JPH07275034A - Tooth brush - Google Patents

Abstract

PURPOSE:To provide a tooth brush which is excellent in strength and appearance by enhancing the resistance to tooth paste at a bristle part to improve the strength of bristles and reflection effect. CONSTITUTION:A grip 3 having bristle holes at the head thereof is molded thermally by a material of a thermoplastic synthetic resin 1 blended with a colored or colorless aluminum powder 2 with a particle size of 0.1-0.3mm in a range of 0.15-0.45wt.% and a bristle part 4 is provided at a head part with a higher strength of bristles. As a result, there is no cracking in bristle holes of the bristle part to obtain a necessary molding accuracy while with a larger strength of welding, the residual stress is reduced to improve the strength of the bristles remarkably. This also enables the enhancing of the heat resistance at the bristle part 4 and the resistance to tooth paste.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a toothbrush used for toothbrushing, in particular, it improves the molding accuracy without cracks in the flocked hole portion, increases weld strength, reduces residual stress, and significantly increases flocking strength. In addition, the present invention relates to a toothbrush having excellent properties that can improve heat resistance and dentifrice resistance at the flocked portion.

[0002]

2. Description of the Related Art Generally, synthetic resins such as polyethylene, polypropylene, polyamide, acrylonitrile / styrene resin, acrylonitrile / butadiene / styrene resin, and cellulose propionate resin are widely used as materials for toothbrush handles. And
Toothbrushes molded with these resins may require higher flocking strength and heat resistance, and we are striving to give specificity by coloring the appearance and changing the shape. However, there are times when we are asked for something more unusual.

[0003]

Conventionally, a toothbrush is liable to deteriorate in dentifrice resistance, which is related to the weld strength of the brush provided in the bristle hole portion, unless the bristle hole portion of the bristle portion has the required molding accuracy. However, there are drawbacks such as hair loss phenomenon occurring, and all of the above resins have a low heat transfer coefficient, and particularly when the product is a thick-walled molded product such as a toothbrush handle, it takes a lot of cooling time and molding conditions It is difficult to shorten the molding cycle, there are many sink marks, and it is impossible to maintain the molding accuracy and weld strength required for the flocking hole part, and cracks easily occur during flocking or toothpaste resistance, especially toothbrushes. May be sterilized and disinfected by boiling water or boiling, and when exposed to heat, it may be a problem because it is inferior in heat resistance such as deformation, deterioration, and deterioration in hair transplant strength.

The present invention eliminates these various drawbacks of the conventional ones, is remarkably good in terms of quality and molding process, can obtain required molding precision without generating cracks in the flocked holes, and can increase weld strength. It is an object of the present invention to provide a toothbrush having excellent characteristics that the residual stress is reduced, the bristle strength is remarkably enhanced, and the heat resistance and the dentifrice resistance at the bristle transplanting portion are improved.

[0005]

SUMMARY OF THE INVENTION According to the present invention, a handle having a head with a hole for implanting a brush is made of a thermoplastic synthetic resin and colored with a particle size of 0.1 to 0.3 mm. 0.15 to 0.45% by weight of uncolored aluminum powder
A toothbrush is prepared by heat-molding from a mixture of the above range and providing a hair-implanted portion on the head with increased hair-implantation strength.

[0006]

[Function] For the thermoplastic synthetic resin of the handle with the flocked part,
Colored or non-colored aluminum powder having a particle size of 0.1 to 0.3 mm was mixed in the range of 0.15 to 0.45% by weight, so that the heat of the Al powder mixed and scattered at the time of molding is on the resin side. In particular, the welded part of the flocked part is easily adhered, the welded strength of the flocked hole part is increased, the residual stress is reduced, and the occurrence of cracks during flocking or dentifrice resistance is reduced, and the reflection effect is also improved. The toothbrush is greatly improved, has a shiny glitter and is unusual, and is used as a fashionable toothbrush.

[0007]

EXAMPLE An example of the present invention will be described with reference to the example of FIG. 1. A handle 3 having a hair-implanted hole in the head is colored with a thermoplastic synthetic resin 1 with a particle size of 0.1 to 0.3 mm. A toothbrush in which a non-colored aluminum powder 2 is blended in a range of 0.15 to 0.45% by weight and which is heat-molded to have a hair-implanted portion 4 on a head having a high hair-implanted strength.

In this case, the thermoplastic synthetic resin 1 used
As the handle 3, a resin composition such as an acrylonitrile styrene resin, a cellulose propionate resin, an acrylonitrile butadiene styrene resin, a polyethylene terephthalate resin, or a polypropylene resin may be used alone or in combination of two or more, and may be used as the handle 3. Further, the aluminum powder 2 (hereinafter referred to as Al powder) is appropriately colored with a pigment, for example, a gold tone, a silver tone or the like, or is not colored, and is a powder as it is, for example, 0.2 mm × 0.
3 mm × 0.01 to 0.015 mm in size of flaky powder, alone or in combination, is added to the transparent resin in an amount of 0.1.
It suffices to mix in the range of 0.5 to 0.5% by weight and perform molding together, and the range of 0.15 to 0.45% by weight is particularly preferable.
If the blending amount is 0.5% by weight or more, it becomes too dense, the head of the flocking part becomes brittle, the interval of the flocking holes cannot be reduced, the number of cracks increases, and the dentifrice resistance deteriorates. The light is also reduced, the reflection effect is greatly reduced and it becomes dirty,
Within the range of 0.1% by weight or less, there is a problem in hair transplant strength in terms of quality, and since a fancy tone does not have strangeness, it should be avoided. Further, if the Al powder particle size is less than 0.1 mm, the sesame salt is scattered, and the appearance is not good, and there is no heat resistance or reflection effect.
This is not preferable because the Al powder is deformed during injection molding and becomes clumped, resulting in poor flocking strength and light reflection effect.

The shape of the Al powder may be foil, square or granular.
Mix one or more of the desired colors and mold together with transparent or translucent resin, and scatter the colors inside the toothbrush handle. For example, the Al powder may be arranged randomly or in a laminated manner to give a fancy tone, and the Al powder has a thermal conductivity (AS: 2.9 × 10 ⁻⁴ Al: 0.5) higher than that of the resin.
3cal / s · cm · ° C) is good, and the cooling time during the molding process can be shortened, and there are few sink marks, and the quality of proper flocking and dentifrice resistance can be greatly improved by the resin alone. With these, the heat of the Al powder mixed and scattered at the time of resin molding injection filling is transmitted to the resin side, and especially the welded portion of the flocked portion easily adheres, the weld strength of the flocked hole portion increases, and the residual stress also decreases. This is because as a result, the occurrence of cracks at the time of flocking or dentifrice resistance is reduced. In the masterbatch method and the method using a color pellet, the Al powder is kneaded into the resin in advance, so that it tends to become finer, so that the side must be taken into consideration.

A molded product obtained by molding the toothbrush of FIG. 1 under the following conditions and a comparative example were tested. 0.3% by weight of Al powder [Dainippon Ink and Chemicals] with a gold pigment attached to acrylonitrile styrene resin (AS resin) [Tyryl 783: Asahi Kasei] is injected, and the toothbrush handle and the base of the flocking part are injected. Molded. It should be noted that pre-drying before injection molding 8
It was carried out at 0 ° C. for 3 hours. This molded product had a good releasability, was free from sink marks and bubbles, and had a glossy transparent surface with gloss. Weight is 1
It was 0.1 g. Next, this molded product is used as samples A and B.
When the hair-implanted portion 4 was formed by dividing hair into different parts and changing the hair-implanting conditions, the results shown in Table 1 were obtained. For comparison, Al
Note also about samples A'and B'in which powders are not mixed.

[0011]

[Table 1]

Five of each of Samples A and B (of the present invention) shown in Table 1 and Comparative Examples A ′ and B ′ (of which Al powder was not mixed) were arbitrarily selected to have flocking strength, heat resistance, and resistance to flocking. When tested for dentifrice properties, the results shown in Table 2 below were obtained.

[0013]

[Table 2]

The above results are summarized in Table 3 below, and the flocking strength is shown in FIG.

[0015]

[Table 3]

[0016]

According to the present invention, a handle having a head with a hair-implanting hole for implanting a brush is made of a thermoplastic synthetic resin and has a particle diameter of 0.
A colored or non-colored Al powder having a size of 1 to 0.3 mm was blended in a range of 0.15 to 0.45% by weight, which was heat-molded to provide a hair-implanted portion on the head with increased hair-implantation strength. As a result, since the thermal conductivity of the Al powder is higher than that of the resin, the heat on the resin side can be made uniform through the Al powder, so that the occurrence of sink marks is small, and the molding cycle is shortened along with the improvement of the molding accuracy. It is possible, and there is little residual stress in the flocked holes of the toothbrush, so that the flocking suitability and dentifrice resistance are also greatly improved, and there is a remarkable effect in the flocked part of the toothbrush, and the weld strength of the flocked holes is increased, Cracks are less likely to occur during flocking or due to dentifrice resistance, and the flocking strength and reflection effect are greatly improved, making the toothbrush extremely remarkably strong in terms of strength and appearance, increasing the commercial value and brushing teeth. Also Can be a pleasure, is a novel in the lame-tone glossy, it can be a fashion overflowing toothbrush.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of the present invention.

FIG. 2 is a characteristic diagram of the flocking strength of the example of FIG.

[Explanation of symbols]

 1 Thermoplastic synthetic resin 2 Aluminum powder 3 Handle 4 Flocking part

Claims (1)

[Claims] 1. A handle 3 having a head with a hair-implanting hole for implanting a brush is made of a thermoplastic synthetic resin 1 having a particle diameter of 0.1 to 0.1.
A colored or non-colored aluminum powder 2 having a size of 0.3 mm was blended in a range of 0.15 to 0.45% by weight, which was heat-molded to provide a hair-implanted portion with a hair-implanted portion 4 on the head. A toothbrush characterized by that.