JP6207808B2 - toothbrush - Google Patents

Description

  The present invention relates to a toothbrush in which a plurality of tufts formed by bundling a plurality of bristles are implanted on a flocking table.

  A toothbrush is made by planting and fixing a tuft formed by bundling a plurality of bristle by, for example, a method of driving a flat wire into a plurality of flock holes formed on a flocking surface of a flocking table or a method of fusing with heat. It is formed. In addition, the toothbrush efficiently performs appropriate brushing according to the type of teeth such as the front teeth and back teeth, and the parts of the teeth such as the interdental part, tooth surface part, tooth neck part, and back part of the tooth, and the like. Various arrangements have been made to the arrangement of the hair bundles and the shape of the tip of the bristle so that the hair can be effectively removed and a good feel can be obtained at the time of brushing.

  For example, by forming the tip of the bristle in a tapered shape, the bristle tips can easily enter the narrow part, making it difficult to clean the back of the interdental part, periodontal pocket, or the boundary of the gums, etc. Toothbrushes have been developed that improve the cleaning force against the tooth and that provides a soft feel that does not damage the gums (see, for example, Patent Document 1 and Patent Document 2). In addition, by making the cross-sectional shape of the bristle a polygonal cross-section other than a circle, the bristle can be easily brought into contact with the surface, and dirt can be easily scraped off by the corners of the polygonal cross-section, thereby improving the plaque removal effect. Toothbrushes have been developed (see, for example, Patent Document 3 and Patent Document 4).

JP 2007-44226 A JP 2011-200352 A JP-A-6-233709 JP-A-11-290133

  However, if the shape of the tip of the bristle that forms the tuft is tapered, the tip of the bristle can easily enter the narrow part, but the tip of the bristle will not be stiff, so it will firmly adhere to the tooth surface. It becomes difficult to hit.

  On the other hand, if the cross-sectional shape at the base end of the bristle that constitutes the tuft is a polygonal cross-section other than circular, the plaque removal effect can be improved, while the direction of the bristle deflection If the properties are exhibited, the flexibility is inferior and only a hard feel can be obtained.

  The present invention, by having moderate flexibility and rigidity at the tapered tip of the bristle, makes it easy to firmly touch the tooth surface while keeping the hair tip easily entering a narrow portion, It is another object of the present invention to provide a toothbrush that can easily bring the bristle into contact with the tooth surface, improve the plaque removal effect, and effectively avoid a hard touch.

  The present invention is a toothbrush in which a plurality of tufts formed by bundling a plurality of bristles are planted on a flocking table, wherein the tuft has a tapered bristles, and the tapered bristles are arranged on the flocking table side. The cross-sectional shape at the base end portion is circular or substantially circular, and includes a distal end side tapered portion formed so as to be tapered toward the distal end, and the distal end side tapered portion has a substantially sectional shape. The object has been achieved by providing a toothbrush that is square, substantially rhombus, or substantially rectangular, and wherein the tip side tapered portion is formed over a length region of 25% or more of the tip side of the tapered bristle. Is.

  According to the toothbrush of the present invention, the tip of the tapered bristle has appropriate flexibility and rigidity, so that the tip of the bristle can easily come into contact with the tooth surface while keeping the tip of the hair easy to enter. In addition, it is possible to easily bring the bristles into contact with the tooth surface, thereby improving the plaque removing effect and effectively avoiding a hard touch.

It is the schematic side view seen from the transversal direction of the flocking table explaining the toothbrush which concerns on preferable one Embodiment of this invention. It is a schematic plan view explaining the toothbrush which concerns on preferable one Embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic front view seen from the longitudinal direction of the flocking table explaining the toothbrush which concerns on preferable one Embodiment of this invention. It is a schematic perspective view explaining a taper bristle provided with a tip side taper part. It is explanatory drawing of the evaluation method of a plaque removal rate. It is a chart explaining the evaluation result of the plaque removal rate of the toothbrush of Example 1, Example 2, Comparative Example 1, and Comparative Example 2. It is the schematic front view seen from the longitudinal direction of the flocking table explaining the toothbrush which concerns on other preferable embodiment of this invention.

  The toothbrush 10 which concerns on preferable one Embodiment of this invention shown in FIGS. 1-4 is formed in the flock base 11 of the toothbrush main body which consists of a holding part (not shown), the flock base 11, and the neck part 12 which connects these. Further, tufts (hair bundles) 15a and 15b formed by bundling a plurality of bristles 14 are respectively implanted (planted) in the plurality of flocked holes 13a and 13b. In the toothbrush 10 of the present embodiment, the bristles 14 constituting the tufts 15a and 15b each include a tapered bristle 14 '(see FIG. 4) having a tapered portion on the distal end side, and the tapered bristles 14' With the function, the hair tips can be made to easily come into contact with the tooth surface while making the hair tips easily enter narrow portions such as interdental portions. Further, the function of these tapered bristle 14 'makes it easy to bring the bristle into contact with the surface to improve the plaque removing effect, and each tuft 15a, 15b has a hard feel. Can be effectively avoided.

  The toothbrush 10 of the present embodiment is a toothbrush in which a plurality of tufts 15a and 15b formed by bundling a plurality of bristles 14 are planted on the flocking table 11, as shown in FIGS. 15a and 15b have tapered bristles 14 ', and the tapered bristle 14' has a circular or substantially circular cross-sectional shape at the base end portion 14b 'on the side of the flocking table 11, as shown in FIG. In addition, a distal end side tapered portion 14a 'formed to be tapered toward the distal end is provided. The shape of the cross section 14c ′ of the distal side tapered portion 14a ′ is substantially square, substantially parallelogram or substantially rectangular, and the distal side tapered portion 14a ′ is longer than 25% of the distal side of the tapered bristle 14 ′. It is formed in the region h1.

  In this embodiment, the toothbrush main body is a well-known thing which consists of synthetic resins, such as a polypropylene, an acrylonitrile, a butadiene, a styrene copolymer synthetic resin, for example. As shown in FIGS. 1 to 3, the flat flocked surface of the flocking base 11 constituting the tip portion of the toothbrush body preferably has an approximately square or approximately rhombus shape with four corners chamfered in an arc shape. A plurality of flocking holes 13a, 13b having an opening shape are arranged in such a manner that one of these diagonal directions is arranged in the longitudinal direction of the flocking table 11 and is distributed and arranged in four rows extending in the longitudinal direction ( (See FIG. 2). That is, the center tufts 15a are respectively planted in the two rows of the center flock holes 13a arranged in the center portion in the width direction of the flocking table 11, and the two rows of the central tuft rows 16a extending in the longitudinal direction of the flocking table 11. Is configured. Outer tufts 15b are respectively planted in each row of outer flock holes 13b arranged in the width direction outer side portion of the flocking table 11, and each one row of outer tuft rows 16b extending in the longitudinal direction of the flocking table 11. Is configured.

  In the present embodiment, each central flocking hole 13a has a width b in the width direction of the substantially square-shaped flocking table 11 of 2 mm or more, and a width c in the longitudinal direction of the flocking table 11 is 2 mm or more. Thus, each of the central tufts 15a implanted in these central flock holes 13a has a large diameter tuft.

  Furthermore, in this embodiment, in each center tuft row | line | column 16a and the outer side tuft row | line | column 16b, the flocking holes 13a and 13b are continuously arranged by the longitudinal direction of the flocking table 11 with the center-to-center pitch P1 of about 2.5 to 6 mm. Has been formed. The central flocking holes 13a of the two central tuft rows 16a are arranged in the short direction of the flocking table 11 with a center-to-center pitch P2 of, for example, about 2.5 to 4 mm. The central tufts 15a constituting the two central tuft rows 16a are preferably arranged side by side in the short direction so as to overlap each other when viewed from the short direction of the flocking table 11, and are respectively arranged in the central flocking holes 13a. It has been planted.

  Furthermore, in this embodiment, the outer flock holes 13b constituting the outer tuft rows 16b on both sides are the longitudinal directions in the flock base 11 of the central flock holes 13a constituting the central tuft row 16a adjacent to each outer tuft row 16b. Are arranged at each intermediate portion of each of the two. Accordingly, the outer tuft 15b constituting the outer tuft row 16b and the central tuft 15a constituting the central tuft row 16a adjacent to the outer tuft row 16b are arranged in a staggered manner and are respectively planted. .

  In this embodiment, the central tuft 15a planted in the central flocking hole 13a and the outer tuft 15b planted in the outer flocking hole 13b have a thickness of, for example, about 5 to 9 mil made of a synthetic resin such as nylon. It is obtained by bundling 40 to 400 bristles 14 that are filament materials. The central tuft 15a is planted in the central flocking hole 13a by flat line flocking or fusion flocking to form a central tuft row 16a, and the outer tuft 15b is formed in the outer flocking hole 13b by flat line flocking or fusion flocking. Implanted to form the outer tuft row 16b.

  In the present embodiment, the bristle 14 constituting the central tuft 15a and the outer tuft 15b is not limited to the tapered bristle 14 ′ described later, but has a round shape at its tip, a tapered shape, and other various types. It is possible to include one having a tip shape.

  And in this embodiment, the center tuft 15a which comprises the center tuft row | line | column 16a is the center flocking hole 13a which has the substantially square opening shape whose width b of the width direction of the flocking table 11 is 2 mm or more and 3 mm or less as mentioned above. By being planted, the width in the width direction of the flocking table 11 at the base end portion is a large diameter tuft of 2 mm or more and 3 mm or less. The central tuft 15a is preferably vertically or substantially vertically erected from the flocking surface of the flocking table 11, and is planted to have a height (hair length) of, for example, about 8 to 12 mm. As shown in FIG. 3, when viewed from the longitudinal direction of the flocking table 11, it has a one-flow tip shape that is inclined to one side so that the center side is high and the outside is low, from the width direction center side to the outside of the flocking table 11. It is planted in. Thus, each central tuft 15a is configured by bundling a plurality of bristles 14 having different flocking heights.

  Here, when viewed from the longitudinal direction of the flocking table 11, the central tufts 15a constituting the central tuft row 16a are arranged on one side so that the center side is higher and the outer side is lower from the center side in the width direction of the flocking table 11. The inclination angle θ of the tip shape of the inclined single flow is preferably an angle of 15 to 45 ° with respect to a plane parallel to the flocked surface of the flocking table 11. The inclination angle θ of the one-sided flow of the tip shape of each central tuft 15a is 15 to 45 °, so that the central bristle 14 of each central tuft 15a becomes long, and force is given priority to the central bristle 14. In addition, since the outward movement of the central bristle 14 is limited by the outer bristle 14, the central bristle 14 that has no place to go is easily moved to the back of the gap. As a result, it becomes possible to polish the tooth surface of the deep position of narrow parts, such as an interdental part, firmly. On the other hand, when the inclination angle θ is larger than 15 °, the length of the bristle 14 of each central tuft 15a is increased and the force tends to be applied only to the specific bristle 14, so that it is easy to fit the unevenness of the dentition. Become. In addition, since the inclination angle θ is smaller than 45 °, an appropriate force is applied in addition to the specific bristle 14, and thus it is possible to polish stably.

  Furthermore, in the present embodiment, the central tuft 15a is formed in a mountain shape that is lowered from the central portion of each central tuft 15a toward both sides as seen from the short direction of the flocking table 11, as shown in FIG. It is planted to have a tip shape. Moreover, in this embodiment, the mountain-shaped tip shape of each center tuft 15a seen from the short direction of the flocking table 11 is directed from the center to both sides via the arcuate tip inclined edge 17 that curves outwardly. It is preferable that it is gradually lowered.

  In this embodiment, the outer tuft 15b constituting the outer tuft row 16b is planted in the outer flock hole 13b having a substantially square (substantially rhombic) opening shape with a width b ′ of the flocking table 11 of 2 mm or more. Thus, similarly to the central tuft 15a, the width direction width of the flocking table 11 at the base end portion is a large diameter tuft of 2 mm or more. The highest hair length of the outer tuft 15b is erected vertically or substantially vertically from the flocked surface of the flocking table 11, and is preferably lower than the highest hair height of the central tuft 15a, for example, about 6 to 10 mm. It is planted so that it becomes the hair length. The difference in length between the highest bristle length of the central tuft 15a and the highest bristle length of the outer tuft 15b is preferably 0.5 to 5 mm, more preferably 1 to 4 mm, and even more preferably 2 to 2 mm. 3 mm. Furthermore, in this embodiment, as shown in FIG. 3, the outer tuft 15 b has a higher center side and a lower outer side as viewed from the longitudinal direction of the flocking table 11 from the center side in the width direction of the flocking table 11. It is planted so as to have a one-flow tip shape that is inclined to one side. Accordingly, each outer tuft 15b is configured by bundling a plurality of bristles 14 having different flocking heights.

  Here, since the outer tuft 15b is planted at a height lower than that of the central tuft 15a, the force is easily applied to the central tuft 15a with priority, and the movement of the central tuft 15a toward the outside is facilitated by the outer tuft 15b. Therefore, the central tuft 15a, which has no place to go, can easily go to the back of the gap. As a result, the tooth surface at a deep position in a narrow part such as an interdental portion can be polished firmly.

  Further, the outer tuft 15b has a one-flow tip shape inclined toward one side from the center in the width direction of the flocking table 11, so that the force is given priority to the bristle 14 on the center side of the outer tuft 15b. In addition, since the outward movement of the central bristle 14 is limited by the outer bristle 14, the central bristle 14 that has no place to go is easily moved to the back of the gap. As a result, the tooth surface at a deep position in a narrow part such as an interdental portion can be polished firmly. In the outer tuft 15b, when viewed from the longitudinal direction of the flocking table 11, the inclination angle θ ′ of the tip shape of a single stream that inclines to one side so that the center side is higher and the outer side is lower from the center side in the width direction to the outer side. Is preferably 15 to 45 °, similarly to the tip-shaped inclination angle θ in the central tuft 15a.

  In the present embodiment, at least a part of the bristle constituting each of the tufts 15a and 15b is a tapered bristle 14 ′ including a distal-side tapered portion 14a ′ formed so as to be tapered toward the distal end. ing.

  That is, as shown in FIG. 4, the tapered bristle 14 ′ is formed so that the cross-sectional shape at the proximal end portion 14 b ′ on the side of the flocking table 11 is circular or substantially circular, and is tapered toward the distal end. The tip end side tapered portion 14a 'is provided. Moreover, the shape of the cross section 14c ′ of the tip side tapered portion 14a ′ is substantially square, substantially parallelogram or substantially rectangular (substantially rectangular in the present embodiment), and the tip side tapered portion 14a ′ is tapered taper 14. It is formed in a length region h1 of 25% or more on the tip side of '.

  Here, the tip side taper portion 14a 'has a length region h1 of 25% or more on the tip side, preferably 40% or more of the length b0 from the flocking surface of the flocking table 11 of the tapered bristle 14'. By being formed in the region h1, it is possible to improve the plaque removing effect and to effectively avoid a hard feeling of use. The length region h1 on the tip side of the tapered bristle 14 'in which the tip side tapered portion 14a' is formed is preferably 25 to 80% of the length h0 of the tapered bristle 14 ', 40 to 65. % Region is more preferable.

  In the present embodiment, the distal side tapered portion 14a ′ of the tapered bristle 14 ′ has a substantially square shape, a substantially parallelogram shape, or a substantially rectangular shape from a circular or substantially circular cross-sectional shape on the base end portion 14b ′ side. An outer periphery having a cross-sectional shape smoothly and continuously changing in a length region h1 of 25% or more on the front end side of the tapered bristles 14 'toward the front end portion 14d' of the tapered bristles while having a cross section 14c '. It has a surface shape.

  The tip-side tapered portion 14a ′ of such a tapered bristle 14 ′ is preferably a so-called grinding of the tip-side portion of the cylindrical bristles from four directions using a known rotating drum having a wire brush on the outer peripheral surface. It can be easily formed by a four-side grinding method.

  Furthermore, in the present embodiment, it is preferable that the bristle 14 constituting each of the tufts 15a and 15b includes 30% or more of the tapered bristle 14 '. The bristles 14 constituting each of the tufts 15a and 15b include 30% or more of the tapered bristles 14 ', so that the plaque removal effect can be improved and a hard feel can be effectively achieved. It can be avoided. The tapered bristle 14 'is more preferably contained in the bristle 14 constituting the tufts 15a and 15b in an amount of 30 to 100%, particularly preferably 32 to 80%.

  In addition, in a single tuft, when the number of the bristles is divided into a bristle group having a low flocking height and a bristle group having a high flocking height, the average bristle height and flocking height of the bristle group having a high flocking height are divided. The difference in length from the average bristle length of the low bristle group is preferably 0.5 to 5 mm, more preferably 1 to 4 mm, and further preferably 2 to 3 mm. Thus, by providing a difference in bristle length in a single tuft, the bristle group with a high flocking height has a cross-section of the tip side taper portion more than a bristle group with a low flocking height during four-side grinding. Many bristles that are approximately square, approximately parallelogram or approximately rectangular in shape are included, and as a result, it becomes easier to enter narrow gaps such as the back part of the interdental part, periodontal pocket, the boundary of the gums, It becomes possible to effectively scrape dirt in these narrow gaps and to obtain a soft and gentle feel that is not hard.

  That is, in a single tuft, when the number of the bristles is divided into a bristle group with a low flocking height and a bristle group with a high flocking height, the bristle group with a low flocking height is divided into a bristle group with a high flocking height. Rather, it is preferable that a lot of bristle whose cross-sectional shape of the tip side tapered portion is substantially square, substantially parallelogram or substantially rectangular is included. As a result, it becomes easier to enter narrow gaps such as the back of the interdental part, periodontal pockets, and the boundary of the gums, so that dirt in these narrow gaps can be effectively scraped and soft, not hard A gentle touch can be obtained.

  And according to the toothbrush 10 of this embodiment provided with the above-mentioned structure, it is easy to enter a hair tip into a narrow part by having moderate softness | flexibility and rigidity together in the front end side taper part 14a 'of taper bristle 14'. As it is, the bristles can be made to contact the tooth surface firmly and the tapered bristles 14 ′ can be easily brought into contact with the surface to improve the plaque removal effect, and the hard feeling can be obtained. It can be effectively avoided.

  That is, according to the toothbrush 10 of the present embodiment, at least a part of the bristle 14 constituting each of the tufts 15a and 15b has a circular or substantially circular cross-sectional shape at the proximal end portion 14b ′ on the flocking table 11 side. In addition, a tapered bristle 14 ′ having a distal side tapered portion 14 a ′ formed so as to taper toward the distal end is formed. The shape of the cross section 14c ′ of the tip side tapered portion 14a ′ is substantially square, substantially parallelogram or substantially rectangular, and the tip side tapered portion 14a ′ is 25% or more of the tip side of the tapered bristle 14 ′. Is formed in the length region h1.

  As a result, the tapered bristle 14 ′ having the tip side tapered portion 14a ′ in the considerable length region h1 can have the hair tip having appropriate flexibility and rigidity, and the tip side tapered portion 14a ′. Since it becomes easy to come into contact with the tooth surface by the four surfaces of the tip side portion, it is possible to efficiently scrape off the dirt on the tooth surface and effectively improve the plaque removal effect. Further, the tip side tapered portion 14a ′ having an appropriate rigidity is likely to enter a narrow gap such as a back part of an interdental part, a periodontal pocket, or a boundary between gums, and effectively scrapes dirt in the narrow gap. In addition, the tapered shape of the distal end side tapered portion 14a ′ makes it possible to obtain a soft and gentle feel that is not hard. Further, each tuft 15a, 15b includes a tapered bristle 14 'having a tip side tapered portion 14a' in a considerable length region h1, thereby effectively avoiding a hard feel. It becomes possible. Furthermore, the bristle 14 constituting each tuft 15a, 15b has a circular or substantially circular cross-sectional shape at the base end portion on the side of the flocking table 11, so that the cross-sectional shape at the base end portion is a polygonal cross section. Thus, it is possible to effectively avoid a hard feeling like that which causes directionality in the bending of the bristle.

  Further, according to the toothbrush 10 of the present embodiment, since the cross-sectional shape of the bristle 14a at the proximal end portion on the side of the flocking base is circular or substantially circular, there is no directionality in the bending of the bristle, and flexibility and stiffness are achieved. The bristle 14a can easily reach the deep end of a narrow part such as the interdental part while maintaining the strength of the tooth, and the tooth surface of the deep part of the narrow part such as the interproximal part can also be used as a gum. It is possible to enhance the plaque removal effect as a whole by firmly touching the tooth surface with the tip of the hair.

  Furthermore, according to the toothbrush 10 of the present embodiment, the central tufts 15a constituting the two central tuft rows 16a are viewed from the longitudinal direction of the flocking table 11 toward the outside from the center side in the width direction of the flocking table 11. In addition, it has a tip shape of a single flow that is inclined to one side so that the center side is high and the outside is low, and when viewed from the short direction of the flocking table 11, it decreases from the central part of each central tuft 15a toward both sides. It has an angled tip shape.

  Accordingly, since there is an appropriate height difference in the bristle 14 in the central tuft 15a, it becomes difficult for many bristles 14 to concentrate on a narrow part such as an interdental part, and a deeper position of a narrow part such as an interdental part. Since the hair tip of the bristle 14 is easy to reach, it becomes possible to polish the tooth surface of the narrow part firmly. Further, each central tuft 15a has a mountain-shaped tip shape when viewed from the short side of the flocking table 11, so that it is formed at the interdental portion such as the gums on the back side of the lower anterior teeth where tartar is easily formed. It becomes easy to fit in the site where the gums are greatly cut, and it becomes possible to effectively remove plaque which is the source of tartar. As a result, the hair tip of the central tuft 15a firmly hits the tooth surface of the deep position of the narrow part such as the interdental portion and the tooth surface of the gum of the gum, and the hair tip is efficiently applied to the dentition. Since it adheres well, the toothbrush 10 with improved plaque removal effect as a whole can be obtained.

  Further, according to the toothbrush 10 of the present embodiment, the central tufts 15a constituting the two central tuft rows 16a are arranged so as to overlap each other when viewed from the short direction of the flocking table 11, and the outer tuft rows. Since the outer tuft 15b constituting 16b and the central tuft 15a constituting the central tuft row 16a adjacent to the outer tuft row 16b are arranged in a staggered manner by shifting the longitudinal position of the flocking table 11, When viewed from the short side direction, the central tuft 15a having a high height and the outer tuft 15b having a low height are alternately planted to form a large unevenness on the entire brush. It becomes easy to fit by the site | part where the gums cut large in the interdental part like Kiwa.

  FIG. 7 illustrates a toothbrush according to another preferred embodiment of the present invention. The toothbrush shown in FIG. 7 has the same configuration as the toothbrush 10 of the above-described embodiment except that the inclination angle θ ′ of the one-sided flow of the tip shape of the outer tuft is set to 0 °. Also with the toothbrush shown in FIG. 7, the same effect as the toothbrush 10 of the said embodiment is show | played.

  The present invention is not limited to the above-described embodiments, and various modifications can be made. For example, the tuft formed by bundling a plurality of bristles may be a tuft having a width in the width direction of the flocking table of the flocking hole of less than 2 mm. The tuft may be a bundle of bristles having substantially the same flocking height. Furthermore, the shape and arrangement of the flock holes in the flocking table are not limited to those in the above embodiment.

  Hereinafter, although the toothbrush of this invention is demonstrated in detail by an Example and a comparative example, this invention is not limited to these.

  A toothbrush having a configuration similar to that of the toothbrush of the first embodiment and having a tapered tuft and a bristle was used as the toothbrushes of Examples 1 and 2. In addition, in the toothbrush of Example 1 and Example 2, the center flock hole 13a and the outer flock hole 13b are substantially rhombus shapes obtained by rotating a substantially square of 1.8 × 1.8 mm (r = 0.5 mm) by 45 °. (Width b = 2.13 mm). Moreover, the center-to-center pitch P1 in the longitudinal direction of the center flocking hole 13a and the outer flocking hole 13b was 4.2 mm, and the center-to-center pitch P2 of the center flocking holes 13a arranged in two rows was 3.0 mm. The thickness of the bristle 14a constituting the central tuft 15a is 8 mil for the toothbrush of the first embodiment, 7 mil for the toothbrush of the second embodiment, and the thickness of the bristle 14b constituting the outer tuft 15b is 7 mil for the toothbrush of the first embodiment. In the toothbrush of Example 2, it was set to 6 mil. The inclination angles θ and θ ′ of the single flow at the tip of each central tuft 15a and each outer tuft 15b were 20 °. The hair length of the longest part of the central tuft 15a was 10.5 mm, and the hair length of the shortest part of the outer tuft 15b was 8.0 mm. As shown in FIG. 6, the tapered bristle 14a ′ of the toothbrushes of Example 1 and Example 2 has a circular or substantially circular cross-sectional shape at the proximal end on the flocking table side, and is tapered toward the tip. The tip side taper part formed in this way is provided, and the cross-sectional shape of the tip side taper part is a substantially square, a substantially parallelogram, or a substantially rectangle. Moreover, the front end side taper part is formed over the length area | region of 6.5 mm from the front-end | tip of a taper bristle as a length area | region of 25% or more of the front end side of a taper bristle.

  A toothbrush having a configuration similar to that of the toothbrush of Example 1 except that the shape of the tip side tapered portion of the tapered bristle included in the tuft is different from that of the toothbrush of Example 1, and the toothbrush of Comparative Example 1 It was. As shown in FIG. 6, the tapered bristle of the toothbrush of Comparative Example 1 was formed so that the cross-sectional shape at the proximal end portion on the flocking table side was circular or substantially circular, and was tapered toward the distal end. A tip side tapered portion is provided, and the tip side tapered portion has a conical shape with a sharp tip. Moreover, the front end side taper part is formed over the length area | region of 6.5 mm from the front-end | tip of a taper bristle as a length area | region of 25% or more of the front end side of a taper bristle.

  A toothbrush having the same configuration as the toothbrush of Example 1 except that the shape of the tip side tapered part of the tapered bristle included in the tuft is different from that of the toothbrush of Example 1, and the toothbrush of Comparative Example 2 It was. As shown in FIG. 6, the tapered bristle of the toothbrush of Comparative Example 2 was formed so that the cross-sectional shape at the proximal end portion on the flocking table side was circular or substantially circular, and tapered toward the distal end. The tip side taper part is provided, and the cross-sectional shape of the tip side taper part is a substantially square, a substantially parallelogram, or a substantially rectangle. Further, the tip side taper portion is formed in a length region of 2.5 mm from the tip of the tapered bristle as a length region of less than 25% on the tip side of the tapered bristle.

  About the toothbrushes of Example 1, Comparative Example 1, and Comparative Example 2, the plaque removal rate was evaluated by the following method. The evaluation results are shown in FIG.

[Evaluation method of plaque removal rate]
(1) As shown in FIG. 5, a tooth model is created in which curved surfaces of square aluminum blocks each having a curved surface with a radius of curvature (R) of 4 mm face each other.
(2) Video tape (Seiyu private brand “S'RIBBON” standard type (120 minutes, model number 3T120SR)) is attached as a dental plaque or colored stain model of the tooth model of (1), and this is a video tape. The magnetic layer.
(3) A tooth model (aluminum block) to which the prepared plaque or colored stain model is attached is mounted on a test stand, and brushing is performed with a toothbrush using a brushing machine.
(4) The brushing conditions were a load of 200 g, an amplitude of 30 mm, a speed of 120 rpm, a brushing frequency of 80 (reciprocating), and 0.5 g of dentifrice (Guard Hello C (manufactured by Kao)).
(5) After brushing, the videotape is developed, the area of (2πR / 2 + 12) mm × 12.5 mm is subjected to image analysis, and the ratio of the area where the magnetic layer is peeled off and whitened is calculated. It was set as the plaque removal rate.

  The test results are shown in Table 1. In the test results shown in Table 1, the plaque removal rate by the toothbrush of Example 1 is set to 100%, and the plaque removal rate by the toothbrushes of Comparative Example 1 and Comparative Example 2 is evaluated as a relative evaluation with respect to the toothbrush of Example 1. expressed.

  According to the evaluation results in Table 1, it is found that the toothbrush of Example 1 can obtain a higher plaque removal rate than the toothbrushes of Comparative Example 1 and Comparative Example 2.

DESCRIPTION OF SYMBOLS 10 Toothbrush 11 Neck | planting base 12 Neck part 13a Center flocking hole 13b Outer flocking hole 14 Bristle 14 'Tapered bristle 14a' Tip side taper part 14b 'Tapered bristle base end part 14c' Tip side taper cross section 14d 'Tip part of taper bristle 15a Central tuft 15b Outer tuft 16a Central tuft row 16b Outer tuft row h0 Length from the flocked surface of the flocked table of the tapered bristle h1 Length region of the tapered portion on the front end side of the tapered bristle

Claims (4)

A toothbrush in which a plurality of tufts formed by bundling a plurality of bristles are planted on a flocking table,
The plurality of bristles include a tapered bristles , and the tapered bristles have a circular or substantially circular cross-sectional shape at the base end portion on the flocking table side and are tapered toward the tip. It has a formed tip side taper part,
The tip side tapered portion has a cross-sectional shape that is substantially square, substantially parallelogram or substantially rectangular, and has four surfaces ground.
The tip side taper portion is formed over a length region of 25% or more on the tip side of the taper bristle;
Each of the tufts is configured by bundling a plurality of bristle with different flocking heights, and in a single tuft, the number of bristles with a low flocking height and a bristle group with a high flocking height A toothbrush in which, when divided into two, the difference in length between the average bristle length of the bristle group with high flocking height and the average bristle length of the bristle group with low flocking height is 0.5 to 5 mm.   The tip-side tapered portion of the tapered bristle is formed on the distal side of the tapered bristle from a circular or substantially circular cross-sectional shape on the base end side toward a distal end portion having a substantially square or substantially rectangular cross-sectional shape. The toothbrush according to claim 1, wherein the toothbrush has an outer peripheral surface shape in which the cross-sectional shape is smoothly and continuously changed in a length region of% or more.   The toothbrush according to claim 1 or 2, wherein 30% or more of the tapered bristle is included in a bristle constituting each tuft. The toothbrush according to any one of claims 1 to 3, wherein each tuft has a width in the width direction of the flocking table of the flocking hole in which the tuft is planted is 2 mm or more.