JP2004103690A - Polyester film for capacitors - Google Patents
Polyester film for capacitors Download PDFInfo
- Publication number
- JP2004103690A JP2004103690A JP2002261067A JP2002261067A JP2004103690A JP 2004103690 A JP2004103690 A JP 2004103690A JP 2002261067 A JP2002261067 A JP 2002261067A JP 2002261067 A JP2002261067 A JP 2002261067A JP 2004103690 A JP2004103690 A JP 2004103690A
- Authority
- JP
- Japan
- Prior art keywords
- film
- less
- capacitor
- heat
- polyester
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000003990 capacitor Substances 0.000 title claims abstract description 66
- 229920006267 polyester film Polymers 0.000 title claims abstract description 40
- 238000000034 method Methods 0.000 claims description 16
- 230000008859 change Effects 0.000 claims description 6
- 238000009413 insulation Methods 0.000 abstract description 10
- 238000010586 diagram Methods 0.000 abstract 1
- 239000010408 film Substances 0.000 description 172
- 239000002245 particle Substances 0.000 description 44
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 29
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 20
- 229920000728 polyester Polymers 0.000 description 19
- 239000010419 fine particle Substances 0.000 description 17
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 16
- -1 polyethylene terephthalate Polymers 0.000 description 15
- 229920001577 copolymer Polymers 0.000 description 11
- 229920000642 polymer Polymers 0.000 description 11
- 238000010438 heat treatment Methods 0.000 description 10
- 238000004519 manufacturing process Methods 0.000 description 10
- 229910000019 calcium carbonate Inorganic materials 0.000 description 9
- 230000015556 catabolic process Effects 0.000 description 9
- MTHSVFCYNBDYFN-UHFFFAOYSA-N diethylene glycol Chemical compound OCCOCCO MTHSVFCYNBDYFN-UHFFFAOYSA-N 0.000 description 9
- 238000011156 evaluation Methods 0.000 description 8
- 230000000704 physical effect Effects 0.000 description 8
- 238000006116 polymerization reaction Methods 0.000 description 8
- 238000005809 transesterification reaction Methods 0.000 description 8
- 150000001875 compounds Chemical class 0.000 description 7
- 238000009998 heat setting Methods 0.000 description 7
- 239000000314 lubricant Substances 0.000 description 7
- 239000000377 silicon dioxide Substances 0.000 description 7
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 description 6
- YKTSYUJCYHOUJP-UHFFFAOYSA-N [O--].[Al+3].[Al+3].[O-][Si]([O-])([O-])[O-] Chemical compound [O--].[Al+3].[Al+3].[O-][Si]([O-])([O-])[O-] YKTSYUJCYHOUJP-UHFFFAOYSA-N 0.000 description 6
- 239000000203 mixture Substances 0.000 description 6
- 238000012545 processing Methods 0.000 description 6
- 239000005995 Aluminium silicate Substances 0.000 description 5
- KKEYFWRCBNTPAC-UHFFFAOYSA-N Terephthalic acid Chemical compound OC(=O)C1=CC=C(C(O)=O)C=C1 KKEYFWRCBNTPAC-UHFFFAOYSA-N 0.000 description 5
- 239000000654 additive Substances 0.000 description 5
- 235000012211 aluminium silicate Nutrition 0.000 description 5
- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 description 5
- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 description 5
- 238000005259 measurement Methods 0.000 description 5
- 229920000139 polyethylene terephthalate Polymers 0.000 description 5
- 239000005020 polyethylene terephthalate Substances 0.000 description 5
- 230000037303 wrinkles Effects 0.000 description 5
- OFOBLEOULBTSOW-UHFFFAOYSA-N Malonic acid Chemical compound OC(=O)CC(O)=O OFOBLEOULBTSOW-UHFFFAOYSA-N 0.000 description 4
- 239000002253 acid Substances 0.000 description 4
- ADCOVFLJGNWWNZ-UHFFFAOYSA-N antimony trioxide Chemical compound O=[Sb]O[Sb]=O ADCOVFLJGNWWNZ-UHFFFAOYSA-N 0.000 description 4
- 239000003054 catalyst Substances 0.000 description 4
- 238000001816 cooling Methods 0.000 description 4
- 239000013078 crystal Substances 0.000 description 4
- 229920001519 homopolymer Polymers 0.000 description 4
- QQVIHTHCMHWDBS-UHFFFAOYSA-N isophthalic acid Chemical compound OC(=O)C1=CC=CC(C(O)=O)=C1 QQVIHTHCMHWDBS-UHFFFAOYSA-N 0.000 description 4
- 230000008569 process Effects 0.000 description 4
- YPFDHNVEDLHUCE-UHFFFAOYSA-N propane-1,3-diol Chemical compound OCCCO YPFDHNVEDLHUCE-UHFFFAOYSA-N 0.000 description 4
- 238000007665 sagging Methods 0.000 description 4
- WPYMKLBDIGXBTP-UHFFFAOYSA-N Benzoic acid Natural products OC(=O)C1=CC=CC=C1 WPYMKLBDIGXBTP-UHFFFAOYSA-N 0.000 description 3
- IAYPIBMASNFSPL-UHFFFAOYSA-N Ethylene oxide Chemical compound C1CO1 IAYPIBMASNFSPL-UHFFFAOYSA-N 0.000 description 3
- 235000019738 Limestone Nutrition 0.000 description 3
- DNIAPMSPPWPWGF-UHFFFAOYSA-N Propylene glycol Chemical compound CC(O)CO DNIAPMSPPWPWGF-UHFFFAOYSA-N 0.000 description 3
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 3
- 239000004927 clay Substances 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 238000007796 conventional method Methods 0.000 description 3
- 239000006028 limestone Substances 0.000 description 3
- 238000002844 melting Methods 0.000 description 3
- 230000008018 melting Effects 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 229920000620 organic polymer Polymers 0.000 description 3
- 229920001187 thermosetting polymer Polymers 0.000 description 3
- 238000004804 winding Methods 0.000 description 3
- MYRTYDVEIRVNKP-UHFFFAOYSA-N 1,2-Divinylbenzene Chemical compound C=CC1=CC=CC=C1C=C MYRTYDVEIRVNKP-UHFFFAOYSA-N 0.000 description 2
- RNFJDJUURJAICM-UHFFFAOYSA-N 2,2,4,4,6,6-hexaphenoxy-1,3,5-triaza-2$l^{5},4$l^{5},6$l^{5}-triphosphacyclohexa-1,3,5-triene Chemical compound N=1P(OC=2C=CC=CC=2)(OC=2C=CC=CC=2)=NP(OC=2C=CC=CC=2)(OC=2C=CC=CC=2)=NP=1(OC=1C=CC=CC=1)OC1=CC=CC=C1 RNFJDJUURJAICM-UHFFFAOYSA-N 0.000 description 2
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 description 2
- NIXOWILDQLNWCW-UHFFFAOYSA-N 2-Propenoic acid Natural products OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 2
- NEQFBGHQPUXOFH-UHFFFAOYSA-N 4-(4-carboxyphenyl)benzoic acid Chemical compound C1=CC(C(=O)O)=CC=C1C1=CC=C(C(O)=O)C=C1 NEQFBGHQPUXOFH-UHFFFAOYSA-N 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 239000005711 Benzoic acid Substances 0.000 description 2
- 229910021532 Calcite Inorganic materials 0.000 description 2
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 2
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 2
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 2
- CERQOIWHTDAKMF-UHFFFAOYSA-N Methacrylic acid Chemical compound CC(=C)C(O)=O CERQOIWHTDAKMF-UHFFFAOYSA-N 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
- 239000004698 Polyethylene Substances 0.000 description 2
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 2
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 2
- 230000000996 additive effect Effects 0.000 description 2
- WNLRTRBMVRJNCN-UHFFFAOYSA-N adipic acid Chemical compound OC(=O)CCCCC(O)=O WNLRTRBMVRJNCN-UHFFFAOYSA-N 0.000 description 2
- LJCFOYOSGPHIOO-UHFFFAOYSA-N antimony pentoxide Chemical compound O=[Sb](=O)O[Sb](=O)=O LJCFOYOSGPHIOO-UHFFFAOYSA-N 0.000 description 2
- TZCXTZWJZNENPQ-UHFFFAOYSA-L barium sulfate Chemical compound [Ba+2].[O-]S([O-])(=O)=O TZCXTZWJZNENPQ-UHFFFAOYSA-L 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 235000010233 benzoic acid Nutrition 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- IISBACLAFKSPIT-UHFFFAOYSA-N bisphenol A Chemical compound C=1C=C(O)C=CC=1C(C)(C)C1=CC=C(O)C=C1 IISBACLAFKSPIT-UHFFFAOYSA-N 0.000 description 2
- WERYXYBDKMZEQL-UHFFFAOYSA-N butane-1,4-diol Chemical compound OCCCCO WERYXYBDKMZEQL-UHFFFAOYSA-N 0.000 description 2
- 239000011575 calcium Substances 0.000 description 2
- 229910052791 calcium Inorganic materials 0.000 description 2
- ZCCIPPOKBCJFDN-UHFFFAOYSA-N calcium nitrate Chemical compound [Ca+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O ZCCIPPOKBCJFDN-UHFFFAOYSA-N 0.000 description 2
- OSGAYBCDTDRGGQ-UHFFFAOYSA-L calcium sulfate Chemical compound [Ca+2].[O-]S([O-])(=O)=O OSGAYBCDTDRGGQ-UHFFFAOYSA-L 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 2
- 229920006037 cross link polymer Polymers 0.000 description 2
- NNBZCPXTIHJBJL-UHFFFAOYSA-N decalin Chemical compound C1CCCC2CCCCC21 NNBZCPXTIHJBJL-UHFFFAOYSA-N 0.000 description 2
- USIUVYZYUHIAEV-UHFFFAOYSA-N diphenyl ether Chemical compound C=1C=CC=CC=1OC1=CC=CC=C1 USIUVYZYUHIAEV-UHFFFAOYSA-N 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000001125 extrusion Methods 0.000 description 2
- 239000003063 flame retardant Substances 0.000 description 2
- YBMRDBCBODYGJE-UHFFFAOYSA-N germanium dioxide Chemical compound O=[Ge]=O YBMRDBCBODYGJE-UHFFFAOYSA-N 0.000 description 2
- XXMIOPMDWAUFGU-UHFFFAOYSA-N hexane-1,6-diol Chemical compound OCCCCCCO XXMIOPMDWAUFGU-UHFFFAOYSA-N 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 239000010954 inorganic particle Substances 0.000 description 2
- PQXKHYXIUOZZFA-UHFFFAOYSA-M lithium fluoride Chemical compound [Li+].[F-] PQXKHYXIUOZZFA-UHFFFAOYSA-M 0.000 description 2
- 239000011777 magnesium Substances 0.000 description 2
- 229910052749 magnesium Inorganic materials 0.000 description 2
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 2
- WPUMVKJOWWJPRK-UHFFFAOYSA-N naphthalene-2,7-dicarboxylic acid Chemical compound C1=CC(C(O)=O)=CC2=CC(C(=O)O)=CC=C21 WPUMVKJOWWJPRK-UHFFFAOYSA-N 0.000 description 2
- SLCVBVWXLSEKPL-UHFFFAOYSA-N neopentyl glycol Chemical compound OCC(C)(C)CO SLCVBVWXLSEKPL-UHFFFAOYSA-N 0.000 description 2
- 239000004745 nonwoven fabric Substances 0.000 description 2
- 235000006408 oxalic acid Nutrition 0.000 description 2
- 239000011574 phosphorus Substances 0.000 description 2
- 229910052698 phosphorus Inorganic materials 0.000 description 2
- XNGIFLGASWRNHJ-UHFFFAOYSA-N phthalic acid Chemical compound OC(=O)C1=CC=CC=C1C(O)=O XNGIFLGASWRNHJ-UHFFFAOYSA-N 0.000 description 2
- 229920000573 polyethylene Polymers 0.000 description 2
- 229920002215 polytrimethylene terephthalate Polymers 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- CXMXRPHRNRROMY-UHFFFAOYSA-N sebacic acid Chemical compound OC(=O)CCCCCCCCC(O)=O CXMXRPHRNRROMY-UHFFFAOYSA-N 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 239000010409 thin film Substances 0.000 description 2
- 239000010936 titanium Substances 0.000 description 2
- 229910052719 titanium Inorganic materials 0.000 description 2
- WVLBCYQITXONBZ-UHFFFAOYSA-N trimethyl phosphate Chemical compound COP(=O)(OC)OC WVLBCYQITXONBZ-UHFFFAOYSA-N 0.000 description 2
- 239000011701 zinc Substances 0.000 description 2
- 229910052725 zinc Inorganic materials 0.000 description 2
- PXGZQGDTEZPERC-UHFFFAOYSA-N 1,4-cyclohexanedicarboxylic acid Chemical compound OC(=O)C1CCC(C(O)=O)CC1 PXGZQGDTEZPERC-UHFFFAOYSA-N 0.000 description 1
- 238000005160 1H NMR spectroscopy Methods 0.000 description 1
- ISPYQTSUDJAMAB-UHFFFAOYSA-N 2-chlorophenol Chemical compound OC1=CC=CC=C1Cl ISPYQTSUDJAMAB-UHFFFAOYSA-N 0.000 description 1
- XFEGRFIENDJTCK-UHFFFAOYSA-N 2-phenyl-2,3-dihydroindene-1,1-dicarboxylic acid Chemical compound C1C2=CC=CC=C2C(C(=O)O)(C(O)=O)C1C1=CC=CC=C1 XFEGRFIENDJTCK-UHFFFAOYSA-N 0.000 description 1
- WMRCTEPOPAZMMN-UHFFFAOYSA-N 2-undecylpropanedioic acid Chemical compound CCCCCCCCCCCC(C(O)=O)C(O)=O WMRCTEPOPAZMMN-UHFFFAOYSA-N 0.000 description 1
- WTKQQTGCQAFYOL-UHFFFAOYSA-N 3,4-dihydro-2h-naphthalene-1,1-dicarboxylic acid Chemical compound C1=CC=C2C(C(=O)O)(C(O)=O)CCCC2=C1 WTKQQTGCQAFYOL-UHFFFAOYSA-N 0.000 description 1
- GZVHEAJQGPRDLQ-UHFFFAOYSA-N 6-phenyl-1,3,5-triazine-2,4-diamine Chemical compound NC1=NC(N)=NC(C=2C=CC=CC=2)=N1 GZVHEAJQGPRDLQ-UHFFFAOYSA-N 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 1
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 1
- 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 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- 229920003171 Poly (ethylene oxide) Polymers 0.000 description 1
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 1
- 235000011941 Tilia x europaea Nutrition 0.000 description 1
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 1
- 229920001807 Urea-formaldehyde Polymers 0.000 description 1
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 1
- 230000005856 abnormality Effects 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 239000001361 adipic acid Substances 0.000 description 1
- 235000011037 adipic acid Nutrition 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- 125000005907 alkyl ester group Chemical group 0.000 description 1
- 229910000323 aluminium silicate Inorganic materials 0.000 description 1
- 150000001463 antimony compounds Chemical class 0.000 description 1
- 239000003963 antioxidant agent Substances 0.000 description 1
- 230000003078 antioxidant effect Effects 0.000 description 1
- 239000002216 antistatic agent Substances 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 229910052788 barium Inorganic materials 0.000 description 1
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 description 1
- AYJRCSIUFZENHW-DEQYMQKBSA-L barium(2+);oxomethanediolate Chemical compound [Ba+2].[O-][14C]([O-])=O AYJRCSIUFZENHW-DEQYMQKBSA-L 0.000 description 1
- 230000000740 bleeding effect Effects 0.000 description 1
- QXDMQSPYEZFLGF-UHFFFAOYSA-L calcium oxalate Chemical compound [Ca+2].[O-]C(=O)C([O-])=O QXDMQSPYEZFLGF-UHFFFAOYSA-L 0.000 description 1
- 239000001506 calcium phosphate Substances 0.000 description 1
- 229910000389 calcium phosphate Inorganic materials 0.000 description 1
- 235000011010 calcium phosphates Nutrition 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000011362 coarse particle Substances 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 238000007334 copolymerization reaction Methods 0.000 description 1
- MHKBNMVNEQRFFF-UHFFFAOYSA-N cyclohexane;methanediol Chemical compound OCO.C1CCCCC1 MHKBNMVNEQRFFF-UHFFFAOYSA-N 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 150000001991 dicarboxylic acids Chemical class 0.000 description 1
- GYUVMLBYMPKZAZ-UHFFFAOYSA-N dimethyl naphthalene-2,6-dicarboxylate Chemical compound C1=C(C(=O)OC)C=CC2=CC(C(=O)OC)=CC=C21 GYUVMLBYMPKZAZ-UHFFFAOYSA-N 0.000 description 1
- HNPSIPDUKPIQMN-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Al]O[Al]=O HNPSIPDUKPIQMN-UHFFFAOYSA-N 0.000 description 1
- GKMXREIWPASRMP-UHFFFAOYSA-J dipotassium;oxalate;oxygen(2-);titanium(4+) Chemical compound [O-2].[K+].[K+].[Ti+4].[O-]C(=O)C([O-])=O.[O-]C(=O)C([O-])=O GKMXREIWPASRMP-UHFFFAOYSA-J 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000003822 epoxy resin Substances 0.000 description 1
- XGZNHFPFJRZBBT-UHFFFAOYSA-N ethanol;titanium Chemical compound [Ti].CCO.CCO.CCO.CCO XGZNHFPFJRZBBT-UHFFFAOYSA-N 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 125000000524 functional group Chemical group 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 150000002291 germanium compounds Chemical class 0.000 description 1
- 229940119177 germanium dioxide Drugs 0.000 description 1
- 230000009477 glass transition Effects 0.000 description 1
- 235000011187 glycerol Nutrition 0.000 description 1
- 239000012760 heat stabilizer Substances 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 239000004571 lime Substances 0.000 description 1
- 229910001386 lithium phosphate Inorganic materials 0.000 description 1
- ZLNQQNXFFQJAID-UHFFFAOYSA-L magnesium carbonate Chemical compound [Mg+2].[O-]C([O-])=O ZLNQQNXFFQJAID-UHFFFAOYSA-L 0.000 description 1
- 239000001095 magnesium carbonate Substances 0.000 description 1
- 229910000021 magnesium carbonate Inorganic materials 0.000 description 1
- GVALZJMUIHGIMD-UHFFFAOYSA-H magnesium phosphate Chemical compound [Mg+2].[Mg+2].[Mg+2].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O GVALZJMUIHGIMD-UHFFFAOYSA-H 0.000 description 1
- 239000004137 magnesium phosphate Substances 0.000 description 1
- 229910000157 magnesium phosphate Inorganic materials 0.000 description 1
- 229960002261 magnesium phosphate Drugs 0.000 description 1
- 235000010994 magnesium phosphates Nutrition 0.000 description 1
- 229940082328 manganese acetate tetrahydrate Drugs 0.000 description 1
- CESXSDZNZGSWSP-UHFFFAOYSA-L manganese(2+);diacetate;tetrahydrate Chemical compound O.O.O.O.[Mn+2].CC([O-])=O.CC([O-])=O CESXSDZNZGSWSP-UHFFFAOYSA-L 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000001465 metallisation Methods 0.000 description 1
- 239000008267 milk Substances 0.000 description 1
- 210000004080 milk Anatomy 0.000 description 1
- 235000013336 milk Nutrition 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 239000000178 monomer Substances 0.000 description 1
- DFFZOPXDTCDZDP-UHFFFAOYSA-N naphthalene-1,5-dicarboxylic acid Chemical compound C1=CC=C2C(C(=O)O)=CC=CC2=C1C(O)=O DFFZOPXDTCDZDP-UHFFFAOYSA-N 0.000 description 1
- RXOHFPCZGPKIRD-UHFFFAOYSA-N naphthalene-2,6-dicarboxylic acid Chemical compound C1=C(C(O)=O)C=CC2=CC(C(=O)O)=CC=C21 RXOHFPCZGPKIRD-UHFFFAOYSA-N 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000002667 nucleating agent Substances 0.000 description 1
- 239000011146 organic particle Substances 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- RVTZCBVAJQQJTK-UHFFFAOYSA-N oxygen(2-);zirconium(4+) Chemical compound [O-2].[O-2].[Zr+4] RVTZCBVAJQQJTK-UHFFFAOYSA-N 0.000 description 1
- WXZMFSXDPGVJKK-UHFFFAOYSA-N pentaerythritol Chemical compound OCC(CO)(CO)CO WXZMFSXDPGVJKK-UHFFFAOYSA-N 0.000 description 1
- 239000005011 phenolic resin Substances 0.000 description 1
- 235000011007 phosphoric acid Nutrition 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 239000002685 polymerization catalyst Substances 0.000 description 1
- 230000000379 polymerizing effect Effects 0.000 description 1
- 229920001296 polysiloxane Polymers 0.000 description 1
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- 229910052700 potassium Inorganic materials 0.000 description 1
- 229940088417 precipitated calcium carbonate Drugs 0.000 description 1
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- 239000007790 solid phase Substances 0.000 description 1
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- 229910052712 strontium Inorganic materials 0.000 description 1
- CIOAGBVUUVVLOB-UHFFFAOYSA-N strontium atom Chemical compound [Sr] CIOAGBVUUVVLOB-UHFFFAOYSA-N 0.000 description 1
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- STCOOQWBFONSKY-UHFFFAOYSA-N tributyl phosphate Chemical compound CCCCOP(=O)(OCCCC)OCCCC STCOOQWBFONSKY-UHFFFAOYSA-N 0.000 description 1
- QORWJWZARLRLPR-UHFFFAOYSA-H tricalcium bis(phosphate) Chemical compound [Ca+2].[Ca+2].[Ca+2].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O QORWJWZARLRLPR-UHFFFAOYSA-H 0.000 description 1
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Landscapes
- Manufacture Of Macromolecular Shaped Articles (AREA)
- Shaping By String And By Release Of Stress In Plastics And The Like (AREA)
- Fixed Capacitors And Capacitor Manufacturing Machines (AREA)
- Organic Insulating Materials (AREA)
Abstract
【課題】絶縁性、加工性に優れ、８０〜１２０℃の環境で使用しても高い信頼性をもって使用できるコンデンサ用を提供する。
【解決手段】ポリエチレン−２，６−ナフタレンジカルボキシレートを主成分とする二軸配向フィルムであって、フィルムの長手方向を０°方向とし、フィルム平面上で方向を１５°刻みに変えて定まる１５°方向、３０°方向、４５°方向、６０°方向、７５°方向、９０°方向、１０５°方向、１２０°方向、１３５°方向、１５０°方向および１６５°方向の各方向においてフィルムの屈折率が１．７４０以上であることを特徴とするコンデンサ用ポリエステルフィルム。
【選択図】 なしAn object of the present invention is to provide a capacitor which is excellent in insulation and workability and can be used with high reliability even when used in an environment of 80 to 120 ° C.
A biaxially oriented film containing polyethylene-2,6-naphthalenedicarboxylate as a main component is determined by setting the longitudinal direction of the film to 0 ° and changing the direction in 15 ° steps on the film plane. 15 °, 30 °, 45 °, 60 °, 75 °, 90 °, 105 °, 120 °, 135 °, 150 ° and 165 ° refraction of the film A polyester film having a ratio of 1.740 or more.
[Selection diagram] None
Description
【０００１】
【発明の属する技術分野】
本発明は、コンデンサ用ポリエステルフィルムに関する。更に詳細には、ポリエチレン−２，６−ナフタレンジカルボキシレートを主成分とし、絶縁性、加工性に優れ、８０〜１２０℃の環境で使用しても高い信頼性をもって使用できるコンデンサ用ポリエステルフィルムに関するものである。
【０００２】
【従来の技術】
コンデンサに対しては、最近の電気・電子機器の小型化に伴い、小型化かつ大容量化が要求されている他、使用電圧帯の高電圧化に伴う絶縁特性向上が要求されている。このような要求に対して、フィルムコンデンサでは誘電体としてのフィルムの薄膜化（誘電体（フィルム）の単位体積当りの静電容量はフィルム厚みの２乗に反比例し、かつ誘電体の誘電率に比例する）やフィルムに存在するピンホールの低減等が検討されている。
【０００３】
このようにフィルムコンデンサでは誘電体であるフィルムの薄膜化の必要性があるものの、フィルムの薄膜化に伴うコンデンサの加工工程での作業性（フィルムヘの電極としての金属蒸着、スリット、素子巻等）の悪化を回避するために、ポリエチレン−２，６−ナフタレンジカルボキシレートフィルム中に滑剤として特定の不活性微粒子を添加することが提案されている（例えば、特許文献１参照）。
【０００４】
しかしながら、フィルムの薄膜化とコンデンサの加工工程での優れた作業性の両立が実現できたものの、フィルム中に含まれる添加物（滑剤、触媒、不純物）等に起因した絶縁特性不良やコンデンサの完成に至るまでにフィルムが受ける様々な熱的ストレスや機械的ストレスを原因とする絶縁特性不良により、本来ポリエステルフィルムが有する優れた絶縁特性が低下するためコンデンサ用フィルムとしては、なお不十分である。また、最近ではコンデンサの生産性を向上させるためにコンデンサ素子巻回後の熱プレスの温度や圧力を高くする傾向があり、ますます誘電体としてのフィルムに要求される性能は厳しくなっている。たとえ誘電体のフィルムが薄膜化されたとしても、コンデンサに求められる耐圧特性は従来品同等以上であるため、実質的にはフィルムの単位厚みあたりの絶縁特性の向上が強く求められることになり、誘電体フィルムの絶縁特性の向上が急務となっている。
【０００５】
【特許文献１】
特開平１０−２９４２３７号公報
【０００６】
【発明が解決しようとする課題】
本発明の目的は上述の従来技術の問題点を解決し、絶縁特性、加工性に優れた８０〜１２０℃の環境で使用しても高い信頼性をもって使用できるフィルムコンデンサの誘電体に好適なフィルムを提供することを課題とする。
【０００７】
【課題を解決するための手段】
本発明者は鋭意研究の結果、コンデンサの誘電体を構成するポリエステルをポリエチレン−２，６−ナフタレンジカルボキシレートを主たる成分とし、フィルム面内の特定の方向における屈折率を特定な範囲とすることにより本発明の目的を達成できることを見出し、本発明に到達した。
【０００８】
即ち、本発明の課題は、ポリエチレン−２，６−ナフタレンジカルボキシレートを主成分とする二軸配向フィルムであって、フィルムの長手方向を０°方向とし、フィルム平面上で方向を１５°刻みに変えて定まる１５°方向、３０°方向、４５°方向、６０°方向、７５°方向、９０°方向、１０５°方向、１２０°方向、１３５°方向、１５０°方向および１６５°方向の各方向においてフィルムの屈折率が１．７４０以上であることを特徴とするコンデンサ用ポリエステルフィルムにより達成される。
【０００９】
【発明の実施の形態】
以下、本発明を詳細に説明する。
【００１０】
［ポリエチレン−２，６−ナフタレンジカルボキシレート］
本発明のコンデンサ用ポリエステルフィルムは、全繰返し単位の８０モル％以上がエチレン−２，６−ナフタレンジカルボキシレートのポリエステルを主たる構成成分とするものである。
【００１１】
従来、コンデンサ用ポリエステルフィルムにはポリエチレンテレフタレートフィルムが使用され、今後も使われるものと予想される。ポリエチレンテレフタレートフィルムは、８０℃以上の温度域で誘電正接が増加し誘電損失により自己発熱して熱暴走になる可能性があるので、コンデンサとしての使用温度の上限は８０℃程度に抑えられている。ポリエチレン−２，６−ナフタレンジカルボキシレートでは誘電正接の増加は１２０℃近辺からであるので、使用温度の上限は約１２０℃と考えられる。従って、高温下ではポリエチレン−２，６−ナフタレンジカルボキシレートフィルムのコンデンサが使われる。また、ポリエチレン−２，６−ナフタレンジカルボキシレートの誘電率は２．９であり、ポリエチレンテレフタレートの３．１に対してやや小さく、一見小型化に不利のようであるが、厚みを薄くする潜在力は高く、この点でもポリエチレン−２，６−ナフタレンジカルボキシレートが有利である。本発明はこのような用途のコンデンサを主対象にするものであり、フィルム巻回型コンデンサおよびフィルム積層型コンデンサに好適に用いられ、また、表面実装型のフィルムコンデンサに好適に使用される。
【００１２】
本発明におけるポリエチレン−２，６−ナフタレンジカルボキシレートは、全繰返し単位の８０モル％以上がエチレン−２，６−ナフタレンジカルボキシレートのポリエステルであるが、全繰返し単位の９０モル％以上、更に９５モル％以上がエチレン−２，６−ナフタレンジカルボキシレート単位であることが好ましく、特にポリエチレン−２，６−ナフタレンジカルボキシレートの実質的な単独重合体であることが好ましい。
【００１３】
本発明におけるポリエチレン−２，６−ナフタレンジカルボキシレートは、共重合成分が２０モル％以内のポリエチレン−２，６−ナフタレンジカルボキシレート共重合体であってもよい。ポリエチレン−２，６−ナフタレンジカルボキシレートが共重合体の場合、共重合成分として、２，７−ナフタレンジカルボン酸、１，５−ナフタレンジカルボン酸を好ましい例として挙げることができる。
【００１４】
この他、ポリエチレン−２，６−ナフタレンジカルボキシレート共重合体の共重合体成分としては、分子内に２つのエステル形成性官能基を有する化合物を用いることができる。このような化合物として例えば、蓚酸、アジピン酸、フタル酸、セバシン酸、ドデカンジカルボン酸、イソフタル酸、テレフタル酸、１，４−シクロヘキサンジカルボン酸、４，４’−ジフェニルジカルボン酸、フェニルインダンジカルボン酸、テトラリンジカルボン酸、デカリンジカルボン酸、ジフェニルエーテルジカルボン酸等の如きジカルボン酸；ｐ−オキシ安息香酸、ｐ−オキシエトキシ安息香酸等の如きオキシカルボン酸；或いはジエチレングリコール、プロピレングリコール、トリメチレングリコール、テトラメチレングリコール、ヘキサメチレングリコール、シクロヘキサンメチレングリコール、ネオペンチルグリコール、ビスフェノールスルホンのエチレンオキサイド付加物、ビスフェノールＡのエチレンオキサイド付加物、ジエチレングリコール、ポリエチレンオキシドグリコール等の如き２価アルコール類等を用いることができる。これらの化合物は１種のみでなく２種以上を同時に用いることができる。また、これらの共重合成分の中で、酸成分としてはイソフタル酸、テレフタル酸、４，４’−ジフェニルジカルボン酸、２，７−ナフタレンジカルボン酸、ｐ―オキシ安息香酸を、グリコール成分としてはジエチレングリコール、トリメチレングリコール、ヘキサメチレングリコール、ネオペンチルグリコール、ビスフェノールスルホンのエチレンオキサイド付加物を好ましい例として挙げることができる。
【００１５】
また、ポリエチレン−２，６−ナフタレンジカルボキシレートは例えば安息香酸、メトキシポリアルキレングリコールなどの一官能性化合物によって末端の水酸基および／またはカルボキシル基の一部または全部を封鎖したものであってもよく、或いは例えば極少量のグリセリン、ペンタエリスリトール等の如き三官能以上のエステル形成性化合物で実質的に線状のポリマーが得られる範囲内で共重合したものであってもよい。
【００１６】
本発明のポリエステルフィルムにおけるポリマーの構成成分は、ポリエチレン−２，６−ナフタレンジカルボキシレートの単独重合体及び／又は共重合体を主成分とするが、他のポリエステルやポリエステル以外の有機高分子との混合体であってもよい。混合体の場合、ポリマーの成分中のエチレン−２，６−ナフタレンジカルボキシレート単位が全繰り返し単位の８０モル％以上であることが必要であるが、９０モル％以上、特に９５モル％以上であることが、ポリエチレン−２，６−ナフタレンジカルボキシレートフィルム本来の特性を極端に失うことがなく、絶縁特性、機械特性および熱寸法安定性を確保できるので好ましい。
【００１７】
ポリエチレン−２，６−ナフタレンジカルボキシレートに混合できるポリエステル或いはポリエステル以外の有機高分子としては、ポリエチレンテレフタレート、ポリエチレンイソフタレート、ポリトリメチレンテレフタレート、ポリエチレン４，４’−テトラメチレンジフェニルジカルボキシレート、ポリエチレン−２，７−ナフタレンジカルボキシレート、ポリトリメチレン−２，６−ナフタレンジカルボキシレート、ポリネオペンチレン−２，６−ナフタレンジカルボキシレート、ポリ（ビス（４−エチレンオキシフェニル）スルホン）−２，６−ナフタレンジカルボキシレート等のポリエステルを挙げることができ、これらの中でポリエチレンイソフタレート、ポリトリメチレンテレフタレート、ポリトリメチレン−２，６−ナフタレンジカルボキシレート、ポリ（ビス（４−エチレンオキシフェニル）スルホン）−２，６−ナフタレンジカルボキシレートが好ましい。
【００１８】
これらのポリエステルまたはポリエステル以外の有機高分子は、１種のみならず２種以上を、ポリエステルフィルムを構成するポリマー成分において、高分子の繰返し単位で１０モル％相当、好ましくは５モル％相当まで、ポリエチレン−２，６−ナフタレンジカルボキシレートと混合した混合体となるように使用できる。
【００１９】
本発明に用いるポリエチレン−２，６−ナフタレンジカルボキシレート単独重合体、共重合体或いは混合体に用いるポリエステルは、一般に知られたポリエステル組成物の製造方法によって製造できる。例えば、ジカルボン酸とグリコールとの反応で直接低重合度ポリエステルを得、或いはジカルボン酸の低級アルキルエステルとグリコールとをエステル交換反応で低重合度ポリエステルを得、この低重合度ポリエステルを重合触媒の存在下で更に重合させてポリエステルを得る方法で製造することができる。
【００２０】
エステル交換反応に用いるエステル交換触媒としては、例えばナトリウム、カリウム、マグネシウム、カルシウム、亜鉛、ストロンチウム、チタン、ジルコニウム、マンガン、コバルトを含む化合物の一種または二種以上を挙げることができる。また、重合触媒としては、三酸化アンチモン、五酸化アンチモンのようなアンチモン化合物、二酸化ゲルマニウムで代表されるようなゲルマニウム化合物、テトラエチルチタネート、テトラプロピルチタネート、テトラフェニルチタネートまたはこれらの部分加水分解物、蓚酸チタニルアンモニウム、蓚酸チタニルカリウム、チタントリスアセチルアセトネートのようなチタン化合物を挙げることができる。
【００２１】
エステル交換反応を経由して重合を行う場合は、重合反応前にエステル交換触媒を失活させる目的でトリメチルホスフェート、トリエチルホスフェート、トリ−ｎ−ブチルホスフェート、正リン酸等のリン化合物を添加することができ、リン元素としてのポリエチレン−２，６−ナフタレンジカルボキシレート中の含有量は２０ｐｐｍ以上１００ｐｐｍ以下で用いることがポリエステルの熱安定性の点から好ましい。
【００２２】
なお、ポリエステルは溶融重合後これをチップ化し、加熱減圧下または窒素などの不活性気流中において固相重合することもできる。
【００２３】
本発明に用いるポリエチレン−２，６−ナフタレンジカルボキシレートの固有粘度は０．５０ｄｌ／ｇ以上０．９０ｄｌ／ｇ以下であることが好ましい。さらに好ましくは０．５２ｄｌ／ｇ以上０．８５ｄｌ／ｇ以下、特に好ましくは０．５３ｄｌ／ｇ以上０．８０ｄｌ／ｇ以下である。固有粘度が０．５０ｄｌ／ｇ未満であると溶融押出し後のフィルムが脆くなり、フィルムの製膜時の破断が発生し易くなる。また、コンデンサの加工工程の搬送でフィルムの破断が発生し易くなるため好ましくない。また、フィルムの固有粘度が０．９０ｄｌ／ｇを超えると、ポリマーの固有粘度をかなり高くする必要があり、通常の合成手法では重合に長時間を要し生産性が悪くなるため好ましくない。以上のようなことから、二軸配向フィルムの固有粘度は０．４５ｄｌ／ｇ以上０．８０ｄｌ／ｇ以下であることが好ましく、０．４７ｄｌ／ｇ以上０．７５ｇ／ｄｌ以下であることがさらに好ましく、０．５０ｄｌ／ｇ以上０．７０ｇ／ｄｌ以下であることが特に好ましい。なお、固有粘度はｏ−クロロフェノールを溶媒として用いて、３５℃で測定した値（単位：ｄｌ／ｇ）である。
【００２４】
［屈折率］
本発明のコンデンサ用ポリエステルフィルムは、フィルムの長手方向を０°方向とし、フィルム平面上で方向を１５°刻みに変えて定まる１５°方向、３０°方向、４５°方向、６０°方向、７５°方向、９０°方向、１０５°方向、１２０°方向、１３５°方向、１５０°方向および１６５°方向の各方向においてフィルムの屈折率が１．７４０以上であることが必要である。この屈折率は、より好ましくは１．７４０以上１．７７４以下、特に好ましくは１．７４２以上１．７７０以下である。上記方向におけるフィルム面内の屈折率が１．７４０未満であるとフィルムの絶縁破壊電圧が低下しコンデンサの誘電体フィルムとしての絶縁性能が不足するため好ましくない。一方、上記方向におけるフィルム面内の屈折率が増大するとフィルムの絶縁特性は良化する傾向にあるが、上記方向の一方向において屈折率が１．７７４を超えると、添加剤の種類、粒径やフィルム厚み等の影響により、フィルムの絶縁性能が低下する場合がある。
【００２５】
［密度］
本発明のコンデンサ用ポリエステルフィルムは密度が１．３４７ｇ／ｃｍ３ 以上１．３６１ｇ／ｃｍ３ 以下であることが好ましい。さらに好ましくは１．３４９ｇ／ｃｍ３ 以上１．３６０ｇ／ｃｍ３ 以下、特に好ましくは１．３５０ｇ／ｃｍ３ 以上１．３５９ｇ／ｃｍ３ 以下である。密度が１．３４７ｇ／ｃｍ３ 未満または１．３６１ｇ／ｃｍ３ を超えるとフィルムの絶縁破壊電圧が低く、コンデンサの誘電体フィルムとしての絶縁性能が不足することがあるため好ましくない。また、密度が１．３６１ｇ／ｃｍ３ を超えた場合には、結晶性が高くなり過ぎてフィルムの靭性が失われるためフィルム搬送時やスリット加工時の破断頻度が増加することがある。
【００２６】
［熱収縮率］
本発明のコンデンサ用ポリエステルフィルムを２００℃で１０分間加熱処理したときの長手方向（０°方向：以下『ＭＤ』ということがある）の熱収縮率が２．５％以上４．２％以下および巾方向（９０°方向：以下『ＴＤ』ということがある）の熱収縮率が３．０％以上４．６％以下であり、かつ巾方向の熱収縮率が長手方向の熱収縮率よりも大きいことが好ましい。
【００２７】
フィルムの長手方向（ＭＤ）または巾方向（ＴＤ）の熱収縮率が上記範囲未満であると、フィルム上に金属を蒸着するときに、蒸着面とは反対面側が接している冷却ロールとの密着が悪く熱負けが生じるため好ましくない。一方、フィルムの長手方向（ＭＤ）または巾方向（ＴＤ）の熱収縮率が上記範囲を超えると、メタリコン（素子の両端面に電極金属を溶射）時のフィルムの変形による接触不良が発生するため好ましくない。
【００２８】
さらに、長手方向（ＭＤ）の熱収縮率が巾方向（ＴＤ）の熱収縮率以上の値になった場合には、コンデンサを製造する各工程における熱履歴によってフィルムにシワが入る等の異常が発生するため好ましくない。
【００２９】
なお、２００℃で１０分間加熱処理したときの長手方向（ＭＤ）の熱収縮率が２．７％以上４．０％以下であることがさらに好ましく、特に好ましくは２．８％以上３．９％以下である。また、２００℃で１０分間加熱処理したときの巾方向（ＴＤ）の熱収縮率が３．２％以上４．５％以下であることがさらに好ましく、３．４％以上４．４％以下であることが特に好ましい。
【００３０】
［熱収縮率の変化比率］
本発明のフィルムを１５０℃で３０分間加熱処理したときの長手方向（ＭＤ）および巾方向（ＴＤ）の熱収縮率と２００℃で１０分間加熱処理したときの長手方向（ＭＤ）および巾方向（ＴＤ）の熱収縮率から下記式（１）によって算出される値（熱収縮率の変化比率）は３３以上９６以下であることが好ましく、さらに好ましくは３７以上９３以下であり、特に好ましくは４０以上９０以下である。
【００３１】
【数２】
熱収縮率の変化比率（％）＝（Ｓ２００ＭＤ−Ｓ１５０ＭＤ）／（Ｓ２００ＴＤ−Ｓ１５０ＴＤ）×１００ ……（１）
ただし、上記式（１）中Ｓ２００ＭＤ、Ｓ２００ＴＤは２００℃で１０分間加熱処理したときの長手方向および巾方向の熱収縮率、Ｓ１５０ＭＤ、Ｓ１５０ＴＤは１５０℃で３０分間加熱処理したときの長手方向および巾方向の熱収縮率を各々示す。
【００３２】
この変化比率が３３未満あるいは９６を超えると、コンデンサ製造過程での熱履歴によりフィルムの平面性が悪化（たるみ、しわ）するため好ましくない。
【００３３】
［添加物］
本発明のポリエステルフィルムには添加剤、例えば滑剤、安定剤、難燃剤等を含有させることができる。フィルムの製造時、加工時、使用時の走行性やハンドリング性を向上させる目的でフィルムに滑り性を付与するために無機粒子、有機粒子、架橋高分子粒子などの不活性微粒子を少割合含有させることが好ましい。
【００３４】
無機粒子としては例えば、炭酸カルシウム、多孔質シリカ、球状シリカ、カオリン、タルク、炭酸マグネシウム、炭酸バリウム、硫酸カルシウム、硫酸バリウム、リン酸リチウム、リン酸カルシウム、リン酸マグネシウム、酸化アルミニウム、酸化ケイ素、酸化チタン、酸化ジルコニウム、フッ化リチウム等を挙げることができる。本発明のコンデンサ用ポリエステルフィルムには上記の例示の中で炭酸カルシウム、板状珪酸アルミニウム、多孔質シリカ、球状シリカを含有することが特に好ましい。
【００３５】
有機塩粒子としては例えば蓚酸カルシウムやカルシウム、バリウム、亜鉛、マンガン、マグネシウム等のテレフタル酸塩などが挙げられる。
【００３６】
架橋高分子粒子としては例えば、ジビニルベンゼン、スチレン、アクリル酸、メタクリル酸、アクリル酸もしくはメタクリル酸のビニル系モノマの単独または共重合体等が挙げられ、この他、ポリテトラフルオロエチレン、シリコーン樹脂、ベンゾグアナミン樹脂、熱硬化エポキシ樹脂、不飽和ポリエステル樹脂、熱硬化性尿素樹脂、熱硬化性フェノール樹脂などの有機微粒子も用いられる。
【００３７】
これら滑剤の粒子径は平均粒径が０．１μｍ以上５μｍ以下である。平均粒子径としてさらに好ましくは０．１５μｍ以上４μｍ以下であり、０．２μｍ以上３．５μｍ以下が特に好ましい。０．１μｍ未満では滑り性改善効果が小さいため添加濃度を非常に高くする必要があり、フィルムの製造工程で破断が多くなるため好ましくない。また、５μｍを超えるとフィルムの製造工程で破断が多くなるばかりでなく、粒子の脱落によるピンホールが増加するので好ましくない。
【００３８】
不活性微粒子の全添加量は０．０５重量％以上３重量％以下、より好ましくは０．０８重量％以上２．５重量％以下であり、０．１量％以上２．０重量％以下が特に好ましい。０．０５重量％未満では滑り性の改善が不十分であり、３重量％を超えるとフィルムの製造工程で破断が多くなるため好ましくない。
【００３９】
フィルムに添加する不活性微粒子は上記に例示した中から選ばれた単一成分でもよく、二成分あるいは三成分以上を含む多成分でもよい。
【００４０】
本発明のポリエステルフィルムは、その用途に応じて結晶核剤、酸化防止剤、熱安定化剤、易滑剤、難燃剤、帯電防止剤、ポリシロキサン等を配合することができる。
【００４１】
不活性微粒子やその他の添加剤の添加時期はポリエチレン−２，６−ナフタレンジカルボキシレートを製膜するまでの段階であれば特に制限はなく、例えば重合段階で添加してもよく、また製膜の際に添加してもよい。均一分散の見地からは、エチレングリコール中に添加して重合時に高濃度添加し、マスターチップとし、無添加チップで希釈するのが好ましい。
【００４２】
［炭酸カルシウム粒子］
本発明のコンデンサ用ポリエステルフィルム中に特に好ましく添加される不活性微粒子である炭酸カルシウム粒子は、フィルムの滑り性、エア抜け性の点から平均粒径は０．２μｍ以上５μｍ以下であることが好ましく、０．３μｍ以上４μｍ以下であることがより好ましく、０．５μｍ以上３μｍ以下であることが特に好ましい。また炭酸カルシウム粒子の添加量は０．０３重量％以上２重量％以下であることが好ましく、さらに好ましくは０．０５重量％以上１．５重量％以下、特に好ましくは０．１重量％以上１重量％以下である。
【００４３】
本発明に用いる炭酸カルシウムとしては、特に限定はされないが、天然に産出する石灰石、チョーク（白亜）、および石灰石から化学的方法によって生成される沈降炭酸カルシウム等のカルサイト結晶、石灰乳に高温で炭酸ガスを反応させて得られるアルゴナイト結晶、バテライト結晶およびこれらを組み合わせたものが例示される。石灰石を機械酌に粉砕して得られる重質炭酸カルシウム（カルサイト結晶）も用いることができる。
【００４４】
［板状ケイ酸アルミニウム粒子］
本発明のコンデンサ用ポリエステルフィルム中に特に好ましく添加される不活性微粒子である珪酸アルミニウム粒子は平均粒径が０．１μｍ以上２μｍ以下であることが好ましく、０．３μｍ以上１．７μｍ以下であることがより好ましく、０．５μｍ以上１．５μｍ以下であることが特に好ましい。また、添加量はフィルムの滑り性、コンデンサの製造工程での取扱い性の点から０．０３重量％以上１重量％以下であることが好ましく、０．０６重量％以上０．８重量％以下であることがより好ましく、０．１重量％以上０．７重量％以下であることが特に好ましい。
【００４５】
本発明における板状珪酸アルミニウムとはアルミノ珪酸塩のことをいうものであり、特に限定はされないが、天然に産出するカオリン鉱物からなるカオリンクレー等が例示される。さらにカオリンクレーは水洗等の精製処理を施されたものであっても良い。
【００４６】
［球状シリカ粒子］
本発明のコンデンサ用ポリエステルフィルム中に特に好ましく添加される不活性微粒子である球状シリカ粒子は粒径比（長径／短径）が１．０以上１．２以下であることが好ましく、さらに平均粒径が０．０１μｍ以上３．０μｍ以下であり、かつフィルム厚み未満であることが好ましい。また、添加量は０．０３重量％以上３重量％以下であることが好ましい。
【００４７】
さらに、球状シリカ粒子のみの添加によってフィルムの滑り性を付与させる場合には、平均粒径の違う２種の球状シリカ粒子を同時に添加するとよい。すなわち、平均粒径がフィルム厚み未満でかつ０．５μｍ以上３．０μｍ以下の球状シリカ粒子（Ａ）と平均粒径がフィルム厚み未満でかつ０．０１μｍ以上１．５μｍ以下の球状シリカ粒子（Ｂ）からなり、かつ球状シリカ粒子（Ａ）の平均粒径が球状シリカ粒子（Ｂ）の平均粒径よりも大きい粒子を同時に添加することが好ましい。そして、該粒子（Ａ）の添加量が０．０３重量％以上１．５重量％以下であり、かつ該粒子（Ｂ）の添加量が０．０５重量％以上２重量％以下であることが好ましい。
【００４８】
［多孔質シリカ粒子］
本発明のコンデンサ用ポリエステルフィルム中に特に好ましく添加される不活性微粒子である多孔質シリカ粒子は、平均粒径が０．５μｍ以上５μｍ以下であることが好ましく、０．７μｍ以上４μｍ以下であることがより好ましく、０．９μｍ以上３．５μｍ以下であることが特に好ましい。なお、多孔質シリカ微粒子の平均粒径はフィルム厚みより大きくてもかまわない。これは前記多孔質シリカ微粒子がポリエステルフィルムに対して高い親和性を持つためである。また、多孔質シリカ微粒子の添加量は０．０５重量％以上２重量％以下（ポリマーに対して）であることが好ましく、０．０８重量％以上１．５重量％以下であることがより好ましく、０．１重量％以上１重量％以下であることが特に好ましい。
【００４９】
なお、上述の不活性微粒子の平均粒径は、島津制作所製ＣＰ−５０型セントリフューグルパーティクルサイズアナライザー（Ｃｅｎｔｒｉｆｕｇａｌ Ｐａｒｔｉｃｌｅ Ｓｉｚｅ Ａｎｎａｌｙｚｅｒ）を用いて測定した値であり、得られる遠心沈降曲線を基に算出した各粒径の粒子とその存在量との積算曲線から、５０重量％に相当する粒径を読み取って平均粒径とした（「粒度測定技術」日刊工業新聞発行、１９７５年頁２４２〜２４７参照）。
【００５０】
上述の特に好ましい不活性微粒子の例示（炭酸カルシウム粒子、板状ケイ酸アルミニウム粒子、球状シリカ粒子、多孔質シリカ粒子）をはじめとしたフィルム表面の突起を形成するための不活性微粒子をフィルム注に添加することにより、本発明のコンデンサ用ポリエステルフィルムは中心線平均粗さ（Ｒａ）が３０ｎｍ以上９０ｎｍ以下であることが好ましく、より好ましくは３５ｎｍ以上８５ｎｍ以下、特に好ましくは４０ｎｍ以上８０ｎｍ以下である。
【００５１】
なお、中心線平均粗さ（Ｒａ）はＪＩＳ−Ｂ−０６０１で定義される値であり、非接触式三次元粗さ計（小坂研究所製ＥＴ−３０ＨＫ）を用いて、波長７８０ｎｍの半導体レーザー、ビーム径１．６μｍの光触針で測定長（Ｌｘ）１ｍｍ、サンプリングピッチ２μｍ、カットオフ０．２５ｍｍ、厚み方向拡大倍率１万倍、面方向拡大倍率２００倍、走査線数１００本（Ｌｙ＝０．２ｍｍ）の条件にてフィルム表面の突起プロファイルを測定した値をもとに算出されるものである。
【００５２】
［厚み］
本発明のコンデンサ用ポリエステルフィルムの厚みは０．３μｍ以上１０μｍ以下であることが好ましく、より好ましくは０．４μｍ以上８．０μｍ以下、特に好ましくは０．５μｍ以上７．０μｍ以下である。フィルムの厚みが０．３μｍ未満ではフィルムが薄過ぎて絶縁特性が現在の要求レベルに達しないため、たとえ製膜が可能であってもコンデンサ用ポリエステルフィルムとして好ましくない。また、フィルムの厚みが１０μｍを超えると、コンデンサの小型大容量化に対する本発明の本来の目的から外れるため、本発明の対象とはならない。
【００５３】
［厚みのバラツキ］
本発明のコンデンサ用ポリエステルフィルムにおいて任意の場所での厚みのバラツキはフィルム厚みに対して２５％以下であることが好ましく、より好ましくは２０％以下、特に好ましくは１５％以下である。フィルムの厚みに対する厚みのバラツキが２５％を超えるとコンデンサの誘電体用薄膜として幾重にも積層して使用した場合、厚みのバラツキによりコンデンサとしての性能にバラツキを生じる原因となるため好ましくない。
【００５４】
なお、フィルム厚みおよび厚みのバラツキは以下に示す方法で算出した。先ず、フィルムの任意の場所から縦１０ｃｍ、横１０ｃｍの大きさに切り出したサンプルを全部で５０枚採取する。次に各々のサンプルの幅（ｃｍ）、長さ（ｃｍ）、重量（ｇ）、密度（ｇ／ｃｍ３ ）から厚みＴ（μｍ）を下記式（２）で算出し、５０サンプルの平均厚みＴａｖを下記式（３）により求めてフィルム厚みとした。さらに、上述の５０サンプルの中の最大厚みＴｍａｘと最小厚みＴｍｉｎの差を求め、平均厚みＴａｖに対する割合を下記式（４）で算出して厚みのバラツキとした。
【００５５】
【数３】
厚みＴ（μｍ）＝（重量／（幅×長さ×密度））×１００００ ……（２）
平均厚みＴａｖ（μｍ）＝（Ｔ１＋Ｔ２＋…＋Ｔ５０）／５０ ……（３）
厚みのバラツキ（％）＝（（最大厚みＴｍａｘ−最小厚みＴｍｉｎ）／平均厚みＴａｖ）×１００……（４）
【００５６】
［製造条件］
本発明のポリエステルフィルムは、ポリエチレン−２，６−ナフタレンジカルボキシレートを主成分とする二軸延伸フィルムである。この二軸延伸フィルムは通常の方法、例えば、該ポリマーを融点以上で溶融させ、溶融ポリマー中の粗大粒子を減少させる目的でフィルターを通過させた後にダイスリットから６０℃近辺に調温されたキャスティングドラム上に押出して密着冷却固化させ、未延伸フィルムを得る。この未延伸フィルムを縦および横方向に二軸延伸した後、熱固定し、必要に応じて縦方向および／または横方向に弛緩処理することで製造することができる。フィルムの延伸は公知のロール式縦延伸機、赤外線加熱縦延伸機、テンタークリッブ式横延伸機、これらの延伸を複数段階にわけて行う多段式延伸機、チューブラ延伸機、オーブン式縦延伸機、同時二軸延伸機などを用いて行うことができるが特に限定されるものではない。本発明においては、フィルムの縦方向の１５０℃における熱歪み率を小さい値に制御する必要があり、同時二軸延伸が好ましい。
【００５７】
次に詳しく本発明のポリエステルフィルムの製造方法について述べるが必ずしもこれに限定されるものではない。
【００５８】
先ず、同時二軸延伸法による製造につき説明する。同時二軸延伸機の縦方向の延伸機構には従来の方式であるスクリューの溝にクリップを乗せてクリップ間隔を拡げていくスクリュー方式、パンタグラフを用いてクリップ間隔を拡げていくパンタグラフ方式がある。これ等には、製膜速度が遅いこと、延伸倍率等の条件変更が容易でない等の問題があったが既にこのような設備を所有する場合、本発明に用いることができる。一方、近年、リニアモーター方式の同時二軸テンターが開発され、その製膜速度の高さ等から注目を集めている。リニアモーター方式の同時二軸延伸では、これらの問題を一挙に解決できる。従って新規に同時二軸延伸機を導入する場合にはこの方式の設備を使用するのが好ましい。また、同時二軸延伸では、逐次二軸延伸のように縦延伸ローラーを使用しないため、フィルム表面の傷が少なくなるという長所がある。その他、同時二軸延伸では逐次二軸延伸に比べてフィルム厚みのバラツキが改善される。また、熱固定領域で縦弛緩できる構造のものがあり、コンデンサ用ポリエステルフィルムの重要特性のひとつであるフィルムの配向の制御が比較的容易である。これらの特徴が本発明のコンデンサ用フィルムへの要求特性と合致するので、本発明においては同時二軸延伸を採用することが好ましい。
【００５９】
本発明でいう同時二軸延伸とは、フィルムの縦方向、横方向に同時に配向を与えるための延伸であり、同時二軸延伸機を用い、フィルムの両端をクリップで把持しながら搬送して、縦方向および横方向に延伸する操作をいう。尚、ここで、フィルムの縦方向とはフィルムの長手方向であり、横方向とはフィルムの幅方向である。もちろん、縦方向と横方向の延伸が時間的に同時に延伸されている部分があればよいのであって、従って、横方向または縦方向に単独に先に延伸した後に、縦方向と横方向とを同時に延伸する方法や、さらに同時二軸延伸後に横方向または縦方向に単独に更に延伸する方法なども本発明の範囲に含まれる。
【００６０】
本発明のコンデンサ用ポリエステルフィルムを製造するには、所定の不活性微粒子を含有させた後、例えばポリエチレン−２，６−ナフタレンジカルボキシレート樹脂を１６０℃以上１９０℃以下の温度で４時間から７時間程度乾燥した後に、通常の押出温度、すなわち２７０℃以上３３０℃以下の温度で溶融し、平均目開きが１０μｍ以上４０μｍ以下のフィルター（望ましくは焼結金属型、網状構造型、さらに好ましくは線径１５μｍ以下のステンレス鋼細線よりなる不織布型）でろ過をした後にダイスリットから押出されたフィルム状溶融物を表面温度が３０℃以上７０℃以下の回転冷却ドラムの表面で急冷して未延伸フィルムを得る。未延伸フィルムの端部と中央部の厚みの比率（端部の厚み／中央部の厚み）は、望ましくは、１以上１０以下であり、好ましくは１以上５未満、さらに好ましくは１以上３未満である。前記厚みの比率が１未満であるか、１０を越えるとフィルム破れまたはクリップ外れが多発するので好ましくない。
【００６１】
次いで、この未延伸フィルムを、同時二軸延伸機に該フィルムの両端部をクリップで把持して導き、予熱ゾーンで８０℃以上１６０℃以下に加熱した後、一段階もしくは二段階以上の多段階で１１５℃以上１７０℃以下の温度で面積倍率１０倍以上４０倍以下（縦倍２倍以上６倍以下）の同時二軸延伸を施す。また必要に応じて、その後さらに、１５０℃以上２５０℃以下の温度で、一段階もしくは二段階以上の多段階で面積倍率２〜５倍に同時二軸延伸しても良い。続いて、１９０℃以上２５５℃以下の温度範囲で熱固定を施し、必要であれば熱固定を施しながら、または熱固定からの冷却過程で、好ましくは１００℃以上２４５℃以下の温度範囲で縦方向および／または横方向に、好ましくは各方向に対して０．５％以上１０％以下の範囲で弛緩処理を行う。本発明のポリエチレン―２，６―ナフタレンジカルボキシレートの場合、予熱温度は１３０℃程度、延伸温度は１４５℃程度、熱固定温度は２３５℃程度が特に好ましい。
【００６２】
尚、本発明では、フィルムの表面特性を付与するため、例えば易接着性、易滑性、離型性、制電性を付与するために、同時二軸延伸の前または後の工程で、ポリエステルフィルムの表面に塗剤をコーテングすることも好ましく行うことができる。
【００６３】
本発明のフィルムは通常の逐次二軸延伸でも製造できる。前述したように公知の方法で得られたポリエチレン−２，６−ナフタレンジカルボキシレートの未延伸フィルムを予熱ゾーンで８０℃以上１５０℃以下に加熱した後、１２０℃以上１８０℃以下、より好ましくは１２５℃以上１７０℃以下、特に好ましくは１３０℃以上１６０℃以下で縦方向にロール式縦延伸機で３．０倍以上５．０倍以下、より好ましくは３．３倍以上４．６倍以下で延伸する。赤外線加熱式縦延伸機を用いてもよいが、特に薄いフィルムを延伸する場合にはフィルム全体を均一に加熱するのに有利であるためロール式縦延伸機の方が好ましい。縦延伸で無理なく延伸するためには延伸を複数回に分けて多段延伸することが好ましい。縦延伸後、再度予熱ゾーンで８０℃以上１５０℃以下に加熱した後、さらにステンター内で１２０℃以上１８０℃以下、より好ましくは１２５℃以上１７０℃以下、特に好ましくは１３０℃以上１６０℃以下で横方向に３．０倍以上４．５倍以下、より好ましくは３．５倍以上４．３倍以下で延伸し、１９５℃以上２５０℃以下、より好ましくは２００℃以上２４５℃以下で０．３〜５０秒間熱処理を行い、その後、縦方向および／または横方向に弛緩率０．５〜１５％の範囲で熱弛緩処理を行うことで所望のポリエステルフィルムを得ることができる。なお、横方向の延伸を複数段階に分割する多段延伸を用いてもよい。
【００６４】
本発明のポリエステルフィルムは、フィルムコンデンサの誘電体として用いられるが、従来のポリエステル（ポリエチレンテレフタレート）フィルムコンデンサに比べて、誘電体フィルムのガラス転移温度が高いために、より使用環境温度が高い場所で使用されるフィルムコンデンサに好ましく適用される。特に電気・電子機器の小型化により従来よりも熱源に接近した整流回路、自動車の電装部品としてエンジン周辺や車内に設置される電装部品の回路等では使用環境温度が高温になるため好ましく用いられる。また、ハイブリッドカーや電気自動車、電子交換機等の変圧回路、電流変換回路等などの高電圧下での耐電圧特性や高周波下での容量安定化が要求されるコンデンサ用のフィルムとして好ましく適用される。
【００６５】
【実施例】
以下実施例により本発明を更に説明するが、本発明はその要旨を変えない限り、以下の実施例のみに限定されるものではない。なお、本発明における種々の物性値及び特性の測定方法、定義は以下の通りである。
【００６６】
（１）ポリエチレン−２，６−ナフタレンジカルボキシレートの成分量（主成分モル比、共重合成分モル比）の算出
フィルムサンプルを測定溶媒（ＣＤＣｌ３：ＣＦ３ＣＯＯＤ＝１：１）に溶解後１Ｈ−ＮＭＲ測定を行い、得られた各シグナルの積分比をもって算出する。
【００６７】
（２）フィルムの屈折率
Ｍｅｔｒｉｃｏｎ社製 プリズムカプラ Ｍｏｄｅｌ ２０１０を用いて、波長４７３ｎｍ、６３３ｎｍ、８３０ｎｍでのフィルム面内の長手方向（０°方向）、１５°方向、３０°方向、４５°方向、６０°方向、７５°方向、９０°方向、１０５°方向、１２０°方向、１３５°方向、１５０°方向および１６５°方向の各方向の屈折率を測定する。次に得られた各方向の、波長４７３ｎｍ、６３３ｎｍ、８３０ｎｍでの測定値をコーシーの分散式である下記式（５）に当てはめる。
【００６８】
【数４】
ｎｉ＝ａ＋［ｂ／（λｉ）２］＋［ｃ／（λｉ）４］ ……（５）
ここで式（５）中のλｉは測定波長。ｎｉは波長λｉで測定された屈折率である。波長４７３ｎｍ、６３３ｎｍ、８３０ｎｍでの屈折率測定結果を式（５）に代入し、連立方程式を解くことによって定数のａ，ｂ，ｃを求める。そして得られたａ，ｂ，ｃの値を用いて、波長５８９ｎｍ（Ｎａ−Ｄ線の波長）での屈折率を計算によって求め、フィルムの屈折率とする。得られた各方向の屈折率のうち、値が最大のものと最小のものをそれぞれ屈折率最大値、屈折率最小値とした。
【００６９】
（３）密度
硝酸カルシウム水溶液を用いた密度勾配管で、２５℃での浮沈法により測定する。
【００７０】
（４）熱収縮率
試料フィルムの長手方向（ＭＤ）または巾方向（ＴＤ）に沿って所定の間隔で標線を入れ、所定の温度（１５０℃または２００℃）に設定されたオーブン中で張力フリーの状態で所定の時間（３０分間または１０分間）フィルムを保持し、熱処理（各１５０℃×３０分間、２００℃×１０分間）前後での寸法変化を熱収縮率として下記式（６）により算出する。
【００７１】
【数５】
熱収縮率（％）＝｛（熱処理前の長さ−熱処理後の長さ）／熱処理前の長さ｝×１００ ……（６）
【００７２】
（５）フィルムの平面性（加工適正）
二軸延伸フィルムを５００ｍｍ巾でスリットし、巻取り長１０００ｍのロールサンプルを作成する。得られたロールサンプルを温度８０℃に設定したオーブン中で４時間熱処理した後、フィルムを水平かつ平行に１ｍの間隔をおいて並んだ２本の搬送ロール間に渡し、一定の張力（４ｋｇ／ｍ巾）を掛けて張った状態にする。フィルムを横から観察し、たるみによって最も垂れ下がった距離を測定してたるみ量とし、また、シワの状態を観察して下記の基準で評価した。なお、下記評価の○および△を合格とした。
○：フィルムにシワは見られず、フィルムのたるみ量は５ｍｍ未満であり、フィルムの平面性は極めて良好。
△：フィルムにシワが見られず、フィルムのたるみ量が５ｍｍ以上１５ｍｍ未満であり、フィルムの平面性は良好。
×：フィルムにシワが見られる、またはフィルムのたるみ量が１５ｍｍ以上であり、フィルムの平面性は不良。
【００７３】
（６）絶縁破壊電圧（ＢＤＶ）
ＪＩＳ Ｃ ２３１８に示す方法に従って測定し、ｎ＝２００の最小値を絶縁破壊電圧（ＢＤＶ）とした。
【００７４】
本発明において、絶縁破壊電圧は２２０Ｖ／μｍ以上であることが好ましく２４０Ｖ／μｍ以上であることが特に好ましい。
【００７５】
［実施例１］
２，６−ナフタレンジカルボン酸ジメチル１００部、エチレングリコール６０部をエステル交換触媒として酢酸マンガン四水塩０．０３部を使用し、滑剤として平均粒径１．１μｍの炭酸カルシウム粒子０．４５重量％および平均粒径０．８μｍのカオリンクレー粒子（板状ケイ酸アルミニウム粒子）を０．３０重量％含有するように添加して、常法に従ってエステル交換反応をさせた後、トリメチルホスフェート０．０２３部を添加し実質的にエステル交換反応を終了させた。
【００７６】
ついで、三酸化アンチモン０．０２４部を添加し、引き続き高温、高真空化で常法にて重合反応を行い、固有粘度０．６２ｄｌ／ｇのポリエチレン−２，６−ナフタレンジカルボキシレート（ＰＥＮ Ｔｇ＝１２１℃）を得た。
【００７７】
このＰＥＮポリマーを１７０℃で５時間乾燥させた後、押出し機に供給し、溶融温度２９０℃で溶融し、線径１４μｍのステンレス鋼細線からなる平均目開き３０μの不織布型フィルターでろ過し、ダイスリットより押出し後、表面温度を５０℃に設定したキャスティングドラム上で冷却固化させて未延伸フィルムを作成した。
【００７８】
この未延伸フィルムを、同時二軸延伸機に導入し、１２５℃で予熱した後、１４５℃で縦方向に３．５倍、横方向に３．８倍にクリップで把持しながら同時に延伸した。その後、第１、２、３熱固定ゾーンにおいてそれぞれ２００℃、２３０℃、２３５℃で２秒間ずつ熱固定しながら、第３熱固定ゾーンで縦および横方向に各々０．７％の弛緩を与え、厚みが２．５μｍの二軸配向フィルムを得た。二軸配向フィルムの物性および評価結果を表１に示す。
【００７９】
［実施例２］
縦方向に３．２倍、横方向に３．６倍で延伸した以外は実施例１と同様に製膜を行った。得られた二軸配向フィルムの物性および評価結果を表１に示す。
【００８０】
［実施例３］
縦方向に３．３倍、横方向に４．１倍で延伸した以外は実施例１と同様に製膜を行った。得られた二軸配向フィルムの物性および評価結果を表１に示す。
【００８１】
［実施例４］
第１、２、３熱固定ゾーン温度をそれぞれ１９５℃、２２０℃、２３０℃にした以外は実施例１と同様に製膜を行った。得られた二軸配向フィルムの物性および評価結果を表１に示す。
【００８２】
［実施例５］
滑剤として添加する不活性粒子を平均粒径１．３μｍの球状シリカ粒子０．２５重量％および平均粒径０．２μｍの球状シリカ粒子を０．２５重量％含有するように添加して、固有粘度０．６２ｄｌ／ｇのポリエチレン−２，６−ナフタレンジカルボキシレート（ＰＥＮ Ｔｇ＝１２１℃）を得た以外は、実施例１と同様に未延伸フィルムを作成し、同様に製膜を行った。得られた二軸配向フィルムの物性および結果を表１に示す。
【００８３】
［比較例１］
縦方向に２．９倍、横方向に３．６倍で延伸した以外は実施例１と同様に製膜を行った。得られた二軸配向フィルムの物性および評価結果を表１に示す。このフィルムは屈折率が低く、フィルムの絶縁破壊電圧が低い。
【００８４】
［比較例２］
縦方向に３．８倍、横方向に３．５倍で延伸し、かつ第３熱固定ゾーン温度を２４５℃にして、縦および横方向に各々３．２％の弛緩を与えた以外は実施例１と同様に製膜を行った。得られた二軸配向フィルムの物性および評価結果を表１に示す。このフィルムは屈折率が小さく、かつフィルムの密度が高く、フィルムの絶縁破壊電圧が低い。
【００８５】
［比較例３］
縦方向に３．４倍、横方向に３．９倍で延伸し、かつ第１、２、３熱固定ゾーン温度をそれぞれ１８０℃、２００℃、１７０℃にした以外は実施例１と同様に製膜した。得られた二軸配向フィルムの評価結果を表１に示す。このフィルムは屈折率が小さく、かつフィルムの密度が低いためにフィルムの絶縁破壊電圧が低い。
【００８６】
【表１】
表１に示した結果から明らかなように、本発明のコンデンサ用ポリエステルフィルムは、絶縁破壊電圧が高く、フィルムの熱収縮挙動が良好であり、かつ、フィルムの平面性と厚みのバラツキも良好であり、コンデンサ用フィルムとして優れたものであった。
【００８８】
【発明の効果】
本発明によれば、絶縁性、加工性に優れ、８０〜１２０℃の環境で使用しても高い信頼性をもって使用できるコンデンサ用ポリエステルフィルムを得ることができる。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a polyester film for a capacitor. More specifically, the present invention relates to a polyester film for a capacitor which contains polyethylene-2,6-naphthalenedicarboxylate as a main component, has excellent insulation properties and workability, and can be used with high reliability even in an environment of 80 to 120 ° C. Things.
[0002]
[Prior art]
With regard to capacitors, there is a demand for miniaturization and large capacity with the recent miniaturization of electric and electronic devices, and an improvement in insulation properties with a higher voltage in a working voltage band. To meet such demands, in film capacitors, the thickness of a film as a dielectric is reduced (the capacitance per unit volume of the dielectric (film) is inversely proportional to the square of the film thickness, and the dielectric constant of the dielectric is And the reduction of pinholes present in the film.
[0003]
As described above, in the case of a film capacitor, although it is necessary to reduce the thickness of the dielectric film, workability in the process of processing the capacitor due to the thinning of the film (metal deposition as an electrode on the film, slit, element winding, etc.) It has been proposed to add specific inert fine particles as a lubricant to a polyethylene-2,6-naphthalenedicarboxylate film in order to avoid deterioration of the film (see, for example, Patent Document 1).
[0004]
However, although thinning of the film and excellent workability in the processing of the capacitor were achieved at the same time, the insulation properties were poor due to additives (lubricants, catalysts, impurities) contained in the film and the completion of the capacitor. Insulation characteristics failure due to various thermal stresses and mechanical stresses applied to the film up to the point where the excellent insulation characteristics originally possessed by the polyester film is deteriorated, so that it is still insufficient as a film for a capacitor. In recent years, there has been a tendency to increase the temperature and pressure of a hot press after winding of a capacitor element in order to improve the productivity of the capacitor, and the performance required for a film as a dielectric has become more severe. Even if the dielectric film becomes thinner, the withstand voltage characteristics required for the capacitor are equal to or higher than those of conventional products. There is an urgent need to improve the insulating properties of dielectric films.
[0005]
[Patent Document 1]
JP-A-10-294237
[0006]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a film suitable for a dielectric of a film capacitor which has excellent insulation properties and processability and can be used with high reliability even in an environment of 80 to 120 ° C. The task is to provide
[0007]
[Means for Solving the Problems]
As a result of intensive studies, the present inventor has determined that the polyester constituting the dielectric of the capacitor is mainly composed of polyethylene-2,6-naphthalenedicarboxylate, and the refractive index in a specific direction in the film plane is in a specific range. As a result, the present inventors have found that the object of the present invention can be achieved, and reached the present invention.
[0008]
That is, an object of the present invention is to provide a biaxially oriented film containing polyethylene-2,6-naphthalenedicarboxylate as a main component, wherein the longitudinal direction of the film is 0 ° and the direction is 15 ° on the film plane. 15 °, 30 °, 45 °, 60 °, 75 °, 90 °, 105 °, 120 °, 135 °, 150 °, and 165 ° directions Wherein the refractive index of the film is 1.740 or more.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail.
[0010]
[Polyethylene-2,6-naphthalenedicarboxylate]
The polyester film for a capacitor of the present invention has a polyester of ethylene-2,6-naphthalenedicarboxylate in which at least 80 mol% of all the repeating units are a main component.
[0011]
Conventionally, a polyethylene terephthalate film has been used as a polyester film for capacitors, and is expected to be used in the future. Since the polyethylene terephthalate film has a possibility that the dielectric loss tangent increases in a temperature range of 80 ° C. or more and self-heats due to dielectric loss to cause thermal runaway, the upper limit of the operating temperature as a capacitor is suppressed to about 80 ° C. . In the case of polyethylene-2,6-naphthalenedicarboxylate, the increase in the dielectric loss tangent is from around 120 ° C., so the upper limit of the working temperature is considered to be about 120 ° C. Therefore, at high temperatures, capacitors of polyethylene-2,6-naphthalenedicarboxylate film are used. Further, the dielectric constant of polyethylene-2,6-naphthalenedicarboxylate is 2.9, which is slightly smaller than 3.1 of polyethylene terephthalate, which seems to be disadvantageous for downsizing at first glance. The power is high, and polyethylene-2,6-naphthalenedicarboxylate is also advantageous in this respect. The present invention is mainly intended for a capacitor for such an application, and is suitably used for a film wound type capacitor and a film laminated type capacitor, and is also suitably used for a surface mount type film capacitor.
[0012]
In the polyethylene-2,6-naphthalenedicarboxylate of the present invention, at least 80 mol% of all repeating units are a polyester of ethylene-2,6-naphthalenedicarboxylate. It is preferable that 95 mol% or more is ethylene-2,6-naphthalenedicarboxylate units, and it is particularly preferable that the polymer is a substantial homopolymer of polyethylene-2,6-naphthalenedicarboxylate.
[0013]
The polyethylene-2,6-naphthalenedicarboxylate in the present invention may be a polyethylene-2,6-naphthalenedicarboxylate copolymer having a copolymer component within 20 mol%. When polyethylene-2,6-naphthalenedicarboxylate is a copolymer, preferred examples of the copolymerization component include 2,7-naphthalenedicarboxylic acid and 1,5-naphthalenedicarboxylic acid.
[0014]
In addition, as the copolymer component of the polyethylene-2,6-naphthalenedicarboxylate copolymer, a compound having two ester-forming functional groups in the molecule can be used. Such compounds include, for example, oxalic acid, adipic acid, phthalic acid, sebacic acid, dodecanedicarboxylic acid, isophthalic acid, terephthalic acid, 1,4-cyclohexanedicarboxylic acid, 4,4′-diphenyldicarboxylic acid, phenylindanedicarboxylic acid, Dicarboxylic acids such as tetralin dicarboxylic acid, decalin dicarboxylic acid and diphenyl ether dicarboxylic acid; oxycarboxylic acids such as p-oxybenzoic acid and p-oxyethoxy benzoic acid; or diethylene glycol, propylene glycol, trimethylene glycol, tetramethylene glycol, Hexamethylene glycol, cyclohexane methylene glycol, neopentyl glycol, ethylene oxide adduct of bisphenolsulfone, ethylene oxide adduct of bisphenol A, Dihydric alcohols such as diethylene glycol and polyethylene oxide glycol can be used. These compounds can be used alone or in combination of two or more. Among these copolymer components, isophthalic acid, terephthalic acid, 4,4′-diphenyldicarboxylic acid, 2,7-naphthalenedicarboxylic acid, and p-oxybenzoic acid are used as acid components, and diethylene glycol is used as a glycol component. , Trimethylene glycol, hexamethylene glycol, neopentyl glycol, and ethylene oxide adduct of bisphenolsulfone as preferred examples.
[0015]
Further, the polyethylene-2,6-naphthalenedicarboxylate may be one in which a terminal hydroxyl group and / or a carboxyl group is partially or entirely blocked with a monofunctional compound such as benzoic acid or methoxypolyalkylene glycol. Alternatively, it may be a copolymer of a tri- or higher functional ester-forming compound such as glycerin or pentaerythritol in a small amount within a range where a substantially linear polymer can be obtained.
[0016]
The components of the polymer in the polyester film of the present invention are mainly composed of a homopolymer and / or a copolymer of polyethylene-2,6-naphthalenedicarboxylate, but may be combined with another polyester or an organic polymer other than the polyester. May be used as a mixture. In the case of the mixture, it is necessary that the ethylene-2,6-naphthalenedicarboxylate unit in the component of the polymer is 80 mol% or more of all the repeating units, but it is 90 mol% or more, particularly 95 mol% or more. This is preferable because the properties inherent in the polyethylene-2,6-naphthalenedicarboxylate film are not extremely lost, and the insulating properties, mechanical properties and thermal dimensional stability can be secured.
[0017]
Polyesters which can be mixed with polyethylene-2,6-naphthalene dicarboxylate or organic polymers other than polyesters include polyethylene terephthalate, polyethylene isophthalate, polytrimethylene terephthalate, polyethylene 4,4'-tetramethylenediphenyldicarboxylate, polyethylene -2,7-naphthalenedicarboxylate, polytrimethylene-2,6-naphthalenedicarboxylate, polyneopentylene-2,6-naphthalenedicarboxylate, poly (bis (4-ethyleneoxyphenyl) sulfone)- Polyesters such as 2,6-naphthalenedicarboxylate can be mentioned, and among these, polyethylene isophthalate, polytrimethylene terephthalate, polytrimethylene-2,6-naphthalene Dicarboxylate and poly (bis (4-ethyleneoxyphenyl) sulfone) -2,6-naphthalenedicarboxylate are preferred.
[0018]
These polyesters or organic polymers other than polyesters are not limited to one kind, and two or more kinds may be used in the polymer component constituting the polyester film in an amount equivalent to 10 mol%, preferably up to 5 mol%, in terms of the repeating unit of the polymer. It can be used in a mixture with polyethylene-2,6-naphthalenedicarboxylate.
[0019]
The polyester used for the polyethylene-2,6-naphthalenedicarboxylate homopolymer, copolymer or mixture used in the present invention can be produced by a generally known method for producing a polyester composition. For example, a low-polymerization degree polyester is directly obtained by a reaction of a dicarboxylic acid and a glycol, or a low-polymerization degree polyester is obtained by a transesterification reaction of a lower alkyl ester of a dicarboxylic acid and a glycol. It can be produced by a method of obtaining a polyester by further polymerizing below.
[0020]
Examples of the transesterification catalyst used in the transesterification reaction include one or more compounds including sodium, potassium, magnesium, calcium, zinc, strontium, titanium, zirconium, manganese, and cobalt. Further, as the polymerization catalyst, antimony trioxide, an antimony compound such as antimony pentoxide, a germanium compound represented by germanium dioxide, tetraethyl titanate, tetrapropyl titanate, tetraphenyl titanate or a partial hydrolyzate thereof, oxalic acid Examples include titanium compounds such as titanyl ammonium, potassium titanyl oxalate, and titanium trisacetylacetonate.
[0021]
When the polymerization is carried out via a transesterification reaction, a phosphorus compound such as trimethyl phosphate, triethyl phosphate, tri-n-butyl phosphate, orthophosphoric acid or the like is added for the purpose of deactivating the transesterification catalyst before the polymerization reaction. The content of polyethylene-2,6-naphthalenedicarboxylate as a phosphorus element is preferably 20 ppm or more and 100 ppm or less from the viewpoint of thermal stability of the polyester.
[0022]
The polyester may be formed into chips after melt polymerization and solid-phase polymerized under reduced pressure under heating or in an inert gas stream such as nitrogen.
[0023]
The intrinsic viscosity of polyethylene-2,6-naphthalenedicarboxylate used in the present invention is preferably 0.50 dl / g or more and 0.90 dl / g or less. It is more preferably from 0.52 dl / g to 0.85 dl / g, and particularly preferably from 0.53 dl / g to 0.80 dl / g. When the intrinsic viscosity is less than 0.50 dl / g, the film after melt extrusion becomes brittle, and the film is likely to break during film formation. Further, it is not preferable because the film is likely to be broken during transportation in the processing step of the capacitor. On the other hand, if the intrinsic viscosity of the film exceeds 0.90 dl / g, it is necessary to increase the intrinsic viscosity of the polymer considerably. From the above, the intrinsic viscosity of the biaxially oriented film is preferably from 0.45 dl / g to 0.80 dl / g, more preferably from 0.47 dl / g to 0.75 g / dl. It is particularly preferably 0.50 dl / g or more and 0.70 g / dl or less. The intrinsic viscosity is a value (unit: dl / g) measured at 35 ° C. using o-chlorophenol as a solvent.
[0024]
[Refractive index]
The polyester film for a capacitor of the present invention has a longitudinal direction of the film of 0 ° direction, and a direction of 15 °, a direction of 30 °, a direction of 45 °, a direction of 60 °, and a direction of 75 ° which are determined by changing the direction in increments of 15 ° on the film plane. Direction, 90 ° direction, 105 ° direction, 120 ° direction, 135 ° direction, 150 ° direction and 165 ° direction, the refractive index of the film must be 1.740 or more. This refractive index is more preferably 1.740 or more and 1.774 or less, and particularly preferably 1.742 or more and 1.770 or less. If the in-plane refractive index in the film direction in the above direction is less than 1.740, the dielectric breakdown voltage of the film decreases, and the insulating performance of the capacitor as a dielectric film becomes insufficient. On the other hand, if the refractive index in the film plane in the above direction increases, the insulating properties of the film tend to improve, but if the refractive index in one direction of the above direction exceeds 1.774, the type and particle size of the additive In some cases, the insulation performance of the film is reduced due to the influence of the film thickness and the like.
[0025]
[density]
The polyester film for a capacitor of the present invention has a density of 1.347 g / cm. 3 1.361 g / cm 3 The following is preferred. More preferably, 1.349 g / cm 3 Above 1.360 g / cm 3 Below, particularly preferably 1.350 g / cm 3 1.359 g / cm 3 It is as follows. Density is 1.347 g / cm 3 Less than or 1.361 g / cm 3 Exceeding the range is not preferred because the dielectric breakdown voltage of the film is low and the insulation performance of the dielectric film of the capacitor may be insufficient. In addition, the density is 1.361 g / cm 3 If the ratio exceeds, the crystallinity becomes too high and the toughness of the film is lost, so that the frequency of breakage during film transport and slit processing may increase.
[0026]
[Heat shrinkage]
When the polyester film for a capacitor of the present invention is heat-treated at 200 ° C. for 10 minutes, the heat shrinkage in the longitudinal direction (0 ° direction: hereinafter sometimes referred to as “MD”) is 2.5% or more and 4.2% or less; The heat shrinkage in the width direction (90 ° direction: hereinafter sometimes referred to as “TD”) is 3.0% or more and 4.6% or less, and the heat shrinkage in the width direction is smaller than the heat shrinkage in the longitudinal direction. Larger is preferred.
[0027]
When the heat shrinkage in the longitudinal direction (MD) or the width direction (TD) of the film is less than the above range, when a metal is vapor-deposited on the film, the film is in close contact with a cooling roll on the side opposite to the vapor-deposited surface. Is not preferred because heat is lost. On the other hand, if the heat shrinkage in the longitudinal direction (MD) or the width direction (TD) of the film exceeds the above range, poor contact due to deformation of the film at the time of metallikon (spraying the electrode metal on both end surfaces of the element) occurs. Not preferred.
[0028]
Further, when the heat shrinkage in the longitudinal direction (MD) becomes equal to or greater than the heat shrinkage in the width direction (TD), abnormalities such as wrinkling of the film due to heat history in each process of manufacturing the capacitor. It is not preferable because it occurs.
[0029]
The heat shrinkage in the machine direction (MD) after heat treatment at 200 ° C. for 10 minutes is more preferably from 2.7% to 4.0%, particularly preferably from 2.8% to 3.9. % Or less. Further, the heat shrinkage in the width direction (TD) after heat treatment at 200 ° C. for 10 minutes is more preferably 3.2% or more and 4.5% or less, more preferably 3.4% or more and 4.4% or less. It is particularly preferred that there is.
[0030]
[Change ratio of heat shrinkage]
The heat shrinkage in the longitudinal direction (MD) and the width direction (TD) when the film of the present invention is heat-treated at 150 ° C. for 30 minutes, and the longitudinal direction (MD) and the width direction when the film is heat-treated at 200 ° C. for 10 minutes (MD) The value (change ratio of heat shrinkage) calculated from the heat shrinkage of TD) by the following formula (1) is preferably 33 or more and 96 or less, more preferably 37 or more and 93 or less, and particularly preferably 40 or less. It is 90 or less.
[0031]
(Equation 2)
Change rate of heat shrinkage (%) = (S 200MD -S 150MD ) / (S 200 TD -S 150TD ) × 100… (1)
However, S in the above equation (1) 200MD , S 200 TD Is the heat shrinkage in the longitudinal and width directions when heat-treated at 200 ° C. for 10 minutes, S 150MD , S 150TD Represents the heat shrinkage in the longitudinal direction and the width direction when heat-treated at 150 ° C. for 30 minutes, respectively.
[0032]
If the change ratio is less than 33 or more than 96, the flatness of the film is deteriorated (sag, wrinkle) due to heat history in the capacitor manufacturing process, which is not preferable.
[0033]
[Additive]
The polyester film of the present invention may contain additives such as a lubricant, a stabilizer, a flame retardant and the like. During the production, processing and use of the film, a small percentage of inert fine particles such as inorganic particles, organic particles, and crosslinked polymer particles are added to impart slipperiness to the film for the purpose of improving the runnability and handling during use. Is preferred.
[0034]
Examples of the inorganic particles include calcium carbonate, porous silica, spherical silica, kaolin, talc, magnesium carbonate, barium carbonate, calcium sulfate, barium sulfate, lithium phosphate, calcium phosphate, magnesium phosphate, aluminum oxide, silicon oxide, and titanium oxide. , Zirconium oxide, lithium fluoride and the like. It is particularly preferable that the polyester film for a capacitor of the present invention contains calcium carbonate, plate-like aluminum silicate, porous silica, and spherical silica among the above examples.
[0035]
Examples of the organic salt particles include terephthalates such as calcium oxalate, calcium, barium, zinc, manganese, and magnesium.
[0036]
Examples of the crosslinked polymer particles include divinylbenzene, styrene, acrylic acid, methacrylic acid, homopolymers or copolymers of vinyl monomers of acrylic acid or methacrylic acid, and others, polytetrafluoroethylene, silicone resin, Organic fine particles such as benzoguanamine resin, thermosetting epoxy resin, unsaturated polyester resin, thermosetting urea resin, and thermosetting phenol resin are also used.
[0037]
The average particle size of these lubricants is 0.1 μm or more and 5 μm or less. The average particle size is more preferably 0.15 μm or more and 4 μm or less, and particularly preferably 0.2 μm or more and 3.5 μm or less. If the thickness is less than 0.1 μm, the effect of improving the slipperiness is small, so that the added concentration needs to be extremely high. On the other hand, if the thickness exceeds 5 μm, not only breakage in the film production process will increase but also pinholes due to falling off of particles will increase, which is not preferable.
[0038]
The total amount of the inert fine particles is 0.05% by weight to 3% by weight, more preferably 0.08% by weight to 2.5% by weight, and 0.1% by weight to 2.0% by weight. Particularly preferred. If the content is less than 0.05% by weight, the improvement of the slipperiness is insufficient, and if it exceeds 3% by weight, breakage increases in the film production process, which is not preferable.
[0039]
The inert fine particles to be added to the film may be a single component selected from those exemplified above, or may be a multicomponent containing two or three or more components.
[0040]
The polyester film of the present invention may contain a nucleating agent, an antioxidant, a heat stabilizer, a lubricating agent, a flame retardant, an antistatic agent, a polysiloxane and the like depending on the use.
[0041]
There is no particular limitation on the timing of addition of the inert fine particles and other additives as long as they are at the stage before the formation of polyethylene-2,6-naphthalenedicarboxylate. For example, they may be added at the polymerization stage. May be added at this time. From the viewpoint of uniform dispersion, it is preferable to add the compound in ethylene glycol at a high concentration at the time of polymerization to prepare a master chip and dilute the mixture with a non-added chip.
[0042]
[Calcium carbonate particles]
The calcium carbonate particles, which are inert fine particles particularly preferably added to the polyester film for a capacitor of the present invention, preferably have an average particle size of 0.2 μm or more and 5 μm or less from the viewpoint of the slipperiness of the film and the air bleeding property. , 0.3 μm or more and 4 μm or less, and particularly preferably 0.5 μm or more and 3 μm or less. The addition amount of the calcium carbonate particles is preferably 0.03% by weight or more and 2% by weight or less, more preferably 0.05% by weight or more and 1.5% by weight or less, and particularly preferably 0.1% by weight or more and 1% by weight or less. % By weight or less.
[0043]
The calcium carbonate used in the present invention is not particularly limited, but calcite crystals such as naturally occurring limestone, chalk (chalk), and precipitated calcium carbonate generated from limestone by a chemical method, and lime milk at high temperatures. Argonite crystals, vaterite crystals obtained by reacting carbon dioxide gas, and combinations thereof are exemplified. Heavy calcium carbonate (calcite crystals) obtained by pulverizing limestone mechanically can also be used.
[0044]
[Plate aluminum silicate particles]
Aluminum silicate particles, which are inert fine particles particularly preferably added to the polyester film for a capacitor of the present invention, preferably have an average particle diameter of 0.1 μm or more and 2 μm or less, and more preferably 0.3 μm or more and 1.7 μm or less. Is more preferable, and it is particularly preferable that it is 0.5 μm or more and 1.5 μm or less. Further, the addition amount is preferably 0.03% by weight or more and 1% by weight or less, from the viewpoint of the slipperiness of the film and the handleability in the manufacturing process of the capacitor, and is preferably 0.06% by weight or more and 0.8% by weight or less. More preferably, it is particularly preferably 0.1% by weight or more and 0.7% by weight or less.
[0045]
The plate-like aluminum silicate in the present invention refers to an aluminosilicate, and is not particularly limited, and examples thereof include kaolin clay composed of a naturally occurring kaolin mineral. Further, the kaolin clay may have been subjected to a purification treatment such as washing with water.
[0046]
[Spherical silica particles]
The spherical silica particles, which are inert fine particles particularly preferably added to the polyester film for a capacitor of the present invention, preferably have a particle size ratio (major axis / minor axis) of 1.0 or more and 1.2 or less, and more preferably an average particle size of It is preferable that the diameter is 0.01 μm or more and 3.0 μm or less and less than the film thickness. Further, the addition amount is preferably 0.03% by weight or more and 3% by weight or less.
[0047]
Further, in the case where the slip property of the film is imparted by adding only spherical silica particles, two types of spherical silica particles having different average particle diameters may be added simultaneously. That is, spherical silica particles (A) having an average particle diameter of less than the film thickness and 0.5 μm or more and 3.0 μm or less and spherical silica particles (B) having an average particle diameter of less than the film thickness and 0.01 μm or more and 1.5 μm or less ) And the particles having an average particle diameter of the spherical silica particles (A) larger than the average particle diameter of the spherical silica particles (B) are preferably added at the same time. And, the addition amount of the particles (A) is from 0.03% by weight to 1.5% by weight, and the addition amount of the particles (B) is from 0.05% by weight to 2% by weight. preferable.
[0048]
[Porous silica particles]
The porous silica particles, which are inert fine particles particularly preferably added to the polyester film for a capacitor of the present invention, preferably have an average particle diameter of 0.5 μm to 5 μm, and more preferably 0.7 μm to 4 μm. Is more preferable, and particularly preferably 0.9 μm or more and 3.5 μm or less. The average particle size of the porous silica fine particles may be larger than the film thickness. This is because the porous silica fine particles have a high affinity for the polyester film. Further, the addition amount of the porous silica fine particles is preferably 0.05% by weight or more and 2% by weight or less (based on the polymer), and more preferably 0.08% by weight or more and 1.5% by weight or less. , 0.1% by weight or more and 1% by weight or less.
[0049]
The average particle diameter of the above-mentioned inert fine particles is a value measured using a Shimadzu Corporation CP-50 type centrifugal particle size analyzer (Centrifugal Particle Size Analyzer), and is based on the obtained centrifugal sedimentation curve. The particle size corresponding to 50% by weight was read from the integrated curve of the calculated particles of each particle size and the amount present as the average particle size ("Particle Size Measurement Technology", published by Nikkan Kogyo Shimbun, p. 241-247, 1975). reference).
[0050]
Inert fine particles for forming protrusions on the film surface, including the above-mentioned particularly preferred inert fine particles (calcium carbonate particles, plate-like aluminum silicate particles, spherical silica particles, porous silica particles), are added to the film. By the addition, the polyester film for a capacitor of the present invention preferably has a center line average roughness (Ra) of 30 to 90 nm, more preferably 35 to 85 nm, particularly preferably 40 to 80 nm.
[0051]
The center line average roughness (Ra) is a value defined by JIS-B-0601. A semiconductor laser having a wavelength of 780 nm is measured using a non-contact three-dimensional roughness meter (ET-30HK manufactured by Kosaka Laboratories). The measurement length (Lx) is 1 mm, the sampling pitch is 2 μm, the cutoff is 0.25 mm, the magnification in the thickness direction is 10,000 times, the magnification in the plane direction is 200 times, and the number of scanning lines is 100 lines (Ly). = 0.2 mm) is calculated based on the value obtained by measuring the protrusion profile on the film surface.
[0052]
[Thickness]
The thickness of the polyester film for a capacitor of the present invention is preferably from 0.3 μm to 10 μm, more preferably from 0.4 μm to 8.0 μm, and particularly preferably from 0.5 μm to 7.0 μm. If the thickness of the film is less than 0.3 μm, the film is too thin and the insulating property does not reach the current required level. Therefore, even if the film can be formed, it is not preferable as a polyester film for a capacitor. On the other hand, when the thickness of the film exceeds 10 μm, the object of the present invention for reducing the size and the capacity of the capacitor is deviated from the original object of the present invention.
[0053]
[Thickness variation]
In the polyester film for a capacitor of the present invention, the variation in the thickness at an arbitrary position is preferably 25% or less, more preferably 20% or less, particularly preferably 15% or less with respect to the film thickness. If the variation in thickness with respect to the thickness of the film exceeds 25%, it is not preferable because when used as a dielectric thin film of a capacitor in multiple layers, the variation in thickness causes variation in performance as a capacitor.
[0054]
The thickness of the film and the variation of the thickness were calculated by the following methods. First, a total of 50 samples cut out from an arbitrary place of the film into a size of 10 cm in length and 10 cm in width are collected. Next, the width (cm), length (cm), weight (g), density (g / cm) 3 )), The thickness T (μm) was calculated by the following equation (2), and the average thickness Tav of 50 samples was determined by the following equation (3) to obtain the film thickness. Further, the difference between the maximum thickness Tmax and the minimum thickness Tmin among the above-mentioned 50 samples was determined, and the ratio to the average thickness Tav was calculated by the following equation (4) to obtain the thickness variation.
[0055]
[Equation 3]
Thickness T (μm) = (weight / (width × length × density)) × 10000 (2)
Average thickness Tav (μm) = (T1 + T2 +... + T50) / 50 (3)
Thickness variation (%) = ((maximum thickness Tmax−minimum thickness Tmin) / average thickness Tav) × 100 (4)
[0056]
[Manufacturing conditions]
The polyester film of the present invention is a biaxially stretched film containing polyethylene-2,6-naphthalenedicarboxylate as a main component. This biaxially stretched film is cast in a usual manner, for example, by melting the polymer at a temperature equal to or higher than its melting point and passing through a filter for the purpose of reducing coarse particles in the molten polymer, and then controlling the temperature around 60 ° C. from a die slit. It is extruded on a drum and solidified by cooling to obtain an unstretched film. The unstretched film can be manufactured by biaxially stretching in the longitudinal and transverse directions, heat setting, and, if necessary, relaxing in the longitudinal and / or transverse directions. The stretching of the film is performed by a known roll type longitudinal stretching machine, infrared heating longitudinal stretching machine, tenter crib type transverse stretching machine, a multi-stage stretching machine which performs these stretchings in a plurality of stages, a tubular stretching machine, and an oven type longitudinal stretching machine. And a simultaneous biaxial stretching machine, etc., but are not particularly limited. In the present invention, it is necessary to control the thermal strain rate at 150 ° C. in the longitudinal direction of the film to a small value, and simultaneous biaxial stretching is preferable.
[0057]
Next, the method for producing the polyester film of the present invention will be described in detail, but is not necessarily limited thereto.
[0058]
First, the production by the simultaneous biaxial stretching method will be described. As a longitudinal stretching mechanism of the simultaneous biaxial stretching machine, there are a conventional method of extending a clip interval by placing a clip on a groove of a screw, and a pantograph method of extending a clip interval using a pantograph. These have problems such as a low film-forming speed and difficulty in changing conditions such as a draw ratio. However, when such equipment is already possessed, it can be used in the present invention. On the other hand, in recent years, a simultaneous biaxial tenter of a linear motor type has been developed and has attracted attention due to its high film forming speed. The simultaneous biaxial stretching of the linear motor system can solve these problems at once. Therefore, when newly introducing a simultaneous biaxial stretching machine, it is preferable to use equipment of this system. In addition, simultaneous biaxial stretching does not use a longitudinal stretching roller unlike sequential biaxial stretching, and thus has the advantage of reducing scratches on the film surface. In addition, in the simultaneous biaxial stretching, the variation in the film thickness is improved as compared with the sequential biaxial stretching. In addition, there is a structure in which the film can be relaxed vertically in the heat setting region, and it is relatively easy to control the orientation of the film, which is one of the important characteristics of the polyester film for a capacitor. Since these characteristics match the characteristics required for the film for a capacitor of the present invention, it is preferable to employ simultaneous biaxial stretching in the present invention.
[0059]
Simultaneous biaxial stretching referred to in the present invention is a stretching for simultaneously giving the orientation in the longitudinal direction and the lateral direction of the film, using a simultaneous biaxial stretching machine, transporting while holding both ends of the film with clips, This refers to an operation of stretching in the vertical and horizontal directions. Here, the longitudinal direction of the film is the longitudinal direction of the film, and the lateral direction is the width direction of the film. Of course, it is sufficient if there is a portion where the stretching in the longitudinal direction and the stretching in the horizontal direction are simultaneously stretched temporally.Therefore, after stretching in the transverse direction or the longitudinal direction independently first, the longitudinal direction and the transverse direction are combined. A method of simultaneous stretching and a method of further stretching independently in the horizontal or vertical direction after simultaneous biaxial stretching are also included in the scope of the present invention.
[0060]
In order to produce the polyester film for a capacitor of the present invention, for example, a polyethylene-2,6-naphthalenedicarboxylate resin is mixed at a temperature of 160 ° C. or more and 190 ° C. or less for 4 hours after containing predetermined inert fine particles. After drying for about an hour, it is melted at a normal extrusion temperature, that is, at a temperature of 270 ° C. or more and 330 ° C. or less, and a filter having an average opening of 10 μm or more and 40 μm or less (preferably a sintered metal type, a network type, more preferably a wire type) After filtering through a non-woven fabric made of stainless steel fine wire having a diameter of 15 μm or less, the film-like melt extruded from the die slit is rapidly cooled on the surface of a rotary cooling drum having a surface temperature of 30 ° C. or more and 70 ° C. or less. Get. The ratio of the thickness of the end portion and the center portion of the unstretched film (the thickness of the end portion / the thickness of the center portion) is desirably 1 or more and 10 or less, preferably 1 or more and less than 5, more preferably 1 or more and less than 3. It is. If the ratio of the thickness is less than 1 or more than 10, film breakage or clip detachment frequently occurs, which is not preferable.
[0061]
Next, this unstretched film is guided to a simultaneous biaxial stretching machine by gripping both ends of the film with clips and heated to 80 ° C. or more and 160 ° C. or less in a preheating zone, followed by one or two or more steps. At the temperature of 115 ° C. or more and 170 ° C. or less, the simultaneous biaxial stretching is performed at an area magnification of 10 times or more and 40 times or less (vertical magnification 2 times or more and 6 times or less). Further, if necessary, the film may be further subjected to simultaneous biaxial stretching at a temperature of 150 ° C. or more and 250 ° C. or less in one stage or in two or more stages at an area magnification of 2 to 5 times. Subsequently, heat fixing is performed in a temperature range of 190 ° C. or more and 255 ° C. or less, and if necessary, while performing heat fixing or in a cooling process after the heat fixing, preferably in a temperature range of 100 ° C. or more and 245 ° C. or less. The relaxation treatment is performed in the direction and / or the lateral direction, preferably in the range of 0.5% to 10% in each direction. In the case of the polyethylene-2,6-naphthalenedicarboxylate of the present invention, the preheating temperature is preferably about 130 ° C, the stretching temperature is about 145 ° C, and the heat setting temperature is preferably about 235 ° C.
[0062]
Incidentally, in the present invention, in order to impart surface properties of the film, for example, in order to impart easy adhesion, easy slip, releasability, antistatic properties, in the process before or after simultaneous biaxial stretching, polyester It is also preferable to coat a coating agent on the surface of the film.
[0063]
The film of the present invention can be produced by ordinary sequential biaxial stretching. As described above, after the unstretched film of polyethylene-2,6-naphthalenedicarboxylate obtained by a known method is heated to 80 ° C or more and 150 ° C or less in the preheating zone, 120 ° C or more and 180 ° C or less, more preferably 125 ° C or more and 170 ° C or less, particularly preferably 130 ° C or more and 160 ° C or less, and 3.0 to 5.0 times, more preferably 3.3 to 4.6 times with a roll-type longitudinal stretching machine in the machine direction. Stretch. Although an infrared heating type vertical stretching machine may be used, a roll type vertical stretching machine is more preferable, particularly when a thin film is stretched, because it is advantageous to uniformly heat the entire film. In order to easily stretch in the longitudinal stretching, it is preferable to perform the stretching in multiple stages by dividing the stretching into a plurality of times. After longitudinal stretching, after heating to 80 ° C or more and 150 ° C or less again in the preheating zone, further in the stenter, 120 ° C or more and 180 ° C or less, more preferably 125 ° C or more and 170 ° C or less, particularly preferably 130 ° C or more and 160 ° C or less. The film is stretched in the transverse direction at a ratio of 3.0 times to 4.5 times, more preferably 3.5 times to 4.3 times, and stretched at 195 ° C to 250 ° C, more preferably 200 ° C to 245 ° C. A desired polyester film can be obtained by performing a heat treatment for 3 to 50 seconds and then performing a heat relaxation treatment in a longitudinal direction and / or a transverse direction at a relaxation rate of 0.5 to 15%. Note that a multi-stage stretching in which the stretching in the horizontal direction is divided into a plurality of stages may be used.
[0064]
The polyester film of the present invention is used as a dielectric of a film capacitor. However, compared to a conventional polyester (polyethylene terephthalate) film capacitor, the dielectric film has a higher glass transition temperature, so that it can be used in a place where the use environment temperature is higher. It is preferably applied to the film capacitor used. In particular, a rectifier circuit which is closer to a heat source than before due to the miniaturization of electric and electronic devices, and a circuit of an electric component installed around an engine or in a vehicle as an electric component of an automobile are preferably used because the use environment temperature becomes high. Further, it is preferably applied as a film for a capacitor which is required to have a withstand voltage characteristic under a high voltage and a capacity stabilization under a high frequency, such as a transformer circuit of a hybrid car, an electric vehicle, an electronic exchange, etc. .
[0065]
【Example】
Hereinafter, the present invention will be further described with reference to examples. However, the present invention is not limited to the following examples unless the gist is changed. The measurement methods and definitions of various physical properties and characteristics in the present invention are as follows.
[0066]
(1) Calculation of the component amounts of polyethylene-2,6-naphthalenedicarboxylate (molar ratio of main component, molar ratio of copolymer component)
The film sample was measured with the solvent 3 : CF 3 After dissolving in COOD = 1: 1) 1 H-NMR measurement is performed, and it is calculated by the integration ratio of each obtained signal.
[0067]
(2) Refractive index of film
Using a Metricon prism coupler Model 2010, the longitudinal direction (0 ° direction), 15 ° direction, 30 ° direction, 45 ° direction, 60 ° direction, and 75 ° direction in the film plane at wavelengths of 473 nm, 633 nm, and 830 nm. , 90 °, 105 °, 120 °, 135 °, 150 °, and 165 ° directions. Next, the obtained measured values at the wavelengths of 473 nm, 633 nm, and 830 nm in each direction are applied to the following Cauchy's dispersion formula (5).
[0068]
(Equation 4)
n i = A + [b / (λ i ) 2 ] + [C / (λ i ) 4 ] …… (5)
Where λ in equation (5) i Is the measurement wavelength. n i Is the wavelength λ i Is the refractive index measured at. The results of the refractive index measurement at the wavelengths of 473 nm, 633 nm, and 830 nm are substituted into Equation (5), and the simultaneous equations are solved to obtain constants a, b, and c. Then, using the obtained values of a, b, and c, the refractive index at a wavelength of 589 nm (the wavelength of the Na-D line) is obtained by calculation, and is used as the refractive index of the film. Among the obtained refractive indices in each direction, the one having the maximum value and the one having the minimum value were defined as the refractive index maximum value and the refractive index minimum value, respectively.
[0069]
(3) Density
It is measured by a floatation method at 25 ° C. in a density gradient tube using an aqueous solution of calcium nitrate.
[0070]
(4) Heat shrinkage
Mark lines are inserted at predetermined intervals along the longitudinal direction (MD) or the width direction (TD) of the sample film, and are tension-free in an oven set at a predetermined temperature (150 ° C or 200 ° C). The film is held for a period of time (30 minutes or 10 minutes), and the dimensional change before and after heat treatment (each 150 ° C. × 30 minutes, 200 ° C. × 10 minutes) is calculated as the heat shrinkage ratio by the following equation (6).
[0071]
(Equation 5)
Heat shrinkage (%) = {(length before heat treatment−length after heat treatment) / length before heat treatment} × 100 (6)
[0072]
(5) Flatness of film (appropriate processing)
The biaxially stretched film is slit with a width of 500 mm to prepare a roll sample having a winding length of 1000 m. After heat-treating the obtained roll sample in an oven set at a temperature of 80 ° C. for 4 hours, the film was transferred horizontally and in parallel between two transport rolls arranged at intervals of 1 m, and a constant tension (4 kg / m width). The film was observed from the side, the distance of the most sagging due to the sag was measured and defined as the amount of sag, and the state of wrinkles was observed and evaluated according to the following criteria. In addition, the following evaluations were evaluated as "good" and "good".
：: No wrinkles were observed in the film, the amount of sagging of the film was less than 5 mm, and the flatness of the film was extremely good.
Δ: No wrinkle was observed in the film, the amount of sagging of the film was 5 mm or more and less than 15 mm, and the flatness of the film was good.
X: Wrinkles are seen in the film, or the sagging amount of the film is 15 mm or more, and the flatness of the film is poor.
[0073]
(6) Breakdown voltage (BDV)
It was measured according to the method shown in JIS C 2318, and the minimum value of n = 200 was taken as the breakdown voltage (BDV).
[0074]
In the present invention, the breakdown voltage is preferably 220 V / μm or more, and particularly preferably 240 V / μm or more.
[0075]
[Example 1]
100 parts of dimethyl 2,6-naphthalenedicarboxylate, 60 parts of ethylene glycol, 0.03 part of manganese acetate tetrahydrate as a transesterification catalyst, 0.45% by weight of calcium carbonate particles having an average particle diameter of 1.1 μm as a lubricant And 0.30% by weight of kaolin clay particles (plate-like aluminum silicate particles) having an average particle size of 0.8 μm were added thereto, and a transesterification reaction was carried out in accordance with a conventional method, followed by 0.023 parts of trimethyl phosphate. Was added to substantially terminate the transesterification reaction.
[0076]
Then, 0.024 parts of antimony trioxide was added, and a polymerization reaction was carried out by a conventional method at a high temperature and a high vacuum, followed by polyethylene-2,6-naphthalenedicarboxylate (PEN Tg) having an intrinsic viscosity of 0.62 dl / g. = 121 ° C).
[0077]
After drying this PEN polymer at 170 ° C. for 5 hours, it is supplied to an extruder, melted at a melting temperature of 290 ° C., filtered through a nonwoven fabric filter having an average opening of 30 μm made of stainless steel fine wire having a wire diameter of 14 μm, and then filtered. After extruding from the slit, it was cooled and solidified on a casting drum having a surface temperature set at 50 ° C. to produce an unstretched film.
[0078]
The unstretched film was introduced into a simultaneous biaxial stretching machine, preheated at 125 ° C., and simultaneously stretched at 145 ° C. with a clip 3.5 times in the vertical direction and 3.8 times in the horizontal direction while holding the clip. Thereafter, while heat-setting at 200 ° C., 230 ° C., and 235 ° C. for 2 seconds in the first, second, and third heat-setting zones, respectively, a 0.7% relaxation is given in the vertical and horizontal directions in the third heat-setting zone. Thus, a biaxially oriented film having a thickness of 2.5 μm was obtained. Table 1 shows the physical properties and evaluation results of the biaxially oriented film.
[0079]
[Example 2]
A film was formed in the same manner as in Example 1 except that the film was stretched by 3.2 times in the vertical direction and 3.6 times in the horizontal direction. Table 1 shows the physical properties and evaluation results of the obtained biaxially oriented film.
[0080]
[Example 3]
A film was formed in the same manner as in Example 1 except that the film was stretched 3.3 times in the vertical direction and 4.1 times in the horizontal direction. Table 1 shows the physical properties and evaluation results of the obtained biaxially oriented film.
[0081]
[Example 4]
A film was formed in the same manner as in Example 1 except that the temperatures of the first, second, and third heat fixing zones were set to 195 ° C., 220 ° C., and 230 ° C., respectively. Table 1 shows the physical properties and evaluation results of the obtained biaxially oriented film.
[0082]
[Example 5]
Inert particles to be added as a lubricant are added so as to contain 0.25% by weight of spherical silica particles having an average particle diameter of 1.3 μm and 0.25% by weight of spherical silica particles having an average particle diameter of 0.2 μm. An unstretched film was prepared in the same manner as in Example 1 except that 0.62 dl / g of polyethylene-2,6-naphthalenedicarboxylate (PEN Tg = 121 ° C.) was obtained, and a film was formed in the same manner. Table 1 shows the physical properties and results of the obtained biaxially oriented film.
[0083]
[Comparative Example 1]
A film was formed in the same manner as in Example 1 except that the film was stretched 2.9 times in the vertical direction and 3.6 times in the horizontal direction. Table 1 shows the physical properties and evaluation results of the obtained biaxially oriented film. This film has a low refractive index and a low dielectric breakdown voltage of the film.
[0084]
[Comparative Example 2]
The procedure was performed except that the film was stretched 3.8 times in the machine direction and 3.5 times in the transverse direction, and the third heat setting zone temperature was set to 245 ° C. to give 3.2% relaxation in both the machine direction and the transverse direction. A film was formed in the same manner as in Example 1. Table 1 shows the physical properties and evaluation results of the obtained biaxially oriented film. This film has a low refractive index, a high film density, and a low dielectric breakdown voltage of the film.
[0085]
[Comparative Example 3]
Same as Example 1 except that the film was stretched by 3.4 times in the vertical direction and 3.9 times in the horizontal direction, and the temperatures of the first, second and third heat fixing zones were set to 180 ° C., 200 ° C. and 170 ° C., respectively. A film was formed. Table 1 shows the evaluation results of the obtained biaxially oriented film. This film has a low refractive index and a low film density, so that the film has a low dielectric breakdown voltage.
[0086]
[Table 1]
As is clear from the results shown in Table 1, the polyester film for a capacitor of the present invention has a high dielectric breakdown voltage, a good heat shrinkage behavior of the film, and a good flatness and thickness variation of the film. It was excellent as a film for capacitors.
[0088]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, the polyester film for capacitors which is excellent in insulation property and processability, and can be used with high reliability even if used at 80-120 degreeC environment can be obtained.
Claims (8)
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| JP2002261067A JP4086598B2 (en) | 2002-09-06 | 2002-09-06 | Polyester film for capacitors |
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| JP2002261067A JP4086598B2 (en) | 2002-09-06 | 2002-09-06 | Polyester film for capacitors |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007059335A (en) * | 2005-08-26 | 2007-03-08 | Toshiba Corp | Electrical insulation material and cast molding |
| JP2008045082A (en) * | 2006-08-21 | 2008-02-28 | Teijin Dupont Films Japan Ltd | Biaxially oriented polyester film for automobile drive motors |
| JP2008083191A (en) * | 2006-09-26 | 2008-04-10 | Mitsubishi Polyester Film Copp | Polyester film roll for optical filters |
| JP2008081552A (en) * | 2006-09-26 | 2008-04-10 | Mitsubishi Polyester Film Copp | Polyester film roll for lens sheet |
| JP2008081551A (en) * | 2006-09-26 | 2008-04-10 | Mitsubishi Polyester Film Copp | Polyester film roll for diffusion plate |
| CN113892153A (en) * | 2019-07-09 | 2022-01-04 | 株式会社村田制作所 | Film capacitor and film for film capacitor |
-
2002
- 2002-09-06 JP JP2002261067A patent/JP4086598B2/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007059335A (en) * | 2005-08-26 | 2007-03-08 | Toshiba Corp | Electrical insulation material and cast molding |
| JP2008045082A (en) * | 2006-08-21 | 2008-02-28 | Teijin Dupont Films Japan Ltd | Biaxially oriented polyester film for automobile drive motors |
| JP2008083191A (en) * | 2006-09-26 | 2008-04-10 | Mitsubishi Polyester Film Copp | Polyester film roll for optical filters |
| JP2008081552A (en) * | 2006-09-26 | 2008-04-10 | Mitsubishi Polyester Film Copp | Polyester film roll for lens sheet |
| JP2008081551A (en) * | 2006-09-26 | 2008-04-10 | Mitsubishi Polyester Film Copp | Polyester film roll for diffusion plate |
| CN113892153A (en) * | 2019-07-09 | 2022-01-04 | 株式会社村田制作所 | Film capacitor and film for film capacitor |
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|---|---|
| JP4086598B2 (en) | 2008-05-14 |
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