TUBULAR OBJECT, TUBULAR BODY, MANUFACTURING METHOD OF TUBULAR OBJECT AND MANUFACTURING DEVICE OF TUBULAR OBJECT

摘要

PROBLEM TO BE SOLVED: To solve the problem that in a tubular object formed by a resin composition, even when the degree of crystallinity of each part is changed, improvement effects of physical property such as impact resistance and moldability cannot be sufficiently obtained.SOLUTION: A tubular object is formed by a resin composition, and the difference of weight average molecular weight between a part of the inner peripheral side of the tubular object and a part of the outer peripheral side thereof is 50,000 or more. Since impact resistance and moldability more affect the length of a molecular chain than the alignment (structure) of the molecular chain, by changing molecular weight distribution in each of the inner peripheral side and outer peripheral side of the tubular object, physical properties such as impact resistance and moldability can be effectively improved.