JP2007195962A - Toothbrush - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toothbrush, achieving excellent penetration performance into a narrow gap, and excellent cleaning performance. <P>SOLUTION: A bristle 21 to compose a bundle of bristles comprises a core part 22, and a sheath part 23 surrounding the core part 22, forming a multi-core structure. It has a number of recessed parts 24 provided from the surface of the sheath part 23 toward the core part 22. The bristle 21 forms a taper part 25 of which thickness is gradually decreased toward the tip. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a toothbrush, and in particular, to a toothbrush bristle.

  In the toothbrush which is an intraoral cleaning tool, conventionally, various devices have been made with respect to the hairs constituting the hair bundle implanted in the head part of the toothbrush. For example, Patent Document 1 and Patent Document 2 describe hairs having a multi-core structure including a core portion formed by coextrusion and a sheath portion surrounding the core portion. There is also known a toothbrush that uses such multi-core structure bristles to display the replacement time by exposing the core portion due to abrasion of the colored sheath portion (Patent Document 3).

On the other hand, in order to enhance the brushing effect, there is also known a hair for which a so-called taper process is applied, in which the thickness is gradually reduced toward the tip. For example, Patent Document 4 describes bristles whose ends are tapered, and Patent Documents 5 and 6 describe bristles having a multi-core structure consisting of a core portion and a sheath portion having a tapered portion. Has been.
JP-T-2001-511379 JP 2001-17854 A JP-T 8-503145 Japanese Patent No. 3145213 JP 2001-178542 A JP 2003-169718 A

  In conventional toothbrushes, the surface of the hair is embossed to improve the brushing force, the surface of the hair is kneaded with an abrasive, or the tooth contact area such as twisted or feathered hair is improved. However, all of them have low penetration into narrow gaps such as periodontal pockets and interdental parts, and there is a problem in plaque cleaning ability. In addition, both ends of the tapered hair are known to improve the ability of the hair to enter the site where oral disease is common, but the surface of such a tapered hair is lubricated because it is formed mainly by chemical treatment, and the periodontal There is a problem that the penetration into narrow gaps such as pockets and interdental portions is high, but the effect of scraping out plaque, food residues and the like is insufficient.

  In the process of roughening the hair surface, it is possible to roughen the surface of the tapered hair, but the effect of scraping plaque, food residue, etc. is low. In addition, toothbrushes with side edges processed on tapered bristles are also known, but the direction of the edges is formed in the direction of extension of the hair, and the surface is smooth so that it can catch plaque, food residues, etc. There is little effect to scrape. Furthermore, toothbrushes that have the same function as conventional toothbrushes by securing one end without tapering both ends of the bristles while ensuring the effect of interdental penetration are also known. The effect of scraping food residues and the like still does not reach a sufficient level.

  This invention is made | formed in view of the said situation, Comprising: It aims at providing the toothbrush which was excellent in the penetration property to a narrow clearance gap, and excellent in wiping property.

  In order to achieve the above object, according to the present invention, there is provided a toothbrush in which a bunch of bundling bristles is planted on a flocked surface, wherein the bristles have a core portion and at least one surrounding the core portion. The core portion and the sheath portion are formed of materials having different molecular weights or chemical structures from the surface of the sheath portion of the outermost layer toward the core portion. A toothbrush is provided in which a large number of recesses formed in this manner are formed. The concave portion referred to here includes all the concave portions that form irregularities, rough surfaces, and the like in which the diameter of the hair is continuously and intermittently increased and decreased, and are formed by mechanical processing or chemical treatment (dissolution treatment) The method for forming the recesses is not limited. Moreover, the recessed part formed by the mechanical uneven | corrugated process which a part of diameter of a hair increases by the elastic deformation by partial compression is also contained.

  The minimum cross-sectional area of the bristle at a position where the concave portion is formed in a cross section perpendicular to the extending direction of the bristle is 40% or more of the maximum cross-sectional area at a position where the concave portion of the bristle is not formed. It may be 95% or less. The position where the recess is formed here is, for example, an arbitrary formation position between one end and the other end of the recess 24 in the hair 21 shown in FIG. 4, and the minimum cross-sectional area at this position is the recess The cross-sectional area S1 in the position where the bottom face of 24 becomes the deepest is shown. The position where the concave portion of the hair is not formed is an arbitrary position between the concave portion 24 and the adjacent concave portion 24, and the maximum cross-sectional area at this position is the position where the diameter of the hair 21 is maximized. Shows the cross-sectional area S2.

  At least one end side of the bristles forms a tapered portion whose thickness is gradually reduced toward the tip, and the concave portion formed in the tapered portion is shallower than the concave portion formed other than the tapered portion. It only has to be done. The shape of the cross section perpendicular to the direction of extension of the hair may be indefinite or polygonal.

  According to the toothbrush of the present invention, by forming a tapered portion while forming a large number of concave portions on the bristles, it is possible to simultaneously improve the cleaning ability by the concave portions and improve the penetration between the teeth by the tapered portion. It became possible. And by making the hairs into a multi-core structure like a core part and a sheath part, the core part and the sheath part are made of materials having different molecular weights or chemical structures even if the taper part has a recess. Thus, it is possible to prevent the durability of the hair from being lowered.

Hereinafter, embodiments of the toothbrush of the present invention will be described with reference to the drawings. FIG. 1 is an external perspective view showing a toothbrush. A head portion 11 having a flocked surface 12 and a handle portion 13 extending from the rear end of the head portion 11 are provided. The handle portion 13 is a portion that grips the toothbrush 10, and may be formed in an optimal shape for a brushing operation using the toothbrush 10. The head part 11 and the handle part 13 may be formed by integral molding with, for example, a hard resin.
The handle portion 13 may be further partially or entirely formed of a flexible resin such as an elastomer to improve gripping properties.

  For example, the material for forming the head portion 11 and the handle portion 13 is preferably a thermoplastic resin having a flexural modulus of 500 to 3000 MPa (conforming to JIS K7203), polyolefin (polypropylene, polyethylene, etc.), polyester (polyethylene terephthalate, poly Trimethylene terephthalate, polybutylene terephthalate, etc.), polycarbonate (including blend with polyester), polyarylate (including blend with polyester), polyoxymethylene resin, AS resin, ABS resin, cellulose propionate, polyamide (nylon) ), Materials such as polyurethane and PMMA resin can be used, but polypropylene is preferred from the viewpoint of price and workability.

  Moreover, when importance is attached to transparency, for example, PCTA resin which is a kind of polyester of Eastman Corporation in the United States is preferable from the viewpoint of cost and dentifrice resistance. In addition, these handles, thermoplastic elastomers (olefins, styrenes, polyesters, urethanes, nylons, etc.), silicone resins, etc. can be combined to make the handle part 13 or the head part 11 a multicolor molded handle. preferable.

  A plurality of hair bundles 15 in which hairs are bundled are planted on the hair planting surface 12 of the head portion 11. In order to plant the hair bundle 15 on the flocked surface 12, it can be fixed to the head portion 11 by a conventional method. Flat wire flocking for flocking and flocking, in-mold flocking in which one end of the hair bundle is bonded by means of heat or the like, and the head portion resin is filled and fixed in a state where the bonded portion is in the mold (for example, JP-A-61 -268208, JP-A-9-512724, etc.), heat fusion flocking (for example, see JP-A-60-241404) or the like in which one end of the hair bundle and the head portion are melt-bonded by means of heat or the like. Can do.

  The angle of the hair bundle or hair to be planted does not necessarily have to be perpendicular to the planting surface 12 of the head portion 11. For example, the hair bundle 15 is implanted for the purpose of enhancing the scraping effect in a specific direction. In some cases, the hair is inclined at an angle of about 15 ° to 20 ° with respect to the flocked surface 12 of the head portion 11. About the hair cutting shape of the flocked portion, generally, it may be appropriately selected such as flat cutting with a uniform plane, mountain cutting with a top, step cutting with a plurality of flat heights, etc. Various shapes can be combined by using a cutting process, a hair-separation device, or the like. Usually, each hair end portion is rounded. Moreover, it may not go through a hair-cutting process with highly tapered hair, and in that case, it is not necessary to perform the hair rounding process.

  The shape of the flocked hole on the flocked surface 12 of the toothbrush 10 may be a normal circle, a square hole, a substantially elliptical shape, a substantially oval shape, a substantially rectangular shape, or the like having different major and minor diameters. In addition, the flock holes are usually arranged in a lattice shape or a staggered pattern, but a combination of flock hole shapes or a combination of arrangements can be appropriately selected according to the intended function. Further, the head portion 11 of the toothbrush 10 is not limited in any way in shape and size. The thickness of the head portion 11 is generally about 2 mm to 6 mm as the minimum thickness, although a slight difference is seen depending on the method of flocking using a flat wire or the method of flocking not using a flat wire.

  FIG. 2 is an enlarged cross-sectional view showing the hairs constituting the hair bundle. FIG. 3 is an enlarged perspective view of the hair. The hair 21 constituting the hair bundle 15 has a multi-core structure including a core portion 22 and a sheath portion 23 surrounding the core portion 22. And it has many recessed parts 24 provided in the direction of the core part 22 from the surface of the sheath part 23. FIG. Further, the bristles 21 are formed with a tapered portion 25 whose thickness is gradually reduced toward the tip.

  For the multi-core structure hair 21 composed of the core portion 22 and the sheath portion 23, a method for producing a normal co-extrusion hair or the like is used, and the concave portion 24 is, for example, before and after the normal stretching step, annealing step, etc. This can be realized by passing the hair 21 through a roller having irregularities on the surface, vertically or horizontally, or a combination thereof, and forming the recess 24 on the surface of the hair 21.

  The means for forming the recess 24 is not particularly limited, and the recess formed in the hair 21 may be provided on both sides, one side, or the entire circumference of the hair 21. In particular, it is preferably applied to the entire hair 21, but may be appropriately selected depending on the size of the recess 24, the cross-sectional shape of the hair, the diameter of the hair, the material of the hair, and the like. For this reason, the formation pitch, shape, size, etc. of the recesses 24 may be set freely.

  For example, as the protrusion shape provided on the roller for forming the recess 24 in the hair 21, a hemispherical shape, a substantially polygonal shape (rectangle, triangle), a substantially oval shape, and the like are conceivable. Specifically, the hemispherical shape may be a radius of 40 to 60 μm and the formation pitch of the recesses 24 is 0.7 to 0.8 mm. As shown in FIG. 7, the formation pitch of the recesses here means that the recesses 24 formed in the hair 21 have, for example, a circular cross section or a triangular cross section, and when the bottom surfaces of the recesses are inclined, the deepest portions of the recesses 24 are formed. In the case where the bottom surface of the concave portion is a plane such as the interval P or the rectangular cross section, it may be defined as the interval P between the centers of the concave portions.

  In addition to attaching the concave portion 24 to the surface after spinning the hairs 21, it is also possible to put an inorganic substance in a master batch in advance and dissolve the surface precipitate of the spun using this to give random concave portions to the surface shape. is there.

  In the hair 21 formed by coextrusion, at least the molecular weight of the material constituting the sheath portion 23 constituting the outermost layer is smaller than the molecular weight of the material constituting the core portion 22, or the sheath portion 23 and the core portion 22 are Materials with different chemical structures may be used. Thereby, even if the recessed part 24 is formed in the bristles 21, it becomes possible to suppress the change of physical functions, such as durability and bending elasticity, by a strong core part.

  The sheath part 23 and the core part 22 can further exhibit the cleaning ability when the tapered part 25 is formed on the bristles 21 by using materials having different molecular weights (polymerization degrees) and chemical structures. That is, when the taper portion 25 is formed at the tip portion while forming a large number of the recess portions 24 in the hair 21, the recess portion 24 can be obtained by using a material having a higher molecular weight and superior strength than the sheath portion 23 for the core portion 22. In addition, it is possible to improve the brushing ability by the concave portion 24 and improve the penetration between the teeth by the tapered portion 25 while preventing the durability of the hair 21 from being lowered due to the formation of the tapered portion 25.

  The thickness of at least one layer of the sheath portion 23 other than the core portion constituting the hair 21 is preferably 5 μm or more. Those having a thickness of less than 5 μm are difficult to spin uniformly.

  As shown in FIG. 4, the minimum cross-sectional area S1 of the bristle 21 at the position where the concave portion 24 is formed in the cross section F perpendicular to the extending direction of the bristle 21 is such that the concave portion 24 is formed in the bristle 21. It is preferably 40% or more and 95% or less of the maximum cross-sectional area S2 at the position where it is not. When the minimum cross-sectional area S1 is less than 40%, the mechanical strength of the portion where the recess 24 is formed is significantly lowered, and the original strength as a hair cannot be exhibited, and the bending strength is significantly lowered. On the other hand, if the minimum cross-sectional area S1 exceeds 95%, a scraping effect such as plaque due to the concave portion 24 cannot be expected. In addition, the calculation method of the cross-sectional area of the recessed part 24 in the taper part 25 of the hair 21 uses the line obtained by connecting the outermost part of the recessed part 24 formed in the taper part 25 of the hair 21 as a substitute for the hair. What is necessary is just to calculate an area.

  The bristles 21 having concave portions 24 on the surface are completed by forming tapered portions 25 at one end and both ends by acid or alkali chemical treatment, and then washing with water to complete the bristles having a smooth surface. In addition, after the hair 21 manufactured in advance is implanted on the flocked surface 12 of the toothbrush, the tip of the hair 21 can be tapered by mechanical polishing to form the tapered portion 25 and completed.

  The recess 24 applied to the surface of the hair 21 is preferably substantially perpendicular to the extending direction L of the hair 21. This is because the part where the plaque adheres, which is said to be a site of frequent occurrence of oral diseases, is often in the gaps between the teeth, and the conventional hair has a smooth surface structure and the ability to scrape off the plaque is weak. In addition, when the tapered part is formed at the tip of the hair, the penetration between the teeth is improved, but the bending strength is lowered, so the insertion feeling into the interdental part is insufficient, and there is not enough strength to scrape the plaque. This is because of the remaining issues.

  Moreover, the depth of the recessed part 24 given to the taper part 25 of the hair 21 should just be formed so that a depth may become shallower than the recessed part 24 formed except the taper part 25. FIG. Thereby, even if the recessed part 24 is formed in the taper part 25, the elasticity and intensity | strength of the taper part 25 are maintained appropriately, and the penetration property between teeth is maintained.

  Examples of the material of the hair 21 include polyesters such as polyethylene terephthalate, polybutylene terephthalate and polytrimethylene terephthalate, polyamides such as nylon 6, nylon 66, nylon 6-10, nylon 6-12 and nylon 12, polyethylene, polypropylene and the like. Materials that can be melt-spun, such as polyolefin, thermoplastic elastomer, and polyvinyl halide such as polyvinylidene fluoride, are not particularly limited. However, because of the multi-core structure, materials that are highly compatible with each other are used. Is preferred. Specifically, hair containing polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), which are polyester resins, and materials having different molecular weights and polymerization degrees as main components is preferable.

  When the material is changed between the core portion 22 and the sheath portion 23 of the multi-core structure hair 21, there is a concern that a problem such as peeling may occur between the core portion 22 and the sheath portion 23. It is possible to improve the affinity between the resins and reduce the peeling of the hairs 21 by mixing the resin constituting the sheath portion 23 with the resin. In addition, it is also possible to add a component with good affinity.

  The purpose of the bristles 21 having a multi-core structure is to suppress deterioration of physical properties such as durability and bending strength of the bristles 21 that are lowered by forming the recesses 24 in the bristles 21. In addition, since the concave portion 24 remains on the surface of the tapered portion 25 even after the tapered portion 25 is formed, it becomes possible to scrape the plaque efficiently without the hair 21 that has entered the gap such as the interdental portion being sagged, The durability of the hair 21 can be secured. Conventionally, when manufacturing hair, it is possible to form a recess along the direction of extension of the hair by changing the shape of the spinning nozzle. However, although it has been difficult to form a recess provided toward the core portion that is substantially perpendicular to the direction of extension of the hair, in the present invention, the hair is sandwiched by a roller having an uneven surface. By allowing it to pass through, it is possible to form the recess 24 provided from the surface of the hair 21 toward the core 22.

  The thickness of the hair 21 is 3 to 10 mil (0.076 to 0.254 mm), preferably 5 to 8 mil (0.125 to 0.203 mm). Usability, brushing feeling, It is also preferable to use a combination of these in consideration of the cleaning effect and durability. In particular, the specifications with a large number of holes make the strength of the brush stiffer or change toward the center from the outer hair bundle (thickness, material, length, color, cross-sectional shape). preferable.

  About the edge part of the hair 21, by setting the hair cutting (or profile) shape and hair length of a free end arbitrarily, it is set as a single plane shape, a mountain shape, an uneven shape, etc. Furthermore, different configurations may be employed for the outer side and the inner side, the front end portion, and the rear end portion.

  The coloring of the hair 21 may be used as it is transparent (natural), and transparent coloring hair with pigments or dyes, or opaque coloring (including white) hair, etc. in consideration of the appearance of the toothbrush appearance. It is selected appropriately. If necessary, two or more of them may be used in combination in the hair bundle unit or hair bundle.

  As a coloring method, as generally used, the resin itself at the time of spinning the hair 21 can be colored, or it can be colored from the surface after spinning or accompanying the spinning process. Moreover, you may color only the front-end | tip part of the hair, or all the hair after the cut piece state (bundle of the hair length of about 25-35 mm) of hair bundle before planting to a toothbrush, or after planting. Furthermore, as long as the properties of the hair are not impaired, heat and light stabilizers, flame retardants, fillers, surface lubricants, antistatic agents, antibacterial materials (antibacterial materials), and other hard resins Or an elastomer may be appropriately blended or applied.

  FIG. 5 shows some examples of hair formation in the toothbrush and hair bundle of the present invention. The item of the bristle cross-sectional area (the bristle concave portion) is the minimum cross-sectional area S1 of the portion where the concave portion 24 is formed with respect to the maximum cross-sectional area S2 of the portion where the concave portion 24 of the bristle 21 shown in FIG. 4 is not formed. The ratio is shown.

  The applicant has verified the effect of the toothbrush of the present invention. In the verification, the toothbrushes of Invention Examples 1 to 6 shown in FIG. 6 and the toothbrushes of conventional Comparative Examples 1 to 3 were prepared. The material was PP resin, and a hair bundle was planted on a toothbrush handle provided with 23 1.6 mm diameter planting holes, and used for the experiment. A model brushing force test was carried out using the toothbrushes of the present invention example and the comparative example. The test method was to apply red paint as model plaque to the interdental part and the occlusal surface of the right buccal first and second molars of an adult maxillary model manufactured by Nissin, with the toothbrush perpendicular to the teeth. After pressing with a load of 200 g and brushing 20 times with a stroke of 20 mm, each plaque removal rate was measured.

The plaque removal rate is measured by image analysis of the model plaque occupancy area of the interproximal part of the first molar, the buccal side of the second molar, and the concave part of the first molar occlusal surface before the brushing force test Then, the plaque occupation area of the same part was measured again after the cleaning power test, and the difference was divided by the plaque occupation area before the test, multiplied by 100, and displayed as a percentage.
Dental plaque removal rate (%) = ((plaque occupation area before cleaning ability test−plaque occupation area after cleaning ability test) / plaque occupation area before cleaning examination) × 100

  Table 1 shows the results of the brushing force test using the toothbrushes of Examples 1 to 3 of the present invention and the toothbrushes of Comparative Examples 1 to 3 of the related art. The sensory evaluation items were carried out by a specialized panelist (n = 20 persons) on the touching feeling on the gums and the feeling of massaging of the gums when the toothbrush was brushed.

  According to the results shown in Table 1, the toothbrushes of the present invention were all evaluated as “good” in the sensory evaluation. On the other hand, the conventional toothbrush of the comparative example was only evaluated as “not good” or “not good” in the sensory evaluation. The effect of the toothbrush of this invention was confirmed.

FIG. 1 is a side plan view showing an embodiment of the toothbrush of the present invention. FIG. 2 is a partial cross-sectional view showing the bristles of the toothbrush of the present invention. FIG. 3 is an enlarged perspective view showing the bristles of the toothbrush of the present invention. FIG. 4 is a cross-sectional view showing one cross section of the bristles of the toothbrush of the present invention. FIG. 5 is an explanatory view showing an embodiment of the toothbrush of the present invention. FIG. 6 is an explanatory view showing a verification sample of the toothbrush of the present invention. FIG. 7 is an explanatory diagram showing the pitch of the recesses.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Toothbrush, 11 ... Head part, 12 ... Flocked surface, 15 ... Hair bundle, 21 ... Hair, 22 ... Core part, 23 ... Sheath part, 24 ... Recessed part, 25 ... Taper part

Claims (4)

A toothbrush in which a bunch of bristles is planted on the flocked surface,
The hair has a multi-core structure having a core and at least one or more sheaths surrounding the core, and the core and the sheath are formed of materials having different molecular weights or chemical structures. A toothbrush comprising a plurality of concave portions provided from the surface of the sheath portion of the outermost layer toward the core portion.   The minimum cross-sectional area of the bristle at a position where the concave portion is formed in a cross section perpendicular to the extending direction of the bristle is 40% or more of the maximum cross-sectional area at a position where the concave portion of the bristle is not formed. The toothbrush according to claim 1, wherein the toothbrush is 95% or less.   At least one end side of the bristles forms a tapered portion whose thickness is gradually reduced toward the tip, and the concave portion formed in the tapered portion is shallower than the concave portion formed other than the tapered portion. The toothbrush according to claim 1 or 2, wherein the toothbrush is made.   The toothbrush according to any one of claims 1 to 3, wherein a shape of a cross section perpendicular to the extending direction of the bristle is an indefinite shape or a polygon.

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