CN116710819A - Method for manufacturing polarizing film - Google Patents
Method for manufacturing polarizing film Download PDFInfo
- Publication number
- CN116710819A CN116710819A CN202180091354.XA CN202180091354A CN116710819A CN 116710819 A CN116710819 A CN 116710819A CN 202180091354 A CN202180091354 A CN 202180091354A CN 116710819 A CN116710819 A CN 116710819A
- Authority
- CN
- China
- Prior art keywords
- film
- stretching
- pva
- laminate
- treatment
- 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.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 40
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 26
- 229920005989 resin Polymers 0.000 claims abstract description 152
- 239000011347 resin Substances 0.000 claims abstract description 152
- 239000004372 Polyvinyl alcohol Substances 0.000 claims abstract description 150
- 229920002451 polyvinyl alcohol Polymers 0.000 claims abstract description 150
- 238000011282 treatment Methods 0.000 claims abstract description 98
- 238000004043 dyeing Methods 0.000 claims abstract description 54
- 238000002834 transmittance Methods 0.000 claims abstract description 51
- 239000003125 aqueous solvent Substances 0.000 claims abstract description 36
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 87
- 229920005992 thermoplastic resin Polymers 0.000 claims description 68
- 239000000758 substrate Substances 0.000 claims description 43
- 238000001035 drying Methods 0.000 claims description 28
- 150000004820 halides Chemical class 0.000 claims description 17
- 238000004378 air conditioning Methods 0.000 claims 2
- 239000010410 layer Substances 0.000 description 64
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 description 42
- 239000004327 boric acid Substances 0.000 description 42
- 239000000463 material Substances 0.000 description 38
- 239000011241 protective layer Substances 0.000 description 37
- NLKNQRATVPKPDG-UHFFFAOYSA-M potassium iodide Chemical compound [K+].[I-] NLKNQRATVPKPDG-UHFFFAOYSA-M 0.000 description 36
- 239000007788 liquid Substances 0.000 description 28
- ZCYVEMRRCGMTRW-UHFFFAOYSA-N 7553-56-2 Chemical compound [I] ZCYVEMRRCGMTRW-UHFFFAOYSA-N 0.000 description 27
- 238000010438 heat treatment Methods 0.000 description 27
- 229910052740 iodine Inorganic materials 0.000 description 27
- 239000011630 iodine Substances 0.000 description 27
- 239000000243 solution Substances 0.000 description 24
- 230000003287 optical effect Effects 0.000 description 22
- 238000000576 coating method Methods 0.000 description 20
- 239000011248 coating agent Substances 0.000 description 18
- 238000002425 crystallisation Methods 0.000 description 17
- 230000008025 crystallization Effects 0.000 description 17
- 238000005401 electroluminescence Methods 0.000 description 13
- XMBWDFGMSWQBCA-UHFFFAOYSA-N hydrogen iodide Chemical compound I XMBWDFGMSWQBCA-UHFFFAOYSA-N 0.000 description 12
- 230000010287 polarization Effects 0.000 description 11
- 238000010521 absorption reaction Methods 0.000 description 10
- 239000007864 aqueous solution Substances 0.000 description 10
- 238000004132 cross linking Methods 0.000 description 9
- 230000009477 glass transition Effects 0.000 description 9
- 238000005259 measurement Methods 0.000 description 9
- -1 polyethylene terephthalate Polymers 0.000 description 9
- QQVIHTHCMHWDBS-UHFFFAOYSA-N isophthalic acid Chemical compound OC(=O)C1=CC=CC(C(O)=O)=C1 QQVIHTHCMHWDBS-UHFFFAOYSA-N 0.000 description 8
- 239000000178 monomer Substances 0.000 description 8
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical group OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 7
- 229920000139 polyethylene terephthalate Polymers 0.000 description 7
- 239000005020 polyethylene terephthalate Substances 0.000 description 7
- 230000008569 process Effects 0.000 description 7
- FVAUCKIRQBBSSJ-UHFFFAOYSA-M sodium iodide Chemical compound [Na+].[I-] FVAUCKIRQBBSSJ-UHFFFAOYSA-M 0.000 description 6
- 239000002904 solvent Substances 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 5
- 150000001925 cycloalkenes Chemical class 0.000 description 5
- 238000004090 dissolution Methods 0.000 description 5
- 238000002156 mixing Methods 0.000 description 5
- 238000007127 saponification reaction Methods 0.000 description 5
- 238000005406 washing Methods 0.000 description 5
- VZSRBBMJRBPUNF-UHFFFAOYSA-N 2-(2,3-dihydro-1H-inden-2-ylamino)-N-[3-oxo-3-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)propyl]pyrimidine-5-carboxamide Chemical compound C1C(CC2=CC=CC=C12)NC1=NC=C(C=N1)C(=O)NCCC(N1CC2=C(CC1)NN=N2)=O VZSRBBMJRBPUNF-UHFFFAOYSA-N 0.000 description 4
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 4
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 4
- 230000008859 change Effects 0.000 description 4
- 239000000470 constituent Substances 0.000 description 4
- 239000004973 liquid crystal related substance Substances 0.000 description 4
- HSZCZNFXUDYRKD-UHFFFAOYSA-M lithium iodide Chemical compound [Li+].[I-] HSZCZNFXUDYRKD-UHFFFAOYSA-M 0.000 description 4
- 230000002093 peripheral effect Effects 0.000 description 4
- 238000006116 polymerization reaction Methods 0.000 description 4
- 239000002356 single layer Substances 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- 238000000870 ultraviolet spectroscopy Methods 0.000 description 4
- 230000037303 wrinkles Effects 0.000 description 4
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 3
- 230000035614 depigmentation Effects 0.000 description 3
- MTHSVFCYNBDYFN-UHFFFAOYSA-N diethylene glycol Chemical compound OCCOCCO MTHSVFCYNBDYFN-UHFFFAOYSA-N 0.000 description 3
- 238000007602 hot air drying Methods 0.000 description 3
- 238000007654 immersion Methods 0.000 description 3
- 239000004014 plasticizer Substances 0.000 description 3
- 238000005507 spraying Methods 0.000 description 3
- 229920008790 Amorphous Polyethylene terephthalate Polymers 0.000 description 2
- BTBUEUYNUDRHOZ-UHFFFAOYSA-N Borate Chemical compound [O-]B([O-])[O-] BTBUEUYNUDRHOZ-UHFFFAOYSA-N 0.000 description 2
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N Dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 description 2
- 229920000219 Ethylene vinyl alcohol Polymers 0.000 description 2
- DKNPRRRKHAEUMW-UHFFFAOYSA-N Iodine aqueous Chemical compound [K+].I[I-]I DKNPRRRKHAEUMW-UHFFFAOYSA-N 0.000 description 2
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 2
- 239000004820 Pressure-sensitive adhesive Substances 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- NIXOWILDQLNWCW-UHFFFAOYSA-N acrylic acid group Chemical group C(C=C)(=O)O NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 2
- 239000000654 additive Substances 0.000 description 2
- 239000012790 adhesive layer Substances 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 229920001577 copolymer Polymers 0.000 description 2
- 238000003851 corona treatment Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 150000002009 diols Chemical class 0.000 description 2
- 238000010828 elution Methods 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 235000011187 glycerol Nutrition 0.000 description 2
- LEQAOMBKQFMDFZ-UHFFFAOYSA-N glyoxal Chemical compound O=CC=O LEQAOMBKQFMDFZ-UHFFFAOYSA-N 0.000 description 2
- 150000004694 iodide salts Chemical class 0.000 description 2
- 239000002346 layers by function Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- JFNLZVQOOSMTJK-KNVOCYPGSA-N norbornene Chemical compound C1[C@@H]2CC[C@H]1C=C2 JFNLZVQOOSMTJK-KNVOCYPGSA-N 0.000 description 2
- 239000003960 organic solvent Substances 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 229920005862 polyol Polymers 0.000 description 2
- 150000003077 polyols Chemical class 0.000 description 2
- BDERNNFJNOPAEC-UHFFFAOYSA-N propan-1-ol Chemical compound CCCO BDERNNFJNOPAEC-UHFFFAOYSA-N 0.000 description 2
- 238000002310 reflectometry Methods 0.000 description 2
- 230000035945 sensitivity Effects 0.000 description 2
- 235000009518 sodium iodide Nutrition 0.000 description 2
- 239000004094 surface-active agent Substances 0.000 description 2
- UAYWVJHJZHQCIE-UHFFFAOYSA-L zinc iodide Chemical compound I[Zn]I UAYWVJHJZHQCIE-UHFFFAOYSA-L 0.000 description 2
- UNMYWSMUMWPJLR-UHFFFAOYSA-L Calcium iodide Chemical compound [Ca+2].[I-].[I-] UNMYWSMUMWPJLR-UHFFFAOYSA-L 0.000 description 1
- RPNUMPOLZDHAAY-UHFFFAOYSA-N Diethylenetriamine Chemical compound NCCNCCN RPNUMPOLZDHAAY-UHFFFAOYSA-N 0.000 description 1
- PIICEJLVQHRZGT-UHFFFAOYSA-N Ethylenediamine Chemical compound NCCN PIICEJLVQHRZGT-UHFFFAOYSA-N 0.000 description 1
- 238000005033 Fourier transform infrared spectroscopy Methods 0.000 description 1
- SXRSQZLOMIGNAQ-UHFFFAOYSA-N Glutaraldehyde Chemical compound O=CCCCC=O SXRSQZLOMIGNAQ-UHFFFAOYSA-N 0.000 description 1
- OFOBLEOULBTSOW-UHFFFAOYSA-N Malonic acid Chemical compound OC(=O)CC(O)=O OFOBLEOULBTSOW-UHFFFAOYSA-N 0.000 description 1
- FXHOOIRPVKKKFG-UHFFFAOYSA-N N,N-Dimethylacetamide Chemical compound CN(C)C(C)=O FXHOOIRPVKKKFG-UHFFFAOYSA-N 0.000 description 1
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 1
- 239000004698 Polyethylene Substances 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 1
- 206010042674 Swelling Diseases 0.000 description 1
- ZJCCRDAZUWHFQH-UHFFFAOYSA-N Trimethylolpropane Chemical compound CCC(CO)(CO)CO ZJCCRDAZUWHFQH-UHFFFAOYSA-N 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- ORLQHILJRHBSAY-UHFFFAOYSA-N [1-(hydroxymethyl)cyclohexyl]methanol Chemical compound OCC1(CO)CCCCC1 ORLQHILJRHBSAY-UHFFFAOYSA-N 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- CECABOMBVQNBEC-UHFFFAOYSA-K aluminium iodide Chemical compound I[Al](I)I CECABOMBVQNBEC-UHFFFAOYSA-K 0.000 description 1
- 150000001412 amines Chemical class 0.000 description 1
- 238000007611 bar coating method Methods 0.000 description 1
- SGUXGJPBTNFBAD-UHFFFAOYSA-L barium iodide Chemical compound [I-].[I-].[Ba+2] SGUXGJPBTNFBAD-UHFFFAOYSA-L 0.000 description 1
- 229910001638 barium iodide Inorganic materials 0.000 description 1
- 229940075444 barium iodide Drugs 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 239000002981 blocking agent Substances 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 229910021538 borax Inorganic materials 0.000 description 1
- 150000001639 boron compounds Chemical class 0.000 description 1
- 229910001640 calcium iodide Inorganic materials 0.000 description 1
- 229940046413 calcium iodide Drugs 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 125000004432 carbon atom Chemical group C* 0.000 description 1
- 229920006026 co-polymeric resin Polymers 0.000 description 1
- GBRBMTNGQBKBQE-UHFFFAOYSA-L copper;diiodide Chemical compound I[Cu]I GBRBMTNGQBKBQE-UHFFFAOYSA-L 0.000 description 1
- 238000007766 curtain coating Methods 0.000 description 1
- QYQADNCHXSEGJT-UHFFFAOYSA-N cyclohexane-1,1-dicarboxylate;hydron Chemical compound OC(=O)C1(C(O)=O)CCCCC1 QYQADNCHXSEGJT-UHFFFAOYSA-N 0.000 description 1
- 238000007607 die coating method Methods 0.000 description 1
- 238000003618 dip coating Methods 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- 238000007606 doctor blade method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 239000005038 ethylene vinyl acetate Substances 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 238000001879 gelation Methods 0.000 description 1
- 229940015043 glyoxal Drugs 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 238000005470 impregnation Methods 0.000 description 1
- PNDPGZBMCMUPRI-UHFFFAOYSA-N iodine Chemical compound II PNDPGZBMCMUPRI-UHFFFAOYSA-N 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000002736 nonionic surfactant Substances 0.000 description 1
- 229920001200 poly(ethylene-vinyl acetate) Polymers 0.000 description 1
- 229920006122 polyamide resin Polymers 0.000 description 1
- 229920005668 polycarbonate resin Polymers 0.000 description 1
- 239000004431 polycarbonate resin Substances 0.000 description 1
- 229920005672 polyolefin resin Polymers 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 239000011118 polyvinyl acetate Substances 0.000 description 1
- 229920002689 polyvinyl acetate Polymers 0.000 description 1
- 229910052700 potassium Inorganic materials 0.000 description 1
- 239000011591 potassium Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 239000011369 resultant mixture Substances 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 239000004328 sodium tetraborate Substances 0.000 description 1
- 235000010339 sodium tetraborate Nutrition 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 238000004528 spin coating Methods 0.000 description 1
- 239000012192 staining solution Substances 0.000 description 1
- 150000005846 sugar alcohols Polymers 0.000 description 1
- 238000004381 surface treatment Methods 0.000 description 1
- 230000008961 swelling Effects 0.000 description 1
- 238000010345 tape casting Methods 0.000 description 1
- KKEYFWRCBNTPAC-UHFFFAOYSA-N terephthalic acid group Chemical group C(C1=CC=C(C(=O)O)C=C1)(=O)O KKEYFWRCBNTPAC-UHFFFAOYSA-N 0.000 description 1
- QPBYLOWPSRZOFX-UHFFFAOYSA-J tin(iv) iodide Chemical compound I[Sn](I)(I)I QPBYLOWPSRZOFX-UHFFFAOYSA-J 0.000 description 1
- NLLZTRMHNHVXJJ-UHFFFAOYSA-J titanium tetraiodide Chemical compound I[Ti](I)(I)I NLLZTRMHNHVXJJ-UHFFFAOYSA-J 0.000 description 1
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/30—Polarising elements
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C55/00—Shaping by stretching, e.g. drawing through a die; Apparatus therefor
- B29C55/02—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C55/00—Shaping by stretching, e.g. drawing through a die; Apparatus therefor
- B29C55/02—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets
- B29C55/04—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets uniaxial, e.g. oblique
- B29C55/06—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets uniaxial, e.g. oblique parallel with the direction of feed
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
- C08J5/18—Manufacture of films or sheets
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
- G02F1/133528—Polarisers
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
- H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
- H10K59/80—Constructional details
- H10K59/8793—Arrangements for polarized light emission
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2329/00—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an alcohol, ether, aldehydo, ketonic, acetal, or ketal radical; Hydrolysed polymers of esters of unsaturated alcohols with saturated carboxylic acids; Derivatives of such polymer
- C08J2329/02—Homopolymers or copolymers of unsaturated alcohols
- C08J2329/04—Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Mechanical Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Nonlinear Science (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Mathematical Physics (AREA)
- Crystallography & Structural Chemistry (AREA)
- Materials Engineering (AREA)
- Polarising Elements (AREA)
- Shaping By String And By Release Of Stress In Plastics And The Like (AREA)
Abstract
The present invention provides a method for manufacturing a polarizing film, which sequentially comprises: a step of subjecting the polyvinyl alcohol resin film to dyeing treatment and stretching treatment; and bringing an aqueous solvent into contact with the surface of the polyvinyl alcohol resin film, wherein the ratio (Δts (λ)) of the transmittance of the polyvinyl alcohol resin film after the contact with the aqueous solvent at a wavelength of λ nm to the transmittance before the contact satisfies a relationship of Δts (415) > Δts (470) > Δts (550).
Description
Technical Field
The present invention relates to a method for producing a polarizing film.
Background
In recent years, image display devices typified by liquid crystal display devices and Electroluminescence (EL) display devices (for example, organic EL display devices and inorganic EL display devices) have been rapidly popularized. In an organic EL display device, it is known that problems such as reflection of external light and reflection of a background are prevented by disposing a circular polarizer including a λ/4 plate on the visible side of an organic EL unit (for example, patent documents 1 and 2).
On the other hand, since the organic EL display device consumes large power for light emission, energy saving is demanded.
Prior art literature
Patent literature
Patent document 1: japanese patent laid-open No. 2002-311239
Patent document 2: japanese patent laid-open No. 2002-372622
Disclosure of Invention
Problems to be solved by the invention
The present invention has been made to solve the above-described conventional problems, and a main object of the present invention is to provide a polarizing film capable of reducing power consumption of an organic EL display device.
Means for solving the problems
According to an aspect of the present invention, there is provided a method of manufacturing a polarizing film, comprising, in order: a step of subjecting the polyvinyl alcohol resin film to dyeing treatment and stretching treatment; and bringing an aqueous solvent into contact with the surface of the polyvinyl alcohol resin film, wherein the ratio (Δts (λ)) of the transmittance of the polyvinyl alcohol resin film after the contact with the aqueous solvent at a wavelength of λ nm to the transmittance before the contact satisfies a relationship of Δts (415) > Δts (470) > Δts (550).
In one embodiment, the aqueous solvent has a temperature of 20℃to 70 ℃.
In one embodiment, the polyvinyl alcohol resin film contacted with the aqueous solvent has a water content of 15 wt% or less.
In one embodiment, the thickness of the polyvinyl alcohol resin film in contact with the aqueous solvent is 12 μm or less.
In one embodiment, the step of applying the polyvinyl alcohol resin film to the dyeing treatment and the stretching treatment includes: forming a polyvinyl alcohol resin film containing a halide and a polyvinyl alcohol resin on one side of a long thermoplastic resin substrate to form a laminate; and sequentially performing an air-assisted stretching treatment, a dyeing treatment, an in-water stretching treatment, and a drying shrinkage treatment for shrinking the laminate by 2% or more in the width direction by carrying the laminate in the longitudinal direction while heating the laminate.
In one embodiment, the method for manufacturing the polarizing film has a haze of 1% or less.
Effects of the invention
According to the method for producing a polarizing film of an embodiment of the present invention, a polyvinyl alcohol (PVA) resin film subjected to dyeing treatment and stretching treatment is subjected to a contact treatment with an aqueous solvent. Thus, the transmittance of the PVA-based resin film in the wavelength region of at least 415nm to 550nm increases, and the ratio of the transmittance of the PVA-based resin film after contact with the aqueous solvent at the wavelength λnm to the transmittance before contact (Δts (λ) =ts after contact (λ)/Ts before contact (λ), hereinafter, Δts (λ) is sometimes referred to as "the transmittance increase rate") satisfies the relationship of Δts (415) > Δts (470) > Δts (550). The polarizing film obtained by the above-described production method can transmit light on the short wavelength side more positively than light on the long wavelength side. Therefore, by using such a polarizing film, even when the amount of blue light emission that consumes a large amount of power is reduced, a decrease in luminance in the short wavelength region can be suppressed, and as a result, both energy saving and high luminance of the organic EL display device can be achieved.
Drawings
Fig. 1 is a schematic diagram showing an example of a drying shrinkage process using a heating roller.
Detailed Description
Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to these embodiments.
A. Method for manufacturing polarizing film
The method for manufacturing a polarizing film according to an embodiment of the present invention sequentially includes: a step (I) of applying a polyvinyl alcohol (PVA) resin film to the dyeing treatment and the stretching treatment; and bringing an aqueous solvent into contact with the surface of the PVA resin film (step II), wherein the ratio of the transmittance of the PVA resin film after the contact with the aqueous solvent at a wavelength of lambda nm (delta Ts (lambda)) to the transmittance before the contact satisfies delta Ts (415)>ΔTs(470)>Relationship of ΔTs (550). P after dyeingIodine in VA resin film as I - 、I 2 、I 3 - 、PVA-I 3 - Complex, PVA-I 5 - The complex exists in the form of I - 、I 2 I 3 - Having absorption in the ultraviolet region (e.g., around wavelength 290nm to 360 nm), PVA-I 3 - Complex and PVA-I 5 - The complex has absorption at a wavelength of 470nm and a wavelength of 600nm, respectively. Thus, consider: Δts is established before and after contact with an aqueous solvent (415)>ΔTs(470)>The relationship of ΔTs (550) represents I relative to the total iodine present in the PVA based resin film - 、I 2 、I 3 - PVA-I 3 - The proportion of complex is reduced (in other words, PVA-I 5 - The proportion of complex increases).
A-1 procedure I
In step I, the PVA-based resin film is subjected to dyeing treatment and stretching treatment, whereby a PVA-based resin film exhibiting dichroism absorption at any one of wavelengths 380nm to 780nm (hereinafter, sometimes referred to as "undechromogenic film") is obtained. Typically, the non-depigmented film is in a state that it can function as a polarizing film.
In one embodiment, the transmittance of the undeveloped raw film (monomer transmittance: ts) is preferably 41.0% or more, more preferably 42.0% or more, and still more preferably 42.5% or more. On the other hand, the transmittance of the non-depigmented film is preferably 46.0% or less, more preferably 45.0% or less. The degree of polarization of the non-depigmented film is preferably 98.0% or more, more preferably 99.0% or more, and even more preferably 99.9% or more. On the other hand, the degree of polarization of the non-depigmented film is preferably 99.998% or less. The transmittance is typically a Y value measured by an ultraviolet-visible spectrophotometer and subjected to a visibility correction. The polarization degree is typically obtained by the following equation based on the parallel transmittance Tp and the orthogonal transmittance Tc measured by an ultraviolet-visible spectrophotometer and subjected to sensitivity correction.
Degree of polarization (%) = { (Tp-Tc)/(tp+tc) } 1/2 ×100
In one embodiment, the transmittance of a thin polarizing film (non-depigmented film) of 12 μm or less is typically measured by an ultraviolet-visible spectrophotometer using a laminate of a polarizing film (refractive index of surface: 1.53) and a protective layer (protective film) (refractive index: 1.50). Depending on the refractive index of the surface of the polarizing film and/or the refractive index of the surface of the protective layer in contact with the air interface, the reflectance at the interface of each layer may vary, and as a result, the measured value of the transmittance varies. Therefore, for example, when a protective layer having a refractive index of not 1.50 is used, the measured value of the transmittance may be corrected based on the refractive index of the surface of the protective layer in contact with the air interface. Specifically, the correction value C of the transmittance uses the reflectance R of polarized light parallel to the transmission axis at the interface of the protective layer and the air layer 1 (transmission axis reflectivity) is expressed by the following equation.
C＝R 1 -R 0
R 0 ＝((1.50-1) 2 /(1.50+1) 2 )×(T 1 /100)
R 1 ＝((n 1 -1) 2 /(n 1 +1) 2 )×(T 1 /100)
Here, R is 0 For the transmission axis reflectivity in the case of using a protective layer having a refractive index of 1.50, n 1 For the refractive index of the protective layer used, T 1 Is the transmittance of the polarizing film. For example, when a base material (cycloolefin film, hard coat film, or the like) having a surface refractive index of 1.53 is used as the protective layer, the correction amount C is about 0.2%. In this case, by adding 0.2% to the transmittance obtained by the measurement, the polarizing film having a refractive index of 1.53 on the surface can be converted into a transmittance in the case of using a protective layer having a refractive index of 1.50. Based on the calculation based on the above formula, the transmittance T of the polarizing film is set to 1 The change amount of the correction value C at the change of 2% is 0.03% or less, and the influence of the transmittance of the polarizing film on the value of the correction value C is limited. In the case where the protective layer has absorption other than surface reflection, appropriate correction can be performed according to the absorption amount.
Transmittance at 415nm of the non-depigmented film (Ts 415 ) For example, may be less than 40%.
The water content of the raw film is typically 15 wt% or less, preferably 12 wt% or less, more preferably 10 wt% or less, and even more preferably 1 wt% to 5 wt%. If the water content of the non-depigmented film falls within this range, dissolution, wrinkles, and the like can be prevented from occurring when the film is contacted with an aqueous solvent in step II.
The thickness of the non-depigmented film is typically 25 μm or less, preferably 12 μm or less, more preferably 1 μm to 12 μm, still more preferably 1 μm to 7 μm, and still more preferably 2 μm to 5 μm.
In step I, a single layer of PVA-based resin film is subjected to dyeing treatment and stretching treatment, whereby a non-depigmented film can be produced. Alternatively, a laminate of two or more layers including a PVA-based resin layer (PVA-based resin film) is subjected to dyeing treatment and stretching treatment, whereby an uncoloured raw film can be produced. The non-depigmented film produced using the laminate of two or more layers can avoid the occurrence of wrinkles and the like even after contact with an aqueous solvent, and can suitably maintain excellent optical characteristics (typically, monomer transmittance and polarization degree).
A-1-1 preparation of non-depigmented film Using laminate of two or more layers
The non-depigmented film using a laminate of two or more layers can be produced, for example, by subjecting a PVA-based resin film containing a halide and a PVA-based resin to dyeing treatment and stretching treatment in the state of a laminate with a long thermoplastic resin substrate. Specifically, the non-depigmented film can be made by a method comprising the steps of: forming a PVA-based resin layer (PVA-based resin film) containing a halide and a PVA-based resin on one side of a long thermoplastic resin substrate to form a laminate; and sequentially performing an air-assisted stretching treatment, a dyeing treatment, an in-water stretching treatment, and a drying shrinkage treatment for shrinking the laminate by 2% or more in the width direction by carrying the laminate in the longitudinal direction while heating the laminate. The content of the halide in the PVA-based resin layer is preferably 5 parts by weight to 20 parts by weight relative to 100 parts by weight of the PVA-based resin. The drying shrinkage treatment is preferably performed using a heated roll, and the temperature of the heated roll is preferably 60 to 120 ℃. The shrinkage in the width direction of the laminate by the drying shrinkage treatment is preferably 2% or more. By using such a production method, a non-dechromic original film having high degree of orientation of the PVA-based resin and excellent optical characteristics can be obtained.
A-1-1-1 laminate production
As a method for producing a laminate of the thermoplastic resin substrate and the PVA-based resin layer, any suitable method can be used. The PVA-based resin layer is preferably formed on the thermoplastic resin substrate by coating a coating liquid containing a halide and a PVA-based resin on the surface of the thermoplastic resin substrate and drying. As described above, the content of the halide in the PVA-based resin layer is preferably 5 parts by weight to 20 parts by weight with respect to 100 parts by weight of the PVA-based resin.
As a coating method of the coating liquid, any suitable method can be used. Examples thereof include a roll coating method, a spin coating method, a wire bar coating method, a dip coating method, a die coating method, a curtain coating method, a spray coating method, a doctor blade coating method (comma knife coating method, etc.), and the like. The coating temperature of the coating liquid is preferably 50 ℃ or higher.
The thickness of the PVA based resin layer is preferably 3 to 40. Mu.m, more preferably 3 to 20. Mu.m.
Before forming the PVA-based resin layer, the thermoplastic resin substrate may be subjected to a surface treatment (for example, corona treatment or the like), or an easy-to-adhere layer may be formed on the thermoplastic resin substrate. By performing such a treatment, the adhesion between the thermoplastic resin base material and the PVA-based resin layer can be improved.
The thickness of the thermoplastic resin substrate is preferably 20 μm to 300. Mu.m, more preferably 50 μm to 200. Mu.m. If the particle size is less than 20. Mu.m, the PVA based resin layer may be difficult to form. If the particle size exceeds 300. Mu.m, for example, in the in-water stretching treatment described later, the thermoplastic resin substrate may take a long time to absorb water, and the stretching may require an excessive load.
The water absorption of the thermoplastic resin substrate is preferably 0.2% or more, more preferably 0.3% or more. The thermoplastic resin base material absorbs water, and the water can play a role of a plasticizer to plasticize. As a result, the tensile stress can be greatly reduced, and the stretching can be performed at a high magnification. On the other hand, the water absorption rate of the thermoplastic resin base material is preferably 3.0% or less, and more preferably 1.0% or less. By using such a thermoplastic resin base material, it is possible to prevent the appearance of the obtained non-depigmented film from being deteriorated due to a significant decrease in the dimensional stability of the thermoplastic resin base material at the time of production. Further, it is possible to prevent the substrate from breaking in stretching in water or the PVA-based resin layer from peeling from the thermoplastic resin substrate. The water absorption of the thermoplastic resin base material can be adjusted by introducing a modifying group into the constituent material, for example. The water absorption was determined in accordance with JIS K7209.
The glass transition temperature (Tg) of the thermoplastic resin substrate is preferably 120℃or lower. By using such a thermoplastic resin base material, crystallization of the PVA-based resin layer can be suppressed, and stretchability of the laminate can be sufficiently ensured. Further, in view of the fact that the thermoplastic resin base material using water is suitably plasticized and stretched in water, it is more preferably 100℃or less, and still more preferably 90℃or less. On the other hand, the glass transition temperature of the thermoplastic resin substrate is preferably 60℃or higher. By using such a thermoplastic resin substrate, when the coating liquid containing the PVA-based resin is applied and dried, it is possible to prevent defects such as deformation (e.g., occurrence of irregularities, looseness, wrinkles, etc.) of the thermoplastic resin substrate, and to produce a laminate satisfactorily. Further, the stretching of the PVA-based resin layer can be performed well at a suitable temperature (for example, about 60 ℃). The glass transition temperature of the thermoplastic resin base material can be adjusted by introducing a modifying group into the constituent material and heating the constituent material with a crystallizing material, for example. The glass transition temperature (Tg) is a value obtained in accordance with JIS K7121.
As the constituent material of the thermoplastic resin base material, any suitable thermoplastic resin may be used. Examples of the thermoplastic resin include ester resins such as polyethylene terephthalate resins, cycloolefin resins such as norbornene resins, olefin resins such as polypropylene, polyamide resins, polycarbonate resins, and copolymer resins thereof. Among them, norbornene-based resins and amorphous polyethylene terephthalate-based resins are preferable.
In one embodiment, an amorphous (uncrystallized) polyethylene terephthalate-based resin is preferably used. Among them, an amorphous (hardly crystallized) polyethylene terephthalate resin is particularly preferably used. Specific examples of the amorphous polyethylene terephthalate resin include copolymers further containing isophthalic acid and/or cyclohexanedicarboxylic acid as dicarboxylic acid and copolymers further containing cyclohexanedimethanol or diethylene glycol as diol.
In a preferred embodiment, the thermoplastic resin base material is composed of a polyethylene terephthalate resin having isophthalic acid units. This is because such a thermoplastic resin base material is extremely excellent in stretchability and can suppress crystallization upon stretching. This is thought to be due to the fact that the main chain is given a large degree of bending by introducing isophthalic acid units. The polyethylene terephthalate resin has terephthalic acid units and ethylene glycol units. The content of isophthalic acid units is preferably 0.1 mol% or more, more preferably 1.0 mol% or more, based on the total of all the repeating units. This is because a thermoplastic resin base material extremely excellent in stretchability can be obtained. On the other hand, the content of isophthalic acid units is preferably 20 mol% or less, more preferably 10 mol% or less, based on the total of all the repeating units. By setting the content ratio as described above, the crystallization degree can be favorably increased in the drying shrinkage treatment described later.
The thermoplastic resin base material may be stretched in advance (before forming the PVA-based resin layer). In one embodiment, the thermoplastic resin substrate is stretched in the transverse direction of the elongated thermoplastic resin substrate. The transverse direction is preferably a direction perpendicular to the stretching direction of the laminate to be described later. In the present specification, "orthogonal" also includes a case of being substantially orthogonal. Here, "substantially orthogonal" includes a case of 90 ° ± 5.0 °, preferably 90 ° ± 3.0 °, further preferably 90 ° ± 1.0 °.
The stretching temperature of the thermoplastic resin substrate is preferably from Tg to 10℃to Tg+50℃. The stretching ratio of the thermoplastic resin base material is preferably 1.5 to 3.0 times.
As the stretching method of the thermoplastic resin substrate, any suitable method can be used. Specifically, the stretching may be performed at the fixed end or at the free end. The stretching mode may be dry or wet. The stretching of the thermoplastic resin substrate may be performed in one stage or may be performed in multiple stages. In the case of performing in multiple stages, the stretching ratio is a product of stretching ratios in the respective stages.
The coating liquid contains a halide and a PVA-based resin as described above. The coating liquid is typically a solution obtained by dissolving the halide and the PVA-based resin in a solvent. Examples of the solvent include water, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, various diols, polyols such as trimethylolpropane, and amines such as ethylenediamine and diethylenetriamine. They may be used alone or in combination of two or more. Among them, water is preferable. The PVA-based resin concentration of the solution is preferably 3 to 20 parts by weight based on 100 parts by weight of the solvent. In such a resin concentration, a uniform coating film can be formed to adhere to the thermoplastic resin substrate. The halide content in the coating liquid is preferably 5 parts by weight to 20 parts by weight relative to 100 parts by weight of the PVA-based resin.
Additives may be blended into the coating liquid. Examples of the additive include a plasticizer and a surfactant. Examples of the plasticizer include polyols such as ethylene glycol and glycerin. Examples of the surfactant include nonionic surfactants. They can be used for the purpose of further improving the uniformity or dyeing property, stretchability of the resulting PVA-based resin layer.
Any suitable resin may be used as the PVA-based resin. For example, polyvinyl alcohol and ethylene-vinyl alcohol copolymers are mentioned. Polyvinyl alcohol can be obtained by saponifying polyvinyl acetate. The ethylene-vinyl alcohol copolymer can be obtained by saponifying an ethylene-vinyl acetate copolymer. The saponification degree of the PVA-based resin is usually 85 mol% to 100 mol%, preferably 95.0 mol% to 99.95 mol%, and more preferably 99.0 mol% to 99.93 mol%. The saponification degree can be determined according to JIS K6726-1994. By using the PVA-based resin having such a saponification degree, a non-depigmented film excellent in durability can be obtained. If the saponification degree is too high, gelation may occur.
The average polymerization degree of the PVA-based resin may be appropriately selected according to the purpose. The average polymerization degree is usually 1000 to 10000, preferably 1200 to 4500, and more preferably 1500 to 4300. The average polymerization degree can be determined according to JIS K6726-1994.
As the above-mentioned halide, any suitable halide may be used. For example, iodide and sodium chloride may be mentioned. Examples of the iodide include potassium iodide, sodium iodide, and lithium iodide. Among them, potassium iodide is preferable.
The amount of the halide in the coating liquid is preferably 5 to 20 parts by weight relative to 100 parts by weight of the PVA-based resin, and more preferably 10 to 15 parts by weight relative to 100 parts by weight of the PVA-based resin. If the amount of the halide exceeds 20 parts by weight relative to 100 parts by weight of the PVA-based resin, the halide may bleed out (bleed-out), and the finally obtained non-depigmented film may be clouded.
In general, the PVA-based resin layer is stretched to increase the orientation of the polyvinyl alcohol molecules in the PVA-based resin layer, but when the stretched PVA-based resin layer is immersed in a liquid containing water, the orientation of the polyvinyl alcohol molecules may be disturbed, and the orientation may be reduced. In particular, when a laminate of a thermoplastic resin substrate and a PVA-based resin layer is stretched in boric acid water, the orientation degree tends to be significantly reduced when the laminate is stretched in boric acid water at a relatively high temperature in order to stabilize the stretching of the thermoplastic resin substrate. For example, stretching of a PVA film monomer in boric acid water is generally performed at 60 ℃, whereas stretching of a laminate of a-PET (thermoplastic resin base material) and a PVA-based resin layer is performed at a temperature as high as about 70 ℃, and in this case, the orientation of PVA at the initial stage of stretching may be reduced at a stage before the enhancement by stretching in water. In contrast, by producing a laminate of a PVA-based resin layer containing a halide and a thermoplastic resin substrate, and stretching the laminate in air at a high temperature (auxiliary stretching) before stretching the laminate in boric acid water, crystallization of the PVA-based resin in the PVA-based resin layer of the laminate after the auxiliary stretching can be promoted. As a result, when the PVA-based resin layer is immersed in a liquid, disturbance of orientation of polyvinyl alcohol molecules and reduction of orientation can be suppressed as compared with the case where the PVA-based resin layer does not contain a halide. This improves the optical properties of the non-depigmented film obtained in the treatment step of immersing the laminate in a liquid, such as dyeing treatment or underwater stretching treatment.
A-1-1-2, air assisted stretching treatment
In particular, in order to obtain high optical characteristics, a method of 2-stage stretching in which dry stretching (auxiliary stretching) and stretching in boric acid water are combined is selected. By introducing the auxiliary stretching as in the 2-stage stretching, the stretching can be performed while suppressing the crystallization of the thermoplastic resin base material, and the problem of the decrease in stretchability due to excessive crystallization of the thermoplastic resin base material in the subsequent stretching in boric acid water can be solved, whereby the laminate can be stretched at a higher magnification. Further, in the case of coating a PVA-based resin on a thermoplastic resin substrate, in order to suppress the influence of the glass transition temperature of the thermoplastic resin substrate, it is necessary to lower the coating temperature as compared with the case of coating a PVA-based resin on a common metal roll, and as a result, there is a problem that crystallization of the PVA-based resin is relatively low and sufficient optical characteristics are not obtained. In contrast, even when the PVA-based resin is coated on the thermoplastic resin substrate, the crystallinity of the PVA-based resin can be improved by introducing the auxiliary stretching, and high optical characteristics can be achieved. In addition, by increasing the orientation of the PVA-based resin in advance, problems such as a decrease in the orientation and dissolution of the PVA-based resin can be prevented when immersed in water in a subsequent dyeing process or stretching process, and high optical characteristics can be achieved.
The stretching method of the air-assisted stretching may be fixed-end stretching (for example, stretching using a tenter), or free-end stretching (for example, uniaxial stretching by passing a laminate between rolls having different peripheral speeds), but free-end stretching may be positively employed in order to obtain high optical characteristics. In one embodiment, the air stretching process includes a heated roll stretching step of stretching the laminate by using a peripheral speed difference between heated rolls while conveying the laminate in the longitudinal direction thereof. The air stretching treatment typically includes a zone stretching step and a heated roll stretching step. The order of the region stretching step and the heat roller stretching step is not limited, and the region stretching step may be performed first, or the heat roller stretching step may be performed first. The zone stretching step may be omitted. In one embodiment, the zone stretching step and the heated roll stretching step are performed sequentially. In another embodiment, the end of the laminate is gripped by a tenter stretching machine, whereby the distance between the tenters is extended in the flow direction (the extension of the distance between the tenters is a stretching ratio). At this time, the distance of the tenter in the width direction (the direction perpendicular to the flow direction) is set so as to be arbitrarily close. It is preferable that the stretching ratio with respect to the flow direction be set so that the stretching ratio becomes close by the free end stretching. In the case of free end stretching, the shrinkage in the width direction= (1/stretch ratio) 1/2 To calculate.
The air-assisted stretching may be performed in one stage or in multiple stages. In the case of performing in multiple stages, the stretching ratio is the product of stretching ratios in the respective stages. The stretching direction in the air-assisted stretching is preferably substantially the same as the stretching direction in the water stretching.
The stretching ratio in the air-assisted stretching is preferably 2.0 to 3.5 times. The maximum stretching ratio in the case of combining the air-assist stretching and the underwater stretching is preferably 5.0 times or more, more preferably 5.5 times or more, and even more preferably 6.0 times or more, relative to the original length of the laminate. In the present specification, "maximum stretch ratio" means a stretch ratio immediately before the laminate breaks, and a stretch ratio at which the laminate breaks is confirmed means a value lower than this by 0.2.
The stretching temperature of the air-assisted stretching may be set to any suitable value depending on the material forming the thermoplastic resin base material, the stretching method, and the like. The stretching temperature is preferably not less than the glass transition temperature (Tg) of the thermoplastic resin substrate, more preferably not less than the glass transition temperature (Tg) +10 ℃ of the thermoplastic resin substrate, and particularly preferably not less than tg+15 ℃. On the other hand, the upper limit of the stretching temperature is preferably 170 ℃. By stretching at such a temperature, the progress of crystallization of the PVA-based resin can be suppressed, and defects caused by the crystallization (for example, the orientation of the PVA-based resin layer by stretching is prevented) can be suppressed. The crystallization index of the PVA based resin after the air-assisted stretching is preferably 1.3 to 1.8, more preferably 1.4 to 1.7. The crystallization index of the PVA-based resin can be measured by ATR method using a fourier transform infrared spectrophotometer. Specifically, measurement was performed using polarized light as measurement light, and 1141cm of the obtained spectrum was used -1 1440cm -1 The crystallization index was calculated according to the following formula.
Crystallization index= (I) C /I R )
Wherein, the liquid crystal display device comprises a liquid crystal display device,
I C : 1141cm for measurement by incidence of measurement light -1 Strength of (2)
I R : 1440cm when measuring light is incident -1 Is a strength of (a) is a strength of (b).
A-1-1-3 insolubilization treatment
If necessary, the insolubilization treatment is performed after the air-assisted stretching treatment and before the underwater stretching treatment and dyeing treatment. The insolubilization treatment is typically performed by immersing the PVA-based resin layer in an aqueous boric acid solution. By performing the insolubilization treatment, water resistance can be imparted to the PVA-based resin layer, and the decrease in orientation of PVA when immersed in water can be prevented. The concentration of the aqueous boric acid solution is preferably 1 to 4 parts by weight based on 100 parts by weight of water. The temperature of the insoluble bath (boric acid aqueous solution) is preferably 20 to 50 ℃.
A-1-1-4 dyeing treatment
The dyeing treatment is typically performed by dyeing the PVA-based resin layer with a dichroic substance (typically iodine). Specifically, iodine is adsorbed on the PVA-based resin layer. Examples of the adsorption method include a method of immersing a PVA-based resin layer (laminate) in a dyeing liquid containing iodine, a method of coating the dyeing liquid on the PVA-based resin layer, and a method of spraying the PVA-based resin layer with the dyeing liquid. A method of immersing the laminate in a dyeing liquid (dyeing bath) is preferable. This is because iodine can be adsorbed well.
The staining solution is preferably an aqueous iodine solution. The amount of iodine to be blended is preferably 0.05 to 0.5 parts by weight based on 100 parts by weight of water. In order to increase the solubility of iodine in water, it is preferable to add iodide to the aqueous iodine solution. Examples of the iodide include potassium iodide, lithium iodide, sodium iodide, zinc iodide, aluminum iodide, lead iodide, copper iodide, barium iodide, calcium iodide, tin iodide, and titanium iodide. Among them, potassium iodide is preferable. The amount of the iodide to be blended is preferably 0.1 to 10 parts by weight, more preferably 0.3 to 5 parts by weight, based on 100 parts by weight of water. In order to suppress dissolution of the PVA-based resin, the liquid temperature at the time of dyeing of the dyeing liquid is preferably 20 to 50 ℃. In the case of immersing the PVA-based resin layer in the dyeing liquid, in order to secure the transmittance of the PVA-based resin layer, the immersion time is preferably 5 seconds to 5 minutes, more preferably 30 seconds to 90 seconds.
The dyeing conditions (concentration, liquid temperature, immersion time) can be set so that the transmittance of the monomer of the finally obtained non-depigmented film becomes a desired value. As such dyeing conditions, an aqueous iodine solution is preferably used as the dyeing solution, and the ratio of the contents of iodine and potassium iodide in the aqueous iodine solution is set to 1:5 to 1:20. the ratio of the iodine content to the potassium iodide content in the aqueous iodine solution is preferably 1:5 to 1:10. thus, a non-depigmented film having optical characteristics as described below can be obtained.
When the dyeing treatment is continuously performed after the laminate is immersed in a treatment bath containing boric acid (typically, an insolubilization treatment), the boric acid concentration in the dyeing bath may change with time due to mixing of the boric acid contained in the treatment bath into the dyeing bath, and as a result, the dyeing property may become unstable. In order to suppress the above-described instability of dyeing properties, the upper limit of the boric acid concentration in the dyeing bath is preferably adjusted to be 4 parts by weight, more preferably 2 parts by weight, relative to 100 parts by weight of water. On the other hand, the lower limit of the boric acid concentration in the dyeing bath is preferably 0.1 part by weight, more preferably 0.2 part by weight, and further preferably 0.5 part by weight, based on 100 parts by weight of water. In one embodiment, the dyeing treatment is performed using a dyeing bath in which boric acid is previously mixed. This reduces the ratio of the change in the boric acid concentration in the case where boric acid in the treatment bath is mixed into the dyeing bath. The amount of boric acid to be previously added to the dyeing bath (i.e., the amount of boric acid not originating from the treatment bath) is preferably 0.1 to 2 parts by weight, more preferably 0.5 to 1.5 parts by weight, based on 100 parts by weight of water.
A-1-1-5 crosslinking treatment
If necessary, the crosslinking treatment is performed after the dyeing treatment and before the stretching treatment in water. The crosslinking treatment is typically performed by immersing the PVA-based resin layer in an aqueous boric acid solution. By performing the crosslinking treatment, water resistance can be imparted to the PVA-based resin layer, and the decrease in the orientation of PVA when immersed in high-temperature water during the subsequent stretching in water can be prevented. The concentration of the aqueous boric acid solution is preferably 1 to 5 parts by weight based on 100 parts by weight of water. In the case of performing the crosslinking treatment after the dyeing treatment, it is preferable to further add an iodide. By adding iodide, elution of iodine adsorbed by the PVA-based resin layer can be suppressed. The amount of iodide to be blended is preferably 1 to 5 parts by weight based on 100 parts by weight of water. Specific examples of iodides are described above. The liquid temperature of the crosslinking bath (aqueous boric acid solution) is preferably 20℃to 50 ℃.
A-1-1-6. In-water stretching treatment
The stretching treatment in water is performed by immersing the laminate in a stretching bath. If the stretching treatment in water is used, the stretching can be performed at a temperature lower than the glass transition temperature (typically, about 80 ℃) of the thermoplastic resin base material and the PVA-based resin layer, and the PVA-based resin layer can be stretched at a high rate while suppressing crystallization. As a result, a non-depigmented film having excellent optical characteristics can be produced.
Any suitable method may be used for stretching the laminate. Specifically, the stretching may be performed at a fixed end or at a free end (for example, a method of uniaxially stretching a laminate by passing the laminate between rolls having different peripheral speeds). The free end stretch is preferably selected. Stretching of the laminate may be performed in one stage or in multiple stages. In the case of performing in multiple stages, the stretching ratio (maximum stretching ratio) of the laminate to be described later is the product of the stretching ratios in the respective stages.
The stretching in water is preferably performed by immersing the laminate in an aqueous boric acid solution (stretching in boric acid water). By using an aqueous boric acid solution as the stretching bath, rigidity against tensile force applied at the time of stretching and water-insoluble water resistance can be imparted to the PVA-based resin layer. Specifically, boric acid can generate tetrahydroxyborate anions in an aqueous solution and crosslink with PVA-based resins through hydrogen bonds. As a result, the PVA-based resin layer can be stretched well while imparting rigidity and water resistance, and a non-depigmented film having excellent optical characteristics can be produced.
The aqueous boric acid solution is preferably obtained by dissolving boric acid and/or a borate in water as a solvent. The boric acid concentration is preferably 1 to 10 parts by weight, more preferably 2.5 to 6 parts by weight, and particularly preferably 3 to 5 parts by weight, based on 100 parts by weight of water. By setting the boric acid concentration to 1 part by weight or more, dissolution of the PVA-based resin layer can be effectively suppressed, and a raw film having higher characteristics without decoloration can be produced. In addition to boric acid or borate, an aqueous solution obtained by dissolving a boron compound such as borax, glyoxal, glutaraldehyde, or the like in a solvent may be used.
Preferably, iodide is blended in the stretching bath (boric acid aqueous solution). By adding iodide, elution of iodine adsorbed by the PVA-based resin layer can be suppressed. Specific examples of iodides are described above. The concentration of iodide is preferably 0.05 to 15 parts by weight, more preferably 0.5 to 8 parts by weight, based on 100 parts by weight of water.
The stretching temperature (liquid temperature of the stretching bath) is preferably 40 to 85 ℃, more preferably 60 to 75 ℃. If the temperature is such, the stretching can be performed at a high rate while suppressing dissolution of the PVA-based resin layer. Specifically, as described above, the glass transition temperature (Tg) of the thermoplastic resin substrate is preferably 60 ℃ or higher, based on the relationship with the formation of the PVA-based resin layer. In this case, if the stretching temperature is lower than 40 ℃, the thermoplastic resin base material may not be stretched well even if plasticization by water is considered. On the other hand, as the temperature of the stretching bath increases, the solubility of the PVA-based resin layer increases, and there is a possibility that excellent optical characteristics cannot be obtained. The immersion time of the laminate in the stretching bath is preferably 15 seconds to 5 minutes.
The stretching ratio by stretching in water is preferably 1.5 times or more, more preferably 3.0 times or more. The total stretch ratio of the laminate is preferably 5.0 times or more, more preferably 5.5 times or more, relative to the original length of the laminate. By achieving such a high stretching ratio, a non-depigmented film having extremely excellent optical characteristics can be produced. Such a high stretching ratio can be achieved by adopting an underwater stretching method (boric acid underwater stretching).
A-1-1-7. Drying shrinkage treatment
The drying shrinkage treatment is performed, for example, by heating a laminate of a long thermoplastic resin substrate and a PVA-based resin film while conveying the laminate in the longitudinal direction, so as to shrink the laminate by 2% or more in the width direction. In the drying shrinkage treatment, the PVA-based resin film is preferably dried until the moisture content is 15 wt% or less, more preferably dried until the moisture content is 12 wt% or less, still more preferably 10 wt% or less, still more preferably 1 to 5 wt% from the viewpoint of obtaining a stable appearance.
The drying shrinkage treatment may be performed by zone heating in which the entire zone is heated, or may be performed by heating a conveying roller (using a so-called heating roller) (heating roller drying method). Both are preferably used. By drying with the heating roller, the heat curl of the laminate can be effectively suppressed, and a non-depigmented film excellent in appearance can be produced. Specifically, by drying the laminate in a state of being brought along the heated roller, the crystallization of the thermoplastic resin base material can be effectively promoted to increase the crystallization degree, and even at a relatively low drying temperature, the crystallization degree of the thermoplastic resin base material can be satisfactorily increased. As a result, the rigidity of the thermoplastic resin base material is increased, and the PVA-based resin layer is allowed to shrink due to drying, whereby curling is suppressed. Further, since the laminate can be dried while maintaining a flat state by using the heating roller, not only curling but also occurrence of wrinkles can be suppressed. At this time, the laminate is shrunk in the width direction by the drying shrinkage treatment, whereby the optical characteristics can be improved. This is because the orientation of PVA and PVA/iodine complex can be effectively improved. The shrinkage in the width direction of the laminate by the drying shrinkage treatment is preferably 1% to 10%, more preferably 2% to 8%, and particularly preferably 4% to 6%. By using the heating roller, the laminate can be continuously contracted in the width direction while being conveyed, and high productivity can be achieved.
Fig. 1 is a schematic diagram showing an example of the drying shrinkage process. In the drying shrinkage process, the laminate 200 is dried while being conveyed by the conveying rollers R1 to R6 and the guide rollers G1 to G4 heated to a predetermined temperature. In the illustrated example, the conveyance rollers R1 to R6 are arranged so as to continuously heat the surface of the PVA-based resin layer and the surface of the thermoplastic resin substrate alternately, but for example, the conveyance rollers R1 to R6 may be arranged so as to continuously heat only one surface (for example, the surface of the thermoplastic resin substrate) of the laminate 200.
The drying condition can be controlled by adjusting the heating temperature of the conveying roller (temperature of the heating roller), the number of heating rollers, the contact time with the heating roller, and the like. The temperature of the heating roller is preferably 60 to 120 ℃, more preferably 65 to 100 ℃, and particularly preferably 70 to 80 ℃. The crystallinity of the thermoplastic resin can be satisfactorily increased to satisfactorily suppress curling, and an optical laminate extremely excellent in durability can be produced. The temperature of the heating roller may be measured by a contact thermometer. In the example of the figure, 6 conveying rollers are provided, but there is no particular limitation as long as there are a plurality of conveying rollers. The number of the conveying rollers is usually 2 to 40, preferably 4 to 30. The contact time (total contact time) between the laminate and the heating roller is preferably 1 to 300 seconds, more preferably 1 to 20 seconds, and even more preferably 1 to 10 seconds.
The heating roller may be provided in a heating furnace (for example, an oven) or may be provided in a general manufacturing line (in a room temperature environment). Preferably, the air blower is provided in a heating furnace provided with an air blowing mechanism. By using both drying by the heating roller and hot air drying, rapid temperature changes between the heating rollers can be suppressed, and shrinkage in the width direction can be easily controlled. The temperature of the hot air drying is preferably 20 to 100 ℃. The hot air drying time is preferably 1 to 300 seconds. The wind speed of the hot air is preferably about 10m/s to 30 m/s. The wind speed is the wind speed in the heating furnace, and can be measured by a small impeller type digital anemometer.
A-1-1-8. Other treatments
The washing treatment is preferably performed after the stretching treatment in water and before the drying shrinkage treatment. The washing treatment is typically performed by immersing the PVA-based resin layer in an aqueous potassium iodide solution.
The contacting of the non-depigmented film with the aqueous solvent in step II may be performed by contacting only one surface of the non-depigmented film with the aqueous solvent, or may be performed by contacting both surfaces with the aqueous solvent. Thus, in one embodiment, the non-depigmented film produced using the laminate may be supplied to step II in the form of a laminate of [ non-depigmented film/thermoplastic resin substrate ]. In another embodiment, a protective layer is bonded to the surface of the undechronized film of the laminate of [ undechronized film/thermoplastic resin base material ] to produce a laminate of [ protective layer/undechronized film/thermoplastic resin base material ], the thermoplastic resin base material is peeled off from the laminate to produce a laminate of [ protective layer/undechronized film ] (polarizing plate), and the obtained laminate is subjected to step II. In still another embodiment, the laminate of [ non-decolorized film/thermoplastic resin substrate ] may be provided with any suitable functional layer (such as a retardation layer or an adhesive layer) on the substrate side or the protective layer side of the laminate of [ protective layer/non-decolorized film ], and then subjected to step II.
A-1-2 production of undechronized film Using Single-layer PVA-based resin film
The production of the non-decolorized raw film using the single-layer PVA-based resin film can be performed by dyeing and stretching (typically, uniaxial stretching using a roll stretcher in an aqueous boric acid solution) the PVA-based resin film in a long form having self-supporting properties (i.e., not supported by a base material), and then drying until the water content becomes preferably 15% by weight or less, more preferably 12% by weight or less, still more preferably 10% by weight or less, still more preferably 1% by weight to 5% by weight. The dyeing is performed, for example, by immersing the PVA-based resin film in an aqueous iodine solution. The stretching ratio of the uniaxial stretching is preferably 3 to 7 times. Stretching may be performed after dyeing treatment or may be performed while dyeing. Alternatively, the stretching may be followed by dyeing. If necessary, the PVA-based resin film is subjected to swelling treatment, crosslinking treatment, washing treatment, and the like. For example, by immersing the PVA-based resin film in water and washing it before dyeing, not only stains and anti-blocking agents on the surface of the PVA-based resin film can be washed away, but also the PVA-based resin film can be swelled to prevent uneven dyeing.
As described above, the contact between the non-depigmented film and the aqueous solvent in step II may be performed by contacting only one surface of the non-depigmented film with the aqueous solvent, or may be performed by contacting both surfaces with the aqueous solvent. Thus, in one embodiment, the non-depigmented film produced using the single-layer PVA-based resin film may be directly fed to step II. In another embodiment, a laminate of [ protective layer/non-depigmentation film ] may be produced by attaching a protective layer to one surface of the non-depigmentation film, and the laminate may be subjected to step II. In still another embodiment, any suitable functional layer (such as a retardation layer and an adhesive layer) may be provided on the protective layer side of the laminate of [ protective layer/non-depigmentation film ] in the step II.
A2 Process II
In step II, the aqueous solvent is brought into contact with the surface of the PVA-based resin film (non-depigmented film) passing through step I. Formation of I by contact with an aqueous solvent - 、I 2 、I 3 - PVA-I 3 - Polyiodide ratio of Complex to PVA-I 5 - The polyiodide of the complex dissolves preferentially from the non-depigmented film, and the transmittance on the short wavelength side increases more, and as a result, the transmittance increase rate (Δts (λ)) at the wavelength λnm can satisfy Δts (415) >ΔTs(470)>Relationship of ΔTs (550).
Any suitable solvent may be used as long as it can dissolve the dichromatic substance (typically iodine) from the non-chromogenic film. The aqueous solvent may be, for example, water or a mixture of water and a water-soluble organic solvent. The water-soluble organic solvent may be preferably a lower monohydric alcohol having 1 to 4 carbon atoms such as methanol, ethanol, n-propanol, and isopropanol, or a polyhydric alcohol such as glycerin and ethylene glycol.
The method of contact with the aqueous solvent is not particularly limited, and any suitable method such as dipping, spraying, and coating may be used. From the viewpoint of uniformly contacting the entire surface of the non-depigmented film with the aqueous solvent, impregnation is preferable.
The contact time with the aqueous solvent and the temperature of the aqueous solvent at the time of contact can be determined according to the desired Ts 415 、Ts 470 Ts 550 And the like, and is appropriately set. By extending the contact time or increasing the temperature of the aqueous solvent, there is a transmittance (especially Ts 415 ) And tends to become larger. The contact time may be, for example, 10 minutes or less, preferably 60 seconds to 9 minutes, and more preferably 60 seconds to 4 minutes. The temperature of the aqueous solvent may be preferably 20 to 70 ℃, more preferably 30 to 65 ℃, still more preferably 40 to 60 ℃.
If necessary, the aqueous solvent may be contacted with the aqueous solvent and then dried. The drying temperature may be, for example, 20℃to 100℃and preferably 30℃to 80 ℃. The moisture content of the dried polarizing film is typically 15 wt% or less, preferably 12 wt% or less, more preferably 10 wt% or less, and even more preferably 1 wt% to 5 wt%.
B. Polarizing film
The polarizing film obtained by the method for producing a polarizing film according to item A is composed of a PVA-based resin film containing a dichroic substance (typically iodine), and has a transmittance that is higher than that of the non-depigmented film at least in a wavelength region of 415nm to 550 nm. Specifically, the rate of increase in transmittance at wavelength λnm (Δts (λ)) satisfies the relationship Δts (415) > Δts (470) > Δts (550). The transmittance increase rate (Δts (415)) at the wavelength of 415nm may be, for example, more than 1.05, preferably 1.1 or more, and more preferably 1.10 to 2.2. If Δts (415) falls within this range, the amount of blue light emission with large power consumption can be reduced, contributing to energy saving of the organic EL display device.
Ts of polarizing film 415 Ts 550 Any suitable value may be used depending on the purpose. Ts (Ts) 415 For example, the content may be 40% or more, preferably 41% or more, more preferably 42% or more, and the content may be 80% or less, preferably 60% or less, more preferably 50% or less. Furthermore, ts 550 For example, the content may be 40% or more, preferably 42% or more, more preferably 43% or more, and the content may be 70% or less, preferably 60% or less, more preferably 50% or less.
The polarizing film preferably exhibits absorption dichroism at any one of wavelengths 380nm to 780 nm. The transmittance of the polarizing film (monomer transmittance: ts) is preferably 41% or more, more preferably 42% or more, and further preferably 42.5% or more. On the other hand, the transmittance of the polarizing film is, for example, 65% or less, preferably 50% or less, and more preferably 48% or less. The polarization degree of the polarizing film is, for example, 40.0% or more, preferably 90.0% or more, more preferably 94.0% or more, still more preferably 96.0% or more, still more preferably 99.0% or more, still more preferably 99.5% or more, and still more preferably 99.998% or less. The transmittance and the polarization degree were obtained by the same procedure as those of the non-depigmented film.
The haze of the polarizing film is preferably 1% or less, more preferably 0.8% or less, and further preferably 0.6% or less. If the haze is within this range, an organic EL display device having a high contrast ratio can be obtained.
The iodine concentration in the polarizing film is preferably 3 wt% or more, more preferably 4 wt% to 10 wt%, and still more preferably 4 wt% to 8 wt%. In the present specification, "iodine concentration" means the amount of all iodine contained in the polarizing film. More specifically, iodine is present as I in the polarizing film - 、I 2 、I 3 - 、PVA-I 3 - Complex, PVA-I 5 - The form of the complex exists, and the iodine concentration in the present specification means the concentration of iodine including all of these forms. The iodine concentration can be calculated from, for example, the fluorescence X-ray intensity and the film (polarizing film) thickness by fluorescence X-ray analysis.
The thickness of the polarizing film is typically 25 μm or less, preferably 12 μm or less, more preferably 1 μm to 12 μm, still more preferably 1 μm to 7 μm, and still more preferably 2 μm to 5 μm.
Examples
Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples. The measurement method of each characteristic is as follows. Unless otherwise specified, "parts" and "%" in examples and comparative examples are weight basis.
(1) Thickness of (L)
The measurement was performed using the product name "Linear Gauge MODEL D-10HS" (manufactured by Kawasaki Co., ltd.).
(2) Monomer transmittance and degree of polarization
The laminate of the PVA-based resin film (polarizing film or non-depigmented film) and the protective layer obtained in examples and comparative examples was obtained by measuring the single transmittance Ts, parallel transmittance Tp, and orthogonal transmittance Tc obtained from the side of the PVA-based resin film using an ultraviolet-visible spectrophotometer (LPF-200, manufactured by the large-scale electronics company) as Ts, tp, and Tc of the PVA-based resin film, respectively. These Ts, tp, and Tc are Y values measured and corrected for sensitivity by a 2-degree field of view (C light source) of JIS Z8701. The refractive index of the protective layer was 1.53, and the refractive index of the surface of the polarizing film opposite to the protective layer was 1.53.
The polarization degree P was obtained from Tp and Tc obtained by the following equation.
Degree of polarization P (%) = { (Tp-Tc)/(tp+tc) } 1/2 ×100
Further, as Ts, ts measured at wavelengths of 415nm, 470nm and 550nm were used, respectively 415 、Ts 470 Ts 550 。
The spectrophotometer may be used for equivalent measurement by "V-7100" manufactured by Japanese Spectrophotometer, etc., and it was confirmed that equivalent measurement results were obtained when either spectrophotometer was used.
(3) Moisture fraction
The non-depigmented film immediately after the drying treatment (in the case of stretching the laminate, peeling the stretched substrate) was cut into a size of 100mm×100mm or more, and the weight before the treatment was measured by an electronic balance. Then, the mixture was put into a heating oven maintained at 120℃for 2 hours, and the weight after removal (weight after treatment) was measured to determine the water content by the following formula.
Moisture content [% ] = (weight before treatment-weight after treatment)/weight before treatment×100
(4) Haze degree
The measurement was performed by using a product name "haze meter (NDH-5000", manufactured by Nippon electric color industry Co., ltd.) according to JISK 7136.
Examples 1 to 1
1. Polarizing film and production of polarizing plate
A long roll of a PVA based resin film (manufactured by KURARAY, product name "PE 3000") having a thickness of 30 μm was immersed in a water bath at 30℃and stretched to 2.2 times in the conveying direction, and then immersed in an aqueous solution at 30℃having an iodine concentration of 0.04% by weight and a potassium concentration of 0.3% by weight to dye, and stretched to 3 times based on the total unstretched film (original length). Then, the stretched film was further stretched to 3.3 times based on the original length while immersed in an aqueous solution of 30℃having a boric acid concentration of 3% by weight and a potassium iodide concentration of 3% by weight, then further stretched to 6 times based on the original length while immersed in an aqueous solution of 60℃having a boric acid concentration of 4% by weight and a potassium iodide concentration of 5% by weight, and finally dried in an oven maintained at 60℃for 5 minutes to prepare a polarizing film (non-depigmented film a 1) having a thickness of 12. Mu.m. The water content of the obtained undechromogen film a1 was 10.0% by weight, and the transmittance of the monomer was 42.5%.
An aqueous PVA-based resin solution (trade name "GOHSEFIMER (registered trademark) Z-200", manufactured by Japanese chemical industry Co., ltd.; resin concentration: 3% by weight) was applied to one surface of the obtained undechromogen film a1, and a cycloolefin film (manufactured by Zeon Corporation, zeonor, thickness: 25 μm) was bonded to obtain an optical laminate having a constitution of [ undechromogen film a 1/protective layer ]. As the protective layer, a protective layer provided with a hard coat layer may be used, and examples of such a protective layer include a cycloolefin Film with a hard coat layer (manufactured by ZEON corporation, product name "G-Film", and total thickness 27 μm (Film thickness 25 μm+hard coat layer thickness 2 μm)).
The optical laminate was cut into a size of 45mm×50mm, and immersed in water at 23 ℃ for 31 hours in a state of being bonded to a glass plate via an acrylic pressure-sensitive adhesive layer (thickness 15 μm) so that the surface on the side of the non-chromogen film became an exposed surface. Then, the film was dried at 50℃for 5 minutes, whereby a polarizing plate having a constitution of [ polarizing film A1/protective layer ] was obtained.
Examples 1 to 2
A polarizing plate having a structure of [ polarizing film A2/protective layer ] was obtained in the same manner as in example 1-1, except that the polarizing plate was immersed in water at 55 ℃ for 9 minutes instead of immersing in water at 23 ℃ for 31 hours.
Examples 1 to 3
A polarizing plate having a structure of [ polarizing film A3/protective layer ] was obtained in the same manner as in example 1-1, except that the polarizing plate was immersed in water at 60 ℃ for 4 minutes instead of immersing in water at 23 ℃ for 31 hours.
Examples 1 to 4
A polarizing plate having a structure of [ polarizing film A4/protective layer ] was obtained in the same manner as in example 1-1, except that the polarizing plate was immersed in water at 65 ℃ for 3 minutes instead of immersing in water at 23 ℃ for 31 hours.
Comparative example 1
An optical laminate having a structure of [ non-depigmented film a 1/protective layer ] produced in the same manner as in example 1-1 was used as a polarizing plate.
Examples 2 to 1
An amorphous isophthalic acid copolymerized polyethylene terephthalate film (thickness: 100 μm) having a long shape and a Tg of about 75 ℃ was used as a thermoplastic resin base material, and one side of the resin base material was subjected to corona treatment.
Polyvinyl alcohol (polymerization degree 4200, saponification degree 99.2 mol%) and acetoacetyl-modified PVA (trade name "GOHSEFIMER" manufactured by Japanese synthetic chemical Co., ltd.) were mixed in a ratio of 9:1 to 100 parts by weight of the PVA-based resin mixed in the above step, 13 parts by weight of potassium iodide was added, and the obtained material was dissolved in water to prepare a PVA aqueous solution (coating liquid).
The PVA aqueous solution was applied to the corona treated surface of the resin substrate and dried at 60 ℃ to form a PVA-based resin layer having a thickness of 13 μm, thereby producing a laminate.
The resulting laminate was uniaxially stretched to 2.4 times in the machine direction (lengthwise direction) in an oven at 130 c (air-assisted stretching treatment).
Next, the laminate was immersed in an insolubilization bath (an aqueous boric acid solution obtained by mixing 4 parts by weight of boric acid with 100 parts by weight of water) at a liquid temperature of 40 ℃ for 30 seconds (insolubilization treatment).
Next, the resultant film was immersed in a dyeing bath (aqueous iodine solution obtained by mixing iodine and potassium iodide in a weight ratio of 1:7 with respect to 100 parts by weight of water) at a liquid temperature of 30 ℃ for 60 seconds while adjusting the concentration so that the monomer transmittance (Ts) of the finally obtained non-depigmented film became 42.3% (dyeing treatment).
Then, the resultant mixture was immersed in a crosslinking bath (aqueous boric acid solution obtained by mixing 3 parts by weight of potassium iodide with 5 parts by weight of boric acid based on 100 parts by weight of water) at a liquid temperature of 40℃for 30 seconds (crosslinking treatment).
Thereafter, the laminate was subjected to uniaxial stretching (in-water stretching treatment) while immersed in an aqueous boric acid solution (boric acid concentration 4 wt% and potassium iodide concentration 5 wt%) at a liquid temperature of 70 ℃ so that the total stretching ratio became 5.5 times in the longitudinal direction (longitudinal direction) between rolls having different peripheral speeds.
Thereafter, the laminate was immersed in a washing bath (aqueous solution obtained by mixing 4 parts by weight of potassium iodide with 100 parts by weight of water) at a liquid temperature of 20 ℃.
After that, the sheet was dried in an oven maintained at about 90℃and brought into contact with a SUS-made heating roller maintained at a surface temperature of about 75 ℃. The shrinkage in the width direction of the laminate resulting from the drying shrinkage treatment was 2%.
In this manner, a non-depigmented film having a water content of 4.5% and a thickness of 5 μm was formed on a resin substrate, a cycloolefin film (manufactured by Zeon Corporation, zeonor, thickness: 25 μm) was bonded to the surface of the non-depigmented film by a UV curable adhesive (thickness: 1.0 μm), and then the resin substrate was peeled off to obtain an optical laminate having a structure of [ non-depigmented film b 1/protective layer ].
The optical laminate was cut into a size of 45mm×50mm, and immersed in water at 50 ℃ for 9 minutes in a state of being bonded to a glass plate via an acrylic pressure-sensitive adhesive layer (thickness 15 μm) so that the surface on the side of the non-chromogen film became an exposed surface. Then, the film was dried at 50℃for 5 minutes, whereby a polarizing plate having a constitution of [ polarizing film B1/protective layer ] was obtained.
Examples 2 to 2
A polarizing plate having a structure of [ polarizing film B2/protective layer ] was obtained in the same manner as in example 2-1, except that the polarizing plate was immersed in water at 55 ℃ for 3 minutes instead of immersing in water at 50 ℃ for 9 minutes.
Examples 2 to 3
A polarizing plate having a structure of [ polarizing film B3/protective layer ] was obtained in the same manner as in example 2-1, except that the polarizing plate was immersed in water at 60 ℃ for 2 minutes instead of immersing in water at 50 ℃ for 9 minutes.
Examples 2 to 4
A polarizing plate having a structure of [ polarizing film B4/protective layer ] was obtained in the same manner as in example 2-1, except that the polarizing plate was immersed in water at 60 ℃ for 3 minutes instead of immersing in water at 50 ℃ for 9 minutes.
Comparative example 2
An optical laminate having a structure of [ non-depigmented film b 1/protective layer ] produced in the same manner as in example 2-1 was used as a polarizing plate.
The non-depigmented films and polarizing films obtained in the examples and comparative examples were evaluated for various properties.
The results are shown in table 1.
As shown in table 1, it is known that, by the manufacturing method of the example, the transmittance increase rate (Δts (λ)) at the wavelength λnm of the PVA-based resin film before and after the contact with water satisfies the relationship of Δts (415) > Δts (470) > Δts (550), and the transmittance increase rate at the wavelength 415nm is large. The polarizing film obtained by such a production method has practically acceptable optical characteristics (typically, a single transmittance and a degree of polarization), and the transmittance of light having a short wavelength increases.
Industrial applicability
The polarizing film of the present invention can be suitably used in image display devices such as liquid crystal display devices and EL display devices, particularly in organic EL display devices.
Claims (6)
1. A method of manufacturing a polarizing film, comprising, in order:
a step of subjecting the polyvinyl alcohol resin film to dyeing treatment and stretching treatment; a kind of electronic device with high-pressure air-conditioning system
An aqueous solvent is brought into contact with the surface of the polyvinyl alcohol resin film,
the ratio (Δts (λ)) of the transmittance of the polyvinyl alcohol resin film after the contact with the aqueous solvent at the wavelength λ nm to the transmittance before the contact satisfies the relationship of Δts (415) > Δts (470) > Δts (550).
2. The production method according to claim 1, wherein the aqueous solvent has a temperature of 20 to 70 ℃.
3. The production method according to claim 1 or 2, wherein the polyvinyl alcohol resin film contacted with the aqueous solvent has a water content of 15% by weight or less.
4. The method according to any one of claims 1 to 3, wherein the thickness of the polyvinyl alcohol resin film in contact with the aqueous solvent is 12 μm or less.
5. The production method according to any one of claims 1 to 4, wherein the step of subjecting the polyvinyl alcohol resin film to dyeing treatment and stretching treatment comprises:
Forming a polyvinyl alcohol resin film containing a halide and a polyvinyl alcohol resin on one side of a long thermoplastic resin substrate to form a laminate; a kind of electronic device with high-pressure air-conditioning system
The laminate is sequentially subjected to an air-assisted stretching treatment, a dyeing treatment, an in-water stretching treatment, and a drying shrinkage treatment in which the laminate is shrunk by 2% or more in the width direction by being conveyed in the longitudinal direction while being heated.
6. The method according to any one of claims 1 to 5, which is a method for producing a polarizing film having a haze of 1% or less.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2021008758A JP2022112801A (en) | 2021-01-22 | 2021-01-22 | Method of manufacturing polarizing film |
| JP2021-008758 | 2021-01-22 | ||
| PCT/JP2021/047761 WO2022158235A1 (en) | 2021-01-22 | 2021-12-23 | Method for producing polarizing film |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116710819A true CN116710819A (en) | 2023-09-05 |
Family
ID=82548255
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202180091354.XA Pending CN116710819A (en) | 2021-01-22 | 2021-12-23 | Method for manufacturing polarizing film |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JP2022112801A (en) |
| KR (1) | KR20230129451A (en) |
| CN (1) | CN116710819A (en) |
| TW (1) | TW202239571A (en) |
| WO (1) | WO2022158235A1 (en) |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002311239A (en) | 2001-04-16 | 2002-10-23 | Nitto Denko Corp | Quarter-wave plate, circularly polarizing plate and display device |
| JP2002372622A (en) | 2001-06-14 | 2002-12-26 | Nitto Denko Corp | Composite optical retardation plate, circularly polarizing plate and liquid crystal display, organic el display device |
| JP6728581B2 (en) * | 2014-06-25 | 2020-07-22 | 住友化学株式会社 | Light-absorption anisotropic film, three-dimensional light-absorption anisotropic film, and method for producing the same |
| CN108603961B (en) * | 2016-01-28 | 2021-04-20 | 柯尼卡美能达株式会社 | Polarizing plate, method for producing polarizing plate, and liquid crystal display device |
| JP7312038B2 (en) * | 2019-06-25 | 2023-07-20 | 日東電工株式会社 | Manufacturing method of polarizing plate |
-
2021
- 2021-01-22 JP JP2021008758A patent/JP2022112801A/en active Pending
- 2021-12-23 WO PCT/JP2021/047761 patent/WO2022158235A1/en active Application Filing
- 2021-12-23 CN CN202180091354.XA patent/CN116710819A/en active Pending
- 2021-12-23 KR KR1020237024444A patent/KR20230129451A/en unknown
-
2022
- 2022-01-17 TW TW111101824A patent/TW202239571A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| JP2022112801A (en) | 2022-08-03 |
| TW202239571A (en) | 2022-10-16 |
| KR20230129451A (en) | 2023-09-08 |
| WO2022158235A1 (en) | 2022-07-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| TWI801599B (en) | Polarizing film and method for manufacturing polarizing film | |
| WO2012032984A1 (en) | Method for producing thin polarizing film | |
| TWI775940B (en) | Polarizing plate, polarizing plate roll material and polarizing film manufacturing method | |
| CN111095051B (en) | Polarizing plate, polarizing plate roll, and method for producing polarizing film | |
| CN112789528B (en) | Polarizing plate, method for manufacturing the same, and image display device including the same | |
| KR20200054192A (en) | Polarizing film, polarizing plate, and manufacturing method of polarizing film | |
| TW201915063A (en) | Polarizing plate, polarizing plate roll, and method for producing polarizing film | |
| KR20200054191A (en) | Polarizing film, polarizing plate, and manufacturing method of polarizing film | |
| CN111316141A (en) | Polarizing plate, polarizing plate roll, and method for producing polarizing film | |
| KR20200034799A (en) | Polarizing film, polarizing plate, and manufacturing method of polarizing film | |
| CN111095053A (en) | Polarizing plate, polarizing plate roll, and method for producing polarizing film | |
| TWI789514B (en) | Polarizing plate, polarizing plate coil, and method for manufacturing polarizing film | |
| CN116710819A (en) | Method for manufacturing polarizing film | |
| CN111095056A (en) | Polarizing plate, polarizing plate roll, and method for producing polarizing film | |
| CN111095052A (en) | Polarizing plate, polarizing plate roll, and method for producing polarizing film | |
| WO2023218822A1 (en) | Method for producing polarizing film | |
| WO2023218821A1 (en) | Method for producing polarizing film | |
| WO2023218820A1 (en) | Method for producing polarizing film | |
| CN113646677B (en) | Polarizing film, polarizing plate, and method for producing polarizing film | |
| WO2022158088A1 (en) | Polarizing plate manufacturing method, image display device manufacturing method, and method for adjusting transmittance of polarizing film | |
| JP2023050226A (en) | Method for producing polarizing film | |
| JP2023050227A (en) | Method for producing polarizing film | |
| TW202346905A (en) | Lens part, laminate, display body, and manufacturing method and display method for display body |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |