JP4864235B2 - Thermal fusion film and package comprising the same - Google Patents
Thermal fusion film and package comprising the same Download PDFInfo
- Publication number
- JP4864235B2 JP4864235B2 JP2001190151A JP2001190151A JP4864235B2 JP 4864235 B2 JP4864235 B2 JP 4864235B2 JP 2001190151 A JP2001190151 A JP 2001190151A JP 2001190151 A JP2001190151 A JP 2001190151A JP 4864235 B2 JP4864235 B2 JP 4864235B2
- Authority
- JP
- Japan
- Prior art keywords
- heat
- layer
- sealing
- weight
- film
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Description
【０００１】
【発明の属する技術分野】
本発明は、エチレン・ビニルエステル共重合体とプロピレン重合体との樹脂組成物からなる熱融着層を備えた易開封性、開封時のソフト感、耐ブロッキング性、衛生性、製膜加工性、ラミネート加工性に優れた熱融着フィルム、かかる熱融着フィルムからなる容器蓋材及びそれを用いた包装体に関する。
【０００２】
【従来の技術】
せんべい、ポテトチップス等のスナック菓子包装、あるいはゼリー、ミルク、ヨーグルト、プリン、とうふ、乳酸飲料等の食品包装や、ブリスター包装、その他日用品や雑貨等の包装として、ボトル、カップ、ないしトレー状のプラスチック容器をプラスチックラミネートフィルムないしアルミ箔ラミネートフィルムからなる蓋材でシールした包装が広く採用されている。このような包装に要求されることは、流通経路に耐える機械的な強度、衛生性の保持ができるシール強度および使用時における開封性の良さである。
【０００３】
そのような包装に使われる資材の一つとして、一方を易開封性（イージーピール性）フィルムと呼ばれる範疇のフィルムを、最内層である熱融着層とした袋に、あるいは蓋材に用いた包装体が広く利用されている。しかし、これまで提案されている各種の熱融着層は、密封するためのヒートシール強度は高いが、開封時のイージーピール性は必ずしも十分ではなく、両者の間に適度なバランスをとることが求められている。ここでイージーピール性に求められている特性は、単に開封性の容易さのみならず、開封後に開封部に糸引き現象等による樹脂断片の付着残留物がなく、開封部の外観の良さをも含めた総合評価であり、それによってその良否が判定されている。
【０００４】
かかる欠点を解決する手段として、例えばエチレン−ビニルエステル共重合体、低結晶性または非晶性のエチレン共重合体と粘着付与剤とからなるヒートシール性樹脂組成物（特公昭６３−２９８９４号公報）、エチレン−αオレフィン共重合体、プロピレン−エチレン共重合体及び低密度ポリエチレンからなる易開封性ヒートシール用樹脂組成物（特開平２−１８５５４７号公報）が提案されている。
【０００５】
しかしながら、低密度ポリエチレンをラミネートした紙容器に、かかる構成のシール材を用いた場合は、低密度ポリエチレン層と完全シ−ルとなり、開封した際に低密度ポリエチレンが剥離して紙剥けし紙くず等が内容物に落下したり、容器が変形して内容物がこぼれてしまう虞がある。又、かかる組成物層を有するフィルムはブロッキングし易くロール状に巻き取ったフィルムを巻き出し難い場合あり、又、ブロッキング跡により外観が劣る虞がある。
【０００６】
【発明が解決しようとする課題】
本発明は、耐ブロッキング性、ソフトな開封性、衛生性、加工性に優れ、エチレン重合体層あるいはプロピレン重合体層からなる熱シール層と熱融着した際の熱融着強度の温度依存性が小さく、輸送時等には被包装物が漏れ出る虞がない熱融着強度を有しながら被包装物を取出す際には、容易に開封でき、開封時にソフトで紙容器表面にコ−ト・押出しされたエチレン重合体との間で糸引き等が無く、綺麗な界面剥離あるいは凝集剥離で開封できるフィルム及び包装体を得るべく、又、夏場の気候のような場合に気温が３０℃以上の時、あるいは流通時・倉庫保管時で５０〜６０℃程度の高温時における保管時においてもシ−ル部、特に容器の段差と蓋材シ−ルの部分でのエアリ−ク・パンクしない耐熱性があり、つまり容器としての封緘性に優れている易開封性可能な熱融着フィルム及び包装体を得るべく、種々検討した。
【０００７】
【課題を解決するための手段】
本発明は、ビニルエステル含量が３〜３０重量％のエチレン・ビニルエステル共重合体（Ａ）９９〜２０重量％とプロピレン重合体（Ｂ）１〜８０重量％との樹脂組成物（Ｃ）からなる熱融着層を有することを特徴とする熱融着フィルム、それを用いた易開封性包装材料及び容器蓋材、相対する面が、ビニルエステル含量が３〜３０重量％のエチレン・ビニルエステル共重合体（Ａ）９９〜４０重量％とプロピレン重合体（Ｂ）１〜６０重量％との樹脂組成物（Ｄ）からなる熱融着層と、エチレン重合体層からなる熱シール層からなることを特徴とする包装体及び相対する面が、ビニルエステル含量が３〜３０重量％のエチレン・ビニルエステル共重合体（Ａ）９５〜２０重量％と、プロピレン重合体（Ｂ）５〜８０重量％との樹脂組成物（Ｅ）からなる熱融着層と、プロピレン重合体層からなる熱シール層からなることを特徴とする包装体に関する。
【０００８】
【発明の具体的説明】
エチレン・ビニルエステル共重合体（Ａ）
本発明に係わるエチレン・ビニルエステル共重合体（Ａ）は、エチレンと、酢酸ビニルやプロピオン酸ビニル等のビニルエステルとの共重合体であって、共重合体中に存在するビニルエステル含量が３〜３０重量％、好ましくは５〜１５重量％の範囲にある。ビニルエステル含量がこの範囲内にあると、ヒートシール強度とイージーピール性とのバランスを良好に保ち、かつ食品充填時に必要な耐熱性を有しているので好適である。また、この共重合体のメルトフローレート（ＭＦＲ）は、ＪＩＳ ６７３０に準拠して測定した値が、通常１〜４０、好ましくは１．５〜３０（ｇ／１０分）の範囲にある共重合体が良好な押出性を有し、包装フィルムとしての十分な機械的強度を有する。このエチレン・ビニルエステル共重合体（Ａ）は熱融着層として用いる場合に低温ヒートシール性を付与する効果がある。
【０００９】
プロピレン重合体（Ｂ）
本発明に係わるプロピレン重合体（Ｂ）は、一般にポリプロピレンの名称で製造・販売されている樹脂でフィルム用途に適するものであり、通常、密度が０．８９０〜０．９３０ｇ／ｃｍ３、ＭＦＲ（ＡＳＴＭ Ｄ１２３８ 荷重２１６０ｇ、温度２３０℃）が０．５〜６０ｇ／１０分、好ましくは０．５〜１０ｇ／１０分のプロピレンの単独重合体若しくはプロピレンと他の少量のα−オレフィン、例えばエチレン、ブテン、ヘキセン−１等とのランダムあるいはブロック共重合体である。
【００１０】
樹脂組成物（Ｃ）
本発明に係わる樹脂組成物（Ｃ）は、前記、エチレン・ビニルエステル共重合体（Ａ）が９９〜２０重量％、好ましくは９８〜４０重量％とプロピレン重合体（Ｂ）が１〜８０重量％、好ましくは２〜６０重量％とからなり、通常、ＭＦＲ（ＡＳＴＭ Ｄ１２３８ 荷重２１６０ｇ、温度１９０℃）が０．１〜４０ｇ／１０分、好ましくは１〜３０ｇ／１０分の範囲にある。プロピレン重合体（Ｂ）の量が１重量％未満では樹脂組成物（Ｃ）面どうしを熱融着した際に、ヒートシール強度が強くなり過ぎて易開封性に劣る傾向にあり、一方８０重量％を越えると低温ヒートシール性、開封強度・実用上での封緘性・密封性（耐熱性）に劣る傾向にある。
【００１１】
樹脂組成物（Ｄ）
本発明に係わる樹脂組成物（Ｄ）は、前記、エチレン・ビニルエステル共重合体（Ａ）が９９〜４０重量％、好ましくは９８〜６０重量％とプロピレン重合体（Ｂ）が１〜６０重量％、好ましくは２〜４０重量％とからなり、通常、ＭＦＲ（ＡＳＴＭ Ｄ１２３８ 荷重２１６０ｇ、温度１９０℃）が０．１〜４０ｇ／１０分、好ましくは１〜３０ｇ／１０分の範囲にある。プロピレン重合体（Ｂ）の量が１重量％未満ではエチレン重合体層と熱融着した際に、ヒートシール強度が強くなり過ぎて易開封性に劣る傾向にあり、一方６０重量％を越えると低温ヒートシール性、開封強度・実用上での封緘性・密封性（耐熱性）に劣る傾向にある。
【００１２】
樹脂組成物（Ｅ）
本発明に係わる樹脂組成物（Ｅ）は、前記、エチレン・ビニルエステル共重合体（Ａ）が９５〜２０重量％、好ましくは８０〜４０重量％とプロピレン重合体（Ｂ）が５〜８０重量％、好ましくは２０〜６０重量％とからなり、通常、ＭＦＲ（ＡＳＴＭ Ｄ１２３８ 荷重２１６０ｇ、温度１９０℃）が０．１〜４０ｇ／１０分、好ましくは１〜３０ｇ／１０分の範囲にある。プロピレン重合体（Ｂ）の量が５重量％未満ではプロピレン重合体層と熱融着した際に、ヒートシール強度が低く、開封強度・実用上での封緘性・密封性に劣る傾向にあり、一方８０重量％を越えるとヒートシール強度が強くなり過ぎて易開封性に劣る傾向にある。
【００１３】
本発明に係わるエチレン・ビニルエステル共重合体（Ａ）、プロピレン重合体（Ｂ）あるいはその樹脂組成物（Ｃ）、（Ｄ）及び（Ｅ）には、本発明の目的を損なわない範囲で、通常用いられる酸化防止剤、耐候安定剤、帯電防止剤、防曇剤等の添加剤を必要に応じて配合することができる。特に、アンチブロッキング剤、スリップ剤を配合することによって、フィルム成形時、ラミネート加工時、包装作業時等における加工性や作業性を向上させることができる。
【００１４】
熱融着フィルム
本発明に係わる熱融着フィルムは前記エチレン・ビニルエステル共重合体（Ａ）、プロピレン重合体（Ｂ）との樹脂組成物（Ｃ）を熱融着層としたフィルムである。かかる熱融着フィルムは種々公知の方法で製造できる。例えば、エチレン・ビニルエステル共重合体（Ａ）とプロピレン重合体（Ｂ）とを所定の量で混合した後、直接フィルム成形機に投入してＴ−ダイ、環状ダイ等を用いてフィルムにする方法、予めエチレン・ビニルエステル共重合体（Ａ）、プロピレン重合体（Ｂ）とを所定の量で混合して押出機等で溶融混練して樹脂組成物（Ｃ）を得た後、Ｔ−ダイ、環状ダイ等を用いてフィルム成形する方法が例示できる。
【００１５】
熱融着フィルムは単層でも用いられるが、補強層として高圧法低密度ポリエチレン、線状低密度ポリエチレン、中密度ポリエチレン及び高密度ポリエチレン等のエチレン重合体、ポリブテン、エチレン・酢酸ビニル共重合体等のオレフィン系重合体層との積層フィルムであってもよい。これらの中でも、密度が０．９０５〜０．９３５ｇ／ｃｍ３、好ましくは０．９１０〜０．９３５ｇ／ｃｍ３、ＭＦＲ（ＡＳＴＭ Ｄ１２３８ 荷重２１６０ｇ、温度１９０℃）が０．５〜３０ｇ／１０分、好ましくは１〜１０ｇ／１０分の高圧下で重合されるエチレンの単独重合体、若しくは５重量％以下の、他のα−オレフィンあるいは酢酸ビニル等のビニル化合物との共重合体で、通常高圧法低密度ポリエチレンと呼ばれている低密度ポリエチレン、及びエチレンと炭素数が３〜１０のα−オレフィン、例えばプロピレン、ブテン−１、ヘプテン−１、ヘキセン−１、オクテン−１、４−メチル−ペンテン−１とのランダム共重合体で、分子量分布（重量平均分子量：Ｍｗ、と数平均分子量：Ｍｎ、との比：Ｍｗ／Ｍｎで表示）が通常１．５〜４．０、好ましくは１．８〜３．５の範囲にある、通常、線状低密度ポリエチレン（ＬＬＤＰＥ）と呼ばれているエチレン・α―オレフィンランダム共重合体等から得られるフィルムとの積層フィルムが好ましく、特に、線状低密度ポリエチレンを補強層に用いた場合に、低温シ−ル性に優れ、しかも熱融着面を開封した際に、凝集剥離を起こし、且つ剥離面（開封面）での糸引きが生ぜず綺麗な開封面が得られる。
【００１６】
かかる積層フィルムを得る場合には、熱融着層となる樹脂組成物と補強層に用いるオレフィン系重合体とを多層ダイを用いて共押出しし熱融着フィルムとし得る。又、予め得られた補強層に樹脂組成物を押出しラミネートあるいは押出しコーティングして熱融着層を有する積層体としても良いし、あるいは夫々別個に得たフィルムを貼り合せて熱融着層を有する積層体としても良い。又、蓋材として用いる場合は、前記製法で得た熱融着層を備えた単層あるいは積層フィルム若しくはシート状の積層体をそのまま蓋材として用いても良いし、印刷して用いても良い。更に印刷されたあるいはされていない紙、アルミ箔等と貼り合せて蓋材にしても良い。又、用途によっては予め容器形状に合わせてカットして蓋材にしても良い。
【００１７】
熱融着フィルムの厚さは、用途に応じて適宜決め得るが、通常、通常１〜１０００μｍ、好ましくは２〜１００μｍの範囲にある。熱融着フィルムを単層フィルムとして用いる場合は、成形加工上、５μｍ以上の厚さが必要であるが、熱融着フィルムを補強層との積層体として用い得る場合は、熱融着層を１μｍと薄くしても優れたシール特性を発揮できる。
【００１８】
基材層
本発明に係わる熱融着層に積層される基材層としては特に限定はされないが、例えば、ポリエチレンテレフタレートに代表されるポリエステルフィルム、ポリアミドフィルム、ポリプロピレンフィルム等の熱可塑性樹脂製フィルム、アルミニューム箔、紙等が挙げられる。かかる熱可塑性樹脂製フィルムからなる補強材は無延伸であっても一軸あるいは二軸延伸フィルムあるいはシ−ト等の基材であっても良い。勿論、基材層は１層でも２層以上としても良い。
【００１９】
熱シール層
本発明に係わる熱シール層は、被包装材料に合わせてエチレン重合体若しくはプロピレン重合体を種々公知の方法でフィルム、シート、トレー、カップ、ボトル等の種々の形状としたものである。フィルム若しくはシートの場合は、上記熱融着フィルムと同様な方法で製造し得る。トレー若しくはカップの場合は、一旦上記方法でシートを製造した後、真空成形、圧空成形等の熱成形によりトレー、カップ等の容器とすることにより製造し得る。又、カップあるいはボトルの場合は射出成形、射出中空成形（インジェクションブロー）、中空成形等により容器として成形し得る。更に用途によっては紙等の上記基材層にエチレン重合体若しくはプロピレン重合体を押出しラミネートあるいは押出しコーティング等により積層した積層体を上記種々の形状に加工したものでもよい。かかるエチレン重合体は、高圧法低密度ポリエチレン、線状低密度ポリエチレン、中密度ポリエチレン及び高密度ポリエチレン等であり、プロピレン重合体は、熱融着フィルムに用いるプロピレン重合体（Ｂ）と同一の範疇のものであるが、個々の物性は同一であっても異なっていてもよい。
【００２０】
容器蓋材
本発明の易開封性包装材料に係わる容器蓋材は、前記熱融着フィルムを最内層としてなる。容器蓋材とする場合には、通常前記熱融着フィルムに基材層として例示される種々材料が積層される。
【００２１】
包装体
本発明の包装体の１つは、相対する面が、ビニルエステル含量が３〜３０重量％のエチレン・ビニルエステル共重合体（Ａ）９９〜４０重量％、好ましくは９８〜６０重量％とプロピレン重合体（Ｂ）が１〜６０重量％、好ましくは２〜４０重量％との樹脂組成物（Ｄ）からなる熱融着層と、エチレン重合体層からなる熱シール層とからなることを特徴とする包装体である。相対する面を樹脂組成物（Ｄ）からなる熱融着層とエチレン重合体層からなる熱シール層にすることにより、低温ヒートシール性に優れ、且つヒートシール（熱融着）面が完全シールにならず、１〜２０N／１５ｍｍと適度なヒートシール強度（剥離強度）を有しているので、輸送時あるいは取扱い時に被包装物が漏れ出す虞もなく、且つ被包装物を取出す際に容易に開封でき、しかも開封する際には凝集剥離し開封時に熱融着面が糸引きを発生しない。
【００２２】
本発明の包装体の、他の１つは、相対する面が、ビニルエステル含量が３〜３０重量％のエチレン・ビニルエステル共重合体（Ａ）９５〜２０重量％、好ましくは８０〜４０重量％とプロピレン重合体（Ｂ）が５〜８０重量％、好ましくは２０〜６０重量％との樹脂組成物（Ｅ）からなる熱融着層と、プロピレン重合体層からなる熱シール層とからなることを特徴とする包装体である。相対する面を樹脂組成物（Ｅ）からなる熱融着層と、プロピレン重合体層からなる熱シール層にすることにより、低温ヒートシール性に優れ、且つヒートシール（熱融着）面が完全シールにならず、１〜２０N／１５ｍｍと適度なヒートシール強度（剥離強度）を有しているので、輸送時あるいは取扱い時に被包装物が漏れ出す虞もなく、且つ被包装物を取出す際に容易に開封でき、しかも開封する際には界面剥離あるいは凝集剥離するので、開封時に熱融着面が糸引きを発生しない。
【００２３】
本発明の包装体を構成する熱シール層を有する部材の形状は、フィルム状物あるいはシート状物に限らず、トレー、カップ、ボトル等の形状が例示できるがそれらに限定はされない。熱シール層の裏面には種々用途に応じて熱融着層に積層される前記基材層と同一あるいは異なる層が積層し得る。
【００２４】
【実施例】
次に実施例を挙げて本発明を更に具体的に説明するが、本発明はその要旨を越えない限りこれらの実施例に制約されるものではない。
【００２５】
実施例及び比較例で使用した原料は次の通りである。
（１）エチレン・酢酸ビニル共重合体（ＥＶＡ）
三井デュポンポリケミカル製（商品名；エバフレックス、銘柄名；Ｐ−１４０５Ｃ）：酢酸ビニル含有１４重量％、密度０．９３ｇ／ｃｍ３、ＭＦＲ３．５ｇ／１０分、融点９０℃
（２）プロピレン重合体−１（ＰＰ−１）
エチレン含量３モル％、ブテン含量１．６モル％のプロピレンランダム共重合体：
密度０．９０ｇ／ｃｍ３、ＭＦＲ７．０ｇ／１０分、融点１３８℃
（３）プロピレン重合体−２（ＰＰ−２）
プロピレン単独重合体：
密度０．９０ｇ／ｃｍ３、ＭＦＲ２．０ｇ／１０分、融点１６０℃
（４）エチレン重合体−１（シングルサイト触媒重合直鎖状低密度ポリエチレン）
三井化学社製（商品名；エボリュー、銘柄名；ＳＰ２５４０）
密度０．９２５ｇ／ｃｍ３、ＭＦＲ４ｇ／１０分、融点１２０℃
（５）エチレン重合体−２（直鎖状低密度ポリエチレン）
三井化学社製（商品名；ウルトゼックス、銘柄名；ＵＺ３５２３Ｌ）
密度０．９３５ｇ／ｃｍ３、ＭＦＲ２．１ｇ／１０分、融点１２３℃
【００２６】
実施例１
熱融着層となるＥＶＡ：９７重量％とＰＰ―１：３重量％をドライブレンドした樹脂組成物と、補強層となるエチレン重合体組成物（エチレン重合体−１：エチレン重合体−２＝３０重量％：７０重量％を混合したもの）を別々の押出機に供給し、Ｔダイ法によって熱融着層／補強層なる構成の２層共押出フイルムからなる熱融着フィルムを得た。フィルムの総厚は３０μｍで、各層の厚みは熱融着層：補強層＝４：２６μｍであった。
【００２７】
実施例２
実施例１で用いたＥＶＡ：９７重量％とＰＰ―１：３重量％をドライブレンドした樹脂組成物に代えて、ＥＶＡ：９５重量％とＰＰ―１：５重量％をドライブレンドした樹脂組成物を用いる以外は実施例１と同様に行い、熱融着層：補強層＝４：２６μｍの熱融着フィルムを得た。
【００２８】
実施例３
実施例１で用いた樹脂組成物に代えて、ＥＶＡ：９０重量％とＰＰ―１：１０重量％をドライブレンドした樹脂組成物を用いる以外は実施例１と同様に行い、熱融着層：補強層＝４：２６μｍの熱融着フィルムを得た。
【００２９】
実施例４
実施例１で用いた樹脂組成物に代えて、ＥＶＡ：７０重量％とＰＰ―１：３０重量％をドライブレンドした樹脂組成物を用いる以外は実施例１と同様に行い、熱融着層：補強層＝４：２６μｍの熱融着フィルムを得た。
【００３０】
実施例５
実施例１で用いた樹脂組成物に代えて、ＥＶＡ：５０重量％とＰＰ―１：５０重量％をドライブレンドした樹脂組成物を用いる以外は実施例１と同様に行い、熱融着層：補強層＝４：２６μｍの熱融着フィルムを得た。
【００３１】
比較例１
実施例１で用いた樹脂組成物に代えて、ＥＶＡを用いる以外は実施例１と同様に行い、熱融着層：補強層＝４：２６μｍの熱融着フィルムを得た。
【００３２】
比較例２
実施例１で用いた樹脂組成物に代えて、ＰＰ−１を用いる以外は実施例１と同様に行い、熱融着層：補強層＝４：２６μｍの熱融着フィルムを得た。
【００３３】
実施例６
実施例１で用いた樹脂組成物に代えて、ＥＶＡ：９７重量％とＰＰ―２：３重量％をドライブレンドした樹脂組成物を用いる以外は実施例１と同様に行い、熱融着層：補強層＝４：２６μｍの熱融着フィルムを得た。
【００３４】
実施例７
実施例１で用いた樹脂組成物に代えて、ＥＶＡ：９５重量％とＰＰ―２：５重量％をドライブレンドした樹脂組成物を用いる以外は実施例１と同様に行い、熱融着層：補強層＝４：２６μｍの熱融着フィルムを得た。
【００３５】
実施例８
実施例１で用いた樹脂組成物に代えて、ＥＶＡ：９０重量％とＰＰ―２：１０重量％をドライブレンドした樹脂組成物を用いる以外は実施例１と同様に行い、熱融着層：補強層＝４：２６μｍの熱融着フィルムを得た。
【００３６】
実施例９
実施例１で用いた樹脂組成物に代えて、ＥＶＡ：７０重量％とＰＰ―２：３０重量％をドライブレンドした樹脂組成物を用いる以外は実施例１と同様に行い、熱融着層：補強層＝４：２６μｍの熱融着フィルムを得た。
【００３７】
実施例１０
実施例１で用いた樹脂組成物に代えて、ＥＶＡ：５０重量％とＰＰ―２：５０重量％をドライブレンドした樹脂組成物を用いる以外は実施例１と同様に行い、熱融着層：補強層＝４：２６μｍの熱融着フィルムを得た。
【００３８】
比較例３
実施例１で用いた樹脂組成物に代えて、ＰＰ−２を用いる以外は実施例１と同様に行い、熱融着層：補強層＝４：２６μｍの熱融着フィルムを得た。
【００３９】
（１）ヒ−トシ−ル性の評価：
▲１▼積層フィルム：
厚さ１２μｍの二軸延伸ポリエチレンテレフタレ−トフィルム（ＰＥＴ）に、上記各実施例および比較例で得られた熱融着フィルムの補強層をウレタン系接着剤を用いてドライラミネ−ションにより積層して、積層フィルムとした。
▲２▼被着体：
前記積層フィルムと熱融着（ヒートシール）する被着体は、以下の種類の被着体を用いた。
ａ．厚さ１２μｍの二軸延伸ポリエチレンテレフタレ−トフィルム（ＰＥＴ）に被着層（熱シール層）として、厚さ２０μｍの高圧法低密度ポリエチレン（ＨＰ−ＬＤＰＥ、密度：０．９２３ｇ／ｃｍ３）を押出ラミネ−トした積層フィルム。
ｂ．厚さ１５μｍの二軸延伸ポリアミドフィルム（Ｏ−ＮＹ）に被着層（熱シール層）として、厚さ５０μｍの直鎖状低密度ポリエチレン（Ｌ−ＬＤＰＥ、密度：０．９１５ｇ／ｃｍ３）を押出ラミネ−トした積層フィルム。
ｃ．厚さ３００μｍのポリプロピレンシ−ト（ＰＰＳ、熱シール層）。
ｄ．上記熱融着フィルム。
▲３▼ヒートシール試験：
１） 上記積層フィルムの熱融着層面と上記各被着体の被着層面を重ね合せ、所定の温度で、幅５ｍｍのシールバーを用い、０．２ＭＰａの圧力で１秒間シールした後放冷した。これから１５ｍｍ幅の試験片を切り取りクロスヘッド速度５００ｍｍ／ｍｉｎでヒートシール部を剥離し、その強度をヒートシール強度（N／１５ｍｍ）とした。
２） 被着体ａ．との評価は、凝集剥離糸引きなしを○、界面剥離を△、完全ヒ−トシ−ルされているものを×、糸引きがあり層間剥離傾向のあるものを□とした。。
３） 被着体ｂ．との評価は、凝集剥離を○、界面剥離を△、完全ヒ−トシ−ルされているものを×とした。
４） 被着体ｃ．との評価は、凝集剥離を◎、界面剥離を○、完全ヒ−トシ−ルされているものを×とした。
５） 被着体ｄ．との評価は、凝集剥離糸引きなしを○とした。
【００４０】
（２）容器との封緘性及び開封性の評価
▲１▼包装体の調整：
内面に高圧法低密度ポリエチレンがラミネートされた紙基材製容器〔東罐興業株式会社製：タイプＡＣ−４３０ＥＰ（無地）〕と上記各実施例及び比較例で得た熱融着フィルムとを、エ−シンパック工業株式会社製のエ−シンパックシ−ラ半自動Ｏ型タイプを用いて、温度１８０℃、１容器に対してのヒ−トシ−ル実圧力９００Ｎ、シ−ル時間１秒で口部を熱融着（カップシ−ル）した。
▲２▼封緘性の評価：
株式会社サン科学製のシ−ルテスタ−ＦＫＴタイプを用い、上記調整法で得た包装体の破裂強度を測定した。尚、破裂強度試験は熱処理しない容器及び６０℃のオ−ブンで２４時間熱処理した後、２３℃・相対湿度６５％の雰囲気下で２４時間放置後の熱処理した容器で行った。
封緘性の評価は、熱処理しない容器と熱処理した容器との破裂強度の変化が少なく、且つ熱処理後の破裂強度が１０ＭＰａを越えるものを○、破裂強度が１０ＭＰａ前後のものを○〜△、１０未満のものを×とした。
▲３▼開封性の評価：
破裂強度を測定したサンプルを用いて、手で熱融着フィルムを剥離し、以下の基準で開封性を評価した。
ａ．開封強度：
ホットメルト材でシールされたスナック容器（市販品）の開封強度と比較して、同程度のもの：◎、少し弱めのもの：○、弱めなもの：△、弱いもの：×、強いもの：××とした。
ｂ．開封時の糸引き：
糸引きなし：◎、微量あり：○、少しあり：△、多数あり：×
ｃ．紙剥け：
熱融着フィルムを紙基材製容器から剥離した際に、紙の内面にラミネートされた高圧法低密度ポリエチレンと紙とが剥離する現象を紙剥けと称し、それぞれ、紙剥けなし：◎、微量あり：○、容器開封部の１／４未満に紙剥けあり：△、容器開封部の１／４以上の紙剥けあり：×として評価した。
【００４１】
各実施例、比較例及び参考例で得られたフィルムの特性値を表１及び表２に示す。
【００４２】
【表１】
【表２】
【発明の効果】
本発明の熱融着フィルムは、エチレン・酢酸ビニル共重合体とプロピレン重合体との組成物とが特定の割合で混合された熱融着層を有する熱融着フィルムである。かかる熱融着フィルムを用いて当該フィルムを熱融着層とした包装袋等の包装材、あるいは熱シール層としてエチレン重合体、プロピレン重合体を有する被着材からなる包装材は、被包装物を包装する際に、低温ヒ−トシ−ル性（低温熱融着性）があり、ヒ−トシ−ル温度幅も広く、又、得られた包装体は、適度なヒートシール強度を有しているので、開封時にはソフトに容易に開封できるという特性を有している。又、本発明の熱融着フィルムはブロキング性にも優れている。
【００４５】
本発明の容器蓋材を用いた紙容器は、熱融着強度の温度依存性が小さく、輸送時等には被包装物が漏れ出る虞がない熱融着強度を有しながら、被包装物を取出す際には容易に開封でき、開封時にソフトで紙容器表面のエチレン重合体層との間で糸引き等が無く、且つ紙剥けの発生がなく、綺麗な凝集剥離で開封できる。又、夏場の気候のような場合に気温が３０℃以上、あるいは流通時・倉庫保管時での５０〜６０℃程度の高温下における保管時にもシ−ル部、特に容器の段差と蓋材シ−ルの部分での空気漏れ、あるいはパンクしない耐熱性、つまり容器としての封緘性に優れているという特徴を有している。
【００４６】
かかる特徴を活かして、本発明の熱融着フィルム、易開封性包装材料、容器蓋材あるいはこれら材料を用いた容器等の包装体は、広く各種のヨ−グルト、プリン、ゼリ−、スナック、麺などの紙ポリ容器の食品包装やブリスタ−包装、その他日用品や雑貨等の袋物包装、ボトル、カップ、ないしトレ−のプラスチックス容器などのシ−ル材等の包装体として好適に利用することができる。[0001]
BACKGROUND OF THE INVENTION
The present invention is easy to open with a heat-sealing layer comprising a resin composition of an ethylene / vinyl ester copolymer and a propylene polymer, soft feeling at the time of opening, blocking resistance, hygiene, film forming processability The present invention relates to a heat-sealing film excellent in laminate processability, a container lid made of such a heat-sealing film, and a packaging body using the same.
[0002]
[Prior art]
Packaging for snacks such as rice crackers, potato chips, etc., food packaging such as jelly, milk, yogurt, pudding, tofu, lactic acid beverages, blister packaging, and other daily necessities and miscellaneous goods packaging, bottles, cups or tray-like plastic containers Wrapped in a lid made of a plastic laminate film or aluminum foil laminate film is widely used. What is required for such packaging is mechanical strength that can withstand distribution channels, sealing strength that can maintain hygiene, and good openability during use.
[0003]
As one of the materials used for such packaging, one of them was used for a bag having a category called an easy-opening (easy peel) film as a heat-sealing layer as the innermost layer, or as a cover material. Packaging is widely used. However, various heat-sealing layers proposed so far have high heat-sealing strength for sealing, but easy peelability at the time of opening is not always sufficient, and an appropriate balance between them can be obtained. It has been demanded. Here, the characteristics required for easy peelability are not only ease of opening, but also there is no residue of resin fragments adhering to the opening after opening due to stringing, etc., and the appearance of the opening is good. It is comprehensive evaluation including, and the quality is judged by it.
[0004]
As a means for solving such a drawback, for example, a heat-sealable resin composition comprising an ethylene-vinyl ester copolymer, a low crystalline or amorphous ethylene copolymer and a tackifier (Japanese Patent Publication No. 63-29894). ), An easily-openable heat-sealing resin composition (Japanese Patent Laid-Open No. 2-185547) comprising an ethylene-α-olefin copolymer, a propylene-ethylene copolymer and low-density polyethylene has been proposed.
[0005]
However, when a sealing material with such a configuration is used in a paper container laminated with low-density polyethylene, it becomes a complete seal with the low-density polyethylene layer, and when opened, the low-density polyethylene peels off, and the paper scraps, etc. May fall into the contents, or the container may be deformed and the contents may be spilled. In addition, a film having such a composition layer may be easily blocked, and it may be difficult to unwind a film wound up in a roll shape, and the appearance may be inferior due to a blocking mark.
[0006]
[Problems to be solved by the invention]
The present invention is excellent in blocking resistance, soft openability, hygiene, and processability, and the temperature dependence of the heat-sealing strength when heat-sealing with a heat-sealing layer comprising an ethylene polymer layer or a propylene polymer layer. It is easy to open when taking out the package while having a heat-sealing strength that prevents the package from leaking out during transportation, etc., and it can be softly coated on the surface of the paper container when opened.・ To obtain a film and package that can be opened by clean interface peeling or cohesive peeling without stringing with the extruded ethylene polymer, and in summer climates, the temperature is 30 ° C or higher. No heat leak or puncture at the seal part, especially at the step of the container and the seal part of the lid, even during storage or during storage and storage at high temperatures of about 50-60 ° C In other words, sealing as a container To obtain the peelable possible heat-sealing film and package is excellent, and various studies.
[0007]
[Means for Solving the Problems]
The present invention relates to a resin composition (C) comprising 99 to 20% by weight of an ethylene / vinyl ester copolymer (A) having a vinyl ester content of 3 to 30% by weight and 1 to 80% by weight of a propylene polymer (B). A heat-sealing film characterized by comprising a heat-sealing layer, an easy-open packaging material and a container lid material using the heat-sealing film, and an ethylene vinyl ester having a vinyl ester content of 3 to 30% by weight It comprises a heat-sealing layer comprising a resin composition (D) of 99 to 40% by weight of copolymer (A) and 1 to 60% by weight of propylene polymer (B), and a heat sealing layer comprising an ethylene polymer layer. The package and the opposite surface are characterized by 95 to 20% by weight of ethylene / vinyl ester copolymer (A) having a vinyl ester content of 3 to 30% by weight and 5 to 80% by weight of propylene polymer (B). % Resin composition ( A thermal fusion layer consisting of), relates to a packaging body, comprising the heat seal layer comprising a propylene polymer layer.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Ethylene / vinyl ester copolymer (A)
The ethylene / vinyl ester copolymer (A) according to the present invention is a copolymer of ethylene and a vinyl ester such as vinyl acetate or vinyl propionate, and has a vinyl ester content of 3 in the copolymer. It is in the range of -30% by weight, preferably 5-15% by weight. When the vinyl ester content is within this range, the balance between the heat seal strength and the easy peel property is kept good, and the heat resistance necessary for filling food is preferable. Moreover, the melt flow rate (MFR) of this copolymer has a value measured in accordance with JIS 6730, usually in the range of 1 to 40, preferably 1.5 to 30 (g / 10 min). The coalescence has good extrudability and sufficient mechanical strength as a packaging film. This ethylene / vinyl ester copolymer (A) has an effect of imparting low temperature heat sealability when used as a heat-sealing layer.
[0009]
Propylene polymer (B)
The propylene polymer (B) according to the present invention is a resin that is generally produced and sold under the name of polypropylene, and is suitable for film use, and usually has a density of 0.890 to 0.930 g / cm.3MFR (ASTM D1238 load 2160 g, temperature 230 ° C.) of 0.5 to 60 g / 10 min, preferably 0.5 to 10 g / 10 min of propylene homopolymer or propylene and other small amount of α-olefin, for example Random or block copolymers with ethylene, butene, hexene-1, etc.
[0010]
Resin composition (C)
In the resin composition (C) according to the present invention, the ethylene-vinyl ester copolymer (A) is 99 to 20% by weight, preferably 98 to 40% by weight, and the propylene polymer (B) is 1 to 80% by weight. %, Preferably 2 to 60% by weight. Usually, MFR (ASTM D1238 load 2160 g, temperature 190 ° C.) is in the range of 0.1 to 40 g / 10 minutes, preferably 1 to 30 g / 10 minutes. When the amount of the propylene polymer (B) is less than 1% by weight, when the resin composition (C) surfaces are heat-sealed, the heat seal strength tends to be too strong and the easy-opening property tends to be inferior, whereas 80% by weight. If it exceeds 50%, it tends to be inferior in low-temperature heat sealability, opening strength, practical sealing performance, and sealing performance (heat resistance).
[0011]
Resin composition (D)
In the resin composition (D) according to the present invention, the ethylene-vinyl ester copolymer (A) is 99 to 40% by weight, preferably 98 to 60% by weight, and the propylene polymer (B) is 1 to 60% by weight. %, Preferably 2 to 40% by weight. Usually, the MFR (ASTM D1238 load 2160 g, temperature 190 ° C.) is in the range of 0.1 to 40 g / 10 minutes, preferably 1 to 30 g / 10 minutes. When the amount of the propylene polymer (B) is less than 1% by weight, when heat-sealing with the ethylene polymer layer, the heat seal strength tends to be too strong and tends to be inferior in easy-opening properties, while when it exceeds 60% by weight. It tends to be inferior in low-temperature heat sealability, opening strength, practical sealing properties, and sealing properties (heat resistance).
[0012]
Resin composition (E)
In the resin composition (E) according to the present invention, the ethylene / vinyl ester copolymer (A) is 95 to 20% by weight, preferably 80 to 40% by weight, and the propylene polymer (B) is 5 to 80% by weight. %, Preferably 20 to 60% by weight. Usually, MFR (ASTM D1238 load 2160 g, temperature 190 ° C.) is in the range of 0.1 to 40 g / 10 minutes, preferably 1 to 30 g / 10 minutes. When the amount of the propylene polymer (B) is less than 5% by weight, when heat-sealing with the propylene polymer layer, the heat seal strength is low, and the opening strength, the sealing performance in practice, and the sealing performance tend to be inferior. On the other hand, if it exceeds 80% by weight, the heat seal strength tends to be too strong and the easy-openability tends to be poor.
[0013]
The ethylene-vinyl ester copolymer (A), the propylene polymer (B) or the resin composition (C), (D) and (E) according to the present invention are within the range not impairing the object of the present invention. Commonly used additives such as antioxidants, weathering stabilizers, antistatic agents, antifogging agents and the like can be blended as necessary. In particular, by blending an anti-blocking agent and a slip agent, workability and workability during film forming, laminating, packaging, etc. can be improved.
[0014]
Heat sealing film
The heat-sealing film according to the present invention is a film in which the resin composition (C) with the ethylene / vinyl ester copolymer (A) and the propylene polymer (B) is used as a heat-sealing layer. Such heat fusion films can be produced by various known methods. For example, an ethylene / vinyl ester copolymer (A) and a propylene polymer (B) are mixed in a predetermined amount, and then directly put into a film molding machine to form a film using a T-die, an annular die or the like. Method, an ethylene / vinyl ester copolymer (A) and a propylene polymer (B) are mixed in a predetermined amount and melt-kneaded with an extruder or the like to obtain a resin composition (C); Examples thereof include a film forming method using a die, an annular die and the like.
[0015]
The heat-sealing film can be used as a single layer, but as a reinforcing layer, high-pressure method low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, high-density polyethylene and other ethylene polymers, polybutene, ethylene / vinyl acetate copolymer, etc. It may be a laminated film with the olefin polymer layer. Among these, the density is 0.905 to 0.935 g / cm.3, Preferably 0.910 to 0.935 g / cm3MFR (ASTM D1238 load 2160 g, temperature 190 ° C.) is a homopolymer of ethylene polymerized under a high pressure of 0.5 to 30 g / 10 minutes, preferably 1 to 10 g / 10 minutes, or 5% by weight or less, Copolymers with other α-olefins or vinyl compounds such as vinyl acetate, usually low-pressure polyethylene called high-pressure method low-density polyethylene, and α-olefins having 3 to 10 carbon atoms and ethylene, such as propylene , Butene-1, heptene-1, hexene-1, octene-1, 4-methyl-pentene-1, a random copolymer of molecular weight distribution (weight average molecular weight: Mw and number average molecular weight: Mn Ratio: expressed as Mw / Mn) is usually in the range of 1.5 to 4.0, preferably 1.8 to 3.5, usually referred to as linear low density polyethylene (LLDPE) A laminated film with a film obtained from an ethylene / α-olefin random copolymer or the like is preferred, and particularly when linear low-density polyethylene is used for the reinforcing layer, it has excellent low-temperature sealing properties and heat. When the fused surface is opened, cohesive peeling occurs, and a fine opened surface is obtained without stringing on the peeled surface (opened surface).
[0016]
In the case of obtaining such a laminated film, the resin composition serving as the heat-sealing layer and the olefin polymer used for the reinforcing layer can be coextruded using a multilayer die to form a heat-sealing film. Alternatively, the resin composition may be extrusion laminated or extrusion coated on a previously obtained reinforcing layer to form a laminate having a heat fusion layer, or a film obtained separately is laminated to have a heat fusion layer. It is good also as a laminated body. When used as a lid, a single layer or a laminated film or a sheet-like laminate provided with the heat-sealing layer obtained by the above production method may be used as a lid, or may be printed and used. . Further, it may be bonded to paper that is printed or not, aluminum foil, or the like to form a lid. Further, depending on the application, it may be cut in advance according to the shape of the container to form a lid.
[0017]
Although the thickness of a heat-fusion film can be suitably determined according to a use, it is usually 1-1000 micrometers normally, Preferably it exists in the range of 2-100 micrometers. When the heat-sealing film is used as a single-layer film, a thickness of 5 μm or more is necessary for molding. However, when the heat-sealing film can be used as a laminate with a reinforcing layer, the heat-sealing layer is used. Excellent sealing properties can be exhibited even when made as thin as 1 μm.
[0018]
Base material layer
Although it does not specifically limit as a base material layer laminated | stacked on the heat sealing | fusion layer concerning this invention, For example, the film made from thermoplastic resins, such as a polyester film represented by a polyethylene terephthalate, a polyamide film, a polypropylene film, Aluminum foil And paper. Such a reinforcing material made of a thermoplastic resin film may be non-stretched or a base material such as a uniaxial or biaxially stretched film or a sheet. Of course, the base material layer may be one layer or two or more layers.
[0019]
Heat seal layer
The heat seal layer according to the present invention is formed by forming ethylene polymer or propylene polymer into various shapes such as a film, a sheet, a tray, a cup, and a bottle by various known methods according to the packaging material. In the case of a film or sheet, it can be produced by the same method as that for the heat-sealing film. In the case of a tray or a cup, it can be produced by once producing a sheet by the above method and then forming a container such as a tray or a cup by thermoforming such as vacuum forming or pressure forming. In the case of a cup or bottle, it can be molded as a container by injection molding, injection hollow molding (injection blow), hollow molding or the like. Furthermore, depending on the use, a laminate obtained by laminating an ethylene polymer or a propylene polymer on the base material layer such as paper by extrusion lamination or extrusion coating may be processed into the above various shapes. Such ethylene polymers are high pressure method low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene and the like, and the propylene polymer is in the same category as the propylene polymer (B) used for the heat-sealing film. However, the individual physical properties may be the same or different.
[0020]
Container lid
The container lid material according to the easy-open packaging material of the present invention has the heat-sealing film as the innermost layer. When the container lid is used, various materials exemplified as a base material layer are usually laminated on the heat-sealing film.
[0021]
Package
One of the packages of the present invention has an ethylene / vinyl ester copolymer (A) 99 to 40% by weight, preferably 98 to 60% by weight, having a vinyl ester content of 3 to 30% by weight. The polymer (B) comprises 1 to 60% by weight, preferably 2 to 40% by weight of a heat sealing layer made of the resin composition (D) and a heat sealing layer made of an ethylene polymer layer. This is a package. By making the opposite faces into a heat-sealing layer made of the resin composition (D) and a heat-sealing layer made of an ethylene polymer layer, it has excellent low-temperature heat-sealing properties and the heat-sealing (heat-sealing) face is completely sealed. Because it has an appropriate heat seal strength (peeling strength) of 1-20 N / 15 mm, there is no risk of the package being leaked during transportation or handling, and it is easy to remove the package. In addition, when it is opened, it is agglomerated and peeled off, and the heat-sealing surface does not cause stringing at the time of opening.
[0022]
The other one of the packaging bodies of the present invention is an ethylene vinyl ester copolymer (A) having a vinyl ester content of 3 to 30% by weight, preferably 20 to 40% by weight. % And propylene polymer (B) 5 to 80% by weight, preferably 20 to 60% by weight of a heat-sealing layer made of a resin composition (E) and a heat sealing layer made of a propylene polymer layer. It is the package characterized by the above. By making the opposite faces into a heat-sealing layer made of the resin composition (E) and a heat-sealing layer made of a propylene polymer layer, it has excellent low-temperature heat-sealing properties and has a completely heat-sealing (heat-sealing) surface. Since it does not become a seal and has an appropriate heat seal strength (peel strength) of 1-20 N / 15 mm, there is no risk of the package being leaked during transportation or handling, and when the package is taken out Since it can be easily opened, and the interface peeling or cohesive peeling occurs when opening, the heat-sealing surface does not cause stringing at the time of opening.
[0023]
The shape of the member having the heat seal layer constituting the package of the present invention is not limited to a film-like material or a sheet-like material, but examples of the shape of a tray, cup, bottle, etc. are not limited thereto. A layer which is the same as or different from the base material layer laminated on the heat-sealing layer can be laminated on the back surface of the heat seal layer according to various uses.
[0024]
【Example】
EXAMPLES Next, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples unless it exceeds the gist.
[0025]
The raw materials used in Examples and Comparative Examples are as follows.
(1) Ethylene / vinyl acetate copolymer (EVA)
Made by Mitsui DuPont Polychemical (trade name; Evaflex, brand name; P-1405C): vinyl acetate containing 14% by weight, density 0.93 g / cm3, MFR 3.5 g / 10 min, melting point 90 ° C.
(2) Propylene polymer-1 (PP-1)
Propylene random copolymer having an ethylene content of 3 mol% and a butene content of 1.6 mol%:
Density 0.90g / cm3, MFR 7.0 g / 10 min, melting point 138 ° C.
(3) Propylene polymer-2 (PP-2)
Propylene homopolymer:
Density 0.90g / cm3, MFR 2.0 g / 10 min, melting point 160 ° C.
(4) Ethylene polymer-1 (single site catalyst polymerization linear low density polyethylene)
Made by Mitsui Chemicals (trade name: Evolue, brand name: SP2540)
Density 0.925g / cm3, MFR 4 g / 10 min, melting point 120 ° C.
(5) Ethylene polymer-2 (linear low density polyethylene)
Made by Mitsui Chemicals, Inc. (trade name; Ultzex, brand name; UZ3523L)
Density 0.935g / cm3, MFR 2.1 g / 10 min, melting point 123 ° C.
[0026]
Example 1
EVA: 97% by weight as a heat-fusible layer and PP-1: 3% by weight of a resin composition dry-blended, and an ethylene polymer composition as a reinforcing layer (ethylene polymer-1: ethylene polymer-2 = 30% by weight: 70% by weight mixed) was supplied to separate extruders, and a heat-sealing film composed of a two-layer coextruded film having a constitution of heat-sealing layer / reinforcing layer was obtained by a T-die method. The total thickness of the film was 30 μm, and the thickness of each layer was heat fusion layer: reinforcing layer = 4: 26 μm.
[0027]
Example 2
Instead of the resin composition obtained by dry blending EVA: 97% by weight and PP-1: 3% by weight used in Example 1, a resin composition obtained by dry blending EVA: 95% by weight and PP-1: 5% by weight Example 1 was performed in the same manner as in Example 1 to obtain a heat-sealing film of heat-sealing layer: reinforcing layer = 4: 26 μm.
[0028]
Example 3
Instead of the resin composition used in Example 1, EVA was used in the same manner as in Example 1 except that a resin composition obtained by dry blending 90% by weight and PP-1: 10% by weight was used. Reinforcing layer = 4: 26 μm heat-sealing film was obtained.
[0029]
Example 4
Instead of the resin composition used in Example 1, EVA was used in the same manner as in Example 1 except that a dry blended resin composition of 70% by weight and PP-1: 30% by weight was used. Reinforcing layer = 4: 26 μm heat-sealing film was obtained.
[0030]
Example 5
In place of the resin composition used in Example 1, EVA was used in the same manner as in Example 1 except that a resin composition obtained by dry blending 50% by weight and PP-1: 50% by weight was used. Reinforcing layer = 4: 26 μm heat-sealing film was obtained.
[0031]
Comparative Example 1
It replaced with the resin composition used in Example 1, and carried out similarly to Example 1 except having used EVA, and obtained the heat sealing | fusion film of heat sealing | fusion layer: reinforcing layer = 4: 26 micrometers.
[0032]
Comparative Example 2
It replaced with the resin composition used in Example 1, and carried out similarly to Example 1 except using PP-1, and obtained the heat sealing | fusion film of heat sealing | fusion layer: reinforcing layer = 4:26 micrometers.
[0033]
Example 6
Instead of the resin composition used in Example 1, EVA was used in the same manner as in Example 1 except that a resin composition obtained by dry blending 97% by weight and PP-2: 3% by weight was used. Reinforcing layer = 4: 26 μm heat-sealing film was obtained.
[0034]
Example 7
Instead of the resin composition used in Example 1, EVA was used in the same manner as in Example 1 except that a resin composition obtained by dry blending 95% by weight and PP-2: 5% by weight was used. Reinforcing layer = 4: 26 μm heat-sealing film was obtained.
[0035]
Example 8
Instead of the resin composition used in Example 1, EVA was used in the same manner as in Example 1 except that a resin composition obtained by dry blending 90% by weight and PP-2: 10% by weight was used. Reinforcing layer = 4: 26 μm heat-sealing film was obtained.
[0036]
Example 9
Instead of the resin composition used in Example 1, EVA was used in the same manner as in Example 1 except that a resin composition obtained by dry blending 70% by weight and PP-2: 30% by weight was used. Reinforcing layer = 4: 26 μm heat-sealing film was obtained.
[0037]
Example 10
Instead of the resin composition used in Example 1, EVA was used in the same manner as in Example 1 except that a resin composition obtained by dry blending 50% by weight and PP-2: 50% by weight was used. Reinforcing layer = 4: 26 μm heat-sealing film was obtained.
[0038]
Comparative Example 3
It replaced with the resin composition used in Example 1, and carried out similarly to Example 1 except using PP-2, and obtained the heat sealing | fusion film of heat sealing | fusion layer: reinforcing layer = 4:26 micrometers.
[0039]
(1) Evaluation of heat sealability:
(1) Laminated film:
A 12 μm thick biaxially stretched polyethylene terephthalate film (PET) was laminated by dry lamination using a urethane adhesive with a reinforcing layer of the heat fusion film obtained in each of the above examples and comparative examples. A laminated film was obtained.
(2) Substrate:
The following types of adherends were used as adherends to be heat-sealed (heat sealed) with the laminated film.
a. A high-pressure low-density polyethylene (HP-LDPE, density: 0.923 g / cm) having a thickness of 20 μm as a coating layer (heat seal layer) on a biaxially stretched polyethylene terephthalate film (PET) having a thickness of 12 μm.3A laminated film obtained by extrusion lamination.
b. A linear low-density polyethylene (L-LDPE, density: 0.915 g / cm) having a thickness of 50 μm as an adherent layer (heat seal layer) on a biaxially stretched polyamide film (O-NY) having a thickness of 15 μm.3A laminated film obtained by extrusion lamination.
c. 300 μm thick polypropylene sheet (PPS, heat seal layer).
d. The heat sealing film.
(3) Heat seal test:
1) The heat-sealable layer surface of the laminated film and the adherend layer surface of each adherend are overlaid, sealed at a predetermined temperature using a seal bar having a width of 5 mm and a pressure of 0.2 MPa for 1 second, and then allowed to cool. did. From this, a test piece having a width of 15 mm was cut off and the heat seal part was peeled off at a crosshead speed of 500 mm / min, and the strength was defined as heat seal strength (N / 15 mm).
2) Substrate a. In the evaluation, ◯ indicates that there is no cohesive peeling yarn pulling, Δ indicates interfacial peeling, × indicates that there is complete heat sealing, and □ indicates that there is stringing and there is a tendency to delaminate. .
3) Substrate b. In the evaluation, agglomerated exfoliation was evaluated as ◯, interfacial exfoliation as Δ, and complete heat sealed as x.
4) Substrate c. In the evaluation, agglomerated peeling is indicated by ◎, interfacial peeling is indicated by ○, and completely heat-sealed is indicated by ×.
5) Substrate d. In the evaluation, “A” indicates that there is no agglomerated release yarn drawing.
[0040]
(2) Evaluation of sealability and openability with containers
(1) Adjustment of package:
A paper base container (made by Toago Kogyo Co., Ltd .: type AC-430EP (plain fabric)) laminated with high-pressure low-density polyethylene on the inner surface and the heat-sealing film obtained in each of the above Examples and Comparative Examples, Using Ashin Pack Sealer semi-automatic O type manufactured by A Shin Pack Industry Co., Ltd., temperature 180 ° C, heat seal actual pressure 900N for 1 container, seal time 1 second. Was heat-sealed (cup seal).
(2) Evaluation of sealing property:
Using a seal tester-FKT type manufactured by San Kagaku Co., Ltd., the burst strength of the package obtained by the above adjustment method was measured. The burst strength test was carried out in a container that was not heat-treated and a heat-treated container that was heat-treated for 24 hours in an oven at 60 ° C. and then left for 24 hours in an atmosphere of 23 ° C. and 65% relative humidity.
The sealability is evaluated as follows: ○ when the change in burst strength between the unheated container and the heat-treated container is small and the burst strength after heat treatment exceeds 10 MPa, and when the burst strength is around 10 MPa; Was marked with x.
(3) Evaluation of openability:
Using the sample whose burst strength was measured, the heat-sealing film was peeled off by hand, and the openability was evaluated according to the following criteria.
a. Opening strength:
Compared to the opening strength of a snack container sealed with a hot-melt material (commercially available): ◎, slightly weak: ○, weak: △, weak: ×, strong: × X.
b. Threading when opened:
No stringing: ◎, trace amount: ○, slightly: △, many: ×
c. Paper peeling:
When the heat-sealing film is peeled from the paper base container, the phenomenon that the paper is peeled off from the high-pressure low-density polyethylene laminated on the inner surface of the paper is called paper peeling. Existence: ○, less than 1/4 of the container opening part was peeled off: Δ, more than 1/4 of the container opening part was peeled off: evaluated as x.
[0041]
Tables 1 and 2 show the characteristic values of the films obtained in the examples, comparative examples, and reference examples.
[0042]
[Table 1]
[Table 2]
【The invention's effect】
The heat fusion film of the present invention is a heat fusion film having a heat fusion layer in which a composition of an ethylene / vinyl acetate copolymer and a propylene polymer is mixed at a specific ratio. A packaging material such as a packaging bag having such a film as a heat-sealing layer using such a heat-sealing film, or a packaging material comprising an ethylene polymer or a propylene polymer as a heat sealing layer is to be packaged. When packaging, it has a low temperature heat seal property (low temperature heat fusion property), a wide heat seal temperature range, and the obtained package has an appropriate heat seal strength. Therefore, it has the characteristic that it can be easily opened softly when opened. Moreover, the heat sealing | fusion film of this invention is excellent also in the blocking property.
[0045]
The paper container using the container lid material of the present invention has a low temperature dependency of the heat-sealing strength, and has a heat-sealing strength that prevents the material to be packaged from leaking during transportation, etc. When taking out, it can be opened easily, it is soft at the time of opening, there is no stringing between the ethylene polymer layer on the surface of the paper container, and there is no occurrence of paper peeling, and it can be opened with clean cohesive peeling. In addition, when the temperature is 30 ° C or higher, such as in summer, or when storing at a high temperature of about 50-60 ° C during distribution or storage in a warehouse, the seal part, especially the step of the container and the cover material -It has the characteristic that it is excellent in heat leakage that does not puncture, or in other words, sealing performance as a container.
[0046]
Taking advantage of such characteristics, the heat-sealing film of the present invention, easy-open packaging materials, container lid materials or containers such as containers using these materials are widely used in various yogurts, puddings, jellies, snacks, It should be suitably used as packaging for food packaging such as paper plastic containers such as noodles, blister packaging, bag packaging such as daily necessities and miscellaneous goods, and seal materials such as bottles, cups, and plastic containers for trays. Can do.
Claims (2)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001190151A JP4864235B2 (en) | 2001-06-22 | 2001-06-22 | Thermal fusion film and package comprising the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001190151A JP4864235B2 (en) | 2001-06-22 | 2001-06-22 | Thermal fusion film and package comprising the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2003001768A JP2003001768A (en) | 2003-01-08 |
| JP4864235B2 true JP4864235B2 (en) | 2012-02-01 |
Family
ID=19028968
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2001190151A Expired - Lifetime JP4864235B2 (en) | 2001-06-22 | 2001-06-22 | Thermal fusion film and package comprising the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4864235B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2019069759A1 (en) * | 2017-10-03 | 2019-04-11 | 住友ベークライト株式会社 | Multi-layered film and package |
| JP7036100B2 (en) * | 2019-10-15 | 2022-03-15 | 住友ベークライト株式会社 | Package |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5584659A (en) * | 1978-12-22 | 1980-06-26 | Denki Kagaku Kogyo Kk | Film capable of being thermally sealed up |
| JPS59196348A (en) * | 1983-04-22 | 1984-11-07 | Mitsubishi Plastics Ind Ltd | Composite film |
| JP2000238738A (en) * | 1999-02-16 | 2000-09-05 | Toppan Printing Co Ltd | Lid material |
-
2001
- 2001-06-22 JP JP2001190151A patent/JP4864235B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JP2003001768A (en) | 2003-01-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7651779B2 (en) | Resin composition having easy-openable property | |
| JP7140105B2 (en) | Laminated film and food packaging bag | |
| JP5394096B2 (en) | Easy peel film | |
| KR101749854B1 (en) | Easily openable laminated film and use therefor | |
| JP4731699B2 (en) | Thermal fusion film and package comprising the same | |
| JP7140104B2 (en) | Laminated film and food packaging bag | |
| JP5855005B2 (en) | Easy peelable laminated film and its use | |
| JP4553545B2 (en) | Easy peelable laminated film and package comprising the same | |
| JP4864235B2 (en) | Thermal fusion film and package comprising the same | |
| JP5159003B2 (en) | Thermal fusion film and package comprising the same | |
| JP5959737B2 (en) | Easy peelable laminated film and package comprising the same | |
| JP4692818B2 (en) | Co-extrusion laminated film and laminate film and packaging container using the same | |
| JP4636479B2 (en) | Polyolefin multilayer film and package | |
| JP4870285B2 (en) | Polyolefin film for packaging and packaging | |
| JP4520605B2 (en) | Easy-open packaging | |
| JP6816850B1 (en) | Laminated film and lid material | |
| JP2020059258A (en) | Easily opening sealant film and package | |
| JP2022080921A (en) | Easily-openable film | |
| JP2022080919A (en) | Easily-openable film | |
| JP2003096214A (en) | Easily openable sealant film | |
| JP2003096213A (en) | Easily openable sealant film |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20080529 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20101019 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20101027 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20101227 |
|
| RD02 | Notification of acceptance of power of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: A7422 Effective date: 20101227 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20111025 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20111109 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20141118 Year of fee payment: 3 |
|
| R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 Ref document number: 4864235 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| EXPY | Cancellation because of completion of term |