JPH10127819A - Solid golf ball - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid golf ball which obtains not only a sufficient flying range but also a soft ball-hitting touch. SOLUTION: In a solid golf ball which consists of a solid core 1 of a three layer structure comprising an internal layer 1a, an intermediate layer 1b and a cover layer 1c and a cover 2c covering the solid core 1, the internal layer 1a is set to JIS-C hardness of 40-90, the intermediate layer 1b is made up of a thermoplastic resin composition to be set to JIS-C hardness of 50-80 and the cover layer 1c is set to JIS-C hardness of 65 or more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a solid golf ball in which a solid core having a three-layer structure is covered with a cover.

[0002]

2. Description of the Related Art A two-piece solid golf ball in which a solid core having a single-layer structure is covered with a cover can provide a long flight distance, but has a drawback that the shot feeling is hard. Accordingly, a three-piece solid golf ball has been developed as an improvement over the above-mentioned disadvantages of a two-piece solid golf ball.

[0003] For example, a three-piece solid golf ball disclosed in Japanese Patent Application Laid-Open No. Sho 60-241264 has a structure in which a solid core is divided into an inner core and an outer core, and the hardness of the inner core is JIS-C hardness. 50-70, hardness of outer core is JIS-C hardness 70
-90, with the inner core being soft and the outer core being hard to obtain a soft feel at impact.

[0004] However, when the impact force against the golf ball is large and the deformation of the ball reaches the inner core, an appropriate spin cannot be obtained, and a problem that the flight distance is reduced occurs. Further, in shots in which the outside of the ball is locally deformed, a good shot feeling is not always obtained due to the influence of the hardness of the outer core.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is a solid golf ball capable of obtaining a sufficient flight distance and a soft feel at impact. The purpose is to provide.

[0006]

The solid golf ball of the present invention has a solid core 1 having three layers and a cover 2 covering the solid core 1, as shown in FIG.
It is composed of

The solid core 1 has a JIS-C hardness of 40-
And an intermediate layer 1b formed of a thermoplastic resin composition and having a JIS-C hardness of 50 to 80.
And a jacket layer 1c having a JIS-C hardness of 65 or more.

The intermediate layer 1b is formed from a composition containing a thermoplastic resin as a component, instead of the polybutadiene rubber composition used for a conventional solid core. As the thermoplastic resin, an ionomer resin, a styrene-based, an olefin-based, a urethane-based, an ester-based, an amide-based thermoplastic elastomer, or the like can be used. Things, for example,
It is preferable to use a thermoplastic polyamide-based elastomer. Further, the thermoplastic resin has a Shore D hardness of 20 to 5
It is preferable to use one having a Shore D hardness of 50. If the one having a Shore D hardness of more than 50 is used, the hardness of the intermediate layer 1b is increased, so that the shot feeling is deteriorated and the ball rebound may be deteriorated. The amount of the thermoplastic resin is not particularly limited, but is preferably 50% by weight or more based on the total weight of the composition. In addition, a filler, a coloring agent, an antioxidant, a dispersant, and the like can be added to the thermoplastic resin composition as necessary.

When the inner layer 1a is softened, the flight distance is reduced at the time of a shot in which the ball is severely crushed. However, the short flight distance is compensated by the high resilience of the intermediate layer 1b. 1a hardness is JIS-C
Hardness can be reduced to 40. On the other hand, since the low hardness intermediate layer 1b is provided, the hardness of the inner layer 1a is:
Even if the JIS-C hardness is increased to 90, the shot feeling does not deteriorate.

Since the outer layer 1c is provided with the intermediate layer 1b having a high rebound, a sufficient flight distance can be obtained even if the hardness is reduced to JIS-C hardness 65. If the hardness of the jacket layer 1c is too high, the shot feeling becomes poor, so the JIS-C
The hardness is preferably 65 to 97.

The inner layer 1a and the outer layer 1c are preferably formed from a rubber composition based on cis-1,4 polybutadiene used for a conventional solid core. Can also be formed from a thermoplastic resin composition containing an ionomer resin, a thermoplastic elastomer, and the like.

In the present invention, the thickness of the intermediate layer 1b is set to 1
Preferably, the combined diameter of the inner layer 1a and the intermediate layer 1b is 26 to 29 mm. These ranges can be changed slightly, but if you make a big change,
The effect of the present invention cannot be obtained. In the present invention, the diameter of the inner layer 1a is set to about 17 to 30 mm,
The diameter of the solid core 1 can be about 37 to 41 mm, but is not limited to these ranges.

To produce the solid core 1, for example,
A method similar to the conventional method for producing a solid core having a two-layer structure can be used. That is, the rubber composition for the inner layer 1a is heated and pressed in a mold to form the inner layer 1a,
A hemispherical shell formed from the resin composition for the intermediate layer 1b is put on the outside of the inner layer 1a, and is heated and pressed in a mold to form an intermediate layer 1b. Layer 1b
Can be made in the same way as Also, the intermediate layer 1b
Can be molded using an injection molding machine for a thermoplastic resin, and therefore, the intermediate layer 1b and the jacket layer 1c can be formed by injection molding.

The cover 2 that covers the solid core 1 is formed from a resin composition based on an ionomer resin used for a conventional solid golf ball. .3 to 2.8 mm).

[0015]

Examples 1 to 4 The rubber composition for the inner layer 1a having the composition shown in Table 1 was heated and pressed in a mold to form the inner layer 1a. This inner layer 1
The intermediate layer 1b was provided by injection molding of a thermoplastic polyamide-based elastomer outside of a. Next, a semi-vulcanized hemispherical shell is formed from the rubber composition for the outer layer 1c having the composition shown in Table 1, and the hemispherical shell is put on the outside of the intermediate layer 1b and heated in a mold. The solid core 1 having a three-layer structure was produced by press-molding to provide a jacket layer 1c. The resin composition for the cover 2 containing 1.5 parts by weight of titanium dioxide with respect to 100 parts by weight of the ionomer resin was injection molded outside the solid core 1, polished and painted, and solid golf balls of Examples 1 to 4 were produced. A ball was made. Examples 5 to 7 and Comparative Example 2 Examples 5 to 7 were carried out in the same manner as in Examples 1 to 4, except that a mixture of a thermoplastic polyamide-based elastomer and an ionomer resin having the composition shown in Table 1 was used for the intermediate layer 1b. Was manufactured. Comparative Example 1 A conventional two-piece solid golf ball, in which a resin composition for a cover used in Examples 1 to 4 was injection-molded outside a solid core having a single-layer structure prepared from a rubber composition according to the composition shown in Table 1. , Polished and painted. Comparative Example 3 A solid golf ball was produced in the same manner as in Examples 1 to 4, except that a thermoplastic polyamide-based elastomer harder than that used in Examples 1 to 4 was used for the intermediate layer 1b.

[0016]

[Table 1]

* 1: Polyether-polyamide block copolymer, Shore D hardness 25.

* 2: Polyether-polyamide block copolymer, Shore D hardness 63.

* 3: trade name, ionomer resin of sodium salt of ethylene-methacrylic acid copolymer manufactured by Du Pont-Mitsui Polychemicals Co., Ltd., Shore D hardness 65.

For Examples 1 to 7 and Comparative Examples 1 to 3,
Table 2 shows the initial speed and shot feeling. As shown in Table 2,
The solid golf balls of Examples 1 to 7 had an initial speed equal to or higher than that of the conventional two-piece solid golf ball of Comparative Example 1, and had good resilience. Also,
The solid golf balls of Examples 1 to 7 were evaluated as having a good shot feeling.

On the other hand, in the solid golf ball of Comparative Example 2, the outer layer of the solid core was soft and the resilience was poor. The solid golf ball of Comparative Example 3 had a solid core intermediate layer made of a hard thermoplastic polyamide-based elastomer having a Shore D hardness of 63, and therefore had a poor shot feeling and poor resilience.

[0022]

[Table 2]

* 4: Measured by a method according to the USGA (American Golf Association) initial speed test.

The larger the value, the better the resilience.

* 5: Evaluation by actual hitting by a senior male golfer. ◎ → very good, ○ → good, × → bad.

[0026]

According to the solid golf ball of the present invention, a sufficient flight distance can be obtained, and the poor hit feeling, which is a drawback of the two-piece solid golf ball, can be eliminated.

[Brief description of the drawings]

FIG. 1 is a sectional structural view of a solid golf ball of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Solid core 1a ... Inner layer 1b ... Intermediate layer 1c ... Outer layer 2 ... Cover

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Taro Izawa 5412 Shido, Shido-cho, Okawa-gun, Kagawa Prefecture Inside Casco Co., Ltd.

Claims (3)

[Claims] 1. A solid golf ball comprising a solid core having a three-layer structure including an inner layer, an intermediate layer, and a jacket layer, and a cover covering the solid core, wherein the inner layer has a JIS-C hardness. Set to 40-90,
The intermediate layer is formed from a thermoplastic resin composition,
-C hardness is set to 50 to 80, and the outer layer is made of JIS
A solid golf ball having a C hardness of 65 or more. 2. The solid golf ball according to claim 1, wherein the thermoplastic resin forming the intermediate layer is made of a thermoplastic polyamide-based elastomer. 3. The golf ball according to claim 1, wherein the amount of the thermoplastic resin forming the intermediate layer is 50% by weight or more based on the total weight of the thermoplastic resin composition. Solid golf ball.