OPTICAL FILM, MULTILAYER OPTICAL FILM INCLUDING SAME, AND METHOD FOR PRODUCING OPTICAL FILM

• Main Authors: KOMURO KOJI, KAKINOKI OSAMU
• Format: Patent
• Language: English; French; Japanese
• Published: 04.02.2016
• Subjects: AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F,C08G; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; CHEMISTRY; COMPOSITIONS BASED THEREON; DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH ISMODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THEDEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY,COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g.SWITCHING, GATING, MODULATING OR DEMODULATING; FREQUENCY-CHANGING; GENERAL PROCESSES OF COMPOUNDING; INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULARARTICLES; INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS; LAYERED PRODUCTS; LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT ORNON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM; METALLURGY; NON-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICAL LOGIC ELEMENTS; OPTICS; ORGANIC MACROMOLECULAR COMPOUNDS; PERFORMING OPERATIONS; PHYSICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; THEIR PREPARATION OR CHEMICAL WORKING-UP; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL; WORKING-UP

Provided are: an optical film that has a good appearance, low in-plane retardation Re, and high thickness-direction retardation Rth; and a method for producing such an optical film. Also provided is a multilayer optical film that uses the optical film, that exhibits little change in retardation as a result of wavelength, and that has small retardation at low wavelengths. The optical film is obtained by sandwiching a melted resin between a first cooling roll comprising an elastic metal roll and a second cooling roll comprising a non-elastic metal roll and molding said melted resin. The optical film has a good appearance, the absolute value of the in-plane retardation Re thereof is 10 nm or less, and the thickness-direction retardation Rth thereof is 40 nm or more. L'invention concerne : un film optique qui a un aspect satisfaisant, un retard faible dans le plan Re, et un retard élevé dans la direction de l'épaisseur Rth ; et un procédé de fabrication d'un tel film optique. L'invention concerne également un film optique multicouche qui utilise le film optique, qui présente peu de changement de retard en fonction de la longueur d'onde, et qui possède un retard faible à des longueurs d'onde faibles. Le film optique est obtenu en intercalant une résine fondue entre un premier rouleau de refroidissement comprenant un rouleau métallique élastique et un deuxième rouleau de refroidissement comprenant un rouleau métallique non élastique et en moulant ladite résine fondue. Le film optique a un aspect satisfaisant, la valeur absolue du retard dans le plan Re de celui-ci est de 10 nm ou moins, et le retard dans le sens de l'épaisseur Rth de celui-ci est de 40 nm ou plus. 　外観が良好であり、面内リターデーションＲｅが低く、厚み方向リターデーションＲｔｈが高いフィルム、およびそのようなフィルムの製造方法を提供する。また、上記光学フィルムを用いて、波長によるリターデーションの変化が小さい、または低波長におけるリターデーションが小さい積層光学フィルムを提供する。　溶融した樹脂を、金属弾性ロールからなる第１の冷却ロールと、金属非弾性ロールからなる第２の冷却ロールとの間に挟持して成形し、光学フィルムを得た。この光学フィルムの外観は良好であり、面内リターデーションＲｅの絶対値は１０ｎｍ以下であり、厚み方向のリターデーションＲｔｈは４０ｎｍ以上であった。