JP2023039808A - toothbrush - Google Patents

Abstract

[Problem] To provide a toothbrush that can easily increase foaming power when brushing teeth. [Solution] The toothbrush includes a roughly rod-shaped handle, a bristle base 4 provided at the tip of the handle, a plurality of first bristle bundles 5 planted on the bristle base 4, and a plurality of second bristle bundles 6, the bristle bundles 5 being shorter in length than the first bristle bundles 5, planted on the bristle base 4, the plurality of first bristle bundles 5 being arranged to surround three of the four directions surrounding the entire circumference of a second bristle bundle group 61, which is a group of the plurality of second bristle bundles 6, and are not arranged in the other direction, and the spatial volume, which is the volume obtained by multiplying the area S of the region surrounded on three sides by the plurality of first bristle bundles 5 by the bristle length difference H between the bristle length of the first bristle bundles 5 and the bristle length of the second bristle bundles 6, is 100 mm3 or more. [Selected Figure] Figure 3

Description

TECHNICAL FIELD The present invention relates to a toothbrush used for brushing teeth.

BACKGROUND ART Conventionally, there has been a demand for a toothbrush with a high foaming power for foaming a dentifrice when brushing teeth. Therefore, the contour shape of the tip of the bristle bundle in the lateral contour shape obtained by cutting the bristle bundle group planted in the head part of the toothbrush along the long axis direction of the handle is jagged like the teeth of a saw to create bubbles. Techniques for increasing force are known (see Patent Document 1, for example).

Japanese Patent Application Laid-Open No. 2003-250632

However, when pasty toothpaste is applied to a toothbrush with a serrated contour at the tip of the tufts, the dentifrice is less likely to adhere to areas other than the protruding tufts of the serrations, resulting in reduced retention of the dentifrice. There was an inconvenience that

SUMMARY OF THE INVENTION An object of the present invention is to provide a toothbrush with which it is easy to increase the foaming force during toothbrushing.

A toothbrush according to the present invention comprises a substantially bar-shaped handle, a bristle-implantation base provided at the tip of the handle, a plurality of first bristle bundles implanted in the bristle-implantation base, and and a plurality of second hair bundles shorter in hair length than the first hair bundle, wherein the plurality of first hair bundles surrounds the entire circumference of a second hair bundle group that is a group of the plurality of second hair bundles. In the area of the region surrounded in the three directions by the plurality of the first hair bundles, the first hair bundles are arranged so as to surround the three directions out of the four directions and are not arranged in the other one direction. A spatial volume, which is a volume obtained by multiplying the difference between the hair length and the hair length of the second hair bundle, is 100 mm ³ or more.

According to this configuration, when the toothbrush is reciprocated along the axial direction of the handle for brushing, since the first bristle bundle having a long bristle length is not provided on one side of the second bristle bundle group, the bristle inner space Air is taken in from the - direction side. The air taken into the tufted inner space is held so as to be embraced by the first tufts surrounding the second tuft group in three directions. Furthermore, in a state in which air is entrapped in the bristle inner space, the tips of the first bristle bundle and the second bristle bundle agitate the dentifrice applied to the teeth and the air, thereby foaming the dentifrice. Therefore, by forming an air intake port on one side of the second tuft group, it becomes easier to take in air, the amount of air stirred with the dentifrice is increased, and foaming is facilitated. It becomes easy to increase the foaming power at the time.

Furthermore, it is preferable that the spatial volume is 314 mm ³ or less.

The effect of increasing the foaming power is experimentally confirmed when the spatial volume is in the range of this upper limit or less, and the certainty of increasing the foaming power is improved.

Moreover, it is preferable that the one direction is the rear end direction of the handle.

By not arranging the first tufts of the second tuft group on the rear end side of the handle and allowing air to be taken in from the rear end side of the handle, when the user brushes his/her teeth, the direction of the opening of the mouth will be reduced. Air is taken in, and as a result, it becomes easier for air to be taken into the space inside the bristles, and as a result, it becomes easy to increase the foaming power during tooth brushing.

Moreover, it is preferable that each of the first tuft bundles includes a filament having a tapered shape in which the tip portion is tapered toward the tip.

A filament with a tapered tip bends flexibly as the tip is brushed, increasing the effect of agitating the toothpaste and air. As a result, the foaming power is further improved.

Moreover, it is preferable that each of the first hair bundles includes a long hair bundle that is longer than the second hair bundle and a short hair bundle that is shorter than the second hair bundle.

By providing a short hair bundle that is shorter and less flexible than the long hair bundle in the first hair bundle, the short hair bundle supports the long hair bundle and the cleaning effect of the short hair bundle can be improved. .

Moreover, it is preferable that the long hair bundle is a bundle of filaments having a tapered tip portion whose diameter decreases toward the tip.

A filament with a tapered tip bends flexibly as the tip is brushed, increasing the effect of agitating the toothpaste and air. As a result, the foaming power is further improved.

Further, among the plurality of first hair bundles, the short hair bundle included in the first hair bundle arranged at the outermost edge in the width direction of the hair-implanting base is the long hair bundle included in the same first hair bundle. It is preferable that the bristles are arranged on the outer side in the width direction of the bristle-implanting base than the bundle.

According to this configuration, the short tufts that are shorter and less bendable than the long tufts can support the long tufts from the outside. can be reduced.

Further, it is preferable that each filament of the plurality of second hair bundles has a shape with a substantially constant thickness.

By making the second tuft bundle a filament having a substantially constant thickness instead of a tapered shape that is easy to bend, it becomes easier to improve the cleaning effect of the second tuft group.

Moreover, it is preferable that the tips of the second tufts are positioned substantially in the same plane.

By locating the tips of the second tufts in substantially the same plane, the tips of the second tuft group are substantially flat. As a result, the air taken in from the air intake port on the one-way side can easily flow into the interior space of the bristles, making it easier to improve the whipping effect over a wider range.

Moreover, it is preferable that the difference between the hair length of each first hair bundle and the hair length of each second hair bundle is 2 to 4 mm.

The hair length difference between the first hair bundle and the second hair bundle is preferably 2 to 4 mm.

A toothbrush having such a configuration facilitates enhancing the foaming power during tooth brushing.

It is a perspective view showing an example of composition of a toothbrush concerning one embodiment of the present invention. FIG. 2 is an enlarged perspective view of the head portion shown in FIG. 1; It is a conceptual diagram which shows arrangement|positioning of each hair bundle in the state which looked at the head part shown in FIG. 1 from the front-end|tip direction of each hair bundle. FIG. 3 is an explanatory diagram showing an example of the shape near the tip of one filament that constitutes the long hair bundle shown in FIG. 2 ; FIG. 2 is an explanatory diagram for explaining foaming when brushing teeth using the toothbrush shown in FIG. 1; FIG. 4 is an explanatory diagram showing the configuration of the head portion of the toothbrush according to the example of the present invention and the bubble area area obtained by experiment. It is explanatory drawing which shows the experimental method for measuring a bubble area area. 8 is a photograph of a molar taken with a microscope after the brushing shown in FIG. 7. FIG. It is an explanatory view for explaining a measuring method of a bubble area area. FIG. 6 is an explanatory diagram showing the configuration of the head portion of a toothbrush according to a comparative example and the bubble area area obtained by experiment. 10. It is a graph which shows the experimental result based on the Example shown in FIG. 6, and the comparative example shown in FIG.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment according to the present invention will be described below with reference to the drawings. It should be noted that the same reference numerals in each figure indicate the same configuration, and the description thereof will be omitted. FIG. 1 is a perspective view showing an example of the configuration of a toothbrush according to one embodiment of the present invention.

A toothbrush 1 shown in FIG. 1 generally includes a substantially bar-shaped handle 2 and a head portion 3 provided at the tip of the handle 2 . The head part 3 includes a substantially flat-plate-shaped hair-transplantation base 4, a plurality of first hair bundles 5 implanted on the hair-transplantation substrate 4, and hair lengths shorter than the first hair bundles 5 implanted on the hair-transplantation substrate 4. A plurality of second tufts 6 and third tufts 7 are provided.

In each drawing, XYZ orthogonal coordinate axes are shown as appropriate to clarify the directional relationship. The X axis coincides with the axial direction of the handle 2, +X is the tip direction of the handle 2, and -X is the rear end direction of the handle 2. The Y-axis is orthogonal to the X-axis and extends along the width direction of the bristle implantation base 4 . The Z-axis extends in a direction perpendicular to the hair-implantation surface 41 of the hair-implantation base 4 on which the hair bundles are implanted. +Z is the tip end direction of each hair bundle of the first hair bundle 5, second hair bundle 6, and third hair bundle 7, and -Z is the base end direction of each hair bundle.

FIG. 2 is an enlarged perspective view of the head section 3 shown in FIG. FIG. 3 is a conceptual diagram showing the arrangement of each hair bundle when the head portion 3 shown in FIG. 1 is viewed from the tip direction (+Z direction) of each hair bundle. In FIG. 3, the first tuft 5 is indicated by a half-hatched circle, the second tuft 6 by a white circle, and the third tuft 7 by an X.

Each hair bundle is arranged on the hair-implanted surface 41 at positions corresponding to intersections of a virtual square lattice, for example. A total of 12 bundles of the second hair tufts 6 are planted, for example, in four rows in the X-axis direction and three rows in the Y-axis direction, substantially in the center of the width direction of the hair planting surface 41 . A second hair bundle group 61 is configured by a total of 12 bundles of the second hair bundles 6 .

The plurality of first hair bundles 5 are arranged so as to surround three directions of +X, +Y, and -Y directions out of the four directions of +X, -X, +Y, and -Y surrounding the entire circumference of the second hair bundle group 61. It is The first tuft 5 is not arranged in the −X direction, which is the other direction of the second tuft group 61 . In the −X direction of the second hair bundle group 61, three third hair bundles 7 are arranged in the Y-axis direction. In the example shown in FIGS. 1 and 2, the second hair bundle 6 and the third hair bundle 7 have the same hair length.

A rectangular region connecting the inner surfaces of the first tufts 5 surrounding the second tuft group 61 shown in FIG. Assuming that the length of the region B in the X direction is the length L and the length in the Y direction is the width W, the area S of the region B is obtained by L×W. The difference between the hair length of the first hair bundle 5 and the hair length of the second hair bundle 6 shown in FIG. Then, the region B in which the tip surfaces of the second hair bundle group 61 are arranged is used as the bottom surface, and the hair transplantation is a substantially rectangular parallelepiped space surrounded on three sides by the side surfaces of the first hair bundle 5 and having a height difference H. An inner space C is obtained. A space volume V, which is the volume of the space C within the flocked hair, is obtained by the following formula (1).

Spatial volume V=S×H=L×W×H (1)

The first hair bundle 5 includes a long hair bundle 51 and a short hair bundle 52 . In FIG. 3 , the hatched portion of the first hair bundle 5 indicates the long hair bundle 51 , and the unhatched portion indicates the short hair bundle 52 . The long hair bundle 51 is longer than the second hair bundle 6 and the short hair bundle 52 is shorter than the second hair bundle 6. - 特許庁Since the long hair bundle 51 is longer than the second hair bundle 6 , the first hair bundle 5 as a whole is longer than the second hair bundle 6 .

Of the plurality of first hair bundles 5, the short hair bundles 52 included in the first hair bundles 5 arranged at the outermost edge A in the width direction (Y direction) of the hair-transplanting base 4 are included in the same first hair bundles 5. The long hair bundles 51 are arranged outside in the width direction of the hair-implantation base 4 .

Each of the first hair bundle 5, the second hair bundle 6, and the third hair bundle 7 is, for example, 5 to 100 wire rods folded in half to form a bundle of 5×2 to 100×2 filaments. It is composed of The filaments that make up each of the short hair bundle 52, the second hair bundle 6, and the third hair bundle 7 have a diameter of about 0.1 to 0.3 mm, a substantially constant thickness, and a rounded tip. The bristles or tips have a flattened shape.

FIG. 4 is an explanatory diagram showing an example of the shape near the tip of one filament forming the long hair bundle 51 shown in FIG. The filament of the long hair bundle 51 has a tapered shape that decreases in diameter toward the tip. The filament of the long hair bundle 51 has a tapered portion length L1 of, for example, 1 to 4 mm, a tapered root portion diameter d1 of, for example, 0.1 to 0.3 mm, and a tip diameter d2 of, for example, 0. .002 to 0.05 mm.

Hereinafter, a filament having a tapered tip as shown in FIG. 4 is simply referred to as a tapered bristle. A filament having a substantially constant thickness and a substantially flat or nearly flat curved tip is referred to as a rounded tip. Saturated polyester is suitable as a material for the tapered bristles. Nylon is suitable as a material for the rounded bristles.

FIG. 5 is an explanatory diagram for explaining foaming when brushing teeth using the toothbrush 1. FIG. In FIG. 5, the first tuft 5, the second tuft 6, and the third tuft 7 are shown in a conceptual diagram as seen from the cross section taken along the line VV shown in FIG. Although not shown, it is assumed that the teeth shown in FIG. 5 are coated with toothpaste.

As shown in FIG. 5, when the toothbrush 1 is reciprocated along the X-axis direction for brushing, the long first bristle tufts 5 are not provided on the -X direction side of the second bristle tuft group 61. , air is taken into the space C in the flocking from the -X direction side. The air taken into the hair-planting internal space C is held so as to be embraced by the first hair tufts 5 surrounding the +X, +Y, and -Y directions. Furthermore, in a state in which air is held in the bristle inner space C, the tips of the first bristle bundle 5, the second bristle bundle 6, and the third bristle bundle 7 agitate the toothpaste applied to the teeth and the air. The toothpaste is thereby foamed.

In this way, the first hair bundle 5 surrounding the +X, +Y, and -Y directions of the second hair bundle group 61 is provided, and the air intake port is formed on the -X direction side, making it easy to take in air. The foaming power increases by increasing the amount of air mixed with the dentifrice and facilitating foaming.

As will be described later, the inventors of the present invention have found that when the spatial volume V is 100 mm ³ or more, a good effect of increasing the foaming power can be obtained.

Furthermore, since the ends of the filaments of the long tufts 51 are tapered, the ends of the tapered bristles are flexibly bent with brushing, increasing the effect of agitating the toothpaste and air. As a result, the foaming power is further improved.

In addition, since the tapered long bristle bundle 51 is flexible and soft, the cleaning effect is likely to be lowered. Therefore, by providing the short tufts 52 that are not tapered like the rounded bristles and therefore have higher strength than the long tufts 51, the long tufts 51 are supported and the short bristle tufts 52 have the ability to remove plaque. It is possible to improve the cleaning effect such as.

Furthermore, the hair lengths of the second tuft bundles 6 are substantially the same, and the tips of the second tuft bundles 6 are positioned substantially in the same plane, so that the tips of the second tuft group 61 are substantially flat. As a result, the air taken in from the air intake port on the -X direction side can easily flow into the interior space C (+X side) of the flocked bristles, and the foaming effect can be improved over a wider range.

Note that "substantially in the same plane" means that a margin of error due to manufacturing variations is allowed with respect to the same plane.

In addition, since the filaments of the second tuft group 61 have rounded ends and are not tapered, the second tuft group 61 can improve the cleaning effect such as the ability to remove plaque.

The direction in which the first tuft 5 is not arranged is not limited to the -X direction (the rear end direction of the handle 2). The plurality of first hair tufts 5 are arranged so as to surround the -X, +Y, and -Y directions of the three directions, and even in a configuration in which the first tufts 5 are not arranged in the +X direction (the tip direction of the handle 2). good.

Moreover, the first hair bundle 5 is not limited to the example composed of the long hair bundle 51 and the short hair bundle 52 . The first hair bundle 5 may be composed of only the long hair bundle 51 . Further, the filament of the long hair bundle 51 is not limited to tapered hair, and may be rounded tip hair.

Further, the short tufts 52 included in the first tuft 5 arranged at the outermost edge A are arranged on the outside in the width direction of the flocking base 4 relative to the long tufts 51 included in the same first tuft 5. The positional relationship between the long hair bundle 51 and the short hair bundle 52 in the first hair bundle 5 may be arbitrary.

Further, the filaments of the second tuft 6 and the third tuft 7 are not limited to the round tip bristles, and may be tapered bristles. Moreover, the second hair bundle 6 and the third hair bundle 7 only need to have a shorter hair length than the first hair bundle 5, and the tips of the second hair bundle 6 and the third hair bundle 7 are positioned substantially in the same plane. Examples are not limited. Further, the toothbrush 1 does not have to include the third bristle tufts 7 .

Further, the toothbrush 1 is arranged so that the first tufts 5 surround the +X, +Y, and -Y directions of the second bristle tuft group 61, and the first bristle tufts 5 extend in the -X direction (the rear end direction of the handle 2). is not arranged, and the first hair bundle 5 is arranged to surround the -X, +Y, -Y directions of the second hair bundle group 61, and the first hair bundle is arranged in the +X direction (the tip direction of the handle 2) It is sufficient that at least one of the portions of the hair bundle arrangement where the hair bundles 5 are not arranged is included, and additional hair bundles may be provided within a range that does not interfere with these hair bundle arrangements.

FIG. 6 is an explanatory diagram showing the configuration of the head portion 3 of the toothbrush 1 according to Examples 1 to 9 of the present invention and the bubble area obtained by experiment.

The second tufts 6 and the third tufts 7 according to Examples 1 to 9 and Comparative Examples 1 to 4 (FIG. 10) described later are made of nylon, and the first tufts 5 are made of saturated polyester. The hair length of the second hair bundle 6 and the third hair bundle 7 is 9 mm, and the hair length of the long hair bundle 51 is the length obtained by adding the hair length difference H in each example and each comparative example to 9 mm. The hair length of the short hair bundle 52 is 7 to 9 mm, the number of filaments in each hair bundle of the first hair bundle 5 is 46, the filament diameter is 0.178 mm, the length L1 of the tapered portion of the tapered hair is 3 mm, and the root portion has a diameter d1 of 0.178 mm and a tip diameter d2 of 0.016 mm. Each of the second hair bundle 6 and the third hair bundle 7 has 34 filaments and a filament diameter of 0.21 mm. The diameter of each hair bundle of the first hair bundle 5, the second hair bundle 6 and the third hair bundle 7 is 1.5 mm, the distance between the hair bundles in the axial direction (X direction) is 2.55 mm, and the width between the hair bundles is 1.5 mm. The spacing in the direction (Y direction) is 2.30 mm. The interval between hair bundles means the distance between the centers of the hair bundles.

Also, the arrangement of each hair bundle is as shown in the hair-implantation patterns of FIGS. Specifically, 6 bundles, 8 bundles, 8 bundles, 8 bundles, and 6 bundles are arranged in order from the row on one end side in the width direction (Y direction). Among them, the first hair tuft 5 is indicated by a black circle. The second hair bundle 6 and the third hair bundle 7 are indicated by white circles, and the column of the number of hair bundles of the second hair bundle 6 + the third hair bundle 7 is written in brackets (the number of bundles in the Y direction × the number of bundles in the X direction). It is described as

In Examples 1 to 6, 8, 9 and Comparative Examples 1 to 4, one long hair bundle 51 has 23 filaments, and one short hair bundle 52 has 23 filaments. In Example 7, one long hair bundle 51 has 46 filaments, and the short hair bundle 52 has zero filaments.

In the hair-implanting pattern of FIG. 6, the first hair bundle 5 is indicated by a black circle, and the second hair bundle 6 and the third hair bundle 7 are indicated by white circles, indicating the arrangement of each hair bundle. The arrangement of the long tufts 51 and the short tufts 52 in the single first tuft 5 is the same as in FIG. The spatial volume V according to FIG. 6 was calculated based on the formula (1).

A method for measuring the bubble area area will be described. FIG. 7 is an explanatory diagram showing an experimental method for measuring the bubble area. As shown in FIG. 7, the head portions 3 according to Examples 1 to 9 and Comparative Examples 1 to 4 described later are pressed against the back teeth T1 and T2 of the tooth model D, respectively, with a load of 200 g and a sliding distance of 20 mm. , 10 times of sliding, brushing was performed at a sliding speed of 1.67 reciprocations per second.

As the test liquid to be applied to the back teeth T1 and T2, an aqueous solution obtained by diluting "Toki no Riki" paste manufactured by Sunstar Co., Ltd. with paste:water = 1:4, and adding a dental plaque stain was used. .

FIG. 8 is a photograph of the molar T1 taken with a microscope after the brushing shown in FIG. As shown in FIG. 8, bubbles E generated by brushing accumulate in the recesses of the back teeth T1. The larger the amount of foam E, the higher the foaming power. In addition, the larger the amount of the bubbles E, the larger the area where the bubbles E spread in the photograph after brushing.

Therefore, from the photographs taken after brushing according to each example, a region where the foam E spreads like the hatched portion shown in FIG. 9 is extracted, and the area of this hatched portion is used as the foam area area shown in FIGS. It was measured.

Comparative example

FIG. 10 is an explanatory diagram showing the configurations of the head portions 3 of the toothbrushes 1 according to Comparative Examples 1 to 4 and the bubble area areas obtained by experiments. Also for Comparative Examples 1 to 4, the foam area was measured by the same measurement method as in the above-described Examples.

In Comparative Example 1, the first hair bundle 5 is arranged only on the +Y and -Y sides of the second hair bundle 6, and the first hair bundle 5 is not arranged on the +X and -X sides of the second hair bundle 6. It's becoming In Comparative Example 2, the first tuft 5 is composed only of a long tuft 51 having rounded ends, and the filaments of the second tuft 6 and the third tuft 7 are tapered filaments.

In Comparative Examples 3 and 4, the first tuft 5 surrounds the second tuft 6 on three sides, but the spatial volume V is less than 100 mm ³ .

FIG. 11 is a graph showing experimental results according to the example shown in FIG. 6 and the comparative example shown in FIG. In the graph shown in FIG. 11, the horizontal axis indicates the spatial volume, and the vertical axis indicates the bubble area area. Examples 1 to 9 shown in FIG. 6 are indicated by black circles, and Comparative Examples 1 to 4 shown in FIG. 10 are indicated by white circles.

From the comparison between Examples 1 to 9 shown in FIG. Compared to Comparative Examples 1 and 2, which do not have the configuration in which the first tufts 5 surround the group 61 in three directions, it was confirmed that the foam area area was significantly larger, and thus the foaming power was higher.

Therefore, it was confirmed that the configuration in which the first tufts 5 surround the second tuft group 61 in three directions can easily increase the foaming power.

Further, from a comparison between Examples 1 to 9 and Comparative Examples 3 and 4, Examples 1 to 9 in which the spatial volume V is 100 mm ³ or more are compared to Comparative Examples 3 ^{and 4} in which the spatial volume V is less than 100 mm 3. On the other hand, it was confirmed that the foam area was remarkably large, and thus the foaming power was high.

Therefore, it was confirmed that the foaming power can be easily increased by setting the space volume V to 100 mm ³ or more. In addition, in Example 6 in which the space volume V is 314 mm ³ , it can be confirmed that a significantly larger foam area area can be obtained than in Comparative Examples 1 to 4, so at least the upper limit of the space volume V is 314 mm ³ or less. It was confirmed that the effect of improving the force was obtained.

Further, from the comparison between Example 9 and Comparative Examples 1 to 4, the first hair bundle 5 is arranged to surround three directions -X, +Y, -Y, and is arranged in the +X direction (the tip direction of the handle 2). It was confirmed that even with the configuration of Example 9 in which the first tuft 5 is not arranged, the effect of improving the foaming power can be obtained.

Furthermore, from the comparison of Examples 5 and 9, which have the same conditions other than the direction in which the first tuft 5 is not arranged, it is found that -X It was confirmed that Example 5, in which the first tufts 5 were not arranged in the direction (toward the rear end of the handle 2), had a larger foam area area and, therefore, a higher foaming power. Therefore, the configuration in which the first tufts 5 are not arranged in the +X direction (the direction toward the tip of the handle 2) is better than the configuration in which the first tufts 5 are not arranged in the −X direction (the direction toward the rear end of the handle 2). preferable.

Further, from the comparison between Example 7 and Comparative Examples 1 to 4, even in Example 7 in which the first hair bundle 5, the second hair bundle 6, and the third hair bundle 7 are all tapered hair, the comparative example It was confirmed that the foam area area was remarkably larger than those of 1 to 4, and therefore the foaming power was high. Therefore, as in the seventh embodiment, the first tuft 5 may be composed only of the long tufts 51 of tapered bristles without providing the short tufts 52 . Also, the second tuft 6 and the third tuft 7 may be tapered bristles instead of rounded bristles.

In addition, according to the configuration of the toothbrush 1, unlike the background art, it is not necessary to make the contour shape of the tips of the bristle bundles jagged, so it is easy to reduce the possibility that the holding power of the toothpaste is reduced.

1 Toothbrush 2 Handle 3 Head 4 Flocking base 5 First tuft 6 Second tuft 7 Third tuft 41 Flocking surface 51 Long tuft 52 Short tuft 61 Second tuft group A Outermost edge B Region C Flocking Inner space D Tooth model d1, d2 Diameter E Foam H Hair length difference L, L1 Length S Area T1, T2 Back tooth V Spatial volume W Width

Claims (10)

a roughly bar-shaped handle;
a flocking base provided at the tip of the handle;
a plurality of first hair bundles implanted on the hair planting base;
a plurality of second hair bundles having shorter hair lengths than the first hair bundle, which are implanted on the hair-planting base;
The plurality of first hair bundles are arranged so as to surround three directions out of four directions surrounding the entire circumference of the second hair bundle group, which is the group of the plurality of second hair bundles, and the other direction is not placed
The space volume, which is the volume obtained by multiplying the area of the region surrounded in the three directions by the plurality of first hair bundles by the difference between the hair length of the first hair bundle and the hair length of the second hair bundle, A toothbrush that is 100 mm ³ or more. 2. The toothbrush according to claim 1, further wherein said void volume is 314 mm ^<3> or less. The toothbrush according to claim 1 or 2, wherein said one direction is the rear end direction of said handle. The toothbrush according to any one of Claims 1 to 3, wherein each of the first bristle tufts includes a filament having a tapered tip portion whose diameter decreases toward the tip. 5. The first hair bundle according to any one of claims 1 to 4, wherein each of the first hair bundles includes a long hair bundle that is longer than the second hair bundle and a short hair bundle that is shorter than the second hair bundle. toothbrush. 6. The toothbrush according to claim 5, wherein the long bristle bundle is a bundle of filaments having a tapered tip portion whose diameter decreases toward the tip. Among the plurality of first hair bundles, the short hair bundles included in the first hair bundle arranged at the outermost edge in the width direction of the hair-transplanting base are more likely than the long hair bundles included in the same first hair bundle. 7. The toothbrush according to claim 5 or 6, wherein the bristles are arranged outside in the width direction of the bristle-implanting base. The toothbrush according to any one of claims 1 to 7, wherein each filament of the plurality of second bristle tufts has a substantially constant thickness. The toothbrush according to any one of claims 1 to 8, wherein the tips of the second bristle tufts are positioned substantially within the same plane. The toothbrush according to any one of claims 1 to 9, wherein the difference between the bristle length of each first bristle bundle and the bristle length of each second bristle bundle is 2 to 4 mm.

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