JPH0871178A - Golf ball - Google Patents

Abstract

PURPOSE: To obtain a golf ball which sufficiently maintains the initial speed of hitting, provides good feeling for hitting and has high durability. CONSTITUTION: A mixture of ionomer resin and block copolymers of polyolefin crystal-ethylenebutyrene-polyolefin crystal block or block copolymers of styrene- ethylenebutylene-polyolefin crystal is used as a covering material for a golf ball. By this method, hardness of a covering material comprising only an ionomer resin is decreated by a specified degree to improve the feeling for hitting and durability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a golf ball having a core covered with a cover.

[0002]

2. Description of the Related Art Conventionally, golf ball covers that cover the core include those using balata rubber and those using ionomer resin. Since the cover using balata rubber is relatively soft, it has a good shot feeling, easy spin control, and excellent controllability in the shot direction, but has the drawback of being easily damaged and having a relatively short life. are doing. In addition, there is a drawback that the performance deteriorates with temperature. On the other hand, a cover using an ionomer resin has a drawback that the shot feeling is poor because the hardness is higher than that of a balata rubber cover, but it is excellent in durability, cut resistance, repulsion, and easy to process. Since it is cheap, it has been used frequently.

By the way, in order to improve the feel at impact and the ease of spin control of the cover made of the ionomer resin, a terpolymer of ethylene, methacrylic acid and an unsaturated monomer of the acrylate class is used as the cover material. There is one that is used as a part to improve the shot feeling (Japanese Patent Laid-Open No. 1-308577).

[0004]

However, with the above-mentioned cover material, the shot feeling is improved, but the hardness of the cover is reduced, so that the initial velocity of the shot is reduced and the flight performance of the golf ball is sacrificed. It causes inconvenience.

An object of the present invention is to provide a golf ball which eliminates the above-mentioned inconveniences, maintains a sufficient initial velocity of a hit ball, has a good shot feeling, and has a high durability.

[0006]

In order to achieve the above object, the present invention is a golf ball having a core covered with a cover, wherein the main material of the cover is (a) an ionomer resin. (B) A mixture of a polyolefin crystal / ethylene butylene / polyolefin crystal block copolymer or a styrene / ethylene butylene / polyolefin crystal block copolymer.

The ionomer resin is a copolymer of α-olefin and α, β-unsaturated carboxylic acid, or a polymer of α-olefin, α, β-unsaturated carboxylic acid and its ester with sodium, potassium and lithium. It is a resin neutralized with metal ions such as copper, magnesium, calcium, zinc and aluminum. “SURLYN” (trade name) manufactured by DuPont and “HIMIRAN (H) manufactured by Mitsui DuPont Polychemicals Co., Ltd.
IMILAN) ”(trade name) is an ethylene-methacrylic acid copolymer-based ionomer resin using ethylene as an α-olefin and methacrylic acid as an α, β-unsaturated carboxylic acid. Further, "IOTEK" (trade name) manufactured by Exxon is an ethylene-acrylic acid copolymer type ionomer resin using ethylene as an α-olefin and acrylic acid as an α, β-unsaturated carboxylic acid. is there.

Polyolefin crystals, ethylene butylene,
Polyolefin crystal block copolymer (hereinafter CEBC
"Dynaron" (trade name) E6100P manufactured by Nippon Synthetic Rubber Co., Ltd.
As a styrene / ethylene butylene / polyolefin crystal block copolymer (hereinafter referred to as SEBC), “DYNARON” manufactured by Nippon Synthetic Rubber Co., Ltd.
(Brand name) E4400P, E4600P and the like are commercially available.

In the present invention, an ionomer resin and C
The mixing ratio with EBC or SEBC is 95: 5-5
The range of 0:50 (weight ratio) is preferable. When CEBC or SEBC is small, the ionomer resin is not softened and the shot feeling of the golf ball is not improved. Also, CE
If BC or SEBC is too much, the initial velocity of the hit ball will be excessively reduced.

Further, the ratio of the mixture of the ionomer resin and CEBC or SEBC to the entire cover is:
90% by weight or more is preferable, and other polymers can be mixed in a range not exceeding 10% by weight of the entire cover.
In addition, if necessary, pigments, optical brighteners, antioxidants,
Additives such as an ultraviolet absorber, an ultraviolet stabilizer and a dispersant can be added.

[0011]

Example A rubber composition having the compounding ratio shown in Table 1 was heated and pressed in a core mold to obtain a solid core having a diameter of 38.3 mm.

Next, injection molding was carried out to coat the solid core with a resin composition having a compounding ratio shown in Tables 2 and 3 to obtain a two-piece golf ball.

Further, paint was applied to the surface of the golf ball to produce golf balls shown in Examples 1-8. These golf balls have a diameter of 42.75 mm
Met. The physical properties and performance of each golf ball obtained by the measurement are shown in Tables 2 and 3.

For the initial velocity of the hit ball, a swing robot apparatus is used, and the club head speed is 4 by the No. 1 wood club.
The measurement was performed by hitting a ball at 0 m / sec. The initial velocity efficiency indicates the speed ratio of the golf ball to the club head velocity at the time of measuring the initial velocity of the hit ball. The durability is an index with the durability of the golf ball of Comparative Example 1 as 100. The shot feeling is evaluated by an actual hit test by a senior male golfer, and ⊚ indicates extremely good, ∘ indicates good, and × indicates bad state.

In this case, Examples 1 to 1 in which the ionomer resins, Himiran 1605 and Himiran 1706, and CEBC, Dynaron E6100P were mixed were used.
In 6, the CEBC is Dynalon E610.
Compared to Comparative Example 1 in which 0P was not mixed, the initial velocity and initial velocity efficiency of the ball were hardly changed, but the surface hardness was decreased.
It is also understood that the durability is improved and the shot feeling is improved. Therefore, it can be understood that the characteristics of the golf ball are improved by mixing CECB with the cover material.

In addition, in Examples 1 to 6, high-milan 1605 and high-milan 1706, which are ionomer resins, are used.
And the blending ratio with Dynalon E6100P, which is CEBC, is set in the range of 95: 5 to 50:50, in Comparative Example 1, the blending ratio is 100: 0, and in Comparative Example 2, 98: 2, Comparative Example 3 is set to 95.2: 4.8, Comparative Example 4 is set to 45:55, and Comparative Example 5 is set to 0: 100. In this case, in Comparative Examples 1 to 3, there is almost no difference in other characteristics, but the surface hardness is higher than that in any of Examples 1 to 6, and in Comparative Examples 4 and 5, the durability is considerably improved. However, the initial velocity of the hit ball decreases as the surface hardness decreases. Further, in each of Comparative Examples 1 to 5, it is evaluated that the shot feeling is poor. Therefore,
The mixing ratio of the ionomer resin and CEBC in the cover material is preferably set in the range of 95: 5 to 50:50.

On the other hand, with respect to the ionomer resins used in Examples 1 to 6, SEBC, Dynaron E4400P.
As can be understood from the results of Examples 7 and 8 and Comparative Examples 6 and 7, in which the above-mentioned ionomer resin and SEBC were mixed.
The compounding ratio with is at least 90:10 to 75:25
It can be understood that in the range of 1, the surface hardness is lowered and the durability and shot feeling are improved while maintaining the initial velocity and initial velocity efficiency.

[0018]

[Table 1]

[0019]

[Table 2]

[0020]

[Table 3]

In Tables 2 and 3, * 1: ethylene-methacrylic acid copolymer type ionomer resin (sodium ion neutralization type) manufactured by Mitsui DuPont Polychemical Co., Ltd., * 2: Mitsui DuPont Polychemical Co., Ltd. ) Ethylene-methacrylic acid copolymer type ionomer resin (zinc ion neutralization type), * 3: polyolefin crystal / ethylene butylene / polyolefin crystal block copolymer (CEBC) manufactured by Nippon Synthetic Rubber Co., Ltd., * 4: Styrene / ethylene butylene / polyolefin crystal block copolymer (SEBC) manufactured by Japan Synthetic Rubber Co., Ltd.

[0022]

As described above, according to the present invention, by using the mixture of the ionomer resin and CEBC or SEBC as the cover material for the golf ball, the initial velocity of the hit ball is sufficiently maintained, and the hit feeling is good, and Thus, a highly durable golf ball can be obtained.

Claims (2)

[Claims] 1. A golf ball having a core covered with a cover, wherein the main material of the cover is (a) an ionomer resin, and (b) a polyolefin crystal / ethylene butylene / polyolefin crystal block copolymer or styrene. A golf ball which is a mixture of an ethylene butylene / polyolefin crystal block copolymer. 2. The golf ball according to claim 1, wherein the compounding ratio of (a) and (b) is 95: 5 to 50:50.
A golf ball having a range of