200923434 九、發明說明 【發明所屬之技術領域】 本發明係關於一種液晶顯示器的亮度提昇薄片（一般 稱爲「稜鏡片」）用聚酯薄膜。 【先前技術】 聚酯薄膜近年大多使用於光學用薄膜，例如使用於液 晶顯示裝置用亮度提昇薄片、觸控面板、背光等的基質薄 膜、抗反射用薄膜之基質薄膜、電漿顯示器的電磁波遮蔽 薄膜、有機EL顯示器的基質薄膜、顯示器的防爆用基質 薄膜等的用途。 於如此用途所使用的基質薄膜，要求優異的透明性， 又要求對設於基質薄膜上的稜鏡層、硬塗層、黏著層、抗 反射層、濺鍍層等之黏著性與密合性。 但是，聚酯薄膜，特別是二軸延伸的聚酯薄膜，一般 與其他材料的黏著性差，例如與以丙烯酸樹脂爲主成分之 棱鏡層、硬塗層等的黏著性差。 其中，作爲改善聚酯薄膜與稜鏡層的黏著性之方法， 多數提案於聚酯薄膜的表面設置結合層，以改善黏著性 (特開平1 1 -27 1 503號公報、特開2000- 1 4 1 5 74號公報、 特開2005 -8 9622號公報、特開2006- 1 3 7046號公報）。 【發明內容】 發明所欲解決之課題 -5- 200923434 但是，傳統的技術之結合層的耐熱性不足，暴露於高 溫環境下，嚴重損害密合性，亦即耐熱黏著性不充分。因 此’無法使用例如作爲如導航系統的車載用機材、溫度容 易上升之高亮度的大畫面顯示器的機材的零件。 本發明係以提供可適合用於車載用機材、高亮度大畫 面顯示器之具備充分耐熱黏著性且具備高透明性、顯示與 稜鏡層高密合性之使用作爲亮度提昇薄片（稜鏡薄片）的基 質薄膜之聚酯薄膜。 解決課題之手段 亦即，本發明係由聚酯薄膜以及設置於其上之塗佈層 所成，其特徵爲塗佈層係由丙烯酸樹脂、交聯劑及聚氧伸 烷基苯醚所成之亮度提昇薄片用聚酯薄膜。 【實施方式】 以下，詳細說明本發明。 聚酯薄膜 本發明之構成聚酯薄膜的聚酯，係由芳香族二元酸或 其酯形成性衍生物與二醇或其酯形成性衍生物所合成之線 狀飽和聚酯。作爲如此的聚酯之具體例，例如聚對苯二甲 酸乙二酯、聚萘二甲酸乙二酯、聚對苯二甲酸丁二酯、聚 對苯二甲酸1，4-環己二甲酯。 聚酯薄膜所使用的聚酯，可爲此等聚酯的共聚合物， 也可與其他樹脂混摻。於任一情況下，上述聚酯爲主體 -6- 200923434 (例如8 0旲耳。/〇以上的成分）作爲共聚合成分，或混摻成分 比例少（例如2 0莫耳％以下的成分）較理想。作爲聚酯，聚 對苯二甲酸乙二酯因力學物性、光學物性等的平衡佳，所 以特別理想。 聚酯薄膜可含有著色劑、帶電防止劑、氧化防止劑、 潤滑劑、觸媒，不含內加微粒子者在透明性的點上較理 想。 聚酯薄膜的厚度，於使用作爲亮度提昇薄片的情況， 爲了得到所需的強度，較理想爲2 5〜3 5 Ο μ m，更理想爲 50 〜250μηι 〇 塗佈層 本發明的亮度提昇薄片用聚酯薄膜，於上述聚酯薄膜 上，設置塗佈層。塗佈層可設置於一側的面，也可設置於 兩側的面，較理想爲設置於兩側的面。 本發明之塗佈層的厚度，較理想爲20〜150nm，更理 想爲 30〜120nm，特別理想爲40〜90 nm，塗佈層的厚度 超過150nm時，容易發生結塊，所以不理想，另一方面 未達20nm時，與紫外線硬化性樹脂的密合性容易變差， 所以不理想。 塗佈層係由丙烯酸樹脂、交聯劑及聚氧伸烷基苯醚所 成。其中，丙烯酸樹脂係作爲黏結劑的作用，交聯劑係賦 予耐熱密合性的作用。 製成亮度提昇薄片時，亮度提昇薄片用聚酯薄膜上所 200923434 設置之稜鏡層’因一般使用能量硬化型，特別是紫外線硬 化型的丙烯酸樹脂’對丙烯酸樹脂必須得到良好的黏著 性。因此’使用丙烯酸樹脂，作爲塗佈層的黏結劑成分。 丙烯酸樹脂 本發明之塗佈層的丙烯酸樹脂，係聚合物的玻璃轉移 溫度（以下玻璃轉移溫度稱爲「T g」），較理想爲3 0〜 8〇°C，更理想爲35〜70°C之丙烯酸樹脂。藉由使用該範圍 的Tg之丙烯酸樹脂，可得具備良好的結塊性及優異的透 明性之薄膜。 作爲該丙烯酸樹脂，例如可使用以下例示的丙烯酸單 體聚合而得之聚合物或共聚合物之丙烯酸樹脂。 作爲丙烯酸酯單體，例如丙烯酸烷酯、甲基丙烯酸烷 酯（作爲烷基，例如甲基、乙基、正丙基、異丙基、正丁 基、異丁基、第3 丁基、2-乙基己基、環己基等）；丙烯 酸2-羥基乙酯、甲基丙烯酸2-羥基乙酯、丙烯酸2-羥基 丙酯、甲基丙烯酸2-羥基丙酯等含有羥基的單體；丙烯 酸縮水甘油酯、甲基丙烯酸縮水甘油酯、烯丙基縮水甘油 基醚等含有環氧基之單體；丙烯酸、甲基丙烯酸、亞甲基 丁二酸、順丁烯二酸 '反丁烯二酸、2- 丁烯酸及其鹽（鈉 鹽、鉀鹽、銨鹽、3級胺鹽等）等的含有羧基或其鹽之單 體；苯乙烯磺酸及其鹽（鈉鹽、鉀鹽、銨鹽、3級胺鹽 等）；丙烯醯胺、甲基丙烯醯胺、N-烷基丙烯醯胺、N-烷 基甲基丙烯醯胺、Ν,Ν-二烷基丙烯醯胺、N，N-二烷基甲基 -8- 200923434 丙烯醯胺（作爲烷基，例如甲基、乙基、正丙基、異丙 基、正丁基' 異丁基、第3 丁基、2-乙基己基、環己基 等）、N-烷氧基丙烯醯胺、N-烷氧基甲基丙烯醯胺、Ν,Ν-二烷氧基丙烯醯胺、Ν，Ν-二烷氧基甲基丙烯醯胺（作爲烷 氧基，例如甲氧基、乙氧基、丁氧基、異丁氧基等）、丙 烯醯基嗎啉、Ν-羥甲基丙烯醯胺、Ν-羥甲基甲基丙烯醯 胺、Ν-苯基丙烯醯胺、Ν-苯基甲基丙烯醯胺等含有醯胺基 之單體；順丁烯二酸酐、亞甲基丁二酸酐等酸酐的單體； 異氰酸乙烯酯、異氰酸烯丙酯、苯乙烯、α-甲基苯乙烯、 乙烯基甲基醚、乙烯基乙基醚、乙烯基三烷氧基矽烷、烷 基順丁烯二酸單酯、烷基反丁烯二酸單酯、烷基亞甲基丁 二酸單酯、丙烯腈、甲基丙烯腈、氯化亞乙烯、乙烯、丙 烯、氯化乙烯、乙酸乙烯酯、丁二烯等的單體。 爲了得到塗佈層與其後的加工所設置之稜鏡層等的加 工層間的高密合性，同時塗佈層與基材間充分的黏著性， 丙烯酸樹脂爲含有氮原子的單體成分之聚合物或共聚合物 之丙烯酸樹脂較理想。丙烯酸樹脂之含有氮原子的單體成 分之含量，爲了達成上述目的，以構成丙烯酸樹脂的單體 成分的合計量爲基準時，較理想爲1〜30莫耳％。 作爲含有氮原子的單體成分，例如丙烯醯胺、甲基丙 烯醯胺、Ν-烷基丙烯醯胺、Ν-烷基甲基丙烯醯胺、Ν,Ν-二 烷基丙烯醯胺、Ν，Ν-二烷基甲基丙烯酸酯（作爲烷基，例 如甲基、乙基、正丙基、異丙基、正丁基、異丁基、第3 丁基、2-乙基己基、環己基等）、Ν-烷氧基丙烯醯胺、Ν- -9 - 200923434 烷氧基甲基丙烯醯胺、Ν,Ν-二烷氧基丙烯醯胺、N，N-二烷 氧基甲基丙烯醯胺（作爲烷氧基，例如甲氧基、乙氧基、 丁氧基、異丁氧基等）、丙燒酸基嗎琳、N -經甲基丙餘釀 胺、N-羥甲基甲基丙烯醯胺、N-苯基丙烯醯胺、N-苯基甲 基丙烯醯胺等含有醯胺基之單體。藉由使用含有此等單體 作爲單體成分之丙烯酸樹脂而可提高黏著性的理由，在於 氮原子具有不成對的電子，極性高，分子間力、反應性比 較高。 丙烯酸樹脂爲可溶於水或可分散於水者較理想。丙烯 酸樹脂，例如可根據特開昭6 3 - 3 7 1 6 7號公報的製造例1 〜3記載的方法製造。亦即，於4 口燒瓶中，放入既定量 的作爲界面活性劑的月桂基礦酸銷以及既定量的離子交換 水’氮氣氣流中’使其昇溫至6 0 °C，然後添加作爲聚合引 發劑的過硫酸銨〇 · 5重量份、亞硝酸氫鈉〇 . 2重量份，使 丙烯酸樹脂的聚合用單體的混合物，經3小時，一邊調整 液溫成爲60〜70 °C，一邊滴下。滴完後，於相同溫度範圍 保持2小時，且於攪拌下繼續反應，然後使其冷卻，得到 丙烯酸樹脂的水分散體。 本發明的丙烯酸樹脂的折射率，較理想爲1 · 4 5〜 1.55’更理想爲1·46〜1.53，特別理想爲148〜1.51。丙 嫌酸樹脂的折射率超過I.55時，UV光的透過率不會上 升，製造亮度提昇薄片時’使用紫外線硬化型丙烯酸樹脂 形成稜鏡有困難，另一方面使其未達1.45，技術上有困 難。 -10- 200923434 丙烯酸樹脂，對構成塗佈層的組成物的合計1 00重量 %，佔 5 5〜9 3重量％較理想，特別理想爲 6 5〜8 7重量 %。藉由丙烯酸樹脂以該範圍含於塗佈層，可得塗佈層與 其後加工所設置的稜鏡層間優異的密合性及耐熱黏著性。 交聯劑 本發明的塗佈層含有交聯劑。作爲交聯劑，可使用環 氧樹脂、噁唑啉（oxazo line)、三聚氰胺及異氰酸酯中的任 一種以上。此等可使用1種，也可使用2種以上。 作爲環氧交聯劑，例如聚環氧化合物、二環氧化合 物、單環氧化合物、縮水甘油胺化合物。 作爲聚環氧化合物，例如山梨醇、聚縮水甘油醚、聚 甘油聚縮水甘油醚、季戊四醇聚縮水甘油醚、二甘油聚縮 水甘油醚、三縮水甘油基三（2 -羥基乙基）異氰酸酯、甘油 聚縮水甘油醚、三羥甲基丙烷聚縮水甘油醚。 作爲二環氧化合物，例如新戊二醇二縮水甘油醚、 1，6 -己二醇二縮水甘油醚、間苯二酚二縮水甘油醚、乙二 醇二縮水甘油醚、聚乙二醇二縮水甘油醚、丙二醇二縮水 甘油醚、聚丙二醇二縮水甘油醚、聚丁二醇二縮水甘油 醚。 作爲單環氧化合物，例如烯丙基縮水甘油醚、2 -乙基 己基縮水甘油醚、苯基縮水甘油醚。 作爲縮水甘油胺化合物，例如N，N, N，，N，-四縮水甘油 基—間_二甲苯二胺、1,3 -雙（N，N -二縮水甘油基胺基）環 -11 - 200923434 己烷。 作爲噁唑啉交聯劑，使用含有噁唑啉基之聚合物較理 想。此係含有加成聚合性噁唑啉基之單體可單獨聚合而製 造，也可與其他單體共聚合而製造。 作爲含有加成聚合性噁唑啉基之單體，例如2-乙烯 基-2-噁唑咐、2-乙烯基-4-甲基-2-噁唑啉、2-乙烯基-5-甲 基-2-噁唑啉、2-異丙烯基-2-噁唑啉、2 -異丙烯基-4 -甲基-2-噁唑啉、2 -異丙烯基-5-乙基-2-噁唑啉。此等可使用1 種，也可使用2種以上。其中，以2-異丙烯基-2-噁唑啉 在工業上容易取得，較適合。 與含有噁唑啉基之共聚合物的共聚合所使用的其他單 體，只要是可與含有加成聚合性噁唑啉基之單體共聚合之 單體即可，例如丙烯酸烷酯、甲基丙烯酸烷酯（作爲烷 基，例如甲基、乙基、正丙基、異丙基、正丁基、異丁 基、第3 丁基、2-乙基己基、環己基）等的（甲基）丙烯酸酯 類；丙烯酸、甲基丙烯酸、亞甲基丁二酸、順丁烯二酸、 反丁烯二酸、2-丁烯酸、苯乙烯磺酸及其鹽（鈉鹽、鉀 鹽、銨鹽、3級胺鹽等）等的不飽和羧酸；丙烯腈、甲基 丙烯腈等的不飽和腈類；丙烯醯胺、甲基丙烯醯胺、N-烷 基丙烯醯胺、N-烷基甲基丙烯醯胺、N，N-二烷基丙烯醯 胺' N，N-二烷基甲基丙烯酸酯（作爲烷基，例如甲基、乙 基 '正丙基、異丙基、正丁基、異丁基、第3 丁基、2-乙 基己基、環己基等）等的不飽和醯胺；乙酸乙烯酯、丙酸 乙稀酯、丙烯酸、甲基丙烯酸的酯部份加成聚環氧烷者等 -12- 200923434 的乙稀醋；甲基乙烯基醚、乙基乙烯基醚等乙烯基醚；乙 烯、丙烯等的α-烯烴；氯乙烯、氯化亞乙烯、氟化乙烯等 含歯素α’β-不飽和單體；苯乙烯、α_甲基苯乙烯等^，^不 飽和芳香族單體。此等單體可使用1種，也可倂用2種以 上。 作爲二聚氰胺交聯劑，係於三聚氰胺與甲醛縮合所得 的經甲基三聚氰胺衍生物，使低級醇反應而醚化之化合物 以及此等的混合物較理想。作爲低級醇，例如可使用甲 醇、乙醇、異丙醇。 作爲經甲基三聚氰胺衍生物，例如單羥甲基三聚氰 胺、二經甲基三聚氰胺、三羥甲基三聚氰胺、四羥甲基三 聚氰胺、五羥甲基三聚氰胺、六羥甲基三聚氰胺。 作爲異氰酸酯交聯劑，例如二異氰酸甲苯醋、二苯基 甲烷_4,4’-二異氰酸酯、間二甲苯二異氰酸酯、六亞甲基-1，6 -二異氰酸酯、ι，6 -二異氰酸酯己烷、二異氰酸甲苯酯 與己三醇的加成物、二異氰酸甲苯酯與三羥甲基丙烷的加 成物、多元醇改性二苯基甲烷-4,4，-二異氰酸酯、碳二亞 胺改性三苯基甲烷-4,4，-二異氰酸酯、異佛酮二異氰酸 酯、1，5-萘二異氰酸酯、3,3’·二甲伸苯基-4,4’-二異氰酸 酯、3,3’-二甲基二苯基甲烷_4,4，_二異氰酸酯、二異氰酸 間亞本醋。 含於塗佈層的交聯劑之含有比例，對塗佈層的組成物 1 0 0重量％而言，較理想爲5〜3 0重量％ ’更理想爲1 〇〜 25重量％。藉由交聯劑的含量爲5〜3 0重量％，可得良好 -13- 200923434 的耐熱黏著性的同時，可得適當硬度的塗膜，塗膜不會太 硬，於延伸步驟不發生薄膜白化的問題，可得透明性佳的 薄膜。 聚氧伸烷基苯醚 本發明的塗佈層含有聚氧伸烷基苯醚。 作爲聚氧伸烷基苯醚，例如聚氧乙烯壬基苯基醚、聚 氧乙烯辛基苯基醚、聚氧乙烯苯乙烯化苯醚、聚氧乙嫌二 苯乙烯化苯醚、聚氧乙烯三苯乙烯化苯醚、聚氧乙烯苯甲 基苯基醚、聚氧乙烯二苯甲基苯基醚、聚氧乙烯三苯甲基 苯基醚、聚氧丙烯壬基苯基醚、聚氧丙烯辛基苯基醚、聚 氧丙烯二苯乙烯化苯醚、聚氧丙烯三苯甲基苯醚。此等單 體可使用1種，也可使用2種以上。 此等聚氧伸烷基苯醚中，較理想爲具有複數芳香族基 之聚氧伸烷基苯醚，又較理想爲苯基上具有複數芳香族基 之聚氧伸烷基苯醚。作爲該聚氧伸烷基苯醚，例如聚氧乙 烯苯乙烯化苯醚、聚氧乙烯二苯乙烯化苯醚、聚氧乙烯三 苯乙烯化苯醚、聚氧乙烯苯甲基苯基醚、聚氧乙烯二苯甲 基苯基醚、聚氧乙烯三苯甲基苯基醚。此等具有複數芳香 族基之聚氧伸烷基苯醚，與構成塗佈層的成分之相溶性良 好，可降低塗佈層的霧度，所以較理想。 作爲聚氧伸烷基苯醚，特別理想者爲苯基上具有複數 苯乙烯基及/或苯甲基之聚氧伸烷基苯醚。作爲該聚氧伸 烷基苯醚，例如聚氧乙烯二苯乙烯化苯醚、聚氧乙烯三苯 -14 - 200923434 乙烯化苯醚、聚氧乙烯二苯甲基苯基醚、聚氧乙烯三苯甲 基苯基醚。 含於塗佈層之聚氧伸烷基苯醚的含有比例，對塗佈層 的組成物1 〇 〇重量％而言，較理想爲2〜1 5重量％，更理 想爲3〜1 0重量％。藉由2〜1 5重量％，可得具備良好的 耐熱黏著性與優異的耐結塊性之薄膜。 於聚氧伸烷基苯醚，對聚酯薄膜之水性塗液的潤濕性 有促進之效果，除此之外也可添加潤濕劑。 塗佈層的形成，使用水性塗液進行較理想，於該情況 的水性塗液的表面張力較理想爲5 0達因/cm以下，更理 想爲40達因/cm以下。爲了得到該表面張力，作爲較理 想的界面活性劑，係以陰離子型界面活性劑、陽離子型界 面活性劑、非離子型界面活性劑等的界面活性劑較理想， 例如聚氧化乙烯•聚氧化丙烯嵌段共聚合物、聚氧乙烯月 桂醚、聚氧乙烯鯨蠟醚、聚氧乙烯硬脂醚、聚氧乙烯油 醚、聚氧乙烯烷醚、聚氧乙烯-脂肪酸酯、山梨醇脂肪酸 酯、甘油脂肪酸酯、脂肪酸金屬肥皂、烷磺酸鹽、烷基硫 酸鹽、烷基苯磺酸鹽、烷基磺酸鹽、烷基二苯基醚二磺酸 鹽、烷基磺基琥珀酸鹽、4級銨氯鹽、烷基胺鹽酸等。 微粒子 本發明之塗佈層，從抑制結塊的觀點，含有平均粒徑 1 0 0〜4 0 0 n m之微粒子較理想。特別是爲了得到咼溫下使 用之不結塊的性質，含於塗佈層的微粒子之平均粒徑超過 -15- 200923434 塗佈層之厚度的3倍較理想。而且，微粒子例如即使平均 粒徑大，配合於塗佈層的組成物中，被塗佈於薄膜的狀態 下，被黏結劑成分的丙烯酸樹脂支持，本發明的範圍在實 用上不會脫落。 於塗佈層含有微粒子的情況，使用具有難以從塗佈層 脫落的性質之有機微粒子較理想。作爲該有機微粒子，例 如丙烯酸系樹脂、苯乙烯系樹脂、聚矽氧系樹脂、氟樹 脂、苯並胍胺樹脂、酚樹脂、尼龍樹脂的微粒子。此等單 體可使用1種，也可使用2種以上。這些之中，以丙烯酸 樹脂的微粒子較理想。 於含有微粒子的情況，對微粒子以外的塗佈層的組成 物之合計1 〇 〇重量份而言，較理想爲0.1〜1 〇重量份。未 達0.1重量時，無法得到充分的潤滑性、耐擦傷性，從耐 擦傷性的觀點不理想，另一方面，超過1 0重量份時，透 明性惡化，所以不理想。 製造方法 本發明之塗佈層的塗設所使用的塗液，爲了使塗膜形 成於薄膜上，使用水溶液、水分散液或乳化液等的水性塗 液的形態較理想。於塗液，依據需要，也可配合例如帶電 防止劑、界面活性劑。 塗液的固體成分濃度，通常爲20重量％以下，較理 想爲1〜1 0重量％以下。未達1重量％時，對聚酯薄膜的 塗佈性不足，所以不理想，另一方面，超過20重量％ -16- 200923434 時，塗液的安定性、塗佈層的外觀會惡化，所以不理想。 塗液對聚酯薄膜的塗佈，可在任意階段實施，但在聚 酯薄膜的製造過程實施較理想，特別是對配向結晶化完成 前的聚酯薄膜進行塗佈較理想。此處，所謂配向結晶化完 成前的聚酯薄膜，係指包含未延伸薄膜、未延伸薄膜經縱 方向或橫方向之任一者配向之一軸延伸薄膜、縱方向與橫 方向的二方向低倍率延伸配向之二軸延伸薄膜（最後使縱 方向或橫方向再使其延伸之配向結晶化完成前的二軸延伸 薄膜）等之槪念。其中，未延伸薄膜或一方向配向之一軸 延伸薄膜上塗佈塗液較理想。於該情況，依照原樣再施以 縱向延伸及/或橫向延伸與熱固定較理想。而且，於未延 伸薄膜塗佈塗液，依照原樣於縱方向及橫方向同時進行延 伸，再施以熱固定而製造二軸延伸薄膜爲較理想的製造方 法。 塗液塗佈於薄膜時，可施以電暈表面處理、火焰處 理、電漿處理等物理處理，作爲提高塗佈性用之準備處理 較理想》 作爲塗佈方法，可應用習知任意的塗佈方法。例如可 應用輥塗佈法、凹版印刷法、滾動刷塗法、噴塗法、氣刀 塗佈法、浸漬法、淋幕塗佈法。此等可單獨應用，也可組 合應用。 實施例 以下，舉實施例更詳細地說明本發明。 -17- 200923434 各種物性係由下述的方法評價。 (1) 霧度 根據JIS K7 136，使用日本電色工業公司製的霧度測 定器NDH-2000，測定薄膜的霧度。 (2) 透明性 透明性係上述（1 )所得的霧度値以下述的基準進行評 價。 ◎:霧度値<0.8% (透明性極好） 〇：〇.8%$霧度値< 1.0% (透明性良好） X : 1 · 〇% S霧度値 （透明性不佳） (3) 塗佈層的厚度 將薄膜切成小塊，以環氧樹脂包住，以切片機切片成 5 Onm厚度之薄膜剖面。將其以2%餓酸，60°C下花費2小 時進行染色。被染色的薄膜之剖面，以透過型電子顯微鏡 (LEM-2000)、20萬倍觀察，測定塗佈層的厚度。 (4) 微粒子的平均粒徑 切成小塊，以環氧樹脂包住，以切片機切片成5〇nm 厚度之薄膜剖面。將其以2%餓酸，60 °C下花費2小時進 行染色。被染色的薄膜之剖面，以透過型電子顯微鏡 (LEM-2000)、50萬倍觀察，測定任意100個微粒子的粒 徑，以粒徑的平均値作爲平均粒徑。 (5) 亮度提昇薄片的製作 於形成有稜鏡圖型之模具，使由下述組成所成的紫外 線硬化型丙烯酸樹脂流入，於其上，本發明的聚酯薄膜的 -18- 200923434 塗佈層面配置於丙烯酸樹脂側而使兩者密著，從聚酯薄膜 面側距離30公分，使用紫外線燈（照射強度80W/公分、 6.4KW)，照射30秒，使樹脂硬化，形成頂角90度、間 距50μιη、高度30μηι之稜鏡層，得到亮度提昇薄片。 作爲紫外線硬化型丙烯酸樹脂，使用由下述組成所成 者。 氧化乙烯改性雙酚Α二甲基丙烯酸酯 (日立化成工業公司製FA-321 M) 46重量％ 新戊二醇改性三羥甲基丙烷二丙烯酸酯 (日立化藥化學工業公司製R-6〇4) 25重量％ 丙烯酸苯氧基乙酯 (大阪有機化學工業公司製BIS-COAT192) 27重量％ 2-經基-2-甲基-1-苯基丙-1-嗣 (默克公司製Darocurl 173) 2重量％ (6) 與稜鏡層的密合性 於上述（5)所得的亮度提昇薄片之加工面，施以棋盤 格之十字切割（lmm2的格子100個），於其上將24mm寬的 賽璐凡黏著膠帶（NICHIBAN 公司製、賽璐凡膠帶 CT405AP-18)以5Kg/5公分寬的金屬輥賦予2來回的加重 而貼附，9 0度的剝離角急遽剝開後，觀察剝離面，以下 述基準進行評價。 〇：剝離面積爲5%以下者 （密合性良好） X :剝離面積超過5 %者 （密合性不佳） (7) 耐熱黏著性 200923434 將上述（5 )所得的亮度提昇薄片於1 〇 〇 〇C的烤箱中施以 12小時的熱處理，從烤箱取出，在室溫下放置冷卻1〇分 鐘後 > 進行與上述（6)同樣的剝離測試，觀察剝離面，以 下述基準進行評價。 〇：剝離面積爲5%以下者（耐熱黏著性良好） △:剝離面積爲5〜20%者（耐熱黏著性稍微不佳） X :剝離面積超過20%者 （耐熱黏著性完全不佳） 實施例1 將熔融的聚對苯二甲酸乙二酯（[η] = 〇.6〇ίΠ/§、BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester film for a brightness enhancement sheet (generally referred to as "strip") of a liquid crystal display. [Prior Art] Polyester film has been used in optical films in recent years, for example, for use in brightness enhancement sheets for liquid crystal display devices, substrate films for touch panels, backlights, substrate films for antireflection films, and electromagnetic wave shielding for plasma displays. The use of a film, a matrix film of an organic EL display, and an explosion-proof substrate film for a display. The matrix film used for such use requires excellent transparency and adhesion and adhesion to a ruthenium layer, a hard coat layer, an adhesive layer, an antireflection layer, a sputter layer, and the like provided on the substrate film. However, the polyester film, particularly the biaxially stretched polyester film, generally has poor adhesion to other materials, and is, for example, poorly adhered to a prism layer or a hard coat layer mainly composed of an acrylic resin. Among them, as a method for improving the adhesion between the polyester film and the ruthenium layer, it is proposed to provide a bonding layer on the surface of the polyester film to improve the adhesion (Japanese Unexamined Patent Publication No. Hei No. Hei. Japanese Unexamined Patent Publication No. Hei No. Hei. No. Hei. No. Hei. SUMMARY OF THE INVENTION Problem to be Solved by the Invention -5- 200923434 However, the heat-insulating property of the bonding layer of the conventional technology is insufficient, and exposure to a high temperature environment seriously impairs the adhesion, that is, the heat-resistant adhesiveness is insufficient. Therefore, it is not possible to use, for example, a component of a large-screen display such as a vehicle-mounted machine such as a navigation system or a high-intensity display having a high temperature. The present invention provides a brightness-increasing sheet (sheet) which is suitable for use in a vehicle-mounted material, a high-brightness large-screen display, has sufficient heat-resistant adhesiveness, and has high transparency and high adhesion of display and enamel layer. A polyester film of a matrix film. Means for Solving the Problem That is, the present invention is formed of a polyester film and a coating layer provided thereon, characterized in that the coating layer is formed of an acrylic resin, a crosslinking agent, and a polyoxyalkylene ether. The brightness enhances the polyester film for the sheet. [Embodiment] Hereinafter, the present invention will be described in detail. Polyester film The polyester constituting the polyester film of the present invention is a linear saturated polyester synthesized from an aromatic dibasic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof. Specific examples of such polyesters include, for example, polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, and polybutylene terephthalate. . The polyester used in the polyester film may be a copolymer of such a polyester or may be blended with other resins. In either case, the polyester is a main component -6-200923434 (for example, a component of 80 Å/min or more) as a copolymerization component, or a blending component ratio is small (for example, a component of 20% by mole or less). More ideal. As the polyester, polyethylene terephthalate is particularly preferable because of a good balance between mechanical properties, optical properties, and the like. The polyester film may contain a coloring agent, a charge preventing agent, an oxidation preventing agent, a lubricant, and a catalyst, and those having no added fine particles are preferable in terms of transparency. The thickness of the polyester film is preferably used in the case of using a brightness-increasing sheet, in order to obtain a desired strength, preferably from 2 5 to 3 5 μm, more preferably from 50 to 250 μm, of the coating layer of the present invention. A coating layer was provided on the above polyester film with a polyester film. The coating layer may be provided on one side or on both sides, and is preferably provided on both sides. The thickness of the coating layer of the present invention is preferably 20 to 150 nm, more preferably 30 to 120 nm, particularly preferably 40 to 90 nm, and when the thickness of the coating layer exceeds 150 nm, agglomeration tends to occur, which is not preferable. On the other hand, when the thickness is less than 20 nm, the adhesion to the ultraviolet curable resin tends to be deteriorated, which is not preferable. The coating layer is composed of an acrylic resin, a crosslinking agent, and a polyoxyalkylene ether. Among them, the acrylic resin acts as a binder, and the crosslinking agent imparts heat-resistant adhesion. When the brightness-enhancing sheet is formed, the enamel layer "200923434 provided on the polyester film for brightness enhancement sheet" must have good adhesion to the acrylic resin due to the use of an energy-hardening type, particularly an ultraviolet-hardening type acrylic resin. Therefore, an acrylic resin is used as a binder component of the coating layer. Acrylic resin The acrylic resin of the coating layer of the present invention is a glass transition temperature of the polymer (hereinafter referred to as "T g"), preferably 30 to 8 ° C, more preferably 35 to 70 °. C acrylic resin. By using an acrylic resin of this range of Tg, a film having good agglomeration properties and excellent transparency can be obtained. As the acrylic resin, for example, a polymer obtained by polymerizing an acrylic monomer exemplified below or an acrylic resin obtained by copolymerization can be used. As the acrylate monomer, for example, an alkyl acrylate or an alkyl methacrylate (as an alkyl group such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, butyl, 2) -ethylhexyl, cyclohexyl, etc.); 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, etc., hydroxyl-containing monomers; An epoxy group-containing monomer such as glyceride, glycidyl methacrylate or allyl glycidyl ether; acrylic acid, methacrylic acid, methylene succinic acid, maleic acid 'fumaric acid a monomer containing a carboxyl group or a salt thereof, such as 2-butenoic acid and a salt thereof (sodium salt, potassium salt, ammonium salt, tertiary amine salt, etc.); styrenesulfonic acid and a salt thereof (sodium salt, potassium salt, Ammonium salt, tertiary amine salt, etc.); acrylamide, methacrylamide, N-alkyl acrylamide, N-alkyl methacrylamide, hydrazine, hydrazine-dialkyl acrylamide, N , N-Dialkylmethyl-8- 200923434 acrylamide (as alkyl, such as methyl, ethyl, n-propyl, isopropyl, n-butyl 'isobutyl, 3 butyl, 2-ethylhexyl, cyclohexyl, etc.), N-alkoxy acrylamide, N-alkoxymethyl acrylamide, hydrazine, hydrazine-dialkoxy acrylamide, hydrazine, Ν-dialkoxymethyl propylene decylamine (as alkoxy group, such as methoxy, ethoxy, butoxy, isobutoxy, etc.), acryloyl morpholine, hydrazine-hydroxymethyl propylene hydrazine a monomer containing a guanamine group such as an amine, hydrazine-hydroxymethyl methacrylamide, hydrazine-phenyl acrylamide, hydrazine-phenyl methacrylamide, maleic anhydride, methylene butyl hydride a monomer of an acid anhydride such as an acid anhydride; vinyl isocyanate, allyl isocyanate, styrene, α-methylstyrene, vinyl methyl ether, vinyl ethyl ether, vinyl trialkoxy decane, Alkyl maleic acid monoester, alkyl fumarate monoester, alkylmethylene succinic acid monoester, acrylonitrile, methacrylonitrile, vinyl chloride, ethylene, propylene, chlorination Monomers such as ethylene, vinyl acetate, butadiene. In order to obtain high adhesion between the coating layer and the processing layer provided by the subsequent processing, and the coating layer and the substrate, the acrylic resin is a polymer of a monomer component containing a nitrogen atom. Or a copolymer of acrylic resin is preferred. The content of the nitrogen atom-containing monomer component of the acrylic resin is preferably from 1 to 30 mol% based on the total amount of the monomer components constituting the acrylic resin in order to achieve the above object. As a monomer component containing a nitrogen atom, for example, acrylamide, methacrylamide, hydrazine-alkyl acrylamide, hydrazine-alkyl methacrylamide, hydrazine, hydrazine-dialkyl acrylamide, hydrazine , Ν-dialkyl methacrylate (as alkyl, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, butyl, 2-ethylhexyl, ring Hexyl, etc., Ν-alkoxy acrylamide, Ν--9 - 200923434 alkoxymethyl acrylamide, hydrazine, hydrazine-dialkoxy acrylamide, N,N-dialkoxymethyl Acrylamide (as alkoxy group, such as methoxy, ethoxy, butoxy, isobutoxy, etc.), propyl acetophenone, N-methyl propyl remaining amine, N-hydroxyl A monomer containing a guanamine group such as methacrylamide, N-phenyl acrylamide or N-phenylmethacrylamide. The reason why the adhesiveness can be improved by using an acrylic resin containing these monomers as a monomer component is that the nitrogen atom has an unpaired electron, has a high polarity, and has a high intermolecular force and reactivity ratio. Acrylic resins are preferably water soluble or dispersible in water. The acryl resin can be produced, for example, according to the methods described in Production Examples 1 to 3 of JP-A-63-1777. That is, in a 4-necked flask, a predetermined amount of a lauryl-based mineral acid pin as a surfactant and a quantitative amount of ion-exchanged water 'in a nitrogen gas stream' were placed to raise the temperature to 60 ° C, and then added as a polymerization initiator. 5 parts by weight of ammonium persulfate and 2 parts by weight of sodium hydrogen nitrite, and a mixture of monomers for polymerization of the acrylic resin was added dropwise while adjusting the liquid temperature to 60 to 70 ° C for 3 hours. After the completion of the dropwise addition, the mixture was kept at the same temperature for 2 hours, and the reaction was continued with stirring, followed by cooling to obtain an aqueous dispersion of an acrylic resin. The refractive index of the acrylic resin of the present invention is more preferably from 1.45 to 1.55', more preferably from 1.46 to 1.53, still more preferably from 148 to 1.51. When the refractive index of the acrylic acid resin exceeds 1.55, the transmittance of UV light does not increase, and when the brightness-enhancing sheet is produced, it is difficult to form the ultraviolet-curable acrylic resin, and on the other hand, it is less than 1.45. There are difficulties. -10-200923434 The acrylic resin is preferably 100% by weight to the total of the composition constituting the coating layer, preferably 5 5 to 93 % by weight, particularly preferably 6 5 to 8 7 % by weight. By containing the acrylic resin in the coating layer in this range, excellent adhesion and heat-resistant adhesiveness between the coating layer and the ruthenium layer provided for the subsequent processing can be obtained. Crosslinking Agent The coating layer of the present invention contains a crosslinking agent. As the crosslinking agent, any one or more of an epoxy resin, an oxazo line, a melamine, and an isocyanate can be used. These may be used alone or in combination of two or more. As the epoxy crosslinking agent, for example, a polyepoxy compound, a diepoxide, a monoepoxy compound, or a glycidylamine compound. As the polyepoxy compound, for example, sorbitol, polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerin polyglycidyl ether, triglycidyl tris(2-hydroxyethyl) isocyanate, glycerin Polyglycidyl ether, trimethylolpropane polyglycidyl ether. As the diepoxy compound, for example, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, resorcinol diglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol II Glycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, polybutylene glycol diglycidyl ether. As the monoepoxy compound, for example, allyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether. As a glycidylamine compound, for example, N,N,N,,N,-tetraglycidyl-m-xylylenediamine, 1,3 -bis(N,N-diglycidylamino)cyclo-11- 200923434 Hexane. As the oxazoline crosslinking agent, it is preferred to use a polymer containing an oxazoline group. The monomer containing an addition-polymerizable oxazoline group may be produced by polymerization alone or may be produced by copolymerization with another monomer. As a monomer containing an addition polymerizable oxazoline group, for example, 2-vinyl-2-oxazole, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5- 2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2- Oxazoline. These may be used alone or in combination of two or more. Among them, 2-isopropenyl-2-oxazoline is industrially easy to obtain and is suitable. The other monomer used for the copolymerization with the oxazoline group-containing copolymer may be a monomer copolymerizable with a monomer having an addition polymerizable oxazoline group, for example, an alkyl acrylate, a An alkyl acrylate (as an alkyl group such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, butyl, 2-ethylhexyl, cyclohexyl), etc. Acrylates; acrylic acid, methacrylic acid, methylene succinic acid, maleic acid, fumaric acid, 2-butenoic acid, styrene sulfonic acid and salts thereof (sodium salt, potassium salt) Unsaturated carboxylic acid such as ammonium salt or tertiary amine salt; unsaturated nitrile such as acrylonitrile or methacrylonitrile; acrylamide, methacrylamide, N-alkyl acrylamide, N -alkyl methacrylamide, N,N-dialkyl acrylamide 'N,N-dialkyl methacrylate (as alkyl group, such as methyl, ethyl 'n-propyl, isopropyl) Unsaturated guanamine such as n-butyl, isobutyl, butyl, 2-ethylhexyl, cyclohexyl, etc.; vinyl acetate, ethyl propionate, acrylic acid, methyl propyl The acid ester is partially added to the polyalkylene oxide, such as ethylene vinegar of -12-200923434; vinyl ether such as methyl vinyl ether or ethyl vinyl ether; α-olefin such as ethylene or propylene; vinyl chloride; An alizarin-containing α'β-unsaturated monomer such as vinylidene chloride or fluorinated ethylene; an unsaturated aromatic monomer such as styrene or α-methylstyrene. These monomers may be used alone or in combination of two or more. As the melamine crosslinking agent, a methyl melamine derivative obtained by condensing melamine with formaldehyde, a compound which reacts a lower alcohol and etherified, and a mixture thereof are preferable. As the lower alcohol, for example, methanol, ethanol or isopropanol can be used. As the methyl melamine derivative, for example, monomethylol melamine, dimethyl melamine, trimethylol melamine, tetramethylol melamine, pentamethylol melamine, hexamethylol melamine. As an isocyanate crosslinking agent, for example, toluene diisocyanate, diphenylmethane-4,4'-diisocyanate, m-xylene diisocyanate, hexamethylene-1,6-diisocyanate, iota, 6-di Isocyanate hexane, adduct of toluene diisocyanate and hexanetriol, adduct of toluene diisocyanate and trimethylolpropane, polyol modified diphenylmethane-4,4,- Diisocyanate, carbodiimide modified triphenylmethane-4,4,-diisocyanate, isophorone diisocyanate, 1,5-naphthalene diisocyanate, 3,3'·dimethylphenylene-4,4 '-Diisocyanate, 3,3'-dimethyldiphenylmethane_4,4,-diisocyanate, diisocyanate. The content ratio of the crosslinking agent to be contained in the coating layer is preferably from 5 to 30% by weight, more preferably from 1 to 25% by weight, based on 100% by weight of the composition of the coating layer. By the content of the crosslinking agent being 5 to 30% by weight, the heat-resistant adhesiveness of good -13 to 200923434 can be obtained, and the coating film of appropriate hardness can be obtained, the coating film is not too hard, and the film does not occur in the stretching step. The problem of whitening gives a film with good transparency. Polyoxyalkylene phenyl ether The coating layer of the present invention contains a polyoxyalkylene alkyl phenyl ether. As polyoxyalkylene alkyl phenyl ether, such as polyoxyethylene nonylphenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene styrene phenyl ether, polyoxyethylene stilbene phenyl ether, polyoxygen Ethylene tristyryl phenyl ether, polyoxyethylene benzyl phenyl ether, polyoxyethylene diphenylmethyl phenyl ether, polyoxyethylene trityl phenyl ether, polyoxypropylene decyl phenyl ether, poly Oxypropylene octyl phenyl ether, polyoxypropylene distyryl phenyl ether, polyoxypropylene triphenylmethyl phenyl ether. These monomers may be used alone or in combination of two or more. Among these polyoxyalkylene ethers, a polyoxyalkylene phenyl ether having a plurality of aromatic groups is preferred, and a polyoxyalkylene phenyl ether having a plurality of aromatic groups on the phenyl group is more preferred. As the polyoxyalkylene alkyl phenyl ether, for example, polyoxyethylene styrenated phenyl ether, polyoxyethylene distyryl phenyl ether, polyoxyethylene tristyryl phenyl ether, polyoxyethylene benzyl phenyl ether, Polyoxyethylene diphenylmethylphenyl ether, polyoxyethylene triphenylmethylphenyl ether. These polyoxyalkylene phenyl ethers having a plurality of aromatic groups are preferred because they have good compatibility with the components constituting the coating layer and can reduce the haze of the coating layer. As the polyoxyalkylene phenyl ether, a polyoxyalkylene phenyl ether having a plurality of styrene groups and/or benzyl groups on the phenyl group is particularly preferable. As the polyoxyalkylene alkyl phenyl ether, for example, polyoxyethylene distyrenated phenyl ether, polyoxyethylene triphenyl-14 - 200923434 vinylated phenyl ether, polyoxyethylene diphenylmethyl phenyl ether, polyoxyethylene three Benzyl phenyl ether. The content of the polyoxyalkylene ether to be contained in the coating layer is preferably from 2 to 15% by weight, more preferably from 3 to 10% by weight based on 1% by weight of the composition of the coating layer. %. A film having good heat-resistant adhesiveness and excellent agglomeration resistance can be obtained by 2 to 15% by weight. The polyoxyalkylene phenyl ether has an effect of promoting the wettability of the aqueous coating liquid of the polyester film, and a wetting agent may be added in addition thereto. The formation of the coating layer is preferably carried out using an aqueous coating liquid. In this case, the surface tension of the aqueous coating liquid is preferably 50 dynes/cm or less, more preferably 40 dynes/cm or less. In order to obtain the surface tension, a surfactant such as an anionic surfactant, a cationic surfactant, or a nonionic surfactant is preferable as a preferred surfactant, such as polyethylene oxide/polyoxypropylene. Block copolymer, polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene ether ether, polyoxyethylene alkyl ether, polyoxyethylene-fatty acid ester, sorbitol fatty acid Ester, glycerin fatty acid ester, fatty acid metal soap, alkane sulfonate, alkyl sulfate, alkyl benzene sulfonate, alkyl sulfonate, alkyl diphenyl ether disulfonate, alkyl sulfo amber An acid salt, a 4-grade ammonium chloride salt, an alkylamine hydrochloric acid or the like. Microparticles The coating layer of the present invention preferably contains fine particles having an average particle diameter of 10 to 400 nm from the viewpoint of suppressing agglomeration. In particular, in order to obtain the non-caking property of the coating at the temperature of the crucible, the average particle diameter of the fine particles contained in the coating layer is more than three times the thickness of the coating layer of -15 to 200923434. Further, for example, even if the average particle diameter is large, the fine particles are supported by the acrylic resin in the state of being applied to the coating layer and applied to the film, and the range of the present invention does not fall off in practice. In the case where the coating layer contains fine particles, it is preferred to use organic fine particles having a property of being difficult to fall off from the coating layer. Examples of the organic fine particles include fine particles of an acrylic resin, a styrene resin, a polyoxynene resin, a fluororesin, a benzoguanamine resin, a phenol resin, and a nylon resin. These monomers may be used alone or in combination of two or more. Among these, fine particles of acrylic resin are preferred. In the case of containing fine particles, the total amount of the composition of the coating layer other than the fine particles is preferably 0.1 to 1 part by weight based on 1 part by weight. When the amount is less than 0.1%, sufficient lubricity and scratch resistance are not obtained, and it is not preferable from the viewpoint of scratch resistance. On the other hand, when it exceeds 10 parts by weight, the transparency is deteriorated, which is not preferable. (Manufacturing method) The coating liquid used for coating the coating layer of the present invention is preferably in the form of an aqueous coating liquid such as an aqueous solution, an aqueous dispersion or an emulsion in order to form a coating film on the film. For the coating liquid, for example, a charging inhibitor or a surfactant may be blended as needed. The solid content concentration of the coating liquid is usually 20% by weight or less, preferably 1 to 10% by weight or less. When the amount is less than 1% by weight, the coating property to the polyester film is insufficient, which is not preferable. On the other hand, when it exceeds 20% by weight -16 to 200923434, the stability of the coating liquid and the appearance of the coating layer are deteriorated. not ideal. The application of the coating liquid to the polyester film can be carried out at any stage, but it is preferably carried out in the production process of the polyester film, and it is particularly preferable to coat the polyester film before the completion of the alignment crystallization. Here, the polyester film before the completion of the crystallization is an axially stretched film including an unstretched film and an unstretched film in either the longitudinal direction or the transverse direction, and a two-direction low magnification in the longitudinal direction and the transverse direction. The two-axis stretched film of the extended alignment (finally, the biaxially stretched film before the alignment crystallization is further extended in the longitudinal direction or the transverse direction) is exemplified. Among them, the coating liquid is preferably applied to the unstretched film or the one-direction alignment film. In this case, it is preferable to apply longitudinal extension and/or lateral extension and heat fixation as they are. Further, it is an ideal production method for producing a biaxially stretched film by stretching the film coating liquid without stretching in the longitudinal direction and the transverse direction as it is, and then thermally fixing it. When the coating liquid is applied to the film, physical treatment such as corona surface treatment, flame treatment, or plasma treatment can be applied, and preparation for the improvement of the coating property is preferable. As the coating method, any conventional coating can be applied. Cloth method. For example, a roll coating method, a gravure printing method, a roll coating method, a spray coating method, an air knife coating method, a dipping method, and a curtain coating method can be applied. These can be used individually or in combination. EXAMPLES Hereinafter, the present invention will be described in more detail by way of examples. -17- 200923434 Various physical properties were evaluated by the following methods. (1) Haze The haze of the film was measured in accordance with JIS K7 136 using a haze meter NDH-2000 manufactured by Nippon Denshoku Industries Co., Ltd. (2) Transparency The transparency is evaluated by the haze obtained in the above (1) on the basis of the following criteria. ◎: haze 値 < 0.8% (excellent transparency) 〇: 〇.8%$ haze 値 < 1.0% (good transparency) X : 1 · 〇% S haze 不 (poor transparency) (3) Thickness of coating layer The film was cut into small pieces, wrapped with epoxy resin, and sliced into a film profile of 5 Onm thickness by a microtome. It was dyed at 2% hungry acid and taken at 60 ° C for 2 hours. The cross section of the dyed film was measured by a transmission electron microscope (LEM-2000) at a magnification of 200,000 times to measure the thickness of the coating layer. (4) The average particle diameter of the microparticles was cut into small pieces, wrapped in epoxy resin, and sliced into a film profile of a thickness of 5 〇 nm by a microtome. It was dyed at 2% with acid and spent 2 hours at 60 °C. The cross section of the dyed film was measured by a transmission electron microscope (LEM-2000) at a magnification of 500,000 times, and the particle diameter of any 100 fine particles was measured, and the average 値 of the particle diameter was taken as the average particle diameter. (5) The brightness-increasing sheet is formed in a mold having a pattern, and an ultraviolet-curable acrylic resin formed by the following composition is introduced, and the polyester film of the present invention is coated on -18 to 200923434. The layer was placed on the acrylic resin side and the two were adhered to each other. The distance from the surface of the polyester film was 30 cm, and an ultraviolet lamp (irradiation intensity: 80 W/cm, 6.4 kW) was used for 30 seconds to harden the resin to form a vertex angle of 90 degrees. A layer of 50 μm and a height of 30 μm is obtained to obtain a brightness enhancement sheet. As the ultraviolet curable acrylic resin, the following composition is used. Ethylene oxide modified bisphenol fluorene dimethacrylate (FA-321 M, manufactured by Hitachi Chemical Co., Ltd.) 46% by weight Neopentyl glycol modified trimethylolpropane diacrylate (R-, manufactured by Hitachi Chemical Chemical Co., Ltd.) 6〇4) 25 wt% phenoxyethyl acrylate (BIS-COAT192, manufactured by Osaka Organic Chemical Industry Co., Ltd.) 27% by weight 2-methyl-2-methyl-1-phenylpropan-1-pyrene (Merck) Darocurl 173) 2% by weight (6) Adhesion to the enamel layer The processing surface of the brightness-increasing sheet obtained in the above (5) is subjected to a cross cut of a checkerboard (100 sheets of 1 mm2) on which A 24mm wide celluloid adhesive tape (made by NICHIBAN Co., Ltd., Saiyanfan tape CT405AP-18) was attached to a 2K back and forth weight by a metal roller of 5 kg/5 5 cm wide, and the 90 degree peeling angle was quickly peeled off. The peeled surface was observed and evaluated on the basis of the following criteria. 〇: The peeling area is 5% or less (good adhesion) X: The peeling area is more than 5% (poor adhesion) (7) Heat-resistant adhesive 200923434 The brightness-increasing sheet obtained in the above (5) is 1 〇 The oven of the crucible C was subjected to heat treatment for 12 hours, taken out from the oven, and left to stand at room temperature for 1 minute. Then, the same peeling test as in the above (6) was carried out, and the peeled surface was observed and evaluated according to the following criteria. 〇: The peeling area is 5% or less (good heat-resistant adhesiveness) △: The peeling area is 5 to 20% (the heat-resistant adhesiveness is slightly poor) X: The peeling area is more than 20% (the heat-resistant adhesiveness is completely poor) Example 1 will melt polyethylene terephthalate ([η] = 〇.6〇ίΠ/§,
Tg = 78°C)從模頭擠出’藉由一般方法以冷卻鼓冷卻，成爲 未延伸薄膜，然後於縱方向延伸3 .3倍後，於其兩面以輥 輪塗佈法均勻塗佈表1所示的組成之塗劑A的濃度5%之 水性塗液。而且，於熔融的聚對苯二甲酸乙二酯，使用不 含作爲潤滑劑之微粒子者。 設有塗佈層的薄膜，接著於120 °C下乾燥，於橫方向 於1 3 5 °C下延伸3.6倍，以2 3 5 °C熱固定後，從1 8 0 °C至 9 0 °C爲止階段性地冷卻薄膜，且在拉幅機內於橫方向進行 3.5 %鬆弛熱處理，得到厚度1 2 5 μιη、塗佈層厚度7 5 nm的 亮度提昇薄片用聚酯薄膜。評價結果表示於表2。 再者，於所得的聚酯薄膜，使用紫外線硬化型丙烯酸 樹脂，形成稜鏡層，得到亮度提昇薄片。評價結果表示於 表2。 -20- 200923434 實施例2 將溶融的聚對苯二甲酸乙二醋（[t)] = 0.61dl/g、Tg = 78 ° C) Extrusion from the die 'cooled by a cooling method to form an unstretched film, and then extended 3.4 times in the longitudinal direction, and then uniformly coated on both sides by roll coating An aqueous coating liquid having a concentration of 5% of the coating agent A of the composition shown in FIG. Further, in the case of molten polyethylene terephthalate, those which do not contain fine particles as a lubricant are used. A film with a coating layer, followed by drying at 120 ° C, 3.6 times in the transverse direction at 1 35 ° C, and heat-set at 2 3 5 ° C, from 180 ° C to 90 ° The film was cooled stepwise, and a 3.5% relaxation heat treatment was performed in the tenter in the transverse direction to obtain a polyester film for a brightness-enhancing sheet having a thickness of 1 25 μm and a coating layer thickness of 75 nm. The evaluation results are shown in Table 2. Further, a ruthenium layer was formed on the obtained polyester film using an ultraviolet curable acrylic resin to obtain a brightness-enhancing sheet. The evaluation results are shown in Table 2. -20- 200923434 Example 2 The molten polyethylene terephthalate ([t)] = 0.61 dl / g,
Tg = 78°C)從模頭擠出，藉由一般方法以冷卻鼓冷卻，成爲 未延伸薄膜’然後於其兩面以輥輪塗佈法均勻塗佈表1所 示的組成之塗劑A的濃度7 %之水性塗液。該塗佈的薄 膜，接著於95 t下乾燥，於1 1 3 °C下同時於縱方向延伸 3.4倍’於橫方向延伸3.6倍，以23 0°C熱固定後，於 185°C，分別對縱方向及寬度方向進行2.2%鬆弛熱處理， 得到厚度125μηι、塗佈層厚度75nm的亮度提昇薄片用聚 酯薄膜。評價結果表示於表2。 於所得的聚酯薄膜，使用紫外線硬化型丙烯酸樹脂， 形成稜鏡層，得到亮度提昇薄片。評價結果表示於表2。 實施例3 除使用塗劑 A，形成塗膜，薄膜的厚度爲188μιη 外，與實施例2同樣的方式，得到亮度提昇薄片用聚酯薄 膜，再使用其製成亮度提昇薄片。評價結果表示於表2。 實施例4〜1 1 除使用表1所記載的塗劑Β、C或D、J、κ、L、Ν 或〇，形成既定厚度的塗膜外’與實施例1同樣的方式， 製作亮度提昇薄片用聚酯薄膜，又使用其製成亮度提昇薄 片。評價結果表示於表2。 -21 - 200923434 比較例1〜5 除使用表1所記載的塗劑E、F、G、Η或I，形成既 定厚度的塗膜外，與實施例1同樣的方式，得到亮度提昇 薄片用聚酯薄膜。又使用其製成亮度提昇薄片。評價結果 表示於表2。 比較例6 除不形成塗佈層’於沒有塗佈層的面’直接設置稜鏡 層外，與實施例1同樣的方式，得到亮度提昇薄片用聚酯 薄膜，又使用其製成亮度提昇薄片。評價結果表示於表 2 ° 而且，所得的亮度提昇薄片’其基質薄膜與稜鏡層的 塗劑的觀 A B Γ D E F G Η I J K L N 0 丙烯酸樹脂1 72 72 7? 72 72 72 72 72 92 72 72 72 丙烯酸樹脂2 Ί2 丙烯酸樹脂3 Ί2 塗劑 交聯劑1 20 ?0 20 20 20 20 20 的組 交聯劑2 20 20 20 20 成 交聯劑3 20 (重量 交聯劑4 20 %) 微粒子 1 1 1 1 1 1 1 1 1 1 1 1 1 潤濕劑] 7 7 7 7 7 7 7 潤濕劑2 7 7 潤濕劑3 7 7 潤濕劑4 7 7 潤濕劑S ------ 7 密合性差，無法滿足作爲亮度提昇薄片 表1 _ -22- 200923434 組成設置塗佈層用之塗液之成分，係使用以下物質。 丙烯酸樹脂1 : 由甲基丙烯酸甲酯60莫耳％/丙烯酸乙酯30莫耳％/ 丙烯酸2-羥基乙酯5莫耳％/N-羥甲基丙烯醯胺5莫耳％所 構成。丙烯酸係根據特開昭63-37167號公報的製造例1 〜3所記載的方法’如下述製造。亦即，於* 口燒瓶中， 放入離子交換水302份，在氮氣氣流中，使其昇溫至 6〇 °C’然後添加作爲聚合引發劑之過硫酸銨ο」重量份、 亞硝酸氫鈉0.2重量份，使作爲單體之甲基丙烯酸甲酯 59,9重量份、丙烯酸乙酯30.0重量份、丙烯酸2 -羥基乙 酯5.8重量份、N -羥甲基丙烯醯胺43重量份的混合物， 經3小時’一邊調整液溫成爲60〜701：，一邊滴下。滴完 後’於相同溫度範圍保持2小時，且於攪拌下繼續反應， 然後使其冷卻，得到固體成分爲2 5 %之丙烯酸樹脂1的水 分散體。 丙烯酸樹脂2 : 由甲基丙烯酸甲酯60莫耳％ /丙烯酸乙酯3〇莫耳％/ 丙烯酸2 -羥基乙酯5莫耳％ /丙烯醯胺5莫耳％所構成。丙 烯酸係根據特開昭63 7 1 67號公報的製造例1〜3所記載 的方法，如下述製造。亦即’於4 口燒瓶中，放入離子交 換水3 0 2份，在氮氣氣流中’使其昇溫至6 0 t：，然後添加 作爲聚合引發劑之過硫酸銨0.5重量份、亞硝酸氫鈉〇.2 重量份，又使作爲單體之甲基丙烯酸甲酯60.8重量份、 丙烯酸乙酯30.4重量份、丙烯酸2 -羥基乙酯5.9重量 -23- 200923434 份、丙燦酸胺2.9重量份的混合物，經3小時，一邊調整 液溫成爲60〜70°C，一邊滴下。滴完後，於相同溫度範圍 保持2小時’且於攪拌下繼續反應，然後使其冷卻，得到 固體成分爲25 %之丙烯酸樹脂2的水分散體。 丙烯酸樹脂3 : 由甲基丙儲酸甲酯60莫耳％ /丙稀酸乙醋莫耳 丙烯酸2 -羥基乙酯5莫耳％ /丙烯腈5莫耳％所構成。丙嫌 酸係根據特開昭6 3 - 3 7 1 6 7號公報的製造例1〜3所記載的 方法’如下述製造。亦即’於4 口燒瓶中，放入離子交換 水3 0 2份，在氮氣氣流中，使其昇溫至6 01，然後添加作 爲聚合引發劑之過硫酸銨0.5重量份、亞硝酸氫鈉〇.2重 量份，又使作爲單體之甲基丙烯酸甲酯61.4重量份、丙 烯酸乙酯30.7重量份、丙烯酸2-羥基乙酯5.9重量份、 丙烯腈2 · 0重量份的混合物，經3小時，一邊調整液溫成 爲60〜7 0 °C，一邊滴下。滴完後，於相同溫度範圍保持2 小時，且於攪拌下繼續反應，然後使其冷卻，得到固體成 分爲25%之丙烯酸樹脂3的水分散體。 交聯劑1 : 甘油聚縮水甘油醚（Nagase Chemtex公司製、 DENACOL EX-3 13) 交聯劑2 : 含有噁唑啉之聚合物（日本觸媒公司製、EPOCROS K-2030E) -24- 200923434 羥 三和化學公司製 NIKALAC MX- 03 5 ) 交聯劑4 : 異氰酸酯（第一工業製藥公司製、ELASTRON H-3) 微粒子： 丙儲酸酯塡充劑（平均粒徑160nm、日本觸媒公司 製、MX-100W) 潤濕劑1 : 聚氧乙烯二苯乙烯化苯醚（花王公司製、EMULGEN A-60) 潤濕劑2 : 聚氧乙烯三苯乙烯化苯醚（花王公司製、EMULGEN B-66) 潤濕劑3 : 聚氧伸烷基烷醚（三洋化成公司製、NAROACTIE N-70)Tg = 78 ° C) was extruded from a die, cooled by a cooling method to a non-stretched film by a general method, and then uniformly applied the coating agent A of the composition shown in Table 1 by roller coating on both sides thereof. Aqueous coating solution with a concentration of 7%. The coated film was then dried at 95 t, extended at 3.4 times in the longitudinal direction at 136 ° C, and extended 3.6 times in the transverse direction, and heat-fixed at 23 ° C, at 185 ° C, respectively. A 2.2% relaxation heat treatment was applied to the longitudinal direction and the width direction to obtain a polyester film for a brightness enhancement sheet having a thickness of 125 μm and a coating layer thickness of 75 nm. The evaluation results are shown in Table 2. To the obtained polyester film, an ultraviolet curable acrylic resin was used to form a ruthenium layer to obtain a brightness-enhancing sheet. The evaluation results are shown in Table 2. (Example 3) A polyester film for brightness enhancement sheet was obtained in the same manner as in Example 2 except that the coating film A was used to form a coating film having a thickness of 188 μm, and a brightness-enhancing sheet was produced. The evaluation results are shown in Table 2. Examples 4 to 1 1 In the same manner as in Example 1, except that the coating agent Β, C or D, J, κ, L, 〇 or 〇 described in Table 1 was used to form a coating film having a predetermined thickness, brightness enhancement was performed. The sheet is made of a polyester film, which is used to form a brightness enhancement sheet. The evaluation results are shown in Table 2. -21 - 200923434 Comparative Examples 1 to 5 In the same manner as in Example 1, except that the coating agents E, F, G, Η or I described in Table 1 were used to form a coating film having a predetermined thickness, a brightness-enhancing sheet was obtained. Ester film. It is also used to make a brightness enhancement sheet. The evaluation results are shown in Table 2. Comparative Example 6 A polyester film for brightness-enhancing sheet was obtained in the same manner as in Example 1 except that the coating layer was formed without directly forming a coating layer on the surface having no coating layer. . The evaluation results are shown in Table 2 ° and the resulting brightness-enhancing sheet's coating of the base film and the enamel layer is AB Γ DEFG Η IJKLN 0 Acrylic resin 1 72 72 7? 72 72 72 72 72 92 72 72 72 Acrylic Resin 2 Ί2 Acrylic resin 3 Ί2 Coating agent Crosslinker 1 20 ?0 20 20 20 20 20 Group crosslinker 2 20 20 20 20 Form crosslinker 3 20 (weight crosslinker 4 20 %) Microparticle 1 1 1 1 1 1 1 1 1 1 1 1 1 Wetting agent] 7 7 7 7 7 7 7 Wetting agent 2 7 7 Wetting agent 3 7 7 Wetting agent 4 7 7 Wetting agent S ------ 7 dense The composition is poor, and it is not possible to satisfy the composition of the coating liquid for setting the coating layer as the brightness enhancement sheet Table 1 _ -22- 200923434, and the following materials are used. Acrylic resin 1: It is composed of methyl methacrylate 60 mol% / ethyl acrylate 30 mol% / 2-hydroxyethyl acrylate 5 mol% / N-methylol acrylamide 5 mol%. The method described in Production Examples 1 to 3 of JP-A-63-37167 is produced as follows. That is, in the flask, 302 parts of ion-exchanged water was placed, and the temperature was raised to 6 ° C in a nitrogen gas stream, and then ammonium persulfate as a polymerization initiator was added. 0.2 parts by weight, a mixture of 59,9 parts by weight of methyl methacrylate as a monomer, 30.0 parts by weight of ethyl acrylate, 5.8 parts by weight of 2-hydroxyethyl acrylate, and 43 parts by weight of N-methylol acrylamide After 3 hours' adjustment of the liquid temperature to 60~701:, drip while dropping. After the completion of the dropwise addition, the mixture was kept at the same temperature for 2 hours, and the reaction was continued with stirring, followed by cooling to obtain an aqueous dispersion of the acrylic resin 1 having a solid content of 25 %. Acrylic resin 2: consisting of methyl methacrylate 60 mol % / ethyl acrylate 3 〇 mol % / 2-hydroxyethyl acrylate 5 mol % / acrylamide 5 mol %. The acrylic acid is produced as follows according to the methods described in Production Examples 1 to 3 of JP-A-63 71 167. That is, in a 4-necked flask, 30 parts of ion-exchanged water was placed, and the temperature was raised to 60 Torr in a nitrogen gas stream, and then 0.5 parts by weight of ammonium persulfate as a polymerization initiator was added, and hydrogen nitrite was added. 2 parts by weight, further, 60.8 parts by weight of methyl methacrylate as a monomer, 30.4 parts by weight of ethyl acrylate, 2.9% by weight of 2-hydroxyethyl acrylate, -23-200923434 parts, and 2.9 parts by weight of glyceryl acrylate The mixture was adjusted to a temperature of 60 to 70 ° C over 3 hours while dropping. After the completion of the dropwise addition, the reaction was continued for 2 hours in the same temperature range, and the reaction was continued with stirring, followed by cooling to obtain an aqueous dispersion of the acrylic resin 2 having a solid content of 25%. Acrylic Resin 3: Consisting of methyl ketone acid ester 60 mol% / acrylic acid ethyl acetate 2-hydroxyethyl acrylate 5 mol% / acrylonitrile 5 mol%. The acrylic acid is produced as follows according to the methods described in Production Examples 1 to 3 of JP-A-63-1777. That is, in a 4-necked flask, 30 parts of ion-exchanged water was placed, and the temperature was raised to 601 in a nitrogen gas stream, and then 0.5 parts by weight of ammonium persulfate as a polymerization initiator was added, and sodium hydrogen nitrite was added. .2 parts by weight, further comprising 61.4 parts by weight of methyl methacrylate as a monomer, 30.7 parts by weight of ethyl acrylate, 5.9 parts by weight of 2-hydroxyethyl acrylate, and 2 parts by weight of acrylonitrile, for 3 hours. While adjusting the liquid temperature to 60~7 0 °C, drip. After the completion of the dropwise addition, the mixture was kept at the same temperature for 2 hours, and the reaction was continued with stirring, followed by cooling to obtain an aqueous dispersion of a 25% solid acrylic resin 3. Crosslinking agent 1: Glycerol polyglycidyl ether (manufactured by Nagase Chemtex, DENACOL EX-3 13) Crosslinking agent 2 : Polymer containing oxazoline (manufactured by Nippon Shokubai Co., Ltd., EPOCROS K-2030E) -24- 200923434 NIKALAC MX-03, manufactured by Hydroxy Sanhe Chemical Co., Ltd. 5) Crosslinking agent 4: Isocyanate (manufactured by Daiichi Kogyo Co., Ltd., ELASTRON H-3) Microparticles: Cyanate ester oxime (average particle size 160 nm, Nippon Shokubai Co., Ltd.) , MX-100W) Wetting agent 1: Polyoxyethylene distyryl phenyl ether (made by Kao Corporation, EMULGEN A-60) Wetting agent 2: Polyoxyethylene tristyryl phenyl ether (made by Kao Corporation, EMULGEN B-66) Wetting agent 3 : Polyoxyalkylene alkyl ether (made by Sanyo Chemical Co., Ltd., NAROACTIE N-70)
潤濕劑4 : 聚氧伸院基油醚（竹本油脂公司製、BI〇NINE D-1504) 潤濕劑5 : 聚氧乙烯一本乙烯化苯醚（花王公司製、EMULGEN A-90) -25- 200923434Wetting agent 4 : Polyoxygen extension base oil ether (made by Takeshi Oil Co., Ltd., BI〇NINE D-1504) Wetting agent 5 : Polyoxyethylene one vinylated phenyl ether (made by Kao Corporation, EMULGEN A-90) - 25- 200923434
表2 薄膜的 厚度(μιη) 塗劑的 種類 塗佈層的 厚度(nm) 霧度 (%) 透明性 稜鏡層 密合性 耐熱 接合性 實施例1 125 塗劑A 75 0.7 ◎ 〇 〇 實施例2 125 塗劑A 75 0.7 ◎ 〇 〇 實施例3 188 塗劑A 75 0.8 〇 〇 〇 實施例4 125 塗劑B 75 0.7 ◎ 〇 〇 實施例5 125 塗劑C 75 0.7 ◎ 〇 〇 實施例6 125 塗劑D 75 0.7 ◎ 〇 〇 實施例7 125 塗劑J 75 0.7 ◎ 〇 〇 實施例8 125 塗劑K 75 0.7 ◎ 〇 〇 實施例9 125 塗劑L 75 0.7 ◎ 〇 〇 實施例10 125 塗劑N 75 0.8 〇 〇 〇 實施例11 125 塗劑〇 75 0.8 〇 〇 〇 比較例1 125 塗劑E 75 1.0 X 〇 Δ 比較例2 125 塗劑F 75 1.0 X 〇 Δ 比較例3 125 塗劑G 75 1.1 X 〇 Δ 比較例4 125 塗劑Η 75 1.1 X 〇 Δ 比較例5 125 塗劑I 75 0.7 ◎ X X 比較例6 125 Μ - 0.6 ◎ X X 發明的效果 根據本發明，可提供適合用於車載用機材、高亮度大 畫面顯示器之具備充分耐熱黏著性且具備高透明性、顯示 與稜鏡層高密合性之使用作爲亮度提昇薄片（稜鏡薄片）的 基質薄膜之聚酯薄膜。 產業上的利用可能性 本發明的亮度提昇薄片用聚酯薄膜，可適合使用於各 種光學用途。特別是適合使用於朝大畫面化及高亮度化進 -26 - 200923434 展之液晶顯示器、車載用之高溫度下使用的亮度提昇薄片 的基材的用途。Table 2 Thickness of film (μιη) Type of coating agent Thickness (nm) of coating layer Haze (%) Transparency 稜鏡 layer adhesion Heat-resistant bonding Example 1 125 Coating agent A 75 0.7 ◎ 〇〇 Example 2 125 Paint A 75 0.7 ◎ 〇〇 Example 3 188 Paint A 75 0.8 〇〇〇 Example 4 125 Paint B 75 0.7 ◎ 〇〇 Example 5 125 Paint C 75 0.7 ◎ 〇〇 Example 6 125 Coating agent D 75 0.7 ◎ 〇〇 Example 7 125 Coating agent J 75 0.7 ◎ 〇〇 Example 8 125 Coating agent K 75 0.7 ◎ 〇〇 Example 9 125 Coating agent L 75 0.7 ◎ 〇〇 Example 10 125 Coating agent N 75 0.8 〇〇〇 Example 11 125 Paint 〇 75 0.8 〇〇〇 Comparative Example 1 125 Paint E 75 1.0 X 〇 Δ Comparative Example 2 125 Paint F 75 1.0 X 〇 Δ Comparative Example 3 125 Paint G 75 1.1 X 〇 Δ Comparative Example 4 125 Paint Η 75 1.1 X 〇 Δ Comparative Example 5 125 Coating agent I 75 0.7 ◎ XX Comparative Example 6 125 Μ - 0.6 ◎ XX Effects of the Invention According to the present invention, it is suitable for use in a vehicle The machine, high-brightness large-screen display has sufficient heat-resistant adhesiveness and high transparency and display A polyester film which is used as a matrix film of a brightness enhancement sheet (tantalum sheet) as a high-adhesion layer. Industrial Applicability The polyester film for brightness-enhancing sheets of the present invention can be suitably used for various optical applications. In particular, it is suitable for use in substrates that are used for large-screen and high-brightness LCD monitors and brightness-increasing sheets used at high temperatures for vehicles.