Balloon for balloon catheter, balloon catheter including same, and method for producing balloon catheter

A balloon for a balloon catheter having a longitudinal axis direction and a radial direction, comprising:

• a balloon body having an outer surface and an inner surface;
• and
• a protrusion part that projects outward from the outer surface of the balloon body in the radial direction and extends in the longitudinal axis direction, wherein
• the protrusion part comprises a tip region including an outer end in the radial direction and a base region located inward from the tip region in the radial direction in a cross-section perpendicular to the longitudinal axis direction;
• the balloon body and the protrusion part are composed of the same material;
• and
• a surface roughness of the base region is smaller than a surface roughness of the tip region where a surface roughness of the protrusion part is measured in a direction extending from the outer end of the tip region toward the balloon body through a lower end of the base region and perpendicular to the longitudinal axis direction, the surface roughness of the base region is a surface roughness of a portion having a reference length extending from the lower end of the base region toward the outer end of the tip region, and the surface roughness of the tip region is a surface roughness of a portion having a reference length extending from the outer end of the tip region toward the lower end of the base region.