CN109890249B

CN109890249B - Tooth brush

Info

Publication number: CN109890249B
Application number: CN201780066424.XA
Authority: CN
Inventors: 金丸直史; 龟井诚一
Original assignee: Lion Corp
Current assignee: Lion Corp
Priority date: 2016-10-28
Filing date: 2017-09-13
Publication date: 2021-05-11
Anticipated expiration: 2037-09-13
Also published as: SG10202107804WA; JP2023026518A; JP2023026521A; CN109890249A; KR20230113407A; KR20190069392A; SG10202107814QA; CN113208262B; JPWO2018079115A1; KR102556407B1; JP2023026519A; CN113208262A; JP2018118169A; JP6385027B1; WO2018079115A1; JP2023026520A

Abstract

A toothbrush having a thin head part with good operability is provided. The toothbrush is provided with a head part (110) which is arranged at the front end side and implanted with hair bundles on a hair implanting surface (111), a neck part (120) which extends from the rear end side of the head part, and a handle part (130) which extends from the rear end side of the neck part. The thickness of the head is 2.0-4.0 mm. The neck part is formed as follows: the minimum value of the width in the direction parallel to the hair-planted surface and perpendicular to the longitudinal direction of the handle portion is 3.5mm to 4.5mm, and the width is constant or gradually increased from the position of the minimum value toward the rear end side. When the width of the neck portion is W mm and the thickness in the direction perpendicular to the flocked surface is D mm, the width of the neck portion gradually increases from the position of the minimum value toward the rear end side, when the width of the neck portion is constant from the position of the minimum value toward the rear end side with the position of the minimum value as a starting point, the position of the minimum value on the most front end side is parallel to the hair-planting surface with the position of the minimum value as a starting point, a value obtained from D/W at a position spaced apart by 10mm from the rear end side is 0.7 to 2.5, and the difference between the value obtained from D/W at the position of the starting point with the minimum width and the value obtained from D/W at the position 20mm away from the rear end side of the position of the starting point is more than 0.05, and D/W at a position 20mm away from the rear end side of the position of the starting point exceeds 1.0, a deflection coefficient M (mm) at a position distant by 10mm from the rear end side of the position of the starting point where the width is the minimum value.⁴)＝W×D³Is 165mm⁴Above, 625mm⁴The following.

Description

Tooth brush

Technical Field

The present invention relates to toothbrushes.

The present application claims priority from Japanese patent application No. 2016-211879 filed in Japan on 2016, 10, 28, and the contents of which are incorporated herein by reference.

Background

Patent documents 1 to 3 propose toothbrushes in which the thickness of the head is reduced in consideration of the operability in the oral cavity and the like. When the thickness of the head portion is made thin, there arises a problem such as a decrease in strength. Therefore, a resin having high strength such as polyacetal resin (POM) is used. In particular, in the case of flat-wire type tufting in which bristles are fixed by driving a flat wire (flat plate) made of metal into a head made of resin, the tufting strength and the folding strength of the head may be insufficient.

Documents of the prior art

Patent document

Patent document 1: JP-A7-143914

Patent document 2: JP 2011-4852 publication

Patent document 3: JP 2011-200296 publication

Disclosure of Invention

Problems to be solved by the invention

After the research of the inventor, the inventor finds that: in the above toothbrush, if the neck portion connecting the head portion and the grip portion is thick, the effect of improving the oral cavity operability due to the head portion becoming thin is impaired. In particular, if the neck portion is widened, the operability is further impaired, the head portion is not remarkably thin in appearance, and the impression of the product is impaired. However, when the neck portion is thinned, excessive deflection may sometimes cause a problem in operability. Further, further improvement in strength is also required. In particular, the problem is more pronounced in the case of general-purpose resins generally used in toothbrushes such as polypropylene (PP).

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 portion, which can be operated with good ease.

Means for solving the problems

The invention according to claim 1 provides a toothbrush comprising a head portion disposed on a front end side and implanted with tufts on a bristle surface, a neck portion extending from a rear end side of the head portion, and a handle portion extending from a rear end side of the neck portion, wherein the head portion has a thickness of 2.0 to 4.0mm, and the toothbrush is characterized in thatThe neck part is formed as follows: a minimum value of a width in a direction parallel to the flocked surface and perpendicular to a longitudinal direction of the grip portion is 3.5mm or more and 4.5mm or less, the width is constant or gradually increased from a position of the minimum value toward a rear end side, the width of the neck portion is W mm, and the thickness in the direction perpendicular to the flocked surface is D mm, when the width of the neck portion is gradually increased from the position of the minimum value toward the rear end side, a value obtained from the D/W at a position 10mm away from the rear end side is 0.7 or more and 2.5 or less from the position of the minimum value toward the rear end side, and a value obtained from the D/W at a position of the start point at which the width is the minimum value, parallel to the flocked surface, from the position of the minimum value toward the rear end side is 0.7 or more and 2.5 or less, the difference between the value obtained by the D/W calculation at the position 20mm away from the rear end of the position of the starting point is more than 0.05, the D/W at the position 20mm away from the rear end of the position of the starting point exceeds 1.0, and the deflection coefficient M (mm) at the position 10mm away from the rear end of the position of the starting point where the width is the minimum value⁴)＝W×D³Is 165mm⁴Above, 625mm⁴The following.

In the toothbrush according to the above aspect of the invention, the neck portion is formed of a resin material, and the resin material has a flexural modulus of elasticity of 1000MPa to 2200 MPa.

In the toothbrush according to one embodiment of the present invention, the neck portion is formed of polypropylene resin.

In the toothbrush according to the above-described aspect of the invention, the rate of change of the flexural coefficient is 1.3 or more and 1.8 or less at a position spaced 10mm from the rear end of the position of the starting point where the width is the minimum value.

In the toothbrush according to the above-described aspect of the present invention, a difference between a value obtained from the D/W at a position of the starting point where the width is the minimum value and a value obtained from the D/W at a position spaced 20mm from the rear end side of the position is 0.07 or less.

Effects of the invention

The present invention can provide a toothbrush which can provide good oral operability even when a general-purpose resin is used.

Drawings

Fig. 1 is a view showing an embodiment of the present invention, which is a plan view of a toothbrush 11.

Fig. 2 is a side view of the same toothbrush 11.

FIG. 3 is an enlarged plan view of the front end side of the toothbrush 11.

FIG. 4 is an enlarged side view of the front end side of the toothbrush 11.

[ description of symbols ]

11 … toothbrush; 12 … a handle body; 110 … head; 111 … flocking surface; 120 … neck; 130 … handle portion.

Detailed Description

Hereinafter, embodiments of a toothbrush handle body and a toothbrush according to the present invention will be described with reference to fig. 1 to 4.

The following embodiments are illustrative of one embodiment of the present invention, and are not intended to limit the present invention, and may be modified within the scope of the technical idea of the present invention. In the following drawings, the actual structure is different from the structures in scale, number, and the like in order to facilitate understanding of the structures.

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

The toothbrush 11 of the present embodiment includes: a head portion 110 disposed at the distal end and implanted with tufts 114 of brush hairs, a neck portion 120 extending from the rear end side of the head portion 110, and a handle portion 130 extending from the rear end side of the neck portion 120 (hereinafter, the head portion 110, the neck portion 120, and the handle portion 130 are collectively referred to as a handle body 12).

The handle body is integrally molded in a long shape as a whole, and can be obtained by injection molding using a resin as a material, for example.

Examples of the material of the grip body include resins having a flexural modulus of elasticity (JIS7171) of 1000MPa to 2200MPa, and examples thereof include polypropylene resins (PP), polyacetal resins (POM), polystyrene resins (PS), polyethylene terephthalate resins (PET), polybutylene terephthalate resins (PBT), acrylonitrile butadiene styrene resins (ABS), polyarylate resins, polycarbonate resins, and acrylonitrile styrene resins (AS). Among them, a polypropylene resin is preferable as a general-purpose resin from the viewpoint of more remarkable effects of the present invention and cost.

The resin can be used alone in 1, or can be combined with more than 2.

Further, in order to improve the grippability, the handle body may be partially or entirely covered with a soft resin such as an elastic body. When a soft resin such as an elastomer is used, for example, polyolefin is preferable, and PP is more preferable, from the viewpoint of improving adhesiveness.

The head 110 has a flocked surface 111 on one side in the thickness direction (hereinafter referred to as an upper surface side). A plurality of implanted holes 112 are formed in the implanted surface 111, and tufts 114 (see fig. 2) of bristles are implanted in the implanted holes 112. In fig. 1, 3, and 4, tufts 114 are not shown.

The rear end side end portion of the head portion 110 in the present embodiment is defined as: when the distance from the outer edge of the hair-planting hole 112 disposed on the most front end side to the front end of the head 110 is L11, the distance is L11 in the direction from the outer edge of the hair-planting hole 112 disposed on the most rear end side to the rear end side. That is, as shown in fig. 3, the head 110 is disposed in a range 110A separated by a distance L11 from the outer edge of the hair-planting hole 112 located 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 distal end of the grip portion 130 is a finger contact portion, and the distal end of the finger contact portion is a boundary between the neck portion 120 and the grip portion 130. The finger contact portion is demarcated by the following ridge lines: for example, a ridge line formed at an intersection of a surface on the side of the hair-planted surface 111 on the rear end side of the neck portion 120 and a surface on the side of the hair-planted surface 111 on the front end side of the grip portion 130, or a ridge line formed at an intersection of a surface on the opposite side of the hair-planted surface 111 on the rear end side of the neck portion 120 and a surface on the opposite side of the hair-planted surface 111 on the front end side of the grip portion 130. At this time, the boundary between the neck portion 120 and the grip portion 130 is defined by the ridge line.

Further, in the case where the surface on the side of the hair-planted surface 111 on the rear end side of the neck portion 120 and the surface on the side of the hair-planted surface 111 on the front end side of the grip portion 130 are on the same plane without forming a ridge line, the finger contact portion is demarcated by a ridge line formed at an intersection of a side surface in the width direction on the rear end side of the neck portion 120 and a side surface in the width direction on the front end side of the grip portion 130. In this case, the boundary between the neck portion 120 and the grip portion 130 is also defined by the ridge line.

For example, in the case of the handle body 12 of the embodiment in which the handle portion 130 is formed in an approximately circular arc shape with a convex shape on the side of the flocked surface 111 and the neck portion 120 is formed in an S-shape with an approximately circular arc shape with a concave shape on the side of the flocked surface 111 in a side view, the boundary between the neck portion 120 and the handle portion 130 is defined as follows.

A curved surface 133 having a circular arc contour whose center position is arranged on the side opposite to the hair-planted surface 111 (the lower side than the grip portion 130 in fig. 2 and 4) and whose hair-planted surface 111 side is convex in a side view is formed on the hair-planted surface 111 side on the distal end side of the grip portion 130. Similarly, a curved surface 134 having a circular arc contour whose center position is disposed on the side opposite to the hair-planted surface 111 and whose hair-planted surface 111 side is convex in a side view is formed on the side opposite to the hair-planted surface 111 on the distal end side of the grip portion 130.

Further, on the side of the hair-planted surface 111 on the rear end side of the neck portion 120, a curved surface 123 having a circular arc contour whose center position is arranged on the hair-planted surface 111 (the upper surface side than the grip portion 130 in fig. 2 and 4) and which is concave on the side of the hair-planted surface 111 in a side view is formed. Similarly, a curved surface 124 having a circular arc contour whose center position is disposed on the hair-planted surface 111 and which is concave on the hair-planted surface 111 side in a side view is formed on the side opposite to the hair-planted surface 111 on the rear end side of the neck portion 120.

As the

curved surfaces

123 and 133 extend in the longitudinal direction of the grip portion 130, the intersection angle between the tangent line and the hair-planted surface 111 in the side view changes continuously, but the intersection between the

curved surfaces

123 and 133 intersects at an angle θ 1 at which the intersection angle between the tangent lines is not 0 or 180 degrees. Therefore, the ridge 131 is formed at the intersection of the curved surface 123 and the curved surface 133.

The

curved surfaces

124 and 134 also continuously change the intersection angle between the tangent line and the hair-planted surface 111 in the side view as extending in the longitudinal direction of the grip portion 130, but intersect at the intersection of the

curved surfaces

124 and 134 at an angle θ 2 at which the intersection angle between the tangent lines is not 0 or 180 degrees. Therefore, the ridge 132 is formed at the intersection of the curved surface 124 and the curved surface 134. Therefore, the neck portion 120 and the grip portion 130 are formed in an approximately S-shape in a side view by connecting the

curved surfaces

133 and 134 having a convex circular arc contour on the side of the flocked surface 111 in a side view on one side in the longitudinal direction of the

ridge lines

131 and 132 and the

curved surfaces

123 and 124 having a concave circular arc contour on the side of the flocked surface 111 in a side view on the other side in the longitudinal direction of the

ridge lines

131 and 132.

The boundary of the rear end side of the neck portion 120 is defined by the

ridges

131 and 132. Therefore, the range 130A in which the handle 130 is arranged is located on the rear end side of the

ridge lines

131 and 132, and the neck portion 120 is arranged in the range 120A between the range 110A in which the head portion 110 is arranged and the range 130A in which the handle 130 is arranged.

The end of the grip portion 130 on the side of the flocked surface 111 (the end on the rear side of the ridge 131) serves as a finger contact portion. The user holds the grip portion 130 by touching the finger contact portion with the thumb, whereby the toothbrush 11 can be stably operated. The ridge 132 of the handle 130 is located at the rear end of the ridge 131 in the longitudinal direction. Therefore, the finger contact portion becomes thicker than the case where the ridge 132 is positioned on the tip side of the ridge 131, and the operation of the toothbrush 11 can be made more stable.

The length of the handle body 12 is not particularly limited, and may be, for example, 100 to 200 mm.

The width of the head 110, i.e., the width in the direction parallel to the bristle surface 111 and perpendicular to the longitudinal direction of the handle 130 (hereinafter, simply referred to as "width") is not particularly limited, and is, for example, preferably 5 to 16mm, more preferably 8 to 12 mm. When the lower limit value is not less than the above-described lower limit value, the area of implanted hair bundle 114 can be sufficiently secured, and when the upper limit value is not more than the above-described upper limit value, the intraoral operability can be further improved.

The length of the head 110 is not particularly limited, but is preferably 10 to 33mm, and more preferably 12 to 28mm, for example. When the lower limit value is not less than the above-described lower limit value, the area of implanted hair bundle 114 can be sufficiently secured, and when the upper limit value is not more than the above-described upper limit value, the intraoral operability can be further improved.

The thickness of the head 110 may be determined in consideration of the material, and is more preferably 2.0 to 4.0mm, for example. When the lower limit value is not less than the lower limit value, the strength of the head 110 can be further improved, and when the upper limit value is not more than the upper limit value, the accessibility to posterior teeth can be improved and the intraoral operability can be further improved.

The length of the neck 120 is preferably 25 to 70mm, for example, in order to allow the neck 120 to contact the lips when the head 110 is inserted into the oral cavity.

The width of the neck 120 is formed as: from the position of the minimum value toward the rear end side, it is constant or gradually larger. When the width of the neck portion 120 is constant from the position of the minimum value toward the rear end side, the position of the minimum value is defined as the position of the most front end side. The neck 120 in the present embodiment is formed as follows: the width thereof becomes gradually larger from the position 121 of the minimum value toward the rear end side. The width of the neck 120 may be determined in consideration of the material, and for example, the minimum width of the neck 120 is preferably 3.5mm or more and 4.5mm or less, and more preferably 3.7mm or more and 4.3mm or less. When the lower limit value is not less than the lower limit value, the strength of the neck portion 120 can be further improved, and when the upper limit value is not more than the upper limit value, the lips are easily closed, and the accessibility to posterior teeth can be improved, and the intraoral operability can be further improved.

When the width of the neck portion 120 is W mm and the thickness in the direction perpendicular to the flocked surface 111 is D mm, the value obtained from D/W at the position 122, which is parallel to the flocked surface 111 and is spaced apart by 10mm from the rear end side with the position 121 where the width of the neck portion 120 is the minimum value, is preferably 0.7 or more and 2.5 or less, more preferably 0.7 or more and 2.0 or less, further preferably 0.8 or more and 2.0 or less, and particularly preferably 0.8 or more and 1.5 or less.

When the minimum width of the neck portion 120 is 3.5mm or more and 4.5mm or less, if the value obtained from D/W is less than the lower limit value, the neck portion 120 may be easily bent during brushing and the operability may be deteriorated, and at the same time, the neck portion 120 may be widened and the operability may be deteriorated, and the head portion 110 may be less thin in appearance and the impression of the product may be deteriorated.

On the other hand, if the value obtained from D/W exceeds the upper limit value, the thickness D may increase, making it difficult to close the lips when brushing the occlusal surface. Further, there is a possibility that the effect of improving operability by thinning the head portion 110 is impaired. Therefore, when the value obtained from D/W is 0.7 or more and 2.5 or less, it is easy to close the lips and brush while maintaining the improved operability obtained by thinning the head 110.

Further, the value obtained by D/W at a position 20mm away from the rear end side with a position 121 at which the width of the neck portion 120 is the minimum as a starting point exceeds 1.0, is preferably 1.3 or less, and is more preferably 1.05 or more and 1.2 or less. Similarly, the value obtained by D/W at a position 30mm away from the rear end side with the position 121 at which the width of the neck portion 120 is the minimum as the starting point exceeds 1.0, is preferably 1.5 or less, and is more preferably 1.05 or more and 1.3 or less.

By making the thickness D larger than the width W at a position 20mm apart from the rear end side with the position 121 of the neck portion 120 where the width is the minimum as the starting point, it is possible to suppress a decrease in operability due to easy flexure of the neck portion 120, and at the same time, to suppress a widening of the neck portion 120 to impair operability. In this way, when the value obtained from D/W at the position is within the above range, even when the position of the neck 120 is inserted into the oral cavity, the effect of improving the operability can be ensured without difficulty in closing the lips. When the value obtained from D/W at a position spaced 30mm from the rear end side starting from the position 121 where the width is the minimum value is within the above range, the effect of improving the operability can be ensured without considering the difficulty in closing the lips.

The difference between the value obtained from the D/W at the position 121 and the value obtained from the D/W at a position 20mm away from the position 121 on the rear end side is preferably 0.05 to 0.07, more preferably 0.06 to 0.07. If the difference between the values obtained from D/W is smaller than the lower limit value and exceeds the upper limit value, the same problem may occur as if the value obtained from D/W is smaller than the lower limit value and if the value obtained from D/W exceeds the upper limit value. Therefore, when the difference between the value obtained from the D/W at the position 121 and the value obtained from the D/W at the position 20mm away from the rear end side from the position 121 is 0.05 or more and 0.07 or less, the brush operation can be performed easily by closing the lips while maintaining the improvement in the operability obtained by thinning the head 110.

Further, it is preferable that the value obtained from the D/W at a position spaced 30mm from the rear end side with the position 121 as a starting point is larger than the value obtained from the D/W at the position 121, and the difference between them is 0.1 to 0.2. When the value obtained from the D/W at the position 30mm away from the rear end side with the position 121 as the starting point and the value obtained from the D/W at the position 121 satisfy the above-described relationship, the improvement in the operability obtained by thinning the head portion 110 is easily maintained, and the lips are easily closed for brushing.

Further, regarding the rate of change in D/W of the position on the rear end side with respect to the position on the front end side in the longitudinal direction of the grip portion 130 as a reference, when the rate of change in D/W of the position on the rear end side at the position 121 where the width of the neck portion 120 is the minimum value is set to R01, the rate of change R01 exceeds 1.00, and is preferably 1.2 or less. When the change rate of D/W at a position 20mm away from the rear end of the position 121 is R02, the change rate R02 exceeds 1.00, and is preferably 1.2 or less. When the change rate of D/W at a position 30mm away from the rear end of the position 121 is R03, the change rate R03 exceeds 1.00, and is preferably 1.3 or less. Preferably, the rates of change R01, R02, R03 satisfy the relationship R01< R02< R03.

Accordingly, the thickness D is already large at the tip side of the neck 120, which is more likely to enter the oral cavity, and it is possible to avoid a situation in which it is difficult to close the lips for brushing. Further, by further increasing the thickness D on the rear end portion side of the neck portion 120 to which a load due to brushing is likely to be applied, it is possible to avoid a problem of operability due to excessive deflection in the thickness D direction.

When the rate of change in D/W from the position 121 as the starting point to the position 10mm away from the rear end side is R12, the rate of change R12 is more than 1.00, preferably 1.2 or less. When the rate of change in D/W from the position 121 as the starting point to the position 20mm away from the rear end side is R23, the rate of change R23 is more than 1.00, preferably 1.3 or less. Preferably, the rates of change R12, R23 satisfy the relationship R01. ltoreq.R 12. ltoreq.R 23. Further, it is preferable that at least one of the rates of change R12, R23 is greater than the rate of change R01.

Accordingly, as described above, the thickness D is already large on the distal end side of the neck 120, which is more likely to enter the oral cavity, and a situation in which it is difficult to close the lips and perform brushing can be avoided. Further, by further increasing the thickness D on the rear end portion side of the neck portion 120 to which a load due to brushing is likely to be applied, it is possible to avoid a problem of operability due to excessive deflection in the thickness D direction.

In general, it is known that the amount of deflection of a rigid body is greatly influenced by the "second moment of area" when the material is the same. Since the amount of deflection is proportional to the 1-power of the width W and the 3-power of the thickness D, it is preferable to minimize the width while maintaining the thickness D in order to reduce the amount of deflection.

For example, let us say the flexural modulus M (mm)⁴)＝W×D³In this case, the deflection coefficient M calculated from the width W and the thickness D at the position 121 of the neck 120 is preferably 165mm⁴Above, 625mm⁴Hereinafter, more preferably 180mm⁴Above, 525mm⁴Hereinafter, 200mm is particularly preferable⁴Above, 330mm⁴The following. Further, the flexural modulus M calculated from the width W and the thickness D at the position 122 of the neck 120 was 165mm⁴Above, 625mm⁴Hereinafter, more preferably 180mm⁴Above, 525mm⁴Hereinafter, more preferably 200mm⁴Above, 330mm⁴Below, more preferably 270mm⁴Above, 310mm⁴The following. Preferably, the deflection coefficient M calculated from the width W and the thickness D of the neck 120 at a position 20mm away from the rear end side in parallel with the hair-planted surface 111 from the position 121 is 350mm⁴Above 550mm⁴The following. Preferably, the flexural coefficient M calculated from the width W and the thickness D of the neck 120 is 600mm at a position 30mm away from the rear end side in parallel with the hair-planted surface 111 from the position 121⁴Above 1500mm⁴The following.

Flexural modulus M at position 122 at 165mm⁴Above, 625mm⁴Hereinafter, it is possible to contribute to improvement of the brushing property when the lips are closed, and it is possible to prevent deterioration of the operability due to excessive deflection.

The rate of change of the deflection coefficient M is preferably 1.0 or more and 1.3 or less between the position 121 and the position 122. The rate of change of the deflection coefficient M between the position 122 and the position 20mm away from the rear end side of the position 121 is preferably 1.3 or more and 1.8 or less. The rate of change in the deflection coefficient M between the position 20mm away from the rear end of the position 121 and the position 30mm away from the rear end of the position 121 is preferably 1.7 or more and 3.0 or less, and more preferably 1.8 or more and 3.0 or less. The change rate is a value obtained by dividing the deflection coefficient at the position on the rear end side by the deflection coefficient at the position on the front end side, and is calculated as M/M from the deflection coefficient M at the position 121 and the deflection coefficient M at the position 122 between the position 121 and the position 122, for example.

When the deflection coefficient M and the rate of change thereof are within the above ranges, the lips are closed and brushing is easily performed without causing a reduction in operability.

Tuft 114 has a plurality of bristles. The length (hair length) from the hair-planted surface 111 to the tip of the hair bundle 114 can be determined in consideration of the stiffness of the bristles required for the hair bundle 114, and can be, for example, 6 to 13 mm. All tufts 114 may be of the same tuft length, or may be of mutually different tuft lengths.

The thickness of the tufts 114 (tuft diameter) can be determined in consideration of the stiffness of the bristles required for the tufts 114, and can be, for example, 1 to 3 mm. All of tufts 114 may be of the same tuft diameter, or may be of different tuft diameters from one another.

Examples of the bristles constituting the tuft 114 include bristles having a diameter gradually decreasing toward the bristle tip and having a sharpened tip (tapered bristles), bristles having a substantially uniform diameter from the bristle attachment surface 111 toward the bristle tip (straight bristles), and the like. As the straight bristles, there may be mentioned: the front end of the brush is a plane substantially parallel to the bristle-implanting surface 111, or the front end of the brush is spherically shaped into a hemisphere.

Examples of the material of the brush include polyamides such as 6-12 nylon (6-12NY) and 6-10 nylon (6-10NY), polyesters such as PET, PBT, polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN) and polybutylene naphthalate (PBN), polyolefins such as PP, polyolefin elastomers such as polyolefin elastomers and styrene elastomers. These resin materials may be used alone in 1 kind or in combination of 2 or more kinds. Further, as the bristles, there may be mentioned bristles made of polyester having a multiple core structure having: a core part and at least 1 layer of sheath part arranged outside the core part.

The cross-sectional shape of the brush is not particularly limited, and may be circular such as a perfect circle and an ellipse, polygonal, star-shaped, three-leaf clover-shaped, four-leaf clover-shaped, or the like. The cross-sectional shape of all bristles may be the same or may be different.

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

The toothbrush 11 is manufactured by first molding the handle body 12 by injection molding.

The tufts 114 are then implanted into the resulting head 110 of the handle body 12. Examples of the method for implanting the hair bundle 114 include: a flat wire (flat plate) type hair-planting in which bundle 114 is implanted by folding bundle 114 in two and driving the flat wire sandwiched therebetween into planting hole 112; a thermal fusion bonding method in which the lower end of the bundle of bristles 114 is pressed into the molten resin to be the implanted portion and fixed; and an in-mold process (in-mold process) in which the lower end of the bundle of bristles 114 is heated to form a molten mass, and then molten resin is injected into a mold to form a bristle-implanted portion.

As described above, according to the toothbrush 11 of the present embodiment, while the minimum width of the neck portion 120 is set to 3.5mm or more and 4.5mm or less, thereby securing a state in which the lips are easily closed and the brush is swiped, the value obtained by D/W is set to 0.7 or more and 2.5 or less, thereby avoiding the deterioration of the operability even when a general-purpose resin such as polypropylene is used.

In the case of flat wire flocking, pressure is applied to the head 110 by driving the flat wire. On the one hand, when the head 110 is thin and has low strength against deformation when a force is applied, and on the other hand, when the neck 120 is thick and has high strength, the following may occur: the pressure during brushing is concentrated on the head 110, and the head 110 is largely warped, thereby reducing usability. In contrast, according to the toothbrush 11 of the present embodiment, since the neck portion 120 is made thin and has a certain degree of flexibility, the pressure during brushing can be dispersed from the head portion 110 to the entire neck portion 120, and usability can be improved. Therefore, in the case of the flat-wire type flocking, the effect of the present invention can be obtained particularly remarkably.

[ examples ]

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

[ Table 1]

(examples 1 to 5 and comparative examples 1 to 7)

Toothbrushes of examples 1 to 5 and comparative examples 1 to 7, in which a neck portion 120 was formed, were manufactured in accordance with the specifications shown in [ table 1 ]. The head part and the handle part have the same width, length, thickness and shape. The PP resin was injection-molded to obtain an integrally molded article of the head and the grip body shown in FIGS. 3 to 4 (from the front end of the head toward the grip body, the arrangement of the graft pores was 3 rows by 1, 4 rows by 6, and 3 rows by 1, the width of the head was 10mm, the length was 25mm, the thickness was 3.0mm, the length of the grip body was 110mm, and the length of the neck was 48 mm). A bundle of tapered bristles (7.5mil) formed of filaments made of PBT was implanted into the head by flat-wire tufting to manufacture a toothbrush.

In each example, the width of the neck part was the smallest, and the value obtained from D/W in each position of the distances 10mm, 20mm, and 30mm from the rear end side of the smallest position was W × D³The values thus obtained are shown in [ Table 2]]. In addition, the number of the groups is W × D in each example³The rate of change of the obtained value calculated from the deflection coefficients at the respective positions as described above is shown in [ Table 3]]. Further, the change rate of D/W values in each example is shown in [ Table 4]]。

(evaluation method)

For the toothbrushes of the respective examples, "the oral cavity operability (ease of movement in the mouth) of the toothbrush" was evaluated by the following method.

< operability of toothbrush >

For the operability of the toothbrush, the "oral operability" was evaluated by the following evaluation criteria using the toothbrushes of each example by the professional experimental group 10. The average score of 10 persons in the professional test group was "very good" at 2.5 or more, the average score was "good" at 2.0 or more and less than 2.5, the average score was "Δ" at 1.5 or more and less than 2.0, and the average score was "x" at less than 1.5.

Reference to evaluation

And 3, dividing: ease of movement in the mouth is very perceptible.

And 2, dividing: ease of movement in the mouth is felt.

1 minute: ease of movement in the mouth is less perceptible.

0 minute: ease of movement in the mouth is not felt.

[ Table 2]

[ Table 3]

Width x thickness³[W×D³]Rate of change of

[ Table 4]

As shown in table 2, it was confirmed that: the thickness of the head part is 2.0-4.0 mm, the minimum value of the width of the neck part is 3.5 mm-4.5 mm, the value obtained by D/W at the position of 10mm distance from the rear end side of the position of the minimum value in the neck part is 0.7-2.5, the difference between the value obtained by D/W at the position 121 with the minimum value of the width and the value obtained by D/W at the position of 20mm distance from the rear end side of the position 121 is 0.05 or more, and the deflection coefficient M (mm and mm) is set⁴)＝W×D³Is 165mm⁴Above, 625mm⁴Hereinafter, good operability can be obtained when the value obtained from D/W at a position 20mm away from the rear end of the position 121 exceeds 1.0, the value obtained from D/W at a position 30mm away from the rear end of the position 121 is larger than the value obtained from D/W at the position 121, and the difference between the two values is 0.1 or more.

In addition, as shown in table 4, it was confirmed that: good operability can be obtained even when the change rates R01, R02, R03, R12 and R13 each exceed 1.00 and satisfy the relationship R01< R02< R03 and the relationship R01< R12 < R23.

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

For example, in the toothbrush 11 of the above embodiment, the configuration in which the neck portion 120 gradually increases in width from the minimum width position toward the rear end side is exemplified, but the configuration is not limited thereto, and a configuration extending toward the rear end side with the same width may be employed. Even in the configuration in which the neck portion 120 extends toward the rear end side with the same width, the value obtained by D/W at the position distant by 10mm from the rear end side of the position of the minimum width is preferably 0.7 or more and 2.5 or less.

Claims

1. A toothbrush is characterized in that a toothbrush head is provided,

the disclosed device is provided with: a head part which is arranged at the front end side and implanted with hair bundles on the hair implanting surface, a neck part which extends from the rear end side of the head part, and a handle part which extends from the rear end side of the neck part,

the thickness of the head part is 2.0-4.0 mm,

the neck portion is formed as: a minimum value of a width in a direction parallel to the bristle surface and perpendicular to the longitudinal direction of the grip portion is 3.5mm or more and 4.5mm or less, the width is constant or gradually increased from a position of the minimum value toward a rear end side,

when the width of the neck part is W mm and the thickness in the direction perpendicular to the hair-planting surface is D mm,

when the width of the neck portion is gradually increased from the position of the minimum value toward the rear end, the width of the neck portion is constant from the position of the minimum value toward the rear end, with the position of the minimum value on the most front end side as a starting point, and in parallel with the flocked surface, the value obtained from D/W at a position spaced apart by 10mm from the rear end side is 0.7 or more and 2.5 or less, and the difference between the value obtained from D/W at the position of the starting point where the width is the minimum value and the value obtained from D/W at a position spaced apart by 20mm from the rear end side of the position of the starting point is 0.05 or more, and D/W at a position spaced apart by 20mm from the rear end side of the position of the starting point exceeds 1.0,

a rate of change of the D/W at a position spaced apart from the rear end side of the starting point position by 20mm exceeds 1.00 from a position spaced apart from the rear end side of the starting point position by 10mm,

the rate of change of D/W at a position spaced 30mm from the rear end of the starting point position exceeds 1.00 from the position spaced 20mm from the rear end of the starting point position,

a deflection coefficient M (mm) at a position 10mm away from the rear end side of the position of the starting point at which the width is the minimum value⁴)＝W×D³Is 165mm⁴Above, 625mm⁴The following.

2. The toothbrush of claim 1,

the neck portion is formed of a resin material,

the resin material has a flexural modulus of elasticity of 1000MPa to 2200 MPa.

3. The toothbrush of claim 1 or 2, wherein the neck is formed of polypropylene resin.

4. The toothbrush according to claim 1 or 2, wherein when a position separated by 10mm from the rear end of the position of the starting point where the width is the minimum value is taken as a reference, the rate of change of the flexural coefficient at the position separated by 10mm from the rear end of the reference position is 1.3 or more and 1.8 or less.

5. The toothbrush according to claim 1 or 2, wherein a difference between a value obtained from the D/W at a position of the starting point at which the width is the minimum and a value obtained from the D/W at a position spaced 20mm from a rear end side of the position is 0.07 or less.

6. The toothbrush according to claim 1 or 2, wherein a value obtained from the D/W at a position 20mm away from the rear end side of the starting position is 1.05 or more and 1.3 or less, and a value obtained from the D/W at a position 30mm away from the rear end side of the starting position is 1.05 or more and 1.5 or less.

7. The toothbrush according to claim 5, wherein a difference between a value obtained from the D/W at the position of the starting point and a value obtained from the D/W at a position spaced 20mm from a rear end side of the position of the starting point is 0.06 or more.

8. The toothbrush according to claim 1 or 2, wherein a difference between a value obtained from the D/W at the position of the starting point and a value obtained from the D/W at a position spaced 30mm from a rear end side of the position of the starting point is 0.1 or more and 0.2 or less.

9. The toothbrush according to claim 1 or 2, wherein the rate of change of D/W at a position spaced 10mm from the rear end side of the starting position is R01, the rate of change of D/W at a position spaced 20mm from the rear end side is R02, and the rate of change of D/W at a position spaced 30mm from the rear end side is R03, based on the starting position, the rates of change R01, R02, and R03 satisfy the relationship of R01< R02< R03.

10. The toothbrush according to claim 1 or 2, wherein a rate of change of the D/W at a position 10mm away from the rear end side of the start position is R01, a rate of change of the D/W at a position 20mm away from the rear end side of the start position is R12, and a rate of change of the D/W at a position 30mm away from the rear end side is R23, from the position 20mm away from the rear end side of the start position, from the start position, the rates of change R12 and R23 satisfy a relationship of R01 ≦ R12 ≦ R23, and at least one of the rates of change R12 and R23 is larger than the rate of change R01.

11. The toothbrush according to claim 1 or 2, wherein the rate of change of D/W at a position spaced apart from 20mm on the rear end side of the starting position is 1.2 or less from a position spaced apart from 10mm on the rear end side of the starting position,

the rate of change of D/W at a position spaced 30mm from the rear end of the starting point position is 1.3 or less from the position spaced 20mm from the rear end of the starting point position.