WO2017155039A1

WO2017155039A1 - Toothbrush

Info

Publication number: WO2017155039A1
Application number: PCT/JP2017/009479
Authority: WO
Inventors: 金丸　直史; 誠一亀井
Original assignee: ライオン株式会社
Priority date: 2016-03-09
Filing date: 2017-03-09
Publication date: 2017-09-14
Also published as: SG10202008662PA; MY194154A; SG10202008657QA; TW202233094A; CN111387693B; KR102424854B1; KR20200106227A; KR20180120143A; CN108697230A; TWI766856B; KR20200106228A; KR102384894B1; SG10202008658SA; KR102384895B1; CN111265000A; CN111265000B; CN108697230B; SG11201807604QA; TW201731416A; CN111387693A

Abstract

Provided is a toothbrush with which operability of a handle portion and operability inside the oral cavity can be ensured. In this toothbrush (1), which is provided with a bristle setting portion (11), a head portion (12), a neck portion (13), and a handle portion (14), the thickness t of the head portion (12) is 2.0-4.0 mm, inclusive, the minimum width W1 and minimum thickness D1 of the neck portion (13) are 3.0-4.5 mm, inclusive, the angle θ formed by a straight line N, which links a center point in the thickness direction of the handle portion (14) at a gripping center position of the toothbrush (1) and a center point in the thickness direction of the head portion (12) at a center position of the bristle setting portion (11), and a plane, which constitutes a bristle setting surface (12a), is 5.0-10.0 degrees, inclusive, and the distance h between the center point in the thickness direction of the handle portion (14) and the plane P is 6.0-12.0 mm, inclusive.

Description

toothbrush

The present invention relates to a toothbrush.
This application claims priority based on Japanese Patent Application No. 2016-045368 filed in Japan on March 9, 2016 and Japanese Patent Application No. 2016-212030 filed in Japan on October 28, 2016. The contents are incorporated herein.

From Patent Documents 1 to 3, toothbrushes with a thin head are proposed from the viewpoint of operability in the oral cavity. When the thickness of the head is reduced, a decrease in strength becomes a problem. Therefore, a resin having high strength such as polyacetal resin (POM) is used. In particular, in the case of a flat wire type flocking in which a metal flat wire is driven into a resin head to hold the brush, the flocking strength and the bending strength of the head portion may be insufficient.

Japanese Patent Laid-Open No. 7-143914 JP 2011-4852 A JP 2011-200206 A

According to the study by the present inventors, in the above-described toothbrush, if the neck portion connecting the head portion and the handle portion is thick, the improvement in operability in the oral cavity due to the thin head portion may be impaired. It was found. In particular, when the neck is wide, the operability is further deteriorated, and the thinness of the head is not conspicuous in appearance and the impression of the product is also impaired. However, when the neck portion is made thin, it may be bent too much and conversely, a problem may occur in operability. Further improvement in strength is also required. In particular, when a general-purpose resin generally used for toothbrushes such as polypropylene (PP) is used, the problem is more remarkable.

One aspect of the present invention has been made in order to solve the above-described problems, and an object thereof is to provide a thin toothbrush with a head capable of obtaining good operability.

In order to achieve the above object, a toothbrush according to one aspect of the present invention includes a flocked portion composed of a plurality of hair bundles, a head portion in which the flocked portion is provided on a flocked surface, and the head portion. A toothbrush comprising a neck portion and a handle portion extending to the neck portion, wherein the head portion has a thickness of 2.0 mm or greater and 4.0 mm or less. The small width and the minimum thickness are 3.0 mm or more and 4.5 mm or less, and the thickness direction center point of the handle portion at the gripping center position of the toothbrush and the thickness direction of the head portion at the center position of the flocked portion An angle formed by a straight line connecting a center point and a plane constituting the flocked surface is 5.0 degrees or more and 10.0 degrees or less, and the thickness direction center point of the handle portion and the plane The distance is 6.0 mm or more, 12.0 mm or less And characterized in that.

In the toothbrush according to one aspect of the present invention, the bending elastic modulus of the constituent material of the neck portion may be 1000 MPa or more and 2200 MPa or less.

In the toothbrush according to one aspect of the present invention, the constituent material of the neck portion may be a polypropylene resin.

According to one aspect of the present invention, it is possible to realize a toothbrush with a thin head portion that can provide good operability.

It is a top view of the toothbrush of one Embodiment of this invention. It is a side view of a toothbrush. It is a top view of a toothbrush concerning one embodiment of the present invention. It is a side view of a toothbrush concerning one embodiment of the present invention. It is a figure explaining the measuring method of the deflection amount of a head part. It is a figure explaining the measuring method of the deflection amount of a head part.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 and 2.
The following embodiment shows one aspect of the present invention, and does not limit the present invention, and can be arbitrarily changed within the scope of the technical idea of the present invention. Moreover, in the following drawings, in order to make each component easy to see, the scale, number, etc. of dimensions may be varied depending on the component.

FIG. 1 is a plan view of the toothbrush of the present embodiment.
FIG. 2 is a front view of the toothbrush.
As shown in FIGS. 1 and 2, the toothbrush 1 of the present embodiment includes a flocked portion 11, a head portion 12 provided with the flocked portion 11, and a neck portion 13 extending from the base end side of the head portion 12. And a handle portion 14 extending from the base end side of the neck portion 13. That is, the head portion 12, the neck portion 13, and the handle portion 14 are integrally formed. Hereinafter, a member in which the head portion 12, the neck portion 13, and the handle portion 14 are integrated is referred to as a handle body 15. In addition, illustration of the hair transplant part 11 is abbreviate | omitted in FIG.

Here, the upper surface of the head portion 12 provided with the flocked portion 11 is referred to as a flocked surface 12a. As shown in FIGS. 1 and 2, the plane P (virtual plane) constituting the flocked surface 12a is the XY plane, the direction in which the handle body 15 extends as a whole is the X-axis direction, and the direction orthogonal to the X-axis is The Y-axis direction is assumed. The normal direction of the plane P is taken as the Z-axis direction. In the following description, the dimension of each member in the Y-axis direction is referred to as the width of the member, the dimension of each member in the Z-axis direction is referred to as the thickness of the member, and the dimension of each member in the X-axis direction is referred to as the length of the member. Called.

The handle body 15 is integrally formed in an elongated shape as a whole, and can be produced by, for example, injection molding using a resin as a material. As a constituent material of the handle body 15, polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polycyclohexylene dimethylene terephthalate (PCT), polyacetal (POM), polyethylene naphthalate (PEN), polystyrene ( PS), acrylonitrile / butadiene / styrene resin (ABS), cellulose propionate (CP), polyarylate, polycarbonate, acrylonitrile / styrene copolymer resin (AS), and the like. Of these resin materials, it is preferable to use materials such as POM, PBT, and PEN in terms of high strength and easy thinning of the head portion.

In particular, polypropylene is generally more versatile and easier to process and lower in cost than a resin such as polyacetal, but has a low bending elastic modulus. For example, the flexural modulus of polyacetal is about 2500 MPa, whereas the flexural modulus of polypropylene is about 1500 to 2000 MPa. Therefore, conventionally, polypropylene is a material that is difficult to use as a material for a toothbrush with a thin head portion and a narrow neck portion. However, by adopting the shape of the toothbrush of the present embodiment described later, a resin having a relatively low bending elastic modulus such as polypropylene can be used.

In the present embodiment, it is preferable that the bending elastic modulus of the constituent material of the handle body 15, particularly the neck portion 13, is 1000 MPa or more and 2200 MPa or less. When the bending elastic modulus is less than 1000 MPa, there is a possibility that sufficient strength cannot be obtained when the neck portion 13 is thinned. On the other hand, if the flexural modulus exceeds 2200 MPa, the hardness increases, but there is a possibility that it becomes brittle.

The above resins may be used alone or in combination of two or more resins. In addition, the handle body 15 may be partially or entirely covered with a soft resin. Since part or all of the handle part 14 is covered with the soft resin, the fit feeling of the hand when the user grips the handle part 14 is improved, and the gripped fingers can be prevented from slipping. As the soft resin, for example, a resin of Shore A 90 or less is preferable, and a resin of Shore A 10 to 40 is more preferable. Examples of such soft resins include elastomer resins such as polyolefin-based elastomers, styrene-based elastomers, polyester-based elastomers, polyurethane-based thermoplastic elastomers, and silicon.

The overall length of the handle body 15 can be determined with respect to operability and the like. The overall length of the handle body 15 is, for example, about 100 to 200 mm.

The head portion 12 has a substantially rectangular flat plate shape in which four apexes are cut off by a curve in plan view. A plurality of flocked holes 12h are provided on the flocked surface 12a which is the upper surface of the head portion 12. The bristles 17 formed of a plurality of bristles 17 are formed by planting the bristles 17 in which the bristles are bundled into the flock holes 12h. Among the plurality of flocking holes 12h, the distance d1 between the flocking hole 12h located on the most distal end side of the head portion 12 and the distal end of the head portion 12, and the flocking hole 12h located on the most proximal side of the head portion 12 and the head portion 12 The distance d2 to the base end is set equal. In other words, a boundary position K1 between the neck portion 13 and the head portion 12, which will be described later, is a position away from the flock hole 12h located on the most proximal side of the head portion 12 toward the neck portion 13 by a distance equal to the distance d1. .

The dimensions of the head unit 12 are determined in consideration of characteristics such as intraoral operability. If the width of the head portion 12 is too large, the operability in the oral cavity is lowered. If the width is too small, the number of hair bundles 17 to be implanted becomes too small, and the cleaning effect tends to be impaired. For this reason, the width of the head portion 12 is set to about 5 mm to 16 mm, for example.

If the length of the head portion 12 is too long, the operability in the oral cavity tends to be impaired, and if it is too short, the number of hair bundles 17 to be implanted becomes too small, and the cleaning effect tends to be impaired. For this reason, the length of the head unit 12 is set in a range of 10 mm to 33 mm, for example.

The shape of the flock hole 12h is not particularly limited, and may be a circle such as a perfect circle or an ellipse, or a polygon such as a triangle or a rectangle. The number of the flock holes 12h is not particularly limited, and is set in the range of 10 to 60, for example. The diameter of the flocked hole 12h is determined according to the thickness of the hair bundle 17, and is set in the range of 1 mm to 3 mm, for example. The arrangement pattern of the flock holes 12h is not particularly limited, and may be any arrangement pattern such as a so-called lattice shape or zigzag shape.

The hair constituting the hair bundle 17 includes hair for which the diameter gradually decreases toward the tip (tapered hair), and hair for which the outer diameter is substantially the same except for the rounded portion of the tip (straight hair). Can be mentioned. The material of the hair is, for example, polyamide such as 6-12 nylon and 6-10 nylon, polyester such as PET, PBT, polytrimethylene terephthalate (PTT), PEN, polybutylene naphthalate (PBN), and polyolefin such as PP. Synthetic resin materials such as olefin elastomers and styrene elastomers can be used. These resin materials may be used individually by 1 type, and may be used in combination of 2 or more type. Further, the bristle may have a multi-core structure having a core part and at least one or more sheath parts provided outside the core part.

The cross-sectional contour of the hair is not particularly limited, and is, for example, a circle such as a perfect circle or an ellipse, a polygon such as a triangle, a rectangle, a pentagon, or a hexagon, a star, a three-leaf clover, or a four-leaf clover. Etc.

The thickness of the hair is not particularly limited, and is 3 mil to 11 mil (1 mil = 1/1000 inch = 0.025 mm) when the cross-sectional outline is circular, for example. The hair bundle may be composed of all the hairs having the same thickness, or two or more hairs having different thicknesses may be combined. The hair length is not particularly limited, and is set to, for example, 6 mm to 12 mm.

As shown in FIG. 2, on the side of the flocked surface 12a on the distal end side of the handle portion 14, the center position is arranged on the side opposite to the flocked surface 12a (lower side than the handle portion 14 in FIG. 2). A curved surface 14a having an arc contour with a convex surface on the flocked surface 12a is formed. Similarly, on the side opposite to the flocked surface 12a on the distal end side of the handle portion 14, a curved surface 14b having an arc outline is formed with a center position opposite to the flocked surface 12a and convex toward the flocked surface 12a in a side view. Has been.

In addition, on the flocked surface 12a side on the rear end side of the neck portion 13, the center position is arranged on the flocked surface 12a side (above the handle portion 14 in FIG. 2), and the flocked surface 12a side is concave in a side view. A contoured curved surface 13a is formed. Similarly, on the opposite side to the flocked surface 12a on the rear end side of the neck portion 13, a curved surface 13b having an arc contour in which the center position is arranged on the flocked surface 12a side and the flocked surface 12a side is concave in a side view is formed. Yes.

As the curved surface 13a and the curved surface 14a proceed in the length direction of the handle portion 14, respectively, the intersection angle between the tangent line and the flocked surface 12a in the side view changes continuously, but at the intersection between the curved surface 13a and the curved surface 14a. Intersects at an angle α1 where the intersection angle between tangents is not 0 degrees or 180 degrees. Therefore, a ridge line K2 is formed at the intersection between the curved surface 13a and the curved surface 14a.

As for the curved surface 13b and the curved surface 14b, the crossing angle between the tangent and the flocked surface 12a in the side view continuously changes as the handle portion 14 proceeds in the length direction, but the intersecting portion between the curved surface 13b and the curved surface 14b. , The intersection angle between tangents intersects at an angle α2 other than 0 degrees or 180 degrees. Therefore, a ridge line K3 is formed at the intersection of the curved surface 13b and the curved surface 14b. Therefore, the neck portion 13 and the handle portion 14 sandwich the ridgelines K2 and K3 and the

curved surfaces

14a and 14b having arcuate contours in which one side in the length direction across the ridgelines K2 and K3 is convex in the side view when viewed from the side. The other side in the length direction is connected to

curved surfaces

13a and 13b having arcuate contours in which the flocked surface 12a side is concave as viewed from the side, thereby forming a substantially S-shape when viewed from the side.

The boundary on the rear end side of the neck portion 13 is defined by ridge lines K2 and K3. Therefore, the rear end side of the ridgelines K2 and K3 is a range where the handle portion 14 is arranged, and a range between the range where the head portion 12 is arranged and the range where the handle portion 14 is arranged. The neck portion 13 is disposed on the front side.

The end portion on the flocked surface 12a side on the front end side of the handle portion 14 (the rear end side with respect to the ridge line K2) is a finger contact portion 19. The user can stably operate the toothbrush 1 by holding the handle portion 14 so that the thumb rests on the finger rest portion 19.

The neck portion 13 connects the head portion 12 and the handle portion 14 together. As an example, the neck portion 13 is the thinnest at a position slightly away from the boundary position K1 between the head portion 12 and the neck portion 13 (the tip of the neck portion 13) and closer to the handle portion 14, and has a small cross-sectional area. It is formed in a shape that extends to the rear end side while maintaining the area and gradually increases in diameter to the boundary K2 with the handle portion 14 on the rear end side. As described above, the neck portion 13 gradually becomes thicker from the head portion 12 side toward the handle portion 14 side, so that the neck portion 13 can be bent even when the toothbrush 1 is used in various ways of gripping and polishing. Absorbed and excellent in usability. However, from the viewpoint of a feeling of use, the neck portion 13 is elastic and needs to bend appropriately.

The length of the neck portion 13 is preferably 25 mm to 70 mm so that the neck portion 13 touches the lips when the head portion 12 is inserted into the oral cavity.

As shown in FIG. 1, the grip center position G1 of the toothbrush 1 is located on the handle portion 14. The grip center position G1 is defined as a position 37 mm away from the ridge line K2 toward the rear end side of the handle portion 14.

As a way of holding the toothbrush, apply a thumb near the finger rest and grip the handle with the entire palm, and a pen grip with the thumb near the finger rest and hold the pen. It has been known. The present inventors have intensively studied the position where force is applied when operating the toothbrush when holding various toothbrushes in each way. As a result, it became clear that a part of the finger hit an average position of 37 mm from the finger rest apex (the position of the ridge line K2), and this part becomes one of the centers of the operation points. Therefore, this position is defined as the grip center. At the same time, it became clear that this position substantially coincided with the position of the center of gravity of many general toothbrushes.

As shown in FIG. 2, the thickness direction center point G2 of the handle portion 14 at the grip center position G1 of the toothbrush 1 and the thickness direction center point S2 of the head portion 12 at the center position S1 of the flocked portion 11 (see FIG. 1) Is a straight line N, the straight line N is located above the plane P (+ Z direction). In other words, the handle body 15 has a bent shape so that the handle portion 14 having the grip center position G1 is positioned closer to the flocked portion 11 side than the flocked surface 12a of the head portion 12.

In the conventional toothbrush in which the handle body extends substantially in a straight line, the inventors of the present invention make the head part thin and the neck part thin, and the head part and the neck part bend, and the flocked part is on the back side of the head part (see FIG. It has been found that it is easy to be displaced in the -Z-axis direction in the case of 2. Especially when brushing, if the neck part bends, the flocked part is displaced from the normal position to the back side of the head part (that is, away from the teeth and gums), and the force applied to the handle part is the flocked part. It becomes difficult to be transmitted sufficiently. As a result, it has been found that the operability of the handle portion is significantly lowered.

Therefore, as a result of intensive studies by the present inventors, the handle portion 14 side of the handle body 15 is bent closer to the flocked portion 11 side than the plane P constituting the flocked surface 12a, like the above-described toothbrush 1 of the present embodiment, Furthermore, it has been conceived that if the parameters such as the angle θ formed by the straight line N and the plane P are optimized, the deflection of the head portion 12 and the neck portion 13 can be offset by the bending of the handle body 15. Thus, according to the toothbrush 1 of the present embodiment, even when the head portion 12 and the neck portion 13 are bent when the head portion 12 is thin and the neck portion 13 is thin, the handle operability is favorably maintained. Therefore, the possible toothbrush 1 excellent in both intraoral operability and handle portion operability can be realized.

Hereinafter, the characteristic design parameter in the toothbrush 1 of this embodiment is demonstrated.
[Head thickness t]
The thinner the thickness t of the head part 12, the higher the operability in the oral cavity. However, when the thickness t is too thin, the strength of the head part 12 tends to be insufficient. For this reason, the thickness t of the head portion 12 can be determined in consideration of the constituent material of the handle body 15, the bending elastic modulus, and the like. The thickness t of the head portion 12 is set in the range of 2.0 mm to 4.0 mm. The thickness t of the head portion 12 is more preferably about 2.5 mm to 3.5 mm.

[Minimum width W1 at the neck]
The smaller the minimum width W1 of the neck portion 13 is, the higher the intraoral operability can be. However, if it is too small, the strength of the neck portion 13 tends to be insufficient. For this reason, the minimum width W1 of the neck portion 13 can be determined in consideration of the constituent material of the handle body 15, the bending elastic modulus, and the like. The minimum width W1 of the neck portion 13 is set to 3.0 mm to 4.5 mm. The minimum width W1 of the neck portion 13 is more preferably about 3.5 mm to 4.3 mm.

[Minimum thickness D1 of neck]
The minimum thickness D1 of the neck portion 13 can be defined as the thickness of the neck portion 13 at a position where the width of the neck portion 13 is minimum in the X-axis direction. That is, in the toothbrush 1 of this embodiment, the shape of the cross section orthogonal to the extending direction of the neck portion 13 is substantially circular, and the position and thickness where the width of the neck portion 13 is minimum in the X-axis direction are minimum. Matches the position. However, the shape of the cross section orthogonal to the extending direction of the neck portion 13 is not necessarily circular, and may be, for example, a polygonal shape. The shape of the cross section perpendicular to the extending direction of the neck portion 13 may be different depending on the position in the X-axis direction, and the position where the width of the neck portion 13 is minimum and the position where the thickness is minimum are not necessarily the same. It does not have to match.

As the minimum thickness D1 of the neck portion 13 is smaller than the minimum width W1 of the neck portion 13, the operability in the oral cavity can be improved, but if it is too small, the strength of the neck portion 13 tends to be insufficient. Therefore, the minimum thickness D1 of the neck portion 13 can be determined in consideration of conditions such as the constituent material of the handle body 15 and the bending elastic modulus. The minimum thickness D1 of the neck portion 13 is set to 3.0 mm to 4.5 mm. The minimum thickness D1 of the neck portion 13 is more preferably about 3.5 mm to 4.3 mm. In the case of this embodiment, since the shape of the cross section orthogonal to the extending direction of the neck portion 13 is substantially circular, the width and thickness are the same. That is, the minimum diameter of the neck portion 13 is preferably 3.0 mm to 4.5 mm, and more preferably 3.5 mm to 4.3 mm.

[Distance a between head base end and finger rest tip a]
The greater the distance a between the proximal end of the head portion 12 (boundary position K1 between the neck portion 13 and the head portion 12) and the distal end of the finger rest portion 19 (boundary K2 between the neck portion 13 and the handle portion 14), the greater the flocking. While the part 11 reaches the back of the oral cavity and can improve the cleaning effect to every corner of the oral cavity, the deflection of the neck 13 increases. On the other hand, the smaller the distance a is, the smaller the bending of the neck portion 13 can be, but it becomes difficult for the flocked portion 11 to reach the back of the oral cavity. Therefore, the distance a is set to about 25 mm to 70 mm, for example, although it depends on conditions such as the constituent material of the handle body 15 and the bending elastic modulus.

[Grip center point angle θ]
A straight line N connecting the thickness direction center point G2 of the handle portion 14 at the grip center position G1 of the toothbrush 1 and the thickness direction center point S2 of the head portion 12 at the center position S1 of the flocking portion 11 constitutes the flocked surface 12a. Hereinafter, an angle θ formed by the plane P is referred to as a grip center point angle θ.

When the grip center point angle θ is too large, the difference between the extending direction of the handle portion 14 and the extending direction of the head portion 12 becomes large, and the operability of the handle portion 14 is deteriorated. If the grip center point angle θ is too small, the shape of the handle body 15 becomes linear, and the original effect of this embodiment cannot be obtained. Taking these into consideration, the grip center point angle θ is set to 5.0 degrees or more and 10.0 degrees or less. The grip center point angle θ is more preferably 6.0 degrees or more and 8.0 degrees or less.

[Grip center point height h]
A distance between the thickness direction center point G2 of the handle portion 14 at the grip center position G1 of the toothbrush 1 and the plane P constituting the flocked surface 12a is defined as a grip center point height h.

If the gripping center point height h is too large, like the gripping center point angle θ, the difference between the extending direction of the handle portion 14 and the extending direction of the head portion 12 becomes large, and the operability of the handle portion 14 is reduced. To do. If the grip center point height h is too small, the shape of the handle body 15 becomes linear, and the original effect of the present embodiment cannot be obtained. Considering these, the grip center point height h is set to 6.0 mm or more and 12.0 mm or less. The grip center point height h is more preferably 7.0 mm or greater and 11.0 mm or less.

(Head deflection A)
The deflection amount A of the head part is measured by the following method (α).
Method (α):
The height of the tip of the handle body in a state in which the position of the boundary P1 between the head portion and the neck portion of the toothbrush is fixed with the flocked surface of the head portion facing upward is taken as the reference height. Further, with the position of the boundary P1 fixed, a weight of 200 g is suspended at a position of 10 ± 3% from the tip of the flocked portion with respect to the length in the major axis direction of the flocked portion in the head portion for 10 seconds. The amount of displacement (unit: mm) of the height of the rear end of the handle body from the reference height is defined as a deflection amount A of the head portion.
The “length in the major axis direction of the flocked portion” refers to the tip of the flocked hole located on the most distal side when the head portion is viewed in plan and the rear end of the flocked hole located on the most rear end side. Means distance.

In a toothbrush having a head portion that is narrower in the width direction than the neck portion, the boundary P1 forms an end point of a curve at both edges that forms a corner cut from the neck portion in the head portion in plan view, that is, a corner cut. It is a position where the curve direction of the curve to be changed changes. In addition, planar view means seeing a toothbrush from the flocked surface side of a head part.

This will be described more specifically with reference to the toothbrush 21 shown in FIGS. 3A, 3B, 4A, and 4B. The toothbrush 21 includes a head portion 22 that is substantially rectangular in plan view, a neck portion 24 that extends to the head portion 22, and a handle portion 26 that extends to the neck portion 24. The head portion 22 is provided with a flocked portion (not shown). Hereinafter, the head portion 22, the neck portion 24, and the handle portion 26 are collectively referred to as a handle body 210.
In plan view, the head portion 22 extends in the width direction from the tip 29 toward the neck portion 24, then extends in the same width, then narrows in the width direction, and reaches the boundary P <b> 1 with the neck portion 24. The neck portion 24 extends from the boundary P1 toward the handle portion 26 with substantially the same diameter, and then expands to reach the boundary P2 with the handle portion 26.

The boundary P1 in the toothbrush 21 is the end point of the curve that forms both edges of the corner cut from the neck portion 24 in the plan view shape of the head portion 22, that is, the position where the bending direction of the curve that forms the corner cut changes. . In FIG. 3A, the boundary P1 between the head portion and the neck portion changes from a curve R1 in which the width forming the both corners of the head portion 22 in the plan view is narrowed to a straight line that forms both edges having the same width. Position. Further, in the case of a toothbrush whose width becomes wider as the neck portion moves toward the handle portion in a plan view, the boundary P1 coincides with a position having the smallest width in the head portion and the neck portion in a plan view.
In addition, for example, like the toothbrush in which the head portion and the neck portion are formed with the same width, it may be difficult to specify the position of the boundary P1. In this case, a position 17.5% from the tip 29 of the handle body 210 with respect to the length L1 (for example, a position 31.5 mm from the tip 29 of the handle body 210 when the length L1 is 180 mm). Let it be a boundary P1.

For example, when the width of the portion from the head portion of the neck portion is the same in plan view, the width is measured while gradually changing the position toward the head portion in the portion of the neck portion from the head portion, and the portion having the same width The boundary position P1 is the position at which the width starts to increase. Also, when the width of the portion from the head portion of the neck portion in the plan view becomes narrower as it approaches the head portion, the width of the portion of the neck portion from the head portion is gradually changed toward the head portion. And the position where the width is minimum is defined as the boundary P1.

The deflection amount A of the head part 22 is measured as follows.
As shown in FIG. 4A, the toothbrush 21 is fixed by using the jig 2100 at the position of the neck portion most detailed (boundary P1) so that the flocked surface 220 faces in the vertical direction. At this time, the height of the tip 29 of the handle body 210 and the reference height _{H 0.}
Then, as shown in FIG. 4B, a weight 2102 200 g, suspended position of S, the handle body 210 height of the tip 29 of the post 10 seconds is measured, and the height and _{H 1.} The S is a position of 10 ± 3% from the tip of the flocked portion with respect to the length L4 (FIG. 3A) in the major axis direction of the flocked portion in the head portion 22. For example, when the flocked portion is 19 mm, S is a position 2.0 mm from the tip of the flocked portion.
Next, the absolute value of the difference between H ₁ and H ₀ is obtained as a (unit is mm). The a is measured by, for example, a height gauge. The measurement is performed at room temperature 25 ± 3 ° C.
The measurement is performed five times, and the average value of the displacement amount a is defined as the deflection amount A of the head portion 22.

The deflection amount A is preferably 0.4 to 3.0, more preferably 0.4 to 2.5, and still more preferably 0.4 to 2.0. The deflection amount A is preferably 0.5 to 3.0, more preferably 0.5 to 2.5, and further preferably 0.5 to 2.0. When the amount of deflection A is in the above range, the head portion 22 itself bends moderately, and the suppleness of the flocked portion implanted in the head portion 22 is expressed, so that the contact feeling against the gingiva, that is, the feeling of use becomes better. Further, when the deflection amount A is equal to or more than the lower limit value, the feeling of use becomes good. When the deflection amount A is equal to or less than the upper limit value, it is easy to ensure sufficient strength in the head portion 22. Furthermore, the toothbrush 21 does not become too soft, and good oral operability and cleaning power are easily obtained.
The deflection amount A is adjusted by adjusting the bending elastic modulus of the material of the head part (that is, the material of the handle body), the thickness, width, etc. of the head part.

(Bend amount of neck part B)
The amount of deflection B of the neck portion is measured by the following method (β).
Method (β):
The height of the tip of the handle body in a state where the flocked surface of the head portion is directed vertically upward and the boundary position between the neck portion and the handle portion of the toothbrush is fixed is defined as the reference height. In the fixed state, a weight of 200 g is suspended at a position of 50 ± 3% from the tip of the flocked portion with respect to the length in the major axis direction of the flocked portion in the head portion, and the tip of the handle body after 10 seconds is suspended. A displacement amount (unit: mm) of the height from the reference height is defined as a deflection amount B of the neck portion.

The boundary P2 between the neck portion and the handle portion is an end point of the diameter expansion of the neck portion, that is, a curved line forming both ends of the straight line forming both edges of the widening portion or both edges of the widening portion in plan view. This is the position where the direction changes. If it is FIG. 3A, it is a position which changes from the straight line or curve R2 which forms the both edges of the part which the width | variety in a neck part spreads in the planar view of a neck part and a handle | steering-wheel part to the curve which becomes narrow gradually.
It may be difficult to specify the position of the boundary P2 like a toothbrush in which the neck portion and the handle portion are formed with the same width. In this case, the position of 42.2% from the tip 29 of the handle body 210 with respect to the length L1 (for example, the position of 76.0 mm from the tip 29 of the handle body 210 when the length L1 is 180 mm). The boundary is P2.

The deflection amount B of the neck portion 24 in the toothbrush 21 is different from the method for measuring the deflection amount A of the head portion 22 except that the position where the toothbrush 21 is fixed by the jig 2100 and the position S where the weight 2102 is suspended are different. It is measured in the same manner as the head deflection amount A.
In the measurement of the deflection amount B of the neck portion 24, the position where the toothbrush 21 is fixed by the jig 2100 is the boundary P2. Further, S is a position of 50 ± 3% from the tip of the flocked portion with respect to the length of the flocked portion in the long axis direction. For example, when the flocked portion is 19 mm, S is 9.5 mm from the tip.
Similarly to the method of measuring the deflection amount A of the head portion, the absolute value of the difference between the reference height H ₀ before the weight 2102 is suspended and the height H ₁ after the weight 2102 is suspended and 10 seconds have elapsed. (The unit is mm). The measurement is performed at room temperature 25 ± 3 ° C. This measurement is performed five times, and the average value is defined as a deflection amount B of the neck portion 24.

The deflection amount B is preferably 2.1 to 5.0, more preferably 2.3 to 4.5, and even more preferably 2.5 to 4.0. When the bending amount B is in the above range, the neck portion is appropriately bent, an appropriate cushioning property is expressed, and the contact comfort of the flocked portion against the gum is further improved. Moreover, if the amount of deflection B is equal to or greater than the lower limit, the hair can reach all corners of the oral cavity such as the back of the back teeth, and the cleaning power in the oral cavity is further enhanced. Furthermore, the penetration property of the hair to a periodontal pocket improves and the cleaning power of a periodontal pocket is improved more. It becomes easy to suppress that the intensity | strength of a neck part falls that the deflection | deviation amount B is below the said upper limit. Furthermore, the toothbrush 21 does not become too soft, and a good feeling of use is easily obtained.
The bending amount B is adjusted by adjusting the bending elastic modulus of the neck portion material (that is, the handle body material), the minimum diameter of the neck portion, the cross-sectional shape of the boundary P2, and the like.

The product (A × B) of the deflection amount A of the head portion and the deflection amount B of the neck portion is 0.8 to 10, more preferably 1 to 10, still more preferably 1 to 6, and 1 to 3. 5 is more preferable. Further, (A × B) is preferably 2 to 10. When (A × B) is in the above range, an appropriate deflection in which the head portion 22 and the neck portion 24 cooperate is obtained. Thereby, when the hair transplantation part is slid with respect to the site | part to be cleaned (a tooth | gear, gingiva etc.), the flexibility and cushioning property of a hair transplantation part express, and the contact | win feeling of a hair transplantation part becomes favorable. Moreover, the lower limit of (A × B) is 0.8 or more, and preferably 1 or more. Moreover, 2 or more is preferable. When (A × B) is equal to or more than the lower limit value, moderate bending can be obtained, so that the contact feeling with the gums is good, a high massage effect is obtained with respect to the gums, and the usability is improved. The upper limit of (A × B) is 10 or less, preferably 6 or less, and more preferably 3.5 or less. When (A × B) is equal to or less than the above upper limit value, it is possible to suppress the region formed by the head portion 22 and the neck portion 24 from being excessively bent, thereby reducing the operability and the cleaning power. Moreover, it can suppress that the massage effect with respect to the gingiva by the said bending too much falls, or a user feels weak when using the toothbrush 21. FIG. Furthermore, the strength of the toothbrush 21 is increased and the durability is improved.

The deflection amount A and the deflection amount B are preferably A <B. When A <B, the operability of the toothbrush 21 is further enhanced.
Further, the difference (BA) between the deflection amount A and the deflection amount B is preferably 1 or more, preferably 1.5 or more, and more preferably 2 or more. When (BA) is equal to or more than the lower limit value, the amount of bending of the neck portion 24 relative to the head portion 22 can be kept large, the cushioning property can be improved, and the comfort against the gingiva can be improved. It becomes easier to feel the massage effect.
Further, (BA) is preferably 4 or less, more preferably 3 or less. When (BA) is equal to or less than the upper limit, the amount of bending of the neck portion 24 with respect to the head portion 22 does not become too large, and the operability in the oral cavity is easily improved. Furthermore, it becomes easy to suppress that a user feels weak when using the toothbrush 21.
(BA) is preferably 1 to 4, and more preferably 1 to 3.
The ratio (B / A) of the deflection amount B and the deflection amount A is preferably 1.5 to 5.0, more preferably 1.8 to 4.8.

When the toothbrush 21 is used, the handle portion 26 is gripped. The form in which the handle portion 26 is gripped is not particularly limited, and may be a palm grip type or a pen grip type. Usually, in order to clean the target portion while applying pressure to the target portion, the handle portion 26 is gripped by placing a thumb or the like near the boundary P2 at the rear end of the neck portion in any gripping form.
Next, the head portion 22 is inserted into the oral cavity, and the flocked portion is slid to the site to be cleaned while pressing the handle portion 26. The force applied to the handle portion 26 is transmitted to the head portion 22 through the neck portion 24, and further transmitted from the head portion 22 to the hair transplantation portion, so that the hair transplantation portion is cleaned while applying pressure to the site to be cleaned. At this time, when the product (A × B) of the deflection amount A of the head portion and the deflection amount B of the neck portion is 0.8 to 10, an appropriate deflection in which the head portion and the neck portion cooperate is obtained. As a result, the bristles implanted in the head portion 22 of the toothbrush 21 can be easily delivered to every corner of the oral cavity such as the back of the back teeth, and the cleaning power in the oral cavity is enhanced. Furthermore, it is easy to allow hair to enter the periodontal pocket, and the cleaning power of the periodontal pocket is enhanced. In addition, by obtaining appropriate bending, the suppleness and cushioning properties of the flocked portion are improved, the contact feeling of the flocked portion with respect to the gingiva is improved, a good massage effect for the gingiva is obtained, and the feeling of use is enhanced.

[Example]
EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples. However, the present invention is not limited to the following examples, and can be appropriately modified and implemented without departing from the gist thereof.

According to the specifications shown in Table 1, toothbrushes of Examples 1 to 6 and Comparative Examples 1 and 2 were produced by an injection molding method. In the above toothbrushes, the handle portion has the same width, length, thickness and shape. Various resins described in Table 1 were injection molded to obtain an integrally molded product of the head portion, the neck portion, and the handle portion described in FIGS. 1 and 2. The arrangement of the flocking holes was 3 holes × 1 row, 4 holes × 6 rows, 3 holes × 1 row from the tip of the head portion toward the neck portion. The width and length of the head are shown in Table 1. A toothbrush was prepared by implanting a bristles of taper hair (7.5 mils) made of PBT filaments into the head portion by flat wire type flocking.

The evaluation items for each sample include two items: intraoral operability and handle operability. Regarding operability in the oral cavity, “very good” is “◎”, “excellent” is “◯”, “somewhat inferior” is “△”, and “very inferior” Was marked “x”. Similarly, regarding steering wheel operability, “very good” is “◎”, “excellent” is “◯”, “somewhat inferior” is “△”, and “very inferior” Is “×”.

As shown in Table 1, in the toothbrush of Comparative Example 1, both the grip center point angle θ and the grip center point height h are outside the numerical range of the present invention. That is, the toothbrush of Comparative Example 1 has a shape in which the handle body is relatively close to a straight line. Therefore, it was confirmed that the toothbrush of the comparative example 1 is inferior in intraoral operability and handle operability. Further, in the toothbrush of Comparative Example 2, the head portion thickness t, the minimum neck portion width W1, and the minimum neck portion thickness D1 are out of the numerical range of the present invention. Therefore, it was confirmed that the toothbrush of the comparative example 2 is inferior in intraoral operability.

On the other hand, in the toothbrushes of Examples 1 to 6, the head portion thickness t, the minimum neck portion width W1, the minimum neck portion thickness D1, the grip center point angle θ, and the grip center point height h are all included. Are within the numerical range of the present invention. Thus, it was confirmed that the toothbrush was excellent in both oral operability and handle operability even when the neck portion was bent.

Generally, when a flat wire type flocking is adopted, the head portion is stressed by driving the flat wire. If the head is thin, the strength against deformation when force is applied is low, while the neck is thick and the strength is high, the stress when brushing teeth concentrates on the head, and the deflection of the head increases. Usability may be reduced. In this case, like the toothbrush 1 of this embodiment, by narrowing the neck and giving a certain degree of flexibility, the stress when brushing teeth can be distributed from the head to the entire neck, improving usability. To do. Therefore, in the case of flat wire type flocking, the effect of the present invention can be obtained particularly remarkably.

DESCRIPTION OF SYMBOLS 1 ... Toothbrush, 11 ... Flocking part, 12 ... Head part, 12a ... Flocking surface, 13 ... Neck part, 14 ... Handle part, 17 ... Hair bundle

Claims

A flocked portion comprising a plurality of hair bundles;
A head portion in which the flocked portion is provided on the flocked surface;
A neck portion extending to the head portion;
A toothbrush comprising a handle portion extending to the neck portion,
The head portion has a thickness of 2.0 mm to 4.0 mm,
The minimum width and minimum thickness of the neck portion are 3.0 mm or more and 4.5 mm or less,
A straight line connecting the thickness direction center point of the handle portion at the gripping center position of the toothbrush and the thickness direction center point of the head portion at the center position of the flocked portion, and a plane constituting the flocked surface are formed. The angle is 5.0 degrees or more and 10.0 degrees or less,
A toothbrush characterized in that a distance between a center point in the thickness direction of the handle portion and the plane is 6.0 mm or more and 12.0 mm or less.
The toothbrush according to claim 1, wherein a bending elastic modulus of a constituent material of the neck portion is 1000 MPa or more and 2200 MPa or less.
The toothbrush according to claim 1 or 2, wherein the constituent material of the neck portion is a polypropylene resin.