MULTILAYER PACKAGING MATERIAL

Abstract

The present invention addresses the problem of providing a packaging material which is configured from a resin species having a low environmental load, and which is improved in terms of the gas barrier properties required for packaging materials and durability of the gas barrier properties, while containing a small amount of a volatile component. The present invention provides a multilayer packaging material which comprises at least one base material film having a resin layer that is mainly composed of a polyolefin resin, an adhesive layer and a heat sealable resin layer, and which is characterized in that: at least one of the base material film is a multilayer gas barrier film having a gas barrier layer; the value (A) of the oxygen transmission rate of a base material film (a), which has the lowest oxygen transmission rate among the multilayer base material film elements, is 30 to 1,500 ml/m2·d·MPa as determined under the conditions of 23°C and 65% RH; the value (P) of the oxygen transmission rate of a multilayer packaging material (p), which is obtained by bonding a base material film and a heat sealable resin, with an adhesive layer being interposed therebetween, is 60 ml/m2·d·MPa or less as determined under the same conditions; and the barrier value improvement ratio between before and after the bonding represented by formula (1) is 10 or more. Formula (1): (Barrier value improvement ratio between before and after film bonding) = (A/P)

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