JPS63212304A - Brush made of polyamide fiber - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a brush made of polyamide fiber.

[Conventional technology]

Polyamide is a general term for polymers that usually have an acid amide bond (-CONH-), and among these, linear polymers that can form fibers are also called nylon.

It is already well known that many types of plastics are produced on an industrial scale, including so-called engineering plastics such as bearings, bushings, gears, and other materials with particularly wear-resistant and self-lubricating properties. , lightweight, moldability, heat and cold resistance, silence, chemical resistance, non-toxicity,
It is not only used for various equipment parts that require dyeability, but also widely used in the clothing field as a synthetic fiber to replace silk, and as a textile material in the field of brushes and other daily miscellaneous goods. However, polyamide is hydrophilic, and if left in humid air, it will adsorb moisture, and if left in dry air, it will release the absorbed moisture, resulting in an absorption rate of 0 to 0.
The amount of absorption varies within a range of about 14%, and although the degree varies depending on the type of polymer, it has the extremely serious drawback that the mechanical properties of the molded product are greatly affected by the amount of absorption. There is.

Therefore, the inventor of the present invention disclosed a method for treating polyamide molded products in Japanese Patent Application No. 58-69818 and No. 61-279220.
While significantly improving the inherent lubricity of polyamide,
It has become possible to prevent deterioration of mechanical properties such as impact resistance, abrasion resistance, and tensile strength due to fluctuations in water absorption, and to obtain polyamide molded products with extremely excellent dimensional stability after processing.

On the other hand, when brushes made of polyamide fibers are used repeatedly in everyday goods, the fibers lose their bending resistance and rebound resilience, which are essential for brushes, and they tend to curve outwards and become crushed. This results in the brush becoming unable to function as a brush. Especially when it comes to toothbrushes, of course there are differences depending on the frequency of use and suppression, but only 15 to 3
After about 0 days, the fibers bend, rendering the brush useless, and it is even said that the bent fiber tips irritate the space between the gums and tooth roots, causing alveolar pyorrhea.

[Problem that the invention seeks to solve]

As described above, brushes based on conventional techniques using polyamide fibers have had the problem that they have not been able to withstand use over a long period of time without losing bending resistance or restoring force.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention adopts a method of making a brush using polyamide fibers whose surface has been treated with silicone oil that has an affinity for polyamide fibers. The details will be described below.

First, the polyamide fibers used in this invention are modified depending on the intended use, such as the inherent properties of the polymer, such as relatively stiffness (hard), flexibility (soft), or neutral (neutral), or the shape and dimensions, such as diameter or length. They may be selected and used as appropriate, and their types are not particularly limited.

Next, the silicone oil that has an affinity for such polyamide fibers is, for example, an oily modified siloxane with a relatively low degree of polymerization into which amino groups, glycidyl groups, carboxyl groups, alcoholic hydroxyl groups, etc. are introduced. Particularly for brushes used in the mouth, such as toothbrushes, modified oil of polydimethylsiloxane, which has been proven to be completely physiologically inert, is preferable, and silicone oil may be used as is when dipping polyamide fibers.
It may also be in the form of an aqueous emulsion. In addition,
Silane coupling agents, catalysts, accelerators, etc. may be added as appropriate to crosslink the silicone oil or increase its affinity or reactivity with polyamide fibers, but from the standpoint of safety and health, heavy metals should not be mixed in. Needless to say, it won't happen.

The polyamide fibers to be immersed in the silicone oil mentioned above may be before being planted in the brush or after being planted and shaped; If cut, the central portion of the fiber, which is difficult for silicone oil to penetrate, will be exposed in an untreated state, so it is desirable to at least re-immerse the cut section for shaping.

Although the specific method of immersion treatment is not particularly limited,
In order to shorten the processing time while suppressing the decomposition or excessive reaction of silicone oil, etc., the immersion temperature should be about 60 to 80°C, and the immersion time should be about 60 minutes. , the conditions may be selected as appropriate depending on the amount, etc.

After the dipping treatment is completed, the excess silicone oil adhering to the polyamide fibers is removed, and a treatment is performed to fix the silicone oil that has penetrated the surface of the polyamide fibers. This promotes and completes the crosslinking reaction between modified silicone oils or the reaction with polyamide molecules, and is usually 50~
It is desirable to adjust the heating time at a temperature of 60° C. depending on the physical properties required for the product. Depending on the length of the heating time, polyamide fibers made of a type of nylon 6, for example, can be made to have arbitrary properties ranging from hard to soft.

[Effect]

The silicone oil that has an affinity for penetrating the surface layer of polyamide fibers reacts with the polyamide molecules or silicone oils to form a strong structure, which improves the water repellency, bending resistance, or restoring force of the polyamide fibers. Conceivable.

〔Example〕

One leg of a hairpin (0 character)-shaped nylon fiber extracted from a commercially available toothbrush using nylon fiber was placed in an aqueous emulsion of amino group-modified silicone oil (Ni-TK#-20 manufactured by Toshi Silicone Co., Ltd.) at 70°C and 60°C. After removing excess silicone oil, a fixing process was performed at 60°C for 20 minutes, and one leg was placed on a stand so that both legs were vertical, without any surface treatment with silicone oil. Fixed. The ends of the fixed hairpin-shaped nylon fiber legs are held together with plastic clothespins, and the weight of the clothespins causes the nylon fiber legs to curve to both sides.
After leaving it at room temperature for 4 days, the clothespins were removed. As a result, the legs treated with silicone oil were restored to a nearly vertical state, while the legs that were not treated were restored to an angle of approximately 70 degrees with respect to the perpendicular line, but curved remains and the limbs were completely restored. No restoration was possible.

Of the two toothbrushes of the same type using nylon fibers, one had the brush part treated with the same amino-modified silicone oil as described above, and the other one was left untreated. The brush part is facing down and is about 100mm on the back.
A weight of g was placed on the handle and a reciprocating motion was performed over a distance of 50 mm in the direction of the handle. The mating material was a tile board with a corrugated pattern on the surface that was kept wet by sprinkling water on it.As a result of continuous reciprocating motion of 200 times per minute for 3 hours, the brush part of the untreated toothbrush had fibers on the outside. The toothbrushes remained in an expanded state and did not recover, and lost their function, but no such symptoms were observed in the toothbrushes treated with silicone oil.

〔effect〕

As is clear from the above, silicone oil, especially polydimethylsiloxane, is odorless, tasteless, and physiologically inert, making it a safe substance.Moreover, it can be easily processed to improve the flexibility and recovery properties that polyamide fibers have. Since the force can be significantly improved, it can be said that the significance of this invention is extremely large.

Claims (1)

[Claims] A polyamide fiber brush characterized by using polyamide fibers whose surface has been treated with silicone oil that has an affinity for polyamide fibers.