JP6721342B2 - Interdental brush - Google Patents

Description

The present invention relates to an interdental brush.

Interdental brushes are widely used for the purpose of efficiently cleaning the spaces between teeth. Interdental brushes include those using a metal wire as a shaft material and those using a synthetic resin as a shaft material. An interdental brush using a metal wire as a shaft material has a good cleaning feeling for the user. An interdental brush including a shaft member made of synthetic resin has a better contact feeling against gums and teeth than an interdental brush including a metal wire. For example, in Patent Document 1, a shaft member in which a synthetic resin core portion extending from a tip of a grip portion (handle portion) is coated with an elastomer, and a plurality of shaft members are radially provided when viewed from the extending direction of the shaft member. An interdental brush having a protrusion made of an elastomer is proposed.

JP, 2013-192866, A

However, in the interdental brush using the conventional synthetic resin as the shaft material, since the protrusions are soft and the protrusion spacing is wide, there is a problem that the cleaning force between teeth and the user's cleaning feeling are lower than those of the metal wire interdental brush. is there.
Then, this invention aims at the interdental brush which improved the cleaning force between teeth and a user's actual feeling of cleaning.

The present invention has the following aspects.
[1] A gripping part and a cleaning part provided at the tip of the gripping part are provided, and the cleaning part includes a shaft member made of synthetic resin extending from the tip end of the gripping part and an extending direction of the shaft member. As seen, the plurality of protruding pieces radially protruding from the shaft member are provided, and the plurality of protruding pieces include one or more first protruding pieces made of a first synthetic resin, and the first synthetic resin. An interdental brush comprising one or more second protruding pieces made of a harder second synthetic resin.
[2] The interdental brush according to [1], wherein the height of the first protruding piece is higher than the height of the second protruding piece.
[3] The shaft member includes a core portion made of the second synthetic resin and a covering portion made of the first synthetic resin for covering the surface of the core portion, and the second projecting piece is The interdental brush according to [1] or [2], which is formed integrally with the core portion and projects through the coating portion.
[4] The plurality of projecting pieces further include one or more third projecting pieces made of the first synthetic resin, and the thickness of the third projecting piece is the same as the thickness of the first projecting piece. The thicker interdental brush according to [1] to [3].
[5] The interdental brush according to [1] to [4], wherein the thickness of the second protruding piece is 0.1 mm or more and 0.5 mm or less.

[6] The plurality of projecting pieces include a first projecting piece row composed of the first projecting pieces arranged on a first straight line along the axis of the shaft member, [4] or [4] 5] The interdental brush according to [5].
[7] The plurality of projecting pieces are the second projecting piece and the third projecting piece that are alternately arranged on a second straight line along an axis of the shaft member different from the first straight line. The interdental brush according to [6], including a second row of protruding pieces consisting of one piece.
[8] The first projecting piece row and the second projecting piece row are alternately arranged in an annular shape at an interval of 45° when viewed from the extending direction of the shaft member, according to [7]. Interdental brush.
[9] The tooth according to [4] to [8], wherein the second protruding piece and the third protruding piece are annularly arranged at intervals of 90° when viewed from the extending direction of the shaft member. Between brushes.
[10] The interdental brush according to [1] to [9], wherein the thickness of the second protruding piece is 0.1 mm or more and 0.2 mm or less.
[11] The interdental brush according to [4] to [10], wherein the thickness of the third protruding piece is 0.3 mm or more and 0.6 mm or less.

According to the interdental brush of the present invention, the brushing force between teeth and the user's feeling of cleaning can be improved.

It is a front view showing the interdental brush 1 of 1st embodiment of this invention. It is the front view which expanded the cleaning part 3 of the interdental brush 1 of FIG. It is an A-A' cross section figure of the interdental brush 1 of FIG. It is a B-B' sectional view of the interdental brush 1 of FIG. It is a C-C' cross section figure of the interdental brush 1 of FIG. It is a D-D' cross section figure of the interdental brush 1 of FIG. It is a top view of the interdental brush 1 seen from the extension direction of the shaft material 4 of 1st embodiment of this invention. It is a front view of the primary product (base) 6.

The following definitions of terms apply throughout the specification and claims.
The "user's actual feeling of cleaning" defined in the present specification is caused by the contact between the interdental brush and the teeth (or gums) when the user cleans the interdental brush with the interdental brush. It means that the user feels that the space between the teeth is cleaned due to vibration or frictional force.

The interdental brush of the present invention includes a grip portion and a cleaning portion provided at the tip of the grip portion. The cleaning unit includes a shaft member made of synthetic resin extending from the tip of the grip unit, and a plurality of protruding pieces radially protruding from the shaft member when viewed from the extending direction of the shaft member. The plurality of projecting pieces include one or more first projecting pieces made of a first synthetic resin, and one or more second projecting pieces made of a second synthetic resin harder than the first synthetic resin. Equipped with.

(First embodiment)
Hereinafter, an example of the interdental brush of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a front view showing an interdental brush 1 of this embodiment. As shown in FIG. 1, the interdental brush 1 of the present embodiment includes a grip portion 2 that gradually narrows toward the tip side, and a cleaning portion 3 provided at the tip of the grip portion 2.
FIG. 2 is an enlarged front view of the cleaning unit 3 of the interdental brush 1 of this embodiment. As shown in FIG. 2, the cleaning unit 3 includes a shaft member 4 extending from the tip of the grip unit 2 and a plurality of projecting pieces 5 a to 5 c (5) protruding from the shaft member 4. The protruding pieces 5 radially protrude when viewed from the extending direction of the shaft member 4. The projecting piece 5 has one or more first projecting pieces 5a, one or more second projecting pieces 5b, and one or more third projecting piece 5c.
FIG. 3 is a cross-sectional view of the interdental brush 1 of FIG. 2 taken along the line AA′. In FIG. 3, only the cross section of the interdental brush 1 is shown for convenience. As shown in FIG. 3, the shaft member 4 includes a core portion 4a whose main material is a second synthetic resin which is a hard resin, and a coating portion 4b which is made of a first synthetic resin which is a soft resin. The covering portion 4b covers the core portion 4a.

<Gripping part>
The grip portion 2 is a member for gripping with a finger. The shape of the grip portion 2 of the present embodiment is not particularly limited as long as it can be gripped with a finger, and examples thereof include a column shape such as a plate shape, a column shape, a triangular column shape, and a square column shape.
For the purpose of making it easier to hold the grip portion 2 with a finger, for example, the grip portion 2 may be formed with irregularities, holes, through holes, or curves.

As shown in FIG. 1, the grip portion 2 is formed with a reduced diameter portion 2a that gradually becomes thinner toward the tip side, and a cleaning portion 3 is formed at the tip of the reduced diameter portion 2a.
When the reduced diameter portion 2a is formed, it becomes easier to visually recognize the state of the cleaning portion 3 between the teeth when the interdental brush 1 is used while checking with a mirror. Further, since the reduced diameter portion 2a is gradually thickened toward the hand, the insertion between the teeth is likely to stop at the reduced diameter portion 2a, and it is possible to prevent the interdental brush 1 from being excessively inserted.

The range of the minimum diameter and the maximum diameter of the reduced diameter portion 2a is not particularly limited. For example, the minimum diameter of the reduced diameter portion 2a is preferably 1 mm to 3 mm, more preferably 1.5 mm to 2.5 mm. The maximum diameter of the reduced diameter portion 2a is preferably 3 mm to 5 mm, more preferably 3.5 mm to 5 mm.
When the minimum diameter is at least the lower limit value of the above range, the structural strength can be increased.
When the maximum diameter is less than or equal to the upper limit of the above range, handling in the mouth becomes easy.

Here, the minimum diameter of the reduced diameter portion 2a is the diameter at the position indicated by the boundary 3a between the cleaning portion 3 and the reduced diameter portion 2a in FIG. In the present embodiment, the boundary 3 a is used as a symbol indicating the base end of the cleaning unit 3 for convenience. The maximum diameter of the reduced diameter portion 2a is the same as the diameter R1 of the grip portion 2.

The width or diameter (thickness) R1 of the grip portion 2 is not particularly limited, and is preferably 5 mm to 10 mm, for example.
When the width or the diameter is equal to or more than the lower limit value of the above range, the structural strength can be increased.
When the width or diameter is equal to or less than the upper limit value of the above range, handling during cleaning of the mouth becomes easy.

The constituent material of the grip portion 2 is not particularly limited, and a known material that constitutes the grip portion of the conventional interdental brush can be applied. The constituent material of the grip portion 2 is preferably a synthetic resin, and from the viewpoint of enhancing the integrity with the core portion 4a of the shaft member 4 extending from the tip of the grip portion 2, the constituent material of the core portion 4a described in detail later. It is preferable that the second synthetic resin is the same. In the present embodiment, it is preferable that the grip portion 2 and the core portion 4a are integrally formed.
The constituent material of the grip portion 2 may be one kind or a composite material containing two or more kinds.

<Cleaning section>
As shown in FIG. 2, the cleaning unit 3 includes a shaft member 4 extending from the tip of the reduced diameter portion 2a of the grip unit 2 (a boundary 3a of the cleaning unit 3) and a plurality of protruding pieces 5. Further, as shown in FIG. 7, the plurality of projecting pieces 5 are provided to radially project in a direction orthogonal to the axis of the shaft member 4. The plurality of protruding pieces 5 includes one or more first protruding pieces 5a, one or more second protruding pieces 5b, and one or more third protruding pieces 5c.
As shown in FIG. 2, the plurality of protruding pieces 5 is a first protruding piece row composed of a plurality of first protruding pieces 5a arranged on a first straight line P along the axis of the shaft member 4. Including. Further, the plurality of projecting pieces 5 are composed of a plurality of second projecting pieces 5b and a plurality of third projecting pieces 5c which are alternately arranged on the second straight line Q along the axis of the shaft member 4. Includes two rows of protruding pieces.

The shape of the shaft member 4 is not particularly limited as long as a plurality of projecting pieces 5 can be installed and can be inserted between the teeth. A shape such as a shape may be mentioned.
The shaft member 4 of the present embodiment has a cylindrical shape that gradually becomes thinner toward the tip. This makes it easier to insert the cleaning unit 3 between the teeth.

The length of the shaft member 4 is preferably 10 mm or more, more preferably 11 mm or more, and even more preferably 12 mm or more in order to improve cleaning efficiency between teeth.
The upper limit of the length of the shaft member 4 is not particularly limited, and is preferably 20 mm or less because the operability in the mouth is improved.

The thickness of the shaft member 4 is not particularly limited, and for example, the area of the cross section orthogonal to the axis of the shaft member 4 at a portion 0.1 mm from the tip of the shaft member 4 is preferably 0.010 mm ^{2 to} 1.500 mm ^2. The thickness is more preferably 0.030 mm ^{2 to} 1.200 mm ² , and further preferably 0.060 mm ^{2 to} 0.800 mm ² . The area of the cross section perpendicular to the longitudinal direction of the border 3a moiety, preferably 0.200mm ² ~3.140mm ^2, more preferably 0.380mm ² ~2.540mm ^2, more preferably 0.500 mm ² to 2 It is preferable that the thickness is 0.270 mm ² .
When the area of the cross section is equal to or more than the above lower limit value, the rigidity of the shaft member 4 can be further enhanced.
When the area of the cross section is less than or equal to the upper limit value, it becomes easier to insert the shaft member 4 into a narrow space between teeth, and the cleaning force can be increased.

The thickness of the shaft member 4 extending from the boundary 3a to the tip of the shaft member 4 may be constant, or may be a tapered shape that gradually becomes thinner or thicker toward the tip. In the case of a tapered shape, the angle (taper angle) formed by the surface of the shaft member 4 with respect to the axis of the shaft member 4 is not particularly limited and may be constant or may change gradually or stepwise.

The shaft member 4 of the present embodiment includes a core portion 4a extending from the tip of the grip portion 2 and a coating portion 4b that covers the surface of the core portion 4a. The core portion 4a is made of a second synthetic resin which is a hard resin. The covering portion 4b is made of a soft resin which is the first synthetic resin. The first synthetic resin is softer than the second synthetic resin. In the present embodiment, when the first synthetic resin satisfies the Shore hardness A (Shore A hardness) described below and the second synthetic resin satisfies the bending elastic modulus described below, the first synthetic resin is , Defined as softer than the second synthetic resin.

The second synthetic resin, which is a constituent material of the core portion 4a, is not particularly limited as long as it is a hard resin. A well-known hard resin can be applied as the hard resin, and for example, a resin having a bending elastic modulus (JIS K7203) in the range of 500 to 3000 MPa can be used.
Examples of such a hard resin include polypropylene (PP), polytrimethylene terephthalate (PTT), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polycyclohexylene dimethylene terephthalate (PCT), polyacetal (POM). , Polystyrene (PS), acrylonitrile-butadiene-styrene resin (ABS), cellulose propionate (CP), polyarylate, polycarbonate, acrylonitrile-styrene copolymer resin (AS), and the like.

An optional component other than the synthetic resin used as the main material may be added to the constituent material of the core portion 4a. Suitable optional components include, for example, a filler made of an inorganic material and a filler made of an organic material. The strength of the core 4a can be improved by adding a filler to the synthetic resin as a constituent material of the core 4a.

[Coating part]
The constituent material of the covering portion 4b is the first synthetic resin. The first synthetic resin is composed of a soft resin. When the covering portion 4b is formed of a soft resin, the gums and teeth are less likely to be damaged when the cleaning portion 3 is inserted between the teeth, and the contact feeling is further improved.
The Shore hardness A (Shore A hardness) of the soft resin forming the coating portion 4b is preferably A95 or less, and more preferably A30 to A90. Suitable soft resins include, for example, known elastomer resins such as polyolefin elastomers, styrene elastomers and polyester elastomers.
The soft resin forming the covering portion 4b may be one kind or two or more kinds.

The thickness of the covering portion 4b is not particularly limited, and for example, 0.1 mm to 1.0 mm is preferable, 0.1 mm to 0.5 mm is more preferable, and 0.1 mm to 0.3 mm is further preferable.
When the thickness of the covering portion 4b is equal to or more than the lower limit value, it is possible to prevent the first protruding piece 5a and the third protruding piece 5c from falling off the covering portion 4b, and enhance the structural strength of the cleaning portion 3. it can.
When the thickness of the covering portion 4b is equal to or less than the upper limit value, it is possible to prevent the diameter of the entire cleaning portion 3 from becoming too thick, and improve the insertability between narrow teeth.

[Protruding piece]
The plurality of projecting pieces 5 that form the cleaning unit 3 include a first projecting piece 5a, a second projecting piece 5b, and a third projecting piece 5c. As shown in FIG. 2, the cleaning portion 3 of the interdental brush 1 of the present embodiment has a first protruding piece 5a, a second protruding piece 5b, and a third protruding piece 5c from the surface of the shaft member 4. One or more are provided for each. These protruding pieces 5 carry out cleaning between teeth and function as a brush (brush) material for scraping plaque.

The first protruding piece 5a is made of a first synthetic resin. In the present embodiment, the first protruding piece 5a is formed integrally with the covering portion 4b, but the present application is not limited to this. As the soft resin forming the first synthetic resin, the materials listed as the soft resin forming the covering portion 4b can be used.

In the present embodiment, the first projecting piece 5a has a rounded columnar shape, but the shape of the first projecting piece 5a is not limited to this. For example, the first protruding piece 5a may have a tapered shape that gradually becomes thinner toward the tip, or may have a conical shape. Further, it may be a polygonal pyramid such as a triangular pyramid or a quadrangular pyramid. Further, in these shapes, the tip end portion and the corner portion of the first projecting piece 5a may be rounded. By rounding the tip and corners of the first projecting piece 5a, it is difficult to damage the gums and teeth when inserting the cleaning unit 3 between the teeth, and the contact feeling becomes better.

The height Ha of the first projecting piece 5a is higher than the height Hb of the second projecting piece 5b and the height Hc of the third projecting piece 5c. Specifically, the height Ha of the first protruding piece 5a is preferably 0.1 mm to 2.0 mm, more preferably 0.5 mm to 1.5 mm, and further preferably 0.6 mm to 1.2 mm.
If the height Ha of the first protruding piece 5a is equal to or less than the upper limit value, the cleaning unit 3 can be easily inserted between the teeth.
Since the first protruding piece 5a is made of a soft resin, the height Ha of the first protruding piece 5a is the height Hb of the second protruding piece 5b and the height Hc of the third protruding piece 5c. Even if it is higher, the gums and teeth are less likely to be damaged when the cleaning unit 3 is inserted between the teeth, and the contact feeling is improved.
The height Ha of the first protruding piece 5a means the length from the base end on the front surface side of the covering portion 4b to the tip of the first protruding piece 5a.
The height Hb of the second protruding piece 5b means the length from the base end on the front surface side of the covering portion 4b to the tip of the second protruding piece 5b.
The height Hc of the third projecting piece 5c means the length from the base end on the front surface side of the covering portion 4b to the tip of the third projecting piece 5c.
If the height Ha of the first protruding piece 5a is equal to or more than the lower limit value, it can be easily molded by injection molding.

The thickness of the first projecting piece 5a is smaller than that of the third projecting piece 5c. Specifically, the thickness of the first protruding piece 5a is preferably 0.1 mm to 0.3 mm, more preferably 0.10 mm to 0.20 mm.
If the thickness of the first protruding piece 5a is equal to or larger than the lower limit value, it can be easily molded by injection molding.
If the thickness of the first protruding piece 5a is equal to or smaller than the upper limit value, the cleaning unit 3 can be easily inserted between the teeth.
Here, when the cross section perpendicular to the projecting direction of the first projecting piece 5a is a perfect circle, the thickness of the first projecting piece 5a is the same as that of the first projecting piece 5a on the same plane as the surface of the covering portion 4b. It means the diameter (ie, the diameter of the proximal end). When the cross section of the first projecting piece 5a perpendicular to the projecting direction is other than a perfect circle, the thickness of the first projecting piece 5a means the circumscribed circle of the first projecting piece 5a on the same plane as the surface of the covering portion 4b. Means the diameter of.
When the cross section of the third projecting piece 5c perpendicular to the projecting direction is a perfect circle, the thickness of the third projecting piece 5c means the diameter of the third projecting piece 5c in the same plane as the surface of the covering portion 4b. To do. When the cross section of the third projecting piece 5c perpendicular to the projecting direction is other than a perfect circle, the thickness of the third projecting piece 5c means the circumscribed circle of the third projecting piece 5c on the same plane as the surface of the covering portion 4b. Means the diameter of.

The second protruding piece 5b of this embodiment is formed integrally with the core portion 4a. The second projecting piece 5b of this embodiment projects from the core portion 4a and penetrates the covering portion 4b. In other words, the second projecting piece 5b radially projects from the shaft member 4 from the connecting portion with the core portion 4a through the opening of the covering portion 4b. The second protruding piece 5b is made of a second synthetic resin which is a hard resin. As the hard resin forming the second protruding piece 5b, the materials listed as the hard resin forming the core portion 4a can be used. By configuring the second projecting pieces 5b with a hard resin, the user can feel a different texture from the first projecting pieces 5a and the third projecting pieces 5c, and all the projecting pieces 5 are composed of only the soft resin. A higher cleaning experience can be obtained as compared with the case of performing. Further, by forming the second protruding pieces 5b with a hard resin, a higher interdental cleaning force (plaque scraping force) can be obtained as compared with the case where all the protruding pieces 5 are formed with only a soft resin. To be

The second projecting piece 5b of the present embodiment has a round columnar shape with a rounded tip, but the shape of the second projecting piece 5b is not limited to this. For example, the second protruding piece 5b may have a tapered shape that gradually becomes thinner toward the tip, or may have a conical shape. Further, it may be a polygonal pyramid such as a triangular pyramid or a quadrangular pyramid. Further, in these shapes, the tip end portion and the corner portion of the second protruding piece 5b may be rounded. Since the tip and corner of the second protruding piece 5b are rounded, the gums and teeth are less likely to be damaged when the cleaning unit 3 is inserted between the teeth, and the contact feeling is improved.

The height Hb of the second projecting piece 5b is lower than the height Ha of the first projecting piece 5a and the height Hc of the third projecting piece 5c. Specifically, the height Hb of the second protruding piece 5b is preferably 0.1 mm to 0.6 mm, more preferably 0.10 mm to 0.50 mm.
When the height Hb of the second protruding piece 5b is equal to or higher than the lower limit value, a high cleaning force can be obtained and the user's actual feeling of cleaning can be improved. Further, when the covering portion 4b is injection-molded, the second projecting piece 5b plays a role of fixing the position of the core portion 4a in the mold, and prevents the core portion 4a from being displaced during the injection molding of the covering portion 4b. Then, it is possible to manufacture the interdental brush 1 having a good appearance.
When the height Hb of the second protruding piece 5b is equal to or less than the upper limit value, resistance when inserting the cleaning unit 3 between the teeth is small, and gingiva and teeth are less likely to be damaged when the cleaning unit 3 is inserted between the teeth. Become.
Since the height Hb of the second projecting piece 5b is lower than the height Ha of the first projecting piece 5a and the height Hc of the third projecting piece 5c, the second projecting piece 5b is made of a hard resin which is the second synthetic resin. However, the gingiva and teeth are not easily damaged when the cleaning unit 3 is inserted between the teeth, which improves the user's actual feeling of cleaning and improves the contact feeling.

The thickness of the second protruding piece 5b is preferably 0.1 mm to 0.2 mm, more preferably 0.10 mm to 0.15 mm. When the cross section perpendicular to the projecting direction of the second projecting piece 5b is a perfect circle, the thickness of the second projecting piece 5b means the diameter of the second projecting piece 5b in the same plane as the surface of the covering portion 4b. To do. When the cross section of the second projecting piece 5b perpendicular to the projecting direction is other than a perfect circle, the thickness of the second projecting piece 5b means the circumscribed circle of the second projecting piece 5b on the same plane as the surface of the covering portion 4b. Means the diameter of.
When the thickness of the second projecting piece 5b is not less than the lower limit value, it can be easily molded by injection molding.
When the thickness of the second protruding piece 5b is equal to or smaller than the upper limit value, the cleaning unit 3 can be easily inserted between the teeth, and the gingiva and the teeth are less likely to be damaged when the cleaning unit 3 is inserted between the teeth.

The third protruding piece 5c is made of a soft resin which is the first synthetic resin. As the soft resin forming the third protruding piece 5c, the materials listed as the hard resin forming the covering portion 4b can be used. The third projecting piece 5c of the present embodiment is formed integrally with the covering portion 4b and the first projecting piece 5a, but the present invention is not limited to this.

The third projecting piece 5c of the present embodiment has a flat rectangular column shape with rounded corners, but the shape of the third projecting piece 5c is not limited to this. For example, the third protruding piece 5c may have a tapered shape that gradually becomes thinner toward the tip, or may have a conical shape. Further, it may be a polygonal pyramid such as a triangular pyramid or a quadrangular pyramid. Further, in these shapes, the tip end portion and the corner portion of the third protruding piece 5c may be rounded. Since the tip and corners of the third projecting piece 5c are rounded, the gums and teeth are less likely to be damaged when the cleaning unit 3 is inserted between the teeth, and the contact feeling is further improved.

The height Hc of the third protruding piece 5c is lower than the height Ha of the first protruding piece 5a and higher than the height Hb of the second protruding piece 5b. Specifically, the height Hc of the third protruding piece 5c is preferably 0.1 mm to 1.0 mm, more preferably 0.2 mm to 0.8 mm, and further preferably 0.3 mm to 0.6 mm.
If the height Hc of the third projecting piece 5c is not less than the lower limit value, it can be easily molded by injection molding.
When the height Hc of the third protruding piece 5c is equal to or less than the upper limit value, the cleaning unit 3 can be easily inserted between the teeth, and the gingiva and the teeth are less likely to be damaged when the cleaning unit 3 is inserted between the teeth.
Since the height Hc of the third projecting piece 5c is lower than the height Ha of the first projecting piece 5a and higher than the height Hb of the second projecting piece 5b, when the cleaning portion 3 is inserted between the teeth. It is less likely to damage the gums and teeth, improves the user's feeling of cleaning and improves the feeling of contact.

The thickness of the third projecting piece 5c is larger than that of the first projecting piece 5a. Specifically, the thickness of the third protruding piece 5c is preferably 0.1 mm to 1.0 mm, more preferably 0.30 mm to 0.60 mm.
When the thickness of the third protruding piece 5c is equal to or larger than the lower limit value, a high cleaning force can be obtained and the user's feeling of cleaning can be improved.
When the thickness of the third protruding piece 5c is equal to or smaller than the upper limit value, it is difficult to damage the gingiva and the teeth when the cleaning unit 3 is inserted between the teeth.
In this way, by providing the first projecting piece 5a and the third projecting piece 5c having different thicknesses, the user's actual feeling of cleaning is improved and a higher cleaning power (plaque scraping power) is obtained. ..

FIG. 3 shows a cross-sectional view of the interdental brush 1 taken along the line A-A′ in FIG. 2. In FIG. 3, the first projecting pieces 5a are annularly arranged in two directions around the axis of the shaft member 4 at equal intervals of 180°.

FIG. 4 shows a cross-sectional view of the interdental brush 1 taken along the line B-B′ in FIG. 2. In FIG. 4, only the cross section of the interdental brush 1 is shown for convenience. In FIG. 4, the first projecting pieces 5 a are annularly arranged in two directions at equal intervals of 180° around the axis of the shaft member 4. Further, the first projecting piece 5a in FIG. 4 is arranged at a position different from the first projecting piece 5a in FIG. 3 by 90°. That is, as shown in FIG. 2, the first projecting pieces 5a that are adjacent to each other with the second projecting piece 5b and the third projecting piece 5c interposed therebetween are arranged so as to be offset from each other by 90°. By arranging the first projecting piece 5a in this way, when the cleaning portion 3 of the interdental brush 1 is inserted between the teeth, the first projecting piece 5a having a height Ha higher than that of the other projecting piece 5 is the shaft. Even when it falls toward the member 4, it does not overlap with the other protruding pieces 5, so that the cleaning unit 3 can be easily inserted between the teeth, and the gums and teeth are less likely to be damaged.

FIG. 5 shows a cross-sectional view of the interdental brush 1 taken along the line C-C′ in FIG. 2. In FIG. 5, for convenience, only the cross section of the interdental brush 1 is shown. In FIG. 5, the second projecting piece 5b and the third projecting piece 5c alternate at equal intervals of 90° around the axis of the shaft member 4, and the second projecting piece 5b and the third projecting piece 5c alternate. Thus, they are arranged annularly in four directions.

FIG. 6 shows a cross-sectional view of the interdental brush 1 taken along the line D-D′ in FIG. 2. In FIG. 6, only the cross section of the interdental brush 1 is shown for convenience. In FIG. 6, the second projecting piece 5b and the third projecting piece 5c are alternated at the second projecting piece 5b and the third projecting piece 5c at equal intervals of 90° around the axis of the shaft member 4. Thus, they are arranged annularly in four directions. Further, the second projecting piece 5b and the third projecting piece 5c in FIG. 5 are arranged at positions different from the second projecting piece 5b and the third projecting piece 5c in FIG. 6 by 90°. That is, as shown in FIG. 2, the second projecting piece 5b and the third projecting piece 5c, which are adjacent to each other with the first projecting piece 5a interposed therebetween, are arranged so as to be offset from each other by 90°. By arranging the second projecting piece 5b and the third projecting piece 5c in this way, the cleaning unit 3 can be easily inserted between the teeth, the gums and teeth are less likely to be damaged, and a feeling of use by the user can be obtained. ..

The number of the protruding pieces 5 arranged in a ring shape when viewed from the extending direction of the shaft member 4 is not particularly limited, and for example, it is preferable that 2 to 8 pieces are arranged in a ring shape at equal intervals around the axis.

FIG. 7 shows a plan view of the interdental brush 1 viewed from the extending direction of the shaft member 4. As shown in FIG. 7, the first projecting piece 5a, the second projecting piece 5b, and the third projecting piece 5c are arranged on the ring in eight directions at equal intervals of 45° around the axis of the shaft member 4. ing. That is, the first projecting piece row composed of the plurality of first projecting pieces 5a arranged on the first straight line P and the plurality of second projecting pieces 5b alternately arranged on the second straight line Q. And a second row of protruding pieces composed of a plurality of third protruding pieces 5c are alternately arranged in an annular shape at 45° intervals.
By arranging the plurality of projecting pieces 5 in this way, when the cleaning portion 3 of the interdental brush 1 is inserted between the teeth, the first projecting piece 5a having a height Ha higher than the other projecting pieces 5 is the shaft member. Even if it falls down toward 4, it does not overlap with the other protruding pieces 5, so that the cleaning unit 3 can be easily inserted between the teeth, and the gums and teeth are less likely to be damaged. Further, since it is possible to dispose a large number of projecting pieces 5 around the axis of the shaft member 4, the cleaning force between the teeth is improved, and the user can actually feel the use.

In addition, as shown in FIG. 2, in the extending direction of the shaft member 4, the first projecting piece 5a, the second projecting piece 5b, and the third projecting piece 5c are alternately arranged. In the present embodiment, the arrangement of the first projecting piece 5a, the second projecting piece 5b, and the third projecting piece 5c is not limited to this.

In the first projecting pieces 5a arranged on the first straight line P, the distance between the first projecting pieces 5a adjacent to each other is not particularly limited. For example, the distance between the adjacent first protruding pieces 5a arranged on the first straight line P is preferably 0.3 mm to 1.5 mm.
Similarly, in the second projecting piece 5b and the third projecting piece 5c arranged on the second straight line Q, the distance between the second projecting piece 5b and the third projecting piece 5c adjacent to each other is particularly limited. Not done. For example, the distance between the second projecting piece 5b and the third projecting piece 5c adjacent to each other, which are arranged on the first straight line P, is preferably 0.3 mm to 0.8 mm.
When the distance is equal to or more than the lower limit value, it becomes easy for each protruding piece 5 to function independently, and when the cleaning piece 3 is inserted between the teeth, the protruding piece 5 falls toward the shaft member 4. Also, since the other protruding pieces 5 do not overlap with each other, the cleaning unit 3 can be easily inserted between the teeth, and the gums and teeth are less likely to be damaged.
When the distance is equal to or less than the upper limit value, plaque is likely to be held between the protruding pieces, and high cleaning force is easily obtained.

The total number of the first projecting pieces 5a arranged on the first straight line P in the cleaning unit 3 is not particularly limited, and for example, 10 to 100 pieces are preferable, and 20 to 60 pieces are more preferable. In addition, the total number of the second protruding pieces 5b and the third protruding pieces 5c arranged on the second straight line Q is not particularly limited, and for example, 20 to 200 are preferable, and 50 to 150 are more preferable. preferable. Further, the total number of the protruding pieces 5 arranged in the cleaning unit 3 is preferably, for example, 30 to 300, and more preferably 70 to 210.
When the total number is equal to or more than the lower limit value, it is easy to obtain a sufficient cleaning force.
When the total number is less than or equal to the upper limit value, both insertion into and removal from the interdental space are facilitated, and workability between interdental spaces is improved.

As shown in FIGS. 2 and 7, the third projecting piece 5c may be thicker as it is closer to the boundary 3a of the cleaning unit 3, and the third projecting piece 5c may be thicker. The thickness of the third protruding piece 5c may be thinner as it is closer to the tip of the cleaning unit 3. However, the present embodiment is not limited to this, and the thickness of the third protruding piece 5c may be the same regardless of the arrangement.

<Manufacturing method>
Below, the manufacturing method of the interdental brush 1 of this invention is demonstrated.
For example, the interdental brush 1 is manufactured by a so-called two-color molding method.
First, a primary product (base body) 6 in which the grip portion 2, the core portion 4a of the shaft member 4 and the second projecting piece 5b are integrally molded by injection molding in which the first mold is filled with hard resin is obtained ( (See FIG. 8). At this time, the height of the portion to be the second protruding piece 5b is the sum of the height Hb of the second protruding piece 5b at the time when the interdental brush is completed and the thickness of the covering portion 4b. To set. Specifically, the height of the portion that becomes the second protruding piece 5b is preferably 0.2 mm to 1.0 mm. As the material of the hard resin, those listed as the constituent materials of the core portion 4a can be used.

Then, the primary product 6 is installed in the second mold, and the mold is filled with the soft resin. Thereby, the core portion 4a is covered with the soft resin, and the covering portion 4b, the first protruding piece 5a, and the third protruding piece 5c are integrally injection-molded (see FIG. 1). As the soft resin used here, those listed as the constituent material of the covering portion 4b can be used. When the primary product 6 is installed in the second mold, the portion that will become the second protruding piece 5b contacts the inner wall of the second mold. When the soft resin is filled in the second mold by contacting the inner wall of the second mold with the portion that will become the second protruding piece 5b, the second protruding piece 5b will be the primary member in the second mold. It can serve to fix the item 6. As a result, it is possible to suppress the deviation of the primary product 6 when the soft resin is filled in the second mold, and to suppress molding defects such as nonuniform film thickness of the coating portion 4b. As a result, the interdental brush 1 having a good appearance can be produced, and the yield is improved.

<Effect>
The interdental brush 1 of the present embodiment has the first protruding piece 5a and the third protruding piece 5c made of a soft resin and the second protruding piece 5b made of a hard resin in the cleaning portion 3, and therefore the interdental brush 1 When inserted between the teeth, the user feels a different texture, and a higher cleaning feeling is obtained as compared with the case where all the protruding pieces 5 are made of only the soft resin. Further, by forming the second protruding pieces 5b with a hard resin, a higher cleaning force (plaque removing force) can be obtained as compared with the case where all the protruding pieces 5 are formed with only a soft resin.
By providing the first protruding piece 5a and the third protruding piece 5c having different heights, it is possible to improve the user's actual feeling of cleaning and obtain a higher cleaning force (plaque removing force).
When the interdental brush 1 is viewed from the extending direction of the shaft member 4, the first projecting piece 5a, the second projecting piece 5b, and the third projecting piece 5c are annular around the shaft material 4 at equal intervals. It is located in. Further, the first projecting piece 5a is displaced from the second projecting piece 5b and the third projecting piece 5c. By disposing the plurality of protruding pieces 5 in this manner, even when the protruding piece 5 falls toward the shaft member 4 when the cleaning portion 3 of the interdental brush 1 is inserted between the teeth, another protruding piece 5 is disposed. Since it does not overlap with 5, the cleaning unit 3 can be easily inserted between the teeth, and the gums and teeth are less likely to be damaged.
Further, in the method for manufacturing the interdental brush 1 according to the present embodiment, when the mold is filled with the soft resin which is the first synthetic resin, the second projecting piece made of the hard resin which is the second synthetic resin is used. 5b can play a role of fixing the primary product 6 in the mold, and can prevent the displacement of the primary product 6 when the mold is filled with the soft resin. As a result, molding defects such as non-uniformity of the film thickness of the covering portion 4b can be suppressed. As a result, the interdental brush 1 having a good appearance can be produced, and the yield is improved.
Since the interdental brush of the present embodiment has at least the cleaning portion made of synthetic resin, it is less likely to cause pain when hitting the gingiva or the like as compared with the conventional interdental brush including the metal wire, and has good contact feeling. Is.

<Other forms>
The following is mentioned as another form of the interdental brush 1 of this invention.
The interdental brush 1 in the first embodiment includes the first protruding piece 5a, the second protruding piece 5b, and the third protruding piece 5c as the plurality of protruding pieces 5, but the present invention is not limited to this. As a second embodiment of the interdental brush 1, the plurality of protruding pieces 5 are a first protruding piece 5a made of a soft resin which is a first synthetic resin and a second protruding piece 5 made of a hard resin which is a second synthetic resin. May include only the protruding piece 5b.
In the interdental brush 1 in the first embodiment, the second protruding piece 5b and the core portion 4a of the shaft member 4 are integrally formed, but the present invention is not limited to this. In the interdental brush 1 according to the third embodiment, the second protruding piece 5b may be made of a hard resin which is the second synthetic resin, and may be formed independently of the core portion 4a. The second protruding piece 5b of the interdental brush 1 in the third embodiment may be formed of a hard resin different from that of the core portion 4a.
In the interdental brush 1 in the first embodiment, the grip portion 2 and the core portion 4a of the shaft member 4 are integrally formed, but the present invention is not limited to this. In the interdental brush 1 according to the fourth embodiment, the grip portion 2 and the core portion 4a of the shaft member 4 may be formed separately. Further, the materials of the grip portion 2 and the core portion 4a may be different as long as they are hard resins.
The interdental brush 1 in the first embodiment has the coating portion 4b, but the present invention is not limited to this. The interdental brush 1 according to the fifth embodiment may not have the covering portion 4b. The first projecting piece 5a and the third projecting piece 5c in the fifth embodiment may be formed so as to be embedded in the core portion 4a of the shaft member 4.

DESCRIPTION OF SYMBOLS 1... Interdental brush, 2... Gripping part, 2a... Reduced part, 3... Cleaning part, 3a... Boundary, 4... Shaft member, 4a... Core part, 4b... Cover part, 5... Projection piece, 5a... First 5b...Second protruding piece, 5c...Third protruding piece, 6...Primary product.

Claims (4)

A grip part, and a cleaning part provided at the tip of the grip part,
The cleaning unit includes a shaft member made of synthetic resin extending from the tip of the grip unit, and a plurality of protruding pieces radially protruding from the shaft member when viewed from the extending direction of the shaft member,
The plurality of projecting pieces include one or more first projecting pieces made of a first synthetic resin, and one or more second projecting pieces made of a second synthetic resin harder than the first synthetic resin. Equipped with
The shaft member includes a core portion made of the second synthetic resin, and a coating portion made of the first synthetic resin for coating the surface of the core portion,
An interdental brush in which the second protruding piece is integrally formed of the same material as the core portion and protrudes through the covering portion. The interdental brush according to claim 1, wherein the height of the first protruding piece is higher than the height of the second protruding piece. The plurality of protruding pieces further includes one or more third protruding pieces made of the first synthetic resin,
The thickness of the said 3rd protrusion piece is thicker than the thickness of the said 1st protrusion piece, The interdental brush of Claim 1 or 2. The interdental brush according to any one of claims 1 to 3, wherein a height of the second protruding piece is 0.1 mm or more and 0.5 mm or less.

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