JPH0560389B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a ball used for ball games such as baseball and softball, and specifically relates to material components forming the core material of the ball.

[Conventional technology]

Traditionally, a ball consists of an internal ball core and an outer shell. A structure in which the material is wrapped around the material and then covered with an outer skin has been seen, and recently, a common structure is one in which synthetic rubber or synthetic resin is mixed with moderately crushed cork particles, molded into one piece, and then covered with an outer skin. It was hot.

[Problem that the invention seeks to solve]

However, with the above structure, if you want the ball core to have appropriate hardness, good resilience, and strong durability, you will inevitably end up with a molded object with a high specific gravity, and conversely, if you want a low specific gravity, you will not be able to meet the above characteristics. It had the disadvantage of losing several species.

For this reason, the ball weight standards were always threatened, and moreover, it was not possible to exhibit satisfactory performance.

In order to eliminate this drawback, we integrated cork grains and moderately crushed baked rubber using an adhesive.
Ball core structures that have lower specific gravity by creating gaps between each grain have been developed, but they have not yet achieved performance commensurate with the high molding cost.

[Means for solving problems]

In view of these drawbacks, the present invention provides a ball core that has all the characteristics of low specific gravity, sufficient hardness, good repulsive force, and strong durability.

A detailed description will be given below with reference to the drawings.

The present invention is a ball core A for a ball used for ball games, especially baseball, etc. As shown in the drawing, the ball core A is made of synthetic rubber 1, cork particles 2 of appropriate particle size, metal polyacrylic acid monomer 3, and melamine. A resin or a thermosetting resin 4 such as a phenolic resin is mixed, and heated and pressurized to chemically react the metal polyacrylic acid monomer 3 having the functional group with the thermosetting resin 4 to form a three-dimensional structure. It is characterized in that the ball core A is formed into a desired shape.

[Effect]

The present invention has succeeded in forming a ball core A having a suitable hardness, producing a pleasant hitting sound, and having excellent restoring force and durability by using the above-described structure.

In other words, the characteristics of each component that makes up this ball core A are that the metal polyacrylic acid monomer 3 added to the synthetic rubber 1 functions to adjust the hardness to low and high levels and improve the resilience, and the cork grain 2 has a corky quality. The ultra-fine bubbles that form the particles exhibit their properties regardless of the size of the particles, providing good repulsion while significantly lowering the overall density. As a representative example of the metal polyacrylic acid monomer 3 having a functional group, (M: divalent metal), and Zn, Mg, Pb, Nd, etc. are used for M. Further, the thermosetting resin 4 is so important that it affects its durability, and strong durability can be obtained by adjusting the amount of this resin mixed.

In the present invention, these components having excellent properties are mixed at an appropriate mixing ratio, and the mixture is heated and pressed in a mold to form a ball core A having a desired shape.
The ball is completed by simply covering the ball core A with a required outer skin B such as synthetic rubber, synthetic resin, or leather.

The resulting ball has an inner ball core A that exhibits the above-mentioned material properties as is, and has an appropriate hardness that provides a pleasant hitting sound and feel.
It has achieved a strong repulsion force that allows for a long flight distance with a low specific gravity, and also has the resilience to withstand numerous blows over a long period of time.

In this way, the ball core A of the present invention has an extremely large allowable range of performance changes compared to the standard.
By adjusting the formulation, it becomes highly usable and can meet any demands.

〔Effect of the invention〕

As explained above, according to the present invention, an ideal ball core with low specific gravity, sufficient hardness and good repulsive force, strong durability, and excellent moldability has been obtained.

[Brief explanation of the drawing]

The drawing is a sectional view showing the ball core of the present invention. A...Ball core, B...Outer skin, 1...Synthetic rubber, 2...Cork grains, 3...Metal polyacrylic acid monomer, 4...Thermosetting resin.

Claims (1)

[Claims] 1 In the ball core A of a ball used for ball games; synthetic rubber 1, cork grains 2, metal polyacrylic acid monomer 3 having a functional group, and thermosetting resin 4 are mixed, and the metal having the functional group is mixed under heat and pressure. A ball core characterized in that the polyacrylic acid monomer 3 is chemically reacted with the thermosetting resin 4 to form a three-dimensional structure.