JP2006149419A - Toothbrush - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toothbrush not injuring the gum, improving sweeping of narrow corners and excellent in durability while having an appropriate firmness of bristles and maintaining a fine brushing effect. <P>SOLUTION: In the toothbrush, each of brush bristles 2 to be planted on a brush part has an exposed core part 3 on the front end side of a conjugate monofilament 20 provided with a core-sheath structure in which a sheath part 4 is disposed around a single core part 3. Particularly a sectional area of the core part 3 occupies 15-80% of a sectional area of the monofilament 20. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a toothbrush having brush bristles made of a composite monofilament having a core-sheath structure.

When the outer diameter of the toothbrush is increased, the brush comes out and the brushing power is improved. However, there is a problem in that the hair ends do not easily reach the details such as the interdental and periodontal pockets, and the stains on the part cannot be removed.
Moreover, if the hair is too strong, the possibility of damaging the gums increases.

On the other hand, in order to improve the cleanability of the details in the oral cavity, a device has been devised such as reducing the outer diameter of the brush hair or processing it into an extremely tapered shape. For example, there is provided a toothbrush obtained by treating a cut piece of a composite monofilament with a chemical treatment, forming sharpened portions at both ends, bending at a central portion, and implanting the brush portion (see, for example, Patent Document 1).
However, in such a case, the bristle becomes weak and the brushing force is reduced, and in an extreme case, even if the toothbrush is operated, the hair only bends and it becomes difficult to brush. Such a problem becomes prominent particularly when applied to an electric toothbrush.

  On the other hand, a filament having a core-sheath structure has been proposed as one aiming at bristle strength and a brushing effect (see, for example, Patent Documents 2 and 3). However, even with the core-sheath structure, it has been difficult to achieve both the strength of the hair and the detail brushing effect.

Japanese Utility Model Publication No. 5-15834 German Patent Application Publication No. 19942147 JP 2003-169718 A

  Therefore, in view of the above-mentioned situation, the present invention intends to solve the problem of maintaining a good brushing effect with an appropriate bristle strength, without damaging the gums, and with a fine cleaning ability. The object is to provide a toothbrush that can be improved and that is also excellent in durability.

  In order to solve the above-mentioned problems, the present invention provides a brush bristle planted in a brush part on the tip side of a composite monofilament having a core-sheath structure in which a sheath part is arranged around one core part. The toothbrush which exposed the part WHEREIN: The cross-sectional area of the said core part was 15 to 80% among the cross-sectional areas of the said composite monofilament, The toothbrush characterized by the above-mentioned was comprised.

  Further, the composite monofilament and the core have a substantially circular cross section, the composite monofilament has an outer diameter of 0.16 mm to 0.25 mm, and the core has an outer diameter of the composite monofilament. 40 to 90% of is preferable.

  Further, the cross-sectional shape of the core part is preferably a substantially elliptical shape, a substantially polygonal shape, or other irregular shapes, and particularly a substantially polygonal shape having an acute angle is preferred.

  Furthermore, what provided the protrusion part or the ditch | groove extended in an axial direction in the outer peripheral surface of the said core part is preferable.

  The cross-sectional shape of the composite monofilament is preferably substantially similar to the cross-sectional shape of the core portion.

  In addition, a polyamide resin is used as a main component of the material of the core, a polyester resin is used as a main component of the material of the sheath, and a brush bristle in which the core is exposed by immersing the tip side of the composite monofilament in an alkaline solution. What has been constructed is a preferred embodiment.

  In the toothbrush according to the present invention as described above, since the cross-sectional area of the core part is set to 15 to 80% of the cross-sectional area of the composite monofilament, the bristle proximal end side having a sheath part has an appropriate bristle strength. With the core portion exposed to the tip side, it is possible to exhibit excellent detail cleaning properties without damaging the gums.

  More specifically, each of the composite monofilament and the core has a substantially circular cross section, the composite monofilament has an outer diameter of 0.16 mm to 0.25 mm, and the core has an outer diameter of the composite. Since it is 40 to 90% of the outer diameter of the monofilament, it is possible to achieve both maintenance of fur and excellent detail cleaning.

  Further, when the cross-sectional shape of the core part is substantially oval, substantially polygonal or other irregular shape, particularly when the core part is substantially polygonal having an acute angle, the end of the sheath part is peeled off from the exposed base end of the core part. Can be prevented, and the durability of the brush hair can be improved.

  Moreover, the thing which provided the protrusion part or the ditch | groove extended in the axial direction in the outer peripheral surface of the said core part can prevent peeling of a sheath part edge part similarly.

  Further, the cross-sectional shape of the composite monofilament is substantially similar to the cross-sectional shape of the core portion. Even if the core portion has a shape other than the circular shape, the thickness of the sheath portion is substantially uniform along the circumferential direction, and the force is increased. It is dispersed and the sheath part can be more reliably prevented from peeling off.

  In addition, a polyamide resin is used as a main component of the material of the core, a polyester resin is used as a main component of the material of the sheath, and a brush bristle in which the core is exposed by immersing the tip side of the composite monofilament in an alkaline solution. What was comprised is a preferable Example at the point which is compatible also with maintenance of a hair back and the outstanding detailed cleaning property, and being suitable also as an electric toothbrush.

  Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a diagram showing an overall configuration of a toothbrush according to the present invention. FIGS. 1 to 8 show typical embodiments, in which 1 is a toothbrush, 2 is a bristle, 3 is a core, and 4 is a sheath. Each part is shown.

  As shown in FIGS. 1 and 2, the toothbrush 1 of the present invention has a core-sheath structure in which the brush bristles 2 implanted in the brush part 10 are arranged with a sheath part 4 around one core part 3. The core 3 is exposed at the front end side of the composite monofilament 20, and in particular, of the cross-sectional area of the composite monofilament 20, that is, the cross-sectional area of the entire composite monofilament including the core 3 and the sheath 4. The cross-sectional area of the core part 3 is 15 to 80%, more preferably 40 to 80%.

The present invention is excellent without damaging the gingiva by the core portion 3 having a cross-sectional area of 15 to 80% exposed on the distal end side while maintaining an appropriate bristle waist on the proximal end side of the brush hair having the sheath portion 4 as described above. Demonstrates fine cleanability.
As for the toothbrush main body excluding the brush bristles, those similar to the conventional one can be widely applied, and as will be described later, not only a manual toothbrush but also an electric toothbrush provided with a driving means for vibrating the brush part is suitable. .

  As a method for exposing the core portion, a means for removing the sheath portion by a mechanical or chemical method can be adopted, and in the following description, an example in which the chemical removal method is adopted will be described, but the method is particularly limited to that method. It is not something.

  The composite monofilament 20 of this embodiment employs a polyamide resin for the core 3 and the sheath 4 is made of polyester resin, and the core 3 is exposed by immersing the tip side of the composite monofilament 20 in an alkaline solution. The brush hair 2 is configured.

  This tip processing may be performed before flocking, but after the composite monofilament is flocked to the brush portion, the tip portion may be immersed in a hydrolyzing solution for dissolution treatment.

  The end of the sheath 4 to be melted as described above is inevitably formed with a tapered portion 40 continuing to the core, but the taper angle and the like can be easily adjusted by controlling the immersion time and the like. . The formation of the tapered portion 40 further improves the insertability and reachability into the oral cavity details, but the formation of the tapered portion 40 is not essential, particularly in the case of machining.

  The cross-sectional shapes of the composite monofilament 20 and the core part 3 are substantially circular, the outer diameter b2 of the composite monofilament 20 is set to 0.16 mm to 0.25 mm, and the outer diameter b1 of the core part 3 is The outer diameter is set to 40 to 90%, more preferably 60 to 80%.

  The bristles 2 formed by exposing the core 3 on both ends of the composite monofilament 20 are bundled in a bundle and bent at a substantially center, and the bent portion is planted on the brush 10 base. In addition, you may provide a level | step difference in the front-end | tip of the bristle 2 planted by shifting a bending position from the center.

  In addition, the brush bristles 2 are planted in such a manner that a tuft constituted by bundling a plurality of bristles 2 is driven into each of a plurality of flock holes provided in the brush base with a flat wire or fused by heat. The method of letting it go can be used suitably.

  The arrangement of the planting holes on the base is not particularly limited, and various arrangement forms can be adopted. In addition, the composite monofilament constituting the bristles may be used alone, or two or more composite monofilaments, or a combination of one or more composite monofilaments and one or more other monofilaments. May be used separately for each flocked hole or mixed with the same flocked hole.

  The hair length a2 from the planted base to the tip of the planted brush hair 2 is preferably in the range of 6 to 12 mm. If the length is too long, the operability in the mouth is deteriorated and the hair is too soft, so that a sufficient cleaning effect cannot be obtained. On the other hand, if the length is too short, the deflection of the hair during brushing is reduced and the feeling of use becomes worse, and the insertability between the teeth becomes worse.

  The exposed length a1 of the core portion is set to 5 to 50%, more preferably 10 to 50% of the bristle length, and specifically to a suitable range of 0.5 to 4.0 mm. If it is less than 5% of the bristle length, it is insufficient for reaching the back part of the interdental part, the neck part, the pit and fissure, and the like. Further, the longer the exposed length a1 of the core portion, the higher the cleaning effect on the deep portion, but on the other hand, the durability decreases. The exposure length that can maintain practical durability is 50% or less of the hair length, specifically about 4.0 mm or less.

In the present embodiment, the composite monofilament has the core 3 exposed at both ends, but may be one in which only one end is exposed.
Moreover, the tip shape of the exposed core part 3 is arbitrary, and it is preferable to process it into an appropriate shape such as a hemisphere. In the case where only one end is exposed, the tip shape of the unexposed end is processed into an appropriate shape such as a hemispherical shape, a spherical shape, a flat shape, a tapered shape, a branched shape, etc. mechanically and chemically. be able to.
In this embodiment, the material of the core 3 is made of a polyamide resin and extends straight in a cylindrical shape. However, by selecting a material that can be machined or dissolved in an alkaline solution as in the case of the sheath, FIG. ) To (d) may be processed into a tapered shape.

  Also, by mixing a predetermined amount of the material of the sheath into the material of the core, or conversely, mixing a predetermined amount of the material of the core into the material of the sheath, the compatibility between the core and the sheath is improved, and the bonding strength In this example, the core material is mainly composed of polyamide resin, and a predetermined amount of polyester resin is mixed therein, or the sheath material is composed mainly of polyester resin. It is preferable to mix a predetermined amount of the polyamide resin, which can more reliably prevent the sheath portion from peeling off.

  3 shows an example in which the cross-sectional shape of the core part 3 is substantially polygonal, FIG. 4 shows an example in which a plurality of protrusions 32 extending in the axial direction are provided on the outer peripheral surface of the core part 3, and FIG. In this example, a plurality of concave grooves 34 extending in the axial direction are provided on the outer peripheral surface of each of the outer peripheral surfaces.

  As shown in FIG. 3, if the cross-sectional shape of the core portion 3 is a substantially polygonal shape having an acute angle portion 30, the sheath portion end portion bites into the recess portion 31 formed in the core portion 3 at the core portion exposed proximal end. Thus, by remaining and forming the biting portion 41, it is possible to prevent the sheath portion from being peeled off from the exposed base end of the core portion by use, and durability can be improved. In the case of FIGS. 4 and 5, as in the case of the above-described substantially polygonal shape, the biting portion 41 that bites into the outer peripheral surface 33 or the groove is formed at the end of the sheath portion 4, and the biting end portion by the biting Peeling is prevented. In this example, five protrusions 32 and five concave grooves 34 are provided along the circumferential direction, but the number is not particularly limited, and only one may be provided.

  In FIG. 6, an adhesive layer 5 is provided between the core portion 3 and the sheath portion 4 so as to adhere them, and this can more reliably prevent the end portion of the sheath portion from peeling off.

  FIG. 7 shows the cross-sectional shape of the composite monofilament that is substantially similar to the cross-sectional shape of the core 3, whereby the thickness of the sheath 4 becomes substantially uniform along the circumferential direction, and the sheath 4 is peeled off. Can be prevented more reliably.

  As shown in FIG. 8, it is also a preferable embodiment to form the core portion 3 in a tapered shape. Even in such a case, as shown in (b) to (d), the cross-sectional shape of the core 3 is substantially polygonal, or the protrusions 32 and the grooves 34 are provided to bite into the end of the sheath. It can be seen that the portion 41 is formed and peeling can be prevented.

  The toothbrush according to the present invention can be applied not only to a manual toothbrush but also to an electric toothbrush. In the present invention, even when the brush portion 10 in which the brush bristles 2 are planted is vibrated at a frequency of 25 to 185 Hz and an amplitude of 0.2 to 3.5 mm, the hair and hips that can follow the vibration are maintained. It is possible to clean effectively.

Next, more specific examples of the present invention and tests conducted to verify the effects of these examples will be described. As shown in Table 1 below, Examples 1 to 7 and Comparative Examples 1 to 4 are provided by coaxially arranging a substantially annular sheath portion around a core portion having a substantially circular cross section. The configuration shown in FIG. 3, Example 9 is the configuration shown in FIG. 4, and Example 10 is the configuration shown in FIG. Both use polyamide resin for the core part and polybutylene terephthalate for the sheath part. By bundling a large number of the composite monofilaments and immersing the end part in the solution, the sheath from the both ends to a position where it enters a certain depth. The core part was exposed by selectively dissolving the part. Each dimension of the brush hair outer diameter, the core outer diameter, the core outer diameter ratio, the core section ratio, and the core exposed length is set as shown in Table 1.
Comparative Examples 5 and 6 are monofilaments made of polyamide resin, Comparative Example 5 has an outer diameter of 0.16 mm, and Comparative Example 6 has a 0.20 mm.

(Cleaning test)
Each filament shown in Table 1 was implanted into a toothbrush planted portion based on a conventional method, cut into hairs, processed to such an extent that the tips of the hairs were arranged in a substantially semicircular shape, and used for evaluation tests. Using a brushing machine manufactured by Sunstar Co., Ltd., which cleans the pseudo oral cavity, the removal rate of the artificial plaque adhered to the teeth of the jaw model was measured. Artificial plaque is applied to the first premolar, second premolar and first premolar on the upper cheek side of the jaw model, and the toothbrush is successively pressed against the tooth with a brushing pressure of 150 g against the tooth. Then, the brushing was performed by moving from the first molar to the first premolar (front side) at a moving speed of 3.16 mm / sec. After brushing the three teeth of the jaw model in this way, the plaque removal rate in the corner area of the tooth was determined by image analysis.

(Durability test)
Also, using a brushing machine manufactured by Sunstar Co., Ltd., brushing 10,000 strokes on the epoxy plate surface under a load of 300 g in water at 37 ° C. and measuring the spread index of the brushed surface. Sex was evaluated.
Here, the spread index means a numerical value represented by (B / A) × 100 when the width of the brushed surface in the initial state is Amm and the width of the brushed surface after brushing is Bmm. is doing.

  The results of each test are shown in Table 2 below. In addition, the result of evaluation of plaque removing power and durability was synthesized and described in the column of comprehensive evaluation. This comprehensive evaluation was the worse one of the above two evaluation results.

  From the results of the plaque removal rate and the hair durability test shown in Table 2, good results have been obtained when the cross-sectional area of the core portion is in the range of 15% to 80% of the cross-sectional area of the composite monofilament. Further, it was confirmed that good performance was exhibited when the outer diameter of the composite monofilament was in the range of 0.16 mm to 0.25 mm. As a result of comparison between Examples 5 and 6, particularly preferable results were observed when the cross-sectional area of the core portion was 40% to 80% of the cross-sectional area of the composite monofilament. Good results were also obtained in Examples 8 to 10 whose cross-sectional shape was not circular.

(Tap tip movement distance)
Even if the electric toothbrush vibrates, if the tip of the filament cannot follow the vibration and does not move so much on the tooth surface, the plaque cannot be sufficiently removed. That is, in the filament for an electric toothbrush, the fact that the filament can move following the vibration leads to an increase in plaque removal force on the tooth surface.
Therefore, in order to evaluate the suitability of the electric toothbrush when using the filament of the present invention, the filament tip movement distance was evaluated.

  Each filament of Table 1 was implanted in a toothbrush flocked portion of an electric toothbrush that drives in the direction of horizontal brushing based on a conventional method and used for an evaluation test. The filament tip was placed in contact with a flat surface, and a load of 150 g was applied to the flocked portion of the toothbrush, and the filament was moved at a frequency of 33.4 Hz with an amplitude of 3 mm. The movement was evaluated using the scale for the movement distance of the hair tip.

  As can be seen in Table 3, superior effects were observed in Examples 1-10 as compared with Comparative Examples 1-6.

Explanatory drawing which shows the principal part of the toothbrush which concerns on embodiment of this invention. (A) is a perspective view which similarly shows the principal part of a bristle, (b) is sectional drawing. (A) is a perspective view which shows the modification of the bristle which made the core part cross-sectional shape the substantially polygon which has an acute angle, (b) is sectional drawing. (A) is a perspective view which shows the modification of the bristle which provided the protrusion part extended in an axial direction on the outer peripheral surface of a core part, (b) is sectional drawing. (A) is a perspective view which shows the modification of the bristle which provided the ditch | groove extended in the axial direction on the outer peripheral surface of a core part, (b) is sectional drawing. (A), (b) is sectional drawing which shows the modification of the brush hair which provided the contact bonding layer between the core part and the sheath part, respectively. Sectional drawing which shows the modification of the bristle which made the filament cross-sectional shape substantially similar to the core part. (A)-(d) is a perspective view which shows the modification of the brush hair which each formed the core part in the taper shape.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Toothbrush 2 Brush bristle 3 Core part 4 Sheath part 5 Adhesion layer 10 Brush part 11 Hair bundle 20 Composite monofilament 30 Acute angle part 31 Concave part 32 Projection part 33 Peripheral part 34 Concave groove 40 Taper part 41 Eating part a1 Exposure length a2 Hair length b1 outer diameter b2 outer diameter

Claims (7)

  In the toothbrush in which the core portion is exposed on the tip side of the composite monofilament having a core-sheath structure in which the bristle planted in the brush portion is arranged around a single core portion, the composite monofilament A toothbrush characterized in that the cross-sectional area of the core portion is 15 to 80% of the cross-sectional area.   The composite monofilament and its core have a substantially circular cross section, the composite monofilament has an outer diameter of 0.16 mm to 0.25 mm, and the core has an outer diameter of 40 of the outer diameter of the composite monofilament. The toothbrush according to claim 1, wherein the toothbrush is -90%.   The toothbrush according to claim 1, wherein the cross-sectional shape of the core portion is substantially elliptical, substantially polygonal, or other irregular shape.   The toothbrush according to claim 3, wherein the cross-sectional shape of the core portion is a substantially polygonal shape having an acute angle.   The toothbrush according to any one of claims 1 to 4, wherein a single or a plurality of protrusions or grooves extending in the axial direction are provided on the outer peripheral surface of the core portion.   The toothbrush according to any one of claims 3 to 5, wherein a cross-sectional shape of the composite monofilament is substantially similar to a cross-sectional shape of the core portion. The main component of the material of the core part is polyamide resin, the main component of the material of the sheath part is a polyester resin, and the tip side of the composite monofilament is immersed in an alkaline solution to constitute a bristle with the core part exposed. The toothbrush according to any one of claims 1 to 6.

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