JP2004209242A - Interdental cleaner and forming method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an interdental cleaner which can realize molding of an interdental inserting part formed by uniformly coating a shaft core with elastic coating resin, is friendly in contact with gums, can efficiently clean interdental parts, and is structurally simple. <P>SOLUTION: This interdental cleaner 10 is equipped with an interdental insertion part 11 comprising a shaft core 13 and elastic coating resin 14 to cover the whole of the shaft core 13, and a grip part 12. Exposed parts 15a, 15b to expose the shaft core 13 is set on the circumferential face of the interdental insertion part 11. The exposed parts 15a, 15b can be structured by forming dent parts 16 in the elastic coating resin 14. The exposing parts 15a, 15b can be also formed by equipping a shaft core projecting part 23 projected outward from the outer circumferential face of the shaft core 13. The exposed parts 15a, 15b are placed along the surface of the interdental insertion part 11 and it is preferable to place the exposed parts 15a, 15b alternately in the axial direction of the shaft core 13 so as not to mutually interfere. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to an interdental cleaning tool and a molding method thereof, and in particular, includes an interdental insertion portion made of an elastic covering resin that covers the entire shaft core and the shaft core, and a handle portion, and is gentle to the gingiva, and the interdental portion. The present invention relates to an interdental cleaning tool and a molding method thereof that can efficiently perform the above-described brushing and are structurally simple.

  Generally known dental floss, interdental brushes, toothpicks, and the like are used as an interdental cleaning tool for removing food residues, plaque, and the like from the interproximal region. Dental floss removes food residues and dental plaque while inserting a thread into the interdental region through the interproximal portion at the tip between the teeth. These tip portions are directly inserted between the portions to remove food residues and plaque.

  In the conventional interdental brush, a large number of fibers are arranged in parallel between the bifurcated wires protruding from the tip of the handle, and then the metal wire is twisted so that the numerous fibers sandwiched over the entire radial direction. Since the wire is covered in a brush-like shape in an upright state, it requires an expensive manufacturing process and is costly. Bending is likely to occur, and when a metal wire comes into contact with teeth or gums, they are easily damaged. In the case of a toothpick, it is usually made of wood and has the advantage of being inexpensive and economical, but the tip is sharp and has little flexibility, which may damage the gums. It is difficult to clean the interdental part of the back teeth.

  On the other hand, the interdental insertion portion of the interdental cleaning tool needs to have appropriate flexibility when inserted between the teeth and slid back and forth, for example, and ensures a certain degree of rigidity. There is a need. Moreover, since the interdental insertion part of an interdental cleaning tool will contact gingiva, if the material of the surface of an insertion part is too hard, it will become easy to damage a gum.

  Therefore, the interdental cleaning tool which formed the interdental insertion part inserted in an interdental part with the synthetic resin is developed (for example, refer patent document 1, patent document 2, patent document 3). Patent Document 1 discloses an interdental cleaning tool in which a petal-like protrusion is provided on a core part at the tip of a handle part. In the interdental cleaning tool disclosed in Patent Document 1, the diameter of the protrusion is several times larger than the diameter of the core part. Such an interdental cleaning tool is a technical problem of resin molding, and the diameter of the protrusion cannot be made too small. Therefore, the interdental cleaning tool can be smoothly used between narrow teeth (about 0.7 to 1.5 mm). There is a problem that the diameter of the core part has to be considerably reduced in order to make it slide.

  Patent Document 2 discloses an interdental cleaning tool in which a fin-like or hair-like protrusion and a shaft are integrally formed of synthetic resin. The interdental cleaning tool disclosed in Patent Document 2 has a small core portion, but the protrusion has a large diameter, so that the interdental cleaning tool is used in narrow interdental spaces (about 0.7 to 1.5 mm). In order to smoothly slide the protrusions, the thickness of these protrusions must be considerably reduced, and there is a problem that the durability of these protrusions deteriorates.

  Patent Document 3 discloses a brush body including a connecting portion provided between a sharp protrusion and a grip portion. Also, the connecting part is formed integrally with the brush body, and since a material having spring elasticity is used, it has a certain flexibility, while the cleaning member is made of a material having rubber elasticity. By doing so, consideration is given to obtaining a gum massage effect and the like. Further, Patent Document 3 discloses that the cleaning member and the brush main body are securely coupled together through the hole. In this case, at the time of the primary molding of the brush body, it is necessary to make a hole in the connecting portion provided in the brush body in advance, and it is necessary to make the brush body itself thick in order to ensure the strength of the connecting portion. However, when the brush body itself is thickened, there is a problem that it becomes difficult to smoothly insert the interdental cleaning tool between narrow teeth. Furthermore, since a hole is made in the brush body during the primary molding, the shape of the primary molding die is considerably complicated, and there is a problem that the cost cannot be reduced.

  In addition, the interdental insertion portion of the interdental cleaning tool having a small cross-sectional area is provided with an appropriate flexibility at the time of primary molding, and a shaft is formed of a synthetic resin having a certain degree of rigidity, and then at the time of secondary molding, If an attempt is made to cover and mold the shaft core with a synthetic resin having different physical properties (high rubber elasticity), an uneven thickness phenomenon may occur due to the difficulty in forming a thin molded product using the synthetic resin.

In other words, the elastic coating resin by secondary molding is formed by filling the mold with the shaft core inserted and arranged along the central axis and cooling and solidifying the mold, but when filling the molten resin Due to the influence of molding pressure, resin temperature, injection speed, etc., the shaft core disposed along the central axis becomes unstable, and the molten resin flows unevenly. Due to the unevenness of the molten resin inside the mold, warpage such as lateral warpage and vertical warpage occurs, and therefore, the problem that the function as an interdental cleaning tool cannot be exhibited by the interdental insertion portion with warpage. There is.
JP-A-11-137777 JP 2000-166945 A Japanese Patent Application Laid-Open No. 2000-24009

  The present invention was made in order to solve the above-mentioned problem of warping, and can realize the formation of an interdental insertion portion formed by uniformly coating an elastic coating resin on the shaft core, and is gentle to the gingiva, It is an object of the present invention to provide an interdental cleaning tool that can efficiently clean the interdental portion and is structurally simple, and a molding method thereof.

  The present invention is an interdental cleaning tool comprising an interdental insertion portion made of an elastic coating resin that covers the entire shaft core and the shaft core, and a handle portion, and the peripheral surface of the interdental insertion portion includes: The above object is achieved by providing an interdental cleaning tool provided with an exposed portion through which the shaft core is exposed.

  Here, the exposed portion can be arranged in at least three directions in the circumferential direction of the interdental portion, for example, can be arranged in four directions, five directions, and the like. These circumferential arrangement intervals may be equiangular intervals or may not be equiangular intervals. In addition, the shaft core may be a straight line and may have a predetermined curvature as long as the shaft core can be fixed in a state of being held so as to overlap the center axis of the designed mold. It may be an arch shape that bends.

  Furthermore, the exposed portions can be arranged in three or more radial directions assigned at substantially equal angular intervals in the circumferential direction, and the shaft cores of the molds are arranged in at least three or more directions assigned at substantially equal angular intervals in the circumferential direction. By tightly supporting the molding surface, it is possible to easily fix the central axis of the shaft core in a state of being held so as to overlap the central axis of the mold. At least three or more directions assigned at substantially equal angular intervals in the circumferential direction can be arranged in a radial direction, for example, toward each corner of a regular polygon centered on the axis. In addition, the exposed portion is not necessarily arranged in the circumferential direction in the same cross section of the interdental insertion portion, and may be arranged in a cross section in which each radial direction is shifted in the axial direction of the interdental insertion portion. good. Furthermore, the exposed portions arranged in two or more directions in the same cross section of the interdental insertion portion can be provided as a belt-like one that is continuously integrated in the circumferential direction.

  The exposed portion that exposes the shaft core on the peripheral surface of the interdental insertion portion can be formed by bringing the shaft core into close contact with the molding surface of a mold used during secondary molding of the elastic coating resin. The exposed portion may be a concave portion provided in the elastic coating resin, or may be a convex portion provided in the shaft core.

  That is, the exposed portion is, for example, a recess formed in the interdental insertion portion after molding by bringing a mold convex portion protruding inward from the molding surface of the mold into close contact with the outer peripheral surface of the shaft core. In, by exposing to the molding surface of the mold, it can be exposed to the peripheral surface of the interdental insertion portion, and also protrudes outward from the peripheral surface of the shaft core, It can also expose to the surrounding surface of the said interdental insertion part after shaping | molding.

  And this invention is a shaping | molding method for forming the said interdental cleaning tool, Comprising: The primary shaping | molding process which forms the said shaft core, and the center axis | shaft of the said shaft core overlap with the center axis | shaft of the said metal mold | die. The above object is achieved by providing a method for forming an interdental cleaning tool comprising a secondary molding step of molding the elastic coating resin while covering the shaft core while holding the free end of the shaft core. It is. Here, in this application, a free end means parts other than the base end part connected with the said handle | pattern part.

  For example, after the shaft core is formed by the primary molding process, when the elastic coating resin is molded on the outer peripheral surface of the shaft core by the secondary molding process, the central axis of the shaft core overlaps the central axis of the mold. In this manner, with the free end of the shaft core held and fixed, a part of the mold is brought into close contact with the peripheral surface of the shaft core (closely attached at three or more points). In this case, even if molten resin is injected into the mold, the shaft core is fixed in close contact with the mold, so that it is hardly affected by molding pressure, resin temperature, injection speed, etc. The elastic coating resin formed by the secondary molding to be coated can be formed with a uniform thickness, so that the interdental insertion as designed without causing the phenomenon of warping in the interdental insertion part formed thereby. It becomes possible to obtain the interdental cleaning tool which comprises a part.

  Further, the inventors devised the shape of the contact point between the mold and the shaft core at the time of secondary molding, to the secondary elastic molded resin, dental plaque as an interdental cleaning tool, An excellent cleaning function was added to remove food residues. That is, the contact point (exposed portion) is formed by covering the peripheral surface of the shaft core with a uniform thickness in the elastic covering resin in the molding process of the interdental insertion portion. Moreover, when it becomes a product as an interdental cleaning tool, since the exposed part has a step between the elastic coating resin, the interdental cleaning tool has an excellent cleaning function for removing plaque and food residue. Become functional.

  That is, by forming the exposed portion of the shaft core in the interdental insertion portion of the interdental cleaning tool according to the present invention, by the secondary molding of a synthetic resin that could not be realized conventionally due to uneven thickness phenomenon It became possible to mold interdental cleaning tools. Not only this, the interdental insertion part of the interdental cleaning tool according to the present invention has an appropriate rigidity while having an appropriate rigidity, is gentle to the gingiva, and is easy to use as an interdental insertion part. Further, by forming the exposed portion of the shaft core in the interdental insertion part of the interdental cleaning tool according to the present invention, the interdental insertion part is gentle to the gingiva and excellent in removing plaque and food residues. Functions will be added. As a result, the interdental cleaning tool according to the present invention can also efficiently clean the periodontal pocket. Therefore, the interdental cleaning tool according to the present invention includes not only the purpose of removing plaque between teeth, but also the purpose of plaque control by cleaning the periodontal pocket. Furthermore, since the exposed portion has a simple structure, it contributes to a reduction in manufacturing cost.

According to the interdental cleaning tool and the molding method thereof of the present invention, it is possible to obtain an interdental cleaning tool that is gentle to the gums and has an excellent function of removing plaque and food residues. In particular, in the periodontal pocket cleaning, in addition to the above-mentioned merits, the problem of warpage of the interdental insertion part is solved and the operation of the cleaning tool is easy, so the resistance to use of the affected part can be reduced. . Further, according to the molding method of the present invention, the elastic coating resin can be formed on the peripheral surface of the shaft core with a uniform thickness. Furthermore, since the interdental cleaning tool according to the present invention is structurally simple, it can contribute to a reduction in manufacturing cost.

  The interdental cleaning tool 10 according to the first preferred embodiment of the present invention shown in FIG. 1 includes an interdental insertion portion 11 and a handle portion 12, and holds the handle portion 12 by hand to provide a space between teeth. This is an interdental cleaning tool used to remove food residues, plaque, etc. adhering to the interdental part by, for example, sliding back and forth while inserting the interdental insertion part 11 into the part.

  That is, the interdental cleaning tool 10 according to the first embodiment includes an interdental insertion comprising an axial core 13 and an elastic coating resin 14 covering the axial core 13 as shown in FIGS. The shaft core 13 is provided with a handle portion 12 and an interdental insertion portion 11 after molding by closely contacting the molding surface 21 (see FIG. 3) of the mold 20 when the elastic coating resin 14 is molded. The exposed portions 15a and 15b exposed on the peripheral surface are directed in the four radial directions assigned at substantially equal angular intervals of 90 degrees in the circumferential direction.

  According to the first embodiment, the handle 12 constituting the interdental cleaning tool 10 is made of, for example, polypropylene, polyethylene, acetal resin, ABS resin, polystyrene, polyester resin, polyamide resin, polycarbonate, fluororesin, acrylic as a synthetic resin. It is an injection-molded product made of resin, vinyl chloride resin, vinyl acetate resin, polyimide resin or the like, and comprises a handle portion main body 12a, a neck portion 12b, and a head portion 12c. Further, the interdental insertion portion 11 is provided on the head portion 12 c in a protruding state by integrally molding the shaft core 13 with the handle portion 12 using the same synthetic resin material as that of the handle portion 12.

  The interdental insertion part 11 which comprises the interdental cleaning tool 10 with the handle | pattern part 12 consists of the axial core 13 and the elastic coating resin 14 which coat | covers this, For example, 4-20 mm from the head 12c of the handle | pattern part 12, Preferably 7 Protrusively provided with a length of ˜15 mm. Further, according to the first embodiment, the interdental insertion portion 11 has a cross-sectional shape of the base end portion connected to the head portion 12c, and the length of the long axis or the short axis is 0.5 to 3.0 mm. Preferably, it has a substantially elliptical shape with a size of 0.7 to 2.0 mm (see FIGS. 4B and 4C), and from the proximal end portion close to the head portion 12c toward the distal end portion. The cross section gradually becomes smaller.

  The shaft core 13 is integrally formed with the handle portion 12 using the same synthetic resin material as that of the handle portion 12 as described above, so that the interdental insertion portion 11 covered with the elastic coating resin 14 is inserted between the teeth. Appropriate flexibility and moderate rigidity when it is inserted into the part and slid back and forth, for example, are imparted. Further, the shaft core 13 has exposed portions 15 a and 15 b exposed on the peripheral surface of the elastic coating resin 14 in a recess 16 formed on the peripheral surface of the elastic coating resin 14 covering the shaft core 13.

The exposed portions 15a and 15b are a set of two vertically exposed portions 15a that are exposed in the vertical direction that is the radial direction, and the horizontal direction that is a radial direction shifted by 90 degrees from the vertical direction in the circumferential direction. A pair of left and right exposed portions 15b that are exposed to each other toward each other are provided alternately at a pitch of 0.2 to 8 mm, preferably 0.5 to 4 mm in the axial direction of the interdental insertion portion 11. , Distributed over substantially the entire length. As a result, the exposed portions 15a and 15b are arranged in the four radial directions assigned at substantially equal angular intervals of 90 degrees in the circumferential direction. According to the first embodiment, two sets of the vertical direction exposed portions 15a are arranged in a total of four locations, and three sets of the horizontal direction exposed portions 15b are arranged in a total of six locations. Each exposed portion 15a, the area of the 15b, 0.1~6.0mm ^2, preferably 0.3 to 1.0 mm ^2.

  The elastic coating resin 14 formed to cover the shaft core 13 may be any synthetic resin that is harmless to the human body having rubber elasticity at room temperature. For example, olefin-based, styrene-based, vinyl chloride-based, polyester-based, urethane-based, It can be molded using a thermoplastic elastomer such as polyamide, fluorine, 1 or 2 polybutadiene, silicone or ester, and is preferably molded using an olefin thermoplastic elastomer or a styrene thermoplastic elastomer. . By molding the elastic coating resin 14 using an olefin-based thermoplastic elastomer or a styrene-based thermoplastic elastomer, the rubber insertion is imparted to the interdental insertion part more gently with respect to the gums and with an excellent massage effect on the gums. In addition, it is possible to more effectively remove dirt between teeth.

  Further, as shown in FIGS. 3A to 3C, for example, the elastic coating resin 14 is formed in the center of the shaft core 13 in the mold 20 for secondary molding for molding the elastic coating resin 14. After the shaft core 13 is arranged so that the shaft and the center axis of the mold overlap (see FIG. 3B), the melted in the gap around the shaft core 13 and the molding surface 21 of the mold 20 By filling and solidifying the resin (see FIG. 3C), the shaft core 13 is covered and easily formed around it.

  In addition, according to the first embodiment, the mold 20 has the pressing piece 22 as a mold convex portion protruding inward from the molding surface 21 thereof, and the exposed portion 15a, A plurality are provided corresponding to the positions where the recesses 16 for exposing 15b are formed. These presser pieces 22 are brought into close contact with the outer peripheral surface of the shaft core 13, and the elastic coating resin is supported and fixed so that the center axis of the shaft core 13 and the center axis of the mold overlap with each other while the shaft core 13 is held. By molding 14, the exposed portions 15a and 15b are formed in the recess 16 formed in the interdental insertion portion 11 after molding from the peripheral surface of the interdental insertion portion 11 toward the radial direction 4 in the above-described position. Will be exposed.

  That is, according to the first embodiment, as shown in FIGS. 3A to 3C, the shaft core 13 formed in the primary molding step of integrally molding the shaft core 13 together with the handle portion 12 is paired with the pair of shaft cores 13. While being disposed between the molds 20 while being sandwiched between the molds 20 (see FIG. 3A), the outer periphery of the shaft core 13 in the secondary molding process for molding the elastic coating resin 14 The surface is brought into close contact with the molding surface 21 of the mold 20 via the pressing pieces 22 in the four radial directions allocated so as to have substantially equal angular intervals in the circumferential direction inside the mold 20 (FIG. 3B )), The elastic coating resin 14 can be molded to cover the shaft core 13 while firmly fixing the shaft core 13 so that the center shaft of the shaft core 13 is overlapped with the center axis of the mold 20 (see FIG. (Refer FIG.3 (c)).

  As a result, as shown in FIGS. 4A to 4C, in the concave portion 16 formed on the peripheral surface, the exposed portion 15a exposed in the four radial directions assigned at substantially equal angular intervals in the circumferential direction. The shaft core 13 having 15b is easily and smoothly formed.

  Therefore, according to the first embodiment, it is possible to easily form the interdental insertion portion 22 capable of efficiently cleaning the interdental portion by covering the shaft core 13 with the elastic coating resin 14. At the same time, when the elastic coating resin 14 is molded, the molding surface 21 of the mold 20 is interposed via the pressing pieces 22 in the radial direction in which the outer circumferential surface of the shaft core 13 is assigned at substantially equal angular intervals in the circumferential direction. Since the molten resin of the elastic coating resin 14 can be filled and solidified while firmly fixing the central axis of the shaft core 13 so as to overlap the central axis of the mold, the mold can be solidified. The molten resin inside 20 can be formed with a uniform thickness, and it is possible to effectively avoid warpage such as lateral warpage and vertical warpage caused by uneven thickness phenomenon in the interdental insertion portion 11. It becomes possible.

  Further, according to the first embodiment, the entire tip of the interdental insertion portion 11 may be covered with the elastic coating resin 14. By covering the entire tip of the interdental insertion portion 11 with the elastic coating resin 14, it is possible to impart appropriate rubber elasticity to the interdental insertion portion 11. When the interdental insertion portion 11 is inserted between the teeth, the interdental insertion portion 11 Even if it comes into contact with the gingiva, the gingiva is not damaged, it is gentle to the gingiva, and the dirt removal efficiency between the teeth can be improved.

  Furthermore, according to the first embodiment, for example, a recess is provided on the molding surface 21 of the secondary molding die 20 for molding the elastic coating resin 14 at a position where the pressing piece 22 is not provided. As shown in FIG. 5, an annular protrusion protruding outward at a position where the exposed portions 15 a and 15 b are not provided on the peripheral surface of the elastic coating resin 14 of the interdental insertion portion 11 after molding. 17 can also be formed. By forming the protrusions 17 on the peripheral surface of the elastic coating resin 14, it is possible to further improve the function of removing food residues, plaque, etc. adhering to the interdental portions due to the unevenness by the protrusions 17 (Table 1).

  In Table 1, Invention 1 is an interdental insertion part having the same configuration as the interdental insertion part of the interdental cleaning tool shown in FIG. 4, and Invention 2 is an interdental cleaning tool shown in FIG. It is an interdental insertion part which has the structure similar to this interdental insertion part. In addition, the comparative product is an interdental insertion portion in which a large number of fibers sandwiched between bifurcated wires in a conventional interdental brush are erected over the entire radial direction. In Table 1, １ indicates excellent, ○ indicates good, Δ indicates acceptable, and × indicates impossibility.

  6 (a) to 6 (d) and FIGS. 7 (a) and 7 (b) show an interdental insertion portion 18 of an interdental cleaning tool according to a second embodiment of the present invention and a molding method thereof. . According to the second embodiment, in the primary molding step of integrally molding the shaft core 19 together with the handle portion 12, the shaft core 19 is provided with the shaft core convex portion 23 protruding outward from the peripheral surface thereof. Keep it. Then, the front end contact surface of the shaft core convex portion 23 is brought into close contact with the molding surface 25 of the mold 24, thereby fixing the center axis of the shaft core 19 so as to be overlapped with the center axis of the mold 24. While (see FIG. 7A), the mold 24 is filled with the molten resin of the elastic coating resin 27 and solidified (see FIG. 7B). As a result, as shown in FIGS. 6A to 6D, the shaft core 19 is made to have a uniform thickness with the tip contact surface of the shaft core convex portion 23 exposed as the exposed portions 26a and 26b on the peripheral surface. The interdental insertion portion 18 that is thick and covered with the elastic coating resin 27 is formed easily and smoothly.

  In addition, according to the second embodiment, the exposed portions 26a and 26b by the tip contact surface of the axial convex portion 23 are two sets, like the exposed portions 15a and 15b of the first embodiment, for a total of four locations. The vertical exposed portions 26a and three sets of six horizontal exposed portions 26b in total are arranged alternately, and arranged in four radial directions assigned at substantially equal angular intervals of 90 degrees in the circumferential direction. Has been. Further, according to the second embodiment, by providing the depression 28 on the molding surface 25 of the secondary molding die 24 for molding the elastic coating resin 27, the molded elastic coating resin 27 is formed. An annular protrusion 29 protruding outward is formed on the peripheral surface.

  Even in the second embodiment, in the secondary molding step for molding the elastic coating resin 27, the outer peripheral surface of the shaft core 19 is arranged in four directions in the radial direction via the tip contact surface of the shaft core convex portion 23. By closely contacting with the molding surface 25 of the mold 24, the center axis of the shaft core 19 can be firmly fixed while being held so as to overlap the center axis of the mold 24. Similarly, effects such as formation of a uniform thickness of the elastic coating resin 27 are exhibited.

  Further, by forming an annular protrusion 29 protruding outward on the peripheral surface of the elastic coating resin 27, the cleaning function for removing plaque and food residue by the exposed portion 26a is further enhanced, and interdental insertion is performed. The interdental cleaning function of the part 18 can be further improved.

  The present invention is not limited to the above-described embodiments, and various modifications can be made. For example, it is not always necessary to expose the exposed portion in the four directions of the vertical direction and the horizontal direction as the radial direction, and at least 3 to fix the shaft core in a state where straightness is maintained at the center of the mold along the central axis. It suffices if the exposed portion is exposed toward the direction. Moreover, it is not always necessary to disperse and arrange the exposed portion over substantially the entire length of the interdental insertion portion.For example, the outer peripheral surface of the shaft core is closely attached to the molding surface of the mold from three or more directions only at the tip portion, The rear end portion of the shaft core can be supported by the handle portion and can be fixed in a state where the center axis of the shaft core is held so as to overlap the center axis of the mold.

  Furthermore, the shaft core is not necessarily made of a synthetic resin as long as it can provide a desired rigidity to the interdental insertion portion, and may be made of a metal, for example. The shaft core does not necessarily have to be integrally formed with the handle. The handle portion may be simply formed in a rod shape, for example, and the interdental cleaning tool may have a toothpick shape.

  Furthermore, the interdental insertion portion does not necessarily have a tapered shape with an elliptical cross section. The cross sectional shape of the concave portion, the cross sectional shape of the axial convex portion, the planar shape of the exposed portion, and the cross section of the elastic coating resin. Various shapes can be adopted as the shape, the cross-sectional shape of the shaft core, the arrangement of the projections, the front shape of the projections, the side shape of the projections, and the like. That is, as the cross-sectional shape of the concave portion, for example, the one shown in FIG. 8 can be adopted, and as the cross-sectional shape of the axial core convex portion, for example, the one shown in FIG. 9 can be adopted. . Further, as the planar shape of the exposed portion, for example, the one shown in FIG. 10 can be adopted, and as the cross-sectional shape of the elastic coating resin, for example, the one shown in FIG. 11 can be adopted. . Furthermore, as the cross-sectional shape of the shaft core, for example, the one shown in FIG. 12 can be adopted, and as the arrangement form of the protrusions, for example, an all-round type as shown in FIG. ), Multiple division types (see (b)), staggered types (see (c)), and the like can be employed. Furthermore, as the front shape of the protrusion, for example, the one shown in FIG. 14 can be adopted, and as the side shape of the protrusion, for example, the one shown in FIG. 15 can be adopted.

It is a side view which shows the interdental cleaning tool which concerns on 1st Embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS (a) which expands and shows the principal part of the interdental cleaning tool which concerns on 1st Embodiment of this invention, (b) is a top view. (A)-(c) is explanatory drawing of the condition which shape | molds the interdental insertion part of the interdental cleaning tool which concerns on 1st Embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS (a) which shows schematically the interdental insertion part of the interdental cleaning tool which concerns on 1st Embodiment of this invention is a top view, (b) is the sectional view on the AA line of (a), (c) is (a) It is a BB line sectional view of). It is a top view which shows schematically the interdental insertion part of the interdental cleaning tool which concerns on 1st Embodiment of this invention provided with the processus | protrusion. The interdental insertion part of the interdental cleaning tool which concerns on 2nd Embodiment of this invention is shown schematically, (a) is a top view, (b) is the CC sectional view taken on the line (a), (c) is (a) It is a DD line sectional view of). (A), (b) is explanatory drawing of the condition which shape | molds the interdental insertion part of the interdental cleaning tool which concerns on 2nd Embodiment of this invention. It is a schematic sectional drawing which illustrates the cross-sectional shape of a recessed part. It is a schematic sectional drawing which illustrates the cross-sectional shape of an axial center convex part. It is a schematic plan view illustrating a planar shape of an exposed portion. It is a schematic sectional drawing which illustrates the cross-sectional shape of elastic coating resin. It is a schematic sectional drawing which illustrates the cross-sectional shape of an axial center. (A)-(c) is the schematic sectional drawing and schematic side view which illustrate the arrangement | positioning form of protrusion. It is a simplified front view illustrating a front shape of a protrusion. It is an abbreviated side view showing an example of a side shape of a protrusion.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Interdental cleaning tool 11, 18 Interdental insertion part 12 Handle part 13, 19 Shaft core 14, 27 Elastic coating resin 15a, 26a Vertical direction exposed part 15b, 26b Left / right direction exposed part 16 Recess 17, 29 Protrusion 20, 24 Gold Molds 21 and 25 Molding surface 22 Pressing piece (mold convex part)
23 Axial core convex part 28 Recessed part

Claims (9)

An interdental cleaning tool comprising an interdental insertion portion made of an elastic coating resin that covers the entire shaft core and the shaft core, and a handle portion,
An interdental cleaning tool in which an exposed portion where the shaft core is exposed is provided on a peripheral surface of the interdental insertion portion. The interdental cleaning tool according to claim 1, wherein a concave portion is provided in the elastic coating resin to constitute the exposed portion. The interdental cleaning tool according to claim 1, wherein the shaft core is provided with a convex portion that protrudes outward from an outer peripheral surface of the shaft core, and constitutes the exposed portion. The said exposed part is arrange | positioned along the surface of the said interdental insertion part, and is arrange | positioned alternately in the axial direction of the said axial core so that it may not mutually interfere. Interdental cleaning tool. The interdental cleaning tool according to any one of claims 1 to 4, wherein the shaft core and the handle are integrally formed of a synthetic resin material. The interdental cleaning tool according to any one of claims 1 to 5, wherein the elastic coating resin is an olefin-based thermoplastic elastomer or a styrene-based thermoplastic elastomer. The interdental cleaning tool according to any one of claims 1 to 6, wherein a protrusion protruding outward is formed on a peripheral surface of the elastic coating resin at a position where the exposed portion is not provided. The interdental cleaning tool according to any one of claims 1 to 7, wherein the interdental insertion portion has a substantially elliptical cross-sectional shape and a cross-sectional area that decreases toward the tip. A molding method for forming the interdental cleaning tool according to claim 1,
A primary forming step of forming the shaft core;
A secondary molding step of molding the elastic covering resin so as to cover the shaft core while holding the free end of the shaft core so that the center axis of the shaft core and the center axis of the mold overlap.
A method for forming an interdental cleaning tool comprising:

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