JPS6358162B2 - - Google Patents
Info
- Publication number
- JPS6358162B2 JPS6358162B2 JP13326081A JP13326081A JPS6358162B2 JP S6358162 B2 JPS6358162 B2 JP S6358162B2 JP 13326081 A JP13326081 A JP 13326081A JP 13326081 A JP13326081 A JP 13326081A JP S6358162 B2 JPS6358162 B2 JP S6358162B2
- Authority
- JP
- Japan
- Prior art keywords
- fluorine
- group
- containing polymer
- membrane
- manufacturing
- 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
- 229920000642 polymer Polymers 0.000 claims description 38
- 229910052731 fluorine Inorganic materials 0.000 claims description 35
- 239000011737 fluorine Substances 0.000 claims description 35
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 claims description 33
- 125000000472 sulfonyl group Chemical group *S(*)(=O)=O 0.000 claims description 28
- 238000000034 method Methods 0.000 claims description 19
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 claims description 17
- 238000004519 manufacturing process Methods 0.000 claims description 12
- 238000005868 electrolysis reaction Methods 0.000 claims description 7
- 125000000542 sulfonic acid group Chemical group 0.000 claims description 7
- 239000003054 catalyst Substances 0.000 claims description 5
- 229910001515 alkali metal fluoride Inorganic materials 0.000 claims description 4
- 229920001577 copolymer Polymers 0.000 claims description 4
- 239000000463 material Substances 0.000 claims description 4
- 125000002128 sulfonyl halide group Chemical group 0.000 claims description 3
- BFKJFAAPBSQJPD-UHFFFAOYSA-N tetrafluoroethene Chemical group FC(F)=C(F)F BFKJFAAPBSQJPD-UHFFFAOYSA-N 0.000 claims description 3
- TXEYQDLBPFQVAA-UHFFFAOYSA-N tetrafluoromethane Chemical group FC(F)(F)F TXEYQDLBPFQVAA-UHFFFAOYSA-N 0.000 claims description 2
- QYKIQEUNHZKYBP-UHFFFAOYSA-N Vinyl ether Chemical compound C=COC=C QYKIQEUNHZKYBP-UHFFFAOYSA-N 0.000 claims 1
- 239000012528 membrane Substances 0.000 description 24
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 15
- 238000010521 absorption reaction Methods 0.000 description 12
- 238000006243 chemical reaction Methods 0.000 description 10
- -1 alkali metal salt Chemical class 0.000 description 9
- 239000010408 film Substances 0.000 description 8
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 6
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 5
- 239000011259 mixed solution Substances 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- 229910052783 alkali metal Inorganic materials 0.000 description 3
- 238000002329 infrared spectrum Methods 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- 150000003839 salts Chemical class 0.000 description 3
- 239000011734 sodium Substances 0.000 description 3
- 239000011780 sodium chloride Substances 0.000 description 3
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N Dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 description 2
- PIICEJLVQHRZGT-UHFFFAOYSA-N Ethylenediamine Chemical compound NCCN PIICEJLVQHRZGT-UHFFFAOYSA-N 0.000 description 2
- 125000000217 alkyl group Chemical group 0.000 description 2
- 150000003863 ammonium salts Chemical class 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 239000004744 fabric Substances 0.000 description 2
- 239000000835 fiber Substances 0.000 description 2
- 125000001153 fluoro group Chemical group F* 0.000 description 2
- 239000008187 granular material Substances 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 239000001257 hydrogen Substances 0.000 description 2
- 230000007062 hydrolysis Effects 0.000 description 2
- 238000006460 hydrolysis reaction Methods 0.000 description 2
- 238000007654 immersion Methods 0.000 description 2
- 239000003014 ion exchange membrane Substances 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000000178 monomer Substances 0.000 description 2
- XHXFXVLFKHQFAL-UHFFFAOYSA-N phosphoryl trichloride Chemical compound ClP(Cl)(Cl)=O XHXFXVLFKHQFAL-UHFFFAOYSA-N 0.000 description 2
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 2
- 239000004810 polytetrafluoroethylene Substances 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- 229910052708 sodium Inorganic materials 0.000 description 2
- 125000000565 sulfonamide group Chemical group 0.000 description 2
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 2
- 229920002554 vinyl polymer Polymers 0.000 description 2
- HCKHZJUPUJQYRH-UHFFFAOYSA-N 1,1,2,3,4,4,6-heptafluorohex-1-ene Chemical compound FCCC(F)(F)C(F)C(F)=C(F)F HCKHZJUPUJQYRH-UHFFFAOYSA-N 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- KRHYYFGTRYWZRS-UHFFFAOYSA-M Fluoride anion Chemical compound [F-] KRHYYFGTRYWZRS-UHFFFAOYSA-M 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 238000004566 IR spectroscopy Methods 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
- 229910019213 POCl3 Inorganic materials 0.000 description 1
- 229910006095 SO2F Inorganic materials 0.000 description 1
- 239000004809 Teflon Substances 0.000 description 1
- 229920006362 Teflon® Polymers 0.000 description 1
- 238000000862 absorption spectrum Methods 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 239000002390 adhesive tape Substances 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 150000001340 alkali metals Chemical class 0.000 description 1
- 150000001412 amines Chemical class 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- ABDBNWQRPYOPDF-UHFFFAOYSA-N carbonofluoridic acid Chemical group OC(F)=O ABDBNWQRPYOPDF-UHFFFAOYSA-N 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 150000004820 halides Chemical class 0.000 description 1
- 229910052736 halogen Inorganic materials 0.000 description 1
- 150000002367 halogens Chemical group 0.000 description 1
- 125000004435 hydrogen atom Chemical group [H]* 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 239000003456 ion exchange resin Substances 0.000 description 1
- 229920003303 ion-exchange polymer Polymers 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- GBMDVOWEEQVZKZ-UHFFFAOYSA-N methanol;hydrate Chemical compound O.OC GBMDVOWEEQVZKZ-UHFFFAOYSA-N 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 150000002989 phenols Chemical class 0.000 description 1
- RLOWWWKZYUNIDI-UHFFFAOYSA-N phosphinic chloride Chemical compound ClP=O RLOWWWKZYUNIDI-UHFFFAOYSA-N 0.000 description 1
- UHZYTMXLRWXGPK-UHFFFAOYSA-N phosphorus pentachloride Chemical compound ClP(Cl)(Cl)(Cl)Cl UHZYTMXLRWXGPK-UHFFFAOYSA-N 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
- 238000010992 reflux Methods 0.000 description 1
- 230000002787 reinforcement Effects 0.000 description 1
- 239000012779 reinforcing material Substances 0.000 description 1
- 238000007086 side reaction Methods 0.000 description 1
- 238000002791 soaking Methods 0.000 description 1
- WBHQBSYUUJJSRZ-UHFFFAOYSA-M sodium bisulfate Chemical compound [Na+].OS([O-])(=O)=O WBHQBSYUUJJSRZ-UHFFFAOYSA-M 0.000 description 1
- 229910000342 sodium bisulfate Inorganic materials 0.000 description 1
- JXAZAUKOWVKTLO-UHFFFAOYSA-L sodium pyrosulfate Chemical compound [Na+].[Na+].[O-]S(=O)(=O)OS([O-])(=O)=O JXAZAUKOWVKTLO-UHFFFAOYSA-L 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- BUUPQKDIAURBJP-UHFFFAOYSA-N sulfinic acid Chemical compound OS=O BUUPQKDIAURBJP-UHFFFAOYSA-N 0.000 description 1
- 125000000626 sulfinic acid group Chemical group 0.000 description 1
- BDHFUVZGWQCTTF-UHFFFAOYSA-M sulfonate Chemical compound [O-]S(=O)=O BDHFUVZGWQCTTF-UHFFFAOYSA-M 0.000 description 1
- 125000002130 sulfonic acid ester group Chemical group 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-N sulfuric acid Substances OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 1
- HIFJUMGIHIZEPX-UHFFFAOYSA-N sulfuric acid;sulfur trioxide Chemical compound O=S(=O)=O.OS(O)(=O)=O HIFJUMGIHIZEPX-UHFFFAOYSA-N 0.000 description 1
- OBTWBSRJZRCYQV-UHFFFAOYSA-N sulfuryl difluoride Chemical compound FS(F)(=O)=O OBTWBSRJZRCYQV-UHFFFAOYSA-N 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 230000003313 weakening effect Effects 0.000 description 1
Landscapes
- Manufacture Of Macromolecular Shaped Articles (AREA)
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
Description
本発明はスルホニル基を有する含弗素高分子体
からカルボキシル基を有する含弗素高分子体の新
規な製造方法に関し、詳しくは該スルホニル基を
効率よくカルボキシル基に変換する方法に関す
る。
従来、含弗素系高分子体に結合するスルホニル
基をカルボキシル基に変換する方法については、
多くの提案がされている。例えば、スルホニル基
を有する含弗素系高分子体を還元する方法（特開
昭52―24177号），酸化反応する方法（特開昭53―
132069号），フエノール類と反応させる方法（特
開昭54―20981号），アミン類と反応させる方法
（特開昭54―21478号）などがある。
本発明者らは、上記とは別の方法について鋭意
研究を重ねた結果、意外にもスルホニル基を有す
る含弗素高分子体をSO3と接触させることによつ
て、該スルホニル基が簡単に且つ効率よくカルボ
キシル基に変換されることを見出し、本発明を提
案するに至つたものである。即ち、本発明はスル
ホニル基を有する含弗素系高分子体をSO3と接触
させることを特徴とするカルボキシル基を有する
含弗素高分子体の製造方法である。
本発明にいうスルホニル基とは、式−SO2Xで
示されるもので、例えばスルホン酸基（ＸがOH
基），スルホン酸基のアルカリ金属塩型またはア
ンモニウム塩型，スルホニルハライド基（Ｘがハ
ロゲン），スルホンアミド基（ＸがNR1R2で、
R1，R2が水素またはアルキル基），スルホン酸エ
ステル基（ＸがOR′で、R′がアルキル基），スル
フイン酸基（Ｘが水素），スルフイン酸のアルカ
リ金属塩型またはアンモニウム塩型などを総称す
る。
本発明で用いられるスルホニル基を有する含弗
弗素系高分子体としては、特にパーフルオロカー
ボン系の高分子母体にスルホニル基を化学的に結
合したものであればよい。含弗素系高分子体の形
状は、一般に膜状，粒状，粉状，溶液状，繊維状
であるが、特に膜状にあつては厚み0.01〜２mm範
囲の少くとも一方向に１cm以上の大きさを有する
ものが好適であり、該含弗素系高分子体にスルホ
ニル基はその断面において均一に分布しているも
の、ある勾配をもつて分布しているもの、層状ま
たは階段状に分布しているものなど何ら制限され
ない。かかるスルホニル基を有する含弗素系高分
子体は、例えばスルホニルハライド基を有する含
弗素ビニルモノマーの重合体，または他の含弗素
ビニルモノマーとの共重合体、あるいは含弗素系
高分子体に後処理によりスルホニル基を導入して
製造される。具体的に好適なスルホニル基を有す
る含弗素系高分子体としては、パーフルオロ
（３，６―ジオキシ―４―メチル―７―オクテン
スルホニルハライド）を主成分とするパーフルオ
ロアルキルビニルエーテルスルホニルハライドと
テトラフルオロエチレン，トリフルオロエチレ
ン，フツ化ビニリデン，クロロトリフルオロエチ
レン，ヘキサフルオロプロピレン，パーフルオロ
アルキルビニルエーテルなどとを公知の重合方法
によつて製造される。かくして得られた含弗素系
高分子体は、そのまま粉状，溶液状または適当に
粒状，繊維状，膜状に成形して用いられる。さら
に、膜状物においては、その寸法安定性および機
械的強度を増加させるために、補強材としてポリ
テトラフルオロエチレンなどの多孔性シート，布
などを裏打ちすることも好適である。
本発明の最大の特徴は、上記したスルホニル基
を有する含弗素系高分子体をSO3と接触させるこ
とにある。用いるSO3は特に無水のSO3が好まし
く、また気体または液体のいずれでもよく、さら
にスルホニル基を有する含弗素系高分子体との接
触時にSO3を遊離するものであれば何ら制限され
ない。したがつて、SO3のみならず発煙硫酸，硫
酸水素ナトリウム，ピロ硫酸ナトリウムなどを加
熱して用いられる。
本発明のスルホニル基を有する含弗素系高分子
体にSO3を接触させる方法は、特に制限されな
い。例えば、SO3を気体の状態で接触させる場合
には、減圧下，加圧下あるいは不活性ガスで希釈
下に存在させてもよい。また、SO3を液体の状態
で接触させる場合には、接触系の温度を均一に調
節するために、濃硫酸などの溶媒で希釈して用い
ることが好ましい。このようなSO3の仕込み量
は、接触系において含弗素系高分子体が有するス
ルホニル基と等モル以上であればよいが、実際に
は一般に５倍モル以上が必要である。また、スル
ホニル基を有する含弗素系高分子体とSO3とを接
触させる温度は、一般に室温〜250℃特に30〜120
℃の温度範囲が好ましく、250℃以上の温度でも
カルボキシル基の生成は認められるが、他の副反
応，生成したカルボキシル基の脱離、あるいは含
弗素高分子体の変形，強度の劣化などの欠点を伴
うため好ましくない。
さらに、本発明の方法においてはスルホニル基
を有する含弗素系高分子体にSO3を接触させる際
に、触媒としてNaF，KF，CsF，RbFなどのア
ルカリ金属弗化物，NaCl，KClなどのアルカリ
金属塩化物、またはAgF，Ag2SO4などを共存さ
せることによつて、該スルホニル基のカルボキシ
ル基への変換率を著しく向上させることが出来
る。上記の触媒としては、特にNaF，KF，CsF
などのアルカリ金属弗化物が好ましい。かかる触
媒の共存量は、存在するSO3量に対して0.001〜
10％（重量比）が好適である。
本発明により得られる含弗素高分子体は、赤外
スペクトル（高分子体が粉状，粒状および繊維状
の場合にはKBr法；膜状の場合にはATR法また
は透過法で測定することによつて、1780cm-1に新
しい吸収帯が生じ、さらにアルカリ処理すること
によつて1680cm-1にシフトすることから、該含弗
素系高分子体に結合したカルボキシル基に起因す
ることが認められる。一方、本発明のSO3で接触
させる前の含弗素系高分子体において例えば1060
cm-1に強く認められるスルホン酸基の吸収帯（ス
ルホニル基かスルホン酸基の場合）は、一般に接
触処理を充分に行うことによつて殆んど消失して
しまう。また、接触処理を弱めることによつて、
上記スルホン酸基は大部分が残存し、少量のカル
ボキシル基の生成が認められる。したがつて、本
発明によれば、接触条件を適宜選択することによ
り、含弗素系高分子体のスルホニル基を任意の割
合でカルボキシル基に変換することも可能であ
る。
本発明の方法により含弗素系高分子体の有する
スルホニル基がカルボキシル基に変換し得る理由
は明確に出来ないが、スルホニル基から１段で容
易に且つ効率よく変換され、連続的に処理するこ
とも出来るため工業的にも有利である。また、本
発明に得られるカルボキシル基を有する含弗素系
高分子体は、従来公知の用途に制限なく用いるこ
とが出来る。例えば、カルボキシル基を有する含
弗素系高分子体が粉状，粒状あるいは可溶性の場
合には、触媒，PHコントローラー，特殊イオン
交換樹脂などに用いられ、また膜状の場合には近
年開発されている食塩電解用のイオン交換膜とし
て極めて有用である。特に食塩電解用のイオン交
換膜の好ましい態様として提案されている。片面
にスルホン酸基と他面にカルボキシル基を有する
膜の製造に本発明の方法は好ましく適用される。
実施例 １
テトラフルオロエチレンとパーフルオロ（３，
６―ジオキサ―４―メチル―７―オクテンスルホ
ニルフルオライド）の共重合体で加水分解したと
きの交換容量が0.91ミリ当量／グラム乾燥樹脂
（H+型），厚さが0.175mmのフイルムを水400部，
ジメチルスルホキシド600部，水酸化カリウム15
部からなる加水分解浴に浸漬してスルホン酸ソー
ダとした膜を用いて次の反応を行なつた。
即ち、セパラブルフラスコ中に膜及び膜が浸漬
する量のSO3を加え、45℃で8hrs反応した。反応
後の膜を10％のNaOHを含むメタノール―水
（容量比１／１）の混合溶液中で一夜浸漬して後、
膜の一方の表面のみサンドペーパーによつて削り
とつて薄膜としたのち、赤外吸収スペクトルを測
定した。その結果、1680cm-1に強い新しい吸収ピ
ークが見られた。次いで、これをメタノールと
4.0N−HClの１：１の混合溶液中に一夜浸漬後
にATRによつて測定したところ、1680cm-1の吸
収は消失して、1790cm-1に新しい吸収ピークが現
われた。反応条件の選定によつて吸収強度の強弱
が変化した。これはパーフルオロのカルボン酸基
に帰属される吸収である。また反応条件の選定に
よつて未反応の膜に見られる1060cm-1のスルン酸
基に帰属される吸収は弱くなるか消滅した。
上記で得た膜を用いて3.5N−NaClを陽極液と
して、有効通電面積0.5dm2の電解槽を用いて電流
密度30A／ｄm2で食塩電解を実施した。陰極室か
ら10規定のNaOHを取得した。電解温度は80℃
であつた。
電解テストの結果、電解電圧3.35V，電流効率
92％及びNaOH中のNaCl濃度は70ppm（as50％
NaOH）であつた。
実施例２および比較例１
膜及び反応条件を変えて実施例１と同様の反応
を行つた。反応条件及び得られた膜の電解テスト
の結果を表―１に示す。得られた膜はいづれも赤
外スペクトルでカルボキシル基の存在が強く認め
られた。又、比較のために本発明の反応を行わな
かつた膜の電解テストの結果を表―１のNo.７に示
す。
この実験で用いた膜（実施例１で用いたもの以
外）は次のものである。
膜Ａ 実施例１で用いた膜を１％のNH4OHを含
む水溶液に一夜浸漬してNH4型の膜とした。
得られた膜をさらに20％のPCl5を含むPOCl3
中で還流下に20時間反応させた。その後、
CCl4中に浸漬してPCl5，POCl3を洗浄した。
得られた膜の一部をATR法で赤外スペクト
ルを測定したところ、1060cm-1の−
SO3 -NH4 +基の吸収帯はなく、代りに1420cm
-1に−SO2Cl基の吸収帯が認められた。
膜Ｂ 膜Ａの一部を10％のNa2SO3を含む水溶液
中に50℃で10時間浸漬した。その後水洗し、
ATR法での赤外スペクトルを測定したとこ
ろ、1420cm-1の−SO2Cl基は殆んど認められ
ず、代りに930，1030cm-1に−SO2Na基に起
因する吸収帯が強く認められた。
膜Ｃ テトラフルオロエチレンとパーフルオロ
（３，６―ジオキサ―７―オクテンスルホニ
ルフルオライド）の共重合体で加水分解後の
交換容量が0.83ミリ当量／グラム乾燥樹脂
（H+）である２枚のフイルムにポリテトラフ
ルオロエチレンの400デニールの糸よりなり
タテ・ヨコインチ当り40本打込んだ布（補強
材）をはさみ、加熱融着して膜とした。この
膜の片面を水とエチレンジアミンの混合溶液
（容量比10／１）中に20時間浸漬して膜の片
面にスルホンアミド基（−SO2NHCH2・
CH2NH2又は−SO2NH・CH2・CH2・
NH・SO2−）を有する膜とした。浸漬後10
％のNaOHを含むメタノール―水混合溶液
中に浸漬して未反応の−SO2F基を加水分解
した。又、本発明の処理を行う時はエチレン
ジアミンと接触しなかつた面をテフロン粘着
テープでシールして行つた。
膜Ｄ 膜Ｃと作るときの中間体であるスルホニル
フルオライドを結合した膜
The present invention relates to a novel method for producing a fluorine-containing polymer having a carboxyl group from a fluorine-containing polymer having a sulfonyl group, and more particularly to a method for efficiently converting the sulfonyl group into a carboxyl group. Conventionally, methods for converting sulfonyl groups bonded to fluorine-containing polymers into carboxyl groups are as follows:
Many proposals have been made. For example, a method of reducing a fluorine-containing polymer having a sulfonyl group (JP-A-52-24177), a method of oxidation reaction (JP-A-53-24177),
132069), a method of reacting with phenols (Japanese Patent Laid-Open No. 54-20981), and a method of reacting with amines (Japanese Patent Laid-Open No. 54-21478). As a result of extensive research into methods other than those described above, the present inventors unexpectedly discovered that by contacting a fluorine-containing polymer having a sulfonyl group with SO 3 , the sulfonyl group can be easily and easily removed. The present inventors have discovered that it can be efficiently converted into a carboxyl group, and have proposed the present invention. That is, the present invention is a method for producing a fluorine-containing polymer having a carboxyl group, which comprises bringing the fluorine-containing polymer having a sulfonyl group into contact with SO 3 . The sulfonyl group referred to in the present invention is represented by the formula -SO 2 X, for example, a sulfonic acid group (X is OH
group), alkali metal salt type or ammonium salt type of sulfonic acid group, sulfonyl halide group (X is halogen), sulfonamide group (X is NR 1 R 2 ,
R 1 , R 2 are hydrogen or an alkyl group), sulfonic acid ester group (X is OR' and R' is an alkyl group), sulfinic acid group (X is hydrogen), alkali metal salt type or ammonium salt type of sulfinic acid etc. collectively. The fluorine-containing polymer having a sulfonyl group used in the present invention may be one in which a sulfonyl group is chemically bonded to a perfluorocarbon polymer matrix. The shape of the fluorine-containing polymer is generally film-like, granular, powder-like, solution-like, or fibrous. In particular, the film-like shape has a thickness in the range of 0.01 to 2 mm and a size of at least 1 cm in one direction. The sulfonyl groups in the fluorine-containing polymer are preferably distributed uniformly in its cross section, distributed with a certain gradient, or distributed in layers or steps. There are no restrictions on who you are. Such a fluorine-containing polymer having a sulfonyl group can be, for example, a polymer of a fluorine-containing vinyl monomer having a sulfonyl halide group, a copolymer with another fluorine-containing vinyl monomer, or a fluorine-containing polymer after being processed. It is produced by introducing a sulfonyl group. Specifically preferred fluorine-containing polymers having sulfonyl groups include perfluoroalkyl vinyl ether sulfonyl halides containing perfluoro (3,6-dioxy-4-methyl-7-octensulfonyl halide) as a main component and tetrafluorocarbons. It is produced by a known polymerization method with fluoroethylene, trifluoroethylene, vinylidene fluoride, chlorotrifluoroethylene, hexafluoropropylene, perfluoroalkyl vinyl ether, etc. The fluorine-containing polymer thus obtained can be used as it is in the form of powder, solution, or appropriately formed into granules, fibers, or films. Furthermore, in order to increase the dimensional stability and mechanical strength of the membrane-like material, it is also suitable to back it with a porous sheet such as polytetrafluoroethylene, cloth, etc. as a reinforcing material. The most important feature of the present invention is that the above-mentioned fluorine-containing polymer having a sulfonyl group is brought into contact with SO 3 . The SO 3 used is particularly preferably anhydrous SO 3 and may be either gas or liquid, and is not particularly limited as long as it liberates SO 3 upon contact with a fluorine-containing polymer having a sulfonyl group. Therefore, not only SO 3 but also fuming sulfuric acid, sodium hydrogen sulfate, sodium pyrosulfate, etc. can be heated and used. The method of bringing SO 3 into contact with the fluorine-containing polymer having a sulfonyl group of the present invention is not particularly limited. For example, when contacting SO 3 in a gaseous state, it may be present under reduced pressure, increased pressure, or diluted with an inert gas. Further, when contacting SO 3 in a liquid state, it is preferable to dilute it with a solvent such as concentrated sulfuric acid in order to uniformly control the temperature of the contact system. The amount of SO 3 to be charged may be at least equimolar to the sulfonyl group possessed by the fluorine-containing polymer in the contact system, but in reality, it is generally required to be at least 5 times the mole. Further, the temperature at which the fluorine-containing polymer having a sulfonyl group and SO 3 are brought into contact is generally room temperature to 250°C, particularly 30 to 120°C.
℃ is preferable, and formation of carboxyl groups is observed even at temperatures of 250℃ or higher, but there are disadvantages such as other side reactions, elimination of the generated carboxyl groups, deformation of the fluorine-containing polymer, and deterioration of strength. This is not desirable because it involves Furthermore, in the method of the present invention, when bringing SO 3 into contact with a fluorine-containing polymer having a sulfonyl group, alkali metal fluorides such as NaF, KF, CsF, and RbF, and alkali metals such as NaCl and KCl are used as catalysts. By coexisting chloride, AgF, Ag 2 SO 4 or the like, the conversion rate of the sulfonyl group to carboxyl group can be significantly improved. The above catalysts include NaF, KF, CsF, etc.
Alkali metal fluorides such as are preferred. The coexisting amount of such a catalyst is 0.001 to 0.001 to the amount of SO3 present.
10% (weight ratio) is suitable. The fluorine-containing polymer obtained by the present invention can be measured by infrared spectroscopy (KBr method if the polymer is in the form of powder, granules, or fibers; ATR method or transmission method if the polymer is in the form of a film). Therefore, since a new absorption band appears at 1780 cm -1 and is further shifted to 1680 cm -1 by alkali treatment, it is recognized that the absorption band is caused by the carboxyl group bonded to the fluorine-containing polymer. On the other hand, in the fluorine-containing polymer before contacting with SO 3 of the present invention, for example, 1060
Generally, the absorption band of sulfonic acid groups (in the case of sulfonyl groups or sulfonic acid groups), which is strongly observed at cm -1 , almost disappears by carrying out sufficient contact treatment. Also, by weakening the contact treatment,
Most of the above sulfonic acid groups remain, and a small amount of carboxyl groups are observed to be formed. Therefore, according to the present invention, by appropriately selecting the contact conditions, it is also possible to convert the sulfonyl groups of the fluorine-containing polymer into carboxyl groups at any ratio. Although it is not clear why the sulfonyl group of the fluorine-containing polymer can be converted into a carboxyl group by the method of the present invention, it is possible to convert the sulfonyl group easily and efficiently in one step, and the process can be carried out continuously. It is also industrially advantageous because it can also be used. Further, the fluorine-containing polymer having a carboxyl group obtained in the present invention can be used in conventionally known applications without any limitations. For example, when fluorine-containing polymers with carboxyl groups are in powder, granular, or soluble form, they are used in catalysts, PH controllers, special ion exchange resins, etc., and when they are in membrane form, they have been developed in recent years. It is extremely useful as an ion exchange membrane for salt electrolysis. In particular, it has been proposed as a preferred embodiment of an ion exchange membrane for salt electrolysis. The method of the present invention is preferably applied to the production of membranes having sulfonic acid groups on one side and carboxyl groups on the other side. Example 1 Tetrafluoroethylene and perfluoro(3,
When hydrolyzed with a copolymer of 6-dioxa-4-methyl-7-octensulfonyl fluoride, the exchange capacity is 0.91 milliequivalents/gram dry resin (H + type), and a film with a thickness of 0.175 mm is mixed with water. 400 copies,
600 parts of dimethyl sulfoxide, 15 parts of potassium hydroxide
The following reaction was carried out using a membrane made of sodium sulfonate by immersing it in a hydrolysis bath consisting of: That is, the membrane and SO 3 in an amount sufficient to immerse the membrane were added to a separable flask, and the reaction was carried out at 45° C. for 8 hours. After the reaction, the membrane was immersed overnight in a mixed solution of methanol and water (volume ratio 1/1) containing 10% NaOH.
After sanding only one surface of the film to make a thin film, the infrared absorption spectrum was measured. As a result, a strong new absorption peak was observed at 1680 cm -1 . This is then mixed with methanol.
When measured by ATR after overnight immersion in a 1:1 mixed solution of 4.0N-HCl, the absorption at 1680 cm -1 disappeared and a new absorption peak appeared at 1790 cm -1 . The strength of the absorption intensity changed depending on the selection of reaction conditions. This absorption is attributed to the perfluoro carboxylic acid group. Furthermore, by selecting the reaction conditions, the absorption attributed to the sulnic acid group at 1060 cm -1 observed in the unreacted film became weaker or disappeared. Using the membrane obtained above, salt electrolysis was carried out at a current density of 30 A/dm 2 using an electrolytic cell with an effective current carrying area of 0.5 dm 2 using 3.5N-NaCl as the anolyte. 10N NaOH was obtained from the cathode chamber. Electrolysis temperature is 80℃
It was hot. As a result of electrolysis test, electrolysis voltage 3.35V, current efficiency
NaCl concentration in 92% and NaOH is 70ppm (as50%
NaOH). Example 2 and Comparative Example 1 The same reaction as in Example 1 was carried out by changing the membrane and reaction conditions. Table 1 shows the reaction conditions and the results of the electrolytic test of the membrane obtained. In all of the obtained films, the presence of carboxyl groups was strongly recognized in the infrared spectrum. For comparison, No. 7 in Table 1 shows the results of an electrolytic test on a membrane that was not subjected to the reaction of the present invention. The membranes used in this experiment (other than those used in Example 1) were as follows. Membrane A The membrane used in Example 1 was immersed overnight in an aqueous solution containing 1% NH 4 OH to form an NH 4 type membrane.
The resulting membrane was further treated with POCl3 containing 20% PCl5 .
The mixture was reacted for 20 hours under reflux. after that,
PCl 5 and POCl 3 were washed away by immersing it in CCl 4 .
When we measured the infrared spectrum of a part of the obtained film using the ATR method, we found that -1060 cm -1
There is no absorption band for the SO 3 - NH 4 + group, instead at 1420 cm
An absorption band of -SO 2 Cl group was observed at -1 . Membrane B A portion of Membrane A was immersed in an aqueous solution containing 10% Na 2 SO 3 at 50° C. for 10 hours. Then wash with water,
When an infrared spectrum was measured using the ATR method, the -SO 2 Cl group at 1420 cm -1 was hardly observed, and instead a strong absorption band due to the -SO 2 Na group was observed at 930 and 1030 cm -1 . It was done. Membrane C: Two sheets of copolymer of tetrafluoroethylene and perfluoro(3,6-dioxa-7-octensulfonyl fluoride) with an exchange capacity of 0.83 milliequivalents/g dry resin (H + ) after hydrolysis. A cloth (reinforcement material) made of 400 denier polytetrafluoroethylene threads (40 threads per inch vertically and horizontally) was sandwiched between the film and heat-fused to form a membrane. One side of this membrane was immersed in a mixed solution of water and ethylenediamine (volume ratio 10/1) for 20 hours to form a sulfonamide group (-SO 2 NHCH 2 ) on one side of the membrane.
CH 2 NH 2 or −SO 2 NH・CH 2・CH 2・
NH・SO 2 −). 10 after soaking
The unreacted -SO2F groups were hydrolyzed by immersion in a methanol-water mixed solution containing % NaOH. Furthermore, when performing the treatment of the present invention, the surface that did not come into contact with ethylenediamine was sealed with Teflon adhesive tape. Membrane D: A membrane that combines sulfonyl fluoride, which is an intermediate when making membrane C.
【表】
＊ オートクレーブ中で加熱した。
[Table] * Heated in an autoclave.
Claims (1)
SO3と接触させることを特徴とするカルボキシル
基を有する含弗素系高分子体の製造方法。 ２ スルホニル基がスルホニルハライド基または
スルホン酸基である特許請求の範囲第１項記載の
製造方法。 ３ 含弗素系高分子体がパーフルオロカーボン系
の高分子体である特許請求の範囲第１項記載の製
造方法。 ４ スルホニル基を有する含弗素系高分子体がテ
トラフルオロエチレンとパーフルオロアルキルス
ルホニルビニルエーテルの共重合体である特許請
求の範囲第１項または第４項記載の製造方法。 ５ 含弗素系高分子体が膜状物である特許請求の
範囲第１項、第３項または第４項記載の製造方
法。 ６ 膜状物が電解用隔膜である特許請求の範囲第
５項記載の製造方法。 ７ 触媒存在下に接触させることを特徴とする特
許請求の範囲第１項記載の製造方法。 ８ アルカリ金属弗化物の共存下に接触させる特
許請求の範囲第７項記載の製造方法。 ９ アルカリ金属弗化物がNaF，KF，CsF，
RbF，AgFのいずれかである特許請求の範囲第
８項記載の製造方法。[Claims] 1. A fluorine-containing polymer having a sulfonyl group
A method for producing a fluorine-containing polymer having a carboxyl group, the method comprising contacting with SO 3 . 2. The manufacturing method according to claim 1, wherein the sulfonyl group is a sulfonyl halide group or a sulfonic acid group. 3. The manufacturing method according to claim 1, wherein the fluorine-containing polymer is a perfluorocarbon polymer. 4. The manufacturing method according to claim 1 or 4, wherein the fluorine-containing polymer having a sulfonyl group is a copolymer of tetrafluoroethylene and perfluoroalkylsulfonyl vinyl ether. 5. The manufacturing method according to claim 1, 3, or 4, wherein the fluorine-containing polymer is a film-like material. 6. The manufacturing method according to claim 5, wherein the membrane-like material is a diaphragm for electrolysis. 7. The production method according to claim 1, characterized in that the contact is carried out in the presence of a catalyst. 8. The manufacturing method according to claim 7, which comprises contacting in the presence of an alkali metal fluoride. 9 Alkali metal fluorides include NaF, KF, CsF,
The manufacturing method according to claim 8, which is either RbF or AgF.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13326081A JPS5834806A (en) | 1981-08-27 | 1981-08-27 | Method for producing fluorine-containing polymer having carboxyl group |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13326081A JPS5834806A (en) | 1981-08-27 | 1981-08-27 | Method for producing fluorine-containing polymer having carboxyl group |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5834806A JPS5834806A (en) | 1983-03-01 |
| JPS6358162B2 true JPS6358162B2 (en) | 1988-11-15 |
Family
ID=15100453
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13326081A Granted JPS5834806A (en) | 1981-08-27 | 1981-08-27 | Method for producing fluorine-containing polymer having carboxyl group |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5834806A (en) |
-
1981
- 1981-08-27 JP JP13326081A patent/JPS5834806A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5834806A (en) | 1983-03-01 |
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