JP2011076026A - Optical laminated body - Google Patents
Optical laminated body Download PDFInfo
- Publication number
- JP2011076026A JP2011076026A JP2009230245A JP2009230245A JP2011076026A JP 2011076026 A JP2011076026 A JP 2011076026A JP 2009230245 A JP2009230245 A JP 2009230245A JP 2009230245 A JP2009230245 A JP 2009230245A JP 2011076026 A JP2011076026 A JP 2011076026A
- Authority
- JP
- Japan
- Prior art keywords
- layer
- optical
- resin
- thickness
- optical laminate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 230000003287 optical effect Effects 0.000 title claims abstract description 179
- 229920005989 resin Polymers 0.000 claims abstract description 79
- 239000011347 resin Substances 0.000 claims abstract description 79
- 238000011282 treatment Methods 0.000 claims description 19
- 239000010410 layer Substances 0.000 description 155
- 239000010408 film Substances 0.000 description 52
- 229920000642 polymer Polymers 0.000 description 43
- 238000005259 measurement Methods 0.000 description 38
- 239000004973 liquid crystal related substance Substances 0.000 description 37
- 238000000034 method Methods 0.000 description 34
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 22
- 125000002723 alicyclic group Chemical group 0.000 description 15
- 210000002858 crystal cell Anatomy 0.000 description 14
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 13
- 229920001577 copolymer Polymers 0.000 description 13
- 230000009477 glass transition Effects 0.000 description 12
- 230000005540 biological transmission Effects 0.000 description 11
- 239000000853 adhesive Substances 0.000 description 10
- 239000000178 monomer Substances 0.000 description 10
- 229920000098 polyolefin Polymers 0.000 description 10
- 230000001070 adhesive effect Effects 0.000 description 9
- 239000012788 optical film Substances 0.000 description 9
- 230000000052 comparative effect Effects 0.000 description 8
- 230000008569 process Effects 0.000 description 8
- 238000004519 manufacturing process Methods 0.000 description 7
- 238000000465 moulding Methods 0.000 description 7
- 239000004372 Polyvinyl alcohol Substances 0.000 description 6
- 239000003795 chemical substances by application Substances 0.000 description 6
- 230000007423 decrease Effects 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 125000005395 methacrylic acid group Chemical group 0.000 description 6
- 229920002451 polyvinyl alcohol Polymers 0.000 description 6
- 239000000654 additive Substances 0.000 description 5
- 239000012790 adhesive layer Substances 0.000 description 5
- -1 ethylene, propylene, butadiene Chemical class 0.000 description 5
- 238000009998 heat setting Methods 0.000 description 5
- 238000010030 laminating Methods 0.000 description 5
- 125000003518 norbornenyl group Chemical group C12(C=CC(CC1)C2)* 0.000 description 5
- 239000002904 solvent Substances 0.000 description 5
- 230000037303 wrinkles Effects 0.000 description 5
- NIXOWILDQLNWCW-UHFFFAOYSA-N 2-Propenoic acid Natural products OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 4
- 229920002284 Cellulose triacetate Polymers 0.000 description 4
- 239000004793 Polystyrene Substances 0.000 description 4
- NNLVGZFZQQXQNW-ADJNRHBOSA-N [(2r,3r,4s,5r,6s)-4,5-diacetyloxy-3-[(2s,3r,4s,5r,6r)-3,4,5-triacetyloxy-6-(acetyloxymethyl)oxan-2-yl]oxy-6-[(2r,3r,4s,5r,6s)-4,5,6-triacetyloxy-2-(acetyloxymethyl)oxan-3-yl]oxyoxan-2-yl]methyl acetate Chemical compound O([C@@H]1O[C@@H]([C@H]([C@H](OC(C)=O)[C@H]1OC(C)=O)O[C@H]1[C@@H]([C@@H](OC(C)=O)[C@H](OC(C)=O)[C@@H](COC(C)=O)O1)OC(C)=O)COC(=O)C)[C@@H]1[C@@H](COC(C)=O)O[C@@H](OC(C)=O)[C@H](OC(C)=O)[C@H]1OC(C)=O NNLVGZFZQQXQNW-ADJNRHBOSA-N 0.000 description 4
- 230000008901 benefit Effects 0.000 description 4
- 230000008859 change Effects 0.000 description 4
- 150000004678 hydrides Chemical class 0.000 description 4
- 230000001771 impaired effect Effects 0.000 description 4
- 230000006872 improvement Effects 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- JFNLZVQOOSMTJK-KNVOCYPGSA-N norbornene Chemical compound C1[C@@H]2CC[C@H]1C=C2 JFNLZVQOOSMTJK-KNVOCYPGSA-N 0.000 description 4
- 229920005672 polyolefin resin Polymers 0.000 description 4
- 229920002223 polystyrene Polymers 0.000 description 4
- 230000001681 protective effect Effects 0.000 description 4
- 238000002834 transmittance Methods 0.000 description 4
- 239000004215 Carbon black (E152) Substances 0.000 description 3
- BAPJBEWLBFYGME-UHFFFAOYSA-N Methyl acrylate Chemical compound COC(=O)C=C BAPJBEWLBFYGME-UHFFFAOYSA-N 0.000 description 3
- 239000003522 acrylic cement Substances 0.000 description 3
- 125000000217 alkyl group Chemical group 0.000 description 3
- 125000004432 carbon atom Chemical group C* 0.000 description 3
- 238000011156 evaluation Methods 0.000 description 3
- 229930195733 hydrocarbon Natural products 0.000 description 3
- 238000003475 lamination Methods 0.000 description 3
- 230000009467 reduction Effects 0.000 description 3
- 238000007142 ring opening reaction Methods 0.000 description 3
- 238000007788 roughening Methods 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- QTBSBXVTEAMEQO-UHFFFAOYSA-M Acetate Chemical compound CC([O-])=O QTBSBXVTEAMEQO-UHFFFAOYSA-M 0.000 description 2
- 239000004925 Acrylic resin Substances 0.000 description 2
- 229920000178 Acrylic resin Polymers 0.000 description 2
- NLHHRLWOUZZQLW-UHFFFAOYSA-N Acrylonitrile Chemical compound C=CC#N NLHHRLWOUZZQLW-UHFFFAOYSA-N 0.000 description 2
- XDTMQSROBMDMFD-UHFFFAOYSA-N Cyclohexane Chemical compound C1CCCCC1 XDTMQSROBMDMFD-UHFFFAOYSA-N 0.000 description 2
- RRHGJUQNOFWUDK-UHFFFAOYSA-N Isoprene Chemical compound CC(=C)C=C RRHGJUQNOFWUDK-UHFFFAOYSA-N 0.000 description 2
- VVQNEPGJFQJSBK-UHFFFAOYSA-N Methyl methacrylate Chemical compound COC(=O)C(C)=C VVQNEPGJFQJSBK-UHFFFAOYSA-N 0.000 description 2
- 229920001890 Novodur Polymers 0.000 description 2
- 239000004820 Pressure-sensitive adhesive Substances 0.000 description 2
- XTXRWKRVRITETP-UHFFFAOYSA-N Vinyl acetate Chemical compound CC(=O)OC=C XTXRWKRVRITETP-UHFFFAOYSA-N 0.000 description 2
- 229920002978 Vinylon Polymers 0.000 description 2
- 235000010724 Wisteria floribunda Nutrition 0.000 description 2
- 238000002679 ablation Methods 0.000 description 2
- 230000000996 additive effect Effects 0.000 description 2
- XYLMUPLGERFSHI-UHFFFAOYSA-N alpha-Methylstyrene Chemical compound CC(=C)C1=CC=CC=C1 XYLMUPLGERFSHI-UHFFFAOYSA-N 0.000 description 2
- 238000004587 chromatography analysis Methods 0.000 description 2
- 150000001924 cycloalkanes Chemical group 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 229920001971 elastomer Polymers 0.000 description 2
- 239000003822 epoxy resin Substances 0.000 description 2
- SUPCQIBBMFXVTL-UHFFFAOYSA-N ethyl 2-methylprop-2-enoate Chemical compound CCOC(=O)C(C)=C SUPCQIBBMFXVTL-UHFFFAOYSA-N 0.000 description 2
- 125000000524 functional group Chemical group 0.000 description 2
- 229920001519 homopolymer Polymers 0.000 description 2
- FPYJFEHAWHCUMM-UHFFFAOYSA-N maleic anhydride Chemical compound O=C1OC(=O)C=C1 FPYJFEHAWHCUMM-UHFFFAOYSA-N 0.000 description 2
- 239000000113 methacrylic resin Substances 0.000 description 2
- PNJWIWWMYCMZRO-UHFFFAOYSA-N pent‐4‐en‐2‐one Natural products CC(=O)CC=C PNJWIWWMYCMZRO-UHFFFAOYSA-N 0.000 description 2
- 229920003229 poly(methyl methacrylate) Polymers 0.000 description 2
- 229920000647 polyepoxide Polymers 0.000 description 2
- 229920000728 polyester Polymers 0.000 description 2
- 229920006393 polyether sulfone Polymers 0.000 description 2
- 229920001721 polyimide Polymers 0.000 description 2
- 229920001195 polyisoprene Polymers 0.000 description 2
- 239000011241 protective layer Substances 0.000 description 2
- 239000005060 rubber Substances 0.000 description 2
- 238000005070 sampling Methods 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 229920005992 thermoplastic resin Polymers 0.000 description 2
- 125000003944 tolyl group Chemical group 0.000 description 2
- 229920002554 vinyl polymer Polymers 0.000 description 2
- 238000004804 winding Methods 0.000 description 2
- 125000004178 (C1-C4) alkyl group Chemical group 0.000 description 1
- NVZWEEGUWXZOKI-UHFFFAOYSA-N 1-ethenyl-2-methylbenzene Chemical compound CC1=CC=CC=C1C=C NVZWEEGUWXZOKI-UHFFFAOYSA-N 0.000 description 1
- YFZHODLXYNDBSM-UHFFFAOYSA-N 1-ethenyl-4-nitrobenzene Chemical compound [O-][N+](=O)C1=CC=C(C=C)C=C1 YFZHODLXYNDBSM-UHFFFAOYSA-N 0.000 description 1
- HIDBROSJWZYGSZ-UHFFFAOYSA-N 1-phenylpyrrole-2,5-dione Chemical compound O=C1C=CC(=O)N1C1=CC=CC=C1 HIDBROSJWZYGSZ-UHFFFAOYSA-N 0.000 description 1
- RNFJDJUURJAICM-UHFFFAOYSA-N 2,2,4,4,6,6-hexaphenoxy-1,3,5-triaza-2$l^{5},4$l^{5},6$l^{5}-triphosphacyclohexa-1,3,5-triene Chemical compound N=1P(OC=2C=CC=CC=2)(OC=2C=CC=CC=2)=NP(OC=2C=CC=CC=2)(OC=2C=CC=CC=2)=NP=1(OC=1C=CC=CC=1)OC1=CC=CC=C1 RNFJDJUURJAICM-UHFFFAOYSA-N 0.000 description 1
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 description 1
- OYUNTGBISCIYPW-UHFFFAOYSA-N 2-chloroprop-2-enenitrile Chemical compound ClC(=C)C#N OYUNTGBISCIYPW-UHFFFAOYSA-N 0.000 description 1
- PYSRRFNXTXNWCD-UHFFFAOYSA-N 3-(2-phenylethenyl)furan-2,5-dione Chemical compound O=C1OC(=O)C(C=CC=2C=CC=CC=2)=C1 PYSRRFNXTXNWCD-UHFFFAOYSA-N 0.000 description 1
- IYMZEPRSPLASMS-UHFFFAOYSA-N 3-phenylpyrrole-2,5-dione Chemical compound O=C1NC(=O)C(C=2C=CC=CC=2)=C1 IYMZEPRSPLASMS-UHFFFAOYSA-N 0.000 description 1
- JLBJTVDPSNHSKJ-UHFFFAOYSA-N 4-Methylstyrene Chemical compound CC1=CC=C(C=C)C=C1 JLBJTVDPSNHSKJ-UHFFFAOYSA-N 0.000 description 1
- LBSXSAXOLABXMF-UHFFFAOYSA-N 4-Vinylaniline Chemical compound NC1=CC=C(C=C)C=C1 LBSXSAXOLABXMF-UHFFFAOYSA-N 0.000 description 1
- IRQWEODKXLDORP-UHFFFAOYSA-N 4-ethenylbenzoic acid Chemical compound OC(=O)C1=CC=C(C=C)C=C1 IRQWEODKXLDORP-UHFFFAOYSA-N 0.000 description 1
- ZCYVEMRRCGMTRW-UHFFFAOYSA-N 7553-56-2 Chemical compound [I] ZCYVEMRRCGMTRW-UHFFFAOYSA-N 0.000 description 1
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- IMROMDMJAWUWLK-UHFFFAOYSA-N Ethenol Chemical compound OC=C IMROMDMJAWUWLK-UHFFFAOYSA-N 0.000 description 1
- JIGUQPWFLRLWPJ-UHFFFAOYSA-N Ethyl acrylate Chemical compound CCOC(=O)C=C JIGUQPWFLRLWPJ-UHFFFAOYSA-N 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- CERQOIWHTDAKMF-UHFFFAOYSA-N Methacrylic acid Chemical compound CC(=C)C(O)=O CERQOIWHTDAKMF-UHFFFAOYSA-N 0.000 description 1
- GYCMBHHDWRMZGG-UHFFFAOYSA-N Methylacrylonitrile Chemical compound CC(=C)C#N GYCMBHHDWRMZGG-UHFFFAOYSA-N 0.000 description 1
- 239000004695 Polyether sulfone Substances 0.000 description 1
- 239000004642 Polyimide Substances 0.000 description 1
- 229920000147 Styrene maleic anhydride Polymers 0.000 description 1
- 229920006397 acrylic thermoplastic Polymers 0.000 description 1
- 125000005907 alkyl ester group Chemical group 0.000 description 1
- 239000003242 anti bacterial agent Substances 0.000 description 1
- 239000003963 antioxidant agent Substances 0.000 description 1
- 230000003078 antioxidant effect Effects 0.000 description 1
- 239000002216 antistatic agent Substances 0.000 description 1
- 239000002981 blocking agent Substances 0.000 description 1
- 150000001732 carboxylic acid derivatives Chemical class 0.000 description 1
- 238000005660 chlorination reaction Methods 0.000 description 1
- 229910052801 chlorine Inorganic materials 0.000 description 1
- 239000000460 chlorine Substances 0.000 description 1
- 229920006026 co-polymeric resin Polymers 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000007334 copolymerization reaction Methods 0.000 description 1
- 238000003851 corona treatment Methods 0.000 description 1
- 238000004132 cross linking Methods 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 125000004122 cyclic group Chemical group 0.000 description 1
- 150000001925 cycloalkenes Chemical group 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 229920005994 diacetyl cellulose Polymers 0.000 description 1
- 150000001993 dienes Chemical class 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 239000002270 dispersing agent Substances 0.000 description 1
- 238000009820 dry lamination Methods 0.000 description 1
- 238000004043 dyeing Methods 0.000 description 1
- 238000004049 embossing Methods 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 229920001038 ethylene copolymer Polymers 0.000 description 1
- 239000005038 ethylene vinyl acetate Substances 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 239000003063 flame retardant Substances 0.000 description 1
- 239000012760 heat stabilizer Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- 239000011256 inorganic filler Substances 0.000 description 1
- 229910003475 inorganic filler Inorganic materials 0.000 description 1
- 229910052740 iodine Inorganic materials 0.000 description 1
- 239000011630 iodine Substances 0.000 description 1
- 239000004611 light stabiliser Substances 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 239000006078 metal deactivator Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 125000000896 monocarboxylic acid group Chemical group 0.000 description 1
- 125000002950 monocyclic group Chemical group 0.000 description 1
- 230000003472 neutralizing effect Effects 0.000 description 1
- 239000002667 nucleating agent Substances 0.000 description 1
- 239000012766 organic filler Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- HDBWAWNLGGMZRQ-UHFFFAOYSA-N p-Vinylbiphenyl Chemical compound C1=CC(C=C)=CC=C1C1=CC=CC=C1 HDBWAWNLGGMZRQ-UHFFFAOYSA-N 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 239000000049 pigment Substances 0.000 description 1
- 230000010287 polarization Effects 0.000 description 1
- 229920001200 poly(ethylene-vinyl acetate) Polymers 0.000 description 1
- 229920002492 poly(sulfone) Polymers 0.000 description 1
- 229920000058 polyacrylate Polymers 0.000 description 1
- 229920002239 polyacrylonitrile Polymers 0.000 description 1
- 229920006122 polyamide resin Polymers 0.000 description 1
- 229920001230 polyarylate Polymers 0.000 description 1
- 229920000515 polycarbonate Polymers 0.000 description 1
- 239000004417 polycarbonate Substances 0.000 description 1
- 229920005668 polycarbonate resin Polymers 0.000 description 1
- 239000004431 polycarbonate resin Substances 0.000 description 1
- 229920001225 polyester resin Polymers 0.000 description 1
- 239000004645 polyester resin Substances 0.000 description 1
- 229920000570 polyether Polymers 0.000 description 1
- 229920000139 polyethylene terephthalate Polymers 0.000 description 1
- 239000005020 polyethylene terephthalate Substances 0.000 description 1
- 239000009719 polyimide resin Substances 0.000 description 1
- 229920001296 polysiloxane Polymers 0.000 description 1
- 229920002635 polyurethane Polymers 0.000 description 1
- 239000004814 polyurethane Substances 0.000 description 1
- 229920000915 polyvinyl chloride Polymers 0.000 description 1
- 239000004800 polyvinyl chloride Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000002516 radical scavenger Substances 0.000 description 1
- 239000012744 reinforcing agent Substances 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 238000005488 sandblasting Methods 0.000 description 1
- 238000007127 saponification reaction Methods 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 238000010186 staining Methods 0.000 description 1
- 125000003011 styrenyl group Chemical group [H]\C(*)=C(/[H])C1=C([H])C([H])=C([H])C([H])=C1[H] 0.000 description 1
- ISXSCDLOGDJUNJ-UHFFFAOYSA-N tert-butyl prop-2-enoate Chemical compound CC(C)(C)OC(=O)C=C ISXSCDLOGDJUNJ-UHFFFAOYSA-N 0.000 description 1
- 229920001169 thermoplastic Polymers 0.000 description 1
- 229920002725 thermoplastic elastomer Polymers 0.000 description 1
- 239000006097 ultraviolet radiation absorber Substances 0.000 description 1
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 1
Abstract
Description
本発明は光学積層体に関し、特に延伸処理を経て製造された延伸フィルムとしての光学積層体に関する。 The present invention relates to an optical laminate, and more particularly to an optical laminate as a stretched film produced through a stretching treatment.
液晶表示装置は、高画質、薄型、軽量、低消費電力などの特徴をもち、例えばテレビジョン、パーソナルコンピューター、カーナビゲーターなどに広く用いられている。液晶表示装置は、通常、液晶セルの上下に透過軸が直交するように２枚の偏光子を備え、液晶セルに電圧を印加することにより液晶分子の配向を変化させて画面に画像を表示させるようになっている。その中でもツイステッドネマチックモードの液晶表示装置では、電圧印加時に液晶分子が垂直配向状態となり、黒表示となる構成が多い。また、インプレーンスイッチング（ＩＰＳ）モードの液晶表示装置では、電圧無印加時に液晶分子が一定の方向に配向し、電圧印加時に配向方向が４５°回転して、白表示となる構成が多い。 A liquid crystal display device has features such as high image quality, thinness, light weight, and low power consumption, and is widely used in televisions, personal computers, car navigators, and the like. The liquid crystal display device usually includes two polarizers so that the transmission axes are orthogonal to each other above and below the liquid crystal cell, and by applying a voltage to the liquid crystal cell, the orientation of the liquid crystal molecules is changed to display an image on the screen. It is like that. Among them, a twisted nematic mode liquid crystal display device often has a configuration in which liquid crystal molecules are in a vertically aligned state when a voltage is applied, resulting in black display. Also, in-plane switching (IPS) mode liquid crystal display devices often have a configuration in which liquid crystal molecules are aligned in a certain direction when no voltage is applied, and the alignment direction rotates 45 ° when a voltage is applied, resulting in white display.
２枚の偏光子の透過軸が上下方向と左右方向を指して直交するように配置された液晶表示装置では、上下左右方向から画面を見るときは、十分なコントラストが得られる。しかし、上下左右から外れた方向から画面を斜めに見ると、入射側偏光子の透過軸と出射側偏光子の透過軸とが見かけ上直交でなくなるために、直線偏光が完全に遮断されずに光洩れが発生し、十分な黒が得られず、コントラストが低下することがある。このために、液晶表示装置に光学補償手段を設けて、画面のコントラストの低下を防止する試みがなされている。 In the liquid crystal display device in which the transmission axes of the two polarizers are arranged so as to be orthogonal to the vertical direction and the horizontal direction, sufficient contrast is obtained when the screen is viewed from the vertical and horizontal directions. However, when the screen is viewed obliquely from a direction deviating from the top, bottom, left, and right, the transmission axis of the incident side polarizer and the transmission axis of the output side polarizer are apparently not orthogonal, so that linearly polarized light is not completely blocked. Light leakage may occur, sufficient black may not be obtained, and contrast may be reduced. For this reason, an attempt has been made to prevent a decrease in contrast of the screen by providing an optical compensation means in the liquid crystal display device.
このような光学補償手段の開発及びその改善は以前よりなされており、例えば、特許文献１には、スチレン系樹脂を５０重量％以上含む延伸フィルムであって、所定の温度における加熱収縮応力、面内方向レターデーション、および配向角の変動幅を所定の範囲に規定した異方性フィルムが開示されている。 Development and improvement of such optical compensation means have been made for some time. For example, Patent Document 1 discloses a stretched film containing 50% by weight or more of a styrene-based resin, which has a heat shrinkage stress and surface at a predetermined temperature. An anisotropic film in which the inward retardation and the variation range of the orientation angle are defined within a predetermined range is disclosed.
特許文献１で用いられているようなスチレン系樹脂は、高い透明性を有し、負の固有複屈折値を有することなどから、所望の光学特性を発現するために有効な材料と考えられる。しかしながら、スチレン系樹脂を用いたフィルムは一般に非常に脆く、また所望の光学特性を発現させるために延伸する際の連続搬送中に破断やしわが生じることが多かった。このため、スチレン系樹脂を用いたフィルムは延伸加工性が良好でなく、加工後に得られる延伸フィルムの耐久性が低かった。さらに、スチレン系樹脂を用いたフィルムは正面レターデーションＲｅの変動幅や配向角θの変動幅を小さくすることが難しく、光学均一性に優れた延伸フィルムを製造することが難しかった。
そこで、前記のような延伸加工性、耐久性及び光学均一性を改善するための技術が、特許文献２において提案されている。
A styrenic resin as used in Patent Document 1 is considered to be an effective material for expressing desired optical characteristics because it has high transparency and a negative intrinsic birefringence value. However, films using styrenic resins are generally very fragile, and breakage and wrinkles often occur during continuous conveyance during stretching in order to develop desired optical properties. For this reason, the film using a styrene resin was not good in stretch processability, and the durability of the stretched film obtained after processing was low. Furthermore, it is difficult to reduce the fluctuation width of the front retardation Re and the fluctuation width of the orientation angle θ, and it is difficult to produce a stretched film excellent in optical uniformity.
Therefore, Patent Document 2 proposes a technique for improving the stretch processability, durability, and optical uniformity as described above.
省スペース化やコスト削減の観点から、光学用途に使用されるフィルムには薄膜化が要求される。ところが、本発明者の検討によれば、特許文献２記載の技術で得られる延伸フィルムの厚みを薄くすると、光学均一性が損なわれる傾向があることが分かった。
本発明は上記の課題に鑑みて創案されたもので、厚みが薄く、耐久性及び光学均一性に優れる光学積層体を提供することを目的とする。
From the viewpoint of space saving and cost reduction, the film used for optical applications is required to be thin. However, according to the study by the present inventors, it has been found that when the thickness of the stretched film obtained by the technique described in Patent Document 2 is reduced, the optical uniformity tends to be impaired.
The present invention has been made in view of the above problems, and an object of the present invention is to provide an optical laminate that is thin and excellent in durability and optical uniformity.
本発明者は、上述した課題を解決して目的を達成するために鋭意検討した結果、スチレン系樹脂等の固有複屈折値が負の樹脂の層を備える光学積層体において、光学積層体における固有複屈折値が負の樹脂の層の割合を高くすれば光学積層体の総厚が薄くても光学積層体の光学均一性を改善できること、及び、光学積層体の総延伸倍率を高くすれば固有複屈折値が負の樹脂の割合が多くても光学積層体が脆くなることを抑制できることを見出し、本発明を完成させた。
すなわち、本発明は以下の〔１〕及び〔２〕を要旨とする。
As a result of diligent studies to achieve the object by solving the above-mentioned problems, the present inventors have found that an optical laminate including a layer of a resin having a negative intrinsic birefringence value such as a styrene resin has a unique property in the optical laminate. Increasing the proportion of the resin layer with a negative birefringence value can improve the optical uniformity of the optical laminate even if the total thickness of the optical laminate is thin, and it is inherent if the total stretch ratio of the optical laminate is increased. The inventors have found that even when the ratio of the resin having a negative birefringence value is large, the optical laminate can be suppressed from becoming brittle, and the present invention has been completed.
That is, the gist of the present invention is the following [1] and [2].
〔１〕 固有複屈折値が負の樹脂ＡからなるＡ層と、透明な樹脂ＢからなるＢ層とを備える光学積層体であって、
｜前記Ａ層の正面レターデーション｜＞｜前記Ｂ層の正面レターデーション｜であり、
前記Ａ層及び前記Ｂ層の総厚が２５μｍ以上６０μｍ以下であり、
前記Ａ層及び前記Ｂ層の総厚に対する前記Ａ層の厚みの割合が４０％以上８０％未満であり、
総延伸倍率が２．３倍以上４．７倍以下の延伸処理を経て得られる、光学積層体。
〔２〕 前記延伸処理が同時二軸延伸処理である、〔１〕記載の光学積層体。
[1] An optical laminate including an A layer made of a resin A having a negative intrinsic birefringence value and a B layer made of a transparent resin B,
| Front retardation of the A layer |> | Front retardation of the B layer |
The total thickness of the A layer and the B layer is 25 μm or more and 60 μm or less,
The ratio of the thickness of the A layer to the total thickness of the A layer and the B layer is 40% or more and less than 80%,
An optical layered body obtained through a stretching treatment in which the total stretching ratio is 2.3 times or more and 4.7 times or less.
[2] The optical laminate according to [1], wherein the stretching treatment is a simultaneous biaxial stretching treatment.
本発明の光学積層体は、厚みが薄く、耐久性及び光学均一性の両方に優れるという効果を奏する。 The optical layered body of the present invention has an effect of being thin and excellent in both durability and optical uniformity.
以下、本発明について実施形態及び例示物等を示して詳細に説明するが、本発明は以下に挙げる実施形態及び例示物等に限定されるものではなく、本発明の要旨及びその均等の範囲を逸脱しない範囲において任意に変更して実施できる。なお、以下の説明において、「樹脂Ａ」及び「Ａ層」の符号「Ａ」、「樹脂Ｂ」及び「Ｂ層」の符号「Ｂ」、「ａ層」の符号「ａ」、「ｂ層」の符号「ｂ」、並びに「未延伸の積層体ｃ」の符号「ｃ」は、いずれもその符号が付された構成要素を他の構成要素から区別するために付された符号であり、構成要素の区別以外に意味を有するものではない。 Hereinafter, the present invention will be described in detail with reference to embodiments and examples, but the present invention is not limited to the embodiments and examples described below, and the gist of the present invention and the equivalent scope thereof are described below. Any change can be made without departing from the scope. In the following description, reference numerals “A” for “resin A” and “A layer”, “B” for “resin B” and “B layer”, “a” for “a layer”, “b layer” "B" as well as "c" of "unstretched laminate c" are signs assigned to distinguish the component to which the sign is attached from other components, It has no meaning other than the distinction between the components.
〔１．概要〕
液晶表示装置の光学補償手段等に使用される光学積層体では、要求される光学特性（面内レタデーションＲｅ、Ｎｚ係数等）を有するようにしながら光学積層体の総厚を薄くすることが求められている。そこで、本発明者の検討によれば光学積層体中における固有複屈折が負の樹脂の層（Ａ層）の割合を所定値以上にすると、光学積層体の総厚を薄くしても光学均一性の低下を抑制できることが判明した。しかしながら、Ａ層の割合を大きくすると、従来の技術常識によれば、光学積層体が脆くなり耐久性が低下するおそれがあった。そこで本発明者が更に検討したところ、光学積層体にレターデーションを発現させるために行なう延伸処理において総延伸倍率を従来よりも大きくすると、光学積層体の強度が向上して耐久性の低下を抑制できることが見出された。
すなわち、本発明の光学積層体は、固有複屈折値が負の樹脂ＡからなるＡ層と、透明な樹脂ＢからなるＢ層とを備える光学積層体であって、（１）｜Ａ層の正面レターデーション｜＞｜Ｂ層の正面レターデーション｜であり、（２）Ａ層及びＢ層の総厚が薄く、（３）Ａ層及びＢ層の総厚に占めるＡ層の厚みの割合が大きく、（４）総延伸倍率が大きい延伸処理を経て得られるものである。これにより、厚みが薄く、耐久性及び光学均一性に優れる光学積層体を実現できる。
[1. Overview〕
In an optical laminate used for an optical compensation means of a liquid crystal display device, it is required to reduce the total thickness of the optical laminate while having required optical characteristics (in-plane retardation Re, Nz coefficient, etc.). ing. Therefore, according to the study of the present inventor, if the ratio of the resin layer (A layer) having a negative intrinsic birefringence in the optical layered body is set to a predetermined value or more, it is optically uniform even if the total thickness of the optical layered body is reduced. It became clear that the fall of sex could be suppressed. However, when the proportion of the A layer is increased, according to the conventional technical common sense, there is a possibility that the optical laminate becomes brittle and the durability is lowered. Therefore, the present inventors further investigated and found that, when the total draw ratio was increased in the drawing process performed to develop retardation in the optical laminate, the strength of the optical laminate was improved and the decrease in durability was suppressed. It was found that it was possible.
That is, the optical layered body of the present invention is an optical layered body including an A layer made of a resin A having a negative intrinsic birefringence value and a B layer made of a transparent resin B, wherein (1) Front retardation |> | Front retardation of B layer | (2) The total thickness of A layer and B layer is thin, and (3) The ratio of the thickness of A layer to the total thickness of A layer and B layer is It is large and (4) obtained through a stretching process having a large total stretching ratio. Thereby, the optical laminated body which is thin and excellent in durability and optical uniformity can be realized.
〔２．光学積層体の構成及び物性〕
本発明の光学積層体は、固有複屈折値が負の樹脂ＡからなるＡ層と、透明な樹脂ＢからなるＢ層とを備える。
[2. Configuration and properties of optical laminates]
The optical layered body of the present invention includes an A layer made of a resin A having a negative intrinsic birefringence value and a B layer made of a transparent resin B.
（１）Ａ層
Ａ層は、固有複屈折値が負の樹脂Ａからなる層である。固有複屈折値が負の樹脂Ａとは、分子の配向方向の屈折率が他の方向の屈折率よりも小さい樹脂のことであり、例えば、それを用いた成形体を延伸した場合に延伸方向の屈折率が最も小さくなる樹脂である。固有複屈折値（Δｎ０）とは、下記式［１］により算出される値である。
Δｎ０＝（２π／９）（Ｎｄ／Ｍ）｛（ｎａ２＋２）２／ｎａ｝（α１−α２） ［１］
（式［１］において、πは円周率、Ｎはアボガドロ数、ｄは密度、Ｍは分子量、ｎａは平均屈折率、α１は高分子の分子鎖軸方向の分極率、α２は高分子の分子鎖軸と垂直な方向の分極率を表す。）
(1) A layer A layer is a layer which consists of resin A with a negative intrinsic birefringence value. Resin A having a negative intrinsic birefringence value is a resin whose refractive index in the molecular orientation direction is smaller than the refractive index in the other direction. For example, when a molded body using the same is stretched, the stretching direction This resin has the smallest refractive index. The intrinsic birefringence value (Δn 0 ) is a value calculated by the following formula [1].
Δn 0 = (2π / 9) (Nd / M) {(na 2 +2) 2 / na} (α1-α2) [1]
(In the formula [1], π is the circularity, N is the Avogadro number, d is the density, M is the molecular weight, na is the average refractive index, α1 is the polarizability of the polymer in the direction of the molecular chain axis, and α2 is the polymer. (Denotes the polarizability in the direction perpendicular to the molecular chain axis.)
樹脂Ａとしては通常は熱可塑性樹脂を用いる。樹脂Ａに含まれる重合体の例を挙げると、スチレン系重合体、ポリアクリロニトリル重合体、ポリメチルメタクリレート重合体、あるいはこれらの多元共重合ポリマーなどが挙げられる。前記のスチレン系重合体は、スチレン単位構造を繰り返し単位の一部又は全部として有する重合体であり、例えば、ポリスチレン；スチレン、α−メチルスチレン、ｏ−メチルスチレン、ｐ−メチルスチレン、ｐ−クロロスチレン、ｐ−ニトロスチレン、ｐ−アミノスチレン、ｐ−カルボキシスチレン、ｐ−フェニルスチレン等のスチレン系単量体と、エチレン、プロピレン、ブタジエン、イソプレン、アクリロニトリル、メタクリロニトリル、α−クロロアクリロニトリル、Ｎ−フェニルマレイミド、アクリル酸メチル、メタクリル酸メチル、アクリル酸エチル、メタクリル酸エチル、アクリル酸、メタクリル酸、無水マレイン酸、酢酸ビニル等のその他の単量体との共重合体などが挙げられる。これらの中でも位相差発現性が高いという観点からスチレン系重合体が好ましく、中でもポリスチレン、スチレンとＮ−フェニルマレイミドとの共重合体又はスチレンと無水マレイン酸との共重合体が特に好ましい。
なお、これらの重合体は１種類を単独で用いてもよく、２種類以上を任意の比率で組み合わせて用いてもよい。
As the resin A, a thermoplastic resin is usually used. Examples of the polymer contained in the resin A include a styrene polymer, a polyacrylonitrile polymer, a polymethyl methacrylate polymer, or a multi-component copolymer thereof. The styrenic polymer is a polymer having a styrene unit structure as a part or all of repeating units, such as polystyrene; styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, p-chloro. Styrene monomers such as styrene, p-nitrostyrene, p-aminostyrene, p-carboxystyrene, p-phenylstyrene, ethylene, propylene, butadiene, isoprene, acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, N -Copolymers with other monomers such as phenylmaleimide, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, acrylic acid, methacrylic acid, maleic anhydride, vinyl acetate and the like. Among these, styrene-based polymers are preferable from the viewpoint of high retardation development, and among them, polystyrene, a copolymer of styrene and N-phenylmaleimide, or a copolymer of styrene and maleic anhydride is particularly preferable.
In addition, these polymers may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.
樹脂Ａに含まれる重合体の分子量は使用目的に応じて適宜選定されるが、溶媒としてシクロヘキサンを用いて（但し、重合体がシクロヘキサンに溶解しない場合にはトルエンを用いてもよい）ゲル・パーミエーション・クロマトグラフィーで測定したポリイソプレン換算（溶媒がトルエンのときは、ポリスチレン換算）の重量平均分子量（Ｍｗ）で、通常１０，０００以上、好ましくは１５，０００以上、より好ましくは２０，０００以上であり、通常１００，０００以下、好ましくは８０，０００以下、より好ましくは５０，０００以下である。重量平均分子量がこのような範囲にあることにより、本発明の光学積層体の機械的強度及び成型加工性などが高度にバランスされる。 The molecular weight of the polymer contained in the resin A is appropriately selected depending on the purpose of use, but using gel as a solvent (however, toluene may be used when the polymer does not dissolve in cyclohexane). The weight average molecular weight (Mw) in terms of polyisoprene measured by ablation chromatography (in terms of polystyrene when the solvent is toluene) is usually 10,000 or more, preferably 15,000 or more, more preferably 20,000 or more. It is usually 100,000 or less, preferably 80,000 or less, more preferably 50,000 or less. When the weight average molecular weight is in such a range, the mechanical strength and molding processability of the optical laminate of the present invention are highly balanced.
樹脂Ａには、必要に応じて、例えば酸化防止剤、熱安定剤、光安定剤、紫外線吸収剤、帯電防止剤、分散剤、塩素捕捉剤、難燃剤、結晶化核剤、強化剤、ブロッキング防止剤、防曇剤、離型剤、顔料、有機又は無機の充填剤、中和剤、滑剤、分解剤、金属不活性化剤、汚染防止剤、抗菌剤やその他の樹脂、熱可塑性エラストマーなどの公知の添加剤を、本発明の効果を損なわない範囲で含ませてもよい。これらの添加剤の量は、樹脂Ａに含まれる重合体１００重量部に対して、通常０〜５０重量部、好ましくは０〜３０重量部である。 For the resin A, for example, an antioxidant, a heat stabilizer, a light stabilizer, an ultraviolet absorber, an antistatic agent, a dispersant, a chlorine scavenger, a flame retardant, a crystallization nucleating agent, a reinforcing agent, and a blocking agent as necessary. Anti-fogging agents, anti-fogging agents, release agents, pigments, organic or inorganic fillers, neutralizing agents, lubricants, decomposing agents, metal deactivators, anti-staining agents, antibacterial agents and other resins, thermoplastic elastomers, etc. These known additives may be included as long as the effects of the present invention are not impaired. The amount of these additives is usually 0 to 50 parts by weight, preferably 0 to 30 parts by weight with respect to 100 parts by weight of the polymer contained in the resin A.
Ａ層を構成する樹脂Ａのガラス転移温度をＴｇ（ａ）（℃）、Ｂ層を構成する樹脂Ｂのガラス転移温度をＴｇ（ｂ）（℃）とした場合、Ｔｇ（ａ）＞Ｔｇ（ｂ）＋８℃であることが好ましく、Ｔｇ（ａ）＞Ｔｇ（ｂ）＋２０℃であることがより好ましく、Ｔｇ（ａ）＞Ｔｇ（ｂ）＋２４℃であることがさらに好ましい。また、一般的には、Ｔｇ（ａ）＜Ｔｇ（ｂ）＋５０℃である。
また、Ａ層を構成する樹脂Ａのビカット軟化温度をＴｅｇ（ａ）（℃）、Ｂ層を構成する樹脂Ｂのビカット軟化温度をＴｅｇ（ｂ）（℃）とした場合、Ｔｅｇ（ａ）＞Ｔｅｇ（ｂ）＋１５℃であることが好ましく、Ｔｅｇ（ａ）＞Ｔｅｇ（ｂ）＋２０℃であることがより好ましく、Ｔｅｇ（ａ）＞Ｔｅｇ（ｂ）＋２５℃であることがさらに好ましい。また、一般的には、Ｔｅｇ（ａ）＜Ｔｅｇ（ｂ）＋５０℃である。
固有複屈折値が負の樹脂Ａからなる未延伸の樹脂層（以下、適宜「ａ層」という。）と、透明な樹脂Ｂからなる未延伸の樹脂層（以下、適宜「ｂ層」という。）が積層された未延伸の積層体ｃを共延伸するとき、温度Ｔｇ（ａ）（℃）付近で延伸すると、樹脂ＡからなるＡ層の複屈折特性を十分かつ均一に発現させることができる。このとき、樹脂Ａのガラス転移温度Ｔｇ（ａ）及びビカット軟化温度Ｔｅｇ（ａ）を前記のように樹脂Ｂのガラス転移温度Ｔｇ（ｂ）及びビカット軟化温度Ｔｅｇ（ｂ）よりも高くしておくと、樹脂Ｂからなる未延伸の樹脂層（ｂ層）は、そのガラス転移温度Ｔｇ（ｂ）又はビカット軟化温度Ｔｅｇ（ｂ）よりも高い温度で延伸されることになるので、高分子はほとんど配向せず、実質的に無配向の状態にできる。
When the glass transition temperature of the resin A constituting the A layer is Tg (a) (° C.) and the glass transition temperature of the resin B constituting the B layer is Tg (b) (° C.), Tg (a)> Tg ( b) + 8 ° C. is preferable, Tg (a)> Tg (b) + 20 ° C. is more preferable, and Tg (a)> Tg (b) + 24 ° C. is more preferable. In general, Tg (a) <Tg (b) + 50 ° C.
Further, when the Vicat softening temperature of the resin A constituting the A layer is Teg (a) (° C.) and the Vicat softening temperature of the resin B constituting the B layer is Teg (b) (° C.), Teg (a)> Teg (b) + 15 ° C. is preferable, Teg (a)> Teg (b) + 20 ° C. is more preferable, and Teg (a)> Teg (b) + 25 ° C. is more preferable. In general, Teg (a) <Teg (b) + 50 ° C.
An unstretched resin layer made of resin A having a negative intrinsic birefringence value (hereinafter referred to as “a layer” as appropriate) and an unstretched resin layer made of transparent resin B (hereinafter referred to as “b layer” as appropriate). When the unstretched layered product c is laminated in the vicinity of the temperature Tg (a) (° C.), the birefringence characteristics of the A layer made of the resin A can be expressed sufficiently and uniformly. . At this time, the glass transition temperature Tg (a) and the Vicat softening temperature Teg (a) of the resin A are set higher than the glass transition temperature Tg (b) and the Vicat softening temperature Teg (b) of the resin B as described above. Since the unstretched resin layer (b layer) made of the resin B is stretched at a temperature higher than its glass transition temperature Tg (b) or Vicat softening temperature Teg (b), most of the polymer is Without orientation, it can be in a substantially non-oriented state.
Ａ層の厚みは、本発明の光学積層体を構成するＡ層及びＢ層の総厚に対する割合で、通常４０％以上、好ましくは５０％以上、より好ましくは６０％以上である。このようにＡ層の厚みを厚くすることにより、総厚を薄くしても本発明の光学積層体の光学均一性が低下することを抑制でき、好適な光学特性を発現させることができる。このような利点が得られる理由は定かではないが、本発明の光学積層体において光学特性を発現する程度はＢ層よりもＡ層の方が大きいと考えられることから、Ａ層の割合を厚くすることにより、Ａ層の厚みに対するＡ層の厚みのムラの割合を小さくして、Ａ層の厚みのムラが延伸時に発現する光学特性へ与える影響の程度を小さく抑えることができるためと推察される。
また、Ａ層及びＢ層の総厚に対するＡ層の厚みの割合の上限は、通常８０％未満である。Ａ層を厚くしすぎると、脆くなりハンドリングが困難となる傾向がある。
ここで、本発明の光学積層体が備えるＡ層及びＢ層の層数は１層でもよく、２層以上でもよい。Ａ層及びＢ層を２層以上備える場合、Ａ層及びＢ層それぞれの厚みの合計により、前記のＡ層及びＢ層の総厚に対するＡ層の厚みの割合を算出するものとする。
なお、本発明の光学積層体における各層の厚みは、光学積層体をエポキシ樹脂に包埋したのち、ミクロトーム（例えば、大和光機工業（株）、ＲＵＢ−２１００）を用いて０．０５μｍ厚にスライスし、透過型電子顕微鏡を用いて断面を観察して測定すればよい。
The thickness of the A layer is usually 40% or more, preferably 50% or more, more preferably 60% or more, as a ratio to the total thickness of the A layer and B layer constituting the optical layered body of the present invention. Thus, by increasing the thickness of the A layer, it is possible to suppress a decrease in optical uniformity of the optical laminate of the present invention even if the total thickness is reduced, and to exhibit suitable optical characteristics. The reason why such an advantage is obtained is not clear, but since the A layer is considered to be larger than the B layer in the optical laminate of the present invention, the ratio of the A layer is increased. It is speculated that the ratio of the unevenness of the thickness of the A layer to the thickness of the A layer can be reduced, and the degree of the influence that the unevenness of the thickness of the A layer exerts on the optical characteristics exhibited during stretching can be suppressed. The
Moreover, the upper limit of the ratio of the thickness of the A layer to the total thickness of the A layer and the B layer is usually less than 80%. If the A layer is too thick, it tends to be brittle and difficult to handle.
Here, the number of layers A and B provided in the optical layered body of the present invention may be one, or two or more. When two or more A layers and B layers are provided, the ratio of the thickness of the A layer to the total thickness of the A layer and the B layer is calculated based on the total thickness of the A layer and the B layer.
The thickness of each layer in the optical layered body of the present invention is 0.05 μm thick using a microtome (for example, Daiwa Koki Kogyo Co., Ltd., RUB-2100) after embedding the optical layered body in an epoxy resin. What is necessary is just to measure by slicing and observing a cross section using a transmission electron microscope.
本発明の光学積層体において、Ａ層の正面レターデーションＲｅ（Ａ）は、Ｂ層の正面レターデーションＲｅ（Ｂ）との間で｜Ｒｅ（Ａ）｜＞｜Ｒｅ（Ｂ）｜との関係を満たすようにする。｜Ｒｅ（Ａ）｜＞｜Ｒｅ（Ｂ）｜とすることにより、光学的に調整を行った樹脂ＡからなるＡ層の光学特性を効果的に利用することができる。｜Ｒｅ（Ａ）｜≦｜Ｒｅ（Ｂ）｜であると、本発明の光学積層体において光学補償機能が十分に発現しないおそれがある。 In the optical layered body of the present invention, the front retardation Re (A) of the A layer and the front retardation Re (B) of the B layer are related to | Re (A) |> | Re (B) | To satisfy. By setting | Re (A) |> | Re (B) |, the optical characteristics of the A layer made of the resin A optically adjusted can be effectively used. If | Re (A) | ≦ | Re (B) |, the optical compensation function may not be sufficiently exhibited in the optical laminate of the present invention.
具体的なＡ層の正面レターデーションＲｅ（Ａ）の範囲を挙げると、例えば波長４００〜７００ｎｍの光で測定したＡ層の正面レターデーションＲｅ（Ａ）（ｎｍ）は、好ましくは３０ｎｍ以上７０ｎｍ以下である。
なお、正面レターデーションＲｅとは、面内の遅相軸方向の屈折率ｎｘと、面内で前記遅相軸に直交する方向の屈折率ｎｙとの差に、フィルム（又は各層）の平均厚みＤを乗算した値、すなわち、Ｒｅ＝（ｎｘ−ｎｙ）×Ｄである。また、Ａ層及びＢ層が２層以上存在する場合、前記のＡ層の正面レターデーションＲｅ（Ａ）及びＢ層の正面レターデーションＲｅ（Ｂ）とは、各Ａ層及びＢ層の正面レターデーションの合計を指す。さらに、レターデーションの評価は、特に断らない限り、波長５９０ｎｍの光に対して行なうものとする。
When the range of the specific front retardation Re (A) of the A layer is given, for example, the front retardation Re (A) (nm) of the A layer measured with light having a wavelength of 400 to 700 nm is preferably 30 nm to 70 nm. It is.
The front retardation Re is the difference between the refractive index nx in the slow axis direction in the plane and the refractive index ny in the direction perpendicular to the slow axis in the plane, and the average thickness of the film (or each layer). A value obtained by multiplying D, that is, Re = (nx−ny) × D. Further, when there are two or more A layers and B layers, the front retardation Re (A) of the A layer and the front retardation Re (B) of the B layer are the front letters of the A layer and the B layer. Refers to the total of the foundation. Further, the retardation is evaluated for light having a wavelength of 590 nm unless otherwise specified.
（２）Ｂ層
Ｂ層は、透明な樹脂Ｂからなる層である。ここで樹脂が透明であるとは、厚み１ｍｍの試験片を形成して測定した全光線透過率が、通常７０％以上、好ましくは８０％以上、より好ましくは９０％以上である樹脂をいう。
(2) B layer B layer is a layer made of transparent resin B. Here, the resin is transparent means a resin having a total light transmittance of 70% or more, preferably 80% or more, and more preferably 90% or more, measured by forming a test piece having a thickness of 1 mm.
樹脂Ｂとしては通常は熱可塑性樹脂を用いる。樹脂Ｂに含まれる重合体の例を挙げると、アクリル重合体、メタクリル重合体、ポリカーボネート重合体、ポリエステル重合体、ポリエーテルスルホン重合体、ポリアリレート重合体、ポリイミド重合体、鎖状ポリオレフィン重合体、ポリエチレンテレフタレート重合体、ポリスルホン重合体、ポリ塩化ビニル重合体、ジアセチルセルロース重合体、トリアセチルセルロース重合体、脂環式オレフィン重合体などを挙げられる。これらの中でも、樹脂Ｂとしては、脂環式オレフィン重合体及びメタクリル重合体が好適である。中でも、樹脂Ｂがメタクリル重合体であれば、本発明の光学積層体全体で光弾性を３×１０−１２ｍ２／Ｎ以下にすることができ、額縁故障などを防止できる。 As the resin B, a thermoplastic resin is usually used. Examples of the polymer contained in the resin B include acrylic polymer, methacrylic polymer, polycarbonate polymer, polyester polymer, polyethersulfone polymer, polyarylate polymer, polyimide polymer, chain polyolefin polymer, Examples include polyethylene terephthalate polymer, polysulfone polymer, polyvinyl chloride polymer, diacetyl cellulose polymer, triacetyl cellulose polymer, and alicyclic olefin polymer. Among these, as the resin B, an alicyclic olefin polymer and a methacrylic polymer are preferable. Among these, if the resin B is a methacrylic polymer, the photoelasticity of the entire optical laminate of the present invention can be reduced to 3 × 10 −12 m 2 / N or less, and a frame failure or the like can be prevented.
メタクリル重合体は、メタクリル酸アルキルエステル単位を主モノマー単位として含む重合体である。メタクリル重合体としては、メタクリル酸メチル、メタクリル酸エチルなどの炭素数１〜４のアルキル基を有するメタクリル酸アルキルエステルの単独重合体；アルキル基の水素がＯＨ基、ＣＯＯＨ基若しくはＮＨ２基などの官能基によって置換された炭素数１〜４のアルキル基を有するメタクリル酸アルキルエステルの単独重合体；又はメタクリル酸アルキルエステルと、スチレン、酢酸ビニル、α，β−モノエチレン性不飽和カルボン酸、ビニルトルエン、α−メチルスチレン、アクリロニトリル、アクリル酸アルキルエステルなどのメタクリル酸アルキルエステル以外のエチレン性不飽和単量体との共重合体等が挙げられる。これらのうち、アクリル酸アルキルエステルがメタクリル酸アルキルエステルとの共重合に好適である。好適なメタクリル重合体では、官能基によって置換されていてもよい炭素数１〜４のアルキル基を有するメタクリル酸アルキルエステル単位を、好ましくは５０〜１００重量％、より好ましくは５０〜９９．９重量％、さらに好ましくは５０〜９９．５重量％含有し、アクリル酸アルキルエステル単位を好ましくは０〜５０重量％、より好ましくは０．１〜５０重量％、さらに好ましくは０．５〜５０重量％含有する。 The methacrylic polymer is a polymer containing a methacrylic acid alkyl ester unit as a main monomer unit. As a methacrylic polymer, a homopolymer of a methacrylic acid alkyl ester having an alkyl group having 1 to 4 carbon atoms such as methyl methacrylate and ethyl methacrylate; the hydrogen of the alkyl group is OH group, COOH group or NH 2 group A homopolymer of a methacrylic acid alkyl ester having a C 1-4 alkyl group substituted by a functional group; or a methacrylic acid alkyl ester and styrene, vinyl acetate, α, β-monoethylenically unsaturated carboxylic acid, vinyl And copolymers with ethylenically unsaturated monomers other than methacrylic acid alkyl esters such as toluene, α-methylstyrene, acrylonitrile, and acrylic acid alkyl esters. Of these, acrylic acid alkyl esters are suitable for copolymerization with methacrylic acid alkyl esters. In a suitable methacrylic polymer, the methacrylic acid alkyl ester unit having an alkyl group having 1 to 4 carbon atoms which may be substituted with a functional group is preferably 50 to 100% by weight, more preferably 50 to 99.9% by weight. %, More preferably 50 to 99.5% by weight, and the alkyl ester unit is preferably 0 to 50% by weight, more preferably 0.1 to 50% by weight, and still more preferably 0.5 to 50% by weight. contains.
脂環式オレフィン重合体は、主鎖及び／又は側鎖に脂環構造を有する非晶性の熱可塑性重合体である。脂環式オレフィン重合体中の脂環構造としては、飽和脂環炭化水素（シクロアルカン）構造、不飽和脂環炭化水素（シクロアルケン）構造などが挙げられるが、機械強度、耐熱性などの観点から、シクロアルカン構造が好ましい。脂環構造を構成する炭素原子数には、格別な制限はないが、通常４〜３０個、好ましくは５〜２０個、より好ましくは５〜１５個であるときに、機械強度、耐熱性、及びフィルムの成形性の特性が高度にバランスされ、好適である。 The alicyclic olefin polymer is an amorphous thermoplastic polymer having an alicyclic structure in the main chain and / or side chain. Examples of the alicyclic structure in the alicyclic olefin polymer include a saturated alicyclic hydrocarbon (cycloalkane) structure and an unsaturated alicyclic hydrocarbon (cycloalkene) structure, but from the viewpoint of mechanical strength, heat resistance and the like. Therefore, a cycloalkane structure is preferable. The number of carbon atoms constituting the alicyclic structure is not particularly limited, but is usually 4 to 30, preferably 5 to 20, more preferably 5 to 15, when the mechanical strength, heat resistance, In addition, the moldability characteristics of the film are highly balanced and suitable.
脂環式オレフィン重合体を構成する脂環構造を有する繰り返し単位の割合は、好ましくは５５重量％以上、さらに好ましくは７０重量％以上、特に好ましくは９０重量％以上である。脂環式オレフィン重合体中の脂環式構造を有する繰り返し単位の割合がこの範囲にあると、透明性および耐熱性の観点から好ましい。 The ratio of the repeating unit having an alicyclic structure constituting the alicyclic olefin polymer is preferably 55% by weight or more, more preferably 70% by weight or more, and particularly preferably 90% by weight or more. It is preferable from a transparency and heat resistant viewpoint that the ratio of the repeating unit which has an alicyclic structure in an alicyclic olefin polymer exists in this range.
脂環式オレフィン重合体としては、例えば、ノルボルネン重合体、単環の環状オレフィン重合体、環状共役ジエン重合体、ビニル脂環式炭化水素重合体、及び、これらの水素化物等が挙げられる。これらの中で、ノルボルネン重合体は、透明性と成形性が良好なため、好適に用いることができる。 Examples of the alicyclic olefin polymer include a norbornene polymer, a monocyclic olefin polymer, a cyclic conjugated diene polymer, a vinyl alicyclic hydrocarbon polymer, and a hydride thereof. Among these, norbornene polymers can be suitably used because of their good transparency and moldability.
ノルボルネン重合体としては、例えば、ノルボルネン構造を有する単量体の開環重合体若しくはノルボルネン構造を有する単量体と他の単量体との開環共重合体、又はそれらの水素化物；ノルボルネン構造を有する単量体の付加重合体若しくはノルボルネン構造を有する単量体と他の単量体との付加共重合体、又はそれらの水素化物等が挙げられる。これらの中で、ノルボルネン構造を有する単量体の開環（共）重合体水素化物は、透明性、成形性、耐熱性、低吸湿性、寸法安定性、軽量性などの観点から、特に好適に用いることができる。
なお、これらの重合体は１種類を単独で用いてもよく、２種類以上を任意の比率で組み合わせて用いてもよい。
Examples of the norbornene polymer include a ring-opening polymer of a monomer having a norbornene structure, a ring-opening copolymer of a monomer having a norbornene structure and another monomer, or a hydride thereof; norbornene structure Or an addition copolymer of a monomer having a norbornene structure with another monomer, or a hydride thereof. Among these, a ring-opening (co) polymer hydride of a monomer having a norbornene structure is particularly suitable from the viewpoints of transparency, moldability, heat resistance, low hygroscopicity, dimensional stability, lightness, and the like. Can be used.
In addition, these polymers may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.
樹脂Ｂに含まれる重合体の分子量は使用目的に応じて適宜選定されるが、溶媒としてシクロヘキサンを用いて（但し、重合体がシクロヘキサンに溶解しない場合にはトルエンを用いてもよい）ゲル・パーミエーション・クロマトグラフィーで測定したポリイソプレン換算（溶媒がトルエンのときは、ポリスチレン換算）の重量平均分子量（Ｍｗ）で、通常１０，０００以上、好ましくは１５，０００以上、より好ましくは２０，０００以上であり、通常１００，０００以下、好ましくは８０，０００以下、より好ましくは５０，０００以下である。重量平均分子量がこのような範囲にあることにより、本発明の光学積層体の機械的強度及び成型加工性などが高度にバランスされる。 The molecular weight of the polymer contained in the resin B is appropriately selected according to the purpose of use, but using gel as a solvent (however, if the polymer does not dissolve in cyclohexane, toluene may be used) The weight average molecular weight (Mw) in terms of polyisoprene measured by ablation chromatography (in terms of polystyrene when the solvent is toluene) is usually 10,000 or more, preferably 15,000 or more, more preferably 20,000 or more. It is usually 100,000 or less, preferably 80,000 or less, more preferably 50,000 or less. When the weight average molecular weight is in such a range, the mechanical strength and molding processability of the optical laminate of the present invention are highly balanced.
樹脂Ｂには、必要に応じて、樹脂Ａと同様に公知の添加剤を、本発明の効果を損なわない範囲で含ませてもよい。これらの添加剤の量は、樹脂Ｂに含まれる重合体１００重量部に対して、通常０〜５０重量部、好ましくは０〜３０重量部である。 If necessary, the resin B may contain a known additive as in the case of the resin A as long as the effects of the present invention are not impaired. The amount of these additives is usually 0 to 50 parts by weight, preferably 0 to 30 parts by weight with respect to 100 parts by weight of the polymer contained in the resin B.
樹脂Ｂのガラス転移温度Ｔｇ（ｂ）は、好ましくは４０℃以上、より好ましくは６０℃以上である。また、樹脂Ｂのガラス転移温度Ｔｇ（ｂ）の上限値は、通常１４０℃以下である。 The glass transition temperature Tg (b) of the resin B is preferably 40 ° C. or higher, more preferably 60 ° C. or higher. Further, the upper limit value of the glass transition temperature Tg (b) of the resin B is usually 140 ° C. or lower.
Ｂ層は、実質的に無配向な層であることが好ましい。実質的に無配向とは、Ｂ層内において直交するｘ方向とｙ方向の屈折率ｎＢｘとｎＢｙの差が小さく、Ａ層内において直交するｘ方向とｙ方向の屈折率をそれぞれｎＡｘ、ｎＡｙ、Ａ層の厚みをｄＡ、Ｂ層の厚みをｄＢとしたとき、｜（ｎＡｘ−ｎＡｙ）×ｄＡ｜＋｜（ｎＢｘ−ｎＢｙ）×ｄＢ｜の値が｜（ｎＡｘ−ｎＡｙ）×ｄＡ｜の値の１．１倍以下であることをいう。 The B layer is preferably a substantially non-oriented layer. Substantially non-oriented means that the difference between the refractive indices nBx and nBy in the x direction and y direction orthogonal in the B layer is small, and the refractive indexes in the x direction and y direction orthogonal in the A layer are nAx, nAy, When the thickness of the A layer is dA and the thickness of the B layer is dB, the value of | (nAx−nAy) × dA | + | (nBx−nBy) × dB | is the value of | (nAx−nAy) × dA |. It is 1.1 times or less.
｜Ｒｅ（Ｂ）｜は、２０ｎｍ以下であることがより好ましく、１０ｎｍ以下であることがさらに好ましく、５ｎｍ以下であることが特に好ましい。｜Ｒｅ（Ｂ）｜を小さくすることにより、本発明の光学積層体に所望の光学補償機能を十分に発揮させることができる。
具体的なＢ層の正面レターデーションＲｅ（Ｂ）の範囲を挙げると、例えば波長４００〜７００ｎｍの光で測定したＢ層の正面レターデーションＲｅ（Ｂ）（ｎｍ）は、好ましくは０ｎｍ以上１５ｎｍ以下である。
| Re (B) | is more preferably 20 nm or less, further preferably 10 nm or less, and particularly preferably 5 nm or less. By reducing | Re (B) |, the optical layered body of the present invention can sufficiently exhibit a desired optical compensation function.
When the range of the specific front retardation Re (B) of the B layer is given, for example, the front retardation Re (B) (nm) of the B layer measured with light having a wavelength of 400 to 700 nm is preferably 0 nm or more and 15 nm or less. It is.
（３）本発明の光学積層体の層構成
本発明の光学積層体において、Ａ層及びＢ層がそれぞれ少なくとも１層ずつ存在していれば、Ａ層及びＢ層の層数及び順番に制限は無い。本発明の光学積層体における層構成の好ましい例を挙げると、Ａ層及びＢ層がこの順で存在する層構成；Ｂ層、Ａ層及びＢ層がこの順で存在する層構成、などが挙げられる。また、Ａ層が２層以上存在する場合は各Ａ層は同じでも異なっていても良く、Ｂ層が２層以上存在する場合は各Ｂ層は同じでも異なっていてもよい。
(3) Layer structure of the optical layered body of the present invention In the optical layered body of the present invention, if there are at least one layer A and one layer B, the number and order of the layers A and B are not limited. No. Preferred examples of the layer structure in the optical layered body of the present invention include a layer structure in which the A layer and the B layer exist in this order; a layer structure in which the B layer, the A layer, and the B layer exist in this order, and the like. It is done. Moreover, when two or more A layers exist, each A layer may be the same or different, and when two or more B layers exist, each B layer may be the same or different.
（４）本発明の光学積層体の寸法
本発明の光学積層体は、Ａ層及びＢ層の総厚（即ち、Ａ層の厚みとＢ層の厚みの総合計）が、通常６０μｍ以下であり、５０μｍ以下や、４０μｍ以下とすることもできる。本発明の光学積層体はこのように薄い総厚でありながらも優れた耐久性及び光学均一性を有するという顕著な利点を有する。また、総厚が薄いため、本発明の光学積層体は反り等の変形を生じにくい。したがって、本発明の光学積層体を光学用パネルに設けた場合でも、当該光学用パネルにおいて反りを生じ難くできる。さらに、総厚が薄いことにより、光学用パネルの軽量化及び薄膜化が可能であり、材料を削減できるので製造コストを下げることが可能である。
前記のＡ層及びＢ層の総厚の下限は、本発明の光学積層体の強度をハンドリング性を損なわない程度に保つ観点から、通常２５μｍ以上、好ましくは３０μｍ以上、より好ましくは３５μｍ以上である。
(4) Dimensions of optical laminate of the present invention The optical laminate of the present invention generally has a total thickness of the A layer and the B layer (that is, the total sum of the thickness of the A layer and the thickness of the B layer) of 60 μm or less. , 50 μm or less, or 40 μm or less. The optical laminate of the present invention has the remarkable advantage of having excellent durability and optical uniformity while having such a thin total thickness. Further, since the total thickness is thin, the optical laminate of the present invention is less likely to be deformed such as warpage. Therefore, even when the optical layered body of the present invention is provided on an optical panel, it is possible to prevent warpage from occurring in the optical panel. Furthermore, since the total thickness is thin, the optical panel can be reduced in weight and thickness, and the material can be reduced, so that the manufacturing cost can be reduced.
The lower limit of the total thickness of the A layer and the B layer is usually 25 μm or more, preferably 30 μm or more, more preferably 35 μm or more, from the viewpoint of maintaining the strength of the optical layered body of the present invention so as not to impair handling properties. .
本発明の光学積層体の平面形状並びに幅及び長さ等の寸法は、光学積層体の用途に応じて任意に設定できる。ただし、本発明の光学積層体は、通常、長尺のフィルムとして製造され、また当該長尺のフィルムをロール状に巻回して保管及び運搬される。この際、長尺のフィルムである場合の本発明の光学積層体の幅は、通常１０００ｍｍを超える。
なお、ここで長尺とは、フィルムの幅に対して、少なくとも５倍程度以上の長さを有するものをいい、好ましくは１０倍若しくはそれ以上の長さを有し、具体的にはロール状に巻回されて保管又は運搬される程度の長さを有するものをいう。
The planar shape and the dimensions such as the width and length of the optical laminate of the present invention can be arbitrarily set according to the use of the optical laminate. However, the optical laminate of the present invention is usually produced as a long film, and is stored and transported by winding the long film into a roll. Under the present circumstances, the width | variety of the optical laminated body of this invention in the case of a elongate film usually exceeds 1000 mm.
In addition, a long thing means what has a length of about 5 times or more with respect to the width | variety of a film here, Preferably it has a length of 10 times or more, Specifically, it is roll shape. It has a length that is wound around and stored or transported.
（５）本発明の光学積層体の物性
本発明の光学積層体のＮｚ係数は、光学補償機能を発揮させる観点から、通常−４．５以上であり、通常−０．５以下である。
さらに、本発明の光学積層体において、Ｎｚ係数のバラツキ（変動幅）は、好ましくは０．７以下、より好ましくは０．５以下、特に好ましくは０．３以下である。
ここでＮｚ係数は、厚み方向の屈折率をｎｚ、厚み方向に垂直な面内において、互いに直交する２方向の屈折率をｎｘ及びｎｙ（ただし、ｎｘ＞ｎｙ）として、Ｎｚ＝（ｎｘ−ｎｚ）／（ｎｘ−ｎｙ）で表される係数である。光学積層体のＮｚ係数は、自動複屈折計を用いて、波長５９０ｎｍで、光学積層体の幅方向に一定間隔（例えば、１００ｍｍ間隔）で測定を行う。この測定を光学積層体の流れ方向に一定間隔（例えば、１００ｍｍ間隔）で所定の長さ（例えば、１０００ｍｍ）にわたって行ない、全測定結果の平均値をＮｚ係数とする。また、Ｎｚ係数のバラツキはＮｚ係数の最大値と最小値の差とする。
(5) Physical properties of the optical laminate of the present invention The Nz coefficient of the optical laminate of the present invention is usually −4.5 or more and usually −0.5 or less from the viewpoint of exhibiting the optical compensation function.
Furthermore, in the optical layered body of the present invention, the variation (variation width) of the Nz coefficient is preferably 0.7 or less, more preferably 0.5 or less, and particularly preferably 0.3 or less.
Here, the Nz coefficient is defined as Nz = (nx−nz), where nz is the refractive index in the thickness direction, and nx and ny are the refractive indexes in two directions orthogonal to each other in a plane perpendicular to the thickness direction (where nx> ny). ) / (Nx−ny). The Nz coefficient of the optical laminate is measured using an automatic birefringence meter at a wavelength of 590 nm and at regular intervals (for example, 100 mm intervals) in the width direction of the optical laminate. This measurement is performed over a predetermined length (for example, 1000 mm) at regular intervals (for example, 100 mm) in the flow direction of the optical laminate, and the average value of all measurement results is defined as the Nz coefficient. Further, the variation of the Nz coefficient is the difference between the maximum value and the minimum value of the Nz coefficient.
本発明の光学積層体は、光学均一性に優れるという利点を有する。具体例には、その配向角θのバラツキが、以下の通り小さくなる。すなわち、本発明の光学積層体において、配向角θのバラツキは、通常１．０°以下、好ましくは０．８°以下、より好ましくは０．６°以下である。
また、本発明の光学積層体の配向角θの平均値の具体的な範囲は、例えば幅方向に平行な遅相軸を有する光学積層体の場合、通常０．６°以下、好ましくは０．４°以下、より好ましくは０．２°以下である。
ここで配向角とは、光学積層体の幅方向と、光学積層体の面内の遅相軸とがなす角である。光学積層体の配向角θは、オンライン位相差計（王子計測機器社製：ＫＯＢＲＡ−ＷＩＳＴ／２ＲＴ）を用い、オンラインで測定間隔は幅方向２５ｍｍ間隔で、ラインスピードは１５０ｍｍ／秒で、フィルム幅方向に２０回測定を行い、全測定結果を平均して配向角の平均値とする。なお、オンライン測定開始前、測定終了時でサンプリングし、オフライン測定を行い、オンライン位相差計の絶対値（平均値）の補正を行う。オフライン測定は、光学積層体の幅方向に一定間隔（例えば、１００ｍｍ間隔）で、偏光顕微鏡を用いて光学積層体の面内の遅相軸を測定し、光学積層体の幅方向と面内の遅相軸とがなす角度を測定する。オンライン測定開始前、測定終了時でサンプリングし測定した２つの測定結果（オンライン測定前、測定終了時）を平均して配向角の平均値（オフライン）とする。オンライン平均値はオフラインの平均値と合うように補正する。また、配向角θのバラツキは、各測定結果の最大値から最小値を差し引いた値とする。
The optical layered body of the present invention has an advantage of excellent optical uniformity. As a specific example, the variation in the orientation angle θ is reduced as follows. That is, in the optical layered body of the present invention, the variation in the orientation angle θ is usually 1.0 ° or less, preferably 0.8 ° or less, more preferably 0.6 ° or less.
In addition, the specific range of the average value of the orientation angle θ of the optical laminate of the present invention is usually 0.6 ° or less, preferably 0. 0, for an optical laminate having a slow axis parallel to the width direction. It is 4 ° or less, more preferably 0.2 ° or less.
Here, the orientation angle is an angle formed by the width direction of the optical laminate and the in-plane slow axis of the optical laminate. The orientation angle θ of the optical laminate is determined by using an on-line phase difference meter (manufactured by Oji Scientific Instruments: KOBRA-WIST / 2RT), the measurement interval is 25 mm in the width direction, the line speed is 150 mm / sec, and the film width Measurement is performed 20 times in the direction, and all measurement results are averaged to obtain an average value of the orientation angles. In addition, sampling is performed before online measurement is started and at the end of measurement, offline measurement is performed, and the absolute value (average value) of the online phase difference meter is corrected. In the off-line measurement, the slow axis in the plane of the optical laminate is measured with a polarizing microscope at a constant interval (for example, 100 mm interval) in the width direction of the optical laminate, and the width direction and the in-plane of the optical laminate are measured. Measure the angle between the slow axis. Two measurement results (before online measurement and at the end of measurement) sampled and measured before the start of online measurement and at the end of measurement are averaged to obtain the average value of the orientation angle (offline). The online average is corrected to match the offline average. The variation in the orientation angle θ is a value obtained by subtracting the minimum value from the maximum value of each measurement result.
本発明者の検討によれば、樹脂Ａからなる層を備える光学積層体においては、Ｎｚ係数が大きくなるほど、また、総厚が薄くなるほど、配向角θのバラツキが大きくなる傾向があることが判明した。ここで、光学積層体の総厚は薄型化の要求から一般に薄くすることが望まれるが、総厚を薄くすると脆くなりハンドリング性が低下する傾向がある。しかしながら、Ｎｚ係数は通常は光学積層体に要求される光学特性に応じて設定することになるため、その値を大きく変更することは難しい。このため配向角θのバラツキなどに代表される光学均一性の改善とハンドリング性の向上とを両立することが困難であったが、本発明の光学積層体は、Ｎｚ係数とＡ層の厚みとのバランスが良いため、配向角θのバラツキ低減とハンドリング性の向上とを両立できる。 According to the study of the present inventor, in an optical laminate including a layer made of resin A, it has been found that the variation in the orientation angle θ tends to increase as the Nz coefficient increases and the total thickness decreases. did. Here, the total thickness of the optical layered body is generally desired to be reduced in order to reduce the thickness, but if the total thickness is reduced, the total thickness becomes brittle and the handling property tends to decrease. However, since the Nz coefficient is normally set according to the optical characteristics required for the optical laminate, it is difficult to change the value greatly. For this reason, it has been difficult to achieve both improvement in optical uniformity typified by variations in the orientation angle θ and improvement in handling properties, but the optical laminate of the present invention has an Nz coefficient, the thickness of the A layer, and the like. Therefore, it is possible to achieve both reduction in variation in the orientation angle θ and improvement in handling properties.
本発明の光学積層体においては、正面レターデーションＲｅのバラツキによっても光学均一性を評価できる。本発明の光学積層体の正面レターデーションＲｅのバラツキは、通常１０ｎｍ以下、好ましくは７ｎｍ以下、より好ましくは４ｎｍ以下である。
また、本発明の光学積層体の正面レターデーションＲｅ（ｎｍ）の平均値は、所望の光学補償機能を発現させる観点から、通常３０ｎｍ以上であり、通常１５０ｎｍ以下、好ましくは８０ｎｍ以下である。
前記の光学積層体の正面レターデーションＲｅは、オンライン位相差計（王子計測機器社製：ＫＯＢＲＡ−ＷＩＳＴ／２ＲＴ）を用い、オンラインで測定間隔は幅方向２５ｍｍ間隔で、ラインスピードは１５０ｍｍ／秒で、フィルム幅方向に２０回測定を行い、全測定結果を平均してＲｅの平均値とする。なお、オンライン測定開始前、測定終了時でサンプリングし、オフライン測定を行い、オンライン位相差計の絶対値（平均値）の補正を行う。オフライン測定は、光学積層体の幅方向に一定間隔（例えば、１００ｍｍ間隔）で、自動複屈折計を用いて波長５９０ｎｍで測定する。オンライン測定開始前、測定終了時でサンプリングし測定した２つの測定結果（オンライン測定前、測定終了時）を平均してＲｅの平均値（オフライン）とする。オンライン平均値はオフラインの平均値と合うように補正する。また、正面レターデーションＲｅのバラツキは、各測定結果の最大値から最小値を差し引いた値とする。
In the optical layered body of the present invention, the optical uniformity can also be evaluated by the variation of the front retardation Re. The variation of the front retardation Re of the optical laminate of the present invention is usually 10 nm or less, preferably 7 nm or less, more preferably 4 nm or less.
Further, the average value of the front retardation Re (nm) of the optical layered body of the present invention is usually 30 nm or more, usually 150 nm or less, preferably 80 nm or less from the viewpoint of developing a desired optical compensation function.
For the front retardation Re of the optical laminate, an on-line phase difference meter (manufactured by Oji Scientific Instruments: KOBRA-WIST / 2RT) is used, and the measurement interval is 25 mm in the width direction and the line speed is 150 mm / sec. The measurement is performed 20 times in the film width direction, and all the measurement results are averaged to obtain the average value of Re. In addition, sampling is performed before online measurement is started and at the end of measurement, offline measurement is performed, and the absolute value (average value) of the online phase difference meter is corrected. The off-line measurement is performed at a wavelength of 590 nm using an automatic birefringence meter at a constant interval (for example, 100 mm interval) in the width direction of the optical laminate. Two measurement results (before online measurement and at the end of measurement) sampled and measured before the start of online measurement and at the end of measurement are averaged to obtain the average value of Re (offline). The online average is corrected to match the offline average. Further, the variation of the front retardation Re is a value obtained by subtracting the minimum value from the maximum value of each measurement result.
本発明の光学積層体のヘイズは、１％を超え５％以下であることが好ましい。ここで、ヘイズとは、入射光のうち、平行光線透過率と拡散光線透過率の比である。ヘイズは、ＪＩＳ Ｋ７３６１−１９９７に準拠して、ヘイズメーターを用いて測定すればよい。なお、ヘイズは、例えば樹脂に含ませる添加剤の量や、フィルム表面の粗面化処理、延伸速度等により調整することができる。 The haze of the optical layered body of the present invention is preferably more than 1% and 5% or less. Here, the haze is the ratio of the parallel light transmittance to the diffuse light transmittance in the incident light. What is necessary is just to measure a haze using a haze meter based on JISK7361-1997. The haze can be adjusted by, for example, the amount of the additive to be included in the resin, the roughening treatment of the film surface, the stretching speed, and the like.
本発明の光学積層体は、その総厚が薄いにもかかわらず強度が高いため、破損などを起こし難く、ハンドリング性が良好である。具体的な指標を挙げると、本発明の光学積層体の引き裂き強度が、通常１Ｎ／ｍｍ以上、好ましくは１.２Ｎ／ｍｍ以上、より好ましくは１．４Ｎ／ｍｍ以上である。なお、光学積層体の引き裂き強度は、ＪＩＳ Ｋ７１２８−２（エルメンドルフ引裂法）に準拠して、光学積層体の中央部について、引っ張り試験機を用いて、遅相軸に直交する方向に引っ張り、クラックが発生した時点の強度を計測して引き裂き強度とすればよい。 The optical layered body of the present invention has high strength despite its thin total thickness. Therefore, the optical layered body hardly breaks and has good handling properties. Specifically, the tear strength of the optical layered body of the present invention is usually 1 N / mm or more, preferably 1.2 N / mm or more, more preferably 1.4 N / mm or more. The tear strength of the optical laminate is determined by pulling the central portion of the optical laminate in the direction perpendicular to the slow axis using a tensile tester in accordance with JIS K7128-2 (Elmendorf tear method). What is necessary is just to measure the intensity | strength at the time of generation | occurrence | production, and to make it tear strength.
さらに、本発明の光学積層体は、総厚が薄いため、反り等の変形を生じにくい。 Furthermore, since the total thickness of the optical layered body of the present invention is thin, deformation such as warpage is unlikely to occur.
（６）本発明の光学積層体に係るその他の事項
本発明の光学積層体では、必要に応じて、Ａ層及びＢ層の表面を粗面化してもよい。粗面化する手段に特に制限はなく、例えば、コロナ放電処理、エンボス加工、サンドブラスト、エッチング、微粒子の付着などが挙げられる。表面を粗面化することにより、接着性を向上させることができる。
(6) Other matters concerning the optical laminate of the present invention In the optical laminate of the present invention, the surfaces of the A layer and the B layer may be roughened as necessary. The means for roughening is not particularly limited, and examples thereof include corona discharge treatment, embossing, sand blasting, etching, and fine particle adhesion. By roughening the surface, the adhesion can be improved.
本発明の光学積層体は、本発明の効果を著しく損なわない限り、Ａ層及びＢ層以外にも層を備えていてもよい。その例を挙げると、接着剤層が挙げられる。
接着剤層は、通常、Ａ層とＢ層との間に設けられる。接着剤層は、光学積層体を構成するＡ層及びＢ層のそれぞれに対して親和性があるものから形成することが好ましい。接着剤層を形成する接着剤としては、例えば、エチレン−（メタ）アクリル酸メチル共重合体、エチレン−（メタ）アクリル酸エチル共重合体等のエチレン−（メタ）アクリル酸エステル共重合体；エチレン−酢酸ビニル共重合体、エチレン−スチレン共重合体等のエチレン系共重合体や他のオレフィン系重合体などが挙げられる。また、これらの（共）重合体を酸化、ケン化、塩素化、クロルスルホン化などにより変性した変性物を用いることもできる。接着剤層の厚みは、好ましくは１〜５０μｍ、さらに好ましくは２〜３０μｍである。ただし、本発明の光学積層体が接着剤層を備える場合は、接着剤のガラス転移温度又は軟化点Ｔｇ（ｄ）は、樹脂Ａのガラス転移温度Ｔｇ（ａ）及び樹脂Ｂのガラス転移温度Ｔｇ（ｂ）よりも低いことが好ましく、樹脂Ａのガラス転移温度Ｔｇ（ａ）及び樹脂Ｂのガラス転移温度Ｔｇ（ｂ）よりも１５℃以上低いことがさらに好ましい。
The optical layered body of the present invention may include layers other than the A layer and the B layer as long as the effects of the present invention are not significantly impaired. When the example is given, an adhesive bond layer will be mentioned.
The adhesive layer is usually provided between the A layer and the B layer. The adhesive layer is preferably formed from those having an affinity for each of the A layer and the B layer constituting the optical layered body. Examples of the adhesive that forms the adhesive layer include ethylene- (meth) acrylate copolymers such as ethylene- (meth) methyl acrylate copolymer and ethylene- (meth) ethyl acrylate copolymer; Examples thereof include ethylene copolymers such as ethylene-vinyl acetate copolymer and ethylene-styrene copolymer, and other olefin polymers. In addition, modified products obtained by modifying these (co) polymers by oxidation, saponification, chlorination, chlorosulfonation, or the like can also be used. The thickness of the adhesive layer is preferably 1 to 50 μm, more preferably 2 to 30 μm. However, when the optical layered body of the present invention includes an adhesive layer, the glass transition temperature or softening point Tg (d) of the adhesive is the glass transition temperature Tg (a) of the resin A and the glass transition temperature Tg of the resin B. It is preferably lower than (b), more preferably 15 ° C. lower than the glass transition temperature Tg (a) of the resin A and the glass transition temperature Tg (b) of the resin B.
〔３．光学積層体の製造方法〕
本発明の光学積層体は、樹脂Ａからなるａ層と、樹脂Ｂからなるｂ層とを備える未延伸の積層体ｃを用意する工程と、この未延伸の積層体ｃに延伸処理を施す工程とを経て得られる。
[3. Method for producing optical laminate]
The optical laminate of the present invention is a step of preparing an unstretched laminate c including an a layer made of resin A and a b layer made of resin B, and a step of subjecting the unstretched laminate c to a stretching process. And get through.
（１）未延伸の積層体ｃの用意
未延伸の積層体ｃを得る方法としては、例えば、共押出Ｔダイ法、共押出インフレーション法、共押出ラミネーション法等の共押出による成形方法；ドライラミネーション等のフィルムラミネーション成形方法；基材樹脂フィルムに対して樹脂溶液をコーティングするようなコーティング成形方法などの公知の方法が適宜できる。中でも、製造効率や、フィルム中に溶剤などの揮発性成分を残留させないという観点から、共押出による成形方法が好ましい。押出し温度は、使用するＡ層を構成する樹脂Ａ、Ｂ層を構成する樹脂Ｂ及び必要に応じて用いられる接着剤の種類に応じて適宜選択され得る。通常、未延伸の積層体ｃは長尺の積層フィルムであり、その幅は１０００ｍｍ以上である。
(1) Preparation of unstretched laminate c As a method for obtaining the unstretched laminate c, for example, a coextrusion molding method such as a coextrusion T-die method, a coextrusion inflation method, or a coextrusion lamination method; dry lamination A known method such as a film lamination molding method such as a coating molding method in which a resin solution is coated on a base resin film can be appropriately used. Among these, a molding method by coextrusion is preferable from the viewpoints of production efficiency and that volatile components such as a solvent do not remain in the film. The extrusion temperature can be appropriately selected according to the type of the resin A constituting the A layer to be used, the resin B constituting the B layer, and the adhesive used as necessary. Usually, the unstretched laminated body c is a long laminated film, and the width thereof is 1000 mm or more.
（２）未延伸の積層体ｃの延伸処理
未延伸の積層体ｃを用意した後、その未延伸の積層体ｃに延伸処理を施す。延伸処理により、未延伸の積層体ｃにおいて所望の光学特性が発現し、本発明の光学積層体が得られる。ただし前記の延伸処理においては、総延伸倍率を、通常２．３倍以上、好ましくは２．７倍以上、より好ましくは３．３倍以上にする。ここで、総延伸倍率とは、１方向のみに延伸する延伸処理においては当該一方向への延伸倍率の事をいい、２方向以上の延伸方向に延伸する延伸処理においては各延伸方向への延伸倍率の積のことをいう。このように総延伸倍率を大きくすることにより、得られる本発明の光学積層体の強度を強くして破損等を抑制できる。
前記の総延伸倍率の上限は、特に限定されないが、用いる樹脂の歩留まりを考慮すれば、通常４．７倍以下である。
(2) Stretching treatment of unstretched laminate c After preparing an unstretched laminate c, the unstretched laminate c is stretched. By the stretching treatment, desired optical properties are expressed in the unstretched laminate c, and the optical laminate of the present invention is obtained. However, in the stretching treatment, the total stretching ratio is usually 2.3 times or more, preferably 2.7 times or more, more preferably 3.3 times or more. Here, the total stretching ratio refers to the stretching ratio in one direction in the stretching process of stretching in only one direction, and stretching in each stretching direction in the stretching process of stretching in two or more stretching directions. The product of magnification. By increasing the total draw ratio in this way, the strength of the optical laminate of the present invention obtained can be increased and damage and the like can be suppressed.
The upper limit of the total draw ratio is not particularly limited, but is usually 4.7 times or less in consideration of the yield of the resin used.
前記の総延伸倍率で延伸処理を行う限り、未延伸の積層体ｃの延伸方法に制限はない。
例えば、一対のガイドレールに沿ってそれぞれ走行する複数のクリップ（把持具）を備えるパンタグラフ方式の同時二軸延伸装置を用いて行えばよい。この同時二軸延伸装置は、未延伸の積層体ｃを把持するクリップの間隔が開かれて縦方向（流れ方向）の延伸がなされると同時に、ガイドレールの広がり角度により横方向（幅方向）に延伸するものである。また、例えば、ロール間の周速の差を利用して縦方向に延伸した後に、その両端部がクリップで把持されてテンターを用いて横方向に延伸する逐次二軸延伸法を行ってもよい。ただし逐次二軸延伸法では、縦方向に延伸してから樹脂が一旦冷却され、その後に横方向に延伸するために再度加熱されるので、熱緩和によって、横方向の延伸時に、縦方向の延伸で得られた所望の光学特性が変化して、所望の光学特性を発現することが難しくなる傾向がある。これに対し、前記の同時二軸延伸装置等を用いた同時二軸延伸処理により延伸処理を行うようにすれば、逐次二軸延伸法のようなことがなく、良好な光学特性を有する光学積層体を得ることができる。
As long as the stretching treatment is performed at the total stretching ratio, there is no limitation on the stretching method of the unstretched laminate c.
For example, a pantograph-type simultaneous biaxial stretching apparatus including a plurality of clips (gripping tools) respectively traveling along a pair of guide rails may be used. In this simultaneous biaxial stretching apparatus, the gap between the clips that hold the unstretched laminate c is opened and the longitudinal direction (flow direction) is stretched, and at the same time, the lateral direction (width direction) is determined by the spread angle of the guide rail. Are stretched. Further, for example, a sequential biaxial stretching method may be performed in which, after stretching in the longitudinal direction using a difference in peripheral speed between rolls, both ends thereof are gripped by clips and stretched in the lateral direction using a tenter. . However, in the sequential biaxial stretching method, the resin is once cooled after being stretched in the longitudinal direction, and then heated again to stretch in the transverse direction. The desired optical characteristics obtained in (1) tend to change, making it difficult to express the desired optical characteristics. On the other hand, if the stretching process is performed by the simultaneous biaxial stretching process using the above-described simultaneous biaxial stretching apparatus or the like, there is no sequential biaxial stretching method, and an optical laminate having good optical characteristics. You can get a body.
未延伸の積層体ｃの延伸温度は、樹脂Ａのビカット軟化温度Ｔｅｇ（ａ）−４℃以上であることが好ましく、樹脂Ａのビカット軟化温度Ｔｅｇ（ａ）＋４℃以上であることがより好ましい。また、未延伸の積層体ｃの延伸温度は、樹脂Ａのビカット軟化温度Ｔｅｇ（ａ）＋２０℃未満であることが好ましく、樹脂Ａのビカット軟化温度Ｔｅｇ（ａ）＋１０℃未満であることがより好ましい。この範囲に設定すると、延伸適正（操業性）が良いからである。 The stretching temperature of the unstretched laminate c is preferably not less than the Vicat softening temperature Teg (a) of the resin A-4 ° C., more preferably not less than the Vicat softening temperature Teg (a) of the resin A + 4 ° C. . Further, the stretching temperature of the unstretched laminate c is preferably less than the Vicat softening temperature Teg (a) + 20 ° C. of the resin A, and more preferably less than the Vicat softening temperature Teg (a) + 10 ° C. of the resin A. preferable. This is because, when set within this range, the stretching suitability (operability) is good.
未延伸の積層体ｃに延伸処理を施す場合、その長手方向（通常は、流れ方向に一致する。）の延伸倍率が、その幅方向の延伸倍率の１．０〜１．５倍の範囲とすることができる。 When the unstretched laminate c is subjected to a stretching treatment, the stretching ratio in the longitudinal direction (usually coincides with the flow direction) is in the range of 1.0 to 1.5 times the stretching ratio in the width direction. can do.
ここで製造するべき本発明の光学積層体の目標の正面レターデーションＲｅは、例えば延伸処理を同時二軸延伸で行う場合には、同時二軸延伸時の未延伸の積層体ｃの延伸温度を変えたり、縦延伸倍率と横延伸倍率の比率を変えたり、未延伸フィルムの設計変更（厚みや層比）を変更することで調整できる。 The target front retardation Re of the optical laminate of the present invention to be produced here is, for example, when the stretching treatment is performed by simultaneous biaxial stretching, the stretching temperature of the unstretched laminate c at the time of simultaneous biaxial stretching. It can be adjusted by changing, changing the ratio of the longitudinal draw ratio and the transverse draw ratio, or changing the design change (thickness or layer ratio) of the unstretched film.
配向角のプロファイルは、なるべくフラットに、即ち、例えば幅方向に遅相軸を発現させる場合には幅方向に対する配向角θの平均値が０°±１°、配向角θのバラツキが０．５°以下となるように、延伸条件（微延伸、熱固定温度、引取張力）で微調整することができる。
ここで、例えば同時二軸延伸装置で延伸処理を行なう場合には、微延伸とは同時二軸延伸装置のオーブン内で未延伸の積層体ｃを延伸終了前に少量延伸あるいは収縮させる（最終延伸倍率は変わらない）ことであり、熱固定温度とは同時二軸延伸装置のオーブン出口の外側近傍に配置される未延伸の積層体ｃを安定化させるための加熱区間の温度（延伸温度よりも低い温度）であり、引取張力とは同じくオーブン出口の外側近傍から未延伸の積層体ｃの巻取に至るまでの区間におけるフィルムの流れ方向に作用させる張力である。前記の微延伸は、同時二軸延伸装置のテンターのレールパターンを調整することにより可能である。また前記の熱固定温度は、（延伸温度−３０℃）以上、延伸温度未満の温度範囲内で設定できる。ボーイングが発生している場合には、通常、上記に示したような微延伸で調整するが、熱固定温度を上げるか、引取張力を下げることによっても調整可能である。また、同様に、逆ボーイングが発生している場合には、熱固定温度を下げるか、引取張力を上げることにより、配向角のプロファイルがフラットとなるように、微調整することが可能である。
The profile of the orientation angle is as flat as possible, that is, for example, when a slow axis is developed in the width direction, the average value of the orientation angle θ with respect to the width direction is 0 ° ± 1 °, and the variation of the orientation angle θ is 0.5. It can be finely adjusted by the stretching conditions (fine stretching, heat setting temperature, take-up tension) so as to be less than 0 °.
Here, for example, when the stretching process is performed by a simultaneous biaxial stretching apparatus, the fine stretching is a small stretch or shrinkage of the unstretched laminate c in the oven of the simultaneous biaxial stretching apparatus before the end of stretching (final stretching). The heat setting temperature is the temperature of the heating section for stabilizing the unstretched laminate c placed near the outside of the oven outlet of the simultaneous biaxial stretching apparatus (rather than the stretching temperature). Similarly, the take-up tension is a tension that acts in the film flow direction in the section from the vicinity of the outside of the oven outlet to the winding of the unstretched laminate c. The fine stretching can be performed by adjusting the rail pattern of the tenter of the simultaneous biaxial stretching apparatus. Moreover, the said heat setting temperature can be set within the temperature range more than (stretching temperature-30 degreeC) and below stretching temperature. When bowing occurs, adjustment is usually performed by fine stretching as described above, but it can also be adjusted by raising the heat setting temperature or lowering the take-up tension. Similarly, when reverse bowing has occurred, it is possible to finely adjust the orientation angle profile to be flat by lowering the heat setting temperature or increasing the take-up tension.
（３）本発明の光学積層体の製造方法に係るその他の事項
本発明の光学積層体の製造方法においては、本発明の光学積層体が得られる限り、上述した以外の処理を行うようにしてもよい。
上述した本発明の光学積層体の製造方法によれば、上述したように優れた利点を有する本発明の光学積層体を、低コストで安定的に製造できる。
(3) Other matters relating to the method for producing an optical laminate of the present invention In the method for producing an optical laminate of the present invention, as long as the optical laminate of the present invention is obtained, treatments other than those described above are performed. Also good.
According to the manufacturing method of the optical laminated body of this invention mentioned above, the optical laminated body of this invention which has the outstanding advantage as mentioned above can be manufactured stably at low cost.
〔４．光学積層体の用途等〕
本発明の光学積層体は、例えば位相差板等の光学フィルムとして好適に使用できる。
その用途の具体例を挙げると、本発明の光学積層体と偏光板とを積層することにより、液晶表示装置等に用いることができる光学素子が得られる。偏光板としては、例えば、二色性物質含有のポリビニルアルコール系偏光フィルム等からなる偏光子の片側又は両側に、適切な接着層を介して、保護層となる透明保護フィルムを接着したものを用いることができる。偏光子としては、例えばポリビニルアルコールや部分ホルマール化ポリビニルアルコール等の従来に準じた適宜なビニルアルコール系ポリマーよりなるフィルムに、ヨウ素や二色性染料等よりなる二色性物質による染色処理、延伸処理、架橋処理等の適宜な処理を適宜な順序や方式で施したもので、自然光を入射させると直線偏光を透過する適宜なものを用いることができる。中でも、偏光子としては光透過率や偏光度に優れるものが好ましい。偏光子の厚みは、５〜８０μｍが一般的であるが、これに限定されない。
[4. Applications of optical laminates etc.)
The optical layered body of the present invention can be suitably used as an optical film such as a retardation plate.
If the specific example of the use is given, the optical element which can be used for a liquid crystal display device etc. will be obtained by laminating | stacking the optical laminated body and polarizing plate of this invention. As the polarizing plate, for example, a polarizing plate made of a dichroic substance-containing polyvinyl alcohol polarizing film or the like having a transparent protective film as a protective layer adhered to one side or both sides of the polarizer is used. be able to. As a polarizer, for example, a film made of a suitable vinyl alcohol-based polymer according to the prior art such as polyvinyl alcohol or partially formalized polyvinyl alcohol, a dyeing treatment with a dichroic substance made of iodine or a dichroic dye, a stretching treatment In addition, an appropriate treatment such as a crosslinking treatment can be performed in an appropriate order and method, and an appropriate material that transmits linearly polarized light when natural light is incident can be used. Among these, a polarizer having excellent light transmittance and polarization degree is preferable. The thickness of the polarizer is generally 5 to 80 μm, but is not limited thereto.
偏光子の片側又は両側に設ける透明保護層となる保護フィルム素材としては、適宜な透明フィルムを用いることができる。中でも、透明性、機械的強度、熱安定性、水分遮蔽性等に優れるポリマーからなるフィルム等が好ましく用いられる。そのポリマーとしては、トリアセチルセルロースの如きアセテート樹脂、ポリエステル樹脂、ポリエーテルスルホン樹脂、ポリカーボネート樹脂、ポリアミド樹脂、ポリイミド樹脂、鎖状ポリオレフィン樹脂、脂環式オレフィン樹脂、アクリル樹脂、メタクリル樹脂等が挙げられる。中でも複屈折が小さい点で、アセテート樹脂及び脂環式オレフィン樹脂が好ましく、透明性、低吸湿性、寸法安定性、軽量性などの観点から、脂環式オレフィン樹脂が特に好ましい。透明保護フィルムの厚みは任意であるが、一般には偏光板の薄型化などを目的に、通常５００μｍ以下、好ましくは５〜３００μｍ、特に好ましくは５〜１５０μｍである。 An appropriate transparent film can be used as a protective film material to be a transparent protective layer provided on one side or both sides of the polarizer. Among them, a film made of a polymer excellent in transparency, mechanical strength, thermal stability, moisture shielding properties, etc. is preferably used. Examples of the polymer include acetate resin such as triacetyl cellulose, polyester resin, polyethersulfone resin, polycarbonate resin, polyamide resin, polyimide resin, chain polyolefin resin, alicyclic olefin resin, acrylic resin, and methacrylic resin. . Among them, acetate resin and alicyclic olefin resin are preferable from the viewpoint of low birefringence, and alicyclic olefin resin is particularly preferable from the viewpoint of transparency, low hygroscopicity, dimensional stability, light weight and the like. Although the thickness of a transparent protective film is arbitrary, generally it is 500 micrometers or less normally for the purpose of thickness reduction of a polarizing plate, etc., Preferably it is 5-300 micrometers, Most preferably, it is 5-150 micrometers.
本発明の光学積層体と偏光板との積層は、例えば、接着剤や粘着剤等の適切な接着手段を用いて貼り合わせることにより行うことができる。接着剤又は粘着剤としては、例えば、アクリル系、シリコーン系、ポリエステル系、ポリウレタン系、ポリエーテル系、ゴム系等のものが挙げられる。これらの中でも、耐熱性や透明性等の観点から、アクリル系のものが好ましい。本発明の光学積層体と偏光板とは、通常、本発明の光学積層体の遅相軸と偏光子の透過軸とが、平行若しくは直交するように積層する。積層方法としては、公知の方法が挙げられ、例えば、本発明の光学積層体及び偏光板をそれぞれ所望の大きさに切り出して積層する方法、長尺状の本発明の光学積層体及び長尺状の偏光板をロールトゥロール法で積層する方法、などが挙げられる。この場合、本発明の光学積層体が偏光板の透明保護フィルムを兼ねることができ、素子の薄型化が可能である。この光学素子の厚みは、通常１００〜７００μｍ、好ましくは２００〜６００μｍである。 Lamination of the optical layered body of the present invention and a polarizing plate can be performed, for example, by bonding using an appropriate bonding means such as an adhesive or a pressure-sensitive adhesive. Examples of the adhesive or pressure-sensitive adhesive include acrylics, silicones, polyesters, polyurethanes, polyethers, and rubbers. Among these, an acrylic type is preferable from the viewpoint of heat resistance and transparency. The optical laminate of the present invention and the polarizing plate are usually laminated so that the slow axis of the optical laminate of the present invention and the transmission axis of the polarizer are parallel or orthogonal. Examples of the laminating method include known methods, for example, a method of cutting out and laminating the optical laminate and the polarizing plate of the present invention into respective desired sizes, a long optical laminate of the present invention, and a long shape. The method of laminating | stacking this polarizing plate by the roll toe roll method, etc. are mentioned. In this case, the optical layered body of the present invention can also serve as a transparent protective film for the polarizing plate, and the device can be thinned. The thickness of this optical element is usually 100 to 700 μm, preferably 200 to 600 μm.
上述した本発明の光学積層体を備える光学フィルム（位相差板等）を、少なくとも１枚用いて液晶表示装置を得ることができる。光学フィルムを液晶表示装置に組み込む態様としては、例えば、偏光板と液晶セルとの間に光学フィルムを配置する態様、偏光板の液晶セルとは反対側に光学フィルムを配置する態様などが挙げられる。前記偏光板と液晶セルとの間に光学フィルムを備える態様においては、上述した光学フィルムと偏光板からなる光学素子を液晶セルに配置することも可能である。 A liquid crystal display device can be obtained by using at least one optical film (a retardation plate or the like) provided with the optical laminate of the present invention described above. As an aspect which incorporates an optical film in a liquid crystal display device, the aspect which arrange | positions an optical film between a polarizing plate and a liquid crystal cell, the aspect which arrange | positions an optical film on the opposite side to the liquid crystal cell of a polarizing plate, etc. are mentioned, for example. . In an embodiment in which an optical film is provided between the polarizing plate and the liquid crystal cell, the optical element composed of the optical film and the polarizing plate described above can be disposed in the liquid crystal cell.
液晶表示装置は、偏光板を液晶セルの片側又は両側に配置してなる透過型や反射型、あるいは透過・反射両用型等の従来に準じた適宜な構造を有するものとして形成することができる。液晶セルに使用する液晶モードとしては、インプレーンスイッチング（ＩＰＳ）方式、バーチカルアラインメント（ＶＡ）方式、マルチドメインバーチカルアラインメント（ＭＶＡ）方式、コンティニュアスピンホイールアラインメント（ＣＰＡ）方式、ツイステッドネマチック（ＴＮ）方式、スーパーツイステッドネマチック（ＳＴＮ）方式、ハイブリッドアラインメントネマチック（ＨＡＮ）方式、オプチカルコンペンセイテッドベンド（ＯＣＢ）方式などを挙げることができる。これらの中で、ＩＰＳ方式に特に好適に適用することができる。 The liquid crystal display device can be formed to have a suitable structure according to the prior art, such as a transmissive type, a reflective type, or a transmissive / reflective type in which polarizing plates are arranged on one side or both sides of a liquid crystal cell. The liquid crystal mode used in the liquid crystal cell includes an in-plane switching (IPS) method, a vertical alignment (VA) method, a multi-domain vertical alignment (MVA) method, a continuous spin wheel alignment (CPA) method, and a twisted nematic (TN) method. , Super twisted nematic (STN) system, hybrid alignment nematic (HAN) system, optical compensated bend (OCB) system, and the like. Among these, it can be particularly preferably applied to the IPS system.
ＩＰＳ方式では、水平方向にホモジニアスな配向をした液晶分子と、透過軸が画面正面に対して上下と左右の方向を指して垂直の位置関係にある２枚の偏光子を用いているので、上下左右の方向から画面を斜めに見るときには、２本の透過軸は直交して見える位置関係にあり、ホモジニアス配向液晶層はツイステッド方式の液晶層で生ずるような複屈折も少ないことから、十分なコントラストが得られる。 The IPS system uses liquid crystal molecules that are homogeneously aligned in the horizontal direction and two polarizers whose transmission axes point vertically and horizontally with respect to the front of the screen. When the screen is viewed obliquely from the left and right directions, the two transmission axes are in a positional relationship that they appear to be orthogonal, and the homogeneously aligned liquid crystal layer has little birefringence that occurs in a twisted liquid crystal layer, so sufficient contrast Is obtained.
これに対して、方位角４５°の方向から画面を斜めに見るときには、２枚の偏光子の透過軸のなす角度が９０°からずれる位置関係となるために、直線偏光が完全に遮断されずに光洩れが発生し、十分な黒が得られず、コントラストが低下する傾向がある。これに対し、ＩＰＳ方式の液晶表示装置の２枚の偏光子の間に、上述した本発明の光学積層体を備える光学フィルムを配置することにより、液晶セル中の液晶により生じる位相差の補償と２枚の偏光子の透過軸の直交配置の補償を行うことができる。これによって、透過光に生ずる複屈折を効果的に補償して光の洩れを防ぎ、全方位角において高いコントラストを得ることが可能である。この効果は、他の方式の液晶表示装置においても同様の効果があると考えられるが、特に前記ＩＰＳ方式において効果が顕著である。 On the other hand, when the screen is viewed obliquely from the direction of the azimuth angle of 45 °, the angle between the transmission axes of the two polarizers is shifted from 90 °, so that linearly polarized light is not completely blocked. There is a tendency for light leakage to occur and sufficient black cannot be obtained, resulting in a decrease in contrast. On the other hand, by arranging an optical film including the above-described optical laminate of the present invention between two polarizers of an IPS liquid crystal display device, compensation of a phase difference caused by liquid crystal in a liquid crystal cell can be achieved. Compensation of the orthogonal arrangement of the transmission axes of the two polarizers can be performed. Accordingly, it is possible to effectively compensate for the birefringence generated in the transmitted light to prevent light leakage and to obtain a high contrast in all azimuth angles. This effect is considered to be the same in other types of liquid crystal display devices, but the effect is particularly remarkable in the IPS mode.
液晶表示装置は、上述した以外の構成要素を備えるようにしてもよい。例えば、プリズムアレイシート、レンズアレイシート、光拡散板、バックライト、輝度向上フィルム等の部品を、適切な位置に、１層又は２層以上配置することができる。 The liquid crystal display device may include components other than those described above. For example, components such as a prism array sheet, a lens array sheet, a light diffusion plate, a backlight, and a brightness enhancement film can be arranged in one or more layers at appropriate positions.
以下、実施例を示して本発明について具体的に説明するが、本発明は以下に示す実施例に限定されるものではなく、本発明の要旨及びその均等の範囲を逸脱しない範囲において任意に変更して実施できる。 EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to the examples shown below, and may be arbitrarily changed without departing from the gist of the present invention and its equivalent scope. Can be implemented.
〔測定方法の説明〕
（１）フィルムの厚みの測定（μｍ）
積層フィルム（未延伸の積層体又は延伸後の光学積層体）をエポキシ樹脂に包埋したのち、ミクロトーム［大和光機工業（株）、ＲＵＢ−２１００］を用いて０．０５μｍ厚にスライスし、透過型電子顕微鏡を用いて断面を観察し、各層の厚み、及び全体の厚み（総厚）を測定した。この測定を流れ方向に１００ｍｍ間隔で、長さ１０００ｍｍに亘って行った。そして、各層の厚み、全体の厚みそれぞれについて、全測定結果の平均値を算出した。
[Explanation of measurement method]
(1) Measurement of film thickness (μm)
After embedding a laminated film (an unstretched laminate or an optical laminate after stretching) in an epoxy resin, it is sliced to a thickness of 0.05 μm using a microtome [Daiwa Koki Kogyo Co., Ltd., RUB-2100], The cross section was observed using a transmission electron microscope, and the thickness of each layer and the total thickness (total thickness) were measured. This measurement was performed over a length of 1000 mm at intervals of 100 mm in the flow direction. And the average value of all the measurement results was computed about the thickness of each layer, and each thickness of the whole.
（２）光学積層体の配向角θのバラツキ（°）及び正面レターデーションＲｅのバラツキ（ｎｍ）の測定
オンライン位相差計（王子計測機器社製：ＫＯＢＲＡ−ＷＩＳＴ／２ＲＴ）を用い、１５０ｍｍ／秒の速度で搬送される長尺の光学積層体の、配向角（光学積層体の幅方向と遅相軸方向とがなす角）θと、正面レターデーションＲｅとを、波長５９０ｎｍにおいて、光学積層体の幅方向２５ｍｍ間隔で、フィルム幅方向に２０回測定した。ここで、光学積層体の評価幅は、１４９０ｍｍとした。測定結果から、配向角θの最大値と最小値の差を配向角θのバラツキとした。また、正面レターデーションＲｅの最大値と最小値の差を正面レターデーションＲｅのバラツキとした。
(2) Measurement of variation in orientation angle θ (°) and variation in front retardation Re (nm) of optical laminated body 150 mm / sec using on-line phase difference meter (manufactured by Oji Scientific Instruments: KOBRA-WIST / 2RT) Of the long optical laminate that is conveyed at a speed of 5 °, the orientation angle (angle formed by the width direction of the optical laminate and the slow axis direction) θ, and the front retardation Re at a wavelength of 590 nm. The film was measured 20 times in the film width direction at intervals of 25 mm. Here, the evaluation width of the optical laminated body was 1490 mm. From the measurement results, the difference between the maximum value and the minimum value of the orientation angle θ was defined as the variation of the orientation angle θ. Further, the difference between the maximum value and the minimum value of the front retardation Re was defined as the variation of the front retardation Re.
（３）光学積層体のＡ層及びＢ層の正面レターデーションの測定
光学積層体のＡ層及びＢ層の正面レターデーションＲｅ（Ａ）及びＲｅ（Ｂ）を、光学積層体を各層に分離したのち、自動複屈折［王子計測機器（株）、ＫＯＢＲＡ−ＡＤＨ２１］を用いて波長５９０ｎｍで各層の幅方向に対し、中央部及び両端部から１０ｍｍの３点で測定し、その平均値を測定値とする。ただし、Ｂ層が複数層ある場合におけるＢ層の正面レターデーションは各Ｂ層の絶対値の合計値である。
(3) Measurement of front retardation of A layer and B layer of optical laminate The front retardations Re (A) and Re (B) of A layer and B layer of the optical laminate were separated into each layer. After that, using automatic birefringence [Oji Scientific Instruments Co., Ltd., KOBRA-ADH21], measured at three points of 10 mm from the center and both ends with respect to the width direction of each layer at a wavelength of 590 nm, and the average value was measured. And However, when there are a plurality of B layers, the front retardation of the B layer is the sum of the absolute values of the B layers.
（４）光学積層体のＮｚ係数の測定
光学積層体のＮｚ係数は、自動複屈折計［王子計測機器（株）、ＫＯＢＲＡ−ＡＤＨ２１］を用いて、波長５９０ｎｍで、光学積層体の幅方向に一定間隔（例えば、１００ｍｍ間隔）で測定を行う。この測定を光学積層体の流れ方向に一定間隔（例えば、１００ｍｍ間隔）で所定の長さ（例えば、１０００ｍｍ）にわたって行ない、全測定結果の平均値をＮｚ係数とする。
(4) Measurement of the Nz coefficient of the optical laminate The Nz coefficient of the optical laminate is measured in the width direction of the optical laminate at a wavelength of 590 nm using an automatic birefringence meter [Oji Scientific Instruments, KOBRA-ADH21]. Measurements are made at regular intervals (eg, 100 mm intervals). This measurement is performed over a predetermined length (for example, 1000 mm) at regular intervals (for example, 100 mm) in the flow direction of the optical laminate, and the average value of all measurement results is defined as the Nz coefficient.
（５）連続搬送性の評価
延伸装置内で長尺の光学積層体を実際に搬送し、破断、しわの発生の有無及びその程度を調べた。その結果、定常状態２０分間においては破断、しわの無いものを「良好」とし、定常状態２０分間においては破断、しわの発生したものを「不良」とした。
判断が困難な場合には、光学積層体から長手方向３００ｍｍ、幅方向３００ｍｍの正方形の試験片を切り出し、一辺の幅方向の中心位置に１０ｍｍのノッチをカッターで入れ、そこから手で引き裂いて評価する。その結果、途中で引っ掛かりがあり、引き裂きにくい場合を「良好」とし、サンプルが一直線に端まで裂けてしまう場合を「不良」とした。
(5) Evaluation of continuous transportability A long optical laminate was actually transported in a stretching apparatus, and the presence or absence of breakage and wrinkles and the degree thereof were examined. As a result, in the steady state for 20 minutes, no fracture or wrinkle was defined as “good”, and in the steady state for 20 minutes, fracture or wrinkle was defined as “defective”.
When it is difficult to judge, a square test piece of 300 mm in the longitudinal direction and 300 mm in the width direction is cut out from the optical laminate, and a 10 mm notch is put in the center position in the width direction of one side with a cutter, and then it is torn by hand from there. To do. As a result, a case where there was a catch on the way and it was difficult to tear was judged as “good”, and a case where the sample was torn to the end in a straight line was judged as “bad”.
（６）パネル反り評価
トリアセチルセルロースからなるＴＡＣ層（厚み４０μｍ、富士写真フィルム社製、品名フジタック）と、ポリビニルアルコールからなるＰＶＡフィルム（厚み３０μｍ、クラレ社製、品名クラレビニロンフィルム）と、ノルボルネン樹脂からなるゼオノアフィルム（厚み３７μｍ、日本ゼオン社製）と、本実施例もしくは比較例で得られる光学積層体とを、接着剤としてアクリル接着剤を用いてこの順で貼り合わせてフロントフィルムを用意した。
(6) Panel warpage evaluation TAC layer (thickness 40 μm, manufactured by Fuji Photo Film Co., Ltd., product name Fujitac) made of triacetyl cellulose, PVA film (thickness 30 μm, manufactured by Kuraray Co., Ltd., product name Kuraray Vinylon film) and norbornene A front film is prepared by laminating a ZEONOR film (thickness 37 μm, manufactured by Nippon Zeon Co., Ltd.) made of resin and the optical laminate obtained in this example or comparative example in this order using an acrylic adhesive as an adhesive. did.
また、アクリル樹脂からなる低レターデーションフィルム（厚み６０μｍ）と、ポリビニルアルコールからなるＰＶＡフィルム（厚み３０μｍ、クラレ社製、品名クラレビニロンフィルム）と、トリアセチルセルロースからなるＴＡＣフィルム（厚み４０μｍ、富士写真フィルム社製、品名フジタック）とを、接着剤としてアクリル接着剤を用いてこの順で貼り合わせて、厚み１６５μｍのリアフィルムを用意した。 Also, a low retardation film (thickness 60 μm) made of acrylic resin, a PVA film (thickness 30 μm, manufactured by Kuraray Co., Ltd., Kuraray Vinylon film) made of polyvinyl alcohol, and a TAC film (thickness 40 μm, Fuji Photo) made of triacetyl cellulose. Film Co., Ltd., product name Fujitac) was bonded together in this order using an acrylic adhesive as an adhesive to prepare a rear film having a thickness of 165 μm.
接着剤としてアクリル接着剤を用いて、前記のフロントフィルムとＩＰＳモードの液晶セル（ＩＰＳ液晶セル）とを貼り合わせた。この際、フロントフィルムは前記光学積層体側の面でＩＰＳ液晶セルに貼り合わせるようにした。
その後、ＩＰＳ液晶セルのフロントフィルムとは反対側の面に、前記のリアフィルムを前記の接着剤を用いて貼り合わせた。この際、リアフィルムは低レターデーションフィルム側の面でＩＰＳ液晶セルに貼り合わせるようにした。
このようにして用意したパネルを、温度６０℃、湿度９０％ＲＨの環境下に５００時間置き、反りの発生の有無を評価した。
The front film and an IPS mode liquid crystal cell (IPS liquid crystal cell) were bonded together using an acrylic adhesive as an adhesive. At this time, the front film was bonded to the IPS liquid crystal cell on the surface of the optical laminate.
Then, the said rear film was bonded together on the surface on the opposite side to the front film of an IPS liquid crystal cell using the said adhesive agent. At this time, the rear film was bonded to the IPS liquid crystal cell on the surface of the low retardation film side.
The panel thus prepared was placed in an environment of a temperature of 60 ° C. and a humidity of 90% RH for 500 hours, and the presence or absence of warpage was evaluated.
〔実施例１〕
固有複屈折値が負の樹脂であるスチレン−無水マレイン酸共重合体樹脂（ノヴァケミカルジャパン社製、品名ダイラークＤ３３２）からなるａ層と、ゴム粒子を含むメタクリル樹脂組成物からなるｂ層とを、ｂ層／ａ層／ｂ層の順に有する未延伸の積層体ｃを、前記の樹脂を共押出成形することにより用意した。この際、２つあるｂ層は、いずれも同じ厚みにした。
得られた未延伸の積層体ｃの各層の平均厚みを測定した。結果を表１に示す。
[Example 1]
A layer composed of a styrene-maleic anhydride copolymer resin (product name: Dirac D332, manufactured by Nova Chemical Japan), which is a resin having a negative intrinsic birefringence value, and a layer b composed of a methacrylic resin composition containing rubber particles. The unstretched laminate c having the order of b layer / a layer / b layer was prepared by coextrusion molding of the resin. At this time, both of the two b layers had the same thickness.
The average thickness of each layer of the obtained unstretched laminate c was measured. The results are shown in Table 1.
得られた未延伸の積層体ｃを、表１に示す延伸温度及び延伸倍率で、ＭＤ方向（流れ方向）及びＴＤ方向（幅方向）に同時二軸延伸し、光学積層体を得た。得られた光学積層体について、上述した要領で、各層の平均厚み及びその総厚、配向角θのバラツキ、正面レターデーションＲｅのバラツキ、Ａ層及びＢ層それぞれの正面レターデーションＲｅ（Ａ）及びＲｅ（Ｂ）、並びにＮｚ係数を測定し、連続搬送性及びパネル反りの評価を行なった。結果を表１に示す。 The obtained unstretched laminate c was biaxially stretched in the MD direction (flow direction) and the TD direction (width direction) at the stretching temperature and stretch ratio shown in Table 1 to obtain an optical laminate. For the obtained optical laminate, in the manner described above, the average thickness and total thickness of each layer, variation in orientation angle θ, variation in front retardation Re, front retardation Re (A) of each of A layer and B layer, and Re (B) and the Nz coefficient were measured, and the continuous transportability and panel warpage were evaluated. The results are shown in Table 1.
〔実施例２，３及び比較例１，２〕
未延伸の積層体ｃにおけるａ層及びｂ層の厚み、並びに未延伸の積層体ｃのＭＤ方向及びＴＤ方向の延伸倍率を表１に示すようにしたこと以外は実施例１と同様にして、光学積層体を得た。得られた光学積層体について、上述した要領で、各層の厚み及び総厚、配向角θのバラツキ、正面レターデーションＲｅのバラツキ、Ａ層及びＢ層それぞれの正面レターデーションＲｅ（Ａ）及びＲｅ（Ｂ）、並びにＮｚ係数を測定し、連続搬送性及びパネル反りの評価を行なった。結果を表１に示す。
[Examples 2 and 3 and Comparative Examples 1 and 2]
In the same manner as in Example 1, except that the thickness of the a layer and the b layer in the unstretched laminate c, and the stretch ratio in the MD direction and TD direction of the unstretched laminate c are shown in Table 1, An optical laminate was obtained. About the obtained optical layered body, in the manner described above, the thickness and total thickness of each layer, variation in orientation angle θ, variation in front retardation Re, front retardation Re (A) and Re ( B) and the Nz coefficient were measured, and the continuous transportability and panel warpage were evaluated. The results are shown in Table 1.
〔結果〕
上述した実施例及び比較例の結果を表１に示す。
〔result〕
Table 1 shows the results of the above-described Examples and Comparative Examples.
表１から分かるように、前記の実施例では、厚みが薄く、耐久性及び光学均一性の両方に優れる光学積層体が得られている。これに対し、比較例１，２ではいずれも光学均一性は良好であるものの、比較例１ではパネル反りが生じ、比較例２では連続搬送時に破断、しわが発生している。実施例１〜３と比較例１との比較から、実施例では光学積層体の総厚が薄いいためにパネル反りが生じていないことが分かる。また、実施例１〜３と比較例２との比較から、実施例では総延伸倍率を大きくしたために強度が向上し、ハンドリング性が向上していることが分かる。 As can be seen from Table 1, in the above examples, an optical laminate having a small thickness and excellent in both durability and optical uniformity is obtained. On the other hand, in both Comparative Examples 1 and 2, the optical uniformity is good, but in Comparative Example 1, panel warpage occurs, and in Comparative Example 2, breakage and wrinkle occur during continuous conveyance. From comparison between Examples 1 to 3 and Comparative Example 1, it can be seen that panel warpage does not occur in the example because the total thickness of the optical laminate is thin. Further, from comparison between Examples 1 to 3 and Comparative Example 2, it can be seen that in the examples, the total stretch ratio was increased, so that the strength was improved and the handling property was improved.
本発明の光学積層体は光学フィルムとして有用であり、特に液晶表示装置の光学補償手段に適している。 The optical layered body of the present invention is useful as an optical film, and is particularly suitable for an optical compensation means of a liquid crystal display device.
Claims (2)
｜前記Ａ層の正面レターデーション｜＞｜前記Ｂ層の正面レターデーション｜であり、
前記Ａ層及び前記Ｂ層の総厚が２５μｍ以上６０μｍ以下であり、
前記Ａ層及び前記Ｂ層の総厚に対する前記Ａ層の厚みの割合が４０％以上８０％未満であり、
総延伸倍率が２．３倍以上４．７倍以下の延伸処理を経て得られる、光学積層体。 An optical laminate including an A layer made of a resin A having a negative intrinsic birefringence value and a B layer made of a transparent resin B,
| Front retardation of the A layer |> | Front retardation of the B layer |
The total thickness of the A layer and the B layer is 25 μm or more and 60 μm or less,
The ratio of the thickness of the A layer to the total thickness of the A layer and the B layer is 40% or more and less than 80%,
An optical layered body obtained through a stretching treatment in which the total stretching ratio is 2.3 times or more and 4.7 times or less.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2009230245A JP5869198B2 (en) | 2009-10-02 | 2009-10-02 | Optical laminate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2009230245A JP5869198B2 (en) | 2009-10-02 | 2009-10-02 | Optical laminate |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2014140280A Division JP5935838B2 (en) | 2014-07-08 | 2014-07-08 | Optical laminate |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2011076026A true JP2011076026A (en) | 2011-04-14 |
| JP5869198B2 JP5869198B2 (en) | 2016-02-24 |
Family
ID=44020047
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2009230245A Active JP5869198B2 (en) | 2009-10-02 | 2009-10-02 | Optical laminate |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP5869198B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11150503B2 (en) | 2015-12-17 | 2021-10-19 | Zeon Corporation | Liquid crystal display device |
| WO2021251355A1 (en) * | 2020-06-10 | 2021-12-16 | 株式会社クラレ | Liquid crystal display protection plate, liquid crystal display protection plate with curved surface, and methods for manufacturing same |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2005019883A1 (en) * | 2003-08-26 | 2005-03-03 | Zeon Corporation | Optically laminated material and manufacturing method thereof |
| JP2005274725A (en) * | 2004-03-23 | 2005-10-06 | Nippon Zeon Co Ltd | Optical laminate, optical element, and liquid crystal display device |
| JP2009192845A (en) * | 2008-02-14 | 2009-08-27 | Nippon Zeon Co Ltd | Method of manufacturing retardation plate |
-
2009
- 2009-10-02 JP JP2009230245A patent/JP5869198B2/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2005019883A1 (en) * | 2003-08-26 | 2005-03-03 | Zeon Corporation | Optically laminated material and manufacturing method thereof |
| JP2005274725A (en) * | 2004-03-23 | 2005-10-06 | Nippon Zeon Co Ltd | Optical laminate, optical element, and liquid crystal display device |
| JP2009192845A (en) * | 2008-02-14 | 2009-08-27 | Nippon Zeon Co Ltd | Method of manufacturing retardation plate |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11150503B2 (en) | 2015-12-17 | 2021-10-19 | Zeon Corporation | Liquid crystal display device |
| WO2021251355A1 (en) * | 2020-06-10 | 2021-12-16 | 株式会社クラレ | Liquid crystal display protection plate, liquid crystal display protection plate with curved surface, and methods for manufacturing same |
Also Published As
| Publication number | Publication date |
|---|---|
| JP5869198B2 (en) | 2016-02-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7964254B2 (en) | Optical laminate, optical element and liquid crystal display device | |
| JP5316421B2 (en) | Stretched film, method for producing the same, and liquid crystal display device | |
| KR101811290B1 (en) | Phase difference film layered body, and method for producing phase difference film layered body | |
| KR101786618B1 (en) | Multilayered film and method of manufacturing multilayered film | |
| JP5585747B1 (en) | Laminated retardation film and method for producing the same | |
| US20170097544A1 (en) | Optical film, polarizing plate and liquid crystal display device | |
| JP2006517684A (en) | Compensator for liquid crystal display | |
| KR20090029537A (en) | An optical anisotropic film with high heat resistance and a liquid crystal display device comprising the same | |
| JP7188386B2 (en) | Method for manufacturing polarizing plate and display device | |
| JPWO2017010368A1 (en) | Viewing angle widening film, polarizing plate, and liquid crystal display device | |
| JP5869198B2 (en) | Optical laminate | |
| JP4433854B2 (en) | Optical laminated body with improved viewing angle characteristics, optical element using the optical laminated body, and liquid crystal display device | |
| JP2012150462A (en) | Phase difference film and method for manufacturing phase difference film | |
| JP2010266723A (en) | Method of manufacturing retardation film, retardation film, circularly polarized film, circularly polarized plate, and liquid crystal display device | |
| JP6131620B2 (en) | Laminated retardation film and method for producing laminated retardation film | |
| JP2010204224A (en) | Polarizing plate, method of manufacturing the same, and liquid crystal display device | |
| JP5935838B2 (en) | Optical laminate | |
| JP4935878B2 (en) | Optical laminate manufacturing method, optical element, and liquid crystal display device | |
| KR20140138689A (en) | Retarder manufacturing method | |
| JP4935873B2 (en) | OPTICAL LAMINATE, OPTICAL ELEMENT, LIQUID CRYSTAL DISPLAY DEVICE, AND METHOD FOR PRODUCING OPTICAL LAMINATE | |
| JP6330367B2 (en) | Method for producing optical laminate | |
| JP6251959B2 (en) | Method for producing retardation film | |
| JP2012073646A (en) | Manufacturing method of retardation plate | |
| JP2007098685A (en) | Method for forming multilayer film | |
| CN115113317A (en) | Optical laminate, method for producing same, and image display device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20120926 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20130723 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20130806 |
|
| A601 | Written request for extension of time |
Free format text: JAPANESE INTERMEDIATE CODE: A601 Effective date: 20131001 |
|
| A602 | Written permission of extension of time |
Free format text: JAPANESE INTERMEDIATE CODE: A602 Effective date: 20131004 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20131025 |
|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20140408 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20140708 |
|
| A911 | Transfer to examiner for re-examination before appeal (zenchi) |
Free format text: JAPANESE INTERMEDIATE CODE: A911 Effective date: 20140715 |
|
| A912 | Re-examination (zenchi) completed and case transferred to appeal board |
Free format text: JAPANESE INTERMEDIATE CODE: A912 Effective date: 20140808 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20150924 |
|
| R155 | Notification before disposition of declining of application |
Free format text: JAPANESE INTERMEDIATE CODE: R155 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20160107 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 5869198 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |