JP2002028028A - Toothbrush handle - Google Patents

Abstract

[57] [Abstract] [Problem] Heat resistance that has moderate elasticity and mechanical strength, has little chemical change due to fragrance in dentifrice, has excellent chemical resistance, and can withstand boiling disinfection from a sanitary point of view. To provide a toothbrush handle having high transparency and high design. SOLUTION: In a toothbrush handle including a head portion 1 on which a brush or a brush bundle is implanted, and a neck portion 2 and a grip portion 3 following the head portion, polyethylene naphthalate is used as a material of the toothbrush handle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toothbrush handle having excellent elasticity, mechanical strength, heat resistance and chemical resistance, and also having excellent transparency which is important in design.

[0002]

2. Description of the Related Art Toothbrush handles are arbitrarily selected from the group consisting of polycarbonate resin, transparent nylon resin, polyethylene terephthalate resin, polybutylene terephthalate resin and polyarylate resin.
Or a mixed resin material obtained by arbitrarily selecting a plurality of resin materials from this group (JP-A-60-2153).
No. 06), and more recently, those using a polyacetal resin (JP-A-7-143914), inexpensive and versatile polypropylene resins, polyamide resins with excellent mechanical strength, and polymers based on polycarbonate resins. Alloys have also been used.

On the other hand, polystyrene resin having excellent transparency,
Acrylonitrile styrene copolymer, cellulose resin, etc. are also used as materials for toothbrush handles,
Polystyrene resins and acrylonitrile-styrene copolymers are inferior in elasticity, chemical resistance and heat resistance, and cellulose resins are inferior in chemical resistance and heat resistance. was there. Also,
An improved PMMA (polymethyl methacrylate) has been filed as a transparent toothbrush handle (Japanese Patent Application Laid-Open No. 7-16)
No. 5988), but there was a problem in mechanical strength.

[0004]

As the toothbrush handle, the head portion can be made small and thin, and the neck portion can be made thin and long, so that it is easy to use as a toothbrush, has excellent operability in the oral cavity, and has high transparency. However, there is a demand for an excellent design, but there are limitations in terms of the strength and flexibility of the material, and no satisfactory toothbrush handle has been found in all respects. In the case of conventional toothbrush handles, the mechanical strength is limited, and if the neck is thin and long, the neck may be broken.On the contrary, even if the strength is satisfied, it can not be satisfied in terms of transparency. Did not. The polypropylene resin widely used as a toothbrush handle at present also has excellent mechanical strength, but is not satisfactory in terms of transparency, which is important in design.

The present invention has been made to solve the above-mentioned problems, and has an appropriate elasticity and mechanical strength, has little chemical change due to a fragrance in a dentifrice, has excellent chemical resistance, and has good hygiene. An object of the present invention is to provide a toothbrush handle having heat resistance enough to withstand boiling disinfection from the surface, and having high transparency and excellent design.

[0006]

The present inventor has conducted various studies to find a material that satisfies the above-mentioned conditions required as a material for a toothbrush handle, and as a result, has found that polyethylene naphthalate is most suitable. Things.

That is, the toothbrush of the present invention is characterized in that polyethylene naphthalate is used as a handle material in a toothbrush handle including a head portion on which a brush or a bundle of brushes is implanted, and a neck portion and a grip portion following the head portion. Things. Note that a multicolor molded handle may be formed by combining polyethylene naphthalate and a thermoplastic elastomer. Further, the thickness of the head part is 3 to
4.5 mm, the thickness and width of the neck portion are 3 to 7 mm, the sum of the lengths of the head portion and the neck portion is in the range of 40 to 85 mm, and the thickness of the grip portion is 5 to 15 mm and the width is 7 to 20 m.
With the range of m, the hair tips can be applied to every corner in the oral cavity, and higher operability and higher plaque removal rate can be obtained.

[0008] The polyethylene naphthalate used in the present invention is a polyester resin obtained by a polycondensation reaction of naphthalenedicarboxylic acid and ethylene glycol, is a crystalline resin having excellent transparency, and has excellent heat resistance and chemical resistance. It has the characteristics of excellent, low water absorption, and high safety. In the past, there have been examples of use in returnable bottles such as soft drinks and soy sauce, but all of them are intended for thin-walled container-like articles, and there are no examples of use for thick-walled items such as toothbrush handles. I can't.

The physical properties of polyethylene naphthalate include flexural modulus (ASTM D790) of 2.3 Gpa,
Thermal deformation deflection temperature 109 ° C, molding shrinkage 0.4% to 0.
8%, Izod strength 39 J / m, having necessary strength and physical properties as a toothbrush, excellent heat resistance and chemical resistance, and excellent moldability. Compared with polyethylene terephthalate, which has been conventionally used as a material for a toothbrush handle, the glass transition temperature Tg, the melting point Tm, the Young's modulus, and the water absorption are small.

In the case of an adult toothbrush, the total handle length is 1
70-180 mm, head part length 12-25 mm, sum of head part and neck length 50-65 mm, head part thickness 3-5 mm, head part width 8-10 mm, grip part thickness 5-8 mm, The handle width is preferably 10 to 13 mm.

In the case of a toothbrush for children, the total length of the handle is 130 to 140 mm and the length of the head is 10 to 22 m.
m, the sum of the length of the head part and the neck part is 40 to 60 mm, the thickness of the head part is 3 to 5 mm, the width of the head part is 6 to 10 mm, the thickness of the grip part is 5 to 8 mm, and the handle width is preferably 10 to 13 mm. In addition, these dimensions are only illustrations and are not limited to these.

[0012] In order to obtain a toothbrush as a final product, it is necessary to implant a brush or a bunch of brushes on the head implanted surface of the toothbrush handle. The flocking hole to be used has a hole diameter of 1.5 to
Preferably, the distance between the holes is 2.5 mm, the distance between the holes is 0.7 to 1.2 mm, and the distance between the outer peripheral edge of the head portion and the flocking hole is 0.5 to 1.0 mm. In addition to the flat wire type flocking method, an in-mold type flocking method (Japanese Patent Laid-Open No. 61-268208,
No. 12724) and a heat fusion method (Japanese Patent Application Laid-Open No. 60-241404).
No.) can be used for flocking.

[0013] As a material of the brush (hair) to be planted,
Polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polyamide resins such as nylon 6, nylon 6,6, nylon 6-10 and nylon 12, polyolefin resins such as polyethylene and polypropylene, and polyhalogens such as melt-spinnable polyvinylidene fluoride A vinyl chloride resin or the like can be used, but nylon is preferred from the viewpoints of usability, durability, cost, and the like.

The thickness of the hair is 5 mils (0.127
mm) to 14 mils (0.356 mm), more preferably 8 mils (0.20 mm) for adults.
3 mils to 11 mils (0.279 mm); for children, 6 mils (0.152 mm) to 8 mils (0.203 mm)
mm), more excellent usability and durability can be obtained.

If the total ratio of the cross-sectional area of the hair to the hole diameter area is set to be 65% to 85%, the frictional resistance between the hair bundle and the flocking hole is large.
The phenomenon of hair loss is less likely to occur, and the occurrence of cracks around the flocking hole due to the impact at the time of driving a flat wire can be prevented.

The length of the brush (height from the planted surface) is preferably from 6 mm to 12 mm. More preferably,
8-10mm for adults, 6 for children
If it is set to be from 8 mm to 8 mm, a toothbrush with more excellent usability can be obtained.

In general, the diameter of a single brush is the same except for the rounded portion of the brush tip. It may be in the form of tapered bristles that become thinner. In addition, the bristle tip shape can also adopt any shape such as a spatula shape, a scraper shape, and a spherical shape.

[0018]

1 to 3 show a first embodiment of the present invention. The toothbrush handle according to the first embodiment shows an example of an adult toothbrush handle, which is injection-molded by a molding die using “PEN TN8065” manufactured by Teijin Limited as polyethylene naphthalate resin. is there. The toothbrush handle thus obtained has excellent elasticity, mechanical strength, heat resistance, and chemical resistance, and has high transparency, as is clear from the examples described later. It was also extremely excellent in design.

The dimensions of the main parts are as follows.
0 mm, length 23.2 mm of head 1 and width 8.8 m
m, thickness 4.5mm, width of neck 2 5mm, thickness about 5m
m, sum of lengths of head part 1 and neck part 70 mm, grip part 3
12 mm in width, 8 mm in thickness, and the hole diameter of the flocking hole 4 is 1.77.
mm. In addition, in FIG. 3, (a) to (e) are cross-sectional views at corresponding positions a to e in FIG. 1B, respectively. Reference numeral 5 denotes a through hole for hooking the toothbrush on a hook or the like.

FIGS. 4 and 5 show a second embodiment of the present invention. The toothbrush handle according to the second embodiment is an example of a toothbrush handle for a child. As in the first embodiment, "PEN TN8065" manufactured by Teijin Limited as polyethylene naphthalate resin.
And injection-molded with a molding die. The toothbrush handle obtained in this manner has elasticity, similar to the toothbrush handle according to the first embodiment.
It was excellent in mechanical strength, heat resistance, and chemical resistance, had high transparency, and was extremely excellent in design.

The dimensions of the main parts are as follows.
0 mm, head section 1 length 17.2 mm, width 8 mm, thickness 4 mm, neck section 2 width 4.5 mm, thickness about 4.5 mm,
The sum of the length of the head part 1 and the neck part 55 is 55 mm, the maximum width of the grip part 3 is 14.3 mm, the maximum thickness is 9.4 mm, and the diameter of the flocking hole 4 is 1.7 mm. In addition, in FIG. 5, (a)-(g) is sectional drawing in the corresponding code | symbol a-g position in FIG.4 (b), respectively.

[0022]

EXAMPLE A use test of a toothbrush handle of the present invention (product of the present invention) made of polyethylene naphthalate resin ("PEN TN8065" manufactured by Teijin Limited) was conducted. Table 1 shows the results. As a comparative example, polymethylpentene resin (“TPXRT18” manufactured by Mitsui Chemicals, Inc.,
A toothbrush handle made of a flexural modulus of 1.6 GPa) was used. The molding conditions for the toothbrush handle were as follows. These molding conditions are merely examples, and the present invention is not limited to these.

(Molding conditions) Cylinder temperature: 300 ° C. Injection pressure: 5 MPa Injection time: 8 seconds Cooling time: 15 seconds Mold temperature: 20 ° C.

[0024]

[Table 1]

The evaluation of each item was based on the following criteria. (Evaluation of transparency) Total light transmittance (ASTM D100
3) was measured and evaluated as follows according to the transmittance. ：: good (transmittance of 80% or more) △: slightly poor (transmittance of 60 to 80%) ×: defective (transmittance of 60% or less)

(Evaluation of Gloss) Evaluation was made by visual judgment. ：: good △: slightly poor ×: bad

(Evaluation of flocking strength) ○: 20 N or more Δ: 10 N or more to less than 20 N ×: less than 10 N

(Evaluation of Thermal Deformation)
After immersion in hot water of 3 ° C. for 3 minutes, the warpage of the head portion was measured and evaluated according to the value as follows. ○: less than 1.0 mm △: 1.0 mm or more to less than 2.0 mm ×: 2 mm or more

(Evaluation of deflection) ○: 6 mm or more to less than 8 mm Δ: 4 mm or more to less than 6 mm, 8 mm or more to less than 12 mm ×: less than 4 mm, 12 mm or more

As is evident from Table 1, the product of the present invention was extremely excellent in transparency, gloss, flocking strength, moldability, and deflection. In addition, when the thickness is reduced, the sink during molding is small and the cooling time is short, so that the molding cycle can be shortened.

Next, Table 2 shows the test results on the stability to dentifrices. For comparison, a toothbrush handle made of polypropylene (bending elastic modulus 1.8 GPa) (conventional product 1) and a toothbrush handle made of polymethylpentene (“TPXRT18” manufactured by Mitsui Chemicals, Inc., bending elastic modulus 1.6 GPa) were used. Conventional product 2) was used.

[0032]

[Table 2]

The evaluation of each item was based on the following criteria. ：: No cracks generated Δ: Cracks generated 2 or more and less than 10 ×: Cracks generated 10 or more

As is clear from Table 2, it was confirmed that the product of the present invention is more stable than the conventional product 1 (made of polypropylene) and the conventional product 2 (made of polymethylpentene) and has excellent chemical resistance. Was done.

[0035]

As described above, according to the present invention,
With moderate elasticity and mechanical strength, little chemical change due to fragrance in dentifrice, excellent chemical resistance, and heat resistance that can withstand boiling disinfection from a sanitary point of view,
It is possible to provide a toothbrush handle which has high transparency and is also excellent in design.

[Brief description of the drawings]

FIG. 1 shows a toothbrush handle according to a first embodiment, in which (a) is a plan view in which a flocking hole is not shown,
(B) is a side view thereof.

FIG. 2 is an enlarged plan view near the head of the toothbrush handle according to the first embodiment.

FIGS. 3A and 3B show cross-sectional shapes of respective parts of the toothbrush handle according to the first embodiment, where FIG.
FIG. 1B is a cross-sectional view taken along line -a, and FIG.
FIG. 1C is a sectional view taken along line -b, and FIG.
FIG. 1D is a cross-sectional view taken along the line c. FIG.
FIG. 1E is a cross-sectional view taken along a line d, and FIG.
FIG. 3F is a cross-sectional view taken along the line e, and FIG.

4A and 4B show a toothbrush handle according to a second embodiment, in which FIG. 4A is a plan view and FIG. 4B is a side view thereof.

5A and 5B show cross-sectional shapes of respective parts of the toothbrush handle according to the second embodiment, where FIG.
FIG. 4B is a cross-sectional view taken along line -a, and FIG.
FIG. 4C is a cross-sectional view taken along a line b, and FIG.
FIG. 4D is a cross-sectional view taken along a line c, and FIG.
FIG. 4E is a sectional view taken along the line d, and FIG.
FIG. 4F is a cross-sectional view taken along line e.
FIG. 4G is a cross-sectional view taken along line -f, and FIG.
Sectional drawing in the position of -g line, (h) is an enlarged sectional view of a flocking hole.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Head part 2 Neck part 3 Grip part 4 Flocked hole 5 Through hole

Claims (4)

[Claims] 1. A toothbrush handle comprising a head portion on which a brush or a bunch of brushes is implanted, and a neck portion and a grip portion following the head portion, wherein polyethylene naphthalate is used as a handle material. 2. The toothbrush handle according to claim 1, wherein a multicolor molded handle is obtained by combining polyethylene naphthalate and a thermoplastic elastomer. 3. The head section has a thickness of 3.0 to 4.5 m.
The toothbrush handle according to claim 1 or 2, wherein the thickness and width of the neck are 3 to 7 mm, and the sum of the length of the head and the neck is in the range of 40 to 85 mm. 4. The method according to claim 1, wherein said grip portion has a thickness of 5 to 15 mm and a width of 7 to 20 mm.
3. The toothbrush handle according to any one of 3.