易引裂き性フィルムおよびその製造方法

Easy tearing film and production thereof

Abstract

(57)【要約】 【目的】 非相溶性の樹脂組成物を押出し成形し、厚み むらがなく表面円滑性及び均一性の高い易引裂き性フィ ルムを得る。 【構成】 ポリプロピレンなどのプロピレン系ポリマー (A)と、ポリスチレンなどのスチレン系重合体(B) を前者(A)/後者(B)=50/50〜98/2(重 量比)の割合で含む樹脂組成物を押出し成形する。その 際、230℃、荷重2.16kgでのプロピレン系ポリ マー(A)のメルトインデックスMI A (g/10分) と、200℃、荷重5kgでのスチレン系重合体(B) のメルトインデックスをMI B (g/10分)との比の 常用対数値[log(MI A /MI B )]をXとし、ダ イリップにおける剪断速度r(秒 -1 )とするとき、延伸 することなく、下記の条件で押出し成形する。 (1)X≧0のとき、r≧(160−135X) (2)X<のとき、r≧(160−63X)
PURPOSE: To obtain an easy tearing film free from thickness irregularity and high in surface smoothness and uniformity by subjecting a non-compatible resin compsn. to extrusion molding. CONSTITUTION: A resin compsn. containing a propylene type polymer (A) such as polypropylene and a styrenic polymer (B) such as polystyrene in an A/B wt. ratio of 50/50-98/2 is subjected to extrusion molding. At this time, when the common logarithm value [log (MIA/MIB) of the ratio of the melt index MIA (g/10min) of the propylene type polymer at 230°C under load of 2.16kg and the melt index MIB (g/10min) of the styrenic polymer at 200°C under load of 5kg is X and the shearing speed at a die lip is r (sec -1 ), the resin compsn. is subjected to extrusion molding under conditions such that r is r≥(160-l35X) (1) when S is X≥0 and r is r≥(160--63X) (2) at the time of X<0 without being stretched. COPYRIGHT: (C)1995,JPO

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Cited By (3)

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    US-8522978-B2September 03, 2013Cryovac, Inc.Stress concentrator for opening a flexible container
    WO-2009139897-A1November 19, 2009Cryovac, Inc.Article d'emballage à ouverture facile réalisé à l'aide d'un film thermorétractable présentant une déchirure directionnelle
    WO-2010059887-A1May 27, 2010Cryovac, Inc.Easy opening packaging article made from heat-shrinkable film exhibiting directional tear