JP2005068184A - Composition and its use - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composition which gives foams (non-crosslinked foams and crosslinked foams) having a low specific gravity and a small permanent compression set (CS) and being excellent in tensile strength property, tear strength property, impact resilience and adhesive property, the foam, and a laminate obtained by using the foam. <P>SOLUTION: The composition comprises 70-99.9 wt% of a graft-modified ethylene-α-olefin copolymer (A) obtained by grafting an unsaturated carboxylic acid or a derivative thereof onto an ethylene-α-olefin copolymer, 30-0.1 wt% of an inorganic metal compound (B) (where the total amount of the components (A) and (B) is 100 wt%), and a blowing agent (C). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００３１】
このようなＴαβ／Ｔαα強度比は、下記のようにして求めることができる。グラフト変性エチレン・α−オレフィン共重合体および／またはグラフト変性前のエチレン・α−オレフィン共重合体の１３Ｃ−ＮＭＲスペクトルを、たとえば日本電子（株）製ＪＥＯＬ−ＧＸ２７０ ＮＭＲ測定装置を用いて測定する。測定は、試料濃度５重量％になるように調整されたヘキサクロロブタジエン／ｄ６−ベンゼン＝２／１（体積比）の混合溶液を用いて、６７．８ＭＨｚ、２５℃、ｄ６−ベンゼン（１２８ｐｐｍ）基準で行う。測定された１３Ｃ−ＮＭＲスペクトルを、リンデマンアダムスの提案（Ａｎａｌｙｓｉｓ Ｃｈｅｍｉｓｔｒｙ４３， ｐ１２４５（１９７１））、Ｊ．Ｃ．Ｒａｎｄａｌｌ （Ｒｅｖｉｅｗ Ｍａｃｒｏｍｏｌｅｃｕｌａｒ Ｃｈｅｍｉｓｔｒｙ Ｐｈｙｓｉｃｓ， Ｃ２９， ２０１（１９８９）） に従って解析してＴαβ／Ｔαα強度比を求める。
【００３２】
また本発明のグラフト変性エチレン・α− オレフィン共重合体（Ａ）および／またはグラフト変性前のエチレン・α−オレフィン共重合体は１３Ｃ−ＮＭＲスペクトルおよび下記一般式（１）から求められるＢ値が０．９〜１．５であるのが好ましい。
Ｂ値＝［ＰＯＥ］／（２・［ＰＥ］［ＰＯ］） …（１）
（式中、［ＰＥ］は共重合体中のエチレンから誘導される構成単位の含有モル分率であり、［ＰＯ］は共重合体中のα−オレフィンから誘導される構成単位の含有モル分率であり、［ＰＯＥ］は共重合体中の全ダイアド（ｄｙａｄ）連鎖に対するグラフト変性エチレン・α−オレフィンおよび／またはグラフト変性前のエチレン・α−オレフィン連鎖数の割合である。）このＢ値は、グラフト変性エチレン・α−オレフィン共重合体および／またはグラフト変性前のエチレン・α−オレフィン共重合体中のエチレンと炭素数３〜１０のα−オレフィンとの分布状態を表す指標であり、Ｊ．Ｃ．Ｒａｎｄａｌｌ （Ｍａｃｒｏｍｏｌｅｃｕｌｅｓ， １５， ３５３（１９８２）） 、Ｊ．Ｒａｙ （Ｍａｃｒｏｍｏｌｅｃｕｌｅｓ， １０， ７７３（１９７７）） らの報告に基づいて求めることができる。
【００３３】
上記Ｂ値が大きいほど、エチレンまたはα−オレフィン共重合体のブロック的連鎖が短くなり、エチレンおよびα−オレフィンの分布が一様であり、共重合ゴムの組成分布が狭いことを示している。なおＢ値が１．０よりも小さくなるグラフト変性エチレン・α−オレフィン共重合体および／またはグラフト変性前のエチレン・α−オレフィン共重合体中の組成分布は広くなり、取扱性が悪化するなどの悪い点がある。
【００３４】
上記のようなグラフト変性前のエチレン・α−オレフィン共重合体は、バナジウム系触媒、チタン系触媒またはメタロセン系触媒などを用いる従来公知の方法により製造することができる。
【００３５】
本発明で用いられるグラフト変性エチレン・α− オレフィン共重合体（Ａ）は、上記のグラフト変性前のエチレン・α−オレフィン共重合体に、特定量の不飽和カルボン酸またはその誘導体をグラフトすることにより得ることができる。
本発明で用いられるグラフト変性エチレン・α−オレフィン共重合体（Ａ）における不飽和カルボン酸またはその誘導体のグラフト量は、未変性エチレン・α− オレフィンランダム共重合体１００重量％に対して、０．１〜４．０重量％、好ましくは０．５〜２．５重量％である。
【００３６】
このグラフト量が上記範囲にあるグラフト変性エチレン・α−オレフィン共重合体（Ａ）は、組成物中において分散性に優れるとともに、熱安定性に優れ、溶融時に樹脂が着色することもない。しかも、このようなグラフト変性エチレン・α−オレフィン共重合体（Ａ）を用いると、機械的強度に優れた架橋発泡体を提供し得る組成物を得ることができる。
【００３７】
上記変性で用いられる不飽和カルボン酸としては、具体的には、アクリル酸、マレイン酸、フマール酸、テトラヒドロフタル酸、イタコン酸、シトラコン酸、クロトン酸、イソクロトン酸およびナジック酸^ＴＭ（エンドシス− ビシクロ［２，２，１］ ヘプト−５− エン−２，３− ジカルボン酸）などが挙げられる。
【００３８】
また、不飽和カルボン酸の誘導体としては、具体的には、上記不飽和カルボン酸の酸ハライド化合物、アミド化合物、イミド化合物、酸無水物およびエステル化合物などを挙げることができる。より具体的には、塩化マレイル、マレイミド、無水マレイン酸、無水シトラコン酸、マレイン酸モノメチル、マレイン酸ジメチル、グリシジルマレエートなどが挙げられる。これらの中では、不飽和ジカルボン酸またはその酸無水物が好適であり、特にマレイン酸、ナジック酸^ＴＭまたはこれらの酸無水物が好適である。
【００３９】
上記のようなグラフト変性エチレン・α−オレフィン共重合体（Ａ）は、従来公知の種々の方法、たとえば次のような方法を用いて調製することができる。
（１）溶融させた上記（変性前の）未変性エチレン・α− オレフィン共重合体に、不飽和カルボン酸またはその誘導体を添加してグラフト共重合させる方法。
（２）上記（変性前の）未変性エチレン・α− オレフィン共重合体を溶媒に溶解させ、その溶解液に不飽和カルボン酸またはその誘導体を添加してグラフト共重合させる方法。
【００４０】
いずれの方法も、上記不飽和カルボン酸等のグラフトモノマーを効率よくグラフト共重合させるためには、ラジカル開始剤の存在下にグラフト反応を行なうのが好ましい。
【００４１】
上記ラジカル開始剤としては、有機ペルオキシド、アゾ化合物などが使用される。このようなラジカル開始剤としては、具体的には、ベンゾイルペルオキシド、ジクロルベンゾイルペルオキシド、ジクミルペルオキシド、ジ−ｔｅｒｔ−ブチルペルオキシド、２，５−ジメチル−２，５− ジ（ペルオキシドベンゾエート）ヘキシン−３、１，４−ビス（ｔｅｒｔ− ブチルペルオキシイソプロピル）ベンゼン、ラウロイルペルオキシド、ｔｅｒｔ− ブチルペルアセテート、２，５−ジメチル−２，５− ジ−（ｔｅｒｔ− ブチルペルオキシド）ヘキシン−３、２，５−ジメチル−２，５− ジ（ｔｅｒｔ− ブチルペルオキシド）ヘキサン、ｔｅｒｔ− ブチルペルベンゾエート、ｔｅｒｔ− ブチルペルフェニルアセテート、ｔｅｒｔ− ブチルペルイソブチレート、ｔｅｒｔ− ブチルペル−ｓｅｃ− オクトエート、ｔｅｒｔ− ブチルペルピバレート、クミルペルピバレート、ｔｅｒｔ− ブチルペルジエチルアセテート等の有機ペルオキシド；アゾビスイソブチロニトリル、ジメチルアゾイソブチレート等のアゾ化合物などが挙げられる。これらの中では、ジクミルペルオキシド、ジ−ｔｅｒｔ−ブチルペルオキシド、２，５−ジメチル−２，５− ジ（ｔｅｒｔ− ブチルペルオキシ）ヘキシン−３、２，５−ジメチル−２，５− ジ（ｔｅｒｔ− ブチルペルオキシ）ヘキサン、１，４−ビス（ｔｅｒｔ− ブチルペルオキシイソプロピル）ベンゼンなどのジアルキルペルオキシドが好ましく用いられる。
【００４２】
これらのラジカル開始剤は、（変性前の）未変性エチレン・α− オレフィン共重合体１００重量部に対して、通常は０．０１〜０．１０重量部、好ましくは０．０２〜０．０８重量部、さらに好ましくは０．０２〜０．０５重量部の量で用いられる。
【００４３】
上記のようなラジカル開始剤を使用したグラフト反応、あるいはラジカル開始剤を使用せずに行なうグラフト反応における反応温度は、通常６０〜３５０℃、好ましくは１５０〜３００℃の範囲内に設定される。
【００４４】
上記のようなグラフト変性エチレン・α− オレフィン共重合体（Ａ）は、未変性エチレン・α− オレフィン共重合体の混合物であってもよく、また高圧法低密度ポリエチレン等の他のエチレン系重合体との混合物であってもよい。
無機金属化合物（Ｂ）
本発明で用いられる無機金属化合物（Ｂ）は、元素の周期律表の第ＩＩ、ＩＩＩ、ＩＶ、ＶＩ、ＶＩＩ族の金属の酸化物、水酸化物、リン酸塩、炭酸塩、およびカルボン酸塩の中から選ぶことができる。好ましくは、亜鉛またはアルミニウムの酸化物が用いられる。
【００４５】
これらの無機金属化合物（Ｂ）は、グラフト変性エチレン・α−オレフィン共重合体（Ａ）と無機金属化合物（Ｂ）の合計量１００重量％として通常は０．１〜３０重量％、好ましくは０．５〜１０重量％、さらに好ましくは０．５〜５重量％の量で用いられる。無機金属化合物（Ｂ）が上記範囲内にあると、高強度、高反撥弾性の架橋発泡体を提供することができる。
発泡剤（Ｃ）
本発明で用いられる発泡剤（Ｃ）としては、化学発泡剤、具体的には、アゾジカルボンアミド（ＡＤＣＡ）、１，１’−アゾビス（１−アセトキシ−１− フェニルエタン）、ジメチル−２，２’−アゾビスブチレート、ジメチル−２，２’−アゾビスイソブチレート、２，２’− アゾビス（２，４，４−トリメチルペンタン）、１，１’−アゾビス（シクロヘキサン−１−カルボニトリル）、２，２’−アゾビス［Ｎ−（２−カルボキシエチル）−２−メチル−プロピオンアミジン］等のアゾ化合物；Ｎ，Ｎ’−ジニトロソペンタメチレンテトラミン（ＤＰＴ）等のニトロソ化合物；４，４’− オキシビス（ベンゼンスルホニルヒドラジド）、ジフェニルスルホン−３，３’−ジスルホニルヒドラジド等のヒドラジン誘導体；ｐ−トルエンスルホニルセミカルバジド等のセミカルバジド化合物；トリヒドラジノトリアジンなどの有機系熱分解型発泡剤、さらには、炭酸水素ナトリウム、炭酸水素アンモニウム等の重炭酸塩、炭酸ナトリウム、炭酸アンモニウム等の炭酸塩；亜硝酸アンモニウム等の亜硝酸塩、水素化合物などの無機系熱分解型発泡剤が挙げられる。中でも、アゾジカルボンアミド（ＡＤＣＡ）、炭酸水素ナトリウムが特に好ましい。
【００４６】
また、本発明においては、物理発泡剤（発泡時に化学反応を必ずしも伴わない発泡剤）、たとえばメタノール、エタノール、プロパン、ブタン、ペンタン、ヘキサン等の各種脂肪族炭化水素類；ジクロルエタン、ジクロルメタン、四塩化炭素等の各種塩化炭化水素類；フロン等の各種フッ化塩化炭化水素類などの有機系物理発泡剤、さらに空気、二酸化炭素、窒素、アルゴン、水などの無機系物理発泡剤も発泡剤（Ｃ）として用いることができる。これらの中で、蒸気にする必要が無く、安価で、環境汚染、発火の可能性が極めて少ない二酸化炭素、窒素、アルゴンが最も優れている。
【００４７】
本発明で発泡剤（Ｃ）として使用される上記物理発泡剤は、発泡剤の分解残さがないため、組成物の架橋発泡時における金型汚れを防止することができる。しかも、物理発泡剤は、粉状ではないので、混練性に優れている。また、この物理発泡剤を用いると、得られる架橋発泡体の異臭（ＡＤＣＡ分解時に生成するアンモニア臭など）を防止することができる。
【００４８】
また、本発明においては、臭気、金型汚れ等の悪影響を生じない範囲で、蒸気のような化学発泡剤を併用することができる。
【００４９】
物理発泡剤の貯蔵方法としては、小規模な生産であれば、二酸化炭素、窒素などをボンベに入った状態で使用し、射出成形機および押出成形機等に減圧弁を通して供給することができるし、またポンプ等により昇圧し、射出成形機および押出成形機等に供給する場合もある。
【００５０】
また、大規模に発泡製品を製造する設備であれば、液化二酸化炭素、液化窒素などの貯蔵タンクを設置し、熱交換機を通し、気化し、配管により、減圧弁により射出成形機および押出成形機等に供給する。
【００５１】
また、液状の物理発泡剤の場合、貯蔵圧力としては、０．１３〜１００ＭＰａの範囲が好ましく、圧力が低すぎると減圧して射出成形機および押出成形機等に注入できず、また、圧力が高すぎると、貯蔵設備の耐圧強度を高くする必要から、設備が大型化、複雑化し好ましくない。なお、ここで定義する貯蔵圧力とは、気化し減圧弁に供給する圧力を言う。
【００５２】
組成物
本発明にかかわる組成物はグラフト変性エチレン・α−オレフィン共重合体（Ａ）、無機金属化合物（Ｂ）および発泡剤（Ｃ）とを含有してなり、
エチレン・α−オレフィン共重合体（Ａ）７０〜９９．９重量％、好ましくは９０〜９９．５重量％、より好ましくは９５〜９９．５重量％、無機金属化合物（Ｂ）３０〜０．１重量％、好ましくは１０〜０．５重量％、より好ましくは５ 〜０．５重量％（ここで、（Ａ）および（Ｂ）の合計量は合わせて１００重量％となる）からなる。
【００５３】
上記発泡剤（Ｃ）として化学発泡剤を用いる場合、化学発泡剤は、グラフト変性エチレン・α−オレフィン共重合体（Ａ）＋無機金属化合物（Ｂ）１００重量部に対して、通常２〜２０重量部、好ましくは３〜１５重量部の割合で用いられる。ただし、化学発泡剤の使用量は、使用する発泡剤の種類・グレードにより発生ガス量が異なるため、目的の発泡倍率により、適宜増減され得る。
【００５４】
また、発泡剤（Ｃ）として物理発泡剤を用いる場合、物理発泡剤の添加量は、所望の発泡倍率に応じて、適宜決定される。
【００５５】
本発明においては、必要に応じて、発泡剤（Ｃ）とともに発泡助剤を使用してもよい。発泡助剤は、発泡剤（Ｃ）の分解温度の低下、分解促進、気泡の均一化などの作用をする。このような発泡助剤としては、サリチル酸、フタル酸、ステアリン酸、しゅう酸等の有機酸、尿素またはその誘導体などが挙げられる。
【００５６】
有機ペルオキシド（Ｄ）
本発明で必要に応じて架橋剤として用いられる有機ペルオキシド（Ｄ）としては、具体的には、ジクミルペルオキシド、ジ−ｔ− ブチルペルオキシド、２，５−ジメチル−２，５− ジ−（ｔ−ブチルペルオキシ）ヘキサン、２，５−ジメチル−２，５− ジ−（ｔ−ブチルペルオキシ）ヘキシン−３、１，３−ビス（ｔ−ブチルペルオキシイソプロピル）ベンゼン、１，１−ビス（ｔ−ブチルペルオキシ）−３，３，５− トリメチルシクロヘキサン、ｎ−ブチル−４，４− ビス（ｔ−ブチルペルオキシ）バレレート、ベンゾイルペルオキシド、ｐ−クロロベンゾイルペルオキシド、２，４−ジクロロベンゾイルペルオキシド、ｔ−ブチルペルオキシベンゾエート、ｔ−ブチルペルベンゾエート、ｔ−ブチルペルオキシイソプロピルカーボネート、ジアセチルペルオキシド、ラウロイルペルオキシド、ｔ−ブチルクミルペルオキシドなどが挙げられる。
【００５７】
本発明においては、有機ペルオキシド（Ｄ）は、グラフト変性エチレン・α−オレフィン共重合体（Ａ）＋無機金属化合物（Ｂ）１００重量部に対して、通常０．１〜１．５重量部、好ましくは０．２〜１．０重量部の割合で用いられる。有機ペルオキシド（Ｄ）を上記のような割合で用いると、適度な架橋構造を有する架橋発泡体を得ることができる。また、有機ペルオキシド（Ｄ）を架橋助剤（Ｅ）とともに、上記のような割合で用いると、より適度な架橋構造を有する架橋発泡体を得ることができる。
【００５８】
架橋助剤（Ｅ）
本発明で必要に応じて用いられる架橋助剤（Ｅ）としては、具体的には、硫黄、ｐ−キノンジオキシム、ｐ，ｐ’− ジベンゾイルキノンジオキシム、Ｎ−メチル−Ｎ−４− ジニトロソアニリン、ニトロソベンゼン、ジフェニルグアニジン、トリメチロールプロパン−Ｎ，Ｎ’−ｍ−フェニレンジマレイミドのようなペルオキシ架橋用助剤；あるいはジビニルベンゼン、トリアリルシアヌレート（ＴＡＣ）、トリアリルイソシアヌレート（ＴＡＩＣ）が好ましい。また、エチレングリコールジメタクリレート、ジエチレングリコールジメタクリレート、ポリエチレングリコールジメタクリレート、トリメチロールプロパントリメタクリレート、アリルメタクリレート等の多官能性メタクリレートモノマー、ビニルブチラート、ビニルステアレートのような多官能性ビニルモノマーなどが挙げられる。中でも、トリアリルシアヌレート（ＴＡＣ）、トリアリルイソシアヌレート（ＴＡＩＣ）が好ましい。
【００５９】
本発明においては、上記のような架橋助剤（Ｅ）は、架橋助剤（Ｅ）と有機ペルオキシド（Ｄ）との重量比［（Ｅ）／（Ｄ）］が１／３０〜５／１、好ましくは１／２０〜３／１、さらに好ましくは１／１５〜２／１になる量で用いることが望ましい。
【００６０】
樹脂組成物の調製
本発明に係る樹脂組成物は、未架橋かつ未発泡状態の組成物であり、溶融状態であってもよいし、また、冷却固化したペレットまたはシートであってもよい。
【００６１】
本発明に係る樹脂組成物のペレットは、たとえば上記のようなグラフト変性エチレン・α−オレフィン共重合体（Ａ）、無機金属化合物（Ｂ）、発泡剤（Ｃ）、および必要に応じて有機ペルオキシド（Ｄ）、架橋助剤（Ｅ）、発泡助剤を上述した割合でヘンシェルミキサ−等で混合し、バンバリ−ミキサー、ロール、押出機等の混練機で発泡剤（Ｃ）および／または有機ペルオキシド（Ｄ）が分解しない温度にて溶融可塑化し、均一に混合分散させて造粒機により調製することができる。
【００６２】
発泡剤（Ｃ）の使用量は、発泡体の発泡倍率を考慮して決定される。
【００６３】
本発明の組成物は必要により架橋剤または架橋助剤を含む。架橋剤としては有機ペルオキシドが挙げられる。架橋剤はグラフト変性エチレン・α−オレフィン共重合体（Ａ）、無機金属化合物（Ｂ）および発泡剤（Ｃ）の合計量１００重量部に対して、、通常０．１〜１．５重量部、好ましくは０．２〜１．０重量部の割合で用いられる。
【００６４】
この組成物中に、上記諸成分の他に、必要に応じて、フィラー、耐熱安定剤、耐候安定剤、難燃剤、塩酸吸収剤、顔料などの各種添加剤を、本発明の目的を損なわない範囲で配合することができる。
【００６５】
また、本発明に係る組成物のシートは、たとえば上記のようにして得られた組成物のペレットを押出機あるいはカレンダー成形機を用いて調製することができる。あるいは組成物の諸成分をブラベンダーなどで混練した後、カレンダーロールでシート状に成形する方法、プレス成形機でシート化する方法、または押出機を用いて混練した後Ｔダイまたは環状ダイを通してシート化する方法などにより、未架橋かつ未発泡状態の発泡性シートを調製することができる。
【００６６】
発泡体
本発明に係る発泡体は、上記のような、本発明に係る樹脂組成物を発泡または架橋発泡、通常は１３０〜２００℃、３０〜３００ｋｇｆ／ｃｍ２、１０〜９０分の条件下で発泡または架橋発泡することにより得られる。ただし、（架橋）発泡時間については、金型の厚さに依存するため、この範囲を超えて、適宜増減され得る。
【００６７】
また、本発明に係る発泡体は、上記条件下で発泡または架橋発泡された成型体を、１３０〜２００℃、３０〜３００ｋｇｆ／ｃｍ２、５〜６０分、圧縮比１．１〜３、好ましくは１．３〜２の条件下で圧縮成形して得られる発泡体であってもよい。
【００６８】
これらの発泡体は、比重（ＪＩＳ Ｋ７２２２）が０．０５〜０．２５である。架橋発泡体としては、ゲル分率が７０％以上であることが望ましく、通常は７０〜９０％である。
【００６９】
このような物性を有する、本発明に係る発泡体、特に架橋発泡体は、圧縮永久歪みが小さく、引裂強度が高く、反撥弾性が高い特性を持つ。
【００７０】
なお、上記ゲル分率（ゲル含量；キシレン不溶解分）は、次のようにして測定される。
【００７１】
架橋発泡体の試料を秤量して細かく裁断し、次いで得られた細片を、密閉容器中にキシレンと共に入れ、３時間還流させた。
【００７２】
次に、この試料をろ紙上に取出し、絶乾させた。この乾燥残渣の重量からポリマー成分以外のキシレン不溶性成分（たとえばフィラー、充填剤、顔料等）の重量を減じた値を、「補正された最終重量（Ｙ）」とする。
【００７３】
一方、試料の重量からポリマー成分以外のキシレン可溶性成分（たとえば安定剤等）の重量およびポリマー成分以外のキシレン不溶性成分（たとえばフィラー、充填剤、顔料等）の重量を減じた値を、「補正された初期重量（Ｘ）」とする。
【００７４】
ここに、ゲル含量（キシレン不溶解分）は、次式により求められる。
【００７５】
ゲル含量［重量％］＝［補正された最終重量（Ｙ）］÷［補正された初期重量（Ｘ）］×１００
発泡体の調製
本発明に係る発泡体（非架橋または架橋発泡体）は、たとえば以下のような方法により調製することができる。
【００７６】
本発明に係る組成物のシートは、たとえば組成物の調製の項で述べた混合物を、カレンダー成形機、プレス成形機、Ｔダイ押出機を用いて得ることができる。このシート成形時においては、発泡剤（Ｃ）および有機ペルオキシド（Ｄ）の分解温度以下でシート成形する必要があり、具体的には、組成物の溶融状態での温度が１００〜１３０℃となる条件に設定してシート成形する必要がある。
【００７７】
上記方法によってシート化された組成物は、１３０〜２００℃に保持された金型に、金型の容積に対して１．０〜１．２の範囲に裁断して、金型内に挿入する。金型の型締め圧力は３０〜３００ｋｇｆ／ｃｍ２、保持時間１０〜９０分の条件下で、一次発泡体（非架橋または架橋発泡体）を作製する。ただし、（架橋）時間については、金型の厚さに依存するため、この範囲を超えて、適宜増減され得る。
【００７８】
上記（架橋）発泡用金型は、その形状は特に制限はされないが、通常シートが得られるような形状を有している金型が用いられる。この金型は、溶融樹脂および発泡剤分解時に発生するガスが抜けないように、完全に密閉された構造とする必要がある。また、型枠としては、内面にテーパーが付いている型枠が樹脂の離型性の面から好ましい。
【００７９】
上記方法により得られた一次発泡体を、圧縮成形により所定の形状の付与を行なう。このときの圧縮成形条件は、金型温度が１３０〜２００℃、型締め圧力が３０〜３００ｋｇｆ／ｃｍ２、圧縮時間が５〜６０分、圧縮比が１．１〜３．０の範囲である。
【００８０】
また、電離性放射線照射による架橋方法により架橋発泡体を得るには、まず、グラフト変性エチレン・α−オレフィン共重合体（Ａ）、無機金属化合物（Ｂ）と、発泡剤（Ｃ）として有機系熱分解型発泡剤と、他の添加剤とを、有機系熱分解型発泡剤の分解温度未満の温度で溶融混練し、得られた混練物をたとえばシート状に成形し、発泡性シートを得る。
【００８１】
次いで、得られた発泡性シートに電離性放射線を所定量照射してグラフト変性エチレン・α−オレフィン共重合体Ａ）と無機金属化合物（Ｂ）とを架橋させた後、得られた発泡性の架橋シートを有機系熱分解型発泡剤の分解温度以上に加熱して発泡させることによって、架橋発泡シートを得ることができる。
【００８２】
電離性放射線としては、α線、β線、γ線、電子線、中性子線、Ｘ線などが用いられる。このうちコバルト−６０のγ線、電子線が好ましく用いられる。
【００８３】
発泡体の製品形状としては、たとえばシート状、厚物ボード状、ネット状、型物などが挙げられる。
【００８４】
上記のようにして得られた架橋発泡体から、上述した二次発泡体の製造方法と同様にして、上記物性を有する二次架橋発泡体を調製することができる。
【００８５】
積層体
本発明に係る積層体は、上記した、本発明に係る発泡体（非架橋または架橋発泡体）からなる層と、ポリオレフィン、ポリウレタン、ゴム、皮革および人工皮革からなる群から選ばれる少なくとも一種の素材からなる層とを有する積層体である。
【００８６】
上記のポリオレフィン、ポリウレタン、ゴム、皮革および人工皮革は、特に制限はなく、従来公知のポリオレフィン、ポリウレタン、ゴム、皮革、人工皮革を用いることができる。このような積層体は、特に履き物ないし履き物用部品の用途に好適である。
【００８７】
履き物ないし履き物用部品
本発明に係る履き物ないし履き物用部品は、上記した、本発明に係る発泡体（非架橋または架橋発泡体）または積層体からなる。
【００８８】
履き物用部品としては、たとえば靴底、靴のミッドソール、インナーソール、ソール、サンダルなどが挙げられる。
【００８９】
【発明の効果】
本発明によれば、低比重で圧縮永久歪み（ＣＳ）が小さく、しかも、引裂強度特性および反撥弾性に優れた発泡体（非架橋および架橋発泡体）を提供し得る組成物、その発泡体（二次圧縮発泡体も含む）、およびその発泡体を用いた積層体を提供することができる。
【００９０】
また、本発明によれば、上記非架橋もしくは架橋発泡体または上記積層体からなる履き物ないし履き物用部品たとえば靴底、靴のミッドソール、靴のインナーソール、サンダルを提供することができる。
【００９１】
【実施例】
なお、実施例および比較例で用いたグラフト変性エチレン・α−オレフィン共重合体（Ａ）および／またはグラフト変性前のエチレン・α−オレフィン共重合体の密度、ＭＦＲ、Ｂ値、Ｔαβ強度比、分子量分布（Ｍｗ／Ｍｎ）また、実施例および比較例で得られた架橋発泡体について、比重、圧縮永久歪み、引裂強度、アスカーＣ硬度（表面硬度）および反発弾性を下記の方法に従って測定した。グラフト変性エチレン・α−オレフィン共重合体（Ａ）および／またはグラフト変性前のエチレン・α−オレフィン共重合体の物性評価
（１）密度
密度は、ＡＳＴＭ Ｄ１５０５に従い、２３℃にて求めた。
（２）ＭＦＲ
ＭＦＲは、ＡＳＴＭ Ｄ１２３８に従い、１９０℃および２３０℃にて求めた。１９０℃，２．１６ｋｇ荷重での測定値をＭＦＲ２、１９０℃，１０ｋｇ荷重での測定値をＭＦＲ１０とした。
【００９２】
グラフト変性前のエチレン・α−オレフィン共重合体の物性評価
（３）Ｂ値、Ｔαβ強度比
１３Ｃ−ＮＭＲにより求めた。
（４）分子量分布（Ｍｗ／Ｍｎ）
ゲルパーミエーションクロマトグラフにより、オルトジクロロベンゼン溶媒、１４０℃にて求めた。
【００９３】
架橋発泡体の物性評価
（１）比重
比重は、ＪＩＳ Ｋ７２２２に従って測定した。
（２）圧縮永久歪み
ＪＩＳ Ｋ６３０１に従って、５０℃×６時間、圧縮量５０％の条件で圧縮永久歪み試験を行い、圧縮永久歪み（ＣＳ）を求めた。
（３）引裂強度
ＢＳ５１３１−２．６に従って、引張速度１０ｍｍ／分の条件で引裂強度試験を行い、引裂強度を求めた。
（４）アスカーＣ硬度
アスカーＣ硬度は、ＪＩＳ Ｋ７３１２−１９９６付属書２記載の「スプリング硬さ試験タイプＣ試験方法」に従って求めた。
（５）反発弾性
反発弾性は、ＪＩＳ Ｋ６２５５に従って測定した。
【００９４】
【製造例】
特開２００３−０７３４９４号公報実施例に準じた方法でメタロセン触媒を用いてエチレン・１−ブテン共重合体（Ｓ−１）を製造した。エチレン・１−ブテン共重合体（Ｓ−１）の性状を表１に示す。
【００９５】
【表１】

【００９６】
［グラフト変性エチレン・１−ブテン共重合体（Ａ−１）の調製］
上記エチレン・１−ブテン共重合体（Ｓ−１）１０ｋｇと、無水マレイン酸５０ｇおよびジ―ｔｅｒｔ−ブチルペルオキシド３ｇを３０ｇのアセトンに溶解させた溶液とをヘンシェルミキサー中でブレンドした。
【００９７】
次に、上記ブレンド物をスクリュー径４０ｍｍ、Ｌ／Ｄ＝２６の１軸押出機のホッパーより投入し、樹脂温２８０℃、押出量６ｋｇ／ｈでストランド状に押出して水冷した後、ペレタイズしてグラフト変性エチレン・１−ブテン共重合体（Ａ−１）を製造した。
【００９８】
得られたグラフト変性エチレン・１−ブテン共重合体（Ａ−１）から未反応の無水マレイン酸をアセトンで抽出後、得られたグラフト変性エチレン・１−ブテン共重合体（Ａ−１）中における無水マレイン酸グラフト量を測定したところ、グラフト量は０．９０重量％であり、密度は８８５ｋｇ／ｍ^３、２３０℃， ２．１６ｋｇ荷重でのＭＦＲは５．０ｇ／１０ｍｉｎであった。
【００９９】
【実施例１】
グラフト変性エチレン・１−ブテン共重合体（Ａ−１）９７重量部、酸化亜鉛（Ｂ−１）３重量部［ここで、（Ａ−１）＋（Ｂ−１）＝１００重量部］、ジクミルペルオキシド（ＤＣＰ）０．６重量部、トリアリルイソシアヌレート（ＴＡＩＣ）［商品名 Ｍ−６０（ＴＡＩＣ含有量６０％）、日本化成（株）製］０．０９重量部（ＴＡＩＣ含量として）、アゾジカルボンアミド４．０重量部、ステアリン酸１．０重量部からなる混合物を、ロールにより、ロール表面温度１２０℃で１０分間混練した後、シート状に成形した。
【０１００】
得られたシートは、プレス金型に充填し、１５０ｋｇ／ｃｍ^２、１５５℃、３０分の条件で、加圧、加熱し、一次架橋発泡体を得た。このプレス金型のサイズは、厚み１５ｍｍ、縦１５０ｍｍ、横２００ｍｍであった。
【０１０１】
次いで、この一次架橋発泡体を、１５０ｋｇ／ｃｍ^２、１５５℃の条件で１０分間圧縮成形を行い、二次架橋発泡体を得た。得られた二次架橋発泡体のサイズは、厚み１５ｍｍ、縦１６０ｍｍ、２５０ｍｍであった。
【０１０２】
次いで、この二次架橋発泡体の比重、圧縮永久歪み、引裂強度、アスカーＣ硬度、反発弾性を上記方法に従って測定した。その結果を表２に示す。
【０１０３】
【比較例１】
実施例１において、グラフト変性エチレン・１−ブテン共重合体（Ａ−１）９７重量部からエチレン・１−ブテン共重合体（Ｓ−１）９７重量部に変更した以外は、実施例１と同様にして二次架橋発泡体を調製し、物性測定を行った。その結果を表２に示す。
【０１０４】
【表２】

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a composition and use thereof. More specifically, the present invention relates to a foam (non-crosslinked and cross-linked foam) having low specific gravity, small permanent compression strain (CS), and excellent tensile strength characteristics, tear strength characteristics, and rebound resilience. ) And a foam thereof.
[0002]
TECHNICAL BACKGROUND OF THE INVENTION
In order to obtain a low specific gravity, that is, lightweight, flexible, and high mechanical strength resin, the technology using cross-linked foam is widely applied to interior / exterior materials, interior parts, automotive parts such as door glass runs, packaging materials, daily necessities, etc. It is used. This is because if the resin is only foamed for weight reduction, the mechanical strength is reduced, so the molecular chain is bonded by the resin crosslinking reaction to reduce the mechanical strength while reducing the weight. It is possible to achieve this.
[0003]
In addition, cross-linked foam of resin is also used for footwear or footwear parts such as sports shoes (mainly midsole), but this is lightweight and suppresses deformation due to long-term use, This is because there is a demand for a material having mechanical strength and rebound resilience that can withstand severe use conditions.
[0004]
Conventionally, a cross-linked foam of ethylene / vinyl acetate copolymer has been used and widely known for shoe soles, but a cross-linked foam molded using this ethylene / vinyl acetate copolymer composition is Since the specific gravity is high and the compression set is large, for example, when used for a shoe sole, there is a problem that the shoe sole is compressed by long-term use and mechanical strength such as rebound resilience is lost. .
[0005]
JP-A-9-501447 and JP-A-11-206406 disclose a crosslinked foam using an ethylene / α-olefin copolymer, an ethylene / vinyl acetate copolymer and an ethylene / α-olefin copolymer. Although the inventions relating to the crosslinked foams using the mixture with each other are described, in these inventions, the low specific gravity and compression set resistance are improved, but sufficient performance is not obtained. Japanese Patent Laid-Open No. 2000-344925 describes an invention related to a crosslinked foam using a mixture of an ethylene / α-olefin copolymer and a graft-modified ethylene / α-olefin copolymer. Although the adhesive strength is improved, sufficient performance is not obtained with respect to tensile strength characteristics, tear strength characteristics, and impact resilience. Accordingly, an elastomer composition for an olefin elastomer foam capable of providing an olefin elastomer foam having a low specific gravity, a small compression set (CS), and excellent in tensile strength characteristics, tear strength characteristics and rebound resilience, and the foam The appearance of is desired. (Patent Documents 1 to 3)
[0006]
[Patent Document 1] Japanese Patent Publication No. 9-501447
[0007]
[Patent Document 2] JP-A-11-206406
[0008]
[Patent Document 3] Japanese Unexamined Patent Publication No. 2000-344925
[0009]
OBJECT OF THE INVENTION
An object of the present invention is to solve the problems associated with the prior art as described above, and has a low specific gravity, a small permanent compression strain (CS), and a tensile strength property, a tear strength property, a rebound resilience and an adhesion. It aims at providing the composition which can provide the foam (non-crosslinked and crosslinked foam) excellent in property, the foam, and the laminated body using the foam.
Another object of the present invention is to provide a footwear component comprising a foam or laminate, for example, a shoe sole, a shoe midsole, a shoe inner sole, or a sandal.
[0010]
Summary of the Invention
The composition according to the present invention comprises:
Graft-modified ethylene / α-olefin copolymer (A), inorganic metal compound (B) and foaming agent (C) are contained, and graft-modified ethylene / α-olefin copolymer (A) 70 to 99. 9% by weight, inorganic metal compound (B) 30 to 0.1% by weight (here, the total amount of (A) and (B) is 100% by weight) and foaming agent (C) It is a composition characterized by these.
[0011]
The graft-modified ethylene / α-olefin copolymer (A) grafts an unsaturated carboxylic acid or a derivative thereof to an ethylene / α-olefin copolymer composed of ethylene and an α-olefin having 3 to 20 carbon atoms. The graft-modified ethylene / α-olefin copolymer (A) has the following properties.
(I) the density (ASTM D1505, 23 ° C.) is in the range of 0.857 to 0.915 g / cm 3;
(Ii) Melt flow rate at 230 ° C. and 2.16 kg load (MFR2)
(ASTM D1238, load 2.16 kg, 190 ° C.) is in the range of 0.01 to 40 g / 10 minutes,
(Iii) Index of molecular weight distribution evaluated by GPC method: Mw / Mn is in the range of 1.5 to 3.5.
[0012]
The ethylene / α-olefin copolymer before graft modification of the graft-modified ethylene / α-olefin copolymer (A) has the following properties.
(Iv) The density (ASTM D1505, 23 ° C.) is in the range of 0.857 to 0.915 g / cm 3,
(V) Melt flow rate (MFR2) at 230 ° C. and 2.16 kg load
(ASTM D1238, load 2.16 kg, 190 ° C.) is in the range of 0.01 to 80 g / 10 minutes,
(Vi) Index of molecular weight distribution evaluated by GPC method: Mw / Mn is in the range of 1.5 to 3.5.
[0013]
The graft-modified ethylene / α-olefin copolymer (A) and / or the ethylene / α-olefin copolymer before graft modification have the following properties.
(Vii) 190 ° C. with a melt flow rate (MFR10) at 10 kg load
Ratio with melt flow rate (MFR2) at 190 ° C. and 2.16 kg load: MFR10 / MFR2 satisfies the following formula:
MFR10 / MFR2 ≧ 6.0
Mw / Mn + 5.0 ≦ MFR10 / MFR2
(Viii) The intensity ratio of Tαβ to Tαα (Tαβ / Tαα) in the 13C-NMR spectrum is 0.5 or less,
(Ix) B value calculated | required from a 13C-NMR spectrum and following General formula (1) is 0.9-1.5.
B value = [POE] / (2 · [PE] [PO]) (1)
(Wherein [PE] is the mole fraction of structural units derived from ethylene in the copolymer, and [PO] is the mole fraction of structural units derived from α-olefin in the copolymer. And [POE] is the ratio of the number of ethylene / α-olefin chains to the total number of dyad chains in the copolymer).
[0014]
The graft-modified ethylene / α-olefin copolymer (A) is a graft-modified ethylene / 1-butene copolymer.
[0015]
The foaming agent (C) is a composition characterized in that it is selected from an organic pyrolytic foaming agent, an inorganic pyrolytic foaming agent, an organic physical foaming agent, and an inorganic physical foaming agent.
[0016]
Moreover, it is a foam obtained by heat-processing the said composition.
The foam is obtained by secondary compression of the foam.
Moreover, it is a laminated body characterized by having the layer which consists of said foam, and the layer which consists of at least 1 type of material chosen from the group which consists of polyolefin, a polyurethane, rubber | gum, leather, and artificial leather.
The footwear or footwear component is characterized by comprising the foam or the laminate.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the composition according to the present invention and its use will be specifically described. The composition according to the present invention comprises a graft-modified ethylene / α-olefin copolymer (A), an inorganic metal compound (B), a foaming agent (C), an organic peroxide (D), and a crosslinking aid (E ) And.
[0018]
The foam according to the present invention is obtained by foaming or cross-linking foaming this composition.
Examples of the crosslinking method include thermal crosslinking and ionizing radiation crosslinking. In the case of thermal crosslinking, it is necessary to mix an organic peroxide (D) and, if necessary, a crosslinking aid (E) in this composition. In the case of ionizing radiation crosslinking, a crosslinking aid may be blended.
[0019]
Graft-modified ethylene / α-olefin copolymer (A)
The graft-modified ethylene / α-olefin copolymer (A) used in the present invention is an amorphous or low crystalline random or block copolymer comprising ethylene and an α-olefin having 3 to 20 carbon atoms. A graft modified product obtained by grafting an unsaturated carboxylic acid or a derivative thereof.
[0020]
The graft-modified ethylene / α-olefin copolymer (A) has a density (ASTM D 1505) of 0.857 g / cm 3 or more and 0.915 g / cm 3 or less, preferably 0.860 to 0.905 g / cm 3, more preferably. Is 0.880-0.905 g / cm3, and melt flow rate (MFR; ASTM D 1238, 230 ° C., load 2.16 kg) is 0.01-40 g / 10 min, preferably 0.05-20 g / A graft-modified soft ethylene / α-olefin copolymer of 10 minutes, more preferably 0.1 to 10 g / 10 minutes is desirable.
[0021]
The α-olefin copolymerized with ethylene is an α-olefin having 3 to 20 carbon atoms, specifically, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, Examples include 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-hexadecene, 1-octadecene, 1-nonadecene, 1-eicocene, 4-methyl-1-pentene, and the like. Of these, α-olefins having 3 to 10 carbon atoms are preferable, and propylene, 1-butene, 1-hexene, and 1-octene are particularly preferable. These α-olefins are used alone or in combination of two or more.
[0022]
In addition, the graft-modified ethylene / α-olefin copolymer (A) contains 75 to 95 mol% of units derived from ethylene and 5 to 25 units derived from α-olefin having 3 to 20 carbon atoms. Units derived from ethylene, preferably in units of 79 to 94% by mole, units derived from α-olefins of 3 to 20 carbon atoms in amounts of 6 to 21% by mole, more preferably It is desirable to contain units derived from ethylene in an amount of 88 to 94 mol% and units derived from an α-olefin having 3 to 20 carbon atoms in an amount of 6 to 12 mol%.
[0023]
The graft-modified ethylene / α-olefin copolymer (A) may contain units derived from other polymerizable monomers in addition to these units as long as the object of the present invention is not impaired. .
[0024]
Specific examples of the graft-modified ethylene / α-olefin copolymer (A) include a graft-modified ethylene / propylene copolymer, a graft-modified ethylene / 1-butene copolymer, and a graft-modified ethylene / propylene / 1-butene. Examples include copolymers, graft-modified ethylene / propylene / ethylidene norbornene copolymers, graft-modified ethylene / 1-hexene copolymers, and graft-modified ethylene / 1-octene copolymers. Among these, a graft-modified ethylene / propylene copolymer, a graft-modified ethylene / 1-butene copolymer, a graft-modified ethylene / 1-hexene copolymer, a graft-modified ethylene / 1-octene copolymer and the like are preferably used. In particular, a graft-modified ethylene / 1-butene copolymer is preferably used. These copolymers are random or block copolymers, but are preferably random copolymers.
[0025]
The graft-modified ethylene / α-olefin copolymer (A) has a crystallinity measured by an X-ray diffraction method of usually 40% or less, preferably 30% or less.
[0026]
The graft-modified ethylene / α-olefin copolymer (A) has a molecular weight distribution (Mw / Mn) determined by gel permeation chromatography (GPC) of 1.5 to 3.0, preferably 1. It is preferable that it exists in the range of 7-2.5. A composition capable of preparing a foam excellent in compression set and shapeability by using a graft-modified ethylene / α-olefin copolymer (A) having a molecular weight distribution (Mw / Mn) within the above range. Is obtained. The graft-modified ethylene / α-olefin copolymer (A) as described above usually exhibits properties as an elastomer.
[0027]
The melt flow rate of the graft-modified ethylene / α-olefin copolymer (A) and / or the ethylene / α-olefin copolymer before graft modification measured at 190 ° C. under a load of 10 kg in accordance with ASTM D 1238 The ratio (MFR10 / MFR2.16) between the melt flow rate (MFR2.16) measured under the condition of (MFR10) and the load of 2.16 kg is the following formula:
MFR10 / MFR2.16 ≧ 6.0
Preferably 7 ≦ MFR10 / MFR2.16 ≦ 15
And the molecular weight distribution (Mw / Mn) and the melt flow rate ratio are
Mw / Mn + 5.0 <MFR10 / MFR2.16
If the above relationship is satisfied, a composition (non-crosslinked foam, cross-linked foam) having a high expansion ratio, that is, a low specific gravity, high elasticity, excellent compression set and shapeability can be prepared. Things are obtained.
[0028]
The graft-modified ethylene / α-olefin copolymer (A) of the present invention and / or the ethylene / α-olefin copolymer before graft modification has a strength ratio (Tαβ / Tαα) of Tαβ to Tαα of 13C-NMR spectrum of 0. 0.5 or less, preferably 0.4 or less.
[0029]
Here, Tαα and Tαβ in the 13C-NMR spectrum are peak intensities of CH2 in the structural unit derived from an α-olefin having 3 or more carbon atoms, and two types having different positions relative to the tertiary carbon as shown below. Means CH2.
[0030]
[Chemical 1]

[0031]
Such a Tαβ / Tαα intensity ratio can be obtained as follows. The 13C-NMR spectrum of the graft-modified ethylene / α-olefin copolymer and / or the ethylene / α-olefin copolymer before graft modification is measured using, for example, JEOL-GX270 NMR measuring apparatus manufactured by JEOL Ltd. . The measurement is performed using a mixed solution of hexachlorobutadiene / d6-benzene = 2/1 (volume ratio) adjusted to a sample concentration of 5% by weight, based on 67.8 MHz, 25 ° C., d6-benzene (128 ppm). To do. The measured 13C-NMR spectrum was analyzed by Lindeman Adams's proposal (Analysis Chemistry 43, p1245 (1971)), J. Am. C. Analysis is performed according to Randall (Review Macromolecular Chemistry Physics, C29, 201 (1989)) to determine the Tαβ / Tαα intensity ratio.
[0032]
Further, the graft-modified ethylene / α-olefin copolymer (A) and / or the ethylene / α-olefin copolymer before graft modification of the present invention has a B value determined from a 13C-NMR spectrum and the following general formula (1). It is preferably 0.9 to 1.5.
B value = [POE] / (2 · [PE] [PO]) (1)
(Wherein [PE] is the mole fraction of structural units derived from ethylene in the copolymer, and [PO] is the mole fraction of structural units derived from α-olefin in the copolymer. [POE] is the ratio of the number of graft-modified ethylene / α-olefin and / or the number of ethylene / α-olefin chains before graft modification to the total dyad chains in the copolymer). Is an index representing a distribution state of ethylene and an α-olefin having 3 to 10 carbon atoms in the graft-modified ethylene / α-olefin copolymer and / or the ethylene / α-olefin copolymer before graft modification, J. et al. C. Randall (Macromolecules, 15, 353 (1982)), J. Am. Ray (Macromolecules, 10, 773 (1977)) and the like.
[0033]
As the B value is larger, the block chain of ethylene or α-olefin copolymer becomes shorter, the distribution of ethylene and α-olefin is more uniform, and the composition distribution of the copolymer rubber is narrower. In addition, the composition distribution in the graft-modified ethylene / α-olefin copolymer and / or the ethylene / α-olefin copolymer before the graft modification becomes smaller than 1.0, and the handleability deteriorates. There are bad points.
[0034]
The ethylene / α-olefin copolymer before graft modification as described above can be produced by a conventionally known method using a vanadium catalyst, a titanium catalyst or a metallocene catalyst.
[0035]
The graft-modified ethylene / α-olefin copolymer (A) used in the present invention is obtained by grafting a specific amount of unsaturated carboxylic acid or a derivative thereof onto the ethylene / α-olefin copolymer before graft modification. Can be obtained.
The graft amount of the unsaturated carboxylic acid or derivative thereof in the graft-modified ethylene / α-olefin copolymer (A) used in the present invention is 0 with respect to 100% by weight of the unmodified ethylene / α-olefin random copolymer. 0.1 to 4.0% by weight, preferably 0.5 to 2.5% by weight.
[0036]
The graft-modified ethylene / α-olefin copolymer (A) having this graft amount in the above range is excellent in dispersibility in the composition and excellent in thermal stability, and the resin is not colored when melted. In addition, when such a graft-modified ethylene / α-olefin copolymer (A) is used, a composition capable of providing a crosslinked foam having excellent mechanical strength can be obtained.
[0037]
Specific examples of the unsaturated carboxylic acid used in the modification include acrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid and nadic acid.^TM(Endocis-bicyclo [2,2,1] hept-5-ene-2,3-dicarboxylic acid) and the like.
[0038]
Specific examples of the unsaturated carboxylic acid derivative include acid halide compounds, amide compounds, imide compounds, acid anhydrides and ester compounds of the above unsaturated carboxylic acids. More specifically, maleyl chloride, maleimide, maleic anhydride, citraconic anhydride, monomethyl maleate, dimethyl maleate, glycidyl maleate and the like can be mentioned. Of these, unsaturated dicarboxylic acids or acid anhydrides thereof are preferred, particularly maleic acid and nadic acid.^TMOr these acid anhydrides are suitable.
[0039]
The graft-modified ethylene / α-olefin copolymer (A) as described above can be prepared by using various conventionally known methods, for example, the following methods.
(1) A method in which an unsaturated carboxylic acid or a derivative thereof is added to the molten unmodified ethylene / α-olefin copolymer (before modification) and graft copolymerized.
(2) A method in which the unmodified ethylene / α-olefin copolymer (before modification) is dissolved in a solvent, and an unsaturated carboxylic acid or a derivative thereof is added to the solution to perform graft copolymerization.
[0040]
In any method, in order to efficiently graft copolymerize the graft monomer such as the unsaturated carboxylic acid, the graft reaction is preferably performed in the presence of a radical initiator.
[0041]
As the radical initiator, organic peroxides, azo compounds and the like are used. Specific examples of such radical initiators include benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di (peroxide benzoate) hexyne- 3,1,4-bis (tert-butylperoxyisopropyl) benzene, lauroyl peroxide, tert-butylperacetate, 2,5-dimethyl-2,5-di- (tert-butylperoxide) hexyne-3,2,5 -Dimethyl-2,5-di (tert-butylperoxide) hexane, tert-butylperbenzoate, tert-butylperphenylacetate, tert-butylperisobutyrate, tert-butylper-sec-octoate, t rt- butyl perpivalate, cumyl perpivalate, tert- butyl organic peroxides such as hydroperoxide diethyl acetate; azobisisobutyronitrile, azo compounds such as dimethyl azoisobutyrate, and the like. Among these, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexyne-3, 2,5-dimethyl-2,5-di (tert -Dialkyl peroxides such as butylperoxy) hexane and 1,4-bis (tert-butylperoxyisopropyl) benzene are preferably used.
[0042]
These radical initiators are usually 0.01 to 0.10 parts by weight, preferably 0.02 to 0.08 parts per 100 parts by weight of the unmodified ethylene / α-olefin copolymer (before modification). It is used in an amount of parts by weight, more preferably 0.02 to 0.05 parts by weight.
[0043]
The reaction temperature in the grafting reaction using the radical initiator as described above or in the grafting reaction performed without using the radical initiator is usually set in the range of 60 to 350 ° C, preferably 150 to 300 ° C.
[0044]
The graft-modified ethylene / α-olefin copolymer (A) as described above may be a mixture of unmodified ethylene / α-olefin copolymer, or other ethylene-based polymer such as high-pressure low-density polyethylene. It may be a mixture with coalescence.
Inorganic metal compound (B)
The inorganic metal compound (B) used in the present invention includes oxides, hydroxides, phosphates, carbonates, and carboxylic acids of metals of Groups II, III, IV, VI, and VII of the Periodic Table of Elements. You can choose from salt. Preferably, an oxide of zinc or aluminum is used.
[0045]
These inorganic metal compounds (B) are usually 0.1 to 30% by weight, preferably 0 as the total amount of the graft-modified ethylene / α-olefin copolymer (A) and the inorganic metal compound (B) is 100% by weight. It is used in an amount of 5 to 10% by weight, more preferably 0.5 to 5% by weight. When the inorganic metal compound (B) is within the above range, a crosslinked foam having high strength and high resilience can be provided.
Foaming agent (C)
As the foaming agent (C) used in the present invention, a chemical foaming agent, specifically, azodicarbonamide (ADCA), 1,1′-azobis (1-acetoxy-1-phenylethane), dimethyl-2, 2′-azobisbutyrate, dimethyl-2,2′-azobisisobutyrate, 2,2′-azobis (2,4,4-trimethylpentane), 1,1′-azobis (cyclohexane-1-carbohydrate) Nitrile), azo compounds such as 2,2′-azobis [N- (2-carboxyethyl) -2-methyl-propionamidine]; nitroso compounds such as N, N′-dinitrosopentamethylenetetramine (DPT); 4 , 4′-oxybis (benzenesulfonylhydrazide), hydrazine derivatives such as diphenylsulfone-3,3′-disulfonylhydrazide; p-tolue Semicarbazide compounds such as sulfonyl semicarbazide; organic thermal decomposition foaming agents such as trihydrazinotriazine; bicarbonates such as sodium bicarbonate and ammonium bicarbonate; carbonates such as sodium carbonate and ammonium carbonate; ammonium nitrite and the like Inorganic pyrolytic foaming agents such as nitrites and hydrogen compounds. Of these, azodicarbonamide (ADCA) and sodium hydrogen carbonate are particularly preferable.
[0046]
In the present invention, physical foaming agents (foaming agents not necessarily accompanied by chemical reaction during foaming), for example, various aliphatic hydrocarbons such as methanol, ethanol, propane, butane, pentane and hexane; dichloroethane, dichloromethane, tetrachloride Various chlorohydrocarbons such as carbon; organic physical foaming agents such as various fluorinated chlorohydrocarbons such as chlorofluorocarbons, and inorganic physical foaming agents such as air, carbon dioxide, nitrogen, argon, and water. ). Among these, carbon dioxide, nitrogen, and argon are the most excellent because they do not need to be vaporized, are inexpensive, and have a very low possibility of environmental pollution and ignition.
[0047]
Since the physical foaming agent used as the foaming agent (C) in the present invention has no decomposition residue of the foaming agent, it is possible to prevent mold contamination during the crosslinking and foaming of the composition. In addition, since the physical foaming agent is not in powder form, it has excellent kneadability. In addition, when this physical foaming agent is used, it is possible to prevent off-flavors (such as ammonia odor generated during ADCA decomposition) of the resulting crosslinked foam.
[0048]
In the present invention, a chemical foaming agent such as steam can be used in combination as long as no adverse effects such as odor and mold contamination occur.
[0049]
As a physical foaming agent storage method, for small-scale production, carbon dioxide, nitrogen, etc. can be used in a cylinder and supplied to an injection molding machine and an extrusion molding machine through a pressure reducing valve. In some cases, the pressure is increased by a pump or the like and supplied to an injection molding machine, an extrusion molding machine, or the like.
[0050]
In addition, if it is a facility that manufactures foamed products on a large scale, a storage tank for liquefied carbon dioxide, liquefied nitrogen, etc. is installed, passed through a heat exchanger, vaporized, piping, injection molding machine and extrusion molding machine with a pressure reducing valve Etc.
[0051]
In the case of a liquid physical foaming agent, the storage pressure is preferably in the range of 0.13 to 100 MPa. If the pressure is too low, the pressure cannot be reduced and cannot be injected into an injection molding machine or an extrusion molding machine. If it is too high, the pressure resistance strength of the storage equipment needs to be increased, which makes the equipment larger and complicated, which is not preferable. The storage pressure defined here refers to the pressure that is vaporized and supplied to the pressure reducing valve.
[0052]
Composition
The composition according to the present invention comprises a graft-modified ethylene / α-olefin copolymer (A), an inorganic metal compound (B) and a foaming agent (C),
Ethylene / α-olefin copolymer (A) 70-99.9% by weight, preferably 90-99.5% by weight, more preferably 95-99.5% by weight, inorganic metal compound (B) 30-0. 1% by weight, preferably 10 to 0.5% by weight, more preferably 5 to 0.5% by weight (wherein the total amount of (A) and (B) is 100% by weight).
[0053]
When a chemical foaming agent is used as the foaming agent (C), the chemical foaming agent is usually 2 to 20 with respect to 100 parts by weight of the graft-modified ethylene / α-olefin copolymer (A) + inorganic metal compound (B). Part by weight, preferably 3 to 15 parts by weight is used. However, the amount of the chemical foaming agent used can be appropriately increased or decreased depending on the target foaming ratio because the amount of generated gas varies depending on the type and grade of the foaming agent used.
[0054]
Moreover, when using a physical foaming agent as a foaming agent (C), the addition amount of a physical foaming agent is suitably determined according to the desired expansion ratio.
[0055]
In this invention, you may use a foaming adjuvant with a foaming agent (C) as needed. The foaming auxiliary agent acts to lower the decomposition temperature of the foaming agent (C), accelerate the decomposition, and make the bubbles uniform. Examples of such foaming assistants include organic acids such as salicylic acid, phthalic acid, stearic acid, and oxalic acid, urea, and derivatives thereof.
[0056]
Organic peroxide (D)
Specific examples of the organic peroxide (D) used as a crosslinking agent in the present invention include dicumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-di- (t -Butylperoxy) hexane, 2,5-dimethyl-2,5-di- (t-butylperoxy) hexyne-3, 1,3-bis (t-butylperoxyisopropyl) benzene, 1,1-bis (t- Butylperoxy) -3,3,5-trimethylcyclohexane, n-butyl-4,4-bis (t-butylperoxy) valerate, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, t-butyl Peroxybenzoate, t-butyl perbenzoate, t-butyl peroxyisopropyl carbonate Nate, diacetyl peroxide, lauroyl peroxide, t-butylcumyl peroxide and the like.
[0057]
In the present invention, the organic peroxide (D) is usually 0.1 to 1.5 parts by weight with respect to 100 parts by weight of the graft-modified ethylene / α-olefin copolymer (A) + inorganic metal compound (B), Preferably it is used in a proportion of 0.2 to 1.0 part by weight. When the organic peroxide (D) is used in the above ratio, a crosslinked foam having an appropriate crosslinked structure can be obtained. Moreover, when an organic peroxide (D) is used in the above ratio together with the crosslinking assistant (E), a crosslinked foam having a more appropriate crosslinked structure can be obtained.
[0058]
Crosslinking aid (E)
Specific examples of the crosslinking aid (E) used as necessary in the present invention include sulfur, p-quinonedioxime, p, p′-dibenzoylquinonedioxime, and N-methyl-N-4-. Peroxy crosslinking aids such as dinitrosoaniline, nitrosobenzene, diphenylguanidine, trimethylolpropane-N, N′-m-phenylenedimaleimide; or divinylbenzene, triallyl cyanurate (TAC), triallyl isocyanurate ( TAIC) is preferred. Also listed are polyfunctional methacrylate monomers such as ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, and allyl methacrylate, and polyfunctional vinyl monomers such as vinyl butyrate and vinyl stearate. It is done. Of these, triallyl cyanurate (TAC) and triallyl isocyanurate (TAIC) are preferable.
[0059]
In the present invention, the crosslinking aid (E) as described above has a weight ratio [(E) / (D)] of the crosslinking aid (E) to the organic peroxide (D) of 1/30 to 5/1. The amount is preferably 1/20 to 3/1, more preferably 1/15 to 2/1.
[0060]
Preparation of resin composition
The resin composition according to the present invention is an uncrosslinked and unfoamed composition, and may be in a molten state, or may be a pellet or a sheet that has been cooled and solidified.
[0061]
The pellet of the resin composition according to the present invention includes, for example, the graft-modified ethylene / α-olefin copolymer (A), the inorganic metal compound (B), the foaming agent (C), and, if necessary, an organic peroxide. (D), the crosslinking aid (E), and the foaming aid are mixed in a Henschel mixer or the like in the above ratio, and the foaming agent (C) and / or the organic peroxide is mixed in a kneader such as a Banbury mixer, roll, or extruder. It can be melt-plasticized at a temperature at which (D) does not decompose, uniformly mixed and dispersed, and prepared by a granulator.
[0062]
The amount of the foaming agent (C) used is determined in consideration of the expansion ratio of the foam.
[0063]
The composition of the present invention optionally contains a crosslinking agent or a crosslinking aid. Examples of the crosslinking agent include organic peroxides. The crosslinking agent is usually 0.1 to 1.5 parts by weight based on 100 parts by weight of the total amount of the graft-modified ethylene / α-olefin copolymer (A), inorganic metal compound (B) and foaming agent (C). The ratio is preferably 0.2 to 1.0 parts by weight.
[0064]
In this composition, in addition to the above-mentioned components, various additives such as fillers, heat stabilizers, weather stabilizers, flame retardants, hydrochloric acid absorbents, pigments, etc., as needed, do not impair the purpose of the present invention. It can mix | blend in the range.
[0065]
Moreover, the sheet | seat of the composition which concerns on this invention can prepare the pellet of the composition obtained as mentioned above, for example using an extruder or a calendering machine. Alternatively, the components of the composition are kneaded with a Brabender or the like, then formed into a sheet with a calender roll, formed into a sheet with a press molding machine, or kneaded with an extruder and then passed through a T die or an annular die. An uncrosslinked and unfoamed foamable sheet can be prepared by a method of converting to a non-crosslinked manner.
[0066]
Foam
The foam according to the present invention is obtained by foaming or cross-linking foaming the resin composition according to the present invention as described above, usually under conditions of 130 to 200 ° C., 30 to 300 kgf / cm 2 and 10 to 90 minutes. Obtained by foaming. However, since the (crosslinking) foaming time depends on the thickness of the mold, it can be appropriately increased or decreased beyond this range.
[0067]
In addition, the foam according to the present invention is a molded body foamed or crosslinked and foamed under the above conditions at 130 to 200 ° C., 30 to 300 kgf / cm 2, 5 to 60 minutes, compression ratio 1.1 to 3, preferably It may be a foam obtained by compression molding under the conditions of 1.3 to 2.
[0068]
These foams have a specific gravity (JIS K7222) of 0.05 to 0.25. The cross-linked foam preferably has a gel fraction of 70% or more, and is usually 70 to 90%.
[0069]
The foam according to the present invention, particularly the crosslinked foam, having such physical properties has characteristics such as low compression set, high tear strength, and high rebound resilience.
[0070]
In addition, the said gel fraction (gel content; xylene insoluble matter) is measured as follows.
[0071]
A sample of the crosslinked foam was weighed and cut into small pieces, and then the obtained pieces were put together with xylene in a sealed container and refluxed for 3 hours.
[0072]
Next, this sample was taken out on a filter paper and allowed to dry completely. A value obtained by subtracting the weight of the xylene-insoluble component (for example, filler, filler, pigment, etc.) other than the polymer component from the weight of the dry residue is referred to as “corrected final weight (Y)”.
[0073]
On the other hand, the value obtained by subtracting the weight of the xylene-soluble component (eg, stabilizer) other than the polymer component and the weight of the xylene-insoluble component (eg, filler, filler, pigment) other than the polymer component from the weight of the sample is corrected. Initial weight (X) ”.
[0074]
Here, the gel content (xylene insoluble matter) is obtained by the following formula.
[0075]
Gel content [wt%] = [corrected final weight (Y)] / [corrected initial weight (X)] × 100
Preparation of foam
The foam (non-crosslinked or crosslinked foam) according to the present invention can be prepared, for example, by the following method.
[0076]
The sheet of the composition according to the present invention can be obtained by using, for example, a calendar molding machine, a press molding machine, or a T-die extruder from the mixture described in the section for preparing the composition. At the time of forming the sheet, it is necessary to form the sheet at a temperature lower than the decomposition temperature of the foaming agent (C) and the organic peroxide (D). Specifically, the temperature in the molten state of the composition is 100 to 130 ° C. It is necessary to set the conditions and form the sheet.
[0077]
The composition formed into a sheet by the above method is cut into a mold maintained at 130 to 200 ° C. in a range of 1.0 to 1.2 with respect to the volume of the mold and inserted into the mold. . A primary foam (non-crosslinked or cross-linked foam) is produced under the conditions of a mold clamping pressure of 30 to 300 kgf / cm 2 and a holding time of 10 to 90 minutes. However, since the (crosslinking) time depends on the thickness of the mold, it can be appropriately increased or decreased beyond this range.
[0078]
The shape of the (crosslinking) foaming mold is not particularly limited, but a mold having such a shape that a sheet is usually obtained is used. This mold must have a completely sealed structure so that the gas generated during decomposition of the molten resin and the foaming agent does not escape. As the mold, a mold having a taper on the inner surface is preferable from the viewpoint of resin releasability.
[0079]
The primary foam obtained by the above method is given a predetermined shape by compression molding. The compression molding conditions at this time are a mold temperature of 130 to 200 ° C., a clamping pressure of 30 to 300 kgf / cm 2, a compression time of 5 to 60 minutes, and a compression ratio of 1.1 to 3.0.
[0080]
In order to obtain a crosslinked foam by a crosslinking method by ionizing radiation irradiation, first, an organic system as a graft-modified ethylene / α-olefin copolymer (A), an inorganic metal compound (B), and a foaming agent (C) is used. A thermal decomposable foaming agent and other additives are melt-kneaded at a temperature lower than the decomposition temperature of the organic thermal decomposable foaming agent, and the resulting kneaded product is formed into a sheet, for example, to obtain a foamable sheet. .
[0081]
Next, the foamable sheet obtained was irradiated with a predetermined amount of ionizing radiation to crosslink the graft-modified ethylene / α-olefin copolymer A) and the inorganic metal compound (B), and then the foamable sheet obtained was obtained. A crosslinked foamed sheet can be obtained by heating the crosslinked sheet to a temperature equal to or higher than the decomposition temperature of the organic pyrolytic foaming agent to cause foaming.
[0082]
As the ionizing radiation, α rays, β rays, γ rays, electron beams, neutron rays, X rays and the like are used. Of these, cobalt-60 γ rays and electron beams are preferably used.
[0083]
Examples of the product shape of the foam include a sheet shape, a thick board shape, a net shape, and a mold.
[0084]
From the crosslinked foam obtained as described above, a secondary crosslinked foam having the above physical properties can be prepared in the same manner as in the method for producing the secondary foam described above.
[0085]
Laminated body
The laminate according to the present invention is the above-described at least one material selected from the group consisting of a foam (non-crosslinked or cross-linked foam) according to the present invention and a polyolefin, polyurethane, rubber, leather and artificial leather. It is a laminated body which has the layer which consists of.
[0086]
The polyolefin, polyurethane, rubber, leather and artificial leather are not particularly limited, and conventionally known polyolefin, polyurethane, rubber, leather and artificial leather can be used. Such a laminate is particularly suitable for footwear or footwear parts.
[0087]
Footwear or footwear parts
The footwear or footwear component according to the present invention comprises the above-described foam (non-crosslinked or crosslinked foam) or laminate according to the present invention.
[0088]
Examples of the footwear component include a shoe sole, a shoe midsole, an inner sole, a sole, and a sandal.
[0089]
【The invention's effect】
According to the present invention, a composition capable of providing a foam (non-crosslinked and cross-linked foam) having a low specific gravity and a small compression set (CS) and excellent in tear strength characteristics and rebound resilience, and the foam ( Secondary compression foams are also included), and laminates using the foams can be provided.
[0090]
Further, according to the present invention, it is possible to provide footwear or footwear parts comprising the non-crosslinked or crosslinked foamed body or the laminated body, such as a shoe sole, a shoe midsole, a shoe inner sole, and a sandal.
[0091]
【Example】
In addition, the density, MFR, B value, Tαβ strength ratio of the graft-modified ethylene / α-olefin copolymer (A) and / or the ethylene / α-olefin copolymer before graft modification used in Examples and Comparative Examples, Molecular weight distribution (Mw / Mn) Further, the specific gravity, compression set, tear strength, Asker C hardness (surface hardness) and impact resilience of the crosslinked foams obtained in Examples and Comparative Examples were measured according to the following methods. Evaluation of physical properties of graft-modified ethylene / α-olefin copolymer (A) and / or ethylene / α-olefin copolymer before graft modification
(1) Density
The density was determined at 23 ° C. according to ASTM D1505.
(2) MFR
The MFR was determined at 190 ° C and 230 ° C according to ASTM D1238. The measured value at 190 ° C. and a load of 2.16 kg was MFR2, and the measured value at 190 ° C. and a load of 10 kg was MFR10.
[0092]
Evaluation of physical properties of ethylene / α-olefin copolymer before graft modification
(3) B value, Tαβ intensity ratio
It was determined by 13C-NMR.
(4) Molecular weight distribution (Mw / Mn)
It determined with the ortho dichlorobenzene solvent and 140 degreeC by the gel permeation chromatograph.
[0093]
Evaluation of physical properties of crosslinked foam
(1) Specific gravity
The specific gravity was measured according to JIS K7222.
(2) Compression set
According to JIS K6301, a compression set test was performed under the conditions of 50 ° C. × 6 hours and a compression amount of 50%, and compression set (CS) was determined.
(3) Tear strength
In accordance with BS5131-2.6, a tear strength test was performed under the conditions of a tensile speed of 10 mm / min to determine the tear strength.
(4) Asker C hardness
The Asker C hardness was determined according to “Spring Hardness Test Type C Test Method” described in Appendix 2 of JIS K7312-1996.
(5) Rebound resilience
The impact resilience was measured according to JIS K6255.
[0094]
[Production example]
An ethylene / 1-butene copolymer (S-1) was produced using a metallocene catalyst by a method according to Examples in JP-A-2003-073494. Table 1 shows the properties of the ethylene / 1-butene copolymer (S-1).
[0095]
[Table 1]

[0096]
[Preparation of graft-modified ethylene / 1-butene copolymer (A-1)]
10 kg of the ethylene / 1-butene copolymer (S-1) was mixed with a solution of 50 g of maleic anhydride and 3 g of di-tert-butyl peroxide in 30 g of acetone in a Henschel mixer.
[0097]
Next, the blend is introduced from a hopper of a single screw extruder having a screw diameter of 40 mm and L / D = 26, extruded into a strand at a resin temperature of 280 ° C. and an extrusion rate of 6 kg / h, water cooled, and then pelletized. A graft-modified ethylene / 1-butene copolymer (A-1) was produced.
[0098]
In the obtained graft-modified ethylene / 1-butene copolymer (A-1), unreacted maleic anhydride is extracted with acetone from the graft-modified ethylene / 1-butene copolymer (A-1). The amount of maleic anhydride grafted in this was measured, the graft amount was 0.90% by weight, and the density was 885 kg / m.³The MFR at 230 ° C. and 2.16 kg load was 5.0 g / 10 min.
[0099]
[Example 1]
97 parts by weight of graft-modified ethylene / 1-butene copolymer (A-1), 3 parts by weight of zinc oxide (B-1) [where (A-1) + (B-1) = 100 parts by weight], Dicumyl peroxide (DCP) 0.6 parts by weight, triallyl isocyanurate (TAIC) [trade name M-60 (TAIC content 60%), manufactured by Nippon Kasei Co., Ltd.] 0.09 parts by weight (as TAIC content) A mixture of 4.0 parts by weight of azodicarbonamide and 1.0 part by weight of stearic acid was kneaded with a roll at a roll surface temperature of 120 ° C. for 10 minutes, and then formed into a sheet.
[0100]
The obtained sheet is filled into a press die and 150 kg / cm.²Pressurization and heating were performed at 155 ° C. for 30 minutes to obtain a primary crosslinked foam. The size of the press mold was 15 mm thick, 150 mm long, and 200 mm wide.
[0101]
Then, this primary crosslinked foamed product was 150 kg / cm.²Compression molding was performed at 155 ° C. for 10 minutes to obtain a secondary cross-linked foam. The size of the obtained secondary cross-linked foam was 15 mm in thickness, 160 mm in length, and 250 mm.
[0102]
Next, the specific gravity, compression set, tear strength, Asker C hardness, and impact resilience of the secondary crosslinked foam were measured according to the above methods. The results are shown in Table 2.
[0103]
[Comparative Example 1]
Example 1 is the same as Example 1 except that 97 parts by weight of the graft-modified ethylene / 1-butene copolymer (A-1) is changed to 97 parts by weight of the ethylene / 1-butene copolymer (S-1). Similarly, a secondary crosslinked foam was prepared and measured for physical properties. The results are shown in Table 2.
[0104]
[Table 2]

Claims (10)

Graft-modified ethylene / α-olefin copolymer (A) obtained by grafting unsaturated carboxylic acid or derivative thereof onto ethylene / α-olefin copolymer (A) 70 to 99.9 wt%, inorganic metal compound (B) 30 to 0.00. 1. A composition comprising 1% by weight (here, the total amount of (A) and (B) is 100% by weight in total) and a foaming agent (C). The graft-modified ethylene / α-olefin copolymer (A) is obtained by grafting an unsaturated carboxylic acid or a derivative thereof to an ethylene / α-olefin copolymer composed of ethylene and an α-olefin having 3 to 20 carbon atoms. The composition according to claim 1, wherein the graft-modified ethylene / α-olefin copolymer (A) has the following properties.
(I) the density (ASTM D1505, 23 ° C.) is in the range of 0.857 to 0.915 g / cm 3;
(Ii) Melt flow rate at 230 ° C. and 2.16 kg load (MFR2)
(ASTM D1238, load 2.16 kg, 190 ° C.) is in the range of 0.01 to 40 g / 10 minutes,
(Iii) Index of molecular weight distribution evaluated by GPC method: Mw / Mn is 1.5 to 3
. It is in the range of 5. 3. The composition according to claim 1, wherein the ethylene / α-olefin copolymer before graft modification of the graft-modified ethylene / α-olefin copolymer (A) has the following properties.
(Iv) The density (ASTM D1505, 23 ° C.) is in the range of 0.857 to 0.915 g / cm 3,
(V) Melt flow rate (MFR2) at 230 ° C. and 2.16 kg load
(ASTM D1238, load 2.16 kg, 190 ° C.) is in the range of 0.01 to 80 g / 10 minutes,
(Vi) Index of molecular weight distribution evaluated by GPC method: Mw / Mn is in the range of 1.5 to 3.5. The composition according to claims 1 to 3, wherein the graft-modified ethylene / α-olefin copolymer (A) and / or the ethylene / α-olefin copolymer before graft modification have the following properties. .
(Vii) Ratio of melt flow rate (MFR10) at 190 ° C. and 10 kg load to melt flow rate (MFR2) at 190 ° C. and 2.16 kg load: MFR10 / MFR2 satisfies the following equation:
MFR10 / MFR2 ≧ 6.0
Mw / Mn + 5.0 ≦ MFR10 / MFR2
(Viii) The intensity ratio of Tαβ to Tαα (Tαβ / Tαα) in the 13C-NMR spectrum is 0.5 or less,
(Ix) B value calculated | required from a 13C-NMR spectrum and following General formula (1) is 0.9-1.5.
B value = [POE] / (2 · [PE] [PO]) (1)
(Wherein [PE] is the mole fraction of structural units derived from ethylene in the copolymer, and [PO] is the mole fraction of structural units derived from α-olefin in the copolymer. ([POE] is the ratio of the number of ethylene / α-olefin chains to the total number of dyad chains in the copolymer) The composition according to any one of claims 1 to 4, wherein the graft-modified ethylene / α-olefin copolymer (A) is a graft-modified ethylene / 1-butene copolymer. The foaming agent (C) is selected from an organic thermal decomposition foaming agent, an inorganic thermal decomposition foaming agent, an organic physical foaming agent, and an inorganic physical foaming agent. A composition according to claim 1. A foam obtained by heat-treating the composition according to claim 1. A foam obtained by secondary compression of the foam according to claim 7. A layer made of the foam according to claim 7 or 8,
A laminate comprising a layer made of at least one material selected from the group consisting of polyolefin, polyurethane, rubber, leather and artificial leather. A footwear or a part for footwear comprising the foam according to claim 7 or 8 or the laminate according to claim 9.