CN116490565A - Polyvinyl alcohol film and polarizing film using the same - Google Patents
Polyvinyl alcohol film and polarizing film using the same Download PDFInfo
- Publication number
- CN116490565A CN116490565A CN202180073426.8A CN202180073426A CN116490565A CN 116490565 A CN116490565 A CN 116490565A CN 202180073426 A CN202180073426 A CN 202180073426A CN 116490565 A CN116490565 A CN 116490565A
- Authority
- CN
- China
- Prior art keywords
- film
- sodium
- pva
- pva film
- polyvinyl alcohol
- 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
- 239000004372 Polyvinyl alcohol Substances 0.000 title claims abstract description 302
- 229920002451 polyvinyl alcohol Polymers 0.000 title claims abstract description 302
- 239000011734 sodium Substances 0.000 claims abstract description 142
- 229910052708 sodium Inorganic materials 0.000 claims abstract description 99
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 claims abstract description 90
- 238000004833 X-ray photoelectron spectroscopy Methods 0.000 claims abstract description 35
- 239000010408 film Substances 0.000 claims description 386
- 239000004094 surface-active agent Substances 0.000 claims description 73
- -1 sodium alkyl sulfate Chemical class 0.000 claims description 39
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 claims description 26
- 238000004519 manufacturing process Methods 0.000 claims description 22
- BDHFUVZGWQCTTF-UHFFFAOYSA-M sulfonate Chemical compound [O-]S(=O)=O BDHFUVZGWQCTTF-UHFFFAOYSA-M 0.000 claims description 20
- 229910052938 sodium sulfate Inorganic materials 0.000 claims description 19
- 235000011152 sodium sulphate Nutrition 0.000 claims description 19
- 239000012788 optical film Substances 0.000 claims description 16
- 229920003171 Poly (ethylene oxide) Polymers 0.000 claims description 13
- QXNVGIXVLWOKEQ-UHFFFAOYSA-N Disodium Chemical compound [Na][Na] QXNVGIXVLWOKEQ-UHFFFAOYSA-N 0.000 claims description 12
- 125000000217 alkyl group Chemical group 0.000 claims description 12
- 150000005215 alkyl ethers Chemical class 0.000 claims description 7
- RTZKZFJDLAIYFH-UHFFFAOYSA-N ether Substances CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 claims description 5
- LGNQGTFARHLQFB-UHFFFAOYSA-N 1-dodecyl-2-phenoxybenzene Chemical compound CCCCCCCCCCCCC1=CC=CC=C1OC1=CC=CC=C1 LGNQGTFARHLQFB-UHFFFAOYSA-N 0.000 claims description 4
- ULUAUXLGCMPNKK-UHFFFAOYSA-N Sulfobutanedioic acid Chemical compound OC(=O)CC(C(O)=O)S(O)(=O)=O ULUAUXLGCMPNKK-UHFFFAOYSA-N 0.000 claims description 4
- 238000004458 analytical method Methods 0.000 claims description 4
- PSZYNBSKGUBXEH-UHFFFAOYSA-M naphthalene-1-sulfonate Chemical compound C1=CC=C2C(S(=O)(=O)[O-])=CC=CC2=C1 PSZYNBSKGUBXEH-UHFFFAOYSA-M 0.000 claims description 4
- 229920001451 polypropylene glycol Polymers 0.000 claims description 4
- 230000003287 optical effect Effects 0.000 abstract description 18
- 238000011282 treatment Methods 0.000 description 162
- 239000007788 liquid Substances 0.000 description 89
- 238000001035 drying Methods 0.000 description 50
- 238000000034 method Methods 0.000 description 47
- 238000004043 dyeing Methods 0.000 description 35
- 238000004132 cross linking Methods 0.000 description 30
- 150000001875 compounds Chemical class 0.000 description 27
- NLKNQRATVPKPDG-UHFFFAOYSA-M potassium iodide Chemical compound [K+].[I-] NLKNQRATVPKPDG-UHFFFAOYSA-M 0.000 description 27
- 239000011550 stock solution Substances 0.000 description 27
- 238000010438 heat treatment Methods 0.000 description 24
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 24
- 206010042674 Swelling Diseases 0.000 description 21
- 239000004014 plasticizer Substances 0.000 description 21
- 230000008961 swelling Effects 0.000 description 21
- 238000004140 cleaning Methods 0.000 description 20
- ZCYVEMRRCGMTRW-UHFFFAOYSA-N 7553-56-2 Chemical compound [I] ZCYVEMRRCGMTRW-UHFFFAOYSA-N 0.000 description 18
- 229910052740 iodine Inorganic materials 0.000 description 18
- 239000011630 iodine Substances 0.000 description 18
- 239000000178 monomer Substances 0.000 description 15
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 14
- 229910052796 boron Inorganic materials 0.000 description 14
- 229920001567 vinyl ester resin Polymers 0.000 description 13
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 description 12
- 239000004327 boric acid Substances 0.000 description 12
- 238000006116 polymerization reaction Methods 0.000 description 12
- 239000002904 solvent Substances 0.000 description 12
- 229920000642 polymer Polymers 0.000 description 10
- 238000007127 saponification reaction Methods 0.000 description 10
- 239000000243 solution Substances 0.000 description 9
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 8
- 239000007864 aqueous solution Substances 0.000 description 8
- 239000003431 cross linking reagent Substances 0.000 description 8
- 150000003839 salts Chemical class 0.000 description 8
- 238000005406 washing Methods 0.000 description 8
- 230000000694 effects Effects 0.000 description 7
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 6
- 238000005266 casting Methods 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 6
- VDQVEACBQKUUSU-UHFFFAOYSA-M disodium;sulfanide Chemical compound [Na+].[Na+].[SH-] VDQVEACBQKUUSU-UHFFFAOYSA-M 0.000 description 6
- 238000001704 evaporation Methods 0.000 description 6
- 230000008020 evaporation Effects 0.000 description 6
- 229910052751 metal Inorganic materials 0.000 description 6
- 239000002184 metal Substances 0.000 description 6
- 239000002994 raw material Substances 0.000 description 6
- 229910052979 sodium sulfide Inorganic materials 0.000 description 6
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 5
- 239000000654 additive Substances 0.000 description 5
- 239000011248 coating agent Substances 0.000 description 5
- 238000000576 coating method Methods 0.000 description 5
- 230000007547 defect Effects 0.000 description 5
- 238000009826 distribution Methods 0.000 description 5
- 229910052731 fluorine Inorganic materials 0.000 description 5
- 239000011737 fluorine Substances 0.000 description 5
- 239000004973 liquid crystal related substance Substances 0.000 description 5
- 239000000155 melt Substances 0.000 description 5
- 239000000853 adhesive Substances 0.000 description 4
- 230000001070 adhesive effect Effects 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 4
- 229910021538 borax Inorganic materials 0.000 description 4
- 125000004432 carbon atom Chemical group C* 0.000 description 4
- 229920006217 cellulose acetate butyrate Polymers 0.000 description 4
- 238000005530 etching Methods 0.000 description 4
- 238000011156 evaluation Methods 0.000 description 4
- 238000001125 extrusion Methods 0.000 description 4
- 235000011187 glycerol Nutrition 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 238000005259 measurement Methods 0.000 description 4
- 239000004328 sodium tetraborate Substances 0.000 description 4
- 235000010339 sodium tetraborate Nutrition 0.000 description 4
- NIXOWILDQLNWCW-UHFFFAOYSA-N 2-Propenoic acid Natural products OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 3
- IMROMDMJAWUWLK-UHFFFAOYSA-N Ethenol Chemical group OC=C IMROMDMJAWUWLK-UHFFFAOYSA-N 0.000 description 3
- DNIAPMSPPWPWGF-UHFFFAOYSA-N Propylene glycol Chemical compound CC(O)CO DNIAPMSPPWPWGF-UHFFFAOYSA-N 0.000 description 3
- 230000000996 additive effect Effects 0.000 description 3
- 239000002981 blocking agent Substances 0.000 description 3
- 238000007664 blowing Methods 0.000 description 3
- 238000002425 crystallisation Methods 0.000 description 3
- 230000008025 crystallization Effects 0.000 description 3
- 239000008367 deionised water Substances 0.000 description 3
- 229910021641 deionized water Inorganic materials 0.000 description 3
- 238000001514 detection method Methods 0.000 description 3
- MTHSVFCYNBDYFN-UHFFFAOYSA-N diethylene glycol Chemical compound OCCOCCO MTHSVFCYNBDYFN-UHFFFAOYSA-N 0.000 description 3
- 230000010287 polarization Effects 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 230000001681 protective effect Effects 0.000 description 3
- 239000000758 substrate Substances 0.000 description 3
- 229920002554 vinyl polymer Polymers 0.000 description 3
- 230000037303 wrinkles Effects 0.000 description 3
- VXNZUUAINFGPBY-UHFFFAOYSA-N 1-Butene Chemical compound CCC=C VXNZUUAINFGPBY-UHFFFAOYSA-N 0.000 description 2
- NLHHRLWOUZZQLW-UHFFFAOYSA-N Acrylonitrile Chemical compound C=CC#N NLHHRLWOUZZQLW-UHFFFAOYSA-N 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- SOGAXMICEFXMKE-UHFFFAOYSA-N Butylmethacrylate Chemical compound CCCCOC(=O)C(C)=C SOGAXMICEFXMKE-UHFFFAOYSA-N 0.000 description 2
- XMWRBQBLMFGWIX-UHFFFAOYSA-N C60 fullerene Chemical compound C12=C3C(C4=C56)=C7C8=C5C5=C9C%10=C6C6=C4C1=C1C4=C6C6=C%10C%10=C9C9=C%11C5=C8C5=C8C7=C3C3=C7C2=C1C1=C2C4=C6C4=C%10C6=C9C9=C%11C5=C5C8=C3C3=C7C1=C1C2=C4C6=C2C9=C5C3=C12 XMWRBQBLMFGWIX-UHFFFAOYSA-N 0.000 description 2
- 229920002284 Cellulose triacetate Polymers 0.000 description 2
- 229920000089 Cyclic olefin copolymer Polymers 0.000 description 2
- BAPJBEWLBFYGME-UHFFFAOYSA-N Methyl acrylate Chemical compound COC(=O)C=C BAPJBEWLBFYGME-UHFFFAOYSA-N 0.000 description 2
- AOMUHOFOVNGZAN-UHFFFAOYSA-N N,N-bis(2-hydroxyethyl)dodecanamide Chemical compound CCCCCCCCCCCC(=O)N(CCO)CCO AOMUHOFOVNGZAN-UHFFFAOYSA-N 0.000 description 2
- XTXRWKRVRITETP-UHFFFAOYSA-N Vinyl acetate Chemical compound CC(=O)OC=C XTXRWKRVRITETP-UHFFFAOYSA-N 0.000 description 2
- 238000000026 X-ray photoelectron spectrum Methods 0.000 description 2
- NNLVGZFZQQXQNW-ADJNRHBOSA-N [(2r,3r,4s,5r,6s)-4,5-diacetyloxy-3-[(2s,3r,4s,5r,6r)-3,4,5-triacetyloxy-6-(acetyloxymethyl)oxan-2-yl]oxy-6-[(2r,3r,4s,5r,6s)-4,5,6-triacetyloxy-2-(acetyloxymethyl)oxan-3-yl]oxyoxan-2-yl]methyl acetate Chemical compound O([C@@H]1O[C@@H]([C@H]([C@H](OC(C)=O)[C@H]1OC(C)=O)O[C@H]1[C@@H]([C@@H](OC(C)=O)[C@H](OC(C)=O)[C@@H](COC(C)=O)O1)OC(C)=O)COC(=O)C)[C@@H]1[C@@H](COC(C)=O)O[C@@H](OC(C)=O)[C@H](OC(C)=O)[C@H]1OC(C)=O NNLVGZFZQQXQNW-ADJNRHBOSA-N 0.000 description 2
- 150000007933 aliphatic carboxylic acids Chemical class 0.000 description 2
- 125000005037 alkyl phenyl group Chemical group 0.000 description 2
- 150000008064 anhydrides Chemical class 0.000 description 2
- 125000004429 atom Chemical group 0.000 description 2
- 150000001639 boron compounds Chemical class 0.000 description 2
- 238000004090 dissolution Methods 0.000 description 2
- 125000003438 dodecyl group Chemical group [H]C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])* 0.000 description 2
- 230000002708 enhancing effect Effects 0.000 description 2
- 150000002148 esters Chemical class 0.000 description 2
- FJKIXWOMBXYWOQ-UHFFFAOYSA-N ethenoxyethane Chemical compound CCOC=C FJKIXWOMBXYWOQ-UHFFFAOYSA-N 0.000 description 2
- 230000001965 increasing effect Effects 0.000 description 2
- 238000010030 laminating Methods 0.000 description 2
- 229940031957 lauric acid diethanolamide Drugs 0.000 description 2
- FQPSGWSUVKBHSU-UHFFFAOYSA-N methacrylamide Chemical class CC(=C)C(N)=O FQPSGWSUVKBHSU-UHFFFAOYSA-N 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 230000002093 peripheral effect Effects 0.000 description 2
- 230000000704 physical effect Effects 0.000 description 2
- 229920003023 plastic Polymers 0.000 description 2
- 239000004033 plastic Substances 0.000 description 2
- 238000011002 quantification Methods 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- ILJSQTXMGCGYMG-UHFFFAOYSA-N triacetic acid Chemical compound CC(=O)CC(=O)CC(O)=O ILJSQTXMGCGYMG-UHFFFAOYSA-N 0.000 description 2
- BQCIDUSAKPWEOX-UHFFFAOYSA-N 1,1-Difluoroethene Chemical compound FC(F)=C BQCIDUSAKPWEOX-UHFFFAOYSA-N 0.000 description 1
- OZCMOJQQLBXBKI-UHFFFAOYSA-N 1-ethenoxy-2-methylpropane Chemical compound CC(C)COC=C OZCMOJQQLBXBKI-UHFFFAOYSA-N 0.000 description 1
- UZKWTJUDCOPSNM-UHFFFAOYSA-N 1-ethenoxybutane Chemical compound CCCCOC=C UZKWTJUDCOPSNM-UHFFFAOYSA-N 0.000 description 1
- LAYAKLSFVAPMEL-UHFFFAOYSA-N 1-ethenoxydodecane Chemical compound CCCCCCCCCCCCOC=C LAYAKLSFVAPMEL-UHFFFAOYSA-N 0.000 description 1
- QJJDJWUCRAPCOL-UHFFFAOYSA-N 1-ethenoxyoctadecane Chemical compound CCCCCCCCCCCCCCCCCCOC=C QJJDJWUCRAPCOL-UHFFFAOYSA-N 0.000 description 1
- OVGRCEFMXPHEBL-UHFFFAOYSA-N 1-ethenoxypropane Chemical compound CCCOC=C OVGRCEFMXPHEBL-UHFFFAOYSA-N 0.000 description 1
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 description 1
- JAHNSTQSQJOJLO-UHFFFAOYSA-N 2-(3-fluorophenyl)-1h-imidazole Chemical compound FC1=CC=CC(C=2NC=CN=2)=C1 JAHNSTQSQJOJLO-UHFFFAOYSA-N 0.000 description 1
- OEPOKWHJYJXUGD-UHFFFAOYSA-N 2-(3-phenylmethoxyphenyl)-1,3-thiazole-4-carbaldehyde Chemical compound O=CC1=CSC(C=2C=C(OCC=3C=CC=CC=3)C=CC=2)=N1 OEPOKWHJYJXUGD-UHFFFAOYSA-N 0.000 description 1
- GOXQRTZXKQZDDN-UHFFFAOYSA-N 2-Ethylhexyl acrylate Chemical compound CCCCC(CC)COC(=O)C=C GOXQRTZXKQZDDN-UHFFFAOYSA-N 0.000 description 1
- PGYJSURPYAAOMM-UHFFFAOYSA-N 2-ethenoxy-2-methylpropane Chemical compound CC(C)(C)OC=C PGYJSURPYAAOMM-UHFFFAOYSA-N 0.000 description 1
- GNUGVECARVKIPH-UHFFFAOYSA-N 2-ethenoxypropane Chemical compound CC(C)OC=C GNUGVECARVKIPH-UHFFFAOYSA-N 0.000 description 1
- WDQMWEYDKDCEHT-UHFFFAOYSA-N 2-ethylhexyl 2-methylprop-2-enoate Chemical compound CCCCC(CC)COC(=O)C(C)=C WDQMWEYDKDCEHT-UHFFFAOYSA-N 0.000 description 1
- FVSAFCHCUDOKSI-UHFFFAOYSA-N 2-methylprop-2-enamide;propane-1-sulfonic acid Chemical compound CC(=C)C(N)=O.CCCS(O)(=O)=O FVSAFCHCUDOKSI-UHFFFAOYSA-N 0.000 description 1
- RUMACXVDVNRZJZ-UHFFFAOYSA-N 2-methylpropyl 2-methylprop-2-enoate Chemical compound CC(C)COC(=O)C(C)=C RUMACXVDVNRZJZ-UHFFFAOYSA-N 0.000 description 1
- CFVWNXQPGQOHRJ-UHFFFAOYSA-N 2-methylpropyl prop-2-enoate Chemical compound CC(C)COC(=O)C=C CFVWNXQPGQOHRJ-UHFFFAOYSA-N 0.000 description 1
- 125000003903 2-propenyl group Chemical group [H]C([*])([H])C([H])=C([H])[H] 0.000 description 1
- HRPVXLWXLXDGHG-UHFFFAOYSA-N Acrylamide Chemical compound NC(=O)C=C HRPVXLWXLXDGHG-UHFFFAOYSA-N 0.000 description 1
- OSDWBNJEKMUWAV-UHFFFAOYSA-N Allyl chloride Chemical compound ClCC=C OSDWBNJEKMUWAV-UHFFFAOYSA-N 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- FBPFZTCFMRRESA-FSIIMWSLSA-N D-Glucitol Natural products OC[C@H](O)[C@H](O)[C@@H](O)[C@H](O)CO FBPFZTCFMRRESA-FSIIMWSLSA-N 0.000 description 1
- FBPFZTCFMRRESA-JGWLITMVSA-N D-glucitol Chemical compound OC[C@H](O)[C@@H](O)[C@H](O)[C@H](O)CO FBPFZTCFMRRESA-JGWLITMVSA-N 0.000 description 1
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 1
- JIGUQPWFLRLWPJ-UHFFFAOYSA-N Ethyl acrylate Chemical compound CCOC(=O)C=C JIGUQPWFLRLWPJ-UHFFFAOYSA-N 0.000 description 1
- JOYRKODLDBILNP-UHFFFAOYSA-N Ethyl urethane Chemical compound CCOC(N)=O JOYRKODLDBILNP-UHFFFAOYSA-N 0.000 description 1
- 239000005977 Ethylene Substances 0.000 description 1
- DKNPRRRKHAEUMW-UHFFFAOYSA-N Iodine aqueous Chemical compound [K+].I[I-]I DKNPRRRKHAEUMW-UHFFFAOYSA-N 0.000 description 1
- VQTUBCCKSQIDNK-UHFFFAOYSA-N Isobutene Chemical group CC(C)=C VQTUBCCKSQIDNK-UHFFFAOYSA-N 0.000 description 1
- HETCEOQFVDFGSY-UHFFFAOYSA-N Isopropenyl acetate Chemical compound CC(=C)OC(C)=O HETCEOQFVDFGSY-UHFFFAOYSA-N 0.000 description 1
- CERQOIWHTDAKMF-UHFFFAOYSA-N Methacrylic acid Chemical compound CC(=C)C(O)=O CERQOIWHTDAKMF-UHFFFAOYSA-N 0.000 description 1
- VVQNEPGJFQJSBK-UHFFFAOYSA-N Methyl methacrylate Chemical compound COC(=O)C(C)=C VVQNEPGJFQJSBK-UHFFFAOYSA-N 0.000 description 1
- GYCMBHHDWRMZGG-UHFFFAOYSA-N Methylacrylonitrile Chemical compound CC(=C)C#N GYCMBHHDWRMZGG-UHFFFAOYSA-N 0.000 description 1
- CNCOEDDPFOAUMB-UHFFFAOYSA-N N-Methylolacrylamide Chemical compound OCNC(=O)C=C CNCOEDDPFOAUMB-UHFFFAOYSA-N 0.000 description 1
- WHNWPMSKXPGLAX-UHFFFAOYSA-N N-Vinyl-2-pyrrolidone Chemical compound C=CN1CCCC1=O WHNWPMSKXPGLAX-UHFFFAOYSA-N 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
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- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
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- UWHCKJMYHZGTIT-UHFFFAOYSA-N Tetraethylene glycol, Natural products OCCOCCOCCOCCO UWHCKJMYHZGTIT-UHFFFAOYSA-N 0.000 description 1
- ZJCCRDAZUWHFQH-UHFFFAOYSA-N Trimethylolpropane Chemical compound CCC(CO)(CO)CO ZJCCRDAZUWHFQH-UHFFFAOYSA-N 0.000 description 1
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- 239000006096 absorbing agent Substances 0.000 description 1
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- 238000004220 aggregation Methods 0.000 description 1
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- 150000001336 alkenes Chemical class 0.000 description 1
- 150000004996 alkyl benzenes Chemical class 0.000 description 1
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- 150000001485 argon Chemical class 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000000740 bleeding effect Effects 0.000 description 1
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- 238000000071 blow moulding Methods 0.000 description 1
- CQEYYJKEWSMYFG-UHFFFAOYSA-N butyl acrylate Chemical compound CCCCOC(=O)C=C CQEYYJKEWSMYFG-UHFFFAOYSA-N 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
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- 230000015556 catabolic process Effects 0.000 description 1
- 230000001413 cellular effect Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003086 colorant Substances 0.000 description 1
- 230000003750 conditioning effect Effects 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
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- 230000002542 deteriorative effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 229940105990 diglycerin Drugs 0.000 description 1
- GPLRAVKSCUXZTP-UHFFFAOYSA-N diglycerol Chemical compound OCC(O)COCC(O)CO GPLRAVKSCUXZTP-UHFFFAOYSA-N 0.000 description 1
- GMSCBRSQMRDRCD-UHFFFAOYSA-N dodecyl 2-methylprop-2-enoate Chemical compound CCCCCCCCCCCCOC(=O)C(C)=C GMSCBRSQMRDRCD-UHFFFAOYSA-N 0.000 description 1
- 238000010828 elution Methods 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- YCUBDDIKWLELPD-UHFFFAOYSA-N ethenyl 2,2-dimethylpropanoate Chemical compound CC(C)(C)C(=O)OC=C YCUBDDIKWLELPD-UHFFFAOYSA-N 0.000 description 1
- GLVVKKSPKXTQRB-UHFFFAOYSA-N ethenyl dodecanoate Chemical compound CCCCCCCCCCCC(=O)OC=C GLVVKKSPKXTQRB-UHFFFAOYSA-N 0.000 description 1
- GFJVXXWOPWLRNU-UHFFFAOYSA-N ethenyl formate Chemical compound C=COC=O GFJVXXWOPWLRNU-UHFFFAOYSA-N 0.000 description 1
- AFSIMBWBBOJPJG-UHFFFAOYSA-N ethenyl octadecanoate Chemical compound CCCCCCCCCCCCCCCCCC(=O)OC=C AFSIMBWBBOJPJG-UHFFFAOYSA-N 0.000 description 1
- BLZSRIYYOIZLJL-UHFFFAOYSA-N ethenyl pentanoate Chemical compound CCCCC(=O)OC=C BLZSRIYYOIZLJL-UHFFFAOYSA-N 0.000 description 1
- UIWXSTHGICQLQT-UHFFFAOYSA-N ethenyl propanoate Chemical compound CCC(=O)OC=C UIWXSTHGICQLQT-UHFFFAOYSA-N 0.000 description 1
- NKSJNEHGWDZZQF-UHFFFAOYSA-N ethenyl(trimethoxy)silane Chemical compound CO[Si](OC)(OC)C=C NKSJNEHGWDZZQF-UHFFFAOYSA-N 0.000 description 1
- SUPCQIBBMFXVTL-UHFFFAOYSA-N ethyl 2-methylprop-2-enoate Chemical compound CCOC(=O)C(C)=C SUPCQIBBMFXVTL-UHFFFAOYSA-N 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- XUCNUKMRBVNAPB-UHFFFAOYSA-N fluoroethene Chemical compound FC=C XUCNUKMRBVNAPB-UHFFFAOYSA-N 0.000 description 1
- 230000008014 freezing Effects 0.000 description 1
- 238000007710 freezing Methods 0.000 description 1
- 229910003472 fullerene Inorganic materials 0.000 description 1
- 108010025899 gelatin film Proteins 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 229910052736 halogen Inorganic materials 0.000 description 1
- 150000002367 halogens Chemical class 0.000 description 1
- 238000007602 hot air drying Methods 0.000 description 1
- 230000003100 immobilizing effect Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000003112 inhibitor Substances 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 230000001678 irradiating effect Effects 0.000 description 1
- PBOSTUDLECTMNL-UHFFFAOYSA-N lauryl acrylate Chemical compound CCCCCCCCCCCCOC(=O)C=C PBOSTUDLECTMNL-UHFFFAOYSA-N 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- VZCYOOQTPOCHFL-UPHRSURJSA-N maleic acid Chemical compound OC(=O)\C=C/C(O)=O VZCYOOQTPOCHFL-UPHRSURJSA-N 0.000 description 1
- 239000011976 maleic acid Substances 0.000 description 1
- 239000002609 medium Substances 0.000 description 1
- 150000002734 metacrylic acid derivatives Chemical class 0.000 description 1
- 150000002736 metal compounds Chemical class 0.000 description 1
- XJRBAMWJDBPFIM-UHFFFAOYSA-N methyl vinyl ether Chemical compound COC=C XJRBAMWJDBPFIM-UHFFFAOYSA-N 0.000 description 1
- LVHBHZANLOWSRM-UHFFFAOYSA-N methylenebutanedioic acid Natural products OC(=O)CC(=C)C(O)=O LVHBHZANLOWSRM-UHFFFAOYSA-N 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- WFKDPJRCBCBQNT-UHFFFAOYSA-N n,2-dimethylprop-2-enamide Chemical compound CNC(=O)C(C)=C WFKDPJRCBCBQNT-UHFFFAOYSA-N 0.000 description 1
- YMDZGJOTVBKZQK-UHFFFAOYSA-N n,n-dimethylpropan-1-amine;2-methylprop-2-enamide Chemical compound CCCN(C)C.CC(=C)C(N)=O YMDZGJOTVBKZQK-UHFFFAOYSA-N 0.000 description 1
- QQGJWWNPACORPU-UHFFFAOYSA-N n,n-dimethylpropan-1-amine;prop-2-enamide Chemical compound NC(=O)C=C.CCCN(C)C QQGJWWNPACORPU-UHFFFAOYSA-N 0.000 description 1
- OMNKZBIFPJNNIO-UHFFFAOYSA-N n-(2-methyl-4-oxopentan-2-yl)prop-2-enamide Chemical compound CC(=O)CC(C)(C)NC(=O)C=C OMNKZBIFPJNNIO-UHFFFAOYSA-N 0.000 description 1
- DNTMQTKDNSEIFO-UHFFFAOYSA-N n-(hydroxymethyl)-2-methylprop-2-enamide Chemical compound CC(=C)C(=O)NCO DNTMQTKDNSEIFO-UHFFFAOYSA-N 0.000 description 1
- RQAKESSLMFZVMC-UHFFFAOYSA-N n-ethenylacetamide Chemical compound CC(=O)NC=C RQAKESSLMFZVMC-UHFFFAOYSA-N 0.000 description 1
- ZQXSMRAEXCEDJD-UHFFFAOYSA-N n-ethenylformamide Chemical compound C=CNC=O ZQXSMRAEXCEDJD-UHFFFAOYSA-N 0.000 description 1
- ZIWDVJPPVMGJGR-UHFFFAOYSA-N n-ethyl-2-methylprop-2-enamide Chemical compound CCNC(=O)C(C)=C ZIWDVJPPVMGJGR-UHFFFAOYSA-N 0.000 description 1
- SWPMNMYLORDLJE-UHFFFAOYSA-N n-ethylprop-2-enamide Chemical compound CCNC(=O)C=C SWPMNMYLORDLJE-UHFFFAOYSA-N 0.000 description 1
- YPHQUSNPXDGUHL-UHFFFAOYSA-N n-methylprop-2-enamide Chemical compound CNC(=O)C=C YPHQUSNPXDGUHL-UHFFFAOYSA-N 0.000 description 1
- 238000006386 neutralization reaction Methods 0.000 description 1
- 230000003472 neutralizing effect Effects 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000002736 nonionic surfactant Substances 0.000 description 1
- HMZGPNHSPWNGEP-UHFFFAOYSA-N octadecyl 2-methylprop-2-enoate Chemical compound CCCCCCCCCCCCCCCCCCOC(=O)C(C)=C HMZGPNHSPWNGEP-UHFFFAOYSA-N 0.000 description 1
- FSAJWMJJORKPKS-UHFFFAOYSA-N octadecyl prop-2-enoate Chemical compound CCCCCCCCCCCCCCCCCCOC(=O)C=C FSAJWMJJORKPKS-UHFFFAOYSA-N 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
- HVAMZGADVCBITI-UHFFFAOYSA-M pent-4-enoate Chemical compound [O-]C(=O)CCC=C HVAMZGADVCBITI-UHFFFAOYSA-M 0.000 description 1
- PNJWIWWMYCMZRO-UHFFFAOYSA-N pent‐4‐en‐2‐one Natural products CC(=O)CC=C PNJWIWWMYCMZRO-UHFFFAOYSA-N 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 239000002985 plastic film Substances 0.000 description 1
- 229920006255 plastic film Polymers 0.000 description 1
- 229920006267 polyester film Polymers 0.000 description 1
- 230000000379 polymerizing effect Effects 0.000 description 1
- 239000003755 preservative agent Substances 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- BOQSSGDQNWEFSX-UHFFFAOYSA-N propan-2-yl 2-methylprop-2-enoate Chemical compound CC(C)OC(=O)C(C)=C BOQSSGDQNWEFSX-UHFFFAOYSA-N 0.000 description 1
- LYBIZMNPXTXVMV-UHFFFAOYSA-N propan-2-yl prop-2-enoate Chemical compound CC(C)OC(=O)C=C LYBIZMNPXTXVMV-UHFFFAOYSA-N 0.000 description 1
- AAYRWMCIKCRHIN-UHFFFAOYSA-N propane-1-sulfonic acid;prop-2-enamide Chemical compound NC(=O)C=C.CCCS(O)(=O)=O AAYRWMCIKCRHIN-UHFFFAOYSA-N 0.000 description 1
- NHARPDSAXCBDDR-UHFFFAOYSA-N propyl 2-methylprop-2-enoate Chemical compound CCCOC(=O)C(C)=C NHARPDSAXCBDDR-UHFFFAOYSA-N 0.000 description 1
- PNXMTCDJUBJHQJ-UHFFFAOYSA-N propyl prop-2-enoate Chemical compound CCCOC(=O)C=C PNXMTCDJUBJHQJ-UHFFFAOYSA-N 0.000 description 1
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 description 1
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 238000005204 segregation Methods 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000000600 sorbitol Substances 0.000 description 1
- 150000005846 sugar alcohols Polymers 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 230000003746 surface roughness Effects 0.000 description 1
- SJMYWORNLPSJQO-UHFFFAOYSA-N tert-butyl 2-methylprop-2-enoate Chemical compound CC(=C)C(=O)OC(C)(C)C SJMYWORNLPSJQO-UHFFFAOYSA-N 0.000 description 1
- ISXSCDLOGDJUNJ-UHFFFAOYSA-N tert-butyl prop-2-enoate Chemical compound CC(C)(C)OC(=O)C=C ISXSCDLOGDJUNJ-UHFFFAOYSA-N 0.000 description 1
- VZCYOOQTPOCHFL-UHFFFAOYSA-N trans-butenedioic acid Natural products OC(=O)C=CC(O)=O VZCYOOQTPOCHFL-UHFFFAOYSA-N 0.000 description 1
- 238000002834 transmittance Methods 0.000 description 1
- ZIBGPFATKBEMQZ-UHFFFAOYSA-N triethylene glycol Chemical compound OCCOCCOCCO ZIBGPFATKBEMQZ-UHFFFAOYSA-N 0.000 description 1
- KOZCZZVUFDCZGG-UHFFFAOYSA-N vinyl benzoate Chemical compound C=COC(=O)C1=CC=CC=C1 KOZCZZVUFDCZGG-UHFFFAOYSA-N 0.000 description 1
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 1
- 229920003169 water-soluble polymer Polymers 0.000 description 1
Classifications
-
- 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
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L29/00—Compositions 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; Compositions of hydrolysed polymers of esters of unsaturated alcohols with saturated carboxylic acids; Compositions of derivatives of such polymers
- C08L29/02—Homopolymers or copolymers of unsaturated alcohols
- C08L29/04—Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/30—Polarising elements
-
- 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
- Chemical & Material Sciences (AREA)
- Physics & Mathematics (AREA)
- Manufacturing & Machinery (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Manufacture Of Macromolecular Shaped Articles (AREA)
- Polarising Elements (AREA)
Abstract
Provided are a PVA film which has good peelability from a support and can produce a polarizing film having little optical unevenness, and a polarizing film obtained using such a PVA film. The polyvinyl alcohol film of the present invention is a water-insoluble polyvinyl alcohol film, wherein when one of two surfaces of the polyvinyl alcohol film orthogonal to a thickness direction is a first surface, a proportion (Na 1S) of sodium element in all elements obtained by analyzing the first surface by an X-ray photoelectron spectroscopy is 0.3 to 1.5 mol%, and a proportion (Na 1B) of sodium element in all elements obtained by analyzing a surface having a depth of 0.01 [ mu ] m from the first surface by an X-ray photoelectron spectroscopy is 0.3 mol% or less.
Description
Technical Field
The present invention relates to a polyvinyl alcohol film which is excellent in peelability from a support at the time of film formation and which can produce a polarizing film having little optical unevenness, and a polarizing film using the same.
Background
A polarizing plate having light transmitting and light shielding functions is the same as a liquid crystal having light switching functions as an essential component of a Liquid Crystal Display (LCD). In recent years, the application field of the LCD has been expanded from the development of small-sized devices such as calculators and wristwatches at the beginning to various fields such as notebook computers, liquid crystal monitors, liquid crystal color projectors, liquid crystal televisions, car navigation systems, cellular phones, and measuring devices used indoors and outdoors.
The polarizing plate is manufactured by laminating a protective film such as a cellulose Triacetate (TAC) film or a Cellulose Acetate Butyrate (CAB) film on the surface of a polarizing film. And, the polarizing film is generally manufactured as follows: a dyed uniaxially stretched film is produced by dyeing a polyvinyl alcohol film (hereinafter, sometimes referred to as "PVA") and then uniaxially stretching the film, or by uniaxially stretching the film while dyeing the film, or by uniaxially stretching the film and then dyeing the film, and by immobilizing the uniaxially stretched film with a boron compound. The immobilization treatment with the boron compound may be performed simultaneously with the uniaxial stretching or dyeing treatment.
In PVA films used for this purpose, various additives such as plasticizers are blended to improve various physical properties, and surfactants are added to improve peelability from a support such as a metal roll or a metal belt used in film formation.
In addition, as the demand for PVA films increases in recent years, improvement in productivity is desired. Although productivity can be improved by increasing the film-forming speed of the PVA film, in this case, peelability from the support at the time of producing the PVA film may be insufficient. As a result, there are problems in that the PVA film is liable to have surface roughness, film surface defects, and polarizing films obtained from the PVA film are also liable to have optical unevenness. Therefore, in order to improve the peelability from the support at the time of producing the PVA film, it is conceivable to add more surfactant to the film-forming stock solution of the PVA film. However, when a large amount of surfactant is added, there is a problem in that optical unevenness derived from the surfactant is liable to occur when the resulting PVA film is used to produce a polarizing film.
In order to solve such a problem of releasability from a support at the time of producing a PVA film, patent document 1 describes adding a fluorine-containing surfactant to a film-producing stock solution of a PVA film. Patent document 2 describes that a cured fluororesin film is formed by coating a casting substrate with a fluororesin.
Prior art literature
Patent literature
Patent document 1: japanese patent laid-open No. 2006-307059
Patent document 2: japanese patent laid-open No. 2006-305924
Disclosure of Invention
Problems to be solved by the invention
However, in the method described in patent document 1, it is sometimes difficult to cope with environmental pollution due to the use of a fluorine-containing surfactant as a halogen substance. In addition, in the method described in patent document 2, since the fluorine-based resin film is formed on a support such as a roll or a belt as a casting base, there is a problem that the cost for forming or maintaining the fluorine-based resin film becomes high and the manufacturing cost of the PVA film becomes high.
Accordingly, an object of the present invention is to provide a PVA film having good peelability from a support and a polarizing film obtained using the PVA film. The present invention also provides a PVA film capable of producing a polarizing film having little optical unevenness, and a polarizing film obtained using the PVA film.
Means for solving the problems
The present inventors have conducted intensive studies and as a result, found that: in the case of a water-insoluble PVA film, when one of the two surfaces of the PVA film orthogonal to the thickness direction is the first surface, the ratio of sodium element to all elements obtained by analyzing the first surface by X-ray photoelectron spectroscopy is set to a specific range, and the ratio of sodium element to all elements obtained by analyzing a surface having a depth of 0.01 μm from the first surface by X-ray photoelectron spectroscopy is set to a specific range, whereby the above-mentioned problems can be solved, and further repeated studies are made based on the findings, and the present invention has been completed.
Further, the present inventors have conducted intensive studies and as a result, found that: in the case of a water-insoluble PVA film, when one of the two surfaces of the PVA film orthogonal to the thickness direction is the first surface, the surface having a depth of 0.01 μm from the first surface is analyzed by X-ray photoelectron spectroscopy, and the proportion of sodium element in all elements is set to a specific range, whereby the above-mentioned problems can be solved, and further research is repeated based on the findings, and the present invention has been completed.
That is, the present invention relates to the following [1] to [8].
[1] A polyvinyl alcohol film which is water-insoluble, wherein, when one of two surfaces of the polyvinyl alcohol film orthogonal to a thickness direction is a first surface, a proportion (Na 1S) of sodium element in all elements obtained by analyzing the first surface by X-ray photoelectron spectroscopy is 0.3 to 1.5 mol%, and a proportion (Na 1B) of sodium element in all elements obtained by analyzing a surface having a depth of 0.01 [ mu ] m from the first surface by X-ray photoelectron spectroscopy is 0.3 mol% or less;
[2] the polyvinyl alcohol film according to the above [1], wherein, when a surface facing the first surface of the two surfaces orthogonal to the thickness direction of the polyvinyl alcohol film is a second surface, a proportion (Na 2S) of sodium element in all elements obtained by analyzing the second surface by X-ray photoelectron spectroscopy is 0.3 to 1.5 mol%, and a proportion (Na 2B) of sodium element in all elements obtained by analyzing a surface having a depth of 0.01 μm from the second surface by X-ray photoelectron spectroscopy is 0.3 mol% or less;
[3] The polyvinyl alcohol film according to the above [1] or [2], which contains a sodium sulfate type surfactant or a sodium sulfonate type surfactant, the sodium element being derived from the sodium sulfate type surfactant or the sodium sulfonate type surfactant;
[4] the polyvinyl alcohol film according to the above [3], wherein the sodium sulfate type surfactant or the sodium sulfonate type surfactant is at least 1 selected from the group consisting of sodium alkyl sulfate, sodium polyoxyethylene alkyl ether sulfate, sodium polyoxypropylene alkyl ether sulfate, sodium polyoxyethylene alkylphenyl ether sulfate, sodium alkyl sulfonate, sodium alkylbenzenesulfonate, disodium dodecyl diphenyl ether disulfonate, sodium alkyl naphthalene sulfonate, disodium alkyl sulfosuccinate and disodium polyoxyethylene alkyl sulfosuccinate;
[5] the polyvinyl alcohol film according to the above [3] or [4], wherein the molecular weight of the sodium sulfate type surfactant or the sodium sulfonate type surfactant is 200 to 10,000, and the content of the sodium sulfate type surfactant or the sodium sulfonate type surfactant is 0.02 to 0.4 parts by mass relative to 100 parts by mass of polyvinyl alcohol contained in the polyvinyl alcohol film;
[6] the polyvinyl alcohol film according to any one of the above [1] to [5], which is a film for producing an optical film;
[7] The polyvinyl alcohol film according to the above [6], wherein the optical film is a polarizing film;
[8] the method for producing a polarizing film, wherein the polyvinyl alcohol film of any one of the above [1] to [7] is used for producing a polarizing film.
Effects of the invention
According to the present invention, a PVA film having good peelability from a support and a polarizing film obtained using such a PVA film can be provided. Further, according to the present invention, a PVA film capable of producing a polarizing film having little optical unevenness and a polarizing film obtained using such a PVA film can be provided.
Drawings
FIG. 1 is a perspective view of a PVA film of the present invention.
Fig. 2 is a view of the PVA film of the present invention as seen from the thickness direction.
Detailed Description
The present invention will be described in detail below.
< PVA film >
(proportion of sodium element in all elements)
Fig. 1 is a perspective view of a PVA film. Fig. 2 is a view of the PVA film of the present invention as seen from the thickness direction. In the present invention, as shown in fig. 1 and 2, one of two surfaces of the PVA film orthogonal to the thickness direction 2 is set as the first surface 3. In the present invention, the proportion of sodium element (Na 1S) in all elements, which is determined by analyzing the first surface 3 of the PVA film 1 by X-ray photoelectron spectroscopy (hereinafter, may be referred to as XPS), is preferably 0.3 to 1.5 mol%. When Na1S is less than 0.3 mol%, the peelability from the support at the time of producing PVA film 1 becomes insufficient. Na1S is preferably 0.3 mol% or more, more preferably 0.5 mol% or more, and still more preferably 0.6 mol% or more. On the other hand, when Na1S exceeds 1.5 mol%, surface defects are likely to occur during production of PVA film 1, and as a result, optical unevenness is likely to occur in the obtained optical film such as a polarizing film. Na1S is preferably not more than 1.5 mol%, more preferably not more than 1.3 mol%. The Na1S can be set to 0.3 to 1.5 mol% by appropriately adjusting the content of the plasticizer of the PVA film, the content of the surfactant, the evaporation fraction of the film-forming stock solution, the thickness of the PVA film, the surface temperature of the support at the time of producing the PVA film, the drying temperature, and the heat treatment temperature.
In the present invention, the proportion of sodium element (Na 1B) in all elements, which is determined by analyzing a surface having a depth of 0.01 μm from the first surface 3 of the PVA film 1 by XPS, is preferably 0.3 mol% or less. Here, the surface at a depth of 0.01 μm from the first surface is also a surface orthogonal to the thickness direction 2 of the PVA film. When Na1B exceeds 0.3 mol%, defects are likely to occur on the surface of PVA film 1 in the production of optical films such as polarizing films, and as a result, optical unevenness is likely to occur in the obtained optical films such as polarizing films. Na1B may be 0 mol% or less, that is, may be equal to or less than the detection limit of the XPS measurement device. The detection limit of a typical XPS measurement device is usually about 0.1 mol%. Na1B is preferably 0.3 mol% or less, more preferably 0.25 mol% or less. The Na1B can be set to 0.3 mol% or less by appropriately adjusting the content of the plasticizer of the PVA film, the content of the surfactant, the evaporation fraction of the film-forming stock solution, the thickness of the PVA film, the surface temperature of the support at the time of producing the PVA film, the drying temperature, and the heat treatment temperature.
In the present invention, as shown in fig. 1 and 2, a surface opposite to the first surface 3 is defined as a second surface 4, among two surfaces of the PVA film orthogonal to the thickness direction 2. In the present invention, the proportion of sodium element (Na 2S) in the total elements, which is determined by analyzing the second surface 4 of the PVA film 1 by XPS, is preferably 0.3 to 1.5 mol%. That is, the proportion of sodium element (Na 1S, na 2S) in all elements obtained by analyzing the two surfaces of the PVA film 1 orthogonal to the thickness direction by XPS is preferably 0.3 to 1.5 mol%. When Na2S is less than 0.3 mol%, the peelability from the support at the time of producing PVA film 1 becomes insufficient. Na2S is preferably 0.3 mol% or more, more preferably 0.5 mol% or more, and still more preferably 0.6 mol% or more. On the other hand, when Na2S exceeds 1.5 mol%, surface defects are likely to occur during production of PVA film 1, and as a result, optical unevenness is likely to occur in the obtained optical film such as a polarizing film. Na2S is preferably not more than 1.5 mol%, more preferably not more than 1.3 mol%. The Na2S can be set to 0.3 to 1.5 mol% by appropriately adjusting the content of the plasticizer of the PVA film, the content of the surfactant, the evaporation fraction of the film-forming stock solution, the thickness of the PVA film, the surface temperature of the support at the time of producing the PVA film, the drying temperature, and the heat treatment temperature.
In the present invention, the proportion of sodium element (Na 2B) in all elements, which is determined by analyzing a surface having a depth of 0.01 μm from the second surface of the PVA film 1 by XPS, is preferably 0.3 mol% or less. That is, the proportion of sodium element (Na 1B, na 2B) in all elements, which is obtained by analyzing a surface of the PVA film perpendicular to the thickness direction 2, which is 0.01 μm deep from the surface thereof by XPS, is preferably 0.3 mol% or less. Here, the surface of the PVA film at a depth of 0.01 μm from the second surface is also a surface orthogonal to the thickness direction 2. When Na2B exceeds 0.3 mol%, defects are likely to occur on the surface of PVA film 1 when producing an optical film such as a polarizing film, and as a result, optical unevenness tends to occur in the obtained optical film such as a polarizing film. The Na2B may be 0 mol% or less, that is, may be not more than the detection limit of the XPS measurement device. Na2B is preferably 0.3 mol% or less, more preferably 0.2 mol% or less. The Na2B can be set to 0.3 mol% or less by appropriately adjusting the content of the plasticizer of the PVA film, the content of the surfactant, the evaporation fraction of the film-forming stock solution, the thickness of the PVA film, the surface temperature of the support at the time of producing the PVA film, the drying temperature, and the heat treatment temperature.
(XPS)
In the present invention, the amounts of sodium element and other elements in the first surface or the second surface of the PVA film, or the surface at a depth of 0.01 μm from the first surface or the second surface, were measured using XPS. XPS refers to: the inner electrons of atoms are excited by irradiating the surface of the sample with X-rays, and the kinetic energy of the photoelectrons released therefrom is detected, whereby the identification and quantification of elements present on the surface of the sample and the analysis of the chemical bonding state are performed. In the present invention, the elements to be measured by XPS are carbon (1 s orbital electron), nitrogen (1 s orbital electron), oxygen (1 s orbital electron), sodium (1 s orbital electron), silicon (2 p orbital electron), phosphorus (2 p orbital electron), and sulfur (2 p orbital electron). These elements were quantified, and the ratio of sodium element to the total amount thereof was set to Na1S, na1B, na S or Na2B.
In XPS, the film surface may also be etched by C60 (buckminsterfullerene), argon clusters, or the like, and analyzed in the depth direction. In the present invention, na1B or Na2B was quantified by exposing a surface having a depth of about 0.01 μm from the film surface by etching for 30 seconds under conditions of an acceleration voltage of 10kV, a sample current of 20nA, and a scanning range of 0.5X2.0 mm using C60.
(physical Properties)
The PVA film of the present invention is preferably water insoluble. By making the PVA film insoluble in water, when uniaxial stretching is performed in an aqueous solution at the time of producing an optical film such as a polarizing film, stretching can be performed without breaking the PVA film at the time of uniaxial stretching even if the maximum stretching speed is high. Here, in the present invention, water-insoluble means: when the PVA film is immersed in water (deionized water) at 30℃in accordance with the following steps <1> to <4>, the PVA film is not completely dissolved but at least a part of the dissolved residue remains.
<1> the PVA film was allowed to stand in a constant temperature and humidity apparatus adjusted to 20 ℃ and-65% rh for 16 hours or more, and subjected to humidity control.
<2> after a rectangular sample having a length of 40mm by a width of 35mm was cut out from the humidity-controlled PVA film, the sample was sandwiched between 2 plastic plates having 50mm by 50mm and each having a rectangular window (hole) having a length of 35mm by a width of 23mm and fixed so that the longitudinal direction of the sample was parallel to the longitudinal direction of the window and the sample was located at the substantially center in the width direction of the window.
<3> 300mL of deionized water was poured into a 500mL beaker, and the mixture was stirred at 280rpm with a magnetic stirrer equipped with a 3cm long rod, and the water temperature was adjusted to 30 ℃.
<4> side note that the sample fixed to the plastic plate in the above <2> was immersed in deionized water in a beaker for 1000 seconds without contacting the rod of the magnetic stirrer rotating.
(PVA)
In the PVA film of the present invention, as PVA, a polymer produced by saponifying a vinyl ester polymer obtained by polymerizing a vinyl ester monomer can be used. Examples of the vinyl ester monomer include vinyl formate, vinyl acetate, vinyl propionate, vinyl valerate, vinyl laurate, vinyl stearate, vinyl benzoate, vinyl pivalate, and vinyl tertiary carboxylate. Among these, vinyl acetate is preferable as the vinyl ester monomer.
The vinyl ester polymer is preferably a polymer obtained by using only 1 or 2 or more vinyl ester monomers as monomers, and more preferably a polymer obtained by using only 1 vinyl ester monomer as monomers. The vinyl ester polymer may be a copolymer of 1 or 2 or more vinyl ester monomers and other monomers copolymerizable therewith.
Examples of the other monomer include ethylene; olefins having 3 to 30 carbon atoms such as propylene, 1-butene and isobutylene; acrylic acid or a salt thereof; acrylic esters such as methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, and octadecyl acrylate; methacrylic acid or a salt thereof; methacrylates such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, 2-ethylhexyl methacrylate, dodecyl methacrylate, and octadecyl methacrylate; acrylamide derivatives such as acrylamide, N-methylacrylamide, N-ethylacrylamide, N-dimethylacrylamide, diacetone acrylamide, acrylamide propane sulfonic acid or a salt thereof, acrylamide propyl dimethylamine or a salt thereof, and N-methylolacrylamide or a derivative thereof; methacrylamide derivatives such as methacrylamide, N-methyl methacrylamide, N-ethyl methacrylamide, methacrylamide propane sulfonic acid or salt thereof, methacrylamide propyl dimethylamine or salt thereof, N-hydroxymethyl methacrylamide or derivative thereof; n-vinylamides such as N-vinylformamide, N-vinylacetamide and N-vinylpyrrolidone; vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, t-butyl vinyl ether, dodecyl vinyl ether and stearyl vinyl ether; vinyl cyanide such as acrylonitrile and methacrylonitrile; vinyl halides such as vinyl chloride, vinylidene chloride, vinyl fluoride, and vinylidene fluoride; allyl compounds such as allyl acetate and allyl chloride; maleic acid or a salt, ester or anhydride thereof; itaconic acid or a salt, ester or anhydride thereof; vinyl silyl compounds such as vinyl trimethoxy silane; isopropenyl acetate, and the like. The vinyl ester polymer may have 1 or 2 or more structural units derived from these other monomers.
The proportion of the structural units derived from other monomers in the vinyl ester-based polymer is preferably 15 mol% or less, more preferably 8 mol% or less, based on the number of moles of all the structural units constituting the vinyl ester-based polymer.
The polymerization degree of PVA is preferably 200 or more, more preferably 300 or more, and still more preferably 500 or more. By setting the degree of polymerization of PVA to the above lower limit or more, excessive crystallization of PVA can be prevented and mechanical strength of the resulting PVA film can be ensured. On the other hand, the polymerization degree of PVA is preferably 8,000 or less, more preferably 6,000 or less, and still more preferably 4,000 or less.
The polymerization degree of PVA refers to the average polymerization degree measured in accordance with JIS K6726-1994. That is, the polymerization degree (Po) is obtained by the following formula (1).
Polymerization degree po= ([ η)]×10 4 /8.29) (1/0.62) (1)
In the above formula (1), η is an intrinsic viscosity (deciliter/g) measured in water at 30℃after re-saponifying and purifying PVA.
The saponification degree of PVA is preferably 90 mol% or more, more preferably 95 mol% or more, still more preferably 99 mol% or more, particularly preferably 99.8 mol% or more. The PVA film 1 thus obtained is easily rendered insoluble in water by setting the degree of saponification of PVA to 99 mol% or more. The definition of water insoluble is as described above.
The saponification degree of PVA means: the proportion of the number of moles of the vinyl alcohol unit (mol%) to the total number of moles of the structural unit (typically, vinyl ester monomer unit) and the vinyl alcohol unit which can be converted into the vinyl alcohol unit by saponification. The saponification degree of PVA can be measured in accordance with JIS K6726-1994.
The PVA may be 1 kind of PVA alone or may be 2 or more kinds of PVA different from each other in polymerization degree, saponification degree, modification degree, and the like.
The PVA content in the PVA film of the present invention is not necessarily limited, but is preferably 50 mass% or more, more preferably 80 mass% or more, and still more preferably 85 mass% or more.
(plasticizer)
The PVA film of the present invention preferably contains a plasticizer. By containing the plasticizer, flexibility equivalent to that of other plastic films can be imparted to the PVA film, and occurrence of breakage of the PVA film can be suppressed in the film-forming and stretching steps of the PVA film.
Examples of the plasticizer include polyhydric alcohols such as ethylene glycol, glycerin, diglycerin, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, trimethylolpropane, and sorbitol. These plasticizers may be used alone or in combination of 1 or more than 2. Among these, ethylene glycol or glycerin is preferable as the plasticizer, and glycerin is more preferable from the viewpoint of difficulty in bleeding out to the surface of the PVA film, and the like.
The plasticizer content in the PVA film of the present invention is preferably 1 part by mass or more, more preferably 3 parts by mass or more, and still more preferably 5 parts by mass or more, per 100 parts by mass of PVA. On the other hand, the content of the plasticizer is preferably 40 parts by mass or less, more preferably 30 parts by mass or less, and still more preferably 20 parts by mass or less, based on 100 parts by mass of PVA. If the content of the plasticizer is within the above range, the proportion of sodium element (Na 1S, na2S, na1B, na B) in the PVA film to the total elements can be easily adjusted to the above range. The effect of improving mechanical properties such as impact strength can be sufficiently obtained. In addition, it is possible to prevent the PVA film from becoming too soft and reducing the handleability, or the plasticizer from oozing out to the surface of the PVA film.
(surfactant)
In the present invention, the proportion of sodium element in the whole elements (Na 1S, na S) in the first surface or the second surface of the PVA film, or the proportion of sodium element in the whole elements (Na 1B, na B) in the surface at a depth of 0.01 μm from the first surface or the second surface is preferably in a specific range. That is, the PVA film of the present invention is characterized in that sodium element is present on the surface and inside of the film. In the present invention, the sodium element is preferably contained in a sodium sulfate type surfactant or a sodium sulfonate type surfactant. That is, the PVA film of the present invention preferably contains a sodium sulfate type surfactant or a sodium sulfonate type surfactant.
Examples of the sodium sulfate type surfactant include sodium alkyl sulfate, sodium polyoxyethylene alkyl ether sulfate, sodium polyoxypropylene alkyl ether sulfate, and sodium polyoxyethylene alkylphenyl ether sulfate. The alkyl group is preferably an alkyl group having 8 to 20 carbon atoms, and more preferably a lauryl group.
Examples of the sodium sulfonate surfactant include sodium alkyl sulfonate, sodium alkylbenzene sulfonate, disodium dodecyl diphenyl ether disulfonate, sodium alkyl naphthalene sulfonate, disodium alkyl sulfosuccinate, and disodium polyoxyethylene alkyl sulfosuccinate. The alkyl group is preferably an alkyl group having 8 to 20 carbon atoms, and more preferably a dodecyl group.
The surfactant may be used alone or in combination of at least 2 kinds. That is, the aforementioned sodium sulfate type surfactant or sodium sulfonate type surfactant is preferably at least 1 selected from the group consisting of sodium alkyl sulfate, sodium polyoxyethylene alkyl ether sulfate, sodium polyoxypropylene alkyl ether sulfate, sodium polyoxyethylene alkyl phenyl ether sulfate, sodium alkyl sulfonate, sodium alkylbenzenesulfonate, disodium dodecyl diphenyl ether disulfonate, sodium alkyl naphthalene sulfonate, disodium alkyl sulfosuccinate and disodium polyoxyethylene alkyl sulfosuccinate. The sodium polyoxyethylene alkyl ether sulfate is easily present on the surface of the PVA film 1, and is preferable from the viewpoint that peeling from the support at the time of producing the PVA film 1 becomes good.
In addition, a surfactant other than the sodium sulfate type surfactant or the sodium sulfonate type surfactant may be contained. The surfactant other than the sodium sulfate surfactant or the sodium sulfonate surfactant is preferably a nonionic surfactant, more preferably an alkanolamide surfactant, and even more preferably a dialkanolamide of an aliphatic carboxylic acid (for example, a saturated or unsaturated aliphatic carboxylic acid having 8 to 30 carbon atoms) (for example, lauric acid diethanolamide) because of excellent effect of reducing surface irregularities in the production of the PVA film.
The molecular weight of the sodium sulfate type surfactant or the sodium sulfonate type surfactant is preferably 200 or more, more preferably 250 or more. The molecular weight of the sodium sulfate type surfactant or the sodium sulfonate type surfactant is preferably 10,000 or less, and more preferably 5,000 or less. When the molecular weight is in the above range, a film having a small amount of surfactant aggregates on the surface of the PVA film and good peelability and film surface quality can be obtained.
In the PVA film of the present invention, the content of the sodium sulfate type surfactant or sodium sulfonate type surfactant is preferably 0.02 parts by mass or more, more preferably 0.03 parts by mass or more, and still more preferably 0.05 parts by mass or more, relative to 100 parts by mass of PVA. The content of the sodium sulfate-type surfactant or sodium sulfonate-type surfactant is preferably 0.4 parts by mass or less, more preferably 0.3 parts by mass or less, still more preferably 0.2 parts by mass or less, and particularly preferably 0.1 parts by mass or less, relative to 100 parts by mass of PVA. When the content of the surfactant is within the above range, the proportion of sodium element (Na 1S, na2S, na1B, na B) in the PVA film to the total elements can be easily adjusted to the above range. In addition, when the content of the surfactant is within the above range, adhesion between PVA films (hereinafter, also referred to as "blocking") can be prevented. In addition, the surfactant can be prevented from oozing out to the surface of the PVA film or from deteriorating the appearance of the PVA film due to aggregation of the surfactant. In addition, the PVA film of the present invention may contain a surfactant other than the aforementioned sodium sulfate type surfactant or sodium sulfonate type surfactant. In this case, the total content of the surfactant in the PVA film is preferably 0.04 parts by mass or more, more preferably 0.1 parts by mass or more, and still more preferably 0.15 parts by mass or more, relative to 100 parts by mass of PVA. The total content of the surfactant in the PVA film is preferably 10 parts by mass or less, more preferably 1 part by mass or less, and further preferably 0.5 part by mass or less.
(other Components)
The PVA film of the present invention may contain, in addition to PVA, components such as water-soluble polymers, moisture, antioxidants, ultraviolet absorbers, lubricants, crosslinking agents, colorants, fillers, preservatives, mold inhibitors, and other polymer compounds within a range that does not inhibit the effects of the present invention. The total amount of the components other than PVA, surfactant, plasticizer, and PVA is preferably 60 to 100% by mass, more preferably 80 to 100% by mass, and even more preferably 90 to 100% by mass based on the total mass of the PVA film.
< method for producing PVA film >
The method for producing the PVA film of the present invention is not particularly limited, and any of the following methods can be used, for example. The method includes: a method of forming a film by using a casting film method, a wet film method (a method of ejecting a poor solvent), a dry-wet film method, a gel film method (a method of extracting a solvent after once cooling and gelling a film-forming stock solution), or a combination thereof, for a film-forming stock solution obtained by adding a solvent, an additive, or the like to PVA and homogenizing the same; a film-forming raw liquid obtained by using an extruder or the like is extruded from a T die or the like, whereby a melt extrusion film-forming method, a blow-molding method, or the like of film formation is performed. Among these, as the method for producing the PVA film, a casting film-forming method and a melt extrusion film-forming method are preferable. If these methods are used, a homogeneous PVA film can be obtained with good productivity. Hereinafter, a case of producing a PVA film by using a casting film-forming method or a melt extrusion film-forming method will be described.
In producing the PVA film of the present invention by using a casting film-forming method or a melt extrusion film-forming method, first, a film-forming stock solution containing PVA, a solvent, and, if necessary, an additive such as a plasticizer is prepared. Then, the film-forming stock solution is cast (supplied) in a film form on a support body rotated by a metal roll, a metal belt, or the like. Thereby, a liquid film of the film-forming raw liquid is formed on the support. The liquid coating film is solidified by heating and removing the solvent from the support, and is formed into a film. The method of heating the liquid coating film may be exemplified by: a method of heating the support itself with a heat medium or the like, a method of blowing hot air to the surface of the liquid film opposite to the surface in contact with the support, and the like. The cured long film (PVA film) is peeled from the support, dried by a drying roll, a drying oven or the like as necessary, heat treated as necessary, and wound into a roll.
In the drying step (solvent removal step) of the liquid coating film cast on the support and the subsequent drying step of the PVA film, crystallization of PVA occurs during the heating period. The crystallization rate at this time is affected by the water content, temperature and draft (tensile elongation in the flow direction) of the PVA in addition to the proportion of the structural unit derived from other monomer in the PVA, the degree of polymerization of the PVA, the degree of saponification of the PVA and the content of plasticizer.
In general, drying of the PVA film is performed by gradually volatilizing the volatile component from the film surface released from contact with the support, the drying roller, or the like. Therefore, in the step of drying, a concentration distribution of volatile components such as water is generated in the thickness direction of the PVA film, and therefore, a distribution of sodium element is generated in the thickness direction of the PVA film according to the temperature and drawing conditions at this time. The distribution of the sodium element, that is, the proportion of the sodium element in the entire element (Na 1S, na B) in the first surface of the PVA film and the proportion of the sodium element in the entire element (Na 2S, na B) in the second surface of the PVA film can be adjusted by the surface temperature of the support, the time of contact with the support, the temperature and the hot air volume of the hot air, the temperature of the drying roll or the drying oven, and the like. Thus, the distribution of the sodium element can be adjusted by appropriately adjusting the above-described elements.
The volatile fraction of the film-forming stock solution (concentration of volatile components such as solvents removed by evaporation or evaporation during film formation) is preferably 50% by mass or more, more preferably 55% by mass or more. The volatile fraction of the film-forming stock solution is preferably 90 mass% or less, more preferably 80 mass% or less. When the volatile fraction is within the above range, the viscosity of the film-forming stock solution can be adjusted to a suitable range, and therefore, the film-forming property of the liquid film cast on the support is improved, and a PVA film having a uniform thickness can be easily obtained. In addition, if the volatile fraction is within the above range, it is easy to adjust the ratio of sodium element in the first surface of the resulting PVA film to all elements (Na 1S, na B) and the ratio of sodium element in the second surface of the PVA film to all elements (Na 2S, na B) to the above range. The film-forming stock solution may contain a dichroic dye as needed. The volatile fraction of the film-forming stock solution is a value obtained by the following formula (2).
Volatile fraction (mass%) of film-forming stock solution = { (Wa-Wb)/Wa } ×100 (2)
In the above formula (2), wa represents the mass (g) of the film-forming stock solution, and Wb represents the mass (g) of the film-forming stock solution obtained by drying Wa (g) in an electrothermal drier at 105 ℃ for 16 hours.
The method for adjusting the film-forming stock solution is not particularly limited, and examples thereof include a method in which PVA, a plasticizer, and an additive such as a surfactant are dissolved in a solvent in a dissolution tank or the like; and a method in which PVA in a water-containing state is melt-kneaded together with additives such as a plasticizer and a surfactant using a single screw extruder or a twin screw extruder.
The film-forming stock solution is generally cast into a film on a support such as a metal roll or a metal belt through a die lip of a die such as a T-die. On the support, the solvent gradually volatilizes from the surface of the cast film-like stock solution that does not contact the support (hereinafter, may be referred to as a free surface), but does not substantially volatilize from the surface that contacts the support (hereinafter, may be referred to as a contact surface), and therefore, a distribution in which the concentration of the solvent on the free surface side is low and the concentration of the solvent on the contact surface side is high with respect to the thickness direction of the film is generated. Thus, the curing of PVA is also carried out from the free surface.
The surface temperature of the support to be cast into the film stock solution is preferably 65℃or higher, more preferably 70℃or higher, and still more preferably 75℃or higher. The surface temperature of the support to be cast into the film stock solution is preferably 110 ℃ or less, more preferably 100 ℃ or less, and still more preferably 95 ℃ or less. If the surface temperature is within the above range, the drying of the liquid coating film cast on the support and the segregation of sodium element near the surface of the film proceed at a moderate rate, whereby the proportion of sodium element (Na 1S, na B) in the first surface of the PVA film to all elements and the proportion of sodium element (Na 2S, na B) in the second surface of the PVA film to all elements can be easily adjusted to the above ranges. As a result, the PVA film can be produced normally and the peeling property from the support is improved.
The PVA film is preferably dried (solvent removed) to a volatile fraction of 5 to 50 mass% on a support, and then peeled off from the support, and further dried as necessary. The drying method is not particularly limited, and a method of passing the material through a drying furnace and a method of contacting the material with a drying roller may be mentioned. In the case of drying the PVA film using a plurality of drying rollers, it is preferable that one surface of the PVA film is alternately brought into contact with the drying rollers with the other surface. Thus, the proportion of sodium element in the PVA film on both sides (both surfaces orthogonal to the thickness direction) of the PVA film can be adjusted. In this case, the number of the drying rolls is preferably 3 or more, more preferably 4 or more, and still more preferably 5 or more. The number of the drying rolls is preferably 30 or less, more preferably 25 or less, and further preferably 20 or less.
The temperature of the drying furnace or the surface temperature of the drying roller is preferably 40 ℃ or higher, more preferably 45 ℃ or higher, and still more preferably 50 ℃ or higher. The temperature of the drying oven or the surface temperature of the drying roller is preferably 120 ℃ or less, more preferably 110 ℃ or less, and still more preferably 100 ℃ or less. By setting the temperature of the drying furnace or the surface temperature of the drying roller to be within the above range, the proportion of sodium element (Na 1S, na B) in the first surface of the PVA film to all elements and the proportion of sodium element (Na 2S, na B) in the second surface of the PVA film to all elements can be easily adjusted to the above range.
After peeling the PVA film from the drying roll, heat treatment may be performed. The heat treatment is performed by alternately contacting one side and the other side of the PVA film with a plurality of heat treatment rolls (for example, 2 heat treatment rolls). The surface temperature of the heat treatment roller is preferably 70 ℃ or higher, more preferably 80 ℃ or higher. The surface temperature of the heat treatment roller is preferably 150 ℃ or less, more preferably 140 ℃ or less. By setting the surface temperature of the heat treatment roller to be within the above range, the proportion of sodium element (Na 1S, na B) in the first surface of the PVA film and the proportion of sodium element (Na 2S, na B) in the second surface of the PVA film can be easily adjusted to the above range.
The PVA film thus produced is further subjected to a humidity conditioning treatment, cutting of both ends (edges) of the film, and the like as needed, and then wound up into a roll on a cylindrical core, and then subjected to moisture-proof packaging to form a product.
The volatile fraction of the PVA film finally obtained through a series of processes is not necessarily limited. The volatile fraction of the PVA film is preferably 1 mass% or more, more preferably 2 mass% or more. The volatile fraction of the PVA film is preferably 5 mass% or less, more preferably 4 mass% or less.
The thickness of the PVA film finally obtained through a series of processes is not necessarily limited. The thickness of the PVA film is preferably 10 μm or more, more preferably 20 μm or more. The thickness of the PVA film is preferably 90 μm or less, more preferably 80 μm or less. There is a tendency that: the thicker the PVA film becomes, the smaller the proportion of sodium element in the first surface of the PVA film (Na 1S, na B) and the proportion of sodium element in the second surface of the PVA film (Na 2S, na B) become; the thinner the PVA film becomes, the greater the proportion of sodium element in the first surface of the PVA film (Na 1S, na B) and the proportion of sodium element in the second surface of the PVA film (Na 2S, na B) become. The thickness of the PVA film can be adjusted by the concentration of the film-forming stock solution, the roll temperature, and the like.
< method for producing optical film >
The PVA film of the present invention is preferably a film for producing an optical film. That is, the PVA film of the present invention can be suitably used as a raw material film in the production of an optical film. Examples of the optical film include a polarizing film, a viewing angle improving film, a phase difference film, and a brightness enhancing film, and a polarizing film is preferable. Hereinafter, a method for producing a polarizing film will be specifically described as an example of a method for producing an optical film.
The polarizing film can be generally produced by using a PVA film as a raw film and subjecting the film to a swelling step, a dyeing step, a crosslinking step, a stretching step, a fixing step, and other treatment steps. Specific examples of the treatment liquid used in each step include a swelling treatment liquid used in a swelling treatment, a dyeing treatment liquid (dyeing liquid) used in a dyeing treatment, a crosslinking treatment liquid used in a crosslinking treatment, a stretching treatment liquid used in a stretching treatment, a fixing treatment liquid used in a fixing treatment, a cleaning treatment liquid (cleaning liquid) used in a cleaning treatment, and the like.
Each processing step that can be employed in the manufacturing method for manufacturing a polarizing film is described in detail below. In the method for manufacturing a polarizing film, 1 or 2 or more of the following treatments may be omitted, the same treatment may be performed a plurality of times, or other treatments may be performed simultaneously.
(washing treatment before swelling treatment)
The PVA film is preferably subjected to a washing treatment before the swelling treatment. By such a washing treatment before the swelling treatment, the anti-blocking agent or the like adhering to the PVA film can be removed, and contamination of each treatment liquid in the production process of the polarizing film by the anti-blocking agent or the like can be prevented. The cleaning treatment is preferably performed by immersing the PVA film in a cleaning treatment liquid, or by blowing a cleaning treatment liquid onto the PVA film. As the cleaning treatment liquid, for example, water can be used. The temperature of the cleaning treatment liquid is preferably in the range of 20 to 40 ℃. The removal of the anti-blocking agent or the like adhering to the PVA film is easily performed by setting the temperature of the cleaning treatment liquid to 20 ℃ or higher. In addition, by setting the temperature of the cleaning treatment liquid to 40 ℃ or lower, dissolution of a part of the surface of the PVA film, sticking of films to each other, and degradation of the handleability can be prevented. The temperature of the cleaning liquid is more preferably 22℃or higher, still more preferably 24℃or higher, and particularly preferably 26℃or higher. The temperature of the cleaning liquid is more preferably 38 ℃ or lower, still more preferably 36 ℃ or lower, and particularly preferably 34 ℃ or lower.
(swelling treatment)
The swelling treatment may be performed by immersing the PVA film in a swelling treatment liquid such as water. The temperature of the swelling treatment liquid is preferably 20℃or higher, more preferably 22℃or higher, and still more preferably 24℃or higher. The temperature of the swelling treatment liquid is preferably 40 ℃ or lower, more preferably 38 ℃ or lower, and still more preferably 36 ℃ or lower. The time for immersing in the swelling treatment liquid is, for example, preferably 0.1 minutes or more, more preferably 0.5 minutes or more. The time for immersing in the swelling treatment liquid is, for example, preferably 5 minutes or less, more preferably 3 minutes or less. The water used as the swelling treatment liquid is not limited to pure water, and may be an aqueous solution in which various components such as a boron-containing compound are dissolved, or may be a mixture of water and an aqueous medium. The type of the boron-containing compound is not particularly limited, and boric acid or borax is preferable from the viewpoint of handling properties. When the swelling treatment liquid contains a boron-containing compound, the concentration thereof is preferably 6 mass% or less from the viewpoint of improving the stretchability of the PVA film.
(dyeing treatment)
The dyeing treatment may be performed using an iodine-based dye as a dichroic dye, and the dyeing period may be any of the stages before, during, and after the stretching treatment. The dyeing treatment is preferably performed by immersing the PVA film in a dyeing treatment liquid using a solution (suitably an aqueous solution) containing iodine-potassium iodide as the dyeing treatment liquid. The concentration of iodine in the dyeing treatment liquid is preferably in the range of 0.005 to 0.2 mass%, and the mass ratio of potassium iodide/iodine is preferably in the range of 20 to 100. The temperature of the dyeing treatment liquid is preferably 20 ℃ or higher, more preferably 25 ℃ or higher. The temperature of the dyeing treatment liquid is preferably 50 ℃ or lower, more preferably 40 ℃ or lower. The dyeing treatment liquid may contain a boron-containing compound such as boric acid as a crosslinking agent. If a dichroic dye is previously contained in the PVA film used as the raw material film, the dyeing treatment can be omitted. In addition, a boron-containing compound such as boric acid and borax may be contained in advance in the PVA film used as the raw material film.
(crosslinking treatment)
In the production of the polarizing film, for the purpose of firmly adsorbing the dichroic dye to the PVA film or the like, it is preferable to perform a crosslinking treatment after the dyeing treatment. The crosslinking treatment may be performed by using a solution (suitably an aqueous solution) containing a crosslinking agent as the crosslinking treatment liquid, and immersing the PVA film in the crosslinking treatment liquid. As the crosslinking agent, 1 or 2 or more kinds of boron-containing compounds such as boric acid and borax can be used. If the concentration of the crosslinking agent in the crosslinking treatment liquid is too high, the following tends to occur: the crosslinking reaction proceeds excessively, and it is difficult to sufficiently stretch the film in the stretching treatment performed thereafter. If the concentration of the crosslinking agent in the crosslinking treatment liquid is too low, the effect of the crosslinking treatment tends to be low. Thus, the concentration of the crosslinking agent in the crosslinking treatment liquid is preferably 1% by mass or more, more preferably 1.5% by mass or more, and still more preferably 2% by mass or more. The concentration of the crosslinking agent in the crosslinking treatment liquid is preferably 6% by mass or less, more preferably 5.5% by mass or less, and still more preferably 5% by mass or less.
In order to inhibit the dichroic dye from eluting from the PVA film after the dyeing treatment, the crosslinking treatment liquid may contain an iodine-containing compound such as potassium iodide. If the concentration of the iodine-containing compound in the crosslinking treatment liquid is too high, the heat resistance of the resulting polarizing film tends to be lowered, although the reason is not clear. If the concentration of the iodine-containing compound in the crosslinking treatment liquid is too low, the effect of suppressing elution of the dichroic dye tends to be lowered. The concentration of the iodine-containing compound in the crosslinking treatment liquid is preferably 1% by mass or more, more preferably 1.5% by mass or more, and still more preferably 2% by mass or more. The concentration of the iodine-containing compound in the crosslinking treatment liquid is preferably 6% by mass or less, more preferably 5.5% by mass or less, and still more preferably 5% by mass or less.
If the temperature of the crosslinking treatment liquid is too high, the polarizing film obtained by eluting the dichroic dye tends to be likely to suffer from uneven dyeing, and if it is too low, the effect of the crosslinking treatment may be reduced. The temperature of the crosslinking treatment liquid is preferably 20℃or higher, more preferably 22℃or higher, and still more preferably 25℃or higher. The temperature of the crosslinking treatment liquid is preferably 45℃or lower, more preferably 40℃or lower, and still more preferably 35℃or lower.
In each of the above-described treatments, the PVA film may be stretched differently from the stretching treatment described later. By performing such stretching (pre-stretching), wrinkles can be prevented from occurring on the surface of the PVA film. From the viewpoint of polarization performance of the obtained polarizing film, etc., the total stretching magnification of the pre-stretching (magnification obtained by multiplying the stretching magnification in each process) is preferably 4 times or less, more preferably 3.5 times or less, depending on the original length of the PVA film of the raw material before stretching. From the viewpoint of polarization performance of the obtained polarizing film, the total stretching magnification of the pre-stretching is preferably 1.5 times or more, preferably 2 times or more, depending on the original length of the PVA film of the raw material before stretching.
The stretching ratio in the swelling treatment is preferably 1.1 times or more, more preferably 1.2 times or more, and still more preferably 1.4 times or more. The stretching ratio in the swelling treatment is preferably 3 times or less, more preferably 2.5 times or less, and still more preferably 2.3 times or less.
The stretch ratio in the dyeing treatment is preferably 2 times or less, more preferably 1.8 times or less, and still more preferably 1.5 times or less. The stretching ratio in the dyeing treatment is preferably 1.1 times or more, more preferably 1.15 times or more, and still more preferably 1.2 times or more.
The stretching ratio in the crosslinking treatment is preferably 2 times or less, more preferably 1.5 times or less, and still more preferably 1.3 times or less. The stretching ratio in the crosslinking treatment is preferably 1.05 times or more, more preferably 1.1 times or more, and still more preferably 1.15 times or more.
(stretching treatment)
The stretching treatment may be performed by either a wet stretching method or a dry stretching method. In the case of the wet stretching method, a solution (suitably an aqueous solution) containing a boron-containing compound such as boric acid may be used as the stretching treatment liquid, and the stretching treatment liquid may be used, or the dyeing treatment liquid or a fixing treatment liquid described later may be used. In the case of the dry stretching method, the PVA film after water absorption may be used and may be used in air. Among these, the wet stretching method is preferable, and the uniaxial stretching is more preferable in an aqueous solution containing boric acid. When the stretching treatment liquid contains a boron-containing compound, the stretchability of the PVA film can be improved, and therefore, the concentration of the boron-containing compound in the stretching treatment liquid is preferably 1.5 mass% or more, more preferably 2.0 mass% or more, and still more preferably 2.5 mass% or more. Further, from the viewpoint of improving the stretchability of the PVA film, the concentration of the boron-containing compound in the stretching treatment liquid is preferably 7 mass% or less, more preferably 6.5 mass% or less, and still more preferably 6 mass% or less.
The stretching treatment liquid preferably contains an iodine-containing compound such as potassium iodide. If the concentration of the iodine-containing compound in the stretching treatment liquid is too high, the resulting polarizing film tends to have a significantly bluish hue. If the concentration of the iodine-containing compound in the stretching treatment liquid is too low, the heat resistance of the resulting polarizing film tends to be lowered, although the reason is not clear. The concentration of the iodine-containing compound in the stretching treatment liquid is preferably 2% by mass or more, more preferably 2.5% by mass or more, and still more preferably 3% by mass or more. The concentration of the iodine-containing compound in the stretching treatment liquid is preferably 8 mass% or less, more preferably 7.5 mass% or less, and still more preferably 7 mass% or less.
If the temperature of the stretching treatment liquid is too high, the PVA film tends to be dissolved and softened and easily broken. If the temperature of the stretching treatment liquid is too low, the stretchability of the PVA film tends to be lowered. The temperature of the stretching treatment liquid is preferably 50℃or higher, more preferably 52.5℃or higher, and still more preferably 55℃or higher. The temperature of the stretching treatment liquid is preferably 70 ℃ or lower, more preferably 67.5 ℃ or lower, and still more preferably 65 ℃ or lower. The preferable range of the stretching temperature in the case of stretching by the dry stretching method is also as described above.
In view of the fact that a polarizing film or the like having more excellent polarizing performance can be obtained when the stretching magnification in the stretching treatment is high, the stretching magnification in the stretching treatment is preferably 1.2 times or more, more preferably 1.5 times or more, and still more preferably 2 times or more. From the viewpoint of the polarizing performance of the obtained polarizing film, the total stretching ratio (the ratio obtained by multiplying the stretching ratio in each step) including the stretching ratio before stretching is preferably 5.5 times or more, more preferably 5.7 times or more, and still more preferably 5.9 times or more, based on the original length of the PVA film of the raw material before stretching. The upper limit of the stretching ratio is not particularly limited, and if the stretching ratio is too high, stretching fracture is likely to occur, and therefore, it is preferably 8 times or less.
The method of stretching by uniaxial stretching is not particularly limited, and uniaxial stretching in the longitudinal direction and transverse uniaxial stretching in the width direction may be employed. In the case of manufacturing a polarizing film, uniaxial stretching in the longitudinal direction is preferable from the viewpoint of obtaining a polarizing film excellent in polarization performance. The uniaxial stretching in the longitudinal direction can be performed by using a stretching device having a plurality of rolls parallel to each other and changing the peripheral speed between the rolls.
In the present invention, the maximum stretching speed (%/min) in the case of stretching treatment by uniaxial stretching is not particularly limited, but is preferably 200%/min or more, more preferably 300%/min or more, and still more preferably 400%/min or more. Here, the maximum stretching speed means: when stretching a PVA film in two or more stages using 3 or more rolls having different peripheral speeds, the stretching speed is the fastest in the stages. When the stretching treatment of the PVA film is performed in 1 stage, not in two or more stages, the stretching speed in the stage becomes the maximum stretching speed. The stretching speed means: an increase in the length of the PVA film increased by stretching relative to the length of the PVA film before stretching per unit time. For example, a stretch speed of 100%/min means: the PVA film was deformed from the length before stretching to a speed of 2 times the length at 1 minute. The larger the maximum stretching speed is, the more the stretching treatment (uniaxial stretching) of the PVA film can be performed at a high speed, and as a result, the productivity of the polarizing film is improved, which is preferable. On the other hand, if the maximum stretching speed becomes too high, excessive tension may be applied locally to the PVA film during the stretching treatment (uniaxial stretching) of the PVA film, and stretch breaking may easily occur. From this point of view, the maximum stretching speed is preferably not more than 900%/min.
(fixing treatment)
In manufacturing the polarizing film, in order to firmly adsorb the dichroic dye to the PVA film, it is preferable to perform a fixing treatment. The fixing treatment may be performed by using a solution (suitably an aqueous solution) containing 1 or 2 or more kinds of boron-containing compounds such as boric acid and borax as the fixing treatment liquid, and immersing the PVA film (suitably a PVA film after the stretching treatment) in the fixing treatment liquid. The fixing treatment liquid may contain an iodine-containing compound or a metal compound, if necessary. The concentration of the boron-containing compound in the fixation treatment liquid is preferably 2% by mass or more, more preferably 3% by mass or more. The concentration of the boron-containing compound in the fixation treatment liquid is preferably 15 mass% or less, more preferably 10 mass% or less. The temperature of the fixing treatment liquid is preferably 15℃or higher, more preferably 25℃or higher. The temperature of the fixing treatment liquid is preferably 60℃or lower, more preferably 40℃or lower.
(washing treatment after dyeing treatment)
After the dyeing treatment, the PVA film after the stretching treatment is preferably subjected to a cleaning treatment. The cleaning treatment is preferably performed by immersing the PVA film in a cleaning treatment liquid, or by blowing a cleaning treatment liquid onto the PVA film. As the cleaning treatment liquid, for example, water can be used. The water is not limited to pure water, and may contain an iodine-containing compound such as potassium iodide. In this case, the concentration of the boron-containing compound is preferably 2.0 mass% or less.
The temperature of the cleaning treatment liquid is preferably in the range of 5 to 40 ℃. By setting the temperature to 5 ℃ or higher, breakage of the PVA film due to freezing of moisture can be suppressed. In addition, the optical characteristics of the resulting polarizing film are improved by setting the temperature to 40 ℃ or lower. The temperature of the cleaning liquid is more preferably 7℃or higher, and still more preferably 10℃or higher. The temperature of the cleaning liquid is more preferably 38 ℃ or lower, and still more preferably 35 ℃ or lower.
Specific methods for producing the polarizing film include a method of dyeing a PVA film, stretching the PVA film, and crosslinking and/or fixing the PVA film. Preferable examples include a method in which a PVA film is sequentially subjected to a swelling treatment, a dyeing treatment, a crosslinking treatment, a stretching treatment (in particular, a uniaxial stretching treatment), and a washing treatment. The stretching treatment may be performed in any treatment step preceding the above step, or may be performed in two or more stages.
The PVA film subjected to each of the treatments described above is subjected to a drying treatment, whereby a polarizing film can be obtained. The method of the drying treatment is not particularly limited, and examples thereof include a contact method in which the film is brought into contact with a heating roller, a method in which the film is dried in a hot air dryer, a floating method in which the film is dried by hot air while floating, and the like.
< polarizing plate >
The polarizing film obtained in the above-described manner is preferably used as a polarizing plate by bonding optically transparent protective films having mechanical strength to both sides or one side thereof. As the protective film, a cellulose Triacetate (TAC) film, a Cyclic Olefin Polymer (COP) film, a Cellulose Acetate Butyrate (CAB) film, an acrylic film, a polyester film, or the like can be used. The adhesive used for bonding may be a PVA-based adhesive, a urethane-based adhesive, or the like, and is preferably a PVA-based adhesive.
The polarizing plate obtained in the above-described manner can be used as a component of an LCD by laminating an acrylic adhesive or the like and then bonding the laminated polarizing plate to a glass substrate. The retardation film, the viewing angle improving film, the brightness enhancing film, and the like may be bonded together.
Examples
The present invention will be specifically described with reference to examples, but the present invention is not limited to the examples.
(1) XPS measurement of PVA film
(1-1) determination of the proportion of sodium element (Na 1S and Na 2S) in all the elements
The PVA film obtained in the following examples or comparative examples was cut into a size of 5mm by 5mm, and was set on the measurement base of the XPS measurement apparatus via a conductive double-sided tape. XPS measurement was performed on the first surface and the second surface (two surfaces of the PVA film perpendicular to the thickness direction) of the PVA film under the following measurement conditions, respectively, to obtain XPS spectra.
(XPS measurement conditions)
Measurement device: ohi Quantera SXM (ULVAX-PHI.INC.)
Analysis software: multi Pack ver9.0 (ULVAX-PHI.INC.)
An X-ray source: monochromatic AlK alpha (1486.6 eV)
X-ray beam diameter:/>
measurement range: 100 μm by 300. Mu.m
Reading angle of signal: 45 degree
Charged neutralization conditions: neutralizing electron gun, ar+ ion gun
Vacuum degree: 1X 10 -6 Pa
Elemental (peak of excited inner layer atoms used in quantification) is determined: b (1S), C (1S), N (1S), O (1S), na (1S), si (2P), P (2P), S (2P)
The XPS spectra obtained were analyzed by the analysis software described above to determine the proportion of sodium element (Na 1S and Na 2S) in all elements in the first surface and the second surface of the PVA film. Here, S is an initial that indicates a surface.
(1-2) determination of the proportion of sodium element (Na 1B and Na 2B) in all the elements
The PVA film obtained in the following examples or comparative examples was cut into 5mm by 5mm sizes, and in the XPS measuring apparatus described above, the first surface and the second surface (two surfaces of the PVA film orthogonal to the thickness direction) of the PVA film were each etched to a depth of 0.01 μm from the thickness direction of the PVA film under the following conditions. Then, XPS measurement and analysis were performed on a surface having a depth of 0.01 μm from the first surface or the second surface of the PVA film under the same conditions as those described above, and the proportion (Na 1B and Na 2B) of sodium element in all elements was determined in the surface having a depth of 0.01 μm from the first surface or the second surface.
(etching treatment conditions)
Treatment conditions: accelerating voltage of 10kV
Sample current: 20mA
Scanning range: 0.5mm by 2.0mm
Etching rate: 20nm/min
Etching material: c60 (Backminst Fullerene)
(2) Evaluation of peelability of PVA film from support
In the following examples or comparative examples, when a PVA film was produced, the peeled state of the PVA film from the support was visually observed, and evaluated according to the following criteria.
Peel evaluation criterion:
a: the peeling position is kept horizontal along the width direction of the PVA film, and no wrinkles or stretching are generated on the surface of the PVA film.
B: the peeling position is kept horizontal along the width direction of the PVA film, but the surface of the PVA film is wrinkled and stretched.
C: the peeling position generates waviness along the width direction of the PVA film, and the surface of the PVA film generates wrinkles and stretches.
(3) Evaluation of optical unevenness of polarizing film
The polarizing films obtained in the examples and comparative examples below were visually observed for optical unevenness, and evaluated according to the following criteria.
A: the optical unevenness is hardly noticeable.
B: optical unevenness was observed.
C: optical unevenness was clearly observed.
< example 1>
A film-forming stock solution (volatile fraction: 66 mass%) was prepared by melt-mixing 100 parts by mass of PVA (having a saponification degree of 99.9 mol%, and a polymerization degree of 2400), 12 parts by mass of glycerin as a plasticizer, 0.08 part by mass of sodium polyoxyethylene lauryl ether sulfate (average molecular weight: 430) as a surfactant, 0.16 part by mass of lauric acid diethanolamide, and 217.6 parts by mass of water using a melt extruder. Then, the film-forming stock solution was discharged from the T die in a film form onto a support (surface temperature: 80 ℃) to form a liquid film on the support. The raw film-forming material was cast on a support, and after peeling off the PVA film from the support, the PVA film was peeled off from the final drying roll after further drying from the first drying roll to a final drying roll (nineteenth drying roll) located immediately before the heat treatment roll so that one surface and the other surface of the PVA film alternately contact each drying roll. At this time, the surface temperature of each drying roller from the first drying roller to the final drying roller was set at 75 ℃. Further, the PVA film was peeled from the final drying roll, and heat treatment was performed so that one surface of the PVA film was alternately contacted with each heat treatment roll. At this time, the heat treatment was performed using 2 heat treatment rolls, and the surface temperatures of the heat treatment rolls were set to 90℃to obtain PVA films (thickness 60 μm, width 1200 mm).
As a result of XPS measurement of the obtained PVA film, the first surface of the PVA film had Na1S of 0.7 mol% and Na1B of 0.2 mol%. The second surface of the PVA film had 0.6 mol% of Na2S and 0.1 mol% of Na 2B. The first surface of the PVA film is a surface where the film-forming stock solution contacts the support. The second surface of the PVA film is a surface (free surface) of the film-forming raw liquid that is not in contact with the support.
The obtained PVA film was cut into 650mm wide, and the film was sequentially subjected to swelling treatment, dyeing treatment, crosslinking treatment, stretching treatment, washing treatment, and drying treatment, to continuously produce a polarizing film. The swelling treatment was carried out by uniaxial stretching to 2.00 times in the longitudinal direction while immersing in pure water (swelling treatment liquid) at 25 ℃. The dyeing treatment is performed by uniaxially stretching to 1.26 times in the longitudinal direction while immersing the dyeing solution (dyeing treatment solution) of potassium iodide/iodine (mass ratio) of 23 and iodine concentration of 0.03 to 0.05 mass%) at 32 ℃. In the dyeing treatment, the iodine concentration in the dyeing treatment liquid is adjusted to be in the range of 0.03 to 0.05 mass% so that the monomer transmittance of the polarizing film obtained after uniaxial stretching in the stretching treatment is in the range of 43.5% ± 0.2%. The crosslinking treatment was carried out by uniaxially stretching the impregnated side to 1.19 times in the longitudinal direction in an aqueous boric acid solution (crosslinking treatment liquid) at 32 ℃. The stretching treatment was carried out by uniaxial stretching to 2.00 times in the longitudinal direction while immersing the substrate in an aqueous boric acid/potassium iodide solution (stretching solution) (boric acid concentration: 2.8 mass% and potassium iodide concentration: 5 mass%) at 55 ℃. The maximum stretching speed of uniaxial stretching in this stretching treatment was 400%/min. The washing treatment was performed by immersing in an aqueous solution of potassium iodide/boric acid (washing treatment liquid) (potassium iodide concentration 3 to 6 mass% and boric acid concentration 1.5 mass%) at 22 ℃ for 12 seconds without stretching. The drying treatment was performed by hot air drying at 80 ℃ for 1.5 minutes without stretching, to obtain a polarizing film. At this time, the peelability of the PVA film from the support was evaluated as "a", and the optical unevenness of the polarizing film was evaluated as "a". The results are shown in Table 1.
Example 2 ]
PVA film and polarizing film were produced and evaluated in the same manner as in example 1 except that the PVA type was changed to PVA having a saponification degree of 99.0 mol% and a polymerization degree of 2400, the surface temperature of each drying roll from the first drying roll to the final drying roll was 70 ℃, and the surface temperature of the heat treatment roll was 85 ℃. The results are shown in Table 1.
Example 3 ]
The same procedure as in example 1 was repeated except that the type of PVA was changed to PVA having a saponification degree of 99.9 mol% and a polymerization degree of 4100, the surface temperature of each drying roller from the first drying roller to the final drying roller was 85 ℃, the surface temperature of the heat treatment roller was 97 ℃, and the thickness of the PVA film was changed to 30 μm, to thereby produce and evaluate a PVA film and a polarizing film. The results are shown in Table 1.
Comparative example 1 ]
The production and evaluation of PVA film and polarizing film were performed in the same manner as in example 1, except that sodium polyoxyethylene lauryl ether sulfate was not used as a surfactant. The results are shown in Table 1.
Comparative example 2 ]
The same procedure as in example 1 was repeated except that the amount of the surfactant added of sodium polyoxyethylene lauryl ether sulfate was changed to 0.45 parts by mass, to thereby produce and evaluate a PVA film and a polarizing film. The results are shown in Table 1.
From the above results, the PVA film of the present invention can produce a polarizing film having good peelability from a support and less optical unevenness by using a small amount of a surfactant without using a surfactant containing fluorine.
Description of the reference numerals
1 PVA film
Thickness direction of 2 PVA film
3. A first surface
4. A second surface
Claims (8)
1. A polyvinyl alcohol film which is a water-insoluble polyvinyl alcohol film,
when one of two surfaces of the polyvinyl alcohol film orthogonal to the thickness direction is set as a first surface,
the proportion (Na 1S) of sodium element in all elements obtained by analyzing the first surface by X-ray photoelectron spectroscopy is 0.3-1.5 mol%,
the proportion (Na 1B) of sodium element in all elements, which is obtained by analysis of a surface having a depth of 0.01 [ mu ] m from the first surface by X-ray photoelectron spectroscopy, is 0.3 mol% or less.
2. The polyvinyl alcohol film according to claim 1, wherein, when a surface opposite to the first surface among two surfaces of the polyvinyl alcohol film orthogonal to a thickness direction is set as a second surface,
the proportion (Na 2S) of sodium element in the total elements obtained by analyzing the second surface by X-ray photoelectron spectroscopy is 0.3 to 1.5 mol%,
The proportion (Na 2B) of sodium element in all elements, which is obtained by analysis of a surface having a depth of 0.01 [ mu ] m from the second surface by X-ray photoelectron spectroscopy, is 0.3 mol% or less.
3. The polyvinyl alcohol film according to claim 1 or 2, which contains a sodium sulfate type surfactant or a sodium sulfonate type surfactant,
the sodium element is derived from the sodium sulfate type surfactant or the sodium sulfonate type surfactant.
4. The polyvinyl alcohol film according to claim 3, wherein the sodium sulfate-type surfactant or the sodium sulfonate-type surfactant is at least 1 selected from the group consisting of sodium alkyl sulfate, sodium polyoxyethylene alkyl ether sulfate, sodium polyoxypropylene alkyl ether sulfate, sodium polyoxyethylene alkylphenyl ether sulfate, sodium alkyl sulfonate, sodium alkylbenzenesulfonate, disodium dodecyl diphenyl ether disulfonate, sodium alkyl naphthalene sulfonate, disodium alkyl sulfosuccinate and disodium polyoxyethylene alkyl sulfosuccinate.
5. The polyvinyl alcohol film according to claim 3 or 4, wherein the molecular weight of the sodium sulfate type surfactant or the sodium sulfonate type surfactant is 200 to 10,000, and the content of the sodium sulfate type surfactant or the sodium sulfonate type surfactant is 0.02 to 0.4 parts by mass relative to 100 parts by mass of polyvinyl alcohol contained in the polyvinyl alcohol film.
6. The polyvinyl alcohol film according to any one of claims 1 to 5, which is a film for producing an optical film.
7. The polyvinyl alcohol film according to claim 6, wherein the optical film is a polarizing film.
8. A method for producing a polarizing film, wherein the polyvinyl alcohol film according to any one of claims 1 to 7 is used for producing a polarizing film.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
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| JP2020180966 | 2020-10-28 | ||
| JP2020-180966 | 2020-10-28 | ||
| PCT/JP2021/039356 WO2022092038A1 (en) | 2020-10-28 | 2021-10-25 | Poly(vinyl alcohol) film and polarizing film obtained therefrom |
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| KR (1) | KR20230097084A (en) |
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|---|---|---|---|---|
| JP2008281838A (en) * | 2007-05-11 | 2008-11-20 | Nippon Synthetic Chem Ind Co Ltd:The | Polarizing plate and adhesive for polarizing plate |
| KR20090013075A (en) * | 2007-07-30 | 2009-02-04 | 닛폰고세이가가쿠고교 가부시키가이샤 | Adhesive for polarizer, polarizer and method for producing the same |
| JP2010191389A (en) * | 2009-02-20 | 2010-09-02 | Sumitomo Chemical Co Ltd | Polarizer plate and method for manufacturing the same |
| WO2018038028A1 (en) * | 2016-08-22 | 2018-03-01 | 株式会社クラレ | Polarizing plate |
| WO2019208618A1 (en) * | 2018-04-27 | 2019-10-31 | 株式会社クラレ | Polyvinyl alcohol film and method for producing polarizing film using same |
| WO2020004608A1 (en) * | 2018-06-29 | 2020-01-02 | 株式会社クラレ | Polyvinyl alcohol film, film roll, and polarization film |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4602777B2 (en) * | 2004-01-26 | 2010-12-22 | 日本合成化学工業株式会社 | Method for producing polyvinyl alcohol film |
| JP4794206B2 (en) | 2005-04-28 | 2011-10-19 | 日本合成化学工業株式会社 | Polyvinyl alcohol film and polarizing film and polarizing plate using the same |
| JP4764659B2 (en) | 2005-04-28 | 2011-09-07 | 日本合成化学工業株式会社 | Method for producing polyvinyl alcohol film |
| JP6629495B1 (en) * | 2018-06-20 | 2020-01-15 | 株式会社クラレ | Polyvinyl alcohol film, stretched film, polarizing film, and method for producing polyvinyl alcohol film |
| EP3960798A4 (en) * | 2019-04-23 | 2023-02-22 | Kuraray Co., Ltd. | Water-soluble film and packaging |
-
2021
- 2021-10-25 CN CN202180073426.8A patent/CN116490565A/en active Pending
- 2021-10-25 JP JP2022559133A patent/JPWO2022092038A1/ja active Pending
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Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008281838A (en) * | 2007-05-11 | 2008-11-20 | Nippon Synthetic Chem Ind Co Ltd:The | Polarizing plate and adhesive for polarizing plate |
| KR20090013075A (en) * | 2007-07-30 | 2009-02-04 | 닛폰고세이가가쿠고교 가부시키가이샤 | Adhesive for polarizer, polarizer and method for producing the same |
| JP2010191389A (en) * | 2009-02-20 | 2010-09-02 | Sumitomo Chemical Co Ltd | Polarizer plate and method for manufacturing the same |
| WO2018038028A1 (en) * | 2016-08-22 | 2018-03-01 | 株式会社クラレ | Polarizing plate |
| WO2019208618A1 (en) * | 2018-04-27 | 2019-10-31 | 株式会社クラレ | Polyvinyl alcohol film and method for producing polarizing film using same |
| CN112004881A (en) * | 2018-04-27 | 2020-11-27 | 株式会社可乐丽 | Polyvinyl alcohol film and method for producing polarizing film using same |
| WO2020004608A1 (en) * | 2018-06-29 | 2020-01-02 | 株式会社クラレ | Polyvinyl alcohol film, film roll, and polarization film |
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| TW202225287A (en) | 2022-07-01 |
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