JPH0563191B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a driving range golf ball, and more particularly to a driving range golf ball having extremely high durability and low repulsion. Prior Art and Problems to be Solved by the Invention Golf balls are generally classified into two types depending on their use. One type is a round ball normally used on a golf course, and the other type is a driving range golf ball used at a driving range. The performance required for the above two types of golf balls is as follows:
Although they are said to be the same golf ball, it is difficult to say that they are the same. That is, the performances required of a round golf ball include good feel at impact, excellent flight distance or extension, and a certain degree of durability. However, when such round golf balls are used at a driving range, the durability of driving range golf balls, which are used over and over again, is extremely poor, and although they have a good feel at impact, the flight distance is limited. is too large to be used as a practice range. In general, golf practice ranges, especially in Japan,
With some exceptions, most places are very narrow, and most have less than a _100n field. At such practice ranges, first of all, high nets are applied,
A ball that is hit hits this net, and a ball that travels a long distance, such as a ball with a high initial velocity, can quickly damage the net, shorten its lifespan, and often make it difficult to manage a practice range. Furthermore, even if there is a large practice field, it is impossible to cover the entire area with nets due to cost considerations. Therefore, the ball that is hit often flies over the net.
However, in places like Japan, where the ball is thrown at a practice field adjacent to a private house or other facility,
Jumping over the net is extremely dangerous. Therefore, it is important to control the flight distance of golf balls for practice ranges to some extent depending on the size and height of the net. Golf balls for driving ranges that are currently in general use are one-piece golf balls that are easy to manufacture and inexpensive, and are made of high-cis polybutadiene as a main component. In this case, if methacrylic acid and acrylic acid were neutralized with zinc oxide and grafted as is, as shown in Japanese Patent Publication No. 55-19615, the repulsion would be too high for use at the practice range, and the practice would be shot hundreds of times. As a course golf ball, it has extremely poor durability. In addition, ester blend products such as those found in Versi's patent (U.S. Patent No. 3,313,545) not only have poor durability, but also have a very poor feel at impact, and although their flight distance is not great, they are extremely poor in other physical properties. Not used in recent years. Therefore, there is currently a desire to develop a golf ball for driving ranges that replaces these. The present invention provides a golf ball for driving ranges that has a reduced flight distance and extremely improved durability while maintaining good performance, shot feel, ball trajectory, etc. generally required of a golf ball. Means for Solving the Problems That is, the gist of the present invention is that 3 to 60 mol% of epoxidized natural rubber is added to 100 parts by weight of the base rubber.
35 parts by weight of methacrylic acid, 20 to 35 parts by weight of methacrylic acid, and 20 to 50 parts by weight of zinc oxide. Examples of the base rubber used in the present invention include high-cis polybutadiene rubber, natural rubber, styrene-butadiene rubber, and ethylene propylene rubber (EPDM). Among others, high-cis polybutadiene rubber contains 90% of cis-1,4 bonds. Polybutadiene rubber having the above properties is preferred. The natural rubber blended into the base rubber is 10 to 60 mol%.
Epoxidized, epoxidation is 10 mol%
Below, it becomes difficult to control the flying distance,
Moreover, if the epoxidation amount exceeds 60 mol%, durability will be impaired. The amount of 10 to 60 mol% epoxidized natural rubber depends on the epoxidation rate, but it is usually 3 to 35 parts by weight, generally 3 parts by weight, based on 100 parts by weight of the base rubber. If it is less than 35 parts by weight, it will be difficult to obtain the desired effect of the present invention, and if it exceeds 35 parts by weight, durability will be impaired. One feature of the present invention is that by appropriately selecting the epoxidation rate of natural rubber and the blending amount of epoxidized natural rubber, flight distance can be freely controlled without impairing other properties. That is, the higher the epoxidation rate, the shorter the flight distance can be without impairing durability, and the higher the blending amount, the shorter the flight distance can be without impairing durability. The amount of methacrylic acid blended is 20 to 35 parts by weight per 100 parts by weight of the base rubber; if it is less than 20 parts by weight, durability will be impaired, and if it is more than 35 parts by weight, the hardness of the golf ball will be too high. In addition, the amount of zinc oxide blended is 20 to 50 parts by weight per 100 parts by weight of the base rubber; if it is less than 20 parts by weight, the impact resistance of the ball will be insufficient, and if it is more than 50 parts by weight, the hardness of the ball will decrease. It's getting too expensive. If desired, a silica-based filler may be added to the above ingredients to facilitate adjustment of ball hardness and shot feel (in the system disclosed in Japanese Patent Publication No. 55-19615, a silica-based filler is used). However, in the system of the present invention, this does not occur due to the large reinforcing effect of epoxidized natural rubber.) It is preferable that such a filler is usually blended in an amount of 3 to 20 parts by weight per 100 parts by weight of the base rubber. The driving range golf ball of the present invention is obtained by vulcanizing a composition containing the above-mentioned substances, but other additives such as anti-aging agents, free radical initiators, etc. are mixed into the above-mentioned composition. Good too. The anti-aging agent is preferably a thiobisphenol type, such as 4,4'-thiobis(6-t-butyl-3-methylphenol). Anti-aging agents are usually
It is preferably contained in an amount of 0.1 to 1.0 parts by weight. Examples of the free radical initiator include dicumyl peroxide, t-butyl peroxybenzoate, t-butyl cumyl peroxide, and the like, with dicumyl peroxide being particularly preferred. The amount of free radical initiator added is not particularly limited, but it is usually
When used in the range of 0.5 to 3.0 parts by weight per 100 parts by weight, a driving range golf ball with excellent hardness can be obtained. The golf ball of the present invention is obtained by vulcanizing the above composition by a conventional method. Any conventional vulcanization temperature range may be used, but from a manufacturing standpoint, the vulcanization temperature should be 170℃, which is higher than the conventional vulcanization temperature of 160℃.
Preferably, vulcanization is performed at ~180°C. Hereinafter, the present invention will be explained with reference to Examples. Examples 1 to 4 One-piece solid golf balls were manufactured by a conventional method using the formulations shown in Table 1. Various physical properties of the obtained ball were measured and the results are shown in Table 1. Comparative Example 1 A one-piece solid golf ball was manufactured according to the formulation shown in Table 1, and the physical properties of the resulting ball are shown in Table 1. Comparative Example 2 (Formulation example according to Japanese Patent Publication No. 19615/1982) Table 1 shows the physical properties of a one-piece solid golf ball manufactured according to the formulation shown in Table 1. Comparative Examples 3 and 4 Table 1 shows the physical properties of one-piece solid golf balls manufactured according to the formulation shown in Table 1.

【table】

[Table] Effects of the Invention The driving range golf ball of the present invention has performance comparable to that of a round golf ball in terms of shot feel and ball hit, is extremely durable, and has a flight distance that can be used even on a narrow driving range. It is short enough to be used. Furthermore, with the golf ball of the present invention, sufficient safety can be maintained with a lower net height than ever before. It may also extend the useful life of the net.

Claims (1)

[Scope of Claims] 1. Contains 3 to 35 parts by weight of 10 to 60 mol% epoxidized natural rubber, 20 to 35 parts by weight of methacrylic acid, and 20 to 50 parts by weight of zinc oxide based on 100 parts by weight of base rubber. A driving range golf ball obtained from the composition. 2. The golf ball according to item 1, wherein the base rubber is polybutadiene rubber containing 90% or more of cis-1,4 bonds. 3. The first containing 5 to 20 parts by weight of silica filler.
The golf ball described in Section 1.