JP6817935B2 - toothbrush - Google Patents

Description

The present invention relates to a toothbrush.
The present 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.

Generally, a toothbrush includes a rod-shaped handle portion, a neck portion extending from the tip of the handle portion, a handle body having a head portion provided at the tip of the neck portion, and a plurality of toothbrushes implanted in the head portion. It has a hair bundle. In a general toothbrush, the handle body is made of hard resin so as to prevent the handle portion from bending excessively during brushing and to give sufficient force to the teeth from the hair bundle. However, a toothbrush in which the handle body is made of only hard resin tends to be inferior in operability because the handle body is hard and does not easily bend. As a result, the toothbrush may be mishandled during brushing, which may injure the oral cavity.

As a toothbrush with improved fit and operability 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. A toothbrush including a handle portion has been proposed (for example, Patent Documents 1 to 3).

However, in toothbrushes such as those in Patent Documents 1 to 3, when bloom or bleed-out occurs due to a change in the soft resin over time, the handle portion becomes sticky when the portion formed of the soft resin is grasped by hand. It is easy to feel and the usability is reduced.

Japanese Unexamined Patent Publication No. 2006-466 Japanese Unexamined Patent Publication No. 2005-144033 Japanese Patent No. 4159739

An object of the present invention is to provide a toothbrush that has excellent operability, does not feel sticky when the handle portion is gripped by a hand, and can suppress a decrease in usability even when used continuously.

The present invention has the following configurations.
[1] The handle portion, the neck portion extending to the tip of the handle portion, the handle body in which the head portion provided at the tip of the neck portion is integrally formed, and the flocked surface of the head portion are planted. In the toothbrush including the plurality of hair bundles, 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 portion and the soft portion are both exposed on the peripheral surface of the handle portion, and the exposed portion of the hard portion is outside the exposed portion of the soft portion. 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 the cross section obtained by cutting the portion of the portion where the soft portion is formed perpendicular to the axial direction is 40% or more and 80%. A toothbrush in which the neck portion and the head portion are made of the hard resin.
[2] The toothbrush according to [1], wherein the hard portion has a rod shape extending from the tip end to the rear end of the handle portion.
[3] The toothbrush according to [2], wherein a recess is formed on the side surface of the rod-shaped hard portion, and the soft portion is formed in the recess.
[4] The toothbrush according to [1], wherein the handle portion is a handle portion in which the hard portion is formed on the surface of a handle core portion which is a rod-shaped soft portion.
[5] The toothbrush according to [4], wherein the hard portion includes a plurality of hard portions formed so as to be separated from each other in the circumferential direction or the axial direction of the handle portion.
[6] The toothbrush according to any one of [1] to [5], wherein the hard portion has flexibility.

The toothbrush of the present invention has excellent operability, and even if it is used continuously, it is difficult to feel stickiness when the handle portion is gripped by hand, and deterioration of usability is suppressed.

It is a top view which showed an example of embodiment (i) of the toothbrush of this invention. FIG. 1 is a cross-sectional view taken along the line II of the toothbrush of FIG. 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 a top view which showed the other example of embodiment (i) of the toothbrush of this invention. It is a top view which showed an example of embodiment (ii) of the toothbrush of this invention. FIG. 7 is a sectional view taken along the line AA of the toothbrush of FIG. It is BB sectional view of the toothbrush of FIG. FIG. 9 is a sectional view taken along the line CC of the toothbrush of FIG. It is a top view which showed the other example of embodiment (ii) of the toothbrush of this invention. It is a top view which showed the other example of embodiment (ii) of the toothbrush of this invention. It is a 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.
The 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.
Shore A hardness means hardness measured according to JIS K 7215 or JIS K 6253.

The toothbrush of the present invention has a handle body in which a handle portion, a neck portion extending to the tip of the handle portion, and a head portion provided at the tip of the neck portion are integrally formed, and a flocked surface of the head portion. It is equipped with a plurality of hair bundles planted in. 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, and a hard portion formed of a hard resin having a shore A hardness higher than that of the soft resin. To be equipped with. Both the hard portion and the soft portion are exposed on the peripheral surface of the handle portion, and the exposed portion of the hard portion is outside the exposed portion of the soft portion. The neck portion and the head portion are made of hard resin.

Examples of the toothbrush of the present invention include the following two aspects.
(I) A mode in which a rigid portion having a rod shape extending from the tip end to the rear end of the handle portion is provided.
(Ii) A mode in which a handle portion having a hard portion formed on the surface of a handle core portion which is a rod-shaped soft portion is provided.
Hereinafter, the embodiment (i) and the embodiment (ii) will be described with reference to examples.

<Embodiment (i)>
Hereinafter, an 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 hair bundles 112 planted in the handle body 110.

[Handle body]
The handle body 110 is provided at the rod-shaped handle portion 114 and the tip of the handle portion 114, and is provided at the neck portion 116 thinner than the handle portion 114 and the tip of the neck portion 116, and a plurality of hair bundles 112 are planted. The head portion 118 is provided.
The handle portion 114 and the neck portion 116 have a curved shape having inflection points a and b in which the outer edges 115a and 115b on both sides of the boundary portion thereof in a plan view gradually approach from the handle portion 114 to the neck portion 116. It is formed integrally like this. As described above, the width of the boundary portion between the handle portion 114 and the neck portion 116 is gradually narrowed from the handle portion 114 to the neck portion 116. In the handle body 110 of the present embodiment, at the boundary portion between the handle portion 114 and the neck portion 116, a straight line L connecting the inflection points a and the inflection points b of the outer edges 115a and 115b on both sides in a plan view is formed by the handle portion. It is the boundary line between 114 and the neck portion 116.

(Handle part)
The handle portion 114 is a portion that is gripped by hand during brushing, and is formed in a rod-shaped hard portion 120 extending from the tip end to the rear end of the handle portion 114 and a recess 122 formed on the side surface of the hard portion 120. It includes a soft portion 124 formed. The hard portion 120 is made of a hard resin. The soft portion 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 tip-side hard portion 126 is located at the tip of the handle 114 and has a reduced diameter toward the tip. The rear end side hard portion 128 is located at the rear end portion of the handle portion 114 and has a hemispherical shape. The base 130 has a long flat plate shape and extends from the front end side hard portion 126 to the rear end side hard portion 128.

Three ridges 132a are formed on one surface of the base 130. The ridges 132a extend in parallel in the axial direction from the front end side hard portion 126 to the rear end side hard portion 128, separated from each other in the width direction of the base portion 130. The respective ridges 132a on both side edges of the base 130 are located inside the side edges in the width direction of the base 130.

Two ridges 132b are formed on the other surface of the base 130. The ridges 132b extend in parallel in the axial direction from the front end side hard portion 126 to the rear end side hard portion 128, separated from each other in the width direction of the base portion 130. Each ridge 132b is formed at a position corresponding to between the three ridges 132a in the width direction of the base 130.

The thickness and length of the handle portion 114 are not particularly limited, and can be appropriately designed according to the target person who uses the toothbrush 11.
The thickness of the base portion 130 and the width and height of the ridges 132a and 132b are not particularly limited, and may be appropriately set according to the thickness of the handle portion 113 so that sufficient rigidity can be 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. The distance between the ridges can be, for example, about 0.5 to 3.0 mm.
The number of ridges 132a is not limited to three, and 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 132b may be the same or different.

In the hard portion 120, the front end side hard portion 126, the rear end side hard portion 128, the base portion 130, and the ridges 132a and 132b are integrally formed, and the hard portion 120 has a rod shape as a whole. On the side surface of the hard portion 120, seven concave grooves 122 extending in the axial direction are formed by the base portion 130 and the protrusions 132a and 132b.

As the hard resin forming the hard portion, 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 polypropylene, polyethylene terephthalate, polybutylene terephthalate, polycyclohexylene methylene terephthalate, polyacetal, polystyrene, acrylonitrile-butadiene-styrene resin, cellulose propionate, polyallylate, polycarbonate, and acrylonitrile-styrene. Among copolymerized resins and the like, resins having a shore A hardness of more than 30 can be mentioned. If the Shore A hardness exceeds 30, even an elastomer can be used as a hard resin. As the hard resin, one type may be used alone, or two or more types may be used in combination.

The hard portion preferably has flexibility. As a result, when the handle portion is gripped by the hand, the portion in contact with the fingers is likely to be deformed appropriately, so that an excellent fit can be easily obtained. The flexibility of the hard portion can be adjusted by adjusting the thickness of the base portion of the hard portion, the width of the ridges, and the like. The hard portion may be formed of a foamed resin obtained by blending a foaming agent with a hard resin and foaming it in order to improve flexibility. The foaming agent is not particularly limited, and known chemical foaming agents and physical foaming agents can be used. Further, since the final hardness of the foamed resin changes depending on the bubble content, the hardness of the base resin (resin before the addition of the foaming agent) does not matter.

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

In this example, in the hard portion 120, both ends in the width direction of the base portion 130, the tip portion of the ridge 132a, and the tip portion of the ridge 132b protrude from the peripheral surface of the handle portion 114, respectively, so that the soft portion 124 An exposed portion 120a located outside the exposed portion 124a is formed. Further, the cross-sectional shape of the soft portion 124 perpendicular to the axial direction 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 120a of the hard portion 120 is located outside the exposed portion 124a of the soft portion 124, so that when the handle portion 114 is grasped by hand, the fingers come into contact with the hard portion 120 and the soft portion It becomes difficult to contact 124. Therefore, even if bloom or bleed-out occurs in the soft portion 124 due to a change with time of the soft resin, it is difficult to feel stickiness when the handle portion 114 is gripped by hand, and the usability is not easily deteriorated.
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, the handle portion has high elasticity and is easily bent as compared with the case where the handle portion is formed only of the hard portion. Further, since the handle portion 114 has one rod-shaped hard portion 120, the handle portion 114 is also ensured with sufficient rigidity to prevent excessive bending during brushing. Therefore, the operability at the time of brushing becomes excellent, and it is easy to apply a sufficient force to the target tooth by applying a hair bundle, so that it is easy to brush the tooth 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 the cross section obtained by cutting the portion of the handle portion 114 in which the soft portion 124 is formed perpendicular to the axial direction is 40%. It is 80% or more and preferably 50% or more and 70% or less. When the ratio is equal to or higher than the lower limit, the flexibility of the handle portion is excellent, and the handle portion flexes appropriately during brushing. Further, when the ratio is not more than the upper limit value, excessive bending of the handle portion during brushing is suppressed. When the ratio is within the above range, the operability of the toothbrush becomes excellent, and the operation of the toothbrush during brushing is less likely to be mistaken.

As the soft resin forming the soft portion, 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-based elastomers, styrene-based elastomers, and polyester-based elastomers. As the soft resin, one type may be used alone, or two or more types may be used in combination.

The shore A hardness of the soft resin is 30 or less, preferably 0 to 25, and more preferably 0 to 20. When the shore A hardness of the soft resin is not more than the upper limit value, an excellent fit can be obtained when the handle portion is gripped by hand.

The soft portion may be formed of a foamed resin obtained by blending a soft resin with a foaming agent and foaming. The foaming agent is not particularly limited, and known chemical foaming agents and physical foaming agents can be used. Further, since the final hardness of the foamed resin changes depending on the bubble content, the hardness of the base resin (resin before the addition of the foaming agent) does not matter.

It is preferable that the surface of the exposed portion of the soft portion is textured. As a result, even if the finger touches the exposed portion of the soft portion, the contact area can be made smaller, so that the usability is less likely to deteriorate.

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

The head portion 118 is a portion provided at the tip of the neck portion 116 for implanting a plurality of hair bundles 112. The upper surface of the head portion 118 is a flocked surface 118a on which the hair bundle 112 is planted. The shape of the head portion 118 is a plate shape in which the corners of a rectangle long in the axial direction are rounded out in a plan view. The length, width, and thickness of the head portion 218 are not particularly limited, and can be appropriately designed according to the target person who uses the toothbrush 11.

The neck portion 116 and the head portion 118 are formed of a hard resin. Examples of the hard resin forming the neck portion 116 and the head portion 118 include the same hard resins as those mentioned as the hard resin forming the hard portion 120. As the hard resin forming the neck portion 116 and the head portion 118, one type may be used alone, or two 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 forming the neck portion 116 and the head portion 118 may be different from the hard resin forming 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 used. The hair bundle 112 may be columnar or prismatic. The hair length and thickness of the hair bundle 112 can be determined in consideration of the hair waist and the like required for the hair bundle 112.

The hair for forming the hair bundle 112 is not particularly limited, and known hair can be used, and the hair may be tapered hair with a sharpened tip, from the flocked surface 118a toward the tip of the hair. 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 circular shape and a polygonal shape.
The material of the hair is not particularly limited, and examples thereof include polyamide (6-12 nylon and the like), polyester (polyethylene terephthalate and the like), and polyolefin (polypropylene and the like).
The thickness of the hair can be determined in consideration of the material and the like, and when the cross section is circular, it is, for example, 4 to 10 mil (1 mil = 1/1000 inch = 0.025 mm).

The mode in which the hair bundle 112 is planted on the flocked surface 118a of the head portion 118 is not particularly limited. In this example, two hair bundles 112 are planted in the width direction near the tip and the rear end of the flocked surface 118a, and three hair bundles 112 are lined up in the area between them in the width direction. Twelve hair bundles 112 are planted so that four hair bundles 112 are lined up in the axial direction.

[Production method]
The production method of the embodiment (i) is not particularly limited, and a known method can be used.
Examples of the method for manufacturing the handle body 110 include the following methods. A rod-shaped hard portion 120, a neck portion 116, and a head portion 118 are integrally formed by injection molding of a hard resin using a primary mold. Next, the soft resin is injected with the integrated product placed in the secondary mold to form the soft portion 124 to obtain the handle body 110.
Examples of the method of implanting the hair bundle 112 in the head portion 118 of the handle body 110 include a flat wire type hair transplantation method, a heat welding type hair transplantation method, and an in-mold method.

In the toothbrush of the embodiment (i) described above, the handle portion is formed of a hard portion and a soft portion, and the total cutting of the hard portion and the soft portion in a cross section obtained by cutting the handle portion perpendicularly to the axial direction. The ratio of the cross-sectional area of the soft portion to the area is 40% or more and 80% or less. As a result, the handle portion has sufficient elasticity and flexibility, and sufficient rigidity is secured, so that excellent operability can be obtained. In addition, since 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 grasped by hand, so that bloom or bleed out occurs in the soft part. Even if you do, you will not feel sticky and the feeling of use will not deteriorate.

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. The same parts as those in FIG. 2 in FIG. 3 are designated by the same reference numerals, and the description thereof will be omitted. The toothbrush 12 is the same as the toothbrush 11 except that the handle body 110 includes the handle portion 114A instead of the handle portion 114.

The handle portion 114A includes a hard portion 120A having eight recesses 122A formed on the side surface thereof, and a soft portion 124A formed in the recess 122A. The hard portion 120A is provided with five ridges 132a on one surface of the base 130 and five ridges 132b on the other surface of the base 130. In each of the five ridges 132a and the five ridges 132b, the central one is the highest in the width direction of the base 130, and the height becomes lower toward the outside. Of the five ridges 132a, the two ridges 132a located on the outer side in the width direction of the base 130 are formed so as to rise from the side ends of the base 130. Of the five ridges 132b, two ridges 132b located outside in the width direction of the base 130 are also formed so as to rise from the side end of the base 130. The positions of the five ridges 132a and the five ridges 132b in the width direction of the base 130 are the same.

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

The toothbrush 12 also has excellent operability, and when the handle portion 114A is gripped by hand, it is difficult for the fingers to come into contact with the soft portion 124A, and the usability is also excellent.

The toothbrush of the embodiment (i) may be the toothbrush 13 illustrated in FIG. The same parts as those in FIG. 2 in FIG. 4 are designated by the same reference numerals, and the description thereof will be omitted. The toothbrush 13 is the same as the toothbrush 11 except that the handle body 110 includes the handle portion 114B instead of the handle portion 114.

The handle portion 114B includes a hard portion 120B having eight recesses 122B formed on the side surface thereof, and a soft portion 124B formed in the recess 122B. In the hard portion 120B, one ridge 132a is provided in the center of one surface of the base 130 in the width direction, and the cross section in which the height increases toward the outside is substantially triangular on both sides of the ridge 132a in the width direction. A ridge 134a having a shape is provided. Similarly, one ridge 132b is provided in the center of the base 130 in the width direction, and the cross section of the ridge 132b whose height increases outward is substantially triangular on both sides in the width direction. A ridge 134b having a shape is provided.

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

The toothbrush 13 also has excellent operability, and when the handle portion 114B is gripped by hand, the fingers do not easily come into contact with the soft portion 124B, and the usability is also excellent.

The toothbrush of the embodiment (i) may be the toothbrush 14 illustrated in FIG. The same parts as those in FIG. 2 in FIG. 5 are designated by the same reference numerals, and the description thereof will be omitted. The toothbrush 14 is the same as the toothbrush 11 except that the handle body 110 includes the handle portion 114C instead of the handle portion 114.

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

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

The toothbrush 14 also has excellent operability, and when the handle portion 114C is gripped by hand, the fingers do not easily come into contact with the soft portion 124C, and the usability is also excellent.

The toothbrush of the embodiment (i) may be the toothbrush 15 illustrated in FIG. The same parts as those in FIG. 1 in FIG. 6 are designated by the same reference numerals, and the description thereof will be omitted. The toothbrush 16 is the same as the toothbrush 11 except that the handle body 110 includes the handle portion 114D instead of the handle portion 114.

In the handle portion 114D, instead of the hard portion 120, a plate portion 136 exposed over the entire circumference is provided on the peripheral surface so as to connect the base portion 130 and the protrusions 132a and 132b at the portion where the concave groove 122 is formed in the hard portion 120. It is provided with the provided hard portion 120D. Three plate portions 136 are provided at intervals in the axial direction of the handle portion 114D. As a result, on the side surface of the hard portion 120D, a concave groove 122D in which the seven concave grooves 122 in the hard portion 120 are divided into four in the axial direction is formed. A soft portion 124D is formed in each of the recesses 122, and the position of the exposed portion 124a of the soft portion 124D on the handle portion 114D is concave. That is, both the hard portion 120D and the soft portion 124D are exposed on the peripheral surface of the handle portion 114D, and the exposed portion 120a of the hard portion 120D is located outside the exposed portion 124a of the soft portion 124D. ..

The toothbrush 15 also has excellent operability, and when the handle portion 114D is gripped by hand, the fingers do not easily come into contact with the soft portion 124D, and the usability is also excellent.

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

<Embodiment (ii)>
Hereinafter, an embodiment (ii) of the toothbrush of the present invention will be described with reference to an example.
As shown in FIGS. 7 to 10, the toothbrush 21 of the embodiment (ii) includes a handle body 210 and a plurality of hair bundles 212 planted in the handle body 210.

[Handle body]
The handle body 210 is provided at the rod-shaped handle portion 214 and the tip of the handle portion 214, and is provided at the tip of the neck portion 216 and the neck portion 216, which are thinner than the handle portion 214, and a plurality of hair bundles 212 are planted. The head portion 218 is provided.
The handle portion 214 and the neck portion 216 have a curved shape having inflection points a and b in which the outer edges 215a and 215b on both sides of the boundary portion thereof in a plan view gradually approach from the handle portion 214 to the neck portion 216. It is formed integrally like this. As described above, the width of the boundary portion between the handle portion 214 and the neck portion 216 is gradually narrowed from the handle portion 214 to the neck portion 216. Also in the handle body 210 of the present embodiment, at the boundary portion between the handle portion 214 and the neck portion 216, a straight line L connecting the inflection points a and the inflection points b of the outer edges 215a and 215b on both sides in a plan view is handled. It is the boundary line between the portion 214 and the neck portion 216.

(Handle part)
The handle portion 214 is a portion that is gripped by hand during brushing, and includes a handle core portion 220 that is a rod-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 portion 222 is made of a hard resin.

The shape of the handle core portion 220 in this example is such that the neck portion 216 side of the cylinder is gradually reduced in diameter.
As shown in FIG. 10, rear end side recesses 224a and 224b, which are recessed inward in the radial direction at positions corresponding to each other, are formed on both side surfaces in a plan view at a portion near the rear end of the handle core portion 220. There is. Similarly, tip-side recesses 226a and 226b that are recessed inward in the radial direction are formed at positions corresponding to each other on both side surfaces of the handle core portion 220 near the tip in a plan view. By using the rear end side recesses 224a and 224b and the front end side recesses 226a and 226b when molding the handle body 210, the position of the handle core portion 220 in the secondary mold becomes easy.

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 target person who uses the toothbrush 21.
The handle core portion 220 is preferably formed from the rear end side to the tip end side of the handle part 214.
The cross-sectional shape of the handle core 220 is circular in this example, but is not limited to circular, and may be rectangular or the like.

The hard portion 222 is a hemispherical rear end side hard portion 222a located at the rear end portion of the handle core portion 220, and a tip side hard portion 222a located at the tip portion of the handle core portion 220 and gradually reducing its diameter toward the tip. 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 lattice-shaped hard portion 222c is formed in a strip shape extending in the axial direction from the rear end side hard portion 222a to the front end side hard portion 222b, and has a plurality of strip-shaped hard portions 222d separated in the circumferential direction and a ring shape in the circumferential direction. It is formed by a plurality of ring-shaped hard portions 222e that are formed and separated in the axial direction. As shown in FIG. 9, six strip-shaped hard portions 222d are formed around the central axis of the handle core portion 220 at equal intervals. As shown in FIG. 7, four ring-shaped hard portions 222e are formed between the rear end side hard portion 222a and the tip end side hard portion 222b in the axial direction.
In the handle portion 214 of this example, a part of the handle core portion 220 is formed from a portion of the grid-like hard portion 222c of the hard portion 222 where the ring-shaped hard portion 222e does not exist between the strip-shaped hard portions 222d separated in the circumferential direction. Is exposed.

As described above, the handle portion 214 includes a handle core portion 220 made of a soft resin, and the handle core portion 220 is partially covered with a hard portion 222. As a result, the handle portion 214 has excellent elasticity, and the portion in contact with the fingers when gripped by the hand is appropriately recessed and deformed, so that an excellent fit can be obtained. Further, 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 capable of suppressing excessive bending during brushing. As a result, the operability at the time of brushing becomes excellent, and it is easy to apply a sufficient force to the target tooth by applying a hair bundle, so that it is easy to brush the tooth firmly.

Breaking of the handle core 220 with respect to the total cross-sectional area of the hard portion 222 and the handle core 220 in a cross section obtained by cutting the portion of the handle 214 where the soft handle core 220 is formed perpendicular to the axial direction. The ratio of the area is 40% or more and 80% or less, preferably 50% or more and 70% or less. When the ratio is equal to or higher than the lower limit, the flexibility of the handle portion is excellent, and the handle portion flexes appropriately during brushing. Further, when the ratio is not more than the upper limit value, excessive bending of the handle portion during brushing is suppressed. When the ratio is within the above range, the operability of the toothbrush becomes excellent, and the operation of the toothbrush during brushing is less likely to be mistaken.

Further, also in the embodiment (ii), the exposed portion 220a of the handle core portion in the handle portion is concave. That is, the exposed portion of the hard portion is located outside the exposed portion of the handle core portion, which is the soft portion. In this example, as shown in FIG. 9, the surface of the exposed portion 220a of the handle core portion 220 is located radially inside the surface of the hard portion 222, and the exposed portion 220a of the handle core portion 220 is concave. ing. This makes it difficult for the fingers to come into contact with the handle core when the handle is gripped by hand. Therefore, as in the case of the toothbrush of the embodiment (i), even if bloom or bleed-out occurs in the handle core due to the change of the soft resin with time, it is difficult to feel stickiness when the handle is gripped, and it is used. The feeling does not easily decrease. In particular, in the embodiment in which the hard portion is formed in a grid pattern and the handle core portion is exposed from the gap as in this example, it is more difficult for the fingers to come into contact with the exposed portion of the handle core portion when grasped by hand, which is due to stickiness. It is easier to suppress the deterioration of usability.

It is preferable that the surface of the exposed portion of the handle core portion is textured. As a result, even if the fingers touch the exposed portion of the handle core portion when the handle portion is gripped by 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 due to the change of the soft resin with time, it is difficult to feel stickiness when the handle is gripped by hand, and the usability is not easily deteriorated.

In the toothbrush of the embodiment (ii), it is preferable that the hard portions include a plurality of hard portions formed so as to be separated from each other in the circumferential direction of the handle portion, as in the band-shaped hard portion 222d of this example. As a result, sufficient rigidity is ensured in the handle portion, and the effect of preventing excessive bending is likely to be obtained, and operability during brushing is likely to be excellent. In particular, as in this example, in the embodiment in which the grid-shaped hard portion is formed by the band-shaped hard portion separated in the circumferential direction and the ring-shaped hard portion separated in the axial direction, the handle portion is excessively bent during brushing. The effect of suppressing is more likely to be obtained, and the operability is more likely to be excellent.

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

The distance between the strip-shaped hard portions 222d separated in the circumferential direction is preferably 0.5 to 20 mm, more preferably 1.5 to 15 mm. When the interval is not less than the lower limit value, an excellent fit can be easily obtained when the handle portion is gripped by hand. When the interval is not more than the upper limit value, the operability at the time of brushing is improved.
The distance between the strip-shaped hard portions 222d separated in the circumferential direction is the maximum distance between the adjacent strip-shaped hard portions 222d when the exposed portion 220a of the handle core portion 220 between the strip-shaped hard portions 222d is viewed from the front. It shall mean a value.

The number of 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 molding, and the like, and can be, for example, 0.5 to 150 mm.

The thickness of the hard portion varies depending on the type of the hard resin forming the hard portion, 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, operability during brushing is improved. If the thickness of the hard portion is not more than the upper limit value, the portion in contact with the fingers when the handle portion is gripped by the hand is likely to be deformed appropriately, so that an excellent fit is easily obtained.

Examples of the soft resin forming the handle core portion include the same soft resins as those mentioned in the embodiment (i). As the hard resin forming the hard portion, the same hard resin as that mentioned in the embodiment (i) can be mentioned.

Also in the embodiment (ii), it is preferable that the hard portion has flexibility. As a result, when the handle portion is gripped by the hand, the portion in contact with the fingers is likely to be deformed appropriately, so that an excellent fit can be easily obtained. The flexibility of the hard portion can be adjusted by adjusting the thickness of the hard portion and the like. Specifically, by thinning the hard portion, the flexibility of the hard portion 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 tends to be sufficiently high.

(Neck, head)
The aspects of the neck portion 216 and the head portion 218 are the same as those of the neck portion 116 and the head portion 118 in the toothbrush 11 of the embodiment (i).

[Hair bundle]
The hair bundle 212 is not particularly limited, and a known hair bundle can be adopted. Examples of the hair bundle 212 include the same modes as those of the hair bundle described in the embodiment (i).

[Production method]
The method for producing the toothbrush according to the embodiment (ii) is not particularly limited, and a known method can be used.
As a method for manufacturing the handle body, for example, a handle core portion is formed by injection molding of a soft resin using a primary mold, and a hard resin is injected with the handle core portion arranged in the secondary mold. A method of obtaining a handle body by molding a hard portion, a neck portion and a head portion can be mentioned. When manufacturing the handle body 210, since the rear end side recesses 224a and 224b and the front end side recesses 226a and 226b are formed in the handle core portion 220, a jig is fitted into these portions in the secondary mold. By inserting it, it becomes easy to position the handle core portion 220 so that it does not move. As a result, the hard portion 222, the neck portion 216, and the head portion 218 can be molded more stably in the secondary mold.
In addition, after molding the hard part, neck part and head part by injection molding of hard resin using the primary mold, the soft resin is injected with the molded product placed in the secondary mold, and the handle core part. May be adopted to obtain a handle body by forming.

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

In the toothbrush of the embodiment (ii) described above, the handle portion is formed of a handle core portion and a hard portion which are soft portions, and the handle portion is formed as a hard portion in a cross section obtained by cutting the handle portion perpendicularly 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 and flexibility, and sufficient rigidity is secured, so that excellent operability can be obtained. In addition, since 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 grasped by hand, so that bloom or bleed out occurs in the soft part. Even if you do, you will not feel sticky and the feeling of use will not deteriorate. Further, in the handle portion, a hard portion that partially covers the surface of the handle core portion made of soft resin is formed. Therefore, the handle portion has excellent elasticity, and when it is gripped by the hand, the portion in contact with the fingers is appropriately recessed and deformed, so that an excellent fit can be obtained. As described above, in the toothbrush of the embodiment (ii), both an excellent fit when gripped by a hand and an excellent operability when brushing are achieved.

The toothbrush of the embodiment (ii) is not limited to the toothbrush 21 described above.
For example, in the embodiment (ii), the mode of the hard portion formed on the surface of the handle core portion is not limited to the mode including the grid-like hard portion. Specifically, for example, the toothbrush of embodiment (ii) may be the toothbrush 22 illustrated in FIG. The same parts as those in FIG. 7 in FIG. 11 are designated by the same reference numerals, and the description thereof will be omitted.
The toothbrush 22 is the same as the toothbrush 21 except that the handle portion 214A in which the hard portion 222A is formed is provided instead of the hard portion 222. The hard portion 222A is formed in a strip shape so as to extend axially from the rear end side hard portion 222a to the front end side hard portion 222b instead of the grid-like hard portion 222c, and a plurality of strip-shaped hard portions 222d separated in the circumferential direction are formed. It is the same as the hard portion 222 except that it is formed. 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.

Even in the toothbrush 22, when the handle portion 214A is gripped by hand, it is difficult for the fingers to come into contact with the handle core portion 220, which is a soft portion, and the usability is excellent, and both an excellent fit and excellent operability are achieved. Toothbrush.
When forming a hard portion including a plurality of strip-shaped hard portions extending in the axial direction of the handle portion and separated in the circumferential direction, such as the toothbrushes 21 and 22, the number of the strip-shaped hard portions is not limited to 6. It may be 5 or less, or 7 or more. Further, the intervals between the band-shaped hard portions separated in the circumferential direction may be equal intervals or different intervals.
A plurality of strip-shaped hard portions extending in the axial direction of the handle portion and separated in the circumferential direction may be formed up to the tip of the handle portion.

The toothbrush of the embodiment (ii) may be the toothbrush 23 illustrated in FIG. The same parts as those in FIG. 7 in FIG. 12 are designated by the same reference numerals, and the description thereof will be omitted.
The toothbrush 23 is the same as the toothbrush 21 except that the handle portion 214B in which the hard portion 222B is formed is provided instead of the hard portion 222. The hard portion 222B is the same as the hard portion 222 except that, instead of the grid-like hard portion 222c, a ring-shaped hard portion 222f is formed in the circumferential direction and a plurality of ring-shaped hard portions 222f separated in the axial direction are formed. .. In this case, the hard portion 222B requires a portion connecting each ring-shaped hard portion 222f.

The toothbrush 23 also has an excellent fit and excellent operability because the handle body 210 is provided with a handle portion 214B having a hard portion 222B formed to partially cover the surface of the handle core portion 220 made of a soft resin. Are compatible.

The toothbrush of the embodiment (ii) may be the toothbrush 24 illustrated in FIG. The same parts as those in FIG. 7 in FIG. 13 are designated by the same reference numerals, and the description thereof will be omitted.
The toothbrush 24 is the same as the toothbrush 21 except that the handle portion 214C in which the hard portion 222C is formed instead of the hard portion 222 is provided. The hard portion 222C is the same as the hard portion 222 except that a spiral 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 grid-like hard portion 222c. is there.

The toothbrush 24 also has an excellent fit and excellent operability because the handle body 210 is provided with a handle portion 214C having a hard portion 222C formed to partially cover the surface of the handle core portion 220 made of a soft resin. Are compatible.

The toothbrush of the embodiment (ii) may have a hard portion of an embodiment other than the above-described embodiment formed as long as a part of the handle core portion is exposed with the soft resin. The toothbrush of the embodiment (ii) may include a handle core portion in which the rear end side recesses 224a and 224b and the front end side recesses 226a and 226b of the handle core portion 220 are not formed.

11-15, 21-24 Toothbrush 110, 210 Handle body 112, 212 Hair bundle 114, 114A-114D, 214, 214A-214C Handle part 116, 216 Neck part 118, 218 Head part 120 Hard part 120a Exposed part 122 Concave 124 Soft part 124a Exposed part 126 Tip side hard part 128 Rear end side hard part 130 Base part 132a, 132b, 134a, 134b Convex 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 Lattice hard part 222d Band hard part 222e, 222f Ring hard part 222g Spiral hard part

Claims (3)

A handle body in which a handle portion, a neck portion extending to the tip of the handle portion, and a head portion provided at the tip of the neck portion are integrally formed, and a plurality of parts planted on the flocked surface of the head portion. In a toothbrush with a bunch of hair,
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.
Both the hard portion and the soft portion are exposed on the peripheral surface of the handle portion, and the exposed portion of the hard portion is outside the exposed portion of the soft portion.
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 the cross section obtained by cutting the portion of the handle portion where the soft portion is formed perpendicular to the axial direction is 40% or more. 80% or less,
The neck portion and the head portion are made of the hard resin .
The handle portion is a handle portion in which the hard portion is formed on the surface of the handle core portion which is a rod-shaped soft portion.
A toothbrush in which the hard portion and the soft portion bend when the handle portion is gripped by hand . The rigid portion comprises a circumferential direction or a plurality of hard segments which are spaced apart in the axial direction of the handle portion, the toothbrush according to claim 1. The toothbrush according to claim 1 or 2 , wherein the hard portion has flexibility.

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