Toothbrush

Abstract

A toothbrush which comprises a brush main body made of a synthetic resin and having a bristle base and bristles made of a thermoplastic resin which have been fusion-bonded to the bristle base to constitute a bristled part, wherein the bristles constituting the bristled part at least partly comprise: tapered bristles which are bristles having split free ends, the split free ends having been tapered beforehand; tapered bristles which have a sectional shape having a core-sheath structure or islands in a sea structure; or tapered bristles in each of which a core bristle comprising a core or island part has been formed beforehand so as to be exposed at the free end. The toothbrush has excellent suitability for bristle insertion into narrow parts. It is highly effective in removing dental plaque and cleaning the teeth. It is highly easy to use in the oral cavity. It further has a highly attractive appearance.

1 . A toothbrush comprising:
 a brush main body made of a synthetic resin; and   a bristled part fusion-bonded to a bristle base of the brush main body, the bristled part being composed of bristles made of a thermoplastic resin,   wherein at least some of the bristles constituting the bristled part comprise tapered bristles with split free ends, the split free ends being tapered beforehand.   
   
   
       2 . A toothbrush comprising
 a brush main body made of a synthetic resin; and   a bristled part fusion-bonded to a bristle base of the brush main body, the bristled part being composed of bristles made of a thermoplastic resin,   wherein at least some of the bristles constituting the bristled part comprise tapered bristles with a sectional shape having a core-sheath structure or islands in a sea structure.   
   
   
       3 . The toothbrush according to  claim 2 , wherein the tapered bristles each comprise a core bristle having a core or island portion exposed beforehand at the free end. 
   
   
       4 . The toothbrush according to any one of  claims 1  to  3 , wherein each of the bristles are fixed to the bristle base at a thick portion formed at each of base end portions of the bristles. 
   
   
       5 . The toothbrush according to  claim 4 , wherein the thick portion comprises a fused mass formed by heat-fusing the base end portion of each of the bristles or bristle tufts. 
   
   
       6 . The toothbrush according to any one of  claims 1  to  3 , wherein the bristle base is not more than 4.0 mm thick. 
   
   
       7 . The toothbrush according to any one of  claims 1  to  3 , wherein each of the tapered bristles are synthetic resin filaments each with a sectional shape composed of a plurality of connected unit cross-sectional elements. 
   
   
       8 . The toothbrush according to  claim 2  or  3 , wherein each of the tapered bristles is formed in a tapered shape in which the sheath portion or sea portion becomes thinner towards the free end and is a split bristle with a plurality of core bristles exposed at the free end. 
   
   
       9 . The toothbrush according to  claim 2  or  3 , wherein each of the tapered bristles is formed in a tapered shape in which the sheath portion or sea portion becomes thinner towards the free end and is a tapered bristle with a single core bristle exposed at the free end. 
   
   
       10 . The toothbrush according to  claim 9 , wherein the cross-sectional shape of each of the core bristles of the tapered bristles exposed at the free end has a nearly same shape throughout the length in the axial direction of the core bristle. 
   
   
       11 . The toothbrush according to any one of  claims 1  to  3 , wherein each of the bristles is made of a material containing at least one kind of thermoplastic resin selected from polyester resin, polyamide resin, and polyolefin resin. 
   
   
       12 . The toothbrush according to  claim 2  or  3 , wherein in each of the tapered bristles, a main component of the material of the core or island is a polyamide resin, and a main component of the material of the sheath or sea portion is a polyester resin. 
   
   
       13 . The toothbrush according to any one of  claims 1  to  3 , wherein the bristled part comprises at least two or more kinds of bristles of different specifications. 
   
   
       14 . The toothbrush according to  claim 13 , wherein the bristled part is formed by implanting at least two or more kinds of tapered bristles of different specifications. 
   
   
       15 . The toothbrush according to any one of  claims 1  to  3 , wherein the tapered bristles are implanted to at least part of a front end portion, right-side surface portion, center portion, left-side surface portion, and rear end portion of the bristled part. 
   
   
       16 . The toothbrush according to any one of  claims 1  to  3 , wherein a brush surface composed of the free ends of the bristles in the bristled part is not flat. 
   
   
       17 . The toothbrush according to  claim 16 , wherein the brush surface has irregularities. 
   
   
       18 . The toothbrush according to  claim 17 , wherein the brush surface has irregularities in both the length direction and the width direction of the bristled part. 
   
   
       19 . The toothbrush according to any one of  claims 1  to  3 , wherein the bristles are fused to the bristle base of the brush main body by an in-mold process or fused-in process.