地抑制加熱時之捲曲，及可獲得良好的加熱時之外觀耐久性。The thickness of the polarizer should be less than 20µm, more preferably 1µm~15µm, more preferably 3µm~12µm, especially 3µm~10µm. If the thickness of the polarizer is within the above-mentioned range, curling during heating can be well suppressed, and good appearance durability during heating can be obtained.

偏光件宜在波長380nm~780nm之任一波長下顯示吸收二色性。偏光件之單體透射率宜為41.5%~46.0%，較宜為43.0%~46.0%，更宜為44.5%~46.0%。偏光件之偏光度宜為97.0%以上，較宜為99.0%以上，更宜為99.9%以上。The polarizer should exhibit absorption dichroism at any wavelength between 380nm and 780nm. The single transmittance of the polarizer is preferably 41.5%~46.0%, more preferably 43.0%~46.0%, more preferably 44.5%~46.0%. The degree of polarization of the polarizer should be above 97.0%, more preferably above 99.0%, more preferably above 99.9%.

B-3.保護層外側保護層20及內側保護層(在有存在內側保護層時)各自係以可作為偏光件之保護層來使用之任意適當的薄膜形成。作為成為該薄膜之主成分的材料之具體例，可列舉：三醋酸纖維素(TAC)等之纖維素系樹脂、或聚酯系、聚乙烯醇系、聚碳酸酯系、聚醯胺系、聚醯亞胺系、聚醚碸系、聚碸系、聚苯乙烯系、環狀烯烴系(例如聚降𦯉烯系)、聚烯烴系、(甲基)丙烯酸系、乙酸酯系等之透明樹脂等。又，亦可舉(甲基)丙烯酸系、胺甲酸酯系、(甲基)丙烯酸胺甲酸酯系、環氧系、聚矽氧系等之熱硬化型樹脂或紫外線硬化型樹脂等。其他還可舉例如矽氧烷系聚合物等玻璃質系聚合物。又，亦可使用日本專利特開2001-343529號公報(WO01/37007)中記載之聚合物薄膜。作為該薄膜之材料，例如可使用含有在側鏈具有取代或非取代之醯亞胺基之熱塑性樹脂、及在側鏈具有取代或非取代之苯基以及腈基之熱塑性樹脂的樹脂組成物，可舉例如具有由異丁烯與N-甲基馬來醯亞胺構成之交替共聚物及丙烯腈-苯乙烯共聚物的樹脂組成物。該聚合物薄膜例如可為上述樹脂組成物之擠製成形物。保護層宜以TAC、環狀烯烴系樹脂或(甲基)丙烯酸系樹脂之薄膜構成。 B-3. Protective layer Each of the outer protective layer 20 and the inner protective layer (when there is an inner protective layer) is formed of any appropriate film that can be used as a protective layer of a polarizer. Specific examples of the material used as the main component of the film include cellulose-based resins such as cellulose triacetate (TAC), polyester-based, polyvinyl alcohol-based, polycarbonate-based, polyamide-based, Polyimide-based, polyether-based, polystyrene-based, polystyrene-based, cyclic olefin-based (such as polynorolefin-based), polyolefin-based, (meth)acrylic-based, acetate-based, etc. Transparent resin, etc. Further, (meth)acrylic, urethane, (meth)acrylate urethane, epoxy, polysiloxane and other thermosetting resins or ultraviolet curable resins may also be mentioned. Other examples include glassy polymers such as siloxane polymers. Moreover, the polymer film described in Unexamined-Japanese-Patent No. 2001-343529 (WO01/37007) can also be used. As the material of the film, for example, a resin composition containing a thermoplastic resin having a substituted or unsubstituted imide group in the side chain, and a thermoplastic resin having a substituted or unsubstituted phenyl group and a nitrile group in the side chain can be used, Examples thereof include a resin composition having an alternating copolymer of isobutylene and N-methylmaleimide and an acrylonitrile-styrene copolymer. The polymer film can be, for example, an extruded product of the above-mentioned resin composition. The protective layer is preferably composed of a thin film of TAC, cyclic olefin resin or (meth)acrylic resin.

偏光板作為視辨側偏光板使用時，外側保護層亦可視需要施行有硬塗處理、抗反射處理、抗黏處理、防眩處理等表面處理。並且/或者，外側保護層亦可視需求施行有用以改善透過偏光太陽眼鏡視辨時之視辨性的處理(代表上為賦予(橢)圓偏光機能、賦予超高相位差)。藉由施行所述處理，即使透過偏光太陽眼鏡等偏光透鏡視辨顯示畫面時，仍可實現優異的視辨性。因此，偏光板及附相位差層之偏光板亦可適宜用於可用於戶外之影像顯示裝置。When the polarizer is used as a polarizer on the viewing side, the outer protective layer can also be treated with surface treatment such as hard coating, anti-reflection, anti-sticking, and anti-glare as required. And/or, the outer protective layer may also be treated to improve visibility through polarized sunglasses (typically, imparting (elliptical) polarizing function, imparting ultra-high retardation) as required. By performing such processing, excellent visibility can be realized even when a display screen is viewed through polarized lenses such as polarized sunglasses. Therefore, the polarizing plate and the polarizing plate with a retardation layer can also be suitably used in image display devices that can be used outdoors.

外側保護層之厚度宜為10µm~50µm，較宜為15µm~35µm。此外，施行有表面處理時，外側保護層之厚度係包含表面處理層之厚度的厚度。The thickness of the outer protective layer is preferably 10µm~50µm, more preferably 15µm~35µm. In addition, when surface treatment is applied, the thickness of the outer protective layer includes the thickness of the surface treatment layer.

內側保護層(在有存在內側保護層時)在一實施形態中宜在光學上為各向同性。本說明書中，「在光學上為各向同性」意指面內相位差Re(550)為0nm~10nm，且厚度方向之相位差Rth(550)為-10nm~+10nm。另一保護層之厚度宜為5µm~80µm，較宜為10µm~40µm，更宜為10µm~30µm。本發明實施形態中可適宜省略內側保護層。In one embodiment, the inner protective layer (when there is an inner protective layer) is preferably optically isotropic. In this specification, "being optically isotropic" means that the retardation Re(550) in the plane is 0nm~10nm, and the retardation Rth(550) in the thickness direction is -10nm~+10nm. The thickness of the other protective layer is preferably 5µm~80µm, more preferably 10µm~40µm, more preferably 10µm~30µm. In the embodiments of the present invention, the inner protective layer may be omitted as appropriate.

C.附相位差層之偏光板使偏光板與相位差層一體化，可構成附相位差層之偏光板。可設於附相位差層之偏光板中的相位差層之數量、光學特性(例如折射率特性、面內相位差、Nz係數、光彈性係數)、組合、配置位置等可按目的適當設定。例如，附相位差層之偏光板亦可從偏光板側起依序包含有第1相位差層及第2相位差層。第1相位差層例如可為折射率特性展現nx＞ny＞nz之關係的所謂負B板；第2相位差層例如可為折射率特性展現nz＞nx＞ny之關係的所謂正B板。此時，第1相位差層亦可兼作偏光件之內側保護層。 C. Polarizing plate with retardation layer The polarizer and the phase difference layer are integrated to form a polarizer with a phase difference layer. The number of retardation layers, optical characteristics (such as refractive index characteristics, in-plane retardation, Nz coefficient, photoelastic coefficient), combination, arrangement position, etc. of the retardation layer that can be provided in the polarizing plate with retardation layer can be appropriately set according to the purpose. For example, a polarizing plate with a retardation layer may include a first retardation layer and a second retardation layer in order from the polarizing plate side. The first retardation layer can be, for example, a so-called negative B plate whose refractive index characteristic exhibits the relationship of nx>ny>nz; the second retardation layer can, for example, be a so-called positive B plate whose refractive index characteristic exhibits the relationship of nz>nx>ny. In this case, the first retardation layer may also serve as the inner protective layer of the polarizer.

附相位差層之偏光板亦可更包含有其他光學機能層。可設於附相位差層之偏光板中的光學機能層之種類、特性、數量、組合、配置位置等可視目的適當設定。例如，附相位差層之偏光板亦可更具有導電層或附導電層之各向同性基材。在設置導電層或附導電層之各向同性基材時，附相位差層之偏光板可應用於在影像顯示面板與偏光板之間組入有觸控感測器之所謂內觸控面板型輸入顯示裝置。The polarizing plate with retardation layer may further include other optical functional layers. The type, characteristics, quantity, combination, arrangement position, etc. of the optical functional layers that can be provided in the polarizing plate with a retardation layer can be appropriately set depending on the purpose. For example, the polarizing plate with a retardation layer may further have a conductive layer or an isotropic substrate with a conductive layer. When a conductive layer or an isotropic substrate with a conductive layer is provided, the polarizer with a retardation layer can be applied to the so-called inner touch panel type input with a touch sensor integrated between the image display panel and the polarizer display device.

實施例以下，藉由實施例來具體說明本發明，惟本發明不受該等實施例所限。各特性之測定方法如以下所述。此外，只要無特別註記，實施例及比較例中之「份」及「%」即為重量基準。 Example Hereinafter, the present invention will be described in detail by means of examples, but the present invention is not limited by these examples. The measuring method of each characteristic is as follows. In addition, "parts" and "%" in Examples and Comparative Examples are based on weight unless otherwise noted.

(1)厚度 10µm以下的厚度係使用干涉膜厚計(大塚電子公司製，製品名「MCPD-3000」)進行測定。大於10µm的厚度係使用數位測微器(Anritsu公司製，產品名「KC-351C」)進行測定。 (2)面粗度Sdr 依循ISO 25178之「非接觸式(光探針)」評估方法進行測定。具體而言，係使用雷射顯微鏡(Olympus公司製，製品名「LEXT OLS 4000」)，測定實施例、及比較例所得附相位差層之偏光板中之偏光件之端面的面粗度。以將平坦面設為100%時之表面積的增加率(%)算出面粗度Sdr。面粗度係針對下述3點進行測定：加工開始地點附近、凹部之直線部之中央部及加工結束地點附近。令加工開始地點附近之偏光件端面的面粗度為Sdr(S)、且令加工結束地點附近之偏光件端面的面粗度為Sdr(E)。又，令凹部之直線部之中央部的偏光件端面的面粗度為「凹部中央之Sdr」。 (3)裂痕將實施例及比較例所得附相位差層之偏光板透過丙烯酸系黏著劑層貼附於玻璃板(厚度1.1mm)，做成試驗樣品。將該試驗樣品供於熱震試驗，並藉由光學顯微鏡(倍率5倍)觀察每100個循環之裂痕發生狀態，按以下基準進行評估，該熱震試驗係在-40℃下保持30分鐘後在85℃下保持30分鐘，並反覆前述操作400個循環者。 ○(良好)：無發生裂痕、或最大之裂痕小於500µm △(可容許)：雖有發生些許最大為500µm以上之裂痕，但幾乎無發生裂痕 ×(不良)：發生多個最大為500µm以上之裂痕 (4)光澤度針對實施例及比較例所得附相位差層之偏光板，在積層為工件之狀態下，使用光澤度計(Gloss Checker)(SATOTECH公司製型號「MJ-GM26」)測定光澤度。 (1) Thickness The thickness of 10 µm or less was measured using an interference film thickness meter (manufactured by Otsuka Electronics Co., Ltd., product name "MCPD-3000"). The thickness of more than 10 µm was measured using a digital micrometer (manufactured by Anritsu Corporation, product name "KC-351C"). (2) Surface roughness Sdr Measured in accordance with the ISO 25178 "non-contact (optical probe)" evaluation method. Specifically, using a laser microscope (manufactured by Olympus, product name "LEXT OLS 4000"), the surface roughness of the end surface of the polarizer in the polarizing plate with a retardation layer obtained in Examples and Comparative Examples was measured. The surface roughness Sdr was calculated as the rate of increase (%) of the surface area when the flat surface was assumed to be 100%. The surface roughness is measured at the following 3 points: the vicinity of the processing start point, the central part of the straight line portion of the concave part, and the vicinity of the processing end point. Let the surface roughness of the end surface of the polarizer near the processing start point be Sdr(S), and let the surface roughness of the polarizer end surface near the processing end point be Sdr(E). In addition, the surface roughness of the polarizer end surface at the central portion of the linear portion of the concave portion is defined as “Sdr at the center of the concave portion”. (3) Cracks The polarizing plates with retardation layers obtained in Examples and Comparative Examples were attached to a glass plate (thickness 1.1 mm) through an acrylic adhesive layer to make a test sample. The test sample was subjected to a thermal shock test, and the state of crack occurrence per 100 cycles was observed by an optical microscope (magnification 5 times), and evaluated according to the following criteria. The thermal shock test was maintained at -40°C for 30 minutes Keep at 85°C for 30 minutes, and repeat the above operation for 400 cycles. ○ (Good): No cracks, or the largest crack is less than 500µm △(Admissible): There are some cracks with a maximum size of 500µm or more, but almost no cracks × (Poor): Multiple cracks with a maximum of 500µm or more occurred (4) Gloss For the polarizing plates with retardation layers obtained in Examples and Comparative Examples, the gloss was measured using a Gloss Checker (model "MJ-GM26" manufactured by SATOTECH Corporation) in the state of lamination as a workpiece.

[實施例1] 1.偏光件之製作將厚度45μm的聚乙烯醇薄膜在速度比不同之輥間，於30℃、0.3%濃度的碘溶液中染色1分鐘並延伸達3倍為止。之後，一邊在60℃且包含4%濃度之硼酸、10%濃度之碘化鉀的水溶液中浸漬0.5分鐘，一邊進行延伸至總延伸倍率達6倍為止。接著，於30℃且包含1.5%濃度之碘化鉀水溶液中浸漬10秒鐘藉此洗淨後，在50℃下進行4分鐘乾燥，而獲得厚18μm之偏光件。 [Example 1] 1. Production of polarizer A polyvinyl alcohol film with a thickness of 45 μm is dyed in a 0.3% iodine solution at 30°C between rollers with different speed ratios for 1 minute and stretched until it reaches 3 times. Thereafter, while dipping in an aqueous solution containing 4% boric acid and 10% potassium iodide at 60° C. for 0.5 minutes, stretching was performed until the total stretching ratio reached 6 times. Next, after immersing in 30 degreeC and 1.5% potassium iodide aqueous solution for 10 seconds to wash, it dried at 50 degreeC for 4 minutes, and obtained the polarizer with thickness 18 micrometers.

2.附相位差層之偏光板之製作於上述所得偏光件之一面藉由聚乙烯醇系接著劑貼合了HC-TAC薄膜(厚度49µm)。此外，HC-TAC薄膜係於三醋酸纖維素(TAC)薄膜(厚度40µm)上形成有硬塗(HC)層(厚度9µm)之薄膜，且以TAC薄膜在偏光件側來貼合。並於偏光件之另一面依序貼合環狀烯烴系薄膜(折射率特性：nx＞ny＞nz，面內相位差：116nm)作為第1相位差層及改質聚乙烯薄膜(折射率特性：nz＞nx＞ny，面內相位差：35nm)作為第2相位差層。貼合係使用紫外線硬化型接著劑。此外，係以使第1相位差層之慢軸相對於偏光件之吸收軸呈0°、第2相位差層之慢軸相對於偏光件之吸收軸呈90°之角度之方式貼合。依上述方式而獲得附相位差層之偏光板。並於第2相位差層之外側設置黏著劑層，於該黏著劑層表面暫時黏附分離件。又，於HC層表面暫時黏附表面保護薄膜。 2. Production of polarizing plate with retardation layer An HC-TAC film (thickness 49 µm) was bonded to one side of the polarizer obtained above with a polyvinyl alcohol-based adhesive. In addition, the HC-TAC film is a film in which a hard coat (HC) layer (thickness 9 µm) is formed on a triacetate cellulose (TAC) film (thickness 40 µm), and the TAC film is bonded on the polarizer side. And on the other side of the polarizer, a cyclic olefin film (refractive index characteristic: nx>ny>nz, in-plane phase difference: 116nm) was sequentially pasted as the first retardation layer and a modified polyethylene film (refractive index characteristic : nz>nx>ny, in-plane retardation: 35 nm) as the second retardation layer. The bonding system uses a UV-curable adhesive. In addition, the slow axis of the first retardation layer forms an angle of 0° with respect to the absorption axis of the polarizer, and the slow axis of the second retardation layer forms an angle of 90° with respect to the absorption axis of the polarizer. A polarizing plate with a retardation layer was obtained in the above manner. And an adhesive layer is provided outside the second retardation layer, and the separator is temporarily adhered to the surface of the adhesive layer. Also, a surface protection film is temporarily attached to the surface of the HC layer.

3.端面加工將上述所得附相位差層之偏光板裁切成300mm×120mm之尺寸，且其於長邊之中央部具有50mm×50mm之如圖6(a)所示之凹部。此時係以偏光件之吸收軸方向在短邊方向之方式進行裁切。積層裁切出之附相位差層之偏光板而形成工件(厚度15mm以上)，並藉由端銑刀對該工件之外周端面整體進行粗加工。端銑刀之直徑為6mm，旋轉數為25000rpm，進給速度為1500mm/分鐘。並且，以如圖6(a)所示，在與偏光件之吸收軸方向相交之方向上利用螺旋銼刀進行端面加工。螺旋銼刀之直徑為6mm，刃數為4片，螺旋角為45°，斜角為5°，無餘隙角，刀尖之平坦面的寬度為0.6mm，且加工為一般加工。螺旋銼刀之銼身部的粒度為#1000。直線部之加工條件係旋轉數S為8000rpm、進給速度為3000mm/分鐘，凹部之加工條件係旋轉數S為8000rpm、進給速度為3000mm/分鐘。將經端面加工之附相位差層之偏光板供於上述(2)~(4)之評估。將結果列於表1。 3. End processing The polarizing plate with retardation layer obtained above was cut into a size of 300mm×120mm, and the center of the long side had a concave portion of 50mm×50mm as shown in FIG. 6( a ). At this time, cutting is performed so that the absorption axis direction of the polarizer is in the short side direction. Laminate and cut polarizers with retardation layers to form a workpiece (thickness above 15mm), and use an end mill to roughly machine the entire outer peripheral end surface of the workpiece. The diameter of the end mill was 6 mm, the rotation speed was 25000 rpm, and the feed rate was 1500 mm/min. And, as shown in FIG. 6( a ), the end surface processing is performed with a spiral file in a direction intersecting with the absorption axis direction of the polarizer. The diameter of the spiral file is 6mm, the number of blades is 4 pieces, the helix angle is 45°, the bevel angle is 5°, there is no clearance angle, the width of the flat surface of the knife tip is 0.6mm, and the processing is general processing. The particle size of the file body of the spiral file is #1000. The processing conditions of the linear part are that the rotation speed S is 8000rpm, and the feed speed is 3000mm/min. The processing conditions of the concave part are that the rotation speed S is 8000rpm, and the feed speed is 3000mm/min. The end-processed polarizing plate with retardation layer was used for the evaluation of (2)~(4) above. List the results in Table 1.

[實施例2~23] 將螺旋銼刀有無餘隙角及刀尖之平端部的寬度、螺旋銼刀之銼身部的粒度、螺旋銼刀之旋轉數及進給速度、以及加工形式(一般加工或刀背加工)變更成如表1所示，除此之外，依與實施例1相同方式，對附相位差層之偏光板的端面進行切削加工。將經端面加工之附相位差層之偏光板供於與實施例1相同之評估。將結果列於表1。 [Example 2~23] Change the clearance angle of the spiral file, the width of the flat end of the blade tip, the grain size of the body of the spiral file, the number of rotations and feed speed of the spiral file, and the processing form (general processing or back processing) as shown in Table 1 As shown, except for this, in the same manner as in Example 1, the end face of the polarizing plate with a retardation layer was cut. The polarizing plate with a retardation layer processed on the end face was subjected to the same evaluation as in Example 1. List the results in Table 1.

[比較例1] 使用棒銼刀(粒度#1000)取代螺旋銼刀、以及將棒銼刀之旋轉數及進給速度變更成如表1所示，除此之外，依與實施例1相同方式，對附相位差層之偏光板的端面進行切削加工。將經端面加工之附相位差層之偏光板供於與實施例1相同之評估。將結果列於表1。 [Comparative example 1] Use a rod file (grain size #1000) instead of a spiral file, and change the rotation speed and feed speed of the rod file as shown in Table 1. In addition, in the same manner as in Example 1, the The end face of the polarizing plate is cut. The polarizing plate with a retardation layer processed on the end face was subjected to the same evaluation as in Example 1. List the results in Table 1.

[表1]

此外，表中之「←」係表示與左邊欄位為相同值，「↓」則表示與上面欄位為相同值。 [Table 1]

In addition, "←" in the table means the same value as the column on the left, and "↓" means the same value as the column above.

[實施例24] 依與實施例1相同方式，製出暫時黏附有表面保護薄膜(SPV)及分離件的附相位差層之偏光板。以SPV在上側之方式，積層該附相位差層之偏光板而形成工件。以下程序係依與實施例1相同方式，對附相位差層之偏光板的端面進行切削加工。確認經端面加工之附相位差層之偏光板中之SPV及分離件之浮凸。將結果列於表2。 [Example 24] In the same manner as in Example 1, a polarizing plate with a retardation layer to which a surface protection film (SPV) and a separator were temporarily adhered was produced. The workpiece is formed by laminating the polarizing plate with the retardation layer with the SPV on the upper side. The following procedure is the same method as in Example 1, and the end surface of the polarizing plate with a retardation layer is cut. Confirm the SPV and the relief of the separator in the end-face processed polarizing plate with retardation layer. List the results in Table 2.

[實施例25] 依與實施例9相同方式，製出暫時黏附有表面保護薄膜(SPV)及分離件的附相位差層之偏光板。以SPV在上側之方式，積層該附相位差層之偏光板而形成工件。以下程序係依與實施例1相同方式，對附相位差層之偏光板的端面進行切削加工。確認經端面加工之附相位差層之偏光板中之SPV及分離件之浮凸。將結果列於表2。 [Example 25] In the same manner as in Example 9, a polarizing plate with a retardation layer to which a surface protection film (SPV) and a separator were temporarily adhered was produced. The workpiece is formed by laminating the polarizing plate with the retardation layer with the SPV on the upper side. The following procedure is the same method as in Example 1, and the end surface of the polarizing plate with a retardation layer is cut. Confirm the SPV and the relief of the separator in the end-face processed polarizing plate with retardation layer. List the results in Table 2.

[參考例1] 除了使分離件在上側之方式形成工件外，依與實施例24相同方式，對附相位差層之偏光板的端面進行切削加工。確認經端面加工之附相位差層之偏光板中之SPV及分離件之浮凸。將結果列於表2。 [Reference example 1] The end face of the polarizing plate with retardation layer was cut in the same manner as in Example 24 except that the separator was formed on the upper side. Confirm the SPV and the relief of the separator in the end-face processed polarizing plate with retardation layer. List the results in Table 2.

[參考例2] 除了使分離件在上側之方式形成工件外，依與實施例25相同方式，對附相位差層之偏光板的端面進行切削加工。確認經端面加工之附相位差層之偏光板中之SPV及分離件之浮凸。將結果列於表2。 [Reference example 2] The end face of the polarizing plate with retardation layer was cut in the same manner as in Example 25, except that the separator was formed on the upper side. Confirm the SPV and the relief of the separator in the end-face processed polarizing plate with retardation layer. List the results in Table 2.

[表2]

[Table 2]

由表1明顯可知，根據本發明實施例，熱震試驗後之裂痕有抑制至可容許之程度。並且，相較於比較例，最初階段加工之偏光件端面的Sdr(S)與最後階段加工之偏光件端面的Sdr(E)之差有變小。可知比較例因該差變大，而Sdr(E)變得不滿足本發明實施形態之要件。此外，由實施例11、18及23可知，藉由進行刀背加工，即便螺旋銼刀具有餘隙角，仍可良好地抑制裂痕。由表2明顯可知，藉由使SPV在上側來進行切削加工，能抑制浮凸。It can be clearly seen from Table 1 that according to the embodiment of the present invention, the cracks after the thermal shock test are suppressed to a tolerable level. Moreover, compared with the comparative example, the difference between the Sdr(S) of the end surface of the polarizer processed in the initial stage and the Sdr(E) of the end surface of the polarizer processed in the last stage becomes smaller. It can be seen that in the comparative example, because of this difference, Sdr(E) does not satisfy the requirements of the embodiment of the present invention. In addition, it can be seen from Examples 11, 18, and 23 that even if the helical file has a clearance angle, cracks can be well suppressed by processing the blade back. As is apparent from Table 2, embossing can be suppressed by cutting the SPV on the upper side.

產業上之可利用性本發明實施形態之偏光板可用於影像顯示裝置，尤其可適宜用於容易被放置於嚴酷環境下之車載用途的影像顯示裝置。 Industrial availability The polarizing plate according to the embodiment of the present invention can be used for an image display device, and is particularly suitable for an on-vehicle image display device that is easily placed in a harsh environment.

A:偏光件之吸收軸方向 B:刀尖之平坦面的寬度 D:銼身部之凹凸的深度 E:加工結束地點 L:銼身部之長度 p:銼身部之凹凸的間距 S:加工開始地點 W:工件 θ:螺旋角 1a,1b,1c,1d:外周面 10:偏光件 20:保護層 60:端銑刀 61:旋轉軸 62:(端銑刀之)切削刃 62a:刀尖 62b:前刀面 62c:後刀面 70:螺旋銼刀 71:旋轉軸 72:(螺旋銼刀之)切削刃 72a:刀尖 72b:前刀面 72c:後刀面 73:銼身部 100:偏光板 A: The direction of the absorption axis of the polarizer B: The width of the flat surface of the tool tip D: The depth of the unevenness of the file body E: processing end location L: The length of the file body p: Spacing between the concave and convex of the file body S: Processing start location W: Workpiece θ: Helix angle 1a, 1b, 1c, 1d: outer peripheral surface 10: Polarizer 20: protective layer 60: end mill 61: axis of rotation 62: (of end mill) cutting edge 62a: Knife tip 62b: rake face 62c: flank 70: spiral file 71: axis of rotation 72: (of spiral file) cutting edge 72a: Knife tip 72b: rake face 72c: flank 73: file body 100: polarizer

圖1係概略立體圖，其係用以說明本發明實施形態之偏光板之製造方法中之端面加工之概略。圖2係概略立體圖，其係用以說明本發明實施形態之偏光板之製造方法中可用於端面加工之螺旋銼刀之結構。圖3係概略圖，其係用以說明本發明實施形態之偏光板之製造方法中可用於端面加工之螺旋銼刀不具有餘隙角之情形。圖4係用以說明圖2之螺旋銼刀中之銼身部的凹凸深度及間距的主要部分概略截面圖。圖5係概略圖，其係用以說明本發明實施形態之偏光板之製造方法中可用於端面加工之具有螺旋刃之端銑刀之結構。圖6中，(a)及(b)係概略俯視圖，係例示說明本發明實施形態中利用螺旋銼刀對工件之外周面的一部分進行端面加工時之加工部分。圖7係藉由本發明實施形態之製造方法獲得之偏光板的概略截面圖。 FIG. 1 is a schematic perspective view for explaining the outline of end surface processing in the method of manufacturing a polarizing plate according to an embodiment of the present invention. Fig. 2 is a schematic perspective view, which is used to illustrate the structure of a spiral file that can be used for end surface processing in the manufacturing method of the polarizing plate according to the embodiment of the present invention. Fig. 3 is a schematic diagram, which is used to illustrate the case where the helical file used for end surface processing does not have a clearance angle in the manufacturing method of the polarizing plate according to the embodiment of the present invention. Fig. 4 is a schematic cross-sectional view of main parts for explaining the depth and pitch of concavities and convexities of the body of the spiral file of Fig. 2 . Fig. 5 is a schematic diagram, which is used to illustrate the structure of an end mill with a helical blade that can be used for end surface processing in the method of manufacturing a polarizing plate according to the embodiment of the present invention. In Fig. 6, (a) and (b) are schematic plan views, which illustrate the processing part when the end surface processing is performed on a part of the outer peripheral surface of the workpiece with a spiral file in the embodiment of the present invention. Fig. 7 is a schematic cross-sectional view of a polarizing plate obtained by the manufacturing method according to the embodiment of the present invention.

W:工件 W: Workpiece

1a,1b,1c,1d:外周面 1a, 1b, 1c, 1d: outer peripheral surface

60:端銑刀 60: end mill

Claims

一種偏光板之製造方法，包含以下步驟：將複數片偏光板疊合而形成工件；及使用螺旋銼刀來加工該工件之外周面，使該偏光板之偏光件端面依循ISO 25178所得之面粗度Sdr為11%以上。 A method of manufacturing a polarizing plate, comprising the following steps: A workpiece is formed by laminating a plurality of polarizers; and Use a spiral file to process the outer peripheral surface of the workpiece, so that the surface roughness Sdr of the end surface of the polarizer of the polarizer following ISO 25178 is more than 11%.

如請求項1之製造方法，其在將前述螺旋銼刀之旋轉數設為S(rpm)、將進給速度設為F(mm/分鐘)時，S/F為14以上。In the manufacturing method according to claim 1, when the rotation speed of the spiral file is S (rpm) and the feed rate is F (mm/min), S/F is 14 or more.

如請求項1或2之製造方法，其中前述螺旋銼刀不具有餘隙角，且刀尖之寬度為0.1mm以上。The manufacturing method according to claim 1 or 2, wherein the spiral file does not have a clearance angle, and the width of the blade tip is 0.1 mm or more.

如請求項1至3中任一項之製造方法，其包含一切削步驟，其係以前述螺旋銼刀之刀的背面側在旋轉方向上游側之方式進行。The manufacturing method according to any one of claims 1 to 3, which includes a cutting step, which is performed in such a manner that the back side of the blade of the aforementioned spiral file is on the upstream side in the direction of rotation.

如請求項1至4中任一項之製造方法，其中前述偏光板更具有：表面保護薄膜，其係以可剝離之方式暫時黏附於其中一側；黏著劑層，其係配置於另一側；及分離件，其係以可剝離之方式暫時黏附於該黏著劑層；該製造方法係使該表面保護薄膜位於前述螺旋銼刀之切削屑的排出方向來疊合該偏光板而形成前述工件。 The manufacturing method according to any one of claims 1 to 4, wherein the polarizing plate further has: a surface protection film, which is temporarily attached to one side in a peelable manner; an adhesive layer, which is arranged on the other side ; and a separate part, which is temporarily adhered to the adhesive layer in a peelable manner; In the manufacturing method, the surface protection film is positioned in the discharge direction of the cutting chips of the aforementioned spiral file, and the polarizing plate is stacked to form the aforementioned workpiece.

如請求項1至5中任一項之製造方法，其包含一以前述螺旋銼刀加工前述工件之外周面的步驟，所述外周面位在與前述偏光板所含偏光件之吸收軸方向相交之方向。The manufacturing method according to any one of Claims 1 to 5, which includes a step of processing the outer peripheral surface of the aforementioned workpiece with the aforementioned spiral file, and the outer peripheral surface is located in a direction intersecting the absorption axis direction of the polarizer contained in the aforementioned polarizing plate direction.

如請求項6之製造方法，其包含一以端銑刀加工前述工件之外周面之步驟，所述外周面位在與前述偏光板所含偏光件之吸收軸方向實質上平行之方向。The manufacturing method according to claim 6, which includes a step of machining the outer peripheral surface of the workpiece with an end mill, the outer peripheral surface is located in a direction substantially parallel to the direction of the absorption axis of the polarizer included in the polarizer.

如請求項1至7中任一項之製造方法，其中前述利用螺旋銼刀進行之加工包含形成異形之步驟；並且，該螺旋銼刀形成該異形時之進給速度小於該螺旋銼刀加工該異形以外之部分的進給速度。The manufacturing method according to any one of claims 1 to 7, wherein the aforementioned processing with a spiral file includes a step of forming a special shape; and, the feed speed of the spiral file when forming the special shape is lower than that of the spiral file for processing other than the special shape part of the feed rate.

一種偏光板，具有偏光件與配置於該偏光件之至少一側的保護層；該偏光板之一對規定外緣且互相對向之邊中，其中一邊的該偏光件端面依循ISO 25178所得之面粗度Sdr(S)為11%以上，且該Sdr(S)與另一邊的該偏光件端面之面粗度Sdr(E)滿足下述關係： Sdr(S)-Sdr(E)≦3%。 A polarizing plate, comprising a polarizer and a protective layer disposed on at least one side of the polarizer; Among a pair of sides facing each other with specified outer edges of the polarizer, the surface roughness Sdr(S) of the end surface of the polarizer on one side in accordance with ISO 25178 is more than 11%, and the Sdr(S) is the same as the other side The surface roughness Sdr(E) of the end face of the polarizer satisfies the following relationship: Sdr(S)-Sdr(E)≦3%.