CN116018109A

CN116018109A - Toothbrush with tooth brush

Info

Publication number: CN116018109A
Application number: CN202180054340.0A
Authority: CN
Inventors: 龟井诚一
Original assignee: Lion Corp
Current assignee: Lion Corp
Priority date: 2020-09-03
Filing date: 2021-09-01
Publication date: 2023-04-25
Also published as: JP2022042744A; TW202216007A; WO2022050305A1; JP7407091B2; KR20230059793A

Abstract

The present invention provides a transparent toothbrush which ensures fatigue resistance. The brush body is formed of transparent saturated polyester resin. Regarding the 1 st direction, the thickness of the head is 2mm or more and 3.8mm or less over the entire area. Regarding the 2 nd direction, the minimum width of the neck is 5.3mm or less, the position in the longitudinal direction where the neck is the minimum width is W, the 1 st-direction cross-sectional secondary wheelbase at the position W is W1, the 1 st-direction cross-sectional secondary wheelbase at the center S of the long axis direction, 1 st direction and 2 nd direction in the head is S1, and when the 1 st-direction cross-sectional secondary wheelbase at the center T of the long axis direction, 1 st direction and 2 nd direction in the grip is T1, the cross-sectional secondary wheelbase W1 is 20mm ⁴ Above, 50mm ⁴ Hereinafter, the value represented by W1/S1 is 0.9 or more and 1.9 or less, and the value represented by T1/W1 is 6 or more and 26 or less.

Description

Toothbrush with tooth brush

Technical Field

The present invention relates to toothbrushes.

The present application claims priority based on japanese patent application publication No. 2020-148309, month 3 of 2020, incorporated herein by reference.

Background

Plaque control (plaque control) is important for the prevention of dental caries and periodontal disease. Conventionally, toothbrushes have been developed which have a size of thinning the head and the neck to improve molar accessibility in order to remove plaque deep in molar teeth at a caries site.

In the development of toothbrushes having a thin head, it is noted that PP (polypropylene) is a relatively soft resin when a general-purpose resin such as PP (polypropylene) is used, and therefore, neck deflection during use is suppressed while ensuring intraoral operability. Therefore, as a countermeasure against this problem, a method of "bending behavior", "transition of width and thickness", and "bending shape" or the like, which are most appropriate in the neck region, has been reported (for example, see patent documents 1 to 3).

[ prior art document ]

[ patent literature ]

[ patent document 1] International publication WO 2017/155033

[ patent document 2] International publication No. WO 2018/079114

[ patent document 3] International publication WO 2018/079115

Disclosure of Invention

[ problem to be solved by the invention ]

Most of toothbrushes having a thin head that are currently on the market are PP or POM (polyacetal) which are opaque resins, and therefore, from the viewpoint of the difference in appearance, thinning of the head based on a transparent (transparent or translucent) resin is desired. Conventionally, polyester resins have been mainly used as transparent resins for toothbrushes, but such resins generally have a problem in terms of fatigue resistance.

Specifically, polyester resins have a characteristic that they are not found in PP, which is strong in terms of instantaneous impact but is easily broken when subjected to a relatively light force (PP itself is plastically deformed and is therefore not easily broken). Therefore, the thickness of the head portion based on the polyester resin is highly difficult to achieve.

The present invention has been made in view of the above-described problems, and an object thereof is to provide a transparent toothbrush which ensures fatigue resistance.

[ means for solving the problems ]

Since fatigue fracture generally occurs in the neck, it is important that load energy is not accumulated in the neck region in order to secure fatigue resistance. Accordingly, the present inventors have intensively studied to solve the above-described problems, and have found that the above-described problems are solved by optimizing the balance of the cross-sectional secondary wheelbase at each position of the head, neck and grip portion in order to disperse the energy over a wide range, instead of the cross-sectional shape transition (i.e., the reinforcement of the neck itself) which is used as a conventional measure for thinning, and thus have been conducted the present invention.

Specifically, according to claim 1 of the present invention, there is provided a toothbrush comprising a brush body having: a brush body formed of a transparent saturated polyester resin, a head portion located on a front end side and having a bristle surface, a grip portion located on a rear end side from the head portion, and a neck portion located between the head portion and the grip portion, wherein a thickness of the head portion is 2mm or more and 3.8mm or less in an entire region with respect to a1 st direction perpendicularly intersecting the bristle surface, a minimum width of the neck portion is 5.3mm or less in a 2 nd direction perpendicularly intersecting a long axis direction in which the brush body extends and the 1 st direction, a position where the neck portion is the minimum width in the long axis direction is set to W, a cross-sectional secondary wheelbase related to bending in the 1 st direction at the position W is set to W1, a center of the head portion in the long axis direction, the 1 st direction and the 2 nd direction is set to S, a cross-sectional secondary wheelbase related to bending in the 1 st direction is set to S, and a center of the center in the long axis direction is set to be 20 th direction is set to W1, and a cross-sectional secondary wheelbase related to bending in the 1T direction is set to T2T is set to be a center of the center in the direction is set to be 2 ⁴ Above, 50mm ⁴ Hereinafter, the value represented by W1/S1 is 0.9 or more and 1.9 or less, and the value represented by T1/W1 is 6 or more and 26 or less.

In addition, in the toothbrush according to the aspect of the present invention, when a position in the middle of the length of the bending region of the neck in the longitudinal direction as viewed from the front side which is the bristle surface side in the 1 st direction is H, and a cross-sectional secondary wheelbase related to the bending in the 1 st direction at the position H is H1, the width in the 2 nd direction at the position H is 5.5mm or less, and the cross-sectional secondary wheelbase H1 is 28mm ⁴ Above, 70mm ⁴ Hereinafter, when the position H is set as a starting point, a position 15mm away from the head side is set as Q, a position 10mm away from the grip side is set as R, a cross-sectional secondary wheelbase related to the bending in the 1 st direction at the position Q is set as Q1, and a cross-sectional secondary wheelbase related to the bending in the 1 st direction at the position R is set as R1, a value represented by H1/Q1 is 1.0 or more and 2.0 or less, and a value represented by R1/H1 is 1.7 or more and 3.0 or less.

In the toothbrush according to the aspect of the present invention, the end portion of the flexible region on the distal end side in the longitudinal direction in the front view is: when an end portion of the flexible region on the rear end side in the longitudinal direction in the front view is an end portion of the grip portion on the front end side, and an end portion of the flexible region on the rear end side in the longitudinal direction is a position I, a straight line connecting an end point on the front end side and an end point on the rear end side in the front view has an inclination of 1.9 ° or more and 6.5 ° or less with respect to the longitudinal direction, and a straight line connecting an end point on the front end side and an end point on the rear end side in the longitudinal direction has an inclination of 3.0 ° or more and 3.5 ° or less with respect to the longitudinal direction, out of contour lines connecting an end point on the front end side and an end point on the rear end side in the front view, out of contour lines connecting an end point on the front end side and an end point on the rear end side in the longitudinal direction, out of contour lines connecting an end point on the end side in the front view, is set to a position I.

In the toothbrush according to the aspect of the present invention, when the position 20mm from the rear end side to the position I is U, the distance between the center S and the position H, the position I, and the position U in the outline on the front side at the side view angle is 5mm or less, and the distance between the center S and the position H, the position I, and the position U in the outline on the rear side at the side view angle is substantially straight.

In the toothbrush according to the aspect of the present invention, the outer contour line of the side view angle is formed entirely by a line selected from a circular arc having a radius of 45mm or more and a straight line between the center S and the position U, and a crossing angle of a straight line connecting any two points of the outer contour line of the side view angle between the center S and the position U with respect to a straight line extending in the longitudinal direction from the center S is 8 ° or less.

In the toothbrush according to the above aspect of the present invention, the transparent saturated polyester resin is PCTA resin.

[ Effect of the invention ]

The present invention can provide a transparent toothbrush which ensures fatigue resistance.

Drawings

Fig. 1 is a view showing an embodiment of the present invention, and is a side view showing the structure of a toothbrush 1.

Fig. 2 is a front view of the toothbrush 1 from the bristle surface 3a side.

[ reference numerals ]

1 … toothbrush; 2 … brush body; 3 … head; 3a … flocked surfaces; 4 … neck; 4a … flex region; 5 … grip; 6. 6a … plant pores; s, T … center

Detailed Description

Hereinafter, an embodiment of the toothbrush of the present invention will be described with reference to fig. 1 and 2.

The following embodiments are illustrative of one embodiment of the present invention, and the present invention is not limited to the embodiment, and may be arbitrarily modified within the scope of the technical idea of the present invention. In the following drawings, the actual configuration and the scale, the number, and the like of the configurations are different for easy understanding of the configurations.

In the following description, the side (bristle surface side) of the bristle surface 3a provided with the head 3, which will be described later, is referred to as the front surface side of the toothbrush 1, and the side opposite to the side facing the bristle surface 3a of the head 3 is referred to as the back surface side of the toothbrush 1. The direction in which the brush body 2 extends is referred to as the long axis direction, the direction parallel to the bristle surface 3a and intersecting the long axis direction perpendicularly is referred to as the width direction (2 nd direction) of the toothbrush 1, and the direction intersecting the bristle surface 3a perpendicularly is referred to as the thickness direction (1 st direction) of the toothbrush 1. The description will be made with the side (head side) on which the head 3 is provided as the front end side, and the side (grip side) on which the grip 5 is provided as the rear end side.

Fig. 1 is a side view showing the structure of a toothbrush 1. Fig. 2 is a front view of the toothbrush 1 from the bristle surface 3a side. In fig. 2, the brush 40 is omitted from illustration.

As shown in fig. 1 and 2, the toothbrush 1 of the present embodiment includes a brush body 2 and a brush 40 formed of a resin molded body integrally formed in an elongated shape.

The brush body 2 has a head 3 having a bristle surface 3a on the front end side, a grip 5 disposed on the rear end side of the head 3, and a neck 4 disposed between the head 3 and the grip 5. In the toothbrush 1, the brush 40 having a plurality of tufts (not shown) implanted on the bristle surface 3a of the head 3 can clean the inside of the oral cavity.

The resin constituting the brush body 2 is formed of a transparent or translucent amorphous hard resin. In the brush body 2 of the present embodiment, a polyester resin is used as an amorphous hard resin. Examples of the amorphous polyester resin include a PCTA resin composed of a dicarboxylic acid component mainly composed of Terephthalic Acid (TA) and isophthalic acid (IPA) and a diol component mainly composed of 1, 4-cyclohexanedimethanol diol (CHDM), and a polybutylene terephthalate (PBT), a polyethylene terephthalate (PET), and a polyarylate resin. Examples of the non-crystalline resin other than the polyester resin include polystyrene resin, polyarylate resin, polycarbonate resin, and acrylonitrile-styrene resin.

(outline shape of front side of brush body)

The toothbrush 1 of the present embodiment has, when the brush body 2 is viewed from a side view, a contour line of the front surface side of the brush body 2: a1 st straight line region L1 extending from the rear end side of the head 3 toward the grip 5 side and continuously toward the rear end side from the hair planting surface 3a of the head 3, a1 st curved line region E1 having a curvature center on the front side and extending in an arc shape from the rear end to the rear end side of the 1 st straight line region L1, and a 2 nd curved line region E2 having a curvature center on the rear side and extending in an arc shape from the rear end to the rear end side of the 1 st curved line region E1. The toothbrush 1 has, on the front side in a side view: a 3 rd curved region E3 having a center of curvature on the front side and extending in an arc shape from the rear end to the rear end side of the 2 nd curved region E2, and a 4 th curved region E4 having a center of curvature on the rear side and extending in an arc shape from the rear end to the rear end side of the 3 rd curved region E3. Further, the toothbrush 1 has, on the front side in a side view: a 5 th curved region E5 having a center of curvature on the front side and extending in an arc shape from the rear end to the rear end side of the 4 th curved region E4, and a 6 th curved region E6 having a center of curvature on the rear side and extending in an arc shape from the rear end to the rear end side of the 5 th curved region E5.

(outline shape of the back surface side of the brush body)

The toothbrush 1 of the present embodiment has, when the brush body 2 is viewed from a side view, a contour line of the back surface side of the brush body 2: the head 3 includes a 2 nd linear region L2 extending linearly from the rear end side toward the grip 5 side from the rear surface of the head 3 to the rear end side continuously, a 7 th curved region E7 having a curvature center on the rear surface side and extending in a circular arc from the rear end side halfway to the rear end side of the 2 nd linear region L2, and a 3 rd linear region L3 extending linearly from the rear end to the rear end side of the 7 rd curved region E7 in parallel with the longitudinal direction. The toothbrush 1 has, on the back side in a side view: an 8 th curved region E8 having a center of curvature on the back surface side and extending in an arc shape from the rear end to the rear end side of the 3 rd straight region L3, a 9 th curved region E9 having a center of curvature on the back surface side and extending in an arc shape from the rear end to the rear end side of the 8 th curved region E8, and a 10 th curved region E10 having a center of curvature on the front surface side and extending in an arc shape from the rear end to the rear end side of the 9 th curved region E9. Further, the toothbrush 1 has, on the back side in a side view: an 11 th curved region E11 having a center of curvature on the back surface side and extending in an arc shape from the rear end to the rear end side of the 10 th curved region E10, a 12 th curved region E12 having a center of curvature on the front surface side and extending in an arc shape from the rear end to the rear end side of the 11 th curved region E11, and a 4 th straight region L4 extending in a straight line parallel to the longitudinal direction from the rear end to the rear end side of the 12 th curved region E12.

(outline shape of both sides in the width direction of the brush body)

In the toothbrush 1 of the present embodiment, when the brush body 2 is viewed from the front view, the contour lines of both sides in the width direction of the brush body 2 are formed in line symmetry with respect to the center line extending in the longitudinal direction at the center in the width direction. Therefore, in the following description, an outline of one side in the width direction (lower side in fig. 2) will be described. The position of the curvature center of the curved region extending in an arc shape is referred to as the inner side with respect to the outer contour line and the center side in the width direction, and the opposite side from the center in the width direction is referred to as the outer side.

The toothbrush 1 of the present embodiment has, when the brush body 2 is viewed from the front view, a contour line in the width direction of the brush body 2: a 5 th linear region L5 extending linearly from a boundary (described in detail later) between the head 3 and the neck 4 toward the rear end side, a 13 th curved region E13 having a curvature center on the outside and extending arcuately from the rear end side halfway toward the rear end side of the 5 th linear region L5, and a 14 th curved region E14 having a curvature center on the inside and extending arcuately from the rear end to the rear end side of the 13 th curved region E13. In addition, the toothbrush 1 of the present embodiment has, in a front view of the brush body 2: a 15 th curved region E15 having a center of curvature on the outer side and extending in an arc shape from the rear end to the rear end side of the 14 th curved region E14, and a 16 th curved region E16 having a center of curvature on the inner side and extending in an arc shape from the rear end to the rear end side of the 15 th curved region E15. Further, the toothbrush 1 has, in a front view of the brush body 2: a 17 th curve region E17 having a curvature center on the outer side and extending in an arc shape from the rear end to the rear end side of the 16 th curve region E16, and an 18 th curve region E18 having a curvature center on the inner side and extending in an arc shape from the rear end to the rear end side of the 17 th curve region E17.

(head)

The head 3 is a part that is brushed into the oral cavity by a plurality of hair bundles, has a substantially rectangular parallelepiped shape, and has a rounded corner. The head 3 has a substantially quadrangular flat plate shape with 4 tops cut by a curve in a front view. In the present embodiment, in the shape of the head 3 in the front view, the boundary between the head 3 and the neck 4 is the end point of the curve forming the chamfer on the neck 4 side, that is, the position where the bending direction of the curve forming the chamfer changes.

The head 3 has a bristle surface 3a on the front side. A plurality of implantation holes 6 having the same diameter are arranged in parallel on the implantation surface 3a. The implantation holes 6 are arranged in a plurality of rows (2 to 4 rows in fig. 2) at intervals in the width direction corresponding to the length of the head 3 in the width direction, and the implantation holes 6 are arranged in a plurality of rows (8 rows in fig. 2) at intervals in the long axis direction. Hair bundles constituting the brush 40 are respectively implanted into the implanted holes 6.

The bundles of a plurality of bristles (filaments) are folded in half after being lifted up, and a metal anti-drop tool (not shown) called a flat wire is inserted into the implantation holes 6, thereby implanting the bundles of bristles into the implantation holes 6. The surface of the hair-planting surface 3a on the front side and the surface of the back side of the head 3 are flat and parallel to each other.

The head 3 is not particularly limited as long as it is easily brushed into the oral cavity, and may be, for example, a shape having a width gradually narrowed from the base end side toward the distal end side. In addition, the head 3 may have a tapered shape in which the thickness thereof gradually decreases from the base end side toward the tip end side, or may have a rounded shape in which the center portion on the back surface side of the head 3 is raised.

The thickness of the head 3 is preferably 2mm or more and 3.8mm or less, more preferably 3.0 to 3.7mm, and still more preferably 3.1 to 3.5mm in the entire region. In the case where the thickness of the head 3 is not constant, the thickness of the head 3 is defined as the maximum thickness of the head 3.

When the thickness of the head 3 is less than 2mm, there is a possibility that durability is lowered. When the thickness of the head 3 is larger than 3.8mm, there is a possibility that the insertion into molar teeth and the operability may be lowered. By setting the thickness of the head 3 to 2mm or more and 3.8mm or less, the insertion performance and operability into molar teeth can be improved without reducing durability.

(neck)

The neck 4 is a portion disposed between the grip 5 and the head 3 and connecting the grip 5 and the head 3. In the present embodiment, the outline of the neck portion 4 and the grip portion 5 in the front view and the side view is a shape in which a plurality of straight lines and gentle curves are connected from the boundary between the head portion 3 and the neck portion 4 toward the grip portion 5 side. In the front view, the intersection between the 14 th curve region E14 and the 15 th curve region E15 shown in fig. 2 and the position I where the curvature changes are defined as the boundary between the neck portion 4 and the grip portion 5. In the case where the curvature change is not clear, or in the case where there is no curvature change, a position that is 42.2% away from the front end of the brush body 2 (head 3) with respect to the entire length of the brush body 2 (for example, a position that is 76.0mm away from the front end of the brush body 2 in the case where the entire length of the brush body 2 is 180 mm) is defined as a boundary.

The length of the neck 4 in the longitudinal direction is defined as the shortest distance between a position W (described in detail later) and a position I in the front view. The length of the neck 4 is preferably 25 to 45mm, more preferably 25 to 40mm.

By setting the length of the neck 4 within the above range, the insertion into the molar teeth and the operability in cleaning the molar teeth can be improved.

Regarding the neck portion 4, from the boundary with the head portion 3 toward the grip portion 5, the region of the outline formed by the 5 th straight line region L5 is a constant minimum width in the front view, and the region of the outline formed by the 13 th curved region E13 and the 14 th curved region E14 gradually widens from the minimum width. The minimum width of the neck portion 4 is preferably 5.3mm or less, more preferably 5.0mm or less, and even more preferably 4.8mm or less. By setting the minimum width of the neck portion 4 to 5.3mm or less, the insertion property into molar teeth and the operability can be improved. The minimum width of the neck portion 4 is preferably 3.5mm or more from the viewpoint of strength.

With respect to the neck portion 4, from the boundary with the head portion 3 toward the grip portion 5, the region where the contour line is formed by the 1 st straight line region L1 and the 3 rd straight line region L3 is a constant minimum thickness in a side view, and the region where the contour line is formed by the curved regions E1, E2 and the curved regions E8, E9 gradually widens from the minimum thickness. The minimum thickness of the neck portion 4 at the position W (described in detail later) is preferably 5.3mm or less, more preferably 5.0mm or less, and still more preferably 4.8mm or less. When the minimum thickness of the neck portion 4 is larger than 5.3mm, there is a possibility that the insertion into molar teeth and the operability may be lowered. The minimum thickness of the neck portion 4 is preferably 3.5mm or more from the viewpoint of strength.

The position in the longitudinal direction of the neck 4, which becomes the minimum width, is W, and the cross-sectional secondary wheelbase (width×thickness ³ With a W1 cross-section secondary wheelbase W1 of preferably 20 mm/12) ⁴ Above, 50mm ⁴ Hereinafter, more preferably 25mm ⁴ Above, 50mm ⁴ Hereinafter, it is more preferably 30mm ⁴ Above 45mm ⁴ The following is given.

The secondary wheelbase W1 of the section is larger than 50mm ⁴ In the case of (a), when the cheek side of the molar teeth is brushed, the neck 4 is pinched by the lips in the width direction, and therefore resistance is felt, and the intra-oral operability is lowered. The secondary wheelbase W1 of the cross section is smaller than 20mm ⁴ In the case of (2), it is difficult to obtain sufficient fatigue resistance. By making the cross-section secondary wheelbase W1 20mm ⁴ Above, 50mm ⁴ The following can be obtainedGood intraoral operability and sufficient fatigue resistance.

Further, when the center of the head 3, which is the center in the longitudinal direction, the thickness direction, and the width direction, is S, and the cross-sectional secondary wheelbase related to the bending in the thickness direction at the center S is S1, the value represented by W1/S1 is preferably 0.9 or more and 1.9 or less, more preferably 0.9 or more and 1.8 or less, and still more preferably 1.0 or more and 1.8 or less.

In the case where the value represented by W1/S1 is smaller than 0.9, the head portion 3 is less likely to flex than the neck portion 4. In this case, stress concentration accompanying bending in the thickness direction is likely to occur on the tip end side of the neck portion 4, and fatigue resistance becomes disadvantageous, while it is difficult to transmit load energy to the grip portion 5 side. In the case where the value represented by W1/S1 is larger than 1.9, the neck portion 4 is less likely to flex than the head portion 3. In this case, the neck portion 4 is linked without being deflected with respect to the flexibility of the head portion 3, and the deflection behavior is greatly deviated, so that it is difficult to transmit load energy to the grip portion 5 side, and load is applied only to the region of the neck portion 4.

The neck portion 4 has a flexing region 4A that flexes when a load is applied to the head portion 3. Regarding the flexure region 4A, the front end side end is a position G of the rear end side of the head 3, and the rear end side end is a position I of the boundary between the neck 4 and the grip 5 (i.e., the front end side end of the grip 5). The position G on the distal end side in the flexure region 4A is, as shown in fig. 2, a position of the edge on the rear end side of the implant holes 6a on the rearmost end side among the plurality of implant holes 6 provided in the implant surface 3a.

When the position H in the longitudinal direction, which is the intermediate position with respect to the length of the flexural area 4A in the longitudinal direction, is H1, and the cross-sectional secondary wheelbase related to the bending in the thickness direction at the position H is H, the width of the neck portion 4 at the position H is preferably 5.5mm or less. By setting the width of the neck portion 4 at the position H to 5.5mm or less, good insertion into molar teeth and operability can be obtained even at the intermediate position of the neck portion 4.

The cross-sectional secondary wheelbase H1 is preferably 28mm ⁴ Above, 70mm ⁴ Hereinafter, more preferably 35mm ⁴ Above, 63mm ⁴ Hereinafter, it is more preferably 37mm ⁴ Above, 60mm ⁴ The following is given. The secondary wheelbase H1 of the section is larger than 70mm ⁴ In the case of (a), when the cheek side of the molar teeth is brushed, the neck 4 is pinched by the lips in the width direction, and therefore resistance is felt, and the intra-oral operability is lowered. The secondary wheelbase H1 of the section is smaller than 28mm ⁴ In the case of (2), it is difficult to obtain sufficient fatigue resistance. By making the cross-section secondary wheelbase H1 28mm ⁴ Above, 70mm ⁴ In the following, good intraoral operability and sufficient fatigue resistance can be obtained.

In the neck 4, when the position H is taken as the starting point, the position Q is taken as the position 15mm apart from the head 3 side, and the cross-sectional secondary wheelbase related to bending in the thickness direction at the position Q is Q1, the value represented by H1/Q1 is preferably 1.0 or more and 2.0 or less, more preferably 1.1 or more and 1.5 or less. Further, when the position H is taken as the starting point, the position R is a position 10mm apart from the grip portion 5 side, and the cross-sectional secondary wheelbase related to bending in the thickness direction at the position R is R1, the value represented by R1/H1 is preferably 1.7 or more and 3.0 or less, more preferably 1.9 or more and 2.8 or less.

By setting the value represented by H1/Q1 and the value represented by R1/H1 in the above ranges, the stress concentration associated with bending in the thickness direction can be moved to the rear end side where the cross-sectional secondary wheelbase is large and the bending strength is large without increasing the width of the position H and reducing the intraoral operability, and fatigue resistance can be ensured.

As shown in fig. 2, in the outline in the width direction from the front view angle between the position H and the position I, it is preferable that a straight line connecting the end point P1 on the front end side and the end point P2 on the rear end side obliquely intersect at an angle of 1.9 ° or more and 6.5 ° or less (hereinafter referred to as an angle θ12) with respect to the long axis direction. As shown in fig. 1, in the outline on the back side in the side view between the position H and the position I, it is preferable that a straight line connecting the end point P4 on the front end side and the end point P5 on the rear end side obliquely intersect at an angle of 3.0 ° or more and 5.3 ° or less (hereinafter referred to as an angle θ45) with respect to the longitudinal direction.

As shown in fig. 2, it is preferable that a straight line connecting the end point P3 on the front end side and the end point P2 on the rear end side in the outline in the width direction between the position W and the position I obliquely intersect at an angle of 1.9 ° or more and 4.5 ° or less, preferably 2.5 ° or more and 4.0 ° or less (hereinafter referred to as an angle θ32) with respect to the longitudinal direction. As shown in fig. 1, in the outline on the rear side in the side view between the position W and the position I, it is preferable that a straight line connecting the end point P6 on the front end side and the end point P5 on the rear end side obliquely intersect at an angle of 2.0 ° or more and 3.5 ° or less, preferably 2.0 ° or more and 3.0 ° or less (hereinafter referred to as an angle θ65) with respect to the longitudinal direction.

The position W at which the position of the minimum width is located at least one point in the longitudinal direction is the position of the forefront side of the minimum width.

In the outline in the width direction from the front view between the position W and the position H, a straight line connecting the end point P3 on the front end side and the end point P1 on the rear end side is preferably at an angle of 3 ° or less, preferably 1 ° or less (hereinafter referred to as an angle θ31) with respect to the longitudinal direction. In the outline on the back side in the side view between the position W and the position H, it is preferable that a straight line connecting the end point P6 on the front end side and the end point P4 on the rear end side obliquely intersect at an angle of 3 ° or less, preferably 1 ° or less (hereinafter referred to as an angle θ64) with respect to the longitudinal direction.

Between the position W and the position H where the neck portion 4 has the smallest width, the angle at which the contour line is inclined with respect to the longitudinal direction is preferably small from the viewpoints of brushing comfort and intraoral operability. On the other hand, if the angle is suddenly increased between the position H and the position I, which are located on the rear end side of the position H, there is a possibility that the effect of brushing comfort and intra-oral operability between the position W and the position H is impaired. Accordingly, by setting the angle θ12 under the front view angle and the angle θ45 under the side view angle between the position H and the position I to the above ranges, and setting the angle θ32 under the front view angle and the angle θ65 under the side view angle between the position W and the position I to the above ranges, the width and the thickness are gently increased toward the rear end side in the outline, whereby the brushing comfort and the intra-oral operability can be ensured in the entire neck 4.

If the above-described cross-sectional secondary wheelbase is satisfied, the cross-sectional shape of the neck 4 is preferably substantially quadrangular, substantially polygonal, right circular, elliptical.

(grip portion)

The grip portion 5 is a portion gripped by a user and is formed in a long column shape. In order to ensure a sufficient length for gripping the grip portion 5 in use, it is preferable that the length from the position W to the rear end of the grip portion 5 is 100 to 200mm in front view.

The grip portion 5 has a width gradually increasing from the position I of the boundary with the neck portion 4 toward the rear end side, from the outline of the outer shape in the front view to the position where the 16 th curve region E16 shows the maximum value. The width gradually becomes narrower from the position where the 16 th curve region E16 shows the maximum value to the position where the 17 th curve region E17 shows the minimum value in the front view angle. The width gradually becomes wider from the outer contour line on the rear end side from the position where the 17 th curve region E17 shows the minimum value to the position where the 18 th curve region E18 shows the maximum value at the front view angle. The grip portion 5 of the present embodiment has a maximum width at a position where the 18 th curve region E18 shows a maximum value. The width gradually decreases from the position where the 18 th curved region E18 shows the maximum value to the end portion on the rear end side from the outline on the front view angle.

Regarding the grip portion 5, the thickness gradually decreases from the position I of the boundary with the neck portion 4 toward the rear end side, from the outline of the profile in the side view to the position where the 3 rd curve region E3 shows the minimum value. The thickness gradually increases from the outline on the rear end side from the position where the 3 rd curve area E3 shows the minimum value to the position where the 4 th curve area E4 shows the maximum value in the side view angle. The thickness gradually decreases from the outline on the rear end side from the position where the 4 th curve region E4 shows the maximum value to the position where the 5 th curve region E5 shows the minimum value in the side view angle. The thickness gradually increases from the outline on the rear end side from the position where the 5 th curve region E5 shows the minimum value to the position where the 6 th curve region E6 shows the maximum value in the side view angle.

As shown in fig. 1 and 2, when the center of the grip portion 5, which is the center in the longitudinal direction, the thickness direction, and the width direction, is T, and the cross-sectional secondary wheelbase related to bending in the thickness direction at the center T is T1, the value represented by T1/W1 is preferably 6 or more and 26 or less, more preferably 7 or more and 20 or less, and still more preferably 7 or more and 14 or less.

If the value represented by T1/W1 is smaller than 6, the neck portion 4 is less likely to flex than the grip portion 5, and stress concentration accompanying bending in the thickness direction tends to occur on the distal end side of the neck portion 4, which is disadvantageous in terms of strength. On the other hand, when the value represented by T1/W1 is larger than 26, the deflection of the grip portion 5 is excessively suppressed with respect to the deflection of the neck portion 4, and stress concentration tends to occur in the vicinity of the boundary between the neck portion 4 and the grip portion 5, which may cause a problem in strength.

Therefore, as described above, by making the cross-sectional secondary wheelbase W1 20mm ⁴ Above, 50mm ⁴ Hereinafter, the deflection behavior among the center S, the position W, and the center T can be controlled by setting the value represented by W1/S1 to 0.9 or more and 1.9 or less and the value represented by T1/W1 to 6 or more and 26 or less. That is, by setting the cross-sectional secondary axial distance as described above, the cross-sectional secondary axial distance smoothly increases from the tip end of the head portion 3 toward the grip portion 5, whereby the cross-sectional secondary axial distance slowly changes. As a result, in the toothbrush 1 of the present embodiment, the front end side is always easily deflected, the rear end side is hardly deflected, and even when the transparent saturated polyester resin is used in the brush body 2, the load energy does not locally stay, and the load energy can be smoothly transferred from the front end side to the rear end side which is advantageous in fatigue resistance.

In addition, when Ta is the position in the longitudinal direction of the grip portion 5 that is the maximum thickness and Ta1 is the second axial distance of the cross section in the thickness direction with respect to the bending at the position Ta, the value represented by Ta1/W1 is preferably 7 or more and 35 or less. In the present embodiment, the position Ta is the same position as the position I. If the value represented by Ta1/W1 is smaller than 7, the neck portion 4 is less likely to flex than the grip portion 5, and stress concentration accompanying bending in the thickness direction tends to occur on the distal end side of the neck portion 4, which is disadvantageous in terms of strength. On the other hand, when the value represented by Ta1/W1 is larger than 35, the deflection of the grip portion 5 is excessively suppressed with respect to the deflection of the neck portion 4, and stress concentration tends to occur in the vicinity of the boundary between the neck portion 4 and the grip portion 5, which may cause a problem in strength.

As shown in fig. 1, when the position of the grip portion 5 at a distance of 20mm from the position I on the rear end side is U and the point on the outline on the rear surface side at the position U is P7 in the side view, the center S, the end point P4 of the position H, the end point P5 of the position I, and the point P7 of the position U are on a substantially straight line. Similarly, when the point at the position H on the outline on the front side in the side view is P8, the point at the position I is P9, and the point at the position U is P10, the center S, the point at the position H P8, the point at the position I P9, and the point at the position U P10 are on a substantially straight line. Here, the substantially straight line means that, when a straight line extending in the longitudinal direction from the center S is SL, the distances between the end points P4, P5, P7, P8, P9, and P10 and the straight line SL are all 5mm or less. By the above-described end points P4, P5, P7, P8, P9, and P10 being located at the above-described positions, a portion of large curvature is not provided in the thickness direction from the front end side to the rear end side of the toothbrush 1. Therefore, in the toothbrush 1, it is possible to prevent the stress load from locally staying and smoothly transferring to the grip portion 5 side having a large bending strength.

Preferably, between the center S and the position U, the outline contour lines under the side view angle are all formed by lines selected from the group consisting of circular arcs and straight lines having a radius of 45mm or more. Preferably, between the center S and the position U, a crossing angle of a straight line connecting any two points in the outline at the side view angle with respect to a straight line SL extending in the long axis direction with the center S as a starting point is 8 ° or less.

By setting the outline of the toothbrush 1 at the side view between the center S and the position U to be the above-described predetermined, the toothbrush 1 can be prevented from being provided with a large concave-convex portion on the outline of the toothbrush at the side view, and the stress load can be prevented from being locally retained and smoothly transferred to the grip portion 5 side having a large bending strength.

When the cross-sectional secondary wheelbase related to bending in the thickness direction at the position U is U1, the value represented by U1/W1 is preferably 6 or more and 25 or less, more preferably 7 or more and 20 or less. If the value indicated by U1/W1 is smaller than 6, the neck portion 4 is less likely to flex than the grip portion 5, and stress concentration due to bending in the thickness direction tends to occur on the distal end side of the neck portion 4, which is disadvantageous in terms of strength. On the other hand, when the value indicated by U1/W1 is larger than 25, the deflection of the grip portion 5 is excessively suppressed with respect to the deflection of the neck portion 4, and stress concentration tends to occur in the vicinity of the boundary between the neck portion 4 and the grip portion 5, which may cause a problem in strength.

As shown in fig. 1, in the grip portion 5, a position spaced 10mm from the position I on the distal end side is J, a cross-sectional secondary wheelbase related to bending in the thickness direction at the position J is J1, and when the cross-sectional secondary wheelbase related to bending in the thickness direction at the position I is I1, a value represented by I1/J1 is preferably 2.0 or more and 6.0 or less, more preferably 2.5 or more and 4.0 or less. The value represented by U1/I1 is preferably 0.5 or more and 1.1 or less.

When the value represented by I1/J1 and the value represented by U1/I1 are within the above ranges, it is possible to prevent (suppress) the local retention of the stress load in the vicinity of the boundary between the neck portion 4 and the grip portion 5, and smoothly shift to the grip portion 5 side having a large bending strength.

Between the above-mentioned position Q and position R, the outline is preferably formed by an arc-shaped curve having a radius of 100mm or more and 500mm or less or a straight line intersecting at an angle of 1.7 ° or more and 4 ° or less with respect to a straight line extending in the longitudinal direction, and more preferably by a straight line intersecting at an angle of 1.8 ° or more and 3 ° or less at the front view angle.

Further, between the position Q and the position R, it is preferable that the outline line is formed by an arc-shaped curve having a radius of 200mm or more or a straight line intersecting at an angle of 1.0 ° or more and 1.4 ° or less with respect to a straight line extending in the longitudinal direction at the side view angle.

By setting the outline of the neck portion 4 between the position Q and the position R in the front view and the side view to the above-described predetermined, the cross-sectional area of the neck portion 4 gradually increases between the position Q and the position R, and further the stress load can be more smoothly transferred to the grip portion 5 side having a large bending strength.

As described above, in the toothbrush 1 of the present embodiment, by optimizing the secondary wheelbase ratio of the cross section in each portion of the head portion 3, the neck portion 4, and the grip portion 5, the load energy is not locally retained, and the load energy can be transferred to the portion on the rear end side that is advantageous in fatigue resistance, and it is possible to provide the transparent toothbrush 1 that ensures fatigue resistance.

Examples (example)

The effects of the present invention will be more clearly illustrated by examples below. The present invention is not limited to the following examples, and may be implemented with appropriate modifications within the scope of not changing the gist thereof.

Examples 1 to 7 and comparative examples 1 to 6

In this example, the toothbrushes of examples 1 to 7 and comparative examples 1 to 6 were prepared into the same samples as the toothbrushes shown in fig. 1 and 2 according to the specifications shown in the following [ table 1A ] and [ table 1B ].

The overall length of the handle of each toothbrush was 180mm, and the dimensions of each part were as shown in Table 1. The brush body uses PCTA resin.

[ evaluation method ]

(1) Fatigue durability

Test method regarding fatigue durability, a portion of the grip portion 60mm away from the rear end was fixed, and a displacement of 50mm (number of samples; n=5) was repeatedly loaded in the head portion at a speed of 240 rpm.

The case where the load was repeatedly applied 100 ten thousand times was designated as "a", the case where the load was applied 100 ten thousand times was not broken, it was confirmed that there was a crack of less than 0.5mm in 1 root was designated as "B", the case where the load was applied 100 ten thousand times was not broken, it was confirmed that there was a crack of 0.5mm or more in 1 root was "C", the case where the load was applied 90 to 100 ten thousand times was not broken, the case where the load was applied 80 to 90 ten thousand times was not broken, the case where the load was applied 80 to 80 ten thousand times was not broken, the case where the load was applied 50 to 80 ten thousand times was applied 1 root was "F", and the case where the load was applied to 1 root was applied less than 50 ten thousand times was broken was 1 root.

(2) Intraoral operability

Test method 10 monitors cleaned the oral cavity and the operability of the toothbrushes of each example was evaluated.

The evaluation of the operability was set to 7 stages of 1 to 7 points, and the higher the score, the better the operability was. The average score of 10 monitors was classified as the following criterion, and the operability in the oral cavity was determined.

< criterion for determination >

A: average division into more than 6.0 minutes

B: the average division is more than 5.5 and less than 6.0

C: the average division is more than 5.0 and less than 5.5

D: the average division is more than 4.5 and less than 5.0

E: the average division is more than 4.0 and less than 4.5

F: the average division is more than 3.5 and less than 4.0

G: average score is less than 3.5 minutes

[ Table 1A ]

[ Table 1B ]

Such as [ Table 1A ]]TABLE 1B]The thickness of the head is 2mm or more and 3.8mm or less in the whole area, the minimum width of the neck is 5.3mm or less, and the cross-section secondary wheelbase W1 is 20mm ⁴ Above, 50mm ⁴ In the samples of examples 1 to 7 below, in which the values represented by W1/S1 were 0.9 to 1.9, and the values represented by T1/W1 were 6 to 26, the fatigue durability, the intraoral operability, and the impact durability were all good results.

On the other hand, in the sample of comparative example 1 in which the value of the section secondary axial distance represented by W1/S1 is deviated from the range of 0.9 or more and 1.9 or less, the fatigue durability cannot be well evaluated. In the sample of comparative example 2 in which the thickness of the head portion, the minimum width of the neck portion, and the cross-sectional secondary wheelbase W1 deviate from the above preferred ranges, no good evaluation of the intraoral operability was obtained. In the sample of comparative example 3 in which the thickness of the head, the minimum width of the neck, and the cross-section secondary wheelbase W1, and the values represented by T1/W1 deviate from the above preferred ranges, good evaluation of intra-oral operability was not obtained.

In the sample of comparative example 4 in which the minimum width of the neck and the value represented by W1/S1 deviate from the above preferred ranges, good evaluation of intra-oral operability was not obtained. In the sample of comparative example 5 in which the value represented by W1/S1 was out of the above preferred range, the fatigue durability could not be well evaluated. In the sample of comparative example 6 in which the cross-sectional secondary wheelbase W1 and the value represented by T1/W1 deviate from the above preferred ranges, good evaluation of fatigue durability was not obtained.

While the preferred embodiments of the present invention have been described above with reference to the drawings, it is needless to say that the present invention is not limited to the related examples. The various shapes, combinations, and the like of the respective constituent members shown in the above examples are examples, and various modifications can be made according to design requirements and the like within a range not departing from the gist of the present invention.

[ Industrial applicability ]

The present invention may be applied to toothbrushes.

Claims

1. A toothbrush is characterized in that,

the toothbrush is provided with a brush body, and the brush body is provided with: a head part positioned on the front end side and having a hair-planting surface, a holding part positioned on the rear end side of the head part, and a neck part positioned between the head part and the holding part,

the brush body is formed by transparent saturated polyester resin,

for the 1 st direction perpendicularly intersecting the bristle surface, the thickness of the head is 2mm or more and 3.8mm or less in the entire region,

for the 2 nd direction perpendicular to the long axis direction of the brush body extension and the 1 st direction, the minimum width of the neck is below 5.3mm,

setting a position where the neck portion is the minimum width in the long axis direction as W, setting a section secondary wheelbase related to the bending in the 1 st direction at the position W as W1,

a center of the head portion at the center in the long axis direction, the 1 st direction, and the 2 nd direction is S, a cross-sectional secondary wheelbase related to the bending in the 1 st direction at the center S is S1,

a center of the grip portion at the center in the long axis direction, the 1 st direction, and the 2 nd direction is T, and a cross-sectional secondary wheelbase related to the bending in the 1 st direction at the center T is T1

The section secondary wheelbase W1 is 20mm ⁴ Above, 50mm ⁴ In the following the procedure is described,

the value represented by W1/S1 is 0.9 or more and 1.9 or less,

the value represented by T1/W1 is 6 to 26.

2. The toothbrush of claim 1, wherein the toothbrush comprises,

when H is a position intermediate to the length of the bending region of the neck in the longitudinal direction as viewed from the front side which is the bristle surface side in the 1 st direction, and H1 is a cross-sectional secondary wheelbase related to bending in the 1 st direction at the position H,

the width in the 2 nd direction at the position H is 5.5mm or less, and the cross-section secondary wheelbase H1 is 28mm ⁴ Above, 70mm ⁴ In the following the procedure is described,

assuming that the position H is set as a starting point, a position 15mm away from the head side is set as Q, a position 10mm away from the grip side is set as R, a cross-sectional secondary wheelbase related to the bending in the 1 st direction at the position Q is set as Q1, a cross-sectional secondary wheelbase related to the bending in the 1 st direction at the position R is set as R1,

the value represented by H1/Q1 is 1.0 or more and 2.0 or less,

the value represented by R1/H1 is 1.7 to 3.0.

3. The toothbrush according to claim 2, wherein,

the end portion of the flexible region on the front end side in the longitudinal direction at the front view is: a plurality of implant holes provided in the implant surface, the implant holes being located at the edge of the implant hole closest to the rear end side,

the end of the flexible region on the rear end side in the longitudinal direction in the front view is the end on the front end side of the grip portion,

when the end of the bending region on the rear end side in the longitudinal direction is set as a position I,

in the outline in the 2 nd direction from the front view angle between the position H and the position I, a straight line connecting the end point on the front end side and the end point on the rear end side has an inclination of 1.9 ° or more and 6.5 ° or less with respect to the longitudinal direction,

in a side view from the side of the 2 nd direction, a straight line connecting the end point of the front end side and the end point of the rear end side has an inclination of 3.0 ° or more and 5.3 ° or less with respect to the longitudinal direction, in an outline of the rear surface side opposite to the front surface side in the 1 st direction between the position H and the position I.

4. The toothbrush according to claim 3, wherein,

when a position 20mm from the position I on the rear end side thereof is set as U,

the center S is on a substantially straight line with respect to a position H, a position I, and a position U in the outline of the front side in the side view,

the center S is on a substantially straight line with respect to a position H, a position I, and a position U in the outline of the back side in the side view,

the distance between the position H, the position I and the position U in the outline of the outline under the side view angle and a straight line extending in the long axis direction with the center S as a starting point is below 5mm.

5. The toothbrush of claim 4, wherein the toothbrush comprises,

between the center S and the position U, the contour lines of the side view angles are all formed by lines selected from arcs and straight lines having a radius of 45mm or more,

a straight line connecting any two points of the outline of the side view angle between the center S and the position U has an intersection angle of 8 ° or less with respect to a straight line extending in the longitudinal direction from the center S.

6. The toothbrush according to any one of claims 1 to 5, wherein,

the transparent saturated polyester resin is PCTA resin.