TOOTHBRUSH

摘要

It is intended to improve the durability of toothbrush having bristles of PTT (polytrimethylene terephthalate) and further to improve, in addition to the durability, toothbrush handleability, actual feeling of toothbrushing and feeling after use. In a toothbrush comprising PTT bristles, the hot water shrinkage ratio of PTT bristles is 0.4% or below. In a hysteresis curve obtained by measuring the elongation degree and load at bristle elongation/recovery, the elongation degree (T max) at which the difference between load at elongation and load at recovery is maximized is 50% or less based on the maximum elongation degree (Tmax); the maximum difference ( Fmax) between, at fixed elongation degree, load at elongation and load at recovery is 70% or less based on the maximum load (Fmax) at maximum elongation degree; the elongation recovery ratio of elongation degree (T0) at which the load is returned to zero at recovery is 50% or more based on the maximum elongation degree (Tmax); and the elongation recovery ratio in hysteresis curve at the point of at least maximum elongation degree 25% is 50% or more. Furthermore, the area of bristles planted is in the range of 0.8 to 1.5 cm<2>, and the density of bristles planted is in the range of 35 to 45%.