Interdental brush

Abstract

DEPCT67 Interdental brushes with high penetration capabilities and a gentle interdental cleaning sensation. Tall and with a gentle tactile feel, featuring a handle and a brush head with bristles bundled in an axial direction. Extending from the end of the handle and the protruding pin that grips the base of the brush head, The brush segment whose maximum length is in the direction perpendicular to the longitudinal axis is the largest in size. The first direction and the smallest size in the second direction are perpendicular to the first direction;

Description

Interdental brushes

[0001] The present invention relates to an interdental brush. This application claims priority to Japanese Patent Application No. 2021-214491, filed on December 28, 2021, the contents of which are incorporated herein by reference.

[0002] Interdental brushes are used as auxiliary cleaning tools to clean the gaps between teeth that are difficult to reach with a toothbrush. Interdental brushes remove food debris and plaque by inserting the brush head between the teeth and moving it back and forth along the longitudinal axis. In addition to basic performance such as ease of insertion, effective cleaning, and ease of cleaning, importance is also attached to the non-harmfulness of interdental brushes, such as painlessness to the gums and a comfortable feel.

[0003] Wire interdental brushes, which use a metal wire for the shaft and have plastic bristles on the wire, have good insertion properties due to the rigidity of the metal and cleaning power due to the bristles, but they can accidentally injure the gums when used.To solve this problem, there are non-wire interdental brushes with a shaft made of hard resin and bristles made of soft resin (for example, Patent Document 1).

[0004] Another interdental cleaning tool is dental floss, which is threaded between two adjacent teeth to clean between the teeth.

[0005] Japanese Patent Application Laid-Open No. 2000-24009

[0006] However, flossing has the advantage of providing a high level of cleaning sensation because the floss can be moved along the curved surface between the teeth.However, when moving the floss between the teeth to be cleaned, the floss must be moved up and down between the two teeth, which has a narrow gap, making it difficult to operate and causing too much force, which can cause the floss to touch the gums and cause pain.

[0007] The interdental brush described in Patent Document 1 reduces irritation to the gums by changing the part that comes into contact with the gums from metal to resin, but the shaft is made of hard resin, giving it a rigidity similar to that of a wire interdental brush. Therefore, if the sharp protrusion is forcibly inserted between narrow teeth, pain may occur in the gums. Therefore, there is an issue regarding the harmlessness of the brush, as it may injure the gums when inserting the interdental brush part.

[0008] One solution is to use a soft material for the brush part that is inserted between the teeth. While this eliminates the risk of harm to the gums, the soft protrusions create problems such as poor insertion and poor cleaning performance.

[0009] The present invention has been made in consideration of the above points, and an object of the present invention is to provide an interdental brush that is easy to insert between teeth, has a high interdental cleaning effect, and is gentle to the touch.

[0010] The present invention has the following aspects. [1] An interdental brush comprising: a handle; and a brush section having bristle bundles extending in a longitudinal direction from the tip side of the handle, wherein the brush section has a maximum length in a direction perpendicular to the longitudinal direction that is a maximum dimension in a first direction and a minimum dimension in a second direction intersecting the first direction. [2] The interdental brush described in [1] above, which has a protruding section that protrudes from the handle and holds the base end of the brush section. [3] The interdental brush described in [1] above, wherein the handle extends linearly parallel to a predetermined plane, and the predetermined plane and the first direction are parallel. [4] The interdental brush according to any one of [1] to [3], wherein the bristle diameter of the base of the bristles constituting the bristle bundle is 0.1 mm or more and 0.4 mm or less, the number of rows of the bristle bundles extending in the first direction is 3 or more and 23 or less, and the maximum length of the bristle bundle in the longitudinal direction is 5 mm or more and 15 mm or less. [5] The interdental brush according to [2], wherein the maximum length in the second direction at the base end side of the brush part is 0.1 mm or more and 1.3 mm or less, and the aspect ratio of the row of the bristle bundles extending in the first direction is 3 or more and 19 or less. [6] The interdental brush according to [2], wherein the bristle tips of the bristle bundles are movable independently of each other, and the bases of the bristle bundles are movable in conjunction with adjacent bristle bundles. [7] The interdental brush according to [6], wherein the brushing force in the first direction of the brush part at a position 2 mm from the bristle tip toward the base end is brushing force A, and the brushing force in the first direction of the brush part at a position 2 mm from the base of the bristle bundle is brushing force B, whereby brushing force A is 0.05 N or more and 0.30 N or less, brushing force B is 0.5 N or more and 15 N or less, and the value expressed as brushing force A / brushing force B is 0.015 or more and 0.6 or less. [8] The interdental brush according to [7], wherein the brushing force B is brushing force B1, and the brushing force in the second direction of the brush part at a position 2 mm from the base of the bristle bundle is brushing force B2, whereby the value expressed as brushing force B2 / brushing force B1 is 0.1 or more and 0.7 or less.[9] The interdental brush described in [2] above, wherein the base end side of the brush section is more flexible in the second direction than in the first direction.

[10] The interdental brush described in [9] above, wherein, if the brushing force A is brushing force A1, and the brushing force in the second direction at a position 2 mm from the bristles of the brush section toward the base end is brushing force A2, the value expressed as brushing force A2 / brushing force A1 is 0.8 or more and 1.0 or less.

[11] The interdental brush described in [2] above, wherein gaps between the bristle bundles at the base end side of the brush section are filled with an elastic material.

[12] The interdental brush described in [2] above, wherein the brush section has a single bristle bundle fixed to the protruding section in a planar manner at the base end side, and the bristle tips of the bristle bundle are unfixed free ends.

[13] The interdental brush described in [2] above, wherein the brush section tapers from the base end side toward the bristle tips when viewed from the side in the second direction.

[0011] The present invention can provide an interdental brush that is easy to insert between teeth, provides a high level of interdental cleaning sensation, and has a gentle feel when touching the teeth.

[0012] FIG. 1 is a front view of an interdental brush according to a first embodiment of the present invention. FIG. 2 is a side view of the interdental brush shown in FIG. 1. FIG. 3 is a view of the protruding portion 20 and the brush portion 30 as viewed from the front. FIG. 4 is a side view of the protruding portion 20 and the brush portion 30. FIG. 5 is a view showing the state in which the brush portion 30 is pressed against a tooth T. FIG. 6 is a view of the protruding portion 20 and the brush portion 30 as viewed from the front. FIG. 7 is a YZ cross-sectional view of the protruding portion 20 according to a third embodiment, in which the bristle bundles 31 are held in the grooves 23. FIG. 8 is a side view of an interdental brush according to a fourth embodiment. FIG. 9 is a side view of the protruding portion 20 and the brush portion 30 according to a fifth embodiment. FIG. 10 is a diagram showing a method for measuring the brushing force A.

[0013] An embodiment of the interdental brush of the present invention will be described below with reference to Figures 1 to 10. Note that 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 component easier to understand.

[0014] [First embodiment] Fig. 1 is a front view of an interdental brush according to a first embodiment of the present invention, and Fig. 2 is a side view of the interdental brush shown in Fig. 1.

[0015] 1 and 2, the interdental brush 1 has a grip portion 10, a protruding portion 20, and a brush portion 30. The grip portion 10 is the portion that is held by hand when using the interdental brush 1. The protruding portion 20 and the brush portion 30 are provided protruding from the tip side of the grip portion 10.

[0016] As shown in Fig. 1, when viewed from the front side, which is the side where the protrusion 20 and the brush portion 30 protrude from the grip portion 10, the grip portion 10 has a linear shaft shape. As shown in Fig. 2, the rear end side of the grip portion 10 extends linearly. The tip side of the grip portion 10 curves in a direction opposite to the side where the protrusion 20 and the brush portion 30 are provided as it approaches the tip. The area of ​​the grip portion 10 where the protrusion 20 and the brush portion 30 are provided is called the head portion 11.

[0017] In the following description, the longitudinal direction of the rear end of the grip portion 10 is defined as the x-direction, the width direction of the grip portion 10 perpendicular to the x-direction is defined as the y-direction, and the direction perpendicular to the x- and y-directions is defined as the z-direction. The side of the grip portion 10 from which the protruding portion 20 and the brush portion 30 protrude is called the front side, and the side opposite the front side is called the back side. The grip portion 10 extends linearly parallel to the xz plane (a predetermined plane).

[0018] The gripping portion 10 having the above configuration is manufactured by, for example, injection molding. The material of the gripping portion 10 can be determined taking into consideration the rigidity and mechanical properties required of the gripping portion 10, but for example, a hard resin with a flexural modulus (JIS K7203) in the range of 500 to 3000 MPa can be used.

[0019] Examples of such hard resins that can be used include polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polycyclohexylene dimethylene terephthalate (PCT), polyacetal (POM), polystyrene (PS), acrylonitrile-butadiene-styrene resin (ABS), cellulose propionate (CP), polyarylate, polycarbonate, and acrylonitrile-styrene copolymer resin (AS), and any one of these or a combination of two or more thereof can be used.

[0020] The protrusion 20 is provided on the tip side of the grip portion 10. The protrusion 20 protrudes from the head portion 11 of the grip portion 10 toward the front side perpendicular to the head portion 11. The protrusion 20 has a first protrusion 21 and a second protrusion 22. The first protrusion 21 protrudes toward the front side from the head portion 11. The second protrusion 22 protrudes toward the front side from the first protrusion 21. Note that the direction in which the protrusion 20 protrudes from the grip portion 10 is inclined with respect to the Z direction, but for ease of understanding, the protrusion 20 will be described below as protruding from the grip portion 10 in the Z direction.

[0021] FIG. 3 is a view of the protrusion 20 and the brush portion 30 as seen from the front side. FIG. 4 is a side view of the protrusion 20 and the brush portion 30. In FIG. 3, only the base end of the brush portion 30 is shown. In the following description, the direction in which the tip side of the grip portion 10 extends is referred to as the X direction, the direction in which the protrusion 20 and the brush portion 30 protrude from the tip of the grip portion 10 is referred to as the Z direction, and the direction perpendicular to the X direction and the Z direction is referred to as the Y direction. The X direction is parallel to the xz plane and is a direction tilted relative to the x direction within a plane parallel to the xz plane. The Z direction is parallel to the xz plane and is a direction tilted relative to the z direction within a plane parallel to the xz plane. The Y direction is a direction parallel to the y direction.

[0022] As shown in Fig. 3, the second protrusion 22 is shorter in the X and Y directions than the first protrusion 21. The first protrusion 21 and the second protrusion 22 are rectangular parallelepiped. The second protrusion 22 has a groove 23 on its front surface. The groove 23 extends in the X direction. As an example, the groove 23 has a dimension of 0.5 mm in the Y direction, a dimension of 4.0 mm in the X direction, and a dimension of 2.0 mm in the Z direction.

[0023] The protrusion 20 is molded integrally with the grip portion 10 by, for example, injection molding. That is, the grip portion 10 and the protrusion 20 are a molded body integrally molded by injection molding. Therefore, like the grip portion 10, the protrusion 20 is formed from the above-mentioned hard resin.

[0024] As shown in FIG. 4 , the brush unit 30 has multiple bristle bundles 31 each composed of multiple bristles H. The multiple bristle bundles 31 each composed of multiple bristles H may be multiple bristle bundles each composed of a single bristle H, or multiple bristle bundles each composed of multiple bristles H. The "multiple bristle bundles each composed of a single bristle H" refers to a brush unit in which the bristles are molded by insert molding. In this embodiment, as shown in FIG. 3 , four bristle bundles 31 are provided. The bristles H and bristle bundles 31 extend with the Z direction as their major axis. Each bristle bundle 31 has a circular outline when viewed in the Z direction. The four bristle bundles 31 are inserted into and held in the grooves 23 and fixed. The bristle bundles 31 are arranged in four rows along the X direction and in a single row along the Y direction.

[0025] Therefore, in the brush unit 30, if the direction in which the maximum dimension is measured in the direction perpendicular to the longitudinal axis of the bristle bundles 31 (bristles H) is defined as a first direction, the first direction is the X direction parallel to the xz plane. Also, in the brush unit 30, if the direction in which the maximum dimension is measured in the direction perpendicular to the longitudinal axis of the bristle bundles 31 (bristles H) and which intersects the first direction is defined as a second direction, the second direction is the Y direction. The brush unit 30 has a flat shape in which the X direction is the maximum dimension and the Y direction is the minimum dimension.

[0026] The maximum length of the bristle bundles 31 in the brush part 30 in the direction perpendicular to the longitudinal axis is greatest in the X direction and least in the Y direction, so that the brush part 30 exhibits anisotropy, with large bending in the Y direction and little bending in the X direction. As a result, the brush part 30 moves easily along the tooth row, improving insertion, and is less likely to move in the X direction, improving cleaning performance.

[0027] With respect to the direction perpendicular to the longitudinal axis of the brush part 30, the direction (first direction) in which the bristle bundle 31 has the largest dimension is the direction along the longitudinal direction of the grip part 10, so that the flat shape of the brush part 30 is oriented in the direction that fits between the teeth. Therefore, the interdental brush 1 of this embodiment can be easily inserted between teeth.

[0028] The maximum length in the Y direction at the base end of the bristle bundles 31 of the brush part 30 is preferably 0.1 mm or more, and more preferably 0.2 mm or more. The maximum length in the Y direction at the base end of the bristle bundles 31 of the brush part 30 is preferably 1.3 mm or less, more preferably 1.0 mm or less, and even more preferably 0.6 mm or less. The maximum length in the Y direction at the base end of the bristle bundles 31 is preferably 0.1 mm or more and 1.3 mm or less, more preferably 0.2 mm or more and 1.0 mm or less, and even more preferably 0.2 mm or more and 0.6 mm or less.

[0029] The maximum length in the X direction at the base end side of the bristle bundles 31 of the brush part 30 is preferably 1.0 mm or more, and more preferably 2.0 mm or more. The maximum length in the X direction at the base end side of the bristle bundles 31 of the brush part 30 is preferably 4.0 mm or less, and more preferably 3.0 mm or less. The maximum length in the X direction at the base end side of the bristle bundles 31 is preferably 1.0 mm or more and 4.0 mm or less, more preferably 1.0 mm or more and 3.0 mm or less, and even more preferably 2.0 mm or more and 3.0 mm or less.

[0030] In the brush part 30, the aspect ratio, which is the ratio of the maximum length in the X direction at the base end of the bristle bundles 31 to the maximum length in the Y direction per row at the base end of the bristle bundles 31, is preferably 3 or more, more preferably 7 or more, and even more preferably 10 or more. The aspect ratio is preferably 19 or less, and more preferably 15 or less. The aspect ratio is preferably 3 or more and 19 or less, more preferably 7 or more and 15 or less, and even more preferably 10 or more and 15 or less. By setting the aspect ratio to 3 or more and 19 or less, the bristle bundles fit the size of the interdental spaces, improving interdental insertion and cleaning performance.

[0031] When there are two rows of hair bundles 31 extending in the X direction, the aspect ratio, which is the ratio of the maximum length in the X direction at the base end of the hair bundles 31 to the maximum length in the Y direction of the two rows of hair bundles 31 at the base end, is preferably 2 or more, more preferably 3 or more, and even more preferably 4 or more. When there are two rows of hair bundles 31 extending in the X direction, the aspect ratio, which is the ratio of the maximum length in the X direction at the base end of the hair bundles 31 to the maximum length in the Y direction of the two rows of hair bundles 31 at the base end, is preferably 13 or less, more preferably 10 or less, and even more preferably 6 or less. The aspect ratio is preferably 2 or more and 13 or less, more preferably 3 or more and 10 or less, and even more preferably 4 or more and 6 or less.

[0032] When there are three rows of hair bundles 31 extending in the X direction, the aspect ratio, which is the ratio of the maximum length in the X direction at the base end of the hair bundles 31 to the maximum length in the Y direction of the three rows at the base end of the hair bundles 31, is preferably equal to or greater than 2. When there are three rows of hair bundles 31 extending in the X direction, the aspect ratio, which is the ratio of the maximum length in the X direction at the base end of the hair bundles 31 to the maximum length in the Y direction of the three rows at the base end of the hair bundles 31, is preferably equal to or less than 9, more preferably equal to or less than 7, and even more preferably equal to or less than 5. The aspect ratio is preferably equal to or greater than 2 and equal to or less than 9, more preferably equal to or greater than 2 and equal to or less than 7, and even more preferably equal to or greater than 2 and equal to or less than 5.

[0033] If the protrusion 20 is not provided and the bristle bundle 31 extends from the grip 10 in the longitudinal direction, the bristle length (length dimension in the longitudinal direction) of the bristle bundle 31 increases, which may weaken the bristle stiffness and reduce cleaning performance. In this embodiment, the bristle bundle 31 extends from the protrusion 20 in the longitudinal direction, so that the bristle length of the bristle bundle 31 protruding from the groove 23 in the longitudinal direction can be shortened even if the length from the grip 10 to the tip of the bristle bundle 31 is the same. Therefore, by having the bristle bundle 31 extend in the longitudinal direction from the protrusion 20, the bristle stiffness of the bristle bundle 31 can be prevented from weakening, improving cleaning performance. As an example, the protrusion 20 has a dimension of 3.0 mm in the Y direction, a dimension of 7.0 mm in the X direction, and a dimension of 6.0 mm in the Z direction. The protrusion 21 has a dimension of 3.0 mm in the Y direction, a dimension of 7.0 mm in the X direction, and a dimension of 2.0 mm in the Z direction. The protrusion 22 has a dimension of 2.0 mm in the Y direction, a dimension of 5.0 mm in the X direction, and a dimension of 4.0 mm in the Z direction.

[0034] Methods for fixing the bristle bundles 31 in the grooves 23 (hair implantation methods) include insert molding, press-fitting the bristle bundles 31 into the grooves 23, flat wire implantation (including offset implantation), welding, etc. An example of a welding method is an anchor-free method (AFT method) in which multiple head cassettes (not shown) are prepared, bristle bundles 31 of bristles H are inserted into implantation holes in the head cassettes, one end of the bristle bundles 31 is heated and melted to fix them to the head cassettes, and the head cassette with the implanted bristle bundles is placed as the protrusion 20 in a mold for molding the grip part 10 and fixed integrally with the grip part 10 by in-mold molding or the like. With the above welding method, the brush part 30 has a single tuft of bristle bundles 31 arranged in a planar shape at the base end.

[0035] Examples of the bristles H include straight bristles, bristles whose diameter gradually decreases towards the tip (tapered bristles, super tapered bristles (ultra-fine bristles; ST bristles)), bristles with branched tips, spiral bristles, bristles with irregular cross sections, and resin-molded bristles. In terms of cleaning effectiveness between teeth, the bristles H that make up the bristle bundle 31 are preferably tapered bristles. By using tapered bristles, the bristles can reach narrow gaps between teeth while ensuring scraping power, improving cleaning effectiveness. Examples of the tip shape of the bristle bundle include flat cut, mountain cut, convex, and concave shapes. By making the tip shape of the bristle bundle mountain cut or hill-shaped, the bristles can reach narrow areas, improving cleaning effectiveness.

[0036] The material of the bristles H is not particularly limited, but examples thereof include synthetic resin materials such as polyamide (e.g., 6-12 nylon, 6-10 nylon), polyester (e.g., polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate), polyolefin (e.g., polypropylene), elastomer (e.g., olefin-based, styrene-based), and polyurethane.

[0037] The bristles H may be made of polyester with a multi-core structure having a core and at least one sheath layer covering the core. A combination of these resin materials may be used, and different resin materials may be used for the core and the sheath, such as a core-sheath structure. The cross-sectional shape of the bristles H (the cross-sectional shape when the bristles H are cut along a plane perpendicular to the longitudinal axis) may be, for example, a circular cross-sectional shape such as a perfect circle or an ellipse, or an irregular cross-sectional shape such as a substantially triangular or substantially rectangular shape.

[0038] The diameter of the bristles H (bristle diameter) is preferably 0.1 mm or more, and more preferably 0.2 mm or more. The diameter of the bristles H is preferably 0.4 mm or less, and more preferably 0.3 mm or less. The diameter of the bristles H is preferably 0.1 mm or more and 0.4 mm or less, and more preferably 0.2 mm or more and 0.3 mm or less.

[0039] The number of rows of bristle bundles 31 extending in the X direction is preferably three or less. The total number of bristle tips in the use bristles H per row of bristle bundles 31 is preferably three or more, more preferably five or more, and even more preferably six or more. The total number of bristle tips in the use bristles H per row of bristle bundles 31 is preferably 23 or less, more preferably 18 or less, and even more preferably 14 or less. The total number of bristle tips in the use bristles H per row of bristle bundles 31 is preferably three or more and 23 or less, more preferably five or more and 18 or less, and even more preferably six or more and 14 or less.

[0040] The maximum length of the bristle bundle 31 in the longitudinal direction is preferably 5 mm or more, more preferably 7 mm or more, and even more preferably 8 mm or more. The maximum length of the bristle bundle 31 in the longitudinal direction is preferably 15 mm or less, more preferably 13 mm or less, and even more preferably 12 mm or less. The maximum length of the bristle bundle 31 in the longitudinal direction is preferably 5 mm or more and 15 mm or less, more preferably 7 mm or more and 13 mm or less, and even more preferably 8 mm or more and 12 mm or less. If the maximum length of the bristle bundle 31 in the longitudinal direction exceeds 15 mm, it will bend too much, reducing its ease of insertion between teeth, and the bristle tips will become uneven, reducing the comfort of the brush. By keeping the maximum length of the bristle bundle 31 in the longitudinal direction within the above range, flexibility is ensured and insertion is improved.

[0041] The bristle diameter of the bristles H is 0.1 mm or more and 0.4 mm or less, the number of rows of bristle bundles 31 is 3 or less, the total number of bristle tips in the bristles H per row of bristle bundles is 3 or more and 23 or less, and the maximum length in the major axis direction of the bristle bundles 31 is 5 mm or more and 15 mm or less, thereby improving the ease of insertion between teeth, cleaning ability, and feel even when the total number of bristle tips per row is small and the number of rows is 3 or less.

[0042] As shown in Figure 4, the brush part 30 is roughly divided into a base part 30A, a central part 30B, and a tip part 30C in the longitudinal direction when viewed from the side in the Y direction. The brush part 30 tapers from the base part 30A to the tip part 30C in the longitudinal direction, from the base end side to the tip side. By tapering the brush part 30 from the base part 30A to the tip part 30C, the area of ​​the tip of the bristles becomes smaller, improving insertion, and also, the bristle bundles 31 become closer together, improving durability.

[0043] Methods for tapering the brush part 30 include inclined implantation in which the bristles H are implanted at an angle to the longitudinal direction, a method in which adjacent bristles H are fixed together with an adhesive substance, and a method in which tapered branched bristles are used. Also, a method in which the brush part 30 is tapered depending on the difference in immersion time when the brush part 30 is immersed in the dissolving solution may be adopted.

[0044] The tip portion 30C is in the range of 0% to 20% of the total length (bristle length) from the tip of the brush part 30 in the longitudinal direction. The central portion 30B is in the range of 20% to 60% of the total length from the tip of the brush part 30 in the longitudinal direction. The base portion 30A is in the range of 60% to 100% of the total length from the tip of the brush part 30 in the longitudinal direction.

[0045] The ratio of the "total cross-sectional area of ​​the brush part 30 at the central part 30B at 40% of the total length (bristle length) from the tip in the longitudinal direction" to the "total cross-sectional area of ​​the brush part 30 at the base part 30A at 100% of the total length (bristle length) from the tip in the longitudinal direction" is preferably 50% or more. The above total cross-sectional area ratio is preferably 90% or less. The above total cross-sectional area ratio is preferably 50% or more and 90% or less, more preferably 60% or more and 90% or less, and even more preferably 75% or more and 90% or less. By setting the total cross-sectional area ratio to 50% or more and 90% or less, the bristle stiffness increases, improving insertion and cleaning properties.

[0046] The ratio of the "total cross-sectional area of ​​the brush part 30 at the tip portion 30C at 10% of the total length (bristle length) from the tip in the longitudinal direction" to the "total cross-sectional area of ​​the brush part 30 at the base portion 30A at 100% of the total length (bristle length) from the tip in the longitudinal direction of the brush part 30" is preferably 0.005% or more. The above total cross-sectional area ratio is preferably 30% or less. The above total cross-sectional area ratio is preferably 0.005% or more and 30% or less, more preferably 0.005% or more and 10% or less, and even more preferably 0.005% or more and 5% or less. By setting the total cross-sectional area ratio to 0.005% or more and 30% or less, insertion ease is improved.

[0047] The length of the central portion 30B in the major axis direction is preferably 3 mm or more from the viewpoint of improving cleaning performance, and the length of the central portion 30B in the major axis direction is preferably 9 mm or less from the viewpoint of improving cleaning performance.

[0048] In the brush unit 30, the gaps between the bristle bundles 31 in the base 30A are filled with an elastic material (not shown). By filling the gaps between the bristle bundles 31 in the base 30A with the elastic material, the bristle bundles 31 in the base 30A are flexibly connected to each other rather than firmly. The central portion 30B and the tip portion 30C of the brush unit 30 are not filled with the elastic material. Therefore, in the base 30A, the bristles are arranged with virtually no gaps, while in the central portion 30B and the tip portion 30C, the bristles H are arranged with gaps.

[0049] Therefore, when a specific bristle bundle 31 moves, the adjacent bristle bundles 31 in the base 30A can move together via the elastic material. In this case, a force is required to elastically deform the elastic material in order to move the surrounding bristle bundles 31. In other words, a larger load can be applied during cleaning compared to when the elastic material is not filled, improving the cleaning experience. Furthermore, the brush unit 30 of this embodiment has stronger bristles at the base 30A, improving interdental insertion. Meanwhile, the bristles H of the brush unit 30 are arranged with gaps between them, so they can move independently of each other.

[0050] The brush unit 30 has bristle bundles 31 connected to each other by filling gaps between the bristle bundles 31 in the base 30A with an elastic material. The brush unit 30 has anisotropy in bending, since the maximum length of the bristle bundles 31 in the direction perpendicular to the longitudinal axis is greatest in the X direction and smallest in the Y direction. That is, the base end of the brush unit 30 has bending characteristics that make it easier to bend in the Y direction than in the X direction. Examples of elastic materials include wax, gel, and adhesive. A similar effect can be achieved with, for example, branched bristles, in which the bristle bundles are connected at the base and branched at the tip. The same effect can also be achieved with branched bristles by not connecting them but by controlling the difference in diameter between the base and the branched bristles. This structure may also be formed by integral molding.

[0051] Fig. 5 is a diagram showing the state in which the brush unit 30 is pressed against a tooth T. As shown in Fig. 5, in this embodiment, when the brush unit 30 is moved in the X direction, friction occurs between the tooth and the brush unit 30, and this friction becomes resistance to the movement of the brush unit 30 in the X direction. As a result, the brush unit 30 moves in the Y direction, where resistance to movement is small and the brush unit 30 is more likely to bend, and is positioned between the teeth. Therefore, in this embodiment, the brush unit 30's ability to be inserted between teeth and cleaning ability is improved.

[0052] [Regarding Brushing Forces A and B in the Brush Unit 30] The brushing force in the X direction at a position 2 mm from the bristles toward the base end in the longitudinal direction of the brush unit 30 is defined as brushing force A. Brushing force A is defined as the brushing force in the X direction at a position 2 mm from the bristles of the brush unit 30. The values ​​of brushing force A were measured using a sample with brushing force B (unfixed) and a sample with brushing force B (fixed in the region 0-2 mm from the base), as described below, and it was confirmed that the value of brushing force A did not change. This is thought to be because the total cross-sectional area of ​​the base 30A of the brush unit 30 is sufficiently large relative to the total cross-sectional area of ​​the tip 30C, including the position 2 mm from the bristles, and whether or not the brush unit 30 is fixed at the base has little effect on the brushing force A at the position 2 mm from the bristles. Therefore, the numerical range of brushing force A in this application does not change regardless of whether or not brushing force B is fixed.

[0053] The brushing force at the base position of the brush part 30 protruding from the protruding part 20 is defined as the brush part brushing force B. Brushing force B is defined as the brushing force in the direction along the X direction of the base of the brush part 30. Two types of samples were used for brushing force B. Specifically, a sample in which no elastic material was used at the base of the brush part 30 and the region 0 to 2 mm from the base to the tip was not fixed so that adjacent bristle bundles 31 could move independently was designated as "unfixed." On the other hand, a sample in which an elastic material was used at the base of the brush part 30 and the region 0 to 2 mm from the base to the tip was fixed was designated as "fixed 2 mm from the base to the tip."

[0054] The brushing force A is preferably 0.05 N or more, and more preferably 0.10 N or more. The brushing force A is preferably 0.30 N or less, and more preferably 0.2 N or less. By setting the brushing force A to 0.05 N or more and 0.3 N or less, a load can be applied during cleaning, improving the cleaning feel.

[0055] The brushing and cleaning force B is preferably 0.5 N or more. The brushing and cleaning force B is preferably 15 N or less. By setting the brushing and cleaning force B to 0.5 N or more and 15 N or less, a load can be applied during cleaning, improving the cleaning experience.

[0056] When the base of the brush part 30 is "not fixed", the brushing force B is preferably 0.5 N or more, and more preferably 1.0 N or more. When the base of the brush part 30 is "not fixed", the brushing force B is preferably 6.0 N or less, and more preferably 4.0 N or less, and even more preferably 3 N or less.

[0057] When "2 mm from the root to the tip of the bristles is fixed," the brushing force B is preferably 1.0 N or more, more preferably 3.0 N or more, and even more preferably 4.0 N or more. When "2 mm from the root to the tip of the bristles is fixed," the brushing force B is preferably 15.0 N or less, more preferably 13.0 N or less, and even more preferably 9.0 N or less.

[0058] The value expressed by the ratio of the brushing force A to the brushing force B is preferably 0.015 or more. The value expressed by the ratio of the brushing force A to the brushing force B is preferably 0.6 or less. By setting the value expressed by the brushing force A to the brushing force B to be 0.015 or more and 0.6 or less, a load can be applied during cleaning, improving the cleaning experience.

[0059] The preferred range of values ​​expressed by the above-mentioned brushing force A / brushing force B is a range that includes the preferred range of values ​​expressed by the brushing force A / (brushing force B without fixing) and the preferred range of values ​​expressed by the brushing force A / (brushing force B with fixing).

[0060] The value expressed as the brushing force A / (brushing force B without fixing) is preferably 0.05 or more, more preferably 0.10 or more. The value expressed as the brushing force A / (brushing force B without fixing) is preferably 0.6 or less, more preferably 0.4 or less, and even more preferably 0.3 or less.

[0061] The value expressed as brushing force A / (brushing force B with "fixed") is preferably 0.015 or more, more preferably 0.02 or more. The value expressed as brushing force A / (brushing force B with "fixed") is preferably 0.5 or less, more preferably 0.3 or less, and even more preferably 0.2 or less.

[0062] [Regarding the brushing forces B1 and B2 at the base end of the brush portion 30] Of the brushing force B, the brushing force in the X direction is defined as brushing force B1. Of the brushing force B, the brushing force in the Y direction is defined as brushing force B2. The value expressed as brushing force B2 / brushing force B1 is preferably 0.1 or more. The value expressed as brushing force B2 / brushing force B1 is preferably 0.7 or less. By setting the value expressed as brushing force B2 / brushing force B1 to 0.1 or more and 0.7 or less, the bristle stiffness in the base portion 30A is increased in the X direction, improving cleaning performance, and the bristle stiffness is reduced in the Y direction, improving insertion between teeth.

[0063] The preferred range of values ​​expressed by the above brushing force B2 / brushing force B1 is a range that includes the preferred range of values ​​expressed by (brushing force B2 without fixing) / brushing force B1 and the preferred range of values ​​expressed by (brushing force B2 with fixing) / brushing force B1.

[0064] The value expressed by (brushing force B2 without fixing) / brushing force B1 is preferably 0.3 or more, more preferably 0.4 or more. The value expressed by (brushing force B2 without fixing) / brushing force B1 is preferably 0.7 or less, more preferably 0.6 or less.

[0065] The value expressed by (brushing force B2 with "fixed") / brushing force B1 is preferably 0.1 or more. The value expressed by (brushing force B2 with "fixed") / brushing force B1 is preferably 0.5 or less, more preferably 0.4 or less, and even more preferably 0.3 or less.

[0066] [Regarding the brushing forces A1 and A2 at the base end of the brush portion 30] Of the brushing force A, the brushing force in the X direction is defined as A1. Of the brushing force A, the brushing force in the Y direction is defined as A2. The value expressed as brushing force A2 / brushing force A1 is preferably 0.80 or more, more preferably 0.85 or more, and even more preferably 0.90 or more. The value expressed as brushing force A2 / brushing force A1 is preferably 1.0 or less. When the value expressed as brushing force A2 / brushing force A1 is 0.8 or more and 1.0 or less, there is less anisotropy at the bristles, making them more flexible and reducing pain, improving the feel.

[0067] The sweeping forces A1 and A2 were measured using the aforementioned sample with sweeping force B (not fixed) and the sample with sweeping force B (fixed in the region 0-2 mm from the base), and it was confirmed that the values ​​of the sweeping forces A1 and A2 did not change. This is thought to be because, as mentioned above, the total cross-sectional area of ​​the base 30A of the brush unit 30 is sufficiently larger than the total cross-sectional area of ​​the tip 30C, including the position 2 mm from the bristle tip, and whether or not the brush unit 30 is fixed at the base has little effect on the sweeping forces A1 and A2 at the position 2 mm from the bristle tip. Therefore, the numerical ranges of the sweeping forces A1 and A2 in this application do not change regardless of whether or not the sweeping force B is fixed.

[0068] The method for measuring the above-mentioned brushing forces A, (A1), and A2 is described below. [Method for Measuring Brushing Force A (X-Axis Direction)] The tip of the protruding portion 20 or the grip portion 10 connected to the protruding portion 20 is fixed. Figure 10 illustrates the method for measuring the brushing force A. As shown in Figure 10, a tool is prepared in which multiple cylindrical rods P extending in the Y-axis direction are arranged at regular intervals in the X-axis direction. The rods P consist of two or more cylindrical rod-shaped bodies (made of stainless steel, diameter: 0.5 mm, maximum surface roughness Ra: 0.4 mm) arranged parallel to each other at regular intervals (3 mm between the centers of the rods). The X-direction, in which the bristle bundle 31 forms its long axis, is the direction in which the rods P are aligned, and the X-direction in which the bristle bundle 31 forms its long axis, and the extension direction of the rods P are perpendicular. The bristle bundle 31 is positioned so that a Z-direction position 31A 2 mm from the tip of the bristle bundle 31 coincides with the Z-direction position of the center point C of the cylindrical rod P of the tool. The maximum value (absolute value) of the test force when the gripping portion 10 and the bristle bundle 31 are moved back and forth in the X direction at a sweeping distance of 30 mm and a sweeping speed of 200 mm / min is measured as the sweeping force A (sweeping force A1).

[0069] [Method for Measuring Brushing Force A1 (X-Axis Direction)] Brushing force A1 is the same as the brushing force A described above.

[0070] [Method for Measuring Brushing Force A2 (Y-Axis Direction)] Fix the tip of the protruding portion 20 or the grip portion 10 connected to the protruding portion 20. Prepare a tool in which multiple cylindrical rods P extending in the Y-axis direction are arranged at regular intervals in the X-axis direction. The rods P consist of two or more cylindrical rod-shaped bodies (made of stainless steel, diameter: 0.5 mm, maximum surface roughness Ra: 0.4 mm) arranged parallel to each other at regular intervals (3 mm between the centers of the rods). The rods P are aligned in the Y-direction, in which the bristle bundles 31 form their minor axes, and the Y-direction, in which the bristle bundles 31 form their minor axes, is perpendicular to the extension direction of the rods P. In other words, the direction in which the bristle bundles 31 form their major axes is parallel to the extension direction of the rods P. The bristle bundles 31 are positioned so that a Z-direction position 31A 2 mm from the tip is aligned with the Z-direction position of the center point C of the cylindrical rods P of the tool. The gripping portion 10 and the bristle bundle 31 are moved back and forth in the X direction at a sweeping distance of 30 mm and a sweeping speed of 200 mm / min, and the maximum value (absolute value) of the test force is measured as the sweeping force A2.

[0071] The method for measuring the above-mentioned brushing forces B, (B1), and B2 is as follows. When measuring the brushing forces B (B1) and B2 "without fixing," a sample is used in which the area from the root to the tip of the bristles is not fixed in place. When measuring the brushing forces B (B1) and B2 "with fixing," a sample is used in which the area from the root to the tip of the bristles is fixed in place with an adhesive or the like in place.

[0072] [Method for Measuring Brushing Force B (X-Axis Direction)] Fix the protruding portion 20 or the tip side of the gripping portion 10 connected to the protruding portion 20. Prepare a tool in which multiple cylindrical rods P extending in the Y-axis direction are arranged at regular intervals in the X-axis direction. The rods P consist of two or more cylindrical rod-shaped bodies (made of stainless steel, diameter: 0.5 mm, maximum surface roughness Ra: 0.4 mm) arranged parallel to each other at regular intervals (3 mm between the centers of the rods). The X-direction, in which the bristle bundles 31 form their long axes, is the direction in which the rods P are lined up, and the X-direction in which the bristle bundles 31 form their long axes and the direction in which the rods P extend are perpendicular. The bristle bundles 31 are positioned so that a Z-direction position 31B 2 mm from the base of the bristle bundles 31 coincides with the Z-direction position of the center point C of the cylindrical rods P of the tool. The maximum value (absolute value) of the test force when the gripping portion 10 and the bristle bundle 31 are moved back and forth in the X direction at a sweeping distance of 30 mm and a sweeping speed of 200 mm / min is measured as the sweeping force B (sweeping force B1).

[0073] [Method for Measuring Brushing Force B1 (X-Axis Direction)] Brushing force B1 is the same as the brushing force B described above.

[0074] [Method for Measuring Brushing Force B2 (Y-Axis Direction)] Fix the protruding portion 20 or the tip side of the gripping portion 10 connected to the protruding portion 20. Prepare a tool in which multiple cylindrical rods P extending in the Y-axis direction are arranged at regular intervals in the X-axis direction. The rods P consist of two or more cylindrical rod-shaped bodies (made of stainless steel, diameter: 0.5 mm, maximum surface roughness Ra: 0.4 mm) arranged parallel to each other at regular intervals (3 mm between the centers of the rods). The rods P are aligned in the Y-direction, in which the bristle bundles 31 form their minor axes, and the Y-direction, in which the bristle bundles 31 form their minor axes, is perpendicular to the extension direction of the rods P. In other words, the direction in which the bristle bundles 31 form their major axes is parallel to the extension direction of the rods P. The bristle bundles 31 are positioned so that a Z-direction position 31B 2 mm from the base of the bristle bundles 31 coincides with the Z-direction position of the center point C of the cylindrical rods P of the tool. The gripping portion 10 and the bristle bundle 31 are moved back and forth in the X direction at a sweeping distance of 30 mm and a sweeping speed of 200 mm / min, and the maximum value (absolute value) of the test force is measured as the sweeping force B2.

[0075] As described above, in the interdental brush 1 of this embodiment, the base end of the brush portion 30 having the bristle bundle 31 is held by the protruding portion 20 that protrudes from the gripping portion 10, which allows the bristles to be shorter and improves cleaning performance.In addition, the brush portion 30 has a flat shape with its maximum length being the maximum dimension in the X direction and its minimum dimension in the Y direction, and is anisotropic with respect to flexure, which allows for high interdental insertion ability and a gentle feel.

[0076] Second Embodiment Next, a second embodiment of the interdental brush 1 will be described with reference to Fig. 6. In this figure, elements that are the same as those in the first embodiment shown in Figs. 1 to 5 are given the same reference numerals, and their description will be omitted.

[0077] Fig. 6 is a front view of the protruding portion 20 and brush head 30 according to the second embodiment. In the first embodiment, four bristle bundles 31 are inserted into and held in the grooves 23 of the protruding portion 20. As shown in Fig. 6, in the interdental brush 1 of this embodiment, a single bristle bundle 31A is inserted into and held in the grooves 23 as a single tuft.

[0078] In the interdental brush 1 configured as described above, the base ends of the bristle bundles 31A are connected to each other and can move together, making the bristles stronger. On the other hand, the tip ends of the bristle bundles 31A are unfixed free ends and can move individually and independently.

[0079] Therefore, the interdental brush 1 of this embodiment can be more easily inserted between teeth. As the bristle bundle 31A, branched bristles with branched tips can be used.

[0080] [Third embodiment] Next, a third embodiment of the interdental brush 1 will be described with reference to Fig. 7. In this figure, the same elements as those in the first embodiment shown in Figs. 1 to 5 are designated by the same reference numerals, and their description will be omitted.

[0081] Figure 7 is a YZ cross-sectional view of the protrusion 20 with the bristle bundle 31 held in the groove 23. As shown in Figure 7, the groove 23 has an inclined portion 23a that extends outward in the Y direction toward the +Z side at the opening. The opening of the groove 23 expands in diameter toward the +Z side, so that the thickness of the second protrusion 22 gradually decreases. The opening of the groove 23 does not expand in diameter in the X direction, but only in the Y direction. The other configurations are the same as those of the first embodiment.

[0082] In the interdental brush 1 of this embodiment, in addition to obtaining the same functions and effects as the first embodiment, the bristle bundles 31 are less likely to bend in the X direction, maintaining interdental insertion, while the bristle bundles 31 are more likely to bend in the Y direction, improving cleaning performance. Note that, as a configuration in which the bristle bundles 31 are more likely to bend in the Y direction, in addition to providing the inclined portions 23a described above, a configuration in which notches are provided may also be used.

[0083] [Fourth embodiment] Next, a fourth embodiment of the interdental brush 1 will be described with reference to Fig. 8. In this figure, elements that are the same as those in the first embodiment shown in Figs. 1 to 5 are given the same reference numerals, and their description will be omitted.

[0084] Fig. 8 is a side view of an interdental brush 1 according to a fourth embodiment. As shown in Fig. 8, the protrusion 20 and the brush head 30 of this embodiment are provided from the tip of the grip portion 10 in the X direction toward the tip side. The configuration is the same as that of the first embodiment.

[0085] In addition to achieving the same functions and effects as the first embodiment, the interdental brush 1 of this embodiment has improved operability because the insertion direction of the gripping portion 10 during cleaning is the same as the insertion direction of the brush portion 30 between the teeth.

[0086] Fifth Embodiment Next, a fifth embodiment of the interdental brush 1 will be described with reference to Fig. 9. In this figure, elements that are the same as those in the first embodiment shown in Figs. 1 to 5 are given the same reference numerals, and descriptions thereof will be omitted.

[0087] Fig. 9 is a side view of the protrusion 20 and the brush unit 30 according to the fifth embodiment. In the first embodiment, the brush unit 30 is configured to taper from the base 30A to the tip 30C. As shown in Fig. 9, in the brush unit 30 of this embodiment, each bristles H tapers, but the bristles H have the same length in the X direction.

[0088] In the interdental brush 1 of this embodiment, in addition to achieving the same effects and advantages as those of the first embodiment, the length dimension of the bristles of the bristle bundles 31 in the X direction is increased, thereby shortening the movement stroke of the bristle bundles 31 along the X direction during cleaning.

[0089] 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.

[0090] For example, in the above embodiment, the brush part 30 has a linear and rectangular shape when viewed in the longitudinal direction, but is not limited to this configuration as long as the brush part 30 has different maximum lengths in the first and second directions and exhibits anisotropy with respect to deflection. The brush part 30 may have a layered, oval, elliptical, polygonal, or flat shape when viewed in the longitudinal direction.

[0091] In the above embodiment, the grip portion 10 has a shape that is curved at the tip end, but is not limited to this configuration. The grip portion 10 may be linear and extend in the X direction, or may have another shape.

[0092] The present invention is applicable to interdental brushes.

[0093] REFERENCE SIGNS LIST 1... interdental brush, 10... gripping portion, 20... protruding portion, 30... brush portion, 31, 31A... bristle bundle, H... bristles

Claims

DEPCT671. An interdental brush with a handle and a bristle bundle extending in the longitudinal direction from the end of such handle, and such bristle bundle is characterized by a maximum length perpendicular to such longitudinal direction being the largest in the first direction and the smallest in the second direction intersecting with such first direction.

2. An interdental brush specified in Reputation 1 in which a pin protrudes from such handle and grasps the base of such bristle bundle.

3. An interdental brush specified in Reputation 1 or 2 in which the handle extends linearly parallel to a given plane and such first direction is parallel to such given plane.

4. Any interdental brush specified in Reputation 1 or 2 in which the diameter of the bristles used at the base of the bristles making up such bristle bundle is greater than or equal to 0.1 mm and less than or equal to 0.1 mm.4 millimeters. The rows of bristle bundles extended in the first direction are less than or equal to 3 rows; the total number of bristle tips in the bristle bundle used per row of such bristle bundle is greater than or equal to 3 and less than or equal to 23; the maximum length of the bristle bundle in the longitudinal direction is greater than or equal to 5 millimeters and less than or equal to 15 millimeters.

5. The interdental brush specified in Reputation 2 in which the maximum length in the second direction at the base of such brush section is greater than or equal to 0.1 millimeters and less than or equal to 1.3 millimeters; the ratio of the rows of bristle bundles extended in the first direction is greater than or equal to 3 and less than or equal to 19.

6. The interdental brush specified in Reputation 2 in which the bristle tips of such bristle bundles can move freely with each other; the base of such bristle bundles can move together with adjacent bristle bundles. 7.The interdental brush specified in Claim 6, where the cleaning force in the first direction at 2 mm from the tip of the bristles of the said brush section to the base is designated as cleaning force A, and where the cleaning force in the first direction of the said brush section at 2 mm from the root base of the bristle bundle is designated as cleaning force B, has cleaning force A greater than or equal to 0.05 N and less than or equal to 0.30 N, and cleaning force B greater than or equal to 0.5 N and less than or equal to 15 N, with the value expressed as Cleaning Force A / Cleaning Force B greater than or equal to 0.015 and less than or equal to 0.

68. The interdental brush specified in Claim 7, where the cleaning force B is designated as cleaning force B1, and where the cleaning force in the second direction of the said brush section at 2 mm from the root base of the bristle bundle is designated as cleaning force B2, with the value expressed as Cleaning Force B2 / Cleaning Force B1 greater than or equal to 0.1 and less than or equal to 0.79.

10. The interdental brush specified in Reputation 9, where the cleaning force A is designated as cleaning force A1 and the cleaning force in the second direction at 2 mm from the bristle tip of the brush section to the base is designated as cleaning force A2, the value expressed as cleaning force A2 / cleaning force A1 is greater than or equal to 0.8 and less than or equal to 1.

0.

11. The interdental brush specified in Reputation 2, where elastic material is filled in the bristle bundle gaps at the base of the brush section.

12. The interdental brush specified in Reputation 2, where the brush section to which the individual bristle bundles are attached to the pivot has a functional characteristic at the base and the bristle tip of the bristle bundles are free, unattached ends.

13. The interdental brush specified in Reputation 2, where the brush section is smooth from the base to the bristle tip when viewed laterally in the second direction.

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