WO2016208333A1

WO2016208333A1 - Toothbrush

Info

Publication number: WO2016208333A1
Application number: PCT/JP2016/066022
Authority: WO
Inventors: 篤人木村; 小林　利彰
Original assignee: ライオン株式会社
Priority date: 2015-06-24
Filing date: 2016-05-31
Publication date: 2016-12-29
Also published as: KR20180021668A; JPWO2016208333A1; CN107708480A; JP6817935B2

Abstract

The purpose of the present invention is to provide a toothbrush that is exceptionally easy to operate, that tends not to become tacky when the handle part thereof is gripped, even during continuous use, and that makes it possible to prevent any adverse effect on the sensations during use. The toothbrush (11) is provided with: a handle body (110) in which a handle part (114), a neck part (116), and a head part (118) are integrally formed; and a plurality of bristles (112) embedded in a bristle bed surface (118a) of a head part (118). The handle part (114) is provided with a soft part (124) formed from a soft resin having a Type A Shore hardness of 30 or less, and a hard part (120) formed from a hard resin having a Type A Shore hardness greater than that of the soft resin. The hard part (120) and the soft part (124) are exposed at the peripheral surface of the handle part (114), the exposed portion (120a) of the hard part (120) being formed outward from the exposed portion (124a) of the soft part (124). The neck part (116) and the head part (118) are formed from the hard resin.

Description

toothbrush

The present invention relates to a toothbrush.
This application claims priority based on Japanese Patent Application No. 2015-126428 filed in Japan on June 24, 2015, the contents of which are incorporated herein by reference.

In general, a toothbrush includes a handle body including a rod-shaped handle portion, a neck portion extending from the tip of the handle portion, and a head portion provided at the tip of the neck portion, and a plurality of implants implanted in the head portion. And a hair bundle. In a general toothbrush, the handle body is formed of a hard resin so that the handle portion can be prevented from being excessively bent during brushing and a sufficient force can be applied to the teeth from the bristle bundle. However, a toothbrush having a handle body made of only a hard resin tends to be inferior in operability because the handle body is hard and difficult to bend. As a result, the operation of the toothbrush may be mistaken during brushing, which may damage the oral cavity.

As a toothbrush that improves the operability by improving the fit when the handle is gripped by hand, the surface of the rod-shaped handle core formed of hard resin is partially or entirely covered with soft resin. Toothbrushes having a handle portion have been proposed (for example, Patent Documents 1 to 3).

However, in the toothbrushes of Patent Documents 1 to 3, when bloom or bleed-out occurs due to the change of the soft resin over time, the handle is sticky when the part formed of the soft resin is gripped by the hand. It is easy to feel and the feeling of use decreases.

JP 2006-466 Gazette Japanese Patent Laid-Open No. 2005-144033 Japanese Patent No. 4159939

The object of the present invention is to provide a toothbrush that is excellent in operability and is less likely to feel sticky when gripped with a hand even when continuously used, and that can suppress a decrease in feeling of use.

The present invention has the following configuration.
[1] A handle body integrally formed with a handle portion, a neck portion extended at the tip of the handle portion, and a head portion provided at the tip of the neck portion, and planted on the flocked surface of the head portion In the toothbrush comprising the plurality of bristles, the handle portion is formed of a soft portion formed of a soft resin having a Shore A hardness of 30 or less and a hard resin having a Shore A hardness higher than that of the soft resin. The hard part and the soft part are both exposed at the peripheral surface of the handle part, and the exposed part of the hard part is outside the exposed part of the soft part. The ratio of the cross-sectional area of the soft part to the total cross-sectional area of the hard part and the soft part in the cross-section obtained by cutting the part where the soft part is formed perpendicular to the axial direction is 40% or more and 80% Below and before Neck and said head portion is formed by the hard resin, the toothbrush.
[2] The toothbrush according to [1], wherein the hard portion has a single bar shape extending from a front end to a rear end of the handle portion.
[3] The toothbrush according to [2], wherein a concave line is formed on a side surface of the rod-shaped hard part, and the soft part is formed in the concave line.
[4] The toothbrush according to [1], wherein the handle portion is a handle portion in which the hard portion is formed on a surface of a handle core portion which is a stick-shaped soft portion.
[5] The toothbrush according to [4], wherein the hard portion includes a plurality of hard portions that are formed apart from each other in a circumferential direction or an axial direction of the handle portion.
[6] The toothbrush according to any one of [1] to [5], wherein the hard portion is flexible.

The toothbrush of the present invention is excellent in operability, and even when continuously used, it is difficult to feel stickiness when the handle portion is gripped with a hand, and a decrease in feeling of use is suppressed.

It is the top view which showed an example of embodiment (i) of the toothbrush of this invention. FIG. 2 is a cross-sectional view taken along the line II of the toothbrush of FIG. 1. It is sectional drawing which showed the other example of embodiment (i) of the toothbrush of this invention. It is sectional drawing which showed the other example of embodiment (i) of the toothbrush of this invention. It is sectional drawing which showed the other example of embodiment (i) of the toothbrush of this invention. It is the top view which showed the other example of embodiment (i) of the toothbrush of this invention. It is the top view which showed an example of embodiment (ii) of the toothbrush of this invention. It is AA sectional drawing of the toothbrush of FIG. FIG. 8 is a BB cross-sectional view of the toothbrush of FIG. FIG. 10 is a cross-sectional view taken along the line CC of the toothbrush of FIG. 9. It is the top view which showed the other example of embodiment (ii) of the toothbrush of this invention. It is the top view which showed the other example of embodiment (ii) of the toothbrush of this invention. It is the top view which showed the other example of embodiment (ii) of the toothbrush of this invention.

In the present invention, the soft resin means a resin having a Shore A hardness of 30 or less.
A hard resin means a resin having a Shore A hardness higher than that of a soft resin, that is, a resin having a Shore A hardness of more than 30.
The Shore A hardness means a hardness measured according to JIS K 7215 or JIS K 6253.

The toothbrush of the present invention includes a handle part, a neck part extending at the tip of the handle part, a handle body integrally formed with a head part provided at the tip of the neck part, and a flocking surface of the head part And a plurality of hair bundles implanted in the. Further, in the toothbrush of the present invention, the handle portion includes a soft portion formed of a soft resin having a Shore A hardness of 30 or less, a hard portion formed of a hard resin having a Shore A hardness higher than the soft resin, Is provided. The hard part and the soft part are both exposed on the peripheral surface of the handle part, and the exposed part of the hard part is outside the exposed part of the soft part. The neck part and the head part are made of hard resin.

As an aspect of the toothbrush of this invention, the following two aspects are mentioned.
(I) A mode provided with a single hard rod-like portion extending from the front end to the rear end of the handle portion.
(Ii) A mode provided with a handle part in which a hard part is formed on the surface of the handle core part which is a stick-like soft part.
Hereinafter, the embodiment (i) and the embodiment (ii) will be described with examples.

<Embodiment (i)>
Hereinafter, the embodiment (i) of the toothbrush of the present invention will be described with reference to an example.
As shown in FIGS. 1 and 2, the toothbrush 11 of the embodiment (i) includes a handle body 110 and a plurality of bristle bundles 112 implanted in the handle body 110.

[Handle]
The handle body 110 is provided with a rod-shaped handle portion 114, a tip portion of the handle portion 114, a neck portion 116 thinner than the handle portion 114, and a tip end of the neck portion 116, and a plurality of hair bundles 112 are implanted. The head unit 118 is provided.
The handle portion 114 and the neck portion 116 have curved shapes having inflection points a and b in which

outer edges

115a and 115b on both sides of the boundary portion in plan view gradually approach from the handle portion 114 to the neck portion 116. Are integrally formed. Thus, the width of the boundary portion between the handle portion 114 and the neck portion 116 gradually decreases from the handle portion 114 to the neck portion 116. In the handle body 110 of the present embodiment, a straight line L connecting the inflection points a and b of the

outer edges

115a and 115b on both sides in a plan view is formed at the boundary portion between the handle portion 114 and the neck portion 116. The boundary line 114 and the neck portion 116 are used.

(Handle part)
The handle portion 114 is a portion that is gripped by a hand during brushing, and is provided in a hard portion 120 that is in the shape of a single bar that extends from the front end to the rear end of the handle portion 114, and in a recess 122 that is formed on the side surface of the hard portion 120. And a soft portion 124 formed. The hard part 120 is made of a hard resin. The soft part 124 is made of a soft resin.

The hard portion 120 includes a front end side hard portion 126, a rear end side hard portion 128, a base portion 130, and

ridges

132a and 132b. The distal end side hard portion 126 is located at the distal end portion of the handle portion 114 and has a diameter that decreases toward the distal end. The rear end side hard portion 128 is located at the rear end portion of the handle portion 114 and is hemispherical. The base 130 is a long flat plate and extends from the front end side hard portion 126 to the rear end side hard portion 128.

Three ridges 132 a are formed on one surface of the base 130. Each protrusion 132a is spaced apart from each other in the width direction of the base portion 130 and extends in parallel in the axial direction from the front end side hard portion 126 to the rear end side hard portion 128. The respective protrusions 132 a on both side edges of the base portion 130 are located on the inner side of the side edges in the width direction of the base portion 130.

Two protrusions 132b are formed on the other surface of the base 130. Each protrusion 132b is spaced apart from each other in the width direction of the base portion 130 and extends in parallel in the axial direction from the front end side hard portion 126 to the rear end side hard portion 128. Each ridge 132b is formed at a position corresponding to the space between the three ridges 132a in the width direction of the base portion 130.

The thickness and length of the handle portion 114 are not particularly limited, and can be appropriately designed according to the subject who uses the toothbrush 11.
The thickness of the base portion 130 and the widths and heights of the

ridges

132a and 132b are not particularly limited, and may be set as appropriate according to the thickness of the handle portion 113 so that sufficient rigidity is obtained. For example, the thickness of the base 130 can be about 1 to 4 mm, the width of the

ridges

132a and 132b can be about 1 to 4 mm, and the height of the

ridges

132a and 132b can be about 1 to 5 mm. Further, the interval between the ridges can be set to about 0.5 to 3.0 mm, for example.
The number of ridges 132a is not limited to three, but may be two or less, or four or more. The number of ridges 132b is not limited to two, and may be one or three or more. The number of ridges 132a and ridges 132b may be the same or different.

The hard portion 120 has a front end side hard portion 126, a rear end side hard portion 128, a base portion 130, and

protrusions

132a and 132b, which are integrally formed as a single bar. Seven concave ridges 122 extending in the axial direction are formed on the side surface of the hard portion 120 by the base 130 and the

ridges

132a and 132b.

As the hard resin forming the hard part, a resin having a Shore A hardness higher than that of the soft resin, that is, a resin having a Shore A hardness of more than 30 can be used. As the hard resin, a resin having a flexural modulus (JIS K7203) of 500 to 3000 MPa is preferable. Specific examples of the hard resin include, for example, polypropylene, polyethylene terephthalate, polybutylene terephthalate, polycyclohexylenedimethylene terephthalate, polyacetal, polystyrene, acrylonitrile / butadiene / styrene resin, cellulose propionate, polyarylate, polycarbonate, acrylonitrile / styrene. Among copolymer resins and the like, resins having a Shore A hardness of more than 30 can be mentioned. If the Shore A hardness exceeds 30, an elastomer can be used as a hard resin. As hard resin, 1 type may be used independently and 2 or more types may be used in combination.

It is preferable that the hard part has flexibility. Thereby, when the handle portion is gripped with a hand, a portion that comes into contact with the finger is easily deformed appropriately, so that an excellent fit can be easily obtained. The flexibility of the hard part can be adjusted by adjusting the thickness of the base part and the width of the ridges in the hard part. The hard portion may be formed of a foamed resin obtained by blending a hard resin with a foaming agent and foaming in order to improve flexibility. It does not specifically limit as a foaming agent, A well-known chemical foaming agent and a physical foaming agent can be used. Further, since the final hardness of the foamed resin varies depending on the bubble content, the hardness of the base resin (the resin before adding the foaming agent) is not limited.

The soft portion 124 is formed in each of the seven recesses 122 such that the position of the exposed portion 124a of the soft portion 124 in the handle portion 114 is concave. That is, the hard part 120 and the soft part 124 are both exposed on the peripheral surface of the handle part 114, and the exposed part 120a of the hard part 120 is positioned outside the exposed part 124a of the soft part 124. . As described above, in the toothbrush 11, the exposed portion 120 a of the hard portion 120 protrudes outward from the exposed portion 124 a of the soft portion 124.

In this example, the hard portion 120 has both ends in the width direction of the base portion 130, the tip end portion of the protrusion 132 a, and the tip end portion of the protrusion 132 b protrude from the peripheral surface of the handle portion 114, respectively. An exposed portion 120a located outside the exposed portion 124a is formed. Further, the cross-sectional shape perpendicular to the axial direction of the soft portion 124 is elliptical as a whole. The cross-sectional shape of the soft portion 124 is not limited to the shape of this example, and may be a rectangular shape as a whole.

In the toothbrush 11, the exposed portion 120 a of the hard portion 120 is positioned outside the exposed portion 124 a of the soft portion 124, so that when the handle portion 114 is gripped by a hand, the finger comes into contact with the hard portion 120 and the soft portion 124 becomes difficult to contact. For this reason, even if bloom or bleed out occurs in the soft portion 124 due to the aging of the soft resin, it is difficult to feel sticky when the handle portion 114 is gripped by hand, and the feeling of use is unlikely to decrease.
The step between the exposed portion 120a of the hard portion 120 and the exposed portion 124a of the soft portion 124 can be, for example, about 0.5 to 3 mm.

In the toothbrush 11, the handle portion 114 is formed of a hard portion 120 and a soft portion 124. Therefore, compared with the case where a handle part is formed only with a hard part, it has high elasticity and is easy to bend. In addition, since the handle portion 114 has one rod-like hard portion 120, the handle portion 114 has sufficient rigidity to suppress excessive bending during brushing. Therefore, the operability at the time of brushing is excellent, and it is easy to apply sufficient force by applying a hair bundle to the target tooth, so it is easy to brush the teeth firmly.

The ratio of the cross-sectional area of the soft portion 124 to the total cross-sectional area of the hard portion 120 and the soft portion 124 in a cross section obtained by cutting the portion where the soft portion 124 of the handle portion 114 is formed perpendicular to the axial direction is 40%. It is 80% or less and preferably 50% or more and 70% or less. If the said ratio is more than a lower limit, the flexibility of a handle part will be excellent and a handle part will bend moderately at the time of brushing. Moreover, if the said ratio is below an upper limit, it will suppress that a handle | steering-wheel part bends excessively at the time of brushing. When the ratio is within the above range, the operability of the toothbrush is excellent, and the operation of the toothbrush during brushing is less likely to be erroneous.

As the soft resin forming the soft part, a resin having a Shore A hardness of 30 or less can be used. Specific examples of the soft resin include resins having a Shore A hardness of 30 or less among elastomer resins such as polyolefin elastomers, styrene elastomers, and polyester elastomers. As the soft resin, one kind may be used alone, or two or more kinds may be used in combination.

The Shore A hardness of the soft resin is 30 or less, preferably 0 to 25, more preferably 0 to 20. If the Shore A hardness of the soft resin is less than or equal to the upper limit value, an excellent fit can be obtained when the handle portion is gripped by hand.

The soft part may be formed of a foamed resin obtained by blending a soft resin with a foaming agent. It does not specifically limit as a foaming agent, A well-known chemical foaming agent and a physical foaming agent can be used. Further, since the final hardness of the foamed resin varies depending on the bubble content, the hardness of the base resin (the resin before adding the foaming agent) is not limited.

The surface of the exposed portion of the soft part is preferably subjected to a textured process. Thereby, even if a finger touches the exposed part of the soft part, the contact area can be made smaller, so that the feeling of use is less likely to be lowered.

(Neck and head)
The neck portion 116 and the head portion 118 are formed integrally with the soft portion 124. The neck portion 116 has a columnar shape that is thinner than the handle portion 114, the rear end portion gradually increases in diameter toward the handle portion 114, and the tip end portion gradually increases in diameter toward the head portion 118. .

The head portion 118 is a portion in which a plurality of hair bundles 112 are provided at the tip of the neck portion 116. An upper surface of the head portion 118 is a flocking surface 118 a for planting the hair bundle 112. The shape of the head portion 118 is a plate shape in which a rectangular corner portion that is long in the axial direction in a plan view is cut out. The length, width, and thickness of the head portion 218 are not particularly limited, and can be appropriately designed according to the subject who uses the toothbrush 11.

The neck part 116 and the head part 118 are made of hard resin. As hard resin which forms the neck part 116 and the head part 118, the same thing as what was mentioned as hard resin which forms the hard part 120 is mentioned, for example. As hard resin which forms the neck part 116 and the head part 118, 1 type may be used independently and 2 or more types may be used in combination. The hard resin forming the neck portion 116 and the head portion 118 is preferably the same as the hard resin forming the hard portion 120 in the handle portion 114. The hard resin that forms the neck portion 116 and the head portion 118 may be different from the hard resin that forms the hard portion 120 in the handle portion 114.

[Hair bundle]
The hair bundle 112 is not particularly limited, and a known hair bundle can be adopted. The hair bundle 112 may be cylindrical or prismatic. The hair length and thickness of the hair bundle 112 can be determined in consideration of the hair and waist required for the hair bundle 112.

The bristles constituting the hair bundle 112 are not particularly limited, and known bristles can be used. The bristles may be tapered hairs with sharpened tips, and face the hair tips from the flocked surface 118a. Straight hairs having substantially the same diameter may be used. The cross-sectional shape of the hair is not particularly limited, and examples thereof include a circle and a polygon.
The material for the hair is not particularly limited, and examples thereof include polyamide (6-12 nylon and the like), polyester (polyethylene terephthalate and the like), polyolefin (polypropylene and the like), and the like.
The thickness of the hair can be determined in consideration of the material and the like. When the cross section is circular, the thickness is 4 to 10 mil (1 mil = 1/1000 inch = 0.025 mm), for example.

A mode in which the hair bundle 112 is planted on the hair planting surface 118a of the head unit 118 is not particularly limited. In this example, two hair bundles 112 are implanted in the width direction near the leading end and the rear end of the flocked surface 118a, respectively, and three hair bundles 112 are arranged in the width direction in an area between them. Twelve hair bundles 112 are implanted so that four hair bundles 112 are arranged in the axial direction.

[Production method]
The manufacturing method of embodiment (i) is not specifically limited, A well-known method can be utilized.
Examples of the method for manufacturing the handle body 110 include the following methods. An integrated body of the rod-like hard part 120, the neck part 116 and the head part 118 is formed by injection molding of a hard resin using a primary mold. Next, in a state where the integrated body is placed in the secondary mold, a soft resin is injected to mold the soft portion 124 to obtain the handle body 110.
Examples of a method for implanting the hair bundle 112 on the head portion 118 of the handle body 110 include a flat wire type flocking method, a heat welding type flocking method, an in-mold method, and the like.

In the toothbrush of the embodiment (i) described above, the handle portion is formed of a hard portion and a soft portion, and in the cross section obtained by cutting the handle portion perpendicular to the axial direction, the total breakage of the hard portion and the soft portion. The ratio of the cross-sectional area of the soft part to the area is 40% or more and 80% or less. As a result, the handle portion has sufficient elasticity, is flexible, and has sufficient rigidity, so that excellent operability can be obtained. In addition, because the exposed part of the hard part is located outside the exposed part of the soft part, it is difficult for the fingers to come into contact with the soft part when the handle part is gripped by hand, so that bloom or bleed out occurs in the soft part. Even if it is done, it is hard to feel stickiness and the feeling of use is unlikely to decrease.

Note that the toothbrush of the embodiment (i) is not limited to the toothbrush 11 described above. For example, the toothbrush 12 illustrated in FIG. 3 may be used. In FIG. 3, the same parts as those in FIG. The toothbrush 12 is the same as the toothbrush 11 except that the handle body 110 includes a handle portion 114A instead of the handle portion 114.

The handle portion 114A includes a hard portion 120A having eight concave stripes 122A formed on the side surface and a soft portion 124A formed in the concave stripe 122A. The hard portion 120 </ b> A is provided with five ridges 132 a on one surface of the base portion 130 and five ridges 132 b on the other surface of the base portion 130. All of the five ridges 132a and the five ridges 132b are the highest at the center in the width direction of the base 130, and the height decreases toward the outside. Of the five ridges 132 a, the two ridges 132 a located outside in the width direction of the base portion 130 are formed so as to rise from the side end of the base portion 130. Of the five ridges 132b, the two ridges 132b positioned outside in the width direction of the base portion 130 are also formed so as to rise from the side end of the base portion 130. The positions of the five ridges 132a and the five ridges 132b in the width direction of the base portion 130 coincide with each other.

Other aspects of the handle portion 114A are the same as those of the handle portion 114. A soft part 124A is formed in the eight concave stripes 122A of the hard part 120A, and the position of the exposed part 124a of the soft part 124A in the handle part 114A is concave. That is, the hard part 120A and the soft part 124A are both exposed on the peripheral surface of the handle part 114A, and the exposed part 120a of the hard part 120A is located outside the exposed part 124a of the soft part 124A. .

Also in the toothbrush 12, excellent operability is obtained, and when the handle portion 114A is grasped with a hand, the finger is unlikely to contact the soft portion 124A, and the usability is also excellent.

The toothbrush of Embodiment (i) may be the toothbrush 13 illustrated in FIG. The same parts in FIG. 4 as those in FIG. The toothbrush 13 is the same as the toothbrush 11 except that the handle body 110 includes a handle portion 114B instead of the handle portion 114.

The handle portion 114B includes a hard portion 120B having eight concave stripes 122B formed on a side surface and a soft portion 124B formed in the concave stripes 122B. In the hard part 120B, one ridge 132a is provided at the center in the width direction of one surface of the base part 130, and the cross section whose height increases toward the outside on both sides in the width direction of the ridge 132a is substantially triangular. A shaped ridge 134a is provided. Similarly, the other surface of the base portion 130 is provided with one protrusion 132b at the center in the width direction, and the cross section whose height increases toward the outside on both sides in the width direction of the protrusion 132b is substantially triangular. A shaped ridge 134b is provided.

Other aspects of the handle portion 114B are the same as the handle portion 114. A soft portion 124B is formed in the eight concave stripes 122B of the hard portion 120B, and the position of the exposed portion 124a of the soft portion 124B in the handle portion 114B is concave. That is, the hard part 120B and the soft part 124B are both exposed at the peripheral surface of the handle part 114B, and the exposed part 120a of the hard part 120B is positioned outside the exposed part 124a of the soft part 124B. .

Also in the toothbrush 13, excellent operability is obtained, and when the handle portion 114B is grasped with a hand, the finger is unlikely to contact the soft portion 124B, and the usability is also excellent.

The toothbrush of Embodiment (i) may be the toothbrush 14 illustrated in FIG. In FIG. 5, the same parts as those in FIG. The toothbrush 14 is the same as the toothbrush 11 except that the handle body 110 includes a handle portion 114C instead of the handle portion 114.

The handle portion 114C includes a hard portion 120C having four concave ridges 122C formed on the side surface and a soft portion 124C formed in the concave ridge 122C. In the hard part 120C, one protrusion 132a is provided at the center in the width direction of one surface of the base 130, and one protrusion 132b is also provided at the center in the width direction of the other surface of the base 130. .

Other aspects of the handle portion 114C are the same as those of the handle portion 114. A soft part 124C is formed in the four concave stripes 122C of the hard part 120C, and the position of the exposed part 124a of the soft part 124C in the handle part 114C is concave. That is, the hard part 120C and the soft part 124C are both exposed on the peripheral surface of the handle part 114C, and the exposed part 120a of the hard part 120C is positioned outside the exposed part 124a of the soft part 124C. .

Also in the toothbrush 14, excellent operability is obtained, and when the handle portion 114C is grasped with a hand, the finger is unlikely to contact the soft portion 124C, and the usability is also excellent.

The toothbrush 15 illustrated in FIG. 6 may be the toothbrush of the embodiment (i). In FIG. 6, the same parts as those in FIG. The toothbrush 16 is the same as the toothbrush 11 except that the handle body 110 includes a handle portion 114D instead of the handle portion 114.

Instead of the hard portion 120, the handle portion 114D has a plate portion 136 that is exposed on the entire circumference so as to connect the base portion 130 and the

ridges

132a and 132b at the portion of the hard portion 120 where the concave stripe 122 is formed. The hard part 120D provided is provided. Three plate portions 136 are provided at intervals in the axial direction of the handle portion 114D. Thereby, on the side surface of the hard part 120D, a concave line 122D in which the seven concave lines 122 in the hard part 120 are divided into four in the axial direction is formed. A soft portion 124D is formed in each recess 122, and the position of the exposed portion 124a of the soft portion 124D in the handle portion 114D is concave. That is, the hard part 120D and the soft part 124D are both exposed on the peripheral surface of the handle part 114D, and the exposed part 120a of the hard part 120D is positioned outside the exposed part 124a of the soft part 124D. .

Also in the toothbrush 15, excellent operability is obtained, and when the handle portion 114D is grasped with a hand, the finger is unlikely to contact the soft portion 124D, and the usability is also excellent.

The toothbrush of embodiment (i) may be provided with the hard part in which the protruding item |

line

132a, 132b is not provided in the hard part 120. FIG.
The groove formed on the side surface of the hard part is not limited to an aspect formed so as to extend in the axial direction of the handle part. For example, the toothbrush of embodiment (i) may be one in which a spiral protrusion is provided on a rod-like base and a recess is spirally formed on the side surface of the hard part. Further, in the toothbrush of the embodiment (i), a plurality of ring-shaped ridges in the circumferential direction are provided in the rod-like base portion with an interval in the axial direction, and a groove extending in the circumferential direction is provided on the side surface of the hard portion in the axial direction. A plurality may be formed at intervals.

<Embodiment (ii)>
Hereinafter, the embodiment (ii) of the toothbrush of the present invention will be described with reference to an example.
The toothbrush 21 of the embodiment (ii) includes a handle body 210 and a plurality of bristle bundles 212 implanted in the handle body 210, as shown in FIGS.

[Handle]
The handle body 210 is provided with a rod-shaped handle portion 214, a neck portion 216 that is narrower than the handle portion 214, and a tip portion of the neck portion 216, and a plurality of hair bundles 212 are implanted. A head portion 218.
The handle portion 214 and the neck portion 216 have curved shapes having inflection points a and b in which

outer edges

215a and 215b on both sides of the boundary portion in plan view gradually approach from the handle portion 214 to the neck portion 216. Are integrally formed. As described above, the width of the boundary portion between the handle portion 214 and the neck portion 216 gradually decreases from the handle portion 214 to the neck portion 216. Also in the handle body 210 of the present embodiment, a straight line L connecting the inflection points a and b of the

outer edges

215a and 215b on both sides in a plan view at the boundary portion between the handle portion 214 and the neck portion 216 A boundary line between the portion 214 and the neck portion 216 is used.

(Handle part)
The handle portion 214 is a portion that is gripped by a hand during brushing, and includes a handle core portion 220 that is a stick-shaped soft portion, and a hard portion 222 formed on the surface of the handle core portion 220. The handle core 220 is made of a soft resin. The hard part 222 is formed of a hard resin.

The shape of the handle core 220 in this example is such that the diameter of the cylindrical neck portion 216 is gradually reduced.
As shown in FIG. 10, rear end side recesses 224 a and 224 b that are recessed inward in the radial direction are formed at corresponding positions on both side surfaces in a portion near the rear end of the handle core portion 220. Yes. Similarly, on both side surfaces in a plan view of the portion near the front end of the handle core 220, front

end side recesses

226a and 226b that are recessed inward in the radial direction are formed at positions corresponding to each other. By using the rear

end side recesses

224a and 224b and the front

end side recesses

226a and 226b when the handle body 210 is molded, the positioning of the handle core part 220 in the secondary mold is facilitated.

The thickness and length of the handle core portion 220 can be appropriately designed according to the thickness and length of the handle body 210. The thickness and length of the handle body 210 can be appropriately designed according to the subject who uses the toothbrush 21.
The handle core 220 is preferably formed from the rear end of the handle 214 to the front end.
The cross-sectional shape of the handle core 220 is a circular shape in this example, but is not limited to a circular shape, and may be a rectangular shape or the like.

The hard part 222 is a hemispherical rear end side hard part 222a located at the rear end part of the handle core part 220 and a front end side hard part located at the front end part of the handle core part 220 and gradually decreasing in diameter toward the front end. A portion 222b and a grid-like hard portion 222c provided between the rear end side hard portion 222a and the front end side hard portion 222b are provided.

The grid-like hard portion 222c is formed in a band shape so as to extend in the axial direction from the rear end side hard portion 222a to the front end side hard portion 222b, and a plurality of band-like hard portions 222d spaced apart in the circumferential direction, and in a ring shape in the circumferential direction It is formed with a plurality of ring-shaped hard portions 222e that are formed and spaced apart in the axial direction. As shown in FIG. 9, six belt-like hard portions 222 d are formed at equal intervals around the central axis of the handle core portion 220. As shown in FIG. 7, four ring-shaped hard portions 222e are formed between the rear end side hard portion 222a and the front end side hard portion 222b in the axial direction.
In the handle part 214 of this example, a part of the handle core part 220 is formed from a part where the ring-like hard part 222e does not exist between the band-like hard parts 222d spaced apart in the circumferential direction in the lattice-like hard part 222c of the hard part 222. Is exposed.

Thus, the handle portion 214 includes the handle core portion 220 formed of a soft resin, and the handle core portion 220 is partially covered by the hard portion 222. As a result, the handle portion 214 has excellent elasticity, and the portion with which the finger comes into contact when gripped with a hand is appropriately dented and deformed, so that an excellent fit can be obtained. In addition, since the hard portion 222 is formed on the surface of the handle core portion 220, the handle portion 214 is secured with sufficient rigidity to prevent excessive bending during brushing. Thereby, the operability at the time of brushing becomes excellent, and since it is easy to apply a sufficient force by applying the hair bundle to the target tooth, it is easy to brush the teeth firmly.

In the cross section obtained by cutting the portion of the handle portion 214 where the handle core portion 220 that is a soft portion is formed perpendicular to the axial direction, the section of the handle core portion 220 with respect to the total cross-sectional area of the hard portion 222 and the handle core portion 220 is cut. The area ratio is 40% or more and 80% or less, and preferably 50% or more and 70% or less. If the said ratio is more than a lower limit, the flexibility of a handle part will be excellent and a handle part will bend moderately at the time of brushing. Moreover, if the said ratio is below an upper limit, it will suppress that a handle | steering-wheel part bends excessively at the time of brushing. When the ratio is within the above range, the operability of the toothbrush is excellent, and the operation of the toothbrush during brushing is less likely to be erroneous.

Also in the embodiment (ii), the exposed portion 220a of the handle core portion in the handle portion is concave. That is, the exposed part of the hard part is located outside the exposed part of the handle core part which is a soft part. In this example, as shown in FIG. 9, the surface of the exposed portion 220 a of the handle core portion 220 is located radially inside the surface of the hard portion 222, and the exposed portion 220 a of the handle core portion 220 is concave. ing. This makes it difficult for fingers to come into contact with the handle core when the handle is gripped by hand. Therefore, similar to the toothbrush of the embodiment (i), even if bloom or bleed-out occurs in the handle core due to the aging of the soft resin, it is difficult to feel stickiness when the handle is gripped by hand. The feeling is difficult to decrease. In particular, the form in which the hard part is formed in a lattice shape and the handle core part is exposed from the gap as in this example, the finger is less likely to contact the exposed part of the handle core part when gripped by hand, and due to stickiness It is easier to suppress a decrease in the feeling of use.

The surface of the exposed part of the handle core part is preferably subjected to a textured process. Thereby, even if a finger touches the exposed part of a handle core part when holding a handle part with a hand, the contact area can be made smaller. As a result, even if bloom or bleed-out occurs on the surface of the handle core portion due to the aging of the soft resin, stickiness is less likely to be felt when the handle portion is gripped by hand, and the feeling of use is less likely to be lowered.

In the toothbrush of the embodiment (ii), it is preferable that the hard part includes a plurality of hard parts formed apart from each other in the circumferential direction of the handle part like the band-like hard part 222d of this example. Thereby, sufficient rigidity is ensured in the handle portion, and an effect of being difficult to bend excessively is easily obtained, and the operability at the time of brushing is easily improved. In particular, as in this example, the form in which the grid-like hard part is formed by the band-like hard part spaced apart in the circumferential direction and the ring-like hard part spaced apart in the axial direction is that the handle part bends excessively during brushing. The suppressing effect is more easily obtained, and the operability is more likely to be improved.

The number of the band-like hard portions 222d is 6 in this example, but may be 5 or less, or 7 or more.
The width of the belt-like hard portion 222d can be appropriately designed in consideration of the number of the belt-like hard portions 222d, ease of molding, and the like, and can be, for example, 0.5 to 20 mm.

The interval between the strip-like hard portions 222d separated in the circumferential direction is preferably 0.5 to 20 mm, and more preferably 1.5 to 15 mm. If the interval is equal to or greater than the lower limit value, it is easy to obtain an excellent fit when the handle portion is gripped by hand. If the interval is less than or equal to the upper limit value, operability during brushing is improved.
In addition, the space | interval of the strip | belt-shaped hard parts 222d spaced apart in the circumferential direction is the maximum of the space | interval of the adjacent strip | belt-shaped hard parts 222d when the exposed part 220a of the handle | steering-core part 220 between these band-shaped hard parts 222d is seen in front. It shall mean a value.

The number of the ring-shaped hard portions 222e is 4 in this example, but may be 3 or less, or 5 or more.
The width of the ring-shaped hard portion 222e can be appropriately designed in consideration of the number of ring-shaped hard portions 222e, ease of forming, and the like, and can be set to 0.5 to 150 mm, for example.

The thickness of the hard part varies depending on the type of hard resin forming the hard part, but is preferably 0.5 to 5 mm, more preferably 1.5 to 3 mm. If the thickness of the hard part is equal to or greater than the lower limit, the operability during brushing is improved. If the thickness of the hard part is less than or equal to the upper limit value, the part that comes into contact with the finger when the handle part is gripped with a hand is likely to be appropriately deformed, so that an excellent fit can be easily obtained.

The soft resin that forms the handle core may be the same as the soft resin mentioned in the embodiment (i). Examples of the hard resin that forms the hard part include the same hard resin as described in the embodiment (i).

Also in the embodiment (ii), it is preferable that the hard portion has flexibility. Thereby, when the handle portion is gripped with a hand, a portion that comes into contact with the finger is easily deformed appropriately, so that an excellent fit can be easily obtained. The flexibility of the hard part can be adjusted by adjusting the thickness of the hard part. Specifically, by reducing the thickness of the hard part, the flexibility of the hard part is improved. As described above, by setting the thickness of the hard portion to 0.5 to 5 mm, more preferably 1.5 to 3 mm, the flexibility of the hard portion is likely to be sufficiently high.

(Neck and head)
The aspect of the neck part 216 and the head part 218 is the same as the aspect of the neck part 116 and the head part 118 in the toothbrush 11 of embodiment (i).

[Hair bundle]
The hair bundle 212 is not particularly limited, and a known hair bundle can be adopted. As an aspect of the hair | bristle bundle 212, the same aspect as the hair | bristle bundle mentioned by embodiment (i) is mentioned.

[Production method]
The manufacturing method of the toothbrush of embodiment (ii) is not specifically limited, A well-known method can be utilized.
As a method of manufacturing the handle body, for example, the handle core is formed by injection molding of a soft resin using a primary mold, and the hard resin is injected while the handle core is disposed in the secondary mold. And a method of obtaining a handle body by molding a hard part, a neck part and a head part. When the handle body 210 is manufactured, the rear end side

concave portions

224a and 224b and the front end side

concave portions

226a and 226b are formed in the handle core portion 220, so that a jig is fitted to those portions in the secondary mold. It becomes easy to position so that handle core part 220 may not move by inserting. Thereby, the hard part 222, the neck part 216, and the head part 218 can be more stably molded in the secondary mold.
In addition, after molding the hard part, neck part and head part by injection molding of a hard resin using a primary mold, a soft resin is injected with the molding placed in the secondary mold, and the handle core part A method may be adopted in which the handle body is obtained by forming.

Examples of the method for implanting the hair bundle in the head portion of the handle body include a flat wire type flocking method, a heat welding type flocking method, an in-mold method, and the like.

In the toothbrush of the embodiment (ii) described above, the handle portion is formed of a handle core portion that is a soft portion and a hard portion, and in a cross section obtained by cutting the handle portion perpendicular to the axial direction, The ratio of the cross-sectional area of the handle core to the total cross-sectional area of the handle core is 40% or more and 80% or less. As a result, the handle portion has sufficient elasticity, is flexible, and has sufficient rigidity, so that excellent operability can be obtained. In addition, because the exposed part of the hard part is located outside the exposed part of the soft part, it is difficult for the fingers to come into contact with the soft part when the handle part is gripped by hand, so that bloom or bleed out occurs in the soft part. Even if it is done, it is hard to feel stickiness and the feeling of use is unlikely to decrease. In the handle portion, a hard portion that partially covers the surface of the handle core portion made of a soft resin is formed. For this reason, the handle portion has excellent elasticity, and when gripped with a hand, the portion with which the finger comes into contact is appropriately recessed and deformed, so that an excellent fit can be obtained. Thus, in the toothbrush of embodiment (ii), the outstanding fitting feeling when grasped by hand and the outstanding operativity at the time of brushing are compatible.

Note that the toothbrush of the embodiment (ii) is not limited to the toothbrush 21 described above.
For example, in the embodiment (ii), the form of the hard part formed on the surface of the handle core part is not limited to the form provided with a grid-like hard part. Specifically, for example, the toothbrush 22 illustrated in FIG. 11 may be used as the toothbrush of the embodiment (ii). In FIG. 11, the same parts as those in FIG.
The toothbrush 22 is the same as the toothbrush 21 except that the toothbrush 22 includes a handle portion 214A in which a hard portion 222A is formed instead of the hard portion 222. The hard portion 222A is formed in a band shape so as to extend in the axial direction from the rear end side hard portion 222a to the front end side hard portion 222b, instead of the lattice-like hard portion 222c, and a plurality of band-like hard portions 222d spaced apart in the circumferential direction are formed. Except for being formed, it is the same as the hard portion 222. That is, the hard portion 222A is the same as the hard portion 222 except that the ring-shaped hard portion 222e is not formed.

Also in the toothbrush 22, when the handle portion 214A is grasped with a hand, the finger is difficult to come into contact with the handle core portion 220 which is a soft portion, the usability is excellent, and an excellent fit and excellent operability are achieved. The
When forming a hard part including a plurality of band-like hard parts extending in the axial direction of the handle part and spaced apart in the circumferential direction like the

toothbrushes

21 and 22, the number of the band-like hard parts is not limited to 6, It may be 5 or less, or 7 or more. Moreover, the space | interval of the strip | belt-shaped hard part spaced apart in the circumferential direction may be equal intervals, and may differ.
The plurality of band-like hard portions extending in the axial direction of the handle portion and spaced apart in the circumferential direction may be formed up to the tip of the handle portion.

The toothbrush of embodiment (ii) may be the toothbrush 23 illustrated in FIG. In FIG. 12, the same parts as those in FIG.
The toothbrush 23 is the same as the toothbrush 21 except that the toothbrush 23 includes a handle portion 214B in which a hard portion 222B is formed instead of the hard portion 222. The hard part 222B is the same as the hard part 222 except that a plurality of ring-like hard parts 222f that are formed in a ring shape in the circumferential direction and spaced apart in the axial direction are formed instead of the lattice-like hard part 222c. . In this case, the hard part 222B requires a part for connecting the ring-like hard parts 222f.

Also in the toothbrush 23, the handle body 210 includes a handle portion 214B formed with a hard portion 222B that partially covers the surface of the handle core portion 220 formed of a soft resin, thereby providing an excellent fit and excellent operability. Are compatible.

The toothbrush of embodiment (ii) may be the toothbrush 24 illustrated in FIG. In FIG. 13, the same parts as those in FIG.
The toothbrush 24 is the same as the toothbrush 21 except that the toothbrush 24 includes a handle portion 214C in which a hard portion 222C is formed instead of the hard portion 222. The hard portion 222C is the same as the hard portion 222 except that a helical hard portion 222g that spirally extends from the rear end side hard portion 222a to the front end side hard portion 222b is formed instead of the lattice-like hard portion 222c. is there.

Also in the toothbrush 24, the handle body 210 includes a handle portion 214C formed with a hard portion 222C that partially covers the surface of the handle core portion 220 formed of a soft resin, thereby providing an excellent fit and excellent operability. Are compatible.

The toothbrush of the embodiment (ii) may be one in which a hard portion other than the above-described embodiment is formed as long as a part of the handle core portion is exposed with a soft resin. The toothbrush of embodiment (ii) may be provided with the handle core part in which the rear end side recessed

part

224a, 224b and the front end side recessed

part

226a, 226b in the handle core part 220 are not formed.

11-15, 21-24

Toothbrush

110, 210

Handle body

112, 212

Hair bundle

114, 114A-114D, 214, 214A-

214C Handle portion

116, 216

Neck portion

118, 218 Head portion 120 Hard portion 120a Exposed portion 122 Concave 124 Soft part 124a Exposed part 126 Front end side hard part 128 Rear end side hard part 130

Base part

132a, 132b, 134a, 134b Projection strip 136 Plate part 220

Handle core part

222, 222A to 222C Hard part 222a Rear end side hard part 222b Tip Side hard part 222c Grid-like hard part 222d Band-like

hard part

222e, 222f Ring-like hard part 222g Spiral hard part

Claims

A handle portion, a neck portion extending at the tip of the handle portion, a handle body integrally formed with a head portion provided at the tip of the neck portion, and a plurality of planted on the flocked surface of the head portion A toothbrush comprising:
The handle portion includes a soft portion formed of a soft resin having a Shore A hardness of 30 or less, and a hard portion formed of a hard resin having a Shore A hardness higher than that of the soft resin.
The hard part and the soft part are both exposed on the peripheral surface of the handle part, and the exposed part of the hard part is outside the exposed part of the soft part,
The ratio of the cross-sectional area of the soft portion to the total cross-sectional area of the hard portion and the soft portion in a cross-section obtained by cutting the portion where the soft portion of the handle portion is formed perpendicular to the axial direction is 40% or more. 80% or less,
The neck part and the head part are toothbrushes formed of the hard resin.
The toothbrush according to claim 1, wherein the hard portion is a single bar extending from the front end to the rear end of the handle portion.
The toothbrush according to claim 2, wherein a concave line is formed on a side surface of the rod-shaped hard part, and the soft part is formed in the concave line.
The toothbrush according to claim 1, wherein the handle portion is a handle portion in which the hard portion is formed on a surface of a handle core portion which is a rod-like soft portion.
The toothbrush according to claim 4, wherein the hard portion includes a plurality of hard portions formed to be spaced apart in a circumferential direction or an axial direction of the handle portion.
The toothbrush according to any one of claims 1 to 5, wherein the hard portion has flexibility.