Pliable plastic film and container using the same

Abstract

A pliable plastic film according to the present invention comprises a heat sealable sealing layer, wherein the sealing layer is made of a mixture of a propylene-α-olefin random copolymer having a crystalline melting point Tm of 135 to 145° C. and a polypropylene (PP) homopolymer having a crystalline melting point Tm of higher than 160° C.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to a pliable plastic film which can maintain a function of an easily releasable sealed portion even after a sterilization treatment at a high temperature of higher than 120° C., and a container using the same.[0003]2. Description of the Related Art[0004]Recently, a multichamber container, which separately contains a plurality of components and is capable of mixing the components in the container when used, is used in the medical field such as infusion solution bag.[0005]The multichamber container comprises a plastic container having pliability, and a plurality of chambers which are partitioned with a so-called easily releasable sealed portion, and the seal strength of the easily releasable sealed portion is adjusted so that the easily releasable sealed portion is released when a pressure is applied by pressing the chamber.[0006]The easily releasable sealed portion is usually formed by heat ...

AI Technical Summary

Benefits of technology

[0011]Thus, an object of the present invention is to provide a pliable plastic film which is excellent in heat resistance and has a wide allowable range of a heat sealing temperature at which an easily releasable seal can be formed, and to provide a container using the same.

[0029]According to the pliable plastic film of the present invention, when a container such as infusion solution bag is formed, the resulting container can be excellent in heat resistance. Even if a container provided with the easily releasable sealed portion is formed using the pliable plastic film of the present invention and this container is subjected to, for example, a sterilization treatment at a high temperature of 120° C. or higher, easy releasability of an easily releasable seal does not deteriorate. Moreover, when the easily releasable sealed portion is formed using the pliable plastic film of the present invention, it is possible to obtain a temperature range (allowable range), which is significant for industrial production, of a heat sealing temperature at which the easily releasable sealed portion is formed.

[0030]Therefore, the pliable plastic film of the present invention and the container using the same are useful in a medical container which requires a steam sterilization treatment at a high temperature, particularly a multichamber container having an easily releasable seal.

Problems solved by technology

However, like the above medical container, even if the innermost layer of the container is formed of a mixture of two kinds of polypropylenes having different crystalline melting points Tm, when the crystalline melting point Tm of polypropylene having a higher crystalline melting point Tm is 160° C. or lower, there is such a problem that an allowable range of a heat sealing temperature, at which an easily releasable seal can be formed, becomes very narrow as 1° C., as is apparent from Examples described later.

Therefore, there is a problem that it becomes necessary to strictly control the heat sealing temperature to form an easily releasable seal and production processes become complicated.

Further, there is a problem that easy releasability of the easily releasable seal deteriorates by a slight change of the heat sealing temperature and therefore the yield of the product decreases.

Moreover, the above medical container is not sufficient in heat resistance and blocking may occur by carrying out a sterilization treatment at a high temperature.

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