toothbrush

Abstract

To provide a toothbrush capable of contributing to improvement of an abutting feeling and cleaning power.SOLUTION: A toothbrush includes: a head part 3 having a bristle implantation surface 3a on which a plurality of bristle bundles are implanted; and a handle body extending from the head part. The bristle bundles include outside bristle bundles 20 arranged at the outermost periphery and inside bristle bundles 30 arranged inside the outside bristle bundles. An outside bristle bundle is formed by folding tip branching bristles 22 in two, each tip branching bristle having branching tips on both sides in a length direction; and has two semi bristle bundle parts 21a, 21b having bristle lengths differing from each other.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a toothbrush. [Background technology]

[0002] Periodontal disease causes pain when the toothbrush comes into contact with the gums. If bristles with low stiffness are used to improve the feeling of contact with the gums, the basic function of cleaning the oral cavity, which is a problem, will be reduced. For example, Patent Document 1 discloses a toothbrush in which bristle bundles with branched bristles, in which only the tips of the bristles are branched, are provided on both outer sides of the head in the width direction. Furthermore, Patent Document 2 discloses a toothbrush in which at least one of the outer bristle bundles and the inner bristle bundles has two half-bristle bundle portions with different bristle lengths.

[0003] In the toothbrush disclosed in Patent Document 1, the branched bristles at the ends bend and function as a cushion, improving the comfort of contact with the gums, and because the branched bristles are only provided at the ends of the bristles, a decrease in bristles stiffness is suppressed, ensuring oral cavity cleaning power.In the toothbrush disclosed in Patent Document 2, the bristles constituting the brush have three levels of height difference in the bristles, which not only allows the bristles to come into contact with a wide range of areas to be cleaned in the oral cavity, but also ensures high cleaning performance for each area to be cleaned. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-209097 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-209016 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the toothbrush of Patent Document 1, when bristle bundles with branched bristles at the ends are folded symmetrically and implanted, the branched bristles have the same bristle length, which restricts the range of movement of the bristle tips and reduces their function as a cushioning material. Also, Patent Document 2 discloses that branched bristles may be used except for the half-hair bundles of the outer bristle bundles that have the longest bristles, but with this configuration, branched bristles are not provided in the half-hair bundles of the outer bristle bundles that are likely to come into contact with the gums, making it difficult to feel them as a cushioning material and not contributing to improving the feeling of contact with the gums.

[0006] The present invention has been made in consideration of the above points, and an object of the present invention is to provide a toothbrush that is gentle on the gums and contributes to improved cleaning power. [Means for solving the problem]

[0007] According to a first aspect of the present invention, there is provided a toothbrush having a head portion having a plurality of bristle bundles planted on a bristle implantation surface, and a handle body extending from the head portion, wherein the bristle bundles have outer bristle bundles arranged at the outermost periphery and inner bristle bundles arranged inside the outer bristle bundles, and the outer bristle bundles are formed by folding in half bristles that have branched tips on both sides of the length, and have two half bristle bundle portions with different bristle lengths.

[0008] In the toothbrush according to the above aspect of the present invention, the bristles are tapered bristles that taper toward the tip.

[0009] In addition, in the toothbrush according to one aspect of the present invention, the inner bristle bundle has a plurality of second bristles, and the second bristles are tapered bristles that taper toward the tip.

[0010] In addition, in the toothbrush according to one aspect of the present invention, the bristles of the inner bristles have a longer length than the bristles of the outer bristles.

[0011] In the toothbrush according to one aspect of the present invention, the outer half hair bundle of the two half hair bundles is shorter than the inner half hair bundle.

[0012] Furthermore, in the toothbrush according to one aspect of the present invention, the difference in bristle length between the two half-hair bundle portions is 0.5 mm or more and 2.0 mm or less, and when the branched length of the tip-branched bristle is L1 and the difference in bristle length between the two half-hair bundle portions is L2, the numerical value expressed as L2 / L1 is 0.08 or more and 4.0 or less.

[0013] In the toothbrush according to one aspect of the present invention, the tip of the branched bristles is branched into two or more branches.

[0014] In addition, in the toothbrush according to one aspect of the present invention, the diameter of the bristles is not less than 6 mil and not more than 9 mil.

[0015] In the toothbrush according to one aspect of the present invention, the diameter of the second bristles constituting the inner bristle bundle is not less than 5 mil and not more than 7 mil. [Effects of the Invention]

[0016] The present invention can provide a toothbrush that is gentle on the gums and contributes to improved cleaning power. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a diagram showing an embodiment of the present invention, and is a front view showing a part of a toothbrush. FIG. [Figure 2] FIG. 2 is a cross-sectional view taken along line AA in FIG. [Figure 3] 10 is a partially enlarged view of the area around the branched portion of the tip-branched hair 22. FIG. [Figure 4] 10 is a partially enlarged view of a modified example of the tip-branched hair 22. FIG. [Figure 5] 10 is a partially enlarged view of a modified example of the tip-branched hair 22. FIG. [Figure 6] 10 is a partially enlarged view of a modified example of the tip-branched hair 22. FIG. [Figure 7] 10 is a partially enlarged view of a modified example of the tip-branched hair 22. FIG. [Figure 8] 10 is a partially enlarged view of a modified example of the tip-branched hair 22. FIG. [Figure 9] 10 is a partially enlarged view of a modified example of the tip-branched hair 22. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, an embodiment of the toothbrush of the present invention will be described with reference to FIGS. The following embodiment shows one aspect of the present invention, does not limit the present invention, and can be modified as desired within the scope of the technical concept of the present invention. In addition, in the following drawings, the scale and number of each structure are different from the actual structure to make each configuration easier to understand.

[0019] FIG. 1 is a front view showing a portion of a toothbrush 10 according to the present embodiment. As shown in FIG. 1, the toothbrush 10 is formed by integrally molding a handle body 2 and a head portion 3 extending from the handle body 2.

[0020] One side of the head part 3 is a bristle-implanted surface 3a on which multiple bristle bundles are planted. In this embodiment, a brush 4 made up of bristle bundles with three different heights is provided on the bristle-implanted surface 3a of the head part 3.

[0021] In the following description, the thickness direction of the head part 3, which is perpendicular to the hair-implanted surface 3a, is defined as the Z direction, the length direction of the head part 3, which is the direction in which the handle body 2 extends, is defined as the Y direction, and the width direction of the head part 3, which is perpendicular to the Y and Z directions, is defined as the X direction. In addition, in the Z direction, the hair-implanted surface 3a side will be defined as the front side, and the side opposite to the hair-implanted surface 3a will be defined as the back side, as appropriate.

[0022] There are no particular limitations on the thickness, length, and width of the head portion 3. The thinner the head portion 3, the easier it is to operate in the oral cavity, but if it is too thin, the strength of the head portion 3 is likely to be insufficient. Therefore, the thickness of the head portion 3 can be determined taking into consideration the material of the handle body 2, and is preferably, for example, 1.5 mm or more and 5 mm or less, and more preferably 2 mm or more and 3 mm or less.

[0023] The brush 4 is composed of a plurality of outer bristle tufts 20 arranged on the outermost periphery and a plurality of inner bristle tufts 30 arranged inside the outer bristle tufts 20. The outer tufts 20 are implanted in each of the tufting holes 5 provided on the periphery of the implantation surface 3a to form an outer tuft group surrounding the inner tufts 30. The inner tufts 30 are implanted in a plurality of tufting holes 6 provided closer to the center of the implantation surface 3a and more inward than the tufting holes 5 to form an inner tuft group. In this embodiment, the tufting holes 5, 6 are arranged in a lattice pattern.

[0024] FIG. 2 is a cross-sectional view taken along line AA in FIG. In this embodiment, as shown in Fig. 2, the outer hair bundle 20 has a half hair bundle portion 21a and a half hair bundle portion 21b with different hair lengths. The hair length is the distance in the Z direction from the implantation surface 3a to the tip of the outer hair bundle 20. In other words, the outer hair bundle 20 is composed of a plurality of bristles 22 implanted with a difference in height between one half hair bundle portion 21a and the other half hair bundle portion 21b on either side of the flat line 7.

[0025] Specifically, the flat wire 7 is sandwiched between the folded outer hair bundles 20, and the flat wire 7 is driven into the tufting hole 5, thereby implanting the outer hair bundles 20 on the tufting surface 3a of the head part 3. In this embodiment, as shown in Fig. 1, all of the flat wires 7 are driven into the tufting hole 5 at a predetermined angle with respect to the longitudinal direction (Y direction) of the head part 3. The orientation of each flat wire 7 is uniform.

[0026] The angle of the flat line 7 is not particularly limited, but is preferably between 0 degrees and 45 degrees relative to the length direction of the head.

[0027] Half hair bundle 21a is arranged on the outer periphery. Half hair bundle 21b is arranged more inward than half hair bundle 21a. The hair length of half hair bundle 21a is shorter than the hair length of half hair bundle 21b. In other words, outer hair bundle 20 including half hair bundle 21a and half hair bundle 21b is folded asymmetrically across flat line 7 and implanted.

[0028] The inner hair bundle 30 has a half hair bundle portion 31a and a half hair bundle portion 31b. Each of the inner hair bundles 30 is also made up of a plurality of second bristles 32, each having one half hair bundle portion 31a and the other half hair bundle portion 31b planted on either side of the flat wire 7.

[0029] Specifically, a flat wire 7 is sandwiched between the folded inner hair bundles 30, and this flat wire 7 is driven into the tufting hole 6, thereby implanting the inner hair bundles 30 on the tufting surface 3a of the head part 3. In this embodiment, as shown in Fig. 1, all of the flat wires 7 are driven into the tufting hole 6 at a predetermined angle with respect to the longitudinal direction (Y direction) of the head part 3. The orientation of each flat wire 7 is uniform.

[0030] Half hair bundle 31a is positioned closer to the outer periphery than half hair bundle 31b. The hair length of half hair bundle 31a is the same as that of half hair bundle 31b. That is, inner hair bundle 30 including half hair bundle 31a and half hair bundle 31b is folded symmetrically with respect to flat line 7 and implanted.

[0031] The bristle length of the half bristle bundles 31a and 31b is, for example, 12 mm. The bristle length of the half bristle bundles 31a and 31b is longer than the bristle length of the half bristle bundles 21a and 21b. Therefore, the brush 4 has the longest bristle length at the center in the X direction (width direction), and the bristle length gradually decreases toward the outer periphery in the X direction, forming a dome-shaped tip when viewed in the Y direction. In other words, the bristle length of the inner bristle bundles 30 is longer than the bristle length of the outer bristle bundles 20. By making the bristle length of the inner bristle bundles 30 longer than the bristle length of the outer bristle bundles 20, the brush has a structure that fits the cervical area of ​​the teeth, improving the cleaning feel and periodontal pocket cleaning power.

[0032] The second bristles 32 constituting the inner bristle bundle 30 are not particularly limited, and examples thereof include straight bristles, ST bristles at both ends (tapered bristles whose diameter gradually narrows toward the tip), spiral ST bristles (spiral tapered bristles whose diameter gradually narrows toward the tip), and branched bristles (feather bristles, tapered branched bristles) described below. In this embodiment, ST bristles are used as the second bristles 32 constituting the inner bristle bundle 30. By forming the inner bristle bundle 30 from ST bristles, the cleaning power of periodontal pockets can be improved. Spiral ST bristles are twisted in the longitudinal direction to form a spiral ridge on the outer periphery. When force or vibration is applied in a bending direction to the multiple bristles in the bundle, the bristles come into contact with each other, generating friction, making the bristles less likely to bend. This provides the bristles bundle with appropriate rigidity, making the bristles stronger. On the other hand, the diameter of the bristles narrows towards the tip, so the tips of the bristles do not interfere with each other and the area near the tips of the bristles can reach deep into the periodontal pockets. For this reason, by configuring the inner bristle bundle 30 with spiral ST bristles, the cleaning power of the periodontal pockets can be further improved.

[0033] The bristle 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 in terms of improving the feel on the gums and cleaning power.

[0034] In this embodiment, bifurcated bristles (hereinafter referred to as bifurcated bristles 22) in which the tips of the bristles 22 are bifurcated on both sides in the length direction are used as the bristles 22 constituting the outer bristle bundles 20. By forming the outer bristle bundles 20 with bifurcated bristles 22, it is possible to improve the gentle contact feeling on the gums.

[0035] Examples of the branched hairs 22 include feathered hairs in which the tip of a hollow filament is cut, and tapered branched hairs in which the diameter of each branched part decreases toward the tip. In this embodiment, tapered branched hairs in which the branched parts are tapered toward the tip are used as the branched hairs 22.

[0036] The tip of the branched bristles 22 are branched, and each branched bristles has a thin tip, and the branched bristles flex to provide cushioning properties, so that when they come into contact with the gums, the bristles do not stand up as much and cause little pain. In addition, the branched bristles 22 are folded asymmetrically across the flat line 7, which creates a difference in hair length between the half hair bundle 21a and the half hair bundle 21b. The difference in hair length between the half hair bundle 21a and the half hair bundle 21b reduces interference between the branches and improves cushioning properties when they come into contact with the gums.

[0037] Furthermore, due to the difference in hair length between half hair bundle 21a and half hair bundle 21b, when the bristles come into contact with the gums, half hair bundle 21b, which has a longer hair length, comes into contact first, followed by half hair bundle 21a, which has a shorter hair length. As a result, the bristles rise even lower when they come into contact with the gums, further reducing pain.

[0038] Furthermore, tapered branched bristles are used as the tip branched bristles 22, which improves the comfort of contact and contributes to improved cleaning power for periodontal pockets.

[0039] The bristle diameter (diameter) of the branched bristles 22 (bristles at the non-branched portions) that make up the outer bristle bundle 20 is not particularly limited, but it is preferably 6 mil or more and 9 mil or less in order to improve the feel on the gums and cleaning power.

[0040] FIG. 3 is a partially enlarged view of the area around the branched portion of the end-branched hair 22. As shown in FIG. 3, branched portions 22a and 22b are provided at the tip of the tip branched hair 22. The branched portion 22a constitutes a part of the half hair bundle portion 21a. The branched portion 22b constitutes a part of the half hair bundle portion 21b.

[0041] The number of branches in branches 22a and 22b is not particularly limited, but is preferably 2 or more (3 branches in FIG. 3), more preferably 2 to 20 branches, even more preferably 2 to 15 branches, and even more preferably 2 to 7 branches. Increasing the number of branches can improve the feel of branches 22a and 22b when they come into contact with the gums.

[0042] The branched portion 22a and the branched portion 22b are formed to have the same branch length (length in the Z direction) L1. The branch length L1 of branch portion 22a and branch portion 22b is preferably 0.5 mm or more, more preferably 1.0 mm or more, and even more preferably 1.5 mm or more. The branch length L1 of branch portion 22a and branch portion 22b is preferably 6.0 mm or less, more preferably 4.0 mm or less, even more 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 hair 22 including the branched portion 22a is shorter than the hair length of the hair 22 including the branched 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.

[0043] By making the bristle length of the half hair bundle part 21a shorter than that of the half hair bundle part 21b, the step is gentle no matter which direction you brush in, so that the brush 4 feels more comfortable when it comes into contact with the gums.

[0044] The difference L2 between the hair length of the bristles 22 including the branched portion 22a and the hair length of the bristles 22 including the branched portion 22b (the difference between the hair length of the half hair bundle portion 21a and the hair length of the half hair bundle portion 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 even more preferably 0.5 mm or more and 1.0 mm or less. That is, the lower limit of the hair length difference L2 is preferably 0.5 mm or more, and more preferably 0.75 mm or more. Moreover, the upper limit of the hair length difference L2 is preferably 2.0 mm or less, more preferably 1.5 mm or less, and even more preferably 1.0 mm or less. If the bristle length difference L2 is less than 0.5 mm, the area where the branches 22a and 22b interfere with each other when the bristle tips bend in the outer bristle bundle 20 becomes longer, potentially reducing the cushioning function and reducing the feel of the brush. If the bristle length difference L2 exceeds 2.0 mm, the length over which the branches 22b are supported by the branches 22a in the outer bristle bundle 20 becomes shorter, reducing the bristle stiffness and potentially preventing the brush from providing sufficient cleaning power for the oral cavity. Furthermore, even if the bristle tips of the branches 22b bend, the branches 22a are less likely to come into contact with the gums, which may result in localized pressure on the gums and reduce the feel of the brush. Therefore, by setting the bristle length difference L2 to 0.5 mm or more and 2.0 mm or less, the feel of the brush and the cleaning power can be improved.

[0045] Furthermore, 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 even more preferably 0.17 or more and 2.0 or less. That is, the lower limit of the numerical value represented by L2 / L1 is preferably 0.08 or more, and more preferably 0.17 or more. The upper limit of the numerical value represented by L2 / L1 is preferably 4.0 or less, more preferably 3.0 or less, and even more preferably 2.0 or less. If the value represented by L2 / L1 is less than 0.08, the area where branched portions 22a and 22b interfere with each other in the outer bristle bundle 20 when the bristle tips bend becomes longer, which may reduce the cushioning function and reduce the feel of the brush. If the value represented by L2 / L1 exceeds 4.0, the length of branched portion 22b supported by branched portion 22a in the outer bristle bundle 20 becomes shorter, which may reduce the bristle stiffness and prevent the brush from providing sufficient cleaning power for the oral cavity. Furthermore, even if the bristle tips of branched portion 22b bend, branched portion 22a is less likely to come into contact with the gums, which may result in localized pressure on the gums and reduce the feel of the brush. Therefore, by setting the value represented by L2 / L1 to be 0.08 or more and 4.0 or less, the feel of the brush and the cleaning power can be improved.

[0046] When the value expressed by L2 / L1 is less than 1.0, that is, when the hair length difference L2 is smaller than the branch length L1 of the branch portion 22b that constitutes the maximum hair length, the branch portion 22a and the branch portion 22b overlap in the Z direction (hair length direction). The overlap amount between branch portion 22a and branch portion 22b (i.e., L1-L2) 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 even more 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 even more preferably 2.0 mm or less. The overlap amount between branched portion 22a and branched portion 22b is preferably 0.8% to 61.1% of the maximum hair length, more preferably 3.8% to 33.3%, and even more preferably 3.8% to 22.2%.

[0047] The hair length of the bristles 22 including the branched portion 22a (the hair length of the half hair bundle 21a) is, for example, 10 mm. The hair length of the bristles 22 including the branched portion 22b (the hair length of the half hair bundle 21b) is, for example, 11 mm. Therefore, the hair length of the half hair bundle 21a and the hair length of the half hair bundle 21b are shorter than the hair length of the inner hair bundle 30.

[0048] As described above, the toothbrush 10 of this embodiment has outer bristle bundles 20 arranged at the outermost periphery and inner bristle bundles 30 arranged inside the outer bristle bundles 20, and the outer bristle bundles 20 are formed by folding in half branched tip bristles 22, which are formed by branching the tips of the bristles on both sides of the length, and have two half bristle bundle portions 21a, 21b with different bristle lengths, which contributes to improved feel and cleaning power.

[0049] [Example] The present invention will be described in detail below with reference to examples. However, the present invention is not limited to the following examples and can be practiced with appropriate modifications within the scope of the present invention.

[0050] (Examples 1 to 6, Comparative Examples 1 to 3) Samples of Examples 1 to 6 and Comparative Examples 1 to 3 were prepared according to the specifications shown in Table 1. Specifically, the folding of the outer hair bundles was asymmetrical in the samples of Examples 1 to 6 and Comparative Examples 2 and 3 (different hair lengths of the half hair bundles), while the sample of Comparative Example 1 was symmetrical (same hair length of the half hair bundles).

[0051] Regarding the hair used for the inner hair bundle, the samples of Example 1 and Comparative Example 1 were branched straight hair, the sample of Example 2 was branched tapered hair, the samples of Examples 3 to 5 and Comparative Example 3 were tapered hair, the sample of Example 6 was spiral tapered hair, and the sample of Comparative Example 2 was straight hair.

[0052] Regarding the hairs used for the outer hair bundles, the samples of Example 1 and Comparative Example 1 were branched straight hairs, the samples of Examples 2 to 6 were branched tapered hairs, the sample of Comparative Example 3 was tapered hairs, and the sample of Comparative Example 2 was straight hairs.

[0053] 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 Comparative Examples 1 to 3 had the same maximum hair length of the outer hair bundle and the maximum hair length of the inner hair bundle, while the samples of Examples 4 to 6 had the maximum hair length of the inner hair bundle longer than the maximum hair length of the outer hair bundle.

[0054] Regarding the relationship between the hair lengths of the half hair bundles in the outer hair bundles, in the samples of Examples 1 to 4 and Comparative Examples 2 to 3, the hair length of the half hair bundle on the outer periphery is longer than the hair length of the inner half hair bundle on only one width side of the head part, in the samples of Examples 5 and 6, the hair length of the half hair bundle on the outer periphery is longer than the hair length of the inner half hair bundle on both width sides of the head part, and in the sample of Comparative Example 1, the hair length of the half hair bundle on the outer periphery is the same as the hair length of the inner half hair bundle.

[0055] The dimensions of each example were evaluated below. Example 1 Hair for inner hair bundle Bristle diameter: 6.5mil Branched straight hair: 5 branches, L1=2mm ·Maximum hair length = 12mm Hair for outer hair bundle Bristle diameter: 8.0mil Branched straight hair: 5 branches, L1=2mm Folding (asymmetric): L2=1 mm, L1-L2=1 mm, as shown in Figure 3. ·Hair length: half hair bundle 21b=12mm, half hair bundle 21a=11mm

[0056] Example 2 Hair for inner hair bundle Bristle diameter: 6.5mil Branched tapered hair: 3 branches, L1=2mm ·Maximum hair length = 12mm Hair for outer hair bundle Bristle diameter: 8.0mil Branched tapered hair: 3 branches, L1=2mm Folding (asymmetric): L2=1 mm, L1-L2=1 mm, as shown in Figure 3. ·Hair length: half hair bundle 21b=12mm, half hair bundle 21a=11mm

[0057] Example 3 Hair for inner hair bundle Bristle diameter: 6.5mil Tapered hair: 0 branches, L1=0mm ·Maximum hair length = 12mm Hair for outer hair bundle Bristle diameter: 8.0mil Branched tapered hair: 3 branches, L1=2mm Folding (asymmetric): L2=1 mm, L1-L2=1 mm, as shown in Figure 3. ·Hair length: half hair bundle 21b=12mm, half hair bundle 21a=11mm

[0058] Example 4 Hair for inner hair bundle Bristle diameter: 6.5mil Tapered hair: 0 branches, L1=0mm ·Maximum hair length = 12mm Hair for outer hair bundle Bristle diameter: 8.0mil Branched tapered hair: 3 branches, L1=0mm Folding (asymmetric): L2=1 mm, L1-L2=1 mm, as shown in Figure 3. ·Hair length: half hair bundle 21b=11mm, half hair bundle 21a=10mm

[0059] Example 5 Hair for inner hair bundle Bristle diameter: 6.5mil Tapered hair: 0 branches, L1=0mm ·Maximum hair length = 12mm Hair for outer hair bundle Bristle diameter: 8.0mil Branched tapered hair: 3 branches, L1=2mm Folding (asymmetric): L2=1 mm, L1-L2=1 mm, as shown in Figure 3. ·Hair length: half hair bundle 21b=11mm, half hair bundle 21a=10mm

[0060] Example 6 Hair for inner hair bundle Bristle diameter: 6.5mil Spiral tapered hair: 0 branches, L1=0mm ·Maximum hair length = 12mm Hair for outer hair bundle Bristle diameter: 8.0mil Branched tapered hair: 3 branches, L1=2mm Folding (asymmetric): L2=1 mm, L1-L2=1 mm, as shown in Figure 3. ·Hair length: half hair bundle 21b=11mm, half hair bundle 21a=10mm

[0061] (Comparative Example 1) Hair for inner hair bundle Bristle diameter: 6.5mil Branched straight hair: 5 branches, L1=2mm ·Maximum hair length = 12mm Hair for outer hair bundle Bristle diameter: 8.0mil Branched straight hair: 5 branches, L1=2mm Folding (symmetric): L2=0mm ·Hair length: Half hair bundle 21b = Half hair bundle 21a = 12mm

[0062] (Comparative Example 2) Hair for inner hair bundle Bristle diameter: 6.5mil Straight hair: 0 branches, L1=0mm ·Maximum hair length = 12mm Hair for outer hair bundle Bristle diameter: 8.0mil Straight hair: 0 branches, L1=0mm Folding (asymmetric): L2=1mm ·Hair length: half hair bundle 21b=12mm, half hair bundle 21a=11mm

[0063] (Comparative Example 3) Hair for inner hair bundle Bristle diameter: 6.5mil Tapered hair: 0 branches, L1=0mm ·Maximum hair length = 12mm Hair for outer hair bundle Bristle diameter: 8.0mil Tapered hair: 0 branches, L1=0mm Folding (asymmetric): L2=1mm ·Hair length: half hair bundle 21b=12mm, half hair bundle 21a=11mm

[0064] [Evaluation items] The samples of Examples 1 to 6 and Comparative Examples 1 to 3 were evaluated for toothbrush feel, cleaning performance, and periodontal pocket cleaning power.

[0065] [Evaluation method] <Evaluation of touch> A panel of 10 experts cleaned the inside of their mouths with each toothbrush and evaluated the feel of the toothbrush on the gums using the following criteria. The following evaluations were made based on the average scores of the 10 expert panels. An average score of 5.5 or more by the 10 expert panels was designated "◎ (Very Good)", an average score of 4.0 to less than 5.5 was designated "○ (Good)", an average score of 2.5 to less than 4.0 was designated "△ (Not Bad)", and an average score of less than 2.5 was designated "× (Bad)". <Evaluation criteria> 7 points: Very comfortable to wear. 6 points: The feel is quite good. 5 points: The feel is somewhat good. 4 points: Neither. 3 points: The feel is a little uncomfortable. 2 points: It feels very uncomfortable to touch. 1 point: Very uncomfortable to touch.

[0066] <Evaluation of cleaning experience> A panel of 10 experts cleaned the inside of their mouths with each toothbrush and evaluated the cleaning sensation (cleaning sensation throughout the oral cavity) using the following criteria. The following evaluations were made based on the average scores of the 10 experts. An average score of 5.5 or more by the 10 experts was designated "◎ (Very Good)", an average score of 4.0 to less than 5.5 was designated "○ (Good)", an average score of 2.5 to less than 4.0 was designated "△ (Not Bad)", and an average score of less than 2.5 was designated "× (Bad)". <Evaluation criteria> 7 points: The cleaning effect is very good. 6 points: The cleaning effect is quite good. 5 points: Cleaning feels fairly good. 4 points: Neither. 3 points: Cleaning effect is somewhat poor. 2 points: The cleaning effect is quite poor. 1 point: The cleaning effect is very poor.

[0067] <Evaluation of periodontal pocket cleaning ability> A panel of 10 experts cleaned the oral cavity with each toothbrush and evaluated the cleaning effect on periodontal pockets using the following criteria. The following evaluations were made based on the average scores of the 10 experts. An average score of 6.0 or more was designated "◎+ (Special Good)", 5.5 to less than 6.0 was designated "◎ (Very Good)", 4.0 to less than 5.5 was designated "○ (Good)", 2.5 to less than 4.0 was designated "△ (Not Bad)", and less than 2.5 was designated "× (Bad)". <Evaluation criteria> 7 points: I can feel a strong sense of dirt being removed from my periodontal pockets. 6 points: I can feel that the dirt in my periodontal pockets has been removed quite strongly. 5 points: I can feel that the dirt in my periodontal pockets has been removed quite strongly. 4 points: Neither. 3 points: I don't really feel like the dirt in my periodontal pockets has been removed. 2 points: I barely feel any dirt coming off my periodontal pockets. 1 point: I don't feel any dirt coming off my periodontal pockets.

[0068] [Table 1]

[0069] As shown in Table 1, the samples of Examples 1 to 6, in which the outer bristle bundles are formed with bristles branched at the ends and the outer bristle bundles are folded asymmetrically so that the bristle lengths of the half-hair bundles are different, received good ratings in all aspects of feel, cleaning feel, and periodontal pocket cleaning power.

[0070] In contrast, the sample of Comparative Example 1, in which the outer bristle bundles were folded symmetrically and the bristle lengths of the half bristle bundles were the same even though the outer bristle bundles were formed with bristles at the ends, did not receive a good evaluation for the feel. Similarly, the samples of Comparative Examples 2 and 3, in which the outer bristle bundles were folded asymmetrically but not formed with bristles at the ends, also did not receive a good evaluation for the feel. Furthermore, the sample of Comparative Example 2, in which the inner bristle bundles were straight bristles, did not receive a good evaluation for the periodontal pocket cleaning ability.

[0071] Furthermore, the samples of Examples 3 to 6, in which the inner bristle bundles are formed with tapered bristles, received better evaluations of periodontal pocket cleaning power than the samples of Examples 1 and 2, in which the inner bristle bundles are formed with branched bristles at the ends. Furthermore, the samples of Examples 4 to 6, in which the maximum bristle length of the inner bristle bundles is longer than the maximum bristle length of the outer bristle bundles, received better evaluations of cleaning feel than the samples of Examples 1 to 3, in which the maximum bristle length of the outer bristle bundles is the same as the maximum bristle length of the inner bristle bundles.

[0072] The samples of Examples 2 to 6, in which the outer bristles were formed of branched tapered bristles, were evaluated as more comfortable to touch than the sample of Example 1, in which the outer bristles were formed of branched straight bristles. The samples of Examples 5 and 6, in which the bristles of the half bristles on the outer periphery were made longer than the bristles of the inner half bristles on both sides of the head in the width direction, were evaluated as more comfortable to touch than the samples of Examples 1 to 4, in which the bristles of the half bristles on the outer periphery were made longer than the bristles of the inner half bristles on only one side of the head in the width direction. Example 6, in which the bristles of the inner bristle bundle of Example 5 were changed from tapered bristles to spiral tapered bristles, received an even better evaluation than Example 5 regarding the periodontal pocket cleaning power.

[0073] While the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to these examples. The shapes and combinations of the components shown in the above examples are merely examples, and various modifications can be made based on design requirements, etc., without departing from the spirit of the present invention.

[0074] For example, in the above embodiment, the branched portion 22a and the branched portion 22b have the same branch length L1, and the bristle length of the bristles 22 including the branched portion 22a is shorter than the bristle length of the bristles 22 including the branched portion 22b. However, the present invention is not limited to this configuration. For example, as shown in Fig. 4, the branched length L3 of the branched portion 22a may be shorter than the branched length L1 of the branched portion 22b, and the bristle length difference L2 may be shorter than the branched length L1 of the branched portion 22b.

[0075] 5, the branch length L3 of branch portion 22a may be longer than the branch length L1 of branch portion 22b, and the hair length difference L2 may be shorter than the branch length L1 of branch portion 22b. Furthermore, as shown in Fig. 6, the branch portion 22a and branch portion 22b may have the same branch length L1, and the hair length difference L2 may be longer than the branch length L1. Furthermore, as shown in Fig. 7, the branch portion 22a and branch portion 22b may have the same branch length L1, and the hair length difference L1 may be the same as the branch length L1.

[0076] 8, the branch length L3 of the branch portion 22a may be shorter than the branch length L1 of the branch portion 22b, and the hair length difference L2 may be longer than the branch length L1 of the branch portion 22b. Furthermore, as shown in Fig. 9, the branch length L3 of the branch portion 22a may be longer than the branch length L1 of the branch portion 22b, and the hair length difference L2 may be longer than the branch length L1 of the branch portion 22b.

[0077] 4 and 5, the branch length L1 of the branched portion 22b that constitutes the maximum bristle length is greater than the bristle length difference L2, so that the branched portion 22a and the branched portion 22b overlap in the Z direction as described above. As shown in Fig. 4, when L1>(L2+L3), the overlap amount is the branch length L3. The overlap amount L3 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 even more preferably 0.5 mm or more and 2.0 mm or less. The overlap amount L3 is preferably 3.8% or more and 61.1% or less of the maximum fabric width, more preferably 3.8% or more and 33.3% or less, and still more preferably 3.8% or more and 22.2% or less. In FIG. 4, when L2 < L1 ≤ (L2 + L3) (that is, in the case of the aspect of FIG. 5), it is also preferable to select the above-described overlap amount.

Explanation of Signs

[0078] 2... Handle body, 3... Head portion, 3a... Hair implanting surface, 20... Outer hair bundle, 21a, 21b... Half hair bundle portions, 22... Working hair (tip-branched hair), 22a, 22b... Branch portions, 30... Inner hair bundle, 32... Second working hair

Claims

1. The brush has a head portion having a plurality of tufts of bristles planted on a bristle planting surface, and a handle body extending from the head portion, The hair bundles include outer hair bundles arranged on the outermost periphery and inner hair bundles arranged inside the outer hair bundles, The outer hair bundle is formed by folding in two end-branched hairs, the ends of which are branched on both sides in the length direction, and has two half hair bundle portions with different hair lengths, and the hair length of one half hair bundle portion provided on the outer side is shorter than that of the other half hair bundle portion provided on the inner side, the tip-branched hairs of the two half hair bundle portions are tapered hairs tapered toward the tip, When the branched length of the tip-branched hair is L1 and the difference in maximum hair length between the two half hair bundle portions is L2, the numerical value represented by L2 / L1 is 0.08 or more and less than 1.0, L1>L2, and the value represented by L1-L2 is 0.1 mm or more and 5.5 mm or less, The flat line is sandwiched between the folded outer hair bundles at an angle of 0 to 45 degrees relative to the head length direction, A toothbrush characterized in that the head portion has at least four rows of bristle holes aligned in the width direction.

2. the inner bristle bundle has a plurality of second bristles, The second bristles are tapered bristles that taper toward the tip. The toothbrush of claim 1.

3. The hair length of the inner hair bundle is longer than the hair length of the outer hair bundle. The toothbrush according to claim 1 or 2.

4. The difference in maximum hair length between the two half hair bundle portions is 0.5 mm or more and 2.0 mm or less.

4. The toothbrush according to claim 1.

5. The tip of the branched hair is branched into two or more.

5. The toothbrush according to any one of claims 1 to 4.

6. The diameter of the bristles is 6 mil or more and 9 mil or less.

6. The toothbrush according to any one of claims 1 to 5.

7. The diameter of the second bristles constituting the inner bristle bundle is 5 mil or more and 7 mil or less. The toothbrush of claim 2.

Images