Easily tearable zipper tape and packaging bag with easily tearable zipper tape

Abstract

A thin portion is provided near an opening of a bag body to a main body of a belt-like base connected to an engagement portion. The thin portion is provided between a thick first projecting portion and a thick second projecting portion. The thin portion is thinner than the first projecting portion and the second projecting portion. On the thin portion, ribs are provided in plural lines.

1 . An easily tearable zipper tape that is attached to an inner surface of a packaging bag, the easily tearable zipper tape comprising:
 an engagement portion at which a pair of male member and a female member are mated with each other; and   belt-like bases provided continuously to the engagement portion, wherein at least one of the belt-like bases comprises:   a main body on which the engagement portion is provided;   a first projecting portion provided to the main body near an opening of the packaging bag, the first projecting portion being thicker than the main body;   a thin portion provided to the first projecting portion near the opening, the thin portion being thinner than the first projecting portion and the main body;   a second projecting portion provided to the thin portion near the opening, the second projecting portion being thicker than the thin portion and the main body; and   a rib provided on at least one surface of the thin portion.   
     
     
         2 . The easily tearable zipper tape according to  claim 1 , wherein the rib is provided on both surfaces of the thin portion. 
     
     
         3 . The easily tearable zipper tape according to  claim 1 , wherein the rib includes a plurality of the ribs. 
     
     
         4 . The easily tearable zipper tape according to  claim 3 , wherein a distance between the ribs is in a range from 0.05 mm to 2 mm. 
     
     
         5 . The easily tearable zipper tape according to  claim 1 , wherein the ribs is formed to be from 1.1 times to 5 times as thick as the thin portion. 
     
     
         6 . The easily tearable zipper tape according to  claim 1 , wherein
 a thickness of the thin portion is 0.12 mm or less, and   a thickness of each of the first projecting portion and the second projecting portion is in a range from 0.20 mm to 1 mm.   
     
     
         7 . The easily tearable zipper tape according to  claim 1 , wherein a width of the thin portion is in a range from 0.5 mm to 5 mm. 
     
     
         8 . The easily tearable zipper tape according to  claim 1 , wherein
 the thin portion, the first projecting portion and the second projecting portion are formed of the same kind of resins.   
     
     
         9 . A packaging bag provided with an easily tearable zipper tape, comprising:
 a packaging bag having an opening through which contents are fed; and   the easily tearable zipper tape according to  claim 1  which is attached to an inner surface of the packaging bag.   
     
     
         10 . The packaging bag provided with the easily tearable zipper tape according to  claim 9 , wherein
 the thin portion of the easily tearable zipper tape is not bonded to the inner surface of the packaging bag.