TWI865667B - toothbrush - Google Patents

Abstract

The purpose of the present invention is to provide a toothbrush that can help improve the touch feeling and cleaning power. The toothbrush comprises: a head (3) with a plurality of hair bundles planted on a hair planting surface (3a), and a handle extending from the head. The hair bundles comprise an outer hair bundle (20) arranged at the outermost periphery, and an inner hair bundle (30) arranged at the inner side of the outer hair bundle. The outer hair bundle is formed by folding the front end bifurcated hair (22) that bifurcates the front end of the bristle on both sides in the length direction, and comprises two half hair bundle portions (21a, 21b) with different hair lengths.

Description

toothbrush

The present invention relates to a toothbrush. This application claims priority based on Japanese Patent Application No. 2019-216857 filed in Japan on November 29, 2019, and the contents thereof are cited in this application.

If you have periodontal disease, you will feel pain when the toothbrush touches the gums. When using low-waisted bristles to improve the contact with the gums, the basic function of the cleaning force in the oral cavity is reduced. For example, Patent Document 1 discloses a toothbrush having a bundle of front-end bifurcated bristles that only bifurcates the front ends of the bristles on both outer sides of the width direction of the head. In addition, Patent Document 2 discloses a toothbrush having at least one of the outer bristle bundle and the inner bristle bundle having two half-bristle bundles with different bristle lengths.

In the toothbrush disclosed in Patent Document 1, the front branched hair is bent to function as a buffer material, which can improve the contact feeling with the gums, and the branched hair is only set at the front end of the bristle, so the lowering of the bristle waist can be suppressed, and the cleaning force in the oral cavity can be ensured. In the toothbrush disclosed in Patent Document 2, the hair length of the hair bundle constituting the toothbrush is set with three stages of height difference, thereby not only the hair bundle contacts the cleaning area in the oral cavity widely, but also the high cleaning performance of each cleaning area can be ensured. [Prior art document] [Patent document]

[Patent document 1] Japanese Patent Publication No. 2016-209097 [Patent document 2] Japanese Patent Publication No. 2016-209016

[Problems to be solved by the invention] However, in the toothbrush of Patent Document 1, when the hair bundles with branched hairs are symmetrically folded and implanted, the hair lengths of the branched hairs become the same, thereby restricting the range of movement of the hair tips and reducing the function as a buffer material. In addition, Patent Document 2 discloses that branched hairs can be used in addition to the half-bundle portion of the outer hair bundle with the longest hair length, but in this structure, the branched hairs are not provided in the half-bundle portion of the outer hair bundle that is easy to contact the gums, so it is difficult to feel real as a buffer material and does not help improve the contact feeling with the gums.

The present invention is made in consideration of the above-mentioned problems, and its purpose is to provide a toothbrush that can help improve the gentle touch and cleaning power on the gums. [Means for solving the problem]

According to the first form of the present invention, a toothbrush is provided, which is characterized in that it includes: a head with multiple bristle bundles implanted on the bristle implantation surface, and a handle extending from the head, the bristle bundles have outer bristle bundles arranged on the outermost periphery, and inner bristle bundles arranged on the inner side of the outer bristle bundles, the outer bristle bundles are formed by folding the front end branched hairs that make the front end of the bristles branch on both sides in the length direction, and have two half bristle bundle parts with different bristle lengths.

In addition, in one aspect of the toothbrush of the present invention, the bristles are tapered bristles that taper toward the front end.

In addition, in one form of the toothbrush of the present invention, the feature is that the inner bristle bundle has a plurality of second bristles, and the second bristles are tapered bristles with the tips becoming thinner toward the front end.

In addition, in the toothbrush of one form of the present invention, it is characterized in that the hair length of the inner hair bundle is longer than the hair length of the outer hair bundle.

In addition, in the toothbrush of one form of the present invention, it is characterized in that: among the two half hair bundle parts, the outer half hair bundle part is shorter than the inner half hair bundle part.

In addition, in one form of the toothbrush of the present invention, the difference in hair length between the two half hair bundles is greater than 0.5 mm and less than 2.0 mm. If the length of the branched hair at the front end is set to L1 and the difference in hair length between the two half hair bundles is set to L2, the value represented by L2/L1 is greater than 0.08 and less than 4.0.

In addition, in the toothbrush of one aspect of the present invention, the front end of the branched bristles is branched into two or more.

In addition, in one aspect of the toothbrush of the present invention, the feature is that the diameter of the bristles is greater than 6 mil and less than 9 mil.

In addition, in a toothbrush of one form of the present invention, the feature is that the diameter of the second bristles constituting the inner bristle bundle is greater than 5 mil and less than 7 mil. [Effect of the invention]

The present invention provides a toothbrush that helps to improve the soft touch feeling and cleaning power on the gums.

Hereinafter, the implementation of the toothbrush of the present invention will be described with reference to Fig. 1 to Fig. 9. Furthermore, the following implementation represents one form of the present invention, does not limit the present invention, and can be arbitrarily changed within the scope of the technical concept of the present invention. In addition, in the following figures, in order to facilitate the understanding of each structure, the scale or quantity in each structure is different from the actual structure.

FIG1 is a front view showing a portion of a toothbrush 10 according to the present embodiment. As shown in FIG1 , the toothbrush 10 is formed by integrally forming a handle 2 and a head 3 extending from the handle 2.

One side of the head 3 is a hair-planting surface 3a on which a plurality of hair bundles are planted. A hair brush 4 is provided on the hair-planting surface 3a of the head 3 of the present embodiment, and the hair brush 4 includes three hair bundles with height differences.

In the following description, the thickness direction of the head 3 orthogonal to the hair-implanted surface 3a is set as the Z direction, the extension direction of the handle 2, that is, the length direction of the head 3 is set as the Y direction, and the direction orthogonal to the Y direction and the Z direction, that is, the width direction of the head 3 is set as the X direction. In addition, in the Z direction, the side of the hair-implanted surface 3a is set as the front side, and the side opposite to the hair-implanted surface 3a is set as the back side for appropriate description.

The thickness, length and width of the head 3 are not particularly limited. The thinner the head 3 is, the better the operability in the oral cavity can be. However, if it is too thin, the strength of the head 3 is likely to be insufficient. Therefore, the thickness of the head 3 can be determined in consideration of the material of the handle 2, and is preferably 1.5 mm or more and 5 mm or less, and more preferably 2 mm or more and 3 mm or less.

The brush 4 includes a plurality of outer hair bundles 20 arranged at the outermost periphery and a plurality of inner hair bundles 30 arranged at the inner side of the outer hair bundles 20. The plurality of outer hair bundles 20 are implanted in each implantation hole 5 provided at the edge of the implantation surface 3a, thereby forming an outer hair bundle group surrounding the inner hair bundles 30. The plurality of inner hair bundles 30 are implanted in a plurality of implantation holes 6 disposed inwardly of the implantation holes 5 and biased toward the center of the implantation surface 3a, thereby forming an inner hair bundle group. In this embodiment, the implantation holes 5 and the implantation holes 6 are arranged in a grid shape.

FIG2 is a cross-sectional view taken along the line A-A in FIG1. In the present embodiment, as shown in FIG2, the outer hair bundle 20 has a half hair bundle portion 21a and a half hair bundle portion 21b having hair lengths different from each other. The hair length is the distance in the Z direction from the hair implantation surface 3a to the front end of the outer hair bundle 20. That is, the outer hair bundle 20 includes a plurality of bristles 22, and the plurality of bristles 22 are implanted by setting a height difference between the half hair bundle portion 21a on one side of the plane 7 and the half hair bundle portion 21b on the other side.

Specifically, the flat wire 7 is inserted between the folded outer hair bundles 20, and the flat wire 7 is driven into the hair-implanting hole 5, so that the outer hair bundles 20 are implanted on the hair-implanting surface 3a of the head 3. In this embodiment, as shown in FIG. 1, all the flat wires 7 are driven into the hair-implanting hole 5 at a predetermined angle relative to the long side direction (Y direction) of the head 3. The directions of the flat wires 7 are the same.

The angle of the horizontal line 7 is not particularly limited, but is preferably greater than 0 degrees and less than 45 degrees with respect to the length direction of the head.

The half hair bundle portion 21a is arranged on the outer peripheral side. The half hair bundle portion 21b is arranged on the inner side than the half hair bundle portion 21a. The hair length of the half hair bundle portion 21a is shorter than the hair length of the half hair bundle portion 21b. That is, the outer hair bundle 20 having the half hair bundle portion 21a and the half hair bundle portion 21b is folded asymmetrically through the horizontal line 7 to implant hair.

The inner hair bundle 30 has a half hair bundle portion 31a and a half hair bundle portion 31b. The plurality of inner hair bundles 30 also include a plurality of second bristles 32, and the plurality of second bristles 32 are respectively planted with a half hair bundle portion 31a on one side of the horizontal line 7 and a half hair bundle portion 31b on the other side.

Specifically, the flat wire 7 is inserted between the inner hair bundles 30 folded in half, and the flat wire 7 is driven into the hair-implanting hole 6, so that the inner hair bundles 30 are implanted on the hair-implanting surface 3a of the head 3. In this embodiment, as shown in FIG. 1 , all the flat wires 7 are driven into the hair-implanting hole 6 at a predetermined angle relative to the long side direction (Y direction) of the head 3. The directions of the flat wires 7 are the same.

The half hair bundle portion 31a is arranged on the outer peripheral side than the half hair bundle portion 31b. The hair length of the half hair bundle portion 31a is the same as the hair length of the half hair bundle portion 31b. That is, the inner hair bundle 30 having the half hair bundle portion 31a and the half hair bundle portion 31b is folded symmetrically through the horizontal line 7 to implant hair.

The hair length of the half hair bundle portion 31a and the hair length of the half hair bundle portion 31b are, for example, 12 mm. The hair length of the half hair bundle portion 31a and the hair length of the half hair bundle portion 31b are longer than the hair length of the half hair bundle portion 21a and the hair length of the half hair bundle portion 21b. Therefore, the hair length of the brush 4 is the longest in the center of the X direction (width direction), and the hair length gradually shortens toward the outer peripheral side in the X direction, and the front end forms a dome shape when observed in the Y direction. That is, the hair length of the inner hair bundle 30 is longer than the hair length of the outer hair bundle 20. By making the hair length of the inner hair bundle 30 longer than the hair length of the outer hair bundle 20, a structure that fits the tooth neck is formed, and the cleaning feeling and periodontal pocket cleaning power are improved.

The second bristles 32 constituting the inner bristle bundle 30 are not particularly limited, and may be straight bristles or super tapered (ST) bristles at both ends (tapered bristles whose diameter gradually tapers toward the bristle tip), spiral ST bristles (spiral tapered bristles whose diameter gradually tapers toward the bristle tip), and the later-described front end branched bristles (feathers, tapered branched bristles). In this embodiment, ST bristles are used as the second bristles 32 constituting the inner bristle bundle 30. By including ST bristles in the inner bristle bundle 30, the cleaning power of the periodontal pocket can be improved. The bristles of the spiral ST bristles are twisted in the long-side direction to form spiral ridges on the periphery. When force or vibration is applied in the direction in which the multiple bristles that have become a bundle are bent, the bristles contact each other and generate friction, so the bristles become difficult to bend. Therefore, the bristles bundle formed by bundling the bristles is given appropriate rigidity, and the waist of the bristles becomes stronger. On the other hand, the bristles are reduced in diameter toward the front end, so the front ends of the bristles do not interfere with each other, and the vicinity of the front ends of the bristles can reach the inside of the periodontal pocket. Therefore, by including the spiral ST bristles in the inner bristle bundle 30, the cleaning power of the periodontal pocket can be further improved.

The bristle diameter (diameter) of the second bristles 32 constituting the inner bristle bundle 30 is not particularly limited, but is preferably 5 mil or more and 7 mil or less from the viewpoint of improving the touch feeling on the gums and the cleaning power.

In this embodiment, the bristles 22 constituting the outer bristle bundle 20 are front branched bristles (hereinafter referred to as front branched bristles 22) whose front ends are branched on both sides in the length direction. By including the front branched bristles 22 in the outer bristle bundle 20, the soft touch feeling on the gums can be improved.

As the front end branched hair 22, for example, feather-shaped bristles formed by cutting the front end of a hollow filament, or tapered branched hairs whose branched parts reduce in diameter toward the front end, etc. As the front end branched hair 22 in this embodiment, tapered branched hairs whose branched parts taper toward the front end are used.

The front end of the bristles of the front branched hair 22 is branched, and the tips of the branched hairs are thin. The branched hair parts are bent to show cushioning properties, so the hair waist is low when it touches the gums, and there is less pain. In addition, the front branched hair 22 is folded asymmetrically through the horizontal line 7, thereby generating a hair length difference between the half hair bundle part 21a and the half hair bundle part 21b. By generating a hair length difference between the half hair bundle part 21a and the half hair bundle part 21b, the interference between the branch parts is suppressed, and the cushioning properties when contacting the gums are improved.

Furthermore, by creating a difference in hair length between the half hair bundle portion 21a and the half hair bundle portion 21b, when the hair tip contacts the gum, the half hair bundle portion 21b with a higher hair length contacts the gum first, and then the half hair bundle portion 21a with a lower hair length contacts the gum. Therefore, the rise of the hair waist when contacting the gum becomes lower, which can further improve the reduction of pain.

In addition, since the front branched hairs 22 are tapered branched hairs, the sense of touch is improved and the cleaning power of the periodontal pocket can be improved.

The bristle diameter (diameter) of the front branched hairs 22 (the bristles in the unbranched portion) constituting the outer bristle bundle 20 is not particularly limited, but is preferably 6 mil or more and 9 mil or less from the viewpoint of improving the touch feeling and cleaning power on the gums.

FIG3 is an enlarged view of the periphery of the forked portion in the front forked hair 22. As shown in FIG3, a forked portion 22a and a forked portion 22b are provided at the front end of the front forked hair 22. The forked portion 22a constitutes a part of the half hair bundle portion 21a. The forked portion 22b constitutes a part of the half hair bundle portion 21b.

The number of branches of the branching portion 22a and the branching portion 22b is not particularly limited, but preferably two or more branches (three branches in FIG. 3 ), more preferably two or more branches and less than twenty branches, further preferably two or more branches and less than fifteen branches, further preferably two or more branches and less than seven branches. By increasing the number of branches, the contact feeling when the branching portion 22a and the branching portion 22b contact the gum can be improved.

The bifurcation portion 22a and the bifurcation portion 22b are formed with the same bifurcation length (length in the Z direction) L1. The bifurcation length L1 of the bifurcation portion 22a and the bifurcation portion 22b is preferably 0.5 mm or more, more preferably 1.0 mm or more, and further preferably 1.5 mm or more. In addition, the bifurcation length L1 of the bifurcation portion 22a and the bifurcation portion 22b is preferably 6.0 mm or less, more preferably 4.0 mm or less, further preferably 3.0 mm or less, particularly preferably 2.5 mm or less, and most preferably 2.0 mm or less. The hair length of the bristles 22 including the bifurcation portion 22a is shorter than the hair length of the bristles 22 including the bifurcation portion 22b. That is, the hair length of the half-hair bundle portion 21a is shorter than the hair length of the half-hair bundle portion 21b.

By making the hair length of the half hair bundle portion 21a shorter than the hair length of the half hair bundle portion 21b, the step difference becomes gentle regardless of the direction in which the teeth are brushed, so that when the brush 4 contacts the gums, the touch feeling can be improved.

The difference L2 between the hair length of the bristles 22 including the bifurcation 22a and the hair length of the bristles 22 including the bifurcation 22b (the difference between the hair length of the half-hair bundle 21a and the hair length of the half-hair bundle 21b) is preferably 0.5 mm or more and 2.0 mm or less, more preferably 0.5 mm or more and 1.5 mm or less, and further preferably 0.5 mm or more and 1.0 mm or less. That is, as the lower limit of the hair length difference L2, it is preferably 0.5 mm or more, and more preferably 0.75 mm or more. In addition, as the upper limit of the hair length difference L2, it is preferably 2.0 mm or less, more preferably 1.5 mm or less, and further preferably 1.0 mm or less. When the hair length difference L2 is less than 0.5 mm, there is a possibility that in the outer hair bundle 20, when the hair tip is bent, the area where the bifurcation 22a and the bifurcation 22b interfere with each other becomes longer, the function as a buffer material is reduced, and the contact feeling is damaged. When the hair length difference L2 exceeds 2.0 mm, there is a possibility that in the outer hair bundle 20, the length of the bifurcation 22b supported by the bifurcation 22a becomes shorter, thereby lowering the hair waist and failing to ensure the cleaning force in the oral cavity. In addition, there is a possibility that even if the hair tip of the bifurcation 22b is bent, the bifurcation 22a is difficult to contact the gum, and the pressure on the gum becomes localized, and the contact feeling is damaged. Therefore, by setting the hair length difference L2 to be greater than 0.5 mm and less than 2.0 mm, it is possible to improve the touch feeling and the cleaning power.

In addition, the value represented by L2/L1 is preferably 0.08 or more and 4.0 or less, more preferably 0.17 or more and 3.0 or less, and further preferably 0.17 or more and 2.0 or less. That is, the lower limit of the value represented by L2/L1 is preferably 0.08 or more, and more preferably 0.17 or more. The upper limit of the value represented by L2/L1 is preferably 4.0 or less, more preferably 3.0 or less, and further preferably 2.0 or less. When the value represented by L2/L1 is less than 0.08, there is a possibility that in the outer hair bundle 20, when the hair tip is bent, the area where the bifurcation 22a and the bifurcation 22b interfere with each other becomes longer, the function as a buffer material is reduced, and the touch sense is damaged. When the value represented by L2/L1 exceeds 4.0, there is a possibility that the length of the outer hair bundle 20 supported by the bifurcation 22a in the bifurcation 22b becomes shorter, thereby lowering the hair waist and failing to ensure the cleaning force in the oral cavity. In addition, there is a possibility that even if the hair tip of the bifurcation 22b is bent, the bifurcation 22a is difficult to contact the gum, and the pressure on the gum becomes localized, and the touch feeling is damaged. Therefore, the value represented by L2/L1 is set to be greater than 0.08 and less than 4.0, thereby seeking to improve the touch feeling and improve the cleaning force.

When the value represented by L2/L1 is less than 1.0, that is, when the hair length difference L2 is smaller than the bifurcation length L1 of the bifurcation 22b constituting the maximum hair length, the bifurcation 22a and the bifurcation 22b overlap in the Z direction (hair length direction). The overlap amount (i.e., L1-L2) between the bifurcation 22a and the bifurcation 22b is preferably 0.1 mm or more and 5.5 mm or less, more preferably 0.5 mm or more and 3.0 mm or less, and further preferably 0.5 mm or more and 2.0 mm or less. That is, the lower limit of the overlap amount is preferably 0.1 mm or more, and more preferably 0.5 mm or more. The upper limit of the overlap amount is preferably 5.5 mm or less, more preferably 3.0 mm or less, and further preferably 2.0 mm or less. The overlap amount between the branching portion 22a and the branching portion 22b is preferably not less than 0.8% and not more than 61.1% of the maximum hair length, more preferably not less than 3.8% and not more than 33.3%, and even more preferably not less than 3.8% and not more than 22.2%.

The length of the bristles 22 including the bifurcated portion 22a (the length of the half-bristle bundle portion 21a) is, for example, 10 mm. The length of the bristles 22 including the bifurcated portion 22b (the length of the half-bristle bundle portion 21b) is, for example, 11 mm. Therefore, the length of the half-bristle bundle portion 21a and the length of the half-bristle bundle portion 21b are shorter than the length of the inner bristle bundle 30.

As described above, the toothbrush 10 of the present embodiment has an outer bristle bundle 20 arranged at the outermost periphery, and an inner bristle bundle 30 arranged on the inner side of the outer bristle bundle 20. The outer bristle bundle 20 is formed by folding the front end branched hair 22 that branches the front end of the bristle on both sides in the length direction in half, and has two half-bristle bundle portions 21a and 21b with different hair lengths, thereby helping to improve the touch and cleaning power.

[Example] The following examples are presented to explain the present invention in detail, but the present invention is not limited to the following examples and can be implemented with appropriate changes within the scope of the gist.

(Example 1 to Example 6, Comparative Example 1 to Comparative Example 3) According to the specifications shown in [Table 1], samples of Example 1 to Example 6 and Comparative Example 1 to Comparative Example 3 were prepared. Specifically, regarding the folding of the outer hair bundles, the samples of Example 1 to Example 6 and Comparative Example 2 to Comparative Example 3 were set to be asymmetric (the hair lengths of the half hair bundles were different), and the sample of Comparative Example 1 was set to be symmetric (the hair lengths of the half hair bundles were the same).

Regarding the bristles of the inner hair bundles, the samples of Example 1 and Comparative Example 1 are set to forked straight hairs, the sample of Example 2 is set to forked tapered hairs, the samples of Examples 3 to 5 and Comparative Example 3 are set to tapered hairs, the sample of Example 6 is set to spiral tapered hairs, and the sample of Comparative Example 2 is set to straight hairs.

Regarding the bristles of the outer bristle bundles, the samples of Example 1 and Comparative Example 1 were set to branched straight bristles, the samples of Examples 2 to 6 were set to branched tapered bristles, the sample of Comparative Example 3 was set to tapered bristles, and the sample of Comparative Example 2 was set to straight bristles.

Regarding the relationship between the maximum hair length of the outer hair bundle and the maximum hair length of the inner hair bundle, the samples of Examples 1 to 3 and Comparison Examples 1 to 3 set the maximum hair length of the outer hair bundle to be the same as the maximum hair length of the inner hair bundle, and the samples of Examples 4 to 6 make the maximum hair length of the inner hair bundle longer than the maximum hair length of the outer hair bundle.

Regarding the relationship of the hair length of the half hair bundle in the outer hair bundle, the samples of Examples 1 to 4 and Comparison Examples 2 to 3 make the hair length of the half hair bundle on the outer side longer than the hair length of the half hair bundle on the inner side only on one side in the width direction of the head, the samples of Examples 5 and 6 make the hair length of the half hair bundle on the outer side longer than the hair length of the half hair bundle on the inner side on both sides in the width direction of the head, and the sample of Comparison Example 1 sets the hair length of the half hair bundle on the outer side and the hair length of the half hair bundle on the inner side to be the same.

The dimensions of each example are evaluated below. (Example 1) Inner bristle tuft ・Bristle diameter (diameter): 6.5 mil ・Branched straight bristles: Number of branches is five, L1 = 2 mm ・Maximum bristle length = 12 mm Outer bristle tuft ・Bristle diameter (diameter): 8.0 mil ・Branched straight bristles: Number of branches is five, L1 = 2 mm ・Folded (asymmetric): L2 = 1 mm, L1-L2 = 1 mm, shape shown in Figure 3. ・Bristle length: Half bristle tuft 21b = 12 mm, half bristle tuft 21a = 11 mm

(Example 2) Inner bristle tuft ・Bristle diameter (diameter): 6.5 mil ・Branched conical bristle: Number of branches is three, L1 = 2 mm ・Maximum bristle length = 12 mm Outer bristle tuft ・Bristle diameter (diameter): 8.0 mil ・Branched conical bristle: Number of branches is three, L1 = 2 mm ・Folded (asymmetric): L2 = 1 mm, L1-L2 = 1 mm, shape shown in Figure 3. ・Bristle length: Half bristle tuft 21b = 12 mm, half bristle tuft 21a = 11 mm

(Example 3) Inner bristle tuft ・Bristle diameter (diameter): 6.5 mil ・Tapered bristle: 0 branches, L1 = 0 mm ・Maximum bristle length = 12 mm Outer bristle tuft ・Bristle diameter (diameter): 8.0 mil ・Forked tapered bristle: 3 branches, L1 = 2 mm ・Folded (asymmetric): L2 = 1 mm, L1-L2 = 1 mm, as shown in Figure 3. ・Bristle length: Half bristle tuft 21b = 12 mm, half bristle tuft 21a = 11 mm

(Example 4) Inner bristle tuft ・Bristle diameter (diameter): 6.5 mil ・Tapered bristle: 0 branches, L1 = 0 mm ・Maximum bristle length = 12 mm Outer bristle tuft ・Bristle diameter (diameter): 8.0 mil ・Forked tapered bristle: 3 branches, L1 = 0 mm ・Folded (asymmetric): L2 = 1 mm, L1-L2 = 1 mm, as shown in Figure 3. ・Bristle length: Half bristle tuft 21b = 11 mm, half bristle tuft 21a = 10 mm

(Example 5) Inner bristle tuft ・Bristle diameter (diameter): 6.5 mil ・Tapered bristle: 0 branches, L1 = 0 mm ・Maximum bristle length = 12 mm Outer bristle tuft ・Bristle diameter (diameter): 8.0 mil ・Forked tapered bristle: 3 branches, L1 = 2 mm ・Folded (asymmetric): L2 = 1 mm, L1-L2 = 1 mm, as shown in Figure 3. ・Bristle length: Half bristle tuft 21b = 11 mm, half bristle tuft 21a = 10 mm

(Example 6) Inner bristle tuft ・Bristle diameter (diameter): 6.5 mil ・Spiral conical bristle: 0 branches, L1 = 0 mm ・Maximum bristle length = 12 mm Outer bristle tuft ・Bristle diameter (diameter): 8.0 mil ・Cranial conical bristle: 3 branches, L1 = 2 mm ・Folded (asymmetric): L2 = 1 mm, L1-L2 = 1 mm, the shape shown in Figure 3. ・Bristle length: half bristle tuft 21b = 11 mm, half bristle tuft 21a = 10 mm

(Comparison example 1) Inner bristle ・Bristle diameter (diameter): 6.5 mil ・Branched straight bristles: 5 branches, L1 = 2 mm ・Maximum bristle length = 12 mm Outer bristle ・Bristle diameter (diameter): 8.0 mil ・Branched straight bristles: 5 branches, L1 = 2 mm ・Folding (symmetric): L2 = 0 mm ・Bristle length: Half bristle 21b = Half bristle 21a = 12 mm

(Comparison example 2) Inner bristle ・Bristle diameter (diameter): 6.5 mil ・Straight bristles: 0 forks, L1 = 0 mm ・Maximum bristle length = 12 mm Outer bristle ・Bristle diameter (diameter): 8.0 mil ・Straight bristles: 0 forks, L1 = 0 mm ・Folding (asymmetric): L2 = 1 mm ・Bristle length: Half bristle 21b = 12 mm, half bristle 21a = 11 mm

(Comparison example 3) Inner bristle ・Bristle diameter (diameter): 6.5 mil ・Tapered bristles: 0 forks, L1 = 0 mm ・Maximum bristle length = 12 mm Outer bristle ・Bristle diameter (diameter): 8.0 mil ・Tapered bristles: 0 forks, L1 = 0 mm ・Fold (asymmetric): L2 = 1 mm ・Bristle length: Half bristle 21b = 12 mm, half bristle 21a = 11 mm

[Evaluation items] For samples of Example 1 to Example 6 and Comparative Example 1 to Comparative Example 3, the touch feeling of the toothbrush, the cleaning feeling, and the periodontal pocket cleaning power were evaluated.

[Evaluation method] <Evaluation of touch feeling> A panel of 10 people cleaned the oral cavity with each toothbrush and evaluated the touch feeling of the gums at that time according to the following evaluation criteria. The following evaluation was performed based on the average score of the 10-person panel. The average score of the 10-person panel was 5.5 points or more, and was set as "◎ (very good)", the average score was 4.0 points or more and less than 5.5 points was set as "○ (good)", the average score was 2.5 points or more and less than 4.0 points was set as "△ (not bad)", and the average score was less than 2.5 points was set as "× (bad)". <Evaluation criteria> 7 points: Very good touch feeling. 6 points: Fairly good touch feeling. 5 points: Slightly good touch feeling. 4 points: Neither. 3 points: The touch is slightly poor. 2 points: The touch is quite poor. 1 point: The touch is very poor.

<Evaluation of cleaning feeling> A panel of 10 people cleaned the oral cavity with each toothbrush and evaluated the cleaning feeling (the overall cleaning feeling in the oral cavity) at that time according to the following evaluation criteria. The following evaluation was performed based on the average score of the 10-person panel. The average score of the 10-person panel was set to "◎ (very good)" if it was 5.5 points or more, "○ (good)" if it was 4.0 points or more but less than 5.5 points, "△ (not bad)" if it was 2.5 points or more but less than 4.0 points, and "× (bad)" if it was less than 2.5 points. <Evaluation criteria> 7 points: The cleaning feeling was very good. 6 points: The cleaning feeling was quite good. 5 points: The cleaning feeling was slightly good. 4 points: Neither. 3 points: The cleaning quality is slightly poor. 2 points: The cleaning quality is quite poor. 1 point: The cleaning quality is very poor.

<Evaluation of periodontal pocket cleaning power> A panel of 10 people cleaned the oral cavity with each toothbrush and evaluated the cleaning effect of the periodontal pocket at that time according to the following evaluation criteria. The following evaluation was performed based on the average score of the 10-person panel. The average score of the 10-person panel was 6.0 points or more, and was set as "◎+ (very good)", the average score was 5.5 points or more and less than 6.0 points was set as "◎ (very good)", the average score was 4.0 points or more and less than 5.5 points was set as "○ (good)", the average score was 2.5 points or more and less than 4.0 points was set as "△ (not bad)", and the average score was less than 2.5 points was set as "× (poor)". <Evaluation criteria> 7 points: The dirt in the periodontal pocket can be felt very strongly. 6 points: The dirt in the periodontal pockets can be felt quite strongly. 5 points: The dirt in the periodontal pockets can be felt slightly strongly. 4 points: Neither. 3 points: The dirt in the periodontal pockets can be felt very little. 2 points: The dirt in the periodontal pockets can be felt almost not. 1 point: The dirt in the periodontal pockets can be felt not at all.

[Table 1] Embodiment 1 Embodiment 2 Embodiment 3 Embodiment 4 Embodiment 5 Embodiment 6 Comparison Example 1 Comparison Example 2 Comparison Example 3 Folding of outer hair tufts Asymmetric Asymmetric Asymmetric Asymmetric Asymmetric Asymmetric Symmetry Asymmetric Asymmetric Inner bristle tufts Straight split hair Branched cone hairs Cone Hair Cone Hair Cone Hair Spiral cone hair Straight split hair Straight hair Cone Hair Outer bristle tufts Straight split hair Branched cone hairs Branched cone hairs Branched cone hairs Branched cone hairs Branched cone hairs Straight split hair Straight hair Cone Hair Maximum hair length Inner hair bundle = Outer hair bundle Inner hair bundle = Outer hair bundle Inner hair bundle = Outer hair bundle Inner hair bundle > Outer hair bundle Inner hair bundle > Outer hair bundle Inner hair bundle > Outer hair bundle Inner hair bundle = Outer hair bundle Inner hair bundle = Outer hair bundle Inner hair bundle = Outer hair bundle Relationship between the hair length of the half-hair bundle in the outer hair bundle Sense of touch △ ○ ○ ○ ◎ ◎ × × × Cleaning up the feeling ○ ○ ○ ◎ ◎ ◎ ○ ○ ○ Periodontal pocket cleaning power △ ○ ◎ ◎ ◎ ◎＋ △ × ○

As shown in [Table 1], in the samples of Examples 1 to 6 in which the outer hair bundles are formed by the front branched hairs and the outer hair bundles are asymmetrically folded, and the hair lengths of the half hair bundles are different, good evaluations were obtained in all aspects of touch, cleaning feel and periodontal pocket cleaning power.

In contrast, even though the outer hair bundles were formed by the front branched hairs, the outer hair bundles were folded symmetrically and the hair length of the half hair bundles was the same, the sample of Comparative Example 1 did not receive good evaluation in terms of touch. In addition, even though the outer hair bundles were folded asymmetrically, the outer hair bundles were not formed by the front branched hairs, and the samples of Comparative Examples 2 to 3 did not receive good evaluation in terms of touch. Furthermore, in the sample of Comparative Example 2, in which the inner hair bundles were straight hairs, the periodontal pocket cleaning power was not received good evaluation.

In addition, the samples of Examples 3 to 6 in which the inner hair bundles were formed by tapered hairs received better evaluations in terms of periodontal pocket cleaning power than the samples of Examples 1 to 2 in which the inner hair bundles were formed by front branched hairs. Furthermore, the samples of Examples 4 to 6 in which the maximum hair length of the inner hair bundles was longer than the maximum hair length of the outer hair bundles received better evaluations in terms of cleaning realism than the samples of Examples 1 to 3 in which the maximum hair length of the outer hair bundles was the same as the maximum hair length of the inner hair bundles.

The samples of Examples 2 to 6 in which the outer hair bundles are formed by forked tapered hairs received better evaluations in terms of touch than the sample of Example 1 in which the outer hair bundles are formed by forked straight hairs. Moreover, the samples of Examples 5 and 6 in which the hair length of the outer half of the hair bundles is longer than the hair length of the inner half of the hair bundles on both sides of the width direction of the head received better evaluations in terms of touch than the samples of Examples 1 to 4 in which the hair length of the outer half of the hair bundles is longer than the hair length of the inner half of the hair bundles on only one side of the width direction of the head. Compared with Example 5, Example 6, in which the bristles of the inner bristle bundle of Example 5 were changed from tapered bristles to spiral tapered bristles, received better evaluation in terms of periodontal pocket cleaning ability.

The above description has been made of suitable embodiments of the present invention with reference to the accompanying drawings, but the present invention is not limited to the examples described above. The various shapes or combinations of the components shown in the examples are examples, and various changes can be made according to design requirements, etc. without departing from the scope of the present invention.

For example, in the above-described embodiment, the bifurcation portion 22a and the bifurcation portion 22b have the same bifurcation length L1, and the bristles 22 of the bifurcation portion 22a are shorter than the bristles 22 of the bifurcation portion 22b, but the present invention is not limited to this structure. For example, as shown in FIG. 4 , the bifurcation length L3 of the bifurcation portion 22a may be shorter than the bifurcation length L1 of the bifurcation portion 22b, and the bristle length difference L2 may be shorter than the bifurcation length L1 of the bifurcation portion 22b.

In addition, as shown in FIG. 5 , the bifurcation length L3 of the bifurcation portion 22a may be longer than the bifurcation length L1 of the bifurcation portion 22b, and the hair length difference L2 may be shorter than the bifurcation length L1 of the bifurcation portion 22b. Furthermore, as shown in FIG. 6 , the bifurcation portion 22a and the bifurcation portion 22b may have the same bifurcation length L1, and the hair length difference L2 may be longer than the bifurcation length L1. In addition, as shown in FIG. 7 , the bifurcation portion 22a and the bifurcation portion 22b may have the same bifurcation length L1, and the hair length difference L1 may be the same length as the bifurcation length L1.

In addition, as shown in Fig. 8, the bifurcation length L3 of the bifurcation portion 22a may be shorter than the bifurcation length L1 of the bifurcation portion 22b, and the hair length difference L2 may be longer than the bifurcation length L1 of the bifurcation portion 22b. Furthermore, as shown in Fig. 9, the bifurcation length L3 of the bifurcation portion 22a may be longer than the bifurcation length L1 of the bifurcation portion 22b, and the hair length difference L2 may be longer than the bifurcation length L1 of the bifurcation portion 22b.

In the configuration shown in FIG. 4 and FIG. 5 , the bifurcation length L1 of the bifurcation portion 22b constituting the maximum hair length is greater than the hair length difference L2, so as described above, the bifurcation portion 22a and the bifurcation portion 22b overlap in the Z direction. As shown in FIG. 4 , in the case of L1> (L2+L3), the overlap amount becomes the bifurcation length L3. As the overlap amount L3, it is preferably 0.5 mm or more and 5.5 mm or less, more preferably 0.5 mm or more and 3.0 mm or less, and further preferably 0.5 mm or more and 2.0 mm or less. As the overlap amount L3, it is preferably 3.8% or more and 61.1% or less of the maximum hair length, more preferably 3.8% or more and 33.3% or less, and further preferably 3.8% or more and 22.2% or less. In FIG. 4 , even in the case of L2＜L1≦（L2＋L3） (i.e., the case of the shape of FIG. 5 ), it is preferable to select the above-mentioned overlap amount. [Industrial Applicability]

The present invention can be applied to toothbrushes.

2: handle 3: head 3a: implanted surface 4: brush 5, 6: implanted holes 7: flat line 10: toothbrush 20: outer hair bundle 21a, 21b, 31a, 31b: half hair bundle 22: bristles (front branched hair) 22a, 22b: branching part 30: inner hair bundle 32: second bristle L1: branching length/hair length difference L2: hair length difference L3: branching length/overlap amount X, Y, Z: direction

FIG. 1 is a diagram showing an embodiment of the present invention and is a front view showing a portion of a toothbrush. FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1 . FIG. 3 is a partially enlarged view of the periphery of the bifurcation portion in the front bifurcation hair 22. FIG. 4 is a partially enlarged view of a modification of the front bifurcation hair 22. FIG. 5 is a partially enlarged view of a modification of the front bifurcation hair 22. FIG. 6 is a partially enlarged view of a modification of the front bifurcation hair 22. FIG. 7 is a partially enlarged view of a modification of the front bifurcation hair 22. FIG. 8 is a partially enlarged view of a modification of the front bifurcation hair 22. FIG. 9 is a partially enlarged view of a modification of the front bifurcation hair 22.

3: Head

3a: Hair-planted surface

5, 6: Pore transplantation

7: Flat line

20: Outer hair bundle

21a, 21b, 31a, 31b: Half hair bundle

22: Bristles (branched hairs at the front)

30: Inner hair bundle

32: Second bristle

X, Y, Z: direction

Claims (9)

A toothbrush, characterized in that it comprises: a head with a plurality of hair bundles planted on a hair planting surface, and a handle extending from the head, wherein the hair bundles have outer hair bundles arranged at the outermost periphery, and inner hair bundles arranged at the inner side of the outer hair bundles, wherein the outer hair bundles are formed by folding the front end bifurcated hairs that bifurcate the front end of the bristles on both sides in the length direction, and have two half hair bundles with different hair lengths, and if the length of the bifurcation in the front end bifurcated hairs is set as L1, and the difference in hair length of the two half hair bundles is set as L2, then the value of L2/L1 is greater than 0.08 and less than 4.0, and the value of L1-L2 is greater than 0.1 mm and less than 5.5 mm. A toothbrush as described in claim 1, wherein the bristles are tapered bristles that taper toward the front end. A toothbrush as described in claim 1 or claim 2, wherein the inner bristle bundle has a plurality of second bristles, and the second bristles are tapered bristles that taper toward the front end. A toothbrush as described in claim 1 or claim 2, wherein the hair length of the inner hair bundle is longer than the hair length of the outer hair bundle. A toothbrush as described in claim 1 or claim 2, wherein among the two half-hair bundle portions, the outer half-hair bundle portion is shorter than the inner half-hair bundle portion. A toothbrush as described in claim 1 or claim 2, wherein the difference in hair length between the two half-hair bundles is greater than 0.5 mm and less than 2.0 mm. A toothbrush as described in claim 1 or claim 2, wherein the front end of the front branched hair branches into two or more. A toothbrush as described in claim 1 or claim 2, wherein the diameter of the bristles is greater than 6 mil and less than 9 mil. A toothbrush as described in claim 1 or claim 2, wherein the diameter of the second bristles constituting the inner bristle bundle is greater than 5 mil and less than 7 mil.

Images