CN108697230B

CN108697230B - Tooth brush

Info

Publication number: CN108697230B
Application number: CN201780016110.9A
Authority: CN
Inventors: 金丸直史; 龟井诚一
Original assignee: Lion Corp
Current assignee: Lion Corp
Priority date: 2016-03-09
Filing date: 2017-03-09
Publication date: 2020-04-24
Anticipated expiration: 2037-03-09
Also published as: SG10202008658SA; CN111265000A; KR102424854B1; SG11201807604QA; KR20180120143A; CN111387693A; TWI766856B; WO2017155039A1; TW201731416A; KR20200106227A; CN108697230A; CN111265000B; SG10202008662PA; KR20200106228A; SG10202008657QA; TW202233094A; CN111387693B; KR102384894B1; KR102384895B1; MY194154A

Abstract

A toothbrush capable of ensuring the operability of a handle and the operability in the oral cavity. A toothbrush (1) is provided with a bristle part (11), a head part (12), a neck part (13), and a grip part (14), wherein the thickness t of the head part (12) is 2.0mm to 4.0mm, the minimum width W1 and the minimum thickness D1 of the neck part (13) are 3.0mm to 4.5mm, the angle theta formed by a straight line N connecting the thickness direction center point of the grip part (14) at the grip center position of the toothbrush (1) and the thickness direction center point of the head part (12) at the center position of the bristle part (11) and a plane P constituting a bristle surface (12a) is 5.0 degrees to 10.0 degrees, and the distance h between the thickness direction center point of the grip part (14) and the plane P is 6.0mm to 12.0 mm.

Description

Tooth brush

Technical Field

The present invention relates to toothbrushes.

The present application claims priority based on 2016 in Japanese patent application No. 2016-.

Background

According to patent documents 1 to 3, a toothbrush having a reduced thickness of the head has been proposed from the viewpoint of oral operability and the like. If the thickness of the head is reduced, the strength is reduced. For this reason, a resin having high strength such as polyacetal resin (POM) is used. In particular, in the case of flat-wire type tufting in which bristles are fixed by driving a flat wire (flat plate) made of metal into a head made of resin, the tufting strength and the folding strength of the head may be insufficient.

[ Prior art documents ]

[ patent document ]

[ patent document 1] Japanese patent laid-open No. Hei 7-143914

[ patent document 2] Japanese patent application laid-open No. 2011-

[ patent document 3] Japanese patent laid-open publication No. 2011-

Disclosure of Invention

[ problem to be solved by the invention ]

After the research, the inventor discovers that: in the above-described toothbrush, if the neck portion connecting the head portion and the grip portion is thick, the effect of improving the oral cavity operability due to the head portion becoming thin is impaired. In particular, if the neck width is increased, the operability is further impaired, and the head thinness is also not conspicuous in appearance, and the impression of the product is also impaired. On the other hand, when the neck portion is narrowed, excessive deflection may cause a problem in operability. Further, further improvement in strength is also required. In particular, the problem is more remarkable when a general-purpose resin such as polypropylene (PP) that is generally used for toothbrushes is used.

One aspect of the present invention is to solve the above problems, and an object thereof is to provide a toothbrush having a thin head portion that can achieve good operability.

[ means for solving the problem ]

In order to achieve the above object, a toothbrush according to one embodiment of the present invention comprises: a toothbrush comprising a bristle-implanted portion including a plurality of tufts, a head portion provided with the bristle-implanted portion on a bristle-implanted surface, a neck portion provided so as to extend to the head portion, and a handle portion provided so as to extend to the neck portion, wherein the head portion has a thickness of 2.0mm or more and 4.0mm or less, the neck portion has a minimum width and a minimum thickness of 3.0mm or more and 4.5mm or less, an angle formed by a straight line connecting a thickness-direction center point of the handle portion at a grip center position of the toothbrush and a thickness-direction center point of the head portion at a center position of the bristle-implanted portion and a plane constituting the bristle-implanted surface is 5.0 degrees or more and 10.0 degrees or less, and a distance between the thickness-direction center point of the handle portion and the plane is 6.0mm or more and 12.0mm or less.

In the toothbrush according to one aspect of the present invention, the flexural modulus of the material constituting the neck portion may be 1000MPa to 2200 MPa.

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

[ Effect of the invention ]

According to one embodiment of the present invention, a toothbrush with a thin head part, which can achieve good operability, can be realized.

Drawings

Fig. 1 is a plan view of a toothbrush according to an embodiment of the present invention.

Fig. 2 is a side view of the toothbrush.

Fig. 3A is a plan view of a toothbrush according to an embodiment of the present invention.

Fig. 3B is a side view of a toothbrush according to an embodiment of the present invention.

FIG. 4A is a diagram illustrating a method of measuring the amount of deflection of the head.

FIG. 4B is a diagram illustrating a method of measuring the amount of deflection of the head.

[ description of symbols ]

1 … toothbrush, 11 … hair-planting part, 12 … head, 12a … hair-planting surface, 13 … neck, 14 … handle part and 17 … hair bundle.

Detailed Description

An embodiment of the present invention will be described below with reference to fig. 1 and 2.

The following embodiments are merely illustrative of the present invention, and are not intended to limit the present invention, and may be modified as desired within the scope of the technical spirit of the present invention. In the following drawings, in order to make it easy to observe each component, the scale and the number of the dimensions shown may be different depending on the component.

Fig. 1 is a plan view of the toothbrush of this embodiment.

Fig. 2 is a front view of the toothbrush.

As shown in fig. 1 and 2, a toothbrush 1 of the present embodiment includes: the bristle part 11 includes a head part 12 provided with the bristle part 11, a neck part 13 extending from a proximal end side of the head part 12, and a grip part 14 extending from a proximal end side of the neck part 13. That is, the head portion 12, the neck portion 13, and the grip portion 14 are formed integrally. Hereinafter, the member in which the head 12, the neck 13, and the grip portion 14 are integrally molded is referred to as a grip body 15. In fig. 1, the illustration of the flocked portion 11 is omitted.

Here, the upper surface of the head portion 12 provided with the flocked portion 11 is referred to as a flocked surface 12 a. As shown in fig. 1 and 2, a plane P (virtual plane) constituting the hair-setting surface 12a is an XY plane, a direction in which the entire handle body 15 extends is an X-axis direction, and a direction perpendicular to the X-axis is a Y-axis direction. 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.

The handle body 15 is integrally molded in a long shape as a whole, and can be manufactured by injection molding using resin as a material, for example. Examples of the material constituting the grip body 15 include polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polycyclohexanedimethanol terephthalate (PCT), Polyacetal (POM), polyethylene naphthalate (PEN), Polystyrene (PS), acrylonitrile-butadiene-styrene resin (ABS), Cellulose Propionate (CP), polyarylate, polycarbonate, and acrylonitrile-styrene copolymer resin (AS). Among these resin materials, materials such as POM, PBT and PEN are preferably used in view of high strength and easy thinning of the head.

In particular, polypropylene is generally more versatile than resins such as polyacetal, easy to process and low in cost, but has a low flexural modulus. For example, the flexural modulus of polyacetal is about 2500MPa, while the flexural modulus of polypropylene is about 1500 to 2000 MPa. Therefore, polypropylene has been a difficult material to use as a material for toothbrushes having thin heads and narrow necks. However, by adopting the toothbrush shape of the present embodiment described later, a resin having a low flexural modulus of elasticity such as polypropylene can be used.

In the present embodiment, the bending modulus of the material constituting the grip body 15 (particularly the neck portion 13) is preferably 1000MPa to 2200 MPa. If the flexural modulus is less than 1000MPa, sufficient strength may not be obtained when the neck portion 13 is thinned. When the flexural modulus exceeds 2200MPa, the hardness may increase, but the material may become brittle.

The above-mentioned resins may be used alone in 1 kind or in combination of 2 or more kinds. In the handle body 15, a part or the whole of the handle portion 14 may be covered with a soft resin. By covering a part or the whole of the grip portion 14 with the soft resin, the user can feel comfortable when gripping the grip portion 14, and can prevent the fingers being gripped from slipping. Examples of the soft resin include resins having a Shore a hardness of 90 or less (Shore hardness) and more preferably 10 to 40. Examples of such soft resins include elastomer resins such as polyolefin elastomers, styrene elastomers, polyester elastomers, and polyurethane thermoplastic elastomers, and silicone resins.

The length of the entire handle body 15 can be determined depending on the operability and the like. The entire length of the handle body 15 is, for example, about 100 to 200 mm.

The head 12 has a flat plate shape of 4 approximate quadrangles whose tops are cut off curvilinearly in a plan view. A plurality of implantation holes 12h are provided in the upper surface of the head 12, i.e., the implantation surface 12 a. The bristle bundles 17 from which bristles are bound are implanted into the respective bristle holes 12h, thereby forming the implanted part 11 including a plurality of bristle bundles 17. Among the plurality of implanted holes 12h, a distance d1 from the implanted hole 12h located on the most distal side of the head 12 to the distal end of the head 12 and a distance d2 from the implanted hole 12h located on the most proximal side of the head 12 to the proximal end of the head 12 are set to be equal. In other words, the boundary position K1 of the neck 13 and the head 12 described later is: a position shifted toward the neck portion 13 side by a distance equal to the distance d1 from the hair-implanting hole 12h located at the most proximal end side of the head portion 12.

The size of the head 12 can be determined in consideration of characteristics such as oral cavity operability. If the width of the head 12 is too large, the oral cavity operability is deteriorated, and if it is too small, the number of flocked tufts 17 becomes too small, and the cleaning effect is easily impaired. Therefore, the width of the head 12 is set to about 5mm to 16mm, for example.

If the length of the head 12 is too long, the oral cavity operability is liable to be impaired, and if it is too short, the number of flocked tufts 17 becomes too small, and the cleaning effect is liable to be impaired. Therefore, the length of the head 12 is set to a range of, for example, 10mm to 33 mm.

The shape of the implantation 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 quadrangle. The number of the implantation holes 12h is not particularly limited, and may be set in a range of, for example, 10 to 60. The diameter of the implanted holes 12h can be determined according to the thickness of the hair bundle 17, and can be set in a range of, for example, 1mm to 3 mm. The arrangement pattern of the implanted holes 12h is not particularly limited, and may be any arrangement pattern such as a lattice pattern or a staggered pattern.

Examples of bristles constituting the bundle 17 include bristles (tapered bristles) having a diameter gradually decreasing toward the bristle tip, and bristles (straight bristles) having substantially the same outer diameter except for a spherical portion of the bristle tip. Examples of the material of the brush include polyamide such as 6-12 nylon and 6-10 nylon, polyester such as PET, PBT, polytrimethylene terephthalate (PTT), PEN, and polybutylene naphthalate (PBN), polyolefin such as PP, olefin elastomer, and synthetic resin material such as styrene elastomer. These resin materials may be used alone in 1 kind, or in combination of 2 or more kinds. Further, the bristle may have a multiple core structure having a core portion and at least 1 or more layers of sheath portions provided outside the core portion.

The cross-sectional profile of the brush is not particularly limited, and examples thereof include a circle such as a perfect circle and an ellipse, a polygon such as a triangle, a quadrangle, a pentagon and a hexagon, a star, a clover of three leaves, and a clover of four leaves.

The thickness of the brush is not particularly limited, and when the cross-sectional contour is circular, it can be set to, for example, 3 to 11 mils (1 mil: 1/1000 inch: 0.025 mm). The tufts may be all composed of bristles of the same thickness, or may be composed of more than 2 kinds of bristles of different thicknesses. The hair length is not particularly limited, and may be set to 6mm to 12mm, for example.

As shown in fig. 2, a curved surface 14a having a convex circular-arc contour in a side view is formed on the bristle surface 12a side of the grip portion 14 on the distal end side thereof, with the center thereof being disposed on the side opposite to the bristle surface 12a (the side lower than the grip portion 14 in fig. 2). Similarly, a curved surface 14b having a circular arc contour whose center position is arranged on the side opposite to the hair-planted surface 12a and whose hair-planted surface 12a side is convex in a side view is formed on the side opposite to the hair-planted surface 12a on the distal end side of the grip portion 14.

Further, on the hair-planted surface 12a side of the rear end side of the neck portion 13, a curved surface 13a having a circular arc contour whose center position is arranged on the hair-planted surface 12a side (the side on the upper surface of the grip portion 14 in fig. 2) and which is concave in a side view is formed. Similarly, a curved surface 13b having a circular arc contour whose center position is disposed on the hair-planted surface 12a side and which is concave on the hair-planted surface 12a side in a side view is formed on the opposite side of the hair-planted surface 12a on the rear end side of the neck portion 13.

While the intersection angle between the tangent line and the hair-planted surface 12a in the side view continuously changes as the curved surface 13a and the curved surface 14a each proceed in the longitudinal direction of the grip portion 14, the intersection between the curved surface 13a and the curved surface 14a intersects at an angle α 1 at which the intersection angle between the tangent lines is not 0 degree or 180 degrees, and therefore, a ridge line K2 is formed at the intersection between the curved surface 13a and the curved surface 14 a.

The curved surface 13b and the curved surface 14b are also continuously changed in the intersection angle between the tangent line and the hair-planted surface 12a in the side view as they go forward in the longitudinal direction of the grip portion 14, but the intersection between the curved surface 13b and the curved surface 14b intersects at an angle α 2 at which the intersection angle between the tangent lines is not 0 degree or 180 degrees, and therefore, the neck portion 13 and the grip portion 14 are formed with the ridge line K3. at the intersection between the curved surface 13b and the curved surface 14b, and therefore, the

curved surfaces

14a and 14b having a convex arc contour on the hair-planted surface 12a side in the side view on one side in the longitudinal direction of the ridge lines K2 and K3 and the

curved surfaces

13a and 13b having a concave arc contour on the hair-planted surface 12a side in the side view on the other side in the longitudinal direction of the ridge lines K2 and K3 are connected to each other, and thereby forming an approximate S shape in the side view.

The boundary of the rear end side of the neck portion 13 is defined by ridge lines K2 and K3. Therefore, the ridge lines K2, K3 are located at the rear end side of the range where the handle portion 14 is provided, and the neck portion 13 is provided in the range between the range where the head portion 12 is provided and the range where the handle portion 14 is provided.

The end portion of the grip portion 14 on the side of the flocked surface 12a on the distal end side (the further rear end side of the ridge line K2) is a finger contact portion 19. The user holds the grip portion 14 by touching the thumb on the finger touch portion 19, thereby stably operating the toothbrush 1.

The neck portion 13 integrally connects the head portion 12 and the grip portion 14. As an example, the neck portion 13 has a shape that is the narrowest at a position slightly shifted from a boundary position K1 (a front end of the neck portion 13) between the head portion 12 and the neck portion 13 toward the grip portion 14, has a small cross-sectional area, extends toward the rear end side with the cross-sectional area kept, and gradually expands in diameter on the rear end side up to a boundary K2 with the grip portion 14. As described above, since the neck portion 13 is gradually thickened from the head portion 12 side toward the handle portion 14 side, when the toothbrush 1 is used in various grasping methods or tooth brushing methods, the flexure of the neck portion 13 can be absorbed, and the usability is excellent. Among them, the neck portion 13 needs to have elasticity and moderate flexibility in view of the feeling of use.

The length of the neck 13 is preferably 25mm to 70mm in order to bring the neck 13 into contact with the lips when the head 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 grip portion 14. The grip center position G1 is defined as a position that is 37mm away from the ridge line K2 on the rear end side of the grip portion 14.

As a method of holding the toothbrush, "palm-grip" in which the thumb is brought into contact with the vicinity of the finger contact portion and the grip portion is held with the palm as a whole, and "pen-grip" in which the thumb is brought into contact with the vicinity of the finger contact portion and the grip portion is held like a pen-grip are known. The present inventors have earnestly studied: in the case of holding various toothbrushes with various grips, the position where the force is applied when the toothbrush is operated. As a result, it was found that: a part of the finger was touched at a position spaced from the vertex of the finger-touch portion (the position of the ridge line K2) by 37mm on average, which became one of the centers of the operation points. Therefore, this position is defined as the center of grip. In addition, it is also known that this position is approximately coincident with the center of gravity of many conventional toothbrushes.

As shown in fig. 2, when a virtual straight line connecting a thickness direction center point G2 of the handle portion 14 at a grip center position G1 of the toothbrush 1 and a thickness direction center point S2 of the head portion 12 at a center position S1 (see fig. 1) of the implanted portion 11 is defined as a straight line N, the straight line N is located further above (+ Z direction) the plane P. In other words, the handle body 15 has a curved shape as follows: the grip portion 14 having the grip center position G1 is curved so as to be located closer to the hair-planted portion 11 than the hair-planted surface 12a of the head portion 12.

The present inventors have found that, in a conventional toothbrush in which a handle body extends in a substantially linear shape, when a head portion becomes thin and a neck portion becomes thin, the head portion and the neck portion are bent, and a bristle implanted portion is easily displaced toward the back surface side of the head portion (the-Z axis direction in fig. 2). In particular, when the neck portion is bent during brushing, the implanted portion is displaced to the back side of the head portion (i.e., in a direction away from the teeth or gum) from the normal position, and the force applied to the grip portion is difficult to be sufficiently transmitted to the implanted portion. As a result, the operability of the grip portion is significantly reduced.

For this reason, the present inventors have made intensive studies and conceived that: as in the toothbrush 1 of the present embodiment, when the parameters such as the angle θ formed by the straight line N and the plane P are optimized by bending the handle body 15 toward the grip portion 14 of the handle body 15 closer to the bristle-implanted portion 11 than the plane P constituting the bristle-implanted surface 12a, the bending of the handle body 15 can cancel out the bending of the head 12 and the neck 13. As described above, according to the toothbrush 1 of the present embodiment, when the head 12 is thinned and the neck 13 is thinned, even if the head 12 and the neck 13 are flexed, the handle operability can be favorably maintained, and the toothbrush 1 having excellent oral operability and handle operability can be realized.

Hereinafter, characteristic design parameters in the toothbrush 1 of the present embodiment will be described.

[ thickness t of head ]

As the thickness t of the head 12 becomes thinner, the intraoral operability can be improved, but if it is too thin, the strength of the head 12 tends to become insufficient. Therefore, the thickness t of the head unit 12 can be determined in consideration of the material constituting the handle body 15, the flexural elastic modulus, and the like. The thickness t of the head 12 may be set in the range of 2.0mm to 4.0 mm. The thickness t of the head 12 is more preferably about 2.5mm to 3.5 mm.

[ minimum neck width W1]

The smaller the minimum width W1 of the neck portion 13 is, the better the oral cavity operability is, but if it is too small, the strength of the neck portion 13 tends to be insufficient. Therefore, 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 13 may be set to 3.0mm to 4.5 mm. The minimum width W1 of the neck portion 13 is more preferably about 3.5mm to 4.3 mm.

[ minimum thickness of neck D1]

The minimum thickness D1 of the neck 13 may be specified as: the thickness of the neck portion 13 at the position where the width of the neck portion 13 is smallest in the X-axis direction. That is, in the toothbrush 1 of the present embodiment, the cross section perpendicular to the extending direction of the neck portion 13 has a substantially circular shape, and the position where the width of the neck portion 13 is smallest coincides with the position where the thickness is smallest in the X-axis direction. However, the shape of the cross section that intersects perpendicularly with the extending direction of the neck portion 13 is not necessarily circular, and may be polygonal, for example. The shape of the cross section that intersects perpendicularly with 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 do not necessarily coincide.

The smaller the minimum thickness D1 of the neck 13 is, the better the oral cavity operability is, similarly to the minimum width W1 of the neck 13, but if it is too small, the strength of the neck 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 flexural modulus. The minimum thickness D1 of the neck portion 13 may be set to 3.0mm to 4.5 mm. The minimum thickness D1 of the neck portion 13 is more preferably about 3.5mm to 4.3 mm. In the present embodiment, the cross section perpendicular to the extending direction of the neck portion 13 has a substantially circular shape, and therefore has the same width and thickness. That is, the minimum diameter of the neck portion 13 is preferably 3.0mm to 4.5mm, more preferably 3.5mm to 4.3 mm.

[ distance a between the proximal end of the head and the distal end of the finger contact part ]

The greater the distance a from the base end of the head 12 (boundary position K1 between the neck 13 and the head 12) to the tip end of the finger contact part 19 (boundary K2 between the neck 13 and the grip part 14), the more the implanted part 11 can reach the deep inside of the oral cavity, and the more the cleaning effect of the corner angle in the oral cavity can be improved, but conversely, the greater the deflection of the neck 13. On the other hand, the smaller the distance a, the smaller the deflection of the neck portion 13 can be made, but the more difficult the implanted portion 11 reaches the deep inside of the oral cavity. Therefore, the distance a may be set to about 25mm to 70mm, for example, although it depends on the conditions such as the material of the handle body 15 and the flexural modulus.

[ grip center angle θ ]

Hereinafter, an angle θ formed by a straight line N connecting a thickness direction center point G2 of the grip portion 14 at the grip center position G1 of the toothbrush 1 and a thickness direction center point S2 of the head portion 12 at the center position S1 of the bristle part 11 and a plane P constituting the bristle surface 12a is referred to as a grip center point angle θ.

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

[ height h of center point of grip ]

The distance between the thickness direction center point G2 of the grip portion 14 and the plane P constituting the bristle surface 12a in the grip center position G1 of the toothbrush 1 is defined as a grip center point height h.

Similarly to the grip center angle θ, if the grip center height h is too large, the difference between the extending direction of the grip portion 14 and the extending direction of the head portion 12 becomes large, and the operability of the grip portion 14 is deteriorated. When the grip center point height h is too small, the shape of the grip body 15 becomes linear, and the original effect of the present embodiment cannot be obtained. In view of these, the height h of the grip center point may be set to 6.0mm or more and 12.0mm or less. The height h of the grip center point is more preferably 7.0mm to 11.0 mm.

(deflection of head A)

The deflection a of the head is measured by the following method (α).

Method (α):

the bristle-implanted surface of the head is directed upward in the vertical direction, and the height of the tip of the handle body in a state where the position of the boundary P1 between the head and the neck of the toothbrush is fixed is set as a reference height. Further, in a state where the position of the boundary P1 was fixed, a 200g hammer was suspended at a position 10 ± 3% away from the distal end of the implanted portion with respect to the length of the implanted portion in the long axis direction of the head, and the amount of displacement (in mm) in height from the reference height of the distal end of the handle body after 10 seconds was used as the deflection amount a of the head.

The "length of the hair-planted portion in the longitudinal direction" means a distance between the distal end of the hair-planted hole located on the most distal side and the rear end of the hair-planted hole located on the most distal side when the head is viewed in a plan view.

In a toothbrush having a head portion with a shape narrowing in the width direction from the neck portion, the boundary P1 is: the end points of the curves of the head forming both edges of the chamfer from the neck in plan view, that is, the positions where the bending directions of the curves forming the chamfer change. The plan view is a view of the toothbrush from the bristle-implanted side of the head.

The toothbrush 21 shown in fig. 3A, 3B, 4A and 4B will be specifically described. The toothbrush 21 includes: a head portion 22 having an approximately quadrangular shape in plan view, a neck portion 24 provided to extend to the head portion 22, and a grip portion 26 provided to extend to the neck portion 24. The head 22 is provided with a bristle-implanted portion (not shown). Hereinafter, the head 22, the neck 24, and the grip 26 are collectively referred to as a grip body 210.

The head portion 22, in plan view, expands in width from the front end 29 toward the neck portion 24, then extends with an equal width, and then narrows in width until its boundary P1 with the neck portion 24. The neck portion 24 extends from the boundary P1 toward the grip portion 26 with substantially the same diameter, and then expands in diameter until it meets the boundary P2 of the grip portion 26.

Boundary P1 in toothbrush 21 is: the end points of the curves forming the both edges of the chamfer from the neck portion 24, that is, the positions where the bending directions of the curves forming the chamfer are changed in the plan view shape of the head portion 22. In fig. 3A, the boundary P1 of the head and neck is: the curve R1 narrowing in width from both edges forming the corner cut of the head portion 22 in plan view changes to the position of a straight line forming both edges of the same width. Further, in the case of a toothbrush in which the neck portion is widened in width toward the handle portion in a plan view, the boundary P1 coincides with a position in which the width in the head portion and the neck portion is smallest in a plan view.

However, the position of the boundary P1 may be difficult to determine, for example, in a toothbrush in which the head and the neck are formed to have the same width. At this time, a position 17.5% away from the front end 29 of the handle body 210 with respect to the length L1 (for example, a position 31.5mm away from the front end 29 of the handle body 210 when the length L1 is 180 mm) is defined as the boundary P1.

For example, in the case where the width of the portion of the neck portion from the head is the same in plan view, the width is measured while gradually changing the position toward the head in the portion of the neck portion from the head, and the position at which the portion having the same width and the portion whose width starts to increase is changed is defined as the boundary P1. In addition, in the case where the width of the portion of the neck portion from the head portion becomes narrower as it approaches the head portion in the 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 position at which the width is smallest is taken as the boundary P1.

The deflection a (unit is mm) of the head 22 is measured as follows.

As shown in fig. 4A, the toothbrush 21 is fixed by a jig 2100 at a position of a narrowest part of the neck (boundary P1) so that the bristle surface 220 faces upward in the vertical direction. At this time, the height H is set to the height of the front end 29 of the handle body 210 as a reference height H₀。

Then, as shown in FIG. 4B, a weight 2102 of 200g was suspended at the position S, and the height of the tip 29 of the handle body 210 after 10 seconds was measured and taken as H₁. The S is: the length L4 (fig. 3A) of the head 22 in the longitudinal direction of the implanted portion is 10 ± 3% from the distal end of the implanted portion. For example, when the implanted portion is 19mm, S is a position 2.0mm away from the tip of the implanted portion.

Next, H is reacted with₁And H₀The absolute value of the difference is determined as a' (unit is mm). The a' may be measured by an altimeter or the like, for example. The assay was performed at 25. + -. 3 ℃ at room temperature.

The measurement was performed 5 times, and the average value of the displacement amounts a' was defined as the deflection amount a of the head 22.

The deflection 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 A is preferably 0.5 to 3.0, more preferably 0.5 to 2.5, and still more preferably 0.5 to 2.0. When the deflection amount a is within the above range, the head 22 itself is appropriately deflected, the implanted part implanted in the head 22 is soft, and the feeling of contact with the gum, i.e., the feeling of use, is further improved. When the deflection amount a is equal to or greater than the lower limit, the feeling of use is good. If the deflection amount a is equal to or less than the upper limit value, sufficient strength can be easily secured in the head 22. Further, toothbrush 21 is not too weak, and good oral cavity operability and cleaning force are easily obtained.

The amount of deflection a can be adjusted by adjusting the flexural modulus of the material of the head (i.e., the material of the handle body), the thickness, width, and the like of the head.

(deflection amount of neck B)

The amount of deflection B (in mm) of the neck portion was measured by the following method (β).

Method (β):

the bristle-implanted surface of the head is directed upward in the vertical direction, and the height of the distal end of the handle body in a state in which the position of the boundary between the neck and the handle of the toothbrush is fixed is set as a reference height. In the fixed state, a 200g hammer was suspended at a position 50 ± 3% away from the tip of the implanted part in the head part with respect to the length of the implanted part in the longitudinal direction, and the amount of displacement (in mm) in height from the reference height of the tip of the handle body after 10 seconds was used as the amount of deflection B of the neck part.

The boundary P2 between the neck and the handle is: the end point of the expansion of the neck portion, that is, the end point of the straight line forming the both edges of the widened portion or the position where the bending direction of the curve forming the both edges of the widened portion changes in plan view. In fig. 3A, it is: starting from a straight line or a curved line R2 forming both edges of the portion with a widened width in a plan view of the neck portion and the grip portion, there is changed a position of a curved line with a gradually narrowed width.

However, the position of the boundary P2 may be difficult to determine, for example, in a toothbrush in which the neck and the grip portion are formed to have the same width. At this time, a position apart from the front end 29 of the handle body 210 by 42.2% with respect to the length L1 (for example, a position apart from the front end 29 of the handle body 210 by 76.0mm when the length L1 is 180 mm) is defined as the boundary P2.

The deflection amount B of the neck portion 24 of the toothbrush 21 is measured in the same manner as the deflection amount a of the head portion 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 from the method of measuring the deflection amount a of the head portion 22.

In the measurement of the deflection B of the neck 24, the position where the toothbrush 21 is fixed by the jig 2100 is the boundary P2. Further, S is: the distance between the tip of the implanted part and the longitudinal length of the implanted part is 50 + -3%. For example, when the implanted portion is 19mm, S is a position 9.5mm away from the tip.

Then, the reference height H before the suspension weight 2102 is obtained in the same manner as the method of measuring the deflection a of the head₀And the height H of the suspension weight 2102 after 10 seconds₁Absolute value of the difference (in mm). The assay was performed at 25. + -. 3 ℃ at room temperature. This measurement was performed 5 times, and the average value thereof was defined as the deflection amount B of the neck portion 24.

The deflection B is preferably 2.1 to 5.0, more preferably 2.3 to 4.5, and still more preferably 2.5 to 4.0. When the deflection amount B is within the above range, the neck portion is deflected appropriately, and an appropriate cushioning property is exhibited, so that the contact feeling of the implanted portion with respect to the gum becomes better. When the deflection B is not less than the lower limit value, the bristles can reach the corners of the oral cavity such as the deep portions of the molars, and the cleaning power in the oral cavity can be further improved. Further, the penetration of the brush into the periodontal pocket is improved, and the cleaning power of the periodontal pocket is further improved. If the deflection B is less than the upper limit, the strength of the neck portion is easily suppressed from decreasing. Further, toothbrush 21 does not become too weak, and a good feeling of use is easily obtained.

The amount of deflection B can be adjusted by adjusting the flexural modulus of the material of the neck portion (i.e., the material of the handle body), the minimum diameter of the neck portion, the cross-sectional shape of the boundary P2, and the like.

The product (A x B) of the value of the deflection A of the head and the value of the deflection B of the neck is 0.8 to 10, preferably 1 to 10, more preferably 1 to 6, and still more preferably 1 to 3.5. Further, (A × B) is preferably 2 to 10. (A B) if within the ranges, a coordinated moderate flexure of the head 22 and neck 24 may be obtained. Thus, when the implanted part is slid with respect to the part to be cleaned (tooth, gum, etc.), the implanted part exhibits softness and cushioning properties, and the contact feeling of the implanted part becomes good. The lower limit of (a × B) is 0.8 or more, preferably 1 or more. Further, 2 or more is preferable. When (a × B) is not less than the lower limit, appropriate deflection is obtained, and a good contact feeling with the gum is obtained, and a high massaging effect with respect to the gum is obtained, thereby improving a feeling of use. The upper limit of (a × B) is 10 or less, preferably 6 or less, and more preferably 3.5 or less. By setting (a × B) to the upper limit or less, the region formed by the head portion 22 and the neck portion 24 is not excessively bent, and a decrease in operability and a decrease in cleaning force can be suppressed. Further, it is possible to suppress a decrease in the massaging effect on the gums due to the excessive deflection and a feeling of weakness when the user uses the toothbrush 21. Further, the strength of the toothbrush 21 is improved, and the durability is improved.

The values of the deflection A and the deflection B are preferably A < B. When A < B, the operability of toothbrush 21 is further improved.

The difference (B-a) between the value of the deflection a and the value of the deflection B is preferably 1 or more, preferably 1.5 or more, and more preferably 2 or more. (B-a) when the value is equal to or higher than the lower limit value, the deflection of the neck portion 24 is kept large relative to the head portion 22, the cushioning is improved, the contact feeling to the gum is good, and the user can easily feel the massage effect to the gum.

Further, (B-a) is preferably 4 or less, more preferably 3 or less. If (B-a) is equal to or less than the upper limit value, the amount of deflection of the neck portion 24 relative to the head portion 22 does not become excessively large, and oral operability is easily improved. Further, the user can easily feel soft when using the toothbrush 21.

(B-A) is preferably 1 to 4, more preferably 1 to 3.

Further, the ratio (B/A) of the value of the deflection B to the value of the deflection A is preferably 1.5 to 5.0, more preferably 1.8 to 4.8.

The handle portion 26 is held while the toothbrush 21 is used. The grip portion 26 may be grasped or held by a pen, without particular limitation. In either of the holding methods, the grip portion 26 is held by touching the thumb or the like near the neck rear end boundary P2, because cleaning is usually performed while applying pressure to the target region.

Then, the head 22 is inserted into the oral cavity, and the bristle planting portion is slid on the cleaning target portion while pressing the grip portion 26. The force applied to the grip portion 26 is transmitted to the head portion 22 through the neck portion 24, and further transmitted from the head portion 22 to the flocked portion, whereby the flocked portion cleans while applying pressure to the cleaning target portion. In this case, when the product (A x B) of the value of the deflection A of the head and the value of the deflection B of the neck is 0.8 to 10, a moderate deflection in cooperation between the head and the neck can be obtained. As a result, the bristles implanted into the head 22 of the toothbrush 21 can easily reach the corner corners in the oral cavity such as the deep side of the molar teeth, and the oral cavity cleaning power is improved. Further, the bristles are easily inserted into the periodontal pocket, and the cleaning power of the periodontal pocket is improved. Further, since appropriate deflection can be obtained, the softness and cushioning property of the implanted part are improved, the contact feeling of the implanted part to the gum becomes good, a good massage effect to the gum can be obtained, and the feeling of use is improved.

[ examples ]

The present invention will be described in detail below with reference to examples, but the present invention is not limited to the following examples, and can be modified and implemented as appropriate within a range not departing from the gist thereof.

The toothbrushes of examples 1 to 6 and comparative examples 1 to 2 were produced by injection molding in accordance with the specifications shown in table 1. In the above toothbrush, the width, length, thickness and shape of the handle portion are all the same. The resins shown in table 1 were injection-molded to obtain an integrally molded product of the head, neck, and grip portions shown in fig. 1 and 2. The arrangement of the implanted holes is 3 × 1 rows, 4 × 6 rows, and 3 × 1 rows from the tip of the head toward the neck. The width and length of the head are shown in table 1. A bundle of tapered bristles (7.5mil) formed of filaments made of PBT was implanted into the head by flat-line tufting to manufacture a toothbrush.

The evaluation items of each sample include 2 items of intraoral operability and handle operability, and "excellent" for intraoral operability is "◎", "excellent" for "○", "slightly inferior" for "△", and "slightly inferior" for "x", and similarly, for handle operability, the "excellent" for "◎", the "excellent" for "○", the "slightly inferior" for "△", and "slightly inferior" for "x".

[ Table 1]

As shown in table 1, the grip center angle θ and the grip center height h of the toothbrush of comparative example 1 were out of the numerical ranges of the present invention. That is, the toothbrush of comparative example 1 has a handle body having a shape relatively close to a straight line. Thus, it was confirmed that: the toothbrush of comparative example 1 was inferior in oral cavity operability and handle operability. Further, the toothbrush of comparative example 2 has a head thickness t, a minimum width W1 of the neck, and a minimum thickness D1 of the neck out of the numerical ranges of the present invention. Thus, it was confirmed that: the toothbrush of comparative example 2 had poor oral operability.

In contrast, the toothbrushes of examples 1-6 all had head thickness t, minimum neck width W1, minimum neck thickness D1, grip center point angle θ, and grip center point height h that were all within the numerical range of the present invention. Thus, it was confirmed that: the toothbrush is excellent in both oral operability and handle operability even when the neck is bent.

In general, when flat wire flocking is used, pressure due to the striking of the flat wire is applied to the head. When the head is thin, the strength against deformation at the time of application of force is low, while when the neck is thick and the strength is high, the pressure at the time of brushing is concentrated on the head, and the deflection of the head becomes large, and usability may be deteriorated. At this time, as in the toothbrush 1 of the present embodiment, by making the neck part thin and maintaining a certain degree of flexibility, the pressure during brushing can be dispersed from the head part to the entire neck part, and usability can be improved. Therefore, in the case of the flat-wire type flocking, the effect of the present invention can be obtained particularly remarkably.

Claims

1. A toothbrush is provided with:

comprises a hair-planting part of a plurality of bundles of hairs planted by flat line type hair-planting,

the hair-planting surface is provided with a head part of the hair-planting part,

a neck portion extending to the head portion,

a handle part extending to the neck part,

it is characterized in that the preparation method is characterized in that,

the thickness of the head part is more than 2.0mm and less than 4.0mm,

the minimum width and the minimum thickness of the neck part are more than 3.0mm and less than 4.5mm,

a curved surface having a circular arc contour whose center is arranged on the hair-planted surface side and whose hair-planted surface side is concave in a side view is formed on the hair-planted surface side of the rear end side of the neck portion,

the distance between the thickness direction central point of the handle part at the holding central position of the toothbrush and the plane forming the bristle implanting surface is more than 6.0mm and less than 12.0mm,

the product of the value of the deflection A in mm of the head portion measured by the following method α and the value of the deflection B in mm of the neck portion measured by the following method β is 0.8 to 10,

α is a method comprising the steps of directing the bristle face of the head vertically upward, setting the height of the tip of the handle body as a reference height in a state where the position of the boundary P1 between the head and the neck of the toothbrush is fixed, suspending a 200g weight at a position 10 + -3% away from the tip of the bristle part in the longitudinal direction of the head with respect to the length of the bristle part in the longitudinal direction in a state where the position of the boundary P1 is fixed, and setting the amount of displacement of the height in mm of the tip of the handle body after 10 seconds from the reference height as the amount of deflection A of the head;

β method comprises directing the bristle-implanted surface of the head upward in the vertical direction, setting the height of the front end of the handle body in a state where the boundary between the neck and the handle of the toothbrush is fixed as a reference height, suspending a hammer of 200g at a position 50 + -3% away from the front end of the bristle-implanted part with respect to the length in the longitudinal direction of the bristle-implanted part in the head in the fixed state, setting the amount of displacement of the height in mm of the front end of the handle body after 10 seconds from the reference height as the amount of deflection B of the neck,

the deflection B is 2.1 to 5.0 mm.

2. The toothbrush of claim 1, wherein the deflection A is 0.5-2.0 mm.

3. The toothbrush of claim 1 or 2, wherein the deflection B is 2.1-4.0 mm.

4. The toothbrush according to claim 1 or 2, wherein an angle formed by a straight line connecting a thickness direction center point of the handle portion at a grip center position of the toothbrush and a thickness direction center point of the head portion at a center position of the bristle-implanted portion and a plane constituting the bristle-implanted surface is 5.0 degrees or more and 10.0 degrees or less.

5. The toothbrush according to claim 1 or 2, wherein a ratio of the value of the deflection B in mm to the value of the deflection A in mm, i.e., B/A, is 1.5 to 5.0.

6. The toothbrush according to claim 1 or 2, wherein a product of the value of the deflection A in mm and the value of the deflection B in mm is 0.8 to 3.5.

7. The toothbrush according to claim 4, wherein an angle formed by a straight line connecting a thickness direction center point of the handle portion at a grip center position of the toothbrush and a thickness direction center point of the head portion at a center position of the bristle-implanted portion and a plane constituting the bristle-implanted surface is 6.0 degrees or more and 10.0 degrees or less.

8. The toothbrush according to claim 1 or 2, wherein the neck portion is made of a material having a flexural modulus of elasticity of 1000MPa or more and 2200MPa or less.

9. The toothbrush according to claim 1 or 2, wherein the neck is formed of a polypropylene resin.