JP3594884B2 - Method for producing composite material and composite material obtained thereby - Google Patents

Description

【００２０】
そして、これらの製法のなかでも、特に、上記加硫剤として、有機過酸化物、金属酸化物およびポリオールのいずれかを用いることが好ましい。
【００２３】
また、これらの製法によって得られる複合材を第１１の要旨とする。
【００２４】
すなわち、本発明者らは、保護膜として用いる樹脂材の表面を改質して、エラストマーとより強固な接合面を形成する方法について一連の研究を重ねた結果、フッ素系樹脂シートに対し、０．１〜１．１ｋｇ／ｃｍ²という、比較的常圧に近い圧力下で低温プラズマ処理を行うとともに、その処理面にシランカップリング剤を塗布し、かつ、シランカップリング剤が未乾燥の、濡れた状態のままで、両者を接合し、加硫成形すると、従来の方法では得られない、非常に高強度の接合面が得られることを見いだし、本発明に到達した。
【００２５】
このような方法によれば、Ｏリング、パッキン、蓋などのシール材、ダイヤフラムやボール弁などの弁もしくはシール面、容器、栓、チューブなどの複合材を好適に製造できる。
【００２６】
【発明の実施の形態】
つぎに、本発明の実施の形態を詳しく説明する。
【００２７】
まず、本発明の複合材に用いるフッ素系樹脂シート（フッ素系樹脂体）は、耐候性、耐汚染性、摺動性、耐薬品性、耐熱性、耐熱水性に優れたフッ素系樹脂を主体とするもので、これに、必要に応じて各種の充填剤（グラファイト、カーボンやガラス等の短繊維、二硫化モリブデン等）を配合したものであってもよい。特に、複合材として用いる場合、少なくとも低気体透過性、耐折り強さ、高引き裂き強さ等の特性が要求されることが多く、これらに留意して、他の配合成分を選択することが好適である。
【００２８】
具体的なフッ素系樹脂としては、四フッ化エチレン（ＰＴＦＥ）、四フッ化エチレン−エチレン共重合体（ＥＴＦＥ）、四フッ化エチレン−パーフロロアルキルビニルエーテル共重合体（ＰＦＡ）、三フッ化塩化エチレン（ＰＣＴＦＥ）、六フッ化プロピレン共重合体（ＦＥＰ）等があるが、なかでも、取扱いの容易さ、入手のし易さ、価格等の点から、特にＥＴＦＥが好適である。
【００２９】
また、本発明の複合材に用いる未加硫エラストマー組成物としては、未硬化のエラストマー成分と、加硫剤と、必要に応じて適宜の充填剤等を配合してなる組成物があげられる。上記エラストマー成分としては、従来から複合材に用いられいるエラストマー成分であればどのようなものでも差し支えない。
【００３０】
そして、上記エラストマー成分と組み合わせて用いる加硫剤としては、有機過酸化物、金属酸化物、ポリオール等があげられる。上記有機過酸化物としては、各種のものが用いられるが、なかでも、ジアルキル系過酸化物が好適である。
【００３１】
上記ジアルキル系過酸化物の具体例としては、ジ−ｔ−ブチルパーオキサイド、ジ−ｔ−アミルパーオキサイド、ｔ−ブチルクミルパーオキサイド、ジクミルパーオキサイド、２，５−ジメチル−２，５−ジ（ｔ−ブチルパーオキシ）ヘキサン、２，５−ジメチル−２，５−ジ（ｔ−ブチルパーオキシ）ヘキサン−（３）、α，α´−ビス（ｔ−ブチルパーオキシ）ジイソプロピルベンゼン、１，１−ビス（ｔ−ブチルパーオキシ）−３，３，５−トリメチルシクロヘキサン、１，３−ビス（ｔ−ブチルパーオキシイソプロピル）ベンゼン、ｎ−ブチル−４，４−ビス（ｔ−ブチルパーオキシ）バレレート、２，２−ビス（４，４−ジ−ｔ−ブチルパーオキシシクロヘキシ）プロパン、２，２−ビス−（ｔ−ブチルパーオキシ）ブタン、１，１−ジ−（ｔ−ブチルパーオキシ）シクロヘキサン等があげられる。なかでも、ジクミルパーオキサイド、２，５−ジメチル−２，５−ジ（ｔ−ブチルパーオキシ）ヘキサンは、取扱いが比較的容易で、一般に入手しやすいことから特に好適である。
【００３２】
また、金属酸化物としては、ＺｎＯ、ＭｇＯ、ＰｂＯ、Ｐｂ_３Ｏ_４等があげられる。
【００３３】
本発明では、まず、フッ素系樹脂シートの少なくとも一面に所定条件で低温プラズマ処理を行って改質面とし、この改質面にシランカップリング剤を塗布する。つぎに、未加硫エラストマー組成物を上記改質面に接した状態で加熱もしくは加熱加圧することにより、フッ素系樹脂シートとエラストマー硬化体とが接合一体化された複合材を得ることができる。
【００３４】
得られた複合材の一例を図１（ａ）に示す。この複合材１０は、全体がシート状で、フッ素系樹脂シート１１（フッ素系樹脂体）と、シート状のエラストマー硬化体１２とが、非常に高い強度で接合一体化されている。
【００３５】
ここで、上記フッ素系樹脂シート１１は１枚に限らず、２枚以上を組み合わせることもできる。例えば、図１（ｂ）、（ｃ）に示すように、エラストマー硬化体１２の両面をフッ素系樹脂シート１１で挟んでよい。また、上記フッ素系樹脂シート１１に対しエラストマー硬化体１２が２個以上接合一体化した構成にしてもよい。例えば、図２（ａ）、（ｂ）に示すように、フッ素系樹脂シート１１の両面をエラストマー硬化体１２で挟む、あるいは、フッ素系樹脂シート１１とエラストマー硬化体１２が交互に積層した構成にしてもよい。これらの場合、エラストマー硬化体１２と接合させるフッ素系樹脂シート１１の面は、どの面についても改質しておくことが望ましい。ここで、図２（ａ）、（ｂ）に示す例では、フッ素系樹脂シート１１とエラストマー硬化体１２との積層体を金属など基材３０の表面に形成した例を示してある。
【００３６】
そして、本発明で用いる低温プラズマ処理とは、電子温度は高いがガス温度が低い領域で発生するプラズマ（非平衡プラズマともいう）を利用して行う処理で、すでに述べたように、プラズマ中を活性種であるイオン、電子、ラジカル、真空紫外線等を素材表面に作用させ、エッチング、インプランテーション、ラジカル生成等の表面改質を行い、表面を活性化する技術である。上記インプランテーションの際、水酸基、カルボニル基、カルボキシル基等の官能基が素材表面に導入され、密着性の改善、濡れ性の向上効果が得られる。これらは、シランカップリング剤と未加硫エラストマー組成物の加硫剤に作用して、密着性を著しく向上させるのみならず、様々な応力に耐えうる強固な複合界面を生成する。
【００３７】
上記低温プラズマ処理に用いるガスとしては、Ｈｅ、Ａｒ、Ｎｅ、Ｋｒ、Ｘｅ等の不活性ガス、ＣＯ_２、ＣＯ等の炭素酸化物ガス、Ｏ_２等の酸化性ガス、ＣＦ_４等の反応ガス、エチレン、プロピレン等の重合性不飽和化合物ガス、空気等があげられる。これらは、目的に応じて、適宜に選択され、単独もしくは組み合わせて用いられる。ただし、本発明では、低温プラズマ処理を、０．１〜１．１ｋｇ／ｃｍ^２の圧力下で行うことから、なかでも、上記不活性ガスと、炭素酸化物ガスと、重合性不飽和化合物ガスとを組み合わせた混合ガス用いることが好適であり、なかでも特に、ＡｒとＣＯ_２とエチレンの混合ガスを用いることが好適である。
【００３８】
そして、上記混合ガスを用いる場合、不活性ガス１００モルに対し、重合性不飽和化合物ガスを１〜１５モル、炭素酸化物ガスを１〜２０モル配合することが好ましく、最も好ましいのは、不活性ガス１００モルに対し、重合性不飽和化合物ガスを３〜１０モル、炭素酸化物ガスを１〜１２モル配合することである。上記重合性不飽和化合物ガスと炭素酸化物ガスの配合割合が多くなると、初期放電電圧が高くなり、放電処理しにくくなるからである。
【００３９】
また、放電処理の方法としては、上記所定のガス雰囲気中にフッ素系樹脂シート１１の処理すべき面を曝し、電極間に、例えば３〜４０ｋＨｚといった高周波電圧を印加することにより行われる。なお、放電処理時の温度は、特に制限はないが、通常１０〜８０℃の範囲が好ましく、特に２５〜６０℃の範囲が好適である。
【００４０】
なお、本発明において、低温プラズマ処理を、０．１〜１．１ｋｇ／ｃｍ^２の圧力下で行うのは、つぎのような理由による。すなわち、０．１ｋｇ／ｃｍ^２未満の圧力下で行おうとすれば、系を真空に保つ必要から特殊な装置が必要となり、設備コストが高くなることと、ガス密度が低くなるため、均一かつ充分な改質面が得られないからである。一方、１．１ｋｇ／ｃｍ^２を超えると、ガスの消費量が増大するにもかかわらずそれ以上の処理効果は得られず、経済的でない。
【００４１】
そして、本発明では、特に、図３に示すような装置を用いると、上記フッ素系樹脂シート１１に対する低温プラズマ処理を連続的に行うことができ、好適である。
【００４２】
図３は、本発明の実施に用いることのできる低温プラズマ処理装置の説明図である。この図において、この低温プラズマ処理装置１００は、上記低温プラズマ処理を大気圧に近い圧力下で行うことから、プラズマ炉１３にスリット１４、１５を設けたもので、供給ロール１６から繰り出される帯状のフッ素系樹脂シート１１を、スリット１４から炉内に導入し、上下の電極１７、１８間を通過させて低温プラズマ処理を行い、スリット１５から炉外に排出して巻取りロール１９に巻き取ることにより、フッ素系樹脂シート１１に対し、連続的に低温プラズマ処理を行うようにしたものである。なお、不活性ガス等のガスは、ガス供給口２０から炉内に連続的に供給され、上記スリット１４、１５から流出するようになっている。また、２１は上下の電極１７、１８に貼付された誘電体被覆である。
【００４３】
つぎに、上記低温プラズマ処理によって得られたフッ素系樹脂シート１１の改質面に塗布するシランカップリング剤としては、下記の一般式（１）で示されるシランカップリング剤があげられる。これらは単独で用いても２種以上を併用してもよい。
【００４４】
【化３】

【００４５】
上記シランカップリング剤の具体例としては、γ−メタクリロキシプロピルトリエトキシシラン、γ−メタクリロキシプロピルメチルジメトキシシラン、γ−メタクリロキシプロピルメチルジエトシキシラン、γ−メタクリロキシプロピルメトキシシラン、Ｎ−β−（アミノエチル）γ−アミノプロピルトリメトキシシラン、Ｎ−β−（アミノエチル）γ−アミノプロピルメチルジメトキシシラン、Ｎ−β−（アミノエチル）γ−アミノプロピルトリエトキシシラン、β−（３，４−エポキシシクロヘキシル）エチルトリメトキシシラン、γ−グリシドキシププロピルトリメトキシシラン、γ−グリシドキシプロピルメチルジエトキシシラン、γ−グリシドキシプロピルトリエトキシシラン、ビニルトリクロルシラン、ビニルトリメトキシシラン、ビニルトリエトキシシラン、ビニルトリス（β−メトキシエトキシ）シラン、γ−イソシアネートプロピルトリエトキシシラン等があげられる。ただし、これらのシランカップリング剤のうち、アミノ官能性シラン化合物は、有効な接着促進剤であるが、多量に使用すると、１００℃程度の高温に連続的に曝されると顕著な変色を引き起こしたり、硬化劣化が進んで接着力が低下したりするので、なるべく単独で用いないのが好ましい。また、イソシアネート系シランカップリングを用いると、接合しようとする材料、接合形態にかかわらず、ほぼ一定以上の高強度の接合面が得られるので、適用範囲が広く、好適である。
【００４６】
そして、これらのシランカップリング剤は、そのまま用いてもよいし、そのままでは用いにくい場合は塗布作業性の点から、水、溶剤等によって希釈して用いてもよい。その場合、希釈倍率は、シランカップリング剤の種類や接合させるエラストマー成分の種類にもよるが、通常、１．１〜２０倍に設定することが、作業性の上で好適である。
【００４７】
上記シランカップリング剤（希釈液を含む）のフッ素系樹脂シート改質面への塗布量は、特に限定されるものではないが、通常、１０〜４０ｇ／ｍ^２に設定することが好適である。すなわち、塗布量が１０ｇ／ｍ^２より少ないと、接着力が安定しにくく、逆に４０ｇ／ｍ^２を超えると、射出成形や圧縮成形の際、圧力によって塗布面と平行な方向に滲み出して成形金型を汚損し、成形物の取り出しに支障をきたすおそれがあるからである。
【００４８】
また、シランカップリング剤の塗布方法は、特に限定するものではなく、どのような塗布方法によっても差し支えはないが、均一に塗布する点で、スプレー塗布か好適である。
【００４９】
なお、通常、シランカップリング剤を二つの素材間の接合補強に用いる場合、片方の素材面にシランカップリング剤を塗布し、その塗布面を乾燥してから、もう一つの素材との接合を行うことが一般的であるが、本発明では、上記フッ素系樹脂シート１１の改質面に塗布したシランカップリング剤が未乾燥の状態で、この面を直ちに未加硫エラストマー組成物と接するようにして、加熱もしくは加熱加圧により両者の一体成形を行うと、より高強度の接合界面が得られ、好適である。
【００５０】
すなわち、フッ素系樹脂シート１１とエラストマー硬化体１２が高強度で接合するには、未加硫エラストマー組成物の、フッ素系樹脂シート１１に対する濡れ性が大きく影響すると考えられるが、上記シランカップリング剤を、未乾燥の、濡れた状態のまま加硫エラストマー組成物と接触させ、加熱または加熱加圧によって一工程で成形一体化すると、未加硫エラストマー組成物の接触圧を受けて、フッ素系樹脂シート改質面に対するシランカップリング剤の濡れと未加硫エラストマー組成物に対するシランカップリング剤の濡れとが同時に実現し、このとき、シランカップリング剤と未加硫エラストマー組成物とが、互いの接触圧と未加硫エラストマー組成物の流動によって相互に混合・拡散し合う。これにより、低温プラズマ処理面／シランカップリング剤／未加硫エラストマー組成物の界面は、加硫剤の働きにより三者が混在した状態で架橋され、従来にない、高強度の接合界面が得られると考えられる。
【００５１】
なお、上記シランカップリング剤が「未乾燥の状態」とは、乾燥のためにシランカップリング剤塗布面を放置したり風乾等に供することなく、塗布作業終了後すぐの状態をいう。
【００５２】
そして、特に、上記シランカップリング剤のうち、前記一般式（１）においてＹがメタクリロキシ基であるメタクリロキシ系シランカップリング剤は、一般に、その水溶液を調製した上で、その調製液を目的とする面に吹き付け、乾燥させてカップリング効果を発現させるようにしているが、本発明では、このメタクリロキシ系シランカップリング剤を原液のまま、フッ素系樹脂シート１１の改質面に塗布するだけで、フッ素系樹脂シート１１と未加硫エラストマー組成物に対し、強固な接合界面を形成することができる。上記メタクリロキシ系シランカップリング剤によれば、工程が大幅に簡略化でき、かつ非常に接合強度に優れたものが得られる。これは、メタクリロキシ系シランカップリング剤のメタクリロキシ基が、加水分解することなくそのまま改質面に供給され、加硫剤を介して、直接架橋に関与するためと考えられる。
【００５３】
なお、本発明において、未加硫エラストマー組成物を硬化させるための加熱もしくは加熱加圧条件は、エラストマー組成物の種類や目的とする硬化体の大きさや厚みにもよるが、通常、加熱温度を１２０〜１８０℃とし、加熱時間を１〜６０分とすることが好適である。加圧条件は、成形装置の種類等に応じて適宜設定される。
【００５４】
上記成形装置は、特に限定するものはでないが、一般的な射出成形機や、加圧成形機等を用いることができる。
【００５５】
このようにして得られた複合材１０は、フッ素系樹脂シート１１への、特殊な圧力範囲で行う低温プラズマ処理による緻密かつ均一な表面処理と、シランカップリング剤と、未加硫エラストマー組成物に含有される加硫剤との複合的な架橋効果とが相俟って、フッ素系樹脂シート１１とエラストマー硬化体１２の接合面が、従来にない、高強度で一体化されている。したがって、上記複合材１０は、大きく屈曲したり長期にわたって繰り返し変位を受ける用途（例えばダイアフラム等）に用いても、上記接合面に剥離や亀裂等の損傷が生じることがなく、良好な状態で長く使用することができる。
【００５６】
そして、本発明の複合材１０は、すでに述べたように、シート状のエラストマー硬化体１２の片面にフッ素系樹脂シート１１が接合一体化された図１（ａ）の態様に限らず、どのような形態であってもよい。例えば、図１（ｂ）、（ｃ）に示すように、エラストマー硬化体１２の両面、あるいは端面も含む全周面に、フッ素系樹脂シート１１が接合一体化された態様等であってもよい。また、全体を、シート状に限らず、環状、ブロック状等、適宜の形状にすることができ、その場合、その全周面、あるいは適宜の部分的な面がフッ素系樹脂シート１１で構成される。特に、従来、高価なフッ素系樹脂で全体を成形していた成形品に代えて、内側がエラストマー硬化体１２で形成され表面がフッ素系樹脂シート１１で被覆された成形品を、真空成形等によって得ることができるため、耐薬品性、耐候性、撥水性、低ガス透過性、無毒性といったフッ素系樹脂の優れた特性を活かした物品を安価に製造することができるという利点を有する。
【００５７】
本発明の複合材１０の用途としては、例えば、浴室回りや医療用、食品用として用いられる撥水性シート、遮光リング、スキージ等の他、図４〜図１１に示す各部材等がある。
【００５８】
図４〜図１１はそれぞれ、本発明を適用した複合材１０の用途を示す説明図である。まず、本発明に係る複合材１０は、図４（ａ）、（ｂ）に示すようなＯリング５１、図５に示すようなパッキン５２に用いることができる。また、図６に示すように、薬品や有毒ガス等を入れる容器５３の蓋５４の内側に取り付けるパッキン５５、図７（ａ）、（ｂ）に示すようなダイアフラム５６、図８（ａ）、（ｂ）に示すようなＩＣトレイやメッキ容器等といった耐薬品性容器６０、図９に示すような栓体６５等が各種のものとしてあげられる。さらに、図１０に示すように、内側がフッ素系樹脂チューブ１１０（フッ素系樹脂体）からなり、外側がエラストマー硬化体１２からなるチューブ７０として構成することができる。さらにまた、図１１に示すボールバルブ８０において、シール面８１、あるいは弁体としてのボール８２のうち、シール面に接する部分８３について、内側をエラストマー硬化体とし、外側をフッ素系樹脂シートとしてもよい。
【００５９】
また、本発明に対する参考例では、前記製法と同様、フッ素系樹脂シート１１の少なくとも一面に低温プラズマ処理を行って改質面とする。一方、シランカップリング剤を含有させた未加硫エラストマー組成物を準備する。そして、上記シランカップリング剤含有未加硫エラストマー組成物を、上記フッ素系樹脂シート１１の改質面に接した状態で硬化させ、フッ素系樹脂シート１１とエラストマー硬化体１２の一体成形品を得るのである。
【００６０】
このようにしても、複合材１０を得ることができるが、その特性については、後述する。
【００６１】
なお、上記製法において、未加硫エラストマー組成物に含有させるシランカップリング剤としては、前述のシランカップリング剤と同様のものを用いることができる。ただし、本発明では、その塗布作業性を考慮して、シランカップリング剤をそのまま用いる以外に、溶剤希釈されたものを用いる場合を含んでいたが、未加硫エラストマー組成物に含有させる場合には、シランカップリング剤を希釈することなく、そのまま配合すればよい。
【００６２】
上記シランカップリング剤の配合割合は、特に限定されるものではないが、なかでも特に、未加硫エラストマー組成物１００重量部（以下「部」と略す）に対し０．１〜２．０部に設定することが好適である。すなわち、配合割合が０．１部より少ないと、得られる複合材１０の接合界面強度が安定しないおそれがあり、逆に２．０部を超えると、得られる複合材１０において、エラストマー硬化体１２の機械的特性が損なわれるおそれがあるからである。
【００６３】
つぎに、実施例について、参考例および比較例と併せて説明する。
【００６４】
【参考例１】
シリコーンゴムコンパウンド（ＫＥ５４１ｕ、信越化学工業社製）１００部と有機過酸化物加硫剤（Ｃ−８、信越化学工業社製）２部とをミキシングロールに混練し、ここに、石英粉末（クリスタライト、龍森社製）１部と、メタクリロシキ系シランカップリング剤（ＫＢＭ−５０３、信越化学工業社製）２部からなるペーストを混ぜ込んで、未加硫エラストマー組成物とした。
【００６５】
また、バッチ式低温プラズマ処理装置（イーシー化学社製）を用い、ＥＴＦＥフィルム（厚み１００μｍ、Ａ４サイズ）の片面に、下記の条件で低温プラズマ処理を行ったのち、上記ＥＴＦＥフィルム処理面が未加硫エラストマー組成物と接する配置で上記未加硫エラストマー組成物のシート状体の両面にＥＴＦＥフィルムがそれぞれ当たるよう重ね合わせ、金型内で一体的に成形し、図１（ｂ）に示すような、総厚み２ｍｍの３層構造のシート状複合材を得た。成形条件は後記のとおりである。
【００６６】
〔低温プラズマ処理条件〕
電源／処理出力 ：５ｋＨｚ／１５０Ｗ
処理時間 ：１５秒
プロセスガスモル比：Ａｒ／ＣＯ_２／エチレン＝１００／２／７
処理圧力 ：１．０２ｋｇ／ｃｍ^２
処理温度 ：３０℃
〔成形条件〕
成形温度 ：１８０℃
成形時間 ：５分
成形圧力 ：１８０ｋｇ／ｃｍ^２
【００６７】
【実施例１】
上記参考例１と同様にして低温プラズマ処理されたＥＴＦＥフィルムの処理面に、メタクリロキシ系シランカップリング剤（ＫＢＭ−５０３、信越化学工業社製）３０部をトルエン７０部で希釈したプライマー液をスプレーガンを用いて塗布した（塗布量は目付３０ｇ／ｍ²）。そして、これを直ちに、シリコーンゴムコンパウンド（ＫＥ５４１ｕ、信越化学工業社製）１００部と有機過酸化物加硫剤（Ｃ−８、信越化学工業社製）２部とを混練した未加硫エラストマー組成物と重ね合わせ、金型内で一体的に成形して、参考例１と同様の３層構造のシート状複合材を得た。
【００６８】
【参考例２】
上記実施例１と同様にして低温プラズマ処理されたＥＴＦＥフィルムの処理面に、メタクリロキシ系シランカップリング剤（ＫＢＭ−５０３、信越化学工業社製）３０部をトルエン７０部で希釈したプライマー液をスプレーガンを用いて塗布し、これを１２０℃×５分の強制乾燥後、シリコーンゴムコンパウンド（ＫＥ５４１ｕ、信越化学工業社製）１００部と有機過酸化物加硫剤（Ｃ−８、信越化学工業社製）２部とを混練した未加硫エラストマー組成物と重ね合わせ、金型内で一体的に成形して、実施例１と同様の３層構造のシート状複合材を得た。
【００６９】
【実施例２】
未加硫エラストマー組成物として、下記の組成からなる有機過酸化物加硫型フッ素系エラストマー組成物（ＸＦＣ０２０１２、ＤＨＩマッハ社製）を用いた。それ以外は、上記実施例１と同様にして、実施例１と同様の３層構造のシート状複合材を得た。
【００７０】
〔ＸＦＣ０２０１２の組成〕
フッ素ゴム（ダイエルＧ９０２、ダイキン工業社製） ５０．０部
〃 （ダイエルＧ９０１Ｈ、ダイキン工業社製） ５０．０〃
ＭＴカーボン（カンカーボ社製） ２０．０〃
パーヘキサ２５Ｂ（日本油脂社製） １．５〃
【００７１】
【実施例３】
未加硫エラストマー組成物として、下記の組成からなるポリオール加硫型フッ素系エラストマー組成物（ＸＦＣ０３０５２、ＤＨＩマッハ社製）を用いた。それ以外は、上記実施例１と同様にして、実施例１と同様の３層構造のシート状複合材を得た。
【００７２】
〔ＸＦＣ０３０５２の組成〕
フッ素ゴム（ダイエルＧ７０１、ダイキン工業社製） １００．０部
キョーワマグ＃１５０（協和化学社製） ３．０〃
アクチベーターＣＦ（近江化学製） ６．０〃
硫酸バリウム＃１００（堺化学社製） ４．０〃
酸化チタン １．０〃
カーボン旭＃３５（旭カーボン社製） ０．５〃
ベンガラ（森下弁柄社製） １．０〃
【００７３】
【参考例３】
未加硫エラストマー組成物として、下記の組成からなる有機過酸化物加硫型ＥＰＤＭ系エラストマー組成物（ＸＦＣ０４０５２、ＤＨＩマッハ社製）を用いた。それ以外は、上記参考例２と同様にして、実施例１、２、３と同様の３層構造のシート状複合材を得た。
【００７４】
〔ＸＦＣ０４０５２の組成〕
ＥＰＤＭゴム（ＥＰ２１、日本合成ゴム社製） １００．０部
ＺｎＯ＃３（白水化学社製） ５．０〃
ステアリン酸（日本油脂社製） １．０〃
旭＃６０ ９Ｇ（旭カーボン社製） ３５．０〃
旭＃３５ Ｇ（旭カーボン社製） ３０．０〃
ホワイトンＳＳＢ（白石カルシウム社製） ２０．０〃
ポリブテン（ＨＶ−３００、日本石油化学社製） ５．０〃
ＰＥＧ＃４０００（東邦化学社製） ２．０〃
ＲＤ（精工化学社製） ２．０〃
ＴＡＩＣ（日本化成） ２．０〃
【００７５】
【比較例１】
上記実施例１と同様にして低温プラズマ処理されたＥＴＦＥフィルムの処理面に、シランカップリング剤を塗布することなく、そのままの状態で、シリコーンゴムコンパウンド（ＫＥ５４１ｕ、信越化学工業社製）１００部と有機過酸化物加硫剤（Ｃ−８、信越化学工業社製）２部とを混練した未加硫エラストマー組成物と重ね合わせ、金型内で一体的に成形して、実施例１と同様の３層構造のシート状複合材を得た。
【００７６】
【比較例２】
ＥＴＦＥフィルムに低温プラズマ処理を行わなかった。それ以外は、参考例１と同様にして、参考例１と同様の３層構造のシート状複合材を得た。
【００７７】
【比較例３】
ＥＴＦＥフィルムに低温プラズマ処理を行わなかった。それ以外は、実施例１と同様にして、実施例１と同様の３層構造のシート状複合材を得た。
【００７８】
【比較例４】
ＥＴＦＥフィルムに、０．１７Ｔｏｒｒの圧力で低温プラズマ処理を行った。それ以外は、実施例１と同様にして、実施例１と同様の３層構造のシート状複合材を得た。
【００７９】
［実施例１〜３、参考例１〜３および比較例１〜４の評価結果］
このようにして得られた実施例１〜３、参考例１〜３および比較例１〜４に係る複合材から、幅２５ｍｍ×長さ１００ｍｍの試験片を作製し、「ＪＩＳ Ｋ ６２５６Ｔ型剥離試験方法」に従って、図１２に示すように、シート両側のフィルム部分３０をＴ型に引っ張って最大破壊荷重を測定するとともに、その破壊状態を観察して、接合面の接着強度を評価した。また、上記と同様の試験片を、沸騰水中で３時間放置し、取り出し後すぐに引き剥がしを行ったものと、取り出し後３時間放置して室温に冷却してから引き剥がしを行ったものについて、その破壊状態を観察して評価した。そして、これらの結果を下記の表１〜表４に示す。
【００８０】
【表１】

【００８１】
【表２】

【００８２】
【表３】

【００８３】
【表４】

【００８４】
【実施例４〜７】
未加硫エラストマー組成物に配合するメタクリロキシ系シランカップリング剤の、組成物全体に対する配合割合を、下記の表５に示すように変えた。それ以外は前記実施例１と同様にして、実施例１と同様の３層構造のシート状複合材を得た。
【００８５】
【表５】

【００８６】
【実施例８〜１１】
ＥＴＦＥフィルムの低温プラズマ処理面に対するシランカップリング剤の塗布量を、下記の表６に示すように変えた。それ以外は前記実施例１と同様にして、実施例１と同様の３層構造のシート状複合材を得た。
【００８７】
【表６】

【００８８】
【実施例１２〜１４】
シランカップリング剤の種類を、下記の表７に示すように変えた。それ以外は前記実施例１と同様にして、実施例１と同様の３層構造のシート状複合材を得た。
【００８９】
【表７】

【００９０】
［実施例４〜１４の評価結果］
このようにして得られた実施例品について、前記と同様にして評価を行い、その結果を表５〜表７に併せて示す。
【００９１】
【実施例１５】
上記実施例１と同様にして、３層構造のシート状複合材を、図７に示すような直径５７ｍｍのダイアフラム５８に成形した。そして、実際に、ダイアフラム装置（形式２０５、ＡＬＬＤＯＳ社製）を装填し、１４４回／分、３ｍｍストロークの条件でサイクル運転を行った。その結果、サイクル運転を６００万回行っても、ダイアフラムに剥離や破損等の異常が生じることはなかった。
【００９２】
【発明の効果】
以上のように、本発明によれば、フッ素系樹脂シート等のフッ素系樹脂体に対し、特殊な圧力範囲で低温プラズマ処理を行い、シランカップリング剤と未加硫エラストマー組成物に含有される加硫剤とで複合的な架橋を行わせることによって、フッ素系樹脂シートとエラストマー硬化体の接合面を、従来にない高強度で一体化することができる。したがって、得られる上記複合材は、大きく屈曲したり長期にわたって繰り返し変位を受ける用途（例えばダイアフラム等）に用いても、上記接合面に剥離や亀裂等の破損が生じることがなく、良好な状態で長く使用することができる。
【００９３】
また、本発明の複合材は、シート状に限らず、環状、ブロック状等、適宜の形状にすることができるため、耐薬品性、耐候性、撥水性、低ガス透過性、無毒性といったフッ素系樹脂の優れた特性を活かした物品を安価に製造することができるという利点を有する。
【図面の簡単な説明】
【図１】（ａ）、（ｂ）、（ｃ）はそれぞれ、本発明の複合材の一例を示す説明図である。
【図２】（ａ）、（ｂ）はそれぞれ、本発明の積層タイプの複合材の一例を示す説明図である。
【図３】本発明に用いることのできる低温プラズマ処理装置の説明図である。
【図４】（ａ）、（ｂ）はそれぞれ、本発明の複合材を用いたＯリングの平面図、および断面図である。
【図５】（ａ）、（ｂ）はそれぞれ、本発明の複合材を用いたパッキンの平面図、および断面図である。
【図６】本発明の複合材をパッキンとして用いた蓋の断面図である。
【図７】（ａ）、（ｂ）はそれぞれ、本発明の複合材を用いたダイアフラムの平面図、および断面図である。
【図８】（ａ）、（ｂ）はそれぞれ、本発明の複合材を用いた耐薬品性容器の斜視図、および断面図である。
【図９】本発明の複合材を用いた栓体の断面図である。
【図１０】本発明の複合材を用いたチューブの説明図である。
【図１１】本発明の複合材を用いたボールバルブの説明図である。
【図１２】Ｔ型剥離試験方法の説明図である。
【図１３】（ａ）は複合材の一例を示す斜視図、（ｂ）はその縦断面図である。
【符号の説明】
１０ 複合材
１１ フッ素系樹脂シート（フッ素系樹脂体）
１２ エラストマー硬化体
３０ 基材
５１ Ｏリング
５２ パッキン
５３ 容器
５４ 蓋
５５ パッキン
５６ ダイアフラム
６０ 耐薬品性容器
６５ 栓体
１１０ フッ素系樹脂チューブ（フッ素系樹脂体）
７０ チューブ
８０ ボールバルブ
８１ シール面
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１００ 低温プラズマ処理装置[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for producing a composite material mainly used in places where antifouling properties, chemical resistance and low gas permeability are required, and to a composite material obtained thereby.
[0002]
[Prior art]
Many equipment such as control, isolation, transportation and transportation of fluids such as gas and liquid are required to have various properties such as antifouling property, chemical resistance and low gas permeability. Examples of such equipment include pressure switches for industrial equipment, chemical liquid pumps, various valves for chemical plants, gas meters for housing-related equipment, gas water heaters, water supply switching valves, home pumps, pressure regulating valves. (Bath pots, washing machines), various carburetors for automobiles, fuel pumps, EGR valves, brake devices, distributors, oil pressure switches, speed controllers, various exhaust control valves, and the like.
[0003]
In these devices, a composite material that combines a flexible elastomer and another material that protects or reinforces the elastomer has been used for a portion that comes into contact with a fluid such as a gas or a liquid.
[0004]
As the elastomer, conventionally, nitrile rubber (NBR), urethane rubber (U), chloroprene rubber (CR), chlorosulfonated polyethylene rubber (Hypalon, CSM), fluorine rubber (FKM), ethylene-propylene copolymer rubber ( EPDM, EPM), silicone rubber (Q), fluorosilicone rubber (FMVQ) and the like are used. Among them, NBR is widely used because it has an advantage that it has excellent oil resistance and can sufficiently withstand antifreeze refrigerant and heat.
[0005]
As another material for protecting or reinforcing the elastomer, for example, a reinforcing cloth such as a polyester fiber, a polyamide fiber, or canvas is used for the purpose of improving pressure resistance. For the purpose of improving chemical resistance, a fluorine-based resin sheet (including a film, the same applies hereinafter) such as ethylene tetrafluoride (PTFE) is used on the liquid contact side. Further, these may be used in combination with a metal.
[0006]
As an example of such a composite material, there is a composite diaphragm 1 for a metering pump shown in FIGS. 13 (a) and 13 (b). In the drawing, reference numeral 2 denotes a sheet body made of an elastomer, 3 denotes a protective film, and 4 denotes a metal bolt for connecting the same to a tappet (not shown). Reference numeral 5 denotes a fixing hole. In general, NBR is suitably used as the material of the sheet body 2, but various elastomers are used depending on the application. Examples of the material of the protective film 3 include a fluorine-based resin excellent in chemical resistance, non-adhesion, heat resistance, stain resistance, and weather resistance, and a PTFE sheet excellent in workability such as punching and drawing. A material is preferably used. Since it is difficult to directly integrate the protective film 3 made of the fluorine-based resin or the like and the sheet body 2 made of the elastomer, the surface of the protective film 3 on the bonding side is usually modified. The sheet body 2 is bonded to the sheet body 2 by vulcanization and the like.
[0007]
[Problems to be solved by the invention]
However, in such a composite material, if the displacement is small, the followability is indeed good, but if it is repeatedly fluctuated for a long time or the displacement is large, the protective film may be damaged or peeled off, and the chemical solution may be an elastomer. Swelling, deformation, dissolution, and breakage may occur on the side. This is because there is a clear modified layer or adhesive layer that can be observed at the optical microscope level on the surface where the protective film such as a fluorine-based resin and the elastomer are adhered. This is because the contact surface has poor relaxation to various stresses.
[0008]
Therefore, regarding the method of combining different kinds of materials such as an elastomer and a fluororesin, methods which have been conventionally used in general surface modification and their problems are listed.
[0009]
First, (1) chemical solution treatment (wet treatment) is modified by immersing in a treatment solution consisting of liquid ammonia solution of metal sodium / naphthalene complex / tetrahydrofuran at room temperature for 5 to 10 minutes, washing with acetone / water and drying. However, problems such as safety and waste liquid treatment are extremely troublesome. And although it is an effective treatment, there is a very serious problem in that the chemical resistance inherent in the material is greatly impaired, such as the tendency for pinholes to occur in the sheet (PTFE film).
[0010]
In addition, (2) corona discharge treatment (dry treatment) is generally a rain-like discharge and lacks uniformity of treatment, so that microscopic dispersion is very large. There is a disadvantage that pinholes are likely to be generated at places where excessive discharge has occurred. As this improvement, there is also an attempt to stabilize the discharge by applying a treatment under a gas atmosphere other than air or applying a low frequency to a high frequency, but the life of the object to be treated after the treatment is as short as about one week. In addition, the adhesive strength is not always stable because of the disadvantage that it is greatly affected by the storage environment.
[0011]
Furthermore, (3) low-temperature plasma treatment (dry treatment) is usually 10 to 10^-3A small amount of an inert gas or an oxidizing gas is introduced under a reduced pressure of Torr, and a high frequency (13.56 MH: radio wave) is applied to the electrode to generate plasma. In this method, ions, electrons, radicals, vacuum ultraviolet rays, and the like, which are active species in the plasma, are applied to an object to be processed to perform surface modification such as etching, implantation, and radical generation. Since the gas phase reaction is performed in a high vacuum, the above-described problem of variation is solved. However, since a vacuum device is required, the device becomes large. In addition, although batch processing is generally used, if efficiency is low, continuous processing is required, so larger equipment and devices are required, which ultimately results in a huge cost of material processing. is there. In addition, since the density of the gas introduced due to high vacuum is usually extremely small, and thus the amount of effective active species generated is small, high-frequency output and treatment must be performed in order to effectively and efficiently reform the workpiece. It is necessary to increase the time.
[0012]
(4) UV treatment (dry treatment) is a type of actinic radiation treatment in which the surface is modified by ultraviolet rays and a combination of oxygen radicals generated by irradiation with ultraviolet rays. There are also those that use an ozonizer or the like to actively control the ozone concentration. There are many achievements because continuous processing is possible, but in general, UV lamps have a short life, are extremely susceptible to humidity, and always take into account the decrease in irradiation amount due to deterioration and the decrease in integrated light amount. Unless the processing is performed, the same effect cannot be obtained, and the processing time becomes long. Although the initial investment is small, it is often preferred, but has the drawback that maintenance of the equipment becomes difficult due to the enormous cost of lamp replacement later (polystyrene, polyphenyl oxide, polyolefin films).
[0013]
(5) Radiation irradiation treatment (dry treatment) is also one of the actinic radiation treatments, and uses X-rays and γ-rays. These have stronger energy than ultraviolet rays, but they must be carefully examined for safety measures. However, there is a disadvantage that the apparatus cost is extremely large and the management is complicated.
[0014]
(6) Coupling agent treatment is used as a supplement to performance that is insufficient in chemical solution treatment and various dry treatments. It mainly combines inorganic fillers such as metals, glass fibers, and silica fillers with organic materials such as resins. It refers to an adhesion promoter treatment that has the function of temporarily joining together. However, since the above treatment alone rarely develops adhesive curing, it is usually combined with the above treatments (1) to (5). Some are applied to each material, some are widely applicable, and the like. In the case of a silane coupling agent, not only the crosslinking is impossible unless the hydrolyzable group in the molecule is hydrolyzed, but also the functional groups are decomposed and volatilized when exposed to high temperatures. When treating glass fiber, specifically, an aqueous solution of a silane coupling agent is prepared, and the material is immersed therein. After immersion, excess solution is squeezed and dried at a temperature of about 100 to 110 ° C. In the case of treating an inorganic filler, it is common to spray-add a solution of a silane coupling agent that has been hydrolyzed in advance while performing high-speed stirring with a Henschel mixer or the like, followed by drying. When used as a primer treatment agent such as a primer, the silane coupling agent is diluted in an appropriate solvent, brush-applied, spray-applied, and then air-dried / forcibly dried at about 80 to 110 ° C. for 1 hour. In any case, since a step of promoting hydrolysis and a step of drying are required, it is considerably complicated and time-consuming. In this case, since there is a problem of poor adhesion due to the wettability of the material, there is an inconvenience that additional steps such as heat cleaning, hot water cleaning, and cleaning / degreasing with a solvent cannot be omitted.
[0015]
The present invention has been made in view of such circumstances, and provides a method of manufacturing a composite material in which a fluorine-based resin sheet and an elastomer cured body are joined with an unprecedented high strength, and to provide a composite material obtained thereby. With that purpose.
[0016]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the present invention provides a method for cleaning at least one surface of a fluororesin body such as a fluororesin sheet under a gas atmosphere of 0.1 to 1.1 kg / cm^TwoA step of modifying by low-temperature plasma treatment under a pressure of, and a step of applying a silane coupling agent to the modified surface of the fluororesin body,While the applied silane coupling agent is wet and wet,By heating or heating and pressing the unvulcanized elastomer composition containing the vulcanizing agent in contact with the silane coupling agent-coated surface of the fluororesin, the fluororesin and the cured elastomer are cured. And a step of obtaining a composite material in which is integrally joined.
[0017]
In addition, among the above-mentioned production methods, in particular, a production method in which the silane coupling agent represented by the following general formula (1) is used as it is or as a dilute solution by diluting the silane coupling agent is used as the silane coupling agent. In a second aspect, a production method using a silane coupling agent in which an organic functional group represented by Y in the following general formula (1) is a methacryloxy group is a third aspect. A fourth aspect is a production method using a silane coupling agent as a base.
[0018]
Embedded image

[0020]
And among these production methods, in particular, any one of an organic peroxide, a metal oxide and a polyol is used as the vulcanizing agent.Preferably, it is used.
[0023]
Further, a composite material obtained by these methods is referred to as an eleventh aspect.
[0024]
That is, the present inventors have conducted a series of studies on a method of forming a stronger bonding surface with an elastomer by modifying the surface of a resin material used as a protective film. .1 to 1.1 kg / cm^TwoIn addition to performing low-temperature plasma treatment under a pressure close to normal pressure, a silane coupling agent is applied to the treated surface.When applied, and while the silane coupling agent is wet and wet, the two are joined and vulcanized and molded.The present inventors have found that a very high-strength joint surface, which cannot be obtained by the conventional method, can be obtained, and arrived at the present invention.
[0025]
According to such a method, a composite material such as a sealing material such as an O-ring, packing, or a lid, a valve or a sealing surface such as a diaphragm or a ball valve, a container, a stopper, or a tube can be suitably manufactured.
[0026]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described in detail.
[0027]
First, the fluorinated resin sheet (fluorinated resin body) used for the composite material of the present invention is mainly composed of a fluorinated resin excellent in weather resistance, stain resistance, slidability, chemical resistance, heat resistance and hot water resistance. Various fillers (such as graphite, short fibers such as carbon and glass, molybdenum disulfide, etc.) may be added to this as needed. In particular, when used as a composite material, characteristics such as at least low gas permeability, folding resistance, and high tear strength are often required, and it is preferable to select other compounding components in consideration of these. It is.
[0028]
Specific examples of the fluorine-based resin include ethylene tetrafluoride (PTFE), ethylene tetrafluoride-ethylene copolymer (ETFE), ethylene tetrafluoride-perfluoroalkyl vinyl ether copolymer (PFA), and trifluorinated chloride. There are ethylene (PCTFE), propylene hexafluoride copolymer (FEP), and the like. Among them, ETFE is particularly preferred from the viewpoints of easy handling, availability, and price.
[0029]
Examples of the unvulcanized elastomer composition used for the composite material of the present invention include a composition obtained by blending an uncured elastomer component, a vulcanizing agent, and, if necessary, an appropriate filler. The elastomer component may be any elastomer component conventionally used in composite materials.
[0030]
Examples of the vulcanizing agent used in combination with the elastomer component include organic peroxides, metal oxides, and polyols. Various organic peroxides are used, and among them, dialkyl peroxides are preferred.
[0031]
Specific examples of the dialkyl peroxide include di-t-butyl peroxide, di-t-amyl peroxide, t-butyl cumyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5- Di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane- (3), α, α′-bis (t-butylperoxy) diisopropylbenzene, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,3-bis (t-butylperoxyisopropyl) benzene, n-butyl-4,4-bis (t-butyl) Peroxy) valerate, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane, 2,2-bis- (t-butylperoxy) butane, 1,1 Di - (t-butylperoxy) cyclohexane, and the like. Among them, dicumyl peroxide and 2,5-dimethyl-2,5-di (t-butylperoxy) hexane are particularly preferred because they are relatively easy to handle and generally available.
[0032]
As the metal oxide, ZnO, MgO, PbO, PbO₃O₄And the like.
[0033]
In the present invention, firstThen, a low-temperature plasma treatment is performed on at least one surface of the fluororesin sheet under predetermined conditions to form a modified surface, and a silane coupling agent is applied to the modified surface. Next, by heating or heating and pressing the unvulcanized elastomer composition in contact with the modified surface, a composite material in which the fluorine resin sheet and the cured elastomer are joined and integrated can be obtained.
[0034]
One example of the obtained composite material is shown in FIG. The composite material 10 has a sheet shape as a whole, and a fluorine-based resin sheet 11 (fluorine-based resin body) and a sheet-shaped elastomer cured body 12 are joined and integrated with extremely high strength.
[0035]
Here, the number of the fluororesin sheets 11 is not limited to one, and two or more may be combined. For example, as shown in FIGS. 1B and 1C, both surfaces of the cured elastomer 12 may be sandwiched between the fluororesin sheets 11. Further, a configuration may be employed in which two or more elastomer cured bodies 12 are joined and integrated with the fluorine-based resin sheet 11. For example, as shown in FIGS. 2A and 2B, both surfaces of the fluororesin sheet 11 are sandwiched between cured elastomers 12, or the fluororesin sheet 11 and the cured elastomer 12 are alternately laminated. You may. In these cases, it is desirable that any surface of the fluororesin sheet 11 to be bonded to the elastomer cured body 12 be modified. Here, in the example shown in FIGS. 2A and 2B, an example is shown in which a laminate of the fluororesin sheet 11 and the cured elastomer 12 is formed on the surface of a base material 30 such as a metal.
[0036]
The low-temperature plasma treatment used in the present invention is a treatment performed using plasma (also called non-equilibrium plasma) generated in a region where the electron temperature is high but the gas temperature is low. This is a technique in which ions, electrons, radicals, vacuum ultraviolet rays, and the like, which are active species, are applied to the surface of a material to perform surface modification such as etching, implantation, and radical generation to activate the surface. At the time of the above-mentioned implantation, functional groups such as a hydroxyl group, a carbonyl group, and a carboxyl group are introduced into the surface of the material, and the effects of improving adhesion and improving wettability are obtained. These act on the silane coupling agent and the vulcanizing agent of the unvulcanized elastomer composition to not only significantly improve the adhesiveness but also generate a strong composite interface that can withstand various stresses.
[0037]
Examples of the gas used for the low-temperature plasma treatment include an inert gas such as He, Ar, Ne, Kr, and Xe;₂, CO and other carbon oxide gases, O₂Oxidizing gas such as CF₄And the like, a gas of a polymerizable unsaturated compound such as ethylene and propylene, and air. These are appropriately selected according to the purpose, and used alone or in combination. However, in the present invention, the low-temperature plasma treatment is performed at 0.1 to 1.1 kg / cm.²Among these, it is preferable to use a mixed gas obtained by combining the above-mentioned inert gas, carbon oxide gas, and polymerizable unsaturated compound gas.₂It is preferable to use a mixed gas of ethylene and ethylene.
[0038]
When the mixed gas is used, it is preferable to mix 1 to 15 mol of the polymerizable unsaturated compound gas and 1 to 20 mol of the carbon oxide gas with respect to 100 mol of the inert gas. 3 to 10 moles of the polymerizable unsaturated compound gas and 1 to 12 moles of the carbon oxide gas are mixed with 100 moles of the active gas. This is because, when the mixing ratio of the polymerizable unsaturated compound gas and the carbon oxide gas is increased, the initial discharge voltage is increased, and it becomes difficult to perform the discharge treatment.
[0039]
The discharge treatment is performed by exposing the surface of the fluororesin sheet 11 to be treated in the above-mentioned predetermined gas atmosphere and applying a high-frequency voltage of, for example, 3 to 40 kHz between the electrodes. The temperature during the discharge treatment is not particularly limited, but is usually preferably in the range of 10 to 80 ° C, and more preferably in the range of 25 to 60 ° C.
[0040]
In the present invention, the low-temperature plasma treatment is performed at 0.1 to 1.1 kg / cm.²This is performed under the following pressure for the following reason. That is, 0.1 kg / cm²If it is attempted to perform the process under a pressure lower than that, a special device is required because the system must be kept in a vacuum, and the equipment cost increases and the gas density decreases, so that a uniform and sufficient reformed surface cannot be obtained. Because. On the other hand, 1.1 kg / cm²If it exceeds, no further processing effect can be obtained despite the increased gas consumption, which is not economical.
[0041]
In the present invention, in particular, it is preferable to use an apparatus as shown in FIG. 3 because the low-temperature plasma treatment for the fluororesin sheet 11 can be continuously performed.
[0042]
FIG. 3 is an explanatory diagram of a low-temperature plasma processing apparatus that can be used for carrying out the present invention. In this figure, since the low-temperature plasma processing apparatus 100 performs the low-temperature plasma processing under a pressure close to the atmospheric pressure, the plasma furnace 13 is provided with slits 14 and 15, and a belt-like shape fed from a supply roll 16 is provided. The fluororesin sheet 11 is introduced into the furnace through the slit 14, passed through the upper and lower electrodes 17, 18 to perform low-temperature plasma treatment, discharged out of the furnace through the slit 15, and taken up by the take-up roll 19. Thus, the low-temperature plasma treatment is continuously performed on the fluorine-based resin sheet 11. A gas such as an inert gas is continuously supplied into the furnace from the gas supply port 20 and flows out of the slits 14 and 15. Reference numeral 21 denotes a dielectric covering attached to the upper and lower electrodes 17 and 18.
[0043]
Next, examples of the silane coupling agent applied to the modified surface of the fluororesin sheet 11 obtained by the low-temperature plasma treatment include a silane coupling agent represented by the following general formula (1). These may be used alone or in combination of two or more.
[0044]
Embedded image

[0045]
Specific examples of the silane coupling agent include γ-methacryloxypropyltriethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropylmethoxysilane, N-β -(Aminoethyl) γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) γ-aminopropylmethyldimethoxysilane, N-β- (aminoethyl) γ-aminopropyltriethoxysilane, β- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, vinyltrichlorosilane, vinyltrimethoxysilane, Vini Lutriethoxysilane, vinyltris (β-methoxyethoxy) silane, and γ-isocyanatopropyltriethoxysilane. However, among these silane coupling agents, amino-functional silane compounds are effective adhesion promoters. However, when they are used in large amounts, they will cause significant discoloration when continuously exposed to high temperatures of about 100 ° C. In addition, it is preferable not to use it alone as much as possible, since the curing force deteriorates and the adhesive strength decreases. In addition, the use of isocyanate-based silane coupling provides a high-strength bonding surface that is substantially constant or higher irrespective of the material to be bonded and the bonding mode.
[0046]
These silane coupling agents may be used as they are, or when they are difficult to use as they are, they may be diluted with water, a solvent, or the like from the viewpoint of coating workability. In this case, the dilution ratio depends on the type of the silane coupling agent and the type of the elastomer component to be bonded, but is preferably set to 1.1 to 20 times in terms of workability.
[0047]
The amount of the silane coupling agent (including the diluent) applied to the modified surface of the fluorine-based resin sheet is not particularly limited, but is usually 10 to 40 g / m.²It is preferable to set That is, the application amount is 10 g / m²If the amount is less, the adhesive strength is difficult to stabilize, and conversely, 40 g / m²This is because, when the pressure exceeds the limit, in injection molding or compression molding, pressure may cause oozing in a direction parallel to the application surface, thereby contaminating the molding die and hindering removal of the molded product.
[0048]
The method for applying the silane coupling agent is not particularly limited, and any application method may be used. However, spray application is preferred in terms of uniform application.
[0049]
Usually, when a silane coupling agent is used to reinforce the bonding between two materials, apply the silane coupling agent to one material surface, dry the applied surface, and then join the other material. In general, in the present invention, the silane coupling agent applied to the modified surface of the fluororesin sheet 11 is in an undried state, and the surface is immediately contacted with the unvulcanized elastomer composition. It is preferable that both are integrally formed by heating or heating and pressurizing because a bonding interface with higher strength is obtained.
[0050]
That is, it is considered that the wettability of the unvulcanized elastomer composition to the fluororesin sheet 11 greatly affects the bonding of the fluororesin sheet 11 and the cured elastomer 12 with high strength. Is brought into contact with the vulcanized elastomer composition in an undried, wet state, and molded or integrated in one step by heating or heating and pressurizing. Upon receiving the contact pressure of the unvulcanized elastomer composition, the fluororesin The wetting of the silane coupling agent on the sheet-modified surface and the wetting of the silane coupling agent on the unvulcanized elastomer composition are simultaneously realized, and at this time, the silane coupling agent and the unvulcanized elastomer composition are Due to the contact pressure and the flow of the unvulcanized elastomer composition, they mix and diffuse with each other. As a result, the interface of the low-temperature plasma-treated surface / silane coupling agent / unvulcanized elastomer composition is crosslinked in a state where the three components are mixed by the action of the vulcanizing agent, and an unprecedented high-strength bonding interface is obtained. It is thought that it is possible.
[0051]
The “undried state” of the silane coupling agent refers to a state immediately after the application operation without leaving the silane coupling agent applied surface for drying or subjecting it to air drying or the like.
[0052]
In particular, among the silane coupling agents, the methacryloxy-based silane coupling agent in which Y in the general formula (1) is a methacryloxy group generally prepares an aqueous solution thereof and aims at the prepared liquid. The surface is sprayed and dried to express the coupling effect. However, in the present invention, the methacryloxy-based silane coupling agent is applied as it is to the modified surface of the fluororesin sheet 11 as it is, A strong bonding interface can be formed between the fluororesin sheet 11 and the unvulcanized elastomer composition. According to the methacryloxy-based silane coupling agent, the process can be greatly simplified and a product having extremely excellent bonding strength can be obtained. This is considered to be because the methacryloxy group of the methacryloxy-based silane coupling agent is directly supplied to the modified surface without being hydrolyzed, and directly participates in crosslinking via the vulcanizing agent.
[0053]
In the present invention, the heating or heating and pressing conditions for curing the unvulcanized elastomer composition depend on the type of the elastomer composition and the size and thickness of the target cured product, but usually, the heating temperature is set at It is preferable that the heating temperature is 120 to 180 ° C. and the heating time is 1 to 60 minutes. The pressurizing condition is appropriately set according to the type of the molding apparatus and the like.
[0054]
The molding apparatus is not particularly limited, but a general injection molding machine, a pressure molding machine, or the like can be used.
[0055]
The composite material 10 thus obtained is obtained by subjecting the fluororesin sheet 11 to a dense and uniform surface treatment by a low-temperature plasma treatment performed in a special pressure range, a silane coupling agent, and an unvulcanized elastomer composition. The bonding surface of the fluororesin sheet 11 and the cured elastomer 12 is integrated with a high strength, which has not been achieved before, in combination with the complex crosslinking effect with the vulcanizing agent contained in the resin. Therefore, even when the composite material 10 is used for an application (for example, a diaphragm or the like) that bends greatly or undergoes repeated displacement for a long period of time, the joint surface does not suffer damage such as peeling or cracking, and is long in a good state. Can be used.
[0056]
As described above, the composite material 10 of the present invention is not limited to the embodiment shown in FIG. 1A in which the fluorine-based resin sheet 11 is integrally joined to one surface of the sheet-like elastomer cured body 12 by any method. It may be a form. For example, as shown in FIGS. 1B and 1C, a mode in which the fluororesin sheet 11 is integrally joined to both surfaces of the elastomer cured body 12 or the entire peripheral surface including the end surface may be employed. . In addition, the whole is not limited to the sheet shape, and can be formed into an appropriate shape such as a ring shape or a block shape. In this case, the entire peripheral surface or an appropriate partial surface is formed of the fluororesin sheet 11. You. In particular, instead of a molded product conventionally formed entirely of an expensive fluororesin, a molded product in which the inside is formed of an elastomer cured body 12 and the surface of which is covered with a fluororesin sheet 11 is formed by vacuum molding or the like. Since it can be obtained, there is an advantage that it is possible to manufacture an article at a low cost by utilizing the excellent properties of the fluorine-based resin such as chemical resistance, weather resistance, water repellency, low gas permeability and non-toxicity.
[0057]
Applications of the composite material 10 of the present invention include, for example, water-repellent sheets, light-shielding rings, squeegees, and the like used around bathrooms, for medical use, and for foods, as well as the members shown in FIGS.
[0058]
4 to 11 are explanatory diagrams each showing the use of the composite material 10 to which the present invention is applied. First, the composite material 10 according to the present invention can be used for an O-ring 51 as shown in FIGS. 4A and 4B and a packing 52 as shown in FIG. Also, as shown in FIG. 6, a packing 55 attached to the inside of a lid 54 of a container 53 for containing a chemical or a toxic gas, etc., a diaphragm 56 as shown in FIGS. 7 (a) and 7 (b), FIG. Various kinds of chemical resistant containers 60 such as an IC tray and a plating container as shown in FIG. 9B and a plug 65 as shown in FIG. Furthermore, as shown in FIG. 10, the tube 70 can be configured such that the inside is made of a fluorine-based resin tube 110 (fluorine-based resin body) and the outside is made of the cured elastomer 12. Further, in the ball valve 80 shown in FIG. 11, of the sealing surface 81 or a portion 83 of the ball 82 serving as a valve body, which is in contact with the sealing surface, the inside may be a cured elastomer and the outside may be a fluororesin sheet. .
[0059]
In the reference example for the present invention, the same as the above-mentioned manufacturing methodThen, at least one surface of the fluororesin sheet 11 is subjected to low-temperature plasma treatment to obtain a modified surface. On the other hand, an unvulcanized elastomer composition containing a silane coupling agent is prepared. Then, the unvulcanized elastomer composition containing the silane coupling agent is cured while being in contact with the modified surface of the fluororesin sheet 11 to obtain an integrally molded product of the fluororesin sheet 11 and the cured elastomer 12. It is.
[0060]
Even in this case, the composite material 10 can be obtained, and its characteristics will be described later.
[0061]
In the above-mentioned production method, as the silane coupling agent to be contained in the unvulcanized elastomer composition, the same silane coupling agent as described above can be used. However,In the present inventionIn consideration of its coating workability, in addition to using the silane coupling agent as it is, the case where a solvent-diluted one was used was included. What is necessary is just to mix | blend an agent without diluting it.
[0062]
The mixing ratio of the silane coupling agent is not particularly limited, but particularly, 0.1 to 2.0 parts with respect to 100 parts by weight of the unvulcanized elastomer composition (hereinafter abbreviated as “parts”). It is preferable to set That is, if the compounding ratio is less than 0.1 part, the bonding interface strength of the obtained composite material 10 may not be stable. Conversely, if the mixing ratio is more than 2.0 parts, in the obtained composite material 10, the elastomer cured product 12 This is because there is a possibility that the mechanical properties of the sapphire are impaired.
[0063]
Next, about an example,Reference examples andThis will be described together with a comparative example.
[0064]
[Reference Example 1]
Mixing roll of 100 parts of silicone rubber compound (KE541u, Shin-Etsu Chemical Co., Ltd.) and 2 parts of organic peroxide vulcanizing agent (C-8, Shin-Etsu Chemical Co., Ltd.)ToThe mixture was mixed, and a paste consisting of 1 part of quartz powder (Crystalite, manufactured by Tatsumori) and 2 parts of a methacryloxy-based silane coupling agent (KBM-503, manufactured by Shin-Etsu Chemical Co., Ltd.) was mixed. This was a sulfur elastomer composition.
[0065]
Further, using a batch type low-temperature plasma processing apparatus (manufactured by EC Chemical Co., Ltd.), one side of an ETFE film (100 μm in thickness, A4 size) was subjected to low-temperature plasma processing under the following conditions, and the above-mentioned ETFE film-treated surface was not added. The sheet of the unvulcanized elastomer composition is superimposed on both sides of the uncured elastomer composition in contact with the vulcanized elastomer composition so that the ETFE films respectively come into contact with each other, and integrally molded in a mold, as shown in FIG. Thus, a sheet-like composite material having a total thickness of 2 mm and a three-layer structure was obtained. The molding conditions are as described below.
[0066]
[Low-temperature plasma processing conditions]
Power / processing output: 5kHz / 150W
Processing time: 15 seconds
Process gas molar ratio: Ar / CO₂/ Ethylene = 100/2/7
Processing pressure: 1.02 kg / cm²
Processing temperature: 30 ° C
〔Molding condition〕
Molding temperature: 180 ° C
Molding time: 5 minutes
Molding pressure: 180kg / cm²
[0067]
Embodiment 1
the aboveReference Example 1Using a spray gun, a primer liquid obtained by diluting 30 parts of a methacryloxy-based silane coupling agent (KBM-503, manufactured by Shin-Etsu Chemical Co., Ltd.) with 70 parts of toluene was applied to the treated surface of the ETFE film that had been subjected to the low-temperature plasma treatment in the same manner as described above. Coated (Coating weight is 30 g / m^Two). An unvulcanized elastomer composition obtained by immediately kneading 100 parts of a silicone rubber compound (KE541u, Shin-Etsu Chemical Co., Ltd.) and 2 parts of an organic peroxide vulcanizing agent (C-8, Shin-Etsu Chemical Co., Ltd.) It is superimposed on the object, molded integrally in the mold,Reference Example 1To obtain a sheet-like composite material having the same three-layer structure.
[0068]
[Reference Example 2]
the aboveExample 1Using a spray gun, a primer liquid obtained by diluting 30 parts of a methacryloxy-based silane coupling agent (KBM-503, manufactured by Shin-Etsu Chemical Co., Ltd.) with 70 parts of toluene was applied to the treated surface of the ETFE film that had been subjected to the low-temperature plasma treatment in the same manner as described above. This was applied and forced dried at 120 ° C. for 5 minutes, and then 100 parts of a silicone rubber compound (KE541u, manufactured by Shin-Etsu Chemical Co., Ltd.) and 2 parts of an organic peroxide vulcanizing agent (C-8, manufactured by Shin-Etsu Chemical Co., Ltd.) And kneaded with an unvulcanized elastomer composition, molded integrally in a mold,Example 1 andA sheet composite having the same three-layer structure was obtained.
[0069]
Embodiment 2
As the unvulcanized elastomer composition, an organic peroxide vulcanized fluoroelastomer composition (XFC02012, manufactured by DHI Mach) having the following composition was used. Otherwise, aboveSimilar to the first embodiment, the same as the first embodimentA sheet-like composite material having a three-layer structure was obtained.
[0070]
[Composition of XFC02012]
Fluorine rubber (Daiel G902, manufactured by Daikin Industries, Ltd.) 50.0 parts
〃 (Daiel G901H, manufactured by Daikin Industries, Ltd.) 50.0〃
MT carbon (manufactured by Kancarbo) 20.0〃
Perhexa 25B (manufactured by NOF Corporation) 1.5）
[0071]
Embodiment 3
As an unvulcanized elastomer composition, a polyol vulcanized type fluoroelastomer composition (XFC03052, manufactured by DHI Mach Co.) having the following composition was used. Otherwise, aboveExample 1 In the same manner as in Example 1,To obtain a sheet-like composite material having the same three-layer structure.
[0072]
[Composition of XFC03052]
Fluorine rubber (Daiel G701, manufactured by Daikin Industries, Ltd.) 100.0 parts
Kyowa mug # 150 (Kyowa Chemical) 3.0 mm
Activator CF (manufactured by Omi Chemical) 6.0mm
Barium sulfate # 100 (Sakai Chemical Co., Ltd.) 4.0 社
Titanium oxide 1.0〃
Carbon Asahi # 35 (made by Asahi Carbon Co.) 0.5〃
Bengala (Morishita Bengala) 1.0〃
[0073]
[Reference Example 3]
As an unvulcanized elastomer composition, an organic peroxide vulcanized EPDM elastomer composition (XFC04052, manufactured by DHI Mach) having the following composition was used. Otherwise, aboveReference Example 2In the same way asExamples 1, 2, and 3To obtain a sheet-like composite material having the same three-layer structure.
[0074]
[Composition of XFC04052]
EP0.0 rubber (EP21, manufactured by Nippon Synthetic Rubber Co.) 100.0 parts
ZnO # 3 (manufactured by Hakusui Chemical Co., Ltd.) 5.0〃
Stearic acid (manufactured by NOF Corporation) 1.0〃
Asahi # 609G (made by Asahi Carbon Co., Ltd.) 35.0）
Asahi # 35 G (made by Asahi Carbon) 30.0３
Whiteton SSB (Shiraishi calcium company) 20.0〃
Polybutene (HV-300, manufactured by Nippon Petrochemical Co.) 5.0〃
PEG # 4000 (Toho Chemical Co., Ltd.) 2.0 社
RD (Seiko Chemical Co., Ltd.) 2.0 社
TAIC (Nippon Kasei) 2.0〃
[0075]
[Comparative Example 1]
the aboveExample 1100 parts of a silicone rubber compound (KE541u, manufactured by Shin-Etsu Chemical Co., Ltd.) and an organic peroxide without applying a silane coupling agent to the treated surface of the ETFE film treated with the low-temperature plasma in the same manner as described above. Two parts of a vulcanizing agent (C-8, manufactured by Shin-Etsu Chemical Co., Ltd.) are superimposed on an unvulcanized elastomer composition kneaded, and integrally molded in a mold to form a three-layer structure similar to that of Example 1. Was obtained.
[0076]
[Comparative Example 2]
No low temperature plasma treatment was performed on the ETFE film. Other than that,Reference exampleIn the same way as 1,Reference Example 1To obtain a sheet-like composite material having the same three-layer structure.
[0077]
[Comparative Example 3]
No low temperature plasma treatment was performed on the ETFE film. Other than that,Example 1In the same manner as in Example 1, a sheet-like composite material having the same three-layer structure as in Example 1 was obtained.
[0078]
[Comparative Example 4]
The ETFE film was subjected to a low-temperature plasma treatment at a pressure of 0.17 Torr. Other than that,Example 1In the same manner as in Example 1, a sheet-like composite material having the same three-layer structure as in Example 1 was obtained.
[0079]
[Example1-3, Reference Examples 1-3And evaluation results of Comparative Examples 1 to 4]
Example obtained in this way1-3, Reference Examples 1-3 andFrom the composite materials according to Comparative Examples 1 to 4, a test piece having a width of 25 mm and a length of 100 mm was prepared, and the film portions 30 on both sides of the sheet were subjected to T as shown in FIG. The maximum breaking load was measured by pulling on the mold, and the breaking state was observed to evaluate the adhesive strength of the joint surface. In addition, the same test specimen as above was left in boiling water for 3 hours and then peeled immediately after removal, and the test specimen which was left for 3 hours after removal and cooled to room temperature and then peeled off The state of destruction was observed and evaluated. The results are shown in Tables 1 to 4 below.
[0080]
[Table 1]

[0081]
[Table 2]

[0082]
[Table 3]

[0083]
[Table 4]

[0084]
Embodiments 4 to 7
The mixing ratio of the methacryloxy-based silane coupling agent to be added to the unvulcanized elastomer composition with respect to the whole composition was changed as shown in Table 5 below. Otherwise,Example 1In the same way asExample 1To obtain a sheet-like composite material having the same three-layer structure.
[0085]
[Table 5]

[0086]
Embodiments 8 to 11
The amount of the silane coupling agent applied to the low-temperature plasma-treated surface of the ETFE film was changed as shown in Table 6 below. Otherwise,Example 1In the same way asExample 1To obtain a sheet-like composite material having the same three-layer structure.
[0087]
[Table 6]

[0088]
Embodiments 12 to 14
The type of silane coupling agent was changed as shown in Table 7 below. Otherwise,Example 1In the same way asExample 1To obtain a sheet-like composite material having the same three-layer structure.
[0089]
[Table 7]

[0090]
[Examples 4 to 14Evaluation result]
The thus obtained example products were evaluated in the same manner as described above, and the results are shown in Tables 5 to 7.
[0091]
Embodiment 15
the aboveExample 1In the same manner as described above, a sheet-like composite material having a three-layer structure was formed into a diaphragm 58 having a diameter of 57 mm as shown in FIG. Then, a diaphragm device (type 205, manufactured by Alldos) was actually loaded, and a cycle operation was performed under the conditions of 144 strokes / minute and a stroke of 3 mm. As a result, even when the cycle operation was performed 6 million times, no abnormality such as peeling or breakage occurred in the diaphragm.
[0092]
【The invention's effect】
As described above, according to the present invention, a fluororesin body such as a fluororesin sheet is subjected to low-temperature plasma treatment in a special pressure range, and is contained in a silane coupling agent and an unvulcanized elastomer composition. By performing the complex crosslinking with the vulcanizing agent, the joining surface between the fluororesin sheet and the cured elastomer can be integrated with an unprecedented high strength. Therefore, even when the obtained composite material is used for an application (for example, a diaphragm or the like) that is greatly bent or subjected to repeated displacement for a long period of time, there is no occurrence of breakage such as peeling or cracking on the bonding surface, and the composite material is in good condition. Can be used for a long time.
[0093]
In addition, the composite material of the present invention is not limited to a sheet shape, and can be formed into an appropriate shape such as a ring shape or a block shape. There is an advantage that an article utilizing the excellent characteristics of the base resin can be manufactured at low cost.
[Brief description of the drawings]
FIGS. 1A, 1B, and 1C are explanatory diagrams each showing an example of a composite material of the present invention.
FIGS. 2A and 2B are explanatory views each showing an example of a laminated composite material of the present invention.
FIG. 3 is an explanatory diagram of a low-temperature plasma processing apparatus that can be used in the present invention.
FIGS. 4A and 4B are a plan view and a cross-sectional view, respectively, of an O-ring using the composite material of the present invention.
FIGS. 5A and 5B are a plan view and a cross-sectional view of a packing using the composite material of the present invention, respectively.
FIG. 6 is a sectional view of a lid using the composite material of the present invention as a packing.
FIGS. 7A and 7B are a plan view and a cross-sectional view of a diaphragm using the composite material of the present invention, respectively.
FIGS. 8A and 8B are a perspective view and a cross-sectional view of a chemical resistant container using the composite material of the present invention, respectively.
FIG. 9 is a sectional view of a plug using the composite material of the present invention.
FIG. 10 is an explanatory diagram of a tube using the composite material of the present invention.
FIG. 11 is an explanatory view of a ball valve using the composite material of the present invention.
FIG. 12 is an explanatory diagram of a T-type peel test method.
13A is a perspective view showing an example of a composite material, and FIG. 13B is a longitudinal sectional view thereof.
[Explanation of symbols]
10 Composite materials
11 Fluorine resin sheet (fluorine resin body)
12 Cured elastomer
30 base material
51 O-ring
52 Packing
53 containers
54 lid
55 Packing
56 Diaphragm
60 Chemical resistant container
65 plug
110 Fluorine resin tube (Fluorine resin body)
70 tubes
80 Ball valve
81 Seal surface
82 balls
83 Part of the ball in contact with the sealing surface
100 low temperature plasma processing equipment

Claims (14)

A step of modifying at least one surface of the fluororesin by low-temperature plasma treatment under a gas atmosphere at a pressure of 0.1 to 1.1 kg / cm ² , and a silane coupling agent on the modified surface of the fluororesin. And applying the unvulcanized elastomer composition containing the vulcanizing agent to the fluororesin body while the applied silane coupling agent is in an undried wet state. Obtaining a composite material in which the fluororesin body and the cured elastomer are joined and integrated by heating or heating and pressing in a state in which the composite material is in contact with the surface. The method according to claim 1, wherein the fluorine-based resin body is a fluorine-based resin sheet. 3. The method for producing a composite material according to claim 1, wherein the silane coupling agent is a silane coupling agent represented by the following general formula (1), which is used as it is or diluted to form a diluent.

The method for producing a composite material according to claim 3, wherein the organic functional group represented by Y in the general formula (1) is a silane coupling agent that is a methacryloxy group. The method for producing a composite material according to claim 3, wherein the organic functional group represented by Y in the general formula (1) is a silane coupling agent that is an isocyanate group. The method according to any one of claims 1 to 5, wherein any one of an organic peroxide, a metal oxide, and a polyol is used as the vulcanizing agent. A composite material obtained by the method according to any one of claims 1 to 6. An O-ring, wherein the composite material according to claim 7 is used. A packing comprising the composite material according to claim 7. A diaphragm, wherein the composite material according to claim 7 is used. A container using the composite material according to claim 7. A plug comprising the composite material according to claim 7. A tube using the composite material according to claim 7. A ball valve comprising the composite material according to claim 7.

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