POLYESTER FILM AND GAS BARRIER LAMINATE FILM

• Main Authors: GOTO TAKAMICHI, TAMATOSHI NOBORU
• Format: Patent
• Language: English; Japanese
• Published: 10.10.2019
• Subjects: ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F,C08G; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; CHEMISTRY; COMPOSITIONS BASED THEREON; CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS,e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES,DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; CONVEYING; GENERAL PROCESSES OF COMPOUNDING; HANDLING THIN OR FILAMENTARY MATERIAL; 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; PACKAGES; PACKAGING ELEMENTS; PACKING; PERFORMING OPERATIONS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; STORING; THEIR PREPARATION OR CHEMICAL WORKING-UP; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL; WORKING-UP

To provide a biaxially oriented polyester film suppressing wrinkles generated during heating transportation when an inorganic thin film layer is formed to manufacture a gas barrier film, and capable of making gas barrier property in a width direction uniform.SOLUTION: There is provided a polyester film containing polybutylene terephthalate of 70 wt.% or more, and satisfying following (1) to (4) at the same time. (1) the piercing strength is 0.6 N/μm or more. (2) the surface orientation degree of a film is 0.144 to 0.165. (3) thermal shrinkage after heating the film at 150°C for 15 hr. is 0 to 4% in a lengthwise direction and -1 to 3% in a crosswise direction. (4) a difference between maximum and minimum of the thermal shrinkage in the lengthwise direction after heating at 150°C for 15 min. of 9 points of a center part of a film whole width, right and left 40%, right and left 30%, right and left 20%, right and left 10% in whole width right and left from the center is 1.0% or less.SELECTED DRAWING: None 【課題】 無機薄膜層を形成してガスバリアフィルムを製造する際の加熱搬送時に発生するシワを抑制し、幅方向のガスバリア性を均一にできる二軸延伸ポリエステルフィルムを提供する。【解決手段】 ポリブチレンテレフタレートを７０重量％以上含有し、下記（１）〜（４）を同時に満することを特徴とするポリエステルフィルム。 （１）突刺し強度が０．６Ｎ／μｍ以上。 （２）フィルムの面配向度が０．１４４〜０．１６５。 （３）フィルムの１５０℃で１５分間加熱後の熱収縮率が、縦方向が０〜４％、横方向が−１〜３％。 （４）フィルム全幅の中央部、および中央から左右に全幅の左右４０％、左右３０％、左右２０％、左右１０％の９点の１５０℃で１５分間加熱後の縦方向の熱収縮率の最大と最小の差が１．０％以下。【選択図】 なし