Patent ID: 8753011

Claim:
An easily openable zipper tape suitable for attachment to an inner surface of a bag body of a packaging bag, said zipper tape comprising: a pair of a male member and a female member that are engaged to define an engagement portion; a first belt-shaped base having a male member side facing the male member and a first side opposite the male member side; and a second belt-shaped base having a female member side facing the female member and a second side opposite the female side, the male member being unsymmetrical relative to a center axis substantially perpendicular to the male member side to define an opening side, the male member being attached to the first belt-shaped base in a manner that the opening side is adapted to face an opening of the packaging bag, and a content side opposite the opening side across the center axis; wherein said first and second belt-shaped bases each comprises a main body, on which said male or female member is provided, a single thin portion provided only in the opening side, and a thick portion; the main body having a greater length than the thin portion, the single thin portion being interposed between the body and the thick portion, said single thin portion being thinner than said main body and the thick portion and being bendable, said single thin portion defining a gap which is provided on only the first side or the second side, the thickness of said single thin portion being 10 to 80% of the thickness of the main body; and a surface of said main body and a surface of said thick portion are located on substantially the same plane, and said gap defined by said single thin portion is recessed relative to said surfaces of said main body and said thick portion, a surface of said thick portion being provided with a projecting portion that is thicker than said thick portion, said projecting potion projecting only from the side of the first and second belt-shaped bases on which said male member side or female member side is provided.