JP6928472B2 - toothbrush - Google Patents

Description

According to the present invention, the contact with the gingiva is soft, and the bristles of each filament do not easily interfere with each other and move naturally. Regarding the toothbrush to have.

The cleanability of the tooth surface by the toothbrush is improved by increasing the repulsive force of the hair bundle. However, there are many recesses in the oral cavity such as the interdental part, the cervical part, the interdental papilla, and the interdental drum-shaped space, and the cleanability of these recesses is also important. Conventionally, various toothbrushes for improving the cleanability of the oral cavity including these recesses have been proposed.

For example, in Patent Document 1, by increasing the filling density of the hairs constituting the hair bundle, a feeling of polishing response and brushing efficiency are obtained, and the shape of the hair bundle is vertically set in the horizontal direction orthogonal to the longitudinal direction of the toothbrush. A toothbrush has been proposed in which the reachability of hair bundles (reachability of recesses) is improved by setting the size larger than the direction.

Further, in Patent Document 2, the burden on the gums is reduced by increasing the filling density of the hair without bias in the entire brush portion, and 1 mm in the lateral direction at any position between the edges of the adjacent hair follicles. A toothbrush has been proposed in which the above intervals are maintained, thereby securing a space in which the hair follicles can move in the lateral direction, and making it easier for the hair follicles to reach the recesses during cleaning.

In both documents, the movement of adjacent hair bundles is not restricted to each other so as to reach the recess. However, with such a toothbrush, there is a limit to improving the cleanability of the recesses, especially the cleanability of the recesses such as the narrow inter-tooth, the cervical region, the interdental papilla, and the interdental drum-shaped space where unpolished parts frequently occur. There is a demand for a toothbrush that can obtain high recess cleaning property.

JP-A-2002-345556 JP-A-2007-143908

Therefore, in view of the above-mentioned situation, the present invention is trying to solve the problem by further improving the cleanability of the concave portion, particularly the cleanability of the concave portion such as a gap between narrow teeth where unpolished residue frequently occurs, and cleaning the oral cavity. The point is to provide a toothbrush that can improve the sex in total.

As a result of diligent studies in view of the current situation, the present inventor has focused on the hair filling density for each of the hair follicles constituting the hair follicle. Regardless of the flocking method (flat wire type, fusion type, in-mold type), each hair that constitutes the hair follicle is firmly held by the inner wall of the flocking hole in order to maintain the pull-out strength against stress in the pull-out direction. As a result, the hairs are planted in a state of being tightly bundled with each other (at least 60% or more of the filling density of the hairs in the pores). In particular, in the flat wire type, since the hair bundle is press-fitted into the hair follicle hole together with the flat wire, it is inevitably necessary to increase the filling density of the hair follicle. Further, it is considered that the larger the number of bristles per toothbrush, the higher the cleanability tends to be because the cleaning effect is easily obtained mainly at the tips of the bristles. It is also common sense that fusion type and in-mold type non-flat wire toothbrushes are also densely transplanted based on the idea of extension of the flat wire type.

On the other hand, the present inventor has focused on the fact that the fusion-type and in-mold type non-flat wire toothbrushes can maintain the pull-out strength even if the density of the hairs constituting the hair bundle is lowered, and the conventional wisdom is that. On the other hand, by reducing the density of the hair that constitutes the hair bundle, it is possible to further improve the ability to clean the recesses of small gaps such as the interdental space, the cervical region, the interdental papilla, and the interdental drum-shaped space. The present invention has been completed.

That is, the present invention includes the following inventions.
(1) A non-flat toothbrush in which hair bundles having a hair filling density of less than 60% are planted in the head portion. Here, the "hair filling density" refers to the ratio of the total cross-sectional area of the hair constituting the hair bundle to the area of the flocked hole mouth where the hair bundle is planted at the position of the mouth.

(2) The toothbrush according to (1), wherein the hair filling density of the hair bundle is 57% or less.

(3) The toothbrush according to (1) or (2), wherein the repulsive force of the hair bundle is 5.5 N or less.

(4) The toothbrush according to any one of (1) to (3), wherein the repulsive force of each hair constituting the hair bundle is 0.02N or more and 0.2N or less.

(5) The toothbrush according to any one of (1) to (4), wherein the hair filling density of the hair bundle is 30% or more.

(6) The toothbrush according to any one of (1) to (5), wherein the repulsive force of the hair bundle is 1.0 N or more.

According to the toothbrush according to the present invention as described above, by providing the hair bundle having a hair filling density of less than 60%, the cleaning property of the concave portion, particularly narrow interdental space, cervical region, interdental papilla, and the like. It is possible to further improve the cleanability of recesses such as interdental drum-shaped voids, and it is possible to improve the cleanability of the oral cavity in total.

The vertical sectional view which shows the main part of the toothbrush which concerns on the typical embodiment of this invention. A plan view of the main part as well. A cross-sectional view at the position of the flocked anaguchi (position of the flocked surface) also showing the bristles of the toothbrush. It is explanatory drawing which shows the structure of the sample used in an Example, (a) is a side view which shows the main part, (b) is also a plan view. The graph which shows the result of the cleanability evaluation test of Examples 1-3 and Comparative Examples 1-3. The graph which compares the interdental insertion depth of Examples 4 and 6 and Comparative Examples 4 and 5, respectively. The plan view of the main part which shows the other embodiment of the toothbrush which concerns on this invention.

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

As shown in FIGS. 1 and 2, the toothbrush 1 of the present invention is a non-flat toothbrush in which a bristles 4 having a filling density of less than 60% of bristles 3 are planted in a head portion 2. A handle portion (not shown) is provided on the base end side opposite to the tip end side where the head portion 2 is located, and a neck portion 5 for connecting the head portion 2 and the handle portion is provided. The handle 10 is composed of the head portion 2, the handle portion, and the neck portion 5, and the brush portion 11 is composed of a plurality of hair bundles 4 planted in the head portion 2.

As described above, according to the toothbrush having the hair bundle 4 having a filling density of less than 60%, the insertability into the recesses such as the interdental space, the cervical region, the interdental papilla, and the interdental drum-shaped space is remarkably improved, and the oral cavity is improved. Internal cleanability can be improved. That is, the mutual restraint of the plurality of hairs constituting the hair bundle 4, particularly the mutual interference of the hair tips is weakened, the contact with the gingiva is soft, and the hair tips of each hair include a narrow gap. Since it reaches every corner firmly, it can be used as a toothbrush with a high cleaning effect.

In the figure, reference numeral 21 is a flocking hole of the head portion 2 in which each hair follicle 4 is transplanted, and reference numeral 21a is a mouth portion opening to the flocking surface 20 of the flocking hole 21. The base end side of the hair follicle 4 is embedded and fixed in the hair follicle hole 21.

The handle 10 is preferably integrally molded with a synthetic resin. Synthetic resins used for molding the handle include polybutylene terephthalate resin, polypropylene terephthalate resin, polyethylene terephthalate resin, polyethylene naphthalate resin, PCTA resin, polyester resin such as PCTG resin, polyacetal resin (homopolymer, copolymer), and polycarbonate resin. , Known materials such as an aliphatic polyamide resin, an aromatic polyamide resin, and a resin whose main component is a resin selected from polystyrene resins (ABS resin, AS resin, PS resin) can be widely adopted.

The hair bundle 4 is not planted with a flat line with respect to the head portion 2, but is fixed without using a flat line. As such a flocking form, a known flocking form of a flat wire toothbrush can be widely adopted. In this example, as disclosed in JP-A-2003-9947, JP-A-2003-102552, etc., when the handle 10 is molded, a plurality of hairs in which a molten mass 40 is formed in advance at the base end portion. The bundles 4 are arranged so that the molten lumps 40 are located in the molding space of the head portion 2, and in this state, the synthetic resin material is injected into the molding space to form the handle 10 (head portion 2). A plurality of hair bundles 4 are integrally molded on the head portion 2 so as not to fall off (in-mold method).

When forming the molten mass 40 of the hair bundle 4, the hairs 3 constituting the hair bundle 4 are arranged substantially evenly so as to form a gap between the adjacent hairs, so that the hairs are similarly arranged between the hairs even after the hair is transplanted. It is possible to arrange them almost evenly with a gap.

In addition to this, for example, as disclosed in Japanese Patent Application Laid-Open No. 2010-194044, the head portion is composed of a head main body portion integrally molded with the handle and a member separate from the handle, and the head main body portion. It is composed of a cover member provided in a laminated manner on the flocked surface side, a bristles are passed through the flocked holes formed in the cover member, and the base end of the penetrating bristles is melted to form a molten mass, and the head portion is molded. A cover member with a bristles is arranged in the molding space so that the molten mass is located in the molding space, and a synthetic resin material is injected into the molding space to integrally mold the handle 10 and the brush portion 11. It is possible.

Further, a handle having a flocked surface with flocked holes opened in the head portion is separately molded, and the flocked lumps are planted in each flocked hole in the head portion of the handle with a flocked mass formed on the proximal end side. It is also preferable that the hair is transplanted by inserting it so as to be pressure-bonded to the inner peripheral surface of the pores.

The opening shape of the hair-implanted hole 21 and the external cross-sectional shape of the hair bundle 4 are not limited to a circle as shown in the figure of this example, but are oval, polygonal, polygonal edges, and one of polygonal shapes. A wide range of shapes, irregular shapes, and other shapes incorporating curved lines can be widely applied, and a plurality of shapes and sizes may be combined. Further, the arrangement form of the flocked holes and the arrangement form of the hair follicles on the flocked surface are not limited to the arrangement of this example, and other arrangement forms can be widely applied. It may be in a form in which a plurality of hair follicles are lined up in a straight line.

In the present invention, the filling density of hair per flocked hole of each hair follicle is set lower than that of the conventional one, but the mouth of the flocked hole with respect to the total area of the flocked surface of the head portion (flocked area area). The ratio of total area (density of flocked pores) is preferably set high. As a result, sufficient wiping power can be maintained even if the filling density of the hair per pore is set low, and the hair is planted more evenly in the head portion as a whole, and the movement of the hair is conventional. As a result, the cleanability of the recesses in the oral tissue is improved, and at the same time, the good cleanability of the total including the tooth surface is maintained. Specifically, it is preferable that the density of the pores is set to 40% or more.

The filling density of the hair 3 of the hair bundle 4 in the pores is preferably 57% or less. As a result, the insertability into the interdental space, the cervical region, the interdental papilla, the interdental drum-shaped space, etc. is remarkably improved. However, if it is too low, the tooth surface and other printability will deteriorate, so it is preferably set to 30% or more. As a result, the tooth surface and other cleanability are also maintained well. In the present invention, the hairs 3 of the hair bundle 4 are sparsely planted from the roots. Inside the hair follicle hole 21 in which the hair follicle 4 is planted, the gap between the hairs becomes larger than before. A different material may be filled in this gap.

The hair bundle 4 according to the present invention has a reduced filling density of the hair 3 in the hair-implanted hole as described above, and has a reduced repulsive force. The repulsive force of the hair can be obtained by the following (Equation 1), and varies depending on the material, thickness, protrusion length, etc. of the hair 3. The repulsive force of the hair bundle is the sum of the repulsive forces of the hairs constituting the hair bundle. The specific value of the repulsive force is preferably 5.5 N or less per 4 hair bundles. This improves the insertability into gaps such as the interdental space, the cervical region, the interdental papilla, and the interdental drum-shaped space. Further, it is preferably 1.0 N or more. As a result, the tooth surface and other cleanability can be maintained.

Hair repulsive force (N) = 2π ³ Eω ⁴ / 64L ² (Equation 1)
(E is Young's modulus, ω is hair diameter, and L is hair length (protrusion length from the flocked surface).)

Further, the brush portion 11 may of course be a mixture of hair follicles 4 having different flocking densities per flocking hole. For example, only one or a predetermined number of hair bundles 4 having a low filling density according to the present invention are arranged, and the hair bundles at other positions have a filling density of 60% or more as in the conventional case. It also includes cases where you do. Here, when planting hair follicles having different filling densities, the lower the filling density, the larger the opening area of the hair follicles is set so that the hairs having the same filament diameter distribution are transplanted under the same conditions. For example, when picking with a picker in production and flocking, even if the flocking holes have different shapes, they can be planted at once without changing the number of flocking holes, which is efficient.

Specifically, as shown in FIG. 7, a plurality of hair bundles 4A having a low filling density are planted at the center of the flocking surface 20, and a plurality of hair bundles 4B having a filling density of 60% or more are planted outside the hair bundles 4A. Is also a preferable example. As a result, the filling density of the hair in the central position, which contributes to cleaning between the teeth, the cervical region, the interdental papilla, and the interdental drum-shaped space, is reduced, and the insertability into the gaps between these teeth is reduced. It becomes possible to efficiently clean the tooth surface and other parts with a hair bundle having a high filling density on the outside.

The material of the hair 3 constituting the hair bundle 4 according to the present invention is not particularly limited. For example, a polyamide resin such as nylon or aramid resin, a polyester resin such as polyethylene terephthalate, polytrimethylene terephthalate or polybutylene terephthalate, a polyolefin resin such as polypropylene, a thermoplastic elastomer resin, or other conventionally known thermoplastic resin filaments may be used. Can be done.

The cross-sectional shape of the hair 3 may be a semicircular shape, a half-moon shape, a polygonal shape such as a triangle or a quadrangle, or an irregular shape such as an indeterminate shape, in addition to the circular shape. Spiral-shaped ones, satinized ones, and ones made by kneading another material into yarn can also be used. By making the shape irregular other than the cylindrical shape in this way, it becomes easy to arrange the hairs substantially uniformly.

The repulsive force of each hair 3 can also be obtained by the above formula 1, and specifically, it is preferably 0.02N or more and 0.2N or less. When the content is 0.2 N or less, the insertability into gaps such as the interdental space, the cervical region, the interdental papilla, and the interdental drum-shaped space is improved. If it is less than 0.02N, the bristles tend to bend and the sweepability is significantly reduced.

The thickness of each hair 3 is preferably 0.1 mm or more and 0.3 mm or less in diameter. More preferably 0.2 mm or less. The thinner the thickness of each hair 3, the better the insertability into the gaps such as the interdental space, the cervical region, the interdental papilla, and the interdental drum-shaped space. If the thickness is within the above range, the thinner the hair and the larger the number of plaques, the more plaque can be removed.

Although the embodiments of the present invention have been described above, the present invention is not limited to these examples, and it goes without saying that the present invention can be implemented in various forms without departing from the gist of the present invention.

(Examples 1 to 6, Comparative Examples 1 to 5)
The toothbrushes 1A shown in FIGS. 4 (a) and 4 (b) were prepared, respectively. All have the same structure and dimensions, and the hair follicle holes 21 have the same arrangement and dimensions. Specifically, as shown in FIG. 4, a total of nine hair follicles 21 are provided in three rows and three rows, and each hair follicle hole 21 has a circular mouth portion 21a and a through hole having an inner diameter of 1.6 mm.

Then, different hair follicles 4 (hair follicles having different thicknesses (diameters) or numbers of hairs 3) were planted in the hair follicles of the toothbrush 1A in Examples 1 to 6 and Comparative Examples 1 to 5. In the planting of the hair follicle 4, the hair follicle was inserted into the flocking hole, and the base end side was melted and fixed by heat on the back surface side of the flocking table. The hairs 3 constituting the hair bundle 4 were all made of nylon resin, and the length protruding from the flocking table was set to 9 mm. As shown in Tables 1 to 3, the thickness (diameter) and the number of hairs were different in each Example and Comparative Example.

Specifically, in Examples 1 to 3 and Comparative Examples 1 to 3, using hairs having a diameter of 0.178 mm and a repulsive force of 0.0961N, in Example 1, 23 hairs were bundled and the filling density for the hair follicles was filled. In Example 2, 30 hair follicles were bundled to form a hair follicle having a filling density of 40% for the hair follicles, and in Example 3, 38 hair follicles were bundled to form a hair follicle having a filling density of 50% for the hair follicles. Comparative Example 1 bundles 45 hair follicles with a filling density of 60% for the pores, Comparative Example 2 bundles 53 hair follicles with a filling density of 70% for the pores, and Comparative Example 3 has 61. The books were bundled into hair follicles having a filling density of 80% for the pores.

Further, in Examples 4, 5 and Comparative Example 4, hairs having a diameter of 0.127 mm and a repulsive force of 0.0249N were used, and in Example 4, 48 hairs were bundled and a hair bundle having a filling density of 32% for the pores was used. In Example 5, 60 hair follicles were bundled to form a hair bundle having a filling density of 40% for the hair follicles, and in Comparative Example 4, 119 hair follicles were bundled to form a hair bundle having a filling density of 80% for the hair follicles. Further, in Example 6 and Comparative Example 5, hairs having a diameter of 0.203 mm and a repulsive force of 0.1625 N were used, and in Example 6, 19 hairs were bundled to form a hair bundle having a filling density of 32% for the pores. In Comparative Example 5, 47 hair follicles were bundled to form a hair bundle having a filling density of 80% for the pores. The repulsive forces of the hair bundles of each Example and Comparative Example are as shown in Tables 1 to 3.

(Cleanability evaluation test)
For each example and comparative example, a brushing simulator designed to brush the teeth of a fixed jaw model (D15-500H, Nissin, Kyoto) while keeping the brushing pressure and moving speed of the toothbrush constant was used. .. A specific tooth of the jaw model (maxillary first molar) is removed, and an occlusion check spray occlude (Pascal, USA) is used as an alternative to plaque on the interdental surface (the surface facing the adjacent maxillary second premolar). The colored powder was applied, returned to the jaw model, and brushed.

The brushing pressure was set to 100 g, and the stroke in the longitudinal direction was brushed at a stroke width of 20 mm and a moving speed of 2.53 mm / sec for 12.5 seconds. After brushing, the specific tooth of the jaw model (maxillary first molar) was removed again, the tooth surface was photographed, and the removal length from the front of the tooth (tooth surface insertion depth) was measured. This makes it possible to determine how much hair has reached the interdental region. The interdental insertability was defined as "◯" in the sense that the interdental insertion depth of 3.5 mm or more was sufficient, and "x" in the sense of inadequate when the interdental insertion depth was less than 3.5 mm. The results are shown in Tables 1 to 3 and FIGS. 5 and 6. The "state after brushing" in Tables 1 to 3 shows the state of the tooth surface photographed above, the left side of each photograph is the front side of the tooth, and the "interdental insertion depth" is the colored powder removed from the front surface. It is a measurement of the length of the interdental surface.

From the graphs of Table 1 and FIG. 5 showing the results of Examples 1 to 3 and Comparative Examples 1 to 3, the filling density of the hair in the pores of the same hair is set to less than 60%. It can be seen that the interdental insertability is significantly improved. Further, when the interdental insertion depth is 3.5 mm or more, sufficient interdental insertability can be obtained, but from the graph of FIG. 5, if the hair filling density for the pores is 57% or less, sufficient teeth can be obtained. It can be seen that interstitial insertability can be obtained. Since it is almost flat at 50% or less, it can be seen that it is more preferable to set it to 45 to 57% if the packing density is maintained to some extent and the total cleanability is improved.

Further, when comparing the same hair filling densities, as can be seen from Tables 2 and 3, for example, in Examples 4 and 6, the hair filling density with respect to the pores is 32%, but they constitute a hair bundle. The result of Example 4 in which the bristles are thin and the number of bristles is large is that the interdental insertion depth is longer in Example 4 than in Example 6 in which the bristles are thick and the number of bristles is small. Further, in each case, the filling density of the hairs in the hair follicles is 80%, but in Comparative Example 4 in which the hairs constituting the hair bundle are thin and the number of hairs is large, the interdental space is compared with Comparative Example 5 in which the hairs are thick and the number of hairs is small. The result is a long insertion depth. FIG. 6 is a graph showing the relationship between Examples 4 and 6 and Comparative Examples 4 and 5. As described above, when the filling density is the same, it can be seen that the thinner the hair and the larger the number of hair bundles, the better the interdental insertability.

1 Toothbrush 2 Head 3 Hair 4 Hair follicles 5 Neck 10 Handle 11 Brush 20 Flocked surface 21 Flocked hole 21a Mouth 40 Melted mass

Claims (2)

No fusion type or in-mold type in which a plurality of hair bundles having a hair filling density of 30% or more and less than 60% and a repulsive force of 1.0 to 5.5 N are planted in the head portion. Flat line toothbrush. The toothbrush according to claim 1, wherein the hair filling density of the hair bundle is 57% or less.

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