toothbrush

Abstract

We aim to provide a toothbrush that offers a good user experience, is easy to clean, and can reach even the back teeth effectively. [Solution] Multiple hair bundles 4, each consisting of multiple tapered hairs 40, are implanted in multiple hair implantation holes 20 formed in the hair implantation base 21 of the head part 2. The thickness of the hair implantation base 21 is 2.0 to 4.0 mm, the number of hair implantation holes 20 in which the hair bundles 4 are implanted is n, and the hair implantation area of ​​the hair implantation base 21 is S cm 2 When the value of n / S is 20 to 35, the opening area of ​​the hair follicle hole 20 in which the hair bundle 4 is implanted is s1 (mm²). 2 ), a toothbrush 1 was constructed such that when the buckling load per bundle of bristles 4 is p(N), s1×p is between 0.4 and 2.5.

Description

[Technical Field]

[0001] The present invention relates to a toothbrush in which a bundle of bristles consisting of multiple tapered bristles is implanted in the head portion. [Background technology]

[0002] To achieve satisfaction from daily brushing, it is important that the toothbrush not only has a high cleaning effect but also a good feel to use. Conventionally, toothbrushes have been proposed that have bristle bundles made of tapered bristles, such as those chemically or mechanically tapered (see, for example, Patent Documents 1-3), or toothbrushes with wide heads that provide a pressure-reducing effect on local areas, in order to improve the feel on the cervical area of ​​the teeth.

[0003] However, current toothbrushes with tapered bristles tend to have poor cleaning performance if they prioritize comfort. Furthermore, toothbrushes with wide heads have difficulty reaching the back teeth. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2017-118939 [Patent Document 2] Japanese Patent Application Publication No. 10-57149 [Patent Document 3] Patent No. 5090164 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] Therefore, in view of the above circumstances, the present invention aims to provide a toothbrush that offers good usability and cleaning performance, as well as good access to the back teeth. [Means for solving the problem]

[0006] This invention encompasses the following inventions. (1) A toothbrush in which a bundle of bristles consisting of multiple tapered bristles is planted in a plurality of bristle implantation holes formed in the bristle implantation base of the head, wherein the thickness of the bristle implantation base is 2.0 to 4.0 mm, the number of bristle implantation holes in which the bundle of bristles is planted is n, and the bristle implantation area of ​​the bristle implantation base is S cm 2 When the value of n / S is 20 to 35, the opening area of ​​the hair follicle where the hair bundle is implanted is s1 (mm²). 2 A toothbrush in which, when the buckling load per bundle of bristles is p (Newtons (N)), s1 × p is 0.4 to 2.5.

[0007] (2) The opening area (s1) of the hair implantation hole is 2.2 mm 2 The toothbrush described in (1) below.

[0008] (3) The toothbrush according to (1) or (2), wherein the length of the tapered bristles is 12.0 mm or less. [Effects of the Invention]

[0009] According to the present invention as described above, it is possible to provide a toothbrush that has good reach to the back teeth and excellent usability and cleaning properties. [Brief explanation of the drawing]

[0010] [Figure 1] A side view of a toothbrush according to a typical embodiment of the present invention. [Figure 2] Similarly, a cross-sectional view of a toothbrush. [Figure 3] This is another explanatory diagram showing the essential parts of a toothbrush. [Figure 4] (a) and (b) are explanatory diagrams showing the method for measuring the single-bundle load (N) of the samples used in the example. [Figure 5] (a) and (b) are explanatory diagrams showing the testing method for user experience. [Figure 6] An explanatory diagram showing how the bristles are inserted between the silicone sheet and the top surface of the jig. [Figure 7] An example of a sample photograph taken with a high-speed camera during a user experience test. [Figure 8]An example of a photograph of the maxillary first molar taken in the cleaning test.

Embodiments for Carrying Out the Invention

[0011] Next, embodiments of the present invention will be described in detail based on the accompanying drawings.

[0012] As shown in FIGS. 1 to 3, the toothbrush 1 of the present invention includes a thin head portion 2 in which a tuft 4 composed of a plurality of tapered hairs 40 with a thin tip is implanted in a plurality of hair implantation holes 20 formed in a substantially flat hair implantation base 21, a handle portion 12 on the proximal end side serving as a handle, and a neck portion 11 having a relatively small and narrow left - right width that connects the head portion 2 and the handle portion 12. However, the present invention is not limited to such a manual toothbrush. Of course, an electric toothbrush in which a toothbrush cleaning body composed of a head portion and a neck portion is connected to the distal end side of a main body portion as a gripping portion having a built - in drive mechanism is also acceptable, and of course, other forms are also acceptable.

[0013] The head portion 2 is preferably integrally formed of a hard synthetic resin such as polypropylene resin, polyethylene resin, polyethylene terephthalate resin, polyacetal resin, polybutylene terephthalate resin, polyamide resin, etc. together with the neck portion 11 and the handle portion 12. In addition to being integrally formed of the same resin, the handle portion 12 and the neck portion 11 may also be formed by two - color molding of a coating portion with a second synthetic resin or an elastomer.

[0014] The thickness T1 of the hair implantation base plate 21 is 2.0 to 4.0 mm, more preferably 2.0 to 3.4 mm or less, and is made thin. By making it thin, it becomes easy for the head portion to reach the depths of narrow gaps (rear teeth) in the oral cavity. If it is thinner than 2.0 mm, it becomes difficult to maintain the strength.

[0015] The hair implantation area S of the hair implantation base 21 is preferably 0.8 to 1.15 cm 2 and more preferably is 1.0 to 1.15 cm 2 If the hair implantation area S is 0.8 cm 2Smaller brush heads tend to have less contact with the teeth, resulting in reduced cleaning effectiveness. (1.15cm) 2 Larger teeth tend to be less likely to be inserted into the narrow spaces of the back teeth.

[0016] In this invention, the hair implantation area is measured by the method described in JIS S 3016 and refers to the area of ​​the region where the outer edges of the hair implantation holes are connected by straight lines. Specifically, in the example in Figure 3, it refers to the area enclosed by the dashed line (area S of the hatched region).

[0017] The number of bristle implantation holes 20 (n), i.e., the number of bristle bundles 4, is preferably 23 to 32. If there are fewer than 23, the opening area of ​​the bristle implantation holes tends to increase when the bristle implantation area S is within the range of 0.8 to 1.15 cm2 as described above, resulting in thicker bristle bundles, excessively high load-bearing capacity per bundle, and a decrease in usability. If there are more than 32, conversely, within the same bristle implantation area S range, the load-bearing capacity per bundle decreases, and cleaning efficiency decreases.

[0018] The opening diameter (d) of the bristle implantation hole 20 into which the bristle bundles 4, consisting of tapered bristles, are implanted is preferably 0.7 to 2.2 mm. If it is smaller than 0.7 mm, the ease of cleaning decreases. If it is larger than 2.2 mm, the load capacity per bundle increases and the usability decreases. It is more preferably set to 0.9 to 2.2 mm. The depth and arrangement of the bristle implantation hole 20 can be widely known and are not particularly limited. The opening shape of the bristle implantation hole 20 may be square or other shapes other than circular. If it is not circular, the opening diameter mentioned above is the opening diameter of a circular hole that is assumed to have the same area as the opening area.

[0019] The hair length (h) of each tapered hair 40 constituting the hair bundle 4 is preferably 12.0 mm or less. The tapered hair 40 constituting the hair bundle 4 can be formed by immersing the tip of the brush hair in a chemical solution containing an alkaline agent (for example, formed by the method described in Patent Document 1 above), or formed by mechanical polishing (for example, formed by the methods described in Patent Documents 2 and 3 above), etc. There are various possibilities, and the degree of taper is not particularly limited, and it may be one with a branched tip, etc. The degree of taper is defined by the diameter ratio of the filaments, and it is preferable that the ratio of the root diameter of the hair at a point 0.1 mm from the tip of the hair is 70% or less.

[0020] Also, the tapered hair 40 may be implanted by driving it into the hair implantation hole 20 together with a flat wire, or may be erected in the hair implantation hole 20 by a fusion method or an in-mold method without using a flat wire. The material of the tapered hair 40 (filament) is not particularly limited, and it may be an artificial hair made of a resin material such as polyamide, polyester, or polyolefin, or a natural hair such as pig hair. Known forms can be widely adopted for the cross-sectional shape and size of each tapered hair 40.

[0021] When the opening area of the hair implantation hole 20 is s1 (mm 2 ), and the buckling load per bundle of the hair bundle is p (N), it is set so that s1 × p is within the range of 0.4 to 2.5. If it is smaller than 0.4, the elasticity decreases and the cleaning property deteriorates. If it is larger than 2.5, each tapered hair 40 becomes difficult to bend, the hair does not enter the gingival groove, and the usability deteriorates. The lower limit is more preferably 0.7 or more. The upper limit is more preferably 2.0 or less.

[0022] Also, when the number of hair implantation holes 20 where the hair bundle 4 is implanted is n, and the hair implantation area of the hair implantation table is S cm 2 , the value of n / S is set to be within the range of 20 to 35. If it is smaller than 20, the adhesion to the tooth surface decreases and the cleaning property deteriorates. If it is larger than 35, there is a risk of the occurrence of table cracking due to excessive hair density.

[0023] When the above conditions are met, such as s1×p being between 0.4 and 2.5 and the n / S value being between 20 and 35, the toothbrush will have a good feel (comfort against the gum line) and high cleaning performance (low plaque retention rate).

[0024] Although embodiments of the present invention have been described above, the present invention is not limited in any way to these embodiments, and can be implemented in various forms without departing from the spirit of the invention. [Examples]

[0025] The following describes the results of tests conducted on usability and cleanability for samples from Examples 1 to 8 and Comparative Examples 1 to 6 according to the present invention.

[0026] (sample) In each sample, the same tapered hairs were implanted in all graft holes (diameter ratio of 70% or less). The graft arrangement was adjusted for each sample according to the hole diameter, number of holes, and graft area, within a range of 6 to 10 rows vertically and 3 to 5 rows horizontally, according to the hole pitch shown in the table.

[0027] Thickness T1 (mm) of the bristle base, diameter of the tapered bristles (diameter of the part closer to the root than the tapered section) (mm), length h (mm) of the bristle length after implantation, diameter d (mm) of the implantation hole, and area s1 (mm) of the hole. 2 ), hair implantation area S (cm 2 The number of holes (n) and the hole pitch (mm) between rows were as shown in Table 1. The single-bundle load (N) of each sample was measured by removing all but one bundle of tapered bristles from the bristle bundles, as shown in Figure 4, and applying a load at a speed of 100 mm / min. The value was measured using a digital force gauge (manufactured by Aiko Engineering Co., Ltd.) when the bristles buckled (buckling occurred at the root end of the tapered portion).

[0028] [Table 1]

[0029] (Testing method for user experience) As shown in Figures 5(a) and (b), a jig simulating a tooth surface with continuous grooves on its upper surface was placed horizontally on a base. A 1.5 mm thick silicone sheet simulating gum tissue, with the grooves running in the direction of the grooves, was placed on a portion of its upper surface. In the area adjacent to the silicone sheet on the upper surface, each sample toothbrush was positioned horizontally with the bristles pointing straight down and the longitudinal direction aligned with the grooves, so that the bristles were in contact with the edge of the silicone sheet.

[0030] Then, with the toothbrush pressed directly downwards so that a load of 250g was applied to the upper surface of the jig through the bristle bundle, it was slid at a constant speed in the longitudinal direction, and the process of whether or not the tips of the toothbrush bristles were inserted into the portion that can be considered as the gingival sulcus at the cervical area between the silicone sheet and the upper surface of the jig (the raised surface) was observed using a high-speed camera (manufactured by Shinano Kenshi Co., Ltd., using a monochrome lens) as shown in Figure 6. If the tips of the bristles were inserted between the silicone sheet and the upper surface of the jig (assuming the gingival sulcus), it was evaluated as having a good feel ("○"), and if they were not inserted, it was evaluated as having a poor feel ("×").

[0031] Figure 7 shows examples captured with a high-speed camera; (a) is a photograph of a sample with the bristles inserted, and (b) is a photograph of a sample without the bristles inserted. The results of the usability tests for each sample are shown in Table 2.

[0032] [Table 2]

[0033] (Test method for cleanability) Pink colored powder from Occlude (Pascal, USA) was applied to a forehead model, and each sample was brushed with a toothbrush using a force of 100g for one stroke (one back-and-forth motion). After brushing, the maxillary first molar was photographed, and the residual adhesion rate (%) was measured. This was defined as the plaque retention rate (%), and if it was less than 12.5%, it was evaluated as good cleanability ("○"), and if it was 12.5% ​​or more, it was evaluated as poor cleanability ("×"). The residual adhesion rate (%) was calculated by binarizing the image of the maxillary first molar using color analysis with Photoshop®. Figure 8 shows an example of a photographed maxillary first molar. The cleanability test results for each sample are shown in Table 3.

[0034] [Table 3]

[0035] From the results in Tables 2 and 3, it can be seen that each of the samples in Examples 1 to 8, which satisfy the conditions of n / S being 20 to 35 and s1 × p being 0.4 to 2.5, is thin and has good reach to the molars, as well as excellent usability and ease of cleaning. [Explanation of Symbols]

[0036] 1. Toothbrush 2 Head section 4 strands of hair 11 Neck section 12 Handle section 20 hair transplant holes 21 Hair implantation stand 40 Tapered Hair S Hair transplant area T1 Thickness d Hole diameter h hair length n Number of holes s1 hole area

Claims

1. A toothbrush in which multiple bristle bundles consisting of tapered bristles are planted in multiple bristle implantation holes formed in the bristle base of the head, The thickness of the aforementioned hair implantation stand is 2.0 to 4.0 mm. n is the number of hair implantation holes in which the hair bundles are implanted, and S is the hair implantation area of ​​the hair implantation base (cm²). ２ When this is the case, the value of n / S is between 20 and 35. The opening area of ​​the hair implantation hole into which the hair bundle is implanted is s1 (mm²). ２ ), when the buckling load per bundle of hair is p (N), s1 × p is 0.4 to 2.

5. toothbrush.

2. The opening area (s1) of the hair implantation hole is 2.2 mm ２ The toothbrush according to claim 1, which is as follows:

3. The toothbrush according to claim 1 or 2, wherein the length of the tapered bristles is 12.0 mm or less.

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