JPS61187875A - Yarn wound golf ball - 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 The present invention relates to a thread-wound golf ball consisting of a core ball, a thread rubber layer and a cover layer. This invention relates to a golf ball with excellent flight performance in cold weather.

Conventional techniques and their problems Conventionally, there have been known lures such as one-piece golf, two-piece golf, and thread-wound pull 711e. In order to improve the performance and increase the flight distance, improvements have been made to the types of food.

Among these, thread-wound golf balls are formed from a core ball, a highly drawn rubber thread layer tightly wound several times on the core ball, and a cover layer. In this case, the conventional core sphere is a solid material made of cis-polybutadiene, poly-isograne, or a mixture thereof, or a liquid core made of barium sulfate, etc. dispersed in water. Although ball-covered balls have been used, it is desired to develop a core ball that can further increase flight distance.

Summary of the Invention The present invention has been made in view of the above circumstances, and the present invention has been made in view of the above circumstances.
In order to improve the flight performance of L-7 Mail and increase its flight distance, a liquid core made of a core liquid with a specific gravity of 0.7 to 1.3 and a freezing point of 12°C or less was used as the core ball from the above core liquid. outer diameter 25-34mm covered with an outer skin layer made of a material with a large specific gravity
The moment of inertia is larger than that of K.

So, when a golfer hits the ball with a club, spin occurs on the sole, and this spin causes? ), the lift force acts in the normal direction to the flight curve of the ball, but when the goal is rising immediately after launch, the lift force is a backward force in the horizontal direction? - The large goal speed immediately after launch is reduced by the lift force. On the other hand, when the goal descends after passing the highest point of the flight curve, the lift force due to spin acts as a forward force in the horizontal direction, so the greater the lift force when the goal descends, the farther the goal will fly. preferred for increasing . Therefore, in order to increase the flight distance to the goal, it is preferable for K to have a small amount of spin when the ball rises immediately after launch, and a large amount of spin when the ball descends. preferable.

Based on this theory, the inventors of the present invention have conducted intensive research to find a way to obtain a ball with a thread-wound golf ball that has a large moment of inertia, and have found that using the above-mentioned ball as the core ball has a smaller moment of inertia. Therefore, the amount of spin immediately after launch is small, and there is little attenuation of the amount of spin from when the goal rises to when it falls, and this makes it possible to obtain a goal that can increase flight distance, and moreover, in cold weather. It was discovered that this flight performance was also maintained well, and this led to the present invention.

Heretofore, Luagol is a thread winding using a liquid core made by dispersing powder such as barium sulfate in water and covered with a rubber outer skin layer as a core ball.

However, the specific gravity of the core liquid of Luagol is usually 1.
．． 4 or more, and the outer skin layer is made of a material with a lower specific gravity than the core liquid, and therefore the moment of inertia is small, so the spin rate is large when the mail rises immediately after launch, and the spin rate when descending is small. Unfortunately, the lift caused by spin had a negative effect on flight distance. On the other hand, the golf of the present invention? The lure has a positive effect on the flight distance by increasing the moment of inertia. The structure and operation and effect are completely different.

The present invention will be explained in more detail below.

Structure of the Invention The thread-wound golf ball according to the present invention is a thread-wound golf ball consisting of a core ball, a thread rubber layer, and a cover layer, wherein the core ball consists of a liquid core and an outer skin layer covering the liquid core. is formed of a core liquid with a specific gravity of 0.7 to 1.3 and a freezing point of 12°C or less, and the outer skin layer is formed of a material with a higher specific gravity than the core liquid, and the outer diameter of the core sphere is 25~
It is characterized by being 34■.

In this case, the core liquid that forms the liquid core is methanol,
Lower alcohols such as ethanol, mixtures of water and lower alcohols, polyhydric alcohols such as ethylene glycol and glycerin, mixtures of water and polyhydric alcohols, chlorides)
Aqueous solutions of chlorides such as IJum, zinc chloride, and potassium chloride can be suitably used, but mixtures of water and lower alcohols or mixtures of water and polyhydric alcohols are preferred from the viewpoint of ease of handling. .

Note that the specific gravity of the core liquid is 0.7: & 1. as mentioned above.
It is necessary that the specific gravity of the core liquid be within the range of 3. If it is outside this range, it will be difficult to obtain a core 9 lure ball with a large moment of inertia, but a particularly preferable range for the specific gravity of the core liquid is 0.95 to 0.95.
It is 1.02. In this case, it is better to use a core liquid with a lower specific gravity [K], which has a moment of inertia, which can prevent the core liquid from freezing in cold weather, and has good flight performance even in cold weather. You can get 9 Ruagol. On the other hand, if the freezing point of the core fluid is higher than 12 degrees Celsius, the core fluid may freeze in cold weather, and if the core fluid solidifies, the initial goal velocity will be lower than that of one that does not solidify. This will significantly reduce flight distance.

Further, there is no particular restriction on the material of the outer skin layer that covers the core, and any material can be used as long as it has a higher specific gravity than the core liquid, but it is particularly preferable to use a rubber material. In this case, the rubber material used may be one whose specific gravity is appropriately adjusted by blending a specific gravity adjusting agent such as zinc white with a rubber component such as NR. It is particularly preferable to use a material for the outer skin layer having a specific gravity of 1.95 to 2.8 from the viewpoint of increasing the moment of inertia of the ring.

The core ball of the present invention is made by covering the above-mentioned core with an outer skin layer and forming the core to have an outer diameter of 25 to 34 cm. in this case,
By increasing the outer diameter of the core ball, it is possible to obtain a lure pole with a larger moment of inertia, but since the number of layers of yarn with high rebound elasticity is reduced, The preferred range is 26 to 30.

In addition, in the core ball of the present invention, the thickness of the outer skin layer is 0.8 to
It is preferable to set it to 2.3■. Furthermore, the ratio of the specific gravity of the cored ball to the specific gravity of the outer skin layer is preferably 1:1.9 to 1:1.3, and the weight of the core ball is preferably 14 to 21N.

The thread-wound golf sol of the present invention can be manufactured by winding a thread rubber around the above-mentioned core ball and covering the thread rubber layer with an outer skin, but in this case, a commonly used material may be used as the thread rubber. It can also be formed using conventional materials such as grasshopper, ionomer resin, etc. as the outer skin.

By using the isogrene-butadiene random copolymer described in Japanese Patent Application No. 59-190080 as the thread rubber, it is possible to further improve the impact resilience and obtain a lure pool with increased flying distance.

As described in detail, the thread-wound golf ball according to the present invention has excellent flight performance, increases flight distance, and does not deteriorate in flight performance even in cold weather.

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

[Example, comparative example]

A nine-core ball with a rubber outer skin layer coated on a core with the composition shown in Table 1,
Examples 1 to 4, Comparative Example 1 consisting of a thread rubber layer and a cover layer
-2 thread-wound golfsols were each manufactured by a conventional method. The properties of these bottles at 23°C were as shown in Table 2.

In addition, the freezing point of the core liquid used in the goal of the example is approximately -8°C.
Met.

Next K, these? The ball was hit with a hitting test machine, and the following items were examined: initial goal velocity, launch angle, carry distance, and total distance. The results are shown in Table 2. From the results in Table 2, it can be seen that the golf ball of the present invention uses a core ball in which a core ball with a specific gravity in the range of 0.7 to 1.3 is covered with a rubber outer skin layer with a higher specific gravity. It was found that the Sol had a longer flight distance than the comparative golf mail, which used a core ball with a high specific gravity covered with a rubber outer skin layer with a lower specific gravity.

Next, using the golf sol of Comparative Example 3, which was the same as the golf ball of Example 4 except that the golf sol of Example 4 and the core liquid were composed of only water, these goals were heated at 0°C and -5°C. Immediately after being left under each condition for 24 hours, the ball was hit using a hitting tester, and the initial goal speed, launch angle, carry distance, and total distance were examined. The results are shown in Table 3. Note that the core removal solidification temperature of the golf sol of Comparative Example 3 was 0°C.

According to the results shown in Table 3, the golf sol of the present invention was found to have excellent flight performance even in cold weather.

Claims (1)

[Claims] 1. In a thread-wound golf ball consisting of a core ball, a thread rubber layer, and a cover layer, the core ball consists of a liquid core and an outer skin layer covering this liquid core, and the liquid core has a specific gravity of 0.7 to 1.3 and a freezing point. is formed of a core liquid having a temperature of -2°C or lower, the outer skin layer is formed of a material having a higher specific gravity than the core liquid, and the outer diameter of the core ball is 25 to 34 mm. ball.