JP3678035B2 - Easy-open container - Google Patents
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- JP3678035B2 JP3678035B2 JP00038099A JP38099A JP3678035B2 JP 3678035 B2 JP3678035 B2 JP 3678035B2 JP 00038099 A JP00038099 A JP 00038099A JP 38099 A JP38099 A JP 38099A JP 3678035 B2 JP3678035 B2 JP 3678035B2
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- 229920005989 resin Polymers 0.000 claims description 72
- 239000011347 resin Substances 0.000 claims description 72
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 claims description 41
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 claims description 41
- 238000007789 sealing Methods 0.000 claims description 28
- 239000011342 resin composition Substances 0.000 claims description 24
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 claims description 9
- 239000005977 Ethylene Substances 0.000 claims description 9
- 239000004711 α-olefin Substances 0.000 claims description 9
- 229920000089 Cyclic olefin copolymer Polymers 0.000 claims description 7
- 229920001038 ethylene copolymer Polymers 0.000 claims description 5
- 229920001519 homopolymer Polymers 0.000 claims description 5
- 239000010410 layer Substances 0.000 description 37
- 238000004806 packaging method and process Methods 0.000 description 15
- 229920001577 copolymer Polymers 0.000 description 11
- 239000000463 material Substances 0.000 description 7
- 239000000565 sealant Substances 0.000 description 7
- 239000000853 adhesive Substances 0.000 description 6
- 230000001070 adhesive effect Effects 0.000 description 6
- 239000000203 mixture Substances 0.000 description 6
- -1 polypropylene Polymers 0.000 description 6
- 229920001384 propylene homopolymer Polymers 0.000 description 6
- 229920005653 propylene-ethylene copolymer Polymers 0.000 description 5
- 239000000155 melt Substances 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 229920005672 polyolefin resin Polymers 0.000 description 4
- VXNZUUAINFGPBY-UHFFFAOYSA-N 1-Butene Chemical compound CCC=C VXNZUUAINFGPBY-UHFFFAOYSA-N 0.000 description 3
- 239000004743 Polypropylene Substances 0.000 description 3
- 229920001903 high density polyethylene Polymers 0.000 description 3
- 229920001200 poly(ethylene-vinyl acetate) Polymers 0.000 description 3
- 229920001155 polypropylene Polymers 0.000 description 3
- 229920005992 thermoplastic resin Polymers 0.000 description 3
- ZGEGCLOFRBLKSE-UHFFFAOYSA-N 1-Heptene Chemical compound CCCCCC=C ZGEGCLOFRBLKSE-UHFFFAOYSA-N 0.000 description 2
- AFFLGGQVNFXPEV-UHFFFAOYSA-N 1-decene Chemical compound CCCCCCCCC=C AFFLGGQVNFXPEV-UHFFFAOYSA-N 0.000 description 2
- LIKMAJRDDDTEIG-UHFFFAOYSA-N 1-hexene Chemical compound CCCCC=C LIKMAJRDDDTEIG-UHFFFAOYSA-N 0.000 description 2
- KWKAKUADMBZCLK-UHFFFAOYSA-N 1-octene Chemical compound CCCCCCC=C KWKAKUADMBZCLK-UHFFFAOYSA-N 0.000 description 2
- WSSSPWUEQFSQQG-UHFFFAOYSA-N 4-methyl-1-pentene Chemical compound CC(C)CC=C WSSSPWUEQFSQQG-UHFFFAOYSA-N 0.000 description 2
- CERQOIWHTDAKMF-UHFFFAOYSA-N Methacrylic acid Chemical compound CC(=C)C(O)=O CERQOIWHTDAKMF-UHFFFAOYSA-N 0.000 description 2
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 2
- 125000004432 carbon atom Chemical group C* 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
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- CCCMONHAUSKTEQ-UHFFFAOYSA-N octadec-1-ene Chemical compound CCCCCCCCCCCCCCCCC=C CCCMONHAUSKTEQ-UHFFFAOYSA-N 0.000 description 2
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- YHQXBTXEYZIYOV-UHFFFAOYSA-N 3-methylbut-1-ene Chemical compound CC(C)C=C YHQXBTXEYZIYOV-UHFFFAOYSA-N 0.000 description 1
- SUWJESCICIOQHO-UHFFFAOYSA-N 4-methylhex-1-ene Chemical compound CCC(C)CC=C SUWJESCICIOQHO-UHFFFAOYSA-N 0.000 description 1
- 229920002126 Acrylic acid copolymer Polymers 0.000 description 1
- 229920000178 Acrylic resin Polymers 0.000 description 1
- 239000004925 Acrylic resin Substances 0.000 description 1
- XTXRWKRVRITETP-UHFFFAOYSA-N Vinyl acetate Chemical compound CC(=O)OC=C XTXRWKRVRITETP-UHFFFAOYSA-N 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
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- QHIWVLPBUQWDMQ-UHFFFAOYSA-N butyl prop-2-enoate;methyl 2-methylprop-2-enoate;prop-2-enoic acid Chemical compound OC(=O)C=C.COC(=O)C(C)=C.CCCCOC(=O)C=C QHIWVLPBUQWDMQ-UHFFFAOYSA-N 0.000 description 1
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- 239000000945 filler Substances 0.000 description 1
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- 229920001684 low density polyethylene Polymers 0.000 description 1
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- 229920001179 medium density polyethylene Polymers 0.000 description 1
- 239000000178 monomer Substances 0.000 description 1
- TVMXDCGIABBOFY-UHFFFAOYSA-N n-Octanol Natural products CCCCCCCC TVMXDCGIABBOFY-UHFFFAOYSA-N 0.000 description 1
- PNJWIWWMYCMZRO-UHFFFAOYSA-N pent‐4‐en‐2‐one Natural products CC(=O)CC=C PNJWIWWMYCMZRO-UHFFFAOYSA-N 0.000 description 1
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Landscapes
- Packages (AREA)
- Closures For Containers (AREA)
- Laminated Bodies (AREA)
- Compositions Of Macromolecular Compounds (AREA)
Description
【０００１】
【発明の属する技術分野】
本発明は、プロピレン系樹脂を熱封着面に有する包装容器又は包装袋等として、充分な封着力を有すると共に、開封時の開封が容易、且つ剥離面の外観にも優れる易開封性容器に関する。
【０００２】
【従来の技術】
従来より、樹脂容器本体を樹脂フィルム状蓋材で熱封着して包装するシールパック包装が、乳製品、菓子、果汁飲料等の主に飲食品の包装に盛んに用いられており、樹脂包装袋と共に重要な地位を占めるに到っている。そして、それらのシーラントとしては、従来より溶液型接着剤やホットメルト型接着剤が用いられているが、これらは、開封時にシーラントが延性破壊を起こして糸状物を形成するため、開封が必ずしも容易ではなかったり、剥離面の外観が良くない等の易開封性に欠けるという問題や、又、耐熱性不足のために、高温下で剥離してしまう等の封着性に欠けるという問題があった。
【０００３】
こうした問題を改良すべく、近年、封着性と易開封性を兼ね備えたシーラントが、種々提案され、用いられている。例えば、エチレン−酢酸ビニル共重合体に粘着付与剤を配合した組成物があり、又、本出願人により提案された、オレフィン系樹脂を芳香族ビニル単量体で改質した改質オレフィン系樹脂を主成分とする材料（例えば、特公平１−４２９６７号公報等参照。）等がある。しかしながら、これらのシーラントも、包装容器又は包装袋等として、内容物を充填してボイル等の加熱処理を施すような、内圧がかかる条件での包装形態の場合には、封着力不足により、その処理時に内容物が噴き出てしまうという問題があった。
【０００４】
一方、易開封性を有すると共に、封着力不足の解消を目的として、エチレン系樹脂のシール層と、エチレン系樹脂とプロピレン系樹脂の混合物の凝集破壊層とからなる積層フィルムをシーラントとして用いる方法（例えば、特開平１０−２６４３３０号公報等参照。）、或いは、ポリプロピレン樹脂のシール層と、ポリプロピレン樹脂とプロピレン−エチレン共重合体樹脂とポリエチレン樹脂の混合物、及びポリプロピレン樹脂とプロピレン−エチレン共重合体樹脂の混合物の凝集破壊層とからなる積層フィルムをシーラントとして用いる方法（例えば、特開平３−２８８６４２号公報等参照。）等が提案されている。しかしながら、本発明者等の検討によると、プロピレン系樹脂を熱封着面に有する包装容器又は包装袋等において、前記積層フィルムからなるシーラントは、剥離面の外観が良くない等の問題を内在していることが判明した。
【０００５】
【発明が解決しようとする課題】
本発明は、易開封性容器における前述の従来技術に鑑みてなされたものであって、従って、本発明は、プロピレン系樹脂を熱封着面に有する包装容器又は包装袋等として、充分な封着力を有すると共に、開封時の開封が容易、且つ剥離面の外観にも優れる開封性容器を提供することを目的とする。
【０００６】
【課題を解決するための手段】
本発明者等は、前述の課題を解決すべく鋭意検討した結果、特定組成のオレフィン系樹脂組成物の層を有する積層フィルムを用いることにより前記目的を達成できることを見出し、本発明を完成したもので、即ち、本発明は、下記の（Ａ）成分、（Ｂ）成分、及び（Ｃ）成分〔但し、各成分の重量％はこの三成分の合計１００重量％に対するものである。〕の樹脂組成物の層とプロピレン系樹脂の層からなり、該プロピレン系樹脂層の厚みが１〜５０μｍであり、且つ該プロピレン系樹脂層に対する樹脂組成物層の厚み比が２以上である積層フィルムの該プロピレン系樹脂層と、プロピレン系樹脂表面とが、熱封着されてなる熱封着構造を有する易開封性容器、を要旨とする。
（Ａ）プロピレン系樹脂：４５〜７５重量％
（Ｂ）エチレン単独重合体樹脂、又は、密度０．９３０ｇ／ｃｍ3 超過のエチレン系共重合体樹脂：５〜４５重量％
（Ｃ）密度０．８６０〜０．９３０ｇ／ｃｍ3 のエチレン−α−オレフィン共重合体：５〜３０重量％
【０００７】
【発明の実施の形態】
本発明において、積層フィルムにおける樹脂組成物層の樹脂組成物を構成する（Ａ）成分のプロピレン系樹脂としては、プロピレンの単独重合体、及び、プロピレンと、エチレン、１−ブテン、３−メチル−１−ブテン等の炭素数２〜８程度の他のα−オレフィンとの共重合体、具体的には、例えば、プロピレン−エチレン共重合体、プロピレン−１−ブテン共重合体、プロピレン−エチレン−１−ブテン共重合体等が挙げられ、中で、プロピレン単独重合体、又は、プロピレン−エチレン共重合体が好ましく、その場合、エチレン含有量は２０重量％までのものが好ましい。
【０００８】
尚、これらプロピレン系樹脂のメルトフローレート（温度２３０℃、荷重２．１６ｋｇ）は０．１〜２０ｇ／１０分であるのが好ましい。
【０００９】
又、積層フィルムにおける樹脂組成物層の樹脂組成物を構成する（Ｂ）成分のエチレン単独重合体樹脂としては、分岐状又は直鎖状の、低・中・高密度ポリエチレンのいずれもが対象となり、中で、高密度ポリエチレンが好ましい。
【００１０】
尚、これらエチレン単独重合体樹脂は、通常、密度が０．９１０〜０．９６０ｇ／ｃｍ3 程度のものであり、又、メルトフローレート（温度１９０℃、荷重２．１６ｋｇ）は０．１〜３０ｇ／１０分であるのが好ましい。
【００１１】
又、同じく（Ｂ）成分のエチレン系共重合体樹脂としては、エチレンと、プロピレン、１−ブテン、３−メチル−１−ブテン、１−ペンテン、４−メチル−１−ペンテン、４，４−ジメチル−１−ペンテン、１−ヘキセン、４−メチル−１−ヘキセン、１−ヘプテン、１−オクテン、１−デセン、１−オクタデセン等の炭素数３〜１８程度のα−オレフィンや、酢酸ビニル、（メタ）アクリル酸、（メタ）アクリル酸エステル等との共重合体等が挙げられ、具体的には、例えば、エチレン−プロピレン共重合体、エチレン−１−ブテン共重合体、エチレン−４−メチル−１−ペンテン共重合体、エチレン−１−ヘキセン共重合体、エチレン−１−オクテン共重合体、エチレン−酢酸ビニル共重合体、エチレン−（メタ）アクリル酸共重合体、エチレン−（メタ）アクリル酸エチル共重合体等が挙げられる。
【００１２】
本発明におけるこれらエチレン系共重合体樹脂は、密度が０．９３０ｇ／ｃｍ3 超過のもので、通常、０．９６０ｇ／ｃｍ3 以下のものであり、又、メルトフローレート（温度１９０℃、荷重２．１６ｋｇ）は０．１〜３０ｇ／１０分であるのが好ましい。
【００１３】
又、積層フィルムにおける樹脂組成物層の樹脂組成物を構成する（Ｃ）成分のエチレン−α−オレフィン共重合体としては、（Ｂ）成分として挙げたエチレン−α−オレフィン共重合体と同様のものが挙げられるが、（Ｃ）成分のエチレン−α−オレフィン共重合体としては、樹脂状のものに限定されず、エラストマー状のものも対象とし得る。
【００１４】
これら（Ｃ）成分のエチレン−α−オレフィン共重合体は、密度が０．８６０〜０．９３０ｇ／ｃｍ3 のものであり、又、メルトフローレート（温度１９０℃、荷重２．１６ｋｇ）は０．１〜３０ｇ／１０分であるのが好ましい。
【００１５】
本発明における積層フィルムの樹脂組成物層を構成する樹脂組成物は、前記（Ａ）成分が４５〜７５重量％、前記（Ｂ）成分が５〜４５重量％、前記（Ｃ）成分が５〜３０重量％からなることが必須であり、前記（Ａ）成分が５０〜７０重量％、前記（Ｂ）成分が１０〜４０重量％、前記（Ｃ）成分が１０〜２５重量％であるのが好ましい〔但し、各成分の重量％はこの三成分の合計１００重量％に対するものである。〕。
【００１６】
（Ａ）成分が前記範囲未満では、積層フィルムのプロピレン系樹脂層との接着強度が不足し、易開封性容器として開封時にプロピレン系樹脂層のフィルム残りが生じることとなり、一方、前記範囲超過では、積層フィルムの樹脂組成物層として封着力が強過ぎて易開封性容器として開封が困難となる。又、（Ｂ）成分が前記範囲未満では、積層フィルムの樹脂組成物層として封着力が強過ぎて易開封性容器として開封が困難となり、一方、前記範囲超過では、開封時に糸引きが生じることとなる。又、（Ｃ）成分が前記範囲未満では、易開封性容器として開封時に糸引きが生じることとなり、一方、前記範囲超過では、積層フィルムの樹脂組成物層として封着力が強過ぎて開封が困難となる。
【００１７】
尚、本発明における積層フィルムの樹脂組成物層を構成する樹脂組成物には、（Ａ）成分の前記プロピレン系樹脂、（Ｂ）成分の前記エチレン単独重合体樹脂、又は、前記エチレン系共重合体樹脂、及び（Ｃ）成分の前記エチレン−α−オレフィン共重合体の外に、本発明の効果を損なわない範囲で、これら以外の熱可塑性樹脂やゴム、及び、酸化防止剤、光安定剤、帯電防止剤、ブロッキング防止剤、滑剤、可塑剤、顔料等の添加剤、充填材等が配合されていてもよい。
【００１８】
又、本発明において、積層フィルムにおけるプロピレン系樹脂層を構成するプロピレン系樹脂としては、前記樹脂組成物を構成する（Ａ）成分において挙げたプロピレン系樹脂と同様のものが挙げられる。
【００１９】
本発明における積層フィルムは、前記樹脂組成物の層と前記プロピレン系樹脂の層とを含んでなり、その積層方法は、特に限定されるものではないが、公知のＴダイ又は環状ダイ等を用いた両層の共押出によるのが好ましい。
【００２０】
又、実用上は、例えば、ポリアミド系樹脂、ポリエステル系樹脂、エチレン−酢酸ビニル共重合体鹸化物、ポリオレフィン系樹脂、ポリカーボネート系樹脂、ポリスチレン系樹脂、アクリル系樹脂等の各種熱可塑性樹脂のフィルム、アルミニウム箔、紙等の基材に押出ラミネートしたラミネートフィルムとして、或いは前記各種熱可塑性樹脂との共押出フィルムとして、作製される。尚、本発明における「フィルム」とは、通常のフィルムのみならず、シートをも包含するものとする。
【００２１】
本発明における積層フィルムは、プロピレン系樹脂層に対する樹脂組成物層の厚み比が２以上であることが必須であり、２．５以上であるのが好ましい。この厚み比が前記範囲未満では、易開封性容器としての開封性に劣り、特に開封時にプロピレン系樹脂層のフィルム残りが生じることとなる。
【００２２】
尚、積層フィルムの前記樹脂組成物層の厚みは５〜１００μｍ程度、前記プロピレン系樹脂層の厚みは１〜５０μｍ程度であるのが好ましい。
【００２３】
本発明の易開封性容器は、前記積層フィルムのプロピレン系樹脂層と、プロピレン系樹脂表面とが、熱封着されてなる熱封着構造を有するものであり、ここで、前記積層フィルムの被熱封着体としてのプロピレン系樹脂表面とは、前記積層フィルムにおいて挙げたと同様のプロピレン系樹脂が被熱封着体表面を形成しているものであれば、単層或いは積層状態のいずれでも構わない。
【００２４】
本発明において、具体的な易開封性容器の形態としては、例えば、（１）容器本体と蓋材からなる包装容器として、（ａ）積層フィルムを蓋材側に用いた場合であって、プロピレン系樹脂を熱封着面に有する容器本体と、積層フィルムを、そのプロピレン系樹脂層を熱封着面として有する蓋材とからなる易開封性容器、（ｂ）積層フィルムを容器本体側に用いた場合であって、積層フィルムを、そのプロピレン系樹脂層を熱封着面として有する容器本体と、プロピレン系樹脂を熱封着面に有する蓋材とからなる易開封性容器、（２）包装袋として、（ａ）積層フィルムを袋の両面に用いた場合であって、積層フィルムを熱封着面として有するそのプロピレン系樹脂層同士を対向させて熱封着した袋体である易開封性容器、及び、（ｂ）積層フィルムを袋の一方の面に用い、他方の面にプロピレン系樹脂を熱封着面に有する袋部材を用いた場合であって、積層フィルムのプロピレン系樹脂層と、プロピレン系樹脂表面とを熱封着した袋体である易開封性容器、等が挙げられる。
【００２５】
【実施例】
以下、本発明を実施例によりさら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、以下の実施例に限定されるものではない。
【００２６】
実施例１〜５、比較例１〜５
（Ａ）成分としてのプロピレン−エチレン共重合体樹脂（エチレン含有量４．５重量％、メルトフローレート６．０ｇ／１０分）と、（Ｂ）成分としての高密度ポリエチレン樹脂（密度０．９５３ｇ／ｃｍ3 、メルトフローレート２．５ｇ／１０分）と、（Ｃ）成分としてのエチレン−１−ブテン共重合体（密度０．９２０ｇ／ｃｍ3 、メルトフローレート２．０ｇ／１０分）とを、表１に示す割合でドライブレンドした後、径４０ｍｍの単軸押出機を用いて２３０℃で溶融混練して樹脂組成物を作製し、該樹脂組成物とプロピレン単独重合体樹脂（メルトフローレート２．５ｇ／１０分）とを、それぞれ、Ｔダイを装備した径３５ｍｍの共押出フィルム成形機に供給して、２３０℃で共押出して、樹脂組成物層とプロピレン単独重合体樹脂層とからなる表１に示す厚みの積層フィルムを成形し、該積層フィルムの樹脂組成物層側表面にコロナ放電処理を施した後、基材としての厚み３０μｍのポリエチレンテレフタレート樹脂フィルムをドライラミネート接着剤を介して貼り合わせて複合フィルムを作製した。
【００２７】
一方、プロピレン単独重合体樹脂のシートから熱成形して作製した角形の容器本体のフランジ部に、前記の複合フィルムを蓋材として用い、そのプロピレン単独重合体樹脂層を接着面として熱封着し、易開封性容器を作製した。
得られた易開封性容器について、以下の方法で、熱封着性能を評価し、結果を表１に示した。
【００２８】
剥離強度
熱板式ヒートシーラーを用い、温度１８０℃、２００℃、及び２２０℃、圧力２ｋｇ／ｃｍ2 、時間１秒で、蓋材を容器本体フランジ部に５ｍｍ幅で熱圧着し、その接着部を１５ｍｍ長さでサンプリングし、インストロン型引張試験機を用い、２３℃で、接着幅方向に引張速度３００ｍｍ／分で剥離することにより１８０度剥離強度を測定した。
【００２９】
開封性
剥離強度測定後の試験片の剥離面における糸引きやフィルム残りの有無を目視観察し、糸引きやフィルム残りがないものを○、糸引きやフィルム残りがあるものを×として、開封性を評価した。
【００３０】
【表１】
【発明の効果】
本発明によれば、プロピレン系樹脂を熱封着面に有する包装容器又は包装袋等として、充分な封着力を有すると共に、開封時の開封が容易、且つ剥離面の外観にも優れる易開封性容器を提供することができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an easily openable container having a sufficient sealing force as a packaging container or packaging bag having a propylene-based resin on a heat-sealing surface, easy to open at the time of opening, and excellent in appearance of a peeling surface. .
[0002]
[Prior art]
Conventionally, seal pack packaging that heat seals and seals the resin container body with a resin film-like lid material has been actively used for packaging mainly dairy products, confectionery, fruit juice beverages, etc. It has come to occupy an important position with the bag. Conventionally, as these sealants, solution type adhesives and hot melt type adhesives have been used. However, since these sealants cause ductile fracture and form filaments when opened, they are not always easy to open. There is a problem that it is not easy to open, such as the appearance of the peeled surface is not good, and there is a problem of lack of sealing properties such as peeling at high temperature due to insufficient heat resistance. .
[0003]
In order to improve these problems, various sealants having both sealing properties and easy opening properties have been proposed and used in recent years. For example, there is a composition in which a tackifier is blended with an ethylene-vinyl acetate copolymer, and a modified olefin resin obtained by modifying the olefin resin with an aromatic vinyl monomer proposed by the present applicant. (For example, see Japanese Patent Publication No. 1-4967). However, these sealants are also used as packaging containers or packaging bags in the form of packaging under conditions where internal pressure is applied, such as filling the contents and performing heat treatment such as boiling. There was a problem that the contents erupted during processing.
[0004]
On the other hand, a method of using a laminated film comprising an ethylene resin seal layer and a cohesive failure layer of a mixture of an ethylene resin and a propylene resin as a sealant for the purpose of eliminating an insufficient sealing force while having easy opening properties ( For example, see JP-A-10-264330, etc.) or a polypropylene resin sealing layer, a mixture of polypropylene resin, propylene-ethylene copolymer resin and polyethylene resin, and polypropylene resin and propylene-ethylene copolymer resin. A method of using a laminated film comprising a cohesive failure layer of the above mixture as a sealant (see, for example, JP-A-3-288642) has been proposed. However, according to the study by the present inventors, in a packaging container or packaging bag having a heat-sealing surface with a propylene-based resin, the sealant composed of the laminated film has a problem that the appearance of the release surface is not good. Turned out to be.
[0005]
[Problems to be solved by the invention]
The present invention has been made in view of the above-described prior art in an easily openable container. Therefore, the present invention provides sufficient sealing as a packaging container or packaging bag having a propylene-based resin on a heat sealing surface. An object of the present invention is to provide an openable container that has an adhesive force, is easy to open at the time of opening, and is excellent in appearance of a peeled surface.
[0006]
[Means for Solving the Problems]
The present inventors have intended to result of extensive investigations to solve the problems described above, found that the above object can be achieved by using a laminate film having a layer of olefin resin composition having a specific composition, and completed the present invention That is, in the present invention, the following (A) component, (B) component, and (C) component [however, the weight% of each component is based on the total of 100 weight% of these three components. And a propylene- based resin layer, the thickness of the propylene-based resin layer is 1 to 50 μm, and the thickness ratio of the resin composition layer to the propylene-based resin layer is 2 or more The gist is an easily openable container having a heat sealing structure in which the propylene resin layer of the film and the propylene resin surface are heat sealed.
(A) Propylene resin: 45 to 75% by weight
(B) Ethylene homopolymer resin or ethylene copolymer resin having a density exceeding 0.930 g / cm 3 : 5 to 45% by weight
(C) Ethylene-α-olefin copolymer having a density of 0.860 to 0.930 g / cm 3 : 5 to 30% by weight
[0007]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, the propylene-based resin of the component (A) constituting the resin composition of the resin composition layer in the laminated film includes propylene homopolymer, propylene, ethylene, 1-butene, 3-methyl- Copolymers with other α-olefins having about 2 to 8 carbon atoms such as 1-butene, specifically, for example, propylene-ethylene copolymer, propylene-1-butene copolymer, propylene-ethylene- Examples include 1-butene copolymers, among which propylene homopolymers or propylene-ethylene copolymers are preferred, and in that case, ethylene content is preferably up to 20% by weight.
[0008]
In addition, it is preferable that the melt flow rate (temperature 230 degreeC, load 2.16kg) of these propylene-type resin is 0.1-20 g / 10min.
[0009]
In addition, as the ethylene homopolymer resin of component (B) that constitutes the resin composition of the resin composition layer in the laminated film, both branched and linear, low, medium and high density polyethylenes are targeted. Of these, high density polyethylene is preferred.
[0010]
These ethylene homopolymer resins usually have a density of about 0.910 to 0.960 g / cm 3 , and a melt flow rate (temperature 190 ° C., load 2.16 kg) is 0.1 to 30 g / 10 min is preferred.
[0011]
Similarly, as the (B) component ethylene copolymer resin, ethylene, propylene, 1-butene, 3-methyl-1-butene, 1-pentene, 4-methyl-1-pentene, 4,4- Α-olefins having about 3 to 18 carbon atoms such as dimethyl-1-pentene, 1-hexene, 4-methyl-1-hexene, 1-heptene, 1-octene, 1-decene, 1-octadecene, vinyl acetate, Examples include (meth) acrylic acid, copolymers with (meth) acrylic acid esters, and the like. Specific examples include ethylene-propylene copolymer, ethylene-1-butene copolymer, and ethylene-4- Methyl-1-pentene copolymer, ethylene-1-hexene copolymer, ethylene-1-octene copolymer, ethylene-vinyl acetate copolymer, ethylene- (meth) acrylic acid copolymer, Styrene - (meth) ethyl acrylate copolymer and the like.
[0012]
These ethylene copolymer resins in the present invention has a density of those of 0.930 g / cm 3 exceeded usually of 0.960 g / cm 3 or less, and a melt flow rate (temperature 190 ° C., load 2.16 kg) is preferably 0.1-30 g / 10 min.
[0013]
In addition, the (C) component ethylene-α-olefin copolymer constituting the resin composition of the resin composition layer in the laminated film is the same as the ethylene-α-olefin copolymer listed as the (B) component. Although the thing is mentioned, as an ethylene-alpha-olefin copolymer of (C) component, it is not limited to a resin-like thing, An elastomer-like thing can also be made into object.
[0014]
These (C) component ethylene-α-olefin copolymers have a density of 0.860 to 0.930 g / cm 3 , and the melt flow rate (temperature 190 ° C., load 2.16 kg) is 0. It is preferable that it is 1-30 g / 10min.
[0015]
In the resin composition constituting the resin composition layer of the laminated film in the present invention, the component (A) is 45 to 75% by weight, the component (B) is 5 to 45% by weight, and the component (C) is 5 to 5% by weight. It is essential to consist of 30% by weight, the component (A) is 50 to 70% by weight, the component (B) is 10 to 40% by weight, and the component (C) is 10 to 25% by weight. Preferred [However, the weight% of each component is based on the total of 100 weight% of the three components. ].
[0016]
If the component (A) is less than the above range, the adhesive strength with the propylene-based resin layer of the laminated film is insufficient, and a film residue of the propylene-based resin layer is generated at the time of opening as an easy-open container, Since the sealing force is too strong as the resin composition layer of the laminated film, it is difficult to open as an easily openable container. In addition, when the component (B) is less than the above range, the sealing force is too strong as the resin composition layer of the laminated film and it is difficult to open the container as an easily openable container, whereas when it exceeds the above range, stringing occurs at the time of opening. It becomes. In addition, when the component (C) is less than the above range, stringing occurs at the time of opening as an easily openable container. On the other hand, when the component exceeds the above range, the sealing composition is too strong as the resin composition layer of the laminated film and is difficult to open. It becomes.
[0017]
The resin composition constituting the resin composition layer of the laminated film in the present invention includes (A) the propylene resin, (B) the ethylene homopolymer resin, or the ethylene copolymer. In addition to the unitary resin and the ethylene-α-olefin copolymer of the component (C), other thermoplastic resins and rubbers, antioxidants, and light stabilizers, as long as the effects of the present invention are not impaired. In addition, additives such as antistatic agents, antiblocking agents, lubricants, plasticizers, pigments, fillers, and the like may be blended.
[0018]
In the present invention, examples of the propylene resin constituting the propylene resin layer in the laminated film include the same propylene resins as mentioned in the component (A) constituting the resin composition.
[0019]
The laminated film in the present invention comprises the resin composition layer and the propylene-based resin layer, and the laminating method is not particularly limited, but a known T die or annular die is used. Preferably, the two layers are coextruded.
[0020]
Moreover, practically, for example, films of various thermoplastic resins such as polyamide resins, polyester resins, saponified ethylene-vinyl acetate copolymers, polyolefin resins, polycarbonate resins, polystyrene resins, acrylic resins, It is produced as a laminate film extruded and laminated on a base material such as aluminum foil or paper, or as a co-extruded film with the various thermoplastic resins. The “film” in the present invention includes not only a normal film but also a sheet.
[0021]
In the laminated film of the present invention, it is essential that the thickness ratio of the resin composition layer to the propylene-based resin layer is 2 or more, and preferably 2.5 or more. When the thickness ratio is less than the above range, the opening property as an easily openable container is inferior, and in particular, the film residue of the propylene-based resin layer is generated at the time of opening.
[0022]
In addition, it is preferable that the thickness of the said resin composition layer of a laminated | multilayer film is about 5-100 micrometers, and the thickness of the said propylene-type resin layer is about 1-50 micrometers.
[0023]
The easy-open container of the present invention has a heat sealing structure in which the propylene-based resin layer of the laminated film and the surface of the propylene-based resin are heat-sealed. The surface of the propylene-based resin as the heat-sealed body may be either a single layer or a laminated state as long as the same propylene-based resin as mentioned in the laminated film forms the surface of the heat-sealed body. Absent.
[0024]
In the present invention, as a specific form of the easy-open container, for example, (1) as a packaging container comprising a container body and a cover material, (a) a laminated film is used on the cover material side, and propylene Easy-open container comprising a container body having a heat-sealing surface with a resin-based resin and a lid film having a laminated film with the propylene-based resin layer as a heat-sealing surface, (b) using the laminated film on the container body side An easily openable container comprising a laminated film and a container body having the propylene-based resin layer as a heat-sealing surface and a lid material having the propylene-based resin on the heat-sealing surface; (2) packaging As a bag, (a) Easy-openability, which is a bag body in which a laminated film is used on both sides of a bag and the propylene-based resin layers having the laminated film as a heat sealing surface are opposed to each other. A container, and (b) a stack In the case of using a bag member having rum on one side of the bag and a propylene resin on the heat sealing surface on the other side, the propylene resin layer of the laminated film and the surface of the propylene resin are heated. Examples include an easily openable container that is a sealed bag.
[0025]
【Example】
EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist.
[0026]
Examples 1-5, Comparative Examples 1-5
Propylene-ethylene copolymer resin (ethylene content 4.5% by weight, melt flow rate 6.0 g / 10 min) as component (A) and high-density polyethylene resin (density 0.953 g) as component (B) / Cm 3 , melt flow rate 2.5 g / 10 min), and ethylene-1-butene copolymer (density 0.920 g / cm 3 , melt flow rate 2.0 g / 10 min) as component (C) Were dry blended in the proportions shown in Table 1, and then melt-kneaded at 230 ° C. using a single screw extruder having a diameter of 40 mm to produce a resin composition. The resin composition and a propylene homopolymer resin (melt flow) Are supplied to a 35 mm diameter coextrusion film forming machine equipped with a T die and coextruded at 230 ° C. to obtain a resin composition layer and a propylene homopolymer resin. After forming a laminated film having the thickness shown in Table 1 and applying a corona discharge treatment to the resin composition layer side surface of the laminated film, a polyethylene terephthalate resin film having a thickness of 30 μm as a base material was dry laminated adhesive And a composite film was prepared.
[0027]
On the other hand, the flange portion of a rectangular container body produced by thermoforming from a sheet of propylene homopolymer resin is heat-sealed using the composite film as a lid and the propylene homopolymer resin layer as an adhesive surface. An easy-open container was prepared.
About the obtained easily openable container, the heat sealing performance was evaluated by the following method, and the results are shown in Table 1.
[0028]
Peel strength Using a hot plate heat sealer, thermocompression bonding the lid material to the container body flange with a width of 5 mm at a temperature of 180 ° C, 200 ° C and 220 ° C, a pressure of 2 kg / cm 2 and a time of 1 second, The bonded portion was sampled at a length of 15 mm, and peel strength was measured by peeling at 23 ° C. in the bonding width direction at a tensile speed of 300 mm / min using an Instron type tensile tester.
[0029]
Openability <br/> Visually observe the presence or absence of stringing or film residue on the peeled surface of the test piece after measuring peel strength. As a result, the openability was evaluated.
[0030]
[Table 1]
【The invention's effect】
According to the present invention, as a packaging container or packaging bag having a propylene-based resin on a heat-sealing surface, it has a sufficient sealing force, is easy to open at the time of opening, and has an excellent appearance on the peeling surface. A container can be provided.
Claims (3)
（Ａ）プロピレン系樹脂：４５〜７５重量％
（Ｂ）エチレン単独重合体樹脂、又は、密度０．９３０ｇ／ｃｍ3 超過のエチレン系共重合体樹脂：５〜４５重量％
（Ｃ）密度０．８６０〜０．９３０ｇ／ｃｍ3 のエチレン−α−オレフィン共重合体：５〜３０重量％The following (A) component, (B) component, and (C) component [However, the weight% of each component is based on the total of 100 weight% of these three components. And a propylene- based resin layer, the thickness of the propylene-based resin layer is 1 to 50 μm, and the thickness ratio of the resin composition layer to the propylene-based resin layer is 2 or more An easily openable container characterized by having a heat sealing structure in which the propylene resin layer of the film and the surface of the propylene resin are heat sealed.
(A) Propylene resin: 45 to 75% by weight
(B) Ethylene homopolymer resin or ethylene copolymer resin having a density exceeding 0.930 g / cm 3 : 5 to 45% by weight
(C) Ethylene-α-olefin copolymer having a density of 0.860 to 0.930 g / cm 3 : 5 to 30% by weight
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP00038099A JP3678035B2 (en) | 1999-01-05 | 1999-01-05 | Easy-open container |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP00038099A JP3678035B2 (en) | 1999-01-05 | 1999-01-05 | Easy-open container |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2000198170A JP2000198170A (en) | 2000-07-18 |
| JP3678035B2 true JP3678035B2 (en) | 2005-08-03 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP00038099A Expired - Lifetime JP3678035B2 (en) | 1999-01-05 | 1999-01-05 | Easy-open container |
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| JP (1) | JP3678035B2 (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000272065A (en) * | 1999-03-26 | 2000-10-03 | Sumitomo Bakelite Co Ltd | Composite multilayer sheet |
| JP2000272064A (en) * | 1999-03-26 | 2000-10-03 | Sumitomo Bakelite Co Ltd | Composite multilayered sheet |
| JP4596210B2 (en) * | 2001-03-22 | 2010-12-08 | Ｄｉｃ株式会社 | Laminated film for openable packaging and packaging container |
| CN100376627C (en) * | 2003-01-31 | 2008-03-26 | 三井-杜邦聚合化学株式会社 | Resin composition having easy-to-open property and use thereof |
| US7871697B2 (en) | 2006-11-21 | 2011-01-18 | Kraft Foods Global Brands Llc | Peelable composite thermoplastic sealants in packaging films |
| US7871696B2 (en) | 2006-11-21 | 2011-01-18 | Kraft Foods Global Brands Llc | Peelable composite thermoplastic sealants in packaging films |
| US9232808B2 (en) | 2007-06-29 | 2016-01-12 | Kraft Foods Group Brands Llc | Processed cheese without emulsifying salts |
| AU2011220783A1 (en) | 2010-02-26 | 2012-09-06 | Intercontinental Great Brands Llc | Package having an adhesive-based reclosable fastener and methods therefor |
| NZ591354A (en) | 2010-02-26 | 2012-09-28 | Kraft Foods Global Brands Llc | A low-tack, UV-cured pressure sensitive acrylic ester based adhesive for reclosable packaging |
| US9533472B2 (en) | 2011-01-03 | 2017-01-03 | Intercontinental Great Brands Llc | Peelable sealant containing thermoplastic composite blends for packaging applications |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS582963U (en) * | 1981-06-30 | 1983-01-10 | セイコーインスツルメンツ株式会社 | Band for portable electronic devices |
| JPS61172517U (en) * | 1985-04-16 | 1986-10-27 | ||
| JP3252380B2 (en) * | 1992-08-14 | 2002-02-04 | 日本ポリウレタン工業株式会社 | Thermoplastic polyurethane resin composition and watch band made of the resin composition |
| JP3043257U (en) * | 1997-01-10 | 1997-11-18 | 株式会社ワコーエイト | Accessories such as bracelets using electroluminescence |
| JPH11103912A (en) * | 1997-10-03 | 1999-04-20 | Kazuya Sugiyama | Accessory belt |
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1999
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