Packaging bag with zipper

Abstract

A packaging bag with zipper is provided that prevents contents from entering between a zipper section and a heat seal section along the edge adjacent to an opening end of the bag, during transportation for example. For this purpose, the packaging bag has a male zipper tape and a female zipper tape bonded to inner faces of the front and rear side sheet sections, or vice versa, in the vicinity of the opening end which comes at the top when the bag is in an upright state. The opening end thus located above the position of the zipper is closed by heat sealing. The zipper tapes are bonded together at least in a region below the engaging section, out of regions above and below the engaging section, with heat sealing strength of a degree that allows the zipper tapes to peel apart by an action of interface peeling, interlayer peeling, or cohesive peeling.

What is claimed is:  
     
         1 . A packaging bag with zipper, having a male zipper tape and a female zipper tape bonded to inner faces of respective front side and rear side sheet sections, or rear side and front side sheet sections, in a vicinity of an opening end of the bag located at an upper end of the bag when said bag is in an upright state, the opening end of the bag being located above a position where the zipper is disposed and being closed by means of heat sealing, wherein 
 the respective zipper tapes are bonded together in at least a region below an engaging section of said zipper tapes, out of regions below and above the engaging section, with heat sealing strength of a degree that allows the zipper tapes to be manually peeled apart, by means of an interface peeling action, an interlayer peeling action, or a cohesive peeling action.    
     
     
         2 . The packaging bag with zipper according to  claim 1 , wherein one of the zipper tapes is made from a hot melt type adhesive resin, and the other zipper tape is made from a polyethylene type resin or polypropylene type resin of a same kind as a material forming inner layers of the bag.  
     
     
         3 . The packaging bag with zipper according to  claim 1 , wherein both zipper tapes are made from a polyethylene type resin or polypropylene type resin of a same kind as a material forming inner layers of the bag, and a hot melt type adhesive resin section is provided on one of the zipper tapes at least in a bonding region formed by heat sealing below the engaging section of the zipper tapes.  
     
     
         4 . The packaging bag with zipper according to  claim 1 , wherein one of the zipper tapes is made from a hot melt type adhesive resin, and the other zipper tape is made to have an outer face made from a polyethylene type resin or polypropylene type resin of a same kind as a material forming inner layers of the bag, and to have an inner face made from a polyethylene type resin or polypropylene type resin of a different kind from the material forming the inner layers of the bag.  
     
     
         5 . The packaging bag with zipper according to  claim 1 , wherein the inner faces of both zipper tapes are made from a polyethylene type resin or polypropylene type resin, and a hot melt type adhesive resin section is provided on the inner face of one of the zipper tapes, at least in a bonding region formed by heat sealing below the engaging section of the zipper tapes.  
     
     
         6 . The packaging bag with zipper according to  claim 1 , wherein a hot melt type adhesive resin section to be bonded to the inner layer of the bag, is provided on an outer face of a zipper tape made from a polyethylene type resin or polypropylene type resin.  
     
     
         7 . The packaging bag with zipper according to  claim 1 , wherein both zipper tapes are made from a resin containing a material comprising a random mixture of a straight-chain low-density polyethylene type resin and a polybutene-1 resin.  
     
     
         8 . The packaging bag with zipper according to  claim 1 , wherein a resin section containing a material comprising a random mixture of a straight-chain low-density polyethylene type resin and a polybutene-1 resin is provided on the inner faces of both zipper tapes, at least in a bonding region formed by heat sealing below the engaging section of the zipper tapes.