KR101786154B1 - Interdental brush - Google Patents

Abstract

The interdental brush of the present invention comprises a handle body, a nozzle body protruding from the handle body, and a brush body provided with a filament on a wire into which the base body is inserted, wherein the nozzle body has a tapered portion and a straight portion, Wherein the nozzle body is flexible following the behavior of the brush body, the tapered portion gradually tapers toward the tip thereof, and the side surface of the tapered portion forms a concave curved surface from the tip end to the base end, The present invention relates to an interdental brush which is connected to the distal end of the tapered portion and whose cross-sectional shape perpendicular to the direction of the piercing is substantially the same throughout the piercing direction. INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide an interdental brush which has a sufficiently high durability of a wire and is hard to bend the wire even if the number of times of use is increased.

Description

INTERDENTAL BRUSH}

The present invention relates to an interdental brush for cleaning an interdental space.

The present application claims priority based on Japanese Patent Application No. 2010-166043 filed on July 23, 2010, the contents of which are incorporated herein by reference.

The interdental brush is used as an auxiliary cleaning tool for cleaning a gap (interdental space) between a tooth and a tooth which is difficult to clean with a toothbrush.

As a general interdental brush, it is known that a brush body formed by interposing a filament between metal wires which are twisted together and a handle body in which a base end of the wire of the brush body is inserted is known . In such an interdental brush, a thin wire having a diameter of about 0.23 to 0.40 mm is used for inserting the brush body between adjacent narrow teeth.

In the interdental cleaning using the interdental brush, the brush is inserted into the interdental space and reciprocally transferred, and the plaque deposited on the interdental space is removed while entangled with the filament.

In the interdental brush used in such a manner, the wire is bent and the restoration is repeated in a linear shape. Therefore, when the number of times of use increases, the number of times of bending increases, so that the wire is subjected to metal fatigue. Since the wire having a small diameter as described above is not necessarily high in strength, the number of times the interdental brush is used increases, and if the wire is metal, it may break. This tendency becomes more remarkable as the diameter of the wire becomes smaller. In addition, when the teeth of the molar teeth are cleaned, since the wires are largely bent, they tend to be more easily broken.

Further, in the conventional interdental brush, the break position of the wire is liable to be close to the boundary between the portion where the wire is exposed and the portion embedded in the handle, etc. However, if the break is broken at that position, the brush body may remain in the teeth . It is difficult to remove the brush body remaining between the teeth of the teeth, particularly between the teeth of the molar teeth.

BACKGROUND ART [0002] In the past, inventions aimed at improving the durability of a wire have been made in response to the above problem. Patent Documents 1 to 4 disclose that a material and a shape of a portion for fixing a wire of a handle body are selected so as to be able to disperse the stress generated in the wire at the time of bending. Patent Document 5 discloses a method in which a portion for fixing a wire of a handle body is formed as a recessed concave portion having a wire as a central axis. Patent Documents 6 to 9 disclose that the front end of a handle body to which a wire is fixed is formed of an elastic material.

Japanese Patent No. 4008284 Japanese Patent Application Laid-Open No. 2001-204549 Japanese Patent Application Laid-Open No. 2005-224268 Japanese Patent Application Laid-Open No. 4-97744 Japanese Patent Laid-Open No. 2000-197520 Japanese Patent Specification No. 2003-513700 Japanese Patent Application Laid-Open No. 9-168426 Japanese Patent Publication No. 4-46576 Japanese Patent Publication No. 4-46577

However, even with the methods described in Patent Documents 1 to 9, it has been difficult to obtain sufficient durability. Further, in the interdental brush, it is required that the wire breaks and the brush body is prevented from remaining in the teeth. However, in the methods described in Patent Documents 1 to 9, the requirement can not be satisfied.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an interdental brush which has a sufficiently high durability of a wire and is hard to bend the wire even if the number of times of use is increased.

The interdental brush of the present invention comprises a handle body, a nozzle body protruding from the handle body, and a brush body provided with a filament on a wire having a base end inserted into the nozzle body, A tapered portion whose side surface is formed in a concave curved surface from the tip end to the base end and a shape of a cross section orthogonal to the direction of the tapered portion 20a, And has substantially the same straight portion 20b extending in the direction of the speech, and follows the behavior of the brush body and is flexible.

Further, in the interdental brush of the present invention, it is preferable that the wire is made of a Co alloy having a Co content of 30 to 60 mass%.

According to a first aspect of the present invention, there is provided a brushless motor comprising a handle body, a nozzle body protruding from the handle body, and a brush body provided with a filament on a wire having a base end inserted into the nozzle body,

Wherein the nozzle body has a tapered portion and a straight portion,

Wherein the nozzle body is flexible following the behavior of the brush body,

The tapered portion gradually tapers toward the tip thereof and the side surface of the tapered portion forms a concave curved surface from the tip end to the base end,

The straight portion relates to an interdental brush which is connected to the tip of the tapered portion and has a cross-sectional shape orthogonal to the direction of the pivoting in which the pivoting direction is substantially the same.

A second aspect of the present invention relates to the inter-gear brush, wherein the wire is made of a Co alloy having a Co content of 30 to 60 mass%.

A third aspect of the present invention relates to the inter-gear brush in which the entire length of the nozzle body is in the range of 1.0 to 8.0 mm.

A fourth aspect of the present invention relates to the inter-gear brush, wherein the length of the tapered portion is in the range of 0.5 to 5.0 mm.

A fifth aspect of the present invention relates to the inter-gear brush in which the length of the straight portion is in the range of 0.5 to 3.0 mm.

A sixth aspect of the present invention relates to the inter-gear brush in which the diameter of the nozzle body is in the range of 0.5 to 5.0 mm.

INDUSTRIAL APPLICABILITY According to the interdental brush of the present invention, it is possible to prevent the wire from being bent even when the durability of the wire is sufficiently high and the number of times of use increases, and the brush body can be prevented from remaining in the teeth when the wire is broken.

When the wire is made of a Co alloy having a Co content of 30 to 60 mass%, the effect of the present invention is particularly exhibited.

1 is a side view showing a main portion of an embodiment of an interdental brush of the present invention.
Fig. 2 is a side view showing a state in which the brush body constituting the interdental brush of Fig. 1 is bent. Fig.
3 is a side view showing a main part of another embodiment of the interdental brush of the present invention.
Fig. 4 is a side view showing main parts of the interdental brushes of Comparative Examples 1 to 4 in which the side surface of the tapered portion is inclined at a certain angle. Fig.
Fig. 5 is a side view showing a state in which the brush body constituting the interdental brush of Fig. 4 is bent. Fig.

One embodiment of the interdental brush of the present invention will be described.

Fig. 1 shows a side view of a main part of an interdental brush of the present embodiment. The interdental brush 1 includes a handle body 10 gripped at the time of use, a nozzle body 20 protruding from the front end of the handle body 10, and a handle body 10 mounted to the handle body 10 and the nozzle body 20 And a brush body (30).

The handle body 10 is not particularly limited as long as it can be held by fingers, and examples thereof include a cylindrical shape, a prismatic shape (triangular prism shape, quadrangular prism shape, etc.) and the like. The handle body 10 may have a curved or curved shape in order to improve the operability of the interdental brush 1. The handle body 10 may have a grip portion and a tapered neck portion disposed at the tip end of the grip portion and tapering toward the front end, and the nozzle body 20 may be provided at the tip of the neck portion.

In order to improve the gripability, the surface of the handle 10 may have unevenness, or may be coated with a non-slip member such as natural rubber or synthetic rubber.

Examples of the material of the handle 10 include polypropylene, polyethylene, an ethylene-alpha olefin copolymer, a thermoplastic elastomer (for example, a polyolefin elastomer, a polystyrene elastomer, Styrene), polystyrene (PS), polycarbonate (PC), ABS resin and the like can be used.

The nozzle body 20 in the present embodiment is constituted by a tapered portion 20a and a straight portion 20b and follows the behavior of the brush body 30 so as to be flexible.

The tapered portion 20a in the present embodiment covers the periphery of the wire 31 in the vicinity of the handle 10 and is conical and tapered gradually in diameter toward the tip. The side surface 21 of the tapered portion 20a forms a concave curved surface extending from the front end to the base end and the end surface 22 of the tapered portion 20a on the side of the handle body 10 is connected to the line And has the same shape as the cross section 11.

The side surface 21 of the tapered portion 20a preferably has a concave curved surface that gradually increases in curvature toward the base end direction from the tip end of the tapered portion 20a in order to increase the stress dispersion effect of the wire 31 Do. Further, the curvature of the concave curved surface is expressed by the radius of curvature (R).

The concave curved surface of the tapered portion may be composed of two or more concave curved surfaces.

In this specification, the tip of the tapered portion means the end portion on the straight side of the tapered portion, and the base end of the tapered portion means the end portion of the side surface of the handle body of the tapered portion.

In this specification, the term " shape " is a concept including not only a shape but also a size. Therefore, the same shape means the same shape and size.

Examples of the soft resin include polypropylene, polyethylene, low density polyethylene, an ethylene-? Olefin copolymer, a polyolefin elastomer, a polystyrene elastomer and a polyester elastomer.

The material of the tapered portion 20a is preferably the same as the material of the handle 10 in that the interdental brush 1 can be easily manufactured.

The straight portion 20b in this embodiment is a columnar body which is connected to the tip end of the tapered portion 20a and has a diameter substantially equal to that of the tapered portion 20a.

As the material of the straight portion 20b, the same material as that of the tapered portion 20a can be used.

Considering the size of the interdental brush 1, the length of the nozzle body 20 is preferably in the range of 1.0 to 8.0 mm, more preferably 1.0 to 6.0 mm, and more preferably 3.0 to 4.0 mm Is particularly preferable. The length of the tapered portion 20a is preferably 0.5 to 5.0 mm, more preferably 1.5 to 3.0 mm. The length of the straight portion 20b is preferably 0.5 to 3.0 mm, more preferably 1.5 to 2.0 mm.

When the total length of the nozzle body 20 is 1.0 mm or more and the tapered portion 20a and the straight portion 20b are 0.5 mm or more, the stress concentration dispersion effect of the wire 31 becomes higher, Making it easier to produce. The operability in the oral cavity (particularly, the inner portion of the oral cavity) is increased when the total length of the nozzle body 20 is 8.0 mm or less, the tapered portion 20a is 5.0 mm or less, and the straight portion 20b is 3.0 mm or less.

The diameter of the nozzle body 20 is preferably in the range of 0.5 to 5.0 mm, and more preferably in the range of 0.7 to 3.5 mm. The diameter of the end face 22 on the side of the handle body 10 is set to be in the range of 1.1 to 3.0 times the diameter of the end face 23 on the side of the straight portion 20b in the tapered portion 20a, 10 times. The diameter of the end surface 23 on the side of the straight portion 20b of the tapered portion 20a is preferably 0.5 to 1.0 mm. The tapered portion 20a can be easily manufactured if the diameter of the end surface 23 on the side of the straight portion 20b of the tapered portion 20a is 0.5 mm or more. If the diameter is 1.0 mm or less, .

The diameter of the straight portion 20b is more preferably 5.0 times or less the diameter of the wire 31 because the stress concentration dispersion effect of the wire 31 is higher.

When the diameter of the nozzle body 20 is in the range of 0.5 to 5.0 mm, it is preferable that the shortest distance from the side surface 21 to the wire 31 is within the range of 0.01 to 2.3 mm.

The brush body 30 has a wire 31 and a filament 32 for interdental cleaning provided on the wire 31. [

In this embodiment, the wire 31 is formed by folding two metal wires into two pieces, folding back and spirally twisted, the folded back portion being the tip end, and the base 31a side Is inserted into the nozzle body (20) and the handle body (10).

It is preferable that the insertion length of the wire 31 into the handle 10 is 0.1 to 10.0 mm, more preferably 1.0 to 4.0 mm. If the insertion length of the wire 31 is 0.1 mm or more, the wire 31 can be securely fixed to the handle 10, and the stress distribution of the wire 31 is further enhanced. However, if it exceeds 10.0 mm, the fixing property of the wire 31 to the handle 10 and the improvement of stress dispersion of the wire 31 become a limit, which is useless.

The length of the exposed portion of the wire 31 at the distal end side with respect to the nozzle body 20 is preferably 5 to 20 mm, more preferably 6 to 15 mm. When the length of the exposed portion of the wire 31 at the distal end side of the nozzle body 20 is 5 mm or more, the teeth are more easily cleaned. When the length is 20 mm or less, the handling property at the time of cleaning is excellent.

The material of the wire 31 is not particularly limited, and examples thereof include austenitic stainless steel, martensitic stainless steel, ferritic stainless steel, and a Co alloy having a Co content of 30 to 60 mass%. Among them, the effect of using the nozzle body 20 composed of the tapered portion 20a and the straight portion 20b is further exerted, and the durability of the wire 31 is further improved, so that the Co content of 30 to 60 mass% Co alloy is preferable.

In the Co alloy, if the Co content is 30 mass% or more, the bending strength and the repeated bending fatigue characteristics are higher, and if the Co content is 60 mass% or less, the wire 31 is hardly broken at the time of processing.

As the Co alloy, a necessary amount of elements such as Cr, Ni, Mo, C, Mn, Si, W, Fe and Ti is added to Co. Specifically, a Co-Cr-Ni-based alloy, a Co-Cr-Mo-based alloy, a Co-Cr-W-Ni alloy, a Co- Fe-based alloys, and the like. Further, in the Co-Cr-Ni alloy, it is preferable that Cr is contained in an amount of 20 to 23 mass% and Ni is contained in an amount of 15 to 18 mass%. In addition, in the Co-Cr-Mo based alloy, it is preferable to contain 27 to 30 mass% of Cr and 5.0 to 7.0 mass% of Mo, and if necessary, 2.5 mass% or less of Ni, 7.5 mass% Or less.

In the Co-Cr-W-Ni alloy, it is preferable to contain Cr in an amount of 19 to 21 mass%, Ni in an amount of 9.0 to 11.0 mass% and W in an amount of 14 to 16 mass% Or less, Mn of 2.0 mass% or less, and Si of 1.0 mass%.

In the Co-Ni-Cr-Mo alloy, it is preferable to contain Cr in an amount of 19 to 21 mass%, Ni in an amount of 33 to 37 mass%, and Mo in an amount of 9.0 to 10.5 mass% May be contained in an amount of 1% by mass.

In the Co-Ni-Cr-Mo-W-Fe alloy, the alloy contains 18 to 22 mass% of Cr, 15 to 25 mass% of Ni, 3 to 4 mass% of Mo, 3 to 4 mass% of W, By mass to 6% by mass, and may contain 1% by mass or less of Mn, 0.5 to 3.5% by mass of Ti and 0.5% by mass or less of Si in accordance with necessity.

Further, as the Co alloy, it is preferable that 30 to 45 mass% of Co, 10 to 20 mass% of Ni, 8 to 15 mass% of Cr, 3 to 12 mass% of Mo, 0.08 mass% of C, 0.045 mass% of P, 0.045 mass% of S 0.03 mass%, respectively, and the balance of Fe (SPRON100) (trade name, manufactured by Seiko Ind. Co., Ltd.) can be used.

Further, SPRON 500 (trade name, manufactured by Seiko Ind. Co., Ltd.) having a composition of 25 to 45 mass% of Co, 12 to 25 mass% of Cr, and 8 to 15 mass% of Mo and having the balance of Ni can be used .

Further, NAS604PH (manufactured by Nippon Seisen Co., Ltd.) having a composition of Co of 40 mass% or more, Ni of 15 to 17.5 mass%, Cr of 20.5 to 22.5 mass% and Mo of 5.8 to 8.3 mass% Trade names) may be used.

The thickness of the wire 31 is suitably selected in the range of, for example, 0.18 to 0.40 mm. However, since the diameter of the wire 31 becomes smaller, the wire 31 is more likely to be bent. In the product of the interdental brush 1, the size is classified according to the thickness of the wire 31. [ SSSS (4S), SSS (3S), SS (2S), S, M, L or the like or a notation using 1 to 6 symbols or numerals can be used as the notation of size.

The length of the portion of the wire 31 on which the filament 32 is provided is appropriately selected in consideration of the use of the interdental brush 1, that is, the shape of the interdental space assumed, and is, for example, 5 to 15 mm .

The filaments 32 are sandwiched by wires 31 that are helically joined together and are attached so that the filaments 32 are radially stretched around the wire 31 as a central axis. When the filament 32 is attached radially to the wire 31, the filament 32 is easily brought into contact with the tooth when the brush 30 is inserted into the teeth, and the removability of the plaque is increased.

The length of the filament 32 is preferably 1.0 to 7.0 mm from the viewpoints of insertion into the interdental space and removability of the plaque. In this embodiment, the filament 32 is shortened at the distal end side and elongated at the proximal end side in order to further improve the insertion property into the interdental space.

Examples of the material of the filament 32 include thermoplastic resins such as polyamide (nylon), polybutylene terephthalate (PBT), polypropylene, and polytrimethylene terephthalate (PTT).

When the interdental brushes 1 are used to clean the interdental brushes 1, the brush body 30 is inserted with the handle body 10 held in the vicinity of the teeth with the distal end of the brush body 30 facing in the direction of the interdental space . Then, the interdental brush 1 is moved so as to reciprocate the brush body 30 between the teeth, thereby cleaning the teeth.

At that time, particularly when the brush body 30 is pulled back to the mouth side, the wire 31 may be bent.

In the interdental brush 1, as shown in Fig. 2, when the wire 31 is bent, the nozzle body 20 around the interdental brush 1 is also bent together with the wire 31. Fig. Here, since the side surface 21 of the tapered portion 20a of the nozzle body 20 forms a concave curved surface from the tip end to the base end, the tapered portion 20a is easily bent toward the tip end side. With such a tapered portion 20a, the abrupt bending of the wire 31 is suppressed, so that the stress generated in the wire 31 can be sufficiently dispersed.

Further, in the present embodiment, since the straight portion 20b is provided at the tip of the tapered portion 20a, the stress generated in the wire 31 can be more dispersed. Therefore, the durability of the wire 31 is sufficiently high, and even if the number of times of use is increased, the wire 31 is not easily broken.

When the stress generated in the wire 31 is dispersed by using the nozzle body 20 having the tapered portion 20a and the straight portion 20b, the breakage of the wire 31 is prevented by the nozzle body 20 ). ≪ / RTI > 3, the base end 31a of the wire 31 can be positioned closer to the nozzle body 20 than the tip end portion 11 of the handle body 10. Therefore, It is possible to make a flexible movement and to improve the durability of the wire 31. In addition, improvement in appearance and cost reduction by molding can be expected. It is preferable that the base end 31a of the wire 31 be at least a cross section of the end surface 23 and the tip end 11. Even if the wire 31 is broken, the brush body 30 can be taken out along with the nozzle body 20 without being separated from the nozzle body 20 if it is inside the nozzle body 20.

In the interdental brush 2 outside the scope of the present invention in which the side surface 24 of the tapered portion 20c is inclined at a predetermined angle from the tip end to the base end as shown in Fig. 4, as shown in Fig. 5 Likewise, when the wire 31 is bent, the tapered portion 20c hardly bends and does not follow the behavior of the brush 30. Therefore, the effect of dispersing the stress in the tapered portion 20c is insufficient, and the stress is concentrated on the exposed portion P of the wire 31 at the tip side of the wire body 31 more rapidly than the nozzle body 20 . As a result, the wire 31 is easily broken, the wire durability is insufficient, and the probability of the wire 31 to be broken at the exposed portion P is increased. As a result, when the wire 31 is broken, The remaining can not be prevented.

The present invention is not limited to the above embodiment. For example, in the present invention, the tapered portion 20a is not a conical shape, and the straight portion 20b may not be a columnar shape. For example, the cross-sectional shape of the tapered portion 20a may be a shape of a ellipse, a polygonal shape of a triangle or more, a shape of a star, or the like. The cross-sectional shape of the straight portion 20b is determined according to the tapered portion 20a.

The length of the filament 32 is not limited to be long on the proximal end side but may be constant or may be made long on the distal end side and short on the proximal end side.

Example

(Example 1)

As shown in Fig. 1, the interdental brush of the first embodiment includes a handle body 10, a nozzle body 20, and a brush body 30, and the nozzle body 20 has a concave curved surface And a tapered portion 20a made of polypropylene and a straight portion 20b were produced by insert molding by injection molding.

The overall length of the nozzle body 20, the diameter of the end surface 22 of the tapered portion 20a on the side of the handle 10 and the diameter of the straight portion 20b were as shown in Table 1. The handle body 10 was made of a polypropylene cylindrical body. A wire made of a high strength Co base alloy wire (Nisshin Chemical Industry Co., Ltd., NAS604PH, Co: 40 mass% or more, Ni: 15 to 17.5 mass% of Cr, 20.5 to 22.5 mass% of Cr, 5.8 to 8.3 mass% of Mo, and the balance of Fe) was folded back and twisted. As the filament 32, 6,12-nylon fiber having a diameter of 0.051 mm was used. The length of the portion where the filament 32 was provided on the wire 31 was 10 mm and the length of the portion where the filament 32 was not provided was 1.0 mm.

(Example 2)

A wire made of a high-strength Co-based alloy wire (NAS604PH manufactured by Nippon Seisen Co., Ltd.) having a diameter of 0.23 mm (size: 3S) was used as the wire 31 instead of the wire made of high strength Co based alloy having a diameter of 0.20 mm An interdental brush was obtained in the same manner as in Example 1, except that a folded back and twisted one was used.

(Example 3)

(Manufactured by Nippon Seisen Co., Ltd., NAS106N, Ni: 10 masses (size: 4S)) having a diameter of 0.20 mm (size: 4S) instead of a high- Except for using a product obtained by folding and folding back the above-mentioned ferrite powder in an amount of 2% by mass, Cr: 22% by mass, Mo: 2% by mass, Mn: 5.9% by mass, C: 0.015% by mass, N: 0.40% by mass, 1, an interdental brush was obtained.

(Example 4)

A general-purpose stainless steel wire (NAS106N, manufactured by Nippon Seisen Co., Ltd.) having a diameter of 0.23 mm (size: 3S) was folded and twisted in place of the general-purpose stainless wire of 0.20 mm Was used, and an interdental brush was obtained in the same manner as in Example 3.

(Comparative Example 1)

The nozzle body 20 and the brush body 30 are provided as the interdental brushes of Comparative Example 1. The nozzle body is composed of the straight portion 20b and the side surface 24 as shown in Fig. And the tapered portion 20c inclined at a predetermined angle was formed by insert molding by injection molding.

The dimensions of the nozzle body 20 were as shown in Table 1. The handle body 10 and the brush body 30 are the same as those of the first embodiment. As the wire 31 of the brush body 30, a wire made of a high-strength Co-based alloy wire (NAS604PH manufactured by Nippon Seisen Co., Ltd.) having a diameter of 0.20 mm (size: 4S) was folded and twisted.

(Comparative Example 2)

A wire made of a high-strength Co-based alloy wire (NAS604PH manufactured by Nippon Seisen Co., Ltd.) having a diameter of 0.23 mm (size: 3S) was used as the wire 31 instead of the wire made of high strength Co based alloy having a diameter of 0.20 mm An interdental brush was obtained in the same manner as in Comparative Example 1, except that the folded back and twisted pieces were used.

(Comparative Example 3)

The nozzle body 20 is provided with the straight body 20b and the side face 24 as shown in Fig. 4, and the nozzle body 20 is provided with the handle body 10, the nozzle body 20 and the brush body 30 as the interdental brushes of the comparative example 2, And the tapered portion 20c inclined at a predetermined angle was formed by insert molding by injection molding.

The dimensions of the nozzle body 20 were as shown in Table 1. The handle body 10 and the brush body 30 are the same as those of the first embodiment. As the wire 31 of the brush 30, a universal stainless steel wire (NAS106N, manufactured by Nippon Seisen Co., Ltd.) having a diameter of 0.20 mm (size: 4S) was folded back and twisted.

(Comparative Example 4)

A general-purpose stainless steel wire (NAS106N, manufactured by Nippon Seisen Co., Ltd.) having a diameter of 0.23 mm (size: 3S) was folded and twisted in place of the general-purpose stainless wire of 0.20 mm Was used, and an interdental brush was obtained in the same manner as in Comparative Example 3.

[Table 1]

The wire durability of the interdental brushes of Examples 1 to 6 and Comparative Examples 1 to 4 was evaluated by the following repetitive bending fatigue test.

[Repetitive bending fatigue test]

First, the handle 10 of the interdental brush 1 was fixed to a chuck, and a weight having a load of 100 g was hanged on the distal end of the wire 31 using a fine fiber. In this state, the wires 31 were repeatedly rotated 90 degrees (180 degrees in total) at a speed of 30 times / part on each of the left and right sides. Thus, the number of times of reversal until the wire was broken by fatigue was measured. In addition, the break position was visually confirmed. The results are shown in Table 1.

In the interdental brushes of Examples 1 to 4, in which the side surface of the nozzle body was composed of the tapered portion and the straight portion of the concave curved surface, the number of inversions until the wire was broken was large and the wire durability was excellent. The wire break position was inside the nozzle body.

On the other hand, in the interdental brushes of Comparative Examples 1 to 4, in which the nozzle body was composed of the tapered portion and the straight portion which were inclined at a constant angle at a certain angle, the number of inversion until the wire broke was small and the wire durability was insufficient. The wire breaking position was a portion where the tip side was slightly exposed as compared with the nozzle body.

When the wires were compared with the number of repetitions of Example 1, Comparative Example 1, and Example 2 and Comparative Example 2 of the wire made of the high strength Co-based alloy, the number of repetitions of Example 1 was 6.2 times that of Comparative Example 1, 2 was 3.2 times as high as that of Comparative Example 2.

On the other hand, when the wire is compared with the general-purpose stainless steel wire in Example 3, Comparative Example 3, and Example 4 and Comparative Example 4, the number of repetitions of Example 3 is 4.7 times that of Comparative Example 3, The recovery was 2.4 times that of Comparative Example 4.

From these results, it was found that the durability was improved by using a wire made of a high strength Co-based alloy. Further, when the tapered portion of the tapered portion has a concave curved surface as the nozzle body, the effect of improving the durability is greater than when the tapered portion of the nozzle body is inclined at a predetermined angle. As a result, it was found that a combination of a wire made of a high-strength Co-based alloy and a nozzle body composed of a tapered portion and a straight portion having a concave curved side surface exerts a synergistic effect on wire durability improvement.

[Industrial Availability]

INDUSTRIAL APPLICABILITY According to the interdental brush of the present invention, it is possible to prevent the wire from being bent even when the durability of the wire is sufficiently high and the number of times of use increases, and the brush body can be prevented from remaining in the teeth when the wire is broken. When the wire is made of a Co alloy having a Co content of 30 to 60 mass%, the effect of the present invention is particularly exhibited.

1, 2: Interdental brush
10:
11:
20: nozzle body
20a and 20c:
21, 24: side
22, 23: section
20b and 20e:
30: Brush body
31: Wire
31a:
32: filament

Claims (6)

And a brush body provided with a filament on a wire having a base end inserted into the nozzle body,
Wherein the nozzle body has a tapered portion and a straight portion,
Wherein the nozzle body is flexible following the behavior of the brush body,
The tapered portion gradually tapers toward the tip thereof and the side surface of the tapered portion forms a concave curved surface having a curvature larger from the tip toward the base end,
Wherein the straight portion is formed on the distal end of the tapered portion and has substantially the same shape in cross section orthogonal to the extending direction and a diameter of not more than 5.0 times the diameter of the wire. The method according to claim 1,
Wherein the wire is made of a Co alloy having a Co content of 30 to 60 mass%. The method according to claim 1,
Wherein the entire length of the nozzle body is in the range of 1.0 to 8.0 mm. The method according to claim 1,
Wherein the length of the tapered portion is in the range of 0.5 to 5.0 mm. The method according to claim 1,
And the length of the straight portion is in the range of 0.5 to 3.0 mm. The method according to claim 1,
Wherein the diameter of the nozzle body is in the range of 0.5 to 5.0 mm.

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