WO2021131553A1

WO2021131553A1 - Toothbrush

Info

Publication number: WO2021131553A1
Application number: PCT/JP2020/044832
Authority: WO
Inventors: 静香川崎; 良祐蜂須賀
Original assignee: ライオン株式会社
Priority date: 2019-12-26
Filing date: 2020-12-02
Publication date: 2021-07-01
Also published as: TW202123844A; JPWO2021131553A1; CN216438707U

Abstract

The objective of the present invention is to provide a toothbrush having excellent insertability, operability, and durability. In this toothbrush: the maximum thickness of a head portion (5) is at least 2.0 mm and less than 4 mm; when a brush main body (2) is viewed from the side, a bristle implanting surface side includes a first linear region (S1) extending continuously in a straight line from a bristle implanting surface (5a), a first curved region (E1) which has a center of curvature on the bristle implanting surface side, and which extends in an arc shape from a first inflection point (P1) toward the rear end side, and a second curved region (E2) which has a center of curvature on the rear surface side, which is the opposite side to the bristle implanting surface side, and which extends in an arc shape from a second inflection point (P2), positioned at the rear end of the first curved region, toward the rear end side; and the angle of inclination of a neck portion is at least equal to 8° and at most equal to 25°, where the angle of inclination is represented by the angle at which, when viewed from the side, a straight line passing through a rear end side edge portion of a bristle implanting hole positioned on the rearmost end side, among a plurality of bristle implanting holes, and the second inflection point, intersects a virtual line (50) passing through the rear end side edge portion (Q1) positioned on the rearmost end side, and a rear end side edge portion (Q2) of the bristle implanting hole positioned second from the rear end side.

Description

toothbrush

The present invention relates to a toothbrush.
The present application claims priority based on Japanese Patent Application No. 2019-237178 filed in Japan on December 26, 2019, the contents of which are incorporated herein by reference.

To prevent caries and periodontal disease, it is important to remove plaque in the oral cavity by brushing with a toothbrush. As a toothbrush that can reach the back of the back teeth (the throat side of the back teeth), which is difficult to reach with a normal toothbrush, for example, by providing a tuft part at the flocked part on the tip side of the head part, the tip of the hair is attached to the back teeth. Easy-to-reach items are commercially available.

Further, in Patent Document 1, a toothbrush having a neck portion in which the center of an arc is located on the flocked surface side and a curved surface of an arc contour having a concave flocked surface side in a side view is formed on both the flocked surface side and the back surface side. Is disclosed. The toothbrush disclosed in Patent Document 1 has the curved surface, so that the toothbrush can be inserted into the last molars and has improved operability.

International Publication No. 2018/079114

However, with a commercially available toothbrush having a tuft portion on the flocked portion on the tip side described above, there is a problem that it is difficult to brush a wide area of the tooth surface because only the tuft portion hits when brushing the tooth surface. It was.

The toothbrush disclosed in Patent Document 1 is an S-shaped toothbrush in which the shape of the neck portion on the back surface side is once curved to the back surface side near the boundary between the head portion and the neck portion and then to the flocked surface side. When inserted into the back of the back teeth in the oral cavity, the back side of the neck portion may come into contact with the cheeks to reduce the usability, and a toothbrush with a more excellent usability has been demanded. Further, if the neck portion extending from the head portion is thick, it becomes necessary to open the lips wide when inserting into the oral cavity, and the operability is deteriorated.

The present invention has been made in consideration of the above points, and an object of the present invention is to provide a toothbrush having excellent insertability and operability.

According to the first aspect of the present invention, a brush provided with a handle portion along a long axis direction, a neck portion extended from the tip of the handle portion, and a head portion located at the tip of the neck portion. A toothbrush having a main body and having hair bundles planted in a plurality of flocked holes formed on the flocked surface of the head portion, wherein the brush main body is a neck portion of the neck portion from the head portion toward the handle portion. It has a shape in which the thickness continuously increases, and the maximum thickness of the head portion is 2.0 mm or more and less than 4 mm. A first straight line region that continuously extends linearly to the rear end side, and a circle from the first turning point that has a center of curvature on the flocked surface side and is located at the rear end of the first straight line region to the rear end side. An arc-shaped first curved region extending in an arc shape and a second curved point located at the rear end of the first curved region having a center of curvature on the back side opposite to the flocked surface side to the rear end side. It has a second curved region extending to, and among the plurality of flocked holes, it is located at the rearmost side edge of the flocked hole and the second rearmost side in the side view. A straight line passing through the rear end side edge of the flocked hole and the second turning point located on the rearmost side in the side view with respect to the virtual line passing through the rear end side edge of the flocked hole. Provided is a toothbrush characterized in that the inclination angle of the neck portion represented by the angle at which the two intersects is 8 ° or more and 25 ° or less.

Further, in the toothbrush according to one aspect of the present invention, on the back surface side in the side view, a second straight line region continuously extending linearly from the back surface of the head portion to the rear end side and the flocked surface side. It is characterized by having a third curved region having a center of curvature and extending in an arc shape from a third inflection point located at the rear end of the second straight line region to the rear end side.

Further, in the toothbrush according to one aspect of the present invention, on the back side in the side view, from the fourth inflection point located at the rear end of the third curve region having the center of curvature on the back side. It is characterized by having a fourth curved region extending in an arc shape on the end side.

Further, in the toothbrush according to one aspect of the present invention, the minimum thickness of the neck portion is 3.0 to 4.0 mm, and the length in the major axis direction is 5 mm or more.

Further, in the toothbrush according to one aspect of the present invention, the cross-sectional shape at the boundary between the neck portion and the handle portion is elliptical.

Further, in the toothbrush according to one aspect of the present invention, the length of the neck portion in the major axis direction is 25 mm or more and 45 mm or less.

Further, in the toothbrush according to one aspect of the present invention, the position in the long axis direction where the distance between the handle portion on the flocked surface side and the virtual line is the longest in the side view is the long axis of the handle portion. It is characterized in that it is located on the tip side of the center of the direction.

Further, in the toothbrush according to one aspect of the present invention, the tip end side of the head portion is inclined at an angle of 5 ° or more and 15 ° or less with respect to the flocked surface side with respect to the virtual line in the side view. It is characterized by that.

The present invention makes it possible to provide a toothbrush having excellent insertability and operability.

It is a figure which shows the embodiment of this invention, and is the side view which shows the structure of the toothbrush 1. It is a front view which saw the toothbrush 1 from the flocking surface 5a side. It is the front view which enlarged the head part 5. It is an enlarged side view of the head part 5.

Hereinafter, embodiments of the toothbrush of the present invention will be described with reference to FIGS. 1 to 4.
It should be noted that the following embodiments show one aspect of the present invention, do not limit the present invention, and can be arbitrarily changed within the scope of the technical idea of the present invention. Further, in the following drawings, in order to make each configuration easy to understand, the scale and number of each structure are different from the actual structure.

Further, in the following description, the side of the head portion 5 provided with the flocked surface 5a is the front side of the toothbrush 1, and the side of the head portion 5 opposite to the side facing the flocked surface 5a is the back side of the toothbrush 1. To do. In addition, the direction parallel to the fluffed surface 5a and orthogonal to the length direction of the brush body 2 will be described as the width direction of the toothbrush 1, and the direction orthogonal to the fluffed surface 5a will be described as the thickness direction of the toothbrush 1. Further, the side on which the head portion 5 is provided will be referred to as the front end side, and the side on which the handle portion 3 is provided will be referred to as the rear end side.

FIG. 1 is a side view showing the configuration of the toothbrush 1. FIG. 2 is a front view of the toothbrush 1 as viewed from the flocked surface 5a side. FIG. 3 is an enlarged front view of the head portion 5. FIG. 4 is an enlarged side view of the head portion 5. In FIGS. 2 to 4, the brush 40 is not shown.

As shown in FIGS. 1 and 2, the toothbrush 1 of the present embodiment includes a brush body 2 and a brush 40 made of a resin molded body formed in an elongated shape as a whole.

The brush body 2 is provided with a handle portion 3 along the long axis direction, a neck portion 4 extended from the tip of the handle portion 3, and a head portion 5 provided at the tip of the neck portion 4. The major axis direction is the direction in which the virtual line 50, which will be described later, extends. In the toothbrush 1, it is possible to clean the inside of the oral cavity by a plurality of hair bundles 41 planted on the flocked surfaces 5a to 5d of the head portion 5.

As the resin constituting the brush body 2, for example, polypropylene (PP) resin, polyacetylene (POM) resin, polybutylene terephthalate (PBT) resin, polyethylene terephthalate (PET) resin, or the like is preferably used. Among them, it is preferable to use the PP resin having a good balance between stress dispersibility and strength in the present invention.

The flexural modulus (JIS K 7171) of the resin constituting the brush body 2 is preferably 1000 to 2800 MPa, more preferably 1200 to 2500 MPa, and even more preferably 1500 to 2000 MPa.

(Shape on the front side of the brush body)
The toothbrush 1 of the present embodiment has a handle from the rear end side of the head portion 5 (“the rear end side of the head portion 5” will be described later) on the front side of the brush main body 2 when the brush main body 2 is viewed from the side. A first straight line region S1 that continuously extends linearly toward the rear end side from the flocked surface 5a of the head portion 5 toward the portion 3 side, and a rear end of the first straight line region S1 that has a center of curvature on the front side. From the first inflection point E1 extending in an arc shape from the first inflection point P1 located to the rear end side, and from the second inflection point P2 having a center of curvature on the back surface side and located at the rear end of the first curve area E1. It has a second curved region E2 extending in an arc shape on the rear end side.

The first inflection point P1 is located at the head portion 5. The second inflection point P2 forms a boundary between the neck portion 4 and the handle portion 3. That is, the handle portion 3 is located at the rear end side of the second inflection point P2. The details of the second inflection point P2 at the boundary between the neck portion 4 and the handle portion 3 will be described later.

(Shape on the back side of the brush body)
The toothbrush 1 of the present embodiment is continuous from the back surface of the head portion 5 from the rear end side of the head portion 5 toward the handle portion 3 side on the back surface side of the brush body 2 when the brush body 2 is viewed from the side. A second substantially straight line region S2 extending linearly to the rear end side and an arc shape to the rear end side from the third inflection point P3 having a center of curvature on the front side and located at the rear end of the second straight line region S2. A third curve region E3 extending to the rear end side and a fourth curve region E4 extending in an arc shape from the fourth inflection point P4 having a center of curvature on the back surface side and located at the rear end of the third curve region E3. Have. The third inflection point P3 is located at the head portion 5.

The fourth curve area E4 is a portion that a finger touches when the handle portion 3 is gripped. The fourth curved area E4 has an arc shape having a center of curvature on the back side, and is curved in a concave shape on the back side. Improves.

If the radius of curvature of the first curve region E1 is R1, the radius of curvature of the second curve region E2 is R2, the radius of curvature of the third curve region E3 is R3, and the radius of curvature of the fourth curve region E4 is R4, then R1 It is preferable to satisfy the relationship of <R3 and R2 <R4. The radius of curvature R1 is preferably 60 mm or more and 150 mm or less. The radius of curvature R2 is preferably 50 mm or more and 100 mm or less. The radius of curvature R3 is preferably 80 mm or more and 400 mm or less. The radius of curvature R4 is preferably 70 mm or more and 200 mm or less.

The radius of curvature R1 is preferably 50 to 250 mm, more preferably 60 to 200 mm, and even more preferably 60 to 150 mm.
The radius of curvature R2 is preferably 50 to 250 mm, more preferably 60 to 200 mm, and even more preferably 50 to 100 mm.
The radius of curvature R3 is preferably 50 to 600 mm, more preferably 60 to 500 mm, and even more preferably 80 to 400 mm.
The radius of curvature R4 is preferably 50 to 400 mm, more preferably 60 to 300 mm, and even more preferably 70 to 200 mm.

The cross-sectional shape at the boundary (P2) between the neck portion 4 and the handle portion 3 is preferably a substantially quadrangular shape, a substantially polygonal shape, a perfect circle, or an elliptical shape, and more preferably an elliptical shape. The above shape reduces the ease of holding and reduces the operability when brushing the back teeth.

Boundary definitive cross-sectional area of the neck portion 4 and the handle portion 3 is preferably 20 ~ 80 mm ^2, more preferably 25 ~ 55 mm ^2, even more preferably 25 ~ 45 mm ² or less. Within the above range, durability can be ensured.

(Head part)
The head portion 5 is a portion for wiping the inside of the oral cavity with a plurality of hair bundles 41, has a substantially rectangular parallelepiped shape, and has a rounded corner portion. In the present embodiment of FIGS. 1 and 4, the head portion 5 has a flat plate portion 51 located on the rear end side and having a flocked surface 5a serving as a reference surface on the front end side, and an inclined plate located on the front end side of the flat plate portion 51. It has a part 52. In the flat plate portion 51, the flocked surface 5a and the back surface on the opposite side form a flat surface with each other. The flat plate portion 51 is substantially parallel to the virtual line 50 described later in the side view. In the present embodiment of FIGS. 1 and 4, the inclined plate portion 52 is provided, but the inclined plate portion 52 may not be provided and only the flat plate portion 51 may be formed.

When the inclined plate portion 52 is provided, it is preferable that the inclined plate portion 52 is inclined in the direction toward the front side (that is, the flocked surface side) toward the tip side. The angle at which the inclined plate portion 52 is inclined with respect to the flat plate portion 51 (virtual line 50 in a side view) is preferably an angle of 5 ° or more and 15 ° or less. In the present embodiment of FIGS. 1 and 4, the angle at which the inclined plate portion 52 is inclined with respect to the flat plate portion 51 is, for example, 10 °.

Since the inclined plate portion 52 is inclined with respect to the flat plate portion 51, the hair length of the hair bundle 41 at the tip of the head portion 5 is shortened, and the hair bundle is bent as compared with the hair bundle 40 at the rear end of the head portion 5. By making it harder, the hair becomes more elastic, which gives a feeling of high cleaning of the back teeth. Since the inclination angle of the inclined plate portion 52 is in the range of 5 ° to 15 °, the feeling of cleaning the back teeth is excellent.

As shown in FIGS. 3 and 4, the inclined plate portion 52 has three flocked surfaces 5b to 5d having different heights. Each flocked surface 5b to 5d is parallel to the flocked surface 5a. The flocked surfaces 5b to 5d are gradually increased toward the tip side according to the inclination of the inclined plate portion 52. Further, as shown in FIG. 1, the hair length of the hair bundle 41 planted on the flocked surface 5b to 5d is the same height as the hair length of the hair bundle 40 planted on the flocked surface 5a.
The hair length of the hair bundle 41 planted on the flocked surfaces 5b to 5d may be lower or higher than the hair length of the hair bundle 40 planted on the flocked surface 5a.

A plurality of flocked holes 6 having the same diameter are arranged side by side in a staggered pattern on the flocked surfaces 5a to 5d. The hair follicles 6 are provided at positions where they are arranged in rows adjacent to each other in the long axis direction with a half pitch shift. Each hair follicle 6 is formed by bundling a plurality of brushes (filaments), folding them in half, sandwiching a metal retaining tool (not shown) called a flat line between them, and driving the hair follicles into the hair follicles 6. It is planted in.

It should be noted that the hair follicles 6 are not limited to the configuration in which a plurality of the hair follicles are arranged side by side in a grid pattern, and the hair follicles holes 6 may be arranged in a staggered pattern. Further, since the inner diameter of the hair transplant hole 6 correlates with the number of hair bundles to be transplanted, it affects the hardness and usability of the hair bundles, but the usability depends on the thickness and length of the hair bundles used for flocking. Although it can be adjusted to some extent, the range of 1.0 to 3.0 mm is generally preferable.

The flocking holes 6 provided on the flocking surface 5a are formed in the normal direction of the flocking surface 5a. The flocked holes 6 provided on the flocked surfaces 5b to 5d are formed so as to be inclined by 5 °, for example, in the direction in which the openings face the rear end side with respect to the normal direction of the flocked surfaces 5b to 5d, respectively. There is.

When the hair follicles 41 are driven into the flocking holes in a folded state using a flat line and the hair is transplanted, the flocking surfaces 5a to 5d are arranged orthogonally to the flocking direction, so that the hair can be stably transplanted. it can. Further, when the flocking hole 6 is greatly inclined with respect to the driving direction (for example, when it is inclined in the direction orthogonal to the inclined plate portion 52), the driving of the hair follicle 41 may become unstable. However, since the flocking holes 6 provided on the flocking surfaces 5b to 5d are only inclined by 5 ° in the direction toward the rear end side, the hair bundle 41 can be driven without any trouble.

The hair bundle 41 is not particularly limited in terms of the material of the brush, but for example, polyamide (eg 6-12 nylon, 6-10 nylon), polyester (eg polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate), polyolefin. (Example: polypropylene), elastomer (eg, olefin-based, styrene-based) and other synthetic resin materials can be mentioned. Further, a plurality of these resin materials may be used in combination, and different resin materials may be used for the core portion and the sheath portion, for example, a core sheath structure or the like.

Further, as the brush constituting the hair bundle 41, for example, the diameter of the hair gradually decreases toward the tip of the hair, and the tip of the hair is sharpened (tapered hair), and the diameter thereof is from the flocked surface 5a toward the tip of the hair. Examples thereof include flocking hair (straight hair) in which the hairs are almost the same. Examples of straight hair include those in which the tips of the hair are flat and substantially parallel to the flocked surface 5a, and those in which the tips of the hair are hemispherically rounded.
The brushes constituting the hair bundles 41 planted on the flocked surfaces 5b to 5d are preferably tapered hairs or straight hairs.
The brush forming the hair bundle 40 planted on the flocked surface 5a is preferably tapered hair or straight hair.
The tip of any of the flocked surfaces 5a to 5d may be cut off.

The cross-sectional shape of the brush is usually circular, but is not limited to such a shape, for example, elliptical, triangular, quadrangular, hexagonal, star-shaped, three-leaf cloverleaf, four-leaf. It can be any shape such as a clover shape.

The hair length of the hair bundle 41 is preferably 8 mm to 13 mm for adults and 6 mm to 9 mm for children from the flocked surface 5a of the head portion 5. The thickness (maximum diameter) of the brush is preferably 0.12 mm to 0.26 mm from the viewpoint of usability and usability in the oral cavity. Further, a plurality of brushes having different thicknesses may be used in any combination in consideration of usability, brushing feeling, cleaning effect, durability and the like.

As a method of flocking the hair bundle 41, in addition to the flat line flocking method in which the above-mentioned bristles of the brush are folded in half and a flat line is sandwiched between them and planted in the flocking hole 6, the lower end of the hair bunch is set at the head portion 5. A heat fusion method in which the hair is press-fitted into the molten resin to be fixed, or a molten mass is formed by heating the lower end of the hair bundle, and then the molten resin is filled in the cavity of the mold and integrated with the head portion 5. An in-mold method for molding or the like can be used.

The head portion 5 has a substantially quadrangular flat plate shape in which four tops are cut into curved corners when viewed from the front. In the present embodiment, the boundary O between the head portion 5 and the neck portion 4 is the end point of the curve forming the corner cut from the neck portion 4 in the front view shape of the head portion 5, that is, the curve forming the corner cut. This is the position where the bending direction changes. Therefore, the boundary O between the head portion 5 and the neck portion 4 is a curve whose width is widened from a curve or a straight line forming both edges in which the width of the corner cut portion of the head portion 5 in the head portion 5 is narrower than that of the neck portion 4 in a plan view. It is a position that changes to.

The head portion 5 may have a shape and size that makes it easy to wipe the inside of the oral cavity, and the shape is not particularly limited. For example, the width gradually narrows from the proximal end side to the distal end side. The shape may be. Further, the head portion 5 may have a tapered shape in which the thickness gradually decreases from the base end side to the tip end side, or may have a rounded shape in which the central portion on the back surface side of the head portion 5 is raised. Good.

The thickness of the head portion 5 is preferably 2 mm or more and less than 4 mm, and more preferably 2.5 to 3.5 mm. If the thickness of the head portion 5 is not constant, the thickness of the head portion 5 is defined as the maximum thickness of the head portion 5.
If the thickness of the head portion 5 is less than 2 mm, the durability may decrease. When the thickness of the head portion 5 is 4 mm or more, the insertability into the back teeth and the operability may be deteriorated. By setting the thickness of the head portion 5 to 2 mm or more and less than 4 mm, it is possible to improve the insertability into the back teeth and the operability without lowering the durability.

(Neck)
The neck portion 4 is a portion that connects the handle portion 3 and the head portion 5.
In the present embodiment, the outer shape of the neck portion 4 and the handle portion 3 in the front view and the side view is a shape in which a plurality of gentle curves are connected from the boundary O of the head portion 5 and the neck portion 4 toward the handle portion 3 side. Is. Then, in the side view, the position where the bending direction of the gentle curve is reversed is defined as the boundary between the neck portion 4 and the handle portion 3. That is, in the side view of FIG. 1, the curve of the neck portion 4 on the front side faces from the boundary O toward the handle portion 3, and the center of curvature of the first straight line region S1 having the center of curvature on the front side changes to the back side. The starting position (second inflection point P2) is defined as the boundary between the neck portion 4 and the handle portion 3.

The length of the neck portion 4 in the major axis direction is defined as the shortest distance between the position of the inflection point P2 and the boundary O in the side view.
The length of the neck portion 4 is preferably 25 to 45 mm, more preferably 25 to 40 mm.
By setting the length of the neck portion 4 within the above range, it is possible to improve the insertability into the back teeth and the operability at the time of cleaning the back teeth.

The cross-sectional shape of the neck portion 4 is preferably a substantially quadrangular shape, a substantially polygonal shape, a perfect circle, or an elliptical shape, and more preferably an elliptical shape. It is more preferable that the ellipse has a major axis in the thickness direction.
The thickness of the neck portion 4 continuously increases from the front end side to the rear end side. By continuously increasing the thickness of the neck portion 4, the strength of the neck portion 4 can be increased as compared with the case where the thickness of the neck portion 4 is constant. Further, since the thickness of the neck portion 4 continuously increases from the distal end side to the posterior end side, the opening of the lips does not increase when inserted into the oral cavity, and operability in the oral cavity is ensured. Can be done. In addition, since the position of stress concentration applied to the neck portion 4 during tooth brushing is provided on the head portion 5, a sufficient distance can be secured to disperse the stress in the three directions of the handle portion, which will be described later, and excessive bending of the neck portion 4 is suppressed. can do.

The minimum thickness of the neck portion is preferably 3.0 to 4.0 mm, more preferably 3.0 to 3.6 mm.
The minimum width of the neck portion is preferably 3.0 to 4.5 mm, more preferably 3.5 to 4.2 mm.
The minimum diameter of the neck portion 4 is preferably 3.0 to 4.0 mm, more preferably 3.0 to 3.6 mm.
If the minimum thickness of the neck portion, the minimum width of the neck portion, and the minimum diameter of the neck portion 4 are less than 3.0 mm, the neck portion 4 tends to bend, which may reduce operability. If the minimum thickness of the neck portion, the minimum width of the neck portion and the minimum diameter of the neck portion 4 exceed 4.0 mm, the operability in the oral cavity may be deteriorated.
Operability can be ensured by setting the minimum thickness of the neck portion, the minimum width of the neck portion, and the minimum diameter of the neck portion 4 to 3.0 mm or more and 4.0 mm or less.
The length of the neck portion having a minimum thickness of 3.0 to 4.0 mm is preferably 5 mm or more, more preferably 6 mm or more, still more preferably 7 mm or more.
The length of the neck portion having a minimum width of 3.0 to 4.5 mm is preferably 5 mm or more, more preferably 6 mm or more, still more preferably 7 mm or more.
The length of the neck portion having a minimum diameter of 3.0 to 4.0 mm is preferably 5 mm or more, more preferably 6 mm or more, still more preferably 7 mm or more.
Within the above range, it is possible to improve the insertability and operability of the back teeth.

As described above, the first curved region E1 forming the front side of the neck portion 4 in the side view and the third curved region E3 forming the back side of the neck portion 4 in the side view are both centered on the front side. Since it has an arc shape, it follows the curve of the dentition and can improve the insertability when brushing the buccal side of the back teeth.

The inclination angle θ of the neck portion 4 is a straight line passing through the rear end side edge portion of the hair follicle hole 6 located on the rearmost end side in the side view and the second inflection point P2, and the virtual line 50 shown in FIG. It is represented by the angle of intersection. The virtual line 50 passes through the rear end side edge portion Q1 of the hair follicle hole 6 located on the rearmost end side and the rear end side edge portion Q2 of the hair follicle hole 6 located on the second rear end side in the side view. It is a straight line. Q1 and Q2 are parallel to the flocked surface on the rear end side of the head portion in a general toothbrush.
The inclination angle of the neck portion 4 is preferably 8 ° or more and 25 ° or less.

If the inclination angle of the neck portion 4 is less than 8 °, it is necessary to open the lips wide sideways when brushing the buccal side of the back teeth, which may reduce insertability and operability. When the inclination angle of the neck portion 4 exceeds 25 °, it is necessary to bend the wrist significantly when changing the polishing portion, which may reduce the operability when brushing the back teeth. By setting the inclination angle of the neck portion 4 to 8 ° or more and 25 ° or less, it is possible to secure the insertability and operability when brushing the buccal side of the molars and the operability when changing the polishing part. ..

The shortest distance between the second inflection point P2 and the virtual line 50 in the side view is preferably 5 mm or more and 15 mm or less, and more preferably 8 mm or more and 12 mm or less. As a result, the S-shape can be secured, and the intraoral insertability and usability can be improved.
The shortest distance between the "rear side P2'" facing the second inflection point P2 in the side view and the virtual line 50 is preferably 1 mm or more and 3 mm or less, and 1.5 mm or more and 3 mm or less. More preferably. As a result, the S-shape can be secured, and the intraoral insertability and usability can be improved.

As described above, the toothbrush disclosed in Patent Document 1 is an S-shaped toothbrush in which the shape of the neck portion on the back surface side warps once on the back surface side near the boundary between the head portion and the neck portion and then on the flocked surface side. Therefore, when it is inserted into the oral cavity, the back side of the neck portion may come into contact with the cheek and the usability may be deteriorated. On the other hand, in the present embodiment, as shown in FIG. 1, the shapes of the head portion and the neck portion on the back surface side in the side view are curved from the third inflection point to the front side and have a curvature center on the front side. It forms the curve region E3 of 3. That is, it does not have a shape that temporarily warps toward the back side near the boundary between the head portion and the neck portion. Therefore, when it is inserted into the oral cavity, it is possible to reduce the contact of the neck portion with the cheek on the back side and improve the usability.
Further, the thickness of the head portion 5 is reduced to 2 to 4 mm, the thickness, width and diameter of the neck portion are reduced to 3.0 to 4.5 mm, and the length in the major axis direction is 5 mm or more. By doing so, the insertability, usability, and operability can be further improved.
In addition, even if the length of the neck portion 4 is shortened to 25 to 45 mm, the first straight line region S1, the first curve region E1 having the center of curvature on the front side, and the second curve having the center of curvature on the back side. By connecting the regions E2 with the inflection points P1 and P2 with a gentle curve, the usability and operability can be further improved.

(Handle part)
The handle portion 3 is a portion to be gripped by the user and is formed in a long columnar shape. In order to secure a sufficient length for gripping and using the handle portion 3, it is preferable that the length from the boundary O in the front view to the rear end of the handle portion 3 is 100 to 200 mm.

In the present embodiment, the handle portion 3 has a thickness (second curve region E2 and fourth) from the front end side (second inflection point P2 side) to the rear end side when the brush body 2 is viewed from the side. It has a shape in which the thickness (distance from the curved region E4) continuously increases, reaches the maximum thickness, and then decreases toward the rear end side.

If there are a plurality of locations having the maximum thickness in the handle portion 3, the portion located closest to the neck portion 4 side shall be uniquely defined as the portion having the maximum thickness of the handle portion 3. In FIG. 1, the portion having the maximum thickness of the handle portion 3 is the handle portion 3Amax.

The handle portion 3 has a position P11 in the long axis direction in which the distance between the front surface in the side view and the virtual line 50 is the longest (that is, the position P11 is the maximum height with respect to the virtual line 50 in the side view). Is located at the handle portion 3A on the tip side of the handle portion 3 in the long axis direction. That is, the position P11 is located at a position closer to the tip of the head portion than the central position of the length of the handle portion 3 in the major axis direction. In the side view, the front end side of the head portion is the handle portion 3A, and the rear end side of the handle portion is the handle portion 3B with the position P11 as a boundary. In the handle portion 3, it is preferable that the position of the front surface in the side view is close to the position of the tip of the hair bundle 41 for fine control of the hair tips.

Here, the position P11 has a longer distance from the virtual line 50 than the tip of the hair bundle 41. On the other hand, the second inflection point P2, which is the tip of the handle portion 3 (handle portion 3A), has a shorter distance from the virtual line 50 than the tip of the hair bundle 41. Further, the rear end of the handle portion 3 (handle portion 3B) has a longer distance from the virtual line 50 than the tip of the hair bundle 41. That is, on the front surface of the handle portion 3, the region between the position P11 and the second inflection point P2 has a large change with respect to the position of the tip of the hair bundle 41, whereas the position P11 and the rear end The region between them has a small change with respect to the position of the tip of the hair bundle 41 and is suitable for fine control of the hair tip. Therefore, since the position P11 is located on the handle portion 3A, the area suitable for fine control of the hair tips becomes long, and the back teeth can be easily brushed even when the rear end side of the handle portion 3 is gripped.

The shortest distance between the position P11 on the front surface of the handle portion 3 and the virtual line 50 in the side view is preferably 20 mm or more and 32 mm or less, and more preferably 22 mm or more and 26 mm or less.
When the distance between the position P11 and the virtual line 50 is less than 20 mm, or when the distance between the position P11 and the virtual line 50 exceeds 32 mm, the position of the front side surface in the side view at the rear end of the handle portion 3. May be far away from the tip of the hair bundle 41 and the controllability of the hair tip may be reduced.
At the position P11 of the front side surface of the handle portion 3 in the side view, the shortest position between the virtual line 50 and the position P11'which extends vertically to the virtual line 50 and is the intersection of the back side surface facing the position P11. The distance is preferably 8 mm or more and 12 mm or less, and more preferably 10 mm or more and 12 mm or less. As a result, the S-shape can be secured, and the intraoral insertability and usability can be improved.

Further, it is preferable that the back surface side of the handle portion 3 has a shape that does not intersect with the virtual line 50 up to the end portion of the handle portion.
In side view, the shortest distance between the back surface of the handle portion 3B on the terminal end side of the handle portion and the virtual line 50 is preferably 8 mm or more and 20 mm or less, and preferably 10 mm or more and 15 mm or less.
The shortest distance between the endmost portion of the handle portion and the virtual line 50 in the side view is preferably 8 mm or more and 20 mm or less, and preferably 12 mm or more and 18 mm or less.
As a result, the S-shape can be secured, and the intraoral insertability and usability can be improved.
Further, in the side view, the shortest distance of the line segment connecting the boundary O and the position P11 is preferably 70 to 110 mm, more preferably 80 to 110 mm, further preferably 80 to 100 mm, and particularly preferably 90 to 100 mm.
Further, the shortest distance of the line segment connecting the inflection point P2 and the position P11 in the side view is preferably 40 to 80 mm, more preferably 50 to 70 mm.

The cross-sectional shape of the handle portion 3 is preferably a substantially quadrangular shape, a substantially polygonal shape, a perfect circle, or an elliptical shape, and more preferably an elliptical shape. Further, it is more preferable that the elliptical shape has a major axis in the width direction.
The thickness of the handle portion 3 is maximum in the handle portion 3A. The maximum thickness of the handle portion 3A is preferably 9 mm or more and 14 mm or less, and more preferably 10.5 mm or more and 12.5 mm or less.

Further, the width of the handle portion 3 is maximum in the handle portion 3A. The maximum width of the handle portion 3A is preferably 11 mm or more and 16 mm or less, and more preferably 12.5 mm or more and 14.5 mm or less.
As a result, the gripability of the handle portion 3 is improved, and excellent operability by a palm grip or the like can be obtained.
It is preferable that the handle portion 3A has a maximum thickness and a maximum width. As a result, the S-shape is secured to improve the intraoral insertion property and the usability, the gripability of the handle portion 3 is improved, and excellent operability by the palm grip or the like can be obtained.
The shortest distance between the position where the maximum thickness of the handle portion 3 is obtained in the side view (handle portion 3Max) and the virtual line 50 is preferably 20 mm or more and 32 mm or less, and more preferably 22 mm or more and 26 mm or less. ..
At the position where the maximum thickness of the handle portion 3 is obtained in the side view (handle portion 3Amax), the handle portion 3Amax'which extends in the direction perpendicular to the virtual line 50 and is the intersection of the handle portion 3Amax and the surface on the back surface facing the handle portion 3Amax'. The shortest distance from the virtual line 50 is preferably 8 mm or more and 12 mm or less, and more preferably 10 mm or more and 12 mm or less. As a result, the S-shape is secured to improve the intraoral insertion property and the usability, the gripability of the handle portion 3 is improved, and excellent operability by the palm grip or the like can be obtained.

The ratio of the maximum thickness of the handle portion 3 to the maximum width of the handle portion 3 (maximum thickness of the handle portion 3 / maximum width of the handle portion 3) is preferably 0.6 or more and 1.3 or less, and is 0. More preferably, it is 0.7 or more and 1.0 or less.

The ratio of the maximum thickness of the handle portion 3 to the maximum thickness of the head portion 5 (maximum thickness of the handle portion 3 / maximum thickness of the head portion 5) is preferably 2.3 or more and 7.0 or less. More preferably, it is 2.8 or more and 4.2 or less.

The ratio of the maximum thickness of the handle portion 3 to the minimum thickness of the neck portion 4 (maximum thickness of the handle portion 3 / minimum thickness of the neck portion 4) is preferably 2.0 or more and 5.6 or less. More preferably, it is 2.6 or more and 4.8 or less.

The cross-sectional area of the handle portion 3 is maximum at the handle portion 3A. The cross-sectional area of the handle portion 3 ^{is preferably 70 mm 2} or more and 200 mm ² or less, and ^{more preferably 90 mm 2} or more and 150 mm ² or less.

In the toothbrush 1 of the present embodiment, the first inflection point P1 is located at the head portion 5, and the second inflection point P2 is provided on the rear end side. The shortest connecting the inflection point P1 and the inflection point P2 when the first inflection point P1 and the second inflection point P2 are viewed from the front side (FIG. 2) in the side view of the brush body 2 (FIG. 1). The distance is preferably 28 mm or more and 40 mm or less, and more preferably 30 mm or more and 35 mm or less. As a result, in a shape in which the thickness of the neck portion 4 continuously increases from the head portion 5 to the handle portion 3, the surface between the head portion 5 and the handle portion 3 is smoothly curved through the neck portion 4. Can be connected continuously with. Further, the neck portion 4 can be made thinner over the entire length.

In the toothbrush 1 of the present embodiment, the first inflection point P1 is located at the head portion 5, and the second inflection point P2 is provided on the rear end side. In the front view of the brush body 2, the distance between the first inflection point P1 and the second inflection point P2 is preferably 28 mm or more and 45 mm or less, more preferably 28 mm or more and 41 mm or less. It is more preferably 30 mm or more and 40 mm or less.
As a result, in a shape in which the thickness of the neck portion 4 continuously increases from the head portion 5 to the handle portion 3, the surface between the head portion 5 and the handle portion 3 has a smooth curve via the neck portion 4. Can be connected continuously. Further, the neck portion 4 can be made thinner over the entire length.

Since the toothbrush 1 of the present embodiment has a thin head portion 5, a thin neck portion 4, and a thick handle portion 3, when a load is applied to the head portion 5 during tooth brushing, first, the first substantially straight line region S1 on the front side is formed. The stress is concentrated on the first inflection point P1 through the passage. The first inflection point P1 is located at a position facing the second substantially straight line region S2 on the back side. Therefore, in the second substantially straight line region S2, a drag force (repulsive force) acts in the front direction in order to disperse the stress received in the back direction at the first inflection point P1.

When stress concentration in the back direction acts at the first inflection point P1, if the region facing the first inflection point P1 has a substantially linear shape (second substantially straight line region S2), the second abbreviation In the straight line region S2, a drag force acts on the front side. Then, this drag force is transmitted to the first curved region E1 on the front side facing the second substantially straight line region S2.

Further, when the first curved region E1 having the center of curvature is provided on the front side of the brush main body 2, when stress concentration in the back direction acts at the first inflection point P1, the front side due to the nature of the curved shape. Has the property that drag is easy to work. In addition, the larger the radius of curvature of the first curved region E1, the more easily the drag force is dispersed and transmitted.

Further, when a third curved region E3 having a center of curvature on the front side is provided on the back side of the brush body 2, when stress in the back direction is transmitted to the third inflection point P3, due to the nature of the curved shape. , In the third curved region E3, the drag force tends to act on the front side. In addition, the larger the radius of curvature of the third curved region E3, the easier it is for the drag to be dispersed and transmitted.

In the side view of the brush body 2, the second inflection point P2 is located at a position facing the third curved region E3. Further, since the first curved region E1 and the third curved region E3 have a center of curvature on the front side of the brush body 2, the drag direction at the second inflection point P2 is the front side. Here, if a second curved region E2 having a center of curvature is provided on the back side of the brush body 2 on the front side, when a drag force in the front direction acts at the second inflection point P2, due to the nature of the curved shape. , There is a property that drag is easy to work on the back side. In addition, the larger the radius of curvature of the second curved region E2, the easier it is for the drag to be dispersed and transmitted.

In the present embodiment, when the drag force in the front direction acts at the second inflection point P2, the drag force in the back direction due to the second curved region E2 becomes easier to work and is transmitted in the direction of the handle portion 3. , Stress distribution is possible. In addition, in the second curved region E2, the effect in the front direction from the third curved region E3 is also transmitted, so that it can be expected that the acting drags cancel each other out on the front side and the back side, and the stress can be further dispersed. In the toothbrush 1 of the present embodiment, stress concentration on the neck portion 4 is avoided due to the characteristic shapes of the front side and the back side in the side view of the brush body 2, and the brush body 2 from the head portion 5 to the handle portion 3 is avoided. It is possible to disperse the stress as a whole and suppress the bending of the neck portion 4.

The handle portion 3 is provided with a covering material 8 on a part of the outer peripheral surface thereof. The covering material 8 is made of a soft resin. The covering material 8 is provided in a spiral shape counterclockwise toward the rear end side. The covering material 8 may be configured to cover the entire outer peripheral surface of the handle portion 3.
As the soft resin, for example, an elastomer resin such as a polyolefin-based elastomer, a styrene-based elastomer, a polyester-based elastomer, a polyurethane-based thermoplastic elastomer, or a silicone resin can be used.

Since the covering material 8 is provided on a part of the outer peripheral surface of the handle portion 3, the toothbrush 1 improves the grip when gripping the handle portion 3 and improves the operability when brushing the back teeth.

As described above, the toothbrush 1 of the present embodiment can provide a toothbrush having excellent insertability, operability and durability even when brushing molars.

Although the preferred embodiments according to 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 such examples. The various shapes and combinations of the constituent members shown in the above-mentioned examples are examples, and can be variously changed based on design requirements and the like within a range that does not deviate from the gist of the present invention.

Hereinafter, the effects of the present invention will be made clearer by examples. The present invention is not limited to the following examples, and can be appropriately modified and implemented without changing the gist thereof.

(Examples 1 to 4, Comparative Examples 1 to 3)
In this example, toothbrushes of Examples 1 to 4 and Comparative Examples 1 to 3 were prepared according to the specifications shown in Table 1 below.
A toothbrush similar to that shown in FIGS. 1 and 1 was produced.
The total length of the handle body of the toothbrush of each example was 180 mm, and each part had the dimensions shown in Table 1.
Twenty-three hairs (manufactured by PBT: 7.5 mil) were bundled into a hair bundle on the head portion, and the hair bundle was planted in the flocking pattern shown in FIG. 2 to provide a flocking portion.

[Operability when cleaning molars in the oral cavity]
Ten monitors cleaned the oral cavity and evaluated the operability of the toothbrushes in each case.
The operability is evaluated on a 7-point scale from 1 to 7, and the higher the operability, the higher the score. The average score of the monitors of 10 people was classified into the following criteria, and the operability in the oral cavity was judged.
<Criteria>
◎◎ (twin double-circle mark): Average score is 6 points or more.
◎ (double-circle mark): The average score is 5 points or more and less than 6 points.
〇 (circle mark): The average score is 4 points or more and less than 5 points.
Δ (triangle mark): The average score is 3 points or more and less than 4 points.
× (cross mark): The average score is 2 points or more and less than 3 points.

[Usability when cleaning molars in the oral cavity]
Ten monitors cleaned the oral cavity and evaluated the feeling of contact with the cheeks on the back side of the neck when the toothbrushes of each example were inserted into the oral cavity.
The operability was evaluated on a 7-point scale from 1 to 7, and when inserted into the oral cavity, there was no feeling of contact with the cheek on the back side of the neck, and the insertability was felt to be good. The higher the score.
The average score of the monitors of 10 people was classified into the following criteria, and the operability in the oral cavity was judged.
<Criteria>
◎◎: The average score is 6 points or more.
⊚: The average score is 5 points or more and less than 6 points.
〇: The average score is 4 points or more and less than 5 points.
Δ: The average score is 3 points or more and less than 4 points.
X: The average score is 2 points or more and less than 3 points.

As shown in [Table 1], Examples 1 to 4 in which the maximum thickness of the head portion is 2.0 mm or more and less than 4 mm, and the inclination angle of the neck portion is 8 ° or more and 25 ° or less. With the toothbrush, good results were obtained in terms of both operability when cleaning the back teeth and usability when cleaning the back teeth.

The present invention can be applied to a toothbrush.

1 ... toothbrush, 2 ... brush body, 3 ... handle part, 4 ... neck part, 5 ... head part, 5a-5d ... hair-planted surface, 6 ... hair-planted hole, 41 ... hair bundle, 50 ... virtual line, E1 ... 1st Curve area, E2 ... 2nd curve area, E3 ... 3rd curve area, E4 ... 4th curve area, P1 ... 1st inflection point, P2 ... 2nd inflection point, P3 ... 3rd inflection point, P4 ... 4th inflection point, S1 ... 1st straight line area, S2 ... 2nd straight line area, θ ... tilt angle

Claims

A brush body provided with a handle portion along a major axis direction, a neck portion extended from the tip of the handle portion, and a head portion located at the tip of the neck portion.
A toothbrush in which hair follicles are planted in a plurality of flocked holes formed on the flocked surface of the head portion.
The brush body has a shape in which the thickness of the neck portion continuously increases from the head portion toward the handle portion.
The maximum thickness of the head portion is 2.0 mm or more and less than 4 mm.
The first straight line having a first straight line region continuously extending from the flocked surface to the rear end side and a center of curvature on the flocked surface side on the flocked surface side when the brush body is viewed from the side. The first curved region extending in an arc shape from the first inflection point located at the rear end of the region to the rear end side and the first curved region having a center of curvature on the back side opposite to the flocked surface side. It has a second curved region extending in an arc shape from the second inflection point located at the rear end to the rear end side.
Of the plurality of hair follicles, the rear end side edge of the hair follicles located on the rearmost end side and the rear end side edge of the hair follicles second located on the rear end side in the side view. The neck represented by an angle at which a straight line passing through the second inflection point and the rear end side edge of the hair follicle hole located on the rearmost end side in the side view intersect with respect to the virtual line passing through. A toothbrush characterized in that the inclination angle of the portion is 8 ° or more and 25 ° or less.
On the back side in the side view, a second straight line region continuously extending linearly from the back side of the head portion to the rear end side, and
It has a center of curvature on the flocked surface side and has a third curved region extending in an arc shape on the rear end side from a third inflection point located at the rear end of the second straight line region.
The toothbrush according to claim 1.
On the back side in the side view, there is a fourth curve region having a center of curvature on the back side and extending in an arc shape from the fourth inflection point located at the rear end of the third curve region to the rear end side. ,
The toothbrush according to claim 2.
The minimum thickness of the neck portion is 3.0 to 4.0 mm, and the length in the major axis direction is 5 mm or more.
The toothbrush according to any one of claims 1 to 3.
The cross-sectional shape at the boundary between the neck portion and the handle portion is elliptical.
The toothbrush according to any one of claims 1 to 4.
The length of the neck portion in the major axis direction is 25 mm or more and 45 mm or less.
The toothbrush according to any one of claims 1 to 5.
The toothbrush according to any one of claims 1 to 6, wherein the toothbrush does not once have a shape that warps toward the back side near the boundary between the head portion and the neck portion.
The position in the long axis direction where the distance between the handle portion on the flocked surface side and the virtual line is the longest in the side view is located on the tip side of the handle portion in the long axis direction.
The toothbrush according to any one of claims 1 to 7.
The tip end side of the head portion is inclined at an angle of 5 ° or more and 15 ° or less toward the flocked surface side with respect to the virtual line in the side view.
The toothbrush according to any one of claims 1 to 8.