JP2002200133A - Rubbing ball used for massaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rubbing ball for a massaging apparatus which achieves a wear resistance as well as better massaging touch. SOLUTION: The rubbing ball 1 is a dough nut-shaped elastic body 3 which has a punched part 2 at the center part thereof and is mounted on a rotating shaft and the elastic body 3 comprises a urethane foam body with the Shore A hardness of 30 to 40 while the urethane foam body contains a skeleton derived from polytetramethylene ether glycol.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a kneading ball mounted on a rotating shaft of a massage device.

[0002]

2. Description of the Related Art In a massaging apparatus, a rotatable roller-shaped elastic body, a so-called kneading ball, is attached to a massaging section for applying pressure to a human body, such as fogging, loosening, and tapping.

[0003] Generally, kneading balls are composed of a rubber vulcanized composition such as NBR or EPDM, and carbon black is blended as a reinforcing material to impart strength that can withstand rotation. As a general specification of a kneading ball in a massage device, it is required that the kneading ball does not wear out and does not cause permanent deformation when operated under a load of 60 kg for 1000 hours.

[0004] However, when the kneading balls are operated with the above specifications, the kneading balls are worn out, and the carbon black contained in the abrasion powder comes out of the skin, causing a problem of soiling the clothes.

[0005] Further, it has been pointed out that a massage ball composed of the rubber composition generally has a high Shore A hardness of about 50 degrees, and thus has a problem of poor massage feeling. Due to the nature of the massage device, a good massage feel is the highest quality among the quality required for a massage ball.

However, in order to meet the above demand, Shore A
When a kneading ball having a reduced hardness is used, the amount of wear is further increased when the device is operated, and the deformation distortion is increased, so that the ball cannot be put to practical use.

[0007]

SUMMARY OF THE INVENTION From the above problems,
The present inventors have conducted extensive research on kneading balls having excellent abrasion resistance and a good massage feeling, and as a result, have found kneading balls that satisfy the above requirements by selecting a specific type of resin and selecting a specific hardness. It is.

[0008]

According to the present invention, in order to achieve the above object, an elastic body forming a kneading ball has a Shore A hardness of 30.
The urethane foam is characterized by comprising a skeleton derived from polytetramethylene ether glycol while being composed of a urethane foam adjusted to ４０40 degrees.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. The present invention is not limited to the following embodiments. According to FIG. 1, a kneading ball 1 according to the present invention is a donut-shaped elastic body 3 having a lightening portion 2 attached to a rotating shaft at a central portion, and the lightening portion 2 is fixed to the rotating shaft. Ring (not shown) made of a rigid body such as metal
Is attached. A stimulating projection 4 is provided on the outer periphery of the elastic body 2.
Can be provided as needed.

A urethane foam is used as the elastic material, and is obtained by casting and heating a liquid urethane raw material. In general, as a foam molding method, a one-shot method in which a premix liquid in which a polyol, a foaming agent, a catalyst, a chain extender, a pigment, etc. are mixed, and a solution containing an isocyanate component are mixed and injected and reacted, or as an isocyanate. A prepolymer method using a prepolymer partially modified with a polyol in advance may be used.

Although the isocyanate is not limited, for example, toluene diisocyanate (TDI)
And methylene diisocyanate (MDI) are generally used. However, as a polyol, the molded product has moisture resistance,
It is essential to use polytetramethylene ether glycol (PTMG) which is excellent in water resistance and has strong physical properties and small hysteresis loss. Also,
As the polyol, for example, a modified PTMG copolymerized with an alkylene oxide also belongs to the present technical category.
In addition, the weight average of PTMG is generally about 500 to 2,000.

As the foaming agent, water is used as a chemical foaming agent, and trichlorofluoromethane or dichloromethane is used as a physical foaming agent. The density of a molded article is controlled by increasing or decreasing the amount of the compounding agent. Affects hardness. However, it is preferable to use water from the viewpoint of environment and safety and health. The expansion ratio is usually 1.5 to 2.5 times.

As the catalyst, amine catalysts such as monoamines, diamines, triamines, cyclic amines, alcohol amines and ether amines and organic tins are generally used. It is important to adjust the amount of the catalyst so as to balance the foaming and gelling of the urethane stock solution.

As the chain extender, a short-chain polyol is generally used, and examples thereof include ethylene glycol, 1.4 butanediol, triethanolamine, and trimethylolpropane. The hardness of the molded article can be controlled by the amount of the compound. is there. In addition to the above-mentioned compounding agents, a coloring agent, a foam stabilizer, a filler, a stabilizer, and the like can be added as necessary.

As a method for foaming and casting the above-mentioned liquid urethane raw material, a high-pressure casting machine is used in which two liquids are lightly circulated at about 150 atm by a high-pressure pump, and a discharge port is opened for a predetermined time to impinge and mix the two liquids. There is a method and a method using a low-pressure casting machine in which two liquids are lightly circulated at about several atmospheres by a low-pressure pump, a discharge port is opened for a predetermined time to guide the two liquids into a mixing chamber, and the mixture is discharged while being stirred by a rotor. Also, the molding die is not limited to open casting, closed casting, and the like, and as a material, resin, ZAS, aluminum, steel, or the like can be used.

The kneading balls obtained according to the above-mentioned technique are constituted by a urethane foamed elastic body containing a skeleton derived from polytetramethylene ether glycol, and the hardness is adjusted so that the Shore A hardness becomes 30 to 40 degrees. Be done. If the Shore A hardness is less than 30 degrees, the strain due to load is large, so that it cannot withstand actual use,
When the Shore A hardness exceeds 40 degrees, the hardness is high and the massage feeling is not good.

[0017]

EXAMPLES As examples, 100 parts by weight of polytetramethylene ether glycol, 0.8 parts of triethylenediamine were used.
101.1 parts by weight previously mixed with 0.3 parts by weight of water
Parts by weight and 483 parts by weight of the modified MDI solution were poured into a mold and foamed at a mold temperature of 45 to 50 ° C. for 15 minutes. Thereafter, the mold was removed to obtain a kneaded ball having a Shore A hardness of 35 degrees.

As Comparative Example 1, 100 parts by weight of polyether polyol, 1.5 parts by weight of triethylenediamine, 0.03 parts by weight of an organotin catalyst, 0.5 parts by weight of water, and 6 parts by weight of ethylene glycol were previously mixed. Solution 108.0
3 parts by weight and 60.4 parts by weight of the modified MDI solution were poured into a mold, and foamed at a mold temperature of 45 to 50 ° C. for 15 minutes. Thereafter, the mold was removed to obtain a kneaded ball having a Shore A hardness of 40 degrees. Furthermore, a conventional kneading ball (Shore A hardness: 45 degrees) using NBR rubber as the elastic body was obtained as Comparative Example 2.

When each of the kneaded balls obtained by the above method was operated for 1000 hours with a load of 60 kg using an actual machine of the massage device, in the example, there was no breakage, distortion, or abrasion of the kneaded balls, and abrasion powder adhered to the cloth. I never did. The massage feeling was also good. On the other hand, the kneading ball of Comparative Example 1 was easily torn and broken by human power, and was not practically usable. In addition, a large amount of wear powder was generated in the kneading balls of Comparative Example 2,
Carbon black was floating on the skin of the massage machine. The massage feeling was hard and unpleasant.

[0020]

As described above, according to the present invention, a kneading ball having excellent abrasion resistance and good massage feeling can be provided by selecting a specific type of resin and a specific hardness.

[Brief description of the drawings]

FIG. 1 is a perspective view of a kneading ball according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Massage ball 2 Lightening part 3 Elastic body 4 Stimulation projection

Claims (1)

[Claims] 1. A massaging ball used in a massage device, wherein the elastic body is made of a urethane foam having a Shore A hardness of 30 to 40 degrees, and the urethane foam contains a skeleton derived from polytetramethylene ether glycol. A massage ball used for a massage device characterized by becoming.