JP2006174905A - Toothbrush - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-quality toothbrush, with excellent distinctiveness of the outside appearance and dental plaque removing capability, without deficient forming caused by the parallel welding at the time of forming a handle or without decline of the strength of a head part. <P>SOLUTION: In the toothbrush, tufts of several bound bristles are double-folded by a flat line and planted at tuft holes 3 on a planting face 2 of the head part 1. All the tuft holes 3 consist of tuft holes with short or long axes. The cross-section area of each tuft hole is not more than 1.2 mm<SP>2</SP>, and the number of tuft holes per unit planting area is from 25 to 80. The number of tuft holes whose angle between the longitudinal direction of the tuft hole and the longitudinal direction X of the handle of the toothbrush is at least 0° and less than 90° is at least 10% of the total number of tuft holes. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a toothbrush for intraoral cleaning.

In conventional toothbrushes, a brush is driven into two folds using a flat wire in a flocked hole having a cross-sectional area of 2.0 mm ² or more, and from 16 to 60 brushes per flocked hole, and from 32 to 120 brushes folded. The thick hair bundle comprised is fixed to the flocked surface.

  When the hair bundle is thick, the lumbar strength is improved, which contributes to the improvement of plaque removal power on the smooth tooth surface. In addition, since the number of flocking holes per hole is large, the number of flocking holes is reduced, and the number of shots of flat line flocking is reduced, leading to improvement in production efficiency.

  Such a thick bristle toothbrush has improved cleaning power on the smooth surface of the tooth, while each bristle bundle constituting the toothbrush has high rigidity and is difficult to bend. The supple movement cannot be demonstrated, and the hair tip is difficult to reach a small part such as an interdental part or an interdental triangle that is considered to be an oral disease prone part. In addition, the hair bundle tends to become stiff, and the irritation to the gingiva and oral mucosa is great.

  For this reason, Patent Document 1 (Japanese Patent Publication No. 11-500946), Patent Document 2 (Japanese Patent Publication No. 2001-513344), Patent Document 3 Japanese Patent Laid-Open No. 2003-9948) has been proposed. However, although the flexibility of the hair bundle is increased, the rigidity is too low and the plaque scraping ability of each brush is lowered.

  Therefore, in order to enhance the plaque removal effect while maintaining the flexibility of the hair bundle, Patent Document 4 (Japanese Patent Laid-Open No. 14-345556), Patent Document 5 (Japanese Patent Laid-Open No. 6-261809), Patent Document 6 (Special The shape of the flocked hole is a shape having a major axis and a minor axis such as an oval, an ellipse, a rectangle, etc. The one arranged so as to be perpendicular to (direction) has been proposed. By reducing the number of brushes in the short axis direction, the hair bundle becomes thinner, and it has a supple feel for the brush and can maintain the rigidity of the hair bundle, so that it can secure plaque removal power. there were.

Japanese National Patent Publication No. 11-500906 (full text, all figures) Special table 2001-513344 gazette (the whole sentence, all figure) JP 2003-9948 A (the whole sentence, all figures) Japanese Patent Laid-Open No. 14-345556 (full text, full figure) JP-A-6-261809 (full text, full figure) JP-A-8-332115 (full text, full figure)

  By the way, when molding a toothbrush handle in which a flock hole having a short axis and a long axis is arranged so that the long axis direction of the flock hole is perpendicular to the long axis direction of the flocked portion, the injected molten resin is applied to the flock pins in the mold. Because of the vertical collision, the resin is less likely to run around the back of the pin and parallel welds are likely to occur.

  The generated weld is not only unfavorable in appearance, but also causes a problem that the impact strength of the head portion is reduced due to residual internal strain. In particular, in order to ensure good contact with the gingiva and high plaque removal power, when flocking holes that are smaller than conventional ones are arranged at high density, the resin flow path becomes narrow, so the occurrence of welds is significant. There was a tendency to become.

  In order to reduce the occurrence of these welds, methods of changing the position of the gate, increasing the number of gates, and using a sequential gate have been devised, but the problem is that the mold becomes complicated and expensive. was there.

  In some cases, the problem can be solved by using a resin with a high melt flow index (MI) value, increasing the resin temperature or mold temperature, slowing the injection speed, or increasing the holding pressure. However, it may be undesirable because it affects other physical properties such as a decrease in flocking strength.

  The present invention has been made to solve the above-mentioned problems, and is excellent in appearance discrimination and plaque removal ability, and has high quality without causing molding defects due to parallel welds occurring at the time of forming a handle or reducing the strength of the head portion. The object is to provide a toothbrush.

In order to achieve the above-mentioned object, the present invention provides a toothbrush in which a bunch of bunches of a plurality of brushes is folded in two into a flock hole on the head flocking surface with a flat line, and all flock holes are formed with a short axis and a long axis. It is composed of a flocking hole having an axis, the cross-sectional area of the flocking hole is 1.2 mm ² or less, the number of flocking holes per unit flocking area is 25 to 80 holes, and the long axis direction of the flocking hole and the toothbrush handle The number of flocked holes whose angle with the major axis direction is 0 degree or more and less than 90 degrees is 10% or more of all flocked holes. Here, the flocked area is based on JIS S 3016 and refers to the area inside the portion where the outside of the flocked hole formed on the head flocked surface is connected by a straight line.

In the conventional toothbrush, the cross-sectional area of the flocked hole formed on the flocked surface of the toothbrush head portion is 2.0 mm ² or more, and the bristles are formed by using a flat wire in the flocked hole having a cross-sectional area of 2.0 mm ² or more. The number of hair bundles per unit planting area is around 20 bundles. The inventors of the present invention have conducted extensive experiments and studies on the effects of differences in the cross-sectional area of flock holes and the number of hair bundles per unit flocking area on plaque removal ability and contact comfort. A toothbrush composed of a bundle of hair bundles having a hair bundle of 1.2 mm ² or less and a number of hair bundles per unit flocking area of 25 bundles or more and 80 bundles or less has good contact with teeth and gums, It was found that the interstitial property and plaque removal ability are excellent.

When the cross-sectional area of the flocked hole is larger than 1.2 mm ² , the hair bundle has high rigidity, so the flexibility is lost, and the ability to remove plaque on the smooth tooth surface is high, but the reachability to fine gaps is poor. In some cases, sufficient oral cleaning could not be performed. In addition, when the number of hair bundles to be planted in a unit hair transplantation area is more than 80, the gap between the hair bundles becomes very narrow, and not only the interdental penetration is remarkably deteriorated, but also the hair bundles move freely. Since the range is limited, it becomes difficult to clean fine brushed parts such as the tooth neck. Moreover, a big problem on hygiene also arises, such as a dentifrice remaining between hair bundles, and the drying property after use becoming extremely worse.

Moreover, even if the cross-sectional area of the flock hole is 1.2 mm ² or less, the appearance as a toothbrush becomes very poor if the number of bristles planted in the unit flocking area is less than 25 bundles. In addition, the bristle strength is weak, it becomes difficult to clean the tooth surface, and the durability as a toothbrush is lowered.

In the toothbrush of the present invention, thin bristle bundles (= flock holes) having a cross-sectional area of 1.2 mm ² or less are arranged at a preferable interval of 25 bundles to 80 bundles per unit area. It becomes easier to reach the gingiva, and the reachability of the hair tip to the site where oral disease is common is improved. Furthermore, by setting a small number of hair bundles of 25 to 80 bundles per unit area, it is possible to express a continuous and supple movement of a thin brush bundle, which is excessive in the oral mucosa such as the tooth neck and interdental papilla. It is possible to develop plaque removal and gingival massage functions without imposing a heavy load.

  On the other hand, when using a flock hole having a short axis and a long axis in a cross-sectional shape such as an oval, an oval, a rectangle, etc. as a flock hole, and arranging the long axis direction to be perpendicular to the long axis direction of the toothbrush handle, It was found that the interdental penetration was improved and the feeling of brushing was improved.

  However, when the long axis direction of the flock hole is arranged so as to be perpendicular to the long axis direction of the toothbrush handle, the molten resin injected into the mold along the long axis direction of the toothbrush handle during injection molding of the toothbrush handle When reaching the position of the flocked pin, it flows while encircling both sides of the flocked pin, and the resin flow front end portion divided into two reassociates on the rear side of the pin, so that a so-called parallel weld is called a V notch. Thin line-shaped traces are generated, leading to a decrease in strength and appearance of the head.

  Thus, when the flock holes are arranged so that the major axis direction is perpendicular to the head major axis direction, the molten resin collides perpendicularly with the large surface area of the flock pin, and the flow rate decreases, Since the wraparound distance of the resin becomes longer, the weld is likely to occur. In particular, this phenomenon becomes more remarkable in the case of multiple hair bundles in which a large number of hair transplant pins are closely arranged at narrow intervals.

  As a result of repeating various experiments and studies in order to avoid the occurrence of the weld, the present inventors have found that the angle formed by the flock hole long axis direction and the toothbrush handle long axis direction is not less than 0 degrees and less than 90 degrees, preferably If the number of flocking holes that are 20 degrees or more and less than 70 degrees is 10% or more of the total flocking holes, the flow of the molten resin can be made smooth and the decrease in the resin speed due to the collision with the flocking pins can be suppressed. It has been found that the occurrence of welds can be reduced. Furthermore, when the hair bundles are arranged in such a relationship, the hair bundles reach between the teeth and between the teeth and the gums, which cannot be entered in the conventional one-way arrangement of hair bundles. It was revealed that the effect of removing plaque can be improved. The toothbrush of this invention is comprised based on these knowledge.

  In addition, the cross-sectional shape of the flock hole is not limited to the above-described oval, oval, or rectangular shape. In addition, for example, the cross-sectional shape of the flock hole may be a rhombus, a bamboo leaf shape, a teardrop shape, or the like. Any shape having a long axis side with a large hole width and a short axis side with a small hole width when viewed as a whole.

  A toothbrush head part does not receive a restriction | limiting at all in the shape, a magnitude | size, and a design. Further, as the material of the flat wire for flocking the hair bundle, in addition to metals such as brass and stainless steel, hard plastics such as biodegradable plastics can be used. In order to reliably fix the flock hole and the hair bundle and reduce the gap, it is possible to adjust the thickness of the flat wire. There is no restriction | limiting in particular in the width and height of the flat line to be used, and it can set arbitrarily according to toothbrush specification.

  As handle materials, polystyrene resin (PS), polypropylene resin (PP), polyethylene terephthalate resin (PET), acrylonitrile butadiene styrene resin (ABS), cellulose propionate resin (CP), polyarylate resin, polycarbonate resin (PC) Saturated polyester resins (PCTA, PCTG), acrylonitrile styrene resin (AS), polyacetal resin (POM), polybutylene terephthalate (PBT) and the like can be used alone or in combination. A multicolor molded handle combined with a thermoplastic elastomer is also preferable. The handle material is not limited to the above, and any material that can be used as a toothbrush handle can be used.

  As materials for the brushes (filaments) constituting the hair bundle, 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 are used. Materials that can be melt-spun such as polyolefins such as polyethylene and polypropylene, and polyvinyl halides such as polyvinylidene fluoride are used. Further, a filament using two or more kinds of raw materials such as a synthetic resin filament containing a resin other than polybutylene terephthalate and polybutylene terephthalate, a monofilament obtained by melt spinning a mixture of a polyester resin other than polypropylene terephthalate and polypropylene terephthalate, The brush can be used in accordance with the purpose, such as a brush formed by forming a multi-core sheath into different outer and inner materials, or a brush having a different surface state.

  The thickness of the brush is 3 to 10 mils (0.076 to 0.254 mm), preferably 5 to 8 mils (0.127 to 0.203 mm). Usability, cleaning feeling, cleaning effect In view of durability, it is also preferable to use these in combination. In particular, when arranging a large number of holes, make the brush strength harder, or change its thickness, material, length, color, cross-sectional shape, etc., toward the hair bundle from the center side rather than the outer hair bundle. If it changes, it will become preferable also in terms of usability and appearance discrimination.

The types of brushes are: normal round hair with rounded tips, pointed taper hair, diamond hair (Tynex (registered trademark) Brilliance Collection filaments), feather hair (Tynex FEATHERED Fillaments), other Tynex HEXAGONAL Fillaments, Tynex RECTANGULAR Fillaments, Tynex GRAINY filaments, spiral catch hair, indicator hair, and the like can be used. The types of brushes are not limited to these.

  In addition, the hairbrush shape (or profile) and brush length (hair length) of the planted brush front surface may be a single flat shape, a mountain shape, or a concavo-convex shape with steps, for example. It can be set arbitrarily according to the specifications. Further, the hair cutting shape and the brush length may be made different between the outer side and the inner side of the head portion flocking surface, the front end portion, and the rear end portion.

According to the present invention, all the flocked holes are constituted by flocked holes having a short axis and a long axis, the cross-sectional area of the flocked holes is 1.2 mm ² or less, and the number of flocked holes per unit flocked area is 25 or more, 80 Because the number of flock holes that are not more than the hole and the angle between the long axis direction of the flocked hole and the long axis direction of the toothbrush handle is not less than 0 degrees and less than 90 degrees is not less than 10% of the total flock holes. Further, it is possible to provide a high-quality toothbrush that is excellent in appearance discrimination and plaque removal ability, and that is free from molding defects due to parallel welds that occur during handle molding and a reduction in head strength.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows a first embodiment of a toothbrush according to the present invention. A hair bundle (not shown) in which a plurality of brushes are bundled is inserted into a flocking hole 3 on a flocking surface 2 of a head portion 1 by a flat line. In the toothbrush planted in a folded manner, the entire flock hole 3 is constituted by an oval flock hole having a short axis and a long axis, and the cross-sectional area of the oblong flock hole 3 is 1.1 mm ² , The number of flocking holes per unit flocking area is set to 25 holes, and 18 holes (shown surrounded by dotted lines) located on the front end side and the rear end side corresponding to 25% of the total 72 flocking holes The angle formed by the long axis direction of the flock hole and the long axis direction X of the toothbrush handle is set to be 0 degree, 30 degrees, 50 degrees, 70 degrees, and 80 degrees, respectively. In addition, in order to avoid becoming indistinct, illustration was abbreviate | omitted about the hair | bristle bundle planted in each flock hole 3. FIG.

FIG. 2 shows a second embodiment of the toothbrush according to the present invention, wherein all the flocked holes 3 are constituted by oblong flocked holes having a short axis and a long axis, and the flocked hole 3 having an oblong shape is shown. Regarding the cross-sectional area of 0.8 mm ² , the number of flocking holes per unit flocking area is set to 40 holes, and further 55 holes corresponding to 81% of the total flocking holes 68 holes (shown surrounded by a dotted line) The angle formed by the long axis direction of the flock hole and the long axis direction X of the toothbrush handle is set to be 0 degree, 30 degrees, 50 degrees, 70 degrees, and 80 degrees, respectively.

FIG. 3 shows a third embodiment of the toothbrush according to the present invention, wherein all the flock holes 3 are constituted by oval flock holes having a short axis and a long axis, and the flock holes 3 having an oval shape are shown. The cross-sectional area is 0.6 mm ² , the number of flocking holes per unit flocking area is set to 40 holes, and 24 holes corresponding to 33% of the total 72 flocking holes (shown surrounded by dotted lines) The angle between the long axis direction of the flock hole and the long axis direction X of the toothbrush handle is set to be 80 degrees.

  Next, using the toothbrush shown in FIGS. 1 to 3 (present inventions 1 to 3) and the comparative toothbrush shown in FIGS. A comparative experiment was conducted with respect to the effect of removing plaque and the feeling of hitting the gums. The results are shown in Table 1. Each evaluation in Table 1 was based on the following criteria.

(1) Weld occurrence state (based on visual judgment by the inspector)
◎: Not seen at all ○: Slightly seen △: Slightly seen ×: Very often seen

(2) Plaque removal effect ◎: Plaque removal rate 80% or more ○: Plaque removal rate 50% or more to less than 80% △: Plaque removal rate 30% or more to less than 50% ×: Plaque removal rate 30% The plaque removal rate was determined from the following equation by conducting a cleaning power test using a tooth model of the neck and pits and fissures. The plaque occupation area was calculated by image analysis.
Plaque removal rate = {1- (plaque occupation area after cleaning power test / plaque occupation area before cleaning power test)} × 100 [%]

(3) Gum contact feeling The sensory evaluation was conducted by 20 professional panelists.
A: Very good.
○: Good △: Neither can be said ×: Not good

  As is apparent from the evaluation results in Table 1, the toothbrush of the present invention was satisfactory in terms of weld occurrence, plaque removal effect, and gingival contact feeling.

It is an enlarged plan view of the toothbrush head part which shows the 1st Embodiment of this invention. It is an enlarged plan view of the toothbrush head part which shows the 2nd Embodiment of this invention. It is an enlarged plan view of the toothbrush head part which shows the 3rd Embodiment of this invention. It is an enlarged plan view of the toothbrush head part of the comparative example 1. It is an enlarged plan view of the toothbrush head part of the comparative example 2. It is an enlarged plan view of the toothbrush head part of the comparative example 3.

Explanation of symbols

1 Toothbrush head part 2 Flocked surface 3 Flocked hole X Long axis direction of toothbrush handle

Claims (1)

In a toothbrush in which a bunch of bundling multiple brushes is folded in half into a flock hole on the head flocking surface with a flat line, all flock holes are constituted by flock holes having a short axis and a long axis. The cross-sectional area of the pores is 1.2 mm ² or less, the number of flocking holes per unit flocking area is 25 or more and 80 or less, and the angle between the flock hole long axis direction and the toothbrush handle long axis direction is 0 degree or more A toothbrush characterized in that the number of flock holes that are less than 90 degrees is 10% or more of the total flock holes.

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