OPTICAL FILM, PRODUCTION METHOD OF THE SAME, FLEXIBLE PRINTED CIRCUIT BOARD, AND LED ILLUMINATION

• Main Authors: UMEDA HIRONORI, MAJIMA KENTA, ITO YASUTOSHI
• Format: Patent
• Language: English; Japanese
• Published: 12.05.2016
• Subjects: AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F,C08G; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; APPLYING LIQUIDS OR OTHER FLUENT MATERIALS TO SURFACES, IN GENERAL; BASIC ELECTRIC ELEMENTS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; CHEMISTRY; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; GENERAL PROCESSES OF COMPOUNDING; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS; METALLURGY; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICS; ORGANIC MACROMOLECULAR COMPOUNDS; PERFORMING OPERATIONS; PHYSICS; PRINTED CIRCUITS; PROCESSES FOR APPLYING LIQUIDS OR OTHER FLUENT MATERIALS TOSURFACES, IN GENERAL; SEMICONDUCTOR DEVICES; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; SPRAYING OR ATOMISING IN GENERAL; THEIR PREPARATION OR CHEMICAL WORKING-UP; TRANSPORTING; USE OF INORGANIC OR NON-MACROMOLECULAR ORGANIC SUBSTANCES ASCOMPOUNDING INGREDIENTS; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL; WORKING-UP

PROBLEM TO BE SOLVED: To provide an optical film that is suitable for a flexible printed circuit board or the like of an LED illumination device, has excellent heat resistance, and shows improved extraction efficiency of light (luminance).SOLUTION: The optical film of the present invention contains fine particles that are optically isotropic and have an average particle diameter of 0.05 to 5.0 μm, and a binder having a glass transition temperature (Tg) of 250°C or higher. The film is characterized in that: a retardation value Rth in a thickness direction represented by formula (i) is in the range from 10 to 150 nm/μm per unit thickness of the optical film; and an absolute value |Δn| of a difference between a refractive index (n) of the fine particles and a refractive index (n) in the thickness direction of the optical film is 0.02 or less.SELECTED DRAWING: None 【課題】本発明の課題は、ＬＥＤ照明装置のフレキシブルプリント基板などに好適な、耐熱性に優れ、かつ光取り出し効率（輝度）が向上した光学フィルムを提供することである。【解決手段】本発明の光学フィルムは、光学的に等方性であり、平均粒径が０．０５〜５．０μｍの範囲内である微粒子と、ガラス転移温度（Ｔｇ）が２５０℃以上であるバインダーを含有する光学フィルムであって、下記式（ｉ）で表される厚さ方向のリターデーション値Ｒｔｈが、前記光学フィルムの単位厚さ当たり、１０〜１５０ｎｍ／μｍの範囲内であり、前記微粒子の屈折率（ｎｚａ）と前記光学フィルムの厚さ方向の屈折率（ｎｚ）との差の絶対値｜Δｎｚ１｜が、０．０２以下であることを特徴とする。【選択図】なし