JP3341960B2 - High performance brush - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a highly functional brush such as a toothbrush, a cosmetic brush, a wiping brush or a paint brush, which is extremely excellent in elastic recovery.

[0002]

2. Description of the Related Art Generally, synthetic brush materials are used for brush materials due to their hygiene and workability. However, those polymer materials typified by nylon are basically easy to absorb moisture, deterioration of physical properties and morphological stability after moisture absorption, and furthermore, for example, in applications such as toothbrushes, oral bacteria are liable to propagate on absorbed hair. It was not always the ideal material from the viewpoint of hygiene. As a material replacing such nylon, for example, JP-A-60-4560
As disclosed in Japanese Unexamined Patent Publication No. 6 (1994), there is a prior art in which the use of polybutylene terephthalate as a bristle material provides brush bristles having excellent elastic recovery and low moisture absorption. Certainly, polybutylene terephthalate can suppress moisture absorption to a low level, but has elastic recovery comparable to or less than that of nylon, and there has been a need for a high-performance toothbrush bristle.

[0003]

That is, an object of the present invention is to provide an ideal brush bristle material which has much higher elastic recovery than conventional nylon and has low moisture absorption.

[0004]

Based on the above viewpoints, the present invention has been intensively studied and, as a result, contains polypropylene terephthalate as a main component and is an ideal material for the above-mentioned bristle material for brushes. The inventors have found that the present invention has been achieved.

That is, the present invention provides a brush in which synthetic polymer brush bristles are planted, and comprises a high-performance brush wherein the main component of the brush bristles is polypropylene terephthalate. The synthetic polymer having polypropylene terephthalate as a main component here means a polycondensate of 1,3-propanediol and terephthalic acid as a monomer as a main component, and ethylene glycol and 1,4-butanediol as diols. 1,4-pentanediol and the like, and the carboxylic acids are copolymers with malonic acid, succinic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid and the like or derivatives thereof, and some combinations thereof. May be blended with a polycondensate consisting of However, the main component of the polypropylene terephthalate is preferably at least 50% by weight or more of the total in the brush bristles, and if it is less than 50% by weight, the elastic recovery is poor. From the viewpoint of mechanical properties, the intrinsic viscosity of the polymer is 0.5 or more, more preferably 0.7 or more.

The polymers or their compositions selected in this way are spun by a conventional melt spinning machine and formed into monofilaments. After the monofilament is cut to a cut length to be used for flocking, the monofilament is transplanted to various brushes to produce a desired high-performance brush.

[0007]

EXAMPLES The present invention will be described below with reference to examples. Example 1 A polypropylene terephthalate resin having an intrinsic viscosity of 0.70 was preliminarily dried at 80 ° C. for 4 hours under a vacuum of 0.1 mmHg, and then dried at 120 ° C. for 12 hours under the same vacuum conditions.
After melting with a screw-type extruder adjusted to 80 ° C., the mixture was spun through a spinneret having a hole of 1.2 mm diameter also adjusted to 280 ° C., and immediately cooled to 85 ° C. after cooling in a water-cooling bath arranged immediately below the nozzle. After preheating with a controlled hot roller, the film was stretched 4 times and wound up under steam at 120 ° C. Thereafter, heat treatment was performed at 140 ° C. for 10 minutes under a constant length to obtain a monofilament having a final diameter of 0.22 mm. The fibers were planted to form a toothbrush as shown in FIG. When the mechanical properties of the brush bristles were evaluated, as shown in Table 1, it was found that the brush bristles had extremely excellent elastic recovery and low moisture absorption, and that the brush had a very excellent touch and durability.

Example 2 The procedure of Example 1 was repeated except that 50 parts by weight of a polybutylene terephthalate resin having an intrinsic viscosity of 0.65 and 50 parts by weight of a polypropylene terephthalate resin having an intrinsic viscosity of 0.70 were mixed and dried, followed by spinning. A brush bristle material was prepared in exactly the same manner as in Example 1, and a brush was similarly manufactured. Table 1 shows the evaluation results.

Comparative Example 1 A brush bristle was produced in exactly the same manner as in Example 1 except that 100 parts by weight of polybutylene terephthalate having an intrinsic viscosity of 0.65 was used, and a brush was similarly produced. As is clear from the evaluation results in Table 1, in the comparative example,
Although the hygroscopicity was low, the elastic recovery was not as high as Examples 1 and 2.

[0010]

[Table 1]

The following evaluation method was used. (Elastic recovery property) Cut the monofilament of the brush into 20 mm, place it on a flat glass surface at room temperature, and then apply a monofilament to a cover glass that has been coated on one side with an adhesive (“Aron Alpha” manufactured by Konishi Co., Ltd.) in advance. It was adhered to the scissor glass surface so that 20 mm was buried. Bend one of the free ends into just two folds, then put a cover glass with no adhesive on it, and adjust the bottom of the cover glass to the size of the cover glass A 100 g weight was placed for 30 minutes. The angle a after 30 minutes has passed and the load has been removed and returned from the bent position after 10 minutes a
In (degrees), the recovery rate was calculated using the following equation. In other words, the recovery rate is 100% when returned by 180 degrees. The experiment was repeated 10 times and the average value was adopted. Elastic recovery rate = 100xa / 180 (%) (Durability) A reciprocating motion is applied to the surface of the tooth profile model without applying paste with a pressing force of about 500 gf, which is considerably stronger than a normal pressing force. The evaluation was performed in the direction, that is, the number of times from the position perpendicular to the shaft portion until it bends 20 degrees on average. That is, in the present invention, the number of repetitions was determined to be 100 or more times as good, less than 100 times and 50 times or more slightly good, less than 50 times and 25 times or more slightly poor, and less than 25 times as poor.

[0012]

As described above, the brush bristles of the present invention and the various brushes using the same are excellent in rubbing and elastic recovery of the bristle material and have little change over time due to low moisture absorption. ,
In addition, it is possible to provide an unprecedented sanitary high-performance brush.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of a toothbrush of a brush according to the present invention from the side.

Claims (1)

(57) [Claims] 1. A high-performance brush in which a synthetic polymer brush bristle is planted, wherein the main component of the brush bristle is polypropylene terephthalate.