CN118308032A - Optically transparent adhesive sheet - Google Patents
Optically transparent adhesive sheet Download PDFInfo
- Publication number
- CN118308032A CN118308032A CN202410011076.8A CN202410011076A CN118308032A CN 118308032 A CN118308032 A CN 118308032A CN 202410011076 A CN202410011076 A CN 202410011076A CN 118308032 A CN118308032 A CN 118308032A
- Authority
- CN
- China
- Prior art keywords
- adhesive sheet
- polyol
- optically transparent
- transparent adhesive
- thickness
- 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
- 239000000853 adhesive Substances 0.000 title claims abstract description 54
- 230000001070 adhesive effect Effects 0.000 title claims abstract description 54
- 229920005862 polyol Polymers 0.000 claims abstract description 125
- 150000003077 polyols Chemical class 0.000 claims abstract description 120
- 239000004814 polyurethane Substances 0.000 claims abstract description 115
- 229920002635 polyurethane Polymers 0.000 claims abstract description 115
- 239000005056 polyisocyanate Substances 0.000 claims abstract description 81
- 229920001228 polyisocyanate Polymers 0.000 claims abstract description 81
- 239000000203 mixture Substances 0.000 claims abstract description 47
- 229920001187 thermosetting polymer Polymers 0.000 claims abstract description 35
- 239000005062 Polybutadiene Substances 0.000 claims abstract description 28
- 229920002857 polybutadiene Polymers 0.000 claims abstract description 28
- 239000010410 layer Substances 0.000 claims description 70
- 239000012790 adhesive layer Substances 0.000 claims description 38
- 230000008859 change Effects 0.000 claims description 27
- IQPQWNKOIGAROB-UHFFFAOYSA-N isocyanate group Chemical group [N-]=C=O IQPQWNKOIGAROB-UHFFFAOYSA-N 0.000 claims description 24
- 125000002887 hydroxy group Chemical group [H]O* 0.000 claims description 22
- 229920001971 elastomer Polymers 0.000 claims description 19
- 239000005060 rubber Substances 0.000 claims description 18
- NIXOWILDQLNWCW-UHFFFAOYSA-M Acrylate Chemical compound [O-]C(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-M 0.000 description 27
- -1 acrylate compound Chemical class 0.000 description 26
- 125000000524 functional group Chemical group 0.000 description 20
- 150000001875 compounds Chemical class 0.000 description 19
- NIMLQBUJDJZYEJ-UHFFFAOYSA-N isophorone diisocyanate Chemical compound CC1(C)CC(N=C=O)CC(C)(CN=C=O)C1 NIMLQBUJDJZYEJ-UHFFFAOYSA-N 0.000 description 14
- 239000003795 chemical substances by application Substances 0.000 description 13
- 239000004611 light stabiliser Substances 0.000 description 13
- 238000000034 method Methods 0.000 description 13
- 239000000047 product Substances 0.000 description 13
- 239000000758 substrate Substances 0.000 description 13
- 230000003287 optical effect Effects 0.000 description 12
- 239000004925 Acrylic resin Substances 0.000 description 11
- 229920000178 Acrylic resin Polymers 0.000 description 11
- NIXOWILDQLNWCW-UHFFFAOYSA-N acrylic acid group Chemical group C(C=C)(=O)O NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 11
- 150000001336 alkenes Chemical group 0.000 description 11
- 230000000052 comparative effect Effects 0.000 description 11
- 229920001195 polyisoprene Polymers 0.000 description 11
- 239000005058 Isophorone diisocyanate Substances 0.000 description 10
- 239000003054 catalyst Substances 0.000 description 10
- 239000011347 resin Substances 0.000 description 10
- 229920005989 resin Polymers 0.000 description 10
- 239000000126 substance Substances 0.000 description 10
- 239000011521 glass Substances 0.000 description 9
- RRAMGCGOFNQTLD-UHFFFAOYSA-N hexamethylene diisocyanate Chemical compound O=C=NCCCCCCN=C=O RRAMGCGOFNQTLD-UHFFFAOYSA-N 0.000 description 9
- 239000005057 Hexamethylene diisocyanate Substances 0.000 description 8
- 125000000217 alkyl group Chemical group 0.000 description 8
- 150000001412 amines Chemical class 0.000 description 8
- 238000003825 pressing Methods 0.000 description 8
- 125000001931 aliphatic group Chemical group 0.000 description 7
- 238000002156 mixing Methods 0.000 description 7
- IAYPIBMASNFSPL-UHFFFAOYSA-N Ethylene oxide Chemical group C1CO1 IAYPIBMASNFSPL-UHFFFAOYSA-N 0.000 description 6
- 125000002947 alkylene group Chemical group 0.000 description 6
- 239000000178 monomer Substances 0.000 description 6
- 239000003208 petroleum Substances 0.000 description 6
- 238000006243 chemical reaction Methods 0.000 description 5
- 238000001723 curing Methods 0.000 description 5
- 238000005227 gel permeation chromatography Methods 0.000 description 5
- 238000005259 measurement Methods 0.000 description 5
- 239000011342 resin composition Substances 0.000 description 5
- 125000002723 alicyclic group Chemical group 0.000 description 4
- 125000004432 carbon atom Chemical group C* 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- RTZKZFJDLAIYFH-UHFFFAOYSA-N ether Substances CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 4
- 230000002209 hydrophobic effect Effects 0.000 description 4
- 239000002904 solvent Substances 0.000 description 4
- 238000002834 transmittance Methods 0.000 description 4
- 230000002087 whitening effect Effects 0.000 description 4
- ZRWNRAJCPNLYAK-UHFFFAOYSA-N 4-bromobenzamide Chemical compound NC(=O)C1=CC=C(Br)C=C1 ZRWNRAJCPNLYAK-UHFFFAOYSA-N 0.000 description 3
- JOYRKODLDBILNP-UHFFFAOYSA-N Ethyl urethane Chemical compound CCOC(N)=O JOYRKODLDBILNP-UHFFFAOYSA-N 0.000 description 3
- 229920006243 acrylic copolymer Polymers 0.000 description 3
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 3
- 229920001577 copolymer Polymers 0.000 description 3
- 150000002009 diols Chemical class 0.000 description 3
- 239000004417 polycarbonate Substances 0.000 description 3
- 229920000139 polyethylene terephthalate Polymers 0.000 description 3
- 239000005020 polyethylene terephthalate Substances 0.000 description 3
- KAKZBPTYRLMSJV-UHFFFAOYSA-N Butadiene Chemical compound C=CC=C KAKZBPTYRLMSJV-UHFFFAOYSA-N 0.000 description 2
- 239000004593 Epoxy Chemical class 0.000 description 2
- VZCYOOQTPOCHFL-OWOJBTEDSA-N Fumaric acid Chemical compound OC(=O)\C=C\C(O)=O VZCYOOQTPOCHFL-OWOJBTEDSA-N 0.000 description 2
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 150000001252 acrylic acid derivatives Chemical class 0.000 description 2
- 239000003522 acrylic cement Substances 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- 238000004220 aggregation Methods 0.000 description 2
- 230000002776 aggregation Effects 0.000 description 2
- 238000004132 cross linking Methods 0.000 description 2
- 239000003431 cross linking reagent Substances 0.000 description 2
- 239000000539 dimer Substances 0.000 description 2
- 238000006073 displacement reaction Methods 0.000 description 2
- 238000004090 dissolution Methods 0.000 description 2
- 150000002148 esters Chemical class 0.000 description 2
- 238000005187 foaming Methods 0.000 description 2
- 238000009472 formulation Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 125000004435 hydrogen atom Chemical class [H]* 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- AYLRODJJLADBOB-QMMMGPOBSA-N methyl (2s)-2,6-diisocyanatohexanoate Chemical compound COC(=O)[C@@H](N=C=O)CCCCN=C=O AYLRODJJLADBOB-QMMMGPOBSA-N 0.000 description 2
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 2
- 229920000233 poly(alkylene oxides) Polymers 0.000 description 2
- 229920001084 poly(chloroprene) Polymers 0.000 description 2
- 229920000515 polycarbonate Polymers 0.000 description 2
- 229920005749 polyurethane resin Polymers 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 150000003254 radicals Chemical class 0.000 description 2
- VZCYOOQTPOCHFL-UHFFFAOYSA-N trans-butenedioic acid Natural products OC(=O)C=CC(O)=O VZCYOOQTPOCHFL-UHFFFAOYSA-N 0.000 description 2
- IMNIMPAHZVJRPE-UHFFFAOYSA-N triethylenediamine Chemical compound C1CN2CCN1CC2 IMNIMPAHZVJRPE-UHFFFAOYSA-N 0.000 description 2
- RSJKGSCJYJTIGS-UHFFFAOYSA-N undecane Chemical compound CCCCCCCCCCC RSJKGSCJYJTIGS-UHFFFAOYSA-N 0.000 description 2
- GGAUUQHSCNMCAU-ZXZARUISSA-N (2s,3r)-butane-1,2,3,4-tetracarboxylic acid Chemical compound OC(=O)C[C@H](C(O)=O)[C@H](C(O)=O)CC(O)=O GGAUUQHSCNMCAU-ZXZARUISSA-N 0.000 description 1
- OVBFMUAFNIIQAL-UHFFFAOYSA-N 1,4-diisocyanatobutane Chemical compound O=C=NCCCCN=C=O OVBFMUAFNIIQAL-UHFFFAOYSA-N 0.000 description 1
- AHBNSOZREBSAMG-UHFFFAOYSA-N 1,5-diisocyanato-2-methylpentane Chemical compound O=C=NCC(C)CCCN=C=O AHBNSOZREBSAMG-UHFFFAOYSA-N 0.000 description 1
- HECLRDQVFMWTQS-RGOKHQFPSA-N 1755-01-7 Chemical compound C1[C@H]2[C@@H]3CC=C[C@@H]3[C@@H]1C=C2 HECLRDQVFMWTQS-RGOKHQFPSA-N 0.000 description 1
- RKMGAJGJIURJSJ-UHFFFAOYSA-N 2,2,6,6-Tetramethylpiperidine Substances CC1(C)CCCC(C)(C)N1 RKMGAJGJIURJSJ-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
- 125000000954 2-hydroxyethyl group Chemical group [H]C([*])([H])C([H])([H])O[H] 0.000 description 1
- UZDMJPAQQFSMMV-UHFFFAOYSA-N 4-oxo-4-(2-prop-2-enoyloxyethoxy)butanoic acid Chemical compound OC(=O)CCC(=O)OCCOC(=O)C=C UZDMJPAQQFSMMV-UHFFFAOYSA-N 0.000 description 1
- RSWGJHLUYNHPMX-UHFFFAOYSA-N Abietic-Saeure Natural products C12CCC(C(C)C)=CC2=CCC2C1(C)CCCC2(C)C(O)=O RSWGJHLUYNHPMX-UHFFFAOYSA-N 0.000 description 1
- 241000428352 Amma Species 0.000 description 1
- 229920002799 BoPET Polymers 0.000 description 1
- 208000011231 Crohn disease Diseases 0.000 description 1
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 1
- 239000005977 Ethylene Substances 0.000 description 1
- 239000013032 Hydrocarbon resin Substances 0.000 description 1
- CERQOIWHTDAKMF-UHFFFAOYSA-N Methacrylic acid Chemical compound CC(=C)C(O)=O CERQOIWHTDAKMF-UHFFFAOYSA-N 0.000 description 1
- IIGAAOXXRKTFAM-UHFFFAOYSA-N N=C=O.N=C=O.CC1=C(C)C(C)=C(C)C(C)=C1C Chemical class N=C=O.N=C=O.CC1=C(C)C(C)=C(C)C(C)=C1C IIGAAOXXRKTFAM-UHFFFAOYSA-N 0.000 description 1
- 239000004721 Polyphenylene oxide Substances 0.000 description 1
- 239000004820 Pressure-sensitive adhesive Substances 0.000 description 1
- OFOBLEOULBTSOW-UHFFFAOYSA-N Propanedioic acid Natural products OC(=O)CC(O)=O OFOBLEOULBTSOW-UHFFFAOYSA-N 0.000 description 1
- GOOHAUXETOMSMM-UHFFFAOYSA-N Propylene oxide Chemical group CC1CO1 GOOHAUXETOMSMM-UHFFFAOYSA-N 0.000 description 1
- KHPCPRHQVVSZAH-HUOMCSJISA-N Rosin Natural products O(C/C=C/c1ccccc1)[C@H]1[C@H](O)[C@@H](O)[C@@H](O)[C@@H](CO)O1 KHPCPRHQVVSZAH-HUOMCSJISA-N 0.000 description 1
- XTXRWKRVRITETP-UHFFFAOYSA-N Vinyl acetate Chemical compound CC(=O)OC=C XTXRWKRVRITETP-UHFFFAOYSA-N 0.000 description 1
- UKLDJPRMSDWDSL-UHFFFAOYSA-L [dibutyl(dodecanoyloxy)stannyl] dodecanoate Chemical compound CCCCCCCCCCCC(=O)O[Sn](CCCC)(CCCC)OC(=O)CCCCCCCCCCC UKLDJPRMSDWDSL-UHFFFAOYSA-L 0.000 description 1
- 125000005396 acrylic acid ester group Chemical group 0.000 description 1
- 150000001491 aromatic compounds Chemical class 0.000 description 1
- JGCWKVKYRNXTMD-UHFFFAOYSA-N bicyclo[2.2.1]heptane;isocyanic acid Chemical compound N=C=O.N=C=O.C1CC2CCC1C2 JGCWKVKYRNXTMD-UHFFFAOYSA-N 0.000 description 1
- 229910052797 bismuth Inorganic materials 0.000 description 1
- 239000013522 chelant Substances 0.000 description 1
- 239000006059 cover glass Substances 0.000 description 1
- LDHQCZJRKDOVOX-NSCUHMNNSA-N crotonic acid Chemical compound C\C=C\C(O)=O LDHQCZJRKDOVOX-NSCUHMNNSA-N 0.000 description 1
- 125000002704 decyl 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])* 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- JGFBRKRYDCGYKD-UHFFFAOYSA-N dibutyl(oxo)tin Chemical compound CCCC[Sn](=O)CCCC JGFBRKRYDCGYKD-UHFFFAOYSA-N 0.000 description 1
- 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 1
- 238000001035 drying Methods 0.000 description 1
- 239000000806 elastomer Substances 0.000 description 1
- 125000001495 ethyl group Chemical group [H]C([H])([H])C([H])([H])* 0.000 description 1
- 239000001530 fumaric acid Substances 0.000 description 1
- 229910052736 halogen Inorganic materials 0.000 description 1
- 150000002367 halogens Chemical class 0.000 description 1
- 238000013007 heat curing Methods 0.000 description 1
- 125000003187 heptyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])[H] 0.000 description 1
- 125000004051 hexyl group Chemical group [H]C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])* 0.000 description 1
- 229920006270 hydrocarbon resin Polymers 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- AMGQUBHHOARCQH-UHFFFAOYSA-N indium;oxotin Chemical compound [In].[Sn]=O AMGQUBHHOARCQH-UHFFFAOYSA-N 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 125000000959 isobutyl group Chemical group [H]C([H])([H])C([H])(C([H])([H])[H])C([H])([H])* 0.000 description 1
- 239000012948 isocyanate Substances 0.000 description 1
- ZFSLODLOARCGLH-UHFFFAOYSA-N isocyanuric acid Chemical compound OC1=NC(O)=NC(O)=N1 ZFSLODLOARCGLH-UHFFFAOYSA-N 0.000 description 1
- 125000001449 isopropyl group Chemical group [H]C([H])([H])C([H])(*)C([H])([H])[H] 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 238000003475 lamination Methods 0.000 description 1
- 239000004973 liquid crystal related substance 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
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910001507 metal halide Inorganic materials 0.000 description 1
- 150000005309 metal halides Chemical class 0.000 description 1
- 125000005397 methacrylic acid ester group Chemical group 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
- 125000004108 n-butyl group Chemical group [H]C([H])([H])C([H])([H])C([H])([H])C([H])([H])* 0.000 description 1
- 125000001400 nonyl group Chemical group [H]C([*])([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])[H] 0.000 description 1
- 125000002347 octyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])[H] 0.000 description 1
- JRZJOMJEPLMPRA-UHFFFAOYSA-N olefin Natural products CCCCCCCC=C JRZJOMJEPLMPRA-UHFFFAOYSA-N 0.000 description 1
- 150000002926 oxygen Chemical class 0.000 description 1
- 125000001147 pentyl group Chemical group C(CCCC)* 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 239000004014 plasticizer Substances 0.000 description 1
- 229920002589 poly(vinylethylene) polymer Polymers 0.000 description 1
- 229920000058 polyacrylate Polymers 0.000 description 1
- 229920000570 polyether Polymers 0.000 description 1
- 239000004848 polyfunctional curative Substances 0.000 description 1
- 229920000582 polyisocyanurate Polymers 0.000 description 1
- 239000011495 polyisocyanurate Substances 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 229920000098 polyolefin Polymers 0.000 description 1
- 229920001296 polysiloxane Polymers 0.000 description 1
- 125000001436 propyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])[H] 0.000 description 1
- 239000000376 reactant Substances 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 238000009738 saturating Methods 0.000 description 1
- 229940116351 sebacate Drugs 0.000 description 1
- CXMXRPHRNRROMY-UHFFFAOYSA-L sebacate(2-) Chemical compound [O-]C(=O)CCCCCCCCC([O-])=O CXMXRPHRNRROMY-UHFFFAOYSA-L 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 125000004079 stearyl group Chemical group [H]C([*])([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])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])[H] 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 239000013589 supplement Substances 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 150000003505 terpenes Chemical class 0.000 description 1
- 235000007586 terpenes Nutrition 0.000 description 1
- 125000000999 tert-butyl group Chemical group [H]C([H])([H])C(*)(C([H])([H])[H])C([H])([H])[H] 0.000 description 1
- 230000008719 thickening Effects 0.000 description 1
- KSBAEPSJVUENNK-UHFFFAOYSA-L tin(ii) 2-ethylhexanoate Chemical compound [Sn+2].CCCCC(CC)C([O-])=O.CCCCC(CC)C([O-])=O KSBAEPSJVUENNK-UHFFFAOYSA-L 0.000 description 1
- 150000003609 titanium compounds Chemical class 0.000 description 1
- 238000004448 titration Methods 0.000 description 1
- DVKJHBMWWAPEIU-UHFFFAOYSA-N toluene 2,4-diisocyanate Chemical class CC1=CC=C(N=C=O)C=C1N=C=O DVKJHBMWWAPEIU-UHFFFAOYSA-N 0.000 description 1
- KHPCPRHQVVSZAH-UHFFFAOYSA-N trans-cinnamyl beta-D-glucopyranoside Natural products OC1C(O)C(O)C(CO)OC1OCC=CC1=CC=CC=C1 KHPCPRHQVVSZAH-UHFFFAOYSA-N 0.000 description 1
- LDHQCZJRKDOVOX-UHFFFAOYSA-N trans-crotonic acid Natural products CC=CC(O)=O LDHQCZJRKDOVOX-UHFFFAOYSA-N 0.000 description 1
- 125000002948 undecyl group Chemical group [H]C([*])([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])[H] 0.000 description 1
- 238000004383 yellowing Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J7/00—Adhesives in the form of films or foils
- C09J7/10—Adhesives in the form of films or foils without carriers
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
- C09J11/02—Non-macromolecular additives
- C09J11/06—Non-macromolecular additives organic
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
- C09J11/08—Macromolecular additives
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J133/00—Adhesives based on 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 only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J175/00—Adhesives based on polyureas or polyurethanes; Adhesives based on derivatives of such polymers
- C09J175/04—Polyurethanes
- C09J175/14—Polyurethanes having carbon-to-carbon unsaturated bonds
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J7/00—Adhesives in the form of films or foils
- C09J7/30—Adhesives in the form of films or foils characterised by the adhesive composition
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2201/00—Properties
- C08L2201/10—Transparent films; Clear coatings; Transparent materials
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J2301/00—Additional features of adhesives in the form of films or foils
- C09J2301/20—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive itself
- C09J2301/208—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive itself the adhesive layer being constituted by at least two or more adjacent or superposed adhesive layers, e.g. multilayer adhesive
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J2301/00—Additional features of adhesives in the form of films or foils
- C09J2301/40—Additional features of adhesives in the form of films or foils characterized by the presence of essential components
- C09J2301/408—Additional features of adhesives in the form of films or foils characterized by the presence of essential components additives as essential feature of the adhesive layer
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J2433/00—Presence of (meth)acrylic polymer
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J2475/00—Presence of polyurethane
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Adhesive Tapes (AREA)
- Adhesives Or Adhesive Processes (AREA)
- Polyurethanes Or Polyureas (AREA)
Abstract
The invention provides an optically transparent adhesive sheet with suppressed roll marks. An optically transparent adhesive sheet comprising a polyurethane layer containing a cured product of a thermosetting polyurethane composition, wherein the thermosetting polyurethane composition contains a polyol component and a polyisocyanate component, the polyol component contains a hydrogenated polybutadiene-based polyol, and the loss tangent at 20 ℃ is 0.1 to 0.4.
Description
Technical Field
The following disclosure relates to an optically clear adhesive sheet.
Background
An optically clear adhesive (OCA: optically CLEAR ADHESIVE) sheet is a transparent adhesive sheet used for bonding optical members. In recent years, there has been a rapid increase in demand for touch panels in the fields of smart phones, tablet personal computers (Personal Computer, PC), portable game machines, car navigation devices, and the like, and along with this, there has also been an increase in demand for OCA sheets for bonding touch panels to other optical members. A display device including a touch panel generally has a structure in which a display panel such as a liquid crystal panel, a transparent member (touch panel body) having a transparent conductive film including Indium Tin Oxide (ITO) or the like on a surface layer, and an optical member such as a cover panel protecting the transparent conductive film are laminated, and an OCA sheet is used for bonding between the optical members.
For example, a photosensitive resin composition containing a (meth) acrylate compound (for example, patent document 1) or a two-component liquid thermosetting polyurethane resin composition (for example, patent document 2) has been studied for bonding optical members.
Patent document 1 discloses a polyurethane compound (F) which is a reactant of a compound (a) and a compound (B), a compound (C), a compound (D), and a compound (E) shown below.
Compound (a): hydrogenated polybutadiene polyol compounds
Compound (B): polyisocyanate compound (C) having an isocyanate group of 3 or more functional groups: diisocyanate compound
Compound (D): polyol compounds other than the compound (A)
Compound (E): (meth) acrylate compound having at least one hydroxyl group
Patent document 2 discloses a two-component liquid-heat-curable polyurethane resin composition comprising a polyol (a) containing a hydrogenated dimer diol (a-1) and a hydroxyl-terminated hydrogenated polybutadiene (a-2), and a polyisocyanate (B), wherein the mass ratio of the hydrogenated dimer diol (a-1) to the hydroxyl-terminated hydrogenated polybutadiene (a-2) in the polyol (a) is in the range of from 99.5/0.5 to 80/20.
[ Prior Art literature ]
[ Patent literature ]
[ Patent document 1] Japanese patent laid-open No. 2017-057349
Patent document 2 Japanese patent laid-open publication No. 2013-018856
Disclosure of Invention
[ Problem to be solved by the invention ]
In the lamination of optical members, a thick OCA sheet capable of covering the thickness of a bezel or the like is required in addition to transparency and flexibility following the level difference of the bezel or the like. The photosensitive resin composition containing the (meth) acrylate compound as described in patent document 1 may not be sufficiently light-cured because it is polymerized and cured (light-cured) by irradiation with light such as ultraviolet rays when the optical member is attached, and therefore, it is shielded by a light shielding member such as a black matrix or light is absorbed by a plastic cover.
Here, the OCA sheet is generally subjected to an attaching operation in a room temperature environment, and one of the attaching methods is a method of attaching the OCA sheet while applying pressure by a roller. When the adhesion is performed while applying pressure by the roller, a trace of the roller for adhesion (hereinafter, also referred to as a roller pressure contact trace) may remain.
The present invention has been made in view of the above-described circumstances, and an object thereof is to provide an optically transparent adhesive sheet in which roll press marks are suppressed.
[ Means of solving the problems ]
(1) An embodiment of the present invention is an optically clear adhesive sheet comprising a polyurethane layer containing a cured product of a thermosetting polyurethane composition, wherein the thermosetting polyurethane composition contains a polyol component and a polyisocyanate component, the polyol component contains a hydrogenated polybutadiene-based polyol, and the loss tangent at 20 ℃ is 0.1 to 0.4.
(2) Another embodiment of the present invention is an optically clear adhesive sheet comprising a polyurethane layer containing a cured product of a thermosetting polyurethane composition, wherein the thermosetting polyurethane composition contains a polyol component containing a hydrogenated polybutadiene-based polyol and a polyisocyanate component, and wherein the optically clear adhesive sheet has a thickness change rate represented by the following formula of 0.75% or less.
Thickness change rate (%) = [ (Y-X)/Y ] ×100
X: a rubber cylinder having a diameter of 12mm was used in an environment of 20℃and was pressed under a pressure of 50N for 2 minutes, followed by leaving the resultant sheet to stand for 30 minutes to give an optically transparent adhesive sheet having a thickness (. Mu.m)
Y: thickness (μm) of optically clear adhesive sheet before pressing
(3) In addition, in one embodiment of the present invention, in addition to the structure of (1), the optically transparent adhesive sheet has a thickness change rate represented by the following formula of 0.75% or less.
Thickness change rate (%) = [ (Y-X)/Y ] ×100
X: a rubber cylinder having a diameter of 12mm was used in an environment of 20℃and was pressed under a pressure of 50N for 2 minutes, followed by leaving the resultant sheet to stand for 30 minutes to give an optically transparent adhesive sheet having a thickness (. Mu.m)
Y: thickness (μm) of optically clear adhesive sheet before pressing
(4) In addition, an embodiment of the present invention is an optically transparent adhesive sheet, wherein the optically transparent adhesive sheet has a loss tangent of 0.1 to 0.4 at 20 ℃.
(5) In addition, an embodiment of the present invention is an optically transparent adhesive sheet, wherein the polyurethane layer has an α ratio represented by the following formula of 1.0 to 1.2 in addition to any one of the structures (1) to (4).
Alpha ratio = moles of hydroxyl groups derived from the polyol component/moles of isocyanate groups derived from the polyisocyanate component
(6) In addition, an embodiment of the present invention is an optically transparent adhesive sheet, wherein the thickness of the polyurethane layer is 200 μm or more and 1500 μm or less in any one of the structures (1) to (5).
(7) In addition, an embodiment of the present invention is an optically transparent adhesive sheet comprising, in addition to any one of the structures (1) to (6): the polyurethane layer; a first surface adhesive layer disposed on one of the surfaces of the polyurethane layer; and a second surface adhesive layer disposed on the other surface of the polyurethane layer.
[ Effect of the invention ]
By the present invention, an optically transparent adhesive sheet with suppressed roll pressure marks can be obtained.
Drawings
Fig. 1 is a schematic cross-sectional view showing an example of an optically transparent adhesive sheet according to an embodiment.
Fig. 2 is a schematic cross-sectional view showing another example of the optically transparent adhesive sheet according to the embodiment.
Fig. 3A is a first explanatory diagram for explaining a method of measuring a pair roller nip.
Fig. 3B is a second explanatory diagram for explaining a method of measuring a pair roller nip.
Fig. 4 is an explanatory diagram for explaining a method of measuring the thickness change rate.
FIG. 5 is a graph showing the relationship between tan delta at 20℃and the thickness change rate of the optically clear adhesive sheets of examples 1 to 7 and comparative examples 1 to 3.
[ Description of symbols ]
10: Optically clear adhesive sheet (OCA sheet)
11: Polyurethane layer
12: A first surface adhesive layer
13: Second surface adhesive layer
100: Rubber roller
101. 102: Glass plate
103: Rubber cylinder
Detailed Description
Hereinafter, the present invention will be described in more detail with reference to the embodiments, but the present invention is not limited to these embodiments. The structures of the embodiments may be appropriately combined and modified within a range not departing from the gist of the present invention.
The optically clear adhesive sheet of the embodiment comprises a polyurethane layer that contains a cured product of a thermosetting polyurethane composition that contains a polyol component that contains a hydrogenated polybutadiene-based polyol and a polyisocyanate component.
The optically clear adhesive sheet (hereinafter, OCA sheet) includes a polyurethane layer containing a cured product of a thermosetting polyurethane composition. The thermosetting polyurethane composition can be formed into a film without using a solvent, and thus the thickness of the obtained polyurethane layer can be made thick. In addition, as in the case of a photosensitive resin composition containing a (meth) acrylate compound, ultraviolet irradiation is not required at the time of curing, and thus the composition is also suitable for thickening. The OCA sheet of the embodiment is excellent in elongation under tensile stress and is extremely unlikely to break. Therefore, the paste can be peeled off without leaving the paste. The composition of the polyurethane layer will be described later.
When a pair of substrates are bonded using an OCA sheet, in general, one of the substrates is bonded with the OCA sheet, and then the other substrate is bonded on the opposite side of the OCA sheet. In addition, as one of the methods of attaching the OCA sheet, there is a method of attaching while applying pressure by a roller. When another substrate is bonded with the roll pressure marks left, air may enter between the substrate and the OCA sheet, and the adhesive force may be reduced. By suppressing the occurrence of the roll pressure mark, air is less likely to enter between the substrate and the OCA sheet.
In one embodiment of the present invention, the OCA sheet has a loss tangent (tan δ at 20 ℃ below) of 0.1 to 0.4 at 20 ℃. When the tan δ at 20 ℃ is set to 0.1 or more and 0.4 or less, the adhesive body can have flexibility suitable for adhesion to the adherend, and the occurrence of roll pressure marks can be suppressed. When the tan δ at 20 ℃ exceeds 0.4, the influence of tackiness becomes large, and recovery becomes difficult, so that roll press-bonding marks are easily attached. If tan δ at 20 ℃ is less than 0.1, the OCA sheet is difficult to deform, and flexibility such as step following property when adhering to an adherend may not be obtained. In view of obtaining more excellent step following property, tan δ at 20 ℃ is preferably 0.2 or more. In view of more effectively suppressing the occurrence of roll press marks, the tan δ at 20 ℃ is preferably 0.27 or less.
The OCA sheet may have a loss tangent at 85 ℃ (tan δ at 85 ℃ below) of 0.1 to 0.6, or 0.2 to 0.55.
The loss tangent (tan delta) is represented by the ratio (G '/G') of the storage modulus of elasticity (G ') to the loss modulus of elasticity (G'). the lower the value of tan δ, the closer the OCA sheet is to the elastomer (rigid body), the more difficult it is to deform against external force, and the higher the value of tan δ, the closer the OCA sheet is to the adhesive body, and the softer. The loss tangent at 20℃and 85℃can be measured, for example, using a "physical (Physica) MCR301" device for measuring viscoelasticity manufactured by the company An Dongpa of Germany (Anton PAAR GERMANY GmbH).
The tan delta at 20℃of the OCA sheet can be adjusted by changing the alpha ratio of the thermosetting polyurethane composition, the structure or functional number of the polyisocyanate component, the structure or functional number of the main component of the polyol component, the molecular weight of the polyol, and the like.
In another embodiment of the present invention, the optically transparent adhesive sheet represented by the following formula has a thickness change rate of 0.75% or less. The OCA sheet used for measurement was cut out to 25mm in the longitudinal direction and 25mm in the transverse direction. For example, MCR302 manufactured by An Dongpa (Anton Paar) is used as the pressurizing device. As the rubber cylinder, a cylinder having a rubber hardness of 30℃as measured by a type A durometer specified in Japanese Industrial Standard (Japanese Industrial Standards, JIS) K6253 was used. The static placement after the rubber cylinder was removed under pressure was performed at 20 ℃. The thickness was measured using a laser displacement meter (for example, CL-P30 manufactured by Keyst (Keyence)) for example.
Thickness change rate (%) = [ (Y-X)/Y ] ×100
X: a rubber cylinder having a diameter of 12mm was used in an environment of 20℃and was pressed under a pressure of 50N for 2 minutes, followed by leaving the resultant sheet to stand for 30 minutes to give an optically transparent adhesive sheet having a thickness (. Mu.m)
Y: thickness (μm) of optically clear adhesive sheet before pressing
Since the OCA sheet is generally attached under room temperature environment, if the thickness change rate of the OCA sheet at 20 ℃ is large, after attaching the OCA sheet to one of the substrates, a roll pressure mark tends to remain on the surface of the side to which the other substrate is attached. When the thickness change rate of the OCA sheet is 0.75% or less, the occurrence of roll pressure marks can be suppressed when the OCA sheet is used to attach a substrate. The thickness change rate is more preferably 0.65% or less, still more preferably 0.45% or less, particularly preferably 0.25% or less, and most preferably 0.15% or less. The thickness of the OCA sheet is preferably unchanged before and after pressurization, and the lower limit of the thickness change rate is preferably 0%.
The thickness change rate of the OCA sheet can be adjusted by changing the α -ratio of the thermosetting polyurethane composition, the structure or functional number of the polyisocyanate component, the structure or functional number of the main agent of the polyol component, the molecular weight of the polyol, and the like.
The haze of the OCA sheet is preferably 1% or less. The total light transmittance is preferably 90% or more. Haze and total light transmittance can be measured using, for example, a haze meter "haze meter (HazeMeter) NDH2000" manufactured by japan electric color industry company. Haze was measured by the method according to JIS K7136, and total light transmittance was measured by the method according to JIS K7361-1.
The thickness of the entire OCA sheet is preferably 200 μm or more. The upper limit of the thickness of the entire OCA sheet is not particularly limited, and is, for example, 3000 μm. The lower limit of the thickness is more preferably 300. Mu.m, and further preferably 500. Mu.m. The upper limit of the thickness is more preferably 2500. Mu.m, and further preferably 2000. Mu.m.
< Polyurethane layer >)
The polyurethane layer is obtained by reacting a polyol component with a polyisocyanate component, and for example, preferably has a structure represented by formula (a).
[ Chemical 1]
In the chemical formula (A), R represents a portion of the polyisocyanate component after removal of isocyanate groups (NCO groups), R' represents a portion of the polyol component after removal of hydroxyl groups (OH groups), and n represents the number of repeating units.
The cured product of the thermosetting polyurethane composition (thermosetting polyurethane) is preferably not modified with acrylic acid, and preferably contains no part derived from acrylic acid ester, methacrylic acid ester, or the like in the main chain of the polyurethane. When the thermosetting polyurethane is modified with acrylic acid, it is rendered hydrophobic, and thus aggregation of moisture is likely to occur at high temperature and high humidity. There are cases where the aggregation of the moisture causes whitening, foaming, or the like, and the optical characteristics are impaired. Further, when modified with acrylic acid, the resin may turn yellow at high temperature. Therefore, the thermally cured polyurethane is not modified with acrylic acid, whereby deterioration of optical properties at high temperature and high humidity and yellowing can be prevented.
The thermosetting polyurethane composition contains a polyol component and a polyisocyanate component. In the polyurethane layer containing the cured product of the thermosetting polyurethane composition, the total amount of the monomer units derived from the polyol component and the monomer units derived from the polyisocyanate component is preferably 80 mol% or more, more preferably 90 mol% or more of the monomer units constituting the entire thermosetting polyurethane.
As the polyol component and the polyisocyanate component, components that are liquid at normal temperature (23 ℃) can be used, and a thermally curable polyurethane can be obtained without using a solvent. Other components such as an adhesion imparting agent may be added to either the polyol component or the polyisocyanate component, and preferably to the polyol component. The thermosetting polyurethane does not require removal of a solvent, and therefore a uniform sheet can be formed thick, and a polyurethane layer which is soft and thick can be produced. In addition, even if the polyurethane layer is formed thick, the optical characteristics can be maintained.
[ Polyol component ]
The thermosetting polyurethane composition contains a hydrogenated polybutadiene polyol as a polyol component. The hydrogenated polybutadiene-based polyol is a polyol containing a structure derived from hydrogenated polybutadiene. By using a hydrogenated polybutadiene polyol as the polyol component, heat resistance superior to that of an ester polyol or an ether polyol can be obtained. In addition, polybutadiene polyol has a lower viscosity than polyisoprene polyol, so that an OCA sheet of a film (for example, 300 μm to 500 μm) can be produced.
Examples of the hydrogenated polybutadiene polyol include 1, 2-polybutadiene polyol and 1, 4-polybutadiene polyol. Specific examples of the hydrogenated polybutadiene polyol include, for example, kelaso (Krasol) (registered trademark) HLBHP3000, kelaso (Krasol) HLBHP2000, manufactured by ke Lei Weili (CRAY VALLEY), GI1000, GI2000, GI3000, etc. of the company, co.
The hydrogenated polybutadiene polyol may have a structure represented by the formula (B-1).
[ Chemical 2]
(Wherein x, y and z represent the number of repeating units)
The hydrogenated polybutadiene polyol is a polyol having an olefin skeleton. By containing a polyol having an olefin skeleton, a polyurethane layer excellent in heat stability can be obtained as compared with the case of using an acrylic, ester or polyether polyol. For example, even in the case of being left at 95 ℃ for 1000 hours, a polyurethane layer in which the polyurethane layer does not dissolve or turn yellow can be obtained.
The thermosetting polyurethane composition may contain a polyol other than the hydrogenated polybutadiene polyol.
The other polyol is preferably a polyol having an olefin skeleton. The main chain of the polyol having an olefin skeleton contains a polyolefin or a derivative thereof. Examples of the polyol having an olefin skeleton include polybutadiene-based polyols such as 1, 2-polychloroprene polyols and 1, 4-polychloroprene polyols, polyisoprene-based polyols, and polyols obtained by saturating double bonds of these polyols with hydrogen, halogen, or the like. The polyol component may be a polyol obtained by copolymerizing an olefin compound such as styrene, ethylene, vinyl acetate, or acrylate with a polybutadiene-based polyol, a polyisoprene-based polyol, or the like, or a hydrogenated product thereof. The polyol component may have a linear structure or may have a branched structure. The polyol component may be used alone or in combination of two or more.
Among them, polyisoprene-based polyols are preferable as the other polyols because of their excellent compatibility with hydrogenated polybutadiene-based polyols. The polyisoprene-based polyol is a polyol containing a structure derived from polyisoprene. Examples of the polyisoprene-based polyol include Ai Poer (Epol) (registered trademark) manufactured by light-producing company. Since the polyisoprene-based polyol has a higher viscosity than the butadiene-based polyol, the polyisoprene-based polyol may be used in combination from the viewpoint that a thick film (for example, 1000 μm or more) OCA sheet can be formed.
The polyisoprene-based polyol may also have a structure represented by the formula (B-2).
[ Chemical 3]
(Wherein x, y and z represent the number of repeating units)
The content of the polyol having an olefin skeleton with respect to the entire polyol component is preferably 80 mol% or more. The thermosetting polyurethane composition more preferably contains only a polyol having an olefin skeleton as a polyol component. The content of the polyol having an olefin skeleton refers to the content of the hydrogenated polybutadiene polyol relative to the entire polyol component in the case where only the hydrogenated polybutadiene polyol is included as the polyol component, and the content of the hydrogenated polybutadiene polyol and the other polyol having an olefin skeleton relative to the entire polyol component in the case where the hydrogenated polybutadiene polyol and the other polyol having an olefin skeleton are included as the polyol component.
The polyol component may also contain a polyol having a hydroxyl group with a functional number of 2.5 or less. The hydroxyl group number means an average hydroxyl group number per mole of polyol. If the hydroxyl group number of the polyol component exceeds 2.5, the hydroxyl group amount becomes large, and the amount of NCO groups to be reacted becomes large, so that foaming may occur. The hydroxyl number is more preferably 2.3 or less.
The polyol component may also comprise a polyol having hydroxyl groups with a functionality of less than 2. In the case of using a polyol component having a hydroxyl group with a functional number of less than 2, it is preferable to use a polyisocyanate having 3 or more functional groups as the polyisocyanate component. If the number of hydroxyl groups is less than 2, it is difficult to form a branched structure when the thermosetting polyurethane composition is cured, and the polyurethane layer may become too soft or the curing speed may be slow, but the use of a polyisocyanate having 3 or more functional groups may allow the curing speed to be increased and the viscoelasticity to be adjusted.
The hydroxyl groups of the entire polyol component may have a number of functions of 1.8 to 2.0. When a plurality of polyol components are contained and the blending ratio of each polyol component and the number of hydroxyl groups of each polyol component are known, the number of hydroxyl groups of the entire polyol component can be calculated from the blending ratio of each polyol component and the number of hydroxyl groups. The blending ratio of each polyol component contained in the entire polyol component may be calculated by gel permeation chromatography (Gel Permeation Chromatography, GPC) based on the peak area corresponding to each polyol component, and the number of hydroxyl groups in the entire polyol component may be calculated by titration.
[ Polyisocyanate component ]
The polyisocyanate component may also contain aliphatic and/or cycloaliphatic polyisocyanates. Specific examples of the aliphatic polyisocyanate include: hexamethylene diisocyanate (Hexamethylene Diisocyanate, HDI), tetramethylene diisocyanate, 2-methyl-pentane-1, 5-diisocyanate, 3-methyl-pentane-1, 5-diisocyanate, lysine diisocyanate (lysine diisocyanate), trioxyethylene diisocyanate, modified ones of these, and the like. Specific examples of the alicyclic polyisocyanate include: isophorone diisocyanate (isophorone diisocyanate, IPDI), cyclohexyl diisocyanate, 4' -dicyclohexylmethane diisocyanate, norbornane diisocyanate, hydrogenated toluene diisocyanate, hydrogenated xylene diisocyanate, hydrogenated tetramethylxylene diisocyanate, modified products of these, and the like. These may be used alone or in combination of two or more.
Among them, hexamethylene diisocyanate, isophorone diisocyanate and modified products thereof are preferable, and isophorone diisocyanate and modified products thereof are particularly preferable. Examples of the modified isophorone diisocyanate include an isocyanurate-modified isophorone diisocyanate, an allophanate-modified isophorone diisocyanate, and/or a urethane-modified isophorone diisocyanate. Specific examples of the IPDI (isophorone diisocyanate) based polyisocyanate include Desmodur I (Desmodur) and Desmodur H (Desmodur) manufactured by kesi (Covestro).
The polyisocyanate component may also contain a modified polyisocyanate containing alkylene oxide units. The modified polyisocyanate containing an alkylene oxide unit can suppress whitening due to moisture absorption by the action of a hydrophilic moiety (a polyalkylene oxide unit), and can exert compatibility with a low-polarity adhesion imparting agent, a plasticizer, or the like by the action of a hydrophobic moiety (another unit). Since the modified polyisocyanate containing an alkylene oxide unit is a hydrophilic polyisocyanate, the use of the modified polyisocyanate in combination with an aliphatic and/or alicyclic polyisocyanate as a hydrophobic polyisocyanate can adjust the balance between the hydrophilicity and the hydrophobicity of the polyurethane layer, and can suppress whitening due to moisture absorption while maintaining the transparency of the OCA sheet for a long period of time.
The modified polyisocyanate containing alkylene oxide units may also be obtained by reacting the aliphatic and/or alicyclic polyisocyanate with an ether compound having a polyalkylene oxide unit. Examples of the alkylene oxide unit include an ethylene oxide unit and a propylene oxide unit. Specific examples of the modified polyisocyanate containing an ethylene oxide unit include HC266 manufactured by Tosoh (Tosoh), crohn (Coronate) 4021, crohn (Coronate) 4022, dochide (Aquanate) 130, dochide (Aquanate) 140, and the like.
The mass ratio of the aliphatic and/or alicyclic polyisocyanate to the modified polyisocyanate containing alkylene oxide units is preferably 2:1 to 1:2. by setting the mass ratio within the above range, the compatibility between the polyisocyanate component and the polyol component and the hygroscopicity of the polyurethane layer can be adjusted. The more preferred range of the mass ratio is 1:1 to 1:1.5.
The polyisocyanate component may contain a polyisocyanate having 3 or more isocyanate groups (hereinafter, also referred to as "polyisocyanate having 3 or more functional groups"). By using a polyisocyanate having 3 or more functional groups, a branched structure can be formed much more when the thermosetting polyurethane composition is cured, and the rigidity of the polyurethane layer can be improved, so that a desired viscoelasticity can be obtained even if the amount of the polyisocyanate component added is reduced. In addition, since the branched structure can be formed much, the growth reaction of polyurethane can be performed well, and the hardening speed of the polyurethane layer can be accelerated.
The number of isocyanate groups refers to the average number of isocyanate groups per mole of polyisocyanate having 3 or more functional groups. The number of isocyanate groups of the polyisocyanate having 3 or more functional groups may be, for example, 4.0 or less.
The polyisocyanates above 3 functional groups can also be synthesized using the aliphatic polyisocyanates. Specific examples of the polyisocyanate having 3 or more functional groups include Desmodur (Desmodur) N3900 (number of isocyanate groups=3.2) manufactured by Korsche (Covestro), desmodur (Desmodur) N3600 (number of isocyanate groups=3.2), desmodur (Desmodur) N3300 (number of isocyanate groups=3.5), desmodur (Desmodur) N3800 (number of isocyanate groups=3.2), and "Su Mi (Sumidur) N3300" (number of isocyanate groups=3.5) manufactured by Bayer Urethane (Bayer Urethane) manufactured by Karsche. The polyisocyanate having 3 or more functional groups may be an isocyanurate of an aliphatic polyisocyanate.
The content of the polyisocyanate having 3 or more functional groups is preferably 2% by mass or more and 10% by mass or less with respect to the entire polyisocyanate component. By setting the content of the polyisocyanate having 3 or more functional groups to the above range, the viscoelasticity such as loss tangent can be adjusted, and the flexibility of the polyurethane layer can be adjusted while maintaining the transparency. The content of the polyisocyanate having 3 or more functional groups is more preferably 3% by mass or more and 7% by mass or less. The content of the polyisocyanate having 3 or more functional groups is preferably 5% by mass or less from the viewpoint of further suppressing whitening of the polyurethane layer.
The number of isocyanate groups in the polyisocyanate component as a whole may be 2 or more. The number of isocyanate groups in the polyisocyanate component as a whole may be, for example, 4 or less. In the case where a plurality of polyisocyanate components are contained and the blending ratio of each polyisocyanate component and the number of isocyanate groups of each polyisocyanate component are known, the number of isocyanate groups of the whole polyisocyanate component can be calculated from the blending ratio of each polyisocyanate component and the number of isocyanate groups. Further, the component ratio of each polymer contained in the polyisocyanate component can be calculated by Gel Permeation Chromatography (GPC), and the number of functional groups of the polyisocyanate component can be calculated.
[ Adhesion-imparting agent ]
The thermosetting polyurethane composition may further contain an adhesion imparting agent. Examples of the adhesion-imparting agent include petroleum resin-based, hydrocarbon resin-based, rosin-based, and terpene-based adhesion-imparting agents. Since the compatibility with the polyol having an olefin skeleton and the like is excellent, a petroleum resin-based adhesion imparting agent is suitably used. Among the petroleum resin-based adhesion imparting agents, hydrogenated petroleum resins obtained by hydrogenating copolymers of dicyclopentadiene and aromatic compounds are preferable. As a known one of the hydrogenated petroleum resins, for example, "Amma section (I-MARV) P-100" manufactured by Hakking Co., ltd.
The content of the adhesion imparting agent is preferably 5 parts by mass or more and 30 parts by mass or less, and more preferably 10 parts by mass or more and 20 parts by mass or less, relative to 100 parts by mass of the polyol component. When the content of the adhesion imparting agent exceeds 30 parts by mass, there is a concern that the haze of the polyurethane layer becomes high.
[ Catalyst ]
The thermosetting polyurethane composition may also contain a catalyst. The catalyst is not particularly limited as long as it can be used for the urethanization reaction, and examples thereof include: organotin compounds such as di-n-butyltin dilaurate, dimethyltin dilaurate, dibutyltin oxide, and tin octoate; an organic titanium compound; an organozirconium compound; tin carboxylates; bismuth carboxylates; amine catalysts such as triethylenediamine.
The catalyst may be contained in an amount of 50ppm to 200ppm based on 100 parts by mass of the polyol component.
[ Light stabilizer ]
The thermosetting polyurethane composition may also contain a light stabilizer. As the light stabilizer, a hindered amine light stabilizer can be suitably used.
When the OCA sheet is exposed to an ultraviolet irradiation environment, for example, a metal halide lamp irradiation, the polyurethane layer is sometimes dissolved. The reason for the dissolution of the polyurethane layer is thought to be due to the reaction of photoactivated oxygen molecules, hydroxyl radicals, etc. with ether bond moieties of the polyurethane. Further, since the radicals and the like are easily generated under a high temperature environment, the polyurethane layer tends to be easily dissolved. The hindered amine light stabilizer can supplement the free radical, and therefore can inhibit dissolution of the polyurethane layer even when the OCA sheet is left in an environment of high Wen Juzi irradiation with ultraviolet light.
The hindered amine light stabilizer is not particularly limited, and examples thereof include: bis- (2, 6-tetramethyl-4-piperidinyl) sebacate, [ dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2, 6-tetramethylpiperidine ] condensate 1,2, 6-pentamethyl-4-piperidinyl-tridecyl-1, 2,3, 4-butanetetracarboxylate esters of 1,2, 6-pentamethyl-4-piperidinol, 3, 9-bis (2-hydroxy-1, 1-dimethylethyl) -2,4,8, 10-tetraspiro [5,5] undecane with butanetetracarboxylic acid. These may be used alone or in combination of two or more.
Specific examples of the hindered amine light stabilizer include Adjacob waves (Adekastab) LA-81, adjacob waves (Adekastab) LA-63P, adjacob waves (Adekastab) LA-72, and the like manufactured by Ai Dike (ADEKA).
Aidi Cola wave (Adekastab) LA-81 comprises a compound represented by the following chemical formula (1).
[ Chemical 4]
Aidi Colta wave (Adekastab) LA-63P comprises a compound represented by the following chemical formula (2).
[ Chemical 5]
(In the formula (2), n is a natural number)
Aidi Cola wave (Adekastab) LA-72 comprises a compound represented by the following chemical formula (3).
[ Chemical 6]
The content of the hindered amine light stabilizer may be 0.1 parts by mass or more and 1 part by mass or less with respect to 100 parts by mass of the polyol component. If the content of the hindered amine-based light stabilizer exceeds 1 part by mass, the light stabilizer may ooze out of the polyurethane layer.
The α ratio represented by the following formula of the polyurethane layer is preferably 1.0 or more and 1.2 or less.
Alpha ratio = moles of hydroxyl groups derived from the polyol component/moles of isocyanate groups derived from the polyisocyanate component
When the α ratio is 1.0 or more and 1.2 or less, the tan δ of the polyurethane layer can be adjusted while the flexibility of the polyurethane layer is obtained. When the α ratio is less than 1.0, the blending amount of the polyisocyanate component is excessive relative to the blending amount of the polyol component, and therefore the thermally cured polyurethane becomes hard, and the flexibility of the entire OCA sheet may be lowered.
The thickness of the polyurethane layer is preferably 200 μm or more and 1500 μm or less. When the thickness is 200 μm or more, the step-following property tends to be excellent. When the thickness is 1500 μm or less, the area of the display portion tends to be enlarged. The more preferable lower limit of the thickness of the polyurethane layer is 300 μm. The polyurethane layer is a cured product of a thermosetting polyurethane composition, and can be formed into a film without using a solvent, so that it is possible to form a thick film while maintaining optical characteristics.
The OCA sheet may include at least a polyurethane layer containing a cured product of a thermosetting polyurethane composition, and may include other layers. Fig. 1 is a schematic cross-sectional view showing an example of an optically transparent adhesive sheet according to an embodiment. Fig. 2 is a schematic cross-sectional view showing another example of the optically transparent adhesive sheet according to the embodiment. As shown in fig. 1, the OCA sheet 10 may include only the polyurethane layer 11. As shown in fig. 2, the OCA sheet 10 may include a polyurethane layer 11, a first surface adhesive layer 12 disposed on one surface of the polyurethane layer 11, and a second surface adhesive layer 13 disposed on the other surface of the polyurethane layer 11.
First surface adhesive layer and second surface adhesive layer
The first surface adhesive layer 12 and the second surface adhesive layer 13 may be located on the outermost surfaces (surfaces facing the adherend) of the OCA sheet 10. Other layers may be provided between the first surface adhesive layer 12 and the polyurethane layer 11 and between the second surface adhesive layer 13 and the polyurethane layer 11, but it is preferable that the first surface adhesive layer 12 is in contact with the polyurethane layer 11 and the second surface adhesive layer 13 is in contact with the polyurethane layer 11.
The first surface adhesive layer and the second surface adhesive layer may also contain polyurethane. The polyurethane is a cured product of a polyurethane composition, and as the polyurethane composition, the same polyurethane composition as the thermosetting polyurethane composition used in the polyurethane layer can be used.
The first surface adhesive layer and the second surface adhesive layer may contain an acrylic resin. By disposing the surface adhesive layer containing an acrylic resin on the surface of the polyurethane layer, the adhesion to the adherend can be improved by the surface adhesive layer containing an acrylic resin while flexibility is obtained by the polyurethane layer. The surface adhesive layer containing an acrylic resin can be produced by curing an acrylic resin composition.
Examples of the acrylic resin composition include an acrylic resin composition containing a (meth) acrylic polymer or a copolymer of these (hereinafter also referred to as a (meth) acrylic copolymer) and a crosslinking agent. Examples of the (meth) acrylic copolymer include a copolymer of an alkyl (meth) acrylate and a carboxyl group-containing monomer.
The alkyl (meth) acrylate includes alkyl (meth) acrylates having 1 to 18 carbon atoms as an alkyl group (CH 2＝CR1-COOR2;R1 is a hydrogen atom or a methyl group, R 2 is an alkyl group having 1 to 18 carbon atoms), and the alkyl group preferably has 4 to 12 carbon atoms.
Examples of the alkyl (meth) acrylate in which the alkyl group has 1 to 18 carbon atoms include: methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate. One kind of these may be used alone, or two or more kinds may be used.
Examples of the carboxyl group-containing monomer include: carboxyl group-containing (meth) acrylates such as β -carboxyethyl (meth) acrylate, 5-carboxypentyl (meth) acrylate, mono (meth) acryloyloxyethyl succinate, ω -carboxypolycaprolactone mono (meth) acrylate, and the like; acrylic acid, methacrylic acid, itaconic acid, crotonic acid, fumaric acid, and maleic acid. One kind of these may be used alone, or two or more kinds may be used.
The crosslinking agent is not particularly limited as long as it is a component capable of causing a crosslinking reaction with a crosslinkable functional group derived from a crosslinkable functional group-containing monomer contained in the (meth) acrylic copolymer, and examples thereof include: isocyanate compounds, metal chelate compounds, epoxy compounds, and the like.
The thickness of the first surface adhesive layer and the second surface adhesive layer is preferably 3 μm or more and 100 μm or less. When the thickness is 100 μm or more, the softness of the OCA sheet may be lowered. The thickness of the first surface adhesive layer and the second surface adhesive layer is more preferably 3 μm to 50 μm.
Release films may be attached to both sides of the OCA sheet. That is, the laminate may be formed by laminating an OCA sheet, a first release film covering one surface of the OCA sheet, and a second release film covering the other surface of the OCA sheet.
Examples of the first release film and the second release film include polyethylene terephthalate (Polyethylene Terephthalate, PET) films and the like. The surfaces of the first release film and the second release film on the side contacting the OCA sheet may be subjected to an easy-release treatment (release treatment) such as silicone treatment.
The OCA sheet of the present embodiment can be suitably used for bonding optical members. Examples of the adherend of the OCA sheet include: display panels, touch panels (glass substrates with ITO transparent conductive films), cover panels (cover glasses), polarizing plates, retardation films, and the like constitute various members of display devices. The OCA sheet of the present embodiment can be suitably used for bonding glass to a resin panel. The OCA sheet according to the embodiment is a pressure-sensitive adhesive sheet, and when used for an adherend, the OCA sheet can be bonded to the adherend by applying pressure without curing treatment such as heating and light irradiation.
Examples of the material of the resin panel include polycarbonate, polyethylene phthalate, and acrylic. The thicker the resin panel, the thicker the OCA sheet is preferably. For example, when the thickness of the polycarbonate substrate is 0.5mm, 1.0mm, or 1.5mm, the thickness of the OCA sheet is preferably 0.3mm or more, 1.0mm or more, or 1.5mm or more, respectively.
Examples (example)
Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.
< Use ingredient >)
The following examples and comparative examples show the components used.
(A) Polyol component
A-1: polyisoprene polyol, "Ai Poer (Epol) (EPOL, registered trademark)", manufactured by light emitting and producing company, the number of hydroxyl groups=2.3
A-2: polybutadiene polyol, "Kelanol (Krasol) (Krasol, registered trademark) HLBHP3000", produced by Ke Lei Weili (CRAY VALLEY), the number of hydroxyl groups=1.9
(B) Polyisocyanate component
B-1: IPDI (isophorone diisocyanate) based polyisocyanate (Desmodur) I manufactured by kesi corporation (Covestro), functional group of isocyanate group=2.0
B-2: modified polyisocyanate containing an ethylene oxide unit ("HC 266" manufactured by Tosoh) corporation), the number of isocyanate groups having a functionality of 2 or more and less than 3
B-3: modified polyisocyanate containing an ethylene oxide unit ("crohn 4021" manufactured by Tosoh corporation), the number of isocyanate groups=2.0
B-4: modified polyisocyanate containing an ethylene oxide unit (crohn's (corona) 4022 manufactured by Tosoh corporation), the number of isocyanate groups having a functional group of 2 or more and less than 3
B-5: polyisocyanate of HDI (hexamethylene diisocyanate) (Su Mi (Sumidur) N3300 manufactured by Bayer Urethane) company), polyisocyanurate of HDI having a functional group number of isocyanate group=3.5
Catalyst: dimethyltin dilaurate ("Buddha Lez catalyst (Fomrez catalyst) UL-28", manufactured by Michigan (Momentive) Co., ltd.)
Adhesion imparting agent: hydrogenated Petroleum resin (manufactured by Yi Ma Ji (I-MARV) P-100 of Yi Zhi Xing Co., ltd.)
Light stabilizers: a hindered amine light stabilizer (Ai Dike (ADEKA) manufactured by the company "Aidi Cola wave (Adekastab) LA-81")
The IPDI-based polyisocyanate is a cycloaliphatic polyisocyanate and is a hydrophobic polyisocyanate. The B-2, B-3, B-4 are hydrophilic polyisocyanates obtained by reacting an ether polyol having an average of three or more ethylene oxide units per molecule with a polyisocyanate starting from hexamethylene diisocyanate.
Example 1
< Preparation of polyurethane layer >
To 100 parts by mass of the polyol component, a polyisocyanate component, a catalyst, an adhesion imparting agent, and a light stabilizer were added in the formulations shown in table 1, and the mixture was stirred and mixed by using a reciprocating rotary stirrer, ajett (Ajiter), to prepare a thermosetting polyurethane composition. In table 1, the catalyst content represents the dimethyltin dilaurate content.
The obtained polyurethane composition was transported while being sandwiched between a pair of release films (PET films whose surfaces were subjected to release treatment), and was crosslinked and cured under conditions of an in-furnace temperature of 120℃and an in-furnace time of several minutes. Thereafter, a polyurethane layer having release films on both sides was produced by a crosslinking reaction (thermal hardening) at 110℃for 2 hours using a heating apparatus. The thickness and the α ratio of the polyurethane layer are shown in table 1.
< Preparation of first surface adhesive layer and second surface adhesive layer >)
An epoxy hardener (E-AX, manufactured by Soy chemical Co., ltd.) was added to the acrylic resin (BITF-2, manufactured by Toyo ink Co., ltd.) so as to be 1.5 mass% relative to the entire acrylic resin composition, to prepare an acrylic resin composition. The obtained acrylic resin composition was applied to a release film by a corner-roll coater, and dried in a drying oven at 80 to 120 ℃ to prepare an acrylic adhesive layer. The thickness of the acrylic adhesive layer was 25 μm.
< Production of laminated OCA sheet >
Two of the release film-carrying surface adhesive layers and one of the release film-carrying polyurethane layers were prepared. One of the release films is peeled from the first surface adhesive layer and the second surface adhesive layer with the release film, and laminated on both surfaces of the polyurethane layer from which the release film is peeled. Thus, an OCA sheet with a release film was produced in which the release film, the first surface adhesive layer, the polyurethane layer, the second surface adhesive layer, and the release film were laminated in this order.
(Examples 2 to 7, comparative examples 1 to 4)
A polyurethane composition was prepared in the same manner as in example 1, except that the formulation was changed as shown in table 1, and a polyurethane layer was produced by heat curing in the same manner as in example 1. Thereafter, a first surface adhesive layer and a second surface adhesive layer were produced and laminated in the same manner as in example 1, and an OCA sheet with a release film was produced, in which a release film, a first surface adhesive layer, a polyurethane layer, a second surface adhesive layer, and a release film were laminated in this order.
The OCA sheets of examples 1 to 7 and comparative examples 1 to 4 were measured for loss tangent, and the effect of suppressing roll marks was evaluated, and the results are shown in table 1.
(Loss tangent)
The loss tangent of each OCA sheet was measured using a viscoelasticity measuring device "physical (physical) MCR301" manufactured by An Dongpa (Anton Paar). The measurement plate was prepared using PP12, and the measurement conditions were set to a strain of 0.1%, a frequency of 1Hz, and a cell temperature of 20℃to 100 ℃ (a temperature rise rate of 3 ℃/min), and loss tangent at 20℃was recorded.
(Effect of suppressing roll contact marks)
Test pieces of 100mm in the longitudinal direction and 150mm in the transverse direction (7 inch dimension) were cut out from the OCA sheets of examples and comparative examples, and test pieces were produced. Hereinafter, a method for measuring roll press-contact marks will be described with reference to fig. 3A and 3B. Fig. 3A and 3B are a first explanatory view and a second explanatory view, respectively, for explaining a method of measuring a roller press mark.
For each test piece, two transparent glass plates of 7 inch size were prepared, and each test piece (OCA piece) 10 was placed on the first glass plate 101, and the rubber roller 100 was moved from one end to the other end of the OCA piece while rotating, so that the first glass plate 101 was bonded to the OCA piece 10, as shown in fig. 3A. The adhesion was performed in a room temperature environment (23 ℃ C., 0.1 MPa). As the rubber roller 100, a rubber roller having a diameter of 40mm and a rubber hardness of 30 ° measured by a type a durometer specified in JIS K6253 was used.
After the first glass plate and the OCA sheet were bonded, as shown in fig. 3B, a second glass plate 102 was bonded to the opposite side of the OCA sheet 10, and the effect of suppressing the roll marks was evaluated on the basis of the following criteria when viewed from the second glass plate 102 side.
And (3) the following materials: no air was confirmed immediately after the sticking
O: immediately after the adhesion, air was confirmed, but when the mixture was placed in an autoclave set at a temperature of 23℃and a pressure of 0.4MPa for 30 minutes, the air disappeared
X: even if the air is put in an autoclave set at a temperature of 23 ℃ and a pressure of 0.4MPa for 30 minutes, the air does not disappear
(Rate of thickness change)
The OCA sheets of examples 1 to 7 and comparative examples 1 to 3 were measured for the thickness change rate by the following method. Fig. 4 is an explanatory diagram for explaining a method of measuring the thickness change rate. Test pieces 25mm in the longitudinal direction and 25mm in the transverse direction were cut out from the OCA sheets of examples 1 to 7 and comparative examples 1 to 3, and the thickness of the pressed portion at room temperature of 20 ℃ was measured in advance. For thickness measurement, a laser displacement meter (for example, CL-P30 manufactured by Keyence) was used.
As shown in FIG. 4, each test piece (OCA piece) 10 was subjected to a pressure of 50N at 20℃for 2 minutes using a rubber cylinder 103 having a diameter of 12mm by using an MCR302 manufactured by An Dongpa (Anton Paar). The rubber cylinder 103 used was a cylinder having a rubber hardness of 30 ° measured by a type a durometer specified in JIS K6253.
After being taken out from the apparatus, the test pieces were allowed to stand at 20℃for 30 minutes, and the thickness of each of the test pieces after standing was measured. Based on the following equation, the thickness change rates of the OCA sheets of examples 1 to 7 and comparative examples 1 to 3 were calculated from the thicknesses of the OCA sheets before and after pressurization.
Thickness change rate (%) = [ (Y-X)/Y ] ×100
X: a rubber cylinder having a diameter of 12mm was used in an environment of 20℃and was pressed under a pressure of 50N for 2 minutes, followed by leaving the resultant sheet to stand for 30 minutes to give an optically transparent adhesive sheet having a thickness (. Mu.m)
Y: thickness (μm) of optically clear adhesive sheet before pressing
The results are shown in Table 1 and FIG. 5. FIG. 5 is a graph showing the relationship between tan delta at 20℃and the thickness change rate of the optically clear adhesive sheets of examples 1 to 7 and comparative examples 1 to 3. Further, with comparative example 4, a sample suitable for thickness measurement could not be obtained.
TABLE 1
As shown in table 1, the OCA sheets of examples 1 to 7 were all inhibited from rolling marks by having tan δ of 0.1 to 0.4 inclusive at 20 ℃. Further, the OCA sheets of examples 1 to 7 all had a thickness change rate of 0.75% or less, and the roll marks were suppressed. In particular, it was found that when tan δ at 20 ℃ is 0.27 or less, the roll pressure mark is less likely to remain. Although not shown in table 1, all examples were of a total light transmittance of 90% or more and a haze of 1.0% or less.
On the other hand, regarding the OCA sheets of comparative examples 1 to 4, tan δ at 20 ℃ exceeded 0.4, the thickness change rate exceeded 0.75%, and the roll crimp mark remained.
As shown in fig. 5, it is clear that there is a relationship between tan δ at 20 ℃ and the thickness change rate that increases when one value increases, the other value also increases. It is known that when bonding a pair of substrates, it is preferable that the tan δ at 20 ℃ is 0.1 or more and 0.4 or less, or the thickness change rate is 0.75% or less, in terms of the difficulty in air remaining between the substrate and the OCA sheet to be bonded later.
Claims (7)
1. An optically clear adhesive sheet comprising a polyurethane layer comprising a cured product of a thermosetting polyurethane composition, characterized in that,
The thermosetting polyurethane composition contains a polyol component and a polyisocyanate component,
The polyol component comprises a hydrogenated polybutadiene-based polyol,
The loss tangent at 20 ℃ is 0.1-0.4.
2. The optically transparent adhesive sheet according to claim 1, wherein the optically transparent adhesive sheet has a thickness change rate of 0.75% or less represented by the following formula,
Thickness change rate = [ (Y-X)/Y ] ×100
X: a rubber cylinder having a diameter of 12mm was used in an environment of 20℃and was pressed under a pressure of 50N for 2 minutes, followed by leaving the resultant sheet to stand for 30 minutes to give an optically transparent adhesive sheet having a thickness of μm
Y: the optically transparent adhesive sheet before pressurization had a thickness of μm.
3. An optically clear adhesive sheet comprising a polyurethane layer comprising a cured product of a thermosetting polyurethane composition, characterized in that,
The thermosetting polyurethane composition contains a polyol component and a polyisocyanate component,
The polyol component comprises a hydrogenated polybutadiene-based polyol,
The optically transparent adhesive sheet has a thickness change rate of 0.75% or less,
Thickness change rate = [ (Y-X)/Y ] ×100
X: a rubber cylinder having a diameter of 12mm was used in an environment of 20℃and was pressed under a pressure of 50N for 2 minutes, followed by leaving the resultant sheet to stand for 30 minutes to give an optically transparent adhesive sheet having a thickness of μm
Y: the optically transparent adhesive sheet before pressurization had a thickness of μm.
4. The optically transparent adhesive sheet according to claim 3, wherein the optically transparent adhesive sheet has a loss tangent at 20 ℃ of 0.1 or more and 0.4 or less.
5. The optically transparent adhesive sheet according to claim 1 or 3, wherein the polyurethane layer has an alpha ratio represented by the following formula of 1.0 or more and 1.2 or less,
Α ratio = moles of hydroxyl groups derived from the polyol component/moles of isocyanate groups derived from the polyisocyanate component.
6. An optically transparent adhesive sheet according to claim 1 or 3, wherein the thickness of the polyurethane layer is 200 μm or more and 1500 μm or less.
7. An optically clear adhesive sheet according to claim 1 or 3, comprising: the polyurethane layer; a first surface adhesive layer disposed on one of the surfaces of the polyurethane layer; and a second surface adhesive layer disposed on the other surface of the polyurethane layer.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2023-001193 | 2023-01-06 | ||
| JP2023001193A JP2024097613A (en) | 2023-01-06 | 2023-01-06 | Optically clear adhesive sheet |
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| Publication Number | Publication Date |
|---|---|
| CN118308032A true CN118308032A (en) | 2024-07-09 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202410011076.8A Pending CN118308032A (en) | 2023-01-06 | 2024-01-04 | Optically transparent adhesive sheet |
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| Country | Link |
|---|---|
| JP (1) | JP2024097613A (en) |
| CN (1) | CN118308032A (en) |
| TW (1) | TW202432759A (en) |
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| JP2024097613A (en) | 2024-07-19 |
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