JP2005177063A - Toothbrush and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toothbrush soft, having a gentle abutment touch, and being suited for the treatment and prevention of the periodontal disease and gingivitis and to provide its manufacturing method. <P>SOLUTION: At least, parts of bristle tufts 5 are composed of synthetic resin bristles 4<SB>1</SB>and 4<SB>2</SB>with two types or more different cross sections, and the synthetic resin bristles 4<SB>1</SB>and 4<SB>2</SB>with different cross sections are randomly disposed in the respective bristle tufts 5. Alternatively, the synthetic resins for use in bristle materials are spun and tufted by an extruder which has a mouth ring randomly disposed with extrusion holes with at least two types or more different extrusion calibers, to manufacture the bristle tufts randomly disposed with the synthetic resin bristles with the two types or more different cross sections. The bristle tufts are implanted in the head part of the toothbrush. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a toothbrush that is soft and comfortable and that is suitable for the treatment or prevention of periodontal disease, gingivitis, and the like, and a method for producing the toothbrush.

  Conventionally, toothbrushes using animal hairs (mixed hairs such as pig hair, eyelashes, goat hair) have been known as toothbrushes obtained by bundling soft and thin hairs of different diameters. This toothbrush using animal hair has been used by periodontitis patients, gingivitis patients and the elderly for some time, but since it is a natural hair, rarely extremely thick hair may be mixed. There was a case where a sense of incongruity was generated in the previous hit feeling. In addition, since there is a large difference between the hair and the back when it is dry and when it contains moisture, there is also a problem of a change in feel during use in which it feels slightly hard at the beginning of use and gradually feels soft. Furthermore, there is a problem that it is slightly inferior in terms of cleanliness as compared with a synthetic resin bristle toothbrush.

  Further, in the production, there is a problem that it is difficult to stabilize the hair diameter and the number of hairs, and careful cleaning and disinfection is necessary before flocking, which complicates the production process. In addition, animal hair has a problem that the cost of the hair itself is high and the toothbrush cannot be provided at a low cost.

  On the other hand, as a toothbrush using synthetic resin bristles, a toothbrush using extreme fine hair is famous, but as a very fine distal hair, a tapered hair with a thin tip but a thick root is common. Some patients with severe gingivitis experienced pain in the hair ends. Below, it illustrates about the toothbrush using the bristles for conventional synthetic resin.

1. Patent Document 1 (Japanese Utility Model Publication No. 63-95828)
A toothbrush is shown in which a portion of the brush bundle is a mixed brush bundle of thick and thin hairs. Although the arrangement of the hair in the hair bundle is described, the optimal hair diameter has not been studied, and thick and thin hair are mixed. Since the previous pain may be felt, it may not be suitable for gingivitis patients who are sensitive to pain. There was also room for research on manufacturing methods.

2. Patent Document 2 (Japanese Utility Model Publication No. 63-185632)
A toothbrush having both a narrow bristle with a diameter in the range of 6/1000 to 10/1000 inches and a thick bristle with a diameter in the range of 8/1000 to 13/1000 inches per flock hole is shown. . This toothbrush is not suitable as a toothbrush for treating or preventing periodontal disease because the hair diameter is too thick. Moreover, the optimal hair material is not prescribed | regulated and the manufacturing method is not researched.

3. Patent Document 3 (Japanese Utility Model Publication No. 63-185633)
The toothbrush described in Patent Document 2 is further finely conditioned, and is not suitable as a toothbrush for treating or preventing periodontal disease, as the toothbrush of Patent Document 3 is too thick. .

4). Patent Document 4 (Japanese Patent Laid-Open No. 2-98310)
A toothbrush is shown in which a bristle having a spherical tip and a bristle having a round tip are mixed and planted on the base. In the case of this toothbrush, the bristle diameter is not clearly specified, but the bristle itself is not different in diameter although the bristle diameter is different.

5). Patent Document 5 (Japanese Patent Publication No. 2002-537880)
A toothbrush is shown in which at least two different types of bristle segments are combined into a bristle bundle that is implanted or secured to the head. In this toothbrush, one type of bristle diameter and shape are bundled into a partial group, and a plurality of bristle bundles of this partial group are combined and converged to form a bristle bundle. Different diameters and irregular hairs are not uniformly dispersed. For this reason, there is a defect that the contact feeling of the hair ends is not uniform and the feeling of use is inferior. Moreover, since it is an in-mold molded toothbrush, productivity is bad and cost becomes high.

Japanese Utility Model Publication No. 63-95828 (all pages, all figures) Japanese Utility Model Publication No. 63-185632 (all pages, all figures) Japanese Utility Model Publication No. 63-185633 (all pages, all figures) JP-A-2-98310 (all pages, all figures) Japanese translation of PCT publication No. 2002-537880 (all pages, all figures)

  As described above, the conventional toothbrush has the following problems as a toothbrush for treating or preventing periodontal disease and gingivitis.

(1) As a toothbrush for the treatment and prevention of periodontal disease, a soft and comfortable toothbrush is necessary so that toothpaste can be massaged.
(2) Although it is necessary to have high plaque removal power to every corner of the oral cavity even with a weak brushing pressure so that it can be used even by people with toothaches, it is sufficient to satisfy this There was no.
(3) Soft bristle toothbrushes are generally composed of brushes with thin diameters, but with the same diameter, the bristle becomes too weak and soft when soft. There was a problem that the feeling was inferior.
(4) There are natural hair toothbrushes such as animal hair as a toothbrush using a bundle of different diameter hairs to achieve both soft feeling and bristle waist, but there are problems with stabilization of quality and cost. In addition, because of animal hair, there is also a problem that it is slightly inferior in terms of cleanliness compared to synthetic resin hair.
(5) In order to realize a hair bundle for mixing different diameters with synthetic resin hair, first, a plurality of types of hair bundles having different hair diameters are manufactured, and these are mixed by a subsequent process. Although it was possible, it was not realistic because of the high cost. As another method, it is possible to plant a hair bundle for mixing hairs on the head as long as it is manufactured by an in-molded toothbrush, but the in-molded toothbrush is low in productivity and high in cost. There is.

  The present invention has been made to solve the above-described problems, and provides a toothbrush that is soft and easy to touch and is suitable for use in the treatment or prevention of periodontal disease and gingivitis, and a method for producing the same. It is for the purpose.

  In order to achieve the above object, the toothbrush of the present invention comprises at least a part of the bristles composed of two or more types of synthetic resin bristles having different cross-sectional areas, and the synthetic resin bristles having different cross-sectional areas are each bristles. Are randomly arranged. In this case, the cross-sectional area of the thickest synthetic resin bristles is equivalent to the cross-sectional area of the bristles made of a circular cross section having a diameter of 0.102 to 0.178 mm (4 to 7 mils), and the cross-sectional area of the thinnest synthetic resin bristles is It is preferable to have a cross-sectional area equivalent to a hair having a circular cross section with a diameter of less than 0.102 mm (4 mil). In addition, if the cross-sectional area of hair is the same, there is no restriction | limiting in the cross-sectional shape, Various cross-sectional shapes, such as a circular cross section, an elliptical cross section, and a polygonal cross section, are employable. If hairs having different cross-sectional shapes are used after satisfying the cross-sectional area condition, a texture closer to natural hair can be obtained.

  Furthermore, the manufacturing method of the toothbrush according to the present invention uses a bristle extrusion molding machine provided with a die having randomly arranged extrusion holes composed of at least two different extrusion diameters in order to produce the toothbrush. A synthetic resin serving as a bristle material is spun and bundled by a hair extrusion molding machine to produce a bundling in which synthetic resin bristles having two or more different cross-sectional areas are randomly arranged, and the bristles are used as a head of a toothbrush It is intended to be planted in the department. In order to plant the hair bundle in the head portion, a conventionally known hair transplantation method such as a flat wire transplantation method, an in-mold molding method, or a heat fusion method may be used.

In order to achieve both soft and gentle contact feeling and moderate bristle, as described above, use a bundle of synthetic resin bristles with two or more different cross-sectional areas randomly arranged, and implant in the flock holes of the toothbrush head. To do. The hair used for toothbrushes with a “normal” (7 mm bristle length and about 50 to 85 N / cm ² ) hardness indication and thicker hair are not suitable for periodontal and gingivitis patients. The thickness (cross-sectional area) of the bristle is smaller than that used for a general toothbrush, and even the thickest bristle is equivalent to a bristle having a circular cross section with a diameter of 0.102 to 0.178 mm (4 to 7 mil) In addition, the hairs having different cross-sectional areas are randomly arranged in each hair bundle so as not to feel the pain of the hair ends.

  In addition, the hair having the smallest cross-sectional area is a hair having a circular cross-section with a diameter of less than 0.102 mm (4 mils) so that high plaque removing power can be exhibited in every corner of the oral cavity even with a weak brushing pressure. It is desirable to use hair having a cross-sectional area, and to make the flock holes (hair bundles) have specifications of large holes (thick hair bundles) in order to improve the bristles of the entire brush. Furthermore, it is desirable to reduce the pitch between the holes as much as possible in order to make the hair dense, and to make the arrangement of the flocked holes a staggered arrangement or the like. As a result, thin hairs can easily enter narrow gaps in teeth, and not only plaque can be removed efficiently by brushing the entire surface of teeth, between teeth, etc. with a thick bundle of hair filled with a large amount of hair, Ginger massage can be performed comfortably and comfortably by using a brush with dense hair.

1. The hair for constituting the hair bundle is synthetic resin hair having two or more different cross-sectional areas as described above, and the cross-sectional area of a thick one is 0.102 to 0.178 mm (4 to 7 mil) in diameter. The cross-sectional area of the hair having a circular cross section is equivalent to, more preferably, 0.127 to 0.152 mm (5 to 6 mil) in diameter. In addition, the cross-sectional area of the thinnest one is equivalent to the cross-sectional area of hair having a circular cross section with a diameter of less than 0.102 mm (4 mil), more preferably 0.0254 (1 mil) or more and 0.102 mm (4 mil) Less, more preferably 0.058 to 0.076 mm (2 to 3 mil) in diameter.

  When two types of hair are mixed to form a hair bundle, the mixing ratio (weight ratio) of thick hair and thin hair is about 40 to 90% for thick hair and 10 to 60% for thin hair. It is desirable to set the degree. Further, when three or more types of hairs are mixed, those corresponding to a hair diameter of 0.102 to 0.178 mm (4 to 7 mils) fall within the range (40 to 90%) of the mixing ratio of the thick hairs. In addition, the respective composition ratios are determined so that the hair diameters less than 0.102 mm (4 mils) are within the range (10 to 60%) of the mixing ratio of the thin hairs. Just decide. However, by mixing a plurality of types of hair, the touch of the hair ends is delicate and good. However, about 2 to 4 types of mixed hairs are sufficient, and even if the number of hairs becomes more complicated, the actual effect does not change much. . The cross-sectional area difference of the hair to be mixed is preferably a cross-sectional area difference within a diameter difference of 0.076 mm (3 mil) in terms of a circular cross section. If the cross-sectional area difference of the hair is large, thick hair may be projected and may be accompanied by pain at the hair tip.

  There are no particular restrictions on the shape, color, surface structure, and internal structure of the hair. The cross-sectional shape of the hair is preferably circular, but is not particularly limited, such as an ellipse or a polygon. In the case of hair having an irregular cross-section other than a circular shape, the cross-sectional area of the hair may be set so as to fall within the range corresponding to the diameter.

  The material of the bristles is not limited as long as it is a synthetic resin conventionally used in toothbrushes. For example, polyamide such as nylon, polybutylene terephthalate, polyethylene terephthalate, polyester such as polytrimethylene terephthalate, or polypropylene Can be used. These blended resins may also be used.

2. Flocking hole The hair bundle is planted on the head of the toothbrush. In the case of flat line type flocking, the size of the flocked hole is preferably in a range corresponding to a circular cross-sectional area of 1.0 to 2.6 mm in diameter, and more preferably in a range corresponding to a circular cross-sectional area of 1.7 to 2.2 mm in diameter. . Even if the hole diameter is small, if the pitch between the holes is reduced to make the hair denser, the fluff falls within an appropriate range, but the productivity decreases. When the hole diameter is too large, even if it is a thin hair, the penetration property to the space between the teeth is lowered, which is not preferable.

  The hole shape is preferably circular, but may be a polygonal hole such as a square hole or an irregularly shaped hole. Further, the size of the flocked hole may be a single type, but may be composed of a plurality of types of flocked holes having different hole diameters and / or hole shapes. Since it is preferable to make the brush denser, the distance between the holes is preferably as small as possible. In the case of flat line type flocking, defects such as cracks and cracks around the flocked hole will occur unless the distance between the driven flat lines is taken to some extent, so the arrangement direction of the flocked holes and the flat line indenting direction match The distance between the holes is preferably about 0.5 mm or more. On the other hand, when the arrangement direction of the flocked holes is different from the indentation direction of the flat line, the distance between the holes is preferably about 0.1 to 1.0 mm. The shortest distance between holes depends on the strength of the head material, but in the case of polypropylene, it is desirable to take 0.2 mm or more.

  The hole arrangement of the flock holes is preferably based on a plover arrangement. Although a grid-like arrangement may be used, it is more difficult to make hair denser than the plover arrangement. However, the above-mentioned various dimensions relate to flat-line type flocking, and this is not limited to anchorless toothbrushes such as in-mold molded toothbrushes and heat fusion toothbrushes, and the dimension range can be set more freely. The filling rate of the hair into the flocked hole (= total cross-sectional area of the hair entering the flocked hole / plantable area × 100 (%)) is preferably in the range of 70% to 95%, and the highest possible filling rate It is desirable that The flockable area is an area obtained by subtracting the area of the flat line from the area of the flocked hole, that is, (flocked hole area-flat line area).

3. Other brush hardness (at Hair length 7 mm) is preferably in a 55N / cm ² or less in the range of "softer", more and more preferably in the range of 30~50N / cm ^2. If it is 30 N / cm ² or less, it may be too soft and may interfere with oral cleaning. If it is more than 50 N / cm ² , it will be too hard to be used as a toothbrush for periodontal disease or gingivitis.

  The brush length (hair length) is preferably in the range of 7.5 to 13 mm. It is preferable to shorten the bristle length with a toothbrush with a small head portion and lengthen the bristle length with a large head. The size of the head portion is preferably in the range of length × width = 15-30 mm × 6-12 mm.

  The trimming of the brush may be an orthodox straight cut, but it is preferable to chamfer the edge of the brush like a dome cut because the contact feeling of the hair tip becomes easier. It is preferable that the hair ends are rounded / polished after being cut.

According to the present invention, the following excellent effects can be achieved.
(1) Since a hair bundle in which two or more kinds of synthetic resin bristles having different cross-sectional areas are randomly arranged is used, a toothbrush having both soft and gentle contact feeling and appropriate bristle and hips can be provided. In particular, the cross-sectional area of the thickest synthetic resin bristles is equivalent to the cross-sectional area of hair having a circular cross section with a diameter of 0.102 to 0.178 mm (4 to 7 mil), and the cross-sectional area of the thinnest synthetic resin bristles is 0 in diameter. If the cross-sectional area of the bristle having a circular cross section of less than .102 mm (4 mil) is used, the above-mentioned effect can be exhibited more reliably.
(2) Since a hair bundle made of thick synthetic resin bristles and thin synthetic resin bristles with different cross-sectional areas is used, high plaque removal power can be demonstrated to every corner of the oral cavity even with a weak brushing pressure, and at the same time weak. You can massage comfortably, including the toothpaste. Furthermore, it becomes a toothbrush with good foaming.
(3) By using synthetic resin bristles as brushes, accurate and stable hair mixing becomes possible, and the change in hair between dry and wet seen in natural hair is reduced. Furthermore, it has good drainage and can always be used with a clean feeling.
(4) A hair bundle in which a plurality of types of synthetic resin bristles having different cross-sectional areas are randomly arranged by spinning using a die provided with an arbitrary number of a plurality of types of extrusion holes having different extrusion diameters is 1 It can be manufactured easily and accurately by a single extrusion operation. For this reason, it is possible to eliminate the need for a hair mixing step for randomly mixing a plurality of types of synthetic resin bristles with different cross-sectional areas, and to reduce the manufacturing cost as with conventional toothbrushes using single diameter bristles. Can do.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a first embodiment of a toothbrush according to the present invention.
This 1st Embodiment shows the example at the time of comprising each hair | bristle bundle using two types of hairs from which a cross-sectional area differs, and is circular from which a diameter differs as two types of hair from which a cross-sectional area differs. A cross-sectional filament was used.

In the figure, 1 is a head portion, 2 is a flocked surface, 3 is a flocked hole, 4 ₁ and 4 ₂ are two types of hairs having different cross-sectional areas, and 5 is composed of two types of bristles 4 ₁ and 4 ₂ . It is a hair bundle. The hairs 4 ₁ and 4 ₂ are filaments each having a circular cross section. The hair 4 _{1 having} a small diameter has a diameter of 0.076 mm (3 mil), and the hair 4 _{2 having} a large diameter has a diameter of 0.127 mm (5 mil). and are, use hair 4 ₁ 2 different kinds of this _size, 4 _2, i.e. two different use hair 4 _1, 4 ₂ cross-sectional area at the weight ratio of fine bristles 4 _1: thick bristles The hair bundle 5 is obtained by randomly mixing the hairs at a ratio of 4 ₂ = 3: 7.

To manufacture the toothbrush made of the configuration of FIG. 1, a mouthpiece for use hair extruder, extrusion for extruding the extruding hole for extruding a small use hair 4 ₁ diameter, the greater use hair 4 ₂ diameter A base is prepared in which holes are randomly formed at a ratio satisfying the weight ratio of 3: 7.

And in the manufacture, the synthetic resin used as a hair material is spun and wound up using the hair extrusion molding machine provided with the above-mentioned mouthpiece, and it collects in the thickness of about 50 mm in diameter as a mixed hair bundle for flocking . Then, after preparing the hair bundle and winding it with paper, cut it to a length of 32 mm, and then set the cut piece on a flat-line hair transplanter, and use a picker to adjust the hair to a filling rate of 85%. While scraping, each flocked hole 3 having an irregular plover arrangement (30 holes) with a diameter of 2.0 mm is folded in half along with a flat line. Thereafter, the tip of the installed brush is cut into a dome shape with a hair length of 10 mm using a rotary cutter, and finally the ends of each hair are rounded / polished to obtain the toothbrush of FIG. The 7 mm bristle waist of the toothbrush according to the first embodiment is about 45 N / cm ² . Depending on the purpose of brushing, the tip of the hair may be tapered after flocking / trimming.

FIG. 2 shows a second embodiment of the toothbrush according to the present invention.
This 2nd Embodiment shows the example at the time of comprising each hair | bristle bundle using three types of bristle with different cross-sectional areas, and as for three types of bristle with different cross-sectional areas, it is circular with different diameters. A cross-sectional filament was used. In addition, the same code | symbol was used for the same part as FIG.

In this second embodiment, small use hair 14 ₁ diameter 0.076mm diameter (3 mil), a large first use hair 14 ₂ diameter 0.102mm diameter (4 mil), a large second diameter the use hair 14 ₃ are the diameter 0.152 mm (6 mil), use hair ₁₄ 1 of 3 different kinds of this _diameter, 14 2, 14 _3, i.e. three different use hair ₁₄ 1 cross-sectional area, 14 ₂ , 14 ₃ in the weight ratio, thin hair 14 ₁ : first thick hair 14 ₂ : second thick hair 14 ₃ = 2: 3: 5 It is what.

To manufacture the toothbrush made of the configuration of FIG. 2, as a mouthpiece for use hair extruder, extruding the small use hair 14 ₁ of diameter and the extrusion holes for extruding the use hair 14 ₂ large first diameter and extruding hole for the extrusion holes for extruding use hair 14 ₃ large second diameter, the weight ratio of 2: 3: preparing a die formed randomly at a ratio that satisfies 5.

And in the manufacture, using the hair extrusion molding machine provided with the said nozzle | cap | die, the synthetic resin of a hair raw material is spun up and wound up, and it bundles to the thickness of about 50 mm in diameter as a mixed hair bundle for flocking. Then, after preparing the hair bundle and winding it with paper, cut it to a length of 32 mm, and then set the cut piece on a flat-line hair transplanter, and use a picker to adjust the hair to a filling rate of 85%. While scraping, each flocked hole 3 having an irregular plover arrangement (34 holes) with a diameter of 1.70 mm is folded in half along with a flat line. Thereafter, the tip of the planted brush is cut into a straight shape having a hair length of 10 mm using a rotary cutter, and finally the ends of each hair are rounded / polished to obtain the toothbrush of FIG. The 7 mm bristle waist of the toothbrush according to the second embodiment is about 35 N / cm ² . Depending on the purpose of brushing, the tip of the hair may be tapered after flocking / trimming.

FIG. 3 shows a third embodiment of the toothbrush according to the present invention.
As in the second embodiment, the third embodiment shows an example in which each hair bundle is configured using three types of hair having different cross-sectional areas. As the type of hair, filaments having a circular cross section with different diameters were used. In addition, the same code | symbol was used for the same part as FIG.

In the case of the third embodiment, the bristle 24 _{1 having} a small diameter has a diameter of 0.051 mm (2 mil), and the first bristle 24 ₂ having a large diameter has a diameter of 0.102 mm (4 mil) and has a large diameter. the use hair 24 ₃ are the diameter 0.152 mm (6 mil), use hair ₂₄ 1 of this diameter three _different, 24 2, 24 _3, i.e. three different use hair ₂₄ 1 cross-sectional area, 24 ₂ , 24 ₃ in the weight ratio, thin hair 24 ₁ : first thick hair 24 ₂ : second thick hair 24 ₃ = 2: 2: 6 and randomly mixed into the hair bundle 5 It is what.

In order to manufacture the toothbrush having the configuration shown in FIG. 3, an extrusion hole for extruding the small bristle 24 ₁ and the first bristle 24 ₂ having a large diameter are extruded as a die of the bristle extrusion molding machine. and extruding hole for the extrusion holes for extruding large second use hair 24 ₃ of diameter, the weight ratio of 2: 2: 6 to prepare a die which is formed at random at a ratio that satisfies.

And in the manufacture, using the hair extrusion molding machine provided with the said nozzle | cap | die, the synthetic resin of a hair raw material is spun up and wound up, and it bundles to the thickness of about 50 mm in diameter as a mixed hair bundle for flocking. Then, after preparing the hair bundle and winding it with paper, cut it to a length of 32 mm, and then set the cut piece on a flat-line hair transplanter, and use a picker to adjust the hair to a filling rate of 85%. While scraping, each flocked hole 3 arranged in a grid pattern (20 holes) with a diameter of 1.77 mm is folded in half together with a flat wire and driven. Thereafter, the tip of the planted brush is cut into a straight shape with a hair length of 9.0 mm using a rotary cutter, and finally the ends of each hair are rounded / polished to obtain the toothbrush of FIG. The 7 mm bristle waist of the toothbrush according to the second embodiment is about 35 N / cm ² . Depending on the purpose of brushing, the tip of the hair may be tapered after flocking / trimming.

  The use test of the toothbrush of the present invention and the conventional toothbrush was conducted, and the results are shown below.

1. Dental plaque removal force test The toothbrush of the present invention (product of the present invention) having the specifications shown in Table 1 and a conventional toothbrush (general toothbrush) were subjected to a comparative test of plaque removal force using a tooth model. The result is shown in FIG.
<Experimental conditions>
Load: 150g
Stroke: 15mm
Cleaning time: 10 seconds Number of test: 10 each

  As is apparent from FIG. 4, it was confirmed that the invention products (Type 1 and Type 2) were superior in plaque removal power to general toothbrushes even when polished with a weaker brush pressure of 150 g.

2. Test of change in hair and hips in dry / wet state Using synthetic resin hair having the specifications shown in Table 2, the change in hair and hips at 7 mm in dry / wet state was measured. The result is shown in FIG.
<Experimental conditions>
Hole diameter x Number of holes: Diameter 1.5mm x 40 holes Hair filling rate: 85%
Dry (dry): Stored for 1 day at 23 ° C. and 50% humidity Wet: Dipped in distilled water for 1 hour, then drained Test number: 10 each

  As is apparent from FIG. 5, natural hair has a difference in hair strength between dry and wet of about 50%, whereas synthetic hair can be reduced to about 30%.

3. Usability Evaluation Test Using a toothbrush having the specifications shown in Table 3, a usability evaluation test was performed. The results are shown in Table 4.
<Experimental conditions>
Number of subjects: n = 50 (periodontal disease patients)
Period: 2 weeks Evaluation method: Based on the following 7-level absolute evaluation. The average value of the evaluation values of 10 subjects was used as the evaluation result.
7: Very good 6: Good 5: Somewhat good 4: Normal 3: Somewhat bad 2: Bad 1: Very bad

  As is apparent from the evaluation results in Table 4, the general toothbrush 1 was slightly unsuitable for the user with weak gums because the brush was too hard. Since the general toothbrush 2 is a thin brush but is not mixed, it did not reach a high evaluation of a feeling of massage and a touch comfort of the hair tip. The natural bristle toothbrush was evaluated to be close to the product of the present invention, but rarely thick hair may be mixed, the touch comfort of the tip is 5.2 points, and the cleanliness is also slightly inferior to the product of the present invention. It became evaluation. It was confirmed that the product of the present invention using a mixed hair bundle having a narrow hair diameter is preferable for periodontal disease patients because it does not hurt the toothpick and feels good plaque, feels like massage, and foams.

1 shows a first embodiment of a toothbrush according to the present invention, in which (a) is a plan view of a head portion, (b) is a front view of the head portion, and (c) is a schematic plan view of a hair bundle. . FIGS. 2A and 2B show a second embodiment of a toothbrush according to the present invention, in which FIG. 1A is a plan view of a head portion, FIG. 1B is a front view of the head portion, and FIG. . FIG. 3 shows a third embodiment of a toothbrush according to the present invention, in which (a) is a plan view of a head portion, (b) is a front view of the head portion, and (c) is a schematic plan view of a hair bundle. . It is a graph which shows the test result of plaque removal power. It is a graph which shows the test result of the hair back change in a dry and wet state.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Head part 2 Flocked surface 3 Flocked hole 4 ₁ Thin hair 4 ₂ Thick hair 5 Hair bundle 14 ₁ diameter thin hair 14 ₂ diameter thick 1st hair 14 ₃ diameter thick 2nd hair 15 ₁ diameter thin hair 15 ₂ diameter thick first hair 15 ₃ diameter thick second hair

Claims (3)

  A toothbrush characterized in that at least a part of the bristles is made of synthetic resin bristles having two or more different cross-sectional areas, and these synthetic resin bristles having different cross-sectional areas are randomly arranged in each bristles .   The cross-sectional area of the thickest synthetic resin bristles is equivalent to the cross-sectional area of the bristles having a circular cross section with a diameter of 0.102 to 0.178 mm (4 to 7 mils). The toothbrush according to claim 1, wherein the toothbrush has a cross-sectional area corresponding to a bristle having a circular cross section of less than 102 mm (4 mil).   By using a hair extrusion molding machine equipped with a die having randomly arranged extrusion holes composed of at least two different extrusion diameters, and spinning and bundling synthetic resin as a hair material with the hair extrusion molding machine A method for producing a toothbrush, comprising producing a hair bundle in which two or more kinds of synthetic resin bristles having different cross-sectional areas are randomly arranged, and implanting the hair bundle in a head portion of the toothbrush.

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