JP2023110733A - toothbrush - Google Patents

Abstract

To provide a toothbrush which can have the sufficient bristle stopping strength even when the thickness of a head part is thin.SOLUTION: In a toothbrush which has a head part in which a hair bundle is planted in a bristle planting hole by driving a flat wire 4 in the flat plate shape into the bristle planting hole, a surface 401 of the flat wire 4 includes a large number of recesses 41 and a plane part 42 other than the recesses 41, the large number of recesses 41 are arranged on the surface 401 such that a straight band-like plane region is not generated on the surface 401, the straight band-like plane region is the region in which the plane part 42 is continuous in the band shape in the straight line from an end to an end in the lateral direction of the surface 401 and the region in which the plane part 42 is continuous in the band shape in the straight line from an end to an end in the vertical direction of the surface 401.SELECTED DRAWING: Figure 8

Description

TECHNICAL FIELD The present invention relates to a toothbrush, and more particularly to a toothbrush with an improved flat wire used to implant tufts of hair.

A toothbrush in which tufts of bristles are planted in the tufting holes of the head portion by means of a so-called "flat wire" is conventionally known. The flat wire has a flat plate shape, is driven into the tufting hole in an upright state, and is fixed to the tufting hole by biting into the periphery of the tufting hole at both lateral ends.

Japanese Patent No. 5427486 JP 2005-177377 A Japanese Patent No. 6943541

By the way, in recent toothbrushes, thin head portions have become popular. However, when the thickness of the head portion is thin, the depth of the tufting hole is shallow, so that the vertical length of the flat wire that can be used is shortened. area becomes smaller. Therefore, the drag force that the flat wire receives from the resin forming the head portion is reduced, and therefore the so-called "bristle fixing strength" is reduced. In order to prevent a decrease in the strength of the tufting, it is conceivable to increase the horizontal length of the flat wire to increase the area of the portion where the flat wire bites into. The lines become close to each other, cracks occur between the flat lines, and there is a risk that the strength of the bristle tie will be lowered and the head portion will become more likely to deform. Therefore, increasing the horizontal length of the flat line is undesirable.

SUMMARY OF THE INVENTION An object of the present invention is to provide a toothbrush that can have sufficient bristle holding strength even when the thickness of the head portion is thin.

The present invention
a head portion in which hair bundles are implanted in each of a large number of flocking holes on the flocking surface;
The tuft of hair is planted by being driven into the tufting hole with a flat line sandwiched inside the folded portion in a state of being folded in two,
The flat wire has a flat plate shape, is driven into the tufting hole in an upright state, and is fixed to the tufting hole by biting into the peripheral edge of the tufting hole at both ends in the horizontal direction. ,
in the toothbrush
At least one of both surfaces of the flat line has a large number of recesses and a flat portion other than the recesses,
The plurality of recesses are arranged on the surface such that no straight band-shaped planar regions are formed on the surface,
The linear band-shaped planar region is a region in which the planar portions are aligned in a strip shape in a straight line from end to end in the horizontal direction of the surface, and the planar portions are aligned in a straight line from end to end in the vertical direction of the surface. It is an area connected in a belt shape,
It is characterized by

According to the present invention, it is possible to improve the bristle retaining strength of the flat wire, so that even when the thickness of the head portion is thin, the bristle retaining strength can be sufficiently increased. Therefore, it is possible to prevent defective products from being produced when the thickness of the head portion is thin.

It is a top view showing the toothbrush of one embodiment of the present invention. It is a II arrow directional view of FIG. It is a perspective view which shows the mode of hair-implantation. It is a longitudinal cross-sectional view which shows the flat wire of the state driven into the tufting hole. It is a top view which shows the flat wire of the state driven into the tufting hole. FIG. 4 is an enlarged plan view of the head portion, particularly showing a flat line; It is a figure which shows the thin-plate-shaped wire used as the origin of a flat wire. It is a figure which shows the recessed part formed in one surface of the flat wire of this embodiment, and its arrangement|positioning (recessed part pattern). 9 is a view in the direction of arrow IX of FIG. 8. FIG. FIG. 10 is a diagram showing an example of a concave pattern for reference; FIG. 10 is a diagram showing another example of a concave pattern for reference; FIG. 9 is a diagram showing the same concave pattern as in FIG. 8; It is a top view which shows two adjacent tufting holes and a flat line of the head part of this embodiment. FIG. 14 is a diagram for reference of FIG. 13; FIG. 4 is a diagram showing a concave pattern of Example 1; FIG. 3 is a plan view of the head portion of toothbrushes of Comparative Examples 1 and 2; FIG. 4 is a diagram showing a first example of another concave pattern of the present invention; FIG. 10 is a diagram showing a second example of another concave pattern of the present invention; FIG. 10 is a diagram showing a third example of another concave pattern of the present invention; FIG. 10 is a diagram showing a fourth example of another concave pattern of the present invention; FIG. 10 is a diagram showing a fifth example of another concave pattern of the present invention; FIG. 10 is a diagram showing a sixth example of another concave pattern of the present invention; FIG. 12 is a diagram showing a seventh example of another concave pattern of the present invention; FIG. 10 is a diagram showing an eighth example of another concave pattern of the present invention;

FIG. 12 is a diagram showing a ninth example of another concave pattern of the present invention; FIG. 10 is a diagram showing a tenth example of another concave pattern of the present invention; FIG. 11 is a diagram showing an eleventh example of another concave pattern of the present invention; FIG. 12 is a diagram showing a twelfth example of another concave pattern of the present invention; FIG. 13 is a diagram showing a thirteenth example of another concave pattern of the present invention; FIG. 14 is a diagram showing a fourteenth example of another concave pattern of the present invention; FIG. 15 is a diagram showing a fifteenth example of another concave pattern of the present invention; FIG. 14 is a diagram showing a sixteenth example of another concave pattern of the present invention; FIG. 21 is a diagram showing a seventeenth example of another concave pattern of the present invention; FIG. 21 is a diagram showing an eighteenth example of another concave pattern of the present invention; FIG. 20 is a diagram showing a nineteenth example of another concave pattern of the present invention; FIG. 11 is a diagram showing a twentieth example of another concave pattern of the present invention; FIG. 12 is a diagram showing a twenty-first example of another concave pattern of the present invention; FIG. 12 is a diagram showing a twenty-second example of another concave pattern of the present invention; FIG. 12 is a diagram showing a twenty-third example of another concave pattern of the present invention; FIG. 12 is a diagram showing a twenty-fourth example of another concave pattern of the present invention; FIG. 12 is a diagram showing a twenty-fifth example of another concave pattern of the present invention; FIG. 12 is a diagram showing a twenty-sixth example of another concave pattern of the present invention; FIG. 12 is a diagram showing a twenty-seventh example of another concave pattern of the present invention; FIG. 12 is a diagram showing a twenty-eighth example of another concave pattern of the present invention; FIG. 4 is a diagram showing a first example of a convex pattern of the present invention; FIG. 46 is a view taken along line XXXXVI of FIG. 45; FIG. 10 is a diagram showing a second example of the convex pattern of the present invention; FIG. 48 is a view in the direction of arrow XXXXVIII of FIG. 47;

FIG. 1 is a plan view showing a toothbrush according to one embodiment of the present invention. FIG. 2 is a view in the direction of arrow II in FIG. This toothbrush 1 comprises a head portion 2, a neck portion 5 and a handle portion 3. The neck portion 5 is the narrow portion between the head portion 2 and the handle portion 3 . The neck portion 5 and the handle portion 3 extend in one direction from the head portion 2 . In FIG. 1, the direction in which the neck portion 5 and the handle portion 3 extend is the longitudinal direction (X direction), and the direction perpendicular to the X direction in plan view is the width direction (W direction). As the resin material that constitutes the head portion 2 and the handle portion 3, polypropylene, polyacetal, polystyrene, polyethylene terephthalate, polybutylene terephthalate, polycyclohexanedimethylene terephthalate, acrylonitrile butadiene styrene, etc. can be used. is preferred.

The head portion 2 has a large number of tufting holes 22 on the tufting surface 21 . A hair bundle 23 is planted in each of all the tufting holes 22 . In the head portion 2 of FIG. 1, the hair tufts 23 are omitted and the tufting holes 22 are shown. The tufting holes 22 are regularly arranged on the tufting surface 21 in plan view. Specifically, the tufting holes 22 are lined up in the W direction to form horizontal rows and lined up in the X direction to form vertical rows. A row consists of four tufting holes 22, the third to seventh tufting holes 22 from the front consist of six tufting holes 22, the last row consists of four tufting holes 22, and the third row from the front. - The last row of tufts 22 also constitutes a column. Therefore, the head part 2 has 41 tufting holes 22 here.

As shown in FIG. 3, the hair bundle 23 is a bundle of many hairs 231 . Natural resins or synthetic resins such as nylon, polyester, and elastomer can be used as the material of the bristles 231, and polybutylene terephthalate, which is a synthetic resin, is preferable. As shown in FIG. 3, the hair tuft 23 is planted by being driven into the tufting hole 22 together with the flat wire 4 sandwiched inside the folded portion 230 in the state of being folded in two.

4 and 5 are a longitudinal sectional view and a plan view showing the flat wire 4 driven into the tuft hole 22. FIG. The flat wire 4 has a flat plate shape and is driven into the tufting hole 22 in an upright state. 22 is fixed. The end portion 40 biting into the peripheral edge portion 220 is also referred to as a "hooking margin". That is, the horizontal length L of the flat line 4 is set to "the diameter D of the tufting hole 22 + the length E of the end portion 40 x 2".

FIG. 6 is an enlarged plan view of the head portion 2, particularly showing the flat line 4. FIG. As shown in FIGS. 5 and 6, the flat line 4 is provided in the tufting hole 22 so as to be inclined in one direction by an angle α with respect to the X direction in plan view. The angle α is between 10 and 80 degrees, preferably 15 degrees.

The flat wire 4 is produced by cutting a thin plate-shaped wire 400 as shown in FIG. Metals, ceramics, plastics, and the like can be used as materials for forming the wire 400 , that is, the flat wire 4 . Brass, nickel, aluminum, etc. can be used as the metal. As plastics, hard plastics, biodegradable plastics, and the like can be used. Note that if ceramic or plastic is used, the flat wires can be made individually rather than from the wire 400 .

The flat wire 4 has, as shown in FIG. A large number of recesses 41 are provided in a predetermined arrangement. Hereinafter, the recesses and their arrangement are collectively referred to as a "recess pattern". The concave portion 41 has an annular shape on the surface 401 . 9 is a view in the direction of arrow IX in FIG. 8. FIG. A large number of recesses 41 are arranged on the surface 401 so that two types of linear belt-like planar regions do not occur on the surface 401 . The two types of linear band-shaped planar regions are a region in which the planar portions 42 are linearly banded from one end to the other in the lateral direction (Xa direction) of the surface 401 (i.e., a lateral linear band-shaped planar region), and and a region in which the plane portions 42 are linearly connected in a band shape from end to end in the vertical direction (H direction) (that is, a vertical linear strip-shaped planar region). Specifically, on the surface 401 of FIG. 8, the plane portions 42 extending in the horizontal direction meander as indicated by the dashed line A. That is, the plane portions 42 extending in the vertical direction are not straight. is also serpentine, ie not straight, as indicated by the dash-dotted line B. Incidentally, in the concave pattern of FIG. 10 for reference, a vertical linear belt-like planar region 421 is formed in which the planar portions 42 are aligned in a straight line from end to end in the vertical direction. Further, in the concave pattern of FIG. 11 for reference, a horizontal linear belt-like plane region 422 is formed in which the plane portions 42 are aligned in a straight line from end to end in the horizontal direction. That is, in this embodiment, the recesses 41 are arranged on the surface 401 so as not to produce straight band-like regions 421, 422 as shown in FIGS.

In addition, the flat wire 4 also has the same concave pattern on the surface 402 as on the surface 401 . That is, the surface 401 and the surface 402 have plane-symmetric concave patterns.

Specifically, the concave pattern shown in FIG. 8 is as follows. It should be noted that the concave pattern of FIG. 8 employs a so-called "staggered arrangement".
(a) All recesses 41 have the same or substantially the same toric shape and dimensions, and thus have the same or substantially the same diameter d.
(b) A plurality of recesses 41 are arranged in rows in the vertical direction, that is, form columns.
(c) In each column, the spacing hd between vertically adjacent recesses 41 is less than the diameter d.
(d) A plurality of columns are arranged in a horizontal direction without gaps.
(e) The center of the top recess 41 of the column is vertically displaced by hp/2 with respect to the center of the top recess 41 of the adjacent column. In addition, hp is the center-to-center distance between the concave portions 41 adjacent to each other in the vertical direction.
(f) The interval Ld between columns spaced horizontally by one is the same as the diameter d.

When the flat wire 4 is produced from the wire 400, since the recessed pattern as described above is formed on the entire surface of the wire 400, no matter where the wire 400 is cut, the shape shown in FIG. a flat line 4 can be obtained. That is, one vertical row of recesses 41 is necessarily cut, so that a part of the recesses 41 is always exposed on the end surface 403 of the flat wire 4, as shown in FIG.

Preferred dimensions of the toothbrush 1 having the above configuration are as follows.
・Longitudinal (X direction) dimension of the head part 2: 15 to 33 mm
Specifically, this dimension is the distance from the point where the contour from the neck portion 5 to the head portion 2 changes from a straight line to a curved line or is discontinuously bent to the tip of the head portion 2 .
・Width direction (W direction) dimension of head part 2: 13 to 16 mm
Specifically, this dimension is the distance of the widest part of the head portion 2 .
・Dimensions in the thickness direction (T direction) of the head part 2: 2 to 4 mm
Specifically, this dimension is the distance in the direction perpendicular to the flocked surface 21 of the head portion 2 .
・Diameter D of tufting hole 22: 1.0 to 1.7 mm
・Depth S of tufting holes 22: 1.6 to 2.7 mm
・ Density of tufting holes 22: 15 to 30/cm ²
In addition, it is "planting hole density = number of holes / flocking area." The term “flocking area” is based on JIS S3016, and is the inner area of the portion where the outsides of the flocking holes 22 lined up on the periphery of the flocking surface 21 of the head portion 2 are connected by straight lines.
・Horizontal length of flat wire 4 L…D+E=1.3 to 2.3 mm
・The vertical length of the flat wire 4 (also referred to as “flat wire width”) h … 1.0 to 1.5 mm
・Thickness t of flat wire 4 … 0.15 to 0.25 mm
・Length E of hooking margin of flat wire 4: 0.3 to 0.6 mm
・Diameter of concave portion 41 d...h/4±10%
・Inner diameter ds of recess 41: 0.07 mm or more, and h/8±10%
If it is smaller than this, the cross-sectional shape of the flat portion 42 becomes long and slender, so that the flat portion 42 may be bent when an upward force is applied to the flat wire 4, resulting in a decrease in the strength of the bristles. Moreover, processing is difficult.
・Depth of concave portion 41: 0.01 to 0.08 mm
・Gap hd: 0.07 mm or more, preferably 0.10 mm or more If the distance is smaller than this, the cross-sectional shape of the flat portion 42 becomes elongated, so that the flat portion 42 bends when an upward force is applied to the flat wire 4. There is a risk that the strength of the hair stopper will be reduced, and processing is difficult.
Interval hp: Distance at which two or more concave portions 41 can exist in the vertical direction

In addition, when the dimensions of the head portion 2 in the longitudinal direction and the width direction are within the above range, the toothbrush 1 can exhibit good intraoral operability. Moreover, when the thickness of the head portion 2 is less than 2 mm, the strength of the head portion 2 becomes insufficient. On the other hand, when the thickness of the head portion 2 exceeds 4 mm, the intraoral operability is deteriorated.

According to the toothbrush 1 using the flat wire 4 configured as described above, the following effects can be exhibited.
(1) When the flat wire 4 is driven into the tufting hole 22 , the resin forming the head portion 2 softens due to frictional heat generated between the flat wire 4 and the end portion 40 of the flat wire 4 . The softened resin enters the concave portions 41 of the surfaces 401 and 402 of the end portion 40 from the surfaces 401 and 402 and from the end surface 403 and hardens. Even if a force is applied in the direction in which the flat wire 4 is pulled out (i.e., upward) in a state where the resin is hardened, the surfaces 401 and 402 of the end portion 40 have many “steps” due to the concave portion 41 and the flat portion 42 . As a result, the hardened resin is caught on the steps, and as a result, the flat wire 4 is difficult to come off. Therefore, it is possible to improve the bristle holding strength of the flat wire 4 . Further, since the resin has toughness, the resin that is pushed aside when the flat wire 4 is driven enters the concave portion 41 in an attempt to restore itself. Therefore, even if the resin has a high softening point, the flat wire 4 is difficult to come off. Therefore, from this point as well, the strength of the flat wire 4 to hold the bristles can be improved.

In particular, since the recesses 41 have the arrangement of (c) above, the number of the recesses 41 in the vertical direction can be increased, and therefore the number of steps that are caught by the cured resin can be increased. Therefore, the bristle fixing strength of the flat wire 4 can be further improved.

Furthermore, since the concave portion 41 has an annular shape, it has a flat portion 42 inside. Therefore, the number of steps on the surfaces 401 and 402 of the flat wire 4 is greater than if the concave portion 41 were circular (that is, if the flat portion 42 was not provided inside). Therefore, it is possible to increase the number of steps that are caught by the cured resin. Therefore, the bristle fixing strength of the flat wire 4 can be further improved.

Since the end portion 40 of the flat wire 4 has the concave portion 41, the strength of the flat wire 4 can be improved. can. Therefore, the following effects can be exhibited.

(1-1) A flat wire 4 having a small longitudinal length h can be used. Therefore, even if the thickness of the head portion 2 is thin, that is, even if the depth of the tufting holes 22 is shallow, the desired bristle fixing strength of the flat wire 4 can be ensured.

(1-2) It is possible to use a flat wire 4 with a small length E of the engagement margin. According to this, it is possible to prevent the occurrence of whitening and the occurrence of cracks between the adjacent flat wires 4, and furthermore, it is possible to prevent the deterioration of the bristle fixing strength and the deformation of the head portion 2. In addition, the distance between adjacent tufts 22, that is, the hole pitch, can be reduced, thereby improving the performance of the toothbrush, such as cleanability and feel.

(2) The flat line 4 does not have a horizontal linear belt-shaped planar area and a vertical linear belt-shaped planar area. By the way, if the flat line 4 has a belt-like plane area with a horizontal straight line, it acts like a single horizontal groove, so the flat line 4 becomes weak against pressure in the vertical direction. The flat line 4 is vulnerable to lateral pressure because the band-like planar area acts like a flute. That is, the flat wire 4 has reduced impact resistance. However, since the flat wire 4 of the present embodiment does not have the horizontal straight belt-shaped planar area and the vertical straight belt-shaped planar area, excellent impact resistance can be exhibited.

Furthermore, as indicated by the dashed line C in FIG. 12, which is the same as FIG. Therefore, the flat line 4 is strong against pressure both in the vertical direction and in the lateral direction. Therefore, the flat wire 4 can exhibit excellent impact resistance also from this point.

Further, since the flat wire 4 can exhibit excellent impact resistance, the following effects can be exhibited.

(2-1) Even if a high-hardness resin is used as the material for forming the head portion 2, deformation of the flat wire 4 during driving can be prevented, thereby preventing defective products from being produced. The high-hardness resin is a resin having a flexural modulus (JIS K7203) in the range of 500 to 3000 MPa, such as polypropylene, polyethylene terephthalate, polybutylene terephthalate, polycyclohexylene dimethylene terephthalate, polystyrene, acrylonitrile butadiene styrene. , cellulose propionate, polyarylate, polycarbonate, acrylonitrile styrene, and the like.

(2-2) The smaller the diameter D of the tufting hole 22, the greater the impact that the flat wire 4 receives during driving. However, since the flat wire 4 of this embodiment has excellent impact resistance, it can be used for a tufting hole 22 having a small diameter D. As a result, the bristle density can be improved, thereby improving the performance of the toothbrush, such as cleanability and feel.

(2-3) The thickness t of the flat wire 4 can be reduced. By using a thin flat line 4 with a thickness t, the number of hairs (amount of hair) included in the hair bundle can be increased, and the spread of the hair can be suppressed. As a result, the performance of the toothbrush can be improved. Also, thin flat wires 4 of thickness t can be used for tufts 22 having a small diameter D. FIG.

(3) As shown in FIG. 13, the flat line 4 is provided in the tufting hole 22 so as to be inclined in one direction by an angle α with respect to the X direction in plan view. FIG. 14 for reference shows the case where the flat line 4 is not inclined. The distance Xd between the ends of adjacent flat lines 4 in FIG. 13 is clearly greater than the distance Xd in FIG. Therefore, in this embodiment, cracks can be prevented from occurring between adjacent flat wires 4 .

[Example 1]
A toothbrush having the following specifications was produced using the flat wire 4 having the concave pattern shown in FIG.

(Concave pattern in FIG. 15)
Only the following points are different from the concave pattern of FIGS.
• Every other column in the horizontal direction has a linear recess 41A at the end.
- The concave pattern on the surface 401 and the concave pattern on the surface 402 are upside down. That is, the concave portion 41A also functions as a mark for indicating the positional relationship of the flat line 4 in the vertical direction.

(specification)
・Longitudinal (X direction) dimension of the head part 2: 27.8 mm
・Width direction (W direction) dimension of head part 2: 14.7 mm
・Dimensions in the thickness direction (T direction) of the head part 2: 3.4 mm
・Diameter D of tufting hole 22: 1.5 mm
・Depth S of tufting holes 22: 2.5 mm
・Number of tufting holes 22: 41 ・Resin material composing head portion 2 and handle portion 3: polypropylene ・Horizontal length L of flat wire 4: 2.0 mm
・Longitudinal length h of flat wire 4 … 1.4 mm
・Thickness t of flat wire 4 … 0.25 mm
・Length E of hooking margin of flat wire 4 … 0.5 mm
・Material constituting the flat wire 4: Brass ・Dimensions of the concave pattern of the flat wire 4 ・Diameter d: 0.36 mm
・Inner diameter ds...0.18mm
・Gap hd...0.10mm
・Interval hds … 0.14mm
・Interval Ld ... 0.36 mm
・Center-to-center distance hp…0.46mm
・Depth td (Fig. 9) ... 0.02 mm

[Comparative Example 1]
A toothbrush having the specifications shown below was produced using a conventional flat wire having no recesses and in the same manner as in the above embodiment.

(specification)
・Longitudinal (X direction) dimension of the head part 2: 30.0 mm
・Width direction (W direction) dimension of head part 2: 14.7 mm
・Dimensions in the thickness direction (T direction) of the head part 2: 3.4 mm
・Diameter D of tufting hole 22: 1.5 mm
・Depth S of tufting holes 22: 2.5 mm
- The number of tufting holes 22: 48 - The arrangement of the tufting holes 22 is as shown in Fig. 16 . That is, the frontmost row consists of three tufting holes 22, the second row from the front consists of five tufting holes 22, and the third to eighth rows of tufting holes 22 from the front consist of six tufting holes 22. , the last row consists of four tufting holes 22, and the tufting holes 22 from the third row to the last row also form columns.
・Resin material composing the head part 2 and the handle part 3: Polypropylene ・Horizontal length L of the flat wire 4: 2.0 mm
・Longitudinal length h of flat wire 4 … 1.5 mm
・Thickness t of flat wire 4 … 0.25 mm
・Length E of hooking margin of flat wire 4 … 0.5 mm
・Material for flat wire 4: brass

[Comparative Example 2]
A toothbrush having the specifications shown below was produced using a conventional flat wire having no recesses and in the same manner as in the above embodiment.

(specification)
・Longitudinal (X direction) dimension of the head part 2: 30.0 mm
・Width direction (W direction) dimension of head part 2: 14.7 mm
・Dimensions in the thickness direction (T direction) of the head part 2: 5.0 mm
・Diameter D of tufting hole 22: 1.5 mm
・Depth S of tufting holes 22: 3.5 mm
Number of tufting holes 22: 48 The arrangement of the tufting holes 22 is the same as in Comparative Example 1 (Fig. 16).
・Resin material composing the head part 2 and the handle part 3: Polypropylene ・Horizontal length L of the flat wire 4: 2.0 mm
・Longitudinal length h of flat wire 4 … 1.5 mm
・Thickness t of flat wire 4 … 0.25 mm
・Length E of hooking margin of flat wire 4 … 0.5 mm
・Material for flat wire 4: brass

[Filling strength evaluation test]
In Example 1 and Comparative Examples 1 and 2, a hair bundle planted in one tuft hole was grasped by a special tool, pulled by a tensile tester until it came out of the tuft hole, and the maximum tensile force (N) was measured. . The tensile condition was a tensile speed of 20 mm/min. Then, the hair tie strength was evaluated according to the value of the maximum tensile force (N). Specifically, when the maximum tensile force was 20N or more, it was marked with “⊚”, when it was 8N or more and less than 20N, it was marked with “◯”, and when it was less than 8N, it was marked with “×”. The results are shown in Table 1.

(evaluation)
According to Example 1 and Comparative Example 1, it can be seen that the recessed pattern of the flat wire 4 contributes to the improvement of the strength of the hair clip. In addition, in Comparative Example 2, even if the flat wire 4 does not have a pattern of recesses, good bristle fixing strength is obtained. From this, it can be seen that the recessed pattern of the flat line 4 is effective in improving the strength of the bristles in the thin head portion.

[Modified configuration]
The present invention can adopt the following modified configurations.

(1) In the flat line 4, the concave pattern may be provided only on one of the surfaces 401 and 402. FIG.

(2) In the flat line 4, the concave pattern on the surface 401 and the concave pattern on the surface 402 may not be plane-symmetrical.

(3) In the flat line 4, the concave pattern of the surface 401 and the concave pattern of the surface 402 may be different.

(4) In the concave pattern of FIG. 15, as indicated by the dashed line, oblique straight belt-like plane regions 423 are formed. It is preferable to According to this, the concave portions 41 are arranged more densely, and the number of steps in the end portion 40 can be increased, so that the strength of the flat wire 4 to hold the hair can be further improved.

(5) The shape of the recess 41 is annular in the recess patterns of FIGS. 8 and 15, but may be circular, triangular, square, hexagonal, or the like. However, a circular shape is preferable to a triangular shape. The reason is as follows.

(5-1) When the recesses 41 are circular, the recesses 41 can be arranged more densely than when they are square, and the overlapping portions (described later) of the recesses 41 in adjacent vertical rows can be increased when viewed from the side in the vertical direction. Therefore, the number of steps at the end 40 of the flat wire 4 can be increased, thereby improving the strength of the hair clip.

(5-2) When the concave portion 41 has a circular shape with a diameter d, the exposed area of the concave portion 41 on the end face 403 after cutting is larger than in the case of an equilateral triangle having the same height as the diameter d, so that the softened The resin easily enters the concave portion 41, thereby improving the strength of the bristles.

(6) For the flat lines 4, recess patterns other than the recess patterns described above, such as those shown in FIGS. 17 to 44, may be employed.

17, 28, 32, and 34 to 44, the flat lines 4 having recessed patterns are not only horizontal straight belt-like plane regions and vertical straight belt-like plane regions, but also oblique straight belt-like plane regions. Since it does not have, it can exhibit more excellent impact resistance.

(6-1) The concave pattern in FIG. 17 differs from the concave pattern in FIG. 15 only in the interval hd. That is, the interval hd is smaller than in FIG. 15, specifically 0.06 mm. As a result, no oblique linear band-shaped flat area is generated. According to this, compared with the case of FIG. 15, the recesses 41 in the vertical direction can be arranged more densely, so that the number of steps that are caught by the cured resin can be increased. Therefore, the bristle fixing strength of the flat wire 4 can be further improved.

(6-2) In the recess pattern of FIG. 18, the recesses 41 have a circular shape, and the interval hd is the same as the diameter d. According to this, for the same reason as in the case of FIG. 8, it is possible to improve the bristle holding strength and impact resistance. Also, the formation of the recess 41 is easy.
(6-3) In the concave pattern of FIG. 19, the interval hd is set smaller than in the case of FIG. 18, the number of steps in the end portion 40 can be increased, so that the strength of the flat wire 4 to hold the hair can be further improved.

(6-4) In the concave pattern of FIG. 20 , the large number of concave portions 41 are arranged such that when viewed from the side in the vertical direction, the concave portions 41 arranged in a vertical row partially overlap with the concave portions 41 arranged in an adjacent vertical row. , is located on surface 401 (and/or surface 402). "Side view from the vertical direction" means viewing the flat line 4 from the Z direction. The “overlapping” portion is the portion in the dashed-dotted line region 431 . Although there are a large number of areas 431 indicated by dashed-dotted lines, only two are shown here. According to this, regardless of where the wire 400 is cut, the vertical row of recesses is always cut, and the recesses 41 can be exposed on the end surface 403 . Therefore, the softened resin reliably enters the concave portion 41 from the end surface 403 .

(6-5) In the recess pattern of FIG. 21, the recess 41 has a laterally long oval shape. The interval hd is smaller than the minor axis dh of the concave portion 41 . The interval Ld is the same as the length dx of the recess 41 . This also makes it possible to improve the strength and impact resistance of the flat wire 4 .
(6-6) In the concave pattern of FIG. 22, the columns of FIG. 21 are arranged obliquely, and as a result, there are a plurality of areas 431 indicated by dashed-dotted lines where there are "overlapping" portions. Here, one region 431 indicated by a dashed line is shown. According to this, the same effect as in the case of FIG. 21 can be exhibited, and the bristle fixing strength can be further improved.

(6-7) The concave pattern of FIG. 23 is different from the case of FIG. 22 only in that the concave portions 41 have an annular shape. According to this, since the flat portion 42 is also present in the concave portion 41, the number of steps in the end portion 40 can be increased compared to the case of FIG. can improve.

(6-8) The concave pattern of FIG. 24 is different from the case of FIG. 20 only in that the concave portions 41 have a rhombic shape. This can also exhibit the same effect as in the case of FIG.
(6-9) The concave pattern of FIG. 25 is different from the case of FIG. 21 only in that the concave portions 41 have a laterally long diamond shape. The interval hd is smaller than the minor axis dh of the concave portion 41 . The interval Ld is the same as the length dx of the recess 41 . With this, the same effect as in the case of FIG. 21 can be exhibited.
(6-10) The concave pattern of FIG. 26 is different from the case of FIG. 22 only in that the concave portions 41 have a laterally long diamond shape. This can also exhibit the same effect as in the case of FIG.

(6-11) The recess pattern in FIG. 27 is different from the pattern in FIG. 24 only in that the recess 41 has a downward triangular shape. With this, the same effect as in the case of FIG. 24 can be exhibited.
(6-12) The concave pattern of FIG. 28 is different from that of FIG. 27 only in that the concave portions 41 have a lateral triangular shape. With this, the same effect as in the case of FIG. 27 can be exhibited.
(6-13) In the pattern of recesses in FIG. 29, the recesses 41 have a lateral triangular shape, and columns facing the right and columns facing the left are alternately arranged in the horizontal direction. and each column is slanted in one direction. According to this, since the flat portion 42 has a triangular structure as indicated by the dashed line D, the flat line 4 has excellent impact resistance as in the case of the honeycomb structure in FIG. are doing. It also has a portion overlapping with a plurality of dashed-dotted line regions 431 (only one is shown here).

(6-14) In the recess pattern of FIG. 30, triangular recesses 41 larger than those in FIG. 27 are employed. With this, the same effect as in the case of FIG. 27 can be exhibited.
(6-15) In the recess pattern of FIG. 31, recesses 41 having a shape of a right-angled triangle and larger than those in FIG. 29 are employed. This can also exhibit the same effects as in the case of FIG.

(6-16) The concave pattern of FIG. 32 differs from the case of FIG. With this, the same effect as in the case of FIG. 28 can be exhibited. Furthermore, since the flat portion 42 is provided inside, the number of steps on the surface 401 (or the surface 402) is greater than in the case of FIG. Therefore, it is possible to increase the number of steps that are caught by the cured resin. Therefore, the bristle fixing strength of the flat wire 4 can be further improved.

(6-17) The concave pattern of FIG. 33 differs from the case of FIG. 18 only in that the concave portions 41 have a regular hexagonal shape. With this, the same effect as in the case of FIG. 18 can be exhibited. In particular, as shown by the dashed line C, the planar portions 42 are connected so as to form a clear honeycomb structure, so that the pressure in the vertical direction and the pressure in the lateral direction are lower than in the case of FIG. Therefore, from this point as well, excellent impact resistance can be exhibited.

(6-18) The concave pattern of FIG. 34 differs from that of FIG. 19 only in that the concave portions 41 have a regular hexagonal shape. 19 and 33 as well.
(6-19) The concave pattern of FIG. 35 differs from that of FIG. 34 only in that the number of concave portions 41 is increased. Therefore, the same effect as in the case of FIG. 34 can be exhibited, and the bristle fixing strength can be further improved.
(6-20) The concave pattern of FIG. 36 differs from the case of FIG. 34 only in that it has a large number of areas 431 indicated by dashed-dotted lines that have "overlapping" portions. Here, two areas 431 indicated by dashed-dotted lines are shown. Therefore, the same effect as in the case of FIG. 34 can be exhibited, and the bristle fixing strength can be further improved.

(6-21) The concave pattern of FIG. 37 differs from that of FIG. 36 only in that the number of concave portions 41 is increased. Therefore, the same effect as in the case of FIG. 36 can be exhibited, and the bristle fixing strength can be further improved.
(6-22) The concave pattern of FIG. 38 differs from the case of FIG. 36 only in that the interval hd is small. Therefore, the same effect as in the case of FIG. 36 can be exhibited, and the bristle fixing strength can be further improved.
(6-23) The concave pattern of FIG. 39 differs from the case of FIG. 34 only in that the interval hd is small. Therefore, the same effect as in the case of FIG. 34 can be exhibited, and the bristle fixing strength can be further improved.

(6-24) The concave pattern of FIG. 40 differs from the case of FIG. 35 only in that the concave portion 41 has a plane portion 42 inside. According to this, the same effect as in the case of FIG. 35 can be exhibited, and the steps are increased more than in the case of FIG.
(6-25) The concave pattern of FIG. 41 differs from the case of FIG. 36 only in that the concave portion 41 has a plane portion 42 inside. According to this, the same effect as in the case of FIG. 36 can be exhibited, and since the steps are increased more than in the case of FIG. 36, the bristle fixing strength can be further improved.
(6-26) In the concave pattern of FIG. 42, the orientation of the concave portions 41 is different from that of FIG. This also can exhibit the same effect as in the case of FIG.

(6-27) In the recess pattern of FIG. 43, the number of recesses 41 is smaller than in the case of FIG. With this, the same effect as in the case of FIG. 42 can be exhibited.

(6-28) In the recess pattern of FIG. 44, the recess 41 has a cross shape. When viewed from the side in the vertical direction, the large number of recesses 41 are arranged in such a manner that the recesses 41 arranged in a column overlap with a part of the recesses 41 arranged in an adjacent column, that is, in a region 431 indicated by a dashed line. It is arranged on surface 401 (and/or surface 402) so as to have overlapping portions. This also makes it possible to improve the strength and impact resistance of the flat wire 4 .

(7) The flat line 4 may have a convex pattern instead of the concave pattern. That is, the flat line 4 obtained by changing all the concave portions 41 to the convex portions 45 in all the concave patterns described above may be used. The height of the protrusions is preferably the same as the depth of the recesses. It should be noted that the flat line 4 does not have a horizontal linear band-shaped planar area and a vertical linear band-shaped planar area.

Even in this case, when the flat wire 4 is driven into the tufting hole 22 , the resin forming the head portion 2 is softened by frictional heat generated between the flat wire 4 and the end portion 40 of the flat wire 4 . The softened resin enters the plane portion 42 of the surfaces 401 and 402 of the end portion 40 from the surfaces 401 and 402 and from the end surface 403 and hardens. Even if a force is applied in the direction in which the flat wire 4 is pulled out (i.e., upward) in the state in which the resin is cured, a large number of steps are formed on the surfaces 401 and 402 of the end portion 40 by the convex portion 45 and the flat portion 42 . As a result, the hardened resin is caught on the steps, and as a result, the flat wire 4 is difficult to come off. Therefore, it is possible to improve the bristle holding strength of the flat wire 4 . In addition, since the flat wire 4 does not have a horizontal linear band-shaped planar region and a vertical linear band-shaped planar region, excellent impact resistance can be exhibited. Other functions and effects are the same as those of the corresponding concave pattern.

(7-1) FIG. 45 shows an example of a convex pattern. In this convex pattern, all the concave portions 41 and 41A in the concave pattern of FIG. 15 are replaced with convex portions 45 and 45A. In addition, in FIG. 45, the convex portion 45 is displayed in gray. 46 is a view taken along line XXXXVI in FIG. 45. FIG. In this convex pattern, the softened resin enters the plane portion 42 .

(7-2) FIG. 47 shows another example of the convex pattern. In this convex pattern, all the concave portions 41 in the concave pattern of FIG. 27 are replaced with convex portions 45 . In addition, in FIG. 47, the convex portion 45 is displayed in gray. FIG. 48 is a view in the direction of arrow XXXXVIII of FIG. 47. FIG. In this case, the softened resin enters the flat portion 42 . In addition, when viewed from the side in the vertical direction, the large number of protrusions 45 are arranged in such a manner that the protrusions 45 arranged in a vertical line partially overlap with the protrusions 45 arranged in an adjacent vertical line, that is, the dashed-dotted line. It is arranged on surface 401 and/or surface 402 so as to have a portion that overlaps region 431a. Although there are a large number of regions 431a indicated by dashed-dotted lines, only two are shown here. Therefore, the number of steps in the end portion 40 can be increased, so that the strength of the flat wire 4 to hold the hair can be further improved.

INDUSTRIAL APPLICABILITY The toothbrush of the present invention has a sufficient bristle-holding strength even when the thickness of the head portion is thin, and therefore has great industrial utility value.

REFERENCE SIGNS LIST 1 toothbrush 2 head portion 21 flocking surface 22 tufting hole 220 peripheral portion 23 tuft of hair 230 bristles 4 flat line 41 concave portion 42 flat portion 401, 402 surface 421 vertical linear belt-like planar area 422 horizontal linear belt-like planar area 45 convex portion

Claims (5)

a head portion in which hair bundles are implanted in each of a large number of flocking holes on the flocking surface;
The tuft of hair is planted by being driven into the tufting hole with a flat line sandwiched inside the folded portion in a state of being folded in two,
The flat wire has a flat plate shape, is driven into the tufting hole in an upright state, and is fixed to the tufting hole by biting into the peripheral edge of the tufting hole at both ends in the horizontal direction. ,
in the toothbrush
At least one of both surfaces of the flat line has a large number of recesses and a flat portion other than the recesses,
The plurality of recesses are arranged on the surface such that no straight band-shaped planar regions are formed on the surface,
The linear band-shaped planar region is a region in which the planar portions are aligned in a strip shape in a straight line from end to end in the horizontal direction of the surface, and the planar portions are aligned in a straight line from end to end in the vertical direction of the surface. It is an area connected in a belt shape,
A toothbrush characterized by: The numerous recesses are arranged on the surface such that the planar portions surrounding the recesses exhibit a honeycomb structure on the surface.
The toothbrush according to claim 1. The plurality of recesses are arranged on the surface such that when viewed from the side in the vertical direction, the recesses arranged in a vertical row partially overlap with the recesses arranged in an adjacent vertical row.
The toothbrush according to claim 1. the recess has a shape that exhibits an annular shape on the surface;
The toothbrush according to any one of claims 1-3. a head portion in which hair bundles are implanted in each of a large number of flocking holes on the flocking surface;
The tuft of hair is planted by being driven into the tufting hole with a flat line sandwiched inside the folded portion in a state of being folded in two,
The flat wire has a flat plate shape, is driven into the tufting hole in an upright state, and is fixed to the tufting hole by biting into the peripheral edge of the tufting hole at both ends in the horizontal direction. ,
in the toothbrush
At least one of both surfaces of the flat wire has a large number of convex portions and a flat portion other than the convex portions,
The plurality of convex portions are arranged on the surface so that no straight belt-like planar region is formed on the surface,
The linear band-shaped planar region is a region in which the planar portions are aligned in a strip shape in a straight line from end to end in the horizontal direction of the surface, and the planar portions are aligned in a straight line from end to end in the vertical direction of the surface. It is an area connected in a belt shape,
A toothbrush characterized by:

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