TWI520698B - Toothbrush - Google Patents

Description

toothbrush Field of invention

The present invention relates to improvements in toothbrushes.

The priority of Japanese Patent Application No. 2010-068132, the entire disclosure of which is hereby incorporated by reference.

Background of the invention

Generally, a toothbrush is manufactured by attaching a hair bundle of a bristles of nylon and polybutylene terephthalate (PBT) in a flat line to a planting hole provided in advance at the head of the grip member. Because the hair bundles that are planted are folded in half using flat lines, they become less likely to fall off the planting holes. As a material of the head, polypropylene (PP) is widely used in terms of cost and formability.

Incidentally, in order to facilitate the brushing of each corner of the oral cavity with a toothbrush, particularly the brushing of the posterior teeth, the thickness of the head of the hair bundle is preferably thin. For example, in Patent Document 1, for the purpose of improving the operability in the oral cavity, a toothbrush having a polyacetal resin and having a head thinned to 3 to 4 mm is proposed.

[Previous Technical Document]

[Patent Document]

[Patent Document 1] JP-A-7-143914.

However, even in the toothbrush described in Patent Document 1, the operability in the oral cavity is insufficient, and a brush may be generated. Moreover, if the head is made thinner, the folding strength of the head may be lowered. Further, as the strength is lowered, there is a situation in which the appearance is poor due to cracks or whitening at the edge portion of the head.

The present invention has been made in view of the above-mentioned circumstances, and it is intended to provide a toothbrush which is excellent in handleability in the oral cavity and which has sufficient strength, and which provides a hair bundle which is not easily detached from the planting hole.

According to a first aspect of the invention, there is provided a slightly plate-shaped head portion, wherein the head portion is provided with a plurality of planting hair points on the hair-planting surface, and the hair bundles of the bristles are folded in half, and the flat wire is inserted between them. Inserting the hair-growing hole into the toothbrush, wherein the hair bundle is implanted in the toothbrush formed by the hair-planting hole, the thickness of the head is 2.0-4.0 mm, and the shortest distance between the outermost hair-planting hole and the edge of the head width direction is 0.4~0.9mm toothbrush.

According to a second aspect of the invention of the present invention, the head of the toothbrush according to the first aspect is a toothbrush comprising a polybutylene terephthalate resin.

In the toothbrush of the present invention, the hair bundle is not easily peeled off from the planting hole, and is excellent in handleability in the oral cavity. Further, since it has sufficient strength, it is possible to prevent the head from being reduced in the folding strength and the appearance from being poor.

Simple illustration

Fig. 1 is a side view showing an embodiment of a toothbrush of the present invention.

Fig. 2 is a plan view showing the enlarged display of the head of the toothbrush shown in Fig. 1.

Detailed description of the preferred embodiment Form for implementing the invention

An embodiment of the toothbrush of the present invention will be described.

The toothbrush of this embodiment is shown in Fig. 1 and Fig. 2 . The toothbrush 1 of the present embodiment has a grip member 1a and a tuft 1b; wherein the grip member 1a is provided with a head portion 10, and the tuft 1b is implanted in the planting hole 11 provided in the head portion 10.

The grip 1a has a head portion 10, a grip portion 20 that is gripped during use, and a neck portion 30 that is disposed between the head portion 10 and the grip portion 20.

In the grip 1a of the present embodiment, the head portion 10, the grip portion 20, and the neck portion 30 are made of the same resin.

As the resin constituting the grip member 1a, for example, polybutylene terephthalate resin (PBT), polypropylene resin (PP), polyacetal resin (POM), and polycyclohexane dimethylene can be used. A part of polycyclohexane dimethylene terephthalate is a resin substituted with isophthalic acid (PCTA).

Further, as the resin constituting the grip 1a, a resin having an appropriate rigidity and toughness is preferable, and a resin having a flexural modulus of 1900 MPA or more and a tensile breakage ratio of 80% or more is preferable. Here, the term "bending modulus" means the value measured in accordance with ISO 178; the term "tensile breakage rate" means the value measured in accordance with ISO 527-1, 2.

When the bending modulus is 1900 MPA or more and the tensile breakage ratio is 80% or more, the toughness of the grip 1a becomes sufficiently high, and even if the head 10 is thinned, the impact becomes less likely to be broken. It can prevent the broken fracture surface from becoming a corner.

The upper limit of the flexural modulus and the tensile breakage rate is not particularly limited as long as it is a resin which is usually used, and the flexural modulus is 5000 MPA or less and the tensile breakage ratio is 500% or less.

From the viewpoint that the above-mentioned flexural modulus and tensile breakage ratio can be easily satisfied, a polybutylene terephthalate resin is preferred. Further, the polybutylene terephthalate resin is excellent in chemical resistance and heat resistance. Therefore, the toothbrush 1 using the polybutylene terephthalate resin in the grip member 1a is less deteriorated even in a long period of use, and since the tuft 1b is firmly fixed even by a flat line, it is not easily broken. And can be of higher quality.

Polybutylene terephthalate resin is a thermoplastic polyester produced by polycondensation reaction using terephthalic acid or dimethyl terephthalate and 1,4 butanediol as raw materials, for example, DURANEX manufactured by Polyplastics Co., Ltd., NOVADURAN manufactured by Mitsubishi Engineering-Plastics Corporation, TORCON manufactured by Toray Inc., and the like.

The head portion 10 is a slightly flat portion, and the hair bundle 1b is implanted in a plurality of planting hair points 11 which are provided on the hair-growing surface 10a. In the present embodiment, the hair-growing surface 10a of the head portion 10 has a substantially rectangular shape, and the two edges 12 in the width direction are parallel to each other and along the longitudinal direction of the grip member 1a, and the edge 13 on the most distal end side is formed in a curved shape.

The thickness T of the head 10 is 2.0 to 4.0 mm, and preferably 2.5 to 3.5 mm. When the thickness T of the head portion 10 is less than 2 mm, the head folding strength is lowered, and when the tooth is being brushed, the head portion 10 is broken, and it is impossible to ensure that the hair bundle 1b is maintained in a flat line. Full planting hole 11 depth. On the other hand, when the thickness T of the head 10 exceeds 4 mm, the operability in the oral cavity becomes insufficient.

In the head portion 10, the shortest distance W between the outermost planting hole 11a and the edge 12 in the width direction of the head portion 10 (the direction perpendicular to the longitudinal direction) (hereinafter, this distance W is referred to as "edge width W"). 0.4~0.9mm, preferably 0.6~0.8mm. When the width W of the edge of the head 10 is less than 0.4 mm, the head has insufficient folding strength, and the edge portion of the head portion 10 is deformed due to the stress generated by the planting. When the edge width W exceeds 0.9 mm, the edge width W becomes wider with respect to the thickness T of the head portion 10. Finally, when the teeth are brushed, the head portion 10 contacts the tooth flesh and the buccal mucosa, and the operability is lowered, and the brush becomes Poor touch.

Further, in the head portion 10, the shortest distance between the planting hole 11b on the longitudinal most distal end side of the head portion 10 and the edge 13 on the distal end side is preferably 0.4 to 0.9 mm. When the shortest distance between the hair-planting hole 11b and the edge 13 on the distal end side is less than 0.4 mm, the head end-resistant strength is insufficient, and when it exceeds 0.9 mm, the intra-oral operability is lowered.

The grip portion 20 is a rod-shaped portion having a length that the user can grip.

In the grip portion 20, the soft resin may be partially or entirely covered in order to improve the grip.

As the soft resin, a soft resin having a hardness (JIS K6253 hardness test and test condition JISA) of 5 to 100 is preferred, and a soft resin of 20 to 60 is more preferable. As long as the hardness of the soft resin is 5 or more, it has sufficient softness and the grip property is further improved.

Specific examples of the soft resin include a polyolefin-based thermoplastic elastomer, a polystyrene-based thermoplastic elastomer, a polyurethane-based thermoplastic elastomer, a polyester-based thermoplastic elastomer, and 1,2-polybutadiene. A thermoplastic elastomer, an ethylene-vinyl acetate-based thermoplastic elastomer, a polyvinyl chloride-based thermoplastic elastomer, a natural rubber-based thermoplastic elastomer, a fluorine-based thermoplastic elastomer, or a trans-polyisoprene-based thermoplastic elastomer.

When a polybutylene terephthalate resin is used as the resin constituting the grip 1a, it is preferable to use a polyester-based thermoplastic elastomer as the soft resin from the viewpoint of compatibility. Examples of the polyester-based thermoplastic elastomer include Hytrel manufactured by DU PONT-TORAY CO., LTD. and PRIMALLOY manufactured by Mitsubishi Chemical Corporation.

The neck portion 30 is a portion that connects the head portion 10 and the grip portion 20. The width of the neck 30 is less than the width of the head 10. Since the width of the neck 30 is smaller than the width of the head 10, it becomes easy to insert the head 10 into the oral cavity.

The tuft 1b is composed of bristles that are folded in half, and is inserted into the planting hole 11 by a flat line that is inserted between the bristles that are folded in half, thereby being fixed to the head 10.

Examples of the material of the bristles include polydecylamine (for example, nylon 6-12, nylon 6-10, 12 nylon, etc.), polyester (for example, polyethylene terephthalate, polypair). Propylene phthalate, polybutylene terephthalate, etc., polypropylene, elastomer, natural materials, and the like. Moreover, these materials can be combined.

The cross-sectional shape of the bristles is not particularly limited, and examples thereof include a circular shape, a triangular shape, a square shape, a hexagonal shape, a petal shape, and an arc shape. Moreover, these shapes may be combined.

Further, the bristles may be processed into a wave shape, a twist shape, a meander shape, or the like in advance.

The outer diameter of the bristles is preferably 3 to 15 mils (i.e., 0.076 to 0.381 mm), more preferably 5 to 10 mils (i.e., 0.127 to 0.254 mm).

Further, each of the bristles may be a normal hair having a slightly smaller diameter than a circular hair tip portion which is usually formed at the tip end of the bristles, or may be a tapered hair which gradually becomes smaller toward the outer diameter of the tip end. These ordinary hairs may also be blended with the tapered hairs, or may be changed for each planting hole 11. The tapered hair system has a good entrance to the narrow gap, which can achieve a soft touch, and is more suitable for brushing and massaging the tooth neck.

For example, the taper hair which is tapered at both ends of the Japanese Patent Publication No. Hei 6-141923, and the one end of which is described in JP-A-57-50220, is tapered. The tapered bristles of the ones which are formed in the hairs of one of the hairs of the Japanese Patent Publication No. 2002-58838, and the tapered hairs having the island-like structure described in Japanese Laid-Open Patent Publication No. Hei 9-322821 The hair is the tapered hair of the core sheath structure described in JP-A-2001-178542.

The length of the bristles is preferably 7 to 15 mm, more preferably 8 to 13 mm. Further, the lengths of the bristles may be the same or not, and may not be the same.

The brushing surface formed by the front end of the whole tuft 1b, for example, a plane parallel to the tufting surface 10a; may be formed as a plane inclined with respect to the tufting surface 10; and gradually separated from the tufting surface 10a along the longitudinal direction Or a curved surface, a convex surface, a concave surface, or a wavy concave surface. From the point of view of the above-mentioned easy-to-sweep, it is preferable to use a plane or a curved surface which is inclined from the front end toward the rear end toward the hair-planting surface 10a.

The length of the aforementioned flat wire is preferably such that the bristles can be surely fixed without causing cracking and whitening at the head portion 10. Specifically, it is better to have a flat line of 0.3 to 0.5 mm longer than the hairy hole.

The height of the flat wire is not particularly limited, and it is preferably in the range of 0.9 to 2.0 mm in order to ensure sufficient penetration strength and at the same time ensure hairiness. Moreover, for the same reason, the thickness of the flat wire is preferably 0.20 to 0.25 mm.

Further, the driving angle of the flat wire is appropriately selected, and in order to avoid the occurrence of cracking and whitening, it is preferably in the range of 5 to 80° with respect to the longitudinal direction of the grip member 1a, and more preferably in the range of 15 to 30°. The angle of the above-mentioned flat line is the same for all the flat lines, and it may be different.

As the material of the flat wire, metal, plastic, or the like can be used. From the viewpoint of strength, productivity, and cost, it is preferable that metal is preferable, and brass or aluminum is more preferable.

On the other hand, the surface of the flat wire is formed so as not to be easily detached from the planting hole 11, and grooves and fine irregularities may be formed.

In the present embodiment, the planting hole 11 is formed in a circular shape and arranged in a lattice shape on the hair-planting surface 10a of the head portion 10.

The shape of the depth direction of the hair-planting hole 11 may be a cylindrical shape having no change in the shape in the depth direction, or may be a tapered shape which becomes smaller toward the lower hole diameter, and a shape having a height difference in the middle of the hole is also formed. can. Further, the height difference and the taper may be formed into respective shapes. Further, a chamfering process of about 0.3 mm can be applied to the bottom of the planting hole 11.

The hole diameter of the opening portion of the planting hole 11 is preferably 1.0 to 2.0 mm (i.e., an area of 0.75 to 3.1 mm ² ). By attaching the hair bundle 1b to such a hole diameter, the touch feeling to the gum portion is improved, and it is possible to provide a toothbrush having a high insertion force into the thin gap of the interdental portion.

In the case of the toothbrush 1 described above, since the thickness T of the head portion 10 is 2.0 mm or more and the edge width W is 0.4 mm or more, sufficient strength can be secured, and as a result, the head endurance strength can be prevented from being lowered and the appearance is poor. In addition, since the thickness T of the head portion 10 is 4.0 mm or less and the edge width W is 0.9 mm or less, the contact of the head portion 10 into the oral cavity can be prevented, and as a result, the oral cavity handleability is excellent.

Further, in the case of the toothbrush 1, since the hair bundle 1b is fixed to the planting hole 11 by the flat wire, it becomes difficult to fall off.

Furthermore, the present invention is not limited to the above embodiment.

The head 10, the grip portion 20, and the neck portion 30 may not be formed of the same resin.

Further, the head portion 10 is preferably in the above-described range with the same thickness as the whole, and a portion of the neck portion 30, preferably 1/3 or less of the length of the head portion 10, may be thickened as in the above embodiment. . By making the neck portion 30 of the head 10 thick, it is possible to smoothly connect with the neck portion 30.

Further, in the toothbrush of the present invention, the neck portion 30 may also be omitted. That is, the grip member may be constituted by the head portion 10 and the grip portion 20.

Further, the head portion 10 and the hair-planting surface 10a may not have a substantially rectangular shape, and may be, for example, a circular shape or a rounded shape.

The shape of the opening portion of the planting hole 11 may be, for example, a polygonal shape such as a circle, a triangle, or a quadrangle, or the like, other than the circular shape. Further, all of the planting holes 11 can be formed into the same opening shape, and two or more opening shapes can be combined.

The configuration pattern of the planting hole 11 may be a staggered in-line, or an end portion on both end sides in the width direction of the head portion 10, and a curved arc-shaped planting hole may be formed on the center side of the head portion 10. The group mode is also available.

In the case of the hairy group of the circular arc shape as described above, the hair bundle 1b is easily adhered to the tooth neck portion. In order to improve the real feeling of the tooth surface, it is preferable that the hair bundle 1b which is planted in the arc-shaped planting hair group is longer than the hair bundle 1b which is planted in the hair-planting hole other than the planting hair group. In this case, the average bristles length difference is preferably 0.3 to 2.0 mm, and more preferably 0.5 to 1.5 mm.

In the case of the present invention, the hair bundle 1b itself may be formed in an arc shape. In this case, the arc-shaped hair bundle 1b provided at the end portions on both end sides in the width direction of the head portion 10 is grown. The outer tuft 1b is preferred.

Example

In the following examples, the following resins were used.

Polybutylene terephthalate (PBT): NOVADURAN5010 manufactured by Mitsubishi Engineering Plastics Co., Ltd.

Resins substituted with isodecanoic acid (PCTA) as part of polycyclohexane dimethylene terephthalate: Eastman Chemical Company BR203

Polypropylene (PP): J700GP manufactured by Prime Polymer Co., Ltd.

Polyacetal (POM): HC490 manufactured by Ashahi Kasei Chemicals Co. Ltd.

Further, the flexural modulus of the resin to be used was measured in accordance with ISO 178. The tensile breakage rate was measured in accordance with ISO 527-1 and 2. The results of these and the like are shown in Table 1.

(Examples 1 to 8 and Comparative Examples 1 to 3)

The resin injection molding shown in Table 1 was used to prepare a planting hole having a hole diameter of 1.55 mm and a distance between the planting holes of 0.725 mm, and having the thickness W, the width L, and the edge width W shown in Table 1. The handle of the head and the grip and the neck.

Next, the bundle of bristles made of nylon (with hair: 8 mil, length: 9.0 mm, flat cut) was folded in half, and the flat line was sandwiched in the folded portion (width: 1.3 mm, length: 2.1 mm, thickness: 0.25 mm) and insert the hair fossa formed on the head, and the hair bundle is implanted. Thereby, a toothbrush is obtained.

The oral operability, head folding strength, hair bundle holding strength, and appearance of each of the obtained toothbrushes were evaluated as follows. The evaluation results are shown in Table 1.

(1) Oral operability

The toothbrush of each of the examples and the comparative examples was actually used for a subject of 10 people, and the operability of the toothbrush in the oral cavity was given to the following points based on the following criteria. Next, oral operability was evaluated based on the average value of 10 persons. The higher the number of points, the superior operability in the oral cavity.

[Point Reference]

7: Very good.

6: Yes.

5: A little better.

4: Nothing can be said on either side.

3 points: A little worse.

2 points: quite poor.

1 point: Very bad.

[evaluation benchmark]

◎: The average value is 5.5 or more

○: The average value is 5.0 points or more and less than 5.5 points.

△: The average value is 4.0 points or more and less than 5.0 points.

×: The average value is less than 4.0 points.

(2) Head folding strength

Cut off the part of the toothbrush that is exposed from the planting hole, and smooth the side of the hair of the head. Thereafter, it was fixed to an Izod impact tester manufactured by Toyo Seiki Co., Ltd., and an impact was applied from the side of the hair-growth side to measure the impact energy at the time of breakage of the head (measurement number 10), and the average value was obtained. Next, it was evaluated based on the following criteria.

[evaluation benchmark]

○: The average value is 0.3J or more

△: The average value is 0.15J or more and less than 0.3J.

×: The average value is less than 0.15J

(3) Hair bundle retention strength

The full bristles in one hole were held by a special instrument, and the maximum tensile stress (N) (stretching speed: 20 mm/min) (N=20) of the hair bundle from the hairy hole was measured using an Autograph manufactured by Shimadzu Corporation. The following benchmark evaluation. The hair bundle maintains a high strength and the hair bundle does not easily fall off.

[evaluation benchmark]

○: The average value is 20N or more

△: average value of 10N or more and less than 20N

×: The average value is less than 10N

(4) Appearance

Ten toothbrushes of each of the examples and the comparative examples were produced, and the deformation, crack, whitening, and warpage of the edge portion of the head were visually evaluated based on the following evaluation criteria.

[evaluation benchmark]

○: deformation, rupture, whitening, warpage generation rate: 0%

△: deformation ‧ rupture ‧ whitening ‧ warp production rate: less than 20%

×: deformation, rupture, whitening, warpage generation rate: 20% or more

When the toothbrush of Examples 1 to 8 having a thickness T of the head portion of 2.0 to 4.0 mm and a width W of 0.4 to 0.9 mm is excellent in handleability in the oral cavity. Among them, the toothbrushes of Examples 1 to 5 in which the polybutylene terephthalate resin was used as the resin for the handle member were excellent in appearance and had sufficient head folding strength. Further, the toothbrushes of Examples 1 to 6 and 8 other than Example 7 in which the polypropylene resin was used as the resin for the handle member had high hair bundle holding strength.

On the other hand, in the toothbrush of Comparative Example 1 in which the edge width W of the head was less than 0.4 mm, the head had a low folding strength and appeared to have a poor appearance.

The toothbrush of Comparative Example 2 in which the thickness T of the head exceeded 4.0 mm and the toothbrush of Comparative Example 3 in which the edge width W of the head exceeded 0.9 was low in the oral cavity.

Industrial availability

The present invention is extremely useful in the industry because it can provide a toothbrush which is not easily detached from the planting hole and which is excellent in handleability in the oral cavity and has sufficient strength.

1. . . toothbrush

1a. . . Grip

1b. . . Hair bundle

10. . . head

10a. . . Hair surface

11, 11a, 11b. . . Planting pore

12, 13. . . edge

20. . . Grip

30. . . neck

Fig. 1 is a side view showing an embodiment of a toothbrush of the present invention.

Fig. 2 is a plan view showing the enlarged display of the head of the toothbrush shown in Fig. 1.

1. . . toothbrush

1a. . . Grip

1b. . . Hair bundle

10. . . head

20. . . Grip

30. . . neck

Claims (2)

A toothbrush having a slightly plate-shaped head, the head being provided with a plurality of hair-planting holes on the hair-planting surface, folding the hair bundles of the bristles into a half, and inserting a flat wire inserted therebetween into the hair-growing hole, thereby The hair bundle is implanted in the hair-growing hole, wherein the head portion is made of a resin having a flexural modulus of 1900 MPa or more and a tensile breakage ratio of 80% or more, and the folding strength is measured by the following measurement method. 0.15J or more, and the thickness is 2.0 to 4.0 mm, and the shortest distance between the outermost planting hole and the edge in the width direction of the head is 0.4 to 0.9 mm, and the portion of the toothbrush that is exposed from the planting hole is cut off. The side of the hair-planting surface of the part was smoothed, and then it was fixed to the Izod punching test machine, and the hammer was applied from the side of the planting surface to measure the punching energy at the time of breakage of the head, and the punching energy was used as the folding strength. A toothbrush according to claim 1, wherein the head portion is composed of a polybutylene terephthalate resin.