WHITE REFLECTIVE FILM FOR EDGE-LIT BACKLIGHT UNIT AND BACKLIGHT UNIT FOR LIQUID CRYSTAL DISPLAY USING THE SAME

• Main Authors: TABATA HISANORI, FUNATOMI TSUYOSHI
• Format: Patent
• Language: English; Japanese
• Published: 22.03.2019
• Subjects: BLASTING; CHEMISTRY; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; 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; FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMSTHEREOF; HEATING; LIGHTING; MECHANICAL ENGINEERING; METALLURGY; NON-LINEAR OPTICS; NON-PORTABLE LIGHTING DEVICES; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICAL LOGIC ELEMENTS; OPTICS; ORGANIC MACROMOLECULAR COMPOUNDS; PHYSICS; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHERARTICLES, NOT OTHERWISE PROVIDED FOR; SYSTEMS THEREOF; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; THEIR PREPARATION OR CHEMICAL WORKING-UP; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLEEXTERIORS; WEAPONS

To provide a white reflective film that offers superior economic efficiency, film formability, whiteness, reflectivity, lightness, and surface profile, and to economically provide a backlight unit that offers superior luminance characteristics and compatibility with other members using the same.SOLUTION: A white reflective film for edge-lit backlight units is provided, which satisfies the following conditions (i)-(vi): (i) The white reflective film is a multilayer film comprised of a surface layer (A) and a base material layer (B) containing air bubbles; (ii) The surface layer (A) practically does not contain particles; (iii) A surface of the surface layer (A) has a center plane average roughness (SRa) of 90 nm or greater and less than 300 nm; (iv) The surface layer (A) includes a resin layer containing a cyclic olefin copolymer polyester; (v) The cyclic olefin copolymer polyester is a copolymer consisting of at least one cyclic olefin selected from a group comprising cycloalkenes, bicycloalkenes, tricycloalkenes, and tetra cycloalkenes, and a linear olefin such as ethylene and propylene; (vi) The surface layer (A) contains polyethylene terephthalate copolymer having an isophthalic acid component as a copolymeric component.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）〜（vi）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３００ｎｍ未満であること（iv）表層（Ａ）に環状オレフィン共重合体ポリエステルを含有する樹脂層を有すること（v）前記環状オレフィン共重合体がシクロアルケン、ビシクロアルケン、トリシクロアルケン、およびテトラシクロアルケンからなる群から選ばれた少なくとも１種の環状オレフィンと、エチレン、プロピレン等の直鎖オレフィンからなる共重合体であること(vi) 表層（Ａ）にイソフタル酸成分を共重合成分とする共重合ポリエチレンテレフタレートを含有すること【選択図】なし