Packaging bag and method for production thereof

Abstract

A packaging bag, characterized in that it comprises 2 sheets of resin film ( 2,2 ) having innermost layers ( 2 a , 2 a ) made from one or more resins selected from the group consisting of a polyester, a polyamide, a polyacrylonitrile, a polycarbonate, a cyclic polyolefin and a polyfluoroethylene, the 2 sheets of resin film are arranged so that the innermost layers ( 2 a , 2 a ) face each other in the inner sides thereof, and peripheral edge portions of the two resin films ( 2,2 ) are bound to each other via a peripheral edge adhesion section ( 3 ) comprising a thermoplastic resin capable of melting and adhering to the resin films ( 2, 2 ).

1 . A packaging bag comprising two resin films each having the innermost layer formed from at least one resin selected from the group consisting of polyesters, polyamides, polyacrylonitriles, polycarbonates, cyclic polyolefins and polyfluoroethylenes, 
 said two resin films being disposed in such a way that each of the two innermost layers faces each other in the inner sides thereof, and    at least a part of the peripheries of said two resin films adhering to each other by a peripheral adhesion section comprising a thermoplastic resin capable of melt bonding to said resin films:    
     
     
         2 . A packaging bag according to  claim 1 , which has a port.  
     
     
         3 . A packaging bag according to  claim 2 , wherein said port is molded and integrated with said peripheral adhesion section.  
     
     
         4 . A packaging bag according to  claim 2  or  3 , wherein at least a part of said port is inserted between said two films.  
     
     
         5 . A packaging bag according to  claim 2 , wherein at least a part of the port which comes in contact with a content filled therein is formed from the same resin or the same type of resins as that if the innermost layer of said packaging bag.  
     
     
         6 . A packaging bag according to  claim 2 , wherein said port and said resin films, and/or said two resin films are sealed with each other in advance.  
     
     
         7 . A packaging bag according to  claim 1 , wherein said peripheral adhesion section is formed from a thermoplastic resin extruded on the outermost layer and/or the innermost layer of said two resin films.  
     
     
         8 . A packaging bag according to  claim 1  or  2 , wherein the peripheral adhesion section is formed by disposing a peripheral adhesion member previously molded from the thermoplastic resin between said two resin films, and heat pressure bonding them to adhere a part of the peripheries of said two resin films.  
     
     
         9 . A method for producing a packaging bag, comprising the steps of, 
 placing two resin films each having the innermost layer formed from at least one resin selected from the group consisting of polyesters, polyamides, polyacrylonitriles, polycarbonates, cyclic polyolefins and polyfluoroethylenes in such a way that each of the two innermost layers faces each other in the inner sides thereof, and    adhering at least a part of the peripheries said two resin films to each other by a thermoplastic resin capable of melt bonding to said resin films to produce the packaging bag.    
     
     
         10 . A method for producing a packaging bag according to  claim 9 , wherein said thermoplastic resin is extruded on the outermost layer and/or the innermost layer of said two resin films.  
     
     
         11 . A method for producing a packaging bag according to  claim 10 , wherein 
 a port is inserted between said resin films and heat sealing them, and then    said resin films and said port are firmly bonded by supplying the thermoplastic resin to the outermost layers of said resin films of the peripheral portion in which at least the port is set.    
     
     
         12 . A method for producing a packaging bag according to  claim 10  or  11 , wherein 
 at least a part of the two resin films is heat sealed, and then    said resin films are firmly bonded by supplying the thermoplastic resin to the outermost layer of said resin films.    
     
     
         13 . A method for producing a packaging bag according to  claim 10 , wherein 
 a peripheral adhesion member which has been bolded in advance with a thermoplastic resin is disposed between said two resin films to heat pressure bond them.