JPS5980261A - Ball core body for hard baseball and production thereof - 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 This invention is a hardball baseball, a core body, specifically, a mixture obtained by kneading cork particles coated with rubber or synthetic resin into an ionomer resin, and pulverized particles thereof are heated and molded under pressure. The present invention relates to a hardball baseball ball and body made of the same material, and a method for manufacturing the same.

Known examples of the bodies of conventional hardball baseballs include ebonite sponge ball feet (1989-8957), sponge rubber cores containing high styrene synthetic rubber (10428-10428, 31-1217). ), the outer layer is made of hard sponge rubber made by blending Kirk powder with high styrene synthetic rubber, and the outer layer is crowned with two pieces of dense rubber with a spaced apart shape. Hardball baseball core made of dense rubber
-32119) etc.

Among these publicly known examples, Utility Model Act 25-8957, Utility Model Number 3,
1-10428, the core body described in Japanese Patent Publication No. 31-1217 is not necessarily satisfactory in terms of durability as a hard type ball, and the core body described in Japanese Publication No. 43-32119 is almost satisfactory in terms of durability, but the structure is The complexity of the process required extra steps in manufacturing, leaving room for improvement.

This invention was made in order to improve the drawbacks of the above-mentioned known examples, and the mutual contact between ionomer resin, which is a synthetic resin with high elasticity and excellent surface impact resistance, and cork particles is brought into close contact by hammering. Furthermore, by uniformly mixing and molding, the present invention provides a 7°C hardball baseball body that has excellent performance such as impact resistance and flight distance, and is easy to manufacture, and a method for manufacturing the same.

The present invention is a one-time baseball ball made by heating and press-molding pulverized particles of a mixture obtained by kneading cork particles covered with rubber or synthetic resin into an ionomer resin, and a method for manufacturing the same.

The size of the cork particles used in this invention is 4.8 mm (
4 meshes) to 2.8 mm (7 meshes) is suitable. If the cork particles are thicker than 4.8 mrn (4 meshes), the internal parts of the cork particles will increase in the crushing process of the mixture obtained by kneading into the ionomer resin, and the area not covered by the ionomer resin will increase. , the impact resistance of the body decreases. Further, large cork particles that remain unpulverized during the crushing process are destroyed from the inside by the impact of impact when used as a ball, reducing the impact resistance of the ball. Cork particles are 2.8 mm (7
When the mesh size is smaller than the mesh size, it becomes difficult to disperse the cork particles into the ionomer resin during kneading in a mill. In addition, the surface area of the cork particles becomes extremely large, and unless the mixing ratio of the ionomer resin is increased, the impact resistance of the body will decrease.

The ionomer resin used in this invention is preferably of a high hardness and high repulsion grade in order to extend the flight distance of the ball and improve the impact sound. (For example, Corporen S-600: trade name, manufactured by Hi-Dow Co., Ltd.) Regarding the mixing ratio of ionomer resin and cork particles, it is better to have more ionomer resin in terms of flight distance, impact sound, etc., but the weight of the ball structure Due to physical limitations, it is necessary to combine cork particles with a light specific gravity.
In view of the balance between performance and specific gravity, the ratio of the ionomer resin to the cork particles is preferably 60/40 to 40/60 in terms of weight ratio.

Comparing cork particles kneaded into ionomer resin without surface treatment and kneaded after surface coating with rubber latex or synthetic resin emulsion, it is found that the impact resistance when made into nine bodies is significantly lower than that of ionomer resin. There are significant differences, and those with surface coating are superior. If the surface is not treated, the ionomer resin that is mixed with it has a high viscosity, so wetting the surface of the cork particles becomes a solid gas, and the adhesion between the cork particles and the ionomer resin is insufficient, resulting in a ball. , if several units result in poor impact resistance during use, 1
If determined.

Simply mix the ionomer resin and cork particles and place it in a mold.jJU! +, when pressurized and molded into a corpse, and 'tfl = obtained by kneading in a mill = The fil material is crushed to make particles for molding, this is placed in a mold, heated, pressurized, and then cooled. Comparing the case where it is used as a light body, the latter case has performance such as impact resistance, distance (L), etc. It is assumed that this is because the mutual dispersion of the ionomer resin and cork particles becomes extremely uniform, which helps improve the performance of the ball core.

Next, one embodiment of the present invention will be described.

43g of cork particles with the size of 5 mesh and 16g of vinyl acetate resin emulsion (solid content 45%) are mixed uniformly, and dried at room temperature for 24 hours to produce about 50g.
Cork particles with surface coating treatment were obtained. This product was kneaded into 50 g of an ionomer resin Kobolene S~600 (trade name, manufactured by Amida Dow Co., Ltd.) using a test mill and mixed uniformly to obtain about 100 g of a mixture. This mixture was crushed with a crusher to produce core/body molding particles. By the way, this? Take 25g of particles for body shaping, put them into a mold with a spherical gap of 46mm in inner diameter, and heat with a hot press at a heating temperature of 150°C and a pressure of 11kg/C! After heating and pressurizing the ball for 20 minutes at C, the ball was cooled to about room temperature for about 10 minutes and then taken out to obtain a hardball baseball ball 1 of the present invention as shown in the figure. The weight of the tail and body was 25 g, and the outer diameter was 46 mm. A reinforcing layer 2 was formed by sprinkling yarn and vinylon single yarn on this material 1, and compounded rubber was further applied to form a skin rubber layer 3, and an unvulcanized ball was formed. This material was packed into a vulcanization mold in the usual manner, and vulcanized under pressure and heat to produce eight hardball baseballs. The weight of the ball is 146g.
The outer diameter was 72.5 mm.

The ball made in the BC1st example and the official hardball baseball ball,
Regarding hardball baseballs and balls made using nine bodies in which cork particles and ionomer resin were simply mixed without kneading, 1. A comparison of the performance as a car body and ball is as shown in the following table. .

In the table, the rebound height is 150c for two bodies or a ball.
The rebound height when dropped onto a marble board from m is cm.
It was shown in Drop impact resistance: 1 bottom diameter 70mm, heavy bank, 1
A 1 kg iron cylindrical weight was dropped from a height of 1 m at a rate of 6 times per minute to apply a falling impact to the sample, and the number of times at which breakage occurred was expressed as the number of times. Sound Quality When measuring the rebound height of a solid body, the sound quality was determined by listening to the sound quality when the body was dropped onto a marble board. In the case of Borl, the players actually hit the ball and listened to the sound quality when the ball just hit the bat. For back-up rebounding, the ball falls when the player actually hits the ball, and visually determines the rebound situation as it runs while touching the ground. Flying distance was determined by the flying distance when the ball was actually hit and just met. Durability was determined by observing the ball's softening, deformation, decrease in flight distance, change in sound quality, change in rebound, etc. due to actual use.

The evaluation symbol ◎ in the table indicates excellent, ○ indicates good, and △ indicates poor.

According to the table, in terms of the performance of one ball, the two example balls of the present invention are particularly excellent in drop impact resistance, and are not inferior to other cores in terms of rebound accuracy and sound quality. . Although the same monthly charge was used, the cork particles and ionomer resin were kneaded and mixed according to the method of production of the present invention.
;The body is significantly inferior in drop impact resistance, and neither rebound height nor sound quality is as good as the ninth body of the present invention. The differences in mold-making methods are clearly visible.

In terms of ball performance, the ball of the present invention is officially recognized as a hard ball! It shows excellent performance of 1y, which is equivalent to 1iIJ ball. On the other hand, the performance of balls using cork particles and ionomer resin, which were not kneaded and mixed but only mixed into flowers, showed poor sound quality, flying distance (L1 durability, and drop impact resistance). Inferior, showing the same tendency as in the case of 1,000 bodies.

The body of the semi-hard baseball ball had poor drop impact resistance, and in terms of ball performance, it had poor durability and drop impact resistance, and irregular bounces were observed in the back rebound.

As described in detail above, the hardball baseball ball of the present invention has legs and bodies, certified hardball IE ball legs and bodies, and semi-hardball baseballs/c.
゛It has superior impact resistance compared to the ball, and hardball balls made using this ball demonstrate performance comparable to certified hardballs in terms of sound quality when hitting, flight distance, durability, impact resistance, etc. However, if the outer cover is formed of a rubber layer as in this embodiment, the outer cover becomes water resistant, making it possible to provide a ball that is optimal as a practice ball for hardball baseball.

Next, according to the production method of the present invention, the surface of the cork particles is coated with rubber latex or a synthetic resin emulsion to improve the adhesion between the cork particles and the ionomer resin, and the cork particles are further kneaded into the ionomer resin. The particles are mixed uniformly, the resulting mixture is pulverized to create particles for molding, the particles are placed in a mold, heated and pressurized, and then cooled and taken out to form a strong bond to each other. This method has the advantage of being able to produce balls and bodies made of a mixture of uniformly dispersed cork particles and ionomer resin.

4.Drawing LD N':i'-Suni'4 The LMJ diagram is a cross-sectional view of +1 (Mr. Ij's baseball), which is an embodiment of the present invention using a blank.

1 is a skin body, 2 is a reinforcing layer, and 3 is an outer skin rubber layer.

Patent applicant: Naigai Rubber Co., Ltd. Agent @Yu Sugihara

Claims (2)

[Claims] (1) A hard baseball ball made by heating and press-molding crushed particles of a mixture obtained by kneading cork particles coated with rubber or synthetic resin into an ionomer resin. (2) Cork particles coated with rubber latex or synthetic resin emulsion are kneaded into ionomer resin after drying,
A method for manufacturing a hard baseball ball body, which comprises: pulverizing the obtained mixture to create molding particles; charging the molding particles into a mold; heating and pressurizing; cooling; and taking out.