200536617 、 九、發明說明： 【發明所屬之技術領域】 本發明係關於光學薄膜之製法，尤其是關於適合對用 於改善光學補償薄膜、防反射薄膜、防眩性薄膜等的光學 薄膜、或液晶層的不勻相當有效的光學薄膜等的製造的光 學薄膜之製法。 【先前技術】 液晶顯示裝置（LCD)與CRT(陰極射線管）比較，具有薄 • 型、輕量、低消耗電力等的大優點。該液晶顯示裝置係由 液晶單元及配置於液晶單元的上下的偏光板所構成。液晶 單元係由棒狀液晶性分子、封入該棒狀液晶性分子用的二 片基板及對棒狀液晶性分子施加電壓用的電極層等所構 成。爲使封入之棒狀液晶性分子配向，在二片基板上設有 配向膜。 爲去除顯示於該液晶單元的影像的上色，大多是在液 晶單元與偏光板之間設置光學補償薄膜（相位差板）。該光 ^學補償薄膜與偏光板的積層體，具有作爲橢圓偏光板的功 能。另外，還有對光學補償薄膜供給放大液晶單元的視野 角的功能。 作爲此種光學補償薄膜係使用合成聚合物的薄膜，但 還提出有取代此，而改用在透明支撐體上具有由碟狀液晶 性分子形成的光學異方向性層的構成（例如，專利文獻1〜4 等）。具體而言，使碟狀液晶性分子配向，並藉由固定其配 向狀態以形成光學補償薄膜。一般，碟狀液晶性分子具有 200536617 大的雙折射率。另外，在碟狀液晶性分子具有各種配向形 態。因此，藉由使用碟狀液晶性分子，可製造具有在以往 的合成聚合物薄膜中無法獲得的光學性質的光學補償薄 膜。 [專利文獻1]日本特開平6-214116號公報 [專利文獻2]美國專利第5 5 83679號 [專利文獻3]美國專利第5646703號 [專利文獻4]西德專利公報第39 1 1 620A1號 【發明內容】 (發明所欲解決之課題） 但是，即使爲上述此種光學補償薄膜，在現實狀況中 仍稱不上能獲得充分的性能。亦即，近年來，伴隨著有關 液晶顯示裝置的技術的進展，越來越強烈地要求能提高影 像顯示品質。尤其是，影像顯示中的不勻等成爲一種問題， 爲提高影像顯示品質，而對此等提出了更高層次的改善要 求。 本發明正是鑒於上述問題而提出者，其目的在於，提 供一種極適合可在液晶顯示裝置中獲得良好的影像顯示品 質的光學薄膜的製法。 (解決問題之裝置） 爲達成上述目的，本發明提供一種光學薄膜之製法， 係在行進中的透明薄膜上藉由塗佈裝置塗佈塗布液所形成 的光學薄膜之製法，其特徵爲：塗佈時上述透明薄膜的張 力係控制爲100〜400N/m。 200536617 根據本發明，因爲將塗佈時之透明薄膜的張力取得最 佳化，因此可防止塗膜厚度的不均勻性，從而可改善影像 顯示的不勻。 在此，張力係指以透明薄膜的寬度（單位：m)來除施加 於透明薄膜的行進方向的張力（單位·· N)的値。該張力以150 〜350N/m爲較佳，而以200〜300N/m爲更佳。 又，光學薄膜係除光學補償薄膜以外，還包含防反射 薄膜、防眩性薄膜等的具有各種功能的薄膜。 • 本發明中，上述塗布裝置最好爲線桿塗布器、凹槽輥 (gravure)塗布器或（roll)輥塗布器的任一種。此種塗布裝置 適合於塗佈均勻的薄膜，另外，藉由採用此種塗布裝置， 較適宜進行透明薄膜的張力的最佳化。 另外，本發明中，在上述塗布裝置中，上述透明薄膜 的對輥構件的捲取角度，以1〜30度爲較佳。利用設爲此 範圍內的捲取角度，可防止塗膜層的不均勻性。 輥構件係指各塗布器（塗布裝置）的塗布液供給用的 Φ輥，在後述的線桿塗布裝置1〇(參照第2圖）中，爲塗佈用 線桿12(參照第3圖），在3支逆輥塗布器（參照第4圖）中， 爲塗布輥108，在凹槽輥塗布器（參照第5圖）中，爲凹槽輥 1 1 5 〇 又’捲取角度係指在機構學的捲取傳導上的捲取角 度。該捲取角度最好爲3〜20度，尤以5〜15度爲較佳。 另外，本發明中，上述透明薄膜的厚度最好爲40〜 3 0 Ομηι。此厚度的透明薄膜較爲適合用於本發明之光學薄 200536617 膜。該透明薄膜的厚度，以50〜20 0/xm爲較佳，而以60〜 120/im爲更佳。 另外，本發明中，上述塗布液的黏度最好爲1〜20mP a · s。此黏度的塗布液較爲適合用於本發明之光學薄膜的製 造。該塗布液的黏度，以1.5〜20mPa · s爲較佳，而以2 〜lOmPa. s爲更佳。 另外，本發明中，上述塗布液的固體成分濃度最好爲 15〜50質量％。此固體成分濃度的塗布液較爲適合用於本 φ 發明之光學薄膜的製造。 另外，本發明中，上述塗布液的塗佈時膜厚最好爲0.01 〜90/im。此膜厚可適合用於本發明之光學薄膜。該膜厚以 0.03〜60/xm爲較佳，而以0.05〜30μιη爲更佳。 (發明效果） 如上述說明，根據本發明，因爲將塗佈時之透明薄膜 的張力取得最佳化，因此可防止塗布膜厚的不均勻性，從 而可改善光學薄膜的不勻。 •【實施方式】 以下，根據所附圖面詳細說明本發明之光學薄膜的製 法的較佳實施形態。第1圖爲說明應用本發明之光學薄膜 的製法的光學補償薄膜的製造線的說明圖。第2圖爲在該 製造線中顯示屬塗佈裝置的線桿塗布裝置1 0的一例的剖 視圖。 在光學補償薄膜的製造線中，如第1圖所示，成爲從 輸出機66輸送預先形成有配向膜形成用的聚合物層的棉 200536617 網16的構成。棉網16係由導輥68所導引而被送入摩擦處 理裝置7 0內。摩擦輥72係設爲應可對聚合物層施以摩擦 處理。在摩擦輥72的下游設有除塵機74，其可除去黏附 於棉網1 6表面的塵埃。在除塵機7 4的下游設有線桿塗布 裝置1 0，含有碟狀向列型液晶的塗布液係形成爲可塗佈於 棉網1 6上的構成。在其下游順序設有乾燥區7 6、加熱區 78，且在棉網16上可形成液晶層。又，在其下游設有紫外 線燈8 0，藉由紫外線照射以使液晶交聯，可形成所需的聚 φ 合物。然後，藉由設於該下游的捲取機82，即可捲取形成 有聚合物的棉網1 6。 在線桿塗布裝置1 0的上下游分別設有一對驅動輥 52、夾輥54及驅動輥56、夾輥58，此等形成張力調整機 構50。亦即，藉由將線桿塗布裝置10下游的驅動輥56及 夾輥58的旋轉速度（周速度）設定爲較線桿塗布裝置10上 游的驅動輥52及夾輥54的旋轉速度（周速度）大，即可成 爲於棉網1 6的行進方向產生指定的張力的狀態。又，張力 • 調整機構50並不限於該構成，其還可採用其他的各種構 成。 如第2圖所示，線桿塗布裝置1 0係相對由一對導輥 18、18導引而行進中的棉網16，由具備塗佈用線桿12的 塗布頭1 4塗佈塗布液的裝置。一對導輥1 8、1 8係配置爲 讓棉網1 6靠近於塗佈用線桿1 2行進的狀態。棉網1 6相對 塗佈用線桿1 2的捲取角度成爲Θ。 塗布頭14主要由塗佈用線桿12、支撐構件20及塗布 -9- 200536617 ' 區塊2 2、2 4所構成，塗佈用線桿1 2係可轉動自如 於支撐構件20上。在支撐構件20及各塗布區塊22 間形成有集流腔26、28及切縫30、32，在各集流B 2 8內供應有塗布液。供給各集流腔2 6、2 8內的塗 介由狹窄的切縫30、32，沿棉網寬度方向均勻地壓 此，相對於塗佈用線桿12，在棉網1 6的傳輸方向 側（以下，稱爲「一次側」）形成一次側塗布液珠34 游側（以下，稱爲「二次側」）形成二次側塗布液珠 φ 由此等塗布液珠34、36，塗布液被塗佈於行進中的^ 上。 從集流腔26、28過剩供給的塗布液，從各塗 22、24與棉網16之間進行溢流，並由未圖示的側 收。又，對集流腔26、28的塗布液的供給，可從 26、28的中央部來進行，也可從端部進行。 如第3圖所示，塗佈用線桿12具備將鋼絲40 狀密接繞捲於圓棒狀桿3 8上所形成的鋼絲列42， φ該鋼絲列42上保持塗布液，即可將塗布液轉移塗佈 中的連接帶16上。 作爲構成塗佈用線桿1 2的桿3 8及鋼絲40的材 使用以不銹鋼爲首的各種金屬，只要不會污染到塗 且能滿足強度即可。另外，桿3 8優先使用直徑5 -者。 另一方面，使用正圓度爲2 μηχ以下者。具體而 好使用相對鋼絲40的單位斷面積（假想正圓），其缺 地支撐 、24之 空26、 布液係 出。藉 的上游 ，在下 3 6 〇介 〖帛網1 6 布區塊 槽所回 集流腔 呈螺旋 藉由在 於行進 質，可 布液， -15 mm 言，最 損或突 -10- 200536617 起等的不整部分的面積的比例較小者 者）。如上述構成的塗佈用線桿1 2，如第 棉網1 6的搬送方向順向旋轉。 本實施形態中，線桿塗布裝置1 0可 清淨環境內。此時，清淨度最好爲等級 級100以下爲較佳，以等級10以下爲j 上述線桿塗布裝置1 0尤其對薄層之 此可適合應用於光學補償薄膜的製造線 P 作爲本發明中使用的連接帶1 6，最 以上的聚合物薄膜。聚合物薄膜最好爲 折射者。聚合物之例子，以含有纖維素 嫌系聚合物（例如，Arton( JSR(股）製）、 由曰本ΖΕΟΝ(股）製）及聚甲基丙烯酸甲 物爲較佳，尤以纖維素酯爲更佳，而以 酸酯爲最佳。 該低級脂肪酸係意味著碳原子數爲 • 其中，最好碳原子數爲2(乙酸纖維素） 4(丁酸纖維素）。纖維素酯以乙酸纖維素 出二乙醯纖維素及三乙醯纖維素等。還 纖維素及乙酸丁酸纖維素的混合脂肪酸 一般，乙酸纖維素的2、3、6的經 在全體取代度的各1/3,而在第6位置經 的傾向。本發明中，乙酸纖維素的第6 f] 以較第2、3位置多者爲較佳。 (例如，0 · 5 %以下 2圖所示，係相對 設置於無塵室等的 1 000以下，而以等 :佳。 :塗佈相當有效，因 〇 好爲透光率爲80% 不易由外力發現雙 系聚合物、原冰片 Zeonor、Zeonex(均 酯的纖維素系聚合 纖維素的低級脂肪 6以下的脂肪酸。 、3(丙酸纖維素）或 爲較佳，該例可舉 可使用如乙酸丙酸 酯。 基，不是均等分配 基的取代度有減少 t置羥基的取代度， -11- 200536617 相對全體的取代度，第6位置羥基最好以3 0%以上、 40%以下的醯基進行取代，而以31%以上爲較佳、尤其以 3 2 %以上爲更佳。又，乙酸纖維素的第6位置羥基的取代 度，以〇·88以上爲較佳。 第6位置羥基除乙醯基以外，還可由屬碳數爲3以上 的醯基的甲基丙醯基、丁醯基、戊醯基、苯甲醯基、丙烯 醯基等所取代。各位置的取代度之測定，可由NMR所求得。 作爲本發明之乙酸纖維素，可使用由日本特開平 φ 11-5851號公報的段落號〇〇43〜0044所記載的合成例1、 段落號0048〜0049所記載的合成例2及段落號005 1〜0052 所記載的合成例3的合成方法所獲得的乙酸纖維素。 爲調整聚合物薄膜的遲滯値，使用至少具有二個的芳 香族環的芳香族化合物作爲遲滯値上升劑。 在使用乙酸纖維素薄膜作爲聚合物薄膜的情況，芳香 族化合物係在相對100質量份的乙酸纖維素的0.01〜20質 量份的範圍內使用。芳香族化合物尤以在相對1 00質量份 # 的乙酸纖維素的〇.〇5〜15質量份的範圍內使用爲較佳，以 〇 · 1〜1 0質量份的範圍內使用爲更佳。還可合倂使用二種類 以上的芳香族化合物。在芳香族化合物的芳香族環內，除 芳香族烴環外，還包含芳香族性雜環。 芳香族烴環尤以6員環（亦即，苯環）爲較佳。芳香族性 雜環一般爲不飽和雜環。芳香族性雜環以5員環、6員環 或7員環爲較佳，尤以5員環或6員環爲較佳。芳香族性 雜環一般具有最多的雙鍵。雜原子最好爲氮原子、氧原子 -12- 200536617 及硫原子，尤以氮原子爲較佳。 芳香族性雜環的例中，含有呋喃環、噻吩環、吡咯環、 噁唑環、異噁唑環、噻唑環、異噻唑環、咪唑環、吡唑環、 呋咕環、三15坐環、卩比喃環、卩比Π定環、卩比塔嗪環、嚼u定環、 吡嗪環及1，3,5-三嗪環。芳香族環最好爲苯環、呋喃環、 噻吩環、吡咯環、噁唑環、噻唑環、咪唑環、***環、吡 啶環、嘧啶環、吡阱環及1，3,5-三阱環，尤以苯環及1，3,5_ 三阱環爲更佳。芳香族化合物最好具有至少一個的1，3,5_ φ 三畊環。 芳香族化合物具有的芳香族環數，最好爲2〜20,以2 〜12爲較佳，尤以2〜8爲更佳，尤以2〜6爲最佳。二個 芳香族環的鍵結關係，可分類爲（a)形成稠環的情況，（b) 以單鍵直接進行鍵結的情況及（c)經由連結基進行鍵結的情 況（因爲是芳香族環，因此無法使用螺環接）。鍵結關係可 爲（a)〜（c)的任一種。 (a)的稠環（二個以上的芳香族環的稠環）的例中，包含 •茚環、萘環、葜環、莽環、菲環、蒽環、苊烯萘環、2,3苯 并蒽環、焦油腦環、吲哚環、異吲哚環、苯并呋喃環、苯 并噻吩環、吲哚畊環、苯并噁唑環、苯并噻唑環、苯并味 唑環、苯并***環、嘌呤環、苯并吡唑環、苯并三氫哌喃 環、喹啉環、異喹啉環、喹嗪環、喹唑啉環、哮啉環、苯 并吡啶環、呔嗪環、喋啶環、咔唑環、吖啶環、3,4苯并-喹啉環、二苯并呱喃環、二苯并吡嗪環、啡噻畊環、啡嚼、 噻環、啡噁嗪環及噻茚環。其中以萘環、葜環、卩引晚環、 -13- 200536617 苯并噁唑環、苯并噻唑環、苯并咪唑環、苯并***環及喹 啉環爲較佳。 (b)單鍵最好爲二個芳香族環的碳原子間的鍵結。以二 個以上的單鍵來鍵結二個芳香族環，還可在二個芳香族環 之間形成脂肪族環或非芳香族性雜環。 (C)連結基也以與二個芳香族環的碳原子鍵結爲較佳。 連結基最好爲伸烷基、伸烯基、伸炔基、-CO-、-0-、-NH-、 -S-或此等的組合。以下，顯示組合而成的連結基的例子。 φ 又，以下的連結基的例子的左右關係，也可相反。 c 1 ： -C0-0-c 2 : -CO-NH-c 3 ·-伸院基-0-c4:-NH-CO-NH-c 5 ： - NH-CO-O-c 6 · - 〇 - C Ο - Ο ~ c 7 · - 〇 -伸院基-〇 · _ c8 : -CO-伸烯基- c9 : -CO-伸烯基· NH-clO : _CO-伸烯基-0- cl 1 :-伸烷基-C0-0_伸烷基-0-C0 -伸烷基- c 1 2 : -伸烷基-C Ο - Ο -伸烷基-Ο - C Ο -伸烷基_ Ο - cl3 : -0-C0 -伸烷基- CO -0- cl4 : - NH-CO-伸烯基- cl5 : -0-C0 -伸烯基- -14- 200536617 芳香族環及連結基還可具有取代基。取代基的例子中 包含，鹵原子（F、Cl、Br、I)、羥基、羧基、氰基、胺基、 硝基、磺酸基、胺基甲醯基、氨磺醯基、脲基、烷基、烯 基、炔基、脂肪族醯基、脂肪族氧化醯基、烷氧基、烷氧 羧基、烷氧羧胺基、烷基硫、胺基磺醯基、脂肪族醯胺基、 脂肪族磺醯胺基、脂肪族取代胺基、脂肪族取代胺基甲醯 基、脂肪族取代氨磺醯基、脂肪族取代脲基及非芳香族性 雜環基。 烷基的碳原子數最好爲1〜8。且相較於環狀烷基，以 鏈狀烷基爲較佳，尤其以直鏈狀烷基爲較佳。烷基還可具 有取代基（例如，羥基、羧基、烷氧基、烷基取代胺基）。 在烷基的（包含烷基）例中包含甲基、乙基、η-丁基、η-正己 基、2-羥乙基、4-羧丁基、2-甲氧乙基及2-二乙胺基乙基。 烯基的碳原子數最好爲2〜8。且相較於環狀烯基，以鏈狀 烯基爲較佳，尤其以直鏈狀烯基爲較佳。烯基還可具有取 代基。 烯基的例中包含乙烯基、丙烯基及1 -己烯基。炔基的 碳原子數最好爲2〜8。且相較於環狀炔基，以鏈狀炔基爲 較佳，尤其以直鏈狀炔基爲較佳。炔基還可具有取代基。 炔基的例中包含乙炔基、1-丁炔基及1-己炔基。 脂肪族醯基的碳原子數最好爲1〜1 〇。脂肪族醯基的例 中包含乙醯、丙醯及丁醯。脂肪族氧化醯基的碳原子數最 好爲1〜10。脂肪族氧化醯基的例中包含乙醯氧基。烷氧 基的碳原子數最好爲1〜8。烷氧基還可具有取代基（例如， -15- 200536617 院氧基）。 烷氧基的（包含取代烷氧基）例中包含甲氧基、乙氧基、 丁氧基及甲氧乙氧基。烷氧基羰基的碳原子數最好爲2〜 10。烷氧基羰基的例中包含甲氧基羰基及乙氧基羰基。烷 氧基羰胺基的碳原子數最好爲2〜1 0。烷氧基羰胺基的例 中包含甲氧基羰胺基及乙氧基羰胺基。 烷硫基的碳原子數最好爲1〜1 2。烷硫基的例中包含甲 硫基、乙硫基及辛硫基。 φ 烷基磺醯基的碳原子數最好爲1〜8。烷基磺醯基的例 中包含甲磺醯基及乙磺醯基。 脂肪族醯胺基的碳原子數最好爲1〜10。脂肪族醯胺基 的例中包含乙醯胺。脂肪族磺醯胺基的碳原子數最好爲1 〜8。脂肪族磺醯胺基的例中包含甲磺醯胺基、丁磺醯胺基 及η-辛磺醯胺基。脂肪族取代胺基的碳原子數最好爲1〜 1 〇。脂肪族取代胺基的例中包含二甲胺、二乙胺及2-羧基 乙胺。 # 脂肪族取代的胺基甲醯基的碳原子數最好爲2〜1 0。脂 肪族取代胺基甲醯基的例中包含甲胺基甲醯基及二乙胺基 甲醯基。脂肪族取代氨磺醯基的碳原子數最好爲1〜8。脂 肪族取代氨磺醯基的例中包含甲氨磺醯基及二乙氨磺醯 基。脂肪族取代脲基的碳原子數最好爲2〜1 0。脂肪族取 代脲基的例中包含甲脲基。非芳香族性雜環基的例中包含 口瓜D定及嗎啉。遲滯値上升劑的分子量最好爲3 0 0〜8 0 0。 遲滯値上升劑的具體例子，記載於日本特開2000-1 1 1914 -16- 200536617 號公報、同2000-275434號公報、PCT/JP00/026 1 9號說明 書等。 以下針對使用乙酸纖維素薄膜作爲聚合物薄膜的情況 進行具體說明。最好藉由溶劑分散法來製造乙酸纖維素薄 膜。在溶劑分散法中，使用將乙酸纖維素溶解於有機溶劑 的溶液（塗料）來製造薄膜。 有機溶劑最好包含從碳原子數爲3〜12的醚、碳原子 數爲3〜12的酮、碳原子數爲3〜12的酯及碳原子數爲1 φ 〜6的鹵化烴中選出的溶劑。 醚、酮及酯還可具有環狀構造。具有醚、酮及酯的官 能基（β卩，-0-、-CO-及-COO-)的任一者的二個以上的化合 物也可用作爲有機溶劑。有機溶劑還可具有如醇性羥基的 其他官能基。在具有二種類以上的官能基的有機溶劑的情 況，其碳原子數只要在具有任一的官能基的化合物的規定 範圍內即可。 碳原子數爲3〜12的醚類的例中，包含二異丙醚、二 φ 甲氧甲烷、二甲氧乙烷、1，4-二噁烷、l，3-二噁茂烷、四氫 呋喃、茴香醚及苯基乙基醚。碳原子數爲3〜12的酮類的 例中，包含丙酮、丁酮、二乙酮、二異丁酮、環己酮及甲 環己酮。碳原子數爲3〜12的酯類的例中，包含甲酸乙酯、 甲酸丙酯、甲酸戊酯、乙酸甲酯、乙酸乙酯及乙酸戊酯。 具有二種類以上的官能基的有機溶劑的例中，包含2 -乙氧乙酸乙酯、2-甲氧乙醇及2-丁氧乙醇。鹵化烴的碳原 子數最好爲1或2，尤以1爲更佳。鹵化烴的鹵素最好爲 200536617 氯。鹵化烴的氫原子取代於鹵素中的比例，最好爲25〜75 旲耳°/〇’尤以30〜70旲耳％爲較佳，以35〜65莫耳％爲更 佳，以40〜60莫耳％爲最佳。二氯甲烷爲具代表性的鹵化 烴。 又，從技術層面而言，可使用如二氯甲烷的鹵化烴而 無任何問題，但從地球環境及作業環境的觀點考慮，有機 溶劑最好實質上未含有鹵化烴。「實質上未含有」係意味 著有機溶劑中的鹵化烴的比例低於5質量％(最好是低於2 φ 質量％)。另外，最好從製造的醯化物纖維素薄膜中，完全 檢測不出如二氯甲烷的鹵化烴。亦可混合二種類以上的有 機溶劑。 另β，能以一般的方法調製乙酸纖維素。一般的方法 係意味著以〇°c以上的溫度（常溫或高溫）進行處理。溶液的 調製可使用通常的溶劑分散法的塗料的調製方法及裝置來 實施。又，在一般方法的情況，最好使用鹵化烴（尤其是二 氯甲烷）作爲有機溶劑。乙酸纖維素的含量係在獲得的溶液 鲁中調整爲含有10〜40質量％。乙酸纖維素的含量最好爲10 〜3 0質量％。 有機溶劑（主溶劑）中還可添加後述的任意添加劑。溶液 可在常溫（〇〜40 °C )下藉由攪拌乙酸纖維素與有機溶劑來 調製。高濃度的溶液還可在加壓及加熱的條件下進行攪 拌。具體而言，將乙酸纖維素與有機溶劑放入加壓容器內 進行密閉，在加壓下邊加熱至溶劑的常溫中的沸點以上且 溶劑未沸騰的範圍內的溫度邊進行攪拌。加熱溫度通常爲 -18- 200536617 40°C以上，而以60〜200°C爲較佳，尤以80〜1 10°C爲更佳。 各成分還可在預先粗混合後放入容器內。另外，還可 順序投入容器內。容器需要形成爲可攪拌的構成。可注入 氮氣等的惰性氣體後加壓容器。另外，還可利用依據加熱 的溶劑的蒸氣壓的上升。或是，還可在密閉容器後，在壓 力下添加各成分。 在加熱的情況，最好從容器外部進行加熱。例如，可 使用外套型的加熱裝置。另外，還可在容器外部設置平板 φ 加熱器，經配管而使液體循環，用以加熱容器全體。最好 在容器內部設置攪拌翼，並使用該攪拌翼進行攪拌。攪拌 翼最好爲可抵達容器壁附近的長度者。在攪拌翼的末端， 爲更新容器壁的液膜，最好設置刮除翼。還可在容器上設 置壓力計、溫度計等的計器類。在容器內將各成分溶解於 溶劑中。調製的塗料係從冷卻後容器中取出或在取出後， 使用熱交換器等進行冷卻。 本發明之乙酸纖維素溶液（塗料）的調製，係依據冷卻溶 •解法來實施，以下針對此進行說明。首先，以接近室溫的 溫度（-10〜40 °c )，於有機溶劑中邊攪拌邊漸漸添加乙酸纖 維素。在使用複數溶劑的情況，其添加順序並無特別的限 定。 例如，可在主溶劑中添加乙酸纖維素後，添加其他的 溶劑（如乙醇等的膠狀溶劑），相反還可加入預先將膠狀溶 劑濕潤乙酸纖維素後的主溶劑，其可有效防止不均勻的溶 解。乙酸纖維素的含量最好調整爲在該混合物中含有10〜 19- 200536617 40質量％。乙酸纖維素的含量尤以10〜30質量％爲較佳。 又，還可在混合物中添加後述的任意添加劑。 其次，混合物被冷卻爲-100°C〜-10°C (以- 80°C〜- l〇°C 爲較佳，而以-50°C〜-20°C爲尤佳，以-50°C〜-30°C爲最 佳）。冷卻如可在乾冰·甲醇浴（-75 °C )或冷卻之二乙二醇溶 液（-3 0°C〜-2 0 °C )中實施。當經由該種冷卻時，乙酸纖維素 與有機溶劑的混合物將達成固化。冷卻速度雖無特別的限 定，但在分批式進行冷卻的情況，隨著冷卻的過程，乙酸 φ 纖維素溶液的黏度上升，而使得冷卻效率變差，因此爲達 成指定的冷卻溫度，需要有效率良好的溶解鍋。 另外，本發明之乙酸纖維素溶液係在膨潤之後，可藉 由短時間移送至設爲指定冷卻溫度的冷卻裝置來達成。冷 卻速度越快越好，但理論上以1 0000°c爲其上限，而技術 上以1 000°C爲其上限，實用上以100°c爲其上限。 又，冷卻速度係由從開始冷卻至達成最終冷卻溫度爲 止的時間除以開始冷卻時的溫度與最終冷卻溫度的差的 • 値。又，當將此加溫至〇〜200°c (以0〜150°c爲較佳，以0 〜120°c爲更佳，以0〜50°c爲最佳）時，成爲在有機溶劑中 流動乙酸纖維素的溶液。升溫可僅僅放置於室溫中進行， 也可在溫浴中加溫。 如上述般可獲得均勻的溶液。又，在溶解不充分的情 況，可重複進行加溫的操作。溶解是否充分，可利用目視 觀察溶液的外觀來判斷。 在冷卻溶解法中，爲避免冷卻時的結露造成的水分混 -20- 200536617 入，最好使用密閉容器。另外，在冷卻加溫操作中，當於 冷卻時進行加壓，而於加溫時進行減壓時’可縮短溶解時 間。爲實施加減壓，最好使用耐壓性容器。 又，利用冷卻溶解法將乙酸纖維素（醋化度：60.9%、 黏度平均聚合度·· 299)溶解於乙酸甲酯中的20質量％的溶 液，根據示差掃描熱量測定（DSC)，在33 °C近旁存在有液 膠狀與凝膠狀的疑似相互轉移點，而在該溫度以下成爲均 勻的凝膠狀態。 • 因此，該溶液需要在該疑似相互轉移點以上進行保 存，最好以高於凝膠相互轉移點的1 〇 °C以上的溫度進行保 存。但是，該疑似相互轉移點係根據乙酸纖維素的醋化度、 黏度平均聚合度、溶液濃度及使用之有機溶劑而變化。 從調製之乙酸纖維素溶液（塗料），藉由溶劑分散法來製 造乙酸纖維素薄膜。另外，塗料中最好添加有上述遲滯値 上升劑。塗料可在鼓狀物或帶上流延，並使溶劑蒸發而形 成薄膜。流延前的塗料最好將固體量調整爲1〇〜40%的濃 # 度，而尤以18〜35%的濃度爲更佳。鼓狀物或帶的表面上 最好精加工爲鏡面狀態。 溶劑分散法中的流延及乾燥方法，記載於美國專利 23 363 1 0 號、同 2367603 號、同 2492078 號、同 2492977 號、同 2492978 號、同 2607704 號、同 2739069 號、同 2739070 號、英國專利640731號、同736892號的各說明書；及日 本特公昭45-4554號、同49-5614號、特開昭60-176834 號、同60-203430號、同62-115035號的各公報。 -2 1- 200536617 塗料最好在表面溫度爲lor以下的鼓狀 延。最好在流延後經2秒以上吹風後進行乾燥 薄0吴從鼓狀物或帶上剝離後，還可進_^步經月 160°C逐漸改變溫度的高溫風的乾燥，以使殘留 以上的方法記載於日本特開平5- 1 7844號公報 法，可縮短從流延至剝離的時間。爲實施該方 時的鼓狀物或帶的表面溫度下，有必要使塗料 可將本發明中獲得的乙酸纖維素溶液，作 φ 延於作爲支撐體的帶上或鼓狀物上，也可流延 複數的乙酸纖維素溶液。在流延複數層的乙酸 的情況’可從沿支撐體的行進方向隔開間隔而 延口分別使含有乙酸纖維素的溶液流延，邊進 作薄膜，例如，可應用日本特開昭61-158414 1 - 1 224 1 9號及特開平1 1 - 1 98285號等所記載的 另外，還可利用從2個流延口流延乙酸纖 達成薄膜化，例如可由日本特公昭60-27562 _ 61 -94 7 24號、特開昭6 1 -947245號、特開昭61· 特開昭6 1 - 1 5 84 1 3號及特開平6- 1 3493 3號所記 另外，還可爲由低黏度的乙酸纖維素溶液包入 56- 1 626 1 7號所記載的高黏度的乙酸纖維素溶货 同時擠壓出該高、低黏度的乙酸纖維素溶液的 薄膜的流延方法。 或是，還可使用2個流延口，剝離由第1 於支撐體上的薄膜，利用在接觸於支撐體面側 物或帶上流 °將獲得的 目從 100至 ?溶劑蒸發。 。根據該方 法，在流延 凝膠化。 爲單層液流 2層以上的 纖維素溶液 設的複數流 行疊層邊製 號、特開平 方法。 維素溶液來 號、特開昭 104813 號、 載的方法。 曰本特開昭 交的液流，並 乙酸纖維素 流延口成形 進行第2流 -22- 200536617 延來製作薄膜，例如，日本特公昭44-20235號記載的方法。 流延之乙酸纖維素溶液可爲相同溶液，也可爲不同的乙酸 纖維素溶液，其並無特別的限定。爲使複數乙酸纖維素層 具有功能，只要從各流延口擠壓出對應該功能的乙酸纖維 素溶液即可。 又，本發明之乙酸纖維素溶液還可實施同時使其他的功 能層（例如，黏接層、染料層、抗靜電層、防眩層、UV吸 收層、偏光層等）的流延。在以往的單層液中，爲設置成必 • 要的薄膜厚度，需要以高濃度擠壓出高黏度的乙酸纖維素 溶液，該情況，乙酸纖維素溶液的穩定性差而產生固體物， 很多會造成凹凸小點故障或平面性不良的問題。作爲解決 此問題的方法，利用從流延口使複數乙酸纖維素溶液流 延，可將高黏度的溶液同時擠壓於支撐體上，不僅可製作 平面性優良的面狀薄膜，而且藉由使用濃厚的乙酸纖維素 溶液，可達成乾燥負荷的降低化，可提高薄膜的生產速度。 在乙酸纖維素薄膜上，爲改良機械物性或提高乾燥速 #度，可添加可塑劑。可塑劑係使用磷酸酯或碳酸酯。磷酸 酯的例中包含磷酸三苯酯（TPP)及磷酸三甲苯酯（TCP)。碳 酸酯則以酞酸酯及檸檬酸酯爲其代表。 酞酸酯的例中包含鄰苯二甲酸二甲酯（DMP)、鄰苯二甲 酸二乙酯（DEP)、鄰苯二甲酸二丁酯（DBP)、鄰苯二甲酸二 辛酯（DOP)、鄰苯二甲酸二苄酯（DPP)及鄰苯二甲酸二乙基 正己酯（DEHP)。檸檬酸酯的例中包含0-乙醯檸檬酸三乙酯 (OACTE)及0-乙醯檸檬酸三丁酯（OACTB)。 -23- 200536617 其他之碳酸酯的例中包含油酸丁酯、乙醯蓖麻油酸甲 酯、癸二酸二丁酯、種種的苯三酸酯。最好使用酞酸酯系 可塑劑（DMP、DEP、DBP、DOP、DPP、DEHP)。尤以 DEP 及DPP爲較佳。可塑劑的添加量最好爲纖維素酯量的n 〜25質量％，且以1〜20質量％爲較佳，以3〜15質量％爲 更佳。 還可在乙酸纖維素薄膜中添加防劣化劑（例如，防氧化 劑、過氧化物分解劑、自由基抑制劑、金屬惰性化劑、捕 φ 氧劑、胺）。有關防劣化劑，在日本特開平3- 1 9920 1號、 同 5-1907073 號、同 5-194789 號、同 5-271471 號、同 6- 1 07 8 54號的各公報中有記載。防劣化劑的添加量最好爲 調製之溶液（塗料）的0.01〜1質量％，而以0.01〜0.2質量％ 爲尤佳。若添加量未滿0.01質量％，則幾乎確認不到防劣 化劑的效果。若添加量超過1質量％時，則有確認出防劣化 劑滲出於薄膜表面的情況。作爲特佳的防劣化劑的例子， 可舉出丁基化羥甲苯（BHT)、三苄胺（TBA)。 φ 其次，說明聚合物薄膜的延伸處理。製成之乙酸纖維 素薄膜（聚合物薄膜），可進一步通過延伸處理來調整遲滯 作用。延伸倍率最好爲3〜100%。聚合物薄膜的厚度最好 爲40〜140μηι，尤其以70〜120μιη爲較佳。另外，藉由調 整該延伸處理的條件，可減小光學補償片的遲相軸的角度 的標準偏差。 延伸處理的方法雖無特別的限定，但作爲例子舉出依 拉幅器的延伸方法。在由上述溶劑分散法製作的薄膜上， -24- 200536617 使用拉幅器實施橫向延伸時，藉由控制延伸後的薄膜的狀 態，可減小薄膜遲相軸角度的標準偏差。具體而言，使用 拉幅器進行調整遲滯値的延伸處理，將剛經延伸後的聚合 物薄膜，在保持該狀態下，利用保持在薄膜的玻璃轉移溫 度附近，即可減小遲相軸角度的標準偏差。 當以該保持之薄膜的溫度較玻璃轉移溫度還低的溫度 來進行時，標準偏差將增大。另外，作爲其他的例子，在 輥子間進行縱向延伸時，若將輥子間的距離設爲較寬廣， • 即可減小遲相軸的標準偏差。 再者，說明聚合物薄膜的表面處理。在將聚合物薄膜 用作爲偏光板的透明保護膜的情況，最好對聚合物薄膜進 行表面處理。表面處理，係實施電暈放電處理、輝光放電 處理、火焰處理、酸性處理、鹼性處理或紫外線照射處理。 尤其以實施酸性處理、鹼性處理、亦即對聚合物薄膜的皂 化處理爲較佳。 再者，說明配向膜。配向膜具有規定光學異方向性層 ® 的碟狀液晶性分子的配向方向的功能。配向膜可由如有機 化合物（最好爲聚合物）的摩擦處理、無機化合物的斜向蒸 鍍、具有微槽層的形成、或依蘭米爾·布洛杰特薄膜法（LB 膜）的有機化合物（例如，ω-二十三烷酸、甲基氯化氨雙十 八烷酯、硬脂酸甲酯）的累積的裝置來設計。另外，還知有 藉由供給電場、供給磁場或光照射生成配向功能的配向膜。 配向膜最好由聚合物的摩擦處理來形成。聚乙烯醇係 一種較佳的聚合物。尤其以結合有疏水性基的變性聚乙烯 -25- 200536617 醇爲較佳。疏水性基因爲與光學異方向性層的碟狀液晶性 分子具有親和性，因此藉由將疏水性基導入聚乙烯醇，可 使碟狀液晶性分子均勻配向。 疏水性基係鍵結於聚乙烯醇的主鍵末端或側鍵。疏水 性基以碳原子數爲6以上的脂肪族基（最好爲烷基或烯基） 或芳香族基。在將疏水性基鍵結於聚乙烯醇的主鍵末端的 情況，最好在疏水性基與主鍵末端之間導入連結基。連結 基的例中包含-S-、、-NR2 -、-CS-及此等的組合。 φ 上述1及R2分別爲氫原子或碳原子爲1〜6的烷基（最好 爲碳原子爲1〜6的烷基）。 在將疏水性基導入聚乙烯醇的側鍵的情況，只要將聚 乙烯醇的乙酸乙烯單位的乙醯基（-CO-CH3)的一部分取代 爲碳原子爲7以上的醯基（-CO-R3)即可。R3係碳原子爲6 以上脂肪族基或芳香族基。還可使用市售的變性聚乙烯醇 (例如，MP103、MP203、R1 130、科拉雷（Kuraray)(股）製）。 用於配向膜的（變性）聚乙烯醇的皂化度，最好爲80%以 # 上。變性聚乙烯醇的聚合度最好爲200以上。 摩擦處理可由紙或布沿一定方向數次擦柔配向膜的表 面來實施。最好使用將長度均勻及粗細度均勻的纖維均勻 植毛而成的布。又，在使用配向膜對光學異方向性層的碟 狀液晶性分子進行配向後，即使除去配向膜，仍可保持碟 狀液晶性分子的配向狀態。亦即，配向膜係用以對碟狀液 晶性分子進行配向，其在橢圓偏光板的製造中是必須的， 而在製造之光學補償片中並不需要。 -26- 200536617 在透明支撐體與光學異方向性層之間設有配向膜的情 況，最好還可於透明支撐體與配向膜之間設置下塗層（黏接 層）。另外，爲達成面狀穩定化，還可依據需要添加檸檬酸 酯。 再者，說明光學異方向性層。光學異方向性層係由碟 狀液晶性分子所形成。碟狀液晶性分子一般具有光學性的 負一軸性。在本發明之光學補償片中，碟狀液晶性分子， 如第2圖所示，其圓盤面與透明支撐體面所成的角度，最 # 好在光學異方向性層的深度方向發生變化（混合配向）。碟 狀液晶性分子的光軸係存在於圓盤面的法線方向。 碟狀液晶性分子，具有圓盤面方向的折射率較光軸方 向的折射率大的雙折射率。光學異方向性層最好藉由上述 配向膜，以使碟狀液晶性分子配向，並利用固定該配向狀 態的碟狀液晶性分子來形成。碟狀液晶性分子最好藉由聚 合反應來固定。 又，光學異方向性層不存在遲滞値成爲0的方向。換言 ® 之，光學異方向性層的遲滯最小値係超過0的値。具體而 言，光學異方向性層，以其由下述式（I )所定義的Re遲滯 値處於10〜l〇〇nm的範圍、由下述式（Π )所定義的Rth遲 滯値處於40〜25 Oiim的範圍，且碟狀液晶性分子的平均傾 斜度爲20〜50度爲較佳。 (I ) Re = (nx — ny)xd (Π) Rth={(n2 + n3)/2~ nl}xd 在式（I )中’ nx爲光學異方向性層面內的遲相軸方向 -27- 200536617 的折射率，ny爲光學異方向性層面內的進相軸方向的折射 率，而d爲光學異方向性層的厚度。在式（Π)中，nl爲由 折射率橢圓體來近似光學異方向性層的情況的折射率主値 的最小値，η 2及η 3爲光學異方向性層的其他折射率主値， 而d爲光學異方向性層的厚度。 碟狀液晶性分子記載於各種文獻（C. Destrade et al.， Mol.Crysr. Liq. Cryst·，vol. 71，page 111(1981);日本化學 會編、季刊化學總說、No. 22、液晶的化學、第5章、第10 _ 章第 2 節（1994); B. Kohne et al., Angew. Chem. Soc· Chem. Comm., Page 1 794( 1 985) ； J. Zhang et al., J Am. Chem. Soc·，vol.116，page 2655(1994)。有關碟狀液晶性分 子的聚合，記載於日本特開平8-27284號公報。 爲利用聚合來固定碟狀液晶性分子，需要在碟狀液晶 性分子的圓盤狀芯上鍵結聚合性基作爲取代基。但是，若 將聚合性基直接鍵結於圓盤狀芯上，在聚合反應中要保持 配向狀態有困難。在此，在圓盤狀芯與聚合性基之間導入 ® 連結基。因此具有聚合性基之碟狀液晶性分子，最好爲由 下述式（m )所表示的化合物。 (ΠΙ ) D(-L-Q)n 在式（m)中，D爲圓盤狀芯，L爲二價的連結基，Q爲 聚合性基，且η爲4〜12的整數。 以下顯示圓盤狀芯（D)的例子。在以下的各例中，LQ(或 QL)意味著二價的連結基（L)與聚合性基（Q)的組合。 在式（I )中，二價的連結基（L)最好從伸烷基、伸烯基、 -28- 200536617 伸芳基、-CO-、-NH-、·0-、-s-及此等的組合所組成的群 中所選出的二價連結基。二價的連結基（L)尤以至少組合二 組以上的從伸烷基、伸芳基、-CO-、-NH-、-0-及-S-組成 的群中所選出的二價基的二價連結基爲較佳。二價的連結 基（L)尤以至少組合二組以上的從伸烷基、伸芳基、-CO-、 及-〇-組成的群中所選出的二價基的二價連結基爲更佳。伸 烷基的碳原子數最好爲1〜12。伸烯基的碳原子數最好爲2 〜12。伸芳基的碳原子數最好爲6〜10。 φ 以下顯示二價的連結基（L)的例子。其左側鍵結於圓盤狀 芯（D)，右側鍵結於聚合性基（Q)。AL意味著伸烷基或伸烯 基，AR意味伸芳基。又，伸烷基、伸烯基及伸芳基可具有 取代基（例如，烷基）。 L 1 ： -AL-C0-0-AL-L 2 : -AL-C0-0-AL-0-L 3 ·· -AL-C0-0-AL-0-AL- L 4 ： -AL-C0-0-AL-0-C0- φ L 5 : -C0-AR-0-AL- L 6 ·· -C0-AR-0-AL-0- L 7 ： -C0-AR-0-AL-0-C0- L 8 : -CO-NH-AL- L9 : -NH-AL-0-L 10 : -NH-AL-0-C0- L 1 1 : -0- AL- L 12 ： -O-AL-0- -29- 200536617 L 13 : -O-AL-O-CO-L 14 : -O-AL-O-CO-NH-AL- L 15 : -O-AL-S-AL- L 1 6 · - O - C O - AR-O-AL-CO- L 17 : -O-CO-AR-O-AL-O-CO-L 18 : -O-CO-AR-O-AL-O-AL-O-CO- L 19 : -O-CO-AR-O-AL-O-AL-O-AL-O-CO-L 20 : -S-AL- • L 21 : -S-AL-O- L 22 : -S-AL-O-CO-L 23 : -S-AL-S-AL-L 24 : -S-AR-AL- 式（I )之聚合性基（Q)係依據聚合反應的種類所決定。 聚合性基（Q)最好爲不飽和聚合性基（Q1〜Q7)或環氧 基（Q 8)，而以不飽和聚合性基爲較佳，尤以乙烯不飽和聚 合性基（Q1〜Q6)爲較佳。在式（瓜）中，η爲4〜12的整數。 鲁具體的數字係依據圓盤狀芯（D)的種類所決定。又，複數的 L與Q的組合可各異，也可爲相同。 光學異方向性層可利用將包含碟狀液晶性分子及依據 需要的聚合性開始劑及任意的成分的塗布液，塗佈於配向 膜上所形成。光學異方向性層的厚度最好爲0.5〜100/xm， 尤以0.5〜30μιη爲較佳。 在維持配向狀態下固定經配向之碟狀液晶性分子。固 定化最好藉由聚合反應來實施。聚合反應包含使用熱聚合 -30- 200536617 開始劑的熱聚合反應與使用光聚合開始劑的光聚合反應。 其中以光聚合反應爲較佳。光聚合開始劑的例中包含α-羰 基化合物（記載於美國專利第2367661號、同2367670號、 的各說明書）、偶姻醚（記載於美國專利第2448828號的說 明書）、α-烴基取代芳香族偶姻化合物（記載於美國專利第 2 7 225 12號的說明書）、多核苯醌化合物（記載於美國專利第 3046127號、同2951758號的各說明書）、三芳基咪唑二聚 物與Ρ-胺基酚酮的組合（記載於美國專利第3 549367號的說 φ 明書）、吖啶及二苯并吡嗪化合物（記載於日本特開昭 60-105667號公報、美國專利第4239850號的說明書）、及 噁二唑（oxadiazole)化合物（記載於美國專利第42 1 2970號 的說明書）。 光聚合開始劑的使用量，最好爲塗布液的固體量的 0.01〜20質量％，其中尤以〇.5〜5質量％爲較佳。碟狀液 晶性分子的聚合用的光照射，最好使用紫外線。照射能量 最好爲20〜5000mJ/cm2，尤以100〜800mJ/cm2爲較佳。另 • 外，爲促進光聚合反應，還可在加熱條件下實施光照射。 還可將保護層設於光學異方向性層上。另外，爲達成面狀 穩定化，還可依據需要添加檸檬酸酯。 接著，說明使用第1圖所示光學補償薄膜的製造線的 光學薄膜的製造方法。首先，從輸出機66輸送預先形成有 配向膜形成用的聚合物層的厚度爲40〜3 ΟΟμηι的棉網16。 棉網16係由導輥68所導引而被送入摩擦處理裝置70內， 藉由摩擦輥子72摩擦處理聚合物層。接著，藉由除塵機 -31- 200536617 74除去黏附於棉網1 6表面的塵埃。然後，藉由線桿塗布 裝置1 0，將含有碟狀向列型液晶的塗布液塗佈於棉網1 6 上。 此時，藉由夾著線桿塗布裝置1 0而設於前後方向的張 力調整機構50，將棉網16的張力控制在100〜40 ON/m。另 外，棉網16的相對塗佈用線桿12(參照第2圖）的捲取角度 0，調整成爲1〜30度。 塗布液的黏度係調整爲1〜20mPa · S，塗布液的固體 φ 濃度係調整爲1 5〜50重量％，塗布液的塗佈時的膜厚係調 整爲 0.01 〜90/im。 藉由此種塗佈條件可防止塗布膜厚的不均勻化，可改 善光學薄膜的不勻。 其後，經乾燥區76、加熱區78後形成液晶層。又，藉 由紫外線燈80照射液晶層以使液晶交聯，可形成所需的聚 合物。然後，形成有聚合物的棉網1 6，係由捲取機82所 捲取。 φ 以上，說明了有關本發明之光學薄膜的製造方法的實 施形態，但本發明並不限於上述實施形態，其可採取各種 的形態。 例如，本實施形態中，採用線桿塗布裝置1 〇作爲塗佈 裝置，但也可採用其他的裝置、如凹槽輥塗布器或輥子塗 布器作爲塗佈裝置。以下，參照圖式進行說明。 第4圖爲顯示3支逆輥塗布器的主要部分的示意圖。 第4圖中，在蓄積有塗布液110的液槽109內，邊局部浸 -32- 200536617 漬塗佈輥子108邊沿箭頭l〇8a方向進行旋轉，利用捲 布液1 1 〇而將塗布液1 1 0供給塗佈輥子1 0 8的表面。 塗佈輥子108表面的塗布液11〇，藉由沿箭頭112a方 轉的測油輥子1 1 2來適宜調整液量。繞捲於沿箭頭1 1 1 向旋轉的支撐輥子1 1 1的棉網1 1 4，邊沿箭頭1 1 4 a方 動邊塗佈塗布液110，在棉網114上形成指定膜壓的 層。 又，第4圖之裝置中，棉網1 1 4係繞捲於支撐輥子 φ 上，因此棉網114的相對塗佈輥子108的捲取角度0， 何學上接近於0度，但利用棉網1 1 4的厚度、塗布液 的塗佈厚度、輥子的彈性變形等，確保指定的捲取角S 第5圖爲顯示凹槽輥塗布器的主要部分的示意圖。 圖中，在蓄積有塗布液117的液槽1116內，邊局部浸 槽輥11 5邊沿箭頭1 1 5a方向進行旋轉，利用捲起塗布液 而將塗布液1 1 7供給凹槽輥輥子1 1 5的表面。供給凹 1 1 5上的塗布液1 1 7，藉由刮板1 1 9來適宜調整液量。 • 於沿箭頭11 8 a方向旋轉的支撐輥子1 1 8的棉網1 2 0， 箭頭120a方向移動邊塗佈塗布液117，在棉網120上 指定膜壓的塗佈層。 又，第5圖之裝置中，棉網120也係繞捲於支撐 1 1 8上，因此棉網1 20的相對塗布輥1 1 5的捲取角度Θ 幾何學上接近於〇度，但利用棉網1 20的厚度、塗布液 的塗佈厚度、輥的彈性變形等’確保指定的捲取角度 以上說明的凹槽輥塗布器或輥塗布器，也可附加 起塗 供給 向旋 • a方 向移 塗佈 111 在幾 1 10 ΐ Θ 〇 第5 漬凹 :1 1 了 槽輥 繞捲 邊沿 形成 輥子 ，在 1 17 Θ 〇 張力 -33- 200536617 調整裝置，藉此可實施本發明之光學薄膜的製造方法。 [實施例] (乙酸纖維素溶液的調製） 將下述的組成物投入混合槽中，邊加熱邊攪拌，溶解 各成分，調製完成乙酸纖維素溶液。 乙酸纖維素溶液的組成 醋化度爲60.9%的乙酸纖維素 1〇〇質量份 磷酸三苯酯（可塑劑） 7.8質量份 聯苯基磷酸二苯酯（可塑劑） 3.9質量份 二氯甲烷（第1溶劑） 3 3 6質量份 甲醇（第2溶劑） 29質量份 (遲滯値上升劑溶液的調製） 於其他的混合槽中投入1 6質量份下述的遲滯値上升 劑，80質量份的二氯甲烷及20質量份的甲醇，邊加熱邊 攪拌，以調製遲滯値上升劑溶液。 [化1]200536617, Nine, Description of the invention: [Technical field to which the invention belongs] The present invention relates to a method for manufacturing an optical film, and more particularly to an optical film suitable for improving optical compensation films, anti-reflection films, anti-glare films, or liquid crystals. The unevenness of the layer is quite effective for producing an optical film such as an optical film. [Prior art] Compared with a CRT (cathode ray tube), a liquid crystal display device (LCD) has the advantages of being thin, light, and low in power consumption. This liquid crystal display device is composed of a liquid crystal cell and polarizing plates arranged above and below the liquid crystal cell. The liquid crystal cell is composed of rod-shaped liquid crystal molecules, two substrates for sealing the rod-shaped liquid crystal molecules, and an electrode layer for applying a voltage to the rod-shaped liquid crystal molecules. In order to align the enclosed rod-shaped liquid crystalline molecules, an alignment film is provided on two substrates. In order to remove the color of the image displayed on the liquid crystal cell, an optical compensation film (a retardation plate) is often provided between the liquid crystal cell and the polarizing plate. The laminated body of the optical compensation film and the polarizing plate has a function as an elliptical polarizing plate. The optical compensation film also has a function of enlarging the viewing angle of the liquid crystal cell. As such an optical compensation film, a thin film made of a synthetic polymer is used. However, it has been proposed to replace the optical compensation film with a structure having an optically anisotropic layer made of a disk-shaped liquid crystalline molecule on a transparent support (for example, patent document). 1 ~ 4, etc.). Specifically, the dish-like liquid crystalline molecules are aligned, and the alignment state is fixed to form an optical compensation film. Generally, dish-shaped liquid crystalline molecules have a large birefringence of 200536617. In addition, the dish-like liquid crystal molecules have various alignment states. Therefore, by using a discotic liquid crystalline molecule, an optical compensation film having optical properties not available in conventional synthetic polymer films can be produced. [Patent Document 1] Japanese Unexamined Patent Publication No. 6-214116 [Patent Document 2] US Patent No. 5 5 83679 [Patent Document 3] US Patent No. 5667703 [Patent Document 4] West German Patent Gazette No. 39 1 1 620A1 [Summary of the Invention] (Problems to be Solved by the Invention) However, even for the above-mentioned optical compensation film, sufficient performance cannot be obtained in actual situations. That is, in recent years, with the advancement of technology related to liquid crystal display devices, there has been an increasing demand for improvement in image display quality. In particular, unevenness in image display has become a problem. In order to improve the image display quality, higher-level improvement requirements have been proposed for this. The present invention has been made in view of the above problems, and an object thereof is to provide a method for producing an optical film which is extremely suitable for obtaining a good image display quality in a liquid crystal display device. (Apparatus for solving the problem) In order to achieve the above object, the present invention provides a method for producing an optical film, which is a method for producing an optical film formed by applying a coating liquid on a transparent film in progress by a coating device. The tension of the transparent film is controlled to be 100 to 400 N / m during cloth deployment. 200536617 According to the present invention, since the tension of the transparent film during coating is optimized, unevenness in the thickness of the coating film can be prevented, and unevenness in image display can be improved. Here, the tension refers to the width (unit: m) of the transparent film divided by the tension (unit ·· N) applied to the traveling direction of the transparent film. The tension is preferably 150 to 350 N / m, and more preferably 200 to 300 N / m. The optical film is a film having various functions such as an anti-reflection film and an anti-glare film, in addition to the optical compensation film. In the present invention, the coating device is preferably any one of a wire coater, a gravure coater, or a roll coater. Such a coating device is suitable for coating a uniform film, and the use of such a coating device is more suitable for optimizing the tension of a transparent film. In the present invention, in the coating device, the winding angle of the roll member of the transparent film is preferably 1 to 30 degrees. By setting the winding angle within this range, unevenness of the coating film layer can be prevented. The roller member refers to a Φ roller for supplying a coating liquid of each applicator (coating device), and is a coating wire rod 12 (see FIG. 3) in a wire rod coating device 10 (see FIG. 2) described later. In the case of three counter roll applicators (refer to FIG. 4), it is the coating roll 108, and in the notch roll applicator (refer to FIG. 5), the notch rolls 1 150 and the “winding angle” refer to Winding angle on coiling conduction in mechanism. The winding angle is preferably 3 to 20 degrees, and more preferably 5 to 15 degrees. In the present invention, the thickness of the transparent film is preferably 40 to 300 μm. This thickness of the transparent film is more suitable for the optical thin 200536617 film of the present invention. The thickness of the transparent film is preferably 50 to 20 0 / xm, and more preferably 60 to 120 / im. In the present invention, the viscosity of the coating liquid is preferably 1 to 20 mP a · s. This viscosity coating solution is more suitable for the production of the optical film of the present invention. The viscosity of the coating liquid to 1. 5 ~ 20mPa · s is preferred, while 2 ~ lOmPa. s is better. In the present invention, the solid content concentration of the coating liquid is preferably 15 to 50% by mass. This coating solution having a solid content concentration is more suitable for the production of the optical film of the φ invention. In addition, in the present invention, the film thickness of the coating liquid is preferably 0. 01 to 90 / im. This film thickness can be suitably used for the optical film of the present invention. The film thickness is 0. 03 ~ 60 / xm is better, and 0. 05 ~ 30μιη is more preferable. (Effects of the Invention) As described above, according to the present invention, since the tension of the transparent film at the time of coating is optimized, unevenness in the thickness of the coating film can be prevented, and unevenness in the optical film can be improved. [Embodiment] Hereinafter, preferred embodiments of the method for producing an optical film of the present invention will be described in detail with reference to the drawings. Fig. 1 is an explanatory diagram illustrating a production line of an optical compensation film to which the method for producing an optical film of the present invention is applied. Fig. 2 is a cross-sectional view showing an example of a wire rod coating device 10 which is a coating device in the manufacturing line. As shown in FIG. 1, the optical compensation film manufacturing line has a configuration in which a cotton 200536617 net 16 having a polymer layer for forming an alignment film formed thereon is transported from an output device 66. The cotton web 16 is guided by the guide roller 68 and is fed into the friction processing device 70. The rubbing roller 72 is provided so that the polymer layer can be rubbed. A dust remover 74 is provided downstream of the friction roller 72, and can remove dust adhered to the surface of the cotton net 16. A wire rod coating device 10 is provided downstream of the dust remover 74, and a coating liquid containing a disc-shaped nematic liquid crystal is formed so as to be applicable to the cotton web 16. A drying area 76 and a heating area 78 are arranged in the downstream thereof, and a liquid crystal layer can be formed on the cotton web 16. Further, an ultraviolet lamp 80 is provided downstream of the ultraviolet lamp 80, and the liquid crystal is cross-linked by irradiation with ultraviolet rays to form a desired poly (phi) compound. Then, with the winder 82 provided downstream, the cotton web 16 on which the polymer is formed can be wound. A pair of driving rollers 52, nip rollers 54, driving rollers 56, and nip rollers 58 are respectively provided on the upstream and downstream sides of the wire coating apparatus 10, and these form a tension adjusting mechanism 50. That is, by setting the rotation speed (peripheral speed) of the driving roller 56 and the nip roller 58 downstream of the wire rod coating device 10 to be higher than the rotational speed (peripheral speed) of the driving roller 52 and the nip roller 54 upstream of the rod coating device 10. ) Is large, it can be a state where a specified tension is generated in the traveling direction of the cotton web 16. The tension adjustment mechanism 50 is not limited to this structure, and various other structures may be adopted. As shown in FIG. 2, the wire rod coating device 10 is applied to the cotton web 16 which is guided by a pair of guide rollers 18 and 18, and the coating liquid is applied by a coating head 14 including a coating wire rod 12 installation. The pair of guide rollers 18 and 18 are arranged in a state where the web 16 is brought closer to the application thread rod 12. The take-up angle of the cotton web 16 with respect to the coating wire rod 12 is Θ. The coating head 14 is mainly composed of a coating wire rod 12, a supporting member 20, and a coating block. The coating wire rod 12 is rotatably supported on the supporting member 20. Collecting cavities 26, 28 and slits 30, 32 are formed between the support member 20 and each coating block 22, and a coating liquid is supplied in each of the current collectors B 2 8. The coating supplied to each of the current collecting chambers 2 6 and 2 8 is uniformly pressed along the width direction of the cotton web through the narrow slits 30 and 32. The coating web 12 is transported in the direction of the cotton web 16 with respect to the coating wire rod 12. Side (hereinafter, referred to as the "primary side") to form the primary side coating liquid beads 34, and the swim side (hereinafter, referred to as the "secondary side") to form the secondary side coating liquid beads φ, and so on The liquid is applied on the traveling ^. The coating liquid supplied excessively from the header chambers 26 and 28 overflows between each of the coatings 22 and 24 and the web 16 and is collected by a side (not shown). The supply of the coating liquid to the header chambers 26 and 28 may be performed from the central portions of 26 and 28 or from the end portions. As shown in FIG. 3, the coating wire rod 12 is provided with a steel wire row 42 formed by tightly winding a steel wire 40 in a round shape on a round rod-shaped rod 38, and the coating liquid is held on the steel wire row 42 to apply the coating. Attachment tape 16 in liquid transfer coating. As the material constituting the rod 38 and the steel wire 40 of the coating wire rod 12, various metals including stainless steel are used, as long as they do not contaminate the coating and satisfy the strength. In addition, the rod 3 8 is preferentially used with a diameter of 5-. On the other hand, one having a roundness of 2 μηχ or less is used. Specifically, it is good to use the unit cross-section area (imaginary perfect circle) of the relative wire 40, which lacks support, 24, 26, and liquid distribution. Borrowed upstream, in the next 36 〇 〖帛 1 16 The distribution chamber returned by the block trough is spiral. It lies in the traveling mass, can be distributed, -15 mm, the most damaged or sudden -10- 200536617, etc. The smaller the proportion of the area of the irregular part). The coating wire rod 12 configured as described above is rotated forward in the conveying direction of the web 16 as described above. In this embodiment, the wire rod coating device 10 can clean the environment. At this time, the degree of cleanliness is preferably a grade of 100 or less, and a grade of 10 or less is j. The above-mentioned wire rod coating device 10 is particularly suitable for a thin layer manufacturing line P that can be applied to an optical compensation film as the present invention. The connecting strips used are 16 or more polymer films. The polymer film is preferably a refractor. Examples of the polymer are preferably cellulose-containing polymers (for example, Arton (produced by JSR), manufactured by ZENON (shares)) and polymethacrylate, especially cellulose esters. For the better, the acid ester is the best. This lower fatty acid means that the number of carbon atoms is preferably 2 (cellulose acetate) 4 (cellulose butyrate). Cellulose esters include cellulose acetate, diacetyl cellulose and triethyl cellulose. In general, cellulose and cellulose acetate butyrate are mixed fatty acids. Generally, the cellulose acetates of 2, 3, and 6 have a tendency to pass at 1/3 of the overall degree of substitution, but at the 6th position. In the present invention, the sixth f] of cellulose acetate is more preferable than the second and third positions. (For example, as shown in Figure 2 below 0.5%, it is relatively less than 1,000 installed in a clean room, etc., and so on: Good .: Coating is quite effective, because the light transmittance is 80%, which is not easy to cause. The external force found that the double polymer, raw borneol Zeonor, Zeonex (homoester-based cellulose-based polymerized cellulose lower fatty acids with a fatty acid of 6 or lower. 3 or 3 (cellulose propionate) is preferred. This example can be used as Acetic acid propionate. The degree of substitution of non-equidistant groups has a degree of substitution to reduce the t-hydroxyl group. -11- 200536617 Relative to the overall degree of substitution, the 6th position of the hydroxyl group is preferably 30% or more and 40% or less. 31% or more is more preferable, and more preferably 32% or more. The degree of substitution of the hydroxyl group at the 6th position of cellulose acetate is more preferably 0.88 or more. In addition to ethenyl, it may be substituted by methylpropionyl, butyryl, pentamyl, benzyl, acryl, etc., which is a fluorenyl group having a carbon number of 3 or more. Measurement of the degree of substitution at each position, It can be determined by NMR. As the cellulose acetate of the present invention, Japanese Patent Application Laid-Open φ Obtained by Synthesis Method 1 in Paragraph Nos. 043 to 0044 of Publication No. 11-5851, Synthesis Example 2 in Paragraph Nos. 0048 to 0049, and Synthesis Method 3 in Paragraph Nos. 005 1 to 0052 Cellulose acetate. To adjust the hysteresis of polymer films, an aromatic compound with at least two aromatic rings is used as a hysteresis raising agent. When cellulose acetate films are used as polymer films, aromatic compounds are used. Relative to 100 parts by mass of cellulose acetate at 0. Use within the range of 01 to 20 parts by mass. Aromatic compounds are especially present at 100% by mass of cellulose acetate. It is more preferable to use it in the range of 5 to 15 parts by mass, and it is more preferable to use it in the range of 0.1 to 10 parts by mass. A combination of two or more kinds of aromatic compounds can also be used. The aromatic compound contains an aromatic heterocyclic ring in addition to the aromatic hydrocarbon ring in the aromatic ring. The aromatic hydrocarbon ring is particularly preferably a 6-membered ring (that is, a benzene ring). Aromatic heterocycles are generally unsaturated heterocycles. The aromatic heterocyclic ring is preferably a 5-membered ring, a 6-membered ring, or a 7-membered ring, and particularly preferably a 5-membered ring or a 6-membered ring. Aromatic heterocycles generally have the most double bonds. The hetero atom is preferably a nitrogen atom, an oxygen atom -12-200536617, and a sulfur atom, and a nitrogen atom is particularly preferred. Examples of the aromatic heterocyclic ring include a furan ring, a thiophene ring, a pyrrole ring, an oxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, an imidazole ring, a pyrazole ring, a furacyl ring, and a tri 15 ring , Cytidine ring, cytidine ring, pibitazine ring, chelation ring, pyrazine ring and 1,3,5-triazine ring. The aromatic ring is preferably a benzene ring, a furan ring, a thiophene ring, a pyrrole ring, an oxazole ring, a thiazole ring, an imidazole ring, a triazole ring, a pyridine ring, a pyrimidine ring, a pyridine ring, and a 1,3,5-triple Ring, especially benzene ring and 1,3,5_ triple well ring are more preferred. The aromatic compound preferably has at least one 1,3,5_ φ three plough ring. The number of aromatic rings of the aromatic compound is preferably 2 to 20, more preferably 2 to 12, particularly preferably 2 to 8, and most preferably 2 to 6. The bonding relationship between two aromatic rings can be classified into (a) the case of forming a fused ring, (b) the case of directly bonding with a single bond, and (c) the case of bonding through a linking group (because it is aromatic Family rings, so you cannot use a splice ring). The bonding relationship may be any one of (a) to (c). Examples of the fused ring of (a) (fused ring of two or more aromatic rings) include an indene ring, a naphthalene ring, a fluorene ring, a manganese ring, a phenanthrene ring, an anthracene ring, a pinene naphthalene ring, and 2,3 Benzoanthracene ring, tar brain ring, indole ring, isoindole ring, benzofuran ring, benzothiophene ring, indole ring, benzoxazole ring, benzothiazole ring, benzotriazole ring, Benzotriazole ring, purine ring, benzopyrazole ring, benzotrihydropiperan ring, quinoline ring, isoquinoline ring, quinazine ring, quinazoline ring, oxoline ring, benzopyridine ring, Triazine ring, pyrimidine ring, carbazole ring, acridine ring, 3,4 benzo-quinoline ring, dibenzopyran ring, dibenzopyrazine ring, phenothion ring, morphine ring, thio ring , Phenoxazine ring and thiaindene ring. Among them, naphthalene ring, fluorene ring, pyrene late ring, -13-200536617 benzoxazole ring, benzothiazole ring, benzimidazole ring, benzotriazole ring and quinoline ring are preferred. (b) The single bond is preferably a bond between carbon atoms of two aromatic rings. Two aromatic rings are bonded with two or more single bonds, and an aliphatic ring or a non-aromatic heterocyclic ring may be formed between the two aromatic rings. The (C) linking group is also preferably bonded to carbon atoms of two aromatic rings. The linking group is preferably an alkylene group, an alkenyl group, an alkynyl group, -CO-, -O-, -NH-, -S- or a combination thereof. Examples of combined linking groups are shown below. φ In addition, the left-right relationship of the following examples of linking groups may be reversed. c 1: -C0-0-c 2: -CO-NH-c 3 · -Yen Yuanji -0-c4: -NH-CO-NH-c 5: -NH-CO-Oc 6 ·-〇- C Ο-Ο ~ c 7 ·-〇- 伸 元 基 -〇 · _ c8: -CO-endenyl- c9: -CO-endenyl · NH-clO: _CO-endenyl-0- cl 1: -Alkylene-C0-0_alkylene-0-C0 -alkylene- c 1 2: -alkylene-C Ο-Ο -alkylene-0-C Ο -alkylene_ Ο- cl3: -0-C0 -alkylene-CO -0- cl4:-NH-CO-alkenyl- cl5: -0-C0 -alkenyl- -14- 200536617 The aromatic ring and linking group may further have Substituents. Examples of the substituent include a halogen atom (F, Cl, Br, I), a hydroxyl group, a carboxyl group, a cyano group, an amine group, a nitro group, a sulfonic acid group, a carbamoyl group, a sulfamoyl group, a urea group, Alkyl, alkenyl, alkynyl, aliphatic fluorenyl, aliphatic fluorenyloxy, alkoxy, alkoxycarboxyl, alkoxycarboxamino, alkylthio, aminesulfonyl, aliphatic sulfonyl, Aliphatic sulfonamido, aliphatic substituted amino, aliphatic substituted aminomethylamido, aliphatic substituted sulfamoamido, aliphatic substituted urea, and non-aromatic heterocyclic groups. The number of carbon atoms of the alkyl group is preferably 1 to 8. Compared with cyclic alkyl groups, chain alkyl groups are preferred, and linear alkyl groups are particularly preferred. The alkyl group may also have a substituent (for example, a hydroxyl group, a carboxyl group, an alkoxy group, and an alkyl-substituted amino group). Examples of alkyl (including alkyl) include methyl, ethyl, η-butyl, η-n-hexyl, 2-hydroxyethyl, 4-carboxybutyl, 2-methoxyethyl, and 2-di Ethylaminoethyl. The number of carbon atoms in the alkenyl group is preferably 2 to 8. Compared with cyclic alkenyl, chain alkenyl is preferred, and linear alkenyl is particularly preferred. The alkenyl group may further have a substituent. Examples of alkenyl include vinyl, propenyl, and 1-hexenyl. The number of carbon atoms in the alkynyl group is preferably 2 to 8. And compared with cyclic alkynyl, chain alkynyl is preferred, and linear alkynyl is particularly preferred. An alkynyl group may further have a substituent. Examples of alkynyl include ethynyl, 1-butynyl, and 1-hexynyl. The number of carbon atoms of the aliphatic fluorenyl group is preferably 1 to 10. Examples of aliphatic fluorenyl include acetamidine, propylamidine, and butylamidine. The number of carbon atoms of the aliphatic fluorene oxide group is preferably 1 to 10. Examples of the aliphatic fluorenyloxy group include ethoxyloxy. The number of carbon atoms of the alkoxy group is preferably 1 to 8. An alkoxy group may also have a substituent (for example, -15-200536617 oxo). Examples of alkoxy groups (including substituted alkoxy groups) include methoxy, ethoxy, butoxy, and methoxyethoxy. The number of carbon atoms of the alkoxycarbonyl group is preferably 2 to 10. Examples of the alkoxycarbonyl group include a methoxycarbonyl group and an ethoxycarbonyl group. The number of carbon atoms of the alkoxycarbonylamino group is preferably 2 to 10. Examples of the alkoxycarbonylamino group include a methoxycarbonylamino group and an ethoxycarbonylamino group. The number of carbon atoms in the alkylthio group is preferably 1 to 12. Examples of the alkylthio group include a methylthio group, an ethylthio group, and an octylthio group. The number of carbon atoms of the φalkylsulfonyl group is preferably 1 to 8. Examples of the alkylsulfonyl group include a methylsulfonyl group and an ethylsulfonyl group. The number of carbon atoms of the aliphatic amido group is preferably 1 to 10. Examples of the aliphatic amido group include acetamide. The number of carbon atoms of the aliphatic sulfonamide group is preferably 1 to 8. Examples of the aliphatic sulfonamido group include a methanesulfenamido group, a busulfenamido group, and an? -Octylsulfenamido group. The number of carbon atoms of the aliphatic substituted amine group is preferably 1 to 10. Examples of the aliphatic substituted amine group include dimethylamine, diethylamine, and 2-carboxyethylamine. # The number of carbon atoms of the aliphatic substituted aminoformyl group is preferably 2 to 10. Examples of the aliphatic substituted aminomethylamidino include methylaminomethylamidino and diethylaminomethylamidino. The number of carbon atoms of the aliphatic substituted sulfamoyl group is preferably 1 to 8. Examples of the aliphatic substituted sulfamoyl group include methylsulfamomethyl and diethylsulfamomethyl. The number of carbon atoms of the aliphatic substituted ureido group is preferably 2 to 10. Examples of the aliphatic substituted ureido group include a methylurea group. Examples of the non-aromatic heterocyclic group include guaridine and morpholine. The molecular weight of the hysteresis ramp-up agent is preferably from 300 to 800. Specific examples of the delayed radon rising agent are described in Japanese Patent Laid-Open No. 2000-1 1 1914 -16- 200536617, the same as Japanese Patent Laid-Open No. 2000-275434, PCT / JP00 / 026 1 9 and the like. A case where a cellulose acetate film is used as the polymer film will be specifically described below. The cellulose acetate film is preferably produced by a solvent dispersion method. In the solvent dispersion method, a solution (paint) in which cellulose acetate is dissolved in an organic solvent is used to produce a thin film. The organic solvent preferably contains an ether having 3 to 12 carbon atoms, a ketone having 3 to 12 carbon atoms, an ester having 3 to 12 carbon atoms, and a halogenated hydrocarbon having 1 to 6 carbon atoms. Solvent. The ether, ketone, and ester may have a cyclic structure. Two or more compounds having any of functional groups (β 卩, -0-, -CO-, and -COO-) of ether, ketone, and ester can also be used as the organic solvent. The organic solvent may have other functional groups such as an alcoholic hydroxyl group. In the case of an organic solvent having two or more kinds of functional groups, the number of carbon atoms may be within a predetermined range of a compound having any one of the functional groups. Examples of the ethers having 3 to 12 carbon atoms include diisopropyl ether, diφmethoxymethane, dimethoxyethane, 1,4-dioxane, 1,3-dioxane, and tetrahydrofuran. , Anisole and phenylethyl ether. Examples of ketones having 3 to 12 carbon atoms include acetone, methyl ethyl ketone, diethyl ketone, diisobutyl ketone, cyclohexanone, and methylcyclohexanone. Examples of the ester having 3 to 12 carbon atoms include ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate, and pentyl acetate. Examples of the organic solvent having two or more kinds of functional groups include ethyl 2-ethoxyacetate, 2-methoxyethanol, and 2-butoxyethanol. The number of carbon atoms of the halogenated hydrocarbon is preferably one or two, and more preferably one. The halogen of the halogenated hydrocarbon is preferably 200536617 chlorine. The ratio of halogen atoms in halogenated hydrocarbons to halogens is preferably 25 to 75 °° / 〇 ', especially 30 to 70 ％%, more preferably 35 to 65 mol%, and 40 to 60 mol% is best. Dichloromethane is a representative halogenated hydrocarbon. From a technical point of view, halogenated hydrocarbons such as dichloromethane can be used without any problems, but from the viewpoint of the global environment and the working environment, it is preferable that the organic solvent does not substantially contain halogenated hydrocarbons. "Substantially not contained" means that the proportion of the halogenated hydrocarbon in the organic solvent is less than 5% by mass (preferably less than 2?% By mass). In addition, it is preferable that halogenated hydrocarbons such as dichloromethane are not completely detectable from the produced halide cellulose film. It is also possible to mix two or more types of organic solvents. In addition, cellulose acetate can be prepared by a general method. A general method means processing at a temperature of 0 ° C or higher (normal temperature or high temperature). The solution can be prepared by a method and a device for preparing a coating material using a general solvent dispersion method. Further, in the case of a general method, it is preferable to use a halogenated hydrocarbon (especially dichloromethane) as an organic solvent. The content of cellulose acetate was adjusted to contain 10 to 40% by mass in the obtained solution. The content of cellulose acetate is preferably 10 to 30% by mass. To the organic solvent (main solvent), any of the additives described below may be added. The solution can be prepared at room temperature (0 ~ 40 ° C) by stirring the cellulose acetate and the organic solvent. High-concentration solutions can also be stirred under pressure and heat. Specifically, the cellulose acetate and the organic solvent are placed in a pressurized container and hermetically sealed, and they are stirred while being heated to a temperature in the range above the boiling point of the solvent at normal temperature and the solvent does not boil. The heating temperature is usually -18-200536617 above 40 ° C, and preferably 60 ~ 200 ° C, especially 80 ~ 1 10 ° C. The ingredients can also be put into a container after rough mixing in advance. Alternatively, they can be put into the container sequentially. The container needs to have a structure capable of being stirred. The container can be pressurized by injecting an inert gas such as nitrogen. It is also possible to take advantage of the increase in the vapor pressure of the heated solvent. Alternatively, the components may be added under pressure after the container is closed. In the case of heating, heating from the outside of the container is preferred. For example, a jacket type heating device can be used. In addition, a flat φ heater can be installed on the outside of the container to circulate the liquid through a pipe to heat the entire container. It is preferable that a stirring blade is provided inside the container, and the stirring blade is used for stirring. The stirring wing is preferably a length that can reach near the wall of the container. At the end of the stirring blade, in order to renew the liquid film on the container wall, it is best to provide a scraping blade. Meters such as pressure gauges and thermometers can also be installed on the container. Each component was dissolved in a solvent in a container. The prepared coating material is taken out from the cooled container or after being taken out, it is cooled using a heat exchanger or the like. The preparation of the cellulose acetate solution (coating material) of the present invention is performed in accordance with a cooling solution method, and this is described below. First, at a temperature close to room temperature (-10 to 40 ° C), gradually add cellulose acetate while stirring in an organic solvent. When plural solvents are used, the order of addition is not particularly limited. For example, after adding cellulose acetate to the main solvent, other solvents (such as a colloidal solvent such as ethanol) can be added. Conversely, a main solvent in which the colloidal solvent is wetted with cellulose acetate in advance can be effectively prevented Dissolve evenly. The content of cellulose acetate is preferably adjusted to contain 10 to 19-200536617 40% by mass in the mixture. The content of cellulose acetate is particularly preferably 10 to 30% by mass. In addition, any of the additives described below may be added to the mixture. Second, the mixture is cooled to -100 ° C ~ -10 ° C (with -80 ° C ~-10 ° C is preferred, and -50 ° C ~ -20 ° C is particularly preferred, at -50 ° C ~ -30 ° C is the best). Cooling can be carried out, for example, in a dry ice · methanol bath (-75 ° C) or a cooled diethylene glycol solution (-3 0 ° C ~ -20 ° C). When cooled through this type, the mixture of cellulose acetate and organic solvent will achieve solidification. Although the cooling rate is not particularly limited, in the case of batch cooling, with the cooling process, the viscosity of the cellulose acetate φ solution increases, resulting in poor cooling efficiency. Therefore, in order to achieve the specified cooling temperature, it is necessary Efficient dissolving pot. In addition, the cellulose acetate solution of the present invention can be achieved by transferring it to a cooling device set to a specified cooling temperature for a short time after swelling. The faster the cooling rate, the better. However, theoretically, the upper limit is 10,000 ° c, while the upper limit is technically 1 000 ° C, and the upper limit is 100 ° c in practice. The cooling rate is calculated by dividing the time from the start of cooling to the final cooling temperature divided by the difference between the temperature at the start of cooling and the final cooling temperature. When this is heated to 0 to 200 ° c (preferably 0 to 150 ° c, more preferably 0 to 120 ° c, and most preferably 0 to 50 ° c), it becomes an organic solvent. A solution of cellulose acetate in flow. The temperature may be raised by leaving it alone at room temperature, or it may be heated in a warm bath. A uniform solution can be obtained as described above. When the dissolution is insufficient, the heating operation can be repeated. Whether the dissolution is sufficient can be judged by visually observing the appearance of the solution. In the cooling and dissolving method, in order to avoid mixing of moisture caused by condensation during cooling, it is best to use a closed container. In addition, in the cooling and heating operation, the dissolution time can be shortened when the pressure is applied during cooling and the pressure is reduced during heating. In order to perform pressure increase and decrease, it is preferable to use a pressure-resistant container. Also, the cellulose acetate (degree of vinegarization: 60. 9%, viscosity average degree of polymerization 299) 20% by mass solution dissolved in methyl acetate, according to differential scanning calorimetry (DSC), there is a suspected mutual relationship of liquid gel and gel near 33 ° C The point shifts to a uniform gel state below this temperature. • Therefore, the solution needs to be stored above the suspected mutual transfer point, preferably at a temperature above 10 ° C above the gel's mutual transfer point. However, the suspected mutual transfer point varies depending on the degree of vinegarization of cellulose acetate, the average degree of polymerization of the viscosity, the concentration of the solution, and the organic solvent used. From the prepared cellulose acetate solution (paint), a cellulose acetate film was produced by a solvent dispersion method. In addition, it is preferable to add the above-mentioned hysteresis rampant to the paint. The coating can be cast on a drum or belt and the solvent can be evaporated to form a thin film. The coating before casting should preferably adjust the solid content to a concentration of 10 to 40%, and more preferably a concentration of 18 to 35%. The surface of the drum or band is preferably finished to a mirror state. Casting and drying methods in the solvent dispersion method are described in U.S. Patent Nos. 23,363 1 0, 2367603, 2492078, 2492977, 2492978, 2607704, 2739069, 2739070, United Kingdom Patent specifications 640731 and 736892; and Japanese Gazettes No. 45-4554, No. 49-5614, No. Sho 60-176834, No. 60-203430, and No. 62-115035. -2 1- 200536617 The coating is preferably extended in a drum shape with a surface temperature below lor. It is best to dry it after blowing for more than 2 seconds after casting. After stripping from the drum or belt, you can also dry it at 160 ° C and gradually change the temperature of the high-temperature air to make the residue The above method is described in Japanese Patent Application Laid-Open No. 5- 1 7844, which can shorten the time from casting to peeling. In order to implement the surface temperature of the drum or belt, it is necessary for the coating to extend the cellulose acetate solution obtained in the present invention as φ on the belt or drum as the support, or A plurality of cellulose acetate solutions were cast. In the case of casting a plurality of layers of acetic acid, a solution containing cellulose acetate can be cast separately at intervals from the direction of travel of the support, and can be made into a thin film. 158414 1-1 224 1 9 and Japanese Patent Application Laid-Open No. 1 1-1 98285, etc. In addition, the film can be formed by casting acetate fiber from two casting ports. For example, Japanese Patent Publication No. 60-27562 _ 61 -94 7 24, JP 6 1 -947245, JP 61 61-JP 6 1-1 5 84 1 3 and JP 6- 1 3493 3 A casting method for encapsulating a cellulose acetate solution having a high viscosity as described in 56-1 626 1 7 while simultaneously extruding a thin film of the cellulose acetate solution having a high viscosity and a low viscosity. Alternatively, two casting ports can be used to peel off the first film on the support, and evaporate the solvent from 100 to 利用 obtained by using a flow on a side or a belt contacting the support surface. . According to this method, the cast gels. For a single-layer flow of two or more cellulosic solutions, a plurality of layers are used for stacking, and the method of kaihei is used. Vitamin solution No., Japanese Patent Application Laid-Open No. 104813, method. The Japanese Patent Publication No. Shokai, and the cellulose acetate casting process were carried out in the second stream -22- 200536617 to make a film, for example, the method described in Japanese Patent Publication No. 44-20235. The cast cellulose acetate solution may be the same solution or different cellulose acetate solutions, and it is not particularly limited. In order to make the plurality of cellulose acetate layers functional, the cellulose acetate solution corresponding to the function may be extruded from each casting port. In addition, the cellulose acetate solution of the present invention may be cast simultaneously with other functional layers (for example, an adhesive layer, a dye layer, an antistatic layer, an antiglare layer, a UV absorbing layer, a polarizing layer, etc.). In the conventional single-layer liquid, in order to set a necessary film thickness, a high-viscosity cellulose acetate solution needs to be extruded at a high concentration. In this case, the cellulose acetate solution has poor stability and generates solids. Causes small bumps or flatness problems. As a method to solve this problem, by using a plurality of cellulose acetate solutions to be cast from a casting port, a high-viscosity solution can be simultaneously pressed onto a support, and not only can a planar film with excellent planarity be produced, but also by using The thick cellulose acetate solution can reduce the drying load and increase the speed of film production. On cellulose acetate film, in order to improve the mechanical properties or increase the drying speed, plasticizers can be added. As the plasticizer, a phosphate or carbonate is used. Examples of the phosphate include triphenyl phosphate (TPP) and tricresyl phosphate (TCP). Carbonate is represented by phthalate and citrate. Examples of phthalates include dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), and dioctyl phthalate (DOP) , Dibenzyl phthalate (DPP) and diethyl n-hexyl phthalate (DEHP). Examples of citrates include 0-acetamidine triethyl citrate (OACTE) and 0-acetamidine tributyl citrate (OACTB). -23- 200536617 Examples of other carbonates include butyl oleate, methyl ricinoleate, dibutyl sebacate, and various trimellitates. Preferably, a phthalate plasticizer (DMP, DEP, DBP, DOP, DPP, DEHP) is used. Especially DEP and DPP are preferred. The addition amount of the plasticizer is preferably n to 25% by mass of the cellulose ester amount, more preferably 1 to 20% by mass, and even more preferably 3 to 15% by mass. Anti-deterioration agents (for example, antioxidants, peroxide decomposers, free radical inhibitors, metal inertizers, oxygen scavengers, amines) can also be added to cellulose acetate films. The anti-deterioration agents are described in various publications of Japanese Patent Application Laid-Open No. 3- 1 9920 1, the same as 5-1907073, the same as 5-194789, the same as 5-271471, and the 6- 1 07 8 54. The amount of the anti-deterioration agent is preferably 0. 01 ~ 1 mass%, while taking 0. 01 ~ 0. 2% by mass is particularly preferred. If the amount added is less than 0. 01 mass%, the effect of the anti-deterioration agent was hardly recognized. When the added amount exceeds 1% by mass, it may be confirmed that the anti-deterioration agent penetrates out of the film surface. Examples of particularly preferred anti-deterioration agents include butylated hydroxytoluene (BHT) and tribenzylamine (TBA). φ Next, the stretching treatment of the polymer film will be described. The resulting cellulose acetate film (polymer film) can be further extended to adjust the hysteresis effect. The stretching ratio is preferably 3 to 100%. The thickness of the polymer film is preferably 40 to 140 µm, and particularly preferably 70 to 120 µm. In addition, by adjusting the conditions of the extension processing, it is possible to reduce the standard deviation of the angle of the retardation axis of the optical compensation sheet. The stretching method is not particularly limited, but an example of the stretching method of an stenter is mentioned. On the film produced by the above-mentioned solvent dispersion method, -24-200536617 When using a tenter to perform transverse stretching, the standard deviation of the retardation angle of the film can be reduced by controlling the state of the stretched film. Specifically, a tenter is used to perform the stretching adjustment of the hysteresis, and the polymer film immediately after stretching is maintained in this state, and the retardation angle can be reduced by maintaining the film near the glass transition temperature of the film Standard deviation. When the temperature of the held film is lower than the glass transition temperature, the standard deviation will increase. In addition, as another example, when the rollers are extended longitudinally, if the distance between the rollers is set to be wide, the standard deviation of the late phase axis can be reduced. The surface treatment of the polymer film will be described. When a polymer film is used as a transparent protective film for a polarizing plate, the polymer film is preferably subjected to a surface treatment. Surface treatment is performed by corona discharge treatment, glow discharge treatment, flame treatment, acid treatment, alkaline treatment, or ultraviolet irradiation treatment. In particular, it is preferable to perform an acidic treatment, an alkaline treatment, that is, a saponification treatment of a polymer film. The alignment film will be described. The alignment film has a function of defining the alignment direction of the discotic liquid crystalline molecules of the optically anisotropic layer ®. The alignment film can be made of, for example, rubbing treatment of an organic compound (preferably a polymer), oblique vapor deposition of an inorganic compound, formation of a micro-groove layer, or an organic compound of the Ilan Mirr Blodget film method (LB film) (Eg, omega-tricosanoic acid, methyl ammonium dioctadecyl ester, methyl stearate). It is also known that an alignment film is produced by supplying an electric field, a magnetic field, or light irradiation. The alignment film is preferably formed by rubbing a polymer. Polyvinyl alcohol is a preferred polymer. In particular, a denatured polyethylene -25-200536617 alcohol having a hydrophobic group bonded is preferred. The hydrophobic gene has affinity for the discotic liquid crystalline molecules of the optically anisotropic layer. Therefore, by introducing a hydrophobic group into polyvinyl alcohol, the discotic liquid crystalline molecules can be uniformly aligned. The hydrophobic group is bonded to the terminal or side bond of the main bond of polyvinyl alcohol. The hydrophobic group is an aliphatic group (preferably an alkyl group or an alkenyl group) having 6 or more carbon atoms or an aromatic group. When a hydrophobic group is bonded to the main bond terminal of the polyvinyl alcohol, it is preferable to introduce a linking group between the hydrophobic group and the main bond terminal. Examples of the linking group include -S-, -NR2-, -CS-, and combinations thereof. φ 1 and R2 above are each a hydrogen atom or an alkyl group having 1 to 6 carbon atoms (preferably an alkyl group having 1 to 6 carbon atoms). In the case of introducing a hydrophobic group into a side bond of polyvinyl alcohol, only a part of the ethenyl group (-CO-CH3) in the vinyl acetate unit of polyvinyl alcohol is replaced with a fluorenyl group (-CO- R3). The R3-based carbon atom is an aliphatic group or an aromatic group having 6 or more carbon atoms. Commercially available denatured polyvinyl alcohols (for example, MP103, MP203, R1 130, Kuraray Co., Ltd.) can also be used. The degree of saponification of (denatured) polyvinyl alcohol used for the alignment film is preferably 80% or more. The degree of polymerization of the modified polyvinyl alcohol is preferably 200 or more. The rubbing treatment can be performed by rubbing the surface of the alignment film several times in a certain direction with paper or cloth. It is best to use a cloth that is uniformly planted with fibers of uniform length and thickness. In addition, after the dish-like liquid crystal molecules of the optically anisotropic layer are aligned using an alignment film, the alignment state of the dish-like liquid crystal molecules can be maintained even if the alignment film is removed. That is, the alignment film is used for aligning the dish-shaped liquid crystal molecules, which is necessary in the manufacture of the elliptically polarizing plate, but is not required in the manufactured optical compensation sheet. -26- 200536617 In the case where an alignment film is provided between the transparent support and the optically anisotropic layer, it is preferable to also provide an undercoat layer (adhesive layer) between the transparent support and the alignment film. To achieve planar stabilization, citrate may be added as needed. The optical anisotropic layer will be described. The optically anisotropic layer is formed of a disk-shaped liquid crystal molecule. Dish-like liquid crystal molecules generally have optical negative uniaxiality. In the optical compensation sheet of the present invention, as shown in FIG. 2, the angle formed by the disc surface and the transparent support surface is best changed in the depth direction of the optical anisotropic layer ( Hybrid alignment). The optical axis of the dish-like liquid crystal molecules exists in the normal direction of the disc surface. Dish-shaped liquid crystalline molecules have a birefringence in which the refractive index in the direction of the disk surface is larger than the refractive index in the direction of the optical axis. The optically anisotropic layer is preferably formed by using the above-mentioned alignment film to align the dish-like liquid crystal molecules and to fix the alignment state of the dish-like liquid crystal molecules. The dish-like liquid crystalline molecules are preferably fixed by a polymerization reaction. In addition, the optically anisotropic layer does not have a direction in which the hysteresis becomes zero. In other words ® the minimum hysteresis of the optical anisotropic layer does not exceed 0. Specifically, the optical anisotropic layer has a Re hysteresis 定义 defined by the following formula (I) in a range of 10 to 100 nm, and an Rth hysteresis 値 defined by the following formula (Π) is 40. It is preferably in a range of ~ 25 Oiim, and the average inclination of the dish-like liquid crystal molecules is preferably 20 to 50 degrees. (I) Re = (nx — ny) xd (Π) Rth = {(n2 + n3) / 2 ~ nl} xd In formula (I), 'nx is the direction of the retardation axis in the optical anisotropy plane -27 -The refractive index of 200536617, ny is the refractive index in the direction of the phase axis in the optically anisotropic layer, and d is the thickness of the optically anisotropic layer. In formula (Π), nl is the minimum 値 of the refractive index principal 情况 when the refractive index ellipsoid approximates the optically anisotropic layer, and η 2 and η 3 are other refractive index principals of the optical anisotropic layer. And d is the thickness of the optically anisotropic layer. Dish-shaped liquid crystal molecules are described in various documents (C. Destrade et al. , Mol. Crysr. Liq. Cryst ·, vol. 71, page 111 (1981); edited by the Chemical Society of Japan, quarterly general chemistry, No. 22. Chemistry of liquid crystals, Chapter 5, Chapter 10 _ Chapter 2 (1994); B. Kohne et al. , Angew. Chem. Soc · Chem. Comm. , Page 1 794 (1 985); J. Zhang et al. , J Am. Chem. Soc ·, vol. 116, page 2655 (1994). The polymerization of dish-like liquid crystal molecules is described in Japanese Patent Application Laid-Open No. 8-27284. In order to fix a discotic liquid crystalline molecule by polymerization, it is necessary to bond a polymerizable group as a substituent to a discotic core of the discotic liquid crystalline molecule. However, if the polymerizable group is directly bonded to the disc-shaped core, it is difficult to maintain the alignment state during the polymerization reaction. Here, a ® linking group is introduced between the disc-shaped core and the polymerizable group. Therefore, the discotic liquid crystalline molecule having a polymerizable group is preferably a compound represented by the following formula (m). (ΠΙ) D (-L-Q) n In formula (m), D is a disc-shaped core, L is a divalent linking group, Q is a polymerizable group, and η is an integer of 4 to 12. An example of a disc-shaped core (D) is shown below. In each of the following examples, LQ (or QL) means a combination of a divalent linking group (L) and a polymerizable group (Q). In formula (I), the divalent linking group (L) is preferably from an alkylene group, an alkenyl group, -28-200536617 an arylene group, -CO-, -NH-, · 0-, -s- and The selected bivalent linking group in the group consisting of these combinations. The divalent linking group (L) is a divalent group selected from the group consisting of at least two groups of alkylene, arylene, -CO-, -NH-, -0, and -S-. Is preferably a divalent linking group. The divalent linking group (L) is more preferably a divalent linking group selected from a group consisting of at least two groups selected from the group consisting of alkylene, arylene, -CO-, and -0- good. The number of carbon atoms of the alkylene group is preferably 1 to 12. The carbon number of the alkenyl group is preferably 2 to 12. The number of carbon atoms of the arylene group is preferably 6 to 10. Examples of divalent linking groups (L) are shown below. The left side is bonded to the disc-shaped core (D), and the right side is bonded to the polymerizable group (Q). AL means alkylene or alkenyl, AR means alkylene. The alkylene, alkenyl, and arylene groups may have a substituent (for example, an alkyl group). L 1: -AL-C0-0-AL-L 2: -AL-C0-0-AL-0-L 3 ·· -AL-C0-0-AL-0-AL- L 4: -AL-C0 -0-AL-0-C0- φ L 5: -C0-AR-0-AL- L 6 ·· -C0-AR-0-AL-0- L 7: -C0-AR-0-AL-0 -C0- L 8: -CO-NH-AL- L9: -NH-AL-0-L 10: -NH-AL-0-C0- L 1 1: -0- AL- L 12: -O-AL -0- -29- 200536617 L 13: -O-AL-O-CO-L 14: -O-AL-O-CO-NH-AL- L 15: -O-AL-S-AL- L 1 6 ·-O-CO-AR-O-AL-CO- L 17: -O-CO-AR-O-AL-O-CO-L 18: -O-CO-AR-O-AL-O-AL- O-CO- L 19: -O-CO-AR-O-AL-O-AL-O-AL-O-CO-L 20: -S-AL- • L 21: -S-AL-O- L 22: -S-AL-O-CO-L 23: -S-AL-S-AL-L 24: -S-AR-AL- Polymerizable group (Q) of formula (I) depends on the type of polymerization reaction Decided. The polymerizable group (Q) is preferably an unsaturated polymerizable group (Q1 to Q7) or an epoxy group (Q 8), and an unsaturated polymerizable group is preferred, especially an ethylene unsaturated polymerizable group (Q1 to Q6) is better. In the formula (melon), η is an integer of 4 to 12. The specific number of Lu is determined by the type of disc-shaped core (D). The combination of the plural numbers L and Q may be different or the same. The optically anisotropic layer can be formed by applying a coating liquid containing a disk-shaped liquid crystalline molecule, a polymerizable starter, and an optional component, if necessary, onto an alignment film. The thickness of the optically anisotropic layer is preferably 0. 5 ~ 100 / xm, especially 0. 5 to 30 μm is preferred. The aligned dish-shaped liquid crystal molecules are fixed while maintaining the alignment state. The immobilization is preferably carried out by a polymerization reaction. The polymerization reaction includes a thermal polymerization reaction using a thermal polymerization -30- 200536617 initiator and a photopolymerization reaction using a photopolymerization initiator. Among them, photopolymerization is preferred. Examples of the photopolymerization initiator include an α-carbonyl compound (described in each specification of U.S. Patent No. 2376661, same as No. 2367670), an indole ether (described in specification of U.S. Patent No. 2448828), an α-hydrocarbon-substituted aromatic Family marriage compounds (described in the specification of U.S. Patent No. 2 7 225 12), polynuclear benzoquinone compounds (described in the respective specifications of U.S. Patent No. 3046127 and the same as No. 2951758), triarylimidazole dimer and P-amine A combination of phenones (described in U.S. Patent No. 3,549,367) and acridine and dibenzopyrazine compounds (described in Japanese Patent Application Laid-Open No. 60-105667 and US Patent No. 4239850) ), And oxadiazole compounds (described in the specification of U.S. Patent No. 42 1 2970). The amount of the photopolymerization initiator used is preferably 0. 01 to 20% by mass, in particular, 〇. 5 to 5 mass% is preferred. It is preferable to use ultraviolet rays for irradiating the dish-like liquid crystal molecules with light. The irradiation energy is preferably 20 to 5000 mJ / cm2, and more preferably 100 to 800 mJ / cm2. In addition, in order to promote the photopolymerization reaction, light irradiation may be performed under heating conditions. A protective layer may also be provided on the optically anisotropic layer. To achieve planar stabilization, citrate may be added as needed. Next, a method for manufacturing an optical film using the manufacturing line of the optical compensation film shown in Fig. 1 will be described. First, a cotton web 16 having a thickness of 40 to 300 μm, in which a polymer layer for forming an alignment film is formed in advance, is conveyed from an output machine 66. The cotton web 16 is guided by the guide roller 68 and sent into the rubbing treatment device 70, and the polymer layer is rubbed by the rubbing roller 72. Next, the dust adhered to the surface of the cotton net 16 was removed by a dust collector -31- 200536617 74. Then, a coating liquid containing a dish-shaped nematic liquid crystal is applied onto the cotton web 16 by a wire coating device 10. At this time, the tension of the cotton web 16 is controlled to 100 to 40 ON / m by a tension adjusting mechanism 50 provided in the front-rear direction with the bar coating device 10 interposed therebetween. In addition, the take-up angle 0 of the cotton web 16 with respect to the coating wire rod 12 (see Fig. 2) is adjusted to 1 to 30 degrees. The viscosity of the coating solution was adjusted to 1 to 20 mPa · S, the solid φ concentration of the coating solution was adjusted to 15 to 50% by weight, and the film thickness of the coating solution at the time of coating was adjusted to 0. 01 to 90 / im. Such coating conditions can prevent unevenness in the thickness of the coating film and can improve unevenness in the optical film. Thereafter, a liquid crystal layer is formed after passing through the drying area 76 and the heating area 78. Further, by irradiating the liquid crystal layer with the ultraviolet lamp 80 to cross-link the liquid crystal, a desired polymer can be formed. Then, a cotton web 16 having a polymer formed thereon is taken up by a winder 82. The above φ has described the embodiment of the method for manufacturing the optical film of the present invention, but the present invention is not limited to the above embodiment, and it can take various forms. For example, in this embodiment, the wire rod coating apparatus 10 is used as the coating apparatus, but other apparatuses such as a grooved roll coater or a roll coater may be used as the coating apparatus. Hereinafter, it demonstrates with reference to drawings. Fig. 4 is a schematic diagram showing the main parts of the three reverse roll applicators. In FIG. 4, in the liquid tank 109 in which the coating liquid 110 is accumulated, the coating liquid roll 1 is rotated in the direction of the arrow 108a while partially dipping -32- 200536617 stain-coating roller 108, and the coating liquid 1 is rolled with the cloth liquid 1 1 〇 10 is supplied to the surface of the coating roller 108. The amount of the coating liquid 11 on the surface of the coating roller 108 is appropriately adjusted by the oil measuring roller 1 12 rotating in the direction of arrow 112a. The web 1 1 4 is wound around a support roll 1 1 1 that rotates in the direction of the arrow 1 1 1. The coating liquid 110 is applied while moving in the direction of the arrow 1 1 4 a to form a layer with a predetermined film pressure on the web 114. In the device of FIG. 4, the cotton web 1 1 4 is wound around the support roller φ. Therefore, the winding angle of the cotton web 114 relative to the coating roller 108 is 0, which is close to 0 degrees. The thickness of the net 1 1 4, the coating thickness of the coating liquid, the elastic deformation of the roller, etc., ensure the specified winding angle S. FIG. 5 is a schematic diagram showing the main part of the grooved roller applicator. In the figure, in the liquid tank 1116 in which the coating liquid 117 is accumulated, the roller 1 15 is rotated in the direction of the arrow 1 1 5a while partially dipping the tank roller 1 1, and the coating liquid 1 1 7 is supplied to the grooved roller roller 1 1 by rolling up the coating liquid. 5 surface. The coating liquid 1 1 7 on the recess 1 1 5 is supplied, and the amount of the liquid is appropriately adjusted by a squeegee 1 1 9. • Apply the coating solution 117 on the cotton web 1 2 0 of the support roller 1 1 8 rotating in the direction of the arrow 11 8 a, and move in the direction of the arrow 120 a, and specify the coating layer on the cotton web 120. In the device of FIG. 5, the cotton web 120 is also wound around the support 1 1 8. Therefore, the winding angle θ of the cotton web 1 20 relative to the coating roll 1 1 5 is geometrically close to 0 °, but using The thickness of the cotton web 1 20, the coating thickness of the coating liquid, the elastic deformation of the roller, etc. Transfer coating 111 at a number of 1 10 〇 Θ 〇 5th dimple recession: 1 1 The grooved roll is wound around the edge of the roll to form a roller, and the tension is adjusted at 1 17 Θ 〇 tension-33- 200536617, whereby the optical film of the present invention can be implemented. Production method. [Examples] (Preparation of cellulose acetate solution) The following composition was charged into a mixing tank, stirred while heating, and the components were dissolved to prepare a cellulose acetate solution. The composition of the cellulose acetate solution was 60. 9% cellulose acetate 100 parts by mass Triphenyl phosphate (plasticizer) 7. 8 parts by mass of diphenyl diphenyl phosphate (plasticizer) 3. 9 parts by mass of dichloromethane (the first solvent) 3 3 6 parts by mass of methanol (the second solvent) 29 parts by mass (preparation of a hysteresis-raising agent solution) Put 16 parts by mass of the following hysteresis into another mixing tank Ascending agent, 80 parts by mass of dichloromethane and 20 parts by mass of methanol, and stirred while heating to prepare a delayed rhenium ascending agent solution. [Chemical 1]
(乙酸纖維素薄膜的製作） 在477質量份的乙酸纖維素溶液內混合52質量份的遲 滯値上升劑溶液，進行攪拌，調製成塗料。遲滯値上升劑 的添加量就相對1 00質量份的乙酸纖維素而言，係6 · 7質 -34- 200536617 - 量份。使用帶流延機以使獲得的塗料流延。從帶上剝離殘 留溶劑量爲50質量％的薄膜，在130°C的條件下，使用張 力器以17%的延伸倍率橫向延伸殘留溶劑量爲40質量％的 薄膜，在維持延伸後的寬度的狀態下，以130°C保持30秒 鐘。其後，拆下夾子，製造完成乙酸纖維素薄膜。 (乙酸纖維素薄膜的皂化處理） 將乙酸纖維素薄膜浸漬於5 5 °C的1 . 5當量的氫氧化納 水溶液內2分鐘。在室溫的水洗浴槽中進行洗淨，在30°C φ 使用0.1當量的硫酸進行中和。再度在室溫的水洗浴槽中 進行洗淨，再以1 〇〇t的溫風進行乾燥。如此般作業後， 而在乙酸纖維素薄膜的表面進行了皂化。 (配向膜的形成） 在經皂化處理的乙酸纖維素薄膜（透明支撐體）的一面 以#14的線桿塗布器塗佈24ml/m2的下述組成的塗布液。以 60°C的溫風進行60秒、再以90°C的溫風進行150秒的乾 燥0 其次，在與乙酸纖維素薄膜（透明支撐體）的延伸方向 (與遲相軸大致一致）成45度的方向，於形成的膜上實施摩 擦處理。 配向膜塗布液的組成 下述的變性聚乙烯醇 20質量份 水 3 60質量份 甲醇 1 2 0質量份 戊二醛（交聯劑） 1.0質量份 -35- 200536617 (塗布液的調製） 在配向膜上，將9 1 ·0質量份的下述碟狀液晶性分 質量份的環氧乙烷改質三羥甲基丙烷丙烷三丙 (V#3 60、大阪有機化學（股）製）、1.5質量份的乙醆 丁酯（CAB53 1-1、伊斯特曼化學公司製）、3,〇質量伤 合開始劑（IRGACURE 907、Ciba-Geigy 公司製）、： 份的增感劑（KAYACURE DETX、日本化藥（股）製）、 量份的氟系界面活性劑MEGAFUCU F-7 80-F溶液， φ 135質量份的丁酮內。隨後，適量添加丁酮，調製 0.909的塗布液1。另外，根據上述，不改變除乙_ 丁酯以外的原材料的添加量，將乙酸纖維素丁酯的 分別設爲1.25、1.0質量份，分別調製比重0.909的 製成塗布液2、3。 [化2] 子、9.0 烯酸酯 纖維素 的光聚 .〇質量 1.25 質 溶解於 成比重 纖維素 添加量 溶液後(Production of cellulose acetate film) In 477 parts by mass of a cellulose acetate solution, 52 parts by mass of a delayed rhenium rising agent solution was mixed and stirred to prepare a coating. The addition amount of the delayed rhenium raising agent is 6.7 mass -34- 200536617-part by weight relative to 100 parts by mass of cellulose acetate. A tape casting machine was used to cast the obtained coating. The film with a residual solvent amount of 50% by mass was peeled from the tape, and the film with a residual solvent amount of 40% by mass was laterally stretched at a stretching rate of 17% using a tensioner at 130 ° C. In the state, hold at 130 ° C for 30 seconds. Thereafter, the clip was removed to complete the cellulose acetate film. (Saponification of cellulose acetate film) The cellulose acetate film was immersed in a 1.5-equivalent sodium hydroxide aqueous solution at 55 ° C for 2 minutes. It was washed in a water bath at room temperature, and neutralized with 0.1 equivalent of sulfuric acid at 30 ° C φ. It was washed again in a water bath at room temperature, and then dried with warm air at 100 t. After such operations, the surface of the cellulose acetate film was saponified. (Formation of alignment film) On one side of the saponified cellulose acetate film (transparent support), a coating solution of the following composition was applied at 24 ml / m2 with a wire rod applicator # 14. Drying at 60 ° C for 60 seconds and 90 ° C for 150 seconds. Secondly, it is formed in the direction in which the cellulose acetate film (transparent support) extends (approximately coincides with the slow axis). In a 45-degree direction, a rubbing treatment is performed on the formed film. Composition of the alignment film coating liquid The following modified polyvinyl alcohol 20 parts by mass of water 3 60 parts by mass of methanol 1 2 0 parts by mass of glutaraldehyde (crosslinking agent) 1.0 parts by mass -35- 200536617 (preparation of the coating solution) On the film, 9 1 · 0 parts by mass of the following dish-like liquid crystals with a mass fraction of ethylene oxide modified trimethylolpropane propane tripropylene (V # 3 60, manufactured by Osaka Organic Chemicals Co., Ltd.), 1.5 parts by mass of acetobutyl ester (CAB53 1-1, manufactured by Eastman Chemical Co., Ltd.), 3.0 mass injury starter (IRGACURE 907, manufactured by Ciba-Geigy),: parts by mass of sensitizer (KAYACURE DETX, manufactured by Nippon Kayaku Co., Ltd.), a part of a solution of a fluorine-based surfactant MEGAFUCU F-7 80-F, and 135 parts by mass of methyl ethyl ketone. Subsequently, an appropriate amount of methyl ethyl ketone was added to prepare a coating liquid 1 of 0.909. In addition, according to the above, the coating liquids 2 and 3 were prepared without changing the amount of raw materials other than ethylene-butyl ester, and setting the cellulose acetate butyl to 1.25 and 1.0 parts by mass, respectively, and preparing the specific gravity of 0.909. Photochemical polymerization of cellulose, 9.0 enoate cellulose. 〇 Mass 1.25 mass dissolved in the specific gravity cellulose added amount solution
(實施例1) 在根據上述所製成的塗設有配向膜的乙酸纖; 上，利用#3的線桿，且以塗布器部張力爲300N/m 爲20m/min的條件塗佈根據上述所調製的碟狀液! 1。塗佈後，在1 3 0 °C的乾燥區中加熱2分鐘，以/ 晶性分子配向。然後，在80°C、使用120W/cm的 素薄膜 線速度 塗布液 碟狀液 壓水銀 -36- 200536617 燈，照射1分鐘的UV射線以使碟狀液晶性分子聚合。其 後，放置冷卻爲室溫爲止。如此般形成光學異方向性層， 製成光學補償片。 (實施例2) 在由實施例1製成的塗設有配向膜的乙酸纖維素薄膜 上，利用#3的線桿，且以塗布器部張力爲300N/m、線速度 爲20m/min的條件塗佈根據上述所調製的碟狀液晶塗布液 2。 塗佈後，與實施例1相同形成光學異方向性層，製成光 #學補償片。 (實施例3) 在由實施例1製成的塗設有配向膜的乙酸纖維素薄膜 上，利用#3的線桿，且以塗布器部張力爲300N/m、線速度 爲20m/min的條件塗佈根據上述所調製的碟狀液晶塗布液 3。 塗佈後，與實施例1相同形成光學異方向性層，製成光 學補償片。 (實施例4) ® 在由實施例1製成的塗設有配向膜的乙酸纖維素薄膜 上，利用#3的線桿，且以塗布器部張力爲25 ON/m、線速度 爲2〇m/min的條件塗佈根據上述所調製的碟狀液晶塗布液 1。塗佈後，與實施例1相同形成光學異方向性層，製成光 學補償片。 (實施例5) 在由實施例1製成的塗設有配向膜的乙酸纖維素薄膜 上，利用#3的線桿，且以塗布器部張力爲150N/m、線速度 -37- 200536617 爲2〇m/min的條件塗佈根據上述所調製的碟狀液晶塗布液 1。塗佈後，與實施例1相同形成光學異方向性層，製成光 學補償片。 (實施例6) 在由實施例1製成的塗設有配向膜的厚度爲1〇8μιη的 乙酸纖維素薄膜上，利用#3的線桿，且以塗布器部張力爲 300N/m、線速度爲20m/min的條件塗佈根據上述所調製的 碟狀液晶塗布液1。塗佈後，與實施例1相同形成光學異 φ 方向性層，製成光學補償片。 (比較例1) 在由實施例1製成的塗設有配向膜的厚度爲8 0/im的乙 酸纖維素薄膜上，利用#3的線桿，且以塗布器部張力爲 5〇N/m、線速度爲20m/min的條件塗佈根據上述所調製的 碟狀液晶塗布液1。塗佈後，與實施例1相同形成光學異 方向性層，製成光學補償片。 (比較例2) # 在由實施例1製成的塗設有配向膜的乙酸纖維素薄膜 上，利用#3的線桿，且以塗布器部張力爲5 OON/m、線速度 爲20m/min的條件塗佈根據上述所調製的碟狀液晶塗布液 1。塗佈後，與實施例1相同形成光學異方向性層，製成光 學補償片。 (比較例3 ) 在由實施例1製成的塗設有配向膜的厚度爲8 O/xm的乙 酸纖維素薄膜上，利用#3的線桿，且以塗布器部張力爲 -38- 200536617 300N/m、線速度爲20m/min、塗布器部卷角（繞捲角）爲40 度的條件塗佈根據上述所調製的碟狀液晶塗布液1。塗佈 後，與實施例1相同形成光學異方向性層’製成光學補償 (比較例4) 在由實施例1製成的塗設有配向膜的乙酸纖維素薄膜 上，利用#20的線桿，且以塗布器部張力爲3 00N/m、線速 度爲20m/min的條件塗佈根據上述所調製的碟狀液晶塗布 φ 液1。塗佈後，與實施例1相同形成光學異方向性層，製 成光學補償片。 (比較例5) 在由實施例1製成的塗設有配向膜的厚度爲80/xm的乙 酸纖維素薄膜上，使用根據上述所調製的碟狀液晶塗布液 1，使溶劑揮發，調製成黏度爲60mPa · s。使用該溶液， 利用#3的線桿，且以塗布器部張力爲3 ΟΟΝ/m、線速度爲 20m/min、塗布器部卷角（繞捲角）爲15度的條件進行塗佈。 •塗佈後，與實施例1相同形成光學異方向性層，製成光學 補償片。 (比較例6) 將由實施例1製成的乙酸纖維素薄膜的厚度調整爲 2 0μηι，利用#3的線桿，且以塗布器部張力爲300N/m、線 速度爲20m/min的條件塗佈根據上述所調製的碟狀液晶塗 布液1。塗佈後，與實施例1相同形成光學異方向性層， 製成光學補償片。 -39- 200536617 (評價） 針對由上述條件製成的光學補償片， 板，使用光源進行照明，針對其面性狀瀆 官能評價。評價項目爲黑條紋、塗佈條怒 綜合評價。評價等級係將明顯有缺點者設 設爲△、合格者設爲◦、非常良好者設爲 中顯示製作條件與評價結果。 實施例1〜3在所有的評價項目中均ί • 在線桿段不勻上爲◎，在黑條紋、塗佈僧 爲〇。 相對於此，比較例1〜6在塗佈條紋上 線桿段不勻上，一例爲◎，但其他均爲Ζ 常差的XX)，綜合評價上也爲χ(僅比較例 【圖式簡單說明】 第1圖爲說明應用本發明之塗佈方沒 的製法的製造線的說明圖。 • 第2圖爲說明線桿塗布裝置的全體構 第3圖爲說明塗佈用線桿的局部放大 第4圖爲顯示3支逆輥塗布器的主要 第5圖爲顯示凹槽輥塗布器的主要部 第6圖爲顯示實施例結果的表。 (元件符號說明） 從兩側夾住偏光 〔施依目視觀察的 〔、線桿段不勻及 爲X、允許範圍者 ◎。第6圖之表 i ◎。實施例4〜6 h紋及綜合評價上 ，2例均爲〇，在 i或x(—部分爲非 1爲△〜X)。 t的光學補償薄膜 成的剖視圖。 剖視圖。 部分的示意圖。 分的示意圖。 10 線桿塗布裝置 12 塗佈用線桿 -40- 200536617(Example 1) On the acetate fiber coated with an alignment film prepared according to the above, a wire rod of # 3 was used, and coating was performed under the condition that the applicator section tension was 300 N / m and 20 m / min according to the above The prepared dish-like liquid! 1. After coating, it was heated in a drying zone at 130 ° C for 2 minutes to align with crystalline molecules. Then, at 80 ° C, using a plain film with a linear speed of 120 W / cm, a coating liquid, a dish-like liquid, and a mercury-36-200536617 lamp were irradiated with UV rays for 1 minute to polymerize the dish-like liquid crystal molecules. Thereafter, it was left to cool to room temperature. An optically anisotropic layer was formed in this manner to prepare an optical compensation sheet. (Example 2) On the cellulose acetate film coated with an alignment film made in Example 1, a wire rod of # 3 was used, and the tension of the applicator section was 300 N / m and the linear velocity was 20 m / min. Conditionally apply the dish-shaped liquid crystal coating liquid 2 prepared as described above. After coating, an optically anisotropic layer was formed in the same manner as in Example 1 to prepare an optical compensation sheet. (Example 3) On a cellulose acetate film coated with an alignment film prepared in Example 1, a wire rod of # 3 was used, and the tension of the applicator section was 300 N / m and the linear velocity was 20 m / min. Conditionally apply the dish-shaped liquid crystal coating liquid 3 prepared as described above. After coating, an optically anisotropic layer was formed in the same manner as in Example 1 to prepare an optical compensation sheet. (Example 4) ® On the cellulose acetate film coated with an alignment film prepared in Example 1, a wire rod of # 3 was used, and the tension of the applicator section was 25 ON / m and the linear velocity was 2 °. The conditions of m / min apply the dish-shaped liquid crystal coating liquid 1 prepared as described above. After coating, an optically anisotropic layer was formed in the same manner as in Example 1 to prepare an optical compensation sheet. (Example 5) On the cellulose acetate film coated with an alignment film made in Example 1, a wire rod of # 3 was used, and the tension of the applicator section was 150 N / m and the linear velocity was -37-200536617 as The dish-like liquid crystal coating liquid 1 prepared as described above was applied at a condition of 20 m / min. After coating, an optically anisotropic layer was formed in the same manner as in Example 1 to prepare an optical compensation sheet. (Example 6) On a cellulose acetate film having a thickness of 108 μm coated with an alignment film made in Example 1, a wire rod of # 3 was used, and the tension of the applicator portion was 300 N / m. The dish-shaped liquid crystal coating liquid 1 prepared as described above was applied under the condition that the speed was 20 m / min. After coating, an optically iso-directional layer was formed in the same manner as in Example 1 to prepare an optical compensation sheet. (Comparative Example 1) On a cellulose acetate film having a thickness of 80 / im coated with an alignment film made in Example 1, a wire rod of # 3 was used, and the applicator portion tension was 50 N / m and a linear velocity of 20 m / min were applied to the dish-like liquid crystal coating liquid 1 prepared as described above. After coating, an optically anisotropic layer was formed in the same manner as in Example 1 to prepare an optical compensation sheet. (Comparative Example 2) # On the cellulose acetate film coated with an alignment film prepared in Example 1, a wire rod of # 3 was used, and the applicator section tension was 5 OON / m and the line speed was 20 m / The conditions of min apply the dish-like liquid crystal coating liquid 1 prepared as described above. After coating, an optically anisotropic layer was formed in the same manner as in Example 1 to prepare an optical compensation sheet. (Comparative Example 3) On a cellulose acetate film having a thickness of 8 O / xm coated with an alignment film made in Example 1, a wire rod of # 3 was used, and the tension of the applicator section was -38- 200536617 The dish-shaped liquid crystal coating liquid 1 prepared as described above was applied under conditions of 300 N / m, a linear velocity of 20 m / min, and a roll angle (winding angle) of the applicator section of 40 degrees. After coating, an optically anisotropic layer was formed in the same manner as in Example 1 to make optical compensation (Comparative Example 4). On the cellulose acetate film coated with an alignment film made in Example 1, a thread of # 20 was used. The dish-shaped liquid crystal coating φ liquid 1 prepared in the manner described above was applied under the conditions that the applicator portion tension was 300 N / m and the linear velocity was 20 m / min. After coating, an optically anisotropic layer was formed in the same manner as in Example 1 to prepare an optical compensation sheet. (Comparative Example 5) On the cellulose acetate film having a thickness of 80 / xm coated with an alignment film prepared in Example 1, the dish-like liquid crystal coating liquid 1 prepared as described above was used to volatilize the solvent to prepare The viscosity is 60mPa · s. Using this solution, coating was performed using a wire rod of # 3 under the conditions that the applicator section tension was 300 N / m, the linear velocity was 20 m / min, and the applicator section roll angle (winding angle) was 15 degrees. • After coating, an optically anisotropic layer was formed in the same manner as in Example 1 to prepare an optical compensation sheet. (Comparative Example 6) The thickness of the cellulose acetate film prepared in Example 1 was adjusted to 20 μm, and a wire rod of # 3 was used, and the condition was that the applicator portion tension was 300 N / m and the line speed was 20 m / min. The dish-shaped liquid crystal coating liquid 1 prepared as described above. After coating, an optically anisotropic layer was formed in the same manner as in Example 1 to prepare an optical compensation sheet. -39- 200536617 (Evaluation) The optical compensation sheet and the plate manufactured under the above conditions were illuminated with a light source, and their surface properties were evaluated. The evaluation items were comprehensive evaluation of black streaks and coated streaks. The evaluation level is set to △ for obvious defects, ◦ for passers, and 合格 for very good ones to display the production conditions and evaluation results. Examples 1 to 3 were all in all evaluation items. • It was ◎ on the unevenness of the line segment, and it was 0 on the black stripes and the coating monk. On the other hand, Comparative Examples 1 to 6 have uneven line segments on the coating stripes. One example is ◎, but the others are XX with a constant difference of XX), and it is also χ in the comprehensive evaluation. Figure 1 is a diagram illustrating a manufacturing line to which the coating method of the present invention is applied. Figure 2 is a diagram illustrating the overall structure of a wire rod coating device. Figure 3 is a partially enlarged view illustrating a wire rod for coating. Fig. 4 shows the main parts of the three reverse roll applicators. Fig. 5 shows the main parts of the groove roll applicator. Fig. 6 is a table showing the results of the examples. Visually observed [, the unevenness of the wire rod segment is X, and the allowable range is ◎. Table i in Figure 6 ◎. In Examples 4 to 6 h and the comprehensive evaluation, both cases are 0, in i or x ( —Part of non-1 is △ ~ X). Sectional view of the optical compensation film made of t. Sectional view. Partial schematic. Partial schematic. 10 Wire rod coating device 12 Coating wire rod -40- 200536617
14 塗 佈 頭 16 棉 網 18 導 向 輥 20 支 撐 構 件 22、 24 塗 佈 區 Lrf-f 塊 26、 28 集 流 腔 30、 32 切 縫 34 —* 次 惻 塗 布 液 36 二 次 側 塗 布 液 38 桿 40 鋼 絲 42 鋼 絲 列 50 張 力 調 整 機 構 52 > 56 驅 動 輥 54、 58 夾 輥 66 輸 出 機 68 導 輥 70 摩 擦 處 理 裝 置 72 摩 擦 輥 74 除 塵 機 76 乾 燥 1® 78 加 熱 80 紫 外 線 燈 82 捲 取 機 -4 1 200536617 108 塗佈輥子 109、 116 液槽 110、 117 塗布液 111' 118 支撐輥子 112 測油輥 114、 120 棉網 115 凹槽輥 1 19 刮板14 Coating head 16 Cotton web 18 Guiding roller 20 Support member 22, 24 Coating area Lrf-f block 26, 28 Manifold 30, 32 Slit 34 — * Secondary coating solution 36 Secondary coating solution 38 Rod 40 Wire 42 Wire line 50 Tension adjustment mechanism 52 > 56 Drive roller 54, 58 Pinch roller 66 Output 68 Guide roller 70 Friction treatment device 72 Friction roller 74 Dust collector 76 Dry 1® 78 Heating 80 UV lamp 82 Winder-4 1 200536617 108 Coating roller 109, 116 Tank 110, 117 Coating liquid 111 '118 Support roller 112 Oil measuring roller 114, 120 Net 115 Groove roller 1 19 Squeegee