JP2011004852A - Toothbrush - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toothbrush improving operability inside the oral cavity more than that of a conventional toothbrush and sufficiently having a bristle retaining strength and head folding endurance.SOLUTION: The toothbrush 1 includes the head 3 provided with a plurality of implanting holes on an implanting face 3b and is manufactured by the following manner: the bundle of the bristles 5 is twice-folded; and a wire sandwiched between them is punched into the holes, while filling the holes with the bundles. The head 3 is made of a polyacetal resin or a polybutylene terephthalate resin. The thickness (t) of the head 3 is at least 2 mm and less than 3 mm.

Description

  The present invention relates to an improvement in a toothbrush.

  Generally, a toothbrush is manufactured by fixing a brush of nylon or polybutylene terephthalate (PBT) with a flat wire in a flock hole provided in a head portion in advance. As the material of the head part, polypropylene (PP) is generally used from the viewpoint of cost and formability.

  By the way, in order to make it easy to clean the corners of the oral cavity, particularly the back teeth, with a toothbrush, it is preferable that the head portion into which the brush is implanted has a small thickness. However, in the conventional method in which a flat wire is driven into a polypropylene handle to hold the brush, the thickness of the head portion cannot be reduced. Specifically, when the thickness of the head portion is 4 mm or less, there is a problem that the defect rate becomes high, such as insufficient flocking strength or cracking or whitening during flocking.

  As a method for solving such a problem, the cross-sectional shape of the back surface of the head part is substantially semicircular, the thickness of the handle neck is 4 to 6 mm, the thickness of the tip of the head part is 1 to 3 mm, and the thickness of the side surface of the head part is A toothbrush having a size of 1 to 3 mm has been proposed (see Patent Document 1).

  In addition, a toothbrush in which the brush is fixed to the head part by thermal fusion without using a flat wire (see Patent Document 2) and a toothbrush in which the brush is fixed to the head part by in-mold are proposed (see Patent Document 3). reference).

  In addition, a toothbrush has been proposed in which polyacetal resin is used as the material of the handle and the thickness of the head is reduced to 3 mm (see Patent Document 4).

Japanese Patent No. 3453028 JP 61-76104 A JP 60-116303 A Japanese Patent No. 3387591

  However, in the toothbrush described in Patent Document 1, in order to ensure sufficient flocking strength and head part bending strength, the thickness of the most part of the head part must be 4 mm or more, improving the oral operability. There is no effect.

  In addition, the toothbrushes described in Patent Document 2 and Patent Document 3 have a problem in that the manufacturing process is complicated and the production cost is high as compared with the method of flocking using a flat wire.

  Further, the toothbrush described in Patent Document 4 has a head portion thickness of 3 mm, and thus the effect of improving intraoral operability cannot be sufficiently obtained.

  Under such circumstances, there has been a demand for a toothbrush having improved oral operability as compared with conventional toothbrushes and having sufficient flocking strength and head bending resistance. However, effective and appropriate ones are provided. There is no actual situation.

  The present invention has been made in view of such circumstances, and its object is to provide a toothbrush having improved oral operability as compared to conventional toothbrushes and having sufficient flocking strength and head bending resistance. It is to be.

Therefore, the present invention employs the following configuration.
The toothbrush according to the present invention includes a head portion having a plurality of flocking holes provided on a flocked surface, folds a bristles of a brush into two, and drives a flat wire sandwiched between the bristles into the flocked hole. A toothbrush in which a bundle is implanted in the flock hole, wherein the head portion is made of polyacetal resin or polybutylene terephthalate resin, and the thickness of the head portion is 2 mm or more and less than 3 mm. .

  In the toothbrush according to the present invention, when the length of the flat wire is w, the width of the flat wire is h, the diameter of the flocked hole is d, and the depth of the flocked hole is D, 0.9 It is preferable that the relationship of ≦ (w−d) × h × D ≦ 2.5 is satisfied.

  Since the head part is comprised by the polyacetal resin or the polybutylene terephthalate resin, the toothbrush which concerns on this invention can have sufficient flocking strength and head part bending strength. Moreover, since the thickness of a head part is comprised in 2 mm or more and less than 3 mm, intraoral operativity improves.

  Further, the toothbrush according to the present invention has a flat wire length of w, a flat wire width of h, a flocked hole diameter of d, and a flocked hole depth of D of 0.9 ≦ (w−d ) × h × D ≦ 2.5 is satisfied so that the flocking strength and the head portion bending strength are further increased.

FIG. 1 is a side view showing a toothbrush according to an embodiment of the present invention. FIG. 2 is an enlarged view of the head portion with the brush omitted, FIG. 2 (a) is a plan view of the head portion, and FIG. 2 (b) is an A view of FIG. 2 (a). FIG. FIG. 3 is an enlarged view of the flocked hole with the brush omitted, FIG. 3 (a) is a plan view of the flocked hole, and FIG. 3 (b) is B in FIG. 3 (a). FIG. FIG. 4 is an enlarged cross-sectional view of the flock hole. FIG. 5 is a plan view showing an enlarged flock hole with the brush omitted. FIG. 6 is an enlarged view of the head portion with the brush of the toothbrush according to one embodiment of the present invention omitted, and FIG. 6A shows Examples 1 to 5, 8, 9 and Comparative Examples. 6B is a cross-sectional view taken along the line EE ′ of FIGS. 6A and 6B of Examples 2 and 8 and Comparative Example 3. FIG.

Hereinafter, the toothbrush which is embodiment of this invention is demonstrated with reference to drawings.
As shown in FIG. 1, the entire toothbrush 1 of the present embodiment is formed in an elongated shape, and includes a handle portion 2, a head portion 3 provided on the distal end side of the handle portion 2, a handle portion 2, The head portion 3 is roughly constituted by a neck portion 4 provided between the head portion 3 and a brush 5 implanted in the head portion 3.

  The handle portion 2 is a portion that is gripped by the user, and is formed of a hard resin material or a soft resin material. Examples of the hard resin material include polyacetal resin (POM) having a flexural modulus of 500 to 3000 Mpa, preferably 1000 to 2000 Mpa, polybutylene terephthalate resin (PBT), polystyrene resin (PS), polypropylene resin (PP), and polyethylene terephthalate resin (PP). PET), acrylonitrile butadiene styrene resin (ABS), cellulose propionate resin (CP), polyarylate resin, polycarbonate resin, acrylonitrile styrene resin (AS), and the like.

  As the soft resin material, one having a hardness (JISK6253 hardness test, test condition JIS A) of 5 to 100, preferably 20 to 60 is preferable. Polyolefin thermoplastic elastomer, polystyrene thermoplastic elastomer, polyurethane thermoplastic Elastomers, polyester-based thermoplastic elastomers, 1-2 polybutadiene-based thermoplastic elastomers, ethylene vinyl acetate-based elastomers, polyvinyl chloride-based thermoplastic elastomers, natural rubber-based thermoplastic elastomers, fluorine-based thermoplastic elastomers, trans-polyisoprene-based thermoplastics An elastomer etc. are mentioned.

  The handle part 2 can be appropriately used in combination with the above materials, but from the physical properties required as a toothbrush material, price and compatibility, polypropylene resin and polyolefin-based thermoplastic elastomer or polystyrene-based thermoplastic elastomer Is preferably used. For example, as a polyolefin-based thermoplastic elastomer, an EPDM (ethylene-butylene-diene terpolymer) is selected as a rubber component, a polypropylene resin is selected as a hard component, and these are blended and partially or fully crosslinked. Used. Furthermore, instead of the thermoplastic elastomer, a thermosetting silicone resin by two-component mixed injection may be used. The handle portion 2 may be partially or entirely covered with a flexible resin such as an elastomer in order to improve the gripping property.

  The neck portion 4 is a portion that connects the handle portion 2 and the head portion 3, but the handle portion 2 and the head portion 3 are not necessarily clearly distinguished portions. Some are not distinguished from part 3. Therefore, it may have a shape in which the head portion 3 is directly provided at the tip of the handle portion 2, and the shape, size, design, and the like can be arbitrarily changed.

  The head unit 3 has a thickness t of 2 mm or more and less than 3 mm. When the thickness t is 3 mm or more, the feeling of use is similar to that of a conventional toothbrush, and high intraoral operability cannot be realized. Moreover, when thickness t is less than 2 mm, it becomes impossible to ensure the depth of the flock hole 8 sufficient to hold the hair bundle 7 with the flat wire 6 described later. As a result, sufficient flocking strength cannot be ensured, and the hair bundle may fall out during brushing. Moreover, since the bending strength of the head part 3 is also lowered, the head part 3 may be broken during tooth brushing, and there is a risk of damaging fingers and the oral cavity. The head portion 3 may have the same thickness from the tip to the neck portion 4, but it is sufficient that the thickness of two-thirds or more of the area of the back surface 3a of the head portion 3 falls within this range. It can also be set as the form which arrange | positions a convex-shaped part to 3a and is connected with the neck part 4 naturally.

  The head portion 3 is formed of polyacetal resin or polybutylene terephthalate resin. The polyacetal resin is a resin having a polyoxymethylene structure mainly composed of formaldehyde or trioxane, and includes a homopolymer having only a polyoxymethylene structure and a copolymer of ethylene oxide, dioxolane, butanediol formal and the like. These have high mechanical strength, rigidity, chemical resistance, and heat resistance, and are widely used as engineering plastics. Either a homopolymer or a copolymer can be used for the head portion 3, but a copolymer with a small amount of formaldehyde is preferable. Specific examples include Duracon manufactured by Polyplastics, Iupital manufactured by Mitsubishi Engineering Plastics, and Tenac C manufactured by Asahi Kasei Chemicals.

  Polybutylene terephthalate resin is a thermoplastic polyester produced by polycondensation reaction using terephthalic acid or dimethyl terephthalate and 1-4 butanediol as raw materials, and has excellent heat resistance, moldability, and chemical resistance. It is known. Specific examples include Juranex manufactured by Polyplastics, Novaduran manufactured by Mitsubishi Engineering Plastics, and Toraycon manufactured by Toray.

  The head portion 3 can be molded integrally with the handle portion 2 using polyacetal resin. However, when a material other than polyacetal resin is used as the material constituting the handle portion 2, the handle portion 2 and the head portion are used. 3 can be integrally molded by a multicolor molding technique. In addition, since the polyacetal resin has low compatibility and low adhesion to foreign materials, it is preferable to join them by fitting or screwing.

  Further, as shown in FIGS. 2 to 4, a plurality of flocking holes 8 for planting the hair bundle 7 of the brush 5 are formed on the flocking surface 3 b which is one surface of the head portion 3. It is provided in a row in the direction and the width direction. In FIGS. 2 and 3, the brush 5 is omitted.

The cross-sectional shape of the flocking hole 8 is circular, and is arranged about 10 to 40 in a lattice shape or a zigzag shape.
Although there is no restriction | limiting in particular in the cross-sectional area of the flocking hole 8, It is preferable to exist in the range of 0.75-3.1mm < ² > (The diameter d of a flocking hole is 1.0 mm-2.0 mm). By configuring in this range, the contact with the toothpick is improved, and the feeling of inserting the hair end into a fine gap such as an interdental portion is enhanced.

  Further, the depth D of the flocking hole 8 is preferably in the range of 60 to 95% of the thickness t of the head portion 3, and more preferably in the range of 70 to 90%. By constituting in this range, the folding strength of the head part 3 can be sufficiently maintained, and a toothbrush with good fuzzing is obtained.

  In addition, the flock hole 8 may use a cylindrical shape that does not change in the depth direction, and is provided with a taper portion or a step so that the hole diameter becomes narrower as it goes downward. Or a combination of a step and a tapered portion. Moreover, what chamfered about 0.3 mm, for example was given to the bottom part of the flocking hole 8 is preferable.

Moreover, when the ratio of the sum total of the cross-sectional area of the flock hole 8 to the flocked area (the area where the outside of the follicle located on the outer circumference of the flocked surface where the bunch is arranged is connected / compliant with JIS3016) is defined as the flock density The flocking density is preferably in the range of 25 to 55%.
By configuring in this range, it is possible to ensure a proper feeling of brushing and a feeling of inserting the hair tips into fine gaps such as the interdental part.

  As shown in FIG. 4, the bristles 7 are formed by bundling a plurality of brushes 5 and folding them into two, and driving the tufts 8 into the tuft holes 8 with a flat wire 6 sandwiched between them. 8 is planted.

  The shape of the brush 5 surface (hair cutting or profile) at the tip of the hair bundle 7 may be arbitrarily designed. For example, the front end of the hair bundle 7 is formed into a single flat surface, or when viewed from the side surface of the head portion 3, a straight inclined surface or a curved inclined surface (preferably, the length of the brush 5 from the front end side toward the rear end side. Or a curved or zigzag shape in which the shape of the brush 5 at the tip of the bristle bundle 7 has a maximum or minimum value of the length of the brush 5 in the middle when viewed from the side of the head portion 3. May be formed.

  The material of the brush 5 is not particularly limited, and examples thereof include polyamide (eg, 6-12 nylon, 6-10 nylon, 12-nylon), polyester (eg, polyethylene terephthalate, polybutylene terephthalate, polytrile). Synthetic resin materials such as methylene terephthalate), polyolefins (eg, polypropylene), elastomers (eg, olefins, styrenes, etc.), natural materials, etc. can be used, and these may be used in combination. A plurality of these resin materials may be used in combination. For example, different resin materials may be used for the core and the sheath, such as a core-sheath structure.

  Moreover, although the cross-sectional shape of the brush 5 is often circular, it is not particularly limited to this. For example, the brush 5 having a cross-sectional shape such as a triangle, a quadrangle, a hexagon, or a petal can be used, or a combination of these can be used. In addition, it is possible to use a brush whose entire outer shape is processed into a wave shape, a twist shape, a jagged shape, or the like, or a combination thereof.

  The diameter of the brush 5 is preferably 3 to 15 mil (0.076 to 0.381 mm), and more preferably 5 to 10 mil (0.127 to 0.254 mm). Further, the brush 5 may be a brush having substantially the same diameter in one brush except for the rounded end portion of the brush, but even toward the tip of the tip of the head 3 even if the thickness is near the flocked surface 3b. Accordingly, tapered hair whose diameter gradually decreases may be used. In this case, since the penetration of the hair tip into the gap is good and soft contact feeling can be realized, it is suitable for brushing and massaging the tooth neck. Moreover, normal hair and taper hair can be appropriately selected for each flock hole 8, can be mixed in the same hair bundle 7, or can be freely combined.

  The length of the brush 5 is preferably in the range of 6 to 15 mm from the flocked surface 3 b of the head portion 3, more preferably in the range of 8 mm to 13 mm for adults and 6 mm to 9 mm for children. . The thickness (maximum diameter) of the brush 5 is preferably 0.12 mm to 0.26 mm in terms of usability in the oral cavity and usability. Further, considering a feeling of use, a feeling of brushing, a cleaning effect, durability, and the like, a plurality of brushes having different thicknesses may be used in any combination.

  As shown in FIG. 3A and FIG. 3B, the flat line 6 passes through the center of the flock hole 8 and is placed in the flock hole 8 so as to straddle the flock hole 8. Examples of the material of the flat wire 6 include metals such as brass and aluminum, and other examples include hard plastics and biodegradable plastics.

The flat wire 6 has a length w larger than the diameter d of the flocked hole 8 and a width h smaller than the depth D of the flocked hole 8. Specifically, the length w of the flat wire 6 is preferably in the range of diameter d + 0.1 to diameter d + 0.8 mm, and the diameter d + 0.3 to diameter d + 0.6 mm. More preferably, it is within the range. If the diameter is longer than d + 0.8 mm, the flocked portion is liable to break, and if the diameter is shorter than d + 0.1 mm, there is a disadvantage that sufficient flocking strength cannot be obtained.
The width h of the flat wire 6 is preferably in the range of 0.9 to 2.0 mm. If it is shorter than 0.9 mm, sufficient driving strength cannot be ensured, and there is a disadvantage that proper flocking cannot be ensured, which is not preferable. The thickness l of the flat wire 6 is also preferably in the range of 0.2 to 0.25 mm for the same reason.

Further, the driving angle of the flat wire 6 can be freely selected, but the driving angle α with respect to the major axis direction C of the toothbrush is 5 to 80 °, preferably 15 to 30 ° in order to avoid the occurrence of cracks and whitening. It is preferable to be within the range. The driving angle α of the flat wire 6 does not have to be the same for all the flock holes 6, and different driving angles may be combined.
Moreover, the vertical cross-sectional shape of the flat wire 6 is not limited to a rectangle, and it may be difficult to come out of the flocked hole 6 by adding grooves or fine irregularities, or the shape of the cut surface at the time of driving may be devised to make it difficult to come off. .

  The toothbrush 1 has a value of (w−d) × h × D for the length w of the flat wire 6, the width h of the flat wire 6, the diameter d of the flocking hole 8, and the depth D of the flocking hole 8, It is comprised so that it may become 0.9 or more and 2.5 or less. If this value is less than 0.9, it is not possible to ensure sufficient flocking strength, and there is a disadvantage that the hair bundle tends to come off during use.・ Whitening and warping occur, which is not preferable.

  Since the thickness t of the head part 3 is in the range of 2 mm or more and less than 3 mm, the toothbrush 1 having the structure as described above is thinner than the head part of the conventional toothbrush, and thus the intraoral operability is improved. Moreover, since the head part 3 is comprised by the polyacetal resin or the polybutylene terephthalate resin, it can have sufficient flocking strength and head part bending strength. Moreover, since the flocking method by the flat wire 6 is employ | adopted, a manufacturing process can be simplified and cost can be suppressed.

  In addition, the toothbrush 1 has 0.9 ≦ (w−d) × h where the length of the flat wire is w, the width of the flat wire is h, the diameter of the flocked hole is d, and the depth of the flocked hole is D. It is comprised so that the relationship of * D <= 2.5 may be satisfied. Thereby, the brush 5 does not come off during use, and it is possible to prevent the head portion 3 from being cracked, whitened or warped, and the flocking strength and the bending strength of the head portion 3 are further increased.

As mentioned above, although this invention was demonstrated based on embodiment, it cannot be overemphasized that this invention can be variously changed in the range which is not limited to the said embodiment and does not deviate from the summary.
For example, in the present embodiment, the cross-sectional shape of the flock hole 8 has been described as a circle, but it may be an indefinite shape combining polygons such as triangles and quadrangles, straight lines, and curves. When a shape other than a circle is adopted, as shown in FIG. 5, the longest length d <b> 1 of the flat wire 6 on the edge of the flock hole 8 is used as a value corresponding to the diameter d of the flock hole 8.

  Hereinafter, the effects of the present invention will be made clearer by examples. In addition, this invention is not limited to a following example, In the range which does not change the summary, it can change suitably and can implement.

  As Examples 1 to 3 and Comparative Examples 1 and 2, toothbrushes as shown in FIG. 6A were actually manufactured by changing the thickness of the head part. The numbers in FIG. 6 are in units of mm.

And about this toothbrush, experiment about oral operability was implemented and evaluation as shown in Table 1 was obtained.
In addition, the thickness t of each toothbrush, the depth D of the flocked hole, the diameter d of the flocked hole, the width h of the flat wire, the length w of the flat wire, the value of (w−d) × h × D, The flat wire driving angle α, the material of the resin constituting the head part, the diameter and material of the brush, the number of flocks, the length of the brush, and the shape of the hair cut were prepared as shown in Table 1.

<Evaluation method>
In addition, experiment was performed by the method of having 10 test subjects actually clean the inside of an oral cavity, and evaluated by the test subject's sensuality. Specifically, when the intraoral operability is “very good”, it is evaluated as 3 points, when “slightly good”, it is evaluated as 2 points, and when it is “same as the currently used toothbrush”, it is evaluated as 1 point. did.
<Criteria>
If the average score obtained as described above is 2.0 or more, it is determined as “◯”, and if it is 1.5 or more and less than 2.0, it is determined as “Δ”. In the case of less than 5 points, the determination was made according to three stages of determining “x”.

  As shown in Table 1, it is recognized that the intraoral operability is good when the thickness of the head portion is less than 3 mm.

Next, as Examples 1 to 9 and Comparative Examples 3 to 5, the thickness t of the head portion, the depth D of the flocked hole, the diameter d of the flocked hole, the width h of the flat wire, the length w of the flat wire, ( The value of w−d) × h × D, the material of the resin constituting the head part, the diameter and material of the brush, the number of flocks, the length of the brush, and the shape of the hair cut were actually made as shown in Table 2. .
Table 2 shows the results of evaluating the flocking strength, the head bending resistance, the appearance, and the overall evaluation of the toothbrush thus obtained.

<Evaluation method>
For “planting strength”, grasp the entire brush in one hole with a dedicated tool, and measure the maximum tensile stress (N) until the bundle of hair pulls out from the planting hole using an autograph made by Shimadzu (pulling speed 20 mm / min (N = 20) and evaluated according to the value. Specifically, when the average value was 20N or more, it was evaluated as “◯”, when it was 10N or more and less than 20N, “Δ”, and when it was less than 10N, it was evaluated as “x”.
For the “head bending strength”, cut the portion of the toothbrush brush from the flocking hole, smooth the flocking surface of the head, and apply it to a digital impact tester (DG-1 type) manufactured by Toyo Seiki Seisakusho. Fixed. An impact was applied from the flocked surface side with a hammer, and the absorbed energy (J) when the head portion was broken was measured (n = 10) and evaluated according to the value. Specifically, “◯” was evaluated when the minimum value was 1.5 J or more, “Δ” was evaluated when 0.5 J or more and less than 1.5 N, and “X” was evaluated when 0.5 J or less.
Regarding the “appearance”, the occurrence of cracks and whitening of the actually produced toothbrush was visually confirmed (n = 50) and evaluated. Specifically, when the crack / whitening occurrence rate was 0%, it was evaluated as “◯”, when it was less than 20%, “Δ”, and when it was 20% or more, it was evaluated as “x”.
Of the evaluations of “flocking strength”, “head bending resistance”, and “appearance”, the worse evaluation was designated as “comprehensive evaluation”.

  As shown in Table 2, when the value of (w−d) × h × D is 0.9 or more and 2.5 or less, it can be seen that the flocking strength and the head part bending strength are high. Moreover, when the material of a head part is polyacetal resin (POM) or polybutylene terephthalate resin (PBT), it turns out that flocking strength and head part bending strength are high.

  DESCRIPTION OF SYMBOLS 1 ... Toothbrush, 2 ... Handle part, 3 ... Head part, 3a ... Back surface of a head part, 3b ... Flocking surface of a head part, 4 ... Neck part, 5 ... Brush, 6 ... flat wire, 7 ... hair bundle, 8 ... flocking hole, t ... head thickness, w ... flat wire length, h ... flat wire Width, d: diameter of the flocked hole, D: depth of the flocked hole

Claims (2)

A head portion having a plurality of flock holes provided on the flocked surface; the bristles of the brush are folded in half; and a flat wire sandwiched therebetween is driven into the flock holes so that the follicles are planted in the flock holes. A toothbrush provided,
The head portion is made of polyacetal resin or polybutylene terephthalate resin,
The toothbrush characterized by the thickness of the said head part being 2 mm or more and less than 3 mm. When the length of the flat wire is w, the width of the flat wire is h, the diameter of the flocked hole is d, and the depth of the flocked hole is D,
0.9 ≦ (w−d) × h × D ≦ 2.5
The toothbrush according to claim 1, wherein the relationship is satisfied.

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