POLYESTER FILM AND POLARIZER PROTECTIVE FILM

• Main Authors: GODA WATARU, FUJIMOTO SOICHI
• Format: Patent
• Language: English; Japanese
• Published: 05.01.2017
• Subjects: AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F,C08G; CHEMISTRY; COMPOSITIONS BASED THEREON; GENERAL PROCESSES OF COMPOUNDING; LAYERED PRODUCTS; LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT ORNON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; PERFORMING OPERATIONS; THEIR PREPARATION OR CHEMICAL WORKING-UP; TRANSPORTING; WORKING-UP

PROBLEM TO BE SOLVED: To provide a polyester film suitably used as a polarizer for liquid crystal display or an ITO substrate film and having no curl nor wrinkle during a manufacturing process or post-processing such as a heat treatment.SOLUTION: There is provided a polyester film having thermal shrinkage of a longer direction at 85°C for 6 hours of 0.5% or less, phase difference at incident angle of 0° (Ra) of 400 nm or less, Young modulus both in the longer direction and a width direction of 2 GPa or more, braking elongation in the longer direction and the width direction of 50% or more and raising temperature of shrinkage stress during TMA measurement in the longer direction of 90°C or more.SELECTED DRAWING: None 【課題】液晶ディスプレイ向け偏光板あるいはＩＴＯ基材フィルムとして好適に用いられ、製造工程や熱処理などの後加工した際にカールやシワの発生がないポリエステルフィルムを提供すること。【解決手段】長手方向の８５℃、６時間の熱収縮率が０．５％以下であり、入射角０°での位相差（Ｒｅ）が４００ｎｍ以下、長手方向および幅方向のヤング率がともに２ＧＰａ以上、長手方向および幅方向の破断伸度がともに５０％以上、長手方向のＴＭＡ測定時の収縮応力の立ち上がり温度が９０℃以上であるポリエステルフィルムとする。【選択図】なし