JPS6149763B2 - - Google Patents
Info
- Publication number
- JPS6149763B2 JPS6149763B2 JP9505678A JP9505678A JPS6149763B2 JP S6149763 B2 JPS6149763 B2 JP S6149763B2 JP 9505678 A JP9505678 A JP 9505678A JP 9505678 A JP9505678 A JP 9505678A JP S6149763 B2 JPS6149763 B2 JP S6149763B2
- Authority
- JP
- Japan
- Prior art keywords
- film
- polyester
- crystallinity
- polyester film
- capacitor
- 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.)
- Expired
Links
- 229920000728 polyester Polymers 0.000 claims description 26
- 239000003990 capacitor Substances 0.000 claims description 25
- 229920006267 polyester film Polymers 0.000 claims description 23
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 claims description 18
- 150000002484 inorganic compounds Chemical class 0.000 claims description 16
- 229910010272 inorganic material Inorganic materials 0.000 claims description 16
- 239000002245 particle Substances 0.000 claims description 16
- -1 phosphorus compound Chemical class 0.000 claims description 13
- KKEYFWRCBNTPAC-UHFFFAOYSA-N Terephthalic acid Chemical compound OC(=O)C1=CC=C(C(O)=O)C=C1 KKEYFWRCBNTPAC-UHFFFAOYSA-N 0.000 claims description 12
- 239000002253 acid Substances 0.000 claims description 10
- 238000005886 esterification reaction Methods 0.000 claims description 9
- 229910052698 phosphorus Inorganic materials 0.000 claims description 8
- 239000011574 phosphorus Substances 0.000 claims description 8
- 239000002994 raw material Substances 0.000 claims description 7
- 238000006243 chemical reaction Methods 0.000 claims description 3
- 239000007858 starting material Substances 0.000 claims description 2
- 239000010408 film Substances 0.000 description 52
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 10
- 238000005259 measurement Methods 0.000 description 8
- 238000000034 method Methods 0.000 description 8
- 230000000052 comparative effect Effects 0.000 description 7
- 238000009998 heat setting Methods 0.000 description 7
- ADCOVFLJGNWWNZ-UHFFFAOYSA-N antimony trioxide Chemical compound O=[Sb]O[Sb]=O ADCOVFLJGNWWNZ-UHFFFAOYSA-N 0.000 description 6
- 229920000642 polymer Polymers 0.000 description 6
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 5
- 238000006116 polymerization reaction Methods 0.000 description 5
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 4
- 230000007423 decrease Effects 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 229920000139 polyethylene terephthalate Polymers 0.000 description 4
- 239000005020 polyethylene terephthalate Substances 0.000 description 4
- 239000005995 Aluminium silicate Substances 0.000 description 3
- DNIAPMSPPWPWGF-UHFFFAOYSA-N Propylene glycol Chemical compound CC(O)CO DNIAPMSPPWPWGF-UHFFFAOYSA-N 0.000 description 3
- 235000012211 aluminium silicate Nutrition 0.000 description 3
- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 description 3
- 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 3
- 238000006068 polycondensation reaction Methods 0.000 description 3
- QPFMBZIOSGYJDE-UHFFFAOYSA-N 1,1,2,2-tetrachloroethane Chemical compound ClC(Cl)C(Cl)Cl QPFMBZIOSGYJDE-UHFFFAOYSA-N 0.000 description 2
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 2
- WERYXYBDKMZEQL-UHFFFAOYSA-N butane-1,4-diol Chemical compound OCCCCO WERYXYBDKMZEQL-UHFFFAOYSA-N 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- WOZVHXUHUFLZGK-UHFFFAOYSA-N dimethyl terephthalate Chemical compound COC(=O)C1=CC=C(C(=O)OC)C=C1 WOZVHXUHUFLZGK-UHFFFAOYSA-N 0.000 description 2
- YBMRDBCBODYGJE-UHFFFAOYSA-N germanium dioxide Chemical compound O=[Ge]=O YBMRDBCBODYGJE-UHFFFAOYSA-N 0.000 description 2
- QQVIHTHCMHWDBS-UHFFFAOYSA-N isophthalic acid Chemical compound OC(=O)C1=CC=CC(C(O)=O)=C1 QQVIHTHCMHWDBS-UHFFFAOYSA-N 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 239000000377 silicon dioxide Substances 0.000 description 2
- ISIJQEHRDSCQIU-UHFFFAOYSA-N tert-butyl 2,7-diazaspiro[4.5]decane-7-carboxylate Chemical compound C1N(C(=O)OC(C)(C)C)CCCC11CNCC1 ISIJQEHRDSCQIU-UHFFFAOYSA-N 0.000 description 2
- 239000010409 thin film Substances 0.000 description 2
- 238000004804 winding Methods 0.000 description 2
- MMINFSMURORWKH-UHFFFAOYSA-N 3,6-dioxabicyclo[6.2.2]dodeca-1(10),8,11-triene-2,7-dione Chemical group O=C1OCCOC(=O)C2=CC=C1C=C2 MMINFSMURORWKH-UHFFFAOYSA-N 0.000 description 1
- ZPPYYOIUDVPKPK-UHFFFAOYSA-L C(CO)(=O)[O-].[Ge+2].C(CO)(=O)[O-] Chemical compound C(CO)(=O)[O-].[Ge+2].C(CO)(=O)[O-] ZPPYYOIUDVPKPK-UHFFFAOYSA-L 0.000 description 1
- 239000004594 Masterbatch (MB) Substances 0.000 description 1
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N Phenol Chemical compound OC1=CC=CC=C1 ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 description 1
- 239000002202 Polyethylene glycol Substances 0.000 description 1
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 1
- WYOFTXWVYIGTCT-UHFFFAOYSA-K [OH-].[Sb+3].OCC([O-])=O.OCC([O-])=O Chemical compound [OH-].[Sb+3].OCC([O-])=O.OCC([O-])=O WYOFTXWVYIGTCT-UHFFFAOYSA-K 0.000 description 1
- 125000005907 alkyl ester group Chemical group 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 229940058905 antimony compound for treatment of leishmaniasis and trypanosomiasis Drugs 0.000 description 1
- 150000001463 antimony compounds Chemical class 0.000 description 1
- 150000007860 aryl ester derivatives Chemical class 0.000 description 1
- DAMJCWMGELCIMI-UHFFFAOYSA-N benzyl n-(2-oxopyrrolidin-3-yl)carbamate Chemical compound C=1C=CC=CC=1COC(=O)NC1CCNC1=O DAMJCWMGELCIMI-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- YHWCPXVTRSHPNY-UHFFFAOYSA-N butan-1-olate;titanium(4+) Chemical compound [Ti+4].CCCC[O-].CCCC[O-].CCCC[O-].CCCC[O-] YHWCPXVTRSHPNY-UHFFFAOYSA-N 0.000 description 1
- 229910000019 calcium carbonate Inorganic materials 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
- 230000015556 catabolic process Effects 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 239000011362 coarse particle Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- JVLRYPRBKSMEBF-UHFFFAOYSA-K diacetyloxystibanyl acetate Chemical compound [Sb+3].CC([O-])=O.CC([O-])=O.CC([O-])=O JVLRYPRBKSMEBF-UHFFFAOYSA-K 0.000 description 1
- 239000003989 dielectric material Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000032050 esterification Effects 0.000 description 1
- 125000004494 ethyl ester group Chemical group 0.000 description 1
- 239000011888 foil Substances 0.000 description 1
- 150000002291 germanium compounds Chemical class 0.000 description 1
- 229940119177 germanium dioxide Drugs 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- XXMIOPMDWAUFGU-UHFFFAOYSA-N hexane-1,6-diol Chemical compound OCCCCCCO XXMIOPMDWAUFGU-UHFFFAOYSA-N 0.000 description 1
- 239000010954 inorganic particle Substances 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 1
- 239000012046 mixed solvent Substances 0.000 description 1
- KYTZHLUVELPASH-UHFFFAOYSA-N naphthalene-1,2-dicarboxylic acid Chemical compound C1=CC=CC2=C(C(O)=O)C(C(=O)O)=CC=C21 KYTZHLUVELPASH-UHFFFAOYSA-N 0.000 description 1
- 150000003018 phosphorus compounds Chemical class 0.000 description 1
- 239000002985 plastic film Substances 0.000 description 1
- 229920006255 plastic film Polymers 0.000 description 1
- 229920001515 polyalkylene glycol Polymers 0.000 description 1
- 229920001223 polyethylene glycol Polymers 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- HKJYVRJHDIPMQB-UHFFFAOYSA-N propan-1-olate;titanium(4+) Chemical compound CCCO[Ti](OCCC)(OCCC)OCCC HKJYVRJHDIPMQB-UHFFFAOYSA-N 0.000 description 1
- 239000011541 reaction mixture Substances 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 239000000454 talc Substances 0.000 description 1
- 229910052623 talc Inorganic materials 0.000 description 1
- KKEYFWRCBNTPAC-UHFFFAOYSA-L terephthalate(2-) Chemical compound [O-]C(=O)C1=CC=C(C([O-])=O)C=C1 KKEYFWRCBNTPAC-UHFFFAOYSA-L 0.000 description 1
- 150000003609 titanium compounds Chemical class 0.000 description 1
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-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
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Fixed Capacitors And Capacitor Manufacturing Machines (AREA)
- Organic Insulating Materials (AREA)
- Manufacture Of Macromolecular Shaped Articles (AREA)
- Shaping By String And By Release Of Stress In Plastics And The Like (AREA)
Description
本発明はコンデンサー用ポリエステルフイルム
に関するものである。更に詳しくは優れた作業性
と電気特性とを兼ね備えたコンデンサー用ポリエ
ステルフイルムに関するものである。
コンデンサーの小型化が押し進められている今
日、ポリエチレンテレフタレート二軸延伸フイル
ムは薄くて均一なフイルムが得られるようにな
り、且つ従来用いられている含浸紙に比べ耐電圧
性が良いため含浸紙に代つて次第に需要が増大し
ている。ポリエチレンテレフタレートで薄いフイ
ルムを製造するためにはかなり高度な製膜技術が
要求されるが、最近では製膜法の進歩も相まつて
2.5μの超薄番手フイルムまで出現してきてい
る。
しかしながらフイルムが薄くなればなるほどフ
イルム取扱い時の作業性及び電気特性に関し種々
の問題が生じて来ている。
プラスチツクフイルムコンデンサーには蒸着コ
ンデンサーと箔巻コンデンサーとがあるが双方と
もフイルムに要求される特性は同様である。まず
ロール巻き、素子巻きなどの製造加工工程におけ
る作業性即ちフイルムの滑り性が良好なことが必
須要件である。またこのポリエステルフイルムは
スリツトして細片として用いられるが、このスリ
ツト時のの作業性が悪いとスリツトした部分が盛
り上る現象が起りポリエステルフイルムとしての
厚さの均一性が損なわれる。従つてスリツト時の
作業性が良好な事もコンデンサー用フイルムとし
て備えるべき重要な要件の一つである。
一方コンデンサー用フイルムとして必要な電気
特性として代表的なものとして耐電圧特性及び常
温並びに高温度における静電容量と電気抵抗との
積即ち「CR値」と呼ばれる特性がある。
かかるコンデンサー用フイルムとして具備すべ
き特性のうちフイルムの滑り性を向上させるには
何らかの方法でフイルム表面に凹凸を予えれば良
く、例えばカオリン、タルク、シリカ、炭酸カル
シウム等の不活性無機化合物を均一に配合したポ
リエステルを用いればよいことが知られている。
しかしこのような無機化合物をポリエステル中
に配合した場合は、CR値特に100℃以上の高温時
におけるCR値の大幅な低下を防ぐことができな
かつた。
一方エネルギーの節約、コストの低下という観
点からは、フイルム形成用ポリエチレンテレフタ
レートの酸成分の原料を従来用いられているテレ
フタル酸ジメチルからテレフタル酸に遡及して求
めることがより切実に望まれるようになつた。こ
のようにいわゆる直接重合法によるポリエステル
を用いて性能の良いフイルムを得ることが要求さ
れているのが実情である。
本発明者らは上記実情に鑑みて鋭意検討を行な
つたところ、直接重合法によるポリエステルから
得られたコンデンサー用フイルムの滑り性、スリ
ツト時の作業性及び耐電圧特性とCR値に代表さ
れる電気特性を同時に満足しようと思えば、特定
のポリエステルに、特定粒径の無機化合物を一定
量配合したポリエステルを用い、しかも該ポリエ
ステルを用いて得られたフイルムの結晶化度をあ
る特定範囲に保つことによつて達成されることを
見出し、本発明に到達した。
即ち、本発明は平均粒径0.5〜３μの不活性無
機化合物を0.05〜１重量％含有してなり、結晶化
度が45〜55％であるコンデンサー用二軸延伸ポリ
エステルフイルムであつて、該ポリエステルフイ
ルムはテレフタル酸とエチレングリコールを主た
る出発原料として、エステル化反応を行つた後、
ポリエステル原料全酸成分に対し、0.005〜0.1モ
ル％のリン化合物を添加して得られるポリエステ
ルを原料として二軸延伸成形したフイルムである
ことを特徴とするコンデンサー用ポリエステルフ
イルムに存する。
以下本発明を詳細に説明する。
本発明におけるポリエステルフイルムはテレフ
タル酸を主たる酸成分としエチレングリコールを
主たるグリコール成分として得られるポリエステ
ルを原料とするが、酸成分及びグリコール成分と
しては他の第三成分を混合使用してもよい。酸成
分としてイソフタル酸、ナフタレンジカルボン酸
等の１種又は２種以上、グリコール成分としてプ
ロピレングリコール、テトラメチレングリコー
ル、ヘキサメチレングリコール等のアルキレング
リコールやポリエチレングリコール等のポリアル
キレングリコールの１種又は２種以上を用いるこ
とができる。いずれにしても本発明におけるポリ
エステルフイルムはエチレンテレフタレート単位
を80モル％以上有するポリエステルフイルムをそ
の対称とする。
本発明においてはフイルムとすべきポリエステ
ルを製造するにあたり、エステル化反応が実質的
に終了した後、全酸成分に対し0.005〜0.1モル％
のリン化合物を添加する。このリン化合物として
は、リン酸、亜リン酸もしくはこれらのアルキル
エステル又はアリールエステルから成る群から選
ばれた化合物の一種以上が好ましく、特にリン
酸、亜リン酸もしくはこのメチルエステル又はエ
チルエステル、就中リン酸が好ましい。
これらリン化合物の使用量がポリエステル原料
全酸成分に対し0.005〜0.1モル％である時初めて
優れた電気特性を有するコンデンサー用フイルム
とすることができる。
即ち、この使用量が0.005モル％未満では、
往々にして高温時のCR値が悪化し、またこの使
用量が0.1モル％を越えるとポリエステル製造時
の重合速度が遅くなり工業的に不利になると共
に、ポリマーの軟化点が低下し耐熱性が悪くなる
のでコンデンサー用フイルムとして使用し難くな
る。
本発明においてはポリエステルフイルムに不活
性無機化合物を配合することが必須である。すな
わち平均粒径0.5〜３μの不活性無機化合物を生
成ポリエステルに対し0.05〜１重量％添加する。
本発明でいう不活性無機化合物は、ポリエステル
製造反応を阻害しないことが必要であり、例えば
カオリン、タルク、シリカ、炭酸カルシウム、酸
化チタン、リン酸カルシウム等を挙げることがで
きる。これら不活性無機化合物は必要に応じ粉
砕、分級され平均粒径0.5〜３μの粒子として使
用される。平均粒径が0.5μ未満ではフイルム表
面が平滑すぎて本発明が目的としている滑り性の
付与に役立たない。一方平均粒径が３μを越える
粗大粒子では絶縁破壊の発生点になるため耐電圧
特性が著しく劣るようになる。この中でも特に平
均粒径１〜２μのものが好ましく使用される。
また該無機化合物の使用量はポリエステルフイ
ルムに対し0.05〜１重量％である。0.05重量％未
満であると最終的に得られたポリエステルフイル
ムの滑り性が不足しまた１重量％を越えるとフイ
ルターの目塞りが起り易くなる。なお0.1〜１重
量％またはそれ以上の無機化合物を含有するマス
ターバツチを製造しておき、無機化合物を添加し
ていないポリマーとブレンドしてポリエステルフ
イルムを製造する方法も好ましく用いられる。い
ずれにしてもポリエステルフイルム中には無機化
合物が0.05〜１重量％、好ましくは0.1〜0.4重量
％含有されていることが必要である。
本発明において用いられるリン化合物及び無機
化合物の添加時期はエステル化反応が実質的に終
了した時点から重縮合反応初期の任意の間であ
る。またリン化合物と無機化合物の添加順序はい
ずれが先でもまた同時でも良い。
なお重縮合反応には任意の触媒を使用すること
ができる。通常三酸化アンチモン、三塩化アンチ
モン、酢酸アンチモン及びアンチモングリコレー
ト等のアンチモン化合物、二酸化ゲルマニウム及
びゲルマニウムグリコレート等のゲルマニウム化
合物、チタニウムテトラプロポキサイド及びチタ
ニウムテトラブトキシサイド等のチタン化合物が
好ましく使用される。かかる重縮合触媒の使用量
は、通常ポリエステルを構成する全酸成分に対し
0.01〜0.3モル％である。
また本発明におけるコンデンサー用ポリエステ
ルフイルムは結晶化度45〜55％の二軸延伸ポリエ
ステルフイルムでなければならない。
即ち、本発明のフイルムは原料ポリエステルを
常法により溶融押出し未延伸フイルムとなし、こ
れを二軸延伸し熱固定することにより得られる
が、これらの条件を調節することにより得られる
フイルムの結晶化度を45〜55％に調節する。
具体的には延伸温度は80〜120℃、延伸倍率は
縦、横、各々2.5〜4.5倍、熱固定温度は1.5〜８秒
間の範囲から選択される。これらのうち得られる
フイルムの結晶化度に特に関係するのは熱固定条
件であり、熱固定温度が高くなるほどまた熱固定
時間が長くなるほど結晶化度は高くなる。
この値は熱処理室の規模、構造、フイルム厚さ
等の条件にも多少左右されるので一概に決まるも
のではないが、例えば熱固定温度を210〜230℃、
熱固定時間を２〜７秒間とすれば得られるフイル
ムの結晶化度を48〜53％程度とすることができ
る。他の条件を一定にして熱固定温度のみを160
〜180℃に下げれば結晶化度38〜42％程度のフイ
ルムとなる。
かかる方法によつて得られたフイルムの結晶化
度が45〜55％、好ましくは48〜53％の範囲にある
時初めてスリツト時の作業性を良好に保つことが
でき、且つ高温時におけるCR値の低下を防ぐこ
とができる。フイルムの結晶化度が45％未満であ
るとスリツト時の作業性が悪くなるし、また55％
を越えると高温時におけるCR値が大幅に低下す
るようになる。
またコンデンサー用フイルムとしては３〜12μ
のフイルム厚さとするのが好ましい。
以上詳述した如く本発明はエステル化反応後特
定量のリン化合物を添加すると共に特定粒径及び
特定量の無機化合物を添加したポリエステルを用
い、しかも該ポリエステルを用いて得られた二軸
延伸ポリエステルフイルムの結晶化度をある特定
範囲に保つた時初めて、滑り性、スリツト時の作
業性、耐電圧特性及び高温時におけるCR値の全
ての特定を満足するコンデンサー用ポリエステル
フイルムを工業的に有利に得ることができその価
は大きい。
以下実施例及び比較例により本発明を更に詳細
に述べる。
なお実施例及び比較例中「部」とあるは「重量
部」を示す。また用いた測定法を次に示す。
極限粘度： ポリマー１ｇをフエノール／テトラ
クロロエタン（１／１重量比）混合溶媒100ml
に溶解させ30.0℃で測定した。
平均粒径： 無機粒子の平均粒径は等価球換算値
であり、その測定は日本科学機械(株)製コールタ
ーカウンター（TA―型）を用いて行なつ
た。
結晶化度： フイルムの結晶化度の算出は密度法
（昭和43年６月10日発行ポリエステル繊維(株)コ
ロナ社 横内澪・中村至著200頁）によつた。
即ち、結晶化度ｘc＝ｄｋ（ｄ−ｄａ）／ｄ（ｄｋ−
ｄａ）×100％
で表わす。
ここで ｄa：非晶質の密度、1331ｇ／cm3
ｄk：結晶質の密度、1455ｇ／cm3
ｄ ：サンプルの密度
滑り性： フイルムの滑り性は摩擦係数で代表し
その測定はASTM Ｄ−1894に準じてテープ状
のサンプルで測定できるように改良した方法で
行なつた。測定は温度21±２℃、湿度65±５％
の雰囲気下で行ない用いたサンプルの大きさは
幅15mm、長さ150mmでその引張り速度は20mm／
minとした。
スリツト時の作業性： ポリエステルフイルムを
スリツトした時のスリツト部分の盛り上りの程
度を電子顕微鏡で観察することにより３ランク
に分けた。Ａは盛り上りがほとんどなく巻き姿
が良好であるもの、Ｃは盛り上りが大きく
（0.3μ以上）巻いた時端部がふくらむもの、Ｂ
は両者の中間である。
耐電圧の測定： 100KV交流対電圧試験機（東洋
精機製 OEL−72034）を用い電圧を上昇させ
てフイルムが破壊して短絡する時の電圧を読み
とつた。
CR値の測定： 供試フイルムを所定の温度に１
時間保つた後測定した。
静電容量、Ｃ、の測定はゼネナルラジオ社製
「RLCデジブリツジ」を用い1KHz、0.3Vrmeの
条件下行ない、電気抵抗Ｒ、の測定は横川ヒユ
レツドパツカード社製超絶縁計を用い直流
100Vを印加した後１分後の測定値を読みとつ
た。両者の積〔Ω・Ｆ〕がCR値である。
実施例 １
撹拌装置、分縮器、原料及び助剤の仕込口、及
び反応生成物取出口を設けたエステル化反応装置
にビス―β―（ヒドロキシエチル）テレフタレー
トオリゴマー100部を取り、テレフタル酸87部と
エチレングリコール42部とを加えた後大気圧下
260℃でエステル化反応を行なつた。４時間後エ
ステル化反応97％のポリエステルオリゴマーが得
られた。
次にこの反応混合物のうち106部（テレフタル
酸87部相当）を取り260℃に保持したまま平均粒
径1.4μのカオリン0.35部及びリン酸0.02部（0.04
モル％対全酸成分）を添加した。
次いで三酸化アンチモン0.03部を添加し常法に
従つて重合した。即ち三酸化アンチモン添加後
100分で系内の温度を275℃、圧力を15mmＨｇに達
せしめ以後も徐々に圧力を減じ最終的に0.3mmＨ
ｇとした。４時間後反応を停止し極限粘度0.66の
ポリマーを得た。
次に得られたポリマーを290℃で押出機よりシ
ート状に押し出し急冷して無定形シートにしたの
ち、95℃で縦及び横方向に各々3.5倍に延伸し200
℃で３秒間熱処理を行ない終晶化度45％の厚さ６
μのフイルムを得た。
このフイルムについて摩擦係数、常温（25℃）
及び高温（125℃）におけるCR値、耐電圧及びス
リツト時の作業性を測定した結果を表１に示す。
実施例 ２
実施例１において平均粒径1.4μのカオリン
0.35部の代りに平均粒径1.2μのシリカ0.20部を用
いる他は実施例１と同様にして、結晶化度47％の
厚さ６μの二軸延伸ポリエチレンテレフタレート
フイルムを得た。
該フイルムについて実施例１と同様な測定を行
ない結果を表１に示した。
比較例 １〜４
実施例１において表１に示す条件に変える他は
実施例１と同様にして厚さ６μのフイルムを得、
該フイルムについて実施例１と同様な測定を行な
つた結果は表１に示した。
比較例 ５〜６
実施例２において表１に示す条件に変える他は
実施例２と同様にして厚さ６μのフイルムを得、
該フイルムについて実施例１と同様な測定を行な
つた。結果は表１に示した。
実施例及び比較例から明らかなように、エステ
ル化反応後特定量のリン化合物及び特定粒径・量
の無機化合物を添加してポリエステルを製造し、
該ポリエステルを用いて結晶化度45〜55％の二軸
延伸ポリエステルフイルムを得た場合のみ、ポリ
マー製造時の重合速度を損うことなく工業的に有
利にコンデンサー誘電体用フイルムとして具備す
べき諸特性を兼ね備えたフイルムを得ることがで
きる。
The present invention relates to a polyester film for capacitors. More specifically, the present invention relates to a polyester film for capacitors that has both excellent workability and electrical properties. Nowadays, as capacitors become smaller, polyethylene terephthalate biaxially stretched film can be used as a substitute for impregnated paper because it can produce a thin and uniform film and has better voltage resistance than conventionally used impregnated paper. Demand is gradually increasing. Producing thin films using polyethylene terephthalate requires fairly advanced film-forming technology, but recent advances in film-forming methods have also been made.
Ultra-thin films as thin as 2.5μ are now appearing. However, as the film becomes thinner, various problems arise regarding the workability and electrical properties of the film when handling it. There are two types of plastic film capacitors: evaporated capacitors and foil-wound capacitors, both of which have similar characteristics required for the film. First, it is essential that the film has good workability in manufacturing processes such as roll winding and element winding, that is, good slipperiness of the film. Further, this polyester film is slit and used as strips, but if the workability during slitting is poor, the slit portions may bulge, impairing the uniformity of the thickness of the polyester film. Therefore, good workability during slitting is one of the important requirements for a capacitor film. On the other hand, representative electrical properties necessary for a capacitor film include withstand voltage properties and a property called "CR value", which is the product of capacitance and electrical resistance at room temperature and high temperature. In order to improve the slipperiness of the film, which is one of the properties that such a capacitor film should have, it is sufficient to make the film surface rough by some method. It is known that polyester blended with However, when such an inorganic compound is blended into polyester, it has not been possible to prevent a significant decrease in the CR value, especially at high temperatures of 100° C. or higher. On the other hand, from the viewpoint of saving energy and reducing costs, it has become more urgent to obtain terephthalic acid from the conventionally used dimethyl terephthalate as the raw material for the acid component of polyethylene terephthalate for film formation. Ta. As described above, the actual situation is that it is required to obtain films with good performance using polyesters produced by the so-called direct polymerization method. In view of the above circumstances, the present inventors conducted intensive studies and found that the slipperiness, workability during slitting, withstand voltage characteristics, and CR value of a capacitor film obtained from polyester by direct polymerization method were found. If you want to satisfy the electrical properties at the same time, you should use a polyester that is a specific polyester mixed with a certain amount of an inorganic compound of a specific particle size, and keep the crystallinity of the film obtained using the polyester within a certain range. The present invention was achieved based on the discovery that this can be achieved by: That is, the present invention provides a biaxially stretched polyester film for a capacitor, which contains 0.05 to 1% by weight of an inert inorganic compound with an average particle size of 0.5 to 3μ, and has a crystallinity of 45 to 55%. After performing an esterification reaction using terephthalic acid and ethylene glycol as the main starting materials, the film is
A polyester film for a capacitor, characterized in that it is a film biaxially stretched using a polyester obtained by adding 0.005 to 0.1 mol % of a phosphorus compound to the total acid component of the polyester raw material. The present invention will be explained in detail below. The polyester film in the present invention is made from a polyester obtained with terephthalic acid as the main acid component and ethylene glycol as the main glycol component, but other third components may be mixed and used as the acid component and the glycol component. One or more types of isophthalic acid, naphthalene dicarboxylic acid, etc. as the acid component, and one or more types of alkylene glycols such as propylene glycol, tetramethylene glycol, hexamethylene glycol, and polyalkylene glycols such as polyethylene glycol as the glycol component. can be used. In any case, the polyester film in the present invention is a polyester film having 80 mol% or more of ethylene terephthalate units. In the present invention, when producing a polyester to be made into a film, after the esterification reaction is substantially completed, 0.005 to 0.1 mol% of the total acid component is used.
of phosphorus compound is added. The phosphorus compound is preferably one or more compounds selected from the group consisting of phosphoric acid, phosphorous acid, or their alkyl esters or aryl esters, particularly phosphoric acid, phosphorous acid, or their methyl or ethyl esters. Medium phosphoric acid is preferred. A capacitor film having excellent electrical properties can only be obtained when the amount of these phosphorus compounds used is 0.005 to 0.1 mol % based on the total acid component of the polyester raw material. That is, if the amount used is less than 0.005 mol%,
The CR value at high temperatures often worsens, and if the amount used exceeds 0.1 mol%, the polymerization rate during polyester production slows down, which is industrially disadvantageous, and the softening point of the polymer decreases, resulting in poor heat resistance. As the film deteriorates, it becomes difficult to use it as a capacitor film. In the present invention, it is essential to blend an inert inorganic compound into the polyester film. That is, an inert inorganic compound having an average particle size of 0.5 to 3 microns is added in an amount of 0.05 to 1% by weight based on the polyester produced.
The inert inorganic compound referred to in the present invention must not inhibit the polyester production reaction, and examples thereof include kaolin, talc, silica, calcium carbonate, titanium oxide, and calcium phosphate. These inert inorganic compounds are crushed and classified as necessary and used as particles having an average particle size of 0.5 to 3 μm. If the average particle size is less than 0.5μ, the film surface will be too smooth and will not be useful in imparting the slipperiness that is the objective of the present invention. On the other hand, coarse particles with an average particle diameter of more than 3 μm become a point of occurrence of dielectric breakdown, resulting in significantly poor withstand voltage characteristics. Among these, those having an average particle size of 1 to 2 μm are particularly preferably used. The amount of the inorganic compound used is 0.05 to 1% by weight based on the polyester film. If it is less than 0.05% by weight, the final polyester film will have insufficient slipperiness, and if it exceeds 1% by weight, the filter will tend to become clogged. Also preferably used is a method in which a masterbatch containing 0.1 to 1% by weight or more of an inorganic compound is produced and blended with a polymer to which no inorganic compound is added to produce a polyester film. In any case, it is necessary that the inorganic compound be contained in the polyester film in an amount of 0.05 to 1% by weight, preferably 0.1 to 0.4% by weight. The timing of addition of the phosphorus compound and inorganic compound used in the present invention is any time between the time when the esterification reaction is substantially completed and the beginning of the polycondensation reaction. Further, the phosphorus compound and the inorganic compound may be added in either order or at the same time. Note that any catalyst can be used in the polycondensation reaction. Generally, antimony compounds such as antimony trioxide, antimony trichloride, antimony acetate and antimony glycolate, germanium compounds such as germanium dioxide and germanium glycolate, and titanium compounds such as titanium tetrapropoxide and titanium tetrabutoxide are preferably used. . The amount of such polycondensation catalyst used is usually based on the total acid components constituting the polyester.
It is 0.01-0.3 mol%. Further, the polyester film for a capacitor in the present invention must be a biaxially oriented polyester film with a crystallinity of 45 to 55%. That is, the film of the present invention can be obtained by melt-extruding a raw material polyester into an unstretched film by a conventional method, biaxially stretching it, and heat-setting it. However, by adjusting these conditions, the resulting film can be crystallized. Adjust the degree to 45-55%. Specifically, the stretching temperature is selected from the range of 80 to 120°C, the stretching ratio is selected from the range of 2.5 to 4.5 times in both the longitudinal and transverse directions, and the heat setting temperature is selected from the range of 1.5 to 8 seconds. Among these, the heat setting conditions are particularly related to the crystallinity of the obtained film, and the higher the heat setting temperature and the longer the heat setting time, the higher the crystallinity. This value cannot be determined unconditionally, as it depends somewhat on conditions such as the size and structure of the heat treatment chamber, film thickness, etc., but for example, if the heat setting temperature is 210 to 230℃,
By setting the heat setting time to 2 to 7 seconds, the crystallinity of the resulting film can be approximately 48 to 53%. Keeping other conditions constant, only the heat fixing temperature is set to 160
If the temperature is lowered to ~180°C, a film with a crystallinity of 38 to 42% will be obtained. Only when the crystallinity of the film obtained by this method is in the range of 45 to 55%, preferably 48 to 53%, it is possible to maintain good workability during slitting, and the CR value at high temperatures can be maintained. can prevent a decline in If the crystallinity of the film is less than 45%, workability during slitting will be poor;
When the temperature exceeds 1, the CR value at high temperatures decreases significantly. Also, as a film for capacitors, 3 to 12μ
It is preferable to set the film thickness to . As detailed above, the present invention uses a polyester to which a specific amount of a phosphorus compound is added after an esterification reaction and a specific particle size and a specific amount of an inorganic compound, and furthermore, a biaxially oriented polyester obtained using the polyester is used. It is only when the crystallinity of the film is maintained within a certain range that polyester films for capacitors that satisfy all the specifications of slipperiness, workability during slitting, withstand voltage characteristics, and CR value at high temperatures can be industrially advantageous. You can get it for a great price. The present invention will be described in more detail below with reference to Examples and Comparative Examples. In the Examples and Comparative Examples, "parts" indicate "parts by weight." The measurement method used is shown below. Intrinsic viscosity: 1 g of polymer in 100 ml of phenol/tetrachloroethane (1/1 weight ratio) mixed solvent
The sample was dissolved in water and measured at 30.0°C. Average particle size: The average particle size of the inorganic particles is an equivalent sphere equivalent value, and was measured using a Coulter Counter (TA-type) manufactured by Nippon Kagaku Kikai Co., Ltd. Crystallinity: The crystallinity of the film was calculated by the density method (Page 200, written by Mio Yokouchi and Itaru Nakamura, published by Polyester Fiber Co., Ltd., Corona Publishing, June 10, 1963). That is, crystallinity x c = d k (d - d a )/d (d k -
It is expressed as d a )×100%. where d a : Density of amorphous, 1331 g/cm 3 d k : Density of crystal, 1455 g/cm 3 d : Density of sample Sliding property: Sliding property of the film is represented by the coefficient of friction, and its measurement is based on ASTM D. -1894, using a method modified to allow measurement with tape-shaped samples. Measurements were made at a temperature of 21±2℃ and a humidity of 65±5%.
The size of the sample used was 15 mm in width and 150 mm in length, and the tensile speed was 20 mm/
It was set as min. Workability during slitting: When a polyester film was slit, the degree of bulge in the slit portion was observed with an electron microscope and divided into three ranks. A: There is almost no bulge and the rolled shape is good, C: the bulge is large (0.3μ or more) and the end bulges when rolled, B
is between the two. Measurement of withstand voltage: Using a 100KV AC voltage tester (OEL-72034 manufactured by Toyo Seiki), the voltage was increased and the voltage at which the film was destroyed and a short circuit occurred was read. Measurement of CR value: Bring the test film to the specified temperature.
Measured after keeping for an hour. The capacitance, C, was measured using "RLC DigiBridge" manufactured by General Radio Co., Ltd. under the conditions of 1 KHz and 0.3 Vrme, and the electrical resistance, R, was measured using a super megohmmeter manufactured by Yokogawa Hyuretsu Card Co., Ltd. using direct current.
The measured value was read 1 minute after applying 100V. The product of both [Ω·F] is the CR value. Example 1 100 parts of bis-β-(hydroxyethyl) terephthalate oligomer was placed in an esterification reactor equipped with a stirring device, a partial condenser, an inlet for raw materials and auxiliaries, and an outlet for the reaction product, and 87 parts of terephthalic acid was added. and 42 parts of ethylene glycol under atmospheric pressure.
The esterification reaction was carried out at 260°C. After 4 hours, a polyester oligomer with 97% esterification reaction was obtained. Next, 106 parts (equivalent to 87 parts of terephthalic acid) of this reaction mixture were taken and kept at 260°C, and 0.35 parts of kaolin with an average particle size of 1.4μ and 0.02 parts of phosphoric acid (0.04 parts of phosphoric acid) were taken.
mol % vs. total acid component) was added. Next, 0.03 part of antimony trioxide was added and polymerization was carried out according to a conventional method. i.e. after adding antimony trioxide
In 100 minutes, the temperature in the system reached 275℃ and the pressure reached 15mmHg, and then the pressure was gradually reduced to 0.3mmHg.
g. After 4 hours, the reaction was stopped and a polymer having an intrinsic viscosity of 0.66 was obtained. Next, the obtained polymer was extruded into a sheet form from an extruder at 290°C, rapidly cooled to form an amorphous sheet, and then stretched at 95°C to 3.5 times in both the longitudinal and transverse directions.
Heat treated at ℃ for 3 seconds to obtain a thickness of 6 with a final crystallinity of 45%.
A film of μ was obtained. About this film Friction coefficient, normal temperature (25℃)
Table 1 shows the results of measuring the CR value, withstand voltage, and workability during slitting at high temperatures (125°C). Example 2 Kaolin with an average particle size of 1.4μ in Example 1
A biaxially stretched polyethylene terephthalate film having a crystallinity of 47% and a thickness of 6 μm was obtained in the same manner as in Example 1, except that 0.20 part of silica having an average particle size of 1.2 μm was used instead of 0.35 part. The same measurements as in Example 1 were carried out on the film, and the results are shown in Table 1. Comparative Examples 1 to 4 Films with a thickness of 6 μm were obtained in the same manner as in Example 1 except that the conditions shown in Table 1 were changed.
The same measurements as in Example 1 were performed on the film, and the results are shown in Table 1. Comparative Examples 5 to 6 A film with a thickness of 6 μm was obtained in the same manner as in Example 2 except that the conditions shown in Table 1 were changed.
The same measurements as in Example 1 were performed on the film. The results are shown in Table 1. As is clear from the Examples and Comparative Examples, after the esterification reaction, a specific amount of phosphorus compound and a specific particle size and amount of inorganic compound are added to produce polyester,
Only when a biaxially oriented polyester film with a crystallinity of 45 to 55% is obtained using the polyester, various features that should be provided as a film for capacitor dielectrics can be realized industrially without impairing the polymerization rate during polymer production. A film having both properties can be obtained.
【表】
参考例
実施例１及び比較例１，２で得られた厚み６μ
のフイルムを用いてコンデンサーを製造し各々の
電気特性を比較した。
即ち実施例１で得られた厚み６μのポリエステ
ルフイルムを幅15mmにスリツトしたのち、厚み６
μのアルミニウム箔と重ねて巻き上げプレスして
偏平化してコンデンサー素子を製造した。比較例
１，２のフイルムについても同様な操作を行ない
コンデンサー素子を製造した。
これらのコンデンサーについて電気特性を評価
した結果を表２に示す。
この結果から特定条件を満した本発明のフイル
ムを用いた時初めて優れた電気特性を有するコン
デンサーを製造することができることが解る。[Table] Reference example Thickness 6μ obtained in Example 1 and Comparative Examples 1 and 2
Capacitors were manufactured using these films and the electrical characteristics of each were compared. That is, after slitting the 6 μm thick polyester film obtained in Example 1 to a width of 15 mm,
A capacitor element was manufactured by stacking it with μ aluminum foil and rolling it up and pressing it to flatten it. The same operation was performed on the films of Comparative Examples 1 and 2 to produce capacitor elements. Table 2 shows the results of evaluating the electrical characteristics of these capacitors. These results show that a capacitor with excellent electrical properties can only be produced by using the film of the present invention that satisfies specific conditions.
Claims (1)
0.05〜１重量％含有してなり、結晶化度が45〜55
％であるコンデンサー用二軸延伸ポリエステルフ
イルムであつて、該ポリエステルフイルムはテレ
フタル酸とエチレングリコールを主たる出発原料
として、エステル化反応を行つた後、反応系ポリ
エステル原料全酸成分に対し、0.005〜0.1モル％
のリン化合物を添加して得られるポリエステルを
原料として二軸延伸成形したフイルムであること
を特徴とするコンデンサー用ポリエステルフイル
ム。1 Inert inorganic compound with an average particle size of 0.5 to 3μ
It contains 0.05 to 1% by weight, and the crystallinity is 45 to 55.
% of the biaxially oriented polyester film for capacitors, the polyester film undergoes an esterification reaction using terephthalic acid and ethylene glycol as the main starting materials, and then has a concentration of 0.005 to 0.1% based on the total acid component of the polyester raw material in the reaction system. mole%
1. A polyester film for a capacitor, which is biaxially stretched and formed using a polyester obtained by adding a phosphorus compound as a raw material.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9505678A JPS5522826A (en) | 1978-08-04 | 1978-08-04 | Polyester film for capacitor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9505678A JPS5522826A (en) | 1978-08-04 | 1978-08-04 | Polyester film for capacitor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5522826A JPS5522826A (en) | 1980-02-18 |
| JPS6149763B2 true JPS6149763B2 (en) | 1986-10-31 |
Family
ID=14127380
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9505678A Granted JPS5522826A (en) | 1978-08-04 | 1978-08-04 | Polyester film for capacitor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5522826A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS572513A (en) * | 1980-06-05 | 1982-01-07 | Unitika Ltd | Biaxially oriented polyethylene telephthalate film for film capacitor |
-
1978
- 1978-08-04 JP JP9505678A patent/JPS5522826A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5522826A (en) | 1980-02-18 |
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