JP5993555B2 - toothbrush - Google Patents

Description

  The present invention relates to a toothbrush.

In the toothbrush, the head portion may be thinned in order to improve operability and allow the oral cavity to be thoroughly wiped. For example, Patent Document 1 discloses that the thickness of the head portion is 3 to 4 mm using a polyacetal resin having high strength and rigidity as a material of the handle. However, when the head portion is thinned, the strength of the head portion itself is reduced, and when the head portion is thinned, the neck portion extending to the head portion is thinned, so that the strength of the neck portion is also lowered. There was a trend.
Therefore, Patent Document 2 proposes that a convex portion is provided on the proximal end side of the flocked surface of the head portion to reinforce the head portion and secure the diameter of the neck portion. However, when a convex portion is provided on the flocked surface, the convex portion becomes an obstacle, and a low-cost, flocking method using a flat wire (hereinafter referred to as “flat-wire flocking method”) is applied. It became difficult.
Further, Patent Document 3 proposes that one convex portion is provided on the base end side of the back surface of the head portion to reinforce the head portion and secure the diameter of the neck portion. However, in the toothbrush described in Patent Document 3, the shape of the convex part of the head part may not be the dimension as designed due to shrinkage after injection molding.

Japanese Patent No. 3387591 Japanese Patent Laid-Open No. 9-252841 Japanese Patent No. 3083655

  An object of the present invention is to provide a toothbrush that has high strength even when the head portion is thinned, that allows the head portion dimensions to be as designed, and that is highly manufacturable by a flat wire type flocking method. .

The present invention has the following aspects.
[1] A head portion in which a plurality of flocking holes are formed on the flocked surface, a neck portion extending from the base end side of the head portion, and a handle portion extending from the base end side of the neck portion A toothbrush in which a bristles for bristles are planted in the flocked hole, and a reinforcing ridge extending from the base end toward the distal end on the back surface of the head portion does not overlap the flocked hole A toothbrush comprising a plurality of toothbrushes.
[2] The toothbrush according to [1], wherein the head portion has a thickness of 3 mm or less.
[3] The toothbrush according to [1] or [2], wherein the reinforcing ridges are disposed in a region of 60% or less from the proximal end side to the distal end side of the flocked region.
[4] The toothbrush according to any one of [1] to [3], wherein the reinforcing ridge has a substantially semi-elliptical cross-sectional shape when cut along the short direction of the head portion.

  The toothbrush of the present invention has high strength even when the head portion is thinned, and the head portion dimensions are easily set as designed, and is highly manufacturable by the flat wire type flocking method.

It is a side view which shows one Embodiment of the toothbrush of this invention. It is a top view which shows the flocking surface of the head part which comprises the toothbrush of FIG. It is a top view which shows the back surface of the head part which comprises the toothbrush of FIG. It is I-I 'sectional drawing of FIG. It is II-II 'sectional drawing of FIG.

An embodiment of the toothbrush of the present invention will be described.
The toothbrush of this embodiment is shown in FIGS. The toothbrush 1 of the present embodiment includes a head portion 10 in which the hair bundle 11 is implanted, a neck portion 20 extending from the proximal end side of the head portion 10, and a handle extending from the proximal end side of the neck portion 20. Portion 30 (hereinafter, the head portion 10, the neck portion 20, and the handle portion 30 are collectively referred to as a handle body).

The handle body is integrally formed in a long shape as a whole. For example, the handle body is obtained by injection molding using a resin as a material.
As the material of the handle body, polypropylene resin (PP), polyacetal resin (POM), polystyrene resin (PS), polyethylene terephthalate resin (PET), polybutylene terephthalate resin (PBT), acrylonitrile butadiene styrene resin (ABS), pore relate Resin, polycarbonate resin, acrylonitrile styrene resin (AS), etc. are mentioned. Among these, polyacetal resin is preferable because it has high strength and can easily reduce the thickness of the head portion.
The above resins may be used alone or in combination of two or more.
Further, the handle body may be partially or wholly covered with a flexible resin such as an elastomer in order to improve gripping properties.

As shown in FIG. 2, a plurality of flocked holes 12 a are formed on the flocked surface 12 that is the surface of the head portion 10, and the hair bundle 11 is flocked on the flocked surface 12.
As shown in FIG. 3, reinforcing protrusions 40 extending from the base end side toward the tip end side are provided on the back surface 13 (surface opposite to the flocked surface 12) of the head portion 10.
The reinforcing ridges 40 in the present embodiment are four ridges, and all of them are arranged at positions that do not overlap the flock holes 12a. Further, the four reinforcing ridges 40 are provided in parallel with each other at equal intervals, and the outer two of them are arranged along the side edge of the head portion 10.
As shown in FIG. 4, each of the reinforcing protrusions 40 in the present embodiment has a substantially semi-elliptical cross-sectional shape when cut along the short direction of the head portion 10. Further, the reinforcing ridges 40 are shaped so as to become lower toward the front end side of the head portion 10.

The width of the reinforcing protrusion 40 is preferably 0.1 to 1.0 mm, and more preferably 0.3 to 0.8 mm. If the width of the reinforcing ridges 40 is equal to or greater than the lower limit value, the head portion 10 can be sufficiently reinforced, and if the width is equal to or less than the upper limit value, the reinforcing ridges 40 can be reliably prevented from overlapping the flocked holes 12a. it can.
The height of the reinforcing ridges 40 is preferably 0.1 to 1.0 mm, and more preferably 0.3 to 0.8 mm. If the height of the reinforcing ridges 40 is equal to or higher than the lower limit value, the head portion 10 can be sufficiently reinforced, and if the height is equal to or lower than the upper limit value, harmfulness in the oral cavity can be further reduced.

  Between the reinforcing ridge 40 and the neck portion 20 is also a convex portion 41, and the convex portion 41 also has a head portion 10 as shown in FIG. The cross-sectional shape when cut along the short direction is substantially semi-elliptical.

  The reinforcing protrusions 40 are preferably arranged in a region of 60% or less from the proximal end side to the distal end side of the flocked region 12b because the operability of the toothbrush 1 becomes higher, and the region of 50% or less It is more preferable that they are arranged in the. Further, since the reinforcing protrusions 40 can sufficiently secure the strength of the head portion 10, it is preferable that the reinforcing protrusions 40 be disposed in a region of 10% or more of the flocked region 12b from the proximal end side toward the distal end side, and 20% or more. It is more preferable that they are disposed in the region. In addition, the flocked area | region 12b is an area | region enclosed by the virtual line T obtained when connecting the outermost part of the hole edge of each outermost flocked hole 12a.

  The thickness of the head portion 10 is preferably 3 mm or less, and more preferably 2 to 3 mm. If the thickness of the head part 10 is less than or equal to the upper limit value, the operability in the oral cavity of the toothbrush 1 can be improved, and if the thickness is greater than or equal to the lower limit value, a decrease in strength of the head part 10 can be prevented.

  The hair constituting the hair bundle 11 includes hairs (taper hairs) whose diameter gradually decreases toward the hair tips, and hairs having the same outer diameter (straight hairs) except for the rounded portion of the hair tips. Further, it is possible to use hair for which the hair tip has a shape such as a spatula shape, a spherical shape, or a tip crack shape.

Examples of the hair material include polyamide (eg, 6-12 nylon, 6-10 nylon), polyester (eg, polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate), polyolefin (eg, polypropylene), elastomer ( Examples: Synthetic resin materials such as olefin and styrene. These resin materials may be used alone or in combination of two or more.
Further, the bristle may have a multi-core structure having a core part and at least one or more sheath parts provided outside the core part.

  The cross-sectional shape of the bristle is preferably a circle, but is not necessarily limited to a circle, and can be any shape depending on the intended use of the toothbrush 1. For example, the shape may be an ellipse, a polygon (for example, a triangle, a quadrangle, a pentagon, a hexagon, or the like), an irregular shape (for example, a star shape, a three-leaf clover shape, a four-leaf clover shape, or the like).

The thickness of each hair is not particularly limited. For example, when the cross section is circular, 4 to 8 mil (1 mil = 1/1000 inch = 0.025 mm) is preferable. If it is more than the lower limit, the self-supporting property is improved and the cleaning property is higher, and if it is not more than the upper limit, the fluff of the hair bundle 11 becomes moderate and the contact feeling becomes better.
The hairs constituting the hair bundle 11 may all have the same thickness, or two or more different types of hairs may be combined.

  The hair length of the hair is preferably 8 to 13 mm for adults and 6 to 9 mm for children. In addition, from the viewpoint of usability in the oral cavity and usability, it is preferable to shorten the hair length of the hair as the diameter of the hair selected is smaller. Further, a plurality of hairs having different thicknesses may be used in combination depending on purposes such as a feeling of use, a feeling of cleaning, a cleaning effect, and durability.

The flocking method of the hair bundle 11 may be a flat wire type flocking method or a heat welding type flocking method in which the hair bundle 11 is heat-welded to the head portion 10, but from the viewpoint of low cost, A flat wire type flocking method is preferred.
The flat line passes through the center of the flock hole 12a and is placed in the flock hole 12a so as to straddle the flock hole 12a. Examples of the material of the flat wire include metals such as brass and stainless steel, and other examples include hard plastic and biodegradable plastic.
The length, width, and thickness of the flat line may be arbitrarily adjusted according to the hair bundle 11 and the flocked hole 12a. Usually, the length of the flat line is larger than the diameter of the flocked hole 12a, and the width of the flat line is It is made smaller than the depth of the flock hole 12a. Further, by adjusting the thickness of the flat wire, the hair bundle 11 can be securely fixed in the flock hole 12a and the gap can be reduced. Moreover, in order to prevent the flat wire from coming out of the flocked hole 12a, the total length of the portions protruding from both sides of the flocked hole 12a is preferably 0.3 to 0.6 mm.

In the present embodiment, the flock holes 12a are arranged in a lattice pattern.
The opening area of the flocking hole 12a is preferably 1.6 mm ² or less, and more preferably 1.4 mm ² or less. If the opening area of the flock hole 12a is 1.6 mm ² or less, the hair bundle 11 becomes thin, so that the flexibility is improved and the usability is improved.
Moreover, it is preferable that the diameter of the flock hole 12a is more than the minimum diameter which can be produced, and it is more preferable that it is 1.0 mm or more from the point which suppresses the excessive bending of the hair | bristle bundle 11 and a hair loss feeling.

  Moreover, in the toothbrush 1 of this embodiment, the thickness and length of the neck part 20 and the handle part 30 are not particularly limited. For example, the thickness of the neck part 20 is 2.5 to 6.0 mm, and the length is The thickness of the handle portion 30 is 7 to 20 mm, and the length is 60 to 120 mm.

In the toothbrush 1 of the said embodiment, since the head part 10 is reinforced with the reinforcement protruding item | line 40, and the reinforcement protrusion item 40 is four, the stress concerning the reinforcement protruding item | line 40 can be disperse | distributed. Thereby, the strength of the head unit 10 can be improved, and even when the head unit 10 is thinned, the strength of the head unit 10 can be sufficiently ensured. Further, since the neck portion 20 is connected not only to the head portion 10 but also to the reinforcing protrusions 40, the neck portion 20 can be thickened and the strength of the neck portion 20 can be increased.
Moreover, in the toothbrush 1, since the reinforcement protrusion 40 is provided in the back surface 13 of the head part 10, and is not provided in the flocking surface 12, the manufacture suitability by a flat wire type flocking method is high.
Further, on the back side of the flocked hole 12a, a phenomenon called “sink” that shrinks and becomes thin after molding tends to occur, but the reinforcing protrusion 40 is provided on the head portion 10 so as not to overlap the flocked hole 12a. Therefore, the reinforcing protrusion 40 is not easily affected by sink marks. Therefore, it is easy to make the dimensions of the head unit 10 as designed.
Moreover, in the toothbrush 1 of this embodiment, since the cross-sectional shape at the time of cut | disconnecting along the transversal direction of the head part 10 of the reinforcement protrusion 40 is a substantially semi-elliptical shape, its harmfulness is low in the oral cavity, A better usability can be obtained.

In addition, this invention is not limited to the said embodiment. For example, the number of reinforcing protrusions need not be four, and may be three or five.
Further, the reinforcing ridges may not be substantially semi-elliptical in cross section when cut along the short direction of the head part, but may be substantially semi-circular, triangular, quadrangular, or the like.

Example 1
A toothbrush in which reinforcing protrusions were provided on the back surface of the head portion (thickness 2.5 mm) and a neck portion (thickness 3.5 mm) was extended to the head portion was produced. The reinforcing ridges in this example were four ridges provided so as not to overlap the flock holes, and the outer two were provided along the side edges of the head portion. Further, the reinforcing ridges were disposed in a 40% region of the flocked region from the proximal end side toward the distal end side.

(Example 2)
A toothbrush was produced in the same manner as in Example 1 except that the reinforcing ridges were two ridges provided so as not to overlap the flock holes along the side edge of the head portion.

(Example 3)
A toothbrush was produced in the same manner as in Example 1 except that the reinforcing ridges were two ridges provided near the center in the width direction of the head portion so as not to overlap the flock holes.

Example 4
A toothbrush was produced in the same manner as in Example 3 except that the reinforcing ridges were arranged in an area of 90% of the flocked area.

(Comparative Example 1)
A toothbrush was produced in the same manner as in Example 1 except that the reinforcing ridge was a single ridge that overlapped the flock hole.

(Comparative Example 2)
A toothbrush having a head portion thickness of 2.5 mm and a neck portion thickness of 3.5 mm was prepared without providing reinforcing ridges.

(Comparative Example 3)
A toothbrush was produced in the same manner as in Example 3 except that the reinforcing ridges were two reinforcing ridges provided near the center in the width direction of the head portion so as to overlap the flock holes.

  About the toothbrushes of Examples 1 to 4 and Comparative Examples 1 to 3, the operability, the strength of the head portion, the strength of the neck portion, the molding shrinkage prevention property, and the productivity were evaluated by the methods described below. The evaluation results are shown in Tables 1 and 2.

[Operability]
Ten testers used the toothbrush of each example, and evaluated the operability of the toothbrush in the oral cavity by sensory evaluation. Evaluation was made into 7 steps of 1 to 7 points, and the higher the score, the better the operability. And the score about each toothbrush was each calculated by averaging the score of 10 testers, and the following references | standards evaluated.
◎: 5.5 points or more ○: 4.5 points or more to less than 5.5 points △: 4.0 points or more to less than 4.5 points ×: less than 4.0 points

[Head strength]
A sample was prepared by cutting the bristles of the toothbrushes of each example and smoothing the flocked surface of the head part. The head end of the sample is held with a clamp, the sample is fixed to a digital impact tester (DG-1 type, manufactured by Toyo Seiki Seisakusho Co., Ltd.), the flocked surface is weighted with 0.5 J, and the head is The absorbed energy (J) when fractured was measured (n = 10). The head strength was evaluated according to the following criteria.
◎: 0.3J or more ○: 0.2J or more and less than 0.3J △: 0.1J or more and less than 0.2J ×: Less than 0.1J

[Neck strength]
The handle part base end of each example sample was clamped and fixed, weighted with 100 N from the flocked surface side, and the breaking strength (N) when the neck part broke was measured (n = 10). The head strength was evaluated according to the following criteria.
◎: 100N or more ○: 70N or more and less than 100N △: 40N or more and less than 70N ×: Less than 40N

[Mold shrinkage prevention]
The dimension _{L 0} of the handle body immediately after removal from the injection molding machine was measured to measure the dimension _{L 1} of the handle body after a lapse of 1 day after _{molding, [(L 0 -L 1)} / L 0] × 100 The shrinkage was calculated from the formula (%), and the molding shrinkage prevention property was evaluated according to the following criteria.
◎: 0 to less than 0.5% ○: 0.5% to less than 1.0% △: 1.0% to less than 1.5% ×: 1.5% or more

[productivity]
Nylon brush (hair: 8 mil, length: 9.0 mm, flat cut) is folded in two and a flat wire (width: 1.3 mm, length: 2.1 mm, thickness) at the folded part : 0.25 mm), and inserted into a flock hole formed in the head portion to plant a hair bundle. The crack occurrence rate of the head at that time was measured, and productivity was evaluated according to the following criteria.
A: Cracking does not occur (burring rate is less than 10 ppm)
○: Almost no cracking occurs (cracking rate 10 ppm or more and less than 50 ppm)
Δ: Cracking occurs slightly (cracking rate of 50 ppm or more and less than 100 ppm)
×: Cracking occurred (cracking rate of 100 ppm or more)

[Comprehensive evaluation]
Comprehensive evaluations determined from the above evaluations are as follows.
◎: Two or more ◎, others are ○
○: One or less ◎, others ○
△: There is no x, and one of them is △
×: Any one is ×

In the toothbrushes of Examples 1 to 4, in which a plurality of reinforcing protrusions are provided on the base end side of the back surface of the head portion so as not to overlap the flocked hole, the operability, the strength of the head portion and the neck portion, and prevention of molding shrinkage Both productivity and productivity were excellent.
On the other hand, in the toothbrush of the comparative example 1 in which the one reinforcement protrusion which overlapped with the flock hole was provided in the back surface of the head part, molding shrinkage prevention property and productivity were low.
In the toothbrush of the comparative example 2 in which the reinforcing protrusions are not provided on the head part, the strength of the head part and the neck part is insufficient, and the productivity is low.
In the toothbrush of Comparative Example 3 in which the reinforcing ridges overlap the flock holes, the molding shrinkage prevention property and the productivity were low.

DESCRIPTION OF SYMBOLS 1 Toothbrush 10 Head part 11 Hair bundle 12 Flocked surface 12a Flocked hole 12b Flocked area | region 20 Neck part 30 Handle part 40 Reinforcement protrusion 41 Protrusion part

Claims (4)

A head portion having a plurality of flocking holes formed on the flocked surface; a neck portion extending from the proximal end side of the head portion; and a handle portion extending from the proximal end side of the neck portion. a toothbrush tufts of bristles have been implanted bristles to said flocking holes,
The hair bundle is fixed to the flock hole by a flat wire attached so as to straddle the flock hole,
A toothbrush characterized in that a plurality of reinforcing ridges extending from the base end side toward the tip end side are provided on the back surface of the head portion at a position that does not overlap the flock hole.
  The toothbrush of Claim 1 whose thickness of a head part is 3 mm or less.   The toothbrush according to claim 1 or 2, wherein the reinforcing ridges are disposed in a region of 60% or less from the proximal end side to the distal end side of the flocked region.   The toothbrush according to any one of claims 1 to 3, wherein the reinforcing protrusion has a substantially semi-elliptical cross-sectional shape when cut along the short direction of the head portion.

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