| 摘要 |
PROBLEM TO BE SOLVED: To provide a toothbrush in which bristle bundles are planted by flat lines, restraining the bristle bundles from spreading in the direction orthogonal to the longitudinal direction of a grip and a planting base from warping in the longitudinal direction of the planting base, while a planting hole is decreased in size, and a number of planting holes are formed in the planting base. SOLUTION: In this toothbrush, the bristle bundle formed by binding a plurality of bristles is folded in two using the flat line and planted in each of the planting holes opened to the top face of the planting base 21, and the area of a planting area of the planting base is 75-150 mm<SP>2</SP>. The ratio of the total sum of areas of portions 25a, 25a sticking out of the inner peripheral surface of the planting hole in the flat line driven in the planting hole to the area of the planting area is 0.02-0.08, the bending stress of resin forming the planting base 21 is 60-120 Mpa, the thickness of the planting base is 3-4.8 mm, and the thickness from the bottom of the planting hole to the lower surface of the planting base is 0.5-3 mm. The flat line 25 has an angle to the longitudinal direction of the planting base 21 above 0° and under 90°. COPYRIGHT: (C)2011,JPO&INPIT |
