JP2020034596A - Method of manufacturing stretched resin film, method of manufacturing polarizer, and device for manufacturing stretched resin film - Google Patents
Method of manufacturing stretched resin film, method of manufacturing polarizer, and device for manufacturing stretched resin film Download PDFInfo
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- JP2020034596A JP2020034596A JP2018158255A JP2018158255A JP2020034596A JP 2020034596 A JP2020034596 A JP 2020034596A JP 2018158255 A JP2018158255 A JP 2018158255A JP 2018158255 A JP2018158255 A JP 2018158255A JP 2020034596 A JP2020034596 A JP 2020034596A
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- resin film
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- film
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- 229920005989 resin Polymers 0.000 title claims abstract description 225
- 239000011347 resin Substances 0.000 title claims abstract description 225
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 56
- 238000000034 method Methods 0.000 claims abstract description 61
- 238000005406 washing Methods 0.000 claims abstract description 26
- 239000004372 Polyvinyl alcohol Substances 0.000 claims description 126
- 229920002451 polyvinyl alcohol Polymers 0.000 claims description 126
- 229920001225 polyester resin Polymers 0.000 claims description 56
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 52
- 238000004140 cleaning Methods 0.000 claims description 42
- 238000004043 dyeing Methods 0.000 claims description 23
- 239000002250 absorbent Substances 0.000 claims description 17
- 230000002950 deficient Effects 0.000 claims description 10
- 238000007689 inspection Methods 0.000 claims description 6
- 238000012545 processing Methods 0.000 claims description 4
- 230000007547 defect Effects 0.000 abstract description 19
- 238000001514 detection method Methods 0.000 abstract 1
- NLKNQRATVPKPDG-UHFFFAOYSA-M potassium iodide Chemical compound [K+].[I-] NLKNQRATVPKPDG-UHFFFAOYSA-M 0.000 description 45
- 239000004645 polyester resin Substances 0.000 description 32
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 description 31
- 239000004327 boric acid Substances 0.000 description 31
- 239000000243 solution Substances 0.000 description 28
- 239000007864 aqueous solution Substances 0.000 description 22
- 230000003287 optical effect Effects 0.000 description 17
- 238000000576 coating method Methods 0.000 description 15
- ZCYVEMRRCGMTRW-UHFFFAOYSA-N 7553-56-2 Chemical compound [I] ZCYVEMRRCGMTRW-UHFFFAOYSA-N 0.000 description 13
- 239000011248 coating agent Substances 0.000 description 13
- 229910052740 iodine Inorganic materials 0.000 description 13
- 239000011630 iodine Substances 0.000 description 13
- 239000007788 liquid Substances 0.000 description 13
- XMBWDFGMSWQBCA-UHFFFAOYSA-N hydrogen iodide Chemical compound I XMBWDFGMSWQBCA-UHFFFAOYSA-N 0.000 description 12
- 206010042674 Swelling Diseases 0.000 description 10
- 230000009477 glass transition Effects 0.000 description 10
- 230000008961 swelling Effects 0.000 description 10
- 238000010521 absorption reaction Methods 0.000 description 9
- 238000004132 cross linking Methods 0.000 description 9
- 238000001035 drying Methods 0.000 description 7
- -1 polyethylene terephthalate Polymers 0.000 description 7
- 238000002425 crystallisation Methods 0.000 description 6
- 230000008025 crystallization Effects 0.000 description 6
- FVAUCKIRQBBSSJ-UHFFFAOYSA-M sodium iodide Chemical compound [Na+].[I-] FVAUCKIRQBBSSJ-UHFFFAOYSA-M 0.000 description 6
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 5
- 238000010438 heat treatment Methods 0.000 description 5
- 238000002156 mixing Methods 0.000 description 5
- 230000002093 peripheral effect Effects 0.000 description 5
- 238000007127 saponification reaction Methods 0.000 description 5
- 239000002904 solvent Substances 0.000 description 5
- DKNPRRRKHAEUMW-UHFFFAOYSA-N Iodine aqueous Chemical compound [K+].I[I-]I DKNPRRRKHAEUMW-UHFFFAOYSA-N 0.000 description 4
- 238000004090 dissolution Methods 0.000 description 4
- 150000004820 halides Chemical class 0.000 description 4
- 238000007654 immersion Methods 0.000 description 4
- HSZCZNFXUDYRKD-UHFFFAOYSA-M lithium iodide Chemical compound [Li+].[I-] HSZCZNFXUDYRKD-UHFFFAOYSA-M 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 229920000139 polyethylene terephthalate Polymers 0.000 description 4
- 239000005020 polyethylene terephthalate Substances 0.000 description 4
- 238000006116 polymerization reaction Methods 0.000 description 4
- 238000002834 transmittance Methods 0.000 description 4
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- MTHSVFCYNBDYFN-UHFFFAOYSA-N diethylene glycol Chemical compound OCCOCCO MTHSVFCYNBDYFN-UHFFFAOYSA-N 0.000 description 3
- 238000011156 evaluation Methods 0.000 description 3
- 239000004014 plasticizer Substances 0.000 description 3
- 238000012795 verification Methods 0.000 description 3
- 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
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- 239000000654 additive Substances 0.000 description 2
- 230000000996 additive effect Effects 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 229920001577 copolymer Polymers 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000010828 elution Methods 0.000 description 2
- 150000002148 esters Chemical class 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
- QQVIHTHCMHWDBS-UHFFFAOYSA-N isophthalic acid Chemical compound OC(=O)C1=CC=CC(C(O)=O)=C1 QQVIHTHCMHWDBS-UHFFFAOYSA-N 0.000 description 2
- 239000012528 membrane Substances 0.000 description 2
- 230000010287 polarization Effects 0.000 description 2
- 235000009518 sodium iodide Nutrition 0.000 description 2
- 238000005507 spraying Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 150000005846 sugar alcohols Polymers 0.000 description 2
- 239000004094 surface-active agent Substances 0.000 description 2
- 229920005992 thermoplastic resin Polymers 0.000 description 2
- UAYWVJHJZHQCIE-UHFFFAOYSA-L zinc iodide Chemical compound I[Zn]I UAYWVJHJZHQCIE-UHFFFAOYSA-L 0.000 description 2
- 229920008790 Amorphous Polyethylene terephthalate Polymers 0.000 description 1
- 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
- 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
- 239000004743 Polypropylene Substances 0.000 description 1
- ZJCCRDAZUWHFQH-UHFFFAOYSA-N Trimethylolpropane Chemical compound CCC(CO)(CO)CO ZJCCRDAZUWHFQH-UHFFFAOYSA-N 0.000 description 1
- ORLQHILJRHBSAY-UHFFFAOYSA-N [1-(hydroxymethyl)cyclohexyl]methanol Chemical compound OCC1(CO)CCCCC1 ORLQHILJRHBSAY-UHFFFAOYSA-N 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
- 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
- 229920006026 co-polymeric resin Polymers 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- GBRBMTNGQBKBQE-UHFFFAOYSA-L copper;diiodide Chemical compound I[Cu]I GBRBMTNGQBKBQE-UHFFFAOYSA-L 0.000 description 1
- 238000003851 corona treatment Methods 0.000 description 1
- 238000007766 curtain coating Methods 0.000 description 1
- 150000001925 cycloalkenes Chemical class 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
- 238000010586 diagram Methods 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
- 208000037265 diseases, disorders, signs and symptoms Diseases 0.000 description 1
- 208000035475 disorder Diseases 0.000 description 1
- 239000005038 ethylene vinyl acetate Substances 0.000 description 1
- 238000001879 gelation Methods 0.000 description 1
- 235000011187 glycerol Nutrition 0.000 description 1
- 150000002334 glycols Chemical class 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
- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 description 1
- PNDPGZBMCMUPRI-UHFFFAOYSA-N iodine Chemical compound II PNDPGZBMCMUPRI-UHFFFAOYSA-N 0.000 description 1
- 238000005259 measurement Methods 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
- JFNLZVQOOSMTJK-KNVOCYPGSA-N norbornene Chemical compound C1[C@@H]2CC[C@H]1C=C2 JFNLZVQOOSMTJK-KNVOCYPGSA-N 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
- 238000000926 separation method Methods 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
- 230000003595 spectral effect Effects 0.000 description 1
- 238000004528 spin coating Methods 0.000 description 1
- 239000012192 staining solution Substances 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 238000004381 surface treatment Methods 0.000 description 1
- 238000010345 tape casting Methods 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
- 238000012546 transfer Methods 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
- 230000037303 wrinkles Effects 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
- B29D7/00—Producing flat articles, e.g. films or sheets
- B29D7/01—Films 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
-
- 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
- B29C71/00—After-treatment of articles without altering their shape; Apparatus therefor
- B29C71/0009—After-treatment of articles without altering their shape; Apparatus therefor using liquids, e.g. solvents, swelling agents
-
- 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
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
- G02B1/04—Optical elements characterised by the material of which they are made; Optical coatings for optical elements made of organic materials, e.g. plastics
-
- 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
- B29C71/00—After-treatment of articles without altering their shape; Apparatus therefor
- B29C71/0009—After-treatment of articles without altering their shape; Apparatus therefor using liquids, e.g. solvents, swelling agents
- B29C2071/0045—Washing using non-reactive liquids
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)
- Materials Engineering (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Polarising Elements (AREA)
- Shaping By String And By Release Of Stress In Plastics And The Like (AREA)
Abstract
Description
本発明は、延伸樹脂膜の製造方法、偏光子の製造方法、および延伸樹脂膜の製造装置に関する。 The present invention relates to a method for manufacturing a stretched resin film, a method for manufacturing a polarizer, and an apparatus for manufacturing a stretched resin film.
長尺状のフィルムの片側に樹脂層が形成された積層体を延伸することにより、樹脂層の厚みが非常に薄い場合であっても樹脂層を破断させることなく延伸し、厚みが薄い延伸樹脂膜を得る方法が知られている。このような延伸樹脂膜の一例として、ポリエステル系樹脂フィルムとポリビニルアルコール系樹脂層（ＰＶＡ系樹脂層）との積層体を延伸および染色することにより、ポリエステル系樹脂フィルム上に偏光子を形成する方法が提案されている（例えば、特許文献１）。しかしながら、上記の方法によって得られる延伸樹脂膜は、外観不良の検出が容易ではない。 By stretching a laminate having a resin layer formed on one side of a long film, the stretched resin is stretched without breaking the resin layer even when the thickness of the resin layer is extremely thin, and the stretched resin having a small thickness is obtained. Methods for obtaining membranes are known. As an example of such a stretched resin film, a method of forming a polarizer on a polyester-based resin film by stretching and dyeing a laminate of a polyester-based resin film and a polyvinyl alcohol-based resin layer (PVA-based resin layer) Has been proposed (for example, Patent Document 1). However, in the stretched resin film obtained by the above method, it is not easy to detect a defective appearance.
本発明は上記従来の課題を解決するためになされたものであり、その主たる目的は、外観不良の検出が容易である延伸樹脂膜の製造方法、そのような製造方法を用いた偏光子の製造方法、および延伸樹脂膜の製造装置を提供することにある。 The present invention has been made to solve the above-mentioned conventional problems, and its main objects are to provide a method for producing a stretched resin film in which the appearance defect can be easily detected, and to produce a polarizer using such a production method. An object of the present invention is to provide a method and an apparatus for producing a stretched resin film.
本発明の延伸樹脂膜の製造方法は、長尺状の非吸水性フィルムの片側に吸水性の樹脂層が形成された積層体を搬送しながら、上記積層体に水中延伸処理と洗浄処理とをこの順に施すことにより、上記非吸水性フィルム上に延伸樹脂膜を形成する、延伸樹脂膜の製造方法であって、上記洗浄処理後の上記延伸樹脂膜の厚みに基づいて、上記延伸樹脂膜の外観不良を検出することを含む。
本発明の延伸樹脂膜の製造方法は、長尺状の非吸水性フィルムの片側に吸水性の樹脂層が形成された積層体を搬送しながら、上記積層体に水中延伸処理と洗浄処理とをこの順に施すことにより、上記非吸水性フィルム上に延伸樹脂膜を形成する、延伸樹脂膜の製造方法であって、上記洗浄処理後の上記延伸樹脂膜の水分率に基づいて、上記延伸樹脂膜の外観不良を検出することを含む。
１つの実施形態においては、上記洗浄処理の後に、上記積層体を搬送しながら上記延伸樹脂膜の厚みを非接触で測定することと、測定された上記延伸樹脂膜の厚みに基づいて、上記洗浄処理後の上記延伸樹脂膜の水分率を算出することと、をさらに含む。
本発明の別の局面によれば、偏光子の製造方法が提供される。この偏光子の製造方法は、上記の製造方法により、上記非吸水性フィルム上に偏光子を形成する、偏光子の製造方法であって、上記非吸水性フィルムがポリエステル系樹脂フィルムであり、上記樹脂層がポリビニルアルコール系樹脂層であり、上記ポリエステル系樹脂フィルムと上記ポリビニルアルコール系樹脂層との積層体に染色処理を施すことをさらに含む。
本発明の別の局面によれば、延伸樹脂膜の製造装置が提供される。この延伸樹脂膜の製造装置は、長尺状の非吸水性フィルムの片側に吸水性の樹脂層が形成された積層体を搬送しながら、上記積層体に処理を施すことにより、上記非吸水性フィルム上に延伸樹脂膜を形成する、延伸樹脂膜の製造装置であって、上記積層体を水中延伸する水中延伸処理部と、水中延伸の後に上記積層体を洗浄する洗浄処理部と、上記洗浄処理後の上記延伸樹脂膜の厚みまたは水分率に基づいて、上記延伸樹脂膜の外観不良を検出する検査部と、を含む。
The method for producing a stretched resin film of the present invention comprises, while transporting a laminate in which a water-absorbent resin layer is formed on one side of a long non-water-absorbent film, performing an underwater stretching treatment and a washing treatment on the laminate. By performing in this order, a stretched resin film is formed on the non-water-absorbing film, and is a method for producing a stretched resin film, based on the thickness of the stretched resin film after the washing treatment, This includes detecting appearance defects.
The method for producing a stretched resin film of the present invention comprises, while transporting a laminate in which a water-absorbent resin layer is formed on one side of a long non-water-absorbent film, performing an underwater stretching treatment and a washing treatment on the laminate. A method for producing a stretched resin film, comprising forming a stretched resin film on the non-water-absorbent film by applying in this order, wherein the stretched resin film is formed based on a moisture content of the stretched resin film after the washing treatment. Detecting the poor appearance of the image.
In one embodiment, after the cleaning treatment, the thickness of the stretched resin film is measured in a non-contact manner while transporting the laminate, and the cleaning is performed based on the measured thickness of the stretched resin film. Calculating the moisture content of the stretched resin film after the treatment.
According to another aspect of the present invention, a method for manufacturing a polarizer is provided. The method for producing a polarizer is a method for producing a polarizer, wherein a polarizer is formed on the non-water-absorbing film by the above-described production method, wherein the non-water-absorbing film is a polyester resin film, The resin layer is a polyvinyl alcohol-based resin layer, and further includes performing a dyeing treatment on a laminate of the polyester resin film and the polyvinyl alcohol-based resin layer.
According to another aspect of the present invention, an apparatus for manufacturing a stretched resin film is provided. This stretched resin film manufacturing apparatus performs the above-mentioned non-water-absorbing process by performing a treatment on the above-mentioned laminated product while conveying a laminated product having a water-absorbing resin layer formed on one side of a long non-water-absorbing film. An apparatus for manufacturing a stretched resin film that forms a stretched resin film on a film, comprising: an underwater stretching section for stretching the laminate in water; a washing section for washing the laminate after stretching in water; and the washing step. An inspection unit for detecting a defective appearance of the stretched resin film based on the thickness or the moisture content of the stretched resin film after the treatment.
本発明によれば、洗浄処理後の前記延伸樹脂膜の厚みまたは水分率に基づいて延伸樹脂膜の外観不良を検出することにより、外観不良を容易に検出することができる。 According to the present invention, the appearance defect can be easily detected by detecting the appearance defect of the stretched resin film based on the thickness or the moisture content of the stretched resin film after the cleaning treatment.
以下、本発明の実施形態について説明するが、本発明はこれらの実施形態には限定されない。 Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to these embodiments.
Ａ．延伸樹脂膜の製造方法
本発明の延伸樹脂膜の製造方法は、長尺状の非吸水性フィルムの片側に吸水性の樹脂層が形成された積層体を搬送しながら、積層体に水中延伸処理と洗浄処理とをこの順に施すことにより、非吸水性フィルム上に延伸樹脂膜を形成する、というものである。上記の製造方法は、洗浄処理後の延伸樹脂膜の厚みまたは水分率に基づいて、延伸樹脂膜の外観不良を検出することを含む。１つの実施形態においては、洗浄処理の後に、積層体を搬送しながら延伸樹脂膜の厚みを非接触で測定することと、測定された延伸樹脂膜の厚みに基づいて、洗浄処理後の延伸樹脂膜の水分率を算出することと、をさらに含む。上記の製造方法によれば、製造工程中で（インラインで）延伸樹脂膜の外観不良を容易に検出し得、さらには、外観不良が発生した場合に水中延伸処理工程などの前工程での処理条件を改善することにより、製造される延伸樹脂膜の品質を改善し得る。
A. Method for Producing Stretched Resin Film The method for producing a stretched resin film of the present invention comprises a step of subjecting a laminate in which a water-absorbent resin layer is formed on one side of a long non-water-absorbent film to an underwater stretching treatment on the laminate. And a washing treatment in this order to form a stretched resin film on the non-water-absorbing film. The above manufacturing method includes detecting a defective appearance of the stretched resin film based on the thickness or the moisture content of the stretched resin film after the cleaning treatment. In one embodiment, after the cleaning treatment, the thickness of the stretched resin film is measured in a non-contact manner while transporting the laminate, and based on the measured thickness of the stretched resin film, the stretched resin after the cleaning treatment is used. Calculating the moisture content of the membrane. According to the above manufacturing method, the appearance defect of the stretched resin film can be easily detected in the manufacturing process (in-line), and furthermore, when the appearance defect occurs, the process is performed in a pre-process such as an underwater stretching process. By improving the conditions, the quality of the produced stretched resin film can be improved.
非吸水性フィルムの吸水率は、好ましくは３％以下であり、より好ましくは２％以下であり、特に好ましくは０．１％〜１％である。吸水率は、ＪＩＳ Ｋ ７２０９−２０００に準じて求められる値である。非吸水性フィルムの厚みは、好ましくは１０μｍ〜２００μｍである。非吸水性フィルムとしては、本発明の効果が得られる限りにおいて、任意の適切なフィルムを用いることができ、代表的には、熱可塑性樹脂により構成されたフィルムを用いることができる。熱可塑性樹脂としては、例えば、ポリエチレンテレフタレート系樹脂等のエステル系樹脂、ノルボルネン系樹脂等のシクロオレフィン系樹脂、ポリプロピレン等のオレフィン系樹脂、ポリアミド系樹脂、ポリカーボネート系樹脂、これらの共重合体樹脂等が挙げられる。 The water absorption of the non-water-absorbing film is preferably 3% or less, more preferably 2% or less, and particularly preferably 0.1% to 1%. The water absorption is a value determined according to JIS K 7209-2000. The thickness of the non-water-absorbing film is preferably from 10 μm to 200 μm. As the non-water-absorbing film, any appropriate film can be used as long as the effects of the present invention can be obtained. Typically, a film made of a thermoplastic resin can be used. Examples of the thermoplastic resin include, for example, ester resins such as polyethylene terephthalate resin, cycloolefin resins such as norbornene resin, olefin resins such as polypropylene, polyamide resins, polycarbonate resins, and copolymer resins thereof. Is mentioned.
吸水性の樹脂層の吸水率は、好ましくは２５％以上であり、より好ましくは２５％〜１３０％であり、特に好ましくは２５％〜１１０％である。延伸処理前の吸水性の樹脂層の厚みは、好ましくは３μｍ〜２０μｍである。吸水性の樹脂層を構成する樹脂材料としては、本発明の効果が得られる限りにおいて、任意の適切な樹脂材料を用いることができ、代表的には、ＰＶＡ系樹脂を用いることができる。 The water absorption of the water-absorbing resin layer is preferably 25% or more, more preferably 25% to 130%, and particularly preferably 25% to 110%. The thickness of the water-absorbing resin layer before the stretching treatment is preferably 3 μm to 20 μm. As the resin material constituting the water-absorbing resin layer, any appropriate resin material can be used as long as the effects of the present invention can be obtained, and a PVA-based resin can be typically used.
本発明の延伸樹脂膜の製造方法は、偏光子の製造方法として利用することができる。以下では、延伸樹脂膜として偏光子を例に挙げて、偏光子の製造方法について説明する。 The method for producing a stretched resin film of the present invention can be used as a method for producing a polarizer. Hereinafter, a method of manufacturing a polarizer will be described using a polarizer as an example of the stretched resin film.
Ｂ．偏光子の製造方法
本発明の偏光子の製造方法は、長尺状のポリエステル系樹脂フィルムの片側にポリビニルアルコール系樹脂層（ＰＶＡ系樹脂層）が形成された積層体を搬送しながら、積層体に染色処理を施すこと、および水中延伸処理と洗浄処理とをこの順に施すことにより、ポリエステル系樹脂フィルム上に偏光子を形成する、というものである。上記の製造方法は、洗浄処理後のＰＶＡ系樹脂層の厚みまたは水分率に基づいて、ＰＶＡ系樹脂層の外観不良を検出することを含む。
B. Method for Producing Polarizer The method for producing a polarizer of the present invention relates to a method for producing a polarizer, comprising transporting a laminate in which a polyvinyl alcohol-based resin layer (PVA-based resin layer) is formed on one side of a long polyester resin film. Is subjected to a dyeing treatment, and an in-water stretching treatment and a washing treatment are performed in this order to form a polarizer on the polyester resin film. The above manufacturing method includes detecting a defective appearance of the PVA-based resin layer based on the thickness or the moisture content of the PVA-based resin layer after the cleaning treatment.
本発明者らの検証によれば、従来の製造方法に比べて積層体の搬送速度を高めた場合、最終的に得られる偏光子（延伸樹脂膜）に外観不良（例えば、スジ状痕）が発生することがわかった。しかしながら、積層体を搬送しながら、インラインでＰＶＡ系樹脂層の外観不良を検出することは容易ではない。そこで、本発明者らは、更なる検証の結果、洗浄処理後のＰＶＡ系樹脂層の水分率と得られる偏光子の外観不良のレベルとの間に相関があることを発見した。これにより、洗浄処理後のＰＶＡ系樹脂層の水分率に基づいて、偏光子の外観不良を検出することができる。特に、洗浄処理後のＰＶＡ系樹脂層の水分率をインラインで測定することにより、インラインでＰＶＡ系樹脂層の外観不良を検出することができる。 According to the verification of the present inventors, when the transport speed of the laminated body is increased as compared with the conventional manufacturing method, the finally obtained polarizer (stretched resin film) has poor appearance (for example, streak marks). It was found to happen. However, it is not easy to detect the appearance defect of the PVA-based resin layer inline while transporting the laminate. Therefore, the present inventors have found, as a result of further verification, that there is a correlation between the moisture content of the PVA-based resin layer after the cleaning treatment and the level of poor appearance of the obtained polarizer. This makes it possible to detect poor appearance of the polarizer based on the moisture content of the PVA-based resin layer after the cleaning treatment. In particular, by measuring the moisture content of the PVA-based resin layer after the cleaning treatment in-line, the appearance defect of the PVA-based resin layer can be detected in-line.
インラインでＰＶＡ系樹脂層（延伸樹脂膜）の水分率を測定する場合、一般的には、ＩＲ水分率計等の非接触式の水分率計が用いられる。しかしながら、本発明者らの検証によれば、非接触式の水分率計を用いてインラインでＰＶＡ系樹脂層の水分率を測定する方法では、空気中の水分やＰＶＡ系樹脂層の表面に付着した水膜等の影響により、高精度で水分率を測定することができないことがわかった。そこで、本発明者らは、更なる検証の結果、図２に示すように、洗浄処理後のＰＶＡ系樹脂層の厚みとＰＶＡ系樹脂層の水分率との間に相関があることを発見した。これは、ＰＶＡ系樹脂層が吸水することによる面内方向の寸法変化は非吸水性のポリエステル系樹脂フィルムによって拘束されており、ＰＶＡ系樹脂層は、吸水量に応じて厚み方向に膨張することが原因のひとつであると考えられる。これにより、洗浄処理後の延伸樹脂膜の厚みに基づいて、偏光子の外観不良を検出することができる。特に、洗浄処理後のＰＶＡ系樹脂層の厚みをインラインで測定することにより、インラインでＰＶＡ系樹脂層の外観不良を検出することができる。なお、図２のグラフは、下記表１に示す様々な延伸条件（具体的には、延伸浴のホウ酸濃度）で積層体に水中延伸処理を施したときの、洗浄処理後のＰＶＡ系樹脂層の厚みおよび水分率のデータをプロットしたものである。グラフ中の近似曲線は、プロットデータから指数関数となるように最小二乗法で求めた近似曲線である。図２中の水分率は、乾燥重量法に基づき、以下の式により算出したものである。
ＰＶＡ系樹脂層の水分率＝（洗浄処理後のＰＶＡ系樹脂層の重量−乾燥後のＰＶＡ系樹脂層の重量）／乾燥後のＰＶＡ系樹脂層の重量
When the moisture content of the PVA-based resin layer (stretched resin film) is measured in-line, a non-contact moisture content meter such as an IR moisture content meter is generally used. However, according to the verification of the present inventors, in the method of measuring the moisture content of the PVA-based resin layer in-line using a non-contact moisture content meter, the moisture in the air or the surface of the PVA-based resin layer is not adhered. It was found that the moisture content could not be measured with high accuracy due to the influence of the water film and the like. Therefore, the present inventors have further found that there is a correlation between the thickness of the PVA-based resin layer after the cleaning treatment and the moisture content of the PVA-based resin layer, as shown in FIG. . This is because the dimensional change in the in-plane direction due to the water absorption of the PVA-based resin layer is restrained by the non-water-absorbing polyester-based resin film, and the PVA-based resin layer expands in the thickness direction according to the amount of water absorption. Is considered to be one of the causes. This makes it possible to detect poor appearance of the polarizer based on the thickness of the stretched resin film after the cleaning treatment. In particular, by measuring the thickness of the PVA-based resin layer after the cleaning treatment in-line, the appearance defect of the PVA-based resin layer can be detected in-line. The graph of FIG. 2 shows the PVA-based resin after the washing treatment when the laminate was subjected to the underwater stretching treatment under various stretching conditions (specifically, boric acid concentration of the stretching bath) shown in Table 1 below. It is a plot of data of layer thickness and moisture content. The approximation curve in the graph is an approximation curve obtained from the plot data by the least square method so as to be an exponential function. The moisture percentage in FIG. 2 is calculated by the following equation based on the dry weight method.
Moisture percentage of PVA-based resin layer = (weight of PVA-based resin layer after cleaning treatment-weight of dried PVA-based resin layer) / weight of dried PVA-based resin layer
図１は、本発明の１つの実施形態に係る偏光子の製造工程を示す概略図である。本実施形態に係る偏光子の製造工程は、代表的には、ポリエステル系樹脂フィルムとＰＶＡ系樹脂層との積層体２００を、繰り出し部１０１から繰り出し、搬送ロールによってホウ酸水溶液の浴１１０中に浸漬した後（膨潤処理）、二色性物質（ヨウ素）およびヨウ化カリウムの水溶液の浴１２０中に浸漬する（染色処理）。次いで、ホウ酸およびヨウ化カリウムの水溶液の浴１３０中に浸漬する（架橋処理）。次いで、積層体２００を、ホウ酸水溶液の延伸浴１４０中に浸漬しながら、速比の異なるロールで縦方向（長手方向、搬送方向、ＭＤ方向）に張力を付与して延伸する（水中延伸処理）。次いで、水中延伸した積層体２００を、ヨウ化カリウム水溶液の浴１５０中に浸漬して洗浄する（洗浄処理）。次いで、検査部１６０により、洗浄処理後の積層体２００におけるＰＶＡ系樹脂層の厚みまたは水分率に基づいて、最終的に得られる偏光子の外観不良を検出する。次いで、オーブン１７０により積層体２００を乾燥する（乾燥処理）ことにより、ポリエステル系樹脂フィルム上に偏光子が形成された光学積層体１００が得られる。その後、得られた光学積層体１００を巻き取り部１８０にて巻き取る。図示は省略するが、積層体２００に膨潤処理を施す前に、空中延伸処理を施してもよい。なお、図１に示す製造工程は一例であり、上記の処理の回数、順序等は、特に限定されない。 FIG. 1 is a schematic view illustrating a manufacturing process of a polarizer according to one embodiment of the present invention. The manufacturing process of the polarizer according to the present embodiment is typically, a laminate 200 of a polyester-based resin film and a PVA-based resin layer is fed out from the feeding unit 101, and is placed in a boric acid aqueous solution bath 110 by a transport roll. After immersion (swelling treatment), the substrate is immersed in a bath 120 of an aqueous solution of a dichroic substance (iodine) and potassium iodide (dyeing treatment). Next, it is immersed in a bath 130 of an aqueous solution of boric acid and potassium iodide (crosslinking treatment). Next, the laminate 200 is stretched by applying tension in the longitudinal direction (longitudinal direction, transport direction, MD direction) with rolls having different speed ratios while being immersed in a stretching bath 140 of an aqueous boric acid solution (underwater stretching treatment). ). Next, the underwater-stretched laminate 200 is immersed and washed in a bath 150 of an aqueous potassium iodide solution (washing treatment). Next, the inspection unit 160 detects a defective appearance of the finally obtained polarizer based on the thickness or the moisture content of the PVA-based resin layer in the laminated body 200 after the cleaning process. Next, the laminated body 200 is dried (drying treatment) by the oven 170 to obtain the optical laminated body 100 in which the polarizer is formed on the polyester resin film. Thereafter, the obtained optical laminated body 100 is wound up by the winding section 180. Although illustration is omitted, an air stretching process may be performed before the swelling process is performed on the laminate 200. Note that the manufacturing process shown in FIG. 1 is an example, and the number, order, and the like of the above processes are not particularly limited.
Ｂ−１．積層体
ポリエステル系樹脂フィルムとＰＶＡ系樹脂層との積層体を作製する方法としては、任意の適切な方法が採用され得る。好ましくは、ポリエステル系樹脂フィルムの表面に、ＰＶＡ系樹脂を含む塗布液を塗布し、乾燥することにより、ポリエステル系樹脂フィルム上にＰＶＡ系樹脂層を形成する。
B-1. Laminate Any appropriate method can be adopted as a method for producing a laminate of the polyester resin film and the PVA resin layer. Preferably, a coating solution containing a PVA-based resin is applied to the surface of the polyester-based resin film, and dried to form a PVA-based resin layer on the polyester-based resin film.
塗布液の塗布方法としては、任意の適切な方法を採用することができる。例えば、ロールコート法、スピンコート法、ワイヤーバーコート法、ディップコート法、ダイコート法、カーテンコート法、スプレーコート法、ナイフコート法（コンマコート法等）等が挙げられる。上記塗布液の塗布・乾燥温度は、好ましくは５０℃以上である。 Any appropriate method can be adopted as a method of applying the coating liquid. For example, 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 knife coating method (such as a comma coating method) and the like can be mentioned. The coating / drying temperature of the coating solution is preferably 50 ° C. or higher.
乾燥後のＰＶＡ系樹脂層の厚みは、好ましくは、３μｍ〜４０μｍ、さらに好ましくは３μｍ〜２０μｍであり、特に好ましくは５μｍ〜１５μｍである。 The thickness of the PVA-based resin layer after drying is preferably 3 μm to 40 μm, more preferably 3 μm to 20 μm, and particularly preferably 5 μm to 15 μm.
ＰＶＡ系樹脂層を形成する前に、ポリエステル系樹脂フィルムに表面処理（例えば、コロナ処理等）を施してもよいし、ポリエステル系樹脂フィルム上に易接着層を形成してもよい。このような処理を行うことにより、ポリエステル系樹脂フィルムとＰＶＡ系樹脂層との密着性を向上させることができる。 Before forming the PVA-based resin layer, the polyester-based resin film may be subjected to a surface treatment (for example, corona treatment) or an easy-adhesion layer may be formed on the polyester-based resin film. By performing such a treatment, the adhesion between the polyester resin film and the PVA resin layer can be improved.
Ｂ−１−１．ポリエステル系樹脂フィルム
ポリエステル系樹脂フィルムの厚みは、好ましくは２０μｍ〜３００μｍ、より好ましくは５０μｍ〜２００μｍである。２０μｍ未満であると、ＰＶＡ系樹脂層の形成が困難になるおそれがある。
B-1-1. Polyester Resin Film The thickness of the polyester resin film is preferably 20 μm to 300 μm, more preferably 50 μm to 200 μm. If it is less than 20 μm, formation of a PVA-based resin layer may be difficult.
ポリエステル系樹脂フィルムは、好ましくは、その吸水率が０．２％以上であり、さらに好ましくは０．３％以上である。ポリエステル系樹脂フィルムは、水を吸収し、水が可塑剤的な働きをして可塑化し得る。その結果、延伸応力を大幅に低下させることができ、高倍率に延伸することができる。一方、ポリエステル系樹脂フィルムの吸水率は、好ましくは３．０％以下、さらに好ましくは１．０％以下である。このようなポリエステル系樹脂フィルムを用いることにより、製造時にポリエステル系樹脂フィルムの寸法安定性が著しく低下して、得られる偏光子の外観が悪化するなどの不具合を防止することができる。また、水中延伸時にポリエステル系樹脂フィルムが破断したり、ポリエステル系樹脂フィルムからＰＶＡ系樹脂層が剥離したりするのを防止することができる。 The polyester resin film preferably has a water absorption of 0.2% or more, more preferably 0.3% or more. The polyester resin film absorbs water, and the water acts as a plasticizer and can be plasticized. As a result, the stretching stress can be greatly reduced, and stretching can be performed at a high magnification. On the other hand, the water absorption of the polyester resin film is preferably 3.0% or less, more preferably 1.0% or less. By using such a polyester-based resin film, it is possible to prevent problems such as the dimensional stability of the polyester-based resin film being remarkably reduced at the time of production and the appearance of the obtained polarizer being deteriorated. Further, it is possible to prevent breakage of the polyester resin film during stretching in water and separation of the PVA resin layer from the polyester resin film.
ポリエステル系樹脂フィルムのガラス転移温度（Ｔｇ）は、好ましくは１２０℃以下である。このようなポリエステル系樹脂フィルムを用いることにより、ＰＶＡ系樹脂層の結晶化を抑制しながら、積層体の延伸性を十分に確保することができる。さらに、水によるポリエステル系樹脂フィルムの可塑化と、水中延伸を良好に行うことを考慮すると、１００℃以下、さらには９０℃以下であることがより好ましい。一方、ポリエステル系樹脂フィルムのガラス転移温度は、好ましくは６０℃以上である。このようなポリエステル系樹脂フィルムを用いることにより、上記ＰＶＡ系樹脂を含む塗布液を塗布・乾燥する際に、ポリエステル系樹脂フィルムが変形（例えば、凹凸やタルミ、シワ等の発生）するなどの不具合を防止して、良好に積層体を作製することができる。また、ＰＶＡ系樹脂層の延伸を、好適な温度（例えば、６０℃程度）にて良好に行うことができる。なお、ポリエステル系樹脂フィルムのガラス転移温度は、例えば、構成材料に変性基を導入する、または、結晶化材料を用いて加熱することにより調整することができる。ガラス転移温度（Ｔｇ）は、ＪＩＳ Ｋ ７１２１に準じて求められる値である。 The glass transition temperature (Tg) of the polyester resin film is preferably 120 ° C. or lower. By using such a polyester resin film, the stretchability of the laminate can be sufficiently ensured while suppressing crystallization of the PVA resin layer. Further, in consideration of good plasticization of the polyester-based resin film with water and good stretching in water, the temperature is more preferably 100 ° C or less, further preferably 90 ° C or less. On the other hand, the glass transition temperature of the polyester resin film is preferably 60 ° C. or higher. When such a polyester resin film is used, when applying and drying the coating solution containing the PVA resin, the polyester resin film is deformed (for example, irregularities, tarmi, wrinkles, etc. are generated). Is prevented, and a laminate can be produced favorably. Further, the stretching of the PVA-based resin layer can be favorably performed at a suitable temperature (for example, about 60 ° C.). The glass transition temperature of the polyester resin film can be adjusted, for example, by introducing a modifying group into the constituent material or by heating using a crystallized material. The glass transition temperature (Tg) is a value determined according to JIS K7121.
ポリエステル系樹脂フィルムを構成するエステル系樹脂として、１つの実施形態においては、非晶質の（結晶化していない）ポリエチレンテレフタレート系樹脂が好ましく用いられる。中でも、非晶性の（結晶化しにくい）ポリエチレンテレフタレート系樹脂が特に好ましく用いられる。非晶性のポリエチレンテレフタレート系樹脂の具体例としては、ジカルボン酸としてイソフタル酸および／またはシクロヘキサンジカルボン酸をさらに含む共重合体や、グリコールとしてシクロヘキサンジメタノールやジエチレングリコールをさらに含む共重合体が挙げられる。 In one embodiment, an amorphous (non-crystallized) polyethylene terephthalate resin is preferably used as the ester resin constituting the polyester resin film. Among them, an amorphous (hard to crystallize) polyethylene terephthalate resin is particularly preferably used. Specific examples of the amorphous polyethylene terephthalate-based resin include a copolymer further containing isophthalic acid and / or cyclohexanedicarboxylic acid as a dicarboxylic acid, and a copolymer further containing cyclohexanedimethanol or diethylene glycol as a glycol.
ポリエステル系樹脂フィルムは、予め（ＰＶＡ系樹脂層を形成する前）、延伸されていてもよい。１つの実施形態においては、長尺状のポリエステル系樹脂フィルムの横方向に延伸されている。横方向は、好ましくは、後述の積層体の延伸方向に直交する方向である。なお、本明細書において、「直交」とは、実質的に直交する場合も包含する。ここで、「実質的に直交」とは、９０°±５．０°である場合を包含し、好ましくは９０°±３．０°、さらに好ましくは９０°±１．０°である。ポリエステル系樹脂フィルムの延伸温度は、ガラス転移温度（Ｔｇ）に対し、好ましくはＴｇ−１０℃〜Ｔｇ＋５０℃である。ポリエステル系樹脂フィルムの延伸倍率は、好ましくは１．５倍〜３．０倍である。ポリエステル系樹脂フィルムの延伸方法としては、任意の適切な方法が採用され得る。具体的には、固定端延伸でもよいし、自由端延伸でもよい。延伸方式は、乾式でもよいし、湿式でもよい。ポリエステル系樹脂フィルムの延伸は、一段階で行ってもよいし、多段階で行ってもよい。多段階で行う場合、上述の延伸倍率は、各段階の延伸倍率の積である。 The polyester-based resin film may be stretched in advance (before forming the PVA-based resin layer). In one embodiment, it is stretched in the transverse direction of a long polyester resin film. The lateral direction is preferably a direction orthogonal to the stretching direction of the laminate described below. In addition, in this specification, "orthogonal" includes a case where they are substantially orthogonal. Here, “substantially orthogonal” includes 90 ° ± 5.0 °, preferably 90 ° ± 3.0 °, and more preferably 90 ° ± 1.0 °. The stretching temperature of the polyester resin film is preferably from Tg-10 ° C to Tg + 50 ° C with respect to the glass transition temperature (Tg). The stretch ratio of the polyester resin film is preferably 1.5 times to 3.0 times. Any appropriate method can be adopted as a method for stretching the polyester resin film. Specifically, fixed-end stretching or free-end stretching may be used. The stretching method may be a dry method or a wet method. The stretching of the polyester-based resin film may be performed in one step or may be performed in multiple steps. In the case of performing in multiple stages, the above-mentioned stretching ratio is a product of the stretching ratios in each stage.
Ｂ−１−２．ＰＶＡ系樹脂を含む塗布液
上記塗布液は、代表的には、上記ＰＶＡ系樹脂を溶媒に溶解させた溶液である。溶媒としては、例えば、水、ジメチルスルホキシド、ジメチルホルムアミド、ジメチルアセトアミド、Ｎ−メチルピロリドン、各種グリコール類、トリメチロールプロパン等の多価アルコール類、エチレンジアミン、ジエチレントリアミン等のアミン類が挙げられる。これらは単独で、または、二種以上組み合わせて用いることができる。これらの中でも、好ましくは、水である。溶液のＰＶＡ系樹脂濃度は、溶媒１００重量部に対して、好ましくは３重量部〜２０重量部である。このような樹脂濃度であれば、ポリエステル系樹脂フィルムに密着した均一な塗布膜を形成することができる。
B-1-2. Coating solution containing PVA-based resin The coating solution is typically a solution in which the PVA-based resin is dissolved in a solvent. Examples of the solvent include water, dimethylsulfoxide, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, various glycols, polyhydric alcohols such as trimethylolpropane, and amines such as ethylenediamine and diethylenetriamine. These can be used alone or in combination of two or more. Among these, water is preferable. The concentration of the PVA-based resin in the solution is preferably 3 parts by weight to 20 parts by weight with respect to 100 parts by weight of the solvent. With such a resin concentration, a uniform coating film adhered to the polyester resin film can be formed.
塗布液に、添加剤を配合してもよい。添加剤としては、例えば、可塑剤、界面活性剤等が挙げられる。可塑剤としては、例えば、エチレングリコールやグリセリン等の多価アルコールが挙げられる。界面活性剤としては、例えば、非イオン界面活性剤が挙げられる。これらは、得られるＰＶＡ系樹脂層の均一性や染色性、延伸性をより一層向上させる目的で使用され得る。１つの実施形態においては、塗布液はハロゲン化物をさらに含む。ハロゲン化物としては、例えば、ヨウ化物および塩化ナトリウムが挙げられる。ヨウ化物としては、例えば、ヨウ化カリウム、ヨウ化ナトリウム、およびヨウ化リチウムが挙げられる。これらの中でも、好ましくは、ヨウ化カリウムである。塗布液におけるハロゲン化物の含有量は、好ましくは、ＰＶＡ系樹脂１００重量部に対して５重量部〜２０重量部である。これにより、ＰＶＡ系樹脂層がハロゲン化物を含まない場合に比べて、ＰＶＡ系樹脂層を液体に浸漬したときのポリビニルアルコール分子の配向の乱れ、および配向性の低下が抑制され得る。その結果、得られる偏光子の光学特性を向上し得る。 An additive may be added to the coating solution. Examples of the additive include a plasticizer and a surfactant. Examples of the plasticizer include polyhydric alcohols such as ethylene glycol and glycerin. Examples of the surfactant include a nonionic surfactant. These can be used for the purpose of further improving the uniformity, dyeability and stretchability of the obtained PVA-based resin layer. In one embodiment, the coating liquid further contains a halide. Halides include, for example, iodide and sodium chloride. Iodides include, for example, potassium iodide, sodium iodide, and lithium iodide. Among these, potassium iodide is preferable. The content of the halide in the coating solution is preferably 5 to 20 parts by weight based on 100 parts by weight of the PVA-based resin. Thereby, compared with the case where the PVA-based resin layer does not contain a halide, the disorder of the orientation of the polyvinyl alcohol molecules when the PVA-based resin layer is immersed in the liquid and the decrease in the orientation can be suppressed. As a result, the optical characteristics of the obtained polarizer can be improved.
上記ＰＶＡ系樹脂としては、任意の適切な樹脂が採用され得る。例えば、ポリビニルアルコールおよびエチレン−ビニルアルコール共重合体が挙げられる。ポリビニルアルコールは、ポリ酢酸ビニルをケン化することにより得られる。エチレン−ビニルアルコール共重合体は、エチレン−酢酸ビニル共重合体をケン化することにより得られる。ＰＶＡ系樹脂のケン化度は、通常８５モル％〜１００モル％であり、好ましくは９５．０モル％〜９９．９５モル％、さらに好ましくは９９．０モル％〜９９．９３モル％である。ケン化度は、ＪＩＳ Ｋ ６７２６−１９９４に準じて求めることができる。このようなケン化度のＰＶＡ系樹脂を用いることによって、耐久性に優れた偏光子が得られ得る。ケン化度が高すぎる場合には、ゲル化してしまうおそれがある。 Any appropriate resin can be adopted as the PVA-based resin. For example, polyvinyl alcohol and an ethylene-vinyl alcohol copolymer are mentioned. Polyvinyl alcohol is obtained by saponifying polyvinyl acetate. The ethylene-vinyl alcohol copolymer is obtained by saponifying the 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 K 6726-1994. By using a PVA-based resin having such a saponification degree, a polarizer having excellent durability can be obtained. If the degree of saponification is too high, gelation may occur.
ＰＶＡ系樹脂の平均重合度は、目的に応じて適切に選択し得る。平均重合度は、通常１０００〜１００００であり、好ましくは１２００〜４５００、さらに好ましくは１５００〜４３００である。なお、平均重合度は、ＪＩＳ Ｋ ６７２６−１９９４に準じて求めることができる。 The average degree of polymerization of the PVA-based resin can be appropriately selected depending on the purpose. The average degree of polymerization is usually from 1,000 to 10,000, preferably from 1,200 to 4,500, and more preferably from 1,500 to 4,300. The average degree of polymerization can be determined according to JIS K 6726-1994.
Ｂ−２．空中延伸処理
特に、高い光学特性を得るためには、乾式延伸（補助延伸）とホウ酸水中延伸を組み合わせる、２段延伸の方法が選択される。２段延伸のように、補助延伸を導入することにより、ポリエステル系樹脂フィルムの結晶化を抑制しながら延伸することができ、後のホウ酸水中延伸においてポリエステル系樹脂フィルムの過度の結晶化により延伸性が低下するという問題を解決し、積層体をより高倍率に延伸することができる。さらには、ポリエステル系樹脂フィルム上にＰＶＡ系樹脂を塗布する場合、ポリエステル系樹脂フィルムのガラス転移温度の影響を抑制するために、通常の金属ドラム上にＰＶＡ系樹脂を塗布する場合と比べて塗布温度を低くする必要があり、その結果、ＰＶＡ系樹脂の結晶化が相対的に低くなり、十分な光学特性が得られない、という問題が生じ得る。これに対して、補助延伸を導入することにより、ポリエステル系樹脂フィルム上にＰＶＡ系樹脂を塗布する場合でも、ＰＶＡ系樹脂の結晶性を高めることが可能となり、高い光学特性を達成することが可能となる。また、同時にＰＶＡ系樹脂の配向性を事前に高めることで、後の染色工程や延伸工程で水に浸漬された時に、ＰＶＡ系樹脂の配向性の低下や溶解などの問題を防止することができ、高い光学特性を達成することが可能になる。
B-2. Aerial stretching treatment In particular, in order to obtain high optical properties, a two-stage stretching method in which dry stretching (auxiliary stretching) and stretching in boric acid in water is selected. By introducing auxiliary stretching as in two-stage stretching, stretching can be performed while suppressing crystallization of the polyester-based resin film, and in subsequent boric acid in water stretching, the polyester-based resin film is stretched due to excessive crystallization. It is possible to solve the problem that the property is reduced and to stretch the laminate at a higher magnification. Furthermore, when applying a PVA-based resin on a polyester-based resin film, in order to suppress the influence of the glass transition temperature of the polyester-based resin film, the application of the PVA-based resin is compared with the case where the PVA-based resin is applied on a normal metal drum. It is necessary to lower the temperature, and as a result, the crystallization of the PVA-based resin becomes relatively low, which may cause a problem that sufficient optical characteristics cannot be obtained. In contrast, by introducing auxiliary stretching, even when a PVA-based resin is applied on a polyester-based resin film, the crystallinity of the PVA-based resin can be increased, and high optical characteristics can be achieved. Becomes At the same time, by increasing the orientation of the PVA-based resin in advance, it is possible to prevent problems such as a decrease in the orientation of the PVA-based resin and dissolution when immersed in water in a subsequent dyeing step or stretching step. , High optical characteristics can be achieved.
空中補助延伸の延伸方法は、固定端延伸（たとえば、テンター延伸機を用いて延伸する方法）でもよいし、自由端延伸（たとえば、周速の異なるロール間に積層体を通して一軸延伸する方法）でもよいが、高い光学特性を得るためには、自由端延伸が積極的に採用されうる。１つの実施形態においては、空中延伸処理は、上記積層体をその長手方向に搬送しながら、加熱ロール間の周速差により延伸する加熱ロール延伸工程を含む。空中延伸処理は、代表的には、ゾーン延伸工程と加熱ロール延伸工程とを含む。なお、ゾーン延伸工程と加熱ロール延伸工程の順序は限定されず、ゾーン延伸工程が先に行われてもよく、加熱ロール延伸工程が先に行われてもよい。ゾーン延伸工程は省略されてもよい。１つの実施形態においては、ゾーン延伸工程および加熱ロール延伸工程がこの順に行われる。また、別の実施形態では、テンター延伸機において、フィルム端部を把持し、テンター間の距離を流れ方向に広げることで延伸される（テンター間の距離の広がりが延伸倍率となる）。この時、幅方向（流れ方向に対して、垂直方向）のテンターの距離は、任意に近づくように設定される。好ましくは、流れ方向の延伸倍率に対して、自由端延伸により近くなるように設定されうる。自由端延伸の場合、 幅方向の収縮率＝（１/延伸倍率）１／２で計算される。 The stretching method in the air-assisted stretching may be fixed-end stretching (for example, a method of stretching using a tenter stretching machine) or free-end stretching (for example, uniaxially stretching through a laminate between rolls having different peripheral speeds). Although good, free end stretching can be actively employed to obtain high optical properties. In one embodiment, the air stretching process includes a heating roll stretching step of stretching the laminate by a peripheral speed difference between the heating rolls while transporting the laminate in the longitudinal direction. The aerial stretching process typically includes a zone stretching step and a heated roll stretching step. The order of the zone stretching step and the heating roll stretching step is not limited, and the zone stretching step may be performed first, or the heating roll stretching step may be performed first. The zone stretching step may be omitted. In one embodiment, the zone stretching step and the hot roll stretching step are performed in this order. In another embodiment, in a tenter stretching machine, the film is stretched by gripping the end of the film and increasing the distance between the tenters in the flow direction (the expansion of the distance between the tenters becomes the stretching ratio). At this time, the distance of the tenter in the width direction (perpendicular to the flow direction) is set to be arbitrarily small. Preferably, it can be set so as to be closer to the free-end stretching with respect to the stretching ratio in the flow direction. In the case of free-end stretching, the shrinkage in the width direction is calculated as (1 / stretch ratio) 1/2 .
空中補助延伸は、一段階で行ってもよいし、多段階で行ってもよい。多段階で行う場合、延伸倍率は、各段階の延伸倍率の積である。空中補助延伸における延伸方向は、好ましくは、水中延伸の延伸方向と略同一である。 The air-assisted stretching may be performed in one stage or may be performed in multiple stages. When the stretching is performed in multiple stages, the stretching ratio is a product of the stretching ratios of the respective stages. The stretching direction in the aerial auxiliary stretching is preferably substantially the same as the stretching direction in the underwater stretching.
空中補助延伸における延伸倍率は、好ましくは２．０倍〜３．５倍である。空中補助延伸と水中延伸とを組み合わせた場合の最大延伸倍率は、積層体の元長に対して、好ましくは５．０倍以上、より好ましくは５．５倍以上、さらに好ましくは６．０倍以上である。本明細書において「最大延伸倍率」とは、積層体が破断する直前の延伸倍率をいい、別途、積層体が破断する延伸倍率を確認し、その値よりも０．２低い値をいう。 The stretching ratio in the air-assisted stretching is preferably 2.0 times to 3.5 times. The maximum stretching ratio in the case where the in-air assisted stretching and the underwater stretching are combined is preferably 5.0 times or more, more preferably 5.5 times or more, and still more preferably 6.0 times, with respect to the original length of the laminate. That is all. In the present specification, the “maximum stretch ratio” refers to a stretch ratio immediately before the laminate is broken, and separately refers to a stretch ratio at which the laminate is broken, and refers to a value 0.2 lower than the value.
空中補助延伸の延伸温度は、好ましくはポリエステル系樹脂フィルムのガラス転移温度（Ｔｇ）以上であり、さらに好ましくはポリエステル系樹脂フィルムのガラス転移温度（Ｔｇ）＋１０℃以上、特に好ましくはＴｇ＋１５℃以上である。一方、延伸温度の上限は、好ましくは１７０℃である。このような温度で延伸することで、ＰＶＡ系樹脂の結晶化が急速に進むのを抑制して、当該結晶化による不具合（例えば、延伸によるＰＶＡ系樹脂層の配向を妨げる）を抑制することができる。 The stretching temperature of the in-air auxiliary stretching is preferably equal to or higher than the glass transition temperature (Tg) of the polyester resin film, more preferably equal to or higher than the glass transition temperature (Tg) of the polyester resin film + 10 ° C., and particularly preferably equal to or higher than Tg + 15 ° C. is there. On the other hand, the upper limit of the stretching temperature is preferably 170 ° C. By stretching at such a temperature, it is possible to suppress the rapid progress of crystallization of the PVA-based resin, and to suppress problems caused by the crystallization (for example, hinder the orientation of the PVA-based resin layer by stretching). it can.
Ｂ−３．膨潤処理
必要に応じて、空中延伸処理の後、水中延伸処理や染色処理の前に、膨潤処理（不溶化処理）を施す。上記膨潤処理は、代表的には、ホウ酸水溶液にＰＶＡ系樹脂層を浸漬することにより行う。膨潤処理を施すことにより、ＰＶＡ系樹脂層に耐水性を付与し、水に浸漬した時のＰＶＡの配向低下を防止することができる。当該ホウ酸水溶液の濃度は、水１００重量部に対して、好ましくは１重量部〜４重量部である。膨潤浴（ホウ酸水溶液）の液温は、好ましくは２０℃〜５０℃である。
B-3. Swelling treatment If necessary, a swelling treatment (insolubilization treatment) is performed after the air stretching treatment and before the underwater stretching treatment and the dyeing treatment. The swelling treatment is typically performed by immersing the PVA-based resin layer in an aqueous boric acid solution. By performing the swelling treatment, it is possible to impart water resistance to the PVA-based resin layer and to prevent a decrease in the orientation of PVA when immersed in water. The concentration of the boric acid aqueous solution is preferably 1 part by weight to 4 parts by weight based on 100 parts by weight of water. The liquid temperature of the swelling bath (boric acid aqueous solution) is preferably from 20C to 50C.
Ｂ−４．染色処理
上記染色処理は、代表的には、ＰＶＡ系樹脂層をヨウ素で染色することにより行う。具体的には、ＰＶＡ系樹脂層にヨウ素を吸着させることにより行う。当該吸着方法としては、例えば、ヨウ素を含む染色液にＰＶＡ系樹脂層（積層体）を浸漬させる方法、ＰＶＡ系樹脂層に当該染色液を塗工する方法、当該染色液をＰＶＡ系樹脂層に噴霧する方法等が挙げられる。好ましくは、染色液（染色浴）に積層体を浸漬させる方法である。ヨウ素が良好に吸着し得るからである。
B-4. Dyeing treatment The above-mentioned dyeing treatment is typically performed by dyeing a PVA-based resin layer with iodine. Specifically, it is performed by adsorbing iodine on the PVA-based resin layer. Examples of the adsorption method include a method of dipping a PVA-based resin layer (laminate) in a dyeing solution containing iodine, a method of coating the PVA-based resin layer with the dyeing solution, and a method of applying the dyeing solution to the PVA-based resin layer. A spraying method and the like can be mentioned. A preferred method is to immerse the laminate in a dye solution (dye bath). This is because iodine can be favorably adsorbed.
上記染色液は、好ましくは、ヨウ素水溶液である。ヨウ素の配合量は、水１００重量部に対して、好ましくは０．０５重量部〜０．５重量部である。ヨウ素の水に対する溶解度を高めるため、ヨウ素水溶液にヨウ化物を配合することが好ましい。ヨウ化物としては、例えば、ヨウ化カリウム、ヨウ化リチウム、ヨウ化ナトリウム、ヨウ化亜鉛、ヨウ化アルミニウム、ヨウ化鉛、ヨウ化銅、ヨウ化バリウム、ヨウ化カルシウム、ヨウ化錫、ヨウ化チタン等が挙げられる。これらの中でも、好ましくは、ヨウ化カリウムである。ヨウ化物の配合量は、水１００重量部に対して、好ましくは０．１重量部〜１０重量部、より好ましくは０．３重量部〜５重量部である。染色液の染色時の液温は、ＰＶＡ系樹脂の溶解を抑制するため、好ましくは２０℃〜５０℃である。染色液にＰＶＡ系樹脂層を浸漬させる場合、浸漬時間は、ＰＶＡ系樹脂層の透過率を確保するため、好ましくは５秒〜５分であり、より好ましくは３０秒〜９０秒である。 The staining solution is preferably an iodine aqueous solution. The amount of iodine 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 an aqueous iodine solution. Examples of iodides include potassium iodide, lithium iodide, sodium iodide, zinc iodide, aluminum iodide, lead iodide, copper iodide, barium iodide, calcium iodide, tin iodide, and titanium iodide. And the like. Among these, potassium iodide is preferable. The amount of iodide 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. The temperature of the dyeing solution at the time of dyeing is preferably 20 ° C to 50 ° C in order to suppress dissolution of the PVA-based resin. When the PVA-based resin layer is immersed in the dyeing solution, the immersion time is preferably from 5 seconds to 5 minutes, more preferably from 30 seconds to 90 seconds, in order to secure the transmittance of the PVA-based resin layer.
染色条件（濃度、液温、浸漬時間）は、最終的に得られる偏光子に求められる光学特性（単体透過率および偏光度）に応じて適切に設定することができる。このような染色条件としては、例えば、染色液としてヨウ素水溶液を用い、ヨウ素水溶液におけるヨウ素およびヨウ化カリウムの含有量の比を、１：５〜１：２０とする。ヨウ素水溶液におけるヨウ素およびヨウ化カリウムの含有量の比は、好ましくは１：５〜１：１０である。これにより、上記のような光学特性を有する偏光子が得られ得る。 Dyeing conditions (concentration, solution temperature, immersion time) can be appropriately set according to the optical properties (single transmittance and degree of polarization) required of the finally obtained polarizer. As such a dyeing condition, for example, an aqueous solution of iodine is used as a dyeing solution, and the ratio of the contents of iodine and potassium iodide in the aqueous solution of iodine is 1: 5 to 1:20. The ratio between the contents of iodine and potassium iodide in the aqueous iodine solution is preferably from 1: 5 to 1:10. Thereby, a polarizer having the above-described optical characteristics can be obtained.
Ｂ−５．架橋処理
必要に応じて、染色処理の後、水中延伸処理の前に、架橋処理を施す。上記架橋処理は、代表的には、ホウ酸水溶液にＰＶＡ系樹脂層を浸漬させることにより行う。架橋処理を施すことにより、ＰＶＡ系樹脂層に耐水性を付与し、後の水中延伸で、高温の水中へ浸漬した際のＰＶＡの配向低下を防止することができる。当該ホウ酸水溶液の濃度は、水１００重量部に対して、好ましくは１重量部〜５重量部である。また、上記染色処理後に架橋処理を行う場合、さらに、ヨウ化物を配合することが好ましい。ヨウ化物を配合することにより、ＰＶＡ系樹脂層に吸着させたヨウ素の溶出を抑制することができる。ヨウ化物の配合量は、水１００重量部に対して、好ましくは１重量部〜５重量部である。ヨウ化物の具体例は、上述のとおりである。架橋浴（ホウ酸水溶液）の液温は、好ましくは２０℃〜５０℃である。
B-5. Crosslinking treatment If necessary, crosslinking treatment is performed after the dyeing treatment and before the underwater stretching treatment. The crosslinking treatment is typically performed by immersing the PVA-based resin layer in an aqueous boric acid solution. By performing the cross-linking treatment, water resistance is imparted to the PVA-based resin layer, and it is possible to prevent a decrease in the orientation of PVA when immersed in high-temperature water during subsequent stretching in water. The concentration of the boric acid aqueous solution is preferably 1 part by weight to 5 parts by weight with respect to 100 parts by weight of water. When a crosslinking treatment is performed after the above-mentioned dyeing treatment, it is preferable to further add an iodide. By blending iodide, elution of iodine adsorbed on the PVA-based resin layer can be suppressed. The amount of iodide is preferably 1 to 5 parts by weight based on 100 parts by weight of water. Specific examples of iodide are as described above. The liquid temperature of the crosslinking bath (boric acid aqueous solution) is preferably from 20C to 50C.
Ｂ−６．水中延伸処理
水中延伸処理は、積層体を延伸浴に浸漬させて行う。水中延伸処理によれば、上記ポリエステル系樹脂フィルムやＰＶＡ系樹脂層のガラス転移温度（代表的には、８０℃程度）よりも低い温度で延伸し得、ＰＶＡ系樹脂層を、その結晶化を抑えながら、高倍率に延伸することができる。その結果、優れた光学特性を有する偏光子を製造することができる。
B-6. Underwater stretching treatment The underwater stretching treatment is performed by immersing the laminate in a stretching bath. According to the in-water stretching treatment, the polyester resin film or the PVA-based resin layer can be stretched at a temperature lower than the glass transition temperature (typically, about 80 ° C.), and the PVA-based resin layer is crystallized. Stretching can be performed at a high magnification while suppressing it. As a result, a polarizer having excellent optical characteristics can be manufactured.
積層体の延伸方法は、任意の適切な方法を採用することができる。具体的には、固定端延伸でもよいし、自由端延伸（例えば、周速の異なるロール間に積層体を通して一軸延伸する方法）でもよい。好ましくは、自由端延伸が選択される。積層体の延伸は、一段階で行ってもよいし、多段階で行ってもよい。多段階で行う場合、後述の積層体の延伸倍率（最大延伸倍率）は、各段階の延伸倍率の積である。 Any appropriate method can be adopted as a method for stretching the laminate. Specifically, fixed-end stretching or free-end stretching (for example, a method of uniaxially stretching through a laminate between rolls having different peripheral speeds) may be used. Preferably, free end stretching is selected. The stretching of the laminate may be performed in one stage or may be performed in multiple stages. In the case of performing in multiple stages, the stretching ratio (maximum stretching ratio) of the laminate described later is a product of the stretching ratios in each stage.
水中延伸は、好ましくは、ホウ酸水溶液中に積層体を浸漬させて行う（ホウ酸水中延伸）。延伸浴としてホウ酸水溶液を用いることで、ＰＶＡ系樹脂層に、延伸時にかかる張力に耐える剛性と、水に溶解しない耐水性とを付与することができる。具体的には、ホウ酸は、水溶液中でテトラヒドロキシホウ酸アニオンを生成してＰＶＡ系樹脂と水素結合により架橋し得る。その結果、ＰＶＡ系樹脂層に剛性と耐水性とを付与して、良好に延伸することができ、優れた光学特性を有する偏光子を製造することができる。 The underwater stretching is preferably performed by immersing the laminate in an aqueous boric acid solution (stretching in boric acid in water). By using a boric acid aqueous solution as the stretching bath, it is possible to provide the PVA-based resin layer with rigidity to withstand the tension applied during stretching and water resistance that does not dissolve in water. Specifically, boric acid can generate a tetrahydroxyborate anion in an aqueous solution and crosslink with a PVA-based resin by hydrogen bonding. As a result, rigidity and water resistance can be imparted to the PVA-based resin layer, the film can be stretched favorably, and a polarizer having excellent optical characteristics can be manufactured.
上記ホウ酸水溶液は、好ましくは、溶媒である水にホウ酸および／またはホウ酸塩を溶解させることにより得られる。ホウ酸濃度は、水１００重量部に対して、好ましくは１重量部〜１０重量部であり、より好ましくは２．５重量部〜６重量部であり、特に好ましくは３重量部〜５重量部である。ホウ酸濃度を１重量部以上とすることにより、ＰＶＡ系樹脂層の溶解を効果的に抑制することができ、より高特性の偏光子を製造することができる。なお、ホウ酸またはホウ酸塩以外に、ホウ砂等のホウ素化合物、グリオキザール、グルタルアルデヒド等を溶媒に溶解して得られた水溶液も用いることができる。 The boric acid aqueous solution is preferably obtained by dissolving boric acid and / or borate in water as a solvent. The boric acid concentration is preferably 1 part by weight to 10 parts by weight, more preferably 2.5 parts by weight to 6 parts by weight, particularly preferably 3 parts by weight to 5 parts by weight with respect to 100 parts by weight of water. It is. By setting the boric acid concentration to 1 part by weight or more, the dissolution of the PVA-based resin layer can be effectively suppressed, and a polarizer having higher characteristics can be manufactured. In addition to the boric acid or the borate, an aqueous solution obtained by dissolving a boron compound such as borax, glyoxal, glutaraldehyde or the like in a solvent can also be used.
好ましくは、上記延伸浴（ホウ酸水溶液）にヨウ化物を配合する。ヨウ化物を配合することにより、ＰＶＡ系樹脂層に吸着させたヨウ素の溶出を抑制することができる。ヨウ化物の具体例は、上述のとおりである。ヨウ化物の濃度は、水１００重量部に対して、好ましくは０．０５重量部〜１５重量部、より好ましくは０．５重量部〜８重量部である。 Preferably, an iodide is blended in the above-mentioned stretching bath (boric acid aqueous solution). By blending iodide, elution of iodine adsorbed on the PVA-based resin layer can be suppressed. Specific examples of iodide are as 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.
延伸温度（延伸浴の液温）は、好ましくは４０℃〜８５℃、より好ましくは６０℃〜７５℃である。このような温度であれば、ＰＶＡ系樹脂層の溶解を抑制しながら高倍率に延伸することができる。具体的には、上述のように、ポリエステル系樹脂フィルムのガラス転移温度（Ｔｇ）は、ＰＶＡ系樹脂層の形成との関係で、好ましくは６０℃以上である。この場合、延伸温度が４０℃を下回ると、水によるポリエステル系樹脂フィルムの可塑化を考慮しても、良好に延伸できないおそれがある。一方、延伸浴の温度が高温になるほど、ＰＶＡ系樹脂層の溶解性が高くなり、優れた光学特性が得られないおそれがある。積層体の延伸浴への浸漬時間は、好ましくは１５秒〜５分である。 The stretching temperature (liquid temperature of the stretching bath) is preferably 40C to 85C, more preferably 60C to 75C. At such a temperature, the film can be stretched at a high magnification while suppressing the dissolution of the PVA-based resin layer. Specifically, as described above, the glass transition temperature (Tg) of the polyester-based resin film is preferably 60 ° C. or higher in relation to the formation of the PVA-based resin layer. In this case, if the stretching temperature is lower than 40 ° C., there is a possibility that the stretching may not be performed well even in consideration of the plasticization of the polyester resin film by water. On the other hand, the higher the temperature of the stretching bath is, the higher the solubility of the PVA-based resin layer is, and there is a possibility that excellent optical properties cannot be obtained. The immersion time of the laminate in the stretching bath is preferably 15 seconds to 5 minutes.
水中延伸による延伸倍率は、好ましくは１．５倍以上、より好ましくは３．０倍以上である。積層体の総延伸倍率は、積層体の元長に対して、好ましくは５．０倍以上であり、さらに好ましくは５．５倍以上である。このような高い延伸倍率を達成することにより、光学特性に極めて優れた偏光子を製造することができる。このような高い延伸倍率は、水中延伸方式（ホウ酸水中延伸）を採用することにより、達成し得る。 The stretching ratio by underwater stretching is preferably 1.5 times or more, more preferably 3.0 times or more. The total stretch ratio of the laminate is preferably at least 5.0 times, more preferably at least 5.5 times, the original length of the laminate. By achieving such a high draw ratio, a polarizer having extremely excellent optical properties can be manufactured. Such a high stretching ratio can be achieved by employing an underwater stretching method (boric acid in water stretching).
Ｂ−７．洗浄処理
洗浄処理は、代表的には、ヨウ化カリウム水溶液を入れた洗浄浴に積層体を浸漬することにより行う。ヨウ化カリウムの濃度は、好ましくは２重量％〜５重量％である。
B-7. Cleaning Treatment The cleaning treatment is typically performed by immersing the laminate in a cleaning bath containing an aqueous potassium iodide solution. The concentration of potassium iodide is preferably between 2% by weight and 5% by weight.
Ｂ−８．ＰＶＡ系樹脂層の厚み測定
洗浄処理後、積層体を搬送しながらＰＶＡ系樹脂層の厚みを非接触で測定する。ＰＶＡ系樹脂層の厚みは、例えば、分光干渉計により測定することができる。厚みの測定頻度は、好ましくは１５秒〜１２０秒に１回、より好ましくは３０秒から９０秒に１回である。図２のグラフに示されるＰＶＡ系樹脂層の厚みと水分率との関係を参照することにより、洗浄処理後のＰＶＡ系樹脂層の厚みからＰＶＡ系樹脂層の水分率を算出することができる。
B-8. Measurement of thickness of PVA-based resin layer After the washing treatment, the thickness of the PVA-based resin layer is measured in a non-contact manner while transporting the laminate. The thickness of the PVA-based resin layer can be measured by, for example, a spectral interferometer. The frequency of measuring the thickness is preferably once every 15 seconds to 120 seconds, more preferably once every 30 seconds to 90 seconds. By referring to the relationship between the thickness of the PVA-based resin layer and the moisture content shown in the graph of FIG. 2, the moisture content of the PVA-based resin layer can be calculated from the thickness of the PVA-based resin layer after the cleaning treatment.
Ｂ−９．乾燥処理
乾燥処理における乾燥温度は、好ましくは３０℃〜１００℃である。
B-9. Drying process The drying temperature in the drying process is preferably 30C to 100C.
Ｃ．偏光子
上記の製造方法により得られる偏光子は、実質的には、ヨウ素が吸着配向されたＰＶＡ系樹脂層である。偏光子の厚みは、好ましくは１０μｍ以下であり、より好ましくは８μｍ以下であり、さらに好ましくは７．５μｍ以下であり、特に好ましくは５μｍ以下である。一方、偏光子の厚みは、好ましくは０．５μｍ以上、より好ましくは１．５μｍ以上である。厚みが薄すぎると得られる偏光子の光学特性が低下するおそれがある。偏光子は、好ましくは、波長３８０ｎｍ〜７８０ｎｍのいずれかの波長で吸収二色性を示す。偏光子の単体透過率は、好ましくは４０．０％以上、より好ましくは４１．０％以上、さらに好ましくは４２．０％以上である。偏光子の偏光度は、好ましくは９９．８％以上、より好ましくは９９．９％以上、さらに好ましくは９９．９５％以上である。
C. Polarizer The polarizer obtained by the above-described production method is substantially a PVA-based resin layer in which iodine is adsorbed and oriented. The thickness of the polarizer is preferably 10 μm or less, more preferably 8 μm or less, further preferably 7.5 μm or less, and particularly preferably 5 μm or less. On the other hand, the thickness of the polarizer is preferably 0.5 μm or more, more preferably 1.5 μm or more. If the thickness is too small, the optical properties of the obtained polarizer may be deteriorated. The polarizer preferably exhibits absorption dichroism at any wavelength from 380 nm to 780 nm. The single transmittance of the polarizer is preferably 40.0% or more, more preferably 41.0% or more, and further preferably 42.0% or more. The degree of polarization of the polarizer is preferably 99.8% or more, more preferably 99.9% or more, and further preferably 99.95% or more.
Ｄ．延伸樹脂膜の製造装置
本発明の実施形態による延伸樹脂膜の製造装置は、長尺状の非吸水性フィルムの片側に吸水性の樹脂層が形成された積層体を搬送しながら、積層体に処理を施すことにより、非吸水性フィルム上に延伸樹脂膜を形成する、延伸樹脂膜の製造装置である。この製造装置は、積層体を水中延伸する水中延伸処理部と、水中延伸の後に積層体を洗浄する洗浄処理部と、洗浄処理後の延伸樹脂膜の厚みまたは水分率に基づいて、延伸樹脂膜の外観不良を検出する検査部と、を含む。上記水中延伸処理部は、上記Ｂ−６項で説明した水中延伸処理を施し得る任意の適切な延伸装置である。上記洗浄処理部は、上記Ｂ−７項で説明した洗浄処理を施し得る任意の適切な洗浄装置（洗浄浴）である。検査部は、延伸樹脂膜の厚みまたは水分率と得られる偏光子の外観不良レベルとの関係が予めメモリーされており、洗浄処理後の延伸樹脂膜の厚みまたは水分率に基づいて偏光子の外観不良を検出する。上記製造装置は、さらに、上記Ｂ項で説明した各処理を実施するのに適した任意の適切な構成を含み得る。また、上記製造装置は、非接触式の膜厚計、および／または、洗浄処理後のＰＶＡ系樹脂層の厚みに基づいてＰＶＡ系樹脂層の水分率を算出する算出部を含み得る。
D. Apparatus for manufacturing stretched resin film The apparatus for manufacturing a stretched resin film according to the embodiment of the present invention is configured to transfer a laminate in which a water-absorbing resin layer is formed on one side of a long non-water-absorbing film, This is an apparatus for producing a stretched resin film that forms a stretched resin film on a non-water-absorbing film by performing a treatment. The manufacturing apparatus includes an underwater stretching section for stretching the laminate in water, a washing section for washing the laminate after stretching in water, and a stretched resin film based on the thickness or moisture content of the stretched resin film after the washing process. And an inspection unit for detecting a poor appearance of the inspection. The underwater stretching section is any suitable stretching apparatus capable of performing the underwater stretching described in the section B-6. The cleaning processing section is any appropriate cleaning apparatus (cleaning bath) that can perform the cleaning processing described in the section B-7. The inspection unit stores in advance the relationship between the thickness or moisture content of the stretched resin film and the level of defective appearance of the obtained polarizer, and based on the thickness or moisture content of the stretched resin film after the cleaning process, the appearance of the polarizer is determined. Detect defects. The manufacturing apparatus may further include any appropriate configuration suitable for performing each processing described in the above section B. In addition, the manufacturing apparatus may include a non-contact type film thickness meter and / or a calculation unit that calculates the moisture content of the PVA-based resin layer based on the thickness of the PVA-based resin layer after the cleaning process.
以下、実施例によって本発明を具体的に説明するが、本発明はこれら実施例によって限定されるものではない。なお、各特性の測定方法は以下の通りである。
（１）ＰＶＡ系樹脂層の厚み
ＰＶＡ系樹脂層の厚みを、光干渉膜厚計（オーシャンオプティクス社製、ＸＵＳＢ４）を用いて測定した。なお、ポリエステル系樹脂フィルム／ＰＶＡ系樹脂層からなる積層体のポリエステル系樹脂フィルム側に光干渉膜厚計を配置し、ＰＶＡ系樹脂層の厚みを測定した。
（２）ＰＶＡ系樹脂層の水分率
洗浄処理後のＰＶＡ系樹脂層の水分率を、ＰＶＡ系樹脂層の厚みおよび図２に示すグラフに基づいて求めた。
（３）偏光子の外観
実施例および比較例で得られた偏光子を目視で確認し、以下の基準で外観の良否を判断した。
○・・・スジ状痕が目視で確認されなかった、または、目視で確認されたが後工程でフィルムに貼り合せた状態ではスジ状痕は視認されなかった
△・・・スジ状痕が目視で確認されたが、後工程で貼り合せるフィルムによってスジ状痕が視認されなくなる場合と視認される場合とがあった
×・・・スジ状痕が目視ではっきりと確認され、かつ、後工程でフィルムに貼り合せた状態でスジ状痕が確認された
また、実施例および比較例で得られた偏光子を目視で確認し、スジ状痕のレベルに応じて０（スジ状痕なし）から８（大きなスジ状痕あり）までの数値付与し、外観不良レベルを数値化した。
Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited to these Examples. In addition, the measuring method of each characteristic is as follows.
(1) Thickness of PVA-based resin layer The thickness of the PVA-based resin layer was measured using an optical interference thickness meter (XUSB4, manufactured by Ocean Optics). The thickness of the PVA-based resin layer was measured by arranging an optical interference thickness meter on the polyester-based resin film side of the laminate composed of the polyester-based resin film / PVA-based resin layer.
(2) Moisture content of PVA-based resin layer The moisture content of the PVA-based resin layer after the cleaning treatment was determined based on the thickness of the PVA-based resin layer and the graph shown in FIG.
(3) Appearance of Polarizer The polarizers obtained in Examples and Comparative Examples were visually checked, and the quality of the appearance was judged based on the following criteria.
・ ・ ・: No streak was visually observed, or streak was visually observed, but no streak was visually observed in a state where it was bonded to a film in a later process. △: Streak was visually observed. However, there were cases where streak marks were not visually recognized and cases where they were visually recognized due to the film to be bonded in the subsequent process. × ... The streak marks were clearly confirmed visually, and in the subsequent process. Streak marks were observed in the state of being stuck to the film. Moreover, the polarizers obtained in Examples and Comparative Examples were visually checked, and depending on the level of the streak marks, from 0 (no streak marks) to 8 Numerical values up to (with large streak marks) were given, and the level of poor appearance was quantified.
［実施例１］
ポリエステル系樹脂フィルムとして、長尺状で、吸水率０．７５％、Ｔｇ約７５℃である、非晶質のイソフタル共重合ポリエチレンテレフタレートフィルム（厚み：１００μｍ）を用いた。
ポリビニルアルコール（重合度４２００、ケン化度９９．２モル％）およびアセトアセチル変性ＰＶＡ（日本合成化学工業社製、商品名「ゴーセファイマーＺ４１０」）を９：１で混合したＰＶＡ系樹脂１００重量部に、ヨウ化カリウム１３重量部を添加し、ＰＶＡ水溶液（塗布液）を調製した。
ポリエステル系樹脂フィルムの一方の面に、上記ＰＶＡ水溶液を塗布して６０℃で乾燥することにより、厚み１３μｍのＰＶＡ系樹脂層を形成し、積層体を作製した。
得られた積層体を所定の搬送速度で搬送しながら、以下の各処理を施した。
第一に、積層体を、１３０℃のオーブン内で周速の異なるロール間で縦方向（長手方向）に２．４倍に自由端一軸延伸した（空中補助延伸処理）。
次いで、積層体を、液温４０℃の膨潤浴（水１００重量部に対して、ホウ酸を４重量部配合して得られたホウ酸水溶液）に４０秒間浸漬させた（膨潤処理）。
次いで、液温３０℃の染色浴（水１００重量部に対して、ヨウ素とヨウ化カリウムを１：７の重量比で配合して得られたヨウ素水溶液）に、最終的に得られる偏光子の単体透過率（Ｔｓ）が約４３％となるように濃度を調整しながら５０秒間浸漬させた（染色処理）。
次いで、液温４０℃の架橋浴（水１００重量部に対して、ヨウ化カリウムを３重量部配合し、ホウ酸を５重量部配合して得られたホウ酸水溶液）に４０秒間浸漬させた（架橋処理）。
次いで、積層体を、液温７０℃のホウ酸水溶液（ホウ酸濃度３．６重量％）に５０秒間浸漬させながら、周速の異なるロール間で縦方向（長手方向）に総延伸倍率が５．５倍となるように一軸延伸を行った（水中延伸処理）。
次いで、積層体を液温２０℃のヨウ化カリウム水溶液（ヨウ化カリウム濃度２．８重量％）に５秒間浸漬させた（洗浄処理）。洗浄処理後のＰＶＡ系樹脂層の厚みを測定したところ、７．３４μｍであった。
その後、７０℃に保たれたオーブン中で積層体を乾燥することにより、ポリエステル系樹脂フィルム上に形成された厚み５．５０μｍの偏光子を得た。さらに、同様の手順により、合計２つの偏光子を作製した。
得られた偏光子を上記（３）の評価に供した。結果を表２に示す。洗浄処理後のＰＶＡ系樹脂層の厚みと、外観不良レベルとの関係を図３に示す。
[Example 1]
As the polyester-based resin film, a long, amorphous isophthalic copolymerized polyethylene terephthalate film (thickness: 100 μm) having a water absorption of 0.75% and a Tg of about 75 ° C. was used.
100% by weight of a PVA-based resin in which polyvinyl alcohol (degree of polymerization: 4200, degree of saponification: 99.2 mol%) and acetoacetyl-modified PVA (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "Gosefimer Z410") are mixed at a ratio of 9: 1. To this part, 13 parts by weight of potassium iodide was added to prepare a PVA aqueous solution (coating solution).
The PVA solution was coated on one surface of the polyester resin film and dried at 60 ° C. to form a 13 μm-thick PVA resin layer to prepare a laminate.
The following processes were performed while the obtained laminate was being conveyed at a predetermined conveyance speed.
First, the laminate was uniaxially stretched 2.4 times in the longitudinal direction (longitudinal direction) between rolls having different peripheral speeds in an oven at 130 ° C. with free-end uniaxial stretching (air-assisted stretching).
Next, the laminate was immersed in a swelling bath at a liquid temperature of 40 ° C. (a boric acid aqueous solution obtained by mixing 4 parts by weight of boric acid with 100 parts by weight of water) for 40 seconds (swelling treatment).
Next, a polarizer finally obtained is placed in a dyeing bath (liquid aqueous 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 ° C. It was immersed for 50 seconds while adjusting the concentration so that the single transmittance (Ts) was about 43% (dyeing treatment).
Next, it was immersed in a crosslinking bath of a liquid temperature of 40 ° C. (a boric acid aqueous solution obtained by mixing 3 parts by weight of potassium iodide and 5 parts by weight of boric acid with respect to 100 parts by weight of water) for 40 seconds. (Crosslinking treatment).
Next, while the laminate was immersed in a boric acid aqueous solution (boric acid concentration: 3.6% by weight) at a liquid temperature of 70 ° C for 50 seconds, the total stretching ratio in the longitudinal direction (longitudinal direction) between rolls having different peripheral speeds was 5%. The film was uniaxially stretched so as to have a magnification of 0.5 (underwater stretching treatment).
Next, the laminate was immersed in a potassium iodide aqueous solution (potassium iodide concentration: 2.8% by weight) at a liquid temperature of 20 ° C. for 5 seconds (washing treatment). When the thickness of the PVA-based resin layer after the washing treatment was measured, it was 7.34 μm.
Thereafter, the laminate was dried in an oven maintained at 70 ° C. to obtain a polarizer having a thickness of 5.50 μm formed on the polyester resin film. Furthermore, a total of two polarizers were produced by the same procedure.
The obtained polarizer was subjected to the evaluation of the above (3). Table 2 shows the results. FIG. 3 shows the relationship between the thickness of the PVA-based resin layer after the cleaning treatment and the appearance defect level.
［実施例２］
積層体の搬送速度を実施例１の搬送速度の１．１倍としたこと以外は実施例１と同様にして偏光子を作製した。洗浄処理後のＰＶＡ系樹脂層の厚みは、７．９５μｍであった。
得られた偏光子を上記（３）の評価に供した。結果を表２に示す。また、洗浄処理後のＰＶＡ系樹脂層の厚みと、外観不良レベルとの関係を図３に示す。
[Example 2]
A polarizer was produced in the same manner as in Example 1, except that the transport speed of the laminate was 1.1 times the transport speed of Example 1. The thickness of the PVA-based resin layer after the cleaning treatment was 7.95 μm.
The obtained polarizer was subjected to the evaluation of the above (3). Table 2 shows the results. FIG. 3 shows the relationship between the thickness of the PVA-based resin layer after the cleaning treatment and the appearance defect level.
［比較例１］
積層体の搬送速度を実施例１の搬送速度の１．２倍としたこと、膨潤浴の液温を４５℃としたこと、水中延伸処理におけるホウ酸水溶液のホウ酸濃度を３．５重量％としたこと、および、洗浄処理におけるヨウ化カリウム水溶液のヨウ化カリウム濃度を４．０重量％としたこと以外は実施例１と同様にして偏光子を作製した。洗浄処理後のＰＶＡ系樹脂層の厚みは、８．２４μｍであった。さらに、同様の手順により、合計２つの偏光子を作製した。
得られた偏光子を上記（３）の評価に供した。結果を表２に示す。また、洗浄処理後のＰＶＡ系樹脂層の厚みと、外観不良レベルとの関係を図３に示す。
[Comparative Example 1]
The transport speed of the laminate was 1.2 times the transport speed of Example 1, the liquid temperature of the swelling bath was 45 ° C., and the boric acid concentration of the boric acid aqueous solution in the underwater stretching treatment was 3.5% by weight. A polarizer was produced in the same manner as in Example 1, except that the potassium iodide concentration of the aqueous potassium iodide solution in the washing treatment was 4.0% by weight. The thickness of the PVA-based resin layer after the cleaning treatment was 8.24 μm. Furthermore, a total of two polarizers were produced by the same procedure.
The obtained polarizer was subjected to the evaluation of the above (3). Table 2 shows the results. FIG. 3 shows the relationship between the thickness of the PVA-based resin layer after the cleaning treatment and the appearance defect level.
表２から明らかなように、洗浄処理後のＰＶＡ系樹脂層の厚みが厚いほど、ＰＶＡ系樹脂層の水分率が高かった。また、洗浄処理後の厚み７．９５μｍ以下である実施例の偏光子は、スジ状痕が発生しなかった。さらに、図３から明らかなように、洗浄処理後のＰＶＡ系樹脂層の厚みと外観不良レベルとの間には相関があった。また、外観不良レベルが０〜４の場合、ＯＫ（偏光子の外観：○）であり、外観不良レベルが４〜５の場合、グレー（偏光子の外観：△）であり、外観不良レベルが５〜８の場合、ＮＧ（偏光子の外観：×）であった。例えば、洗浄処理後のＰＶＡ系樹脂層の厚みが約８．２５μｍ以上の場合、外観不良レベルが５以上となり、偏光子として実用に耐えないレベルであった。上記のとおり、洗浄処理後のＰＶＡ系樹脂層の厚みまたは水分率に基づいて、インラインで、スジ状痕などの外観不良を検出することができる。 As is clear from Table 2, the greater the thickness of the PVA-based resin layer after the cleaning treatment, the higher the moisture content of the PVA-based resin layer. In the polarizer of Example having a thickness of 7.95 μm or less after the cleaning treatment, no streak-like marks were generated. Furthermore, as is clear from FIG. 3, there was a correlation between the thickness of the PVA-based resin layer after the cleaning treatment and the level of poor appearance. When the appearance defect level is 0 to 4, it is OK (appearance of the polarizer: ○), and when the appearance defect level is 4 to 5, it is gray (appearance of the polarizer: Δ), and the appearance defect level is In the case of 5 to 8, it was NG (appearance of polarizer: x). For example, when the thickness of the PVA-based resin layer after the cleaning treatment is about 8.25 μm or more, the appearance defect level is 5 or more, which is a level that cannot be practically used as a polarizer. As described above, based on the thickness or the moisture content of the PVA-based resin layer after the cleaning treatment, it is possible to detect inferior appearance such as streak marks in-line.
本発明の延伸樹脂膜の製造方法は、画像表示装置に用いられる偏光子の製造に好適に用いられる。 The method for producing a stretched resin film of the present invention is suitably used for producing a polarizer used for an image display device.
１６０ 膜厚測定部
２００ 積層体
160 Thickness measuring unit 200 Stack
Claims (5)
前記洗浄処理後の前記延伸樹脂膜の厚みに基づいて、前記延伸樹脂膜の外観不良を検出することを含む、延伸樹脂膜の製造方法。 While transporting a laminate having a water-absorbent resin layer formed on one side of a long non-water-absorbent film, the laminate is subjected to an in-water stretching treatment and a washing treatment in this order, whereby the non-water-absorbent film is obtained. Forming a stretched resin film on, a method for manufacturing a stretched resin film,
A method for manufacturing a stretched resin film, comprising detecting a defective appearance of the stretched resin film based on a thickness of the stretched resin film after the cleaning treatment.
前記洗浄処理後の前記延伸樹脂膜の水分率に基づいて、前記延伸樹脂膜の外観不良を検出することを含む、延伸樹脂膜の製造方法。 While transporting a laminate having a water-absorbent resin layer formed on one side of a long non-water-absorbent film, the laminate is subjected to an in-water stretching treatment and a washing treatment in this order, whereby the non-water-absorbent film is obtained. Forming a stretched resin film on, a method for manufacturing a stretched resin film,
A method for manufacturing a stretched resin film, comprising detecting a defective appearance of the stretched resin film based on a moisture content of the stretched resin film after the washing treatment.
測定された前記延伸樹脂膜の厚みに基づいて、前記洗浄処理後の前記延伸樹脂膜の水分率を算出することと、をさらに含む、請求項１または２に記載の製造方法。 After the cleaning treatment, the thickness of the stretched resin film is measured in a non-contact manner while transporting the laminate,
The method according to claim 1, further comprising: calculating a moisture content of the stretched resin film after the cleaning process based on the measured thickness of the stretched resin film.
前記非吸水性フィルムがポリエステル系樹脂フィルムであり、前記樹脂層がポリビニルアルコール系樹脂層であり、
前記ポリエステル系樹脂フィルムと前記ポリビニルアルコール系樹脂層との積層体に染色処理を施すことをさらに含む、偏光子の製造方法。 A method for producing a polarizer, comprising: forming a polarizer on the non-water-absorbent film by the production method according to any one of claims 1 to 3.
The non-water-absorbing film is a polyester-based resin film, the resin layer is a polyvinyl alcohol-based resin layer,
A method for producing a polarizer, further comprising performing a dyeing treatment on a laminate of the polyester-based resin film and the polyvinyl alcohol-based resin layer.
前記積層体を水中延伸する水中延伸処理部と、
水中延伸の後に前記積層体を洗浄する洗浄処理部と、
前記洗浄処理後の前記延伸樹脂膜の厚みまたは水分率に基づいて、前記延伸樹脂膜の外観不良を検出する検査部と、を含む、延伸樹脂膜の製造装置。
By carrying out a treatment on the laminate while conveying the laminate having a water-absorbent resin layer formed on one side of a long non-water-absorbent film, a stretched resin film is formed on the non-water-absorbent film. An apparatus for manufacturing a stretched resin film,
An underwater stretching section for stretching the laminate underwater,
A washing processing unit for washing the laminate after stretching in water,
A stretched resin film manufacturing apparatus, comprising: an inspection unit configured to detect a defective appearance of the stretched resin film based on a thickness or a moisture content of the stretched resin film after the cleaning process.
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Also Published As
| Publication number | Publication date |
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| CN110861325A (en) | 2020-03-06 |
| CN110861325B (en) | 2023-03-31 |
| JP6535799B1 (en) | 2019-06-26 |
| KR20200024100A (en) | 2020-03-06 |
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