| 摘要 |
<p>PURPOSE:To provide a high elasticity and high durability gut which can be stretched hard on the frame of a racket even if is fine and exhibit high instantaneous force when it is stretched and holds resilient force for a long time by forming a gut by polybenzasol fiber, the tensile strength, tensile elastic modulus and void diameter of which are specific values. CONSTITUTION:A gut is formed by polybenzasol fiber having tensile strength of 29g/denier at leas, tensile elastic modulus of 1020g/denier at least and a void diameter of 25Angstrom or less. The reason why the tensile strength of polybenzasol (PBZ) is lowered owing to moisture is hydrolysis of PBZ molecular chain caused by moisture, and the hydrolysis action is accelerated by invasion of water through comparatively large voids. If the void diameter is decreased, the hydrolytic characteristic can be improved. The gut is strong even if it is fine, so that the gut can be stretched strongly on the frame of a racket, and when it is stretched, the resilient force is high, the resilient force can be retained for a long time, high resilient force excellent in shock resistance is exhibited, and good durability including water resistance is exhibited.</p> |
