JP2005029636A - Polyolefin resin composition and multilayered structure using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive resin composition which excels in the adhesion for a polyarylene sulfide resin with a polyolefin resin, furthermore retains high adhesiveness even after dipped in a hydrocarbon liquid such as gasoline for a long time, and excels in the moldability on high temperature molding, and a multilayered structure using the composition. <P>SOLUTION: The resin composition as the adhesive composition comprises (A) a polyolefin graft copolymer grafted with an unsaturated carboxylic acid and/or its derivative and (B) an olefin copolymer containing a glycidyl ester of an α,β-unsaturated acid, and the multilayered structure is obtained from the adhesive composition. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

（式中、Ｒは炭素数２〜１８のアルケニル基、Ｘはカルボニルオキシ基を表す。）で示される化合物であり、不飽和酸と、グルシジル基を有するアルコール化合物とのエステル形成された構造を有する。具体的な化合物としては、アクリル酸グリシジル、メタクリル酸グリシジル、エタクリル酸グリシジル、イタコン酸グリシジルなどが例示される。これらの中では、メタクリル酸グリシジルが好適に使用できる。
【００１８】
また、任意成分であるα，β不飽和酸および／又はその誘導体としては、上記グリシジルエステル以外に、カルボン酸基を１以上有する不飽和化合物、無水カルボン酸基を１以上有する不飽和化合物、カルボン酸基を有する化合物とアルキルアルコールとのエステル等を挙げることができる。具体的な化合物としては、アクリル酸、メタクリル酸、マレイン酸、イタコン酸、シトラコン酸、メサコン酸などの不飽和カルボン酸、無水マレイン酸などの不飽和カルボン酸無水物、酢酸ビニル、プロピオン酸ビニル、酪酸ビニル等の飽和カルボン酸のビニルエステル、アクリル酸メチル、アクリル酸エチル、アクリル酸ブチル、メタクリル酸メチル、メタクリル酸エチル、メタクリル酸ブチル等の不飽和カルボン酸のアルキルエステルなどが挙げられる。これらの中では、酢酸ビニル、アクリル酸メチル、アクリル酸エチル、メタクリル酸メチルが好ましい。
【００１９】
α，β不飽和酸のグリシジルエステルと共重合されるオレフィンとしては、炭素数２〜１０のα−オレフィンを挙げることができ、これらの中では特に、エチレン、プロピレンおよび１−ブテンが好ましい。また、α，β不飽和酸のグリシジルエステルとオレフィンの共重合方法は、特に限定されず、従来周知の方法により行うことができる。
【００２０】
ポリオレフィン樹脂組成物
本発明のポリオレフィン樹脂組成物は、前述のポリオレフィングラフト共重合体（Ａ）と、α，β不飽和酸のグリシジルエステルとオレフィンとの共重合体（Ｂ）とを含有してなる組成物である。
【００２１】
ポリオレフィン樹脂組成物全体に占める不飽和カルボン酸及び／又はその誘導体の含有率は、通常０．０１〜２．０重量％、好ましくは０．０１５〜１．０ 重量％、更に好ましくは０．０２〜０．５重量％である。組成物中に不飽和カルボン酸及び／又はその誘導体が上記範囲にあることにより、ガソリン等に長期間浸漬した後でも、高度な接着性を保持することが可能となる。
【００２２】
ポリオレフィン樹脂組成物全体に占めるα，β不飽和グリシジルエステルの含有率は、通常１．０〜６．０重量％、好ましくは１．５〜５．０重量％、更に好ましくは２．０〜４．０重量％である。組成物中にα，β不飽和グリシジルエステルが上記範囲にあることにより、ポリアリーレンサルファイド樹脂との接着性に優れた組成物を得ることが可能となる。
【００２３】
さらに、ポリオレフィン樹脂組成物全体に占める、不飽和カルボン酸及び／又はその誘導体のモル量とα，β不飽和グリシジルエステルのモル量の比は、通常０．００１〜１．０、好ましくは０．００５〜０．５、更に好ましくは０．０１〜０．３である。組成物の含有される不飽和カルボン酸及び／又はその誘導体とα，β不飽和グリシジルエステルとのモル比が上記範囲にあると、ポリアリーレンサルファイド樹脂との接着性、流動性や高温での成形安定性に優れた樹脂組成物を得ることが可能となる。
【００２４】
また、本発明のポリオレフィン樹脂組成物は、組成物全体に占める不飽和カルボン酸及び／又はその誘導体の含有率およびα，β不飽和グリシジルエステルの含有率が上述の範囲となれば、本発明の目的を損なわない範囲で、ポリオレフィングラフト共重合体（Ａ）と混合できる他の樹脂、エラストマー等を配合することができる。他の樹脂等の配合は、上述の（Ａ）、（Ｂ）と同時であっても、（Ａ）、（Ｂ）を組成物とした後の混合であってもよい。
【００２５】
本発明のポリオレフィン樹脂組成物の製造方法は、特に限定されるものではなく、公知の方法を採用できる。例えば、（Ａ）、（Ｂ）、あるいは更に、組成物中の不飽和カルボン酸量等が前述の範囲となるよう必要に応じ配合される樹脂等を一括で、または逐次に溶融混練する方法が挙げられる。溶融混練する方法としては、例えば、樹脂組成物をドライブレンドした後、一軸もしくは二軸のスクリュー押出し機、バンバリーミキサー、ロール、各種ニーダー等で溶融混練する方法などが挙げられる。溶融混練における温度については、（Ａ）、（Ｂ）、必要に応じ配合される樹脂等が溶融していれば特に限定はないが、通常１６０〜３００℃、好ましくは１８０℃〜２５０℃の温度範囲で実施するのが一般的である。
【００２６】
本発明のポリオレフィン樹脂組成物のＡＳＴＭ Ｄ１２３８による１９０℃、２．１６ｋｇ荷重におけるメルトフローレート（ＭＦＲ）は、通常０．０１〜５０ｇ／１０分、好ましくは０．１〜２０ｇ／１０分、更に好ましくは０．２〜１０ｇ／１０分であるものが望ましい。ＭＦＲが上記範囲にあることにより、多層構造物とする際の成形性に優れる。
【００２７】
本発明のポリオレフィン樹脂組成物は、海島構造を形成していることが特に好ましい。好ましい態様としては、島相が、α，β不飽和酸のグリシジルエステルとオレフィンの共重合体（Ｂ）からなり、平均粒子径が通常０．３μｍ以下である。（Ｂ）相の平均粒子径は、通常０．３μｍ以下、特に好ましくは０．２８μｍ以下であり、平均粒子径がこの範囲にあると、初期接着性に優れるとともに、ガソリン等に長期間浸漬した後でも、高度な接着性を保持することが可能となる。尚、本発明の樹脂組成物においては、島相となる（Ｂ）相は、酸化ルテニウムなどの染色剤を用いて染色される相として、透過型電子顕微鏡により観察することができる。本発明における（Ｂ）からなる島相の平均粒子径は、得られた観察像を、市販の画像解析ソフトを用いて、画像処理および画像解析をすることにより（Ｂ）からなる島相の平均長径として得ることができる。
【００２８】
本発明のポリオレフィン樹脂組成物は、ポリアリーレンサルファイド樹脂とポリオレフィン樹脂の積層成形体の接着樹脂として好適に用いられる。本発明の樹脂組成物は、ポリアリーレンサルファイド層及びポリオレフィン層の両者に対し、強い接着力を発現する。
【００２９】
一般に、α，β不飽和酸のグリシジルエステルとオレフィンの共重合体（Ｂ）は、ポリアリーレンサルファイド層に対し強い接着力を持つものの、ガソリン等の炭化水素液体に接触すると膨潤し接着力が低下する。しかしながら、本発明のポリオレフィン樹脂組成物は、ガソリン等に対して比較的耐性のあるポリオレフィングラフト共重合体（Ａ）相中に（Ｂ）相が微分散しているため、ガソリン等への浸漬後にも、接着力の低下が低減できる。
【００３０】
また通常、α，β不飽和酸のグリシジルエステルとオレフィンの共重合体（Ｂ）相は、反応性の高いエポキシ基を多量に有していることから、高温に保持するとエポキシ基同士が反応、架橋構造を形成するため、ゲルが発生しやすく、成形性が著しく低下する。しかしながら、本発明のポリオレフィン樹脂組成物は、エポキシ基の含有量が小さいため、高温での成形安定性に優れる。熱安定性の指標としてはＭＦＲ保持率で表すことができ、本発明の組成物の２３０℃、２．１６ｋｇ荷重における保持時間６分間のメルトフローレート（Ｍ１）と、保持時間３０分間のメルトフローレート（Ｍ２）との比（Ｍ２／Ｍ１）は通常０．５０以上、好ましい組成では０．５８以上、特に好ましい組成では０．６５以上である。ＭＦＲ保持率が１に近いほど、熱安定性は良好である。
【００３１】
必要に応じ配合することができるポリオレフィンとしては、上述のグラフト変性に用いるポリオレフィンを用いることができ、特に直鎖状ポリエチレンが好ましく用いられる。直鎖状ポリエチレンとしては、密度０．９００〜０．９８０ｋｇ／ｃｍ^３、好ましくは０．９１０〜０．９７５ｋｇ／ｃｍ^３、更に好ましくは０．９１５〜０．９７０ｋｇ／ｃｍ^３のエチレン単独重合体、あるいはエチレン・α−オレフィン共重合体が挙げられる。密度が上記範囲にあることにより、ガソリン等に長期間浸漬した後でも高度な接着性を保持することが可能となる。直鎖状ポリエチレンの中では、エチレン・α−オレフィン共重合体を好適に利用でき、具体的には、エチレン・プロピレン共重合体、エチレン・１−ブテン共重合体、エチレン・１−ヘキセン共重合体、エチレン・１−オクテン共重合体、エチレン・４−メチル−１−ペンテン共重合体が好ましい。このような直鎖状ポリエチレンは、公知の方法で得ることができる。
【００３２】
また、本発明のポリオレフィン樹脂組成物には、本発明の目的を損なわない範囲で、公知のプロセス安定剤、耐熱安定剤、耐熱老化剤、フィラー等を添加することも可能である。
【００３３】
ポリアリーレンサルファイド樹脂
本発明において多層構造物に用いられるポリアリーレンサルファイド樹脂としては、ポリフェニレンサルファイド樹脂（以下ＰＰＳ樹脂として略す）が好適に使用できる。
【００３４】
ここでＰＰＳ樹脂とは、下記構造式（２）で示される繰り返し単位を有する重合体であり、
【００３５】
【化２】

耐熱性の観点から、上記構造式で示される繰り返し単位を含む重合体を通常７０モル％以上、好ましくは９０モル％以上含む重合体が望ましい。
【００３６】
また、ＰＰＳ樹脂はその繰り返し単位の３０モル％未満程度が、下記の構造を有する繰り返し単位等で構成されていてもよい。
【００３７】
【化３】

【００３８】
かかる構造を一部に有するＰＰＳ重合体は、融点が低くなるため、本発明の積層構造体においてバリア層以外に用いられる熱可塑性樹脂の融点が低い場合に、成形性の点で有利となる。
【００３９】
本発明で用いられるＰＰＳ樹脂の溶融粘度は、溶融混練が可能であれば特に制限はないが、通常５０〜２００００ｐｏｉｓｅ（３２０℃、剪断速度１０００ｓｅｃ−１）のものが使用され、好ましくは１００〜５０００ｐｏｉｓｅの範囲のものである。溶融粘度がこの範囲にあると、多層構造物とする際の成形性に優れる。
【００４０】
かかるＰＰＳ樹脂は、通常公知の方法、即ち特公昭４５−３３６８号公報に記載される比較的分子量の小さな重合体を得る方法、或は特公昭５２−１２２４０号公報や特開昭６１−７３３２号公報に記載される比較的分子量の大きな重合体を得る方法などによって製造できる。
【００４１】
本発明においては、ＰＰＳ樹脂を、空気中加熱による架橋／高分子量化、窒素などの不活性ガス雰囲気下あるいは減圧下での熱処理、有機溶媒、熱水、酸水溶液などによる洗浄、酸無水物、アミン、イソシアネート、官能基含有ジサルファイド化合物などの官能基含有化合物による活性化など、種々の処理を施した上で使用することももちろん可能である。
【００４２】
ポリオレフィン樹脂
本発明において多層構造物に用いられるポリオレフィン樹脂としては、上述のポリオレフィンを使用することができ、好ましくは、エチレンの共重合体、特に好ましくは密度が０．９４５〜０．９８０ｇ／ｃｍ^３である高密度ポリエチレンを挙げることができる。ここでポリオレフィン樹脂は１種単独でも、２種以上の樹脂の組成物であってもよい。多層構造物の用途に応じて適切な組成を選択し、ポリアリーレンサルファイド樹脂との流動性に応じて、適切な樹脂を使用することが可能である。
【００４３】
多層構造物として用いられるポリオレフィン樹脂のＡＳＴＭ Ｄ１２３８による１９０℃、２．１６ｋｇ荷重におけるメルトフローレート（ＭＦＲ）は、通常０．００１〜１００ｇ／１０分、好ましくは０．０１〜５０ｇ／１０分、更に好ましくは０．０１〜３０である。ＭＦＲがこの範囲にあると、多層構造物とする際の成形性に優れるとともに、満足しうる強度の多層構造物を得ることが可能となる。
【００４４】
本発明で使用されるポリオレフィン樹脂は、公知の方法で得ることができる。また、本発明のポリオレフィン樹脂には、本発明の目的を損なわない範囲で、公知のプロセス安定剤、耐熱安定剤、耐熱老化剤、フィラー等を添加することも可能である。
多層構造物
【００４５】
本発明の多層構造物は、複数種の樹脂が積層された構造物であって、ポリアリーレンサルファイド樹脂が少なくとも１層（以下（イ）ＰＡＳ層という）に構成され、ポリオレフィン樹脂が少なくとも１層（以下（ロ）ＰＯ層という）に構成され、該両層の間に、本発明の接着性樹脂組成物層（以下（ハ）接着層という）が構成された積層体である。具体的には、例えば（イ）層／（ハ）層／（ロ）層の３種３層構造、（ロ）層／（ハ）層／（イ）層／（ハ）層／（ロ）層の３種５層構造などの積層構造が挙げられるが、これらに限定されるものではない。
【００４６】
本発明の多層構造物は公知の種々の方法により製造することができる。例えば、インフレーション成形、キャスト成形、押出コーティング成形、中空成形、射出成形などの公知の共押出法により製造することができ、また、単層あるいは複層のフィルム等を成形した後に、加熱によりドライラミする方法等を例示することができる。
【００４７】
本発明の多層構造物は、耐熱性や気体、液体バリア性に優れるポリアリーレンサルファイド樹脂層と耐衝撃性や低温での靭性に優れるポリオレフィン樹脂層とが接着樹脂層を介して強固に接着されているため、ボトル、タンクおよびダクトなどのブロー成形品、シート、パイプ、チューブなどの押出成形品として、また、機械部品、電気・電子部品、更には薬品用途等にも有効である。特に、接着性樹脂組成物層の耐ガソリン性が優れるため、自動車用の燃料タンクや燃料チューブなどの部品として有用である。
【００４８】
【実施例】
以下、実施例及び比較例を挙げて更に具体的に説明するが、本発明はこれらの実施例等によって何等限定されるものではない。
尚、本実施例等においては、以下の方法に従って測定・評価を実施した。
【００４９】
＜ポリオレフィン樹脂組成物の熱安定性（ＭＦＲ保持率）＞
ポリオレフィン樹脂組成物につき、２５０℃、２．１６ｋｇ荷重における保持時間６分間のメルトフローレート（Ｍ１）、および保持時間３０分間のメルトフローレート（Ｍ２）を測定し、熱安定性の指標として、ＭＦＲ保持率（Ｍ１とＭ２の比：Ｍ２／Ｍ１）を求めた。ＭＦＲ保持率が１に近いほど、熱安定性は良好である。
【００５０】
＜多層成形体の初期接着強度＞
所定の方法で成形した多層成形体を、２３℃、５０％ＲＨ雰囲気下に４８時間以上保持した後、１５ｍｍ幅、長さ８〜１５ｃｍの短冊状試験片を切り出した。次いで、試験片の一方の端面からポリフェニレンサルファイド樹脂（ＰＰＳ樹脂）層と接着樹脂層間を１〜２ｃｍを剥離させ、引張試験機（インストロン１１２３型、インストロン社製）のチャックの一方に接着樹脂層、一方にポリフェニレンサルファイド樹脂層を固定し、Ｔ字型にしてクロスヘッドスピード１００ｍｍ／ｍｉｎの条件で、剥離試験を行い、その強度により接着力を評価した。尚、接着力が強いため強度を正確に計測できないものは、以下に示す評点を付した。
剥離不可 ：試験片の剥離が全く出来ないため、引張試験機のチャックに試験片を取り付けることができず、剥離試験の実施が不可能のもの
基材破壊 ：基材の強度より接着強度が上回るため、剥離試験中にＰＰＳ樹脂層あるいは接着樹脂層が破壊し、接着強度が正確に計測できないもの
【００５１】
＜多層成形体のガソリン浸漬後の接着強度＞
所定の方法で成形した多層成形体を、２３℃、５０％ＲＨ雰囲気下に４８時間以上保持した後、１５ｍｍ幅、長さ８〜１５ｃｍの短冊状試験片を切り出した。次いで、切り出した短冊状試験片を試験用ガソリンに、４０℃の温度で１６８時間浸漬を行った。その後、試験片をガソリンから取り出し、２３℃、５０％ＲＨ雰囲気下に２４時間保持後、上記の初期接着強度と同様の剥離試験を実施し、接着強度を求めた。
【００５２】
＜ポリオレフィン樹脂組成物の相構造＞
ポリオレフィン樹脂組成物を酸化ルテニウムで染色したのち、透過型電子顕微鏡にて観察を行った。濃く染色されている領域が（Ｂ）相ドメインに相当する。また、得られた観察像について、オプティマス社製画像解析ソフトを用いて、画像処理、画像解析を行うことで（Ｂ）相ドメインの平均長軸長さを求め、平均粒子径とした。
【００５３】
実施例及び比較例において使用した物質を以下に示す。なお、特に断らない限りはいずれも常法に従い重合を行い調製した。
【００５４】
＜ポリオレフィングラフト共重合体（Ａ１）の調整＞
常法に従い得たポリエチレン（ＭＦＲ＝２０ｇ／１０分、密度＝０．９２０ｇ／ｃｍ^３）１００重量部に対して、無水マレイン酸（ＭＡＨ）を０．２重量部、２，５−ジメチル−２，５−ジ（Ｔ−ブチルパーオキシ）ヘキサンを０．０４重量部配合し、ベント付き３０ＭＭΦ二軸押出機（日本製鋼所製）により、２５０℃にて溶融混練することにより無水マレイン酸変性ポリエチレン（Ａ１）を得た。得られた変性物の無水マレイン酸含有量（変性量）は０．２重量％であった。同様に、ＭＦＲ・密度が異なるポリエチレンに対し、無水マレイン酸グラフト量を変え、以下の（Ａ２）〜（Ａ６）のグラフト共重合体を得た。
【００５５】
＜ポリオレフィングラフト共重合体（Ａ）＞
（Ａ１）無水マレイン酸含有量０．２ｗｔ％、密度０．９２０、ＭＦＲ＝９．６（１９０℃、２１６０ｇ荷重）の変性ポリエチレン
（Ａ２）無水マレイン酸含有量０．２ｗｔ％、密度０．９３０、ＭＦＲ＝０ ．３の変性ポリエチレン
（Ａ３）無水マレイン酸含有量０．２ｗｔ％、密度０．９４０、ＭＦＲ＝０ ．２の変性ポリエチレン
（Ａ４）無水マレイン酸含有量０．２ｗｔ％、密度０．９６５、ＭＦＲ＝４ ．９の変性ポリエチレン
（Ａ５）無水マレイン酸含有量１．０ｗｔ％、密度０．９２０、ＭＦＲ＝８ ．８の変性ポリエチレン
（Ａ６）無水マレイン酸含有量０．２ｗｔ％、密度０．９６５、ＭＦＲ＝４ ．９の変性ポリエチレン
【００５６】
＜グリシジルエステル共重合エチレン系共重合体＞
（Ｂ１）エチレン−グリシジルメタクリレート共重合体（グリシジルメタクリレート１２ｗｔ％含有、ボンドファーストＥ（住友化学工業社製））
【００５７】
＜直鎖状ポリエチレン＞
（Ｃ１）密度０．９２０、ＭＦＲ（１９０℃、２１６０ｇ荷重）＝１．１の直鎖状低密度ポリエチレン
（Ｃ２）密度０．９２０、ＭＦＲ＝２．２の直鎖状低密度ポリエチレン
【００５８】
＜ＰＰＳ樹脂＞
（ＰＰＳ１）融点２８０℃、ＭＦＲ＝１６０ｇ／１０分（３１５℃、５０００ｇ荷重）のＰＰＳ樹脂
【００５９】
＜ポリオレフィン樹脂＞
（ＰＯ１）密度０．９５６、ＭＦＲ＝６の高密度ポリエチレン
【００６０】
（実施例１）
変性ポリエチレン（Ａ１）８０重量部とエチレン−グリシジルメタクリレート共重合体（Ｂ１）２０重量部とを３０ｍｍφ二軸押出機（日本製鋼所製）を用いて、シリンダ温度２００℃、樹脂吐出量１００ｇ／分の条件で混合し、接着性樹脂組成物を得た。この接着樹脂組成物について、上述の方法に従ってメルトフローレートＭ１およびＭ２の測定を行い、熱安定性（ＭＦＲ保持率）の算出を行った。ＭＦＲ保持率は０．８７であった。結果を表１に示す。
【００６１】
＜樹脂組成物フィルムの成形＞
得られた接着性樹脂組成物を、８０℃１２時間以上減圧下にて乾燥の後、２枚の真鍮板、アルミ板およびテフロン（登録商標）製離型フィルムの間に所定量をはさみ、プレス成形機（神藤金属工業社製）を用いて２００℃で溶融させた。１０ＭＰａで３分間圧縮したのち、２０℃の温度に設定した圧縮成形機で再び１０ＭＰａで圧縮冷却することにより、厚さ１００μｍのプレスフィルムを得た。
＜ポリオレフィン樹脂フィルムの成形＞
上記の接着性樹脂組成物のフィルムを得た場合と同様の方法で、プレス成形を行い、厚さ１００μｍの高密度ポリエチレン（ＨＤＰＥ）のフィルムを得た。
＜ＰＰＳ樹脂フィルムの成形＞
加熱温度３２０℃、冷却温度２０℃とした以外は、接着性樹脂組成物のフィルムを得た場合と同様の方法で、プレス成形を行い、厚さ２００μｍのＰＰＳ樹脂（ＰＰＳ１）のフィルムを得た。
＜多層積層体の成形＞
これらのフィルムをＨＤＰＥ／接着性樹脂組成物／ＰＰＳの順に重ね、プレス成形機（神藤金属工業社製）を用いて、加熱温度３００℃、予熱時間５分、加圧時間２分、圧力５ＭＰａの条件で加熱プレス、引き続き２０℃における冷却プレスを行うことにより、３枚のフィルムを貼り合わせた。
【００６２】
得られた貼り合わせシートを用いて、上述した条件に従って初期接着強度の剥離試験を行った。その結果、ＰＰＳ樹脂層が破壊し、接着強度が強いことが確認された。尚、ＨＤＰＥ／接着樹脂組成物の層間についても剥離を試みたが、強固に接着しており、剥離は不可能であった。結果を表１に示す。
次いで、貼り合わせシートを上述の条件でガソリンに浸漬し、ガソリン浸漬後の接着強度の剥離試験を実施した。浸漬前と同様に、ＰＰＳ樹脂層が破壊し、接着力が保持されていることが確認された。結果を表１に示す。
【００６３】
（実施例２〜４）
表１に示す配合により、実施例１と同様の方法で接着性樹脂組成物を得た。得られた接着性組成物を用いて、実施例１と同様にメルトフローレートＭ１およびＭ２の測定を行い、熱安定性（ＭＦＲ保持率）の算出を行った。結果を表１に示す。
次に、得られた接着性樹脂組成物を用いて実施例１と同様の方法で、プレス成形によりフィルムを作成し、その後、実施例１と同様の方法で、ＨＤＰＥ／接着性樹脂組成物／ＰＰＳの貼り合わせシートを得た。得られた貼りあわせシートを用いて、初期接着強度、ガソリン浸漬後の接着強度の剥離試験を実施し、評価を行った。結果を表１に示す。変性ポリエチレンの流動性、密度に関わらず、接着樹脂組成物はＰＰＳ樹脂と良好な接着性を示した。
【００６４】
（比較例１）
接着性樹脂としてエチレン−グリシジルメタクリレート共重合体（Ｂ１）を単独で用いた以外は、実施例１と同様の方法で、接着性樹脂および貼り合わせシートの測定・評価を行った。結果を表１に示す。初期接着力は強いが、ガソリン浸漬後は、接着樹脂が膨潤し接着力が著しく低下した。また、熱安定性もよくなかった。
【００６５】
（比較例２）
接着性樹脂として実施例２で用いた変性ポリエチレン（Ａ２）を単独で用いた以外は、実施例１と同様の方法で、接着性樹脂および貼り合わせシートの測定・評価を行った。結果を表１に示す。マレイン酸で変性したポリエチレンのみではＰＰＳ樹脂との接着性を殆ど示さなかった。
【００６６】
【表１】

【００６７】
（実施例５）
変性ポリエチレン（Ａ５）５０重量部とエチレン−グリシジルメタクリレート共重合体（Ｂ１）５０重量部とを、３０ｍｍφ二軸押出機（日本製鋼所製）を用いて、シリンダ温度２００℃、樹脂吐出量１００ｇ／分の条件で溶融混合し、樹脂組成物を得た。引き続き、この樹脂組成物４０重量部と直鎖状ポリエチレン（Ｃ１）６０重量部とを、上記条件と同様に溶融混合を行い、接着性樹脂組成物を得た。得られた接着性樹脂組成物について、実施例１と同様にメルトフローレートＭ１およびＭ２の測定を行い、熱安定性（ＭＦＲ保持率）の算出を行った。結果を表２に示す。
【００６８】
次に、得られた接着性樹脂組成物を用いて実施例１と同様の方法で、プレス成形によりフィルムを作成し、その後、実施例１と同様の方法で、ＨＤＰＥ／接着性樹脂組成物／ＰＰＳの貼り合わせシートを得た。得られた貼りあわせシートを用いて、初期接着強度、ガソリン浸漬後の接着強度の剥離試験を実施し、評価を行った。結果を表２に示す。マレイン酸変性ポリエチレン（Ａ）とエチレン−グリシジルメタクリレート共重合体（Ｂ１）からなる樹脂組成物を未変性の直鎖状ポリエチレン（Ｃ）で希釈した接着性樹脂組成物も、ＰＰＳ樹脂と良好な接着性を示した。
【００６９】
（比較例３〜４）
エチレン−グリシジルメタクリレート共重合体（Ｂ１）と直鎖状ポリエチレン（Ｃ１）とを表２に示す組成で、実施例１と同様の方法で溶融混合を行い、接着性樹脂組成物を得た。次いで、実施例１と同様の方法で、接着性樹脂および貼り合わせシートの測定・評価を行った。結果を表２に示す。エチレン−グリシジルメタクリレート共重合体共重合体（Ｂ１）を直鎖状ポリエチレン（Ｃ１）で希釈した接着樹脂組成物は、初期接着力、ガソリン浸漬後の接着力ともに低かった。
【００７０】
（実施例６）
変性ポリエチレン（Ａ６）５０重量部とエチレン−グリシジルメタクリレート共重合体（Ｂ１）５０重量部とを、３０ｍｍφ二軸押出機（日本製鋼所製）を用いて、シリンダ温度２００℃、樹脂吐出量１００ｇ／分の条件で溶融混合し、樹脂組成物を得た。引き続き、この樹脂組成物４０重量部と直鎖状ポリエチレン（Ｃ２）６０重量部とを、上記条件と同様に溶融混合を行い、接着性樹脂組成物を得た。得られた接着性樹脂組成物について、実施例１と同様にメルトフローレートＭ１およびＭ２の測定を行い、熱安定性（ＭＦＲ保持率）の算出を行った。結果を表２に示す。
【００７１】
次に、得られた接着性樹脂組成物を用いて実施例１と同様の方法で、プレス成形によりフィルムを作成し、その後、実施例１と同様の方法で、ＨＤＰＥ／接着性樹脂組成物／ＰＰＳの貼り合わせシートを得た。得られた貼り合わせシートを用いて、初期接着強度、ガソリン浸漬後の接着強度の剥離試験を実施し、評価を行った。結果を表２に示す。樹脂組成物の無水マレイン酸含量、無水マレイン酸とグリシジルエステルとの比が小さいにも関わらず、接着樹脂組成物はＰＰＳ樹脂およびポリオレフィン樹脂と良好な接着性を示した。
【００７２】
（実施例７〜８）
表２に示す組成の樹脂について、３０ｍｍφ二軸押出機（日本製鋼所製）を用いて、シリンダ温度２００℃、樹脂吐出量１００ｇ／分の条件で一括で溶融混合し、接着性樹脂組成物を得た。得られた接着性樹脂組成物を用いて、実施例１と同様の方法で、接着性樹脂および貼り合わせシートの測定・評価を行った。結果を表２に示す。実施例６の結果と同様、一括で混合した場合にも、接着性樹脂組成物はＰＰＳ樹脂と良好な接着性を示した。
【００７３】
【表２】

【００７４】
（実施例９）
実施例６、実施例８および比較例３で調整した接着性樹脂組成物の透過型電子顕微鏡観察を行った。写真を図１，図２，図３に示す。濃く染色されている領域が（Ｂ）エチレン−グリシジルメタクリレート共重合体の存在する領域である。これらの写真から得られた接着性樹脂組成物の解析結果を表３に示す。図１，２から求められた（Ｂ）相の平均粒径はともに０．３μｍ以下で分散性が良好であった。一方、図３から求められた平均断粒径は約０．３７μｍであった。
【００７５】
【表３】

【００７６】
【本発明の効果】
本発明の接着性樹脂組成物は、ポリアリーレンサルファイド樹脂とポリオレフィン樹脂の接着用樹脂として使用した場合に、初期接着力に優れるとともに、該多層構造物が長期間にわたりガソリンなどの有機溶媒に曝露されても高度な接着性を保持し、更に、高温成形時の成形安定性に優れる。
【００７７】
【図面の簡単な説明】
【図１】実施例９における、実施例６にて調整した接着性樹脂組成物の相相構造を示す電子顕微鏡写真であり、濃く染まっている部分がエチレングリシジルメタクリレート共重合体のドメインを示す。所定の方法で求めた平均粒径は０．２４μｍであった。
【図２】実施例９における、実施例８にて調整した接着性樹脂組成物の相相構造を示す電子顕微鏡写真であり、濃く染まっている部分がエチレングリシジルメタクリレート共重合体のドメインを示す。所定の方法で求めた平均粒径は０．２５μｍであった。
【図３】実施例９における、比較例３にて調整した接着性樹脂組成物の相相構造を示す電子顕微鏡写真であり、濃く染まっている部分がエチレングリシジルメタクリレート共重合体のドメインを示す。所定の方法で求めた平均粒径は０．３７μｍであった。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a polyolefin resin composition comprising a copolymer of an unsaturated carboxylic acid and / or derivative thereof and a glycidyl ester of an α, β unsaturated acid, and more particularly, a polyarylene sulfide resin and The present invention relates to an adhesive resin composition for laminated molded bodies of polyolefin resin, and a multilayer structure using the composition.
[0002]
[Prior art]
Polyolefin resins such as polyethylene and polypropylene are widely used as daily general goods, toys, machine parts, electrical / electronic parts, and automobile parts as the most common plastics. However, since polyolefin has insufficient barrier properties against hydrocarbon liquids such as gasoline and gas, its use range is often limited, and improvement has been desired.
[0003]
In order to improve the barrier properties of polyolefins, laminated molded bodies of polyolefin resins and polyarylene sulfide resins have been proposed. Polyarylene sulfide resins represented by polyphenylene sulfide resins are known to exhibit extremely high barrier properties against chemicals such as gasoline and automobile oil, water, and carbon dioxide. Under such circumstances, a multi-layer hollow container (see Patent Document 1) that attempted to bond a polyphenylene sulfide resin and a polyolefin resin via a mixture of a polyphenylene sulfide resin and a polyolefin resin, and a polyphenylene sulfide resin and a polyethylene, A multilayer structure using an ethylene-glycidyl methacrylate copolymer or maleic anhydride-modified polyethylene as an adhesive resin has been proposed (see Patent Document 2). However, these materials have insufficient interlayer adhesion, and even when initial adhesion is good, when they are immersed in a liquid such as gasoline for a long time, the adhesion is remarkably lowered or coextruded with polyarylene sulfide resin. When molded under high temperature conditions, the adhesive resin is denatured and the moldability is remarkably lowered.
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 55-079233
[Patent Document 2]
Japanese Patent Laid-Open No. 05-193061
[0005]
[Problems to be solved by the invention]
The object of the present invention is excellent in adhesion between polyarylene sulfide resin and polyolefin resin, and further maintains high adhesion even after being immersed in a hydrocarbon liquid such as gasoline for a long period of time. It is an object of the present invention to provide a polyolefin resin composition excellent in the present invention and a multilayer structure using the composition.
[0006]
[Means for Solving the Problems]
The present inventors diligently studied and found that a specific composition is extremely excellent in adhesiveness, and completed the present invention.
That is, the present invention relates to a polyolefin graft copolymer (A) obtained by graft polymerization of an unsaturated carboxylic acid and / or a derivative thereof onto a polyolefin, and a copolymer of an glycidyl ester of an α, β unsaturated acid and an olefin (B ), Wherein the content of the unsaturated carboxylic acid and / or derivative thereof is 0.01 to 2.0% by weight, and α, β-unsaturated glycidyl with respect to 100% by weight of the composition. A polyolefin resin composition having an ester content of 1.0 to 6.0% by weight.
Moreover, this invention is a multilayer structure which adhere | attached polyarylene sulfide resin and polyolefin resin with the said polyolefin resin composition.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail.
Polyolefin graft copolymer (A)
The polyolefin graft copolymer (A) used in the present invention can be obtained by graft copolymerizing an unsaturated carboxylic acid and / or a derivative of an unsaturated carboxylic acid with a polyolefin.
[0008]
The polyolefin used for graft modification is a polymer mainly composed of an α-olefin having 2 to 20 carbon atoms, preferably an α-olefin having 2 to 10 carbon atoms, more preferably an α-olefin having 2 to 6 carbon atoms. It is a polymer as a component. These α-olefins may be used alone or in combination of two or more. The content of other α-olefins is usually 10 mol% or less, preferably 5 mol% or less. In the present invention, a homopolymer or copolymer of ethylene, propylene, 1-butene, 4-methyl-1-pentene, 1-hexene can be preferably used, and ethylene and an α-olefin having 3 or more carbon atoms can be used. A copolymer is particularly preferred.
[0009]
The density of the copolymer of ethylene and an α-olefin having 3 or more carbon atoms is usually 0.900 to 0.980 g / cm.³, Preferably 0.910 to 0.975 g / cm³, Particularly preferably 0.915 to 0.970 g / cm³The melt flow rate (MFR) at 190 ° C. and 2.16 kg load according to ASTM D1238 is usually 0.1 to 100 g / 10 minutes, preferably 0.5 to 50 g / 10 minutes. If the density and MFR are within this range, even after the modified graft copolymer is immersed in gasoline for a long period of time, high adhesion can be maintained, and the fluidity of the modified graft copolymer can be improved. Also excellent.
[0010]
The polyolefin used for graft modification can be obtained by a known method, and a commercially available resin can be used as it is.
[0011]
Examples of the unsaturated carboxylic acid and / or derivative thereof used as a graft monomer include unsaturated compounds having one or more carboxylic acid groups and unsaturated compounds having one or more carboxylic anhydride groups. , Vinyl group, vinylene group, unsaturated cyclic hydrocarbon group and the like. Specific compounds include acrylic acid, methacrylic acid, maleic acid, itaconic acid, citraconic acid, mesaconic acid, maleic anhydride, hymic anhydride, 4-methylcyclohex-4-ene-1,2-dicarboxylic anhydride , Α-ethylacrylic acid, fumaric acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, endocis-bicyclo [2,2,1] hept-5-ene-2,3-dicarboxylic acid (nadic acid [trademark]), Bicyclo [2.2.2] oct-5-ene-2,3-dicarboxylic anhydride, 1,2,3,4,5,8,9,10-octahydronaphthalene-2,3-dicarboxylic anhydride , 2-octa-1,3-diketospiro [4.4] non-7-ene, bicyclo [2.2.1] hept-5-ene-2,3-dicarboxylic anhydride, maleopima Acid, tetrahydrophthalic anhydride, x-methyl-bicyclo [2.2.1] hept-5-ene-2,3-dicarboxylic anhydride, x-methyl-norbornene-5-ene-2,3-dicarboxylic acid Examples thereof include acid anhydrides and norborn-5-ene-2,3-dicarboxylic acid anhydrides. Unsaturated carboxylic acid and / or its derivative can be used individually by 1 type, and can also be used in combination of 2 or more type. Of these, maleic anhydride is preferably used.
[0012]
The method for grafting the graft monomer to the polyolefin is not particularly limited, and conventionally known graft polymerization methods such as a solution method and a melt kneading method can be employed.
[0013]
The melt flow rate (MFR) at a load of 2.16 kg and 190 ° C. according to ASTM D1238 of the polyolefin graft copolymer (A) is usually 0.01 to 50 g / 10 min.
[0014]
The density of the polyolefin graft copolymer (A) is usually 0.900 to 0.980 g / cm.³, Preferably 0.910 to 0.975 g / cm³More preferably, 0.915-0.970 g / cm³It is. If the density is within the above range, high adhesion can be maintained even after being immersed in gasoline or the like for a long time.
[0015]
Copolymer of glycidyl ester of α, β unsaturated acid and olefin (B)
The α, β unsaturated acid glycidyl ester and olefin copolymer (B) used in the present invention is an α, β unsaturated acid glycidyl ester unit of 1 to 20 wt%, an olefin unit of 80 to 99 wt%, Furthermore, a copolymer containing 0 to 40% by weight of α, β unsaturated acid and / or a derivative unit thereof is preferable.
[0016]
Here, the α, β unsaturated acid glycidyl ester is represented by the general formula (1).
[0017]
[Chemical 1]

(Wherein R represents an alkenyl group having 2 to 18 carbon atoms, and X represents a carbonyloxy group), and has an ester-formed structure of an unsaturated acid and an alcohol compound having a glycidyl group. Have. Specific examples of the compound include glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, and glycidyl itaconate. In these, glycidyl methacrylate can be used conveniently.
[0018]
In addition to the glycidyl ester, the α, β unsaturated acid and / or its derivative, which is an optional component, include unsaturated compounds having one or more carboxylic acid groups, unsaturated compounds having one or more carboxylic anhydride groups, An ester of a compound having an acid group and an alkyl alcohol can be exemplified. Specific compounds include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, itaconic acid, citraconic acid and mesaconic acid, unsaturated carboxylic acid anhydrides such as maleic anhydride, vinyl acetate, vinyl propionate, Examples thereof include vinyl esters of saturated carboxylic acids such as vinyl butyrate, alkyl esters of unsaturated carboxylic acids such as methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, and butyl methacrylate. Among these, vinyl acetate, methyl acrylate, ethyl acrylate, and methyl methacrylate are preferable.
[0019]
Examples of the olefin copolymerized with the glycidyl ester of an α, β unsaturated acid include α-olefins having 2 to 10 carbon atoms. Among these, ethylene, propylene and 1-butene are particularly preferable. Moreover, the copolymerization method of the glycidyl ester of α, β unsaturated acid and the olefin is not particularly limited, and can be performed by a conventionally known method.
[0020]
Polyolefin resin composition
The polyolefin resin composition of the present invention is a composition comprising the above-mentioned polyolefin graft copolymer (A) and a copolymer (B) of a glycidyl ester of an α, β unsaturated acid and an olefin. .
[0021]
The content of unsaturated carboxylic acid and / or derivative thereof in the entire polyolefin resin composition is usually 0.01 to 2.0% by weight, preferably 0.015 to 1.0% by weight, more preferably 0.02%. ~ 0.5 wt%. When the unsaturated carboxylic acid and / or derivative thereof is in the above range in the composition, it is possible to maintain a high degree of adhesiveness even after being immersed in gasoline or the like for a long time.
[0022]
The content of α, β unsaturated glycidyl ester in the whole polyolefin resin composition is usually 1.0 to 6.0% by weight, preferably 1.5 to 5.0% by weight, more preferably 2.0 to 4%. 0.0% by weight. When the α, β unsaturated glycidyl ester is in the above range in the composition, it is possible to obtain a composition excellent in adhesiveness with the polyarylene sulfide resin.
[0023]
Furthermore, the ratio of the molar amount of the unsaturated carboxylic acid and / or derivative thereof to the molar amount of the α, β unsaturated glycidyl ester in the entire polyolefin resin composition is usually 0.001 to 1.0, preferably 0.00. 005 to 0.5, more preferably 0.01 to 0.3. When the molar ratio of the unsaturated carboxylic acid and / or derivative thereof contained in the composition to the α, β unsaturated glycidyl ester is in the above range, the adhesiveness with the polyarylene sulfide resin, fluidity, and molding at high temperature A resin composition having excellent stability can be obtained.
[0024]
In addition, the polyolefin resin composition of the present invention can be used as long as the content of unsaturated carboxylic acid and / or its derivative in the entire composition and the content of α, β unsaturated glycidyl ester are within the above ranges. Other resins, elastomers and the like that can be mixed with the polyolefin graft copolymer (A) can be blended within a range that does not impair the purpose. Other resins may be blended at the same time as (A) and (B) described above, or after mixing (A) and (B) as a composition.
[0025]
The manufacturing method of the polyolefin resin composition of this invention is not specifically limited, A well-known method is employable. For example, (A), (B), or a method of melt-kneading resins or the like that are blended as necessary so that the amount of unsaturated carboxylic acid in the composition is within the above-mentioned range, in a batch or sequentially. Can be mentioned. Examples of the melt kneading method include a method of dry blending the resin composition and then melt kneading with a uniaxial or biaxial screw extruder, a Banbury mixer, a roll, various kneaders, and the like. The temperature in the melt-kneading is not particularly limited as long as (A), (B) and the resin blended as necessary are melted, but the temperature is usually 160 to 300 ° C, preferably 180 to 250 ° C. It is common to implement in a range.
[0026]
The melt flow rate (MFR) at 190 ° C. under a load of 2.16 kg according to ASTM D1238 of the polyolefin resin composition of the present invention is usually 0.01 to 50 g / 10 minutes, preferably 0.1 to 20 g / 10 minutes, more preferably Is preferably 0.2 to 10 g / 10 min. When the MFR is in the above range, the moldability when forming a multilayer structure is excellent.
[0027]
It is particularly preferable that the polyolefin resin composition of the present invention forms a sea-island structure. In a preferred embodiment, the island phase is made of a copolymer (B) of an glycidyl ester of an α, β unsaturated acid and an olefin, and the average particle size is usually 0.3 μm or less. (B) The average particle diameter of the phase is usually 0.3 μm or less, particularly preferably 0.28 μm or less. When the average particle diameter is in this range, the initial adhesiveness is excellent and the film is immersed in gasoline for a long time. Even later, it becomes possible to maintain a high degree of adhesion. In addition, in the resin composition of this invention, the (B) phase used as an island phase can be observed with a transmission electron microscope as a phase dye | stained using dyeing agents, such as ruthenium oxide. The average particle diameter of the island phase consisting of (B) in the present invention is the average of the island phase consisting of (B) by subjecting the obtained observation image to image processing and image analysis using commercially available image analysis software. It can be obtained as a long diameter.
[0028]
The polyolefin resin composition of the present invention is suitably used as an adhesive resin for a laminate of a polyarylene sulfide resin and a polyolefin resin. The resin composition of the present invention expresses strong adhesion to both the polyarylene sulfide layer and the polyolefin layer.
[0029]
Generally, glycidyl ester of α, β unsaturated acid and olefin copolymer (B) have strong adhesion to polyarylene sulfide layer, but swell and decrease adhesion when in contact with hydrocarbon liquid such as gasoline. To do. However, in the polyolefin resin composition of the present invention, the (B) phase is finely dispersed in the polyolefin graft copolymer (A) phase, which is relatively resistant to gasoline, etc. However, a decrease in adhesive strength can be reduced.
[0030]
Moreover, since the copolymer (B) phase of the glycidyl ester of an α, β unsaturated acid and an olefin has a large amount of highly reactive epoxy groups, the epoxy groups react with each other when kept at a high temperature. Since a cross-linked structure is formed, gel is easily generated, and the moldability is remarkably lowered. However, since the polyolefin resin composition of the present invention has a low epoxy group content, it is excellent in molding stability at high temperatures. An index of thermal stability can be expressed by MFR retention rate, and the composition of the present invention has a melt flow rate (M1) at a retention time of 6 minutes at 230 ° C. and a load of 2.16 kg, and a melt flow at a retention time of 30 minutes. The ratio (M2 / M1) to the rate (M2) is usually 0.50 or more, 0.58 or more in a preferred composition, and 0.65 or more in a particularly preferred composition. The closer the MFR retention is to 1, the better the thermal stability.
[0031]
As polyolefin which can be mix | blended as needed, the polyolefin used for the above-mentioned graft modification can be used, and especially linear polyethylene is used preferably. The linear polyethylene has a density of 0.900 to 0.980 kg / cm.³, Preferably 0.910 to 0.975 kg / cm³More preferably, 0.915-0.970 kg / cm³Ethylene homopolymer or ethylene / α-olefin copolymer. When the density is in the above range, a high degree of adhesion can be maintained even after being immersed in gasoline for a long time. Among linear polyethylenes, ethylene / α-olefin copolymers can be preferably used. Specifically, ethylene / propylene copolymers, ethylene / 1-butene copolymers, ethylene / 1-hexene copolymers. Polymers, ethylene / 1-octene copolymers, and ethylene / 4-methyl-1-pentene copolymers are preferred. Such linear polyethylene can be obtained by a known method.
[0032]
In addition, a known process stabilizer, heat-resistant stabilizer, heat-resistant aging agent, filler and the like can be added to the polyolefin resin composition of the present invention within a range not impairing the object of the present invention.
[0033]
Polyarylene sulfide resin
As the polyarylene sulfide resin used for the multilayer structure in the present invention, polyphenylene sulfide resin (hereinafter abbreviated as PPS resin) can be preferably used.
[0034]
Here, the PPS resin is a polymer having a repeating unit represented by the following structural formula (2),
[0035]
[Chemical formula 2]

From the viewpoint of heat resistance, a polymer containing usually 70 mol% or more, preferably 90 mol% or more of a polymer containing a repeating unit represented by the above structural formula is desirable.
[0036]
Moreover, about 30 mol% of the repeating units of the PPS resin may be composed of repeating units having the following structure.
[0037]
[Chemical Formula 3]

[0038]
Since the PPS polymer having such a structure in part has a low melting point, it is advantageous in terms of moldability when the melting point of the thermoplastic resin used other than the barrier layer in the laminated structure of the present invention is low.
[0039]
The melt viscosity of the PPS resin used in the present invention is not particularly limited as long as melt kneading is possible. Of the range. When the melt viscosity is within this range, the moldability when forming a multilayer structure is excellent.
[0040]
Such a PPS resin can be obtained by a generally known method, that is, a method for obtaining a polymer having a relatively small molecular weight described in JP-B-45-3368, or JP-B-52-12240 and JP-A-61-7332. It can be produced by a method for obtaining a polymer having a relatively large molecular weight described in the publication.
[0041]
In the present invention, the PPS resin is subjected to crosslinking / polymerization by heating in air, heat treatment under an inert gas atmosphere such as nitrogen or reduced pressure, washing with an organic solvent, hot water, an acid aqueous solution, an acid anhydride, Of course, it can be used after various treatments such as activation with a functional group-containing compound such as amine, isocyanate, or a functional group-containing disulfide compound.
[0042]
Polyolefin resin
As the polyolefin resin used in the multilayer structure in the present invention, the above-mentioned polyolefin can be used, preferably an ethylene copolymer, particularly preferably a density of 0.945 to 0.980 g / cm.³Can be mentioned high density polyethylene. Here, the polyolefin resin may be a single type or a composition of two or more types of resins. It is possible to select an appropriate composition according to the use of the multilayer structure and to use an appropriate resin according to the fluidity with the polyarylene sulfide resin.
[0043]
The melt flow rate (MFR) at 190 ° C. under a load of 2.16 kg according to ASTM D1238 of polyolefin resin used as a multilayer structure is usually 0.001 to 100 g / 10 min, preferably 0.01 to 50 g / 10 min. Preferably it is 0.01-30. When the MFR is within this range, it is possible to obtain a multilayer structure having satisfactory strength as well as excellent moldability when forming a multilayer structure.
[0044]
The polyolefin resin used in the present invention can be obtained by a known method. In addition, known process stabilizers, heat stabilizers, heat aging agents, fillers, and the like can be added to the polyolefin resin of the present invention as long as the object of the present invention is not impaired.
Multilayer structure
[0045]
The multilayer structure of the present invention is a structure in which a plurality of types of resins are laminated, wherein the polyarylene sulfide resin is composed of at least one layer (hereinafter referred to as (A) PAS layer), and the polyolefin resin is at least one layer ( (B) PO layer), and a laminate in which the adhesive resin composition layer of the present invention (hereinafter referred to as (c) adhesive layer) is formed between the two layers. Specifically, for example, (b) layer / (c) layer / (b) layer, three types and three-layer structure, (b) layer / (c) layer / (b) layer / (c) layer / (b) A laminated structure such as a three-kind five-layer structure of layers may be mentioned, but is not limited thereto.
[0046]
The multilayer structure of the present invention can be produced by various known methods. For example, it can be produced by a known co-extrusion method such as inflation molding, cast molding, extrusion coating molding, hollow molding, injection molding, etc. Also, after forming a single layer or multilayer film, etc., it is dry-laminated by heating. A method etc. can be illustrated.
[0047]
In the multilayer structure of the present invention, a polyarylene sulfide resin layer excellent in heat resistance, gas and liquid barrier properties and a polyolefin resin layer excellent in impact resistance and low temperature toughness are firmly bonded via an adhesive resin layer. Therefore, it is effective as blow molded products such as bottles, tanks and ducts, extrusion molded products such as sheets, pipes and tubes, as well as mechanical parts, electrical / electronic parts, and chemicals. In particular, since the adhesive resin composition layer is excellent in gasoline resistance, it is useful as a component such as a fuel tank or a fuel tube for automobiles.
[0048]
【Example】
Hereinafter, although an example and a comparative example are given and explained still more concretely, the present invention is not limited at all by these examples.
In Examples and the like, measurement and evaluation were performed according to the following methods.
[0049]
<Thermal stability of polyolefin resin composition (MFR retention)>
The polyolefin resin composition was measured for a melt flow rate (M1) with a holding time of 6 minutes at 250 ° C. and a load of 2.16 kg, and a melt flow rate (M2) with a holding time of 30 minutes, and MFR was used as an index of thermal stability. The retention rate (ratio between M1 and M2: M2 / M1) was determined. The closer the MFR retention is to 1, the better the thermal stability.
[0050]
<Initial adhesive strength of multilayer molded body>
After holding the multilayer molded body molded by a predetermined method for 48 hours or more in an atmosphere of 23 ° C. and 50% RH, strip-shaped test pieces having a width of 15 mm and a length of 8 to 15 cm were cut out. Then, 1 to 2 cm is peeled from the polyphenylene sulfide resin (PPS resin) layer and the adhesive resin layer from one end face of the test piece, and the adhesive resin is attached to one of the chucks of a tensile tester (Instron 1123 type, manufactured by Instron). A polyphenylene sulfide resin layer was fixed to one of the layers, a T-shape was formed, a peel test was performed under the condition of a crosshead speed of 100 mm / min, and the adhesive strength was evaluated based on the strength. In addition, the thing shown below was attached | subjected to the thing which cannot measure intensity | strength correctly because of strong adhesive force.
Cannot be peeled: The test piece cannot be peeled at all, so the test piece cannot be attached to the chuck of the tensile tester and the peel test cannot be performed.
Substrate failure: Since the adhesive strength exceeds the strength of the substrate, the PPS resin layer or adhesive resin layer breaks during the peel test, and the adhesive strength cannot be measured accurately
[0051]
<Adhesive strength after gasoline immersion of multilayer molded product>
After holding the multilayer molded body molded by a predetermined method for 48 hours or more in an atmosphere of 23 ° C. and 50% RH, a strip-shaped test piece having a width of 15 mm and a length of 8 to 15 cm was cut out. Next, the cut strip-shaped test piece was immersed in test gasoline at a temperature of 40 ° C. for 168 hours. Thereafter, the test piece was taken out from gasoline and kept in an atmosphere of 23 ° C. and 50% RH for 24 hours, and then a peel test similar to the above initial adhesive strength was performed to determine the adhesive strength.
[0052]
<Phase structure of polyolefin resin composition>
The polyolefin resin composition was dyed with ruthenium oxide and then observed with a transmission electron microscope. The darkly stained region corresponds to the (B) phase domain. Moreover, about the obtained observed image, the average major axis length of the (B) phase domain was calculated | required by performing image processing and image analysis using the image analysis software made from Optimus, and set it as the average particle diameter.
[0053]
Substances used in Examples and Comparative Examples are shown below. In addition, unless otherwise indicated, all were prepared by polymerization according to a conventional method.
[0054]
<Preparation of polyolefin graft copolymer (A1)>
Polyethylene obtained according to a conventional method (MFR = 20 g / 10 min, density = 0.920 g / cm³) 100 parts by weight of maleic anhydride (MAH) 0.2 parts by weight, 2,5-dimethyl-2,5-di (T-butylperoxy) hexane 0.04 parts by weight, A maleic anhydride-modified polyethylene (A1) was obtained by melt kneading at 250 ° C. with a 30 MMφ twin screw extruder (manufactured by Nippon Steel). The resulting modified product had a maleic anhydride content (modified amount) of 0.2% by weight. Similarly, graft copolymers (A2) to (A6) below were obtained by changing the amount of maleic anhydride grafted on polyethylene having different MFR / density.
[0055]
<Polyolefin graft copolymer (A)>
(A1) Modified polyethylene having a maleic anhydride content of 0.2 wt%, a density of 0.920, and MFR = 9.6 (190 ° C., 2160 g load)
(A2) Maleic anhydride content 0.2 wt%, density 0.930, MFR = 0. 3 modified polyethylene
(A3) Maleic anhydride content 0.2 wt%, density 0.940, MFR = 0. 2 modified polyethylene
(A4) Maleic anhydride content 0.2 wt%, density 0.965, MFR = 4. 9 modified polyethylene
(A5) Maleic anhydride content 1.0 wt%, density 0.920, MFR = 8. 8 modified polyethylene
(A6) Maleic anhydride content 0.2 wt%, density 0.965, MFR = 4. 9 modified polyethylene
[0056]
<Glycidyl ester copolymer ethylene copolymer>
(B1) Ethylene-glycidyl methacrylate copolymer (containing 12 wt% glycidyl methacrylate, Bond First E (manufactured by Sumitomo Chemical Co., Ltd.))
[0057]
<Linear polyethylene>
(C1) Linear low-density polyethylene having a density of 0.920 and MFR (190 ° C., 2160 g load) = 1.1
(C2) Linear low-density polyethylene having a density of 0.920 and MFR = 2.2
[0058]
<PPS resin>
(PPS1) PPS resin having a melting point of 280 ° C. and MFR = 160 g / 10 minutes (315 ° C., 5000 g load)
[0059]
<Polyolefin resin>
(PO1) High density polyethylene with a density of 0.956 and MFR = 6
[0060]
Example 1
Using a 30 mmφ twin screw extruder (manufactured by Nippon Steel), 80 parts by weight of modified polyethylene (A1) and 20 parts by weight of ethylene-glycidyl methacrylate copolymer (B1) were used. Then, an adhesive resin composition was obtained. About this adhesive resin composition, melt flow rate M1 and M2 were measured in accordance with the above-mentioned method, and thermal stability (MFR retention) was calculated. The MFR retention was 0.87. The results are shown in Table 1.
[0061]
<Molding of resin composition film>
The obtained adhesive resin composition is dried under reduced pressure at 80 ° C. for 12 hours or more, and a predetermined amount is sandwiched between two brass plates, an aluminum plate, and a Teflon (registered trademark) release film, and pressed. It was melted at 200 ° C. using a molding machine (manufactured by Shinto Metal Industry Co., Ltd.). After compression at 10 MPa for 3 minutes, the film was compressed and cooled again at 10 MPa with a compression molding machine set at a temperature of 20 ° C. to obtain a press film having a thickness of 100 μm.
<Molding of polyolefin resin film>
Press molding was performed in the same manner as in the case of obtaining the above adhesive resin composition film to obtain a high-density polyethylene (HDPE) film having a thickness of 100 μm.
<Formation of PPS resin film>
Except for the heating temperature of 320 ° C. and the cooling temperature of 20 ° C., press molding was performed in the same manner as in the case of obtaining the adhesive resin composition film to obtain a 200 μm-thick PPS resin (PPS1) film. .
<Formation of multilayer laminate>
These films are layered in the order of HDPE / adhesive resin composition / PPS, and using a press molding machine (manufactured by Shinto Metal Industry Co., Ltd.), a heating temperature of 300 ° C., a preheating time of 5 minutes, a pressing time of 2 minutes, and a pressure of 5 MPa. Three films were bonded to each other by performing a heating press under conditions, followed by a cooling press at 20 ° C.
[0062]
Using the obtained bonded sheet, a peel test for initial adhesive strength was performed according to the above-described conditions. As a result, it was confirmed that the PPS resin layer was broken and the adhesive strength was strong. In addition, although it tried to peel also about the layer of HDPE / adhesive resin composition, it adhered firmly and peeling was impossible. The results are shown in Table 1.
Next, the bonded sheet was immersed in gasoline under the above-described conditions, and a peel test for the adhesive strength after immersion in gasoline was performed. As before the immersion, it was confirmed that the PPS resin layer was broken and the adhesive strength was maintained. The results are shown in Table 1.
[0063]
(Examples 2 to 4)
An adhesive resin composition was obtained in the same manner as in Example 1 with the formulation shown in Table 1. Using the obtained adhesive composition, the melt flow rates M1 and M2 were measured in the same manner as in Example 1, and the thermal stability (MFR retention) was calculated. The results are shown in Table 1.
Next, using the obtained adhesive resin composition, a film was prepared by press molding in the same manner as in Example 1, and then HDPE / adhesive resin composition / A laminated sheet of PPS was obtained. Using the obtained laminated sheet, a peel test of initial adhesive strength and adhesive strength after immersion in gasoline was performed and evaluated. The results are shown in Table 1. Regardless of the fluidity and density of the modified polyethylene, the adhesive resin composition showed good adhesion to the PPS resin.
[0064]
(Comparative Example 1)
The adhesive resin and the laminated sheet were measured and evaluated in the same manner as in Example 1 except that the ethylene-glycidyl methacrylate copolymer (B1) was used alone as the adhesive resin. The results are shown in Table 1. Although the initial adhesive strength was strong, after immersion in gasoline, the adhesive resin swelled and the adhesive strength significantly decreased. Also, the thermal stability was not good.
[0065]
(Comparative Example 2)
The adhesive resin and the laminated sheet were measured and evaluated in the same manner as in Example 1 except that the modified polyethylene (A2) used in Example 2 was used alone as the adhesive resin. The results are shown in Table 1. Only polyethylene modified with maleic acid showed little adhesion to the PPS resin.
[0066]
[Table 1]

[0067]
(Example 5)
Using a 30 mmφ twin screw extruder (manufactured by Nippon Steel), 50 parts by weight of modified polyethylene (A5) and 50 parts by weight of ethylene-glycidyl methacrylate copolymer (B1) were used. The mixture was melted and mixed under the conditions of minutes to obtain a resin composition. Subsequently, 40 parts by weight of this resin composition and 60 parts by weight of linear polyethylene (C1) were melt-mixed in the same manner as above to obtain an adhesive resin composition. About the obtained adhesive resin composition, the melt flow rate M1 and M2 were measured similarly to Example 1, and the thermal stability (MFR retention) was calculated. The results are shown in Table 2.
[0068]
Next, using the obtained adhesive resin composition, a film was prepared by press molding in the same manner as in Example 1, and then HDPE / adhesive resin composition / A laminated sheet of PPS was obtained. Using the obtained laminated sheet, a peel test of initial adhesive strength and adhesive strength after immersion in gasoline was performed and evaluated. The results are shown in Table 2. An adhesive resin composition obtained by diluting a resin composition comprising a maleic acid-modified polyethylene (A) and an ethylene-glycidyl methacrylate copolymer (B1) with an unmodified linear polyethylene (C) is also excellently bonded to a PPS resin. Showed sex.
[0069]
(Comparative Examples 3-4)
An ethylene-glycidyl methacrylate copolymer (B1) and linear polyethylene (C1) were melt-mixed in the same manner as in Example 1 with the composition shown in Table 2 to obtain an adhesive resin composition. Next, the adhesive resin and the laminated sheet were measured and evaluated in the same manner as in Example 1. The results are shown in Table 2. The adhesive resin composition obtained by diluting the ethylene-glycidyl methacrylate copolymer (B1) with linear polyethylene (C1) had low initial adhesive strength and adhesive strength after gasoline immersion.
[0070]
(Example 6)
Using a 30 mmφ twin screw extruder (manufactured by Nippon Steel), 50 parts by weight of modified polyethylene (A6) and 50 parts by weight of ethylene-glycidyl methacrylate copolymer (B1) were used. The mixture was melted and mixed under the conditions of minutes to obtain a resin composition. Subsequently, 40 parts by weight of this resin composition and 60 parts by weight of linear polyethylene (C2) were melt-mixed in the same manner as above to obtain an adhesive resin composition. About the obtained adhesive resin composition, the melt flow rate M1 and M2 were measured similarly to Example 1, and the thermal stability (MFR retention) was calculated. The results are shown in Table 2.
[0071]
Next, using the obtained adhesive resin composition, a film was prepared by press molding in the same manner as in Example 1, and then HDPE / adhesive resin composition / A laminated sheet of PPS was obtained. Using the obtained bonded sheet, a peel test of initial adhesive strength and adhesive strength after gasoline immersion was performed and evaluated. The results are shown in Table 2. Despite the low maleic anhydride content of the resin composition and the ratio of maleic anhydride to glycidyl ester, the adhesive resin composition exhibited good adhesion to PPS resins and polyolefin resins.
[0072]
(Examples 7 to 8)
About resin of the composition shown in Table 2, it melt-mixed collectively on conditions of cylinder temperature 200 degreeC and resin discharge amount 100g / min using 30 mmphi twin-screw extruder (made by Nippon Steel Works), and adhesive resin composition is obtained. Obtained. Using the obtained adhesive resin composition, the adhesive resin and the laminated sheet were measured and evaluated in the same manner as in Example 1. The results are shown in Table 2. Similar to the results of Example 6, the adhesive resin composition exhibited good adhesion with the PPS resin even when mixed together.
[0073]
[Table 2]

[0074]
Example 9
The adhesive resin compositions prepared in Example 6, Example 8, and Comparative Example 3 were observed with a transmission electron microscope. The photographs are shown in FIGS. The area | region currently dye | stained deeply is an area | region where (B) ethylene-glycidyl methacrylate copolymer exists. Table 3 shows the analysis results of the adhesive resin composition obtained from these photographs. The average particle size of the (B) phase determined from FIGS. 1 and 2 was 0.3 μm or less, and the dispersibility was good. On the other hand, the average grain size determined from FIG. 3 was about 0.37 μm.
[0075]
[Table 3]

[0076]
[Effect of the present invention]
The adhesive resin composition of the present invention is excellent in initial adhesive force when used as an adhesive resin between a polyarylene sulfide resin and a polyolefin resin, and the multilayer structure is exposed to an organic solvent such as gasoline over a long period of time. However, it retains a high degree of adhesiveness and is excellent in molding stability during high temperature molding.
[0077]
[Brief description of the drawings]
1 is an electron micrograph showing the phase structure of the adhesive resin composition prepared in Example 6 in Example 9, and the darkly dyed portion shows the domain of the ethylene glycidyl methacrylate copolymer. The average particle size determined by a predetermined method was 0.24 μm.
2 is an electron micrograph showing the phase structure of the adhesive resin composition prepared in Example 8 in Example 9, and the darkly dyed portion shows the domain of the ethylene glycidyl methacrylate copolymer. FIG. The average particle size determined by a predetermined method was 0.25 μm.
FIG. 3 is an electron micrograph showing the phase structure of the adhesive resin composition prepared in Comparative Example 3 in Example 9, and the darkly dyed portion shows the domain of the ethylene glycidyl methacrylate copolymer. The average particle size determined by a predetermined method was 0.37 μm.

Claims (4)

A polyolefin graft copolymer (A) obtained by graft polymerization of an unsaturated carboxylic acid and / or a derivative thereof onto a polyolefin; and a copolymer of an glycidyl ester of an α, β unsaturated acid and an olefin (B). The content of the unsaturated carboxylic acid and / or derivative thereof is 0.01 to 2.0% by weight, and the content of the α, β unsaturated glycidyl ester is 1. A polyolefin resin composition of 0 to 6.0% by weight. 2. The polyolefin resin composition according to claim 1, wherein the glycidyl ester of α, β unsaturated acid in the glycidyl ester of α, β unsaturated acid and olefin copolymer (B) is 1 to 20 wt%. The polyolefin resin composition forms a sea-island structure, and the island phase is a phase having an average particle diameter of 0.3 μm or less composed of a copolymer (B) of a glycidyl ester of an α, β unsaturated acid and an olefin. Item 3. A polyolefin resin composition according to Item 1 or 2. A multilayer structure in which a polyarylene sulfide resin and a polyolefin resin are bonded by the polyolefin resin composition according to claim 1.

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