JPH05318682A - Stretch and shrink packaging film - Google Patents
Stretch and shrink packaging filmInfo
- Publication number
- JPH05318682A JPH05318682A JP3130378A JP13037891A JPH05318682A JP H05318682 A JPH05318682 A JP H05318682A JP 3130378 A JP3130378 A JP 3130378A JP 13037891 A JP13037891 A JP 13037891A JP H05318682 A JPH05318682 A JP H05318682A
- Authority
- JP
- Japan
- Prior art keywords
- film
- stretch
- density polyethylene
- outer layers
- ethylene
- 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.)
- Granted
Links
- 229920006280 packaging film Polymers 0.000 title abstract description 10
- 239000012785 packaging film Substances 0.000 title abstract description 10
- 239000010410 layer Substances 0.000 claims abstract description 35
- 229920001577 copolymer Polymers 0.000 claims abstract description 13
- 239000012792 core layer Substances 0.000 claims abstract description 13
- 229920001684 low density polyethylene Polymers 0.000 claims abstract description 6
- 239000004702 low-density polyethylene Substances 0.000 claims abstract description 6
- 229920000092 linear low density polyethylene Polymers 0.000 claims description 16
- 239000004707 linear low-density polyethylene Substances 0.000 claims description 16
- -1 polyethylene Polymers 0.000 claims description 7
- 239000004698 Polyethylene Substances 0.000 claims 1
- 239000000155 melt Substances 0.000 claims 1
- 229920000573 polyethylene Polymers 0.000 claims 1
- 229920000642 polymer Polymers 0.000 claims 1
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 abstract description 27
- 238000011084 recovery Methods 0.000 abstract description 19
- 238000004806 packaging method and process Methods 0.000 abstract description 13
- 239000000470 constituent Substances 0.000 abstract 1
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 abstract 1
- 238000000034 method Methods 0.000 description 14
- 229920005989 resin Polymers 0.000 description 10
- 239000011347 resin Substances 0.000 description 10
- 230000000052 comparative effect Effects 0.000 description 8
- 239000004743 Polypropylene Substances 0.000 description 6
- 229920001155 polypropylene Polymers 0.000 description 6
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 5
- 239000005977 Ethylene Substances 0.000 description 5
- 239000005038 ethylene vinyl acetate Substances 0.000 description 3
- 229920001200 poly(ethylene-vinyl acetate) Polymers 0.000 description 3
- VXNZUUAINFGPBY-UHFFFAOYSA-N 1-Butene Chemical compound CCC=C VXNZUUAINFGPBY-UHFFFAOYSA-N 0.000 description 2
- 235000009849 Cucumis sativus Nutrition 0.000 description 2
- 240000008067 Cucumis sativus Species 0.000 description 2
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 2
- IAQRGUVFOMOMEM-UHFFFAOYSA-N butene Natural products CC=CC IAQRGUVFOMOMEM-UHFFFAOYSA-N 0.000 description 2
- 235000013305 food Nutrition 0.000 description 2
- 238000010030 laminating Methods 0.000 description 2
- 239000005026 oriented polypropylene Substances 0.000 description 2
- 238000012536 packaging technology Methods 0.000 description 2
- XTXRWKRVRITETP-UHFFFAOYSA-N Vinyl acetate Chemical compound CC(=O)OC=C XTXRWKRVRITETP-UHFFFAOYSA-N 0.000 description 1
- 125000004432 carbon atom Chemical group C* 0.000 description 1
- 238000007334 copolymerization reaction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 235000011187 glycerol Nutrition 0.000 description 1
- 238000003475 lamination Methods 0.000 description 1
- 229920005684 linear copolymer Polymers 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 229920005673 polypropylene based resin Polymers 0.000 description 1
- 229920001384 propylene homopolymer Polymers 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- 229920001169 thermoplastic Polymers 0.000 description 1
- 229920005992 thermoplastic resin Polymers 0.000 description 1
- 239000004416 thermosoftening plastic Substances 0.000 description 1
- 239000004711 α-olefin Substances 0.000 description 1
Abstract
Description
【００１】[001]
【産業上の利用分野】本発明は、包装時にある程度引き
伸ばしながら包装し、その後更に熱収縮させて緊迫性を
生じさせるストレッチシュリンク包装用フィルムに関す
るものである。尚、この様な包装方法のことを以下「ス
トレッチシュリンク包装」と称する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stretch-shrink wrapping film which is stretched to some extent during packaging and then further heat-shrinked so as to generate tension. Incidentally, such a packaging method is hereinafter referred to as "stretch shrink packaging".
【００２】[002]
【従来技術】包装時にフィルムを引き伸ばしながら包装
する方法、即ち、ストレッチ包装方法は、従来から良く
知られている。例えば、社団法人・日本包装技術協会刊
「包装技術便覧」等に記載されている。しかも、該包装
に用いられるフィルムとしては、単層のフィルムは勿
論、最近では、特公平２−１２１８７号公報に記載され
ているような多層構成のフィルムも知られている。しか
し、該包装方法では全体を均一に引き伸ばすのが困難な
ため、充分な緊迫性を有する包装体が得られ難い。 そ
こで、最近ではストレッチシュリンク包装方法が行なわ
れるようになってきた。そのような包装に用いるストレ
ッチシュリンク包装用フィルムとしては、芯層がポリプ
ロピレン系樹脂で、両外層がエチレン−酢酸ビニル共重
合体からなる多層フィルムが用いられている。しかし、
ストレッチシュリンク包装方法は熱収縮トンネル内で加
熱されるために該フィルムでは酢酸臭が発生し、被包装
物に匂いが付着するので食品等の包装には不適当であ
る。2. Description of the Related Art A method of stretching a film during packaging, that is, a stretch packaging method, has been well known. For example, it is described in "Packaging Technology Handbook" published by Japan Packaging Technology Association. Moreover, as a film used for the packaging, not only a single-layer film but also a film having a multi-layer structure as described in Japanese Patent Publication No. 2-12187 is known recently. However, since it is difficult to uniformly stretch the whole body by the packaging method, it is difficult to obtain a package having sufficient tenacity. Therefore, recently, the stretch shrink wrapping method has been used. As a stretch shrink wrapping film used for such packaging, a multilayer film in which a core layer is made of polypropylene resin and both outer layers are made of ethylene-vinyl acetate copolymer is used. But,
The stretch shrink wrapping method is unsuitable for packaging foods and the like, because acetic acid odor is generated in the film because it is heated in a heat shrinking tunnel and the odor adheres to the object to be packaged.
【００３】又、特公昭６１−３２６４号公報には、配向
ポリプロピレン基層の少なくとも片面にエチレンと炭素
数３〜１０のα−オレフィンとの低密度線状コーポリマ
ーを被覆している多層熱可塑性塑性フィルムが記載され
ている。しかし、該発明には、該フィルムがヒートシー
ル性に優れていることは明記されているが、本発明のよ
うな特殊なストレッチシュリンク包装用フィルムに使用
出来ることは何等記載されておらず、しかも、その様な
ことを示唆する記載もない。更に、上記条件のみの多層
熱可塑性フィルムでは、弾性回復率が不十分で、ストレ
ッチシュリンク包装用フィルムとして好ましくない。即
ち、指等で包装体を押してフィルムに窪みを生じさせて
も、そのうち回復して窪みが無くなるような弾性回復率
の高いフィルムが好ましい。Further, Japanese Patent Publication No. 61-3264 discloses a multilayered thermoplastic resin in which at least one surface of an oriented polypropylene base layer is coated with a low density linear copolymer of ethylene and an α-olefin having 3 to 10 carbon atoms. The film is described. However, although it is specified in the invention that the film is excellent in heat sealability, there is no description that it can be used for a special stretch shrink packaging film such as the present invention, and , There is no description suggesting such a thing. Further, the multilayer thermoplastic film only under the above conditions has an insufficient elastic recovery rate and is not preferable as a stretch shrink packaging film. That is, it is preferable to use a film having a high elastic recovery rate so that even if the package is pressed with a finger or the like to form a dent in the film, it is recovered and the dent disappears.
【００４】[004]
【発明が解決しようとする課題】本発明は、熱収縮トン
ネルを通過させた後でも酢酸臭を発せず、しかも、熱収
縮応力の強いストレッチシュリンク包装用フィルムを提
供しようとするものである。そしてより好ましくは、芯
層に配向されたポリプロピレン系樹脂層を用いることに
よる欠点であるフィルムの弾性率をカバーし、弾性回復
率の高いストレッチシュリンク包装用フィルムを提供し
ようとするものである。DISCLOSURE OF THE INVENTION The present invention is intended to provide a stretch shrink wrapping film which does not emit an acetic acid odor even after passing through a heat shrink tunnel and has a high heat shrink stress. And more preferably, it is intended to provide a stretch shrink wrapping film having a high elastic recovery rate by covering the elastic modulus of the film, which is a defect due to the use of the oriented polypropylene resin layer as the core layer.
【００５】[0095]
【課題を解決するための手段】本発明は、これらの課題
を解決するために次のような手段を講じた。即ち、酢酸
臭がなく熱収縮応力の強いストレッチシュリンク包装用
フィルムを得るために、芯層をエチレン−プロピレン共
重合体又はエチレン−ブテン−プロピレン共重合体と
し、両外層をＭＩ０．５乃至１０ｇ／１０ｍｉｎの直鎖
状低密度ポリエチレンとし、しかも、該両外層の厚みの
和がフィルム全体厚みの１０乃至９０％になるようにし
た。更にその上に、弾性回復率の高いストレッチストレ
ッチ包装用フィルムを得るためには、上記直鎖状低密度
ポリエチレンの密度が０．９０５ｇ／ｃｍ3 以下のもの
を使用した。The present invention has taken the following means in order to solve these problems. That is, in order to obtain a stretch shrink packaging film having no acetic acid odor and strong heat shrinkage stress, the core layer is made of ethylene-propylene copolymer or ethylene-butene-propylene copolymer, and both outer layers are MI 0.5 to 10 g / The linear low-density polyethylene of 10 min was used, and the total thickness of both outer layers was 10 to 90% of the total thickness of the film. Furthermore, in order to obtain a stretch-stretch packaging film having a high elastic recovery rate, the linear low-density polyethylene having a density of 0.905 g / cm 3 or less was used.
【００６】芯層には、延伸性や熱収縮性更には弾性回復
率等の面から、プロピレンのホモポリマーでなくエチレ
ン−プロピレン共重合体やエチレン−ブテン−プロピレ
ン共重合体のポリプロピレン系樹脂を用いることが必要
である。該樹脂のＭＩとしては、１．２乃至６．０ｇ／
１０ｍｉｎが好ましい。又、該樹脂の共重合割合として
は、エチレン−プロピレン共重合体の場合、エチレンの
含有率が３乃至５ｗｔ％が好ましく、エチレン−ブテン
−プロピレン共重合体の場合、エチレンとブテンとの合
計の含有率が４乃至１３ｗｔ％が好ましい。これら共重
合体の樹脂を用いることにより両外層の直鎖状低密度ポ
リエチレン層との積層延伸が容易に行えるようになり、
しかも、低温延伸が可能になるため低温での熱収縮性が
良好になる。In view of stretchability, heat shrinkability and elastic recovery rate, the core layer is made of a polypropylene resin such as an ethylene-propylene copolymer or an ethylene-butene-propylene copolymer instead of a propylene homopolymer. It is necessary to use. The MI of the resin is 1.2 to 6.0 g /
10 min is preferable. As the copolymerization ratio of the resin, in the case of ethylene-propylene copolymer, the ethylene content is preferably 3 to 5 wt%, and in the case of ethylene-butene-propylene copolymer, the total content of ethylene and butene is The content is preferably 4 to 13 wt%. By using the resin of these copolymers, it becomes possible to easily perform the laminate stretching with the linear low-density polyethylene layers of both outer layers,
Moreover, since low temperature stretching is possible, the heat shrinkability at low temperature is improved.
【００７】両外層には酢酸臭や熱収縮応力の面から、直
鎖状低密度ポリエチレンを用いることが必要である。し
かも、製膜性や延伸加工性の面からＭＩ０．５乃至１０
ｇ／１０ｍｉｎの範囲のものが必要である。ＭＩが、１
０ｇ／１０ｍｉｎを越えると強い熱収縮応力が得られな
い。又、ＭＩが、０．５ｇ／１０ｍｉｎ未満でも１０を
越えても共に芯層のポリプロピレン系樹脂層との共押出
積層製膜性や積層延伸性が悪くなる。より好ましくは、
芯層に用いられるポリプロピレン系樹脂の溶融特性に似
た直鎖状低密度ポリエチレンを用いることが製膜性や延
伸加工性の面から好ましい。又、より弾性回復率の優れ
たストレッチシュリンク包装用フィルムを得るために
は、両外層の直鎖状低密度ポリエチレンの密度が０．９
０５ｇ／ｃｍ3 以下であることが好ましい。より好まし
くは、密度が０．８３０乃至０．９０５ｇ／ｃｍ3 の範
囲のものが好ましい。密度が０．９０５ｇ／ｃｍ3 を越
える直鎖状低密度ポリエチレンを用いると、得られるフ
ィルムの弾性回復率が低く、ストレッチシュリンク包装
体の弾性回復率が悪くなる。しかも、該両外層の厚みの
和は延伸性や弾性回復率の面から、フィルム全体厚みの
１０乃至９０％であることが必要である。両外層の厚み
の和が１０％未満では弾性回復率に劣り、９０％を越え
ると熱収縮応力が弱くなる。It is necessary to use linear low-density polyethylene for both outer layers from the viewpoint of acetic acid odor and heat shrinkage stress. Moreover, MI 0.5 to 10 from the viewpoint of film forming property and stretching processability.
The range of g / 10min is required. MI is 1
If it exceeds 0 g / 10 min, a strong heat shrinkage stress cannot be obtained. Further, if the MI is less than 0.5 g / 10 min or more than 10, both the coextrusion laminating film-forming property and the laminating stretchability with the polypropylene resin layer of the core layer are deteriorated. More preferably,
It is preferable to use a linear low-density polyethylene having a melting property similar to that of the polypropylene resin used for the core layer from the viewpoint of film-forming property and stretching processability. Further, in order to obtain a stretch shrink wrapping film having an excellent elastic recovery rate, the linear low density polyethylene in both outer layers has a density of 0.9 or less.
It is preferably 05 g / cm 3 or less. More preferably, the density is in the range of 0.830 to 0.905 g / cm 3 . When linear low density polyethylene having a density of more than 0.905 g / cm 3 is used, the elastic recovery rate of the obtained film is low and the elastic recovery rate of the stretch shrink package is poor. In addition, the sum of the thicknesses of both outer layers must be 10 to 90% of the total thickness of the film in terms of stretchability and elastic recovery rate. If the sum of the thicknesses of both outer layers is less than 10%, the elastic recovery rate is poor, and if it exceeds 90%, the heat shrinkage stress becomes weak.
【００８】又、本発明のストレッチシュリンク包装用フ
ィルムは、上記フィルム構成で延伸加工されていること
が熱収縮性を持たせるために必要である。しかも、該フ
ィルムは低温で熱収縮を生じさせることが好ましい。そ
の点、上記フィルム構成は低温で容易に延伸加工が行え
るので、低温で熱収縮性させることが出来る。尚、芯層
と両最外層との積層は共押出法で行われるのが容易で一
般的である。又、延伸加工方法としては特に限定される
ものではなく、従来一般に行われているテンター方式
や、インフレーション方式が採用出来る。そして、好ま
しくは二軸方向に延伸加工されているのが包装仕上がり
の面から望ましい。The stretch shrink wrapping film of the present invention is required to be stretched with the above-mentioned film constitution in order to have heat shrinkability. Moreover, it is preferable that the film causes heat shrinkage at a low temperature. In that respect, since the above-mentioned film structure can be easily stretched at a low temperature, it can be heat-shrinkable at a low temperature. Incidentally, the lamination of the core layer and both outermost layers is generally easy and commonly performed by a coextrusion method. Further, the stretching method is not particularly limited, and a tenter method or an inflation method which has been generally used conventionally can be adopted. And, it is desirable that it is stretched in the biaxial direction from the viewpoint of finished packaging.
【００９】[0109]
【作用】本発明のストレッチシュリンク包装用フィルム
は、エチレン−酢酸ビニル共重合体を全く使用していな
いので酢酸臭を発するようなことがない。しかも、両外
層に熱収縮性を有する直鎖状低密度ポリエチレンを使用
することにより、芯層に用いられているポリプロピレン
系樹脂の特徴である熱収縮応力を大幅に低下させず、強
い熱収縮応力を発揮させることができる。更に、両外層
に弾性率の高い、密度が０．９０５ｇ／ｃｍ3 以下の直
鎖状低密度ポリエチレンが用いられているので、ストレ
ッチシュリンク包装体の弾性回復率が良好になる。The stretch shrink wrapping film of the present invention does not emit an acetic acid odor because it does not contain any ethylene-vinyl acetate copolymer. Moreover, the use of linear low-density polyethylene having heat-shrinkability in both outer layers does not significantly reduce the heat-shrinkage stress, which is a characteristic of the polypropylene-based resin used in the core layer, and provides strong heat-shrinkage stress. Can be demonstrated. Furthermore, since linear low-density polyethylene having a high elastic modulus and a density of 0.905 g / cm 3 or less is used for both outer layers, the elastic recovery rate of the stretch shrink package is improved.
【０１０】[0101]
【実施例及び比較例】以下、実施例及び比較例を示し、
本発明の内容をより具体的に説明する。尚、本発明は、
実施例に記載された事項によって、限定されるものでな
いことは当然である。尚、本発明において、弾性回復率
は次のような方法によって測定した。まず、幅１０ｍ
ｍ、長さ２００ｍｍの試験片の中央部に標線間５０ｍｍ
の標線を付ける。該試験片をチャック間が１００ｍｍに
なるように引張試験機に装着し、標線間が１００ｍｍに
なるまで２００ｍｍ／ｍｉｎの速度で引っ張る。そし
て、そのままの状態で１分間放置する。次に、引張応力
が零になるまで２００ｍｍ／ｍｉｎの速度で緩めてから
試験片をチャックから取りはずし、６０分間放置する。
そして、標線間の距離Ｌ（ｍｍ）を測り、次の式により
求めた。[Examples and Comparative Examples] Examples and comparative examples will be shown below.
The contents of the present invention will be described more specifically. The present invention is
Of course, the matters described in the examples are not limiting. In the present invention, the elastic recovery rate was measured by the following method. First, width 10m
50 mm between the marked lines at the center of the test piece of m and length of 200 mm
Mark the line. The test piece is mounted on a tensile tester so that the chuck distance is 100 mm, and is pulled at a speed of 200 mm / min until the marked distance is 100 mm. Then, it is left as it is for 1 minute. Then, the test piece is removed from the chuck by loosening it at a speed of 200 mm / min until the tensile stress becomes zero, and left for 60 minutes.
Then, the distance L (mm) between the marked lines was measured and determined by the following formula.
【０１１】 弾性回復率（％）＝｛（１００−Ｌ）÷５０｝×１００Elastic recovery rate (%) = {(100−L) ÷ 50} × 100
【００１２】又、熱収縮応力は次のような方法によって
測定した。まず、幅１０ｍｍ、長さ５０ｍｍの試験片を
チャック間が３０ｍｍになるように熱収縮応力測定機に
装着し、１００℃のグリセリンバス中に侵責させる。そ
の際、チャック間に生じる応力を熱収縮応力として単位
「ｋｇ／ｃｍ2 」で求めた。The heat shrinkage stress was measured by the following method. First, a test piece having a width of 10 mm and a length of 50 mm is mounted on a heat-shrinkage stress measuring machine so that the gap between chucks is 30 mm and impregnated in a glycerin bath at 100 ° C. At that time, the stress generated between the chucks was determined as a heat shrinkage stress in the unit of “kg / cm 2 ”.
【０１３】[0113]
【実施例１】芯層がエチレン含有率４．７ｗｔ％のエチ
レン−プロピレン共重合体で、両外層が密度０．９２０
ｇ／ｃｍ3 、ＭＩ０．８ｇ／１０ｍｉｎの直鎖状低密度
ポリエチレンのチューブ状未延伸原反を共押出法によっ
て得た。得られた原反をインフレーション法により二軸
延伸し、ストレッチシュリンク包装用フィルムを得た。
尚、得られたフィルムは全体厚みが約１５μｍで、各外
層の厚みはそれぞれ約３．５μｍ（フィルム全体厚みに
対する両外層の厚みの和が約４７％）であった。得られ
たストレッチシュリンク包装用フィルムを用いて、トレ
ーに山盛りにされた胡瓜のストレッチシュリンク包装を
行った。その結果、熱収縮トンネル通過後においても包
装体内に酢酸臭が存在するようなこともなく、しかも、
結束力と緊迫性に優れたストレッチシュリンク包装体で
あった。尚、該フィルムの熱収縮応力は１７ｋｇ／ｃｍ
2 で、弾性回復率は５８％であった。Example 1 The core layer was an ethylene-propylene copolymer having an ethylene content of 4.7 wt%, and both outer layers had a density of 0.920.
A tube-shaped unstretched raw material of linear low-density polyethylene having g / cm 3 and MI 0.8 g / 10 min was obtained by a coextrusion method. The obtained raw fabric was biaxially stretched by an inflation method to obtain a stretch shrink packaging film.
The obtained film had a total thickness of about 15 μm, and each outer layer had a thickness of about 3.5 μm (the sum of the thickness of both outer layers to the total thickness of the film was about 47%). The obtained stretch shrink wrapping film was used to perform stretch shrink wrapping of cucumbers piled on a tray. As a result, the odor of acetic acid does not exist in the package even after passing through the heat-shrinking tunnel.
It was a stretch-shrink package with excellent cohesion and tension. The heat shrinkage stress of the film is 17 kg / cm.
At 2 , the elastic recovery rate was 58%.
【０１４】[0142]
【比較例１】実施例１における両最外層の直鎖状低密度
ポリエチレンを酢酸ビニル含有量１．５ｗｔ％、ＭＩ
３．０ｇ／１０ｍｉｎのエチレン−酢酸ビニル共重合体
に変える以外は実施例１と同じ方法によってストレッチ
シュリンク包装用フィルムを得た。該フィルムを用い
て、実施例１と同様、トレーに山盛りにされた胡瓜のス
トレッチシュリンク包装を行った。しかし、開封時に包
装体内には酢酸臭が漂い、商品価値を大幅に低下させる
ものであった。又、結束力にも劣るものであった。尚、
該フィルムの熱収縮応力は５．５ｋｇ／ｃｍ2 で、弾性
回復率は５３％であった。[Comparative Example 1] A linear low-density polyethylene in both outermost layers in Example 1 was used as a vinyl acetate content of 1.5 wt% and MI
A stretch shrink packaging film was obtained in the same manner as in Example 1 except that the ethylene-vinyl acetate copolymer was changed to 3.0 g / 10 min. The film was used to carry out stretch shrink wrapping of cucumbers piled on a tray in the same manner as in Example 1. However, the odor of acetic acid drifts inside the package when it is opened, which greatly reduces the commercial value. Moreover, the binding strength was also poor. still,
The heat shrinkage stress of the film was 5.5 kg / cm 2 , and the elastic recovery rate was 53%.
【０１５】[0115]
【実施例２及び比較例２乃至５】芯層のポリプロピレン
系樹脂としてエチレン含有率２．８ｗｔ％、ブテン含有
率３．６ｗｔ％のエチレン−ブテン−プロピレン共重合
体を使用し、両外層の直鎖状低密度ポリエチレンとして
は、表１に示される密度やＭＩのものを使用し、実施例
１と同様な方法によってストレッチシュリンク包装用フ
ィルムを得た。尚、フィルムの全体厚みは全て１５μｍ
とし、両最外層の厚みは同じでその合計厚みが表１に示
されるようにした。その結果を表１に示す。Example 2 and Comparative Examples 2 to 5 An ethylene-butene-propylene copolymer having an ethylene content of 2.8 wt% and a butene content of 3.6 wt% was used as a polypropylene resin for the core layer, and both outer layers were directly bonded. As the chain low density polyethylene, those having the densities and MIs shown in Table 1 were used, and a stretch shrink packaging film was obtained in the same manner as in Example 1. The total thickness of the film is 15 μm
The outermost layers have the same thickness, and the total thickness is as shown in Table 1. The results are shown in Table 1.
【０１６】[0163]
【表１】 [Table 1]
【０１７】表１から明らかな如く、両外層の直鎖状低密
度ポリエチレンの密度が０．９００ｇ／ｃｍ3 で、ＭＩ
が５．０ｇ／１０ｍｉｎ、両外層の厚みの和が１０．５
μｍ（フィルム全体厚みに対する両外層の厚みの和が７
０％）の実施例２は、熱収縮応力が強く、弾性回復率に
優れており、ストレッチシュリンク包装用フィルムとし
て適していた。これに対し、両外層の直鎖状低密度ポリ
エチレンの厚みの和が１．３μｍ（フィルム全体厚みに
対する両外層の厚みの和が１０％以下）の比較例２は弾
性回復率に劣り、１３．８μｍ（フィルム全体厚みに対
する両外層の厚みの和が９０％以上）の比較例３は熱収
縮応力が弱く、共にストレッチシュリンク包装用フィル
ムとして不適当であった。 又、両外層の直鎖状低密度
ポリエチレンのＭＩが０．５ｇ／１０ｍｉｎ未満の比較
例４や、ＭＩが１０．０ｇ／１０ｍｉｎを越える比較例
３は、芯層のポリプロピレン系樹脂との共押出加工時に
メルトフラクチャーを生じ、しかも、延伸加工性に劣っ
ていた。更に、得られる延伸フィルムは厚み精度に劣る
ものであった。As is clear from Table 1, the linear low-density polyethylene in both outer layers had a density of 0.900 g / cm 3 and MI.
Is 5.0 g / 10 min, and the sum of the thicknesses of both outer layers is 10.5
μm (The sum of the thickness of both outer layers to the total film thickness is 7
Example 2 (0%) had a strong heat shrinkage stress and an excellent elastic recovery rate, and was suitable as a film for stretch shrink packaging. On the other hand, Comparative Example 2 in which the sum of the thicknesses of the linear low-density polyethylene in both outer layers is 1.3 μm (the sum of the thicknesses of both outer layers with respect to the total film thickness is 10% or less) is inferior in elastic recovery rate. Comparative Example 3 having a thickness of 8 μm (the sum of the thicknesses of both outer layers with respect to the entire thickness of the film is 90% or more) has a weak heat shrinkage stress, and both are unsuitable as stretch shrink wrapping films. Further, Comparative Example 4 in which the MI of the linear low-density polyethylene of both outer layers is less than 0.5 g / 10 min and Comparative Example 3 in which the MI exceeds 10.0 g / 10 min are coextruded with the polypropylene resin of the core layer. Melt fracture occurred during processing, and the stretchability was poor. Furthermore, the obtained stretched film was inferior in thickness accuracy.
【０１８】The
【効果】本発明のストレッチシュリンク包装用フィルム
を用いたストレッチシュリンク包装体は、熱収縮トンネ
ルを通過させても酢酸臭を発生させないので食品等の包
装に好適である。又、本発明のストレッチシュリンク包
装用フィルムは、集積包装用に用いた場合、結束力の優
れたストレッチシュリンク包装体が得られる。更に、両
外層の直鎖状低密度ポリエチレンとして極低密度ポリエ
チレンを用いたストレッチシュリンク包装用フィルム
は、回復弾性率が高いので、該フィルムを用いたストレ
ッチシュリンク包装体は、握った際に指等で生じるた窪
みが時間の経過とともに無くなる。[Effect] A stretch shrink package using the stretch shrink wrapping film of the present invention does not generate an acetic acid odor even when passed through a heat shrink tunnel, and is suitable for packaging foods and the like. Further, when the stretch shrink wrapping film of the present invention is used for integrated wrapping, a stretch shrink wrapping body having an excellent binding force can be obtained. Furthermore, since the stretch shrink wrapping film using extremely low density polyethylene as the linear low density polyethylene of both outer layers has a high recovery elastic modulus, the stretch shrink wrapping body using the film is a finger or the like when gripped. The dents that occur at point disappear with the passage of time.
Claims (2)
はエチレン−ブテン−プロピレン共重合体で、両外層が
メルトインデックス（以下、ＭＩと称す。）０．５乃至
１０ｇ／１０ｍｉｎの直鎖状低密度ポリエチレンで、し
かも、該両外層の厚みの和がフィルム全体厚みの１０乃
至９０％である延伸加工の施されたストレッチシュリン
ク包装用フィルム1. A linear low polymer having an ethylene-propylene copolymer or an ethylene-butene-propylene copolymer as a core layer and a melt index (hereinafter referred to as MI) of 0.5 to 10 g / 10 min for both outer layers. A stretch shrink wrapping film which is a density polyethylene and is stretched such that the sum of the thicknesses of both outer layers is 10 to 90% of the total thickness of the film.
０５ｇ／ｃｍ3 以下の極低密度ポリエチレンである請求
項１に記載のストレッチシュリンク包装用フィルム2. The linear low-density polyethylene has a density of 0.9.
The stretch shrink wrapping film according to claim 1, which is an extremely low density polyethylene of not more than 05 g / cm 3.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP03130378A JP3119676B2 (en) | 1991-05-01 | 1991-05-01 | Stretch shrink wrapping film |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP03130378A JP3119676B2 (en) | 1991-05-01 | 1991-05-01 | Stretch shrink wrapping film |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05318682A true JPH05318682A (en) | 1993-12-03 |
| JP3119676B2 JP3119676B2 (en) | 2000-12-25 |
Family
ID=15032915
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP03130378A Expired - Fee Related JP3119676B2 (en) | 1991-05-01 | 1991-05-01 | Stretch shrink wrapping film |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3119676B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4846907A (en) * | 1987-06-26 | 1989-07-11 | Bridgestone Corporation | Method of producing tire belts |
| US5614297A (en) * | 1994-05-19 | 1997-03-25 | Viskase Corporation | Polyolefin stretch film |
-
1991
- 1991-05-01 JP JP03130378A patent/JP3119676B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4846907A (en) * | 1987-06-26 | 1989-07-11 | Bridgestone Corporation | Method of producing tire belts |
| US5614297A (en) * | 1994-05-19 | 1997-03-25 | Viskase Corporation | Polyolefin stretch film |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3119676B2 (en) | 2000-12-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5614315A (en) | Heat-shrinkable multi-layer polyolefin films | |
| EP0229715B1 (en) | Multilayered polyolefin high shrinkage low-shrink force shrink film | |
| TW394731B (en) | Polyolefin-based laminate film | |
| KR100319247B1 (en) | Heat-shrinkable polypropylene laminate film | |
| US6344250B1 (en) | Multilayered polyolefin high shrinkage, low shrink force shrink film | |
| JP3096350B2 (en) | Laminated stretch shrink film | |
| JPH0815774B2 (en) | Heat shrinkable film | |
| JP3112553B2 (en) | Multi-layer stretch shrink film | |
| JP2551612B2 (en) | Heat shrinkable multi-layer film | |
| EP1532203A1 (en) | Schrink film | |
| JP3751965B2 (en) | Polyolefin multilayer shrink film | |
| JPH05318682A (en) | Stretch and shrink packaging film | |
| JP2008036844A (en) | Multilayered polyolefinic heat-shrinkable film | |
| JP3093468B2 (en) | Laminated stretch shrink film | |
| JPH0625620A (en) | Self-tack film | |
| JPH04310735A (en) | Polyethylenic multilayer stretched film | |
| JP3140198B2 (en) | Stretch shrink packaging film | |
| JP3097874B2 (en) | Crosslinked heat shrinkable laminated film | |
| JP2570359B2 (en) | Multi-layer shrink film | |
| JP2605114B2 (en) | Laminated product of stretched polypropylene film and its use | |
| CA2207698C (en) | Multilayered polyolefin high shrinkage, low shrink force shrink film | |
| JP3493474B2 (en) | Polyolefin-based heat-shrinkable multilayer film | |
| JP3092339B2 (en) | Heat shrinkable laminated film for sleeve packaging | |
| JP3093469B2 (en) | Multi-layer stretch shrink film | |
| JPH08300470A (en) | Biaxially stretched polypropylene film |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 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 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20081013 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20081013 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20091013 Year of fee payment: 9 |
|
| LAPS | Cancellation because of no payment of annual fees |