TWI766856B - Toothbrush - Google Patents

Abstract

Provided is a toothbrush that is capable of ensuring operability of a handle section and operability in an oral cavity. The toothbrush 1 comprises a bristle implanting section 11, a head section 12, a neck section 13, and a handle section 14. The thickness t of the head section 12 is in range of 2.0 to 4.0 mm. Both the minimum width W1 and the minimum thickness D1 of the neck section 13 are in a range of 3.0 to 4.5 mm. When a straight line connecting the center point in the thickness direction of the handle section 14 at the center position of a grip part of the toothbrush 1 and the center point in the thickness direction of the head section 12 at the center position of the bristle implanting section 11 is expressed as straight line N, and a plane constituting a bristle implanting surface 12 is expressed as plane P, the angle θ between the straight line N and the plane P is in a range of 5.0 to 10.0 degrees. The distance h between the center point in the thickness direction of the handle section 14 and the plane P is in a range of 6.0 to 12.0 mm.

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 cited in this application.

According to Patent Documents 1 to 3, from the viewpoints of operability in the oral cavity, etc., a toothbrush having a thin head portion is proposed. When the thickness of the head portion is reduced, a decrease in strength and the like becomes a problem. Therefore, high-strength resins such as polyacetal resins (polyoxymethylene (POM)) are used. In particular, in the case of the flat-wire type hair implantation in which a metal flat wire is driven into a resin-made head and the bristles are held, the hair-implantation strength and the bending strength of the head may become insufficient. [Prior Art Document] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open No. 7-143914 [Patent Document 2] Japanese Patent Laid-Open No. 2011-4852 [Patent Document 3] Japanese Patent Laid-Open No. 2011-200296

[Problem to be Solved by the Invention] As a result of research by the present inventors, it was found that in the toothbrush as described above, if the neck portion connecting the head portion and the handle portion is thick, the thinning of the head portion is damaged. Improves the operability in the oral cavity. In particular, when the width of the neck portion is increased, the operability is further impaired, and the thickness of the head portion is not conspicuous in appearance, and the impression of the product is also impaired. However, when the neck is made thin, it may be bent excessively, which may cause problems in operability. In addition, the strength also needs to be further improved. In particular, when a general-purpose resin such as polypropylene (PP), which is generally used for toothbrushes, is used, the problem is more significant.

One aspect of this invention was made in order to solve the said subject, and one of the objective is to provide the toothbrush of the thin head part which can obtain favorable handleability. [Means of Solving Problems]

In order to achieve the object, a toothbrush according to one aspect of the present invention includes: a hair-implantation part including a plurality of hair bundles; a head part, the hair-implantation part is provided on the hair-implantation surface; a neck part is extended from the head part; and The handle part is extended on the neck; it is characterized in that: the thickness of the head is more than 2.0 mm and less than 4.0 mm, the minimum width and minimum thickness of the neck are more than 3.0 mm and less than 4.5 mm, and the A straight line connecting the thickness direction center point of the handle portion at the grip center position of the toothbrush and the thickness direction center point of the head portion at the center position of the hair-implantation portion, and a plane constituting the hair-implantation surface The formed angle is 5.0 degrees or more and 10.0 degrees or less, and the distance between the center point in the thickness direction of the shank and the plane is 6.0 mm or more and 12.0 mm or less.

In the toothbrush of 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 of one aspect of the present invention, the constituent material of the neck portion may be polypropylene resin. [Effect of invention]

According to one aspect of the present invention, it is possible to realize a toothbrush with a thin head that can obtain favorable handleability.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 and 2 . In addition, the following embodiment shows one form of this invention, It does not limit this invention, It can change arbitrarily within the range of the technical idea of this invention. In addition, in the following drawings, in order to make it easier to see each component, the scale and the number of dimensions may be different 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 hair-implanting portion 11; a head portion 12 provided with the hair-implanting portion 11; 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 13. That is, the head portion 12 is integrally formed with the neck portion 13 and the handle portion 14 . 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, in FIG. 1, illustration of the hair-implanting part 11 is abbreviate|omitted.

Here, the upper surface of the head part 12 in which the hair-implantation part 11 is provided is called the hair-implantation surface 12a. As shown in FIGS. 1 and 2 , the plane P (imaginary plane) constituting the hair-implanting surface 12 a is an XY plane, the direction in which the entire handle body 15 extends is the X-axis direction, and the direction orthogonal to the X-axis is Y-axis direction. Let the normal line direction of the plane P be the Z-axis direction. In the following description, the dimension in the Y-axis direction of each member is referred to as the width of the member, the dimension in the Z-axis direction of each member is referred to as the thickness of the member, and the dimension in the X-axis direction of each member is referred to as the member. The length of the member.

The handle body 15 is integrally formed in a long shape as a whole, and can be produced by, for example, injection molding using resin as a material. As a constituent material of the handle body 15, polypropylene (Polypropylene, PP), polyethylene terephthalate (Polyethylene terephthalate, PET), polybutylene terephthalate (Polybutylene terephthalate, PBT), polyester Polycyclohexylene dimethylene terephthalate (PCT), polyacetal (POM), polyethylene naphthalate (PEN), polystyrene (PS), propylene Nitrile-butadiene-styrene resin (Acrylonitrile Butadiene Styrene, ABS), cellulose propionate (Cellulose Propionate, CP), polyarylate, polycarbonate, acrylonitrile-styrene copolymer resin (Acrylonitrile Styrene, AS), etc. . Among these resin materials, materials such as POM, PBT, and PEN are preferably used in terms of high strength and ease of thinning the head.

In particular, compared with resins such as polyacetal, polypropylene generally has the properties of high versatility, easy processing, and low cost, but a low flexural modulus of elasticity. For example, the flexural modulus of elasticity of polyacetal is approximately 2500 MPa, whereas the flexural modulus of elasticity of polypropylene is approximately 1500 MPa to 2000 MPa. Therefore, in the past, polypropylene was a material that was difficult to use as a material for a toothbrush with a thin head and a thin neck. However, by adopting the shape of the toothbrush of the present embodiment to be described later, it is also possible to use a resin having a relatively low flexural modulus of elasticity, such as polypropylene.

In the present embodiment, the bending elastic modulus of the material constituting the handle body 15, particularly the neck portion 13, is preferably 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 made thin. In addition, when the flexural elastic modulus exceeds 2200 MPa, although the hardness increases, it may become brittle.

As the resin, one kind of resin may be used alone, or two or more kinds of resin may be used in combination. In addition, a part or all of the handle portion 14 of the handle body 15 may be covered with a soft resin. Since a part or the whole of the handle portion 14 is covered with soft resin, the user's hand feels more comfortable when holding the handle portion 14 , and the gripping fingers can be prevented from slipping. As a soft resin, the resin of Shore A90 or less is preferably mentioned, for example, and the resin of Shore A10 to Shore A40 is more preferable. Examples of such soft resins include elastomer resins such as polyolefin-based elastomers, styrene-based elastomers, polyester-based elastomers, and polyurethane-based thermoplastic elastomers, and silicon.

The total length of the handle body 15 can be determined in relation to operability and the like. The total length of the handle body 15 is, for example, about 100 mm to 200 mm.

In plan view, the head 12 has a substantially quadrangular flat plate shape in which four tops are chamfered by curved lines. A plurality of planting holes 12h are provided on the hair planting surface 12a serving as the upper surface of the head 12 . By planting the hair bundle 17 which bundled the toothbrush bristles in each implantation hole 12h, the hair implantation part 11 containing the some hair bundle 17 is formed. The distance d1 between the vegetative hole 12h located on the frontmost side of the head 12 and the front end of the head 12, and the vegetative hole 12h located on the most proximal side of the head 12 and the proximal end of the head 12 among the plurality of tufts 12h The distance d2 to this point is set to be equal. In other words, the boundary position K1 between the neck 13 and the head 12 described later is a position separated from the neck 13 by a distance equal to the distance d1 from the implant hole 12h on the proximalmost side of the head 12 .

The size of the head 12 is determined in consideration of characteristics such as operability in the oral cavity. If the width of the head portion 12 is too large, the operability in the oral cavity will decrease, and if it is too small, the number of the hair bundles 17 to be implanted will be too small, and the cleaning effect will be easily impaired. Therefore, the width of the head 12 is set to, for example, about 5 mm to 16 mm.

When the length of the head 12 is too long, the operability in the oral cavity is easily impaired, and when it is too short, the number of the hair bundles 17 to be implanted becomes too small, and the cleaning effect is easily impaired. Therefore, the length of the head part 12 is set in the range of 10 mm - 33 mm, for example.

The shape of the implanted pores 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 and a quadrangle. The number of the vegetative pores 12h is not particularly limited, but is set within the range of 10 to 60, for example. The diameter of the planting hole 12h is determined according to the thickness of the hair bundle 17, and is set within a range of, for example, 1 mm to 3 mm. The arrangement pattern of the implanted pores 12h is not particularly limited, and may be any arrangement pattern such as a so-called lattice shape and a zigzag shape.

As toothbrush bristles constituting the bristle bundle 17 , toothbrush bristles (tapered bristles) whose diameters gradually decrease toward the bristle tip, and toothbrush bristles (straight bristles) having substantially the same outer diameter except for the circular portion of the bristle tip can be mentioned. For example, the material of the toothbrush bristles can be used: polyamides such as 6-12 nylon and 6-10 nylon, PET, PBT, polytrimethylene terephthalate (PTT), PEN, polybutylene naphthalate (PBN) Such as polyester, PP and other polyolefins, olefin-based elastomers, styrene-based elastomers and other synthetic resin materials. These resin materials may be used alone or in combination of two or more. Moreover, the multiple core structure which has a core part and a sheath part provided in the outer side of a core part at least 1 layer or more may be sufficient as toothbrush bristles.

The cross-sectional profile of the toothbrush bristles is not particularly limited, and examples thereof include circles such as perfect circles and ellipses, polygons such as triangles, quadrilaterals, pentagons, and hexagons, star shapes, three-leaf clover shapes, and four-leaf clover shapes. shape etc.

The thickness of the toothbrush bristles is not particularly limited, but when the cross-sectional profile is circular, it is, for example, 3 mil to 11 mil (1 mil=1/1000 inch=0.025 mm). The bristle bundle may contain the toothbrush bristles of all the same thickness, and may combine two or more types of toothbrush bristles with different thicknesses. The hair length is not particularly limited, but is set to, for example, 6 mm to 12 mm.

As shown in FIG. 2 , on the side of the hair-implantation surface 12 a on the distal end side of the shank portion 14 , a center position is formed on the opposite side to the hair-implantation surface 12 a (lower side than the shank portion 14 in FIG. 2 ), and viewed from the side The curved surface 14a of the circular arc profile convex on the hair-implantation surface 12a side. Similarly, a curved surface 14b having a center position opposite to the hair-implantation surface 12a and raised on the side of the hair-implantation surface 12a in side view is formed on the opposite side to the hair-implantation surface 12a on the distal end side of the shank 14 .

In addition, on the hair-implantation surface 12a side on the rear end side of the neck portion 13, a center position is formed on the hair-implantation surface 12a side (upper side of the shank portion 14 in FIG. 2 ), and the hair-implantation surface 12a side is recessed in a side view. The curved surface 13a of the arc profile. Similarly, on the rear end side of the neck portion 13 opposite to the hair-implantation surface 12a, there is formed a curved surface 13b with an arcuate profile having a center position on the hair-implantation surface 12a side and concave on the hair-implantation surface 12a side in side view.

As the curved surface 13a and the curved surface 14a advance in the longitudinal direction of the shank portion 14, respectively, the intersection angle between the tangent line and the hair-implanted surface 12a in side view changes continuously, but at the intersection of the curved surface 13a and the curved surface 14a, the intersection angle between the tangent lines Cross at an angle α1 of 0 degrees or not 180 degrees. Therefore, the ridgeline K2 is formed in the intersection of the curved surface 13a and the curved surface 14a.

As the curved surface 13b and the curved surface 14b also advance in the longitudinal direction of the shank portion 14, respectively, the intersection angle between the tangent line and the hair-implanted surface 12a in side view changes continuously, but at the intersection of the curved surface 13b and the curved surface 14b, the tangent lines intersect each other. The angles intersect at an angle α2 of 0 degrees or not 180 degrees. Therefore, the ridgeline K3 is formed in the intersection of the curved surface 13b and the curved surface 14b. Therefore, the neck portion 13 and the shank portion 14 are formed from the curved surface 14a and the curved surface 14b of the circular arc profile convex on the side of the hair-implantation surface 12a in the side view across the ridgeline K2 and the ridgeline K3 in the longitudinal direction, and are separated from the ridgeline K2 and the ridgeline K3. The other side in the longitudinal direction of the ridge line K3 is connected to the curved surface 13a and the curved surface 13b of the circular arc profile recessed on the side of the hair-implantation surface 12a in a side view, thereby forming a substantially S-shape in a side view.

The boundary on the rear end side of the neck portion 13 is defined by the ridgeline K2 and the ridgeline K3. Therefore, the rear end side of the ridgeline K2 and the ridgeline K3 is the range where the shank portion 14 is arranged, and the neck portion 13 is arranged in the range between the range where the head portion 12 is arranged and the range where the shank portion 14 is arranged.

The end portion (on the rear end side from the ridge line K2 ) on the side of the hair-implantation surface 12 a on the front end side of the shank portion 14 becomes the finger contact portion 19 . The user holds the handle 14 by placing the thumb on the finger contact portion 19, whereby the toothbrush 1 can be stably operated.

The neck 13 integrally connects the head 12 with the handle 14 . As an example, the neck 13 is formed into a shape such that a position slightly deviated from the shank 14 from the boundary position K1 (the front end of the neck 13 ) of the head 12 and the neck 13 is thinnest and has a small cross-sectional area, and the cross-section is maintained. The area extends toward the rear end side, and gradually expands in diameter on the rear end side until the boundary K2 with the shank portion 14 . In this way, the neck 13 is gradually thickened from the head 12 side toward the handle portion 14 side, so that when the toothbrush 1 is used by various gripping methods or brushing methods, the bending of the neck portion 13 is absorbed, and the usability is excellent. However, from the viewpoint of the feeling of use, the neck portion 13 needs to have elasticity and be properly curved.

Since the neck 13 contacts the lips when the head 12 is inserted into the oral cavity, the length of the neck 13 is preferably 25 mm to 70 mm.

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 from the rear end side of the handle portion 14 from the ridge line K2.

As a method of holding a toothbrush, there are known "palm grip" in which the thumb is placed near the finger contact portion and the handle is grasped with the entire hand, and the thumb is placed near the finger contact portion and grips the pen. The "pen grip" to hold. The inventors of the present invention have made intensive studies on the position where force is applied when operating the toothbrush when various toothbrushes are held by each grip method. As a result, it was confirmed that a part of the finger was placed at an average position of 37 mm from the vertex of the finger contact portion (position of the ridge line K2 ), and this portion became one of the centers of the operation points. Therefore, this position is defined as the grip center. Furthermore, it is also clear that this position roughly corresponds to the position of the center of gravity of many general toothbrushes.

As shown in FIG. 2 , when 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 of the head portion 12 at the center position S1 (see FIG. 1 ) of the hair-implanted portion 11 Assuming that the imaginary straight line at the point S2 is the straight line N, the straight line N is positioned above the plane P (+Z direction). In other words, the handle body 15 has a shape in which the handle portion 14 having the grip center position G1 is bent so as to be closer to the hair-implantation portion 11 side than the hair-implantation surface 12a of the head portion 12 .

The inventors of the present invention have found that in a conventional toothbrush in which the handle body extends substantially linearly, if the head portion is made thinner and the neck portion is made thinner, the head portion or the neck portion tends to bend, and the hair-implanted portion tends to move to the head. The back side of the part (in the case of Fig. 2, it is the -Z axis direction). In particular, when the neck is bent during toothbrushing, the hair-implanted portion is displaced to the back side of the head (ie, away from the teeth or gums) than usual, making it difficult to transmit the force applied to the handle to the hair-implantation sufficiently. department. As a result, it was found that the operability of the handle portion was significantly reduced.

Therefore, as a result of diligent research conducted by the present inventors, the inventors have come up with the idea that, as in the toothbrush 1 of the present embodiment, the handle portion 14 side of the handle body 15 is oriented toward the hair-implantation portion 11 side rather than the plane P constituting the hair-implantation surface 12a. By bending, and further optimizing parameters such as the angle θ formed by the straight line N and the plane P, the bending of the head 12 or the neck 13 can be offset by the bending of the handle body 15 . In this way, according to the toothbrush 1 of the present embodiment, when the head 12 is made thinner and the neck 13 is made thinner, even if the head 12 or the neck 13 is bent, the handle operability can be maintained favorably, and it is possible to achieve an intraoral The toothbrush 1 which is excellent in both operability and handle operability.

Hereinafter, characteristic design parameters in the toothbrush 1 of this embodiment are demonstrated. [Thickness t of the head portion] The thinner the thickness t of the head portion 12, the more the operability in the oral cavity can be improved, but if it is too thin, the strength of the head portion 12 tends to be insufficient. Therefore, 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 coefficient, and the like. The thickness t of the head portion 12 is set within 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 of neck portion] The smaller the minimum width W1 of the neck portion 13 is, the more the operability in the oral cavity can be improved, but when 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 elasticity coefficient, 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 13 can be specified as the thickness of the neck 13 at the position where the width of the neck 13 becomes the smallest in the X-axis direction. That is, in the toothbrush 1 of the present embodiment, the shape of the cross section perpendicular to the extending direction of the neck portion 13 is substantially circular, and the position where the width of the neck portion 13 becomes the smallest in the X-axis direction coincides with the position where the thickness becomes the smallest . However, the shape of the cross section orthogonal to the extending direction of the neck portion 13 may not necessarily be circular, and may be polygonal, for example. In addition, the shape of the cross section perpendicular to the extending direction of the neck 13 may vary depending on the position in the X-axis direction, and the position where the width of the neck 13 becomes the smallest and the position where the thickness becomes the smallest may not necessarily match.

Similar to the minimum width W1 of the neck portion 13 , the smaller the minimum thickness D1 of the neck portion 13 is, the more 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 coefficient. The minimum thickness D1 of the neck 13 is set to 3.0 mm to 4.5 mm. The minimum thickness D1 of the neck 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, more preferably 3.5 mm to 4.3 mm.

[Distance a between the base end of the head and the tip of the finger contact portion] The base end of the head 12 (the boundary position K1 between the neck 13 and the head 12 ) and the tip of the finger contact 19 (the boundary between the neck 13 and the handle 14 ) The larger the distance a between K2) is, the deeper the hair-implanted portion 11 can reach in the oral cavity, and the cleaning effect can be improved to every corner in the oral cavity, but the curvature of the neck portion 13 increases. On the other hand, as the distance a is smaller, the curvature of the neck portion 13 can be reduced, but it is difficult for the hair-implanted portion 11 to reach the deep inside the oral cavity. Therefore, the distance a also depends on conditions such as the constituent material of the handle body 15 and the bending elasticity coefficient, and is set to, for example, about 25 mm to 70 mm.

[Grip Center Point Angle θ] Hereinafter, 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 hair planting portion 11 are connected The angle θ formed by the straight line N and the plane P constituting the hair-implanting surface 12a is referred to as the 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 decreases. In addition, if the grip center point angle θ is too small, the shape of the handle body 15 becomes a straight line, and the original effect of the present embodiment cannot be obtained. Taking these circumstances 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] The 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 hair-implantation surface 12a is defined as the grip center point height h.

Similarly to the grip center point angle θ, if the grip center point height h is too large, the difference between the extension direction of the handle portion 14 and the extension direction of the head portion 12 increases, and the operability of the handle portion 14 decreases. In addition, if the height h of the grip center point is too small, the shape of the handle body 15 becomes a straight line, and the original effect of the present embodiment cannot be obtained. Taking these circumstances into consideration, the grip center point height h is set to 6.0 mm or more and 12.0 mm or less. The height h of the grip center point is more preferably 7.0 mm or more and 11.0 mm or less.

(Amount of curvature A of the head) The amount of curvature A of the head was 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 used as a reference height. Furthermore, in a state where the position of the boundary P1 was fixed, a weight of 200 g was suspended at a position of 10±3% from the front end of the hair-implantation part with respect to the length of the hair-implantation part in the head in the long-axis direction. , and the displacement amount (unit is mm) of the height of the front end of the handle body from the reference height after 10 seconds is defined as the bending amount A of the head. In addition, the "length in the long axis direction of the hair-implantation part" refers to the distance between the front end of the tufting hole located on the most distal side and the rear end of the tufting hole located on the rearmost side in a plan view of the head.

In the toothbrush provided with the head part of the shape which reduces in the width direction from the neck part, the boundary P1 is the end point of the curve of the both edges which form the chamfer from the neck part in the head in plan view, that is, the chamfer is formed. The position where the bending direction of the curve changes. In addition, a top view means seeing a toothbrush from the hair-implantation surface side of a head.

It will be described in more detail with reference to the toothbrush 21 shown in FIGS. 3A , 3B, 4A, and 4B. The toothbrush 21 includes a head 22 that is substantially quadrangular in plan view, a neck 24 extending from the head 22 , and a handle 26 extending from the neck 24 . A hair-implanting portion (not shown) is provided in the head portion 22 . Hereinafter, the head 22 , the neck 24 and the handle 26 are collectively referred to as a handle body 210 . In a plan view, the head 22 expands in the width direction from the front end 29 toward the neck 24 , then extends with the same width, then shrinks in the width direction, and finally reaches the boundary P1 with the neck 24 . The neck 24 extends from the boundary P1 toward the shank 26 with substantially the same diameter, then expands in diameter, and finally reaches the boundary P2 with the shank 26 .

The boundary P1 in the toothbrush 21 is the end point of the curve forming both edges of the chamfered corner from the neck 24 in the plan view of the head 22, that is, the position where the bending direction of the chamfered curve changes. In FIG. 3A , the boundary P1 between the head and the neck is the position where the curve R1 of the two edges that form the chamfers in the plan view becomes smaller and the two edges of the head 22 are changed into straight lines of the same width. Moreover, in the case of the toothbrush whose width increases as the neck goes toward the handle in a plan view, the boundary P1 corresponds to the position where the width between the head and the neck in plan view is the smallest. Furthermore, for example, like a toothbrush in which the head and the neck are formed with the same width, it may be difficult to specify the position of the boundary P1 in particular. In this case, with respect to the length L1, the position of 17.5% from the front end 29 of the handle body 210 (for example, when the length L1 is 180 mm, the position of 31.5 mm from the front end 29 of the handle body 210) is set as the boundary. P1.

For example, when the width of the portion of the neck from the head in plan view is the same, the width of the portion of the neck from the head is measured while the position is gradually changed toward the head, and the width is the same. The position of the turning point between the portion where the width begins to increase and the portion where the width begins to increase is set as the boundary P1. In addition, when the width of the portion of the neck from the head becomes smaller as it approaches the head in a plan view, the width of the portion of the neck from the head is measured while gradually changing the position toward the head. The position where the width becomes the smallest is set as the boundary P1.

The bending amount A of the head 22 is measured as follows. As shown in FIG. 4A , the toothbrush 21 is fixed with the jig 2100 at the position of the thinnest part of the neck (boundary P1 ) with the bristle-implanting surface 220 facing upward in the vertical direction. At this time, let the height of the front end 29 of the handle body 210 be the reference height H ₀ . Next, as shown in FIG. 4B , the weight 2102 of 200 g was suspended at the position S, the height of the front end 29 of the handle body 210 after 10 seconds was measured, and the height was set to H ₁ . Said S is a position of 10±3% from the front end of the hair-implantation part with respect to the length L4 ( FIG. 3A ) in the long-axis direction of the hair-implantation part in the head part 22 . For example, when the hair-planting part is 19 mm, S is a position 2.0 mm from the front end of the hair-planting part. Next, the absolute value of the difference between H ₁ and H ₀ is determined as a (unit: mm). The a is measured by, for example, a height gauge or the like. Measurements were performed at room temperature 25±3°C. The measurement was performed five times, and the average value of the displacement amount a was defined as the bending amount A of the head portion 22 .

The bending 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. In addition, the bending amount 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 bending amount A is within the above-mentioned range, the head 22 itself is moderately bent, the flexibility of the hair-implanted portion implanted in the head 22 is exhibited, and the feeling of contact with the gum, that is, the feeling of use becomes better. In addition, when the bending amount A is equal to or more than the lower limit value, the usability becomes good. When the bending 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 it becomes easy to obtain favorable intraoral operability and cleaning power. Furthermore, the bending amount A is adjusted by adjusting the bending elasticity coefficient of the material of the head (ie, the material of the handle body) or the thickness and width of the head.

(Bending Amount B of Neck) The bending amount B of the neck 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 front end of the handle body in a state where the position of the boundary between the neck of the toothbrush and the handle is fixed as a reference height. In the above-mentioned fixed state, a weight of 200 g was suspended at a position of 50±3% from the front end of the hair-implanted part with respect to the length of the long-axis direction of the hair-implanted part in the head, and 10 seconds later The displacement amount (unit is mm) of the height of the front end of the handle body from the reference height is defined as the bending amount B of the neck.

The boundary P2 between the neck and the shank is the end point of the diameter expansion of the neck, that is, the end point of the straight line forming the both edges of the widened portion or the change in the bending direction of the curve forming the two edges of the widened portion in plan view. s position. 3A , it is a position where the straight line or curve R2 from both edges of the neck and the shank that forms a portion with a larger width changes into a curve whose width gradually decreases. Furthermore, like a toothbrush in which the neck portion and the handle portion are formed with the same width, it may be difficult to specify the position of the boundary P2 in particular. In this case, with respect to the length L1, a position of 42.2% from the front end 29 of the handle body 210 (for example, when the length L1 is 180 mm, a position of 76.0 mm from the front end 29 of the handle body 210) is set as the boundary. P2.

The measurement method of the bending amount A of the head 22 is the same as that of the bending amount A of the head portion, except that the position where the toothbrush 21 is fixed by the jig 2100 and the position S at which the weighing weight 2102 is suspended are different. Bending amount B. In the measurement of the bending amount B of the neck portion 24, the position where the toothbrush 21 is fixed by the jig 2100 is the boundary P2. In addition, S is the position of 50±3% from the front end of the hair-implantation part with respect to the length of the long-axis direction of the hair-implantation part. For example, when the flocked portion is 19 mm, S is a position of 9.5 mm from the tip. Then, the absolute value (unit is mm) 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 has elapsed is obtained in the same manner as in the method of measuring the amount of curvature A of the head. . Measurements were performed at room temperature 25±3°C. This measurement is performed five times, and the average value thereof is taken as the bending amount B of the neck portion 24 .

The bending amount 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 bending amount B is in the above-mentioned range, the neck portion is moderately bent, moderate cushioning properties are exhibited, and the touch feeling of the hair-implanted portion with respect to the gum becomes more favorable. Moreover, when the bending amount B is more than the said lower limit, the toothbrush bristles can be made to reach every corner in an oral cavity, such as the depth of a molar, and the cleaning force in an oral cavity can be improved further. Furthermore, the penetration of the toothbrush bristles into the periodontal pocket is improved, and the cleaning power of the periodontal pocket can be further improved. When the bending amount B is equal to or less than the upper limit value, it is easy to suppress the reduction in the strength of the neck portion. Furthermore, the toothbrush 21 does not become too soft, and it is easy to obtain a good feeling in use. In addition, the bending amount B is adjusted by adjusting the bending elasticity coefficient of the material of the neck portion (ie, 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×B) of the amount of curvature A of the head and the amount of curvature B of the neck is 0.8 to 10, more preferably 1 to 10, still more preferably 1 to 6, still more preferably 1 to 3.5. In addition, (A×B) is preferably 2 to 10. As long as (A×B) is in the above-mentioned range, an appropriate curvature of the head 22 and the neck 24 can be obtained. Thereby, when the hair-implantation part is slid with respect to the cleaning target site (teeth, gum, etc.), the flexibility and cushioning properties of the hair-implantation part are exhibited, and the touch feeling of the hair-implantation part becomes good. In addition, the lower limit of (A×B) is 0.8 or more, preferably 1 or more. Moreover, it is more preferable that it is 2 or more. When (A×B) is equal to or more than the lower limit value, a moderate curvature can be obtained, the feeling of contact with the gums is good, a high massage effect can be obtained with respect to the gums, and the feeling of use 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 upper limit, the region formed by the head portion 22 and the neck portion 24 can be prevented from being excessively curved, resulting in lowering of operability and lowering of cleaning power. In addition, it is possible to suppress the reduction of the massage effect on the gums caused by the excessive bending, or the feeling that the user feels loose when using the toothbrush 21 . Furthermore, the strength of the toothbrush 21 can be improved, and the durability can be improved.

The bending amount A and the bending amount B are preferably A<B. When A<B is satisfied, the operability of the toothbrush 21 can be further improved. In addition, the difference (BB) between the bending amount A and the bending amount B is preferably 1 or more, more preferably 1.5 or more, and still more preferably 2 or more. When (BB) is equal to or greater than the lower limit value, the amount of curvature of the neck 24 is kept large with respect to the head 22 , the cushioning properties can be improved, the feeling of contact with the gums can be improved, and the user can be easily assured Feel the massage effect on the gums. Moreover, (BB) becomes like this. Preferably it is 4 or less, More preferably, it is 3 or less. If (BB) is below the said upper limit, the bending amount of the neck part 24 will not become too large with respect to the head part 22, and it becomes easy to improve the operability in an oral cavity. Furthermore, when a user uses the toothbrush 21, it becomes easy to suppress that it feels loose. (B-A) is preferably 1-4, more preferably 1-3. In addition, the ratio (B/A) of the bending amount B to the bending amount A is preferably 1.5 to 5.0, and more preferably 1.8 to 4.8.

When using the toothbrush 21, the handle portion 26 is held. The form of the grip portion 26 is not particularly limited, and may be a grip type or a pen grip type. Usually, cleaning is performed while applying pressure to the target site, so in any of the gripping forms, the handle 26 is gripped by placing the thumb or the like in the vicinity of the boundary P2 at the rear end of the neck. Next, the head portion 22 is inserted into the oral cavity, and the hair implantation portion is slid on the cleaning target site while pressing the handle portion 26 . The force applied to the handle portion 26 is transmitted to the head portion 22 via the neck portion 24, and is further transmitted from the head portion 22 to the hair-implantation portion, whereby the hair-implantation portion performs cleaning while applying pressure to the cleaning target site. At this time, if the product (A×B) of the bending amount A of the head and the bending amount B of the neck is 0.8 to 10, an appropriate bending in harmony with the head and the neck can be obtained. As a result, the bristles implanted in the head 22 of the toothbrush 21 can be easily made to reach every corner of the oral cavity such as the depths of the molars, and the cleaning power in the oral cavity can be improved. Furthermore, the toothbrush bristles can be easily entered into the periodontal pocket, and the cleaning power of the periodontal pocket can be improved. In addition, by obtaining a moderate curvature, the flexibility and cushioning properties of the hair-implanted part are improved, the touch of the hair-implanted part to the gums becomes good, a good massage effect on the gums can be obtained, and the feeling of use can be improved.

[Examples] Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to the following Examples, and can be implemented with appropriate modifications within a range that does not deviate from the gist.

According to the specifications shown in Table 1, the toothbrushes of Examples 1 to 6 and Comparative Examples 1 to 2 were produced by the injection molding method. In the toothbrush, the width, length, thickness, and shape of the handle portion are all made the same. Various resins described in Table 1 were injection-molded to obtain an integrally molded product of the head, neck, and shank described in FIGS. 1 and 2 . The arrangement of the implanted pores was set to 3 holes×1 row, 4 holes×6 rows, and 3 holes×1 row from the front end of the head toward the neck. The width and length of the head are described in Table 1. A toothbrush was produced by planting a tuft of tapered toothbrush bristles (7.5 mil) containing PBT filaments on the head by flat-wire planting.

As evaluation items of each sample, two items of intraoral operability and handle operability are listed. Regarding intraoral operability, "Very excellent" was set to "◎", "Excellent" was set to "○", "Slightly poor" was set to "△", and "Very poor" was set to "X". Similarly, with regard to handle operability, "Excellent" was set to "◎", "Excellent" was set to "○", "Slightly poor" was set to "△", and "Very poor" was set to "X" .

[Table 1]

As shown in Table 1, the grip center point angle θ and the grip center point height h of the toothbrush of Comparative Example 1 are all out of the numerical range of the present invention. That is, the toothbrush of Comparative Example 1 has a shape with a handle body relatively close to a linear shape. Therefore, it was confirmed that the toothbrush of Comparative Example 1 was inferior in intraoral operability and handle operability. Furthermore, the head thickness t of the toothbrush of the comparative example 2, the minimum width W1 of a neck part, and the minimum thickness D1 of a neck part deviate from the numerical range of this invention. Therefore, it was confirmed that the toothbrush of Comparative Example 2 was inferior in intraoral operability.

On the other hand, the toothbrushes of Examples 1 to 6 have all parameters of the head thickness t, the minimum width W1 of the neck, the minimum thickness D1 of the neck, the angle θ of the grip center point, and the height h of the grip center point within the numerical range of the present invention. Thereby, it was confirmed that it was a toothbrush excellent in both the intraoral operability and handle operability even if the neck was bent.

Generally, when a flat wire is used for hair transplanting, the stress generated by the driving of the flat wire is applied to the head. When the head is thin, the strength against deformation when a force is applied is low. On the other hand, when the neck is thick and the strength is high, the stress during brushing may be concentrated on the head, and the bending of the head may increase, and Usability declines. In this case, by making the neck portion thinner like the toothbrush 1 of the present embodiment and making it bendable to some extent, the stress at the time of brushing can be dispersed from the head to the entire neck, and it can be used. Sexual enhancement. Therefore, in the case of the flat-line type hair planting, the effect of the present invention can be obtained particularly remarkably.

1. 21‧‧‧Toothbrush

11‧‧‧ Hair transplant

12, 22‧‧‧Head

12a, 220: Flocked surface

12h, 222: Plant pores

13, 24: Neck

14, 26: Handle

15, 210: handle body

17: Hair Bundle

19: Finger contact part

29: Front end of handle body

13a, 13b, 14a, 14b: Surfaces

2100: Fixtures

2102: Scale Hammer

a: absolute value of the difference between H ₁ and H ₀

d1, d2: distance

D1: Minimum thickness

G1: Hold the center position

G2: Center point in thickness direction

h: the height of the grip center point

H ₀ : Base height

H ₁ : height

K1: Boundary position of head and neck

K2, K3: Ridgeline

L1, L2, L3, L4: length

N: straight line

P: plane

P1, P2: Boundary

R1: Curve

R2: Straight line or curve

S: The position of 10±3% from the front end of the hair-implantation part with respect to the length in the long-axis direction of the hair-implantation part in the head

S1: Center position

S2: center point in thickness direction

T2: Thickness

t: thickness

W1: Minimum width

α1, α2: Angle

θ: Holding the center point angle

Fig. 1 is a plan view of the toothbrush according to one embodiment of the present invention. Fig. 2 is a side view of the toothbrush. 3A is a plan view of the toothbrush according to the embodiment of the present invention. 3B is a side view of the toothbrush according to the embodiment of the present invention. 4A is a diagram illustrating a method of measuring the amount of curvature of the head. FIG. 4B is a diagram illustrating a method of measuring the amount of curvature of the head.

1‧‧‧Toothbrush

11‧‧‧ Hair transplant

12‧‧‧Head

12a‧‧‧Fressed surface

13‧‧‧Neck

14‧‧‧Handle

15‧‧‧Handle

17‧‧‧hair bundle

19‧‧‧Finger contact part

13a, 13b, 14a, 14b‧‧‧Surface

a‧‧‧Absolute value of the difference between H ₁ and H ₀

d1, d2‧‧‧distance

D1‧‧‧Minimum thickness of neck

G2‧‧‧Central point in thickness direction of shank

h‧‧‧Grip center height

K1‧‧‧Boundary position of head and neck

K2, K3‧‧‧ridgeline

N‧‧‧straight line

P‧‧‧plane

S2‧‧‧Central point in the thickness direction of the head

t‧‧‧Thickness of the head

α1, α2‧‧‧angle

θ‧‧‧Grip center point angle

Claims (3)

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

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