WHITE REFLECTION FILM FOR EDGE LIGHT TYPE BACKLIGHT AND BACKLIGHT FOR LIQUID CRYSTAL DISPLAY USING THE SAME

• Main Authors: TABATA HISANORI, FUNATOMI TSUYOSHI
• Format: Patent
• Language: English; Japanese
• Published: 05.03.2020
• Subjects: BLASTING; 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; HEATING; LAYERED PRODUCTS; LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT ORNON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM; LIGHTING; MECHANICAL ENGINEERING; NON-LINEAR OPTICS; NON-PORTABLE LIGHTING DEVICES; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICAL LOGIC ELEMENTS; OPTICS; PERFORMING OPERATIONS; PHYSICS; SYSTEMS THEREOF; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; TRANSPORTING; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLEEXTERIORS; WEAPONS

To provide a white reflection film excellent in economical efficiency, film-forming property, whiteness, reflectivity, lightweight property and surface profile, and an inexpensive backlight excellent in luminance characteristics and compatibility with other members by using the above film.SOLUTION: A white reflection film for an edge light type backlight, described in Claim 1, satisfies the following conditions (i) to (v). (i) The film is a laminate film composed of a surface layer (A) and a base material layer (B) containing foams; (ii) the surface layer (A) contains substantially no particles; (iii) the center surface average roughness (SRa) on the surface of the surface layer (A) is 90 nm or more and less than 500 nm; (iv) the surface layer (A) comprises a polyester resin (A) by 70 to 99 mass% and a thermoplastic resin (B) incompatible with the polyester resin (A) by 1 to 30 mass%; and (v) the thermoplastic resin (B) is a crystalline resin, and a melting point TmA of the polyester resin (A) and a melting point TmB of the thermoplastic resin (B) satisfy (expression 1) of 30<TmA-TmB<140.SELECTED DRAWING: None 【課題】経済性、製膜性、白色性、反射性、軽量性、表面形状に優れ、この白色反射フィルムを用いることにより輝度特性及び他部材との相性に優れたバックライトを安価に提供する。【解決手段】次の（i）〜（v）を満たすエッジライト型バックライト用白色反射フィルム（i）表層（Ａ）と気泡を含有する基材層（Ｂ）から構成された積層フィルムであること（ii）表層（Ａ）は実質的に粒子を含まないこと（iii）表層（Ａ）の表面の中心面平均粗さ（ＳＲａ）が９０ｎｍ以上５００ｎｍ未満であること（iv）表層（Ａ）ポリエステル樹脂（Ａ）７０〜９９質量％と、前記ポリエステル樹脂（Ａ）と非相溶な熱可塑性樹脂（Ｂ）１〜３０質量％とを含むこと。（v）熱可塑性樹脂（Ｂ）が結晶性樹脂であり、ポリエステル樹脂（Ａ）の融点ＴｍＡと、前記熱可塑性樹脂（Ｂ）の融点ＴｍＢが以下の（式１）を満たす請求項１に記載の白色反射フィルム。３０＜ＴｍＡ−ＴｍＢ＜１４０ （式１）【選択図】なし