TW201731416A - 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 [theta] 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

This invention relates to a toothbrush. The present application claims priority based on Japanese Patent Application No. Hei. No. 2016-045368, filed on Jan. 09,,,,,,,,,,, The content is cited in this application.

According to Patent Document 1 to Patent Document 3, a toothbrush that reduces the thickness of the head is proposed from the viewpoint of operability in the oral cavity and the like. When the thickness of the head is made thin, a decrease in strength or the like becomes a problem. Therefore, a resin having a high strength such as a polyacetal resin (Polyoxymethylene (POM)) is used. In particular, when a flat wire made of metal is inserted into a resin-made head and the flat-line hair of the bristles is held, the planting strength and the folding strength of the head may be insufficient. [Prior Art Document] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. Hei. No. Hei. No. Hei. No. Hei.

[Problems to be Solved by the Invention] As a result of research by the inventors of the present invention, it has been found that in the toothbrush as described above, if the neck portion connecting the head portion and the handle portion is thick, damage is caused by thinning the head portion. The operability improvement effect in the oral cavity. In particular, if the width of the neck portion is made larger, the operability is further impaired, and the thinness of the head is also inconspicuous in appearance, and the impression of the product is also impaired. However, when the neck is made thinner, it may be excessively bent, and on the contrary, there is a problem in operability. In addition, the strength needs further improvement. In particular, in the case of using a general-purpose resin generally used for a toothbrush such as polypropylene (PP), the problem is more remarkable.

One aspect of the present invention has been made to solve the above problems, and an object of the invention is to provide a toothbrush having a thin head which can obtain good operability. [Means for solving the problem]

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

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

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

According to one aspect of the present invention, it is possible to realize a toothbrush having a thin head which can obtain good operability.

Hereinafter, an embodiment of the present invention will be described with reference to Figs. 1 and 2 . In addition, the following embodiment is an embodiment of the present invention, and the present invention is not limited thereto, and can be arbitrarily changed within the scope of the technical idea of the present invention. In addition, in the following drawings, in order to make each component easy to see, the scale, the number, and the like of the size may be different depending on the constituent elements.

Fig. 1 is a plan view showing a toothbrush of the embodiment. Figure 2 is a front elevational view of the toothbrush. As shown in FIGS. 1 and 2, the toothbrush 1 of the present embodiment includes a hair-planting portion 11, a head portion 12 provided with a hair-planting portion 11, a neck portion 13 extending from a proximal end side of the head portion 12, and a handle portion. 14. Extending from the proximal end side of the neck portion 13. That is, the head portion 12 is integrally formed with the neck portion 13 and the shank portion 14. Hereinafter, a member in which the head portion 12 is integrated with the neck portion 13 and the shank portion 14 is referred to as a shank body 15. In addition, in FIG. 1, the illustration of the hair-planting part 11 is abbreviate|omitted.

Here, the upper surface of the head portion 12 provided with the hair-planting portion 11 is referred to as a hair-planting surface 12a. As shown in FIG. 1 and FIG. 2, the plane P (imaginary plane) constituting the hair-planting surface 12a is set to the XY plane, the direction in which the entire body 15 is extended is set to the X-axis direction, and the direction orthogonal to the X-axis is set to Y-axis direction. The normal direction of the plane P is set to 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, and 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 component.

The handle body 15 is integrally formed into a long strip as a whole, and can be produced, for example, by injection molding a resin as a material. Examples of the constituent material of the handle body 15 include polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polybutylene terephthalate (PBT). Polycyclohexylene dimethylene terephthalate (PCT), polyacetal (POM), polyethylene naphthalate (PEN), polystyrene (PS), propylene Acrylonitrile Butadiene Styrene (ABS), Cellulose Propionate (CP), Polyarylate, Polycarbonate, Acrylonitrile Styrene (AS), etc. . Among these resin materials, materials such as POM, PBT, and PEN are preferably used in terms of high strength and easy thinning of the head.

In particular, polypropylene is generally more versatile than a resin such as polyacetal, and is easy to process and has a low cost, but has a low flexural modulus. For example, the flexural modulus of polyacetal is about 2500 MPa, whereas the flexural modulus of polypropylene is about 1500 MPa to 2000 MPa. Therefore, if it is a former material, polypropylene is a material which is difficult to use as a material of a toothbrush having a thin head and a thin neck. However, a resin having a relatively low bending elastic modulus such as polypropylene can also be used by adopting the shape of the toothbrush of the present embodiment to be described later.

In the present embodiment, the bending elastic modulus of the constituent material of the handle body 15, particularly the neck portion 13, is preferably 1000 MPa or more and 2200 MPa or less. If 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 fine. Further, when the bending elastic modulus exceeds 2,200 MPa, the hardness may increase, but it may become brittle.

The resin may be used alone or in combination of two or more. Further, part or all of the shank portion 14 of the handle body 15 may be covered with a soft resin. When a part or all of the handle portion 14 is covered with a soft resin, the user's feeling of comfort when the user grips the handle portion 14 is improved, and the gripped finger can be prevented from slipping. As the soft resin, for example, a resin having a Shore A of 90 or less is preferable, and a resin having a Shore A10 to A40 is more preferable. Examples of such a soft resin include elastomer resins such as polyolefin elastomers, styrene elastomers, polyester elastomers, and polyurethane elastomers, and the like.

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

In a plan view, the head portion 12 has a substantially quadrangular flat shape in which four top portions are formed by curves to form a chamfer. A plurality of planting holes 12h are provided on the hair-planting surface 12a which is the upper surface of the head 12. The tufting portion 11 including the plurality of tufts 17 is formed by implanting the tufts 17 formed by bundling the bristles in the respective planting holes 12h. Among the plurality of planting holes 12h, a distance d1 between the planting hole 12h on the foremost end side of the head portion 12 and the front end of the head portion 12, and a planting hole 12h at the most proximal end side of the head portion 12 and the base end of the head portion 12 The distance d2 is set to be equal. In other words, the boundary position K1 between the neck portion 13 and the head portion 12 to be described later is a position spaced apart from the neck portion 13 by a distance equal to the distance d1 from the planting hole 12h located on the most proximal end side of the head portion 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 is lowered. If the width of the head portion 12 is too small, the number of hair bundles 17 to be implanted is too small, and the cleaning effect is easily impaired. Therefore, the width of the head portion 12 is set, for example, to about 5 mm to 16 mm.

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

The shape of the planting pores 12h is not particularly limited, and may be a circle such as a perfect circle or an ellipse, or may be a polygon such as a triangle or a quadrangle. The number of the planting holes 12h is not particularly limited, and is set, for example, in the range of 10 to 60. The diameter of the planting hole 12h is determined corresponding to the thickness of the tuft 17, and is set, for example, in the range of 1 mm to 3 mm. The arrangement pattern of the planting pores 12h is not particularly limited, and may be any arrangement pattern such as a lattice shape or a zigzag shape.

Examples of the bristles constituting the tufts 17 include bristles (conical bristles) having a diameter which gradually decreases toward the apex, and bristles (straight bristles) having substantially the same outer diameter except for the circular portion of the apex. For the material of the toothbrush, for example, 6-12 nylon, 6-10 nylon, etc., PET, PBT, polytrimethylene terephthalate (PTT), PEN, polybutylene naphthalate (PBN) can be used. A polyester resin, a polyolefin such as PP, a synthetic resin material such as an olefin elastomer or a styrene elastomer. These resin materials may be used alone or in combination of two or more. Further, the bristles may be a multiple core structure having a core portion and at least one or more sheath portions provided on the outer side of the core portion.

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

The thickness of the bristles is not particularly limited. When the cross-sectional profile is circular, for example, it is set to 3 mil to 11 mil (1 mil = 1/1000 inch = 0.025 mm). The tuft may include bristles of the same thickness, and two or more bristles of different thickness may be combined. The length of the hair is not particularly limited, and is set, for example, to 6 mm to 12 mm.

As shown in Fig. 2, on the side of the hair-planting surface 12a on the distal end side of the shank portion 14, a central position is formed on the opposite side of the hair-planting surface 12a (the lower side of the shank portion 14 in Fig. 2), and is viewed from the side. A curved surface 14a of a circular arc profile convex on the side of the hair-planting surface 12a. Similarly, on the side of the distal end side of the shank portion 14 opposite to the hair-planting surface 12a, a curved surface 14b whose center position is disposed on the side opposite to the hair-planting surface 12a and which is convex on the side of the hair-planting surface 12a in the side view is formed.

Further, on the side of the hair-receiving surface 12a on the rear end side of the neck portion 13, a center position is formed on the side of the hair-planting surface 12a (the upper side of the shank portion 14 in Fig. 2), and the side of the hair-planting surface 12a is recessed in the side view. The curved surface 13a of the circular contour. Similarly, on the side of the rear end side of the neck portion 13 opposite to the hair-planting surface 12a, a curved surface 13b having a circular arc profile in which the center position is disposed on the side of the hair-planting surface 12a and recessed on the side of the hair-planting surface 12a in the side view is formed.

As the curved surface 13a and the curved surface 14a advance in the longitudinal direction of the shank portion 14, the intersection angle between the tangent line in the side view and the hair-planting surface 12a continuously changes, but at the intersection of the curved surface 13a and the curved surface 14a, the intersection angle of the tangent lines Crossing at an angle α1 of 0 degrees or not 180 degrees. Therefore, a ridge line K2 is formed at an 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, the intersection angle between the tangent line in the side view and the hair-planting surface 12a continuously changes, but at the intersection of the curved surface 13b and the curved surface 14b, the tangent lines cross each other. The angles intersect at an angle α2 of 0 degrees or not 180 degrees. Therefore, a ridge line K3 is formed at the intersection of the curved surface 13b and the curved surface 14b. Therefore, the neck portion 13 and the shank portion 14 have a curved surface 14a and a curved surface 14b which are convexly arranged on the side of the ridge line K2 and the ridge line K3 in the longitudinal direction, and which are convex on the side of the side-side lower hair-planting surface 12a, and are separated by the ridge line K2. The other side of the ridge line K3 in the longitudinal direction is connected to the curved surface 13a and the curved surface 13b of the circular arc profile which is recessed on the side of the planting surface 12a in the side view, and is formed in a substantially S-shape in a side view.

The boundary of the rear end side of the neck portion 13 is defined by the ridge line K2 and the ridge line K3. Therefore, the rear end side of the ridge line K2 and the ridge line K3 is a range in which the shank portion 14 is disposed, and the neck portion 13 is disposed in a range between the range in which the head portion 12 is disposed and the range in which the shank portion 14 is disposed.

The end portion on the side of the hair-receiving surface 12a on the distal end side of the shank portion 14 (the rear end side of the ridge line K2) becomes the finger contact portion 19. The user places the thumb on the finger contact portion 19 to hold the handle portion 14, 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 portion 13 is formed in such a shape that the position from the head portion 12 and the neck portion 13 at the boundary position K1 (the front end of the neck portion 13) slightly deviates slightly from the shank portion 14 to a small cross-sectional area, and the section is maintained. The area extends toward the rear end side, and the diameter is gradually increased to the boundary K2 with the shank portion 14 on the rear end side. As a result, the neck portion 13 gradually thickens from the side of the head portion 12 toward the side of the shank portion 14, whereby the neck portion 13 is also absorbed when the toothbrush 1 is used by various gripping or brushing methods, and the usability is excellent. However, from the viewpoint of the feeling of use, the neck portion 13 must have elasticity and be moderately bent.

Since the neck 13 contacts the lips when the head 12 is inserted into the oral cavity, the length of the neck portion 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 14. The grip center position G1 is defined as a position 37 mm away from the rear end side of the shank portion 14 from the ridge line K2.

As a gripping method of the toothbrush, it is known to hold the thumb near the finger contact portion, grasp the "palm grip" of the handle with the entire hand, and place the thumb near the finger contact portion, and hold the pen. Hold the "pen grip". The inventors of the present invention have conducted an effort to study the position at which the force is applied when the toothbrush is operated while holding various toothbrushes in each grip. As a result, it has been clarified that a part of the finger is placed at an average of 37 mm from the vertex of the finger contact portion (the position of the ridge line K2), and this portion becomes one of the centers of the operation points. Therefore, this position is defined as the grip center. Furthermore, it is also clear that the position is approximately the same as the position of the center of gravity of many general toothbrushes.

As shown in Fig. 2, the center of the thickness direction of the head portion 12 on the center portion G1 of the shank portion 14 of the toothbrush 1 and the center position S1 of the hair-planting portion 11 (see Fig. 1) The imaginary straight line of the point S2 is set to the straight line N, and the straight line N is located above the plane P (+Z direction). In other words, the handle body 15 has a shape in which the shank portion 14 having the grip center position G1 is curved more toward the hair-planting portion 11 side than the hair-planting surface 12a of the head portion 12.

The present inventors have found that in the prior toothbrush in which the handle body extends substantially linearly, if the head is made thinner and the neck is made thinner, the head or the neck is easily bent, and the planting portion is easily displaced to the head. The back side of the portion (in the case of Fig. 2, the -Z axis direction). In particular, when brushing, if the neck is bent, the hair-planting portion is displaced to the back side of the head (ie, away from the tooth or gum) than the normal position, and the force applied to the handle is difficult to be sufficiently transmitted to the hair-planting. unit. As a result, it was found that the handleability of the handle portion was remarkably lowered.

Therefore, as a result of the intensive study by the inventors of the present invention, it has been considered that the shank portion 14 side of the handle body 15 faces the planting portion 11 side more than the plane P constituting the hair-planting surface 12a as in the toothbrush 1 of the present embodiment. 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 portion 12 or the neck portion 13 can be offset by the bending of the handle body 15. As described above, according to the toothbrush 1 of the present embodiment, when the head portion 12 is made thinner and the neck portion 13 is made thinner, even if the head portion 12 or the neck portion 13 is bent, the handle operability can be favorably maintained, and the oral cavity can be realized. The toothbrush 1 is excellent in both operability and handle handling.

Hereinafter, characteristic design parameters in the toothbrush 1 of the present embodiment will be described. [Thickness t of the head] The thinner the thickness t of the head portion 12, the more the operability in the oral cavity can be improved. However, if the thickness 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 modulus, and the like. The thickness t of the head portion 12 is set in the range of 2.0 mm to 4.0 mm. The thickness t of the head portion 12 is more preferably about 2.5 mm to 3.5 mm.

[Minimum Width W1 of the Neck] The smaller the minimum width W1 of the neck portion 13 is, the more the operability in the oral cavity can be improved. However, if the thickness 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 portion 13 is set to be 3.0 mm to 4.5 mm. The minimum width W1 of the neck portion 13 is preferably about 3.5 mm to 4.3 mm.

[Minimum Thickness D1 of the Neck] The minimum thickness D1 of the neck portion 13 can be defined as the thickness of the neck portion 13 at a position where the width of the neck portion 13 becomes the smallest in the X-axis direction. In the toothbrush 1 of the present embodiment, the shape of the cross section orthogonal 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 at which the thickness becomes minimum. . However, the shape of the cross section orthogonal to the extending direction of the neck portion 13 may not necessarily be a circular shape, and may be, for example, a polygonal shape. Further, the shape of the cross section orthogonal to the extending direction of the neck portion 13 may be different depending on the position in the X-axis direction, and the position at which the width of the neck portion 13 becomes the smallest and the position at which the thickness becomes the smallest may not necessarily coincide.

Similarly to the minimum width W1 of the neck portion 13, the smaller the minimum thickness D1 of the neck portion 13, the more the oral operability can be improved. However, if the thickness 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, the bending elastic modulus, and the like. The minimum thickness D1 of the neck portion 13 is set to be 3.0 mm to 4.5 mm. The minimum thickness D1 of the neck portion 13 is preferably about 3.5 mm to 4.3 mm. In the case of this embodiment, since the cross section orthogonal to the extending direction of the neck portion 13 has a substantially circular shape, the width is the same as the thickness. That is, the minimum diameter of the neck portion 13 is preferably from 3.0 mm to 4.5 mm, more preferably from 3.5 mm to 4.3 mm.

[The distance between the head base end and the finger contact portion front end a] The base end of the head portion 12 (the boundary position K1 between the neck portion 13 and the head portion 12) and the front end of the finger contact portion 19 (the boundary between the neck portion 13 and the handle portion 14) The larger the distance a between K2), the more the hair-planting portion 11 can reach the depth in the oral cavity, and the cleaning effect can be improved up to the respective corners in the oral cavity, but the bending of the neck portion 13 becomes large. On the other hand, the smaller the distance a, the more the bending of the neck portion 13 can be reduced, but it is difficult for the hair-planting portion 11 to reach the depth in the oral cavity. Therefore, the distance a also depends on the constituent material of the handle body 15, the bending elastic modulus, and the like, and is set, for example, to about 25 mm to 70 mm.

[Current Center Point Angle θ] Hereinafter, the center point G2 in the thickness direction of the shank portion 14 on the grip center position G1 of the toothbrush 1 and the center point S2 in the thickness direction of the head portion 12 on the center position S1 of the tufting portion 11 are connected. The angle θ formed by the straight line N and the plane P constituting the hair-planting surface 12a is referred to as a grip center point angle θ.

When the grip center point angle θ is excessively large, the difference between the extending direction of the shank portion 14 and the extending direction of the head portion 12 is increased, and the operability of the shank portion 14 is lowered. Further, 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 embodiment cannot be obtained. In view of these circumstances, the grip center point angle θ is set to be 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.

[Holding Center Point Height h] The distance between the center point G2 in the thickness direction of the shank portion 14 on the grip center position G1 of the toothbrush 1 and the plane P constituting the hair-planting 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 excessively large, the difference between the extending direction of the shank portion 14 and the extending direction of the head portion 12 is increased, and the operability of the shank portion 14 is lowered. Further, if the grip center point height h is too small, the shape of the handle body 15 becomes a straight line, and the original effect of the embodiment cannot be obtained. In view of these circumstances, the grip center height h is set to be 6.0 mm or more and 12.0 mm or less. The height h of the grip center point is preferably 7.0 mm or more and 11.0 mm or less.

(Bending A of Head) The amount of bending A of the head is measured by the following method (α). Method (α): The height of the tip end of the handle body in a state in which the hair-planting surface of the head is directed upward in the vertical direction to fix the position of the boundary P1 between the head of the toothbrush and the neck is the reference height. Further, in a state where the position of the boundary P1 is fixed, a weight of 200 g is suspended at a position of 10 ± 3% from the tip end of the hair-planting portion with respect to the length in the long-axis direction of the hair-planting portion in the head portion. The amount of displacement (in mm) from the height of the front end of the handle body after 10 seconds is set as the amount of bending A of the head. In addition, the "length of the hair-planting portion in the long-axis direction" means the distance between the tip end of the planting hole located at the foremost end side and the rear end of the planting hole located at the rearmost end when the head portion is viewed from the top.

In the toothbrush having the head having a shape that is reduced in the width direction from the neck, the boundary P1 is the end point of the curve of the two edges forming the chamfer angle from the neck in the head in a plan view, that is, the chamfer is formed. The position of the curved direction of the curve changes. In addition, the "top view" means that the toothbrush is viewed from the side of the hair-planting surface of the head.

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

The boundary P1 in the toothbrush 21 is the end point of the curve of the two edges forming the chamfer angle from the neck portion 24 in the plan view shape of the head portion 22, that is, the position where the bending direction of the curve forming the chamfer angle changes. In FIG. 3A, the boundary P1 between the head and the neck is a position where a curve R1 in which the width of both edges forming the chamfered corner in the head portion 22 in the plan view is changed to a straight line forming both edges having the same width. Further, in the case of a toothbrush in which the width becomes larger as the neck faces the shank in plan view, the boundary P1 coincides with the position where the width of the head and the neck is the smallest in plan view. Further, for example, in the case where a toothbrush having the same width as the head and the neck is formed, it is difficult to specify the position of the boundary P1 in particular. In this case, with respect to the length L1, a position of 17.5% from the front end 29 of the shank 210 (for example, a position of 31.5 mm from the front end 29 of the shank 210 when the length L1 is 180 mm) is set as a boundary. P1.

For example, when the width of the portion from the head of the neck is the same in plan view, in the portion of the neck from the head, the width is measured while the position is slowly changed toward the head, and the width is the same. The position of the turning point of the portion where the width starts to become larger is set as the boundary P1. Further, when the width of the portion from the head in the neck portion is smaller as it approaches the head in a plan view, the width is measured while gradually changing the position toward the head in the portion of the neck from the head. The position where the width is minimized is set as the boundary P1.

The amount of bending A of the head 22 was measured as follows. As shown in FIG. 4A, the toothbrush 21 is made to have the hair-growing surface 220 facing upward in the vertical direction, and is fixed at the position of the neckmost portion (boundary P1) by the jig 2100. At this time, the height of the front end 29 of the handle body 210 is set as the reference height H ₀ . Then, as shown in FIG. 4B, a 200 g weight 2102 was suspended at the position of S, and the height of the front end 29 of the handle 210 after 10 seconds was measured, and the height was set to H ₁ . The S is a length L4 (Fig. 3A) with respect to the long axis direction of the hair-planting portion in the head portion 22, and is 10 ± 3% from the tip end of the hair-planting portion. For example, when the hair-planting part is 19 mm, S is a position of 2.0 mm from the front end of the hair-planting part. Then, the absolute value of the difference between H ₁ and H ₀ as a (in mm) is obtained. The a is measured, for example, by a height gauge or the like. The measurement was carried out at room temperature of 25 ± 3 °C. The measurement is performed 5 times, and the average value of the displacement amount a is set to the bending amount A of the head portion 22.

The amount of warpage A is preferably from 0.4 to 3.0, more preferably from 0.4 to 2.5, still more preferably from 0.4 to 2.0. Further, the amount of warpage A is preferably from 0.5 to 3.0, more preferably from 0.5 to 2.5, still more preferably from 0.5 to 2.0. When the amount of bending A is in the above range, the head portion 22 itself is appropriately curved, and the flexibility of the hair-planting portion implanted in the head portion 22 appears and the feeling of contact with the gums, that is, the feeling of use becomes better. In addition, when the amount of bending A is equal to or higher than the lower limit value, the feeling of use becomes good. When the amount of bending A is equal to or less than the upper limit value, it is easy to ensure sufficient strength in the head portion 22. Further, the toothbrush 21 does not become too soft, and it is easy to obtain good oral operability and cleaning power. Further, the amount of bending A is adjusted by adjusting the bending elastic modulus of the material of the head (that is, the material of the handle), the thickness and width of the head, and the like.

(Bending amount B of the neck) The amount of bending B of the neck is measured by the following method (β). Method (β): The height of the tip end of the handle body in a state in which the hair-planting surface of the head is directed upward in the vertical direction to fix the position of the neck of the toothbrush and the shank is the reference height. In the fixed state, and further, with respect to the length in the long axis direction of the hair-planting portion in the head, a weight of 200 g is suspended at a position of 50 ± 3% from the front end of the hair-planting portion, and after 10 seconds The amount of displacement (in mm) of the height of the tip end of the handle from the reference height is defined as the amount of bending 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 bending direction of the curve forming the both edges of the widened portion in plan view s position. In the case of FIG. 3A, in a plan view of the neck portion and the shank portion, a straight line or a curve R2 from both edges of a portion where the width of the neck portion is increased is changed to a position where the width gradually decreases. Further, as in the case of a toothbrush in which the neck portion and the shank are formed to have the same width, it is difficult to particularly specify the position of the boundary P2. In this case, with respect to the length L1, a position of 42.2% from the front end 29 of the shank 210 (for example, when the length L1 is 180 mm, a position of 76.0 mm from the front end 29 of the shank 210) is set as a boundary. P2.

The neck portion 24 of the toothbrush 21 is measured in the same manner as 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 of the hanging weight 2102 are different from the measurement method of the bending amount A of the head portion 22. The amount of bending 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. Further, S is a length in the longitudinal direction of the hair-planting portion, and is 50 ± 3% from the tip end of the hair-planting portion. For example, when the hair-planting portion is 19 mm, S is a position of 9.5 mm from the front end. Further, in the same manner as the method of measuring the amount of bending A of the head, the absolute value (unit: mm) of the difference between the reference height H ₀ before the suspension weight 2102 and the height H ₁ after the suspension weight 2102 has elapsed for 10 seconds is obtained. . The measurement was carried out at room temperature of 25 ± 3 °C. This measurement was performed 5 times, and the average value was made into the bending amount B of the neck part 24.

The amount of bending B is preferably from 2.1 to 5.0, more preferably from 2.3 to 4.5, still more preferably from 2.5 to 4.0. When the bending amount B is in the above range, the neck portion is appropriately curved, and moderate cushioning properties are exhibited, and the contact feeling of the hair-planting portion with respect to the gums is further improved. Further, when the bending amount B is equal to or higher than the lower limit value, the bristles can be reached at various corners in the oral cavity such as deep in the molars, and the cleaning force in the oral cavity can be further improved. Further, the entry of the toothbrush into the periodontal pocket is improved, and the cleaning force 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 strength reduction of the neck portion. Further, the toothbrush 21 does not become too soft, and it is easy to obtain a good feeling of use. Further, the amount of bending B is adjusted by adjusting the bending elastic modulus of the material of the neck (that is, the material of the handle), 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 bending A of the head and the amount of bending B of the neck is 0.8 to 10, more preferably 1 to 10, still more preferably 1 to 6, and still more preferably 1 to 3.5. Further, (A × B) is preferably 2 to 10. If (A x B) is in the range, a moderate curvature in which the head 22 and the neck 24 are coordinated can be obtained. As a result, when the hair-planting portion is slid with respect to the cleaning target portion (teeth, gum, etc.), the flexibility and cushioning property of the hair-planting portion appear, and the contact feeling of the hair-planting portion becomes good. Further, the lower limit of (A × B) is 0.8 or more, preferably 1 or more. Further, it is more preferably 2 or more. When (A × B) is at least the lower limit value, moderate bending can be obtained, whereby the contact feeling to the gums is good, and a high massage effect can be obtained for the gums, and the feeling of use is improved. The upper limit of (A × B) is 10 or less, preferably 6 or less, more preferably 3.5 or less. When (A × B) is equal to or less than the upper limit value, it is possible to suppress excessive bending of the region formed by the head portion 22 and the neck portion 24, and the operability is lowered and the cleaning force is lowered. In addition, it is possible to suppress a decrease in the massage effect on the gum caused by the excessive bending or a feeling that the user feels soft when using the toothbrush 21. Further, the strength of the toothbrush 21 can be improved and the durability can be improved.

The amount of bending A and the amount of bending B are preferably A < B. If A<B, the operability of the toothbrush 21 can be further improved. Further, the difference (B-A) between the amount of bending A and the amount of bending B is preferably 1 or more, more preferably 1.5 or more, still more preferably 2 or more. When (B-A) is at least the lower limit value, the amount of bending of the neck portion 24 is kept large with respect to the head portion 22, the cushioning property can be improved, and the contact feeling with respect to the gums is improved, and the user can easily confirm Feel the massage effect on the gums. Further, (B-A) is preferably 4 or less, more preferably 3 or less. When (B-A) is equal to or less than the upper limit value, the amount of bending of the neck portion 24 does not become excessive with respect to the head portion 22, and the operability in the oral cavity is easily improved. Further, it is easy to suppress a feeling that the user feels soft when using the toothbrush 21. (B-A) is preferably from 1 to 4, more preferably from 1 to 3. Further, the ratio (B/A) of the amount of bending B to the amount of bending A is preferably from 1.5 to 5.0, more preferably from 1.8 to 4.8.

When the toothbrush 21 is used, the handle 26 is gripped. The form of the grip handle portion 26 is not particularly limited, and may be a grasping type or a pen grip type. Usually, the object-facing portion is cleaned while applying pressure. Therefore, in any of the holding forms, the thumb portion or the like is placed near the boundary P2 of the rear end of the neck to grip the handle portion 26. Then, the head portion 22 is inserted into the oral cavity, and the shank portion 26 is pressed to slide the hair-planting portion on the cleaning target portion. The force applied to the handle portion 26 is transmitted to the head portion 22 via the neck portion 24, and is transmitted from the head portion 22 to the hair-planting portion, whereby the hair-planting portion is cleaned while applying pressure to the cleaning target portion. 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 which the head and the neck are coordinated can be obtained. As a result, it is easy to cause the bristles implanted in the head portion 22 of the toothbrush 21 to reach the respective corners of the oral cavity such as the deep part of the molars, and the cleaning force in the oral cavity can be improved. Further, it is easy to allow the bristles to enter the periodontal pocket, and the cleaning force of the periodontal pocket can be improved. Further, by obtaining moderate bending, the flexibility and cushioning property of the hair-planting portion are improved, and the contact feeling of the hair-planting portion with respect to the gums is good, and a good massage effect for the gums can be obtained, and the feeling of use can be improved.

[Examples] The present invention is not limited by the following examples, but the present invention is not limited thereto, and may be appropriately modified without departing from the spirit and scope of the invention.

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

As an evaluation item of each sample, two items of oral operability and handle operability are listed. Regarding the operability in the oral cavity, "very good" is set to "◎", "excellent" is set to "○", "slightly worse" is set to "△", and "very bad" is set to "x". Similarly, regarding handle operability, "very good" is set to "◎", "excellent" is set to "○", "slightly poor" is set to "△", and "very bad" is 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 all depart from the numerical range of the present invention. That is, the toothbrush of Comparative Example 1 has a shape in which the handle body is relatively close to a straight line. Therefore, it was confirmed that the oral cavity operability and handle handling property of the toothbrush of Comparative Example 1 were inferior. Further, the head thickness t of the toothbrush of Comparative Example 2, the minimum width W1 of the neck portion, and the minimum thickness D1 of the neck portion deviated from the numerical range of the present invention. Therefore, it was confirmed that the toothbrush of Comparative Example 2 had poor oral operability.

On the other hand, in the toothbrushes of Examples 1 to 6, the head thickness t, the neck minimum width W1, the neck minimum thickness D1, the grip center point angle θ, and the grip center point height h are all parameters. It is within the numerical range of the invention. In this way, it is confirmed that the toothbrush is excellent in both the oral cavity handling property and the handle handling property even if the neck is curved.

Usually when flat wire type hair is used, the stress generated by the flat wire is applied to the head. When the head is thin, the strength of the deformation when the force is applied is low. On the other hand, if the neck is thick and the strength is high, the stress at the time of brushing may concentrate on the head, and the curvature of the head may become large. Decreased usability. In this case, by making the neck portion thin as in the toothbrush 1 of the present embodiment and having a certain degree of flexibility, the stress during brushing can be dispersed from the head to the entire neck and used. Sexual improvement. Therefore, in the case of flat-line hair planting, the effects of the present invention can be particularly remarkable.

1, 21‧‧‧ toothbrushes
11‧‧‧Flocking Department
12, 22‧‧‧ head
12a, 220‧‧‧Flocked surface
12h, 222‧‧‧ planting pores
13, 24‧‧‧ neck
14, 26‧‧ ‧ handle
15, 210‧‧ ‧ handle body
17‧‧‧ hair bundle
19‧‧‧ finger contact
29‧‧‧ front end of the handle
13a, 13b, 14a, 14b‧‧‧ surface
2100‧‧‧ fixture
2102‧‧‧Weighing hammer
a‧‧‧The absolute value of the difference between H ₁ and H ₀
D1, d2‧‧‧ distance
D1‧‧‧ minimum thickness of the neck
G1‧‧‧ Holding center position
G2‧‧‧ center point of thickness direction of the handle
H‧‧‧holding the height of the center point
H ₀ ‧‧‧reference height
H ₁ ‧‧‧ Height
K1‧‧‧Boundary position of the head and neck
K2, K3‧‧‧ ridgeline
L1, L2, L3, L4‧‧‧ length
N‧‧‧ Straight line
P‧‧‧ plane
P1, P2‧‧‧ border
R1‧‧‧ curve
R2‧‧‧ straight line or curve
S‧‧‧ The length in the long axis direction of the hair-planting part in the head, 10 ± 3% from the front end of the hair-planting part
Central location of the S1‧‧•Flocking Department
S2‧‧‧ center point of thickness direction of the head
T2‧‧‧ thickness
t‧‧‧The thickness of the head
W1‧‧‧ minimum width of the neck
W2‧‧‧Width α1, α2‧‧‧ Angle θ‧‧‧ Holding center point angle

Fig. 1 is a plan view showing a toothbrush according to an embodiment of the present invention. Figure 2 is a side view of the toothbrush. Fig. 3A is a plan view showing a toothbrush according to an embodiment of the present invention. Fig. 3B is a side view of the toothbrush according to the embodiment of the present invention. 4A is a view for explaining a method of measuring the amount of bending of the head. 4B is a view for explaining a method of measuring the amount of bending of the head.

1‧‧‧ toothbrush

11‧‧‧Flocking Department

12‧‧‧ head

12a‧‧‧Flocking surface

13‧‧‧ neck

14‧‧‧ handle

15‧‧‧Handle

17‧‧‧ hair bundle

19‧‧‧ finger contact

13a, 13b, 14a, 14b‧‧‧ surface

The absolute value of the difference between the H ₀ and a‧‧‧H ₁

D1, d2‧‧‧ distance

D1‧‧‧ minimum thickness of the neck

G2‧‧‧ center point of thickness direction of the handle

H‧‧‧holding the height of the center point

K1‧‧‧Boundary position of the head and neck

K2, K3‧‧‧ ridgeline

N‧‧‧ Straight line

P‧‧‧ plane

S2‧‧‧ center point of thickness direction of the head

t‧‧‧The thickness of the head

Α1, α2‧‧‧ angle

Θ‧‧‧ Holding the center point angle

Claims (3)

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