JPH0339827B2 - - Google Patents
Info
- Publication number
- JPH0339827B2 JPH0339827B2 JP2192206A JP19220690A JPH0339827B2 JP H0339827 B2 JPH0339827 B2 JP H0339827B2 JP 2192206 A JP2192206 A JP 2192206A JP 19220690 A JP19220690 A JP 19220690A JP H0339827 B2 JPH0339827 B2 JP H0339827B2
- Authority
- JP
- Japan
- Prior art keywords
- film
- ethylene
- weight
- vinyl acetate
- foamed
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 239000005038 ethylene vinyl acetate Substances 0.000 claims description 14
- 229920001200 poly(ethylene-vinyl acetate) Polymers 0.000 claims description 14
- 239000004604 Blowing Agent Substances 0.000 claims description 13
- 239000002344 surface layer Substances 0.000 claims description 13
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 claims description 12
- 239000005977 Ethylene Substances 0.000 claims description 12
- 239000002131 composite material Substances 0.000 claims description 12
- 229920005674 ethylene-propylene random copolymer Polymers 0.000 claims description 12
- 239000000203 mixture Substances 0.000 claims description 12
- XTXRWKRVRITETP-UHFFFAOYSA-N Vinyl acetate Chemical compound CC(=O)OC=C XTXRWKRVRITETP-UHFFFAOYSA-N 0.000 claims description 8
- 229920000098 polyolefin Polymers 0.000 claims description 5
- 238000010030 laminating Methods 0.000 claims description 3
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 claims description 2
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 claims description 2
- 229920005604 random copolymer Polymers 0.000 claims description 2
- 239000002654 heat shrinkable material Substances 0.000 claims 1
- 239000010410 layer Substances 0.000 description 11
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 description 9
- 238000001125 extrusion Methods 0.000 description 8
- 230000000694 effects Effects 0.000 description 7
- UIIMBOGNXHQVGW-UHFFFAOYSA-M Sodium bicarbonate Chemical compound [Na+].OC([O-])=O UIIMBOGNXHQVGW-UHFFFAOYSA-M 0.000 description 6
- 229920001577 copolymer Polymers 0.000 description 6
- 239000006260 foam Substances 0.000 description 6
- 238000000034 method Methods 0.000 description 6
- 239000000463 material Substances 0.000 description 5
- 230000000704 physical effect Effects 0.000 description 5
- OFBQJSOFQDEBGM-UHFFFAOYSA-N Pentane Chemical compound CCCCC OFBQJSOFQDEBGM-UHFFFAOYSA-N 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 239000006261 foam material Substances 0.000 description 3
- 238000005187 foaming Methods 0.000 description 3
- 229920000642 polymer Polymers 0.000 description 3
- 229910000030 sodium bicarbonate Inorganic materials 0.000 description 3
- 235000017557 sodium bicarbonate Nutrition 0.000 description 3
- 229920001169 thermoplastic Polymers 0.000 description 3
- 239000004416 thermosoftening plastic Substances 0.000 description 3
- OZAIFHULBGXAKX-UHFFFAOYSA-N 2-(2-cyanopropan-2-yldiazenyl)-2-methylpropanenitrile Chemical compound N#CC(C)(C)N=NC(C)(C)C#N OZAIFHULBGXAKX-UHFFFAOYSA-N 0.000 description 2
- ATRRKUHOCOJYRX-UHFFFAOYSA-N Ammonium bicarbonate Chemical compound [NH4+].OC([O-])=O ATRRKUHOCOJYRX-UHFFFAOYSA-N 0.000 description 2
- OAKJQQAXSVQMHS-UHFFFAOYSA-N Hydrazine Chemical compound NN OAKJQQAXSVQMHS-UHFFFAOYSA-N 0.000 description 2
- 239000004743 Polypropylene Substances 0.000 description 2
- 239000004793 Polystyrene Substances 0.000 description 2
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 2
- 239000000654 additive Substances 0.000 description 2
- 239000002216 antistatic agent Substances 0.000 description 2
- 210000004027 cell Anatomy 0.000 description 2
- 239000000945 filler Substances 0.000 description 2
- 239000004088 foaming agent Substances 0.000 description 2
- 239000004615 ingredient Substances 0.000 description 2
- 239000000314 lubricant Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000008188 pellet Substances 0.000 description 2
- 239000000049 pigment Substances 0.000 description 2
- -1 polypropylene Polymers 0.000 description 2
- 229920001155 polypropylene Polymers 0.000 description 2
- 229920002223 polystyrene Polymers 0.000 description 2
- 239000011253 protective coating Substances 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 239000004156 Azodicarbonamide Substances 0.000 description 1
- FEWJPZIEWOKRBE-JCYAYHJZSA-N Dextrotartaric acid Chemical compound OC(=O)[C@H](O)[C@@H](O)C(O)=O FEWJPZIEWOKRBE-JCYAYHJZSA-N 0.000 description 1
- FEWJPZIEWOKRBE-UHFFFAOYSA-N Tartaric acid Natural products [H+].[H+].[O-]C(=O)C(O)C(O)C([O-])=O FEWJPZIEWOKRBE-UHFFFAOYSA-N 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 239000001099 ammonium carbonate Substances 0.000 description 1
- 235000012501 ammonium carbonate Nutrition 0.000 description 1
- XOZUGNYVDXMRKW-AATRIKPKSA-N azodicarbonamide Chemical compound NC(=O)\N=N\C(N)=O XOZUGNYVDXMRKW-AATRIKPKSA-N 0.000 description 1
- 235000019399 azodicarbonamide Nutrition 0.000 description 1
- 230000003139 buffering effect Effects 0.000 description 1
- 239000001273 butane Substances 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 238000004040 coloring Methods 0.000 description 1
- 238000003851 corona treatment Methods 0.000 description 1
- 229920006248 expandable polystyrene Polymers 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 210000000497 foam cell Anatomy 0.000 description 1
- 230000004927 fusion Effects 0.000 description 1
- 229910010272 inorganic material Inorganic materials 0.000 description 1
- 239000011147 inorganic material Substances 0.000 description 1
- 238000004898 kneading Methods 0.000 description 1
- 229920001684 low density polyethylene Polymers 0.000 description 1
- 239000004702 low-density polyethylene Substances 0.000 description 1
- IJDNQMDRQITEOD-UHFFFAOYSA-N n-butane Chemical compound CCCC IJDNQMDRQITEOD-UHFFFAOYSA-N 0.000 description 1
- 150000007524 organic acids Chemical class 0.000 description 1
- 235000005985 organic acids Nutrition 0.000 description 1
- 239000005022 packaging material Substances 0.000 description 1
- 229920006327 polystyrene foam Polymers 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 229920006300 shrink film Polymers 0.000 description 1
- 229910000029 sodium carbonate Inorganic materials 0.000 description 1
- 238000004381 surface treatment Methods 0.000 description 1
- 235000002906 tartaric acid Nutrition 0.000 description 1
- 239000011975 tartaric acid Substances 0.000 description 1
- 229920005992 thermoplastic resin Polymers 0.000 description 1
Landscapes
- Laminated Bodies (AREA)
Description
（産業上の利用分野）
本発明は緩衝効果等の優れた横方向に熱収縮性
を有するポリオレフイン系複合発泡フイルムに関
する。
（従来の技術）
従来、熱収縮性を有する発泡フイルム（シー
ト）は、その原料をポリスチレンを使用したもの
が主流をしめ、特にこれがビン等の容器類の外装
に用いることにより、破ビン防止効果と緩衝効果
を発揮するので有用な包装材料として周知であ
る。
ところが、前記ポリスチレンからなる熱収縮性
を有する発泡フイルムは、その原料の特性から衝
撃に弱く脆いものであり、例えばビン等のラベル
用として装着しても、その洗浄工程や充填工程、
更には輸送中に発泡フイルムが破損するという欠
点があり、又同フイルム表面に印刷を施こしても
鮮明に表出できず、その上発泡フイルムが端縁か
ら層状になつて部分的に剥離する等の現象がみら
れた。
更に発泡ポリスチレン材は延伸の際、その脆さ
が原因でテンター等により横方向の延伸がしにく
く、比較的延伸を行い易いロール延伸等による縦
延伸が主流であるため、例えばこのフイルムをビ
ン等の外装として使用する際、自動機への適応が
制限され、従前の横延伸フイルム用（例えば
PVC用）自動機には適応できず、新たに縦延伸
フイルム用自動機を準備せねばならないことも孝
えられ、又使用面でも、例えばビンに複覆して熱
収縮させビンに密着させる筒状体を作成する工程
が、横延伸材に比しどうしても煩雑化する等の問
題点もあつた。
一方、上記の発泡ポリスチレン収縮フイルム以
外に、ビン等の保護被覆のためのフイルム材料に
ポリプロピレン等のポリオレフイン系発泡材を使
用されることが特公昭56−18371号として知られ
ている。
（発明が解決しようとする課題）
ところが、前記特公昭56−18371号には、ビン
等の保護被覆のためのフイルム材料にポリオレフ
イン系発泡材料が使用されるという単なる例示に
止まり、依然として発泡ポリスチレン収縮フイル
ムが主流として用いられ、既述の諸問題を有して
いた。
本発明は、上記問題点に鑑み、破ビン防止効果
に優れ、また強度等の諸物性にも優れ、特に印刷
性に優れたポリオレフイン系複合発泡フイルムを
提供することを目的とする。
（課題を解決するための手段）
本発明は上記の目的を達成するため、エチレン
含有量が１〜10モル％のエチレン−プロピレンラ
ンダム共重合体50〜95重量％と、酢酸ビニル含有
量３〜40重量％のエチレン−酢酸ビニル共重合体
５〜50重量％、及び発泡剤とを配合した組成物か
らなる横方向に熱収縮性を有する発泡フイルム
と、
エチレン含有量１〜10モル％のエチレン−プロ
ピレンランダム共重合体および／または酢酸ビニ
ル含有量３〜40重量％のエチレン酢酸ビニル共重
合体からなる横方向に熱収縮性を有する表層フイ
ルムとが積層一体化してなる構成を採用した。
（実施例）
以下、本発明の実施例を説明する。
本発明の発泡フイルムを構成するエチレン−プ
ロピレンランダム共重合体は、通常エチレン含有
量１〜10モル％、好ましくは２〜６モル％のもの
で、このさい10モル％を越える製造された発泡フ
イルムがべたついてブロツキングを起し易くなつ
て好ましくなく、また１モル％未満ではその性質
がポリプロピレンに近づき、従つて延伸しても収
縮率が小さく、熱収縮性部材として不満足である
上に発泡セルが破れて毛羽立ち現象を起し易くな
る。この際、前記共重合体の使用量は効果の表わ
れる量として重合体全量に対し50〜95重量％が必
要である。
次に本発明の発泡フイルムを構成するエチレン
−酢酸ビニル共重合体は、発泡材料の発泡セルに
弾性を付与するために添加するもので、この共重
合体を添加しない場合は発泡の際の内部圧力に耐
えられず発泡セルが膨張し易くなるので微細な発
泡構造のものが得られない。
前記共重合体は酢酸ビニル含有量３〜40重量％
のエチレン−酢酸ビニル共重合体である。この
際、エチレン−酢酸ビニル共重合体の使用量はそ
の効果が表われる量として重合体全量に対し５〜
50重量％が必要である。
又本発明の発泡フイルムを構成する発泡剤は、
公知のものであれば如何なるものでも良く、適応
可能な発泡剤としてその種類を例示すると、揮発
性のものとしてペンタン、ブタン等、有機系のも
のとしてヒドラジン系、ニトソン系、アゾ系等
が、又無機系のものとして重炭酸ソーダ、炭酸ア
ンモニア等がある。この際より好ましい例として
は前記アゾ系発泡剤ではアゾジカルボンアミド、
アゾビスイソブチロニトリル等、無機系発泡剤で
は重炭酸ナトリウム、炭酸アンモン等の炭酸塩と
クエン酸、酒石酸等の有機酸とからなるものをあ
げることができる。なおこの発泡剤の使用量は少
なくともその効果が表われる量を加えれば良い
が、特に制限はなく、エチレン含有量１〜10モル
％のエチレン−プロピレンランダム共重合体と、
エチレン−酢酸ビニル共重合体との合計量。（全
重合体量）100重量部に対し、0.2〜５重量部、更
に好ましくは0.5〜２重量部程度を例示できる。
上記発泡剤は本発明に係るエチレン−プロピレン
ランダム共重合体に直接ブレンドしたり、濃度の
高い発泡剤を含むマスターペレツトを加えてブレ
ンドしたり、予じめ前記共重合体中に発泡剤を適
宜量練り込んで用いたりすればよく、その用法に
は特に制限はない。
なお、本発明の発泡フイルムを構成する上記３
者からなる成分の他に適宜の添加剤や充填剤等を
加えることもあり、例えば滑剤、帯電防止剤等を
必要に応じ加えて物性の改善を図ることも適宜行
い得、必要ならば顔料を添加することにより希望
する着色も可能である。
次に本発明の表層フイルムを構成する材料は、
エチレン含有量１〜10モル％のエチレン−プロピ
レンランダム共重合体及び酢酸ビニル含有量３〜
40重量％のエチレン−酢酸ビニル共重合体の混合
物若しくは前記各共重合体の単品を用いる。
なお、この表層フイルムは前述の発泡フイルム
と同様に、適宜の添加剤や充填剤等を加えること
もあり、例えば滑剤、帯電防止剤等を必要に応じ
加えて物性の改善を図ることも適宜行に得、必要
ならば顔料を添加することにより希望する着色も
可能である。
本発明の発泡フイルム及び表層フイルムを構成
する組成物は以上のとおりであるが、これら組成
物を使用して、本発明の目的とする表層フイルム
が積層（ラミネート）された複合発泡フイルムを
作成する１例を説明すると次のとおりである。
先ず、エチレン含有量１〜10モル％のエチレン
−プロピレンランダム共重合体と、エチレン−酢
酸ビニル共重合体及び発泡材を配合した組成物を
ダイス内で発泡しない程度に押出成形機の条件設
定を行い、ダイスからフラツトのフイルム状に押
出させる。そしてこの際同時に発泡するようにす
れば好適である。一方では前記発泡フイルムの原
料組成物と同種のエチレン１〜10モル％のエチレ
ン−プロピレンランダム共重合体とエチレン−酢
酸ビニル共重合体とからなる熱可塑性樹脂配合物
を押出すと同時に、前記発泡フイルム上に溶融押
出してラミネートし、熱可塑性フイルムによる表
層フイルム層（ラミネート層）を形成する。
この際、表層フイルムはその押出しの際の熱の
ため簡単なニツプロールにより発泡フイルムと容
易に積層一体化する。次いでテンターにより横方
向に延伸させるが、この延伸により発泡フイルム
と表層フイルムがより強力に接着し、両者はあた
かも一層のフイルムとなり、極めて剥離し難いも
のとなる。次に延伸温度であるが、これは適宜選
択でき、例えば100〜130℃が好ましい。また延伸
倍率は必要に応じその大きさを選定するが２倍以
上、要すれば３〜10倍程度に延伸すればよく、上
記の各数値条件で延伸を行えば好ましい横方向の
熱収縮性を有する表層フイルム層（ラミネート
層）を有する複合発泡フイルムが得られるが、本
発明は勿論これを限定するものでない。このよう
にして複合発泡フイルムが作成されるのであり、
この際、発泡フイルム、表層フイルム（ラミネー
ト層）の厚さは用途に応じて適宜選択すればよ
い。また印刷性の向上を図るため表層フイルムの
表面にコロナ放電処理等の表面処理を施すことも
自由である。
以上は発泡フイルム上に同種の熱可塑性フイル
ムを溶融押出ラミネートする方法であるが、この
他に同種の熱可塑性フイルムを予じめ製膜してお
き、発泡フイルムがダイスから押出し、発泡した
と同時に、該フイルムを発泡フイルム上にニツプ
ロール等により押圧してラミネートしてもよい。
この際発泡フイルム側に押出しの際の熱が残つて
いるため、両者は極めて容易に積層一体化でき
る。また発泡は製膜と同時が好ましいが、製膜前
であつても、製膜後であつても、更に延伸と同時
であつても差し支えないことは勿論である。
以上は、本発明の複合発泡フイルムの製造法と
して、発泡フイルムを押出し製膜し、次いで表層
フイルムを溶融押出してラミネートした後、横延
伸するものを説明したが、発泡フイルムを横延伸
したものに、横延伸した表層フイルムを接着剤を
介し、または熱融着でもつて直接積層（ラミネー
ト）一体化しても良い。なお、表層フイルム側に
装飾印刷を施すと商品価値が上り、この際、前記
印刷は表層フイルムの表面側でも裏面（内面）側
でも良く、特に裏面側に設けた場合は、印刷部分
が接触等により剥落することがなく好ましい。
本発明は全てフイルムという表現を用いたが、
シート状の厚手のものも当然フイルムに包含され
るものである。
以下、本発明の複合発泡フイルムの製造法のよ
り具体的な実施例を説明する。
実施例 １
エチレン含有量4.5モル％のエチレン−プロピ
レンランダム共重合体70重量％に酢酸ビニル含有
量15重量％のエチレン−酢酸ビニル共重合体30重
量％を含む組成物100重量部に対し、重炭酸ナト
リウムとクエン酸の配合物からなる発泡剤１重量
部を配合し、押出成型機のダイスを通してフラツ
トシート状に押出し、発泡させてなる厚さ900μ
の発泡フイルムを作成した。一方、エチレン含有
量4.5モル％のエチレン−プロピレンランダム共
重合体70重量％と、酢酸ビニル含有量15重量％の
エチレン−酢酸ビニル共重合体30重量％からなる
厚さ100μの表層フイルムを押出し、前記の発泡
フイルム上に直接溶融押出しラミネートしたとこ
ろ、両者は表層フイルム押出時の残熱により、か
なり接着されていた。しかる後テンター温度115
℃にて、５倍に横延伸したところ、発泡層180μ、
ラミネート層20μを有する厚さ200μの表層を有す
る複合発泡フイルムを得た。このフイルムの発泡
層と表層は延伸工程で強力に接着しており、横方
向に熱収縮する好ましいものであつた。
実施例 ２
発泡剤として重炭酸ナトリウムとクエン酸を使
用（使用量20重量％）した主成分が抵密度ポリエ
チレンのマスターペレツト５重量部（発泡剤成分
は１重量部）を用いる以外実施例１と同様の組成
物を用い、同様に製膜して厚さ900μのフラツト
状発泡フイルムを得た。しかる後、実施例１と同
様に表層を形成した後、テンターにて温度110〜
120℃で横方向に約５倍に延伸したところ、発泡
層180μ、表層20μの合計厚さ200μである横方向に
熱収縮する複合発泡フイルムを得た。
以上の実施例１，２で得られた複合発泡フイル
ムの各物性を下記第１表に掲げる。
(Industrial Application Field) The present invention relates to a polyolefin composite foamed film that has excellent cushioning effect and heat shrinkability in the lateral direction. (Prior art) Conventionally, heat-shrinkable foamed films (sheets) have mainly been made from polystyrene, and have been particularly effective in preventing bottles from breaking when used for the exterior of containers such as bottles. It is well known as a useful packaging material because it exhibits a buffering effect. However, the heat-shrinkable foamed film made of polystyrene is weak and brittle against impact due to the characteristics of its raw material, and even if it is attached to a label for a bottle, for example, it will be difficult to clean, fill, etc.
Furthermore, there is a disadvantage that the foamed film is damaged during transportation, and even if the surface of the film is printed, it cannot be clearly printed, and furthermore, the foamed film forms a layer from the edges and partially peels off. The following phenomena were observed. Furthermore, when stretching polystyrene foam, it is difficult to stretch it in the transverse direction using a tenter or the like due to its brittleness, and longitudinal stretching using roll stretching or the like, which is relatively easy to do, is the mainstream. When used as an exterior for
It cannot be applied to an automatic machine (for PVC), and it is necessary to prepare a new automatic machine for longitudinally stretched film.Also, in terms of use, for example, the cylindrical shape that is wrapped double over a bottle and heat-shrinked to tightly fit it to the bottle. There were also problems such as the process of creating the body was inevitably more complicated than that for horizontally stretched materials. On the other hand, in addition to the above-mentioned foamed polystyrene shrink film, it is known from Japanese Patent Publication No. 18371/1983 that a polyolefin foam material such as polypropylene is used as a film material for protective coating of bottles and the like. (Problem to be Solved by the Invention) However, the above-mentioned Japanese Patent Publication No. 18371/1983 merely exemplifies the use of polyolefin foam materials as film materials for protective coatings of bottles, etc. Film was the mainstream and had the problems mentioned above. In view of the above-mentioned problems, an object of the present invention is to provide a polyolefin composite foamed film that is excellent in preventing bottle breakage, has excellent physical properties such as strength, and has particularly excellent printability. (Means for Solving the Problems) In order to achieve the above object, the present invention uses an ethylene-propylene random copolymer having an ethylene content of 1 to 10 mol% and a vinyl acetate content of 3 to 95% by weight. A foamed film having heat shrinkability in the transverse direction and made of a composition containing 40% by weight of ethylene-vinyl acetate copolymer (5 to 50% by weight) and a blowing agent, and ethylene having an ethylene content of 1 to 10% by mole. - A structure in which a surface layer film having heat shrinkability in the transverse direction and made of a propylene random copolymer and/or an ethylene vinyl acetate copolymer having a vinyl acetate content of 3 to 40% by weight is laminated and integrated is adopted. (Example) Hereinafter, an example of the present invention will be described. The ethylene-propylene random copolymer constituting the foamed film of the present invention usually has an ethylene content of 1 to 10 mol%, preferably 2 to 6 mol%. If it is less than 1 mol %, its properties will approach that of polypropylene, and therefore the shrinkage rate will be small even when stretched, making it unsatisfactory as a heat-shrinkable member, and the foamed cells will become unfavorable. It tends to tear and cause fuzzing. At this time, the amount of the copolymer used is required to be 50 to 95% by weight based on the total amount of the polymer in order to exhibit the effect. Next, the ethylene-vinyl acetate copolymer constituting the foamed film of the present invention is added to impart elasticity to the foam cells of the foam material, and if this copolymer is not added, the internal Since the foamed cells cannot withstand pressure and tend to expand, a fine foamed structure cannot be obtained. The copolymer has a vinyl acetate content of 3 to 40% by weight.
It is an ethylene-vinyl acetate copolymer. At this time, the amount of ethylene-vinyl acetate copolymer used is 5 to 5 to 50% of the total amount of the polymer to achieve its effect.
50% by weight is required. The foaming agent constituting the foamed film of the present invention is
Any known blowing agent may be used. Examples of suitable blowing agents include volatile ones such as pentane and butane, organic ones such as hydrazine type, Nitson type, and azo type. Inorganic materials include sodium bicarbonate and ammonia carbonate. In this case, more preferable examples of the azo blowing agents include azodicarbonamide,
Examples of inorganic blowing agents such as azobisisobutyronitrile include those consisting of carbonates such as sodium bicarbonate and ammonium carbonate and organic acids such as citric acid and tartaric acid. The amount of this blowing agent to be used is not particularly limited, as long as it is at least in an amount that exhibits its effect.
Total amount including ethylene-vinyl acetate copolymer. (Total polymer amount) 0.2 to 5 parts by weight, more preferably about 0.5 to 2 parts by weight, based on 100 parts by weight.
The above blowing agent may be directly blended into the ethylene-propylene random copolymer of the present invention, blended with a master pellet containing a high concentration blowing agent, or the blowing agent may be added to the copolymer in advance. It may be used by kneading an appropriate amount, and there are no particular restrictions on its usage. In addition, the above-mentioned 3 constituting the foamed film of the present invention
Appropriate additives and fillers may also be added in addition to the ingredients consisting of the above ingredients. For example, lubricants, antistatic agents, etc. may be added as necessary to improve the physical properties, and if necessary, pigments may be added. Desired coloring can also be achieved by adding them. Next, the materials constituting the surface film of the present invention are:
Ethylene-propylene random copolymer with an ethylene content of 1 to 10 mol% and a vinyl acetate content of 3 to 10 mol%
A mixture of 40% by weight of ethylene-vinyl acetate copolymer or a single product of each of the above copolymers is used. In addition, similar to the above-mentioned foamed film, this surface layer film may contain appropriate additives, fillers, etc., and for example, lubricants, antistatic agents, etc. may be added as necessary to improve the physical properties. It is also possible to obtain the desired coloration by adding pigments, if necessary. The compositions constituting the foamed film and surface film of the present invention are as described above, and these compositions are used to create a composite foamed film in which the surface film is laminated, which is the object of the present invention. An example will be explained as follows. First, the conditions of the extrusion molding machine were set to such an extent that a composition containing an ethylene-propylene random copolymer with an ethylene content of 1 to 10 mol%, an ethylene-vinyl acetate copolymer, and a foaming material would not foam in the die. and extrude it into a flat film from a die. At this time, it is preferable to foam at the same time. On the other hand, at the same time as extruding a thermoplastic resin mixture consisting of an ethylene-propylene random copolymer and an ethylene-vinyl acetate copolymer containing 1 to 10 mol% of the same ethylene as the raw material composition of the foamed film, the foamed film is It is melt-extruded and laminated onto a film to form a surface film layer (laminate layer) of thermoplastic film. At this time, the surface film is easily laminated and integrated with the foamed film using a simple nip roll due to the heat generated during extrusion. Next, the foamed film and the surface layer film are stretched in the transverse direction using a tenter, and as a result of this stretching, the foamed film and the surface film become more strongly bonded, and the two become as if they were one layer of film, making it extremely difficult to separate them. Next, the stretching temperature can be selected as appropriate, and is preferably 100 to 130°C, for example. In addition, the stretching ratio should be selected according to need, but it should be 2 times or more, if necessary, about 3 to 10 times.If stretching is carried out under the above numerical conditions, the desired lateral heat shrinkability can be achieved. Although a composite foamed film having a surface film layer (laminate layer) having the following properties is obtained, the present invention is of course not limited to this. This is how a composite foam film is created.
At this time, the thickness of the foamed film and the surface film (laminate layer) may be appropriately selected depending on the application. Furthermore, in order to improve printability, the surface of the surface layer film may be subjected to surface treatment such as corona discharge treatment. The above is a method of laminating the same type of thermoplastic film on a foamed film by melt extrusion, but in addition to this method, the same type of thermoplastic film is formed in advance, and the foamed film is extruded from a die and foamed at the same time. Alternatively, the film may be laminated onto a foamed film by pressing it with a nip roll or the like.
At this time, since the heat from extrusion remains on the foamed film side, the two can be laminated and integrated extremely easily. Further, although it is preferable that the foaming be carried out at the same time as the film formation, it is of course possible to perform the foaming before the film formation, after the film formation, or even at the same time as the stretching. The method for manufacturing the composite foamed film of the present invention has been described above, in which the foamed film is formed by extrusion, the surface layer film is then melt-extruded, laminated, and then laterally stretched. Alternatively, the transversely stretched surface film may be directly laminated into one body using an adhesive or heat fusion. In addition, if decorative printing is applied to the surface layer film side, the commercial value increases, and in this case, the printing may be on the front side or the back (inner surface) side of the surface layer film, and especially if it is provided on the back side, the printed part will not come into contact with the other side. This is preferable because it does not peel off. Although the present invention uses the expression “film”,
Of course, thick sheets are also included in films. Hereinafter, more specific examples of the method for manufacturing a composite foamed film of the present invention will be described. Example 1 For 100 parts by weight of a composition containing 70% by weight of an ethylene-propylene random copolymer with an ethylene content of 4.5% by weight and 30% by weight of an ethylene-vinyl acetate copolymer with a vinyl acetate content of 15% by weight, Add 1 part by weight of a foaming agent consisting of a mixture of sodium carbonate and citric acid, extrude it through the die of an extrusion molding machine into a flat sheet, and foam to a thickness of 900 μm.
foamed film was created. On the other hand, a 100μ thick surface film was extruded, consisting of 70% by weight of an ethylene-propylene random copolymer with an ethylene content of 4.5 mol% and 30% by weight of an ethylene-vinyl acetate copolymer with a vinyl acetate content of 15% by weight. When laminated directly onto the foamed film by melt extrusion, the two were significantly adhered due to residual heat from extrusion of the surface film. Then tenter temperature 115
When horizontally stretched 5 times at ℃, the foam layer was 180μ,
A composite foamed film was obtained having a surface layer 200μ thick with a laminate layer of 20μ. The foamed layer and surface layer of this film were strongly bonded during the stretching process, and the film had a favorable property of being heat-shrinkable in the transverse direction. Example 2 Example 1 except that 5 parts by weight of master pellets whose main component was low density polyethylene (the blowing agent component was 1 part by weight) using sodium bicarbonate and citric acid as blowing agents (amount used: 20% by weight) A flat foamed film with a thickness of 900 μm was obtained by forming a film in the same manner using the same composition as above. After that, a surface layer was formed in the same manner as in Example 1, and then heated to a temperature of 110~110°C using a tenter.
When the film was stretched approximately 5 times in the transverse direction at 120° C., a composite foamed film which was heat-shrinkable in the transverse direction and had a total thickness of 200 μm, including a foam layer of 180 μm and a surface layer of 20 μm, was obtained. The physical properties of the composite foamed films obtained in Examples 1 and 2 are listed in Table 1 below.
【表】
（発明の効果）
本発明は、特定のエチレン−プロピレンランダ
ム共重合体の特定量と、特定のエチレン−酢酸ビ
ニル共重合体の特定量、及び発泡剤を配合した組
成物からなる横方向に熱収縮性を有する発泡フイ
ルムと、前記特定のエチレン−プロピレンランダ
ム共重合体および／または前記特定のエチレン−
酢酸ビニル共重合体からなる同じく横方向に熱収
縮性を有する表層フイルムとが積層一体化してな
る複合発泡フイルムであるから、破ビン防止効果
に優れ、また第１表に示す如く強度等の諸物性に
優れ、特に印刷にさいし発泡フイルムに直接印刷
するものでなく表層フイルム側に印刷するもので
あるから、平滑で印刷性に優れたものが得られる
という顕著な効果を奏するものである。[Table] (Effects of the Invention) The present invention provides a horizontal composition comprising a specific amount of a specific ethylene-propylene random copolymer, a specific amount of a specific ethylene-vinyl acetate copolymer, and a blowing agent. a foamed film having heat shrinkability in the direction; and the specific ethylene-propylene random copolymer and/or the specific ethylene-propylene random copolymer.
Since it is a composite foamed film formed by laminating and integrating a surface layer film made of vinyl acetate copolymer that also has heat shrinkability in the lateral direction, it has excellent effects on preventing bottle breakage, and has excellent strength and other properties as shown in Table 1. It has excellent physical properties, and in particular, since it is printed on the surface film side rather than directly on the foamed film, it has the remarkable effect of producing a smooth product with excellent printability.
Claims (1)
プロピレンランダム共重合体50〜95重量％と、酢
酸ビニル含有量３〜40重量％のエチレン−酢酸ビ
ニル共重合体５〜50重量％、及び発泡剤とを配合
した組成物からなる横方向に熱収縮性を有する発
泡フイルムと、 エチレン含有量１〜10モル％のエチレン−プロ
ピレンランダム共重合体および／または酢酸ビニ
ル含有量３〜40重量％のエチレン酢酸ビニル共重
合体からなる横方向に熱収縮性を有する表層フイ
ルムとが積層一体化してなることを特徴とするポ
リオレフイン系複合発泡フイルム。[Scope of Claims] 1. Ethylene with an ethylene content of 1 to 10 mol%
A composition containing 50 to 95% by weight of a propylene random copolymer, 5 to 50% by weight of an ethylene-vinyl acetate copolymer having a vinyl acetate content of 3 to 40% by weight, and a blowing agent is heated in the lateral direction. A foamed film with shrinkability and a transversely heat-shrinkable material made of an ethylene-propylene random copolymer with an ethylene content of 1 to 10 mol% and/or an ethylene-vinyl acetate copolymer with a vinyl acetate content of 3 to 40% by weight. 1. A polyolefin-based composite foamed film, characterized in that it is formed by laminating and integrating a surface layer film having properties.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2192206A JPH0373334A (en) | 1990-07-19 | 1990-07-19 | Polyolefin-based composite foamed film |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2192206A JPH0373334A (en) | 1990-07-19 | 1990-07-19 | Polyolefin-based composite foamed film |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP57135975A Division JPS5926230A (en) | 1982-08-03 | 1982-08-03 | Polyolefinic expanded sheet or film |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0373334A JPH0373334A (en) | 1991-03-28 |
| JPH0339827B2 true JPH0339827B2 (en) | 1991-06-17 |
Family
ID=16287430
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2192206A Granted JPH0373334A (en) | 1990-07-19 | 1990-07-19 | Polyolefin-based composite foamed film |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0373334A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113308016B (en) * | 2021-05-26 | 2022-03-22 | 无锡德立柯特纳米新材料科技有限公司 | Foaming film based on composite antibacterial nano material and preparation method thereof |
-
1990
- 1990-07-19 JP JP2192206A patent/JPH0373334A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0373334A (en) | 1991-03-28 |
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