| 摘要 |
PROBLEM TO BE SOLVED: To insert easily into a constricted site by forming a foldable balloon to be used for medical purposes of a polymer material having a crystallized area and setting the degree of crystallization of the balloon within a specified range. SOLUTION: In a catheter shaft to which a balloon 3 is connected, the distal portion comprises an inner tube 1 having a lumen 1L and an outer tube 2 having a lumen 2L in a space between itself and the inner tube 1. This distal portion of the catheter shaft is provided with the balloon 3 having the function of expanding a constricted portion of a blood vessel. In this case, the balloon 3 is formed of a polymed material having a crystallized area, and the degree of crystallization is set between 10% and 40%. Such balloon 3 is molded by biaxial drawing and blowing of a single lumen tube whose extension fracture percentage is 250 to 450%, which is extruded, and the balloon is made by annealing at 10 deg.C to 40 deg.C higher than the biaxial drawing and blowing temperature. |
