JP2002219192A - One-piece solid golf ball - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a one-piece solid golf ball whose flying distance is suppressed by reducing the repulsion, which can be used favorably as a ball for practice field, and whose processability in production is satisfactory. SOLUTION: This one-piece solid golf ball has ground rubber which is obtained by grinding the one-piece solid golf ball composed principally of butadiene rubber, mixed with a one-piece solid golf ball matrix composed principally of butadiene rubber. Out of 100 mass part of the rubber ingredient in the matrix, 1 to 30 mass part is mixed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a one-piece solid golf ball which has a reduced rebound so that its flight distance is suppressed and which is suitably used as a driving range ball.

[0002]

2. Description of the Related Art One-piece solid golf balls (hereinafter sometimes simply referred to as "one-piece balls") are sometimes used as course balls (balls used in golf courses), but are mainly used as practice field balls. .

[0003] On the other hand, in recent years, the flight distance of a hit ball has been remarkably increased due to the improvement of golf clubs, and in Japan, which has many narrow practice ranges, there is an increasing possibility that the hit ball will jump out of the practice range. Therefore, it has been desired to reduce the rebound of the one-piece ball used as a practice field ball and to suppress the flight distance.

On the other hand, as a one-piece ball having a reduced flight distance, a one-piece ball in which acrylonitrile / butadiene rubber is blended in an amount of 3 to 40 parts by weight with respect to 100 parts by weight of a base rubber has been proposed (Japanese Patent Laid-Open No. 7-1995). -2
No. 4087).

[0005]

However, in the above-mentioned one-piece ball disclosed in JP-A-7-24087, it is necessary to knead different kinds of rubber in the manufacturing process. The number of control items for manufacturing, such as the method and setting of the optimum kneading temperature, has increased, and there has been a problem in workability.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a one-piece ball which achieves low resilience, suppresses the flight distance, and has good workability during manufacturing.

[0007]

Means for Solving the Problems As a result of various studies to achieve the above object, the present inventor has found that, in a one-piece ball mainly composed of butadiene rubber, a similar crushed one-piece ball is contained in a matrix thereof. When a predetermined amount is mixed, it has been found that the repulsive force of the ball is reduced, the initial speed at the time of hitting is appropriately reduced, and the flight distance is suppressed.

The present invention has been made based on the above findings, and is obtained by crushing a one-piece solid golf ball mainly composed of butadiene rubber into a matrix of a one-piece solid golf ball mainly composed of butadiene rubber. The ground rubber has a rubber component 100 in the matrix.
Provided is a one-piece solid golf ball, wherein 1 to 30 parts by mass is mixed with respect to parts by mass.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. In the present invention, one-piece ball ground rubber mainly composed of butadiene rubber is mixed into the matrix of one-piece ball mainly composed of butadiene rubber. Typical examples of butadiene rubber include 1,4-cis-polybutadiene. The matrix is a rubber composition that becomes a base rubber of a one-piece ball.

In the present invention, the pulverized rubber is adjusted so as to contain approximately 30% of those having an average particle size of more than 0.80 mm and approximately 70% of those having an average particle size of 0.80 mm or less. Is preferred. Here, the average particle size is an average value obtained by measuring the diameter of the sphere with respect to 100 particles randomly sampled from the crushed rubber, assuming that each particle of the crushed rubber is a sphere.

The crushed rubber may be obtained by removing the surface coating of a one-piece ball and then crushing the ball, or may be obtained by crushing a one-piece ball with the surface coating applied. Is also good. When the latter ground rubber is used, the step of removing the surface coating in the process of manufacturing the ground rubber can be omitted. In general, in the surface painting of one-piece balls, after vulcanizing and molding the ball, the surface is painted white, then an identification mark (a stamp such as a brand name or logo) is printed, and then a clear paint is applied for reinforcement. Is applied.

The mixing amount of the pulverized rubber is 1 to 30 parts by mass, more preferably 5 to 20 parts by mass, based on 100 parts by mass of the rubber component in the matrix, in consideration of kneading workability and durability. If the amount is less than 1 part by mass, the resilience of the ball cannot be effectively reduced and the initial velocity cannot be suppressed. If the amount exceeds 30 parts by mass, the rubber does not bite into the rotor of the kneading machine in the kneading step, so that the workability is significantly deteriorated. In the one-piece ball of the present invention, it is desirable that the decrease in the total flight distance by the driver of the ball due to the decrease in the initial speed is shorter by about 4 to 5 m than the flight distance of a general conventional product.

The one-piece ball of the present invention can be recycled and reused many times. In other words, the durability of the conventional general one-piece ball shows an extremely high level not to be damaged up to 1500 times in a durability test in which the driver is repeatedly hit with a head speed of 45 m / s. In this case, the decrease in the durability due to the mixing of the ground rubber is extremely small. Therefore, according to the present invention, it is possible to repeatedly recycle the one-piece ball mixed with the crushed rubber and crush the one-piece ball and use the crushed rubber again as the crushed rubber.

[0014]

EXAMPLES A one-piece ball manufactured was crushed by a crusher to produce crushed rubber. The matrix composition of the crushed one-piece ball was as shown in Table 1.

[0015]

[Table 1]

Next, the above-mentioned ground rubber was mixed with a matrix of a one-piece ball mainly composed of butadiene rubber to produce one-piece balls of Examples 1 to 3. As a comparative example, a conventional one-piece ball mainly composed of butadiene rubber was manufactured. The composition of the one-piece balls of Examples and Comparative Examples was as shown in Table 2. In Examples and Comparative Examples, predetermined vulcanization, deburring, and coating were performed to complete one-piece balls. Thereafter, the outer diameter, weight, hardness, initial speed, impact durability, and kneading workability of the one-piece balls of the examples and comparative examples were examined (see below for measurement methods and the like). Table 2 shows the results.

Measurement was made at 15 points using an outer diameter dial gauge. The hardness was measured at 10 to 130 Kg with a μ hardness tester. N = 30
It was made into pieces. It was measured the initial velocity at the time of 1376rpm by the initial velocity USGA type initial velocity instrument. Head speed 45m by hitting durability driver (No.1 wood)
The number of hits at which cracking started earliest (number of crack initiations) and the average value of the number of impacts at which cracking began (average number of cracks) were examined. N = 10. Kneading workability Kneading workability was evaluated according to the following criteria. ○… Good △… Slightly difficult to knead

[0018]

[Table 2]

From Table 2, it can be seen that the one-piece ball of the present invention
It can be seen that the outer diameter, weight, and hardness are the same as the conventional one-piece ball of the comparative example, but the initial velocity is lower than the one-piece ball of the comparative example. In addition, it can be seen that the impact durability slightly deteriorates as the amount of the crushed rubber mixed increases, but that the durability as a practice ball is maintained sufficiently. In addition,. A normal course ball (competition ball) which is not a one-piece ball has an average number of cracks of about 300 times.

[0020]

As described above, the one-piece solid golf ball of the present invention maintains the feel and durability of the ball at the level of a conventional one-piece ball, suppresses the flight distance by reducing rebound, and It has good workability during manufacturing. The one-piece solid golf ball of the present invention also has an advantage that it can be recycled and reused many times.

Claims (1)

[Claims] A crushed rubber obtained by crushing a one-piece solid golf ball mainly composed of butadiene rubber into a matrix of a one-piece solid golf ball mainly composed of butadiene rubber has a rubber component of 100 mass% in the matrix. A one-piece solid golf ball, wherein 1 to 30 parts by mass of the one-piece solid golf ball is mixed.