Zipper tape and packing bag with zipper tape

Abstract

A thick portion is formed thick at an end of a female belt-like base near a containing space. To the thick portion near the containing space, a cut portion thinner than the female belt-like base is provided. To the cut portion near the containing space, a seal base that is thicker than the female belt-like base and is sealed to an inner surface of a bag body to which a male belt-like base is attached, is provided. Seal strength of the thick portion to the inner surface is lower than that of the seal base. The cut portion is provided to have a lower seal strength than that of the seal base. An area surrounded by the thick portion, the cut portion, the seal base and the inner surface becomes hermetically sealed. Even when external pressure is applied on the bag body, damages to the cut portion can be prevented.

1 . A zipper tape comprising:
 a pair of a male member and a female member comprising:   an engagement portion that is engageable and disengageable and defines a containing space inside a bag body; and   belt-like bases that are continuously connected to the engagement portion and are bondable to an inner surface of the bag body, wherein   a first one of the belt-like bases comprises:   a thick portion that is formed thicker than the first one of the belt-like bases at an end near the containing space;   a cut portion that is continuously connected to the end of the thick portion near the containing space and is formed thinner than the first one of the belt-like bases; and   a seal base that is continuously connected to an end of the cut portion near the containing space, formed thicker than the first one of the belt-like bases, and attached to the inner surface of the bag body to which a second one of the belt-like bases is attached, wherein   the thick portion is attached to the inner surface of the bag body to which the second one of the belt-like bases is attached by a strength lower than a strength for the seal base to be attached to the inner surface of the bag body, and   the cut portion is provided in a form of a belt spaced away from the inner surface of the bag body, the cut portion isolating the containing space from the outside and having a strength lower than the strength for the seal base to be attached to the inner surface of the bag body.   
     
     
         2 . The zipper tape according to  claim 1 , wherein
 the thick portion and the seal base are formed substantially in the same thickness.   
     
     
         3 . The zipper tape according to  claim 1 , wherein,
 the thick portion is formed narrower toward the inner surface of the bag body.   
     
     
         4 . The zipper tape according to  claim 3 , wherein
 a surface of the thick portion and a surface of the seal base which face each other across the cut portion are substantially parallel to each other and are substantially orthogonal to the inner surface of the bag body to which the thick portion and the seal base are attached.   
     
     
         5 . A packaging bag with a zipper tape, comprising:
 a bag body having an opening portion for defining a containing space; and   the zipper tape according to  claim 1 , the zipper tape being provided on an inner surface of the bag body.