JP3539801B2 - Ethylene / α-olefin copolymer - Google Patents

Description

【００２１】
ここでｃ_ｊとｂ_ｊはそれぞれｊ番目の区分の相対濃度と分岐度である。組成分布パラメーターＣｂは試料の組成が均一である場合に１．０となり、組成分布が広がるに従って値が大きくなる。
【００２２】
なお、エチレン・α−オレフィン共重合体の組成分布を記述する方法は多くの提案がなされている。例えば特開昭６０−８８０１６号では、試料を溶剤分別して得た各分別試料の分岐数に対して、累積重量分率が特定の分布（対数正規分布）をすると仮定して数値処理を行い、重量平均分岐度（Ｃｗ）と数平均分岐度（Ｃｎ）の比を求めている。この近似計算は、試料の分岐数と累積重量分率が対数正規分布からずれると精度が下がり、市販のＬＬＤＰＥについて測定を行うと相関係数Ｒ^２はかなり低く、値の精度は充分でない。このＣｗ／Ｃｎと本発明のＣｂとは、定義および測定方法が異なる。
【００２３】
本発明のエチレン・α−オレフィン共重合体は、２５℃におけるＯＤＣＢ可溶分の量Ｘは、エチレン・α−オレフィン共重合体に含まれる高分岐度成分および低分子量成分の割合を示すものであり、耐熱性の低下や成形品表面のベタツキの原因となるため少ないことが望ましい。ＯＤＣＢ可溶分の量は、共重合体全体のα−オレフィンの含有量および平均分子量、すなわち密度とＭＦＲに影響される。
【００２４】
従って、前記ＯＤＣＢ可溶分の量Ｘ（重量％）は密度ｄとＭＦＲの関係が、ｄ−０．００８×ｌｏｇＭＦＲ≧０．９３を満たす場合は２重量％未満、好ましくは１重量％未満、さらに好ましくは０．５重量％未満である。
【００２５】
また、ｄとＭＦＲの関係が、ｄ−０．００８×ｌｏｇＭＦＲ＜０．９３を満たす場合はＸ＜９．８×１０^３×（０．９３００−ｄ＋０．００８×ｌｏｇＭＦＲ）^２＋２．０の関係を満足し、好ましくはＸ＜７．４×１０^３×（０．９３００−ｄ＋０．００８×ｌｏｇＭＦＲ）^２＋１．０、さらに好ましくはＸ＜５．６×１０^３×（０．９３００−ｄ＋０．００８×ｌｏｇＭＦＲ）^２＋０．５の範囲である。
【００２６】
密度、ＭＦＲとＯＤＣＢ可溶分の量が上記の関係を満たすことは、共重合体全体に含まれているα−オレフィンが遍在していないことを示している。
【００２７】
なお、前記の２５℃におけるＯＤＣＢ可溶分Ｘは、下記の方法により測定する。
すなわち試料０．５ｇを２０ｍｌのＯＤＣＢに加え１３５℃で２時間加熱し、試料を完全に溶解した後、２５℃まで冷却する。この溶液を２５℃で一晩放置後、テフロン製フィルターで濾過して濾液を採取する。試料溶液である濾液を赤外分光器によりメチレンの非対称伸縮振動の波数２９２５ｃｍ^−１付近の吸収ピーク強度を測定し、あらかじめ作成した検量線により濾液中の試料濃度を算出する。この値より、２５℃におけるＯＤＣＢ可溶分を求める。
【００２８】
本発明のエチレン・α−オレフィン共重合体は、連続昇温溶出分別法（ＴＲＥＦ）により求めた溶出温度−溶出量曲線において、ピークが複数個（Ｆ）あることが好ましく、さらにその高温側のピークが８５℃から１００℃の間に存在することが特に好ましい。このピークが存在することにより、融点が高くなりまた結晶化度が上昇し成形体の耐熱性および剛性が向上する。図１に本発明の共重合体の溶出温度−溶出量曲線を示し、図２にいわゆるメタロセン触媒による共重合体の溶出温度−溶出量曲線を示した。
【００２９】
ＴＲＥＦの測定方法は下記のとおりである。即ち、試料に耐熱安定剤を加え、ＯＤＣＢに試料濃度０．０５重量％となるように１３５℃で加熱溶解する。この加熱溶液５ｍｌを、ガラスビーズを充填したカラムに注入した後、０．１℃／ｍｉｎの冷却速度で２５℃まで冷却し、試料をガラスビーズ表面に沈着する。次に、このカラムにＯＤＣＢを一定流量で流しながら、カラム温度を５０℃／ｈｒの一定速度で昇温し、各温度において溶液に溶解可能な試料を順次溶出させる。この際、溶剤中の試料濃度はメチレンの非対称伸縮振動の波数２９２５ｃｍ^−１に対する吸収を赤外検出器で連続的に検出される。この濃度から、溶出温度−溶出量曲線を得ることができる。
【００３０】
ＴＲＥＦ分析は極少量の試料で、温度変化に対する溶出速度の変化を連続的に分析出来るため、分別法では検出出来ない比較的細かいピークの検出が可能である。
【００３１】
本発明の特定のエチレン・α−オレフィン共重合体の製造は、上記（Ａ）〜（Ｄ）、好ましくは（Ａ）〜（Ｅ）、より好ましくは（Ａ）〜（Ｆ）の性状を満足すればよく、チグラー触媒、フイリップス触媒、メタロセン触媒等により製造してもよいが、好ましくは以下のＣ１〜Ｃ５からなる触媒で重合することが望ましい。
【００３２】
すなわち、Ｃ１：一般式Ｍｅ^１Ｒ^１ _ｐ（ＯＲ^２）_ｑＸ^１ _{４−ｐ−ｑ}で表される化合物（式中Ｍｅ^１はＺｒ、Ｔｉ、Ｈｆを示し、Ｒ^１およびＲ^２は各々炭素数１〜２４の炭化水素基、Ｘ^１はハロゲン原子を示し、ｐ、ｑおよびｒは各々０≦ｐ＜４、０≦ｐ＋ｑ≦４の範囲を満たす整数である）、Ｃ２：一般式Ｍｅ^２Ｒ^３ _ｍ（ＯＲ^４）_ｎＸ^２ _{ｚ−ｍ−ｎ}で表される化合物（式中Ｍｅ^２は周期律表第Ｉ〜ＩＩＩ族元素、Ｒ^３およびＲ^４は各々炭素数１〜２４の炭化水素基、Ｘ^２はハロゲン原子または水素原子（ただし、Ｘ^２が水素原子の場合はＭｅ^２は周期律表第ＩＩＩ族元素の場合に限る）を示し、ｚはＭｅ^２の価数を示し、ｍおよびｎは各々０≦ｍ≦ｚ、０≦ｎ≦ｚの範囲を満たす整数であり、かつ、０≦ｍ＋ｎ≦ｚである）、Ｃ３：共役二重結合を持つ有機環状化合物、およびＣ４：有機アルミニウム化合物と水との反応によって得られるＡｌ−Ｏ−Ａｌ結合を含む変性有機アルミニウム化合物、Ｃ５：無機担体および／または粒子状ポリマー担体を相互に接触させて得られる触媒である。
【００３３】
上記触媒成分（Ｃ１）の一般式Ｍｅ^１Ｒ^１ _ｐ（ＯＲ^２）_ｑＸ^１ _{４−ｐ−ｑ}で表される化合物の式中Ｍｅ^１はＺｒ、Ｔｉ、Ｈｆを示す。これらの遷移金属の種類は限定されるものではなく、複数を用いることもできるが、共重合体の耐候性がより優れる点でＺｒが含まれることが特に好ましい。Ｒ^１およびＲ^２は各々炭素数１〜２４の炭化水素基で、好ましくは炭素数１〜１２、さらに好ましくは炭素数１〜８の炭化水素基であり、具体的にはメチル基、エチル基、プロピル基、イソプロピル基、ブチル基などのアルキル基；ビニル基、アリル基などのアルケニル基；フェニル基、トリル基、キシリル基、メシチル基、インデニル基、ナフチル基などのアリール基；ベンジル基、トリチル基、フェネチル基、スチリル基、ベンズヒドリル基、フェニルブチル基、ネオフイル基などのアラルキル基などが挙げられる。これらは分岐があってもよい。Ｘ^１はフッ素、ヨウ素、塩素および臭素などのハロゲン原子を示し、ｐおよびｑはそれぞれ０≦ｐ＜４、０≦ｑ＜４、０≦ｐ＋ｑ≦４の範囲を満たし、好ましくは０≦ｐ＋ｑ≦４の範囲である。
【００３４】
上記触媒成分（Ｃ１）一般式で示される化合物の例としては、テトラメチルジルコニウム、テトラエチルジルコニウム、テトラベンジルジルコニウム、テトラプロポキシジルコニウム、トリプロポキシモノクロロジルコニウム、ジプロポキシジクロロジルコニウム、テトラブトキシジルコニウム、トリブトキシモノクロロジルコニウム、ジブトキシジクロロジルコニウム、テトラブトキシチタン、テトラブトキシハフニウムなどが挙げられ、これらを２種以上混合して用いても差し支えない。
【００３５】
上記触媒成分（Ｃ２）の一般式Ｍｅ^２Ｒ^３ _ｍ（ＯＲ^４）_ｎＸ^２ _{ｚ−ｍ−ｎ}で表される化合物の式中Ｍｅ^２は周期律表第Ｉ〜ＩＩＩ族元素を示し、リチウム、ナトリウム、カリウム、マグネシウム、カルシウム、亜鉛、ホウ素、アルミニウムなどである。Ｒ^３およひＲ^４は各々炭素数１〜２４の炭化水素基、好ましくは炭素数１〜１２、さらに好ましくは炭素数１〜８の炭化水素基であり、具体的にはメチル基、エチル基、プロピル基、イソプロピル基、ブチル基などのアルキル基；ビニル基、アリル基などのアルケニル基；フェニル基、トリル基、キシリル基、メシチル基、インデニル基、ナフチル基などのアリール基；ベンジル基、トリチル基、フェネチル基、スチリル基、ベンズヒドリル基、フェニルブチル基、ネオフィル基などのアラルキル基などが挙げられる。これらは分岐があってもよい。Ｘ^２はフッ素、ヨウ素、塩素および臭素などのハロゲン原子または水素原子を示すものである。ただし、Ｘ^２が水素原子の場合はＭｅ^２はホウ素、アルミニウムなどに例示される周期律表第ＩＩＩ族元素の場合に限るものである。また、ｚはＭｅ^２の価数を示し、ｍおよびｎは各々０≦ｍ≦ｚ、０≦ｎ≦ｚの範囲を満たす整数であり、かつ、０≦ｍ＋ｎ≦ｚである。
【００３６】
上記触媒成分（Ｃ２）の一般式で示される化合物の例としては、メチルリチウム、エチルリチウムなどの有機リチウム化合物；ジメチルマグネシウム、ジエチルマグネシウム、メチルマグネシウムクロライド、エチルマグネシウムクロライドなどの有機マグネシウム化合物；ジメチル亜鉛、ジエチル亜鉛などの有機亜鉛化合物；トリメチルボロン、トリエチルボロンなどの有機ボロン化合物；トリメチルアルミニウム、トリエチルアルミニウム、トリイソブチルアルミニウム、トリヘキシルアルミニウム、トリデシルアルミニウム、ジエチルアルミニウムクロライド、エチルアルミニウムジクロライド、エチルアルミニウムセスキクロライド、ジエチルアルミニウムエトキサイド、ジエチルアルミニウムハイドライドなどの有機アルミニウム化合物等の誘導体が挙げられる。
【００３７】
上記触媒成分（Ｃ３）の共役二重結合を持つ有機環状化合物とは、環状で共役二重結合を２個以上、好ましくは２〜４個、さらに好ましくは２〜３個有する環を１個または２個以上もち、全炭素数が４〜２４、好ましくは４〜１２である環状炭化水素化合物；前記環状炭化水素化合物が部分的に１〜６個の炭化水素残基（典型的には、炭素数１〜１２のアルキル基またはアラルキル基）で置換された環状炭化水素化合物；共役二重結合を２個以上、好ましくは２〜４個、さらに好ましくは２〜３個有する環を１個または２個以上もち、全炭素数が４〜２４、好ましくは４〜１２である環状炭化水素基を有する有機ケイ素化合物；前記環状炭化水素基が部分的に１〜６個の炭化水素残基またはアルカリ金属塩（ナトリウムまたはリチウム塩）で置換された有機ケイ素化合物が含まれる。特に好ましくは分子中のいずれかにシクロペンタジエン構造をもつものが望ましい。
【００３８】
上記の好適な化合物としては、シクロペンタジエン、インデン、アズレンまたはこれらのアルキル、アリール、アラルキル、アルコキシまたはアリールオキシ誘導体などが挙げられる。また、これらの化合物がアルキレン基（その炭素数は通常２〜８、好ましくは２〜３）を介して結合（架橋）した化合物も好適に用いられる。
【００３９】
環状炭化水素基を有する有機ケイ素化合物は、下記一般式で表示することができる。
【００４０】
ＡＬＳｉＲ^４−Ｌ
【００４１】
ここで、Ａはシクロペンタジエニル基、置換シクロペンタジエニル基、インデニル基、置換インデニル基で例示される前記環状水素基を示し、Ｒはメチル基、エチル基、プロピル基、イソプロピル基、ブチル基などのアルキル基；メトキシ基、エトキシ基、プロポキシ基、ブトキシ基などのアルコキシ基；フェニル基などのアリール基；フェノキシ基などのアリールオキシ基；ベンジル基などのアラルキル基で示され、炭素数１〜２４、好ましくは１〜１２の炭化水素残基または水素を示し、Ｌは１≦Ｌ≦４、好ましくは１≦Ｌ≦３である。
【００４２】
上記成分（Ｃ３）の有機環状炭化水素化合物の具体例は、シクロペンタジエン、メチルシクロペンタジエン、エチルシクロペンタジエン、１，３−ジメチルシクロペンタジエン、インデン、４−メチル−１−インデン、４，７−ジメチルインデン、シクロヘプタトリエン、メチルシクロヘプタトリエン、シクロオクタテトラエン、アズレン、フルオレン、メチルフルオレンのような炭素数７〜２４のシクロポリエンまたは置換シクロポリエン、モノシクロペンタジエニルシラン、ビスシクロペンタジエニルシラン、トリスシクロペンタジエニルシラン、モノインデニルシラン、ビスインデニルシラン、トリスインデニルシラン等が挙げられる。
【００４３】
触媒成分（Ｃ４）有機アルミニウム化合物と水との反応によって得られるＡｌ−Ｏ−Ａｌ結合を含む変性有機アルミニウム化合物とは、アルキルアルミニウム化合物と水とを反応させることにより、通常アルミノキサンと称される変性有機アルミニウムか得られ、分子中に通常１〜１００個、好ましくは１〜５０個のＡｌ−Ｏ−Ａｌ結合を含有する。また、変性有機アルミニウム化合物は線状でも環状でもいずれでもよい。
【００４４】
有機アルミニウムと水との反応は通常不活性炭化水素中で行われる。該不活性炭化水素としては、ペンタン、ヘキサン、ヘプタン、シクロヘキサン、ベンゼン、トルエン、キシレン等の脂肪族、脂環族、芳香族炭化水素が好ましい。
【００４５】
水と有機アルミニウム化合物との反応比（水／Ａｌモル比）は通常０．２５／１〜１．２／１、好ましくは０．５／１〜１／１であることが望ましい。
【００４６】
触媒成分（Ｃ５）無機物担体および／または粒子状ポリマー担体とは、炭素質物、金属、金属酸化物、金属塩化物、金属炭酸塩またはこれらの混合物あるいは熱可塑性樹脂、熱硬化性樹脂等が挙げられる。該無機物担体に用いることができる好適な金属としては、鉄、アルミニウム、ニッケルなどが挙げられる。
【００４７】
具体的にはＳｉＯ_２、Ａｌ_２Ｏ_３、ＭｇＯ、ＺｒＯ_２、ＴｉＯ_２、Ｂ_２Ｏ_３、ＣａＯ、ＺｎＯ、ＢａＯ、ＴｈＯ_２等またはこれらの混合物が挙げられ、ＳｉＯ_２−Ａｌ_２Ｏ_３、ＳｉＯ_２−Ｖ_２Ｏ_５、ＳｉＯ_２−ＴｉＯ_２、ＳｉＯ_２−Ｖ_２Ｏ_５、ＳｉＯ_２−ＭｇＯ、ＳｉＯ_２−Ｃｒ_２Ｏ_３等が挙げられる。これらの中でもＳｉＯ_２およびＡｌ_２Ｏ_３からなる群から選択された少なくとも１種の成分を主成分とするものが好ましい。
【００４８】
また、有機化合物としては、熱可塑性樹脂、熱硬化性樹脂のいずれも使用でき、具体的には、粒子状のポリオレフィン、ポリエステル、ポリアミド、ポリ塩化ビニル、ポリ（メタ）アクリル酸メチル、ポリスチレン、ポリノルボルネン、各種天然高分子およびこれらの混合物等が挙げられる。
【００４９】
上記無機物担体および／または粒子状ポリマー担体は、このまま使用することもできるが、好ましくは予備処理としてこれらの担体を有機アルミニウム化合物やＡｌ−Ｏ−Ａｌ結合を含む変性有機アルミニウム化合物などで接触処理させた後に成分（Ｃ５）として用いることもできる。
【００５０】
本発明のエチレン・α−オレフィン共重合体の製造方法は、気相法、スラリー法、溶液法等で製造され、一段重合法、多段重合法など特に限定されるものではない。
【００５１】
本発明においては、本発明の共重合体の特性を本質的に損なわない範囲において、必要に応じて酸化防止剤は勿論のこと造核剤、滑剤、帯電防止剤、防曇剤、顔料、紫外線吸収剤、分散剤などの公知の添加剤を添加することができる。また、本発明のエチレン・α−オレフィン共重合体は他の熱可塑性樹脂、例えば低密度ポリエチレン、中密度ポリエチレン、高密度ポリエチレン、ポリプロピレン等のポリオレフィンとブレンドして使用することもできる。
【００５２】
【発明の効果】
本発明のエチレン・α−オレフィン共重合体は、チーグラー触媒によるエチレン・α−オレフィン共重合体より優れた機械的強度、光学的特性を有し、かつメタロセン触媒によるエチレン・α−オレフィン共重合体のもつ低温ヒートシール性、透明性を保持しながらホットタック性等の特性に優れており、特にＴダイ成形、インフレーションフィルム成形等によって製造される各種包装用フィルム、ラミネート用原反等のフィルム成形体として好適である。また、本発明のエチレン・α−オレフィン共重合体は、マヨネーズ用容器、わさび等用のチューブ状容器、段ボール等の内装用肉薄容器、液体洗剤用容器等の中空成形体、栓、キャップ、容器の蓋、スキーシューズ等の射出成形体、電線、ケーブルの被覆、鋼管の被覆等の用途にも好適である。本発明のエチレン・α−オレフィン共重合体は、ドライラミネート法、共押出法、押出ラミネート法により各種多層フィルムあるいは積層シートとして使用することもできる。
【００５３】
【実施例】
次に実施例により本発明を更に詳しく説明するが、本発明はこれらによって限定されるものではない。
【００５４】
なお本実験例に用いた試験方法は以下の通りである。

【００５５】
（インフレーションフィルム成形）
重合した共重合体粉末は造粒して、５０ｍｍφのＬＬＤＰＥフィルム専用成形機に直径１００ｍｍφ、リップギャップ２ｍｍのダイスを取りつけ、ブロー比１．９、引き取り速度２０ｍ／ｍｉｎ、成形温度２００℃の成形条件で厚さ３０μｍのフィルムを成形した。
【００５６】

【００５７】
（シート成形法）
共重合体をロールで均一化した後、切断してチップ状とし、これを１８０℃でプレス成形しシートを得た。

【００５８】
実施例１〜５で用いた試料Ａ１〜Ａ５は以下の方法で重合した。
【００５９】
（固体触媒の調製）
窒素下で電磁誘導攪拌機付き触媒調製器（Ｎｏ．１）に精製トルエンを加え、ついでジプロポキシジクロロジルコニウム（Ｚｒ（ＯＰｒ）₂ Ｃｌ ₂ ）２８ｇおよびメチルシクロペンタジエン４８ｇを加え、０℃に系を保持しながらトリデシルアルミニウムを４５ｇを滴下し、滴下終了後、反応系を５０℃に保持して１６時間攪拌した。この溶液をＡ液とする。次に窒素下で別の攪拌器付き触媒調製器（Ｎｏ．２）２に精製トルエンを加え、前記Ａ溶液と、ついでメチルアルミノキサン６．４ｍｏｌのトルエン溶液を添加し反応させた。これをＢ液とする。
【００６０】
次に窒素下で攪拌器付き調製器（Ｎｏ．１）に精製トルエンを加え、ついであらかじめ４００℃で所定時間焼成処理したシリカ（富士デビソン社製、グレード＃９５２、表面積３００ｍ^２／ｇ）１４００ｇを加えた後、前記Ｂ溶液の全量を添加し、室温で攪拌した。ついで窒素ブローにて溶媒を除去して流動性の良い固体触媒粉末を得た。これを触媒Ｃとする。
【００６１】
（試料Ａ１の重合）
連続式の流動床気相法重合装置を用い、重合温度７０℃、全圧２０ｋｇｆ／ｃｍ^２Ｇでエチレンと１−ブテンの共重合を行った。系内のガス組成は、１−ブテン／エチレンモル比０．１２、エチレン濃度６０ｍｏｌ％とした。前記触媒Ｃを連続的に供給して重合を行い、系内のガス組成を一定に保つため、各ガスを連続的に供給した。
なお、生成した共重合体の物性は表１に示した。
【００６２】
（試料Ａ２の重合）
１−ブテン／エチレンのモル比を変化させたこと以外は（Ａ１）と同様の操作を行って重合した。共重合体の物性は実験結果と併せて表１に示した。
【００６３】
（試料Ａ３〜Ａ５の重合）
（Ａ３）、（Ａ４）、（Ａ５）はコモノマーをそれぞれ１−ペンテン、１−ヘキセン、４−メチル−ペンテン−１とした以外は（Ａ１）と同様の操作を行って重合した。共重合体の物性は実験結果と併せて表１に示した。
【００６４】
（試料Ａ７〜Ａ１０の重合）
１−ブテン／エチレンのモル比を変化させたこと以外は（Ａ１）と同様の操作を行って重合した。共重合体の物性は実験結果と併せて表２または表３に示した。
【００６５】
（試料Ｂ２の重合）
窒素で置換した攪拌機付きの５０Ｌ加圧反応器に精製トルエン２５Ｌ入れた。次いで、ブテン−１を１８３ｇ添加し、更にビス（ｎ−ブチルシクロペンタジエニル）ジルコニウムジクロライド、メチルアルモキサン〔ＭＡＯ〕の混合液を（Ａｌ／Ｚｒモル比＝５００）をＺｒとして０．３３ミリモルとなるように加えた後、８０℃に昇温した。次にエチレン９ｋｇ／ｃｍ^２Ｇとなるように張り込み重合を開始した。エチレンを連続的に重合しつつ全圧を９ｋｇ／ｃｍ^２Ｇに維持して１時間重合を行い共重合体を製造した。共重合体の物性は実験結果と併せて表１に示した。
【００６６】
（試料Ｂ８の重合）
１−ブテンを４１０ｇ添加した以外は（Ｂ２）と同様の操作を行って重合した。共重合体の物性は実験結果と併せて表３に示した。
【００６７】
上記以外に用いた試料（Ｂ１）、（Ｂ３）、（Ｂ７）、（Ｂ９）は四塩化チタン、トリエチルアルミニウム触媒を用い気相法またはスラリー法にてエチレンと１−ブテンを共重合して得たＬＬＤＰＥまたはＶＬＤＰＥである。また（Ｂ４）は市販ウルトゼックス３０１０Ｆ（三井石油化学（株）製）である。その物性は実験結果と併せて表１〜表３に示した。
【００６８】
実施例１〜５
表１には前記手順により造粒した後インフレーションフィルム成形し、各種物性の比較を行ったものである。
【００６９】
比較例１〜４
実施例１〜５との比較をするため表１に示した樹脂を用い同様の操作を行ったものである。結果を表１に示した。比較例１はダート衝撃強度と透明性が、比較例２は表１に示したように融点が低く耐熱性が劣り、また比較例３、４は使用したα−オレフィンの種類を勘案して実施例３、４と比べるとダート強度と透明性が劣る。
【００７０】
実施例６、比較例５〜６
実施例２で得たフィルムを用いホットタック特性を測定し、比較例１、２で得たフィルムで測定した比較例５、６と比較した。結果を表３に示す。実施例６は剥離距離の短いシール温度範囲が広い。
【００７１】
実施例７〜８、比較例７〜８
前記の方法でシートを成形し物性試験を行い表３に示した。比較例７は引っ張り衝撃強度が劣り、比較例８は耐熱性が劣る。
【００７２】
実施例９〜１０、比較例９
前記の方法で射出成形による試験片を成形し物性試験を行い表４に示した。比較例９は引っ張り衝撃強度および引っ張り破壊強さが劣る。
【００７３】
【表１】

【００７４】
【表２】

【００７５】
【表３】

【００７６】
【表４】

【図面の簡単な説明】
【図１】本発明共重合体のＴＲＥＦにより求めた溶出温度−溶出量曲線。
【図２】メタロセン触媒による共重合体のＴＲＥＦにより求めた溶出温度−溶出量曲線。[0001]
[Industrial applications]
The present invention relates to a novel ethylene / α-olefin copolymer having excellent physical properties and processability. More specifically, despite having a narrow molecular weight distribution, it has a relatively wide composition distribution, and has a low content of low molecular weight components and amorphous components, and is excellent in mechanical properties, moldability, optical properties and heat resistance. In particular, various types of packaging films produced by T-die molding, blown film molding, etc., film molded products such as raw materials for lamination, various containers produced by hollow molding, etc., various containers produced by injection molding, lids, injection molded products such as containers, Alternatively, the present invention provides an ethylene / α-olefin copolymer suitable for covering electric wires, cables, steel pipes, and the like.
[0002]
[Prior art]
Linear low-density polyethylene (LLDPE), which is an ethylene / α-olefin copolymer obtained with a Ziegler-type catalyst, has higher strength and toughness than films and high-pressure low-density polyethylene (HPLDPE), Although it is used for various applications such as a hollow molded article and an injection molded article, further higher strength is required to reduce the weight of the molded article. In recent years, a high-strength ethylene / α-olefin copolymer having a very narrow molecular weight distribution and composition distribution has been developed by using a metallocene catalyst. However, these metallocene ethylene / α-olefin polymers have some disadvantages. For example, since the composition distribution is very narrow, the change in viscosity and strength with respect to temperature is very sharp, and therefore, the applicable range of the temperature and the extrusion conditions at the time of molding is narrow, and molding is difficult. Further, molded articles also have drawbacks such as a low heat resistance, a narrow temperature range in which appropriate heat seal strength or good hot tack strength is exhibited. For example, in the field of films, sheets and the like, heat sealing is easy, and thus heat sealing is often used as a bag, and such applications require hot tack properties. That is, the seal portion may be pulled immediately after the heat sealing, for example, when the contents are filled, and a load may be applied, and the seal portion may be peeled off. In such a material, a material having a wide temperature range of a seal capable of performing heat sealing showing a strong value against peeling immediately after the sealing is preferable.
[0003]
As an attempt to improve such hot tack characteristics, attempts have been made to mix polyethylene resins with a plurality of Ziegler-type catalysts (for example, JP-A-3-207736 and JP-A-3-207737). However, in this method, the molecular weight distribution is also widened at the same time, so that improvement in strength cannot be expected.
[0004]
Next, as a method for improving the moldability of a polymer using a metallocene catalyst, an attempt has been made to improve the melting characteristics of a resin by using a metallocene catalyst having a plurality of ligands while keeping a narrow composition distribution ( For example, JP-A-6-206939). However, there is a problem that the molecular weight distribution is widened or the strength is reduced due to generation of long-chain branches. Attempts have also been made to improve moldability by using a mixed system of a metallocene-based catalyst and a Ziegler-based catalyst (for example, Japanese Patent Application Laid-Open No. H6-157631).
[0005]
[Problems to be solved by the invention]
The object of the present invention is to have superior mechanical strength and optical properties to LLDPE using a Ziegler-type catalyst, and to have low-temperature heat sealability and transparency equivalent to those of a metallocene-based ethylene / α-olefin copolymer. An object of the present invention is to provide an ethylene / α-olefin copolymer having better heat resistance, hot tack properties, and moldability than the metallocene-based ethylene / α-olefin copolymer.
[0006]
[Means for Solving the Problems]
The present inventors have conducted intensive studies along the above-mentioned object, and as a result, despite having a narrow molecular weight distribution, have a relatively wide composition distribution, and have a low content of low molecular weight components and amorphous components. -An olefin copolymer was produced, thereby achieving the above object.
[0007]
That is, in the present invention, first, (A) the density d is 0.86 to 0.96 g / cm³, (B) MFR of 0.01 to 200 g / 10 min, (C) Mw / Mn of 1.8 to 3.5, and (D) composition distribution parameter Cb of 1.10 to 2.00. Ethylene-α-olefin copolymer.
[0008]
Secondly, the present invention provides (A) a density d of 0.86 to 0.96 g / cm³, (B) MFR 0.01 to 200 g / min, (C) Mw / Mn 1.8 to 3.5, (D) composition distribution parameter Cb 1.10 to 2.00, (E) 25 ° C ODCB soluble content X (% by weight) and density d and MFR are as follows: i) When d−0.008 × log MFR ≧ 0.93, X <2.0, b) d−0.008 × log MFR In the case of <0.93, X <9.8 × 10³× (0.9300-d + 0.008 × log MFR)²An ethylene / α-olefin copolymer characterized by satisfying +2.0.
[0009]
Third, the present invention relates to (A) the density d of 0.86 to 0.96 g / cm³, (B) MFR 0.01 to 200 g / 10 min, (C) Mw / Mn 1.8 to 3.5, (D) composition distribution parameter Cb 1.10 to 2.00, (E) 25 ° C ODCB soluble content X (% by weight) and density d and MFR are as follows: i) When d−0.008 × log MFR ≧ 0.93, X <2.0, b) d−0.008 × log MFR In the case of <0.93, X <9.8 × 10³× (0.9300-d + 0.008 × log MFR)²+2.0, and (F) an ethylene / α-olefin copolymer characterized by satisfying a plurality of peaks in an elution temperature-elution amount curve by TREF.
[0010]
Hereinafter, the present invention will be described in more detail.
The ethylene / α-olefin copolymer of the present invention is a copolymer of ethylene and at least one selected from α-olefins having 3 to 20 carbon atoms. The α-olefin having 3 to 20 carbon atoms is preferably one having 3 to 12 carbon atoms, specifically, propylene, 1-butene,1-pentene,4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, and the like. In addition, the content of these α-olefins is desirably selected in a total of usually 30 mol% or less, preferably 3 to 20 mol%.
[0011]
The density (A) of the ethylene / α-olefin copolymer of the present invention is 0.86 to 0.96 g / cm.³, Preferably 0.88 to 0.945 g / cm³, More preferably 0.90 to 0.930 g / cm³Range. If the density is less than 0.86, rigidity and heat resistance are poor, and if it is 0.96 or more, impact resistance is not sufficient.
[0012]
The MFR (B) of the ethylene / α-olefin copolymer of the present invention is in the range of 0.01 to 200 g / 10 min, preferably 0.1 to 100 g / 10 min, more preferably 0.2 to 50 g / 10 min. Is desirable. If the MFR is less than 0.01, the moldability is poor, and if it is 200 or more, mechanical strength such as impact resistance is reduced.
[0013]
The method for calculating the molecular weight distribution Mw / Mn (C) of the ethylene / α-olefin copolymer of the present invention is as follows: the weight average molecular weight (Mw) and the number average molecular weight (Mn) are determined by gel permeation chromatography (GPC). This ratio Mw / Mn is determined.
[0014]
Mw / Mn of the ethylene / α-olefin copolymer of the present invention is 1.8 to 3.5, preferably 2.0 to 3.0, and more preferably 2.2 to 2.8. It is desirable. If Mw / Mn is less than 1.8, the moldability is poor, and if it is 3.5 or more, the impact resistance is poor.
[0015]
The composition distribution parameter Cb (D) of the ethylene / α-olefin copolymer of the present invention is 1.10 to 2.00, preferably 1.12 to 1.70, and more preferably 1.15 to 1.50. It is desirable to be within the range. If it is less than 1.10, the hot tack property is inferior, and if it is 2.00 or more, the transparency is lowered and a polymer gel is formed on the molded article.
[0016]
The method for measuring the composition distribution parameter Cb of the ethylene / α-olefin copolymer of the present invention is as follows.
[0017]
A heat stabilizer is added to the sample, and the sample is heated and dissolved in ODCB at 135 ° C. so that the sample temperature becomes 0.2% by weight. The heated solution is transferred to a column filled with diatomaceous earth (Celite 545), filled and cooled to 25 ° C. at a rate of 0.1 ° C./min, and the sample is deposited on the celite surface. Next, a solution in which a sample is dissolved is collected at each temperature while the column temperature is raised stepwise to 120 ° C. in steps of 5 ° C. while flowing ODCB through this column at a constant flow rate. After cooling the solution, the sample is re-pillowed with methanol, filtered and dried to obtain samples at each elution temperature. The weight fraction and the degree of branching (the number of branches per 1000 carbon atoms) of the separated sample are measured. The degree of branching is measured by 13 C-NMR.
[0018]
With respect to each fraction collected at 30 ° C. to 90 ° C. by such a method, the degree of branching is corrected as follows. That is, the degree of branching measured with respect to the elution temperature is plotted, and the correlation is approximated to a straight line by the least squares method to create a calibration curve. The correlation coefficient of this approximation is large enough. The value obtained from this calibration curve is defined as the degree of branching of each fraction. Note that, for a fraction collected at an elution temperature of 95 ° C. or higher, this correction is not performed because a linear relationship is not always established between the elution temperature and the degree of branching.
[0019]
Next, the weight fraction wi of each fraction is determined by the degree of branching b per 5 ° C. of elution temperature._i(B)_i-B_i-l) Divided by the relative density c_iIs obtained, and the relative concentration is plotted against the degree of branching to obtain a composition distribution curve. This composition distribution curve is divided by a certain width, and the composition distribution parameter Cb is calculated from the following equation.
[0020]
(Equation 1)

[0021]
Where c_jAnd b_jIs the relative density and branching degree of the j-th section, respectively. The composition distribution parameter Cb is 1.0 when the composition of the sample is uniform, and the value increases as the composition distribution spreads.
[0022]
Many proposals have been made for a method of describing the composition distribution of the ethylene / α-olefin copolymer. For example, in Japanese Patent Application Laid-Open No. 60-88016, numerical processing is performed on the assumption that the cumulative weight fraction has a specific distribution (log normal distribution) with respect to the number of branches of each separated sample obtained by solvent separation of the sample. The ratio between the weight average branching degree (Cw) and the number average branching degree (Cn) is determined. The accuracy of this approximation calculation decreases when the number of branches of the sample and the cumulative weight fraction deviate from the lognormal distribution, and when the measurement is performed on a commercially available LLDPE, the correlation coefficient R²Is rather low and the accuracy of the values is not sufficient. This Cw / Cn and Cb of the present invention have different definitions and measurement methods.
[0023]
In the ethylene / α-olefin copolymer of the present invention, the amount X of the ODCB-soluble component at 25 ° C. indicates the ratio of the high branching degree component and the low molecular weight component contained in the ethylene / α-olefin copolymer. Yes, it is desirable to reduce the heat resistance and cause stickiness on the surface of the molded product. The amount of the ODCB-soluble component is affected by the α-olefin content and the average molecular weight of the entire copolymer, that is, the density and the MFR.
[0024]
Therefore, the amount X (% by weight) of the ODCB-soluble component is less than 2% by weight, preferably less than 1% by weight when the relationship between the density d and the MFR satisfies d−0.008 × log MFR ≧ 0.93. More preferably, it is less than 0.5% by weight.
[0025]
When the relationship between d and MFR satisfies d−0.008 × log MFR <0.93, X <9.8 × 10³× (0.9300-d + 0.008 × log MFR)²+2.0, preferably X <7.4 × 10³× (0.9300-d + 0.008 × log MFR)²+1.0, more preferably X <5.6 × 10³× (0.9300-d + 0.008 × log MFR)²The range is +0.5.
[0026]
The fact that the density, the MFR and the amount of the ODCB-soluble component satisfy the above relationship indicates that the α-olefin contained in the entire copolymer is not ubiquitous.
[0027]
The ODCB-soluble component X at 25 ° C. is measured by the following method.
That is, 0.5 g of a sample is added to 20 ml of ODCB, heated at 135 ° C. for 2 hours to completely dissolve the sample, and then cooled to 25 ° C. After leaving this solution at 25 ° C. overnight, it is filtered through a Teflon filter to collect the filtrate. The filtrate, which is a sample solution, was subjected to infrared spectroscopy to measure the asymmetric stretching vibration of methylene using a wave number of 2925 cm.^-1The absorption peak intensity in the vicinity is measured, and the concentration of the sample in the filtrate is calculated from a calibration curve created in advance. From this value, the ODCB-soluble matter at 25 ° C. is determined.
[0028]
The ethylene / α-olefin copolymer of the present invention preferably has a plurality of peaks (F) in an elution temperature-elution amount curve obtained by a continuous heating elution fractionation method (TREF). It is particularly preferred that the peak is between 85 ° C and 100 ° C. The presence of this peak increases the melting point and the crystallinity, thereby improving the heat resistance and rigidity of the molded body. FIG. 1 shows an elution temperature-elution amount curve of the copolymer of the present invention, and FIG. 2 shows an elution temperature-elution amount curve of the copolymer using a so-called metallocene catalyst.
[0029]
The measuring method of TREF is as follows. That is, a heat-resistant stabilizer is added to the sample, and the sample is heated and dissolved at 135 ° C. in ODCB so that the sample concentration becomes 0.05% by weight. After injecting 5 ml of the heated solution into a column filled with glass beads, the solution is cooled to 25 ° C. at a cooling rate of 0.1 ° C./min, and the sample is deposited on the surface of the glass beads. Next, the column temperature is raised at a constant rate of 50 ° C./hr while flowing ODCB through the column at a constant flow rate, and samples that can be dissolved in the solution at each temperature are sequentially eluted. At this time, the sample concentration in the solvent was 2925 cm, the wave number of the asymmetric stretching vibration of methylene.^-1Is continuously detected by an infrared detector. From this concentration, an elution temperature-elution amount curve can be obtained.
[0030]
In the TREF analysis, a change in the elution rate with respect to a temperature change can be continuously analyzed with a very small amount of sample, so that relatively fine peaks that cannot be detected by the fractionation method can be detected.
[0031]
The production of the specific ethylene / α-olefin copolymer of the present invention satisfies the above properties (A) to (D), preferably (A) to (E), and more preferably (A) to (F). It may be produced by a Ziegler catalyst, a Phillips catalyst, a metallocene catalyst or the like, but it is preferable to carry out polymerization with a catalyst composed of the following C1 to C5.
[0032]
That is, C1: general formula Me¹R¹ _p(OR²)_qX¹ _4-pqA compound represented by the formula:¹Represents Zr, Ti, Hf, and R¹And R²Is a hydrocarbon group having 1 to 24 carbon atoms, X¹Represents a halogen atom, p, q and r are each an integer satisfying the range of 0 ≦ p <4, 0 ≦ p + q ≦ 4), C2: general formula Me²R³ _m(OR⁴)_nX² _zmnA compound represented by the formula:²Is a group I-III element of the periodic table, R³And R⁴Is a hydrocarbon group having 1 to 24 carbon atoms, X²Is a halogen atom or a hydrogen atom (however, X²When Me is a hydrogen atom,²Represents only a group III element of the periodic table), and z is Me²M and n are integers satisfying the ranges of 0 ≦ m ≦ z and 0 ≦ n ≦ z, respectively, and 0 ≦ m + n ≦ z), and C3: an organic compound having a conjugated double bond A cyclic compound, and C4: a modified organoaluminum compound containing an Al-O-Al bond obtained by reacting an organoaluminum compound with water, C5: a catalyst obtained by bringing an inorganic carrier and / or a particulate polymer carrier into contact with each other. It is.
[0033]
General formula Me of the catalyst component (C1)¹R¹ _p(OR²)_qX¹ _4-pqIn the formula of the compound represented by¹Represents Zr, Ti, and Hf. The type of these transition metals is not limited, and a plurality of transition metals can be used. However, it is particularly preferable that Zr is contained because the copolymer has more excellent weather resistance. R¹And R²Each represents a hydrocarbon group having 1 to 24 carbon atoms, preferably a hydrocarbon group having 1 to 12 carbon atoms, more preferably a hydrocarbon group having 1 to 8 carbon atoms, and specifically, a methyl group, an ethyl group, a propyl group, and an isopropyl group. Alkenyl groups such as vinyl group and allyl group; aryl groups such as phenyl group, tolyl group, xylyl group, mesityl group, indenyl group and naphthyl group; benzyl group, trityl group, phenethyl group, An aralkyl group such as a styryl group, a benzhydryl group, a phenylbutyl group, and a neofuyl group is exemplified. These may have branches. X¹Represents a halogen atom such as fluorine, iodine, chlorine and bromine, and p and q each satisfy the range of 0 ≦ p <4, 0 ≦ q <4, 0 ≦ p + q ≦ 4, preferably 0 ≦ p + q ≦ 4. Range.
[0034]
Examples of the compound represented by the above-mentioned catalyst component (C1) represented by the general formula include tetramethyl zirconium, tetraethyl zirconium, tetrabenzyl zirconium, tetrapropoxy zirconium, tripropoxy monochlorodiconium, dipropoxy dichloro zirconium, tetrabutoxy zirconium, and tribubutoxy monochlorosiliconium. , Dibutoxydichlorozirconium, tetrabutoxytitanium, tetrabutoxyhafnium and the like, and two or more of these may be used in combination.
[0035]
The general formula Me of the catalyst component (C2)²R³ _m(OR⁴)_nX² _zmnIn the formula of the compound represented by²Represents an element in Groups I to III of the periodic table, such as lithium, sodium, potassium, magnesium, calcium, zinc, boron, and aluminum. R³Ohihi R⁴Is a hydrocarbon group having 1 to 24 carbon atoms, preferably a hydrocarbon group having 1 to 12 carbon atoms, more preferably a hydrocarbon group having 1 to 8 carbon atoms, and specifically, a methyl group, an ethyl group, a propyl group, and an isopropyl group Alkyl groups such as butyl and butyl groups; alkenyl groups such as vinyl and allyl groups; aryl groups such as phenyl, tolyl, xylyl, mesityl, indenyl and naphthyl; benzyl, trityl, phenethyl and styryl And aralkyl groups such as a benzhydryl group, a phenylbutyl group and a neophyl group. These may have branches. X²Represents a halogen atom or a hydrogen atom such as fluorine, iodine, chlorine and bromine. Where X²When Me is a hydrogen atom,²Is limited to a group III element of the periodic table exemplified by boron, aluminum and the like. Z is Me²Where m and n are integers satisfying the ranges of 0 ≦ m ≦ z and 0 ≦ n ≦ z, respectively, and 0 ≦ m + n ≦ z.
[0036]
Examples of the compound represented by the general formula of the catalyst component (C2) include organic lithium compounds such as methyllithium and ethyllithium; organic magnesium compounds such as dimethylmagnesium, diethylmagnesium, methylmagnesium chloride and ethylmagnesium chloride; dimethylzinc Organic boron compounds such as trimethylboron and triethylboron; trimethylaluminum, triethylaluminum, triisobutylaluminum, trihexylaluminum, tridecylaluminum, diethylaluminum chloride, ethylaluminum dichloride, ethylaluminum sesquichloride Aluminum, such as diethyl aluminum ethoxide, diethyl aluminum hydride Derivatives such compounds can be mentioned.
[0037]
The organic cyclic compound having a conjugated double bond of the catalyst component (C3) is one or more rings having two or more, preferably 2 to 4, more preferably 2 to 3, conjugated double bonds. A cyclic hydrocarbon compound having 2 or more and having a total carbon number of 4 to 24, preferably 4 to 12; wherein the cyclic hydrocarbon compound is partially a hydrocarbon residue of 1 to 6 (typically, carbon A cyclic hydrocarbon compound substituted with an alkyl group or an aralkyl group of formulas 1 to 12); one or two rings having two or more conjugated double bonds, preferably two to four, more preferably two to three. An organosilicon compound having a cyclic hydrocarbon group having at least one and having a total carbon number of 4 to 24, preferably 4 to 12; a hydrocarbon residue or an alkali metal in which the cyclic hydrocarbon group is partially 1 to 6 With salt (sodium or lithium salt) It includes organic silicon compounds conversion. Particularly preferably, those having a cyclopentadiene structure in any of the molecules are desirable.
[0038]
Examples of suitable compounds include cyclopentadiene, indene, azulene, and alkyl, aryl, aralkyl, alkoxy or aryloxy derivatives thereof. Further, a compound obtained by bonding (crosslinking) these compounds via an alkylene group (the number of carbon atoms of which is usually 2 to 8, preferably 2 to 3) is also preferably used.
[0039]
The organosilicon compound having a cyclic hydrocarbon group can be represented by the following general formula.
[0040]
ALSiR⁴-L
[0041]
Here, A represents the cyclic hydrogen group exemplified by a cyclopentadienyl group, a substituted cyclopentadienyl group, an indenyl group, and a substituted indenyl group, and R represents a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group. An alkyl group such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group; an aryl group such as a phenyl group; an aryloxy group such as a phenoxy group; an aralkyl group such as a benzyl group; Represents 24 to 24, preferably 1 to 12 hydrocarbon residues or hydrogen, and L is 1 ≦ L ≦ 4, preferably 1 ≦ L ≦ 3.
[0042]
Specific examples of the organic cyclic hydrocarbon compound of the component (C3) include cyclopentadiene, methylcyclopentadiene, ethylcyclopentadiene, 1,3-dimethylcyclopentadiene, indene, 4-methyl-1-indene, and 4,7-dimethyl. C7-C24 cyclopolyene or substituted cyclopolyene such as indene, cycloheptatriene, methylcycloheptatriene, cyclooctatetraene, azulene, fluorene, methylfluorene, monocyclopentadienylsilane, biscyclopentadienyl Examples include silane, triscyclopentadienylsilane, monoindenylsilane, bisindenylsilane, and trisindenylsilane.
[0043]
Catalyst component (C4) A modified organoaluminum compound containing an Al-O-Al bond obtained by reacting an organoaluminum compound with water is obtained by reacting an alkylaluminum compound with water to form a modified so-called aluminoxane. It is obtained from organoaluminum and usually contains 1 to 100, preferably 1 to 50 Al-O-Al bonds in the molecule. The modified organoaluminum compound may be linear or cyclic.
[0044]
The reaction between the organoaluminum and water is usually performed in an inert hydrocarbon. As the inert hydrocarbon, aliphatic, alicyclic, and aromatic hydrocarbons such as pentane, hexane, heptane, cyclohexane, benzene, toluene, and xylene are preferable.
[0045]
The reaction ratio (water / Al molar ratio) between water and the organoaluminum compound is usually from 0.25 / 1 to 1.2 / 1, preferably from 0.5 / 1 to 1/1.
[0046]
The catalyst component (C5) inorganic carrier and / or particulate polymer carrier include carbonaceous materials, metals, metal oxides, metal chlorides, metal carbonates or mixtures thereof, thermoplastic resins, thermosetting resins and the like. . Suitable metals that can be used for the inorganic carrier include iron, aluminum, nickel and the like.
[0047]
Specifically, SiO₂, Al₂O₃, MgO, ZrO₂, TiO₂, B₂O₃, CaO, ZnO, BaO, ThO₂And mixtures thereof.₂-Al₂O₃, SiO₂-V₂O₅, SiO₂-TiO₂, SiO₂-V₂O₅, SiO₂-MgO, SiO₂−Cr₂O₃And the like. Among them, SiO₂And Al₂O₃The main component is preferably at least one component selected from the group consisting of:
[0048]
In addition, as the organic compound, any of a thermoplastic resin and a thermosetting resin can be used. Specifically, particulate polyolefin, polyester, polyamide, polyvinyl chloride, polymethyl (meth) acrylate, polystyrene, poly Examples include norbornene, various natural polymers, and mixtures thereof.
[0049]
The above-mentioned inorganic carrier and / or particulate polymer carrier can be used as they are, but preferably, as a preliminary treatment, these carriers are contact-treated with an organoaluminum compound or a modified organoaluminum compound containing an Al-O-Al bond. Can be used as component (C5).
[0050]
The method for producing the ethylene / α-olefin copolymer of the present invention is produced by a gas phase method, a slurry method, a solution method or the like, and is not particularly limited, such as a one-stage polymerization method and a multi-stage polymerization method.
[0051]
In the present invention, as long as the properties of the copolymer of the present invention are not substantially impaired, a nucleating agent, a lubricant, an antistatic agent, an antifogging agent, a pigment, an ultraviolet ray, if necessary, as well as an antioxidant. Known additives such as an absorbent and a dispersant can be added. Further, the ethylene / α-olefin copolymer of the present invention can be used by blending with other thermoplastic resins, for example, polyolefins such as low density polyethylene, medium density polyethylene, high density polyethylene, and polypropylene.
[0052]
【The invention's effect】
The ethylene / α-olefin copolymer of the present invention has better mechanical strength and optical properties than the Ziegler-catalyzed ethylene / α-olefin copolymer, and has a metallocene-catalyzed ethylene / α-olefin copolymer. It is excellent in properties such as hot tack property while maintaining low temperature heat sealability and transparency that it has, especially film forming such as various packaging films manufactured by T-die forming, blown film forming, raw material for lamination etc. Suitable as a body. Further, the ethylene / α-olefin copolymer of the present invention may be a container for mayonnaise, a tubular container for wasabi or the like, a thin-walled container for interior such as cardboard, a hollow molded article such as a container for liquid detergent, a stopper, a cap, or a container. It is also suitable for uses such as lids, injection molded articles such as ski shoes, covering electric wires and cables, and covering steel pipes. The ethylene / α-olefin copolymer of the present invention can be used as various multilayer films or laminated sheets by a dry lamination method, a coextrusion method, or an extrusion lamination method.
[0053]
【Example】
Next, the present invention will be described in more detail by way of examples, but the present invention is not limited thereto.
[0054]
The test method used in this experimental example is as follows.

[0055]
(Blown film molding)
The polymerized copolymer powder was granulated, and a die having a diameter of 100 mm and a lip gap of 2 mm was attached to a molding machine for LLDPE film of 50 mm φ, a blow ratio of 1.9, a take-up speed of 20 m / min, and a molding temperature of 200 ° C. To form a 30 μm thick film.
[0056]

[0057]
(Sheet forming method)
After homogenizing the copolymer with a roll, it was cut into chips, which were pressed at 180 ° C. to obtain sheets.

[0058]
Samples A1 to A5 used in Examples 1 to 5 were polymerized by the following method.
[0059]
(Preparation of solid catalyst)
Purified toluene was added to the catalyst preparation device (No. 1) with an electromagnetic induction stirrer under nitrogen, and then dipropoxydichlorozirconium (Zr (OPr)_Two Cl _Two ) And 48 g of methylcyclopentadiene were added, and 45 g of tridecylaluminum was added dropwise while maintaining the system at 0 ° C. After completion of the addition, the reaction system was maintained at 50 ° C and stirred for 16 hours. This solution is referred to as solution A. Next, purified toluene was added to another catalyst preparation device with a stirrer (No. 2) 2 under nitrogen, and the above solution A and then a 6.4 mol solution of methylaluminoxane in toluene were added and reacted. This is called liquid B.
[0060]
Next, purified toluene was added to a preparation device with a stirrer (No. 1) under nitrogen, and silica (Grade # 952, manufactured by Fuji Devison, surface area: 300 m) previously calcined at 400 ° C. for a predetermined time.²/ G) After adding 1400 g, the whole amount of the B solution was added, followed by stirring at room temperature. Then, the solvent was removed by nitrogen blowing to obtain a solid catalyst powder having good fluidity. This is designated as catalyst C.
[0061]
(Polymerization of sample A1)
Using a continuous fluidized bed gas phase polymerization apparatus, polymerization temperature 70 ° C, total pressure 20kgf / cm²G copolymerized ethylene and 1-butene. The gas composition in the system was 1-butene / ethylene molar ratio 0.12, ethylene concentration 60 mol%. The polymerization was carried out by continuously supplying the catalyst C, and each gas was continuously supplied in order to keep the gas composition in the system constant.
The physical properties of the produced copolymer are shown in Table 1.
[0062]
(Polymerization of sample A2)
The polymerization was carried out in the same manner as in (A1) except that the molar ratio of 1-butene / ethylene was changed. The physical properties of the copolymer are shown in Table 1 together with the experimental results.
[0063]
(Polymerization of Samples A3 to A5)
(A3), (A4) and (A5) were polymerized by performing the same operation as (A1) except that the comonomer was 1-pentene, 1-hexene and 4-methyl-pentene-1, respectively. The physical properties of the copolymer are shown in Table 1 together with the experimental results.
[0064]
(Polymerization of Samples A7 to A10)
The polymerization was carried out in the same manner as in (A1) except that the molar ratio of 1-butene / ethylene was changed. The physical properties of the copolymer are shown in Table 2 or Table 3 together with the experimental results.
[0065]
(Polymerization of sample B2)
25 L of purified toluene was placed in a 50 L pressure reactor equipped with a stirrer and purged with nitrogen. Next, 183 g of butene-1 was added, and a mixed solution of bis (n-butylcyclopentadienyl) zirconium dichloride and methylalumoxane [MAO] was further added in an amount of 0.33 mmol based on Zr (Al / Zr molar ratio = 500). Then, the temperature was raised to 80 ° C. Next, ethylene 9kg / cm²G. Polymerization was started so as to obtain G. Total pressure is 9 kg / cm while continuously polymerizing ethylene²While maintaining at G, polymerization was carried out for 1 hour to produce a copolymer. The physical properties of the copolymer are shown in Table 1 together with the experimental results.
[0066]
(Polymerization of sample B8)
Polymerization was carried out in the same manner as in (B2) except that 410 g of 1-butene was added. The physical properties of the copolymer are shown in Table 3 together with the experimental results.
[0067]
Samples (B1), (B3), (B7) and (B9) used in addition to the above were obtained by copolymerizing ethylene and 1-butene by a gas phase method or a slurry method using titanium tetrachloride and triethylaluminum catalyst. LLDPE or VLDPE. (B4) is a commercially available Ultex X 3010F (manufactured by Mitsui Petrochemical Co., Ltd.). The physical properties are shown in Tables 1 to 3 together with the experimental results.
[0068]
Examples 1 to 5
Table 1 shows the results of comparison of various physical properties after granulation according to the above-described procedure, followed by forming an inflation film.
[0069]
Comparative Examples 1-4
For comparison with Examples 1 to 5, similar operations were performed using the resins shown in Table 1. The results are shown in Table 1. Comparative Example 1 has dirt impact strength and transparency, Comparative Example 2 has a low melting point and poor heat resistance as shown in Table 1, and Comparative Examples 3 and 4 have been carried out in consideration of the type of α-olefin used. Dart strength and transparency are inferior to Examples 3 and 4.
[0070]
Example 6, Comparative Examples 5 to 6
The hot tack property was measured using the film obtained in Example 2, and compared with Comparative Examples 5 and 6 measured using the films obtained in Comparative Examples 1 and 2. Table 3 shows the results. Example 6 has a wide sealing temperature range where the peel distance is short.
[0071]
Examples 7-8, Comparative Examples 7-8
The sheet was formed by the above-mentioned method and subjected to a physical property test. Comparative Example 7 was inferior in tensile impact strength,Example 8 isPoor heat resistance.
[0072]
Examples 9 to 10, Comparative Example 9
A test piece was formed by injection molding according to the method described above, and a physical property test was performed. Comparative Example 9 is inferior in tensile impact strength and tensile breaking strength.
[0073]
[Table 1]

[0074]
[Table 2]

[0075]
[Table 3]

[0076]
[Table 4]

[Brief description of the drawings]
FIG. 1 is an elution temperature-elution amount curve obtained by TREF of the copolymer of the present invention.
FIG. 2 is an elution temperature-elution amount curve obtained by TREF of a copolymer using a metallocene catalyst.

Claims (4)

Produced by a catalyst obtained by bringing the following (C1) to (C5) into contact with each other;
(A) density 0.86-0.96 g / cm ³ , (B) melt flow rate (MFR) 0.01-200 g / 10 min, (C) molecular weight distribution (Mw / Mn) 1.8-3.5, (D) A copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms satisfying a composition distribution parameter (Cb) of 1.10 to 2.00 .
^{(C1): Me 1 R 1} p (OR 2) q X 1 4- p - q
(In the formula, Me ¹ represents Zr, Ti, Hf, R ¹ and R ² each represent a hydrogen atom having 1 to 24 carbon atoms, X ¹ represents a halogen atom, and p and q each represent 0 ≦ p + q ≦ It is an integer that satisfies the range of 4.)
(C2): Me ² R ³ _m (OR ⁴ ) _n X ² _{z - m - n}
(In the formula, Me ² is an element in Groups I to III of the periodic table, R ³ and R ⁴ are each a hydrocarbon group having 1 to 24 carbon atoms, X ² is a halogen atom or a hydrogen atom (provided that X ² is a hydrogen atom In the case, Me ² represents a group III element of the periodic table), z represents the valence of Me ² , and m and n satisfy the ranges of 0 ≦ m ≦ z and 0 ≦ n ≦ z, respectively. An integer and 0 ≦ m + n ≦ z
(C3): Organic cyclic compound having a conjugated double bond
(C4): a modified organoaluminum compound containing an Al-O-Al bond obtained by reacting an organoaluminum compound with water
(C5): inorganic carrier and / or particulate carrier The ethylene / α-olefin copolymer further has (E) an orthodichlorobenzene (ODCB) soluble content X (wt%) at 25 ° C., a density d and an MFR satisfying the following relationship (formula 1): The ethylene-α-olefin copolymer according to claim 1, characterized in that:
(Equation 1)
B) When d−0.008 × log MFR ≧ 0.93, X <2.0
B) When d−0.008 × log MFR <0.93, X <9.8 × 10 ³ × (0.9300−d + 0.008 × log MFR) ² +2.0 3. The ethylene-α-olefin copolymer according to claim 1, wherein a plurality of peaks of an elution temperature-elution amount curve obtained by (F) continuous heating elution fractionation (TREF) are used. 4. Ethylene - α-olefin copolymer. 4. The peak on the high temperature side among a plurality of peaks of the elution temperature-elution amount curve by the (F) continuous temperature elution fractionation method (TREF) is in the range of 85 to 100 ° C. 4. Ethylene - α-olefin copolymer.

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