JPH0313338A - Polypropylene type multilayer shrink film - Google Patents
Polypropylene type multilayer shrink filmInfo
- Publication number
- JPH0313338A JPH0313338A JP15001189A JP15001189A JPH0313338A JP H0313338 A JPH0313338 A JP H0313338A JP 15001189 A JP15001189 A JP 15001189A JP 15001189 A JP15001189 A JP 15001189A JP H0313338 A JPH0313338 A JP H0313338A
- Authority
- JP
- Japan
- Prior art keywords
- film
- polypropylene resin
- crystalline polypropylene
- ethylene
- multilayer
- 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
- -1 Polypropylene Polymers 0.000 title claims abstract description 56
- 239000004743 Polypropylene Substances 0.000 title claims abstract description 54
- 229920001155 polypropylene Polymers 0.000 title claims abstract description 54
- 229920006300 shrink film Polymers 0.000 title claims abstract description 31
- 229920005989 resin Polymers 0.000 claims abstract description 49
- 239000011347 resin Substances 0.000 claims abstract description 49
- 239000010410 layer Substances 0.000 claims abstract description 32
- 239000012792 core layer Substances 0.000 claims abstract description 21
- 238000002844 melting Methods 0.000 claims abstract description 18
- 230000008018 melting Effects 0.000 claims abstract description 18
- 229920001577 copolymer Polymers 0.000 claims abstract description 11
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 claims abstract description 9
- 239000005977 Ethylene Substances 0.000 claims abstract description 9
- VVQNEPGJFQJSBK-UHFFFAOYSA-N Methyl methacrylate Chemical compound COC(=O)C(C)=C VVQNEPGJFQJSBK-UHFFFAOYSA-N 0.000 claims description 5
- 239000000155 melt Substances 0.000 claims description 5
- 238000000034 method Methods 0.000 abstract description 13
- 238000010438 heat treatment Methods 0.000 abstract description 3
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 abstract description 3
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 abstract description 3
- VXNZUUAINFGPBY-UHFFFAOYSA-N 1-Butene Chemical compound CCC=C VXNZUUAINFGPBY-UHFFFAOYSA-N 0.000 abstract description 2
- IAQRGUVFOMOMEM-UHFFFAOYSA-N butene Natural products CC=CC IAQRGUVFOMOMEM-UHFFFAOYSA-N 0.000 abstract description 2
- 238000001816 cooling Methods 0.000 abstract description 2
- 238000004458 analytical method Methods 0.000 abstract 1
- 238000012856 packing Methods 0.000 abstract 1
- 238000004806 packaging method and process Methods 0.000 description 27
- 239000004744 fabric Substances 0.000 description 22
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 12
- 230000000052 comparative effect Effects 0.000 description 12
- 239000005038 ethylene vinyl acetate Substances 0.000 description 6
- 229920001200 poly(ethylene-vinyl acetate) Polymers 0.000 description 6
- 230000000694 effects Effects 0.000 description 3
- 235000013305 food Nutrition 0.000 description 3
- 230000008602 contraction Effects 0.000 description 2
- 238000001125 extrusion Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 229920013716 polyethylene resin Polymers 0.000 description 2
- 229920000915 polyvinyl chloride Polymers 0.000 description 2
- 239000004800 polyvinyl chloride Substances 0.000 description 2
- BBEAQIROQSPTKN-UHFFFAOYSA-N pyrene Chemical compound C1=CC=C2C=CC3=CC=CC4=CC=C1C2=C43 BBEAQIROQSPTKN-UHFFFAOYSA-N 0.000 description 2
- 230000037303 wrinkles Effects 0.000 description 2
- YJLUBHOZZTYQIP-UHFFFAOYSA-N 2-[5-[2-(2,3-dihydro-1H-inden-2-ylamino)pyrimidin-5-yl]-1,3,4-oxadiazol-2-yl]-1-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)ethanone Chemical compound C1C(CC2=CC=CC=C12)NC1=NC=C(C=N1)C1=NN=C(O1)CC(=O)N1CC2=C(CC1)NN=N2 YJLUBHOZZTYQIP-UHFFFAOYSA-N 0.000 description 1
- 239000004698 Polyethylene Substances 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 239000000443 aerosol Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 210000000481 breast Anatomy 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000000593 degrading effect Effects 0.000 description 1
- 238000000113 differential scanning calorimetry Methods 0.000 description 1
- GVEPBJHOBDJJJI-UHFFFAOYSA-N fluoranthrene Natural products C1=CC(C2=CC=CC=C22)=C3C2=CC=CC3=C1 GVEPBJHOBDJJJI-UHFFFAOYSA-N 0.000 description 1
- 230000005764 inhibitory process Effects 0.000 description 1
- 230000002452 interceptive effect Effects 0.000 description 1
- 239000011229 interlayer Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000009965 odorless effect Effects 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000010526 radical polymerization reaction Methods 0.000 description 1
- 229920005604 random copolymer Polymers 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 239000010902 straw Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 230000002087 whitening effect Effects 0.000 description 1
Abstract
Description
【発明の詳細な説明】
〈産業上の利用分野）
本発明のポリプロピレン系多層シュリンクフィルムは、
商品をラフに包んでおき、これを加熱装置く収縮トンネ
ル）によって加熱収縮させ、タイトな包装を行う方式の
熱収縮包装に用いるものである。そして、カップ食品、
乳ｉＩ！２菌飲料品、紙パツク飲料品、冷凍・冷蔵食品
、医藁品、エアゾール缶、或は、文具・玩具等の日用品
の熱収縮包装に利用され、特に、集積包装や改ざん防止
包装に優れた効果を発揮するものであ゛る。[Detailed description of the invention] <Industrial application field> The polypropylene multilayer shrink film of the present invention is
This method is used for heat shrink packaging, in which the product is roughly wrapped and then heated and shrunk using a heating device (shrink tunnel) to form a tight package. And cup food,
Breasts II! It is used for heat shrink packaging of 2-bacterial drinks, paper packaged drinks, frozen/refrigerated foods, medical straw products, aerosol cans, and daily necessities such as stationery and toys, and is especially excellent for stacking packaging and tamper-proof packaging. It is something that is effective.
（従来の技術）
熱収縮包装分野に利用されているシュリンクフィルムと
しては、ポリエチレン樹脂やポリプロピレン樹脂、或は
、ポリ塩化ビニル樹脂等からなる種々のフィルムがあり
、しかも、数多く市販されている。中でも、ポリプロピ
レン樹脂よりなるシュリンクフィルムは、その本来有し
ている透明性、光沢、防湿性、或は、無公害性等の優れ
た特性によって広く一般に利用されている。しかし、ボ
リプロピレン樹脂からなるシュリンクフィルムは、ポリ
塩化ビニル樹脂等からなるシュリンクフィルムと比較し
て、かなり高温にしなければ熱収縮を生じさせることが
出来ず、しかも、熱収縮包装温度範囲が狭く、熱収縮包
装適性としては必ずしも良好とは言えない。(Prior Art) As shrink films used in the heat shrink packaging field, there are various films made of polyethylene resin, polypropylene resin, polyvinyl chloride resin, etc., and many of them are commercially available. Among them, shrink films made of polypropylene resin are widely used because of their inherent excellent properties such as transparency, gloss, moisture resistance, and non-pollution. However, compared to shrink films made of polyvinyl chloride resin, etc., shrink films made of polypropylene resin cannot undergo heat shrinkage unless they are heated to a considerably high temperature, and the temperature range for heat shrink packaging is narrow. It cannot be said that the suitability for heat shrink packaging is necessarily good.
この様な欠点を解決させたものとして、雨量外層をポリ
プロピレン系樹脂とし、芯層を直鎖状底密度ポリエチレ
ン樹脂を主体としたシュリンクフィルムが特開昭５８−
１６６０４９に開示されている。又、密度が非常に低い
特殊な直鎖状底密度ポリエチレンｗｉを用いたシュリン
クフィルムが特開昭６３−２１４４４６に、更に、芯層
をエチレン−酢酸ビニル共重合体（以下、エチレン−酢
酸ビニル共重合体をＥＶＡと称す。）を主体としたシュ
リンクフィルムが特開昭５４−１５５２８２や特開昭５
７−１６５２５４に開示されている。In order to solve these drawbacks, a shrink film was developed in which the outer layer of the rain layer was made of a polypropylene resin and the core layer was made of a linear bottom density polyethylene resin.
No. 166049. In addition, a shrink film using a special linear bottom density polyethylene wi with a very low density was published in JP-A-63-214446, and the core layer was made of ethylene-vinyl acetate copolymer (hereinafter referred to as ethylene-vinyl acetate copolymer). Shrink films based on polymers such as EVA) have been published in JP-A-54-155282 and JP-A-5.
No. 7-165254.
しかし、これらのうち芯層にＥ Ｖ入を使用したものは
、酢酸臭を有するばかりか、共押出による多層未延伸原
反の製膜にあたり色々なトラブルを生じていた。However, among these, those using EV in the core layer not only had an acetic acid odor, but also caused various troubles when forming a multilayer unstretched original film by coextrusion.
（本発明が解決しようとする問題点）
本発明は、ポリプロピレン系樹脂を用いたシュリンクフ
ィルムに於て、熱収縮包装温度範囲が広く、低温での熱
収縮性に優れ、良好なる゛包装仕上がりが得られ易く、
しかも、溶断シール強度や引き裂き伝播強度が強く、無
臭であるばかりか、共押出りこよる製膜性や延伸性等の
良好なるフィルムを提供しようとするものである。(Problems to be Solved by the Invention) The present invention provides a shrink film using polypropylene resin that has a wide heat shrink packaging temperature range, has excellent heat shrink properties at low temperatures, and has a good packaging finish. easy to obtain,
Moreover, the present invention aims to provide a film which not only has strong melt sealing strength and tear propagation strength, is odorless, but also has good film formability and stretchability due to coextrusion.
即ち、ポリプロピレン系樹脂が本来有している透明性や
光沢、更には、防湿性や無公害性等の特性を損なう事な
く、上記特性をも兼ね備えたポリプロピレン系多層シュ
リンクフィルムを得ようとするものである。In other words, the aim is to obtain a polypropylene multilayer shrink film that has the above characteristics without impairing the transparency and gloss inherent to polypropylene resin, as well as moisture resistance and non-pollution properties. It is.
（問題を解決するための手段〉
本発明は、前記した種々の特性を有するポリプロピレン
系多層シュリンクフィルムを得るため一二、両層外Ｎを
ポリプロピレン系樹脂とし、芯層をエチレンとメチルメ
タクリレートとの共重合体（以下、エチレンとメチルメ
タクリレートとの共重合体をＥＭＭＡと称す、）とする
ものである。即ち、雨量外層が融点１３５〜１５０℃で
、メルトフローインデックスが１〜７の結晶性ポリプロ
ピレン系樹脂からなり、芯層が融点９０〜１０２℃で、
メルトフローインデックスが雨量外層に用いられている
結晶性ポリプロピレン系樹脂のメルトフローインデック
スの１／３〜２倍のエチレンとメチルメタクリレートと
の共重合体からなる共押出された多層未延伸原反な延伸
処理されてなるポリプロピレン系多層シュリンクフィル
ムである。そして、好ましくは、雨量外層に用いられて
いる結晶性ポリプロピレン系樹脂が、エチレン−プロピ
レン共重合体、或は、エチレン−プロピレン−プテン共
重合体である。(Means for Solving the Problems) In order to obtain a polypropylene multilayer shrink film having the above-mentioned various properties, the present invention consists of: A copolymer (hereinafter, a copolymer of ethylene and methyl methacrylate is referred to as EMMA). That is, the outer layer is made of crystalline polypropylene with a melting point of 135 to 150°C and a melt flow index of 1 to 7. The core layer has a melting point of 90 to 102°C,
A coextruded multilayer unstretched original fabric made of a copolymer of ethylene and methyl methacrylate whose melt flow index is 1/3 to 2 times the melt flow index of the crystalline polypropylene resin used for the outer layer. This is a processed polypropylene multilayer shrink film. Preferably, the crystalline polypropylene resin used in the outer rain layer is an ethylene-propylene copolymer or an ethylene-propylene-putene copolymer.
以下、本発明の内容を詳細に説明する。Hereinafter, the content of the present invention will be explained in detail.
まず、雨量外層に用いられる結晶性ポリプロピレン系樹
脂としては、融点が１３５〜１５０℃の範囲で、ＭＩが
１〜７の範囲内のものである。この様な結晶性ポリプロ
ピレン系樹脂としては、プロピレンにエチレンを２〜４
ｂ・ｔ％程度共重合させたものや、プロピレンにエチレ
とブテンとを３〜８νｔ％程度共重合させたものが好ん
で用いられる。First, the crystalline polypropylene resin used for the outer layer has a melting point of 135 to 150°C and an MI of 1 to 7. Such crystalline polypropylene resin is made by adding 2 to 4 ethylene to propylene.
Preferably used are those obtained by copolymerizing about b·t% or about 3 to 8 νt% of propylene and ethylene and butene.
次に、芯層に用いられるＥＭＭＡは、エチレンとメチル
メタクリレートの高圧ラジカル重合によるランダム共重
合樹脂で、ＭＩが雨量外層に用いられている結晶性ポリ
プロピレン系樹脂のＭＩの１／３〜２倍の範囲内のもの
である。そして、該樹脂はメチルメタクリレートの側鎖
による結晶阻害効果により、柔軟性のある樹脂で、しか
も、ＥＶＡより熱安定性がよく、熱分解したとしてもＥ
ＶＡの様に酸を発生させる様な樹脂ではない。Next, EMMA used for the core layer is a random copolymer resin made by high-pressure radical polymerization of ethylene and methyl methacrylate, and its MI is 1/3 to 2 times that of the crystalline polypropylene resin used for the outer rain layer. It is within the range. The resin is flexible due to the crystal inhibition effect of the side chains of methyl methacrylate, and has better thermal stability than EVA, and even if thermally decomposed,
It is not a resin that generates acid like VA.
雨量外層に用いられている結晶性ポリプロピレン系樹脂
の融点が１５０℃を越えると、低温での延伸加工が困難
になるため、高温で延伸加工される櫟になるので、低温
での熱収縮性が低下するのは勿論、この様な樹脂を使用
ずろと、高温での熱収縮性も悪くなるので、熱収縮包装
適性が低下してしまう、又、１３５℃未満であると、耐
熱性に劣り、収縮トンネル中で溶融白化等を生じ易くな
り、やはり熱収縮包装適性が低下してしまう。又、収縮
トンネルを出た直後の包装体の滑り性（ホットスリップ
性）にも劣る。If the melting point of the crystalline polypropylene resin used for the outer layer exceeds 150°C, it will be difficult to stretch at low temperatures. Of course, if such a resin is used, the heat shrinkability at high temperatures will also deteriorate, resulting in a decrease in suitability for heat shrink packaging, and if the temperature is below 135°C, the heat resistance will be poor. Melting and whitening etc. are likely to occur in the shrink tunnel, which also reduces suitability for heat shrink packaging. Furthermore, the slip properties (hot slip properties) of the package immediately after exiting the shrink tunnel are poor.
更に、雨量外層に用いられている結晶性ポリプロピレン
系樹脂のＭＩが１未満であると延伸応力が高くなり、又
、７を越えると延伸時に局ｌｖ延伸を生し、共に延伸性
に劣る様になる。Furthermore, if the MI of the crystalline polypropylene resin used for the outer layer is less than 1, the stretching stress will be high, and if it exceeds 7, local lv stretching will occur during stretching, and both will result in poor stretching properties. Become.
次に、芯層に用いられているＥＭＭＡの融点が１０２℃
を越えると、延伸性が低下し、特に低温での延伸が不可
能になり、熱収縮包装温度範囲が狭くなってしまう、そ
の上、層間接着強度も弱くなり、溶断シール強度等の低
下を招いてしまう。Next, the melting point of EMMA used in the core layer is 102°C.
If it exceeds this, the stretchability will decrease, making stretching especially at low temperatures impossible, narrowing the temperature range for heat-shrink packaging, and furthermore, interlayer adhesion strength will also weaken, leading to a decrease in fusing seal strength, etc. I'll be there.
又、融点が９０℃未満であると、共押出による多層未延
伸原反の製膜性が劣るばかりか、得られたシュリンクフ
ィルムの自然収縮を無くするための熱処理効果を発揮さ
せることが困難になり、該フィルムを自然放置している
と変形し・たり、平滑性が悪化したりしてしまう。In addition, if the melting point is less than 90°C, not only will the film forming properties of the multilayer unstretched film by coextrusion be inferior, but it will also be difficult to exert the heat treatment effect to eliminate natural shrinkage of the obtained shrink film. If the film is left alone, it may become deformed or its smoothness may deteriorate.
更に、ＥＭＭ ＡのＭｌが両層外、＋Ｗに用いられた結
晶性ポリプロピレン系樹脂のｒｖｌ Ｉの１／３未満で
あると、共押出された多層未延伸原反の地合が悪く、透
明性に劣り、２倍を越えると、共押出された多層未延伸
原反表面の一部が樹脂の流れ方向に断続的な凹凸を生じ
、共に良好なる多層未延伸原反を共押出する事が出来な
かった。Furthermore, if the Ml of EMM A is less than 1/3 of the rvl I of the crystalline polypropylene resin used for the outside of both layers and +W, the coextruded multilayer unstretched original fabric will have poor texture and poor transparency. If it exceeds 2 times, intermittent unevenness will occur on the surface of the coextruded multilayer unstretched fabric in the flow direction of the resin, making it impossible to coextrude a good multilayer unstretched fabric. There wasn't.
尚、本発明に於ける融点は、結晶性ポリプロピレン系樹
脂もＥＭＭＡも共に示差走査熱分析法によって測定され
た値である。The melting points in the present invention are values measured by differential scanning calorimetry for both the crystalline polypropylene resin and EMMA.
又、Ｍ ｒは、 ＪＩＳ−に−７２１０のＡン去に準じ
て、結晶性ポリプロピレン系樹脂では温度２３０℃、荷
重２１６０ ｇ、 ＥＭＭＡでは温度１９０℃、荷重
２１６０ｇの条件で測定された値である。In addition, Mr is a value measured under the conditions of temperature 230 ° C. and load 2160 g for crystalline polypropylene resin, and temperature 190 ° C. and load 2160 g for EMMA, in accordance with JIS-7210 A removal. .
本発明のポリプロピレン系多層シュリンクフィルムの各
層の厚み構成としては、芯層の厚み割合が全体厚みに対
し、３０〜７０％の範囲内であることが好ましい。芯層
の厚み割合が３０％未満であると、低温での熱収縮性に
劣り、熱収縮包装温度範囲を広げる事が困難になり、包
装機械適性に重要な引き裂き伝播強度も弱くなる。又、
７０％を越えると、延伸性が劣るようになるばかりか、
耐熱性にも劣るようになり、熱収縮包装適性が低下する
様になる。Regarding the thickness structure of each layer of the polypropylene multilayer shrink film of the present invention, it is preferable that the thickness ratio of the core layer is within the range of 30 to 70% of the total thickness. If the thickness ratio of the core layer is less than 30%, the heat shrinkability at low temperatures will be poor, it will be difficult to expand the temperature range of heat shrink packaging, and the tear propagation strength, which is important for packaging machine suitability, will also be weak. or,
If it exceeds 70%, not only will the stretchability become inferior,
It also becomes inferior in heat resistance and becomes less suitable for heat shrink packaging.
又、全体厚みとしては、８〜１００μ、より好ましくは
、１０〜５０μの範囲内であることが適当である。Further, the overall thickness is suitably in the range of 8 to 100 microns, more preferably 10 to 50 microns.
尚、本発明の主旨を変更しない範囲で、各層に他の樹脂
や添加剤を混入したり、或は、新たな層を設けたりする
事は何等妨げられろものではない。It should be noted that, without changing the gist of the present invention, there is no hindrance to mixing other resins or additives into each layer or providing new layers.
次に、本発明のポリプロピレン系多層シュリンクフィル
ムを製造する方法としては、まず、複数の押出機を用い
て多層グイより多層未延伸原反を共押出する。そして、
該多層未延伸原反を冷却固化させた後、延伸可能な温度
まで再加熱して、縦方向、横方向共に少なくとも３．０
倍以上延伸した後に冷却させる。延伸方法としては、テ
ンター方式、或は、インフレーション方式とも可能であ
るが、縦方向と横方向の熱収縮特性をよく似させるのが
容易である事から、インフレーション方式により延伸す
るのが好ましい、そのためには、多層未延伸原反は多層
サーキュラ−ダイを用い、多層チューブ状シートとして
得る事が必要である。Next, as a method for manufacturing the polypropylene multilayer shrink film of the present invention, first, a multilayer unstretched original film is coextruded from a multilayer gouer using a plurality of extruders. and,
After the multilayer unstretched original fabric is cooled and solidified, it is reheated to a temperature at which it can be stretched, and the film is heated to a temperature of at least 3.0 in both the longitudinal and transverse directions.
It is cooled after being stretched at least twice as long. The stretching method can be either the tenter method or the inflation method, but it is preferable to use the inflation method because it is easy to make the heat shrinkage characteristics in the longitudinal and transverse directions very similar. For this purpose, it is necessary to use a multilayer circular die to obtain a multilayer unstretched original fabric into a multilayer tubular sheet.
そして、導られた多層二軸延伸フィルムは、自然放置し
ていると該フィルム自体の持っている自然収縮性によっ
て変形したり、表面状態が悪化したりするので、これを
防止するために熱収縮特性を余り低下させない擾に熱処
理して、自然収縮量を減らす事がより好ましい。If the multilayer biaxially stretched film is left alone, it will deform due to the film's natural shrinkage and the surface condition will deteriorate. It is more preferable to reduce the amount of natural shrinkage by heat-treating the material without significantly degrading the properties.
又、本発明のポリプロピレン系多層シュリンクフィルム
を用いた熱収縮包装方法としては、従来のポリプロピレ
ン樹脂よりなるシュリンクフィルムに用いられている熱
収縮包装ラインをそのまま使用する事ができる。そして
、従来のシュリンクフィルムと比較して、収縮トンネル
温度が低温から高温までの幅広い温度範囲に於て良好な
る熱収縮包装体が得られるので、収縮トンネル内の温度
をシビャーに設定しなくても容易に良好なる熱収縮包装
体を得る事が出来る。更に、引き裂き伝播強度が強いの
で自動包装時に空気抜けの孔より破袋する様な事もなく
、しかも、溶断シール強度が強いので溶断シール部より
破袋を生じる様な事も無い。Further, as a heat shrink packaging method using the polypropylene multilayer shrink film of the present invention, the heat shrink packaging line used for conventional shrink films made of polypropylene resin can be used as is. In addition, compared to conventional shrink film, good heat shrink packaging can be obtained in a wide temperature range from low to high temperatures in the shrink tunnel, so there is no need to set the temperature inside the shrink tunnel severely. A good heat-shrinkable package can be easily obtained. Furthermore, since the tear propagation strength is strong, there is no possibility that the bag will be torn from the air vent hole during automatic packaging, and since the fusing seal strength is strong, the bag will not be torn from the fusing seal.
（発明の効果）
本発明のポリプロピレン系多層シュリンクフィルムは、
低温熱収縮性に便れ、熱収縮包装温度範囲が広いので、
良好なる熱収縮包装体を容易に得ろことが出来ろ。そし
て、引き裂き伝播強度や溶断シール強度が強いので、熱
収縮包装でのトラブルも少ない。又、得られた熱収縮包
装体にはＥ ＶＡを芯層に使用したシュリンクフィルム
の様な酢酸臭もない。更に、本発明のポリプロピレン系
多層シュリンクフィルムは、多層未延伸原反の共押出製
膜が容易であるばかりか、延伸加工も容易であるので生
産性に擾れている。(Effects of the invention) The polypropylene multilayer shrink film of the present invention is
It has good low-temperature heat shrinkability and has a wide heat shrink packaging temperature range.
Good heat shrink packaging can be easily obtained. In addition, because it has strong tear propagation strength and fusing seal strength, there are fewer problems with heat shrink packaging. Furthermore, the resulting heat-shrinkable package does not have an acetic acid odor unlike a shrink film using EVA as a core layer. Furthermore, the polypropylene multilayer shrink film of the present invention is not only easy to coextrude into a film from a multilayer unstretched original film, but also easy to stretch, resulting in poor productivity.
尚、本発明品は、ポリプロピレン樹脂が有している透明
性、光沢、防湿性、或は、無公害性等の特性を阻害する
事なく全て備えている。The product of the present invention has all of the properties of polypropylene resin, such as transparency, gloss, moisture resistance, and non-polluting properties, without interfering with them.
（実施例）
以下に実施例、及び、比較例を示し、本発明をより具体
的に説明する。(Example) The present invention will be explained in more detail by showing Examples and Comparative Examples below.
実施例 ｌ
融点１３８℃、Ｍｌ １． ５の結晶性ポリプロピレ
ン系樹脂（エチレン−プロピレン−プテン共重合体）を
雨量外層とし、融点９５°Ｃ，Ｍｌ ０． ８のＥＭ
ＭＡを芯層とするチューブ状の３層未延伸原反な３台の
押出機と３Ｎの共押出用サーキュラ−ダイによって試作
したが、容易に製膜する事が出来た。そして、得られた
多層未延伸原反の全体厚みは約２４０μで、各層の厚み
比は一方の外層から１：２：１てあった。尚、共押出製
膜に際しては、共押出直後に従来の水冷方式によって急
冷させた。Example l Melting point 138°C, Ml 1. The crystalline polypropylene resin (ethylene-propylene-butene copolymer) of No. 5 was used as the outer layer, and the melting point was 95°C and Ml 0. 8 EM
A trial production was carried out using three extruders using a 3-layer unstretched unstretched fabric with MA as the core layer and a 3N co-extrusion circular die, and it was possible to form a film easily. The total thickness of the obtained multilayer unstretched original fabric was about 240 μm, and the thickness ratio of each layer was 1:2:1 from one outer layer. In addition, when forming a film by coextrusion, immediately after coextrusion, it was rapidly cooled by a conventional water cooling method.
この多層未延伸原反を従来のインフレーション方式によ
って縦方向、横方向共に４．２倍の延伸を試みたが、従
来のポリプロピレン樹脂よりも低温で容易に延伸する事
が出来、多層二軸延伸フィルムを得ることが出来た。そ
して、この多層二軸延伸フィルムに弛緩を与えながら熱
固定を行い、全体厚みが約１５μのポリプロピレン系多
層シュリンクフィルムを得た。An attempt was made to stretch this multilayer unstretched original film by 4.2 times in both the longitudinal and transverse directions using a conventional inflation method, but it was found that the multilayer biaxially stretched film could be easily stretched at a lower temperature than conventional polypropylene resin. I was able to obtain. Then, this multilayer biaxially stretched film was heat-set while being relaxed to obtain a polypropylene multilayer shrink film having a total thickness of about 15 μm.
得られたポリプロピレン系多層シュリンクフィルムを用
いて、紙容器入りの日本酒（１，８Ｒ）の熱収縮包装を
行った。その結果、１６０’Ｃに設定させた収縮トンネ
ル温度を上下に１５°Ｃ程度変化させても、緊迫性に劣
ったり、コーナ一部に皺を生したりする様な事もなく、
しかも、透明性や光沢に優れた良好なる仕上がりが得ら
れた。又、得られた熱収縮包装体は、−船釣な取扱では
溶断シールａ５や空気抜きの孔から破袋を生じる様な事
も無かった。The obtained polypropylene multilayer shrink film was used to heat shrink package sake (1,8R) in a paper container. As a result, even if the contraction tunnel temperature, which is set at 160'C, is changed up or down by about 15°C, there will be no loss of tightness or wrinkles in some corners.
Moreover, a good finish with excellent transparency and gloss was obtained. In addition, the obtained heat-shrinkable package did not cause any breakage from the fusing seal A5 or the air vent hole when handled on a boat.
実施例 ２
融点１４５℃、Ｍｌ ６． ０の結晶性ポリプロピレ
ン系樹脂（エチレン−プロピレン共重合体）を雨量外層
とし、融点１００℃、Ｍｌ４．５のＥＭＭＡを芯層とす
るチューブ状の３層未延伸原反を実施例１と同様の方法
により製膜した。尚、得られた多層未延伸原反の全体厚
みは約３１０／ハ各層の厚み比は一方の外層から１：４
：１であった。Example 2 Melting point 145°C, Ml 6. A tube-shaped three-layer unstretched raw fabric having a precipitation outer layer of 0 crystalline polypropylene resin (ethylene-propylene copolymer) and a core layer of EMMA with a melting point of 100°C and Ml of 4.5 was prepared in the same manner as in Example 1. A film was formed by the method. The overall thickness of the obtained multilayer unstretched fabric was approximately 310/c, and the thickness ratio of each layer was 1:4 from one outer layer.
:1.
この多層未延伸原反を、実施例１と同様、従来のインフ
レーション方式によって二軸延伸し、その後、熱固定を
行う事により容易に全体厚みが約２０μのポリプロピレ
ン系多層シュリンクフィルムを得ることが出来た。As in Example 1, this multilayer unstretched original film was biaxially stretched using the conventional inflation method, and then heat set to easily obtain a polypropylene multilayer shrink film with a total thickness of about 20 μm. Ta.
得られたポリプロピレン系多層シュリンクフィルムを用
いてノートブック３冊の熱収縮包装を行フた。その結果
、１７０″ｃここ設定された収縮トンネル温度を上下に
２０℃程度変化させても、緊迫性に劣ったり、コーナ部
に皺を生じたりする様な事もなく、しかも、透明性、光
沢に便れた良好なる仕上がりが得られた。又、得られた
包装体は落下させてもシール部より破袋を生じる様な事
もなく、しかも、包装体同士を擦り合わせても、空気抜
けの孔から破袋を生じる様な事もなった。Three notebooks were heat-shrink wrapped using the obtained polypropylene multilayer shrink film. As a result, even if the contraction tunnel temperature set at 170"c is changed up or down by about 20 degrees Celsius, there will be no loss of tightness or wrinkles at the corners, and it will maintain transparency and gloss. A good finish was obtained that was easy to use.Furthermore, even when the resulting packaging was dropped, there was no breakage at the sealed part, and even when the packaging was rubbed against each other, there was no air release. In some cases, the bag broke due to the hole in the bag.
比較例 １〜２
比較例１では、雨量外層を１１９．０の結晶性ボリブａ
ピレン系樹脂とし、芯層を実施例２の芯層に使用したＭ
ｌ４．５のＥＭＭＡとし、比較例２では、雨量外層をＭ
Ｉｏ、５の結晶性ポリプロピレン系樹脂とし、芯層を実
施例１の芯層に使用したＭｌ ０． ８のＥＭＭＡと
する多層未延伸原反を実施例１と同様の方法によって製
膜した。尚、それぞれの結晶性ポリプロピレン系樹脂や
ＥＭｒＶＬへの融点は本発明の規定に合致するものであ
った。又、得られろ多層未延伸原反の全体厚み、及び、
各層の厚み比は共に実施例１と同じとし・ た。Comparative Examples 1 to 2 In Comparative Example 1, the rainfall outer layer was made of crystalline bolide a of 119.0.
M made of pyrene resin and using the core layer as the core layer of Example 2
In Comparative Example 2, the rainfall outer layer is M
Io, 5 crystalline polypropylene resin, and the core layer was used as the core layer of Example 1. A multilayer unstretched original fabric having EMMA No. 8 was formed into a film in the same manner as in Example 1. The melting points of each crystalline polypropylene resin and EMrVL met the specifications of the present invention. In addition, the total thickness of the obtained multilayer unstretched original fabric, and
The thickness ratio of each layer was the same as in Example 1.
この多層未延伸原反を用いて、実施６す１と同様、従来
のインフレーション方式：こよって二軸延伸を試みた。Using this multilayer unstretched original fabric, as in Example 6-1, conventional inflation method: Biaxial stretching was attempted.
しかし、比較例１に於いては、局部延伸がひどく、固自
精度が悪くなるばかりか、延伸安定性ζご劣ろものであ
った。又、比較例２に於いては、延伸応力が強く、延伸
バブルの破裂を生し易かった。However, in Comparative Example 1, the local stretching was severe and not only the self-adhesive precision was poor, but also the stretching stability was inferior to ζ. Furthermore, in Comparative Example 2, the stretching stress was strong and the stretching bubbles were likely to burst.
比較例 ３〜４
比較例３では、雨量外層をＭ Ｉ が５．５の結晶性
ポリプロピレン系樹脂とし、芯層を実施例１で使用した
Ｍｌ が０． ８のＥＭＭＡとし、比較例４ては、雨
量外層をき４１ が１．５の結晶性ポリプロピレン系
樹脂とし、芯層を実在例２て使用したＭｌ が４．５
のＥＭＭ−１！Ｘとする多層未延伸原反の製膜を実施Ｉ
ＷＩ＋ １と同様の方法によって試みた。尚、それぞれ
の結晶性ポリプロピレン系樹脂やＥＭＭＡの融点は本発
明の規定に合致するものであった。又、多層未延伸原反
の全体厚み、及び、各層の厚み構成比についても実施例
１と同じとした。Comparative Examples 3 to 4 In Comparative Example 3, the rainfall outer layer was made of a crystalline polypropylene resin with an M I of 5.5, and the core layer was made of a crystalline polypropylene resin having an M I of 0.5 as used in Example 1. In Comparative Example 4, the outer layer was made of a crystalline polypropylene resin with a 41 of 1.5, and the core layer was made of a crystalline polypropylene resin with an Ml of 4.5 in Example 2.
EMM-1! Film formation of multilayer unstretched original fabric designated as X was carried out I
An attempt was made in the same manner as WI+1. The melting points of each crystalline polypropylene resin and EMMA met the specifications of the present invention. Furthermore, the overall thickness of the multilayer unstretched original fabric and the thickness composition ratio of each layer were also the same as in Example 1.
しかし、これらは全て良好なる多層未延伸原反を得るこ
とか出来なかった。即ち、比較例３に於いては、共押出
された未延伸原反の地合が悪く、透明性に劣るものであ
った。又、比較例４に於いては、多層サーキュラ−ダイ
から共押出された多層未延伸原反表面に、極少部ではあ
るが、数カ所樹脂の流れ方向に沿って連続的な凹凸を生
じてしまい、延伸原反としては不適当てあった。However, none of these methods could provide a good multilayer unstretched fabric. That is, in Comparative Example 3, the coextruded unstretched original fabric had poor texture and poor transparency. In addition, in Comparative Example 4, continuous irregularities were generated in several places along the flow direction of the resin on the surface of the multilayer unstretched fabric coextruded from the multilayer circular die, albeit in very small areas. It was unsuitable for use as a stretched original fabric.
比較例５
雨量外層には実施例１と同じ結晶性ポリプロピレン系樹
脂を、芯層には融点９７°Ｃ，きＴ１１．０のＥＶＡを
使用し、実施例１と同じ方法によって多層未延伸原反の
試作を行った。しかし、適性な押出温度範囲が非常に狭
く、良好なる多層未延伸原反を得ることが困難であった
。Comparative Example 5 The same crystalline polypropylene resin as in Example 1 was used for the outer layer, and EVA with a melting point of 97°C and T of 11.0 was used for the core layer, and a multilayer unstretched original fabric was prepared in the same manner as in Example 1. We made a prototype. However, the suitable extrusion temperature range is very narrow, making it difficult to obtain a good multilayer unstretched original fabric.
更に、この未延伸原反を用いて、実在例１と同じ方法に
よって延伸処理されて得られたシュリンクフィルム；よ
、熱収縮包装時での溶断シールに於いて酢酸臭を生じる
ばかりか、得られた熱収縮包装体にも酢酸臭があり、食
品包装等には適しないものであった。Furthermore, a shrink film obtained by stretching this unstretched original fabric in the same manner as in Example 1; not only did it produce an acetic acid odor in the melt-cut seal during heat-shrink packaging, but it also produced a shrink film. The heat-shrinkable packaging also had an acetic acid odor, making it unsuitable for food packaging, etc.
Claims (1)
インデックスが１〜７の結晶性ポリプロピレン系樹脂か
らなり、芯層が融点９０〜１０２℃で、メルトフローイ
ンデックスが両最外層に用いられている結晶性ポリプロ
ピレン系樹脂のメルトフローインデックスの１／３〜２
倍のエチレンとメチルメタクリレートとの共重合体から
なる共押出された多層未延伸原反を延伸処理されてなる
ポリプロピレン系多層シュリンクフィルム。 ２）両最外層に用いられている結晶性ポリプロピレン系
樹脂が、エチレン−プロピレン共重合体、或は、エチレ
ン−プロピレン−プテン共重合体からなることを特徴と
する特許請求の範囲第１項記載のポリプロピレン系多層
シュリンクフィルム。[Claims] 1) Both outermost layers are made of a crystalline polypropylene resin with a melting point of 135 to 150°C and a melt flow index of 1 to 7, and the core layer is made of a crystalline polypropylene resin with a melting point of 90 to 102°C and a melt flow index of 1 to 7. 1/3 to 2 of the melt flow index of the crystalline polypropylene resin used in the outermost layer
A polypropylene multilayer shrink film made by stretching a coextruded multilayer unstretched original film made of a copolymer of ethylene and methyl methacrylate. 2) Claim 1, characterized in that the crystalline polypropylene resin used in both outermost layers is composed of an ethylene-propylene copolymer or an ethylene-propylene-putene copolymer. polypropylene multilayer shrink film.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15001189A JP2750610B2 (en) | 1989-06-12 | 1989-06-12 | Polypropylene multilayer shrink film |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15001189A JP2750610B2 (en) | 1989-06-12 | 1989-06-12 | Polypropylene multilayer shrink film |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0313338A true JPH0313338A (en) | 1991-01-22 |
| JP2750610B2 JP2750610B2 (en) | 1998-05-13 |
Family
ID=15487528
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15001189A Expired - Fee Related JP2750610B2 (en) | 1989-06-12 | 1989-06-12 | Polypropylene multilayer shrink film |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2750610B2 (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11333998A (en) * | 1998-05-29 | 1999-12-07 | Achilles Corp | Multilayered film or sheet made of olefinic resin |
| WO2013010639A1 (en) * | 2011-07-20 | 2013-01-24 | Huhtamaki Films Germany Gmbh & Co. Kg | A multilayer film with high tear propagation resistance and low shrinkage |
| CN102950858A (en) * | 2012-11-14 | 2013-03-06 | 海南赛诺实业有限公司 | Heat-seal two-way-stretch polypropylene aluminized-based film and manufacturing method thereof |
| US10232594B2 (en) * | 2013-07-12 | 2019-03-19 | Upm Raflatac Oy | Multilayer film for label and a method for providing such |
| US10239294B2 (en) | 2013-07-12 | 2019-03-26 | Upm Raflatac Oy | Heat shrink label film, a heat shrink label and a method for labelling of an item |
| US10406786B2 (en) | 2013-07-12 | 2019-09-10 | Upm Raflatac Oy | Multilayer film for label and a method for providing such |
| US10556410B2 (en) | 2013-07-12 | 2020-02-11 | Upm Raflatac Oy | Multilayer film for label and a method for providing such |
-
1989
- 1989-06-12 JP JP15001189A patent/JP2750610B2/en not_active Expired - Fee Related
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11333998A (en) * | 1998-05-29 | 1999-12-07 | Achilles Corp | Multilayered film or sheet made of olefinic resin |
| WO2013010639A1 (en) * | 2011-07-20 | 2013-01-24 | Huhtamaki Films Germany Gmbh & Co. Kg | A multilayer film with high tear propagation resistance and low shrinkage |
| US9951253B2 (en) | 2011-07-20 | 2018-04-24 | Infiana Germany Gmbh & Co., Kg | Multilayer film with high tear propagation resistance and low shrinkage |
| CN102950858A (en) * | 2012-11-14 | 2013-03-06 | 海南赛诺实业有限公司 | Heat-seal two-way-stretch polypropylene aluminized-based film and manufacturing method thereof |
| US10232594B2 (en) * | 2013-07-12 | 2019-03-19 | Upm Raflatac Oy | Multilayer film for label and a method for providing such |
| US10239294B2 (en) | 2013-07-12 | 2019-03-26 | Upm Raflatac Oy | Heat shrink label film, a heat shrink label and a method for labelling of an item |
| US10406786B2 (en) | 2013-07-12 | 2019-09-10 | Upm Raflatac Oy | Multilayer film for label and a method for providing such |
| US10556410B2 (en) | 2013-07-12 | 2020-02-11 | Upm Raflatac Oy | Multilayer film for label and a method for providing such |
| US11541646B2 (en) | 2013-07-12 | 2023-01-03 | Upm Raflatac Oy | Multilayer film for label and a method for providing such |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2750610B2 (en) | 1998-05-13 |
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| R250 | Receipt of annual fees |
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