JP2002219194A - Multi-piece solid golf ball - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multi-piece solid golf ball whose flying distance is suppressed by reducing the repulsion, and which can be used favorably as a ball for practice field. SOLUTION: This multi-piece golf ball has ground rubber which is acquired by grinding a one-piece solid golf ball mixed with the matrix of a multi-piece golf ball core which comprises a core and a cover layer of more than one layer. 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 multi-piece golf ball whose flight distance is suppressed by low resilience and which can be 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") have been conventionally used as balls for practice ranges. This one-piece ball is designed so that the flight distance can be reduced in Japan where there are many narrow practice ranges, and the durability to repeated hits is high in terms of cost. A general-purpose driving range golf ball is designed to have a slightly higher hardness than a course ball (a ball used in a golf course).

[0003]

On the other hand, as for the driving range, there is a demand for using a multi-piece golf ball such as a two-piece solid golf ball or a three-piece solid golf ball in the driving range as well as the course. The main reason for this is that we want to use it as a means of distinguishing it from other practice ranges from a business perspective.

[0004] Also, from the golf player's point of view, the conventional practice range ball has a dissatisfaction that it does not give a sense of distance no matter how much practice, due to the difference in flight distance from the course ball. In addition, a general-purpose ball for a practice range has a different trajectory (launch angle, that is, a height of a hit ball) of a hit ball in an approach shot due to a difference in hardness between the course ball and the ball, which is an effective practice ball. Complained that she was not satisfied.

However, it is not possible to convert an existing multi-piece golf ball to a practice range ball as it is, because the flight distance is so long that the hit ball may jump out of the practice range. For example, 1376
When launched at rpm, the initial speed of a conventional one-piece practice range ball is about 74 m / s, whereas the initial velocity of a commercially available multi-piece golf ball is about 77 m / s. If the difference in ball flight distance is estimated using only this difference in initial velocity excluding the difference in dimples and the like, it is 20 to 3
It seems that there is a difference of about 0 m.

Therefore, in order to put the multi-piece golf ball into practical use as a driving range ball, it is necessary to suppress the flight distance at least. However, an existing multi-piece golf ball in which a core is covered with at least one layer of cover is required. Since the ball has been developed as a course ball with an emphasis on increasing the flight distance, practical means for suppressing the flight distance and making it a low-cost practice field ball have been proposed. Not.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a multi-piece golf ball having a reduced rebound and a reduced flight distance.

[0008]

The present inventor has conducted various studies to achieve the above object. As a result, in a multi-piece golf ball having a core and one or more cover layers, the multi-piece golf ball has a core matrix. It has been found that, when a predetermined amount of crushed one-piece ball is mixed, the repulsive force of the ball decreases, the initial velocity at the time of hitting decreases, and the flight distance is suppressed.

The present invention has been made on the basis of the above findings, and a ground rubber obtained by grinding a one-piece solid golf ball into a matrix of a core of a multi-piece golf ball comprising a core and one or more cover layers. Is 1 to 100 parts by mass of the rubber component in the matrix.
Provided is a multi-piece golf ball characterized by being mixed with 30 parts by mass.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. In the present invention, a crushed rubber obtained by crushing a one-piece ball is mixed into a matrix of a core of a multi-piece golf ball. The matrix is a rubber composition that becomes a base rubber of the core. In this case, as a matrix of the core of the multi-piece golf ball, for example, a cross-linked matrix mainly containing butadiene rubber such as 1,4-cis-polybutadiene and zinc acrylate as a main component can be used. Further, as a one-piece ball for producing pulverized rubber, for example, a one-piece ball made mainly of butadiene rubber such as 1,4-cis-polybutadiene and crosslinked with methacrylic acid and zinc as main components is exemplified.

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 one obtained by removing the surface coating of a one-piece ball and then crushing the ball, or one 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 from 1 to 30 parts by mass, more preferably from 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.

[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 the matrix of the core of a two-piece solid golf ball (two-piece ball) mainly composed of butadiene rubber to produce two-piece balls of Examples 1 and 2. As a comparative example, a conventional general two-piece ball was manufactured. The composition of the two-piece balls of Examples and Comparative Examples was as shown in Table 2. In Examples and Comparative Examples, two-piece balls were completed by performing predetermined vulcanization, deburring, cover molding, and painting. Thereafter, the outer diameter, weight, hardness, initial speed, impact durability, and kneading workability of the two-piece balls of the examples and comparative examples were examined (see the measurement method and the like below). Table 2 shows the results. When 50 parts by mass of the pulverized rubber was blended with 100 parts by mass of the rubber component in the matrix of the core, poor engagement of the rubber into the rotor of the kneader occurred, and a ball could not be produced.

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 (poor rubber biting into rotor)

[0018]

[Table 2]

According to Table 2, the two-piece ball of the present invention
The outer diameter, weight, hardness, and impact durability are almost the same as the conventional two-piece ball of the comparative example, but the initial speed decreases as the compounding amount of the crushed rubber increases as compared with the one-piece ball of the comparative example. It can be seen that the great flight distance difference between the ball and the practice ground ball can be reduced to about 3 to 10 m.

[0020]

As described above, the multi-piece golf ball of the present invention can be suitably used as a driving range ball because the flight distance is suppressed by the low rebound. More specifically, the multi-piece golf ball of the present invention has the following advantages. According to the present invention, the rebound of the core of the multi-piece golf ball is reduced by mixing an appropriate amount of the crushed rubber, and the initial velocity of the ball at the time of hitting is reduced.
A large flight distance difference between the course ball estimated to be 30 m and the practice field ball can be reduced to approximately 3 to 10 m. The conventional general-purpose one-piece ball for practice ranges has a different ball spin rate at the time of hitting due to the hardness difference between the ball and the course ball, resulting in a difference in the trajectory of the hit ball. However, when practicing with the multi-piece golf ball of the present invention, a trajectory close to a course ball can be obtained at the time of practicing, so that the above-described miss shot can be prevented. it can. In the multi-piece golf ball of the present invention, the material cost of the ball decreases due to the mixing of the crushed rubber, and the manufacturing cost approaches a level at which the ball can be profitable as a practice field ball.

Claims (1)

[Claims] A crushed rubber obtained by crushing a one-piece solid golf ball into a matrix of a core of a multi-piece golf ball comprising a core and one or more cover layers is added to 100 parts by mass of a rubber component in the matrix. A multi-piece golf ball, wherein 1 to 30 parts by mass of the golf ball is mixed.