Toothbrush

Abstract

A tooth brush which is excellent in durability and can give a high massaging effect to a person even with weak gum with a low stimulus and without damaging the gum in various tooth brushing methods, especially in a Bass method. The toothbrush comprises bristles ( 4 ) tufted on an toothbrush head ( 20 ), wherein thermoplastic elastomer bristles ( 41 , - - - ) are tufted in the inner portion (R 1 ) in a width direction of the toothbrush head ( 20 ) and synthetic resin bristles ( 42 , - - - ) harder than the thermoplastic elastomer bristles are tufted in the both outer portion (R 2 , R 3 ) in a width direction of the toothbrush head ( 20 ) respectively. Especially, each tuft ( 5 ) tufted on the toothbrush head ( 20 ) is so trimmed that bristles ( 4 ) are continuously or stepwise shorter from the inner portion to the outer portion in the width direction

1 : A toothbrush, comprising a head in which bristles are tufted, the head having:
 thermoplastic elastomer bristles containing a polyester elastomer or a polyamide elastomer being tufted in an inner portion in the width direction of the head; and   synthetic resin bristles harder than the thermoplastic elastomer bristles being tufted in both outer portion in the width direction of the head.   
   
   
       2 : The toothbrush according to  claim 1 , wherein the diameter of the thermoplastic elastomer bristles is 0.1 mm to 0.4 mm. 
   
   
       3 : The toothbrush according to  claim 1 , wherein, in the inner portion in the width direction of the head, the synthetic resin bristles harder than the thermoplastic elastomer bristles are tufted in the tip side and the base end side in the longitudinal direction. 
   
   
       4 : The toothbrush according to  claim 3 , wherein, among tuft holes of the head, a tuft made of the thermoplastic elastomer bristles are tufted in each tuft hole except tuft holes at the tip in the longitudinal direction in a single inner row or a plurality inner rows and tuft holes at the base end near a neck of handle in the longitudinal direction in a single inner row or a plurality inner rows, and a tuft made of the synthetic resin bristles are tufted in each tuft hole forming both outer rows sandwiching the single inner row or the plurality of inner rows. 
   
   
       5 : The toothbrush according to  claim 1 , wherein the synthetic resin bristle contains a polyamide resin or a polyester resin. 
   
   
       6 : The toothbrush according to  claim 1 , wherein the synthetic resin bristles contain nylon as a polyamide resin or a resin in which one or two or more members selected from polyethylene terephthalate, polytrimethylene terephthalate, and polybutylene terephthalate, which are polyester resins, have been melt-mixed. 
   
   
       7 : The toothbrush according to  claim 1 , wherein the synthetic resin bristles are sheath-core type composite filaments each containing core filaments made of a polyamide resin and a sheath portion made of polyester resin. 
   
   
       8 : The toothbrush according to  claim 1 , wherein the bristle length of each bristle tufted in the head becomes successively or stepwise shorter from the inner portion to the outer portion in the width direction. 
   
   
       9 : The toothbrush according to  claim 8 , wherein the angle of inclination of a straight line, which passes through the tip of bristles at the central portion and the tip of bristles at the outermost portion, relative to a tufting surface as viewed in a cross section is 5 to 40° angle. 
   
   
       10 : The toothbrush according to  claim 8 , wherein the bristle length of the bristles at the outermost side is shorter by 0.5 to 2.5 mm than the bristle length of the bristles at the central portion. 
   
   
       11 : The toothbrush according to  claim 8 , wherein a line passing through the tip of each tuft substantially linearly inclines from the central portion to the outer portion in the width direction, and the bristle length of each tuft becomes successively shorter from the central portion to the outer portion. 
   
   
       12 : The toothbrush according to  claim 8 , wherein the bristles of the tuft tufted in each tuft hole have the substantially same bristle length; the bristle length of the bristles of the tufts at the outer portions in the width direction of the head is shorter than the bristle length of the bristles of the tuft at the inner portion in the width direction of the head; and the bristle length of each bristle becomes stepwise shorter from the central portion to the outer portion. 
   
   
       13 : The toothbrush according to  claim 1 , wherein the thermoplastic elastomer bristles contain a thermoplastic elastomer having a hardness of 30 D to 100 D.