BINDER HAVING SHEATH WITH RIVET

PROBLEM TO BE SOLVED: To prevent rivets from being exposed to the external surface of a back face paper by a method wherein two or more holes are provided in the longitudinal direction on the back part of the sheath, and in the holes, the rivet made of a heat-weldable resin, comprising a head part which comes into contact with the internal surface of the back part of the sheath, a column-shaped part which is inserted in the hole, and a stopper part which is provided on the column-shaped part, is arranged. SOLUTION: For base plates 1, 2, an opening is formed at two or more locations in the longitudinal direction on the internal edge parts, and two or more holes 12 are formed in the same manner along a central axis which extends in the longitudinal direction of the back part of a sheath 5 corresponding with the openings. To respective holes 12, a rivet 13 formed of a stopper part and made of a resin which can be heat-welded by an ultrasonic wave or the like, comprising a flange or a head part which comes into contact with the internal surface of the back part of the sheath 5, a column-shaped part which is inserted in the hole, and a stopper part which is provided on the column-shaped part, is attached. The stopper part for the rivet 13 is made slightly larger than the diameter of the hole 12 of the sheath 5, and when the rivet 13 is fitted in the hole 12, the rivet 13 is explosively inserted in the hole by using the elasticity of the rivet, and once having been inserted, the rivet is held in a manner to be prevented from slipping off.