Multi-Layer Structure and Method of Producing the Same

Abstract

A multi-layer structure comprising a functional resin layer obtained by covering a core layer of a base body resin or a second functional resin with a shell layer of a first functional resin, and a base body resin layer containing the functional resin layer therein. The layers of the functional resins are formed at positions where they are allowed to exhibit their functions to a sufficient degree, a plurality of functions can be imparted, and a molten resin mass having the above multi-layer structure can be formed by the compression-forming.

1 . A multi-layer structure having a base body resin layer of a thermoplastic resin and a functional resin layer of a functional resin, wherein said functional resin layer comprises a core layer of the base body resin or a second functional resin covered with a shell layer of a first functional resin, and said base body resin layer wraps the functional resin layer therein.  
   
   
       2 . A multi-layer structure according to  claim 1 , wherein said multi-layer structure is a container closure comprising a top panel and a skirt portion hanging down from the peripheral edge of the top panel, and at least the top panel is formed in said multi-layer structure.  
   
   
       3 . A container closure according to  claim 2 , wherein a sealing member is formed on the inner surface of the top panel, the sealing member having a layer of a functional resin different from the functional resin used for the container closure.  
   
   
       4 . A multi-layer structure according to  claim 1 , wherein said multi-layer structure is a preform including a mouth portion, a body wall and a bottom portion, and at least the body wall and the bottom portion are formed in the multi-layer structure.  
   
   
       5 . A multi-layer structure according to  claim 1 , wherein said functional resin is any one of a gas-barrier resin, an oxygen-absorbing resin, a cyclic olefin resin or a liquid crystal polymer.  
   
   
       6 . A method of producing a multi-layer structure by press-forming a molten resin mass of a thermoplastic resin and a functional resin, wherein said molten resin mass is the one that wraps therein a functional resin mass which comprises a core layer of a base body resin or a second functional resin covered with a shell layer of a first functional resin.  
   
   
       7 . A method of producing a multi-layer structure according to  claim 6 , wherein said multi-layer structure is a container closure comprising a top panel and a skirt portion hanging down from the peripheral edge of the top panel, and after the container closure is formed by compression-forming said molten resin mass, a sealing member is formed on the inner surface of the top panel by feeding and compressing a molten resin mass containing therein a functional resin different from the functional resin used for said molten resin mass.  
   
   
       8 . A method of producing a multi-layer structure according to  claim 6 , wherein said functional resin is any one of a gas-barrier resin, an oxygen-absorbing resin, a cyclic olefin resin or a liquid crystal polymer.