JP3674680B2 - Curable fluoropolyether rubber composition - Google Patents

Description

（ｏ，ｍ又はｐ位）
【００１３】
このような（Ａ）成分の直鎖状フルオロポリエーテル化合物としては、下記一般式（２），（３）で示されるものが好ましい。
ＣＨ₂＝ＣＨ−（Ｘ）_p―Ｒｆ’−（Ｘ）_p―ＣＨ＝ＣＨ₂ （２）
ＣＨ₂＝ＣＨ−（Ｘ）_p―Ｑ−Ｒｆ’−Ｑ−（Ｘ）_p―ＣＨ＝ＣＨ₂ （３）
〔式中、Ｘは独立に−ＣＨ₂−，−ＣＨ₂Ｏ−，又は−Ｙ−ＮＲ’−ＣＯ−（但し、Ｙは−ＣＨ₂−又は下記構造式（Ａ）で示される基であり、Ｒ’は水素原子、メチル基、フェニル基又はアリル基である。）であり、Ｑは炭素数１〜１５の２価炭化水素基であり、エーテル結合、アミド結合又はカルボニル結合を含んでいてもよく、Ｒｆ’は２価のパーフルオロアルキレン基又はパーフルオロオキシアルキレン基である。ｐは独立に０又は１である。〕
【００１４】
【化６】

（ｏ，ｍ又はｐ位）
これらの中でも、特に下記一般式（４）で示されるものが好適である。
【００１５】
【化７】

〔式中、Ｘは上記と同様である。ｐは独立に０又は１、ｒは２〜６の整数、ｕは１〜６の整数、ｍ，ｎはそれぞれ０〜２００の整数である。〕
【００１６】
上記式（４）の直鎖状フルオロポリエーテル化合物は、重量平均分子量が４００〜１００，０００、特に１，０００〜５０，０００であることが望ましい。
【００１７】
式（４）で表されるフルオロポリエーテル化合物の具体例としては、下記化合物等を例示することができる。なお、式中、ｍ，ｎは前記と同様である。
【００１８】
【化８】

【００１９】
【化９】

【００２０】
更に、本発明では、直鎖状フルオロポリエーテル化合物を目的に応じた所望の重量平均分子量に調節するため、予め上記した直鎖状フルオロポリエーテル化合物を分子内にＳｉＨ基を２個含有する有機ケイ素化合物と通常の方法及び条件でヒドロシリル化反応させ、鎖長延長した生成物を（Ａ）成分として使用することも可能である。
【００２１】
次に（Ｂ）成分は、上記（Ａ）成分の架橋剤、鎖長延長剤として作用するものである。（Ｂ）成分は１分子中にケイ素原子に結合した水素原子を少なくとも２個有し、水素原子に結合したケイ素原子が全てベンゼン環に結合する有機ケイ素化合物であれば特に制限されるものではない。このような有機ケイ素化合物の例としては、下記一般式（１）で表されるものが挙げられる。
【００２２】
【化１０】

（式中、Ｒは同一又は異種の炭素数１〜２０の１価炭化水素基である。ｘ及びｙは１〜５の整数であり、ａは１又は２であり、ｂは０，１又は２であり、ｓ及びｔは０又は１である。Ｚは水素原子、酸素原子、−Ｒ、−Ｑ−Ｒｆ、−ＳｉＲ₂−、−Ｑ−、−Ｒｆ’−、又は−Ｑ−Ｒｆ’−Ｑ−で表される１価又は２価の基である。但し、Ｑは炭素数１〜１５の２価炭化水素基であり、エーテル結合、アミド結合又はカルボニル結合を含んでいてもよく、Ｒｆは１価のパーフルオロアルキル基又はパーフルオロオキシアルキル基であり、Ｒｆ’は２価のパーフルオロアルキレン基又はパーフルオロオキシアルキレン基である。また、それぞれのベンゼン環の水素原子はハロゲン原子、メチル基、エチル基等の低級アルキル基などで置換されていてもよい。）
【００２３】
ここで、Ｒの１価炭化水素基としては、メチル、エチル、プロピル等のアルキル基、フェニル等のアリール基などが挙げられ、詳しくは後述する。また、Ｑの２価炭化水素基としては、メチレン、エチレン、プロピレン、テトラメチレン、ヘキサメチレン等のアルキレン基、フェニレン等のアリーレン基、これらアルキレン基とアリーレン基とが結合した基などが挙げられ、これらはエーテル結合、アミド結合、カルボニル結合を含んでいてもよい。
【００２４】
Ｚは、上述した通り、１価の基（−Ｈ、−Ｒ、−Ｑ−Ｒｆ）又は２価の基（−Ｏ−、−ＳｉＲ₂−、−Ｑ−、−Ｒｆ’−、−Ｑ−Ｒｆ’−Ｑ−）であり、これはａ、ｂ、ｓ、ｔの値によって選定される。
【００２５】
上記式（１）で示される有機ケイ素化合物として、具体的には次に示すものが挙げられる。なお、Ｍｅはメチル基を示す（以下、同様）。
【００２６】
【化１１】

【００２７】
【化１２】

【００２８】
また、（Ａ）成分との相溶性、分散性、硬化後の均一性を考慮して、１分子中に１個以上の１価のパーフルオロアルキル基、１価のパーフルオロオキシアルキル基、２価のパーフルオロアルキレン基又は２価のパーフルオロオキシアルキレン基を有しているものを使用することができる。なお、パーフルオロアルキル基、パーフルオロアルキレン基は炭素数１〜２０のものが好ましく、パーフルオロオキシアルキル基、パーフルオロオキシアルキレン基としては炭素数１〜５００、特に４〜５００のものが好ましい。
【００２９】
上記パーフルオロアルキル基、パーフルオロオキシアルキル基、パーフルオロアルキレン基、パーフルオロオキシアルキレン基としては、下記一般式で示される基を例示することができる。
【００３０】
【化１３】

【００３１】
また、これらパーフルオロ（オキシ）アルキル基、パーフルオロ（オキシ）アルキレン基は、ケイ素原子に直接結合していてもよいが、ケイ素原子と２価の連結基を介して結合していてもよい。ここで、２価の連結基としては、アルキレン基、アリーレン基やこれらの組み合わせでも、あるいはこれらにエーテル結合酸素原子やアミド結合、カルボニル結合等を介在するものであってもよく、例えば炭素原子数２〜１２のものが好ましく、下記の基等が挙げられる。
−ＣＨ₂ＣＨ₂−，−ＣＨ₂ＣＨ₂ＣＨ₂−，−ＣＨ₂ＣＨ₂ＣＨ₂ＯＣＨ₂−
−ＣＨ₂ＣＨ₂ＣＨ₂−ＮＨ−ＣＯ−，
−ＣＨ₂ＣＨ₂ＣＨ₂−Ｎ（Ｐｈ）−ＣＯ−，
−ＣＨ₂ＣＨ₂ＣＨ₂−Ｎ（ＣＨ₃）−ＣＯ−，−ＣＨ₂ＣＨ₂ＣＨ₂−Ｏ−ＣＯ−
（Ｐｈはフェニル基である。）
【００３２】
また、この（Ｂ）成分の有機ケイ素化合物における１価又は２価の含フッ素置換基、即ちパーフルオロアルキル基、パーフルオロオキシアルキル基、パーフルオロアルキレン基あるいはパーフルオロオキシアルキレン基を含有する１価の有機基以外のケイ素原子に結合した１価の置換基（Ｒ）としては、例えばメチル基、エチル基、プロピル基、ブチル基、ヘキシル基、シクロヘキシル基、オクチル基、デシル基等のアルキル基；ビニル基、アリル基等のアルケニル基；フェニル基、トリル基、ナフチル基等のアリール基；ベンジル基、フェニルエチル基等のアラルキル基；あるいはこれらの基の水素原子の一部が塩素原子、シアノ基等で置換された、例えばクロロメチル基、クロロプロピル基、シアノエチル基等の炭素原子数１〜２０の非置換又は置換炭化水素基が挙げられる。
【００３３】
更に、この有機ケイ素化合物における分子中のケイ素原子数は特に制限されないが、通常２〜６０、特に３〜３０程度が好ましい。
【００３４】
このような有機ケイ素化合物としては、例えば下記のような化合物が挙げられ、これらの化合物は、１種単独で使用しても２種以上を併用して用いてもよい。なお、下記式でＭｅはメチル基、Ｐｈはフェニル基を示す。
【００３５】
【化１４】

【００３６】
【化１５】

【００３７】
【化１６】

【００３８】
【化１７】

【００３９】
【化１８】

【００４０】
【化１９】

【００４１】
（Ｂ）成分の配合量は、通常（Ａ）成分中に含まれるビニル基、アリル基、シクロアルケニル基等のアルケニル基１モルに対して、（Ｂ）成分中のヒドロシリル基、即ちＳｉＨ基の量が好ましくは０．５〜５モル、より好ましくは１〜２モル供給する量が好適である。（Ｂ）成分の配合量が少なすぎると架橋度合いが不十分になる場合があり、多すぎると鎖長延長が優先し、硬化が不十分となったり、発泡したり、耐熱性、圧縮永久歪み特性等が悪化する場合がある。
【００４２】
（Ｃ）成分のヒドロシリル化反応触媒としては、遷移金属、例えばＰｔ、Ｒｈ、Ｐｄ等の白金族金属やこれら遷移金属の化合物などが好ましく使用される。本発明では、これら化合物が一般に貴金属の化合物で高価格であることから、比較的入手しやすい白金化合物が好適に用いられる。
【００４３】
白金化合物としては、具体的に塩化白金酸又は塩化白金酸とエチレン等のオレフィンとの錯体、アルコールやビニルシロキサンとの錯体、白金／シリカ、アルミナ又はカーボン等を例示することができるが、これらに限定されるものではない。
【００４４】
白金化合物以外の白金族金属化合物としては、ロジウム、ルテニウム、イリジウム、パラジウム系化合物等が知られており、例えば、ＲｈＣｌ（ＰＰｈ₃）₃，ＲｈＣｌ（ＣＯ）（ＰＰｈ₃）₂，ＲｈＣｌ（Ｃ₂Ｈ₄）₂，Ｒｕ₃（ＣＯ）₁₂，ＩｒＣｌ（ＣＯ）（ＰＰｈ₃）₂，Ｐｄ（ＰＰｈ₃）₄等が挙げられる（なお、Ｐｈはフェニル基を示す）。
【００４５】
これらの触媒の使用量は、特に制限されるものではなく、触媒量で所望とする硬化速度を得ることができるが、経済的見地又は良好な硬化物を得るためには硬化性組成物全量に対して０．１〜１，０００ｐｐｍ（白金族金属換算）、より好ましくは０．１〜５００ｐｐｍ（同上）程度の範囲とすることがよい。
【００４６】
本発明の硬化性組成物には（Ａ）成分の架橋剤、鎖長延長剤として（Ｂ）成分に加えて、作業性、ゴム物性等の調整のためＨ−Ｓｉ−Ｏ−Ｓｉ構造やＨ−ＳｉＣＨ₂−構造等の（Ｂ）成分に該当しない構造で、１分子中にＳｉＨ構造を少なくとも２個有する有機ケイ素化合物を任意の割合で配合することもできる。このような（Ｂ）成分に該当しない含ＳｉＨ有機ケイ素化合物は、ＳｉＨ基を１分子中に２個以上有するものであれば特に限定されず、鎖状、環状、網目状などの構造をとっていてもよい。
【００４７】
（Ａ）成分の架橋剤、鎖長延長剤として（Ｂ）成分のほかにヒドロシリル基、即ちＳｉＨ基を有する有機ケイ素化合物を添加する場合、通常（Ａ）成分中に含まれるビニル基、アリル基、シクロアルケニル基等のアルケニル基１モルに対して、ＳｉＨ基の合計量が好ましくは０．５〜５モル、より好ましくは１〜２モル供給する量が好適である。ＳｉＨ基の量が少なすぎると架橋度合いが不十分になる場合があり、多すぎると鎖長延長が優先し、硬化が不十分となったり、発泡したり、耐熱性、圧縮永久歪み特性等が悪化する場合がある。
【００４８】
（Ｂ）成分に対する（Ｂ）成分以外のＳｉＨ構造を有する有機ケイ素化合物の配合量は特に限定されるものではなく、用途に応じて任意に設定できる。
【００４９】
本発明の硬化性組成物には、その実用性を高めるために種々の添加剤を必要に応じて添加することができる。これら添加剤として、具体的には硬化性組成物の硬化速度を制御する目的で加えるＣＨ₂＝ＣＨ（Ｒ）ＳｉＯ単位（式中、Ｒは水素原子又は置換もしくは非置換の１価炭化水素基である。）を含むポリシロキサン（特公昭４８−１０９４７号公報参照）及びアセチレン化合物（米国特許第３４４５４２０号及び特公平４−３７７４号公報参照）、更に、重金属のイオン性化合物（米国特許第３５３２６４９号参照）等を例示することができる。
【００５０】
本発明の硬化性組成物には、硬化時における熱収縮の減少、硬化して得られる弾性体の熱膨張率の低下、熱安定性、耐候性、耐薬品性、難燃性あるいは機械的強度を向上させたり、ガス透過率を下げる目的で充填剤を添加してもよい。この場合、添加剤としては、例えばヒュームドシリカ、石英粉末、ガラス繊維、カーボン、酸化鉄、酸化チタン及び酸化セリウム等の金属酸化物、炭酸カルシウム、炭酸マグネシウム等の金属炭酸塩を挙げることができる。更に必要に応じて適当な顔料、染料を添加することも可能である。
【００５１】
本発明の硬化性組成物の製造方法は特に制限されず、上記成分を練り合わせることにより製造することができる。また（Ａ）成分，（Ｂ）成分と（Ｃ）成分及び（Ａ）成分と（Ｃ）成分との２組成物とし、使用時に混合するようにしてもよい。また、得られた組成物を硬化させるには、（Ａ）成分の官能基の種類、（Ｃ）成分の触媒の種類などにより室温硬化も可能であるが、通常は組成物を１００〜２００℃にて数分から数時間程度の時間で硬化させることが好ましい。
【００５２】
本発明の硬化性組成物を使用するに当たり、その用途、目的に応じて該組成物を適当なフッ素系溶剤、例えば１，３−ビストリフルオロメチルベンゼン、パーフルオロオクタン等を加えて所望の濃度に溶解してから使用することもできる。
【００５３】
【発明の効果】
本発明の硬化性フルオロポリエーテルゴム硬化物は、耐熱性、耐薬品性、耐溶剤性、離型性、撥水性、撥油性、耐候性等に優れている上、耐酸性、耐アルカリ性に優れた硬化物を与え、幅広い成形用途に利用可能で、例えば半導体製造装置のシール材、自動車用、航空機用Ｏ−リング、ダイヤフラム、シール材料、複写機用のロール材料、二次電池及び燃料電池の電極構成材料等に有用である。
【００５４】
【実施例】
以下、実施例及び比較例を示し、本発明を具体的に説明するが、本発明は下記の実施例に制限されるものではない。
【００５５】
［実施例１］
下記式（６）で表されるポリマー（粘度８５００ｃｓ，平均分子量２２０００，ビニル基量０．００９モル／１００ｇ）１００重量部にジメチルシロキシ基で処理された比表面積２００ｍ²／ｇの煙霧質シリカ２０重量部を加え、混合、熱処理の後、三本ロールミル上にて混合し、更に下記式（７）で表される含フッ素有機ケイ素化合物１．０２重量部、塩化白金酸をＣＨ₂＝ＣＨＳｉＭｅ₂ＯＳｉＭｅ₂ＣＨ＝ＣＨ₂で変性した触媒のトルエン溶液（白金濃度１．０重量％）０．２重量部及びエチニルシクロヘキサノールの５０％トルエン溶液０．４重量部を加え、混合し、組成物Ｉを作成した。
【００５６】
【化２０】

【００５７】
これを減圧下で脱泡し、２ｍｍ厚の長方形の枠に置き、再び空気抜きをし、１００ｋｇ／ｃｍ²、１５０℃で１０分間プレス硬化した。試験片を硬化した試料から切り取り、ＪＩＳ Ｋ６２５１，６２５３に準じて物性を測定し、次の結果を得た。
硬さ（デュロメータータイプＡ） ４５
伸び（％） ６７０
引張り強さ（ＭＰａ） １１．２
次に、この試験片を用い、耐熱性、耐薬品性、溶剤膨潤性、低温特性及び透湿性を測定したところ、表１〜５に示す結果を得た。
【００５８】
［比較例１］
実施例１の式（７）の含フッ素有機化合物の代わりに下記式（８）で示される含フッ素水素シロキサン２．４９重量部を使用した以外は実施例１と同様にして組成物ＩＩを作成した。
【００５９】
【化２１】

【００６０】
この組成物ＩＩを実施例１と同様の条件で硬化シートを作成した。試験片を切り取り、ＪＩＳ Ｋ６２５１，６２５３に準じて物性を測定したところ、以下の結果が得られた。
硬さ（デュロメータータイプＡ） ４１
伸び（％） ６２０
引張り強さ（ＭＰａ） １１．８
次に、この試験片を用い、耐薬品性を測定したところ、表２に示す結果を得た。
【００６１】
【表１】

【００６２】
【表２】

（ ）内はポイント数の増減
劣化条件：２０℃−３日
組成物Ｉは組成物ＩＩと比較し、耐酸性に優れる。
【００６３】
【表３】

バイトンＧＦＬＴ…デュポン社製フッ素ゴム
ＦＥ６１…信越化学工業製フロロシリコーンゴム
【００６４】
【表４】

バイトンＥ−６０Ｃ…デュポン社製フッ素ゴム
ＫＥ９５１…信越化学工業製フロロシリコーンゴム
【００６５】
【表５】

条件：４０℃−９０％ＲＨ；単位：ｇ／ｍ²・２４Ｈｒ
ＫＥ９５１…信越化学工業製シリコーンゴム
バイトンＧＦＬＴ…デュポン社製フッ素ゴム
ＦＥ２５１…信越化学工業製フロロシリコーンゴム
【００６６】
［実施例２］
実施例１で使用したポリマーの代わりに、下記式（９）で表されるポリマー（粘度５３００ｃｓ，平均分子量１７０００，ビニル基量０．０１２モル／１００ｇ）を使用し、実施例１で使用した含フッ素ケイ素化合物３．５３重量部を使用した以外は、実施例１と同様にして硬化シートを作成した。
【００６７】
【化２２】

【００６８】
この硬化シートから試験片を切り取り、ＪＩＳ Ｋ６２５１，６２５３に準じて物性を測定したところ、以下の結果が得られた。
硬さ（デュロメータータイプＡ） ４９
伸び（％） ４５０
引張り強さ（ＭＰａ） １０．８
次に、この試験片を用い、耐薬品性を測定したところ、表６に示す結果を得た。
【００６９】
［実施例３］
実施例１で使用したポリマーの代わりに、下記式（１０）で表されるポリマー（粘度１３６０００ｃｓ，平均分子量２３３００，ビニル基量０．００８モル／１００ｇ）１００重量部、実施例１で使用した含フッ素有機ケイ素化合物２．３０重量部を用いた以外は、実施例１と同様に組成物を調整し、硬化シートを作成した。
【００７０】
【化２３】

【００７１】
この硬化シートから試験片を切り取り、ＪＩＳ Ｋ６２５１，６２５３に準じて物性を測定したところ、以下の結果が得られた。
硬さ（デュロメータータイプＡ） ３８
伸び（％） ５９０
引張り強さ（ＭＰａ） １１．０
次に、この試験片を用い、耐薬品性を測定したところ、表６に示す結果を得た。
【００７２】
［実施例４］
実施例１で使用したポリマーの代わりに、下記式（１１）で表されるポリマー（粘度８７０００ｃｓ，平均分子量２７９００，ビニル基量０．００７モル／１００ｇ）１００重量部、実施例１で使用した含フッ素ケイ素化合物１．９５重量部を使用した以外は、実施例１と同様に組成物を調整し、硬化シートを作成した。
【００７３】
【化２４】

【００７４】
この硬化シートから試験片を切り取り、ＪＩＳ Ｋ６２５１，６２５３に準じて物性を測定したところ、以下の結果が得られた。
硬さ（デュロメータータイプＡ） ３７
伸び（％） ５７０
引張り強さ（ＭＰａ） ９．９
次に、この試験片を用い、耐薬品性を測定したところ、表６に示す結果を得た。
【００７５】
［実施例５］
実施例１で使用した含フッ素有機ケイ素化合物０．６２重量部、及び、下記式（１２）で表される有機ケイ素化合物０．４６重量部を使用した以外は、実施例１と同様に組成物を調整し、硬化シートを作成した。
【００７６】
【化２５】

【００７７】
この硬化シートから試験片を切り取り、ＪＩＳ Ｋ６２５１，６２５３に準じて物性を測定したところ、以下の結果が得られた。
硬さ（デュロメータータイプＡ） ６０
伸び（％） ４００
引張り強さ（ＭＰａ） ９．３
次に、この試験片を用い、耐薬品性を測定したところ、表７に示す結果を得た。
【００７８】
［実施例６］
実施例１で使用した有機ケイ素化合物０．４１重量部、及び比較例１で使用した含フッ素水素シロキサン１．５１重量部を使用した以外は、実施例１と同様に組成物を調整し、硬化シートを作成した。
【００７９】
この硬化シートから試験片を切り取り、ＪＩＳ Ｋ６２５１，６２５３に準じて物性を測定したところ、以下の結果が得られた。
硬さ（デュロメータータイプＡ） ４３
伸び（％） ６６０
引張り強さ（ＭＰａ） １２
次に、この試験片を用い、耐薬品性を測定したところ、表７に示す結果を得た。
【００８０】
【表６】

（ ）内はポイント数の増減
劣化条件：２０℃−３日
【００８１】
【表７】

（ ）内はポイント数の増減
劣化条件：２０℃−３日
【００８２】
表２，６及び７の結果から、実施例に示されるＳｉＨ基のケイ素原子がベンゼン環に結合した有機ケイ素化合物を使用した硬化性フルオロポリエーテルゴム組成物の場合、比較例に示されるＨ−ＳｉＯＳｉ型の有機ケイ素化合物を単独に使用した場合に比べて非常に優れた耐酸性を示す。また、実施例６からＳｉＨ基のケイ素原子がベンゼン環に結合した有機ケイ素化合物とＨ−ＳｉＯＳｉ型の有機ケイ素化合物の併用でも耐酸性の向上が見られることが明らかである。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a curable fluoropolyether composition that is excellent in heat resistance, chemical resistance, solvent resistance, mold release property, water repellency, oil repellency, weather resistance, and can obtain a cured product with improved acid resistance. .
[0002]
[Prior art and problems to be solved by the invention]
Linear fluoropolyether compound having at least two alkenyl groups in one molecule and having a perfluoropolyether structure in the main chain, and organosilicon compound having at least two H-SiOSi structures in one molecule And a composition comprising a hydrosilylation reaction catalyst, which is well-balanced in properties such as heat resistance, chemical resistance, solvent resistance, releasability, water repellency, oil repellency, weather resistance, etc. It is proposed in Japanese Patent Publication No. 2990646.
[0003]
However, although such a fluoropolyether rubber composition has sufficient performance in most applications, it may have higher acid resistance in semiconductor-related applications and engine oil applications that require acid resistance. Required.
[0004]
The present invention was made to meet the above-mentioned demands, and is excellent in heat resistance, chemical resistance, solvent resistance, mold release, water repellency, oil repellency, weather resistance, etc., and also in acid resistance. An object of the present invention is to provide a curable fluoropolyether rubber composition that gives a cured product.
[0005]
Means for Solving the Problem and Embodiment of the Invention
As a result of intensive investigations to achieve the above object, the present inventors have found that a linear fluoropolymer having at least two alkenyl groups in one molecule and a perfluoropolyether structure in the main chain. By blending an ether compound, an organosilicon compound having at least two hydrogen atoms bonded to silicon atoms in one molecule, and all silicon atoms bonded to hydrogen atoms being bonded to a benzene ring, and a hydrosilylation reaction catalyst , A curable fluoropolyether rubber composition that is excellent in heat resistance, chemical resistance, solvent resistance, mold release, water repellency, oil repellency, weather resistance, etc. and gives a cured product with excellent acid resistance. I found out that
[0006]
That is, a fluoropolyether rubber composition using an organosilicon compound having an H—SiOSi structure as shown in Japanese Patent Publication No. 2990646 (Japanese Patent Laid-Open No. Hei 8-199070) has an SiOSi bond to an acid. This is not very strong because of the cleavage between silicon and oxygen. Thus, as a result of various studies, the present inventors have found that the silicon-carbon bond of the benzene ring bonded to the silicon atom has a very stable structure with respect to the acid and bonded to the hydrogen atom. It has been found that a fluoropolyether rubber composition having excellent acid resistance can be obtained by using an organosilicon compound in which a benzene ring is bonded to a silicon atom, and the present invention has been made.
[0007]
Therefore, the present invention
(A) a linear fluoropolyether compound having at least two alkenyl groups in one molecule and a perfluoropolyether structure in the main chain;
(B) an organosilicon compound having at least two hydrogen atoms bonded to silicon atoms in one molecule, and all silicon atoms bonded to hydrogen atoms are bonded to a benzene ring;
(C) A curable fluoropolyether rubber composition comprising a hydrosilylation reaction catalyst is provided.
[0008]
Hereinafter, the present invention will be described in more detail.
The linear fluoropolyether compound of the component (A) used in the present invention has at least two alkenyl groups in one molecule and a divalent perfluoroalkyl ether structure in the main chain. .
[0009]
Here, the perfluoroalkyl ether structure includes a large number of repeating units of —C _d F _2d O— (wherein _d in each unit is an integer of 1 to 6). Examples thereof include those represented by the general formula (5).
(C _d F _2d O) _q (5)
(Q is an integer of 1 to 500, preferably 2 to 400, more preferably 10 to 200.)
[0010]
Examples of the repeating unit represented by the above formula (5) include the following units. The perfluoroalkyl ether structure may be composed of one of these repeating units alone, or may be a combination of two or more.
_{-CF 2 O -, - CF 2} CF 2 O -, - CF 2 CF 2 CF 2 O-,
—CF (CF ₃ ) CF ₂ O—, —CF ₂ CF ₂ CF ₂ CF ₂ O—,
_{-CF 2 CF 2 CF 2 CF 2} CF 2 CF 2 O -, - C (CF 3) 2 O-
Of these, the following units are particularly preferred.
_{-CF 2 O -, - CF 2} CF 2 O -, - CF 2 CF 2 CF 2 O-,
-CF (CF ₃ ) CF ₂ O-
[0011]
Further, the alkenyl group in the linear fluoropolyether compound (A) is preferably an alkenyl group having 2 to 8 carbon atoms, particularly 2 to 6 and having a CH ₂ ═CH— structure at the terminal, such as vinyl. Group, allyl group, propenyl group, isopropenyl group, butenyl group, hexenyl group and the like. Among them, vinyl group and allyl group are preferable. The alkenyl group may be present in the molecule, but is preferably bonded to both ends of the molecular chain. In this case, the alkenyl group is directly bonded to both ends of the main chain of the linear fluoropolyether compound. It may be bonded to the main chain via a divalent linking group as shown below.
_{-CH 2 -, - CH 2 O} -, - Y-NR'-CO-
(However, Y is —CH ₂ — or a group represented by the following structural formula (A), and R ′ is a hydrogen atom, a methyl group, a phenyl group, or an allyl group.)
[0012]
[Chemical formula 5]

(O, m or p position)
[0013]
As such a linear fluoropolyether compound of component (A), those represented by the following general formulas (2) and (3) are preferable.
_{CH 2 = CH- (X) p} -Rf '- (X) p -CH = CH 2 (2)
_{CH 2 = CH- (X) p} -Q-Rf'-Q- (X) p -CH = CH 2 (3)
Wherein, X is independently _{-CH 2 -, - CH 2 O-} , or -Y-NR'-CO- (where, Y is -CH ₂ - is a group represented by or the following structural formula (A) , R ′ is a hydrogen atom, a methyl group, a phenyl group, or an allyl group.), Q is a divalent hydrocarbon group having 1 to 15 carbon atoms, and includes an ether bond, an amide bond, or a carbonyl bond. Rf ′ may be a divalent perfluoroalkylene group or a perfluorooxyalkylene group. p is independently 0 or 1. ]
[0014]
[Chemical 6]

(O, m or p position)
Among these, those represented by the following general formula (4) are particularly preferable.
[0015]
[Chemical 7]

[Wherein X is the same as above. p is independently 0 or 1, r is an integer of 2 to 6, u is an integer of 1 to 6, and m and n are each an integer of 0 to 200. ]
[0016]
The linear fluoropolyether compound of the above formula (4) preferably has a weight average molecular weight of 400 to 100,000, particularly 1,000 to 50,000.
[0017]
The following compounds etc. can be illustrated as a specific example of the fluoro polyether compound represented by Formula (4). In the formula, m and n are the same as described above.
[0018]
[Chemical 8]

[0019]
[Chemical 9]

[0020]
Furthermore, in the present invention, in order to adjust the linear fluoropolyether compound to a desired weight average molecular weight according to the purpose, the above-mentioned linear fluoropolyether compound is an organic compound containing two SiH groups in the molecule. It is also possible to use as a component (A) a product obtained by hydrosilylation reaction with a silicon compound by a conventional method and conditions to extend the chain length.
[0021]
Next, the component (B) acts as a crosslinking agent and a chain extender for the component (A). The component (B) is not particularly limited as long as it has at least two hydrogen atoms bonded to silicon atoms in one molecule and all silicon atoms bonded to hydrogen atoms are bonded to the benzene ring. . Examples of such an organosilicon compound include those represented by the following general formula (1).
[0022]
[Chemical Formula 10]

(In the formula, R is the same or different monovalent hydrocarbon group having 1 to 20 carbon atoms. X and y are integers of 1 to 5, a is 1 or 2, and b is 0, 1 or it is 2, s and t is 0 or 1 .Z represents a hydrogen atom, an oxygen atom, -R, -Q-Rf, -SiR 2 -, - Q -, - Rf'-, or -Q-Rf ' A monovalent or divalent group represented by -Q-, wherein Q is a divalent hydrocarbon group having 1 to 15 carbon atoms and may contain an ether bond, an amide bond or a carbonyl bond; Rf is a monovalent perfluoroalkyl group or a perfluorooxyalkyl group, Rf ′ is a divalent perfluoroalkylene group or a perfluorooxyalkylene group, and the hydrogen atom of each benzene ring is a halogen atom, Even if it is substituted with a lower alkyl group such as a methyl group or an ethyl group It has.)
[0023]
Here, examples of the monovalent hydrocarbon group for R include alkyl groups such as methyl, ethyl, and propyl, and aryl groups such as phenyl, which will be described in detail later. Examples of the divalent hydrocarbon group for Q include alkylene groups such as methylene, ethylene, propylene, tetramethylene, and hexamethylene, arylene groups such as phenylene, and groups in which these alkylene groups and arylene groups are bonded. These may contain an ether bond, an amide bond, or a carbonyl bond.
[0024]
Z is a monovalent group (—H, —R, —Q—Rf) or a divalent group (—O—, —SiR ₂ —, —Q—, —Rf′—, —Q— as described above. Rf′−Q−), which is selected by the values of a, b, s, and t.
[0025]
Specific examples of the organosilicon compound represented by the above formula (1) include the following. Me represents a methyl group (hereinafter the same).
[0026]
Embedded image

[0027]
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[0028]
In consideration of compatibility with component (A), dispersibility, and uniformity after curing, one or more monovalent perfluoroalkyl group, monovalent perfluorooxyalkyl group, 2 Those having a valent perfluoroalkylene group or a divalent perfluorooxyalkylene group can be used. The perfluoroalkyl group and perfluoroalkylene group preferably have 1 to 20 carbon atoms, and the perfluorooxyalkyl group and perfluorooxyalkylene group preferably have 1 to 500 carbon atoms, particularly 4 to 500 carbon atoms.
[0029]
Examples of the perfluoroalkyl group, perfluorooxyalkyl group, perfluoroalkylene group, and perfluorooxyalkylene group include groups represented by the following general formula.
[0030]
Embedded image

[0031]
These perfluoro (oxy) alkyl groups and perfluoro (oxy) alkylene groups may be directly bonded to the silicon atom, but may be bonded to the silicon atom via a divalent linking group. Here, the divalent linking group may be an alkylene group, an arylene group, a combination thereof, or an ether bond oxygen atom, an amide bond, a carbonyl bond, or the like interposed therebetween. The thing of 2-12 is preferable and the following group etc. are mentioned.
—CH ₂ CH ₂ —, —CH ₂ CH ₂ CH ₂ —, —CH ₂ CH ₂ CH ₂ OCH ₂ —
_{-CH 2 CH 2 CH 2 -NH-} CO-,
_{-CH 2 CH 2 CH 2 -N (} Ph) -CO-,
—CH ₂ CH ₂ CH ₂ —N (CH ₃ ) —CO—, —CH ₂ CH ₂ CH ₂ —O—CO—
(Ph is a phenyl group.)
[0032]
Further, the monovalent or divalent fluorine-containing substituent in the organosilicon compound of component (B), that is, a monovalent containing a perfluoroalkyl group, a perfluorooxyalkyl group, a perfluoroalkylene group or a perfluorooxyalkylene group. Examples of the monovalent substituent (R) bonded to the silicon atom other than the organic group include alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, a cyclohexyl group, an octyl group, and a decyl group; Alkenyl groups such as vinyl groups and allyl groups; aryl groups such as phenyl groups, tolyl groups and naphthyl groups; aralkyl groups such as benzyl groups and phenylethyl groups; or a part of hydrogen atoms of these groups are chlorine atoms, cyano groups For example, chloromethyl group, chloropropyl group, cyanoethyl group, etc.換又 is a substituted hydrocarbon group.
[0033]
Further, the number of silicon atoms in the molecule of the organosilicon compound is not particularly limited, but usually 2 to 60, particularly about 3 to 30 is preferable.
[0034]
Examples of such organosilicon compounds include the following compounds, and these compounds may be used alone or in combination of two or more. In the following formulae, Me represents a methyl group, and Ph represents a phenyl group.
[0035]
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[0036]
Embedded image

[0037]
Embedded image

[0038]
Embedded image

[0039]
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[0040]
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[0041]
The blending amount of the component (B) is usually that of the hydrosilyl group in the component (B), that is, the SiH group with respect to 1 mol of the alkenyl group such as vinyl group, allyl group, cycloalkenyl group and the like contained in the component (A). The amount is preferably 0.5 to 5 mol, more preferably 1 to 2 mol. If the blending amount of the component (B) is too small, the degree of crosslinking may be insufficient. If it is too large, the chain length extension is prioritized, curing becomes insufficient, foams, heat resistance, compression set. The characteristics may be deteriorated.
[0042]
As the hydrosilylation reaction catalyst of component (C), transition metals, for example, platinum group metals such as Pt, Rh, and Pd, and compounds of these transition metals are preferably used. In the present invention, since these compounds are generally precious metal compounds and are expensive, platinum compounds that are relatively easily available are preferably used.
[0043]
Specific examples of the platinum compound include chloroplatinic acid or a complex of chloroplatinic acid and an olefin such as ethylene, a complex of alcohol or vinylsiloxane, platinum / silica, alumina, or carbon. It is not limited.
[0044]
As platinum group metal compounds other than platinum compounds, rhodium, ruthenium, iridium, palladium compounds and the like are known. For example, RhCl (PPh ₃ ) ₃ , RhCl (CO) (PPh ₃ ) ₂ , RhCl (C ₂₎ H ₄ ) ₂ , Ru ₃ (CO) ₁₂ , IrCl (CO) (PPh ₃ ) ₂ , Pd (PPh ₃ ) ₄ (Ph represents a phenyl group).
[0045]
The amount of these catalysts used is not particularly limited, and a desired curing rate can be obtained with the amount of catalyst. However, in order to obtain an economical viewpoint or a good cured product, the total amount of the curable composition is used. On the other hand, it is good to set it as the range of about 0.1-1,000 ppm (platinum group metal conversion), More preferably about 0.1-500 ppm (same as above).
[0046]
In addition to the component (B) as the crosslinking agent and the chain extender of the component (A), the curable composition of the present invention has an H-Si-O-Si structure and H for adjusting workability and rubber properties. An organosilicon compound having a structure that does not correspond to the component (B) such as a —SiCH ₂ — structure and having at least two SiH structures in one molecule can be blended in an arbitrary ratio. The SiH-containing organosilicon compound not corresponding to the component (B) is not particularly limited as long as it has two or more SiH groups in one molecule, and has a chain shape, a ring shape, a network shape, or the like. May be.
[0047]
When a hydrosilyl group, that is, an organosilicon compound having a SiH group is added in addition to the component (B) as a crosslinking agent or chain extender of the component (A), a vinyl group or an allyl group usually contained in the component (A) The total amount of SiH groups is preferably 0.5 to 5 moles, more preferably 1 to 2 moles per mole of an alkenyl group such as a cycloalkenyl group. If the amount of SiH group is too small, the degree of cross-linking may be insufficient, and if it is too large, chain length extension takes precedence, curing becomes insufficient, foaming, heat resistance, compression set characteristics, etc. It may get worse.
[0048]
The compounding amount of the organosilicon compound having an SiH structure other than the component (B) relative to the component (B) is not particularly limited, and can be arbitrarily set according to the application.
[0049]
Various additives can be added to the curable composition of the present invention as necessary in order to enhance its practicality. As these additives, specifically, a CH ₂ ═CH (R) SiO unit added for the purpose of controlling the curing rate of the curable composition (wherein R is a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group). Polysiloxane (see Japanese Patent Publication No. 48-10947) and acetylene compounds (see US Pat. No. 3,445,420 and Japanese Patent Publication No. 4-3774), and ionic compounds of heavy metals (US Pat. No. 3,532,649). For example).
[0050]
The curable composition of the present invention includes a reduction in thermal shrinkage at the time of curing, a decrease in the coefficient of thermal expansion of the elastic body obtained by curing, thermal stability, weather resistance, chemical resistance, flame resistance or mechanical strength. A filler may be added for the purpose of improving the gas permeability or lowering the gas permeability. In this case, examples of the additive include fumed silica, quartz powder, glass fiber, carbon, metal oxide such as iron oxide, titanium oxide and cerium oxide, and metal carbonate such as calcium carbonate and magnesium carbonate. . Furthermore, it is possible to add an appropriate pigment or dye as required.
[0051]
The manufacturing method in particular of the curable composition of this invention is not restrict | limited, It can manufacture by kneading the said component. Alternatively, the two components of the component (A), the component (B) and the component (C), and the component (A) and the component (C) may be used and mixed at the time of use. Further, in order to cure the obtained composition, room temperature curing is possible depending on the type of functional group of component (A), the type of catalyst of component (C), etc. It is preferable to cure in about several minutes to several hours.
[0052]
In using the curable composition of the present invention, an appropriate fluorine-based solvent such as 1,3-bistrifluoromethylbenzene, perfluorooctane or the like is added to the composition to a desired concentration according to its use and purpose. It can also be used after being dissolved.
[0053]
【The invention's effect】
The curable fluoropolyether rubber cured product of the present invention is excellent in heat resistance, chemical resistance, solvent resistance, releasability, water repellency, oil repellency, weather resistance, etc., and also in acid resistance and alkali resistance. Can be used for a wide range of molding applications such as sealing materials for semiconductor manufacturing equipment, automotive, aircraft O-rings, diaphragms, sealing materials, roll materials for copying machines, secondary batteries and fuel cells. Useful for electrode constituent materials.
[0054]
【Example】
EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not restrict | limited to the following Example.
[0055]
[Example 1]
A fumed silica 20 having a specific surface area of 200 m ² / g treated with dimethylsiloxy group on 100 parts by weight of a polymer represented by the following formula (6) (viscosity 8500 cs, average molecular weight 22000, vinyl group amount 0.009 mol / 100 g) Add parts by weight, and after mixing and heat treatment, mix on a three roll mill, and further add 1.02 parts by weight of a fluorine-containing organosilicon compound represented by the following formula (7), and chloroplatinic acid is CH ₂ = CHSiMe _2. Add 0.2 parts by weight of a toluene solution of a catalyst modified with OSiMe ₂ CH═CH ₂ (platinum concentration: 1.0% by weight) and 0.4 parts by weight of a 50% toluene solution of ethynylcyclohexanol, and mix them together. It was created.
[0056]
Embedded image

[0057]
This was degassed under reduced pressure, placed in a 2 mm thick rectangular frame, vented again, and press cured at 100 kg / cm ² and 150 ° C. for 10 minutes. The test piece was cut from the cured sample and measured for physical properties in accordance with JIS K6251, 6253, and the following results were obtained.
Hardness (Durometer type A) 45
Elongation (%) 670
Tensile strength (MPa) 11.2
Next, when the heat resistance, chemical resistance, solvent swellability, low temperature characteristics and moisture permeability were measured using this test piece, the results shown in Tables 1 to 5 were obtained.
[0058]
[Comparative Example 1]
A composition II was prepared in the same manner as in Example 1 except that 2.49 parts by weight of the fluorine-containing hydrogen siloxane represented by the following formula (8) was used instead of the fluorine-containing organic compound of the formula (7) in Example 1. did.
[0059]
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[0060]
A cured sheet was prepared from the composition II under the same conditions as in Example 1. When the test piece was cut out and the physical properties were measured according to JIS K6251, 6253, the following results were obtained.
Hardness (Durometer type A) 41
Elongation (%) 620
Tensile strength (MPa) 11.8
Next, when the chemical resistance was measured using this test piece, the results shown in Table 2 were obtained.
[0061]
[Table 1]

[0062]
[Table 2]

(): Increase / decrease deterioration condition of the number of points: 20 ° C.-3 days Composition I is superior in acid resistance compared to Composition II.
[0063]
[Table 3]

Viton GFLT… Fluoro rubber FE61 made by DuPont… Fluorosilicone rubber made by Shin-Etsu Chemical Co., Ltd.
[Table 4]

Viton E-60C: Fluoro rubber KE951 manufactured by DuPont Fluorosilicone rubber manufactured by Shin-Etsu Chemical Co., Ltd. [0065]
[Table 5]

Condition: 40 ° C.-90% RH; Unit: g / m ² · 24 Hr
KE951 ... Shin-Etsu Chemical Silicone Rubber Viton GFLT ... DuPont Fluoro Rubber FE251 ... Shin-Etsu Chemical Fluorosilicone Rubber
[Example 2]
Instead of the polymer used in Example 1, a polymer represented by the following formula (9) (viscosity 5300 cs, average molecular weight 17000, vinyl group content 0.012 mol / 100 g) was used. A cured sheet was prepared in the same manner as in Example 1 except that 3.53 parts by weight of the fluorosilicon compound was used.
[0067]
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[0068]
When a test piece was cut out from the cured sheet and measured for physical properties according to JIS K6251, 6253, the following results were obtained.
Hardness (Durometer type A) 49
Elongation (%) 450
Tensile strength (MPa) 10.8
Next, when chemical resistance was measured using this test piece, the results shown in Table 6 were obtained.
[0069]
[Example 3]
Instead of the polymer used in Example 1, 100 parts by weight of the polymer represented by the following formula (10) (viscosity 136000 cs, average molecular weight 23300, vinyl group amount 0.008 mol / 100 g), the content used in Example 1 was included. Except having used 2.30 weight part of fluorine organosilicon compounds, the composition was adjusted similarly to Example 1 and the cured sheet was created.
[0070]
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[0071]
When a test piece was cut out from the cured sheet and measured for physical properties according to JIS K6251, 6253, the following results were obtained.
Hardness (Durometer type A) 38
Elongation (%) 590
Tensile strength (MPa) 11.0
Next, when chemical resistance was measured using this test piece, the results shown in Table 6 were obtained.
[0072]
[Example 4]
Instead of the polymer used in Example 1, 100 parts by weight of the polymer represented by the following formula (11) (viscosity 87000 cs, average molecular weight 27900, vinyl group amount 0.007 mol / 100 g), the content used in Example 1 was included. A cured sheet was prepared by adjusting the composition in the same manner as in Example 1 except that 1.95 parts by weight of the fluorosilicon compound was used.
[0073]
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[0074]
When a test piece was cut out from the cured sheet and measured for physical properties according to JIS K6251, 6253, the following results were obtained.
Hardness (Durometer type A) 37
Elongation (%) 570
Tensile strength (MPa) 9.9
Next, when chemical resistance was measured using this test piece, the results shown in Table 6 were obtained.
[0075]
[Example 5]
The composition was the same as in Example 1 except that 0.62 part by weight of the fluorine-containing organosilicon compound used in Example 1 and 0.46 part by weight of the organosilicon compound represented by the following formula (12) were used. Was adjusted to produce a cured sheet.
[0076]
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[0077]
When a test piece was cut out from the cured sheet and measured for physical properties according to JIS K6251, 6253, the following results were obtained.
Hardness (Durometer type A) 60
Elongation (%) 400
Tensile strength (MPa) 9.3
Next, when the chemical resistance was measured using this test piece, the results shown in Table 7 were obtained.
[0078]
[Example 6]
The composition was prepared and cured in the same manner as in Example 1 except that 0.41 part by weight of the organosilicon compound used in Example 1 and 1.51 part by weight of the fluorine-containing hydrogen siloxane used in Comparative Example 1 were used. Created a sheet.
[0079]
When a test piece was cut out from the cured sheet and measured for physical properties according to JIS K6251, 6253, the following results were obtained.
Hardness (Durometer type A) 43
Elongation (%) 660
Tensile strength (MPa) 12
Next, when the chemical resistance was measured using this test piece, the results shown in Table 7 were obtained.
[0080]
[Table 6]

(): Increase / decrease conditions of the number of points: 20 ° C-3 days [0081]
[Table 7]

(): Increase / decrease conditions of the number of points: 20 ° C-3 days [0082]
From the results of Tables 2, 6 and 7, in the case of a curable fluoropolyether rubber composition using an organosilicon compound in which the silicon atom of the SiH group shown in the examples is bonded to the benzene ring, H- Compared to the case where an SiOSi type organosilicon compound is used alone, the acid resistance is very excellent. In addition, it is clear from Example 6 that acid resistance is improved even when an organosilicon compound in which a silicon atom of SiH group is bonded to a benzene ring and an H-SiOSi type organosilicon compound are used in combination.

Claims (4)

(A) a linear fluoropolyether compound having at least two alkenyl groups in one molecule and a perfluoropolyether structure in the main chain;
(B) an organosilicon compound having at least two hydrogen atoms bonded to silicon atoms in one molecule, and all silicon atoms bonded to hydrogen atoms are bonded to a benzene ring;
(C) A curable fluoropolyether rubber composition comprising a hydrosilylation reaction catalyst. The curable fluoropolyether rubber composition according to claim 1, wherein the silicon compound as component (B) is represented by the following general formula (1).

(In the formula, R is the same or different monovalent hydrocarbon group having 1 to 20 carbon atoms. X and y are integers of 1 to 5, a is 1 or 2, and b is 0, 1 or it is 2, s and t is 0 or 1 .Z represents a hydrogen atom, an oxygen atom, -R, -Q-Rf, -SiR 2 -, - Q -, - Rf'-, or -Q-Rf ' A monovalent or divalent group represented by -Q-, wherein Q is a divalent hydrocarbon group having 1 to 15 carbon atoms and may contain an ether bond, an amide bond or a carbonyl bond; Rf is a monovalent perfluoroalkyl group or perfluorooxyalkyl group, Rf ′ is a divalent perfluoroalkylene group or perfluorooxyalkylene group, and the hydrogen atom of each benzene ring is substituted. May be.) The curable fluoropolyether rubber composition according to claim 1, wherein the component (A) is a linear fluoropolyether compound represented by the following general formula (2) or (3).
_{CH 2 = CH- (X) p} -Rf '- (X) p -CH = CH 2 (2)
_{CH 2 = CH- (X) p} -Q-Rf'-Q- (X) p -CH = CH 2 (3)
Wherein, X is independently _{-CH 2 -, - CH 2 O-} , or -Y-NR'-CO- (where, Y is -CH ₂ - is a group represented by or the following structural formula (A) , R ′ is a hydrogen atom, a methyl group, a phenyl group, or an allyl group.), Q is a divalent hydrocarbon group having 1 to 15 carbon atoms, and includes an ether bond, an amide bond, or a carbonyl bond. Rf ′ may be a divalent perfluoroalkylene group or a perfluorooxyalkylene group. p is independently 0 or 1. ]

The curable fluoropolyether rubber composition according to claim 3, wherein the component (A) is a linear fluoropolyether compound represented by the following general formula (4).

Wherein, X is independently _{-CH 2 -, - CH 2 O-} , or -Y-NR'-CO- (where, Y is -CH ₂ - is a group represented by or the following structural formula (A) , R ′ is a hydrogen atom, a methyl group, a phenyl group or an allyl group. p is independently 0 or 1, r is an integer of 2 to 6, u is an integer of 1 to 6, and m and n are integers of 0 to 200, respectively. ]