TW201733492A - Toothbrush - Google Patents

Abstract

Provided is a toothbrush having a thin head with which good operability can be obtained. This toothbrush is provided with a head portion (110), which is disposed at the tip side and has a bristle setting surface (111) in which a bundle of bristles is set, a neck portion (120), which extends to the rear end side of the head portion, and a handle portion (130), which extends to the rear end side of the neck portion. The thickness of the head portion is 2.0-4.0 mm. The neck portion is formed in such a manner that the minimum value for the width in a direction that is parallel to the bristle setting surface and orthogonal to the longitudinal direction of the handle portion is 3.5-4.5 mm, inclusive, and the width remains constant or increases gradually from the position of said minimum value toward the rear end side. If the width at a position separated by 10 mm from the position of said minimum value in the neck portion toward the rear end side parallel to the bristle setting surface is defined as W mm and the thickness in a direction that is orthogonal to the bristle setting surface is defined as D mm, the value of D/W is 0.7-2.5, inclusive, and the coefficient of bending M (mm4) = W*D3 is 165-625 mm4, inclusive.

Description

toothbrush

This invention relates to a toothbrush. The present application claims priority from Japanese Patent Application 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 a general-purpose resin generally used for a toothbrush such as polypropylene (PP), the problem is more remarkable.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a toothbrush having a thin head which can obtain good operability. [Means for solving the problem]

According to a first aspect of the present invention, a toothbrush includes a head portion disposed on a distal end side and having a hair bundle implanted on the planting surface, and a neck portion extending from a rear end side of the head portion; a handle extending from a rear end side of the neck; the head having a thickness of 2.0 mm to 4.0 mm, the neck being parallel to the hair-planting surface and orthogonal to the longitudinal direction of the handle The minimum value of the width of the direction is 3.5 mm or more and 4.5 mm or less, and is formed in such a manner that the width becomes fixed or gradually becomes larger from the position at which the minimum value is changed to the rear end side. The width at a position parallel to the hair-planting surface and 10 mm from the rear end side is set to W mm from a position at which the minimum value is changed, and a thickness in a direction orthogonal to the hair-planting surface is set. In the case of D mm, the value obtained by D/W is 0.7 or more and 2.5 or less, and the bending coefficient M (mm ⁴ ) = W × D ³ is 165 mm ⁴ or more and 625 mm ⁴ or less.

Further, in the toothbrush according to the aspect of the invention, the neck portion is formed of a resin material, and the resin material has a bending elastic modulus of 1000 MPa or more and 2200 MPa or less.

Further, in the toothbrush according to the aspect of the invention, the neck portion is formed of a polypropylene resin. [Effects of the Invention]

In the present invention, it is possible to provide a toothbrush which can obtain good oral operability even when a general-purpose resin is used.

Hereinafter, an embodiment of a toothbrush body and a toothbrush of the present invention will be described with reference to Figs. 1 to 4 . In addition, the following embodiment is a form 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 it easy to understand each structure, the actual structure differs from the scale, the number, etc. in each structure.

1 is a plan view of a toothbrush 11. 2 is a side view of the toothbrush 11. FIG. 3 is an enlarged plan view showing the front end side of the toothbrush 11. FIG. 4 is an enlarged side view showing the distal end side of the toothbrush 11.

The toothbrush 11 of the present embodiment includes a head portion 110, a tuft 114 disposed at the front end and having a bristles, a neck portion 120 extending from the rear end side of the head portion 110, and a handle portion 130 extending from the neck portion. The rear end side of the 120 (hereinafter, the head 110 and the neck portion 120 and the handle portion 130 are collectively referred to as the handle body 12).

The handle body is integrally formed into a long strip as a whole, and is obtained, for example, by using a resin as a material and by injection molding. The material of the handle body is a resin having a bending elastic modulus (Japanese Industrial Standards (JIS) 7171) of 1000 MPa or more and 2200 MPa or less, and examples thereof include polypropylene resin (PP) and polycondensation. Aldehyde resin (POM), polystyrene resin (PS), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), acrylonitrile - Acrylonitrile Butadiene Styrene (ABS), polyarylate resin, polycarbonate resin, Acrylonitrile Styrene (AS), and the like. Among these, a polypropylene resin which is a general-purpose resin is preferable in view of the fact that the effects of the present invention are more remarkable and cost.

These resins may be used alone or in combination of two or more. Further, in order to improve the grip, a part or all of the handle may be coated with a soft resin such as an elastomer. When a soft resin such as an elastomer is used, from the viewpoint of improving the adhesion, for example, a polyolefin is preferable, and PP is more preferable.

The head portion 110 has a hair-planting surface 111 on one side in the thickness direction (hereinafter, referred to as an upper side). A plurality of planting holes 112 are formed in the planting surface 111, and a tuft 114 of bristles is implanted in the planting holes 112 (refer to FIG. 2). Furthermore, the illustration of the tuft 114 is omitted in FIGS. 1, 3, and 4.

When the distance from the outer edge of the planting hole 112 disposed at the foremost end side to the tip end of the head portion 110 is L11, the distance from the outer edge to the rear end side of the planting hole 112 disposed on the rearmost side is L11. The end portion on the rear end side of the head portion 110 in the present embodiment is defined by the position. That is, as shown in FIG. 3, the head portion 110 is disposed in a range 110A separated by a distance L11 from the outer edges of the planting holes 112 at both ends in the longitudinal direction. The position of the rear end side of the range 110A is the boundary between the head 110 and the neck 120.

The end portion on the distal end side of the handle portion 130 becomes a finger contact portion, and the end portion on the distal end side of the finger contact portion becomes a boundary between the neck portion 120 and the handle portion 130. The finger contact portion is divided by, for example, a ridge line formed on the side of the hair-receiving surface 111 on the rear end side of the neck portion 120 and the ridge line at the intersection of the surface on the side of the hair-receiving surface 111 on the distal end side of the shank portion 130, or The ridge line at the intersection of the surface on the opposite side of the hair-planting surface 111 on the rear end side of the neck portion 120 and the surface on the opposite side of the hair-planting surface 111 on the distal end side of the shank portion 130. In this case, the boundary between the neck 120 and the handle 130 is defined by the ridgeline.

In addition, when the surface on the side of the hair-receiving surface 111 on the rear end side of the neck portion 120 and the surface on the side of the hair-planting surface 111 on the distal end side of the shank portion 130 are the same surface and no ridge line is formed, it is formed at the rear end of the neck portion 120. The finger contact portion is divided by the ridge line of the intersection of the side surface in the width direction of the side and the side surface in the width direction of the front end side of the shank portion 130. In this case, the boundary between the neck 120 and the handle 130 is also defined by the ridgeline.

For example, in the side view, the shank portion 130 is formed in a substantially circular arc shape that is convex toward the hair-planting surface 111 side, and the neck portion 120 is formed in a substantially arc-shaped S-shape that is recessed toward the hair-planting surface 111 side. In the case of the handle body 12, the boundary between the neck portion 120 and the handle portion 130 is defined as follows.

On the side of the hair-planting surface 111 on the distal end side of the shank portion 130, a central position is formed on the side opposite to the hair-planting surface 111 (lower than the shank portion 130 in FIGS. 2 and 4), and the side of the hair-planting surface 111 is viewed from the side. Curved surface 133 of the raised arc profile. Similarly, on the side of the distal end side of the shank portion 130 opposite to the hair-planting surface 111, a curved surface 134 whose center position is disposed on the side opposite to the hair-planting surface 111 and which is convex on the side of the hair-planting surface 111 side in the side view is formed.

Further, on the side of the hair-receiving surface 111 on the rear end side of the neck portion 120, a central position is formed on the tufting surface 111 (above the handle portion 130 in FIGS. 2 and 4), and the side of the tufting surface 111 is viewed from the side. The curved surface 123 of the concave arc profile. Similarly, on the side of the rear end side of the neck portion 120 opposite to the hair-planting surface 111, a curved surface 124 having a circular arc profile in which the center position is disposed on the hair-planting surface 111 and recessed on the side of the hair-planting surface 111 in the side view is formed.

As the curved surface 123 and the curved surface 133 advance in the longitudinal direction of the shank portion 130, respectively, the tangential line in the side view and the intersection angle of the hair-planting surface 111 continuously change, but at the intersection of the curved surface 123 and the curved surface 133, the intersection angles of the tangent lines are mutually Cross at an angle θ1 of 0 degrees or not 180 degrees. Therefore, a ridge line 131 is formed at an intersection of the curved surface 123 and the curved surface 133.

As the curved surface 124 and the curved surface 134 also advance in the longitudinal direction of the shank portion 130, the tangential line in the side view continuously changes with the intersection angle of the hair-planting surface 111, but at the intersection of the curved surface 124 and the curved surface 134, the tangent lines cross each other. The angles intersect at an angle θ2 of 0 degrees or not 180 degrees. Therefore, a ridge line 132 is formed at an intersection of the curved surface 124 and the curved surface 134. Therefore, the neck portion 120 and the shank portion 130 have a curved surface 133 and a curved surface 134 which are convexly arranged on the side of the ridge line 131 and the ridge line 132 in the longitudinal direction, and which are convex in the side view of the lower hair-planting surface 111 side, and the ridge line 131, The other side of the ridgeline 132 in the longitudinal direction is connected to the curved surface 123 and the curved surface 124 of the circular arc profile which is recessed on the side of the tufting surface 111 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 120 is defined by the ridge line 131 and the ridge line 132. Therefore, the rear end side of the ridge line 131 and the ridge line 132 is the range 130A in which the shank portion 130 is disposed, and the neck portion is disposed in the range 120A between the range 110A in which the head portion 110 is disposed and the range 130A in which the shank portion 130 is disposed. 120.

The end portion on the side of the hair-planting surface 111 on the distal end side of the shank portion 130 (the rear end side of the ridge line 131) becomes a finger contact portion. The user places the thumb on the finger contact portion to hold the handle 130, whereby the toothbrush 11 can be stably operated. Further, the position of the ridge line 132 in the longitudinal direction of the shank portion 130 is closer to the rear end side than the ridge line 131. Therefore, as compared with the case where the position of the ridgeline 132 is located on the front end side of the ridgeline 131, the finger contact portion becomes thicker, and the operation of the toothbrush 11 can be made more stable.

The length of the handle body 12 is not particularly limited, and is, for example, 100 mm to 200 mm. The width of the head portion 110, that is, the width in the direction orthogonal to the hair-growing surface 111 and orthogonal to the longitudinal direction of the shank portion 130 (hereinafter, simply referred to as the width) is not particularly limited, and is, for example, preferably 5 mm to 16 mm, and more preferably Good for 8 mm to 12 mm. When the value is equal to or greater than the lower limit value, the area of the implanted hair bundle 114 can be sufficiently ensured, and if it is equal to or less than the upper limit value, the operability in the oral cavity can be further improved. The length of the head portion 110 is not particularly limited, and is, for example, preferably 10 mm to 33 mm, more preferably 12 mm to 28 mm. When the value is equal to or greater than the lower limit value, the area of the implanted hair bundle 114 can be sufficiently ensured, and if it is equal to or less than the upper limit value, the operability in the oral cavity can be further improved. The thickness of the head portion 110 can be determined in consideration of a material or the like, and is more preferably 2.0 mm to 4.0 mm. When the value is equal to or greater than the lower limit value, the strength of the head portion 110 can be further increased. When the value is equal to or less than the upper limit value, the reachability to the caries can be improved, and the operability in the oral cavity can be further improved.

Since the neck 120 contacts the lips when the head 110 is inserted into the oral cavity, the length of the neck 120 is preferably, for example, 25 mm to 70 mm. The width of the neck portion 120 is formed in such a manner that the position becomes the minimum value, and the rear end side is fixed or gradually enlarged. When the width of the neck portion 120 is fixed from the position at which the minimum value is changed to the position on the rear end side, the position at which the minimum value is changed is defined as the position on the most front end side. The neck portion 120 in the present embodiment is formed so as to gradually increase in width toward the rear end side from the position 121 which becomes the minimum value. The width of the neck portion 120 can be determined in consideration of the material or the like. For example, the minimum width of the neck portion 120 is preferably 3.5 mm or more and 4.5 mm or less, more preferably 3.7 mm or more and 4.3 mm or less. When the value is equal to or greater than the lower limit value, the strength of the neck portion 120 can be further increased. When the value is equal to or less than the upper limit value, the lips are easily closed, and the reachability to the molars can be improved, and the oral cavity can be further improved. Operationality.

Further, if the width in the neck portion 120 from the width becomes the minimum value, the width at the position 122 parallel to the hair-planting surface 111 and 10 mm from the rear-end side is set to W ₁ mm, and the hair is raised at the position 122. When the thickness in the direction orthogonal to the surface 111 is D ₁ mm, the value obtained by D ₁ /W ₁ is preferably 0.7 or more and 2.5 or less, more preferably 0.8 or more and 2.0 or less, and particularly preferably 0.8 or more. 1.5 or less.

When the minimum width of the neck portion 120 is 3.5 mm or more and 4.5 mm or less, when the value obtained by D ₁ /W ₁ is less than the lower limit value, the neck portion 120 is easily bent and operated when brushing. There is a possibility that the width of the neck portion 120 is increased to impair the operability, and in appearance, the thinness of the head portion 110 is inconspicuous and the possibility of the impression of the product is also impaired. On the other hand, when the value obtained by D ₁ /W ₁ exceeds the upper limit value, the thickness D ₁ becomes large, and there is a possibility that the lips are difficult to close when the occlusal surface is brushed. In addition, there is a possibility that the effect of improving the operability obtained by thinning the head 110 is impaired. Therefore, when the value obtained by D ₁ /W ₁ is 0.7 or more and 2.5 or less, it is easy to maintain the effect of improving the workability obtained by thinning the head portion 110, and it is easy to close the lips to perform brushing.

Further, it is known that when the materials are the same, the amount of bending of the rigid body is greatly affected by the "moment of inertia of area". The amount of bending is proportional to the square of the width W and the square of the thickness D. Therefore, in order to reduce the amount of bending, it is desirable to maintain the thickness D and minimize the width. For example, if the bending coefficient M (mm ⁴ )=W×D ^{3 is set} , the bending coefficient M ₀ calculated from the width W ₀ and the thickness D ₀ at the position 121 of the neck portion 120 is preferably 165 mm ⁴ or more. 625 mm ⁴ or less, more preferably 180 mm ⁴ or more, 525 mm ⁴ or less, particularly preferably 200 mm ⁴ or more and 330 mm ⁴ or less. Further, the bending coefficient M ₁ calculated from the width W ₁ and the thickness D ₁ at the position 122 of the neck portion 120 is 165 mm ⁴ or more and 625 mm ⁴ or less, more preferably 180 mm ⁴ or more and 525 mm ⁴ or less. Preferably, it is 200 mm ⁴ or more, 330 mm ⁴ or less, and more preferably 270 mm ⁴ or more and 310 mm ⁴ or less. The bending coefficient M ₂ calculated from the width W ₂ and the thickness D ₂ in the neck portion 120 is preferably 350 mm ⁴ or more and 550 at a position parallel to the hair-growing surface 111 from the position 121 and 20 mm from the rear end side. Below mm ⁴ . The bending coefficient M ₃ calculated from the width W ₃ and the thickness D ₃ in the neck portion 120 is preferably 600 mm ⁴ or more and 1500 at a position parallel to the hair-growing surface 111 from the position 121 and 30 mm from the rear end side. Below mm ⁴ . If the bending coefficient M at the position 122 is 165 mm ⁴ or more and 625 mm ⁴ or less, the brushing property of closing the lips can be improved, and the deterioration of the operability caused by excessive bending can be prevented.

The rate of change of the bending coefficient M is preferably 1.0 or more and 1.3 or less between the position 121 and the position 122. Further, the rate of change of the bending coefficient M between the position 122 and the position from the position 121 20 mm from the rear end side is preferably 1.3 or more and 1.8 or less. The rate of change of the bending coefficient M between the position from the position 121 of 20 mm from the rear end side and the position from the position 121 to the rear end side of 30 mm is preferably 1.7 or more and 3.0 or less, and more preferably 1.8 or more. , 3.0 or less. Furthermore, the rate of change is a value obtained by dividing the bending coefficient at the position on the rear end side by the bending coefficient at the position on the front end side, for example, between the position 121 and the position 122, according to the bending coefficient M _{0 at the} position 121. The value calculated as M ₁ /M ₀ with the bending coefficient M ₁ at the position 122. When the bending coefficient M and the rate of change thereof are in the above range, the operability is not lowered and the lips are easily closed to perform brushing.

The tuft 114 is a bundle of a plurality of toothbrushes. The length (hair length) from the hair-planting surface 111 to the front end of the tuft 114 can be determined in consideration of the hardness required for the tuft 114, and is, for example, 6 mm to 13 mm. All of the tufts 114 may have the same hair length or different from each other.

The thickness (hair bundle diameter) of the tuft 114 can be determined in consideration of the hardness required for the tuft 114, for example, 1 mm to 3 mm. The tufts of all the tufts 114 may have the same diameter or different from each other.

Examples of the bristles constituting the tuft 114 include a bristles (conical hairs) whose diameter gradually decreases toward the tip of the hair and sharpens the tip of the hair, and bristles whose hair diameter is substantially the same from the hair-planting surface 111 toward the apex (straight hair) )Wait. Examples of the straight hair include those in which the hair tip is substantially parallel to the hair-planting surface 111 or the hair tip is rounded into a hemisphere.

Examples of the material of the bristles include polyamines such as 6-12 nylon (6-12NY) and 6-10 nylon (6-10NY), and PET, PBT, and polytrimethylene terephthalate (PTT). Polyethylene naphthalate (PEN), polybutylene naphthalate (PBN) and other polyesters, polyolefins such as PP, polyolefin elastomers, styrene elastomers, etc. Body resin, etc. These resin materials may be used alone or in combination of two or more. Further, examples of the bristles include polyester bristles having a multi-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 shape of the bristles is not particularly limited, and may be a circular shape such as a perfect circle or an ellipse, a polygonal shape, a star shape, a three-leaf clover shape, and a four-leaf clover shape. The cross-sectional shape of all the bristles may be the same or different.

The thickness of the bristles can be determined in consideration of the material, etc., and when the cross section is circular, for example, it is set to 6 mil to 9 mil (1 mil = 1/1000 inch = 0.025 mm). In addition, a plurality of bristles having different thicknesses may be arbitrarily combined and used in consideration of feeling of use, brushing feeling, cleaning effect, durability, and the like.

The method of manufacturing the toothbrush 11 first shapes the shank 12 by injection molding. The tufts 114 are then implanted into the head 110 of the obtained handle body 12. As a method of cultivating the hair bundle 114, a hairline 114 is folded in half and a flat line sandwiched between the hair bundles 114 is inserted into the planting pores 22, whereby the flat-line hairs of the hair bundles 114 are implanted; and the molten resin which becomes the hair-planting portion is formed. a heat fusion method in which the lower end of the tuft 114 is press-fitted and fixed; after the lower end of the tuft 114 is heated to form a molten mass, molten resin is injected into the mold to form an in-mold portion of the tufting portion. Law and so on.

As described above, according to the toothbrush 11 of the present embodiment, the minimum width of the neck portion 120 is 3.5 mm or more and 4.5 mm or less, thereby ensuring that the lips are easily closed to perform brushing, and by D/ The value obtained by W is 0.7 or more and 2.5 or less, and engineering plastics such as polyacetal are self-evident, and even when a general-purpose resin such as polypropylene is used, the operability can be prevented from being lowered.

In the case of flat wire implants, the stress generated by the flat wire drive is applied to the head 110. When the head 110 is thin and the strength of the deformation when the force is applied is low, on the other hand, when the neck portion 120 is thick and the strength is high, the stress at the time of brushing is concentrated on the head portion 110, and the warpage of the head portion 110 is changed. Large and usable. On the other hand, according to the toothbrush 11 of the present embodiment, the neck portion 120 is made thin and has a certain degree of flexibility, whereby the stress at the time of brushing can be dispersed from the head portion 110 to the entire neck portion 120. And the usability is improved. Therefore, in the case of flat-line hair planting, the effects of the present invention can be particularly remarkable.

(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. 5A, 5B, 6A, and 6B 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. 5A, 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 the 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 L21, 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 L21 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. 6A, 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. 6B, 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 L24 (Fig. 5A) 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. 5A, 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 L21, a position of 42.2% from the front end 29 of the shank 210 (for example, when the length L21 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 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 palm grip 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.

[Table 1]

(Examples 1 to 5, Comparative Examples 1 to 7) According to the specifications shown in [Table 1], Examples 1 to 5 and Comparative Example 1 in which the neck portion 120 was formed were prepared. The toothbrush of Example 7. The width, length, thickness, and shape of the head and the handle are all set to be the same. The PP resin was injection-molded to obtain an integrally formed body of the head and the handle described in FIGS. 3 to 4 (the arrangement of the pores was 3 holes × 1 row, 4 holes from the front end of the head toward the handle body × 6 rows, 3 holes x 1 row. The head has a width of 10 mm, a length of 25 mm and a thickness of 3.0 mm. The length of the handle is 110 mm. The length of the neck is 48 mm). 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.

The position obtained by D/W at each position of 10 mm, 20 mm, and 30 mm from the rearmost side from the minimum position from the minimum position, by W × D The values obtained by ³ are shown in [Table 2]. In addition, the rate of change calculated from the bending coefficient of each position as described above by the value obtained by W × D ³ in each example is shown in [Table 3].

(Evaluation Method) The toothbrush of each example was evaluated by the following method as "the in-oral operability of the toothbrush (ease of movement in the mouth)". <Operationality of Toothbrush> With regard to the operability of the toothbrush, the panel of 10 people used the toothbrush of each example, and evaluated "intraoral operability" by the following evaluation criteria. The average score of the group of 10 people is 2.5 points or more, and it is set to "◎", and the average is divided into 2.0 points or more, and less than 2.5 points is set to "○", and the average is divided into 1.5 points or more and less than 2.0 points. "△", the average score is less than 1.5 points and is set to "X".

≪Evaluation benchmark ≫ 3 points: I feel very easy to move in the mouth. 2 points: I feel the ease of movement in the mouth. 1 point: I don't feel the ease of movement in the mouth. 0 points: I don't feel the ease of movement in the mouth.

[Table 2]

[Table 3] Width × thickness ³ [W × D ³ ] rate of change

As shown in Table 2, it can be confirmed that when the thickness of the head is 2.0 mm to 4.0 mm, the minimum value of the width of the neck is 3.5 mm or more and 4.5 mm or less, and the position in the neck from the position which becomes the minimum value is from the rear end side. The value obtained by D/W at a position of 10 mm is 0.7 or more and 2.5 or less, and when the bending coefficient M (mm ⁴ ) = W × D ³ is 165 mm ⁴ or more and 625 mm ⁴ or less, good results are obtained. Operational.

The present invention has been described above with reference to the accompanying drawings, and the invention is of course not limited to the examples. The various shapes, combinations, and the like of the respective constituent members shown in the above-described examples are merely examples, and various modifications can be made based on design requirements and the like without departing from the gist of the invention.

For example, in the toothbrush 11 of the above-described embodiment, the width of the neck portion 120 is gradually increased from the position which becomes the minimum width toward the rear end side, but the configuration is not limited thereto, and the same width may be used. A configuration that extends toward the rear end side. Even if the neck portion 120 is configured to extend toward the rear end side with the same width, the value obtained by D/W at a position 10 mm from the position of the rear end side from the position of the minimum width is preferably 0.7 or more and 2.5. the following.

11, 21‧‧‧ toothbrushes
12‧‧‧Handle
22‧‧‧ head
24‧‧‧ neck
26‧‧‧ handle
29‧‧‧ front end of the handle
110‧‧‧ head
110A, 120A, 130A‧‧‧Scope
111, 220‧‧‧Flocked surface
112, 222‧‧‧Pore pores
114‧‧‧ hair bundle
120‧‧‧ neck
121‧‧‧The position where the width becomes the minimum
122‧‧‧ Position parallel to the planted surface and 10 mm from the rear end side
123, 124, 133, 134‧‧‧ surface
130‧‧‧ handle
131, 132‧‧‧ ridgeline
210‧‧‧Handle
2100‧‧‧ fixture
2102‧‧‧Weighing hammer
The absolute value of the difference between the H ₀ and a‧‧‧H ₁
D‧‧‧thickness
H ₀ ‧‧‧reference height
H ₁ ‧‧‧Height of the scale hammer 2102 and after 10 seconds
L11‧‧‧ Distance from the outer edge of the planting hole on the foremost side to the front end of the head
L21, L22, L23, L24‧‧‧ length
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
T2‧‧‧ thickness
W, W1, W2‧‧‧width θ1, θ2‧‧‧ angle

Fig. 1 is a plan view showing an embodiment of the present invention and showing a toothbrush 11. FIG. 2 is a side view of the toothbrush 11. FIG. 3 is an enlarged plan view showing the front end side of the toothbrush 11. FIG. 4 is an enlarged side view showing the distal end side of the toothbrush 11. Fig. 5A is a plan view showing a toothbrush according to an embodiment of the present invention. Fig. 5B is a side view of the toothbrush according to the embodiment of the present invention. Fig. 6A is a view for explaining a method of measuring the amount of bending of the head. Fig. 6B is a view for explaining a method of measuring the amount of bending of the head.

11‧‧‧ toothbrush

110‧‧‧ head

110A, 120A, 130A‧‧‧Scope

111‧‧‧Flocking surface

112‧‧‧Pores

120‧‧‧ neck

121‧‧‧The position where the width becomes the minimum

122‧‧‧ Position parallel to the planted surface and 10mm from the rear end side

130‧‧‧ handle

131‧‧‧ ridgeline

L11‧‧‧ Distance from the outer edge of the planting hole on the foremost side to the front end of the head

W‧‧‧Width

Claims (3)

A toothbrush comprising: a head disposed on a front end side and having a tuft on the planting surface; a neck extending from a rear end side of the head; and a handle extending from the a rear end side of the neck; and the thickness of the head portion is 2.0 mm to 4.0 mm, and the width of the neck portion parallel to the hair-planting surface and orthogonal to the longitudinal direction of the shank portion The value is 3.5 mm or more and 4.5 mm or less, and is formed in such a manner that the width becomes a position from the minimum value to the rear end side fixed or gradually becomes larger, and if the self in the neck is changed to the minimum value The position is parallel to the hair-planting surface and the width at a position 10 mm from the rear end side is set to W mm, and the thickness in the direction orthogonal to the hair-planting surface is set to D mm, The value obtained by D/W is 0.7 or more and 2.5 or less, and the bending coefficient M (mm ⁴ ) = W × D ³ is 165 mm ⁴ or more and 625 mm ⁴ or less. The toothbrush according to claim 1, wherein the neck portion is formed of a resin material, and the resin material 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 portion is formed of a polypropylene resin.