JP3749606B2 - Easily openable ethylene resin composition - Google Patents

Description

【００３４】
式中、Ｍは、周期律表第IVＢ族の遷移金属原子であり、具体的には、チタニウム、ジルコニウム、ハフニウムであり、特に好ましくはジルコニウムである。
Ｒ¹ は、炭素原子数１〜６の炭化水素基である。
【００３５】
Ｒ² 、Ｒ⁴ 、Ｒ⁵ 、Ｒ⁶ は、それぞれ同一または相異なっていてもよく、水素原子、ハロゲン原子またはＲ¹ と同様の炭素原子数１〜６の炭化水素基である。Ｒ³ は、炭素原子数６〜１６のアリール基である。このアリール基は、ハロゲン原子、炭素原子数１〜２０の炭化水素基、有機シリル基で置換されていてもよい。
【００３６】
Ｘ¹ およびＸ² は、水素原子、ハロゲン原子、炭素原子数１〜２０の炭化水素基、酸素含有基またはイオウ含有基である。
Ｙは、炭素原子数１〜２０の２価の炭化水素基、炭素原子数１〜２０の２価のハロゲン化炭化水素基、２価のケイ素含有基、２価のゲルマニウム含有基等である。
【００３７】
このようなメタロセン化合物は、Journal of Organometallic Chem.288(1985)、第63〜67頁、ヨーロッパ特許出願公開第0,320,762 号明細書に準じて製造することができる。
【００３８】
上記文献に記載されている製造方法により得られた低密度エチレン・α- オレフィン共重合体（Ｃ）は、分子量分布および組成分布が狭く、長鎖分岐を持つため溶融張力が大きいという特徴を有している。
【００３９】
本発明で用いられるメタロセン系のエチレン・α- オレフィン共重合体は、上記のようなオレフィン重合用触媒の存在下に、気相、またはスラリー状あるいは溶液状の液相で種々の条件で、エチレンと炭素原子数３〜２０のα- オレフィンとを共重合させることにより得ることができる。また、チーグラー系重合触媒を用いる場合も、同様の条件でエチレン・α- オレフィン共重合体を製造することができる。
【００４０】
［上記エチレン・α- オレフィン共重合体以外のエチレン系重合体］
本発明で上記エチレン・α- オレフィン共重合体とともに、エチレン系樹脂（Ａ）を構成することがある他のエチレン系重合体としては、具体的には、高圧法低密度ポリエチレン、高密度ポリエチレン、エチレン・酢酸ビニル共重合体、エチレン・アクリル酸エチル共重合体、エチレン・アクリル酸メチル共重合体、エチレン・メタクリル酸共重合体、エチレン・アクリル酸共重合体、およびアイオノマーなどを挙げることができる。特に本発明に係るエチレン系樹脂組成物を押出ラミネートする場合は、溶融膜のネックインを小さくするために、エチレン系重合体を下記の割合で用いることが特に好ましい。
【００４１】
これらのエチレン系重合体は、上記のエチレン・α- オレフィン共重合体および他のエチレン系重合体の合計量１００重量％に対して、５０〜０重量％、好ましくは４０〜０重量％、さらに好ましくは３５〜０重量％の割合で用いることができる。
【００４２】
これらのエチレン系重合体のメルトフローレート（ASTM D 1238，190℃、荷重2.16kg）は、０．５〜５０ｇ／１０分、好ましくは１．０〜３０ｇ／１０分の範囲にある。これらのエチレン系重合体のメルトフローレートが０．５ｇ／１０分より小さいと、成形時のモーターの負荷が過大になり、高速成形が困難になる。また、このメルトフローレートが５０ｇ／１０分より大きいと、成形時の溶融膜が不安定となり、成形自体が困難になる。
【００４３】
4- メチル -1- ペンテン系重合体（Ｂ）
本発明で用いられる4-メチル-1- ペンテン系重合体（Ｂ）は、4-メチル-1- ペンテン単独重合体、4-メチル-1- ペンテンと炭素原子数２以上のα- オレフィンとの共重合体、または4-メチル-1- ペンテンとα- オレフィン以外のモノマーとの共重合体である。
【００４４】
4-メチル-1- ペンテンとの共重合に用いられる炭素原子数２以上のα- オレフィンとしては、具体的には、エチレン、プロピレン、1-ブテン、1-ペンテン、1-ヘキセン、1-ヘプテン、1-オクテン、1-デセン、1ーテトラデセン、1-ヘキサデセン、1-オクタデセン、1-エイコセンなどが挙げられる。中でも、炭素原子数４〜２４のα- オレフィンが好ましく、炭素原子数６〜１８のα- オレフィンが更に好ましい。特に1-デセン、1-ヘキサデセン、1-オクタデセンが好ましい。これらのα- オレフィンは、単独あるいは２種以上組み合わせて用いることができる。
【００４５】
上記のα- オレフィン以外のモノマーとしては、具体的にはブタジエン、ジシクロペンタジエン、エチリデンノルボルネン、メチルアクリルレート、メチルメタクリレート、エチルアクリレート、エチルメタクリレートなどが挙げられる。
【００４６】
本発明では、特に4-メチル-1- ペンテン単独重合体、および4-メチル-1- ペンテンから誘導される繰り返し単位を９４重量％以上含む、4-メチル-1- ペンテンと炭素原子数４〜２４のα- オレフィンとの共重合体が好ましい。
【００４７】
本発明で用いられる4-メチル-1- ペンテン系重合体（Ｂ）は、メルトフローレート（ＭＦＲ；ASTM D 1238，260℃、荷重 5.0kg）が１〜３００ｇ／１０分、好ましくは１０〜２７０ｇ／１０分、さらに好ましくは１５〜２５０ｇ／１０分の範囲内にある。
【００４８】
本発明に係るエチレン系樹脂組成物の易開封性は、4-メチル-1- ペンテン系重合体（Ｂ）のメルトフローレートが大きい程その効果が大きく、従って4-メチル-1- ペンテン系重合体（Ｂ）の添加量は少量で済むが、メルトフローレートが３００ｇ／１０分を超えると、ヒートシール強度が低くなり過ぎたり、4-メチル-1- ペンテン系重合体（Ｂ）の添加量の少しのバラツキによってヒートシール強度が大きく振れる不具合を生じる。また、4-メチル-1- ペンテン系重合体（Ｂ）のメルトフローレートが１ｇ／１０分未満であると、易開封性が不充分なエチレン系樹脂組成物しか得られない。
【００４９】
4-メチル-1- ペンテン系重合体（Ｂ）は、密度（ASTM D 1505)が通常０．８３０〜０．８３５ｇ／ｃｍ³ 、好ましくは０．８３２〜０．８３５ｇ／ｃｍ³ の範囲内にある。
【００５０】
上記のような4-メチル-1- ペンテン系重合体（Ｂ）は、たとえば従来公知の以下のような触媒および方法を用いて製造することができる。
(i) チタン触媒成分、
(ii)有機金属化合物触媒成分、および
(iii) 下記一般式で表わされる有機ケイ素化合物触媒成分
Ｒ_nＳｉ（ＯＲ’）_4-n
（式中、ＲおよびＲ’は炭化水素基であり、０＜ｎ＜４である。）
から形成される重合用触媒の存在下に、約２０〜１００℃の温度で、4-メチル-1- ペンテンを重合させるか、または4-メチル-1- ペンテンと前記α- オレフィンとを共重合させることによって得られる。この際には、たとえば上述したα- オレフィン以外のモノマーを少量共重合させてもよい。
【００５１】
本発明においては、4-メチル-1- ペンテン系重合体（Ｂ）は、エチレン系樹脂（Ａ）１００重量部に対して、０．５〜７０重量部、好ましくは１〜６０重量部、さらに好ましくは２〜５０重量部の割合で用いられる。
【００５２】
その他の成分
本発明に係る易開封性エチレン系樹脂組成物中に、上記エチレン系樹脂（Ａ）および4-メチル-1- ペンテン系重合体（Ｂ）の他に、必要に応じて、従来公知のアンチブロッキング剤、静電防止剤、酸化防止剤、耐候安定剤、熱安定剤、滑剤などの添加剤を、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。
【００５３】
上記アンチブロッキング剤としては、具体的には、天然シリカ、合成シリカ、ゼオライト、非晶質ゼオライト、ケイソウ土、ポリアクリル酸エステル、ポリメタクリル酸エステルなどが挙げられる。中でも、ゼオライト、非晶質ゼオライト、天然シリカ、合成シリカが好ましく用いられる。
【００５４】
易開封性エチレン系樹脂組成物
本発明に係る易開封性エチレン系樹脂組成物は、そのフィルムの引張弾性率が５００〜３，６００ｋｇｆ／ｃｍ² 、好ましくは６００〜３，５００ｋｇｆ／ｃｍ² 、さらに好ましくは７００〜３，４００ｋｇｆ／ｃｍ² の範囲内にある。
【００５５】
また、本発明に係る易開封性エチレン系樹脂組成物をシーラント層として直接またはポリエチレン系樹脂を介してラミネート基材と複合した積層体のシーラント層同士を１２０〜２００℃でヒートシールしたとき、そのヒートシール強度が０．２〜１．６ｋｇ／15ｍｍ、好ましくは０．３〜１．６ｋｇ／15ｍｍ、さらに好ましくは０．５〜１．５ｋｇ／15ｍｍの範囲内にある。
【００５６】
なお、引張弾性率とヒートシール強度の求め方は、実施例の項において、後述する。
本発明に係る易開封性エチレン系樹脂組成物から形成されたフィルムのヒートシール強度と引張弾性率とが上記範囲内にあると、適度な腰があり、かつ、易開封性の包装材料が得られる。
【００５７】
上記積層体を製造する際に用いられるポリエチレン系樹脂としては、低密度ポリエチレン、中密度ポリエチレン、エチレン・プロピレン共重合体やエチレン・1-ブテン共重合体のようなエチレン・α- オレフィン共重合体等のエチレン系樹脂が好ましく用いられる。。
【００５８】
また、上記ラミネート基材としては、具体的には、ポリプロピレンフィルム、ポリアミドフィルム、ポリエステルフィルム、アルミニウム箔、紙、板紙などが挙げられる。
【００５９】
上記ポリアミドフィルムとしては、特に制限はないが、具体的には、ナイロン−６、ナイロン−１１、ナイロン−６６、ナイロン−６１０などのフィルムが挙げられる。
【００６０】
上記ポリエステルフィルムとしては、特に制限はないが、具体的には、テレフタール酸とエチレングリコールとの縮合ポリエステルであるポリエチレンテレフタレート、テレフタル酸- イソフタル酸- エチレングリコールの共重合ポリエステル、テレフタル酸とシクロヘキサン-1,4- ジメタノールとからなるポリエステルなどのフィルムが挙げられる。
【００６１】
上記のポリプロピレンフィルム、ポリアミドフィルムおよびポリエステルフィルムは、２軸延伸されたフィルムであることが好ましい。
本発明に係る易開封性エチレン系樹脂組成物は、上記の各成分を従来公知の方法、たとえばヘンシェルミキサー、Ｖ- ブレンダー、リボンブレンダー、タンブラーブレンダー等で混合する方法、あるいはこのような方法で混合して得られた混合物を、さらに一軸押出機、二軸押出機、ニーダー、バンバリーミキサー等で溶融混練した後、造粒あるいは得られた樹脂塊を粉砕することによって得ることができる。
【００６２】
上記のような方法で得られたエチレン系樹脂組成物から、まずフィルムを製造し、次いで、従来公知の方法で袋状の包装材料を製造することができる。
本発明に係るエチレン系樹脂組成物のフィルムは、Ｔダイ付き押出機やインフレーション成形機を用いて成形することができ、フィルムの厚さは、特に制限はないが、通常１０〜１５０μｍである。
【００６３】
また、本発明に係るエチレン系樹脂組成物を用いて、ポリプロピレンフィルム、ポリアミドフィルム、ポリエステルフィルム、アルミニウム箔、紙または板紙等のフィルムないしシート状物（ラミネート基材）との多層フィルムを製造することができる。この際ラミネート基材上に、本発明に係るエチレン系樹脂組成物をフィルム状に押し出し、接合し、冷却することにより多層フィルムを製造することができる。
【００６４】
さらに、上述したフィルム製造方法により、本発明に係るエチレン系樹脂組成物からポリエチレンフィルムを製造した後、このポリエチレンフィルムを、ラミネート基材とウレタン系等の接着剤を介して接合し、多層フィルムを製造することもできる。
【００６５】
また、本発明に係るエチレン系樹脂組成物を、上記ポリエチレン系樹脂を介してラミネート基材に接合してもよい。具体的には、（１）上記ラミネート基材に予めポリエチレン系樹脂を積層した多層フィルム上に、本発明に係るエチレン系樹脂組成物を押出して接合し冷却する方法、（２）ラミネート基材上に、ポリエチレン系樹脂と本発明に係るエチレン系樹脂組成物を共押出して接合し冷却する方法、および（３）ラミネート基材と、本発明に係るエチレン系樹脂組成物からなるフィルム状物とを、上記ポリエチレン系樹脂の溶融物を用いて接合し冷却する方法などが挙げられる。
【００６６】
上記のようにして製造される多層フィルムは２層構造の多層フィルムであるが、さらに、この２層構造を含む３層以上の層構造を有する多層フィルムとしてもよい。ただし、このような多層フィルムにおいては、本発明に係るエチレン系樹脂組成物からなる層をシーラント層（ヒートシール層）とする。
【００６７】
【発明の効果】
本発明に係る易開封性エチレン系樹脂組成物は、包装材料として必要なヒートシール強度を保持しつつ、易開封性と剛性とのバランスに優れた包装材料を提供することができる。したがって、食品等の包装材料としてフィルム成形、および製袋加工ができ、かつ衛生的な包装を可能とする。そして、弱い力で左右に引っ張って開封することが容易にできる。
【００６８】
また、本発明に係る易開封性エチレン系樹脂組成物は、ポリプロピレンフィルム、ポリアミドフィルム、ポリエステルフィルム、アルミニウム箔、紙または板紙等のフィルムないしシート状物用のシール材として用いることができるので、ガスバリヤー性等を要する食品等、多様な商品の包装に利用することができる。
【００６９】
【実施例】
以下、本発明を実施例により説明するが、本発明は、これら実施例に限定されるものではない。
【００７０】
なお、実施例および比較例で得られたラミネートフィルムの、引張弾性率（剛性）、易開封性およびホットタック性については、下記の試験方法により試験を行なった。
＜試験方法＞
【００７１】
（１）引張弾性率（剛性）
熱プレスした２ｍｍ厚のシートについて、クロスヘッド移動速度一定型引張り試験機（インストロン社製）を用いて引張試験を行なった。
［試験条件］
試 料：ＪＩＳ Ｋ ６７８１
雰囲気温度：２３℃
引張り速度：５００ｍｍ／分
チャート速度：２００ｍｍ／分
【００７２】
上記試験で得られたチャートから次式によりシートの引張弾性率を計算し、求めた値の平均値を引張弾性率（Ｅ）とした。
Ｅ₀ ＝Ｒ₀（Ｌ₀／Ａ）
［式中、Ｅ₀ は引張弾性率（ヤング率）を、Ｒ₀ は初期勾配を、Ｌ₀ はチャック間距離を、Ａは試料作製時の最小面積をそれぞれ示す。］
このＲ₀ は、次式により計算した。
Ｒ₀ ＝Ｆ₁ ／Ｌ₁
［式中、Ｆ₁ は初期接線上の任意の点の荷重を、Ｌ₁ は接線上のＦ₁ に相当する伸びをそれぞれ示す。］
【００７３】
（２）易開封性、ヒートシール強度
ニューロングＨＳ−３３Ｄトップシーラ［商品名、テスター産業（株）製］でフィルムを流れ方向と直角にヒートシールした後、クロスヘッド移動速度一定型引張試験機（インストロン社製）で引張試験を行なって破断強度を測定し、この破断強度をヒートシール強度とした。クロスヘッド移動速度は、３００ｍｍ／分とした。上記ヒートシールは、１２０℃、１４０℃および１６０℃の各シール温度で行なった。
また、易開封性の評価は、次のような基準で行なった。
良好 ・・・ ０．２〜１．６kg／15mm
不良 ・・・ ＜０．２kg／15mm（シール不良）、または＞１．６kg／15mm
【００７４】
（３）ホットタック性（ホットタック剥離距離）
２枚の積層フィルム試験片（長さ５５０ｍｍ×幅２０ｍｍ）の同一端部にガイドロールを介して、４５ｇの錘を別々につけ、この試験片同士を重ね合わせて、１２０℃、１４０℃および１６０℃の各温度で幅５ｍｍ、長さ３００ｍｍのシールバーにより、２ｋｇ／ｃｍ² の圧力で１秒間シールした後、シールバーを試験片から離すと同時にシール部に、２３度の角度で錘による剥離力が作用するようにして（この角度は錘をかけるガイドロールの位置関係を調整することにより調整される）シール部を強制剥離し、剥離した距離（mm）を測定し、この剥離距離をもってホットタック性の評価を行なった。剥離距離の短いものほどホットタック性に優れている。
【００７５】
【実施例１】
メタロセン系触媒を使用して、溶液重合法により製造したエチレン・α- オレフィン共重合体（ＥＣ−１）［エチレン・1-オクテン共重合体；エチレン含量＝７８重量％、密度(ASTM D 1505）＝０．８９５ｇ／ｃｍ³ 、ＭＦＲ（ASTM D 1238, 190℃、荷重2.16kg）＝４．０ｇ／１０分］１００重量部に対して、4-メチル-1- ペンテン共重合体（ＰＭＰ−１）［4-メチル-1- ペンテン・1-デセン共重合体；4-メチル-1- ペンテン含量＝９５重量％、1-デセン含量＝５重量％、密度(ASTM D 1505）＝０．８３３ｇ／ｃｍ³ 、ＭＦＲ（ASTM D 1238，260℃、荷重 5kg）＝２０ｇ／１０分］を３０重量部添加してエチレン系樹脂組成物を得た。
【００７６】
次いで、Ｔダイフィルム成形機を用いて、成形温度２３０〜２４０℃、および成形速度２０ｍ／分の条件で、上記組成物から厚さ４０μｍのフィルムを成形した。
【００７７】
得られたフィルムの片面をコロナ放電処理した後、このフィルムと、表面にウレタン系接着剤を塗布した厚さ１５μｍの二軸延伸ナイロンフィルムとを圧着し、エチレン系樹脂組成物をシーラント層（ヒートシール層）とする厚さ約５５μｍのドライラミネートフィルムを製造した。
【００７８】
上記のようにして得られたラミネートフィルムの易開封性、ヒートシール強度およびホットタック性について上記の方法による試験を行なった。
また、上記エチレン系樹脂組成物について、引張弾性率を上記の方法に従って求めた。
【００７９】
結果を第１表に示す。
【００８０】
【実施例２】
エチレン・α- オレフィン共重合体（ＥＣ−１）１００重量部に対して、4-メチル-1- ペンテン共重合体（ＰＭＰ−２）［4-メチル-1- ペンテン・1-オクタデセン共重合体；4-メチル-1- ペンテン含量＝９５重量％、1-オクタデセン含量＝５重量％、密度(ASTM D 1505）＝０．８３３ｇ／ｃｍ³ 、ＭＦＲ（ASTM D 1238，260℃、荷重 5kg）＝１８０ｇ／１０分］を５重量部添加してエチレン系樹脂組成物を得た。
【００８１】
以下、実施例１と同様にして、この組成物をシーラント層とする厚さ約５５μｍのドライラミネートフィルムを得た。
上記のようにして得られたラミネートフィルムの易開封性、ヒートシール強度およびホットタック性について上記の方法による試験を行なった。
【００８２】
また、上記エチレン系樹脂組成物について、引張弾性率を上記の方法に従って求めた。
結果を第１表に示す。
【００８３】
【実施例３】
メタロセン系触媒を使用して、溶液重合法により製造したエチレン・α- オレフィン共重合体（ＥＣ−２）［エチレン・1-オクテン共重合体；エチレン含量＝７８重量％、密度(ASTM D 1505）＝０．８９５ｇ／ｃｍ³ 、ＭＦＲ（ASTM D 1238, 190℃、荷重2.16kg）＝１５．０ｇ／１０分］７０重量部、および高圧法低密度ポリエチレン（ＬＤ−１）［エチレン含量＝１００重量％、密度(ASTM D 1505）＝０．９１７ｇ／ｃｍ³ 、ＭＦＲ（ASTM D 1238, 190℃、荷重2.16kg）＝７．２ｇ／１０分］３０重量部に対して、4-メチル-1- ペンテン共重合体（ＰＭＰ−１）を３０重量部添加してエチレン系樹脂組成物を得た。
【００８４】
次いで、厚さ１５μｍの二軸延伸ナイロンフィルム上にウレタン系アンカーコート剤を塗布し、その塗布面に、高圧法低密度ポリエチレン（ＬＤ−１）を厚さ２５μｍになるように押出しラミネートした。
【００８５】
次いで、この高圧法低密度ポリエチレン（ＬＤ−１）層上に、上記エチレン系樹脂組成物を、加工速度６０ｍ／分、ダイ下樹脂温度２９０〜２９５℃、厚さ４０μｍの条件で押出しラミネートし、この組成物をシーラント層とする厚さ約８０μｍの押出しラミネートフィルムを製造した。
【００８６】
上記のようにして得られたラミネートフィルムの易開封性、ヒートシール強度およびホットタック性について上記の方法による試験を行なった。
また、上記エチレン系樹脂組成物について、引張弾性率を上記の方法に従って求めた。
【００８７】
結果を第１表に示す。
【００８８】
【実施例４】
実施例３において、4-メチル-1- ペンテン共重合体（ＰＭＰ−１）３０重量部を4-メチル-1- ペンテン共重合体（ＰＭＰ−２）５重量部に変更した以外は、実施例３と同様にして、エチレン系樹脂組成物を得た。
【００８９】
以下、実施例３と同様にして、この組成物からなる厚さ４０μｍのシーラント層を含む厚さ約８０μｍの押出しラミネートフィルムを得た。
上記のようにして得られたラミネートフィルムの易開封性、ヒートシール強度およびホットタック性について上記の方法による試験を行なった。
【００９０】
また、上記エチレン系樹脂組成物について、引張弾性率を上記の方法に従って求めた。
結果を第１表に示す。
【００９１】
【実施例５】
メタロセン系触媒を使用して、気相重合法により製造したエチレン・α- オレフィン共重合体（ＥＣ−３）［エチレン・1-ヘキセン共重合体；エチレン含量＝８９重量％、密度(ASTM D 1505）＝０．９１５ｇ／ｃｍ³ 、ＭＦＲ（ASTM D 1238, 190℃、荷重2.16kg）＝１５．０ｇ／１０分］６０重量部、メタロセン系触媒を使用して、溶液重合法により製造したエチレン・α- オレフィン共重合体（ＥＣ−４）［エチレン・1-ブテン共重合体；エチレン含量＝８２重量％、密度(ASTM D 1505）＝０．８８５ｇ／ｃｍ³ 、ＭＦＲ（ASTM D 1238, 190℃、荷重2.16kg）＝３．６ｇ／１０分］１０重量部、および高圧法低密度ポリエチレン（ＬＤ−１）３０重量部に対して、4-メチル-1- ペンテン共重合体（ＰＭＰ−２）を５重量部添加してエチレン系樹脂組成物を得た。
以下、実施例３と同様にして、この組成物からなる厚さ４０μｍのシーラント層を含む厚さ約８０μｍの押出しラミネートフィルムを得た。
【００９２】
上記のようにして得られたラミネートフィルムの易開封性、ヒートシール強度およびホットタック性について上記の方法による試験を行なった。
また、上記エチレン系樹脂組成物について、引張弾性率を上記の方法に従って求めた。
【００９３】
結果を第１表に示す。
【００９４】
【実施例６】
チーグラー系触媒を使用して、溶液重合法により製造したエチレン・α- オレフィン共重合体（ＥＣ−５）［エチレン・4-メチル-1- ペンテン共重合体；エチレン含量＝９０重量％、密度(ASTM D 1505）＝０．９２０ｇ／ｃｍ³ 、ＭＦＲ（ASTM D 1238, 190℃、荷重2.16kg）＝２．０ｇ／１０分］８０重量部、およびエチレン・α- オレフィン共重合体（ＥＣ−４）２０重量部に対して、4-メチル-1- ペンテン共重合体（ＰＭＰ−１）を３０重量部添加してエチレン系樹脂組成物を得た。
【００９５】
以下、実施例１と同様にして、この組成物を厚さ４０μｍのシーラント層とする厚さ約５５μｍのドライラミネートフィルムを得た。
上記のようにして得られたラミネートフィルムの易開封性、ヒートシール強度およびホットタック性について上記の方法による試験を行なった。
【００９６】
また、上記エチレン系樹脂組成物について、引張弾性率を上記の方法に従って求めた。
結果を第１表に示す。
【００９７】
【実施例７】
チーグラー系触媒を使用して、溶液重合法により製造したエチレン・α- オレフィン共重合体（ＥＣ−６）［エチレン・4-メチル-1- ペンテン共重合体；エチレン含量＝９４重量％、密度(ASTM D 1505）＝０．９３０ｇ／ｃｍ³ 、ＭＦＲ（ASTM D 1238, 190℃、荷重2.16kg）＝２．０ｇ／１０分］６０重量部、およびメタロセン系触媒を使用して、溶液重合法により製造したエチレン・α- オレフィン共重合体（ＥＣ−７）［エチレン・1-ブテン共重合体；エチレン含量＝７４重量％、密度(ASTM D 1505）＝０．８７０ｇ／ｃｍ³ 、ＭＦＲ（ASTM D 1238, 190℃、荷重2.16kg）＝３．６ｇ／１０分］４０重量部に対して、4-メチル-1- ペンテン共重合体（ＰＭＰ−２）を５重量部添加してエチレン系樹脂組成物を得た。
【００９８】
以下、実施例１と同様にして、この組成物を厚さ４０μｍのシーラント層とする厚さ約５５μｍのドライラミネートフィルムを得た。
上記のようにして得られたラミネートフィルムの易開封性、ヒートシール強度およびホットタック性について上記の方法による試験を行なった。
【００９９】
また、上記エチレン系樹脂組成物について、引張弾性率を上記の方法に従って求めた。
結果を第１表に示す。
【０１００】
【実施例８】
チーグラー系触媒を使用して、溶液重合法により製造したエチレン・α- オレフィン共重合体（ＥＣ−８）［エチレン・4-メチル-1- ペンテン共重合体；エチレン含量＝８８重量％、密度(ASTM D 1505）＝０．９１５ｇ／ｃｍ³ 、ＭＦＲ（ASTM D 1238, 190℃、荷重2.16kg）＝１５．０ｇ／１０分］６０重量部、エチレン・α- オレフィン共重合体（ＥＣ−４）１０重量部、および高圧法低密度ポリエチレン（ＬＤ−１）３０重量部に対して、4-メチル-1- ペンテン共重合体（ＰＭＰ−２）を５重量部添加してエチレン系樹脂組成物を得た。
【０１０１】
以下、実施例３と同様にして、この組成物からなる厚さ４０μｍのシーラント層を含む厚さ約８０μｍの押出しラミネートフィルムを得た。
上記のようにして得られたラミネートフィルムの易開封性、ヒートシール強度およびホットタック性について上記の方法による試験を行なった。
【０１０２】
また、上記エチレン系樹脂組成物について、引張弾性率を上記の方法に従って求めた。
結果を第１表に示す。
【０１０３】
【実施例９】
エチレン・α- オレフィン共重合体（ＥＣ−８）４５重量部、エチレン・α- オレフィン共重合体（ＥＣ−４）２５重量部、および高圧法低密度ポリエチレン（ＬＤ−１）３０重量部に対して、4-メチル-1- ペンテン共重合体（ＰＭＰ−１）を６５重量部添加してエチレン系樹脂組成物を得た。
【０１０４】
以下、実施例３と同様にして、この組成物からなる厚さ４０μｍのシーラント層を含む厚さ約８０μｍの押出しラミネートフィルムを得た。
上記のようにして得られたラミネートフィルムの易開封性、ヒートシール強度およびホットタック性について上記の方法による試験を行なった。
【０１０５】
また、上記エチレン系樹脂組成物について、引張弾性率を上記の方法に従って求めた。
結果を第１表に示す。
【０１０６】
【実施例１０】
エチレン・α- オレフィン共重合体（ＥＣ−８）６０重量部、エチレン・α- オレフィン共重合体（ＥＣ−４）１０重量部、および高圧法低密度ポリエチレン（ＬＤ−１）３０重量部に対して、4-メチル-1- ペンテン共重合体（ＰＭＰ−２）を５重量部添加してエチレン系樹脂組成物を得た。
【０１０７】
以下、実施例３と同様にして、この組成物からなる厚さ４０μｍのシーラント層を含む厚さ約８０μｍの押出しラミネートフィルムを得た。
上記のようにして得られたラミネートフィルムの易開封性、ヒートシール強度およびホットタック性について上記の方法による試験を行なった。
【０１０８】
また、上記エチレン系樹脂組成物について、引張弾性率を上記の方法に従って求めた。
結果を第１表に示す。
【０１０９】
【実施例１１】
エチレン・α- オレフィン共重合体（ＥＣ−２）８０重量部、および高圧法低密度ポリエチレン（ＬＤ−２）［エチレン含量＝１００重量％、密度(ASTM D 1505）＝０．９１９ｇ／ｃｍ³ 、ＭＦＲ（ASTM D 1238, 190℃、荷重2.16kg）＝３．１ｇ／１０分］２０重量部に対して、4-メチル-1- ペンテン重合体（ＰＭＰ−３）［4-メチル-1- ペンテン含量＝１００重量％、密度(ASTM D 1505）＝０．８３５ｇ／ｃｍ³ 、ＭＦＲ（ASTM D 1238，260℃、荷重 5kg）＝１１０ｇ／１０分］を１０重量部添加してエチレン系樹脂組成物を得た。
【０１１０】
以下、実施例３と同様にして、この組成物からなる厚さ４０μｍのシーラント層を含む厚さ約８０μｍの押出しラミネートフィルムを得た。
上記のようにして得られたラミネートフィルムの易開封性、ヒートシール強度およびホットタック性について上記の方法による試験を行なった。
【０１１１】
また、上記エチレン系樹脂組成物について、引張弾性率を上記の方法に従って求めた。
結果を第１表に示す。
【０１１２】
【比較例１】
実施例１において、4-メチル-1- ペンテン共重合体（ＰＭＰ−１）を用いなかった以外は、実施例１と同様にして、エチレン・α- オレフィン共重合体（ＥＣ−１）を厚さ４０μｍのシーラント層とする厚さ約５５μｍのドライラミネートフィルムを得た。
【０１１３】
上記のようにして得られたラミネートフィルムの易開封性、ヒートシール強度およびホットタック性について上記の方法による試験を行なった。
また、上記エチレン系樹脂組成物について、引張弾性率を上記の方法に従って求めた。
【０１１４】
結果を第１表に示す。
【０１１５】
【比較例２】
実施例３において、4-メチル-1- ペンテン共重合体（ＰＭＰ−１）を用いなかった以外は、実施例３と同様にして、エチレン・α- オレフィン共重合体（ＥＣ−２）７０重量部と高圧法低密度ポリエチレン（ＬＤ−１）３０重量部とからなる厚さ４０μｍのシーラント層と含む厚さ約８０μｍの押出しラミネートフィルムを得た。
【０１１６】
上記のようにして得られたラミネートフィルムの易開封性、ヒートシール強度およびホットタック性について上記の方法による試験を行なった。
また、上記エチレン系樹脂組成物について、引張弾性率を上記の方法に従って求めた。
【０１１７】
結果を第１表に示す。
【０１１８】
【比較例３】
実施例５において、4-メチル-1- ペンテン共重合体（ＰＭＰ−２）を用いなかった以外は、実施例５と同様にして、エチレン・α- オレフィン共重合体（ＥＣ−３）６０重量部とエチレン・α- オレフィン共重合体（ＥＣ−４）１０重量部と高圧法低密度ポリエチレン（ＬＤ−１）３０重量部とからなる厚さ４０μｍのシーラント層と含む厚さ約８０μｍの押出しラミネートフィルムを得た。
【０１１９】
上記のようにして得られたラミネートフィルムの易開封性、ヒートシール強度およびホットタック性について上記の方法による試験を行なった。
また、上記エチレン系樹脂組成物について、引張弾性率を上記の方法に従って求めた。
【０１２０】
結果を第１表に示す。
【０１２１】
【比較例４】
実施例６において、4-メチル-1- ペンテン共重合体（ＰＭＰ−１）を用いなかった以外は、実施例６と同様にして、エチレン・α- オレフィン共重合体（ＥＣ−５）８０重量部とエチレン・α- オレフィン共重合体（ＥＣ−４）２０重量部とからなる厚さ４０μｍのシーラント層を含む厚さ約５５μｍのドライラミネートフィルムを得た。
【０１２２】
上記のようにして得られたラミネートフィルムの易開封性、ヒートシール強度およびホットタック性について上記の方法による試験を行なった。
また、上記エチレン系樹脂組成物について、引張弾性率を上記の方法に従って求めた。
【０１２３】
結果を第１表に示す。
【０１２４】
【比較例５】
実施例６において、4-メチル-1- ペンテン共重合体（ＰＭＰ−１）の添加量を８０重量部に変更した以外は、実施例６と同様にして、エチレン系樹脂組成物を得た。
【０１２５】
以下、実施例６と同様にして、この組成物を厚さ４０μｍのシーラント層とする厚さ約５５μｍのドライラミネートフィルムを得た。
上記のようにして得られたラミネートフィルムの易開封性、ヒートシール強度およびホットタック性について上記の方法による試験を行なった。
【０１２６】
また、上記エチレン系樹脂組成物について、引張弾性率を上記の方法に従って求めた。
結果を第１表に示す。
【０１２７】
【比較例６】
実施例７において、4-メチル-1- ペンテン共重合体（ＰＭＰ−２）を用いなかった以外は、実施例７と同様にして、エチレン・α- オレフィン共重合体（ＥＣ−６）６０重量部とエチレン・α- オレフィン共重合体（ＥＣ−７）４０重量部とからなる厚さ４０μｍのシーラント層を含む厚さ約５５μｍのドライラミネートフィルムを得た。
【０１２８】
上記のようにして得られたラミネートフィルムの易開封性、ヒートシール強度およびホットタック性について上記の方法による試験を行なった。
また、上記エチレン系樹脂組成物について、引張弾性率を上記の方法に従って求めた。
【０１２９】
結果を第１表に示す。
【０１３０】
【比較例７】
実施例８において、4-メチル-1- ペンテン共重合体（ＰＭＰ−２）を用いなかった以外は、実施例８と同様にして、エチレン・α- オレフィン共重合体（ＥＣ−８）６０重量部とエチレン・α- オレフィン共重合体（ＥＣ−４）１０重量部と高圧法低密度ポリエチレン（ＬＤ−１）３０重量部とからなる組成物を厚さ４０μｍのシーラント層とする厚さ約８０μｍの押出しラミネートフィルムを得た。
【０１３１】
上記のようにして得られたラミネートフィルムの易開封性、ヒートシール強度およびホットタック性について上記の方法による試験を行なった。
また、上記エチレン系樹脂組成物について、引張弾性率を上記の方法に従って求めた。
【０１３２】
結果を第１表に示す。
【０１３３】
【比較例８】
実施例１１において、4-メチル-1- ペンテン重合体（ＰＭＰ−３）を用いなかった以外は、実施例１１と同様にして、エチレン・α- オレフィン共重合体（ＥＣ−２）８０重量部と高圧法低密度ポリエチレン（ＬＤ−２）２０重量部とからなる組成物を厚さ４０μｍのシーラント層とする厚さ約８０μｍの押出しラミネートフィルムを得た。
【０１３４】
上記のようにして得られたラミネートフィルムの易開封性、ヒートシール強度およびホットタック性について上記の方法による試験を行なった。
また、上記エチレン系樹脂組成物について、引張弾性率を上記の方法に従って求めた。
【０１３５】
結果を第１表に示す。
【０１３６】
【表１】

【０１３７】
【表２】

【０１３８】
【表３】

【０１３９】
【表４】

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an easily openable ethylene-based resin composition, and more particularly, an easily openable ethylene-based resin capable of providing a packaging material excellent in balance between easy-openability and rigidity, for example, a food packaging material. Relates to the composition.
[0002]
TECHNICAL BACKGROUND OF THE INVENTION
In food packaging materials, particularly packaging materials for confectionery bags such as rice crackers, the heat-sealed portion of the packaging material is opened by hand pulling, but if the heat-sealing strength is high, it is difficult to open the packaging. However, if the heat seal strength is too low, it cannot be used as a packaging material. Therefore, in bag-shaped packaging materials, it is required to appropriately control the heat seal strength.
[0003]
One of the control methods is known to improve by blending polyethylene with poly 1-butene, but the heat seal strength of the packaging material is certainly better than that with polyethylene without poly 1-butene blend. However, when opened, a phenomenon of pulling the yarn from the peeled surface of the heat seal portion appears and the appearance is impaired.
[0004]
As another heat seal strength control method, a method of blending polypropylene with 4-methyl-1-pentene resin is also known. For example, Japanese Patent Application Laid-Open No. 63-87221 describes an easy-cleavage film obtained by mixing 15 to 45 parts by weight of methylpentene resin with 100 parts by weight of polypropylene resin. Japanese Laid-Open Patent Publication No. 63-87229 discloses that a layer made of 15 to 45 parts by weight of a methylpentene resin is laminated on at least one side of a layer made of a polypropylene resin with respect to 100 parts by weight of the polypropylene resin. A cleaving laminated film is described.
[0005]
However, the single-layer or laminated film described in these publications can lower the heat seal strength, but the rigidity increases as the amount of 4-methyl-1-pentene resin is increased. As a bag-like food packaging material, it is too strong and not necessarily suitable.
[0006]
Therefore, the emergence of an ethylene-based resin composition that can provide a packaging material excellent in the balance between easy-openability and rigidity while maintaining the heat seal strength necessary for the packaging material is desired.
[0007]
OBJECT OF THE INVENTION
The present invention seeks to solve the problems associated with the prior art as described above, and provides a packaging material having an excellent balance between easy-openability and rigidity while maintaining the heat seal strength required as a packaging material. It aims at providing the easily openable ethylene-type resin composition which can be obtained.
[0008]
SUMMARY OF THE INVENTION
  The easy-open ethylene resin composition according to the present invention is
  Having structural units derived from ethylene in an amount of 60 to 99% by weight;Density is 0.860-0.940g / cm^Three100 parts by weight of an ethylene-based resin (A) containing at least 50% by weight of an ethylene / α-olefin copolymer having a melt flow rate (ASTMD 1238, 190 ° C., load 2.16 kg) of 0.5 to 50 g / 10 min Against
  An ethylene resin composition comprising 0.5 to 70 parts by weight of a 4-methyl-1-pentene polymer (B), and a hot-pressed 2 mm thick sheet formed from the composition, A tensile test was performed at a tensile speed of 500 mm / min with a constant crosshead moving speed type tensile tester, and the tensile modulus obtained from the following formula (1) from the obtained chart was 500 to 3,600 kgf / cm.²And
  When the sealant layers of the laminate obtained by combining the composition as a sealant layer directly or via a polyethylene-based resin are heat-sealed at 120 to 200 ° C. perpendicular to the flow direction, the crosshead moving speed is constant. The heat seal strength obtained as a breaking strength measured by performing a tensile test with a mold tensile tester at a crosshead moving speed of 300 mm / min is 0.2 to 1.6 kg / 15 mm.
    E₀= R₀(L₀/ A) ... (1)
(In formula (1), E₀ Is the tensile modulus, R₀ Is the initial slope, L₀ Represents the distance between chucks, and A represents the minimum area during sample preparation. R₀ Is a value calculated by the following equation.
  R₀ = F₁ / L₁(Where F₁ Is the load at any point on the initial tangent, L₁ Is tangential F₁ Shows the elongation corresponding to
[0009]
The ethylene / α-olein copolymer is preferably an ethylene / α-olefin copolymer produced using a Ziegler- or metallocene olefin polymerization catalyst.
[0010]
The easily openable ethylene-based resin composition according to the present invention can be suitably used for a sealant layer of a laminate substrate made of polypropylene film, polyamide film, polyester film, aluminum foil, paper, paperboard, or the like.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the easily openable ethylene resin composition according to the present invention will be described in detail. The easily openable ethylene-based resin composition according to the present invention comprises an ethylene-based resin (A) containing at least 50% by weight of an ethylene / α-olefin copolymer, that is, 50-100% by weight of an ethylene / α-olefin copolymer, and It contains an ethylene resin (A) comprising 50 to 0% by weight of another ethylene polymer and a 4-methyl-1-pentene polymer (B). Here, the “resin” in the ethylene-based resin (A) is a resin composed of a single component of the ethylene / α-olefin copolymer, and the ethylene / α-olefin copolymer and other ethylene-based polymers. A resin composition comprising two or more components is also included.
[0012]
Ethylene resin (A)
[Ethylene / α-olefin copolymer]
The ethylene / α-olefin copolymer constituting the ethylene-based resin (A) used in the present invention is obtained by copolymerizing ethylene and an α-olefin having 3 to 20 carbon atoms.
[0013]
Specific examples of the α-olefin having 3 to 20 carbon atoms used for copolymerization with ethylene include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1- Examples include octene, 1-decene, and 1-dodecene. Among these, α-olefins having 4 to 10 carbon atoms, particularly α-olefins having 4 to 8 carbon atoms are preferable.
[0014]
The α-olefins as described above can be used alone or in combination of two or more.
In the ethylene / α-olefin copolymer used in the present invention, the structural unit derived from ethylene is 50 wt% or more and less than 100 wt%, preferably 60 to 99 wt%, more preferably 65 to 95 wt%. It is desirable that the structural unit derived from the α-olefin having 3 to 20 carbon atoms is present in an amount of 50% by weight or less, preferably 1 to 40% by weight, more preferably 5 to 35% by weight.
[0015]
The composition of the ethylene / α-olefin copolymer is usually that of a sample in which about 200 mg of polyethylene is uniformly dissolved in 1 ml of hexachlorobutadiene in a 10 mmφ sample tube.¹³The C-NMR spectrum is determined by measurement under measurement conditions of a measurement temperature of 120 ° C., a measurement frequency of 25.05 MHz, a spectrum width of 1500 Hz, a pulse repetition time of 4.2 sec., And a pulse width of 6 μsec.
[0016]
The ethylene / α-olefin copolymer used in the present invention has a density (ASTM D 1505) of 0.860 to 0.940 g / cm.^Three , Preferably 0.865 to 0.935 g / cm^Three More preferably, 0.870-0.933g / cm^Three It is in the range. When an ethylene / α-olefin copolymer having a density in the above range is used, a composition capable of providing a polyethylene film excellent in low-temperature heat sealability and hot tackiness is obtained.
[0017]
The density is determined by measuring the melt flow rate (MFR) at 190 ° C. under a load of 2.16 kg at 100 to 125 ° C. for 1 hour, gradually cooling to room temperature over 1 hour, and then using a density gradient tube. taking measurement.
[0018]
The melt flow rate (MFR; ASTM D 1238, 190 ° C., load 2.16 kg) of this ethylene / α-olefin copolymer is 0.5 to 50 g / 10 minutes, preferably 1.0 to 30 g / 10 minutes. It is in the range. If the melt flow rate is less than 0.5 g / 10 min, the motor load during molding becomes excessive and high-speed molding becomes difficult. On the other hand, if the melt flow rate is larger than 50 g / 10 min, there is a drawback that the molten film at the time of molding becomes unstable, and thus molding itself becomes difficult.
[0019]
In the present invention, two or more of the above ethylene / α-olefin copolymers may be mixed and used. In particular, the density is 0.910 to 0.940 g / cm^ThreeAn ethylene α-olefin copolymer having a density of 0.860 to 0.890 g / cm^ThreeWhen an ethylene / α-olefin copolymer is used as a mixture, a sealant resin excellent in flexibility, heat sealability and heat resistance can be obtained.
[0020]
The ethylene / α-olefin copolymer is 50 to 100% by weight, preferably 60 to 100% by weight, based on 100% by weight of the total amount of the ethylene / α-olefin copolymer and other ethylene-based polymers described later. %, More preferably 65 to 100% by weight.
[0021]
The ethylene / α-olefin copolymer as described above can be produced by a conventionally known method, for example, using a Ziegler-based olefin polymerization catalyst under medium to low pressure, and JP-A-6-9724 In the presence of a so-called metallocene olefin polymerization catalyst containing a metallocene catalyst component described in JP-A-6-136195, JP-A-6-136196, JP-A-6-207057, etc. It can be produced by copolymerizing an α-olefin having 3 to 20 carbon atoms.
[0022]
Such a metallocene olefin polymerization catalyst is usually a metallocene catalyst component (a1) composed of a transition metal compound of Group IVB of the periodic table having at least one ligand having a cyclopentadienyl skeleton, organoaluminum oxy It is formed from a compound catalyst component (b), a particulate carrier (c), and, if necessary, an organoaluminum compound catalyst component (d) and an ionized ionic compound catalyst component (e).
[0023]
The metallocene catalyst component (a1) preferably used in the present invention includes a group IVB transition metal compound having at least one ligand having a cyclopentadienyl skeleton. Examples of such a transition metal compound include a transition metal compound represented by the following general formula [I].
[0024]
ML¹ _x                ... [I]
In the formula, x is the valence of the transition metal atom M.
M is a transition metal atom selected from Group IVB of the periodic table, and specifically, zirconium, titanium, and hafnium. Of these, zirconium is preferable.
[0025]
L¹ Is a ligand coordinated to the transition metal atom M, of which at least one ligand L¹ Is a ligand having a cyclopentadienyl skeleton.
Ligand L having cyclopentadienyl skeleton coordinated to transition metal atom M as described above¹ Specific examples include alkyl-substituted cyclopentadienyl groups such as cyclopentadienyl group, indenyl group, 4,5,6,7-tetrahydroindenyl group, fluorenyl group and the like. These groups may be substituted with a halogen atom, a trialkylsilyl group or the like.
[0026]
When the compound represented by the general formula [I] includes two or more groups having a cyclopentadienyl skeleton, the groups having two cyclopentadienyl skeletons are alkylene groups such as ethylene and propylene. And may be bonded via a substituted silylene group such as a silylene group or a dimethylsilylene group, a diphenylsilylene group, and a methylphenylsilylene group.
[0027]
As the organoaluminum oxy compound catalyst component (b), aluminoxane is preferably used. Specifically, the formula
-Al (R) O- [wherein R is an alkyl group]
In general, methylaluminoxane, ethylaluminoxane, methylethylaluminoxane, or the like having about 3 to 50 repeating units is used.
[0028]
The particulate carrier (c) used in the preparation of the olefin polymerization catalyst is an inorganic or organic compound and has a particle size of usually about 10 to 300 μm, preferably 20 to 200 μm in a granular or particulate solid. It is.
[0029]
The inorganic carrier is preferably a porous oxide, specifically SiO.₂, Al₂O_Three, MgO, ZrO₂TiO₂ Etc. can be illustrated.
Specific examples of the organoaluminum compound catalyst component (d) used in the preparation of the olefin polymerization catalyst include trialkylaluminum such as trimethylaluminum, dialkylaluminum halide such as dimethylaluminum chloride, and methylaluminum sesquichloride. Examples thereof include alkyl aluminum sesquihalides.
[0030]
Examples of the ionized ionic compound catalyst component (e) include triphenylboron and MgCl described in USP-5,321,106.₂, Al₂O_Three,
SiO₂-Al₂O_Three Lewis acids such as: ionic compounds such as triphenylcarbenium tetrakis (pentafluorophenyl) borate; carborane compounds such as dodecaborane and bis n-butylammonium (1-carbedodeca) borate.
[0031]
The ethylene / α-olefin copolymer used in the present invention includes, for example, the following metallocene catalyst component (a2), the organoaluminum oxy compound catalyst component (b) and / or the ionized ionic compound catalyst component described above. A catalyst for metallocene-based olefin polymerization formed from (e), or a metallocene catalyst component (a2), an organoaluminum oxy compound (b) and / or an ionized ionic compound catalyst component (e) and the organoaluminum compound catalyst component You may prepare by copolymerizing ethylene and a C3-C20 alpha olefin using the catalyst for olefin polymerization formed from (d).
[0032]
Examples of the metallocene catalyst component (a2) include compounds represented by the following general formula [II].
[0033]
[Chemical 1]

[0034]
In the formula, M is a transition metal atom of Group IVB of the periodic table, specifically, titanium, zirconium or hafnium, and particularly preferably zirconium.
R¹Is a hydrocarbon group having 1 to 6 carbon atoms.
[0035]
R², R^Four, R^Five, R⁶May be the same or different and each represents a hydrogen atom, a halogen atom or R¹And a hydrocarbon group having 1 to 6 carbon atoms. R^ThreeIs an aryl group having 6 to 16 carbon atoms. This aryl group may be substituted with a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or an organic silyl group.
[0036]
X¹And X²Is a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, an oxygen-containing group or a sulfur-containing group.
Y is a divalent hydrocarbon group having 1 to 20 carbon atoms, a divalent halogenated hydrocarbon group having 1 to 20 carbon atoms, a divalent silicon-containing group, a divalent germanium-containing group, or the like.
[0037]
Such metallocene compounds can be produced according to Journal of Organometallic Chem. 288 (1985), pp. 63-67, European Patent Application No. 0,320,762.
[0038]
The low density ethylene / α-olefin copolymer (C) obtained by the production method described in the above document has the characteristics that the molecular weight distribution and the composition distribution are narrow and the melt tension is large due to the long chain branching. is doing.
[0039]
The metallocene-based ethylene / α-olefin copolymer used in the present invention is prepared under various conditions in the gas phase or slurry or solution liquid phase in the presence of the olefin polymerization catalyst as described above. And an α-olefin having 3 to 20 carbon atoms can be copolymerized. Further, when a Ziegler polymerization catalyst is used, an ethylene / α-olefin copolymer can be produced under the same conditions.
[0040]
[Ethylene polymers other than the above ethylene / α-olefin copolymers]
Other ethylene polymers that may constitute the ethylene-based resin (A) together with the ethylene / α-olefin copolymer in the present invention include, specifically, high-pressure low-density polyethylene, high-density polyethylene, Examples include ethylene / vinyl acetate copolymer, ethylene / ethyl acrylate copolymer, ethylene / methyl acrylate copolymer, ethylene / methacrylic acid copolymer, ethylene / acrylic acid copolymer, and ionomer. . In particular, when extrusion-laminating the ethylene-based resin composition according to the present invention, it is particularly preferable to use an ethylene-based polymer in the following ratio in order to reduce the neck-in of the molten film.
[0041]
These ethylene polymers are 50 to 0% by weight, preferably 40 to 0% by weight, based on 100% by weight of the total amount of the above ethylene / α-olefin copolymer and other ethylene polymers. Preferably, it can be used at a ratio of 35 to 0% by weight.
[0042]
The melt flow rate (ASTM D 1238, 190 ° C., load 2.16 kg) of these ethylene polymers is in the range of 0.5 to 50 g / 10 minutes, preferably 1.0 to 30 g / 10 minutes. If the melt flow rate of these ethylene-based polymers is less than 0.5 g / 10 min, the motor load during molding becomes excessive, and high-speed molding becomes difficult. On the other hand, if the melt flow rate is larger than 50 g / 10 min, the molten film at the time of molding becomes unstable, and molding itself becomes difficult.
[0043]
                  Four- Methyl -1- Pentene polymer (B)
The 4-methyl-1-pentene polymer (B) used in the present invention comprises 4-methyl-1-pentene homopolymer, 4-methyl-1-pentene and an α-olefin having 2 or more carbon atoms. A copolymer, or a copolymer of 4-methyl-1-pentene and a monomer other than α-olefin.
[0044]
Specific examples of α-olefins having 2 or more carbon atoms used for copolymerization with 4-methyl-1-pentene include ethylene, propylene, 1-butene, 1-pentene, 1-hexene and 1-heptene. 1-octene, 1-decene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene and the like. Of these, α-olefins having 4 to 24 carbon atoms are preferable, and α-olefins having 6 to 18 carbon atoms are more preferable. In particular, 1-decene, 1-hexadecene and 1-octadecene are preferable. These α-olefins can be used alone or in combination of two or more.
[0045]
Specific examples of the monomer other than the α-olefin include butadiene, dicyclopentadiene, ethylidene norbornene, methyl acrylate, methyl methacrylate, ethyl acrylate, and ethyl methacrylate.
[0046]
In the present invention, 4-methyl-1-pentene containing 4-methyl-1-pentene homopolymer and 94% by weight or more of repeating units derived from 4-methyl-1-pentene are particularly preferred. A copolymer of 24 α-olefins is preferred.
[0047]
The 4-methyl-1-pentene polymer (B) used in the present invention has a melt flow rate (MFR; ASTM D 1238, 260 ° C., load 5.0 kg) of 1 to 300 g / 10 minutes, preferably 10 to 270 g. / 10 minutes, more preferably in the range of 15 to 250 g / 10 minutes.
[0048]
The ease of opening of the ethylene resin composition according to the present invention increases as the melt flow rate of the 4-methyl-1-pentene polymer (B) increases. The addition amount of the blend (B) may be small, but if the melt flow rate exceeds 300 g / 10 minutes, the heat seal strength becomes too low, or the addition amount of the 4-methyl-1-pentene polymer (B). There is a problem that the heat seal strength greatly fluctuates due to a slight variation of. Further, when the melt flow rate of the 4-methyl-1-pentene polymer (B) is less than 1 g / 10 minutes, only an ethylene resin composition having insufficient ease of opening can be obtained.
[0049]
The 4-methyl-1-pentene polymer (B) has a density (ASTM D 1505) of usually 0.830 to 0.835 g / cm.^Three, Preferably 0.832 to 0.835 g / cm^ThreeIt is in the range.
[0050]
The 4-methyl-1-pentene polymer (B) as described above can be produced using, for example, conventionally known catalysts and methods as described below.
(i) titanium catalyst component,
(ii) an organometallic compound catalyst component, and
(iii) Organosilicon compound catalyst component represented by the following general formula
R_nSi (OR ')_4-n
(In the formula, R and R ′ are hydrocarbon groups, and 0 <n <4.)
4-methyl-1-pentene is polymerized or copolymerized with 4-methyl-1-pentene and the α-olefin at a temperature of about 20 to 100 ° C. in the presence of a polymerization catalyst formed from To obtain. In this case, for example, a small amount of monomers other than the α-olefin described above may be copolymerized.
[0051]
In the present invention, the 4-methyl-1-pentene polymer (B) is 0.5 to 70 parts by weight, preferably 1 to 60 parts by weight, based on 100 parts by weight of the ethylene resin (A). Preferably it is used in a proportion of 2 to 50 parts by weight.
[0052]
Other ingredients
In addition to the ethylene resin (A) and the 4-methyl-1-pentene polymer (B), an easily openable ethylene resin composition according to the present invention may include a conventionally known anti-blocking if necessary. Additives such as an agent, an antistatic agent, an antioxidant, a weathering stabilizer, a heat stabilizer, and a lubricant can be blended within a range that does not impair the object of the present invention.
[0053]
Specific examples of the antiblocking agent include natural silica, synthetic silica, zeolite, amorphous zeolite, diatomaceous earth, polyacrylic acid ester, and polymethacrylic acid ester. Among these, zeolite, amorphous zeolite, natural silica, and synthetic silica are preferably used.
[0054]
Easily openable ethylene resin composition
The easily openable ethylene-based resin composition according to the present invention has a tensile elastic modulus of 500 to 3,600 kgf / cm.², Preferably 600-3,500 kgf / cm²More preferably, 700 to 3,400 kgf / cm²It is in the range.
[0055]
Further, when the sealant layers of the laminate obtained by combining the easily openable ethylene resin composition according to the present invention as a sealant layer directly or through a polyethylene resin with a laminate substrate are heat-sealed at 120 to 200 ° C., The heat seal strength is in the range of 0.2 to 1.6 kg / 15 mm, preferably 0.3 to 1.6 kg / 15 mm, more preferably 0.5 to 1.5 kg / 15 mm.
[0056]
In addition, the method of calculating | requiring a tensile elasticity modulus and heat seal strength is mentioned later in the term of an Example.
When the heat seal strength and tensile modulus of the film formed from the easily openable ethylene-based resin composition according to the present invention are within the above ranges, an appropriate open and easily openable packaging material is obtained. It is done.
[0057]
Polyethylene resins used in the production of the laminate include low density polyethylene, medium density polyethylene, ethylene / α-olefin copolymers such as ethylene / propylene copolymers and ethylene / 1-butene copolymers. An ethylene resin such as is preferably used. .
[0058]
Specific examples of the laminate substrate include polypropylene film, polyamide film, polyester film, aluminum foil, paper, and paperboard.
[0059]
Although there is no restriction | limiting in particular as said polyamide film, Specifically, films, such as nylon-6, nylon-11, nylon-66, nylon-610, are mentioned.
[0060]
The polyester film is not particularly limited, and specifically, polyethylene terephthalate, which is a condensation polyester of terephthalic acid and ethylene glycol, terephthalic acid-isophthalic acid-ethylene glycol copolymer polyester, terephthalic acid and cyclohexane-1 , 4-dimethanol and other films such as polyester.
[0061]
The polypropylene film, polyamide film and polyester film are preferably biaxially stretched films.
The easy-open ethylene-based resin composition according to the present invention is prepared by mixing each of the above components with a conventionally known method such as a Henschel mixer, a V-blender, a ribbon blender, a tumbler blender, or the like. The obtained mixture can be further melt-kneaded with a single screw extruder, a twin screw extruder, a kneader, a Banbury mixer or the like, and then granulated or the resin mass obtained can be pulverized.
[0062]
From the ethylene-based resin composition obtained by the method as described above, a film can be first produced, and then a bag-shaped packaging material can be produced by a conventionally known method.
The film of the ethylene-based resin composition according to the present invention can be molded using an extruder with a T die or an inflation molding machine, and the thickness of the film is not particularly limited, but is usually 10 to 150 μm.
[0063]
Moreover, using the ethylene-based resin composition according to the present invention, a multilayer film with a film such as a polypropylene film, a polyamide film, a polyester film, an aluminum foil, paper or paperboard, or a sheet-like material (laminate substrate) is produced. Can do. Under the present circumstances, a multilayer film can be manufactured by extruding the ethylene-type resin composition which concerns on this invention on a laminate base material, joining, and cooling.
[0064]
Furthermore, after manufacturing the polyethylene film from the ethylene-based resin composition according to the present invention by the above-described film manufacturing method, the polyethylene film is bonded to the laminate base material through an adhesive such as urethane, and the multilayer film is bonded. It can also be manufactured.
[0065]
Moreover, you may join the ethylene-type resin composition which concerns on this invention to a laminate base material through the said polyethylene-type resin. Specifically, (1) a method of extruding, joining and cooling the ethylene resin composition according to the present invention on a multilayer film in which a polyethylene resin is previously laminated on the laminate substrate, (2) on a laminate substrate And a method of coextruding, joining and cooling the polyethylene resin and the ethylene resin composition according to the present invention, and (3) a laminate substrate and a film-like material comprising the ethylene resin composition according to the present invention. And a method of bonding and cooling using a melt of the polyethylene resin.
[0066]
The multilayer film produced as described above is a multilayer film having a two-layer structure, but may be a multilayer film having a layer structure of three or more layers including the two-layer structure. However, in such a multilayer film, a layer made of the ethylene-based resin composition according to the present invention is used as a sealant layer (heat seal layer).
[0067]
【The invention's effect】
The easy-opening ethylene-based resin composition according to the present invention can provide a packaging material excellent in the balance between easy-opening properties and rigidity while maintaining the heat seal strength required as a packaging material. Therefore, film forming and bag making can be performed as packaging materials for foods and the like, and hygienic packaging is possible. And it can be easily opened by pulling left and right with a weak force.
[0068]
Further, the easily openable ethylene-based resin composition according to the present invention can be used as a sealing material for films or sheet-like materials such as polypropylene film, polyamide film, polyester film, aluminum foil, paper or paperboard, and so on. It can be used for packaging various products such as foods that require barrier properties.
[0069]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples.
[0070]
In addition, about the tensile elasticity modulus (rigidity), easy-open property, and hot tack property of the laminate film obtained by the Example and the comparative example, it tested by the following test method.
<Test method>
[0071]
(1) Tensile modulus (rigidity)
The hot-pressed 2 mm thick sheet was subjected to a tensile test using a constant crosshead moving speed type tensile tester (Instron).
[Test conditions]
Sample: JIS K 6781
Atmospheric temperature: 23 ° C
Pulling speed: 500mm / min
Chart speed: 200 mm / min
[0072]
The tensile modulus of the sheet was calculated from the chart obtained in the above test by the following formula, and the average value of the obtained values was defined as the tensile modulus (E).
E₀ = R₀(L₀/ A)
[Where E₀ Is the tensile modulus (Young's modulus), R₀ Is the initial slope, L₀ Represents the distance between chucks, and A represents the minimum area during sample preparation. ]
This R₀ Was calculated by the following equation.
R₀ = F₁ / L₁
[Where F₁ Is the load at any point on the initial tangent, L₁ Is tangential F₁ The elongation corresponding to is shown respectively. ]
[0073]
(2) Easy openability and heat seal strength
After heat-sealing the film with New Long HS-33D Top Sealer (trade name, manufactured by Tester Sangyo Co., Ltd.) at a right angle to the flow direction, the tensile test was performed with a constant crosshead moving speed type tensile tester (Instron) The breaking strength was measured and this breaking strength was defined as the heat seal strength. The crosshead moving speed was 300 mm / min. The heat sealing was performed at each sealing temperature of 120 ° C, 140 ° C, and 160 ° C.
The easy-openability was evaluated according to the following criteria.
Good ・ ・ ・ 0.2-1.6kg / 15mm
Defect ... <0.2kg / 15mm (seal failure) or> 1.6kg / 15mm
[0074]
(3) Hot tack property (hot tack peeling distance)
45 g weights are separately attached to the same end portion of two laminated film test pieces (length 550 mm × width 20 mm) via a guide roll, and the test pieces are overlapped with each other to be 120 ° C., 140 ° C. and 160 ° C. 2kg / cm with a seal bar of 5mm width and 300mm length at each temperature² The seal bar is separated from the test piece for 1 second, and at the same time, the peeling force by the weight acts on the seal portion at an angle of 23 degrees (this angle indicates the positional relationship of the guide roll for applying the weight). The seal portion (adjusted by adjusting) was forcibly peeled off, the peeled distance (mm) was measured, and the hot tack property was evaluated based on the peel distance. The shorter the peel distance, the better the hot tack.
[0075]
[Example 1]
Ethylene / α-olefin copolymer (EC-1) [ethylene / 1-octene copolymer; ethylene content = 78 wt%, density (ASTM D 1505) produced by solution polymerization using a metallocene catalyst = 0.895 g / cm^Three, MFR (ASTM D 1238, 190 ° C., load 2.16 kg) = 4.0 g / 10 min] with respect to 100 parts by weight, 4-methyl-1-pentene copolymer (PMP-1) [4-methyl-1 -Pentene / 1-decene copolymer; 4-methyl-1-pentene content = 95% by weight, 1-decene content = 5% by weight, density (ASTM D 1505) = 0.833 g / cm^Three, MFR (ASTM D 1238, 260 ° C., load 5 kg) = 20 g / 10 minutes] was added to obtain an ethylene-based resin composition.
[0076]
Next, using a T-die film molding machine, a film having a thickness of 40 μm was molded from the above composition at a molding temperature of 230 to 240 ° C. and a molding speed of 20 m / min.
[0077]
After one side of the obtained film was subjected to corona discharge treatment, this film and a 15 μm-thick biaxially stretched nylon film coated with a urethane-based adhesive were pressure-bonded, and the ethylene-based resin composition was sealed with a sealant layer (heat A dry laminate film having a thickness of about 55 μm was prepared as a sealing layer.
[0078]
The laminate film obtained as described above was tested for easy opening, heat seal strength, and hot tack by the above method.
Moreover, about the said ethylene-type resin composition, the tensile elasticity modulus was calculated | required according to said method.
[0079]
The results are shown in Table 1.
[0080]
[Example 2]
4-methyl-1-pentene copolymer (PMP-2) [4-methyl-1-pentene / 1-octadecene copolymer with respect to 100 parts by weight of ethylene / α-olefin copolymer (EC-1) 4-methyl-1-pentene content = 95% by weight, 1-octadecene content = 5% by weight, density (ASTM D 1505) = 0.833 g / cm^ThreeMFR (ASTM D 1238, 260 ° C., load 5 kg) = 180 g / 10 min] was added to obtain 5 parts by weight of an ethylene-based resin composition.
[0081]
Thereafter, in the same manner as in Example 1, a dry laminate film having a thickness of about 55 μm was obtained using this composition as a sealant layer.
The laminate film obtained as described above was tested for easy opening, heat seal strength, and hot tack by the above method.
[0082]
Moreover, about the said ethylene-type resin composition, the tensile elasticity modulus was calculated | required according to said method.
The results are shown in Table 1.
[0083]
[Example 3]
Ethylene / α-olefin copolymer (EC-2) produced by a solution polymerization method using a metallocene-based catalyst [ethylene / 1-octene copolymer; ethylene content = 78 wt%, density (ASTM D 1505) = 0.895 g / cm^Three, MFR (ASTM D 1238, 190 ° C., load 2.16 kg) = 15.0 g / 10 min], and high-pressure low-density polyethylene (LD-1) [ethylene content = 100 wt%, density (ASTM D 1505 ) = 0.917 g / cm^Three, MFR (ASTM D 1238, 190 ° C., load 2.16 kg) = 7.2 g / 10 minutes] 30 parts by weight of 4-methyl-1-pentene copolymer (PMP-1) was added to 30 parts by weight. Thus, an ethylene resin composition was obtained.
[0084]
Next, a urethane-based anchor coating agent was applied onto a biaxially stretched nylon film having a thickness of 15 μm, and high-pressure low-density polyethylene (LD-1) was extruded and laminated on the coated surface so as to have a thickness of 25 μm.
[0085]
Next, the ethylene-based resin composition is extruded and laminated on the high-pressure method low-density polyethylene (LD-1) layer under the conditions of a processing speed of 60 m / min, a resin temperature under the die of 290 to 295 ° C., and a thickness of 40 μm, An extruded laminated film having a thickness of about 80 μm was produced using this composition as a sealant layer.
[0086]
The laminate film obtained as described above was tested for easy opening, heat seal strength, and hot tack by the above method.
Moreover, about the said ethylene-type resin composition, the tensile elasticity modulus was calculated | required according to said method.
[0087]
The results are shown in Table 1.
[0088]
[Example 4]
In Example 3, except that 30 parts by weight of 4-methyl-1-pentene copolymer (PMP-1) was changed to 5 parts by weight of 4-methyl-1-pentene copolymer (PMP-2), Example In the same manner as in No. 3, an ethylene resin composition was obtained.
[0089]
Thereafter, in the same manner as in Example 3, an extruded laminate film having a thickness of about 80 μm including a sealant layer having a thickness of 40 μm made of this composition was obtained.
The laminate film obtained as described above was tested for easy opening, heat seal strength, and hot tack by the above method.
[0090]
Moreover, about the said ethylene-type resin composition, the tensile elasticity modulus was calculated | required according to said method.
The results are shown in Table 1.
[0091]
[Example 5]
Ethylene / α-olefin copolymer (EC-3) [ethylene / 1-hexene copolymer; ethylene content = 89 wt%, density (ASTM D 1505) produced by vapor phase polymerization using a metallocene catalyst ) = 0.915 g / cm^Three, MFR (ASTM D 1238, 190 ° C., load 2.16 kg) = 15.0 g / 10 min] 60 parts by weight, ethylene / α-olefin copolymer (EC) produced by a solution polymerization method using a metallocene catalyst -4) [Ethylene / 1-butene copolymer; ethylene content = 82 wt%, density (ASTM D 1505) = 0.885 g / cm^Three, MFR (ASTM D 1238, 190 ° C., load 2.16 kg) = 3.6 g / 10 min] and 10 parts by weight, and 30 parts by weight of high-pressure low-density polyethylene (LD-1), 4-methyl-1- 5 parts by weight of a pentene copolymer (PMP-2) was added to obtain an ethylene-based resin composition.
Thereafter, in the same manner as in Example 3, an extruded laminate film having a thickness of about 80 μm including a sealant layer having a thickness of 40 μm made of this composition was obtained.
[0092]
The laminate film obtained as described above was tested for easy opening, heat seal strength, and hot tack by the above method.
Moreover, about the said ethylene-type resin composition, the tensile elasticity modulus was calculated | required according to said method.
[0093]
The results are shown in Table 1.
[0094]
[Example 6]
Ethylene / α-olefin copolymer (EC-5) [ethylene / 4-methyl-1-pentene copolymer; ethylene content = 90% by weight, density (made by Ziegler catalyst) ASTM D 1505) = 0.920 g / cm^Three, MFR (ASTM D 1238, 190 ° C., load 2.16 kg) = 2.0 g / 10 min] and 80 parts by weight, and 20 parts by weight of ethylene / α-olefin copolymer (EC-4), 4-methyl -1- 30 parts by weight of pentene copolymer (PMP-1) was added to obtain an ethylene-based resin composition.
[0095]
Thereafter, in the same manner as in Example 1, a dry laminate film having a thickness of about 55 μm was obtained using this composition as a sealant layer having a thickness of 40 μm.
The laminate film obtained as described above was tested for easy opening, heat seal strength, and hot tack by the above method.
[0096]
Moreover, about the said ethylene-type resin composition, the tensile elasticity modulus was calculated | required according to said method.
The results are shown in Table 1.
[0097]
[Example 7]
Ethylene / α-olefin copolymer (EC-6) [ethylene / 4-methyl-1-pentene copolymer; ethylene content = 94% by weight, density (made by Ziegler catalyst) ASTM D 1505) = 0.930 g / cm^Three, MFR (ASTM D 1238, 190 ° C., load 2.16 kg) = 2.0 g / 10 min], and an ethylene / α-olefin copolymer produced by a solution polymerization method using a metallocene catalyst ( EC-7) [Ethylene / 1-butene copolymer; ethylene content = 74 wt%, density (ASTM D 1505) = 0.870 g / cm^Three, MFR (ASTM D 1238, 190 ° C., load 2.16 kg) = 3.6 g / 10 min] With respect to 40 parts by weight, 5 parts by weight of 4-methyl-1-pentene copolymer (PMP-2) was added. Thus, an ethylene resin composition was obtained.
[0098]
Thereafter, in the same manner as in Example 1, a dry laminate film having a thickness of about 55 μm was obtained using this composition as a sealant layer having a thickness of 40 μm.
The laminate film obtained as described above was tested for easy opening, heat seal strength, and hot tack by the above method.
[0099]
Moreover, about the said ethylene-type resin composition, the tensile elasticity modulus was calculated | required according to said method.
The results are shown in Table 1.
[0100]
[Example 8]
Ethylene / α-olefin copolymer (EC-8) [ethylene / 4-methyl-1-pentene copolymer; ethylene content = 88 wt%, density (made by Ziegler catalyst) ASTM D 1505) = 0.915 g / cm^Three, MFR (ASTM D 1238, 190 ° C., load 2.16 kg) = 15.0 g / 10 min] 60 parts by weight, 10 parts by weight of ethylene / α-olefin copolymer (EC-4), and high-pressure low-density polyethylene ( LD-1) With respect to 30 parts by weight, 5 parts by weight of 4-methyl-1-pentene copolymer (PMP-2) was added to obtain an ethylene-based resin composition.
[0101]
Thereafter, in the same manner as in Example 3, an extruded laminate film having a thickness of about 80 μm including a sealant layer having a thickness of 40 μm made of this composition was obtained.
The laminate film obtained as described above was tested for easy opening, heat seal strength, and hot tack by the above method.
[0102]
Moreover, about the said ethylene-type resin composition, the tensile elasticity modulus was calculated | required according to said method.
The results are shown in Table 1.
[0103]
[Example 9]
For 45 parts by weight of ethylene / α-olefin copolymer (EC-8), 25 parts by weight of ethylene / α-olefin copolymer (EC-4), and 30 parts by weight of high-pressure low-density polyethylene (LD-1) Then, 65 parts by weight of 4-methyl-1-pentene copolymer (PMP-1) was added to obtain an ethylene-based resin composition.
[0104]
Thereafter, in the same manner as in Example 3, an extruded laminate film having a thickness of about 80 μm including a sealant layer having a thickness of 40 μm made of this composition was obtained.
The laminate film obtained as described above was tested for easy opening, heat seal strength, and hot tack by the above method.
[0105]
Moreover, about the said ethylene-type resin composition, the tensile elasticity modulus was calculated | required according to said method.
The results are shown in Table 1.
[0106]
[Example 10]
For 60 parts by weight of ethylene / α-olefin copolymer (EC-8), 10 parts by weight of ethylene / α-olefin copolymer (EC-4), and 30 parts by weight of high-pressure method low density polyethylene (LD-1) Then, 5 parts by weight of 4-methyl-1-pentene copolymer (PMP-2) was added to obtain an ethylene-based resin composition.
[0107]
Thereafter, in the same manner as in Example 3, an extruded laminate film having a thickness of about 80 μm including a sealant layer having a thickness of 40 μm made of this composition was obtained.
The laminate film obtained as described above was tested for easy opening, heat seal strength, and hot tack by the above method.
[0108]
Moreover, about the said ethylene-type resin composition, the tensile elasticity modulus was calculated | required according to said method.
The results are shown in Table 1.
[0109]
Example 11
80 parts by weight of ethylene / α-olefin copolymer (EC-2), and high pressure method low density polyethylene (LD-2) [ethylene content = 100 wt%, density (ASTM D 1505) = 0.919 g / cm^Three, MFR (ASTM D 1238, 190 ° C., load 2.16 kg) = 3.1 g / 10 min] with respect to 20 parts by weight, 4-methyl-1-pentene polymer (PMP-3) [4-methyl-1- Pentene content = 100 wt%, density (ASTM D 1505) = 0.835 g / cm^Three, MFR (ASTM D 1238, 260 ° C., load 5 kg) = 110 g / 10 minutes] was added to obtain 10 parts by weight of an ethylene resin composition.
[0110]
Thereafter, in the same manner as in Example 3, an extruded laminate film having a thickness of about 80 μm including a sealant layer having a thickness of 40 μm made of this composition was obtained.
The laminate film obtained as described above was tested for easy opening, heat seal strength, and hot tack by the above method.
[0111]
Moreover, about the said ethylene-type resin composition, the tensile elasticity modulus was calculated | required according to said method.
The results are shown in Table 1.
[0112]
[Comparative Example 1]
In Example 1, except that 4-methyl-1-pentene copolymer (PMP-1) was not used, the ethylene / α-olefin copolymer (EC-1) was thickened in the same manner as in Example 1. A dry laminate film having a thickness of about 55 μm was obtained as a sealant layer having a thickness of 40 μm.
[0113]
The laminate film obtained as described above was tested for easy opening, heat seal strength, and hot tack by the above method.
Moreover, about the said ethylene-type resin composition, the tensile elasticity modulus was calculated | required according to said method.
[0114]
The results are shown in Table 1.
[0115]
[Comparative Example 2]
In Example 3, except that 4-methyl-1-pentene copolymer (PMP-1) was not used, an ethylene / α-olefin copolymer (EC-2) of 70 wt. An extruded laminate film having a thickness of about 80 μm including a sealant layer having a thickness of 40 μm and 30 parts by weight of high-pressure method low density polyethylene (LD-1) was obtained.
[0116]
The laminate film obtained as described above was tested for easy opening, heat seal strength, and hot tack by the above method.
Moreover, about the said ethylene-type resin composition, the tensile elasticity modulus was calculated | required according to said method.
[0117]
The results are shown in Table 1.
[0118]
[Comparative Example 3]
In Example 5, except that 4-methyl-1-pentene copolymer (PMP-2) was not used, 60 wt.% Of ethylene / α-olefin copolymer (EC-3) was carried out in the same manner as in Example 5. Extruded laminate having a thickness of about 80 μm, including a 40 μm-thick sealant layer consisting of 10 parts by weight of ethylene / α-olefin copolymer (EC-4) and 30 parts by weight of high-pressure low-density polyethylene (LD-1) A film was obtained.
[0119]
The laminate film obtained as described above was tested for easy opening, heat seal strength, and hot tack by the above method.
Moreover, about the said ethylene-type resin composition, the tensile elasticity modulus was calculated | required according to said method.
[0120]
The results are shown in Table 1.
[0121]
[Comparative Example 4]
In Example 6, except that 4-methyl-1-pentene copolymer (PMP-1) was not used, the ethylene / α-olefin copolymer (EC-5) 80 wt. A dry laminate film having a thickness of about 55 μm including a sealant layer having a thickness of 40 μm and 20 parts by weight of ethylene / α-olefin copolymer (EC-4) was obtained.
[0122]
The laminate film obtained as described above was tested for easy opening, heat seal strength, and hot tack by the above method.
Moreover, about the said ethylene-type resin composition, the tensile elasticity modulus was calculated | required according to said method.
[0123]
The results are shown in Table 1.
[0124]
[Comparative Example 5]
In Example 6, an ethylene-based resin composition was obtained in the same manner as in Example 6 except that the amount of 4-methyl-1-pentene copolymer (PMP-1) added was changed to 80 parts by weight.
[0125]
Thereafter, in the same manner as in Example 6, a dry laminate film having a thickness of about 55 μm was obtained using this composition as a sealant layer having a thickness of 40 μm.
The laminate film obtained as described above was tested for easy opening, heat seal strength, and hot tack by the above method.
[0126]
Moreover, about the said ethylene-type resin composition, the tensile elasticity modulus was calculated | required according to said method.
The results are shown in Table 1.
[0127]
[Comparative Example 6]
In Example 7, except that the 4-methyl-1-pentene copolymer (PMP-2) was not used, 60 wt.% Of ethylene / α-olefin copolymer (EC-6) was carried out in the same manner as in Example 7. A dry laminate film having a thickness of about 55 μm including a sealant layer having a thickness of 40 μm and 40 parts by weight of an ethylene / α-olefin copolymer (EC-7) was obtained.
[0128]
The laminate film obtained as described above was tested for easy opening, heat seal strength, and hot tack by the above method.
Moreover, about the said ethylene-type resin composition, the tensile elasticity modulus was calculated | required according to said method.
[0129]
The results are shown in Table 1.
[0130]
[Comparative Example 7]
In Example 8, except that the 4-methyl-1-pentene copolymer (PMP-2) was not used, the ethylene / α-olefin copolymer (EC-8) 60 wt. About 80 μm in thickness with a composition comprising 10 parts by weight, 10 parts by weight of ethylene / α-olefin copolymer (EC-4) and 30 parts by weight of high-pressure low-density polyethylene (LD-1) as a sealant layer having a thickness of 40 μm An extruded laminate film was obtained.
[0131]
The laminate film obtained as described above was tested for easy opening, heat seal strength, and hot tack by the above method.
Moreover, about the said ethylene-type resin composition, the tensile elasticity modulus was calculated | required according to said method.
[0132]
The results are shown in Table 1.
[0133]
[Comparative Example 8]
80 parts by weight of an ethylene / α-olefin copolymer (EC-2) in the same manner as in Example 11 except that the 4-methyl-1-pentene polymer (PMP-3) was not used in Example 11. An extruded laminate film having a thickness of about 80 μm was obtained using a composition consisting of 20 parts by weight of high-pressure method low density polyethylene (LD-2) as a sealant layer having a thickness of 40 μm.
[0134]
The laminate film obtained as described above was tested for easy opening, heat seal strength, and hot tack by the above method.
Moreover, about the said ethylene-type resin composition, the tensile elasticity modulus was calculated | required according to said method.
[0135]
The results are shown in Table 1.
[0136]
[Table 1]

[0137]
[Table 2]

[0138]
[Table 3]

[0139]
[Table 4]

Claims (3)

It has a structural unit derived from ethylene in an amount of 60 to 99% by weight, a density of 0.860 to 0.940 g / cm ³ , and a melt flow rate (ASTMD 1238, 190 ° C., load of 2.16 kg) of 0.1. For 100 parts by weight of an ethylene-based resin (A) containing at least 50% by weight of an ethylene / α-olefin copolymer of 5 to 50 g / 10 minutes,
An ethylene resin composition containing 0.5 to 70 parts by weight of a 4-methyl-1-pentene polymer (B),
A hot-pressed 2 mm thick sheet formed from the composition was subjected to a tensile test at a tensile speed of 500 mm / min using a constant crosshead moving speed type tensile tester, and the following chart (1) was obtained from the obtained chart. The obtained tensile elastic modulus is 500 to 3,600 kgf / cm ² , and
When the sealant layers of the laminate obtained by combining the composition as a sealant layer directly or via a polyethylene-based resin are heat-sealed at 120 to 200 ° C. perpendicular to the flow direction, the crosshead moving speed is constant. Easily openable ethylene characterized by a heat seal strength of 0.2 to 1.6 kg / 15 mm determined as a breaking strength measured by performing a tensile test at a crosshead moving speed of 300 mm / min with a mold tensile tester Resin composition;
E ₀ = R ₀ (L ₀ / A) (1)
(In Equation (1), E ₀ is the tensile modulus, R ₀ is the initial gradient, L ₀ is the distance between chucks, and A is the minimum area during sample preparation. R ₀ is calculated by the following equation: It is the value.
R ₀ = F ₁ / L ₁ (where F ₁ represents the load at an arbitrary point on the initial tangent, and L ₁ represents the elongation corresponding to F ₁ on the tangent)). 2. The easily openable ethylene resin composition according to claim 1, wherein the ethylene / α-olefin copolymer is a copolymer produced using a Ziegler or metallocene olefin polymerization catalyst. . 3. The easily-openable ethylene-based resin composition according to claim 1, wherein the easily-openable ethylene-based resin composition is used as a sealant layer of a laminate substrate made of a polypropylene film, a polyamide film, a polyester film, an aluminum foil, paper, or paperboard. object.