JP2001314530A - Multipiece solid golf ball - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multipiece solid golf ball obtaining a soft hitting feeling and having excellent carry performance. SOLUTION: This multipiece solid golf ball 10 is constituted by covering a solid core 12 having an inner layer 16, an intermediate layer 18 composed of a first layer 18a and a second layer 18b and an outer layer 20 with a cover 14. Shore D hardness of the second layer 18b is set to 40 to 65, and Shore D hardness of the inner layer 16 (an A layer) positioned inside the second layer 18b is set to 35 to 65. While, Shore D hardness of the first layer 18a (a B layer) and the outer layer 20 is in a range of 20 to 50 and set lower than the inner layer 16 and the second layer 18b. In the layers 16, 18a, 18b and 20 for constituting the solid core 12, Shore D hardness difference between the mutually adjacent layers is set not less than 5. One layer or plural layers may be interposed between the first layer 18a and the second layer 18b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-piece solid golf ball, and more particularly, to a multi-piece solid golf ball having a soft feel at impact and excellent flight distance performance.

[0002]

2. Description of the Related Art A two-piece solid golf ball having a single-layer solid core covered with a single-layer cover is conventionally known. However, although this type of golf ball has excellent flight distance performance, it has a disadvantage that the shot feeling is hard. Therefore, in recent years, at least one of the solid core and the cover has been replaced by two.
By forming one or more layers, or by interposing one or more intermediate layers between the solid core and the cover, a so-called multi-piece solid golf ball is formed,
Attempts have been made to provide golf balls having the same flight distance performance as a two-piece solid golf ball and a soft feel at impact.

Such golf balls include three-piece solid golf balls disclosed in JP-A-6-23069, JP-A-8-322964 and JP-A-8-332247, and JP-A-9-26695.
No. 9 and Japanese Patent Application Laid-Open No. 10-127818, etc., are exemplified. Further, Japanese Patent Application Laid-Open No. 10-216270 discloses a five-piece solid golf ball.

[0004]

However, there are not a few players who desire a golf ball that can provide a softer feel at impact than the above-mentioned multi-piece solid golf balls. In order to obtain a golf ball with a soft feel at impact, the hardness of the solid core and the cover may be reduced, but the soft solid core and the cover have poor resilience, so the flight distance performance as a golf ball is low. Invites the problem of

[0005] As described above, a multi-piece solid golf ball having a softer shot feeling and an excellent flight distance performance as compared with the above-described multi-piece solid golf balls has not yet been known.

An object of the present invention is to provide a multi-piece solid golf ball that can provide a soft feel at impact and has excellent flight distance performance.

[0007]

In order to achieve the above object, the present invention provides an inner layer, an intermediate layer covering the inner layer and comprising at least two layers, and an outermost layer located at the outermost side of the intermediate layer. A solid core having an outer layer covering the intermediate layer, and a cover covering the outer layer and having a higher Shore D hardness than the outer layer, wherein the outermost intermediate layer has a Shore D hardness of 40 to 65, Between the outermost intermediate layer and the A layer which is located inside the outermost intermediate layer and has a Shore D hardness of 35 to 65, the Shore D hardness is 20 to
50 and a B layer having a lower Shore D hardness than the outermost intermediate layer and the A layer is interposed, and the remaining solid except the outermost intermediate layer, the A layer and the B layer is interposed. The layer constituting the core has a Shore D hardness of 20 to 50, is lower than the outermost intermediate layer and the A layer, and further has a Shore D hardness difference of 5 or more between adjacent layers. Features.

In the present specification, the “layer A” is not a name of a specific layer but a “layer located inside the outermost intermediate layer and having a Shore D hardness of 35 to 65”. This is expressed for convenience. Similarly, the “layer B” is not a specific layer name, but “the layer B is interposed between the outermost intermediate layer and the layer A and has a Shore D hardness of 20 to 50.
And a layer having a lower Shore D hardness than the outermost intermediate layer and the A layer. " Therefore, the layer corresponding to the A layer or the B layer changes according to the number of intermediate layers of the solid core in the multi-piece solid golf ball according to the present invention, as described later.

By defining the Shore D hardness of each layer constituting the solid core as described above, the multi-piece solid golf ball having the same flight distance performance as a commercially available two-piece solid golf ball and having the above-mentioned prior art is used. The golf ball can provide a softer feel at impact than the golf ball.

In this multi-piece solid golf ball, the outermost intermediate layer preferably has a thickness of 1.0 to 6.0 mm and the outer layer preferably has a thickness of 1.0 to 3.0 mm. If the thickness of the outermost intermediate layer is greater than 6.0 mm or the thickness of the outer layer is less than 1.0 mm, the shot feeling may be hard. Further, the thickness of the outermost intermediate layer is less than 1.0 mm, or the thickness of the outer layer is 3.0 mm.
If the thickness is larger, the resilience of the multi-piece solid golf ball tends to be poor, and as a result, the flight distance performance may be reduced.

It is preferable that at least one of the layers constituting the solid core is made of a material containing a thermoplastic elastomer. This is because, when a layer is formed from a material containing a thermoplastic elastomer, an injection molding method can be employed as the method, so that the layer can be formed easily and efficiently in a short time.

The term "material containing a thermoplastic elastomer" as used herein includes a material composed of a single thermoplastic elastomer.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a multi-piece solid golf ball according to the present invention will be described below.
This will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic sectional view of a multi-piece solid golf ball according to a first embodiment of the present invention. The multi-piece solid golf ball 10 has a solid core 12 covered with a cover 14.

The solid core 12 includes an inner layer 16 and an intermediate layer 1.
8 and the outer layer 20 in this order from the inside. Also,
The intermediate layer 18 is formed by laminating a first layer 18a and a second layer 18b in this order from the inside. That is, the multi-piece solid golf ball 10 according to the first embodiment
This is a multi-layer solid golf ball having a five-layer structure including a solid core 12 having a layer structure and a cover 14 having a single layer structure.

By setting the Shore D hardness and thickness of each of the layers 16, 18 a, 18 b and 20 constituting the solid core 12, it is possible to control the flight distance performance and shot feeling of the multi-piece solid golf ball 10. it can.

Specifically, the Shore D hardness of the second layer 18b is set to 40 to 65, and the Shore D hardness of the inner layer 16 is set to 35 to 65. When the Shore D hardness of the inner layer 16 is less than 35 or the Shore D hardness of the second layer 18b is less than 40, the flight distance performance of the multi-piece solid golf ball 10 is reduced. In addition, the inner layer 16 or the second layer 1
When the Shore D hardness of any one of 8b exceeds 65, the shot feeling becomes hard.

On the other hand, of the layers constituting the solid core 12, the remaining layers other than the inner layer 16 and the second layer 18b,
That is, the Shore D hardness of the first layer 18a and the outer layer 20 is set to 20 to 50, and the inner layer 16 and the second layer 18
lower than b. When the Shore D hardness of either the first layer 18a or the outer layer 20 is less than 20, the flight distance performance of the multi-piece solid golf ball 10 is reduced. When the Shore D hardness of either the first layer 18a or the outer layer 20 exceeds 50, the shot feeling becomes hard. Further, when the Shore D hardness of either the first layer 18a or the outer layer 20 is equal to or higher than the Shore D hardness of the inner layer 16 and the second layer 18b, the shot feeling becomes hard.

That is, in the multi-piece solid golf ball 10 according to the first embodiment, the second layer 18b (outermost intermediate layer) having a Shore D hardness of 40 to 65 and the inner layer 18b located inside the second layer 18b. And Shore D hardness is 35 ~
The first layer 18a (layer B) having a Shore D hardness of 20 to 50 and having a lower Shore D hardness than the second layer 18b and the inner layer 16 between the inner layer 16 (layer A) and the inner layer 16 (layer A) within the range of 65. )
Is interposed. The Shore D hardness of the outer layer 20 covering the second layer 18b is in the range of 20 to 50
It is set lower than the layer 18b and the inner layer 16.

As described above, by alternately laminating a layer having a high Shore D hardness and a layer having a low Shore D hardness, the multi-piece solid golf ball 10 is a golf ball having a soft feel at impact and excellent flight distance performance. be able to.

Further, in each of the layers 16, 18a, 18b and 20 constituting the solid core 12, the difference in Shore D hardness between adjacent layers is set to 5 or more. Shore D
If the hardness difference is less than 5, the flight distance performance will be reduced or the shot feeling will be hard.

The material for forming the inner layer 16, the first layer 18a, the second layer 18b and the outer layer 20 may be a rubber composition containing natural rubber or synthetic rubber, a thermoplastic elastomer, a thermoplastic resin, or a thermoplastic elastomer. An elastomer / resin composition that is a mixture of a thermoplastic resin and a thermoplastic resin can be exemplified, and at least one of the inner layer 16, the first layer 18a, the second layer 18b, or the outer layer 20 is a thermoplastic elastomer or an elastomer / resin composition. It is preferable to form from a resin composition. This is because, when a layer is formed using a thermoplastic elastomer or an elastomer / resin composition, an injection molding method can be employed, so that the multi-piece solid golf ball 10 can be manufactured efficiently.

Examples of the rubber composition include synthetic rubbers such as polybutadiene rubber and polyisoprene rubber, metal salts of unsaturated carboxylic acids such as zinc acrylate, organic peroxides such as dicumyl peroxide, and fillers such as zinc oxide. Is exemplified. The rubber composition may further contain an antioxidant, a coloring agent, and the like, if necessary.

On the other hand, as the thermoplastic elastomer, polyurethane elastomer, polyester elastomer,
Examples thereof include polyamide elastomers, and examples of the thermoplastic resin include polyurethane resins and ionomer resins. In addition, as a preferable example of the ionomer resin,
Examples include a metal salt of an ethylene- (meth) acrylic acid copolymer and a metal salt of an ethylene- (meth) acrylate- (meth) acrylic acid terpolymer.

In the multi-piece solid golf ball 10, the second layer 18b has a thickness of 1.0 to 1.0.
6.0 mm, and the thickness of the outer layer 20 is 1.0 to 3.0.
mm is preferable. 5. The thickness of the second layer 18b is set to 6.
0 mm or the outer layer 20 has a thickness of 1.0
If it is less than mm, the shot feeling may be hard. Further, when the thickness of the second layer 18b is less than 1.0 mm or the thickness of the outer layer 20 is more than 3.0 mm, the resilience of the multi-piece solid golf ball 10 tends to be poor, and as a result, The flight distance performance may decrease.

The solid core 12 constructed as described above
Are covered by a cover 14.

The Shore D hardness of the cover 14 is set higher than that of the outer layer 20. When the Shore D hardness of the cover 14 is equal to or less than the Shore D hardness of the outer layer 20, the resilience of the multi-piece solid golf ball 10 becomes poor, and
Since the spin rate when the multi-piece solid golf ball 10 is hit tends to increase, the flight distance performance may decrease. The Shore D hardness of the cover 14 can be, for example, 45 to 75, but is not particularly limited thereto.

Examples of the material for forming the cover 14 include the above-mentioned thermoplastic elastomers, thermoplastic resins, and elastomer / resin compositions. Also, the cover 14
Can be, for example, 1.0 to 3.0 mm, but is not particularly limited to this.

Next, a multi-piece solid golf ball according to a second embodiment of the present invention will be described with reference to FIG. Note that the same reference numerals are given to the components shown in FIG. 1, and detailed description thereof will be omitted.

In the multi-piece solid golf ball 30 shown in FIG. 2, the intermediate layer 18 of the solid core 32 has a third layer 18c interposed between the first layer 18a and the second layer 18b. Except for the above, the multi-piece solid golf ball 10 according to the first embodiment described above
It is configured similarly to. That is, the multi-piece solid golf ball 30 according to the second embodiment is a six-layer solid golf ball having a five-layer solid core 32 and a single-layer cover 14.

This multi-piece solid golf ball 3
0, the Shore D hardness of the second layer 18b is 40-6.
5, and the Shore D hardness of the first layer 18a is set to 35 to 65. The inner layer 16, the third layer 18c and the outer layer 20, which are the remaining layers, have a Shore D hardness of 2
0 to 50, and these layers 16, 18
c and 20 have the first layer 18a and the second
It is set lower than the layer 18b.

That is, in the multi-piece solid golf ball 30 according to the second embodiment, the first layer 18a
Corresponds to the A layer, and the third layer 18c interposed between the second layer 18b (outermost intermediate layer) and the first layer 18a corresponds to the B layer. The Shore D hardness of the inner layer 16 and the outer layer 20, which are the remaining layers excluding the second layer 18b, the first layer 18a, and the third layer 18c, is in the range of 20 to 50 and the second layer 18b.
It is set lower than the layer 18b and the first layer 18a.

As will be understood from the above, in the multi-piece solid golf ball 30 according to the second embodiment, the outermost second layer 18b of the intermediate layer 18 has a Shore D hardness of 40. It is set in the range of ~ 65. A third layer 18c having a Shore D hardness in the range of 20 to 50 and lower than the second layer 18b is disposed inside the second layer 18b, and a shore is provided inside the third layer 18c. A first layer 18a having a D hardness of 35 to 65 is disposed, and an inner layer having a Shore D hardness within a range of 20 to 50 and lower than that of the first layer 18a is provided inside the first layer 18a. 16 are arranged.

As described above, by alternately laminating layers having a high Shore D hardness and layers having a low Shore D hardness, the multi-piece solid golf ball 30 is a golf ball having a soft feel at impact and excellent flight distance performance. be able to.

The reason why the Shore D hardness of each of the layers 16, 18a, 18c, 18b and 20 is within the above range is that the multi-piece solid golf ball 1 according to the first embodiment
Same as 0. In addition, these layers 16, 18a, 18
Shore D between adjacent layers among c, 18b and 20
The hardness difference is 5 or more and the reason is also as described above.

In the multi-piece solid golf ball 30 according to the second embodiment, the third layer 18c can be formed from a rubber composition, a thermoplastic elastomer, a thermoplastic resin, or an elastomer / resin composition as described above. . The thickness of the third layer 18c is, for example,
It can be about 1.0 to 8.0 mm.

In the above embodiment, the case where the intermediate layer 18 is composed of two or three layers has been described as an example, but the intermediate layer 18 is provided between the first layer 18a and the second layer 18b. You may make it interpose more than a layer. For example, the first
The third layer between the layer 18a and the second layer 18b (outermost intermediate layer)
When the layer, the fourth layer, and the fifth layer are interposed in this order from the inside, the Shore D hardness of the second layer 18b is set to 40 to 65 and the Shore D hardness of the fourth layer (A layer) is set to 35 to 65. 65
The Shore D hardness of the remaining layers including the inner layer 16 and the outer layer 20 may be set to 20 to 50. In this case, the fifth layer interposed between the second layer 18b and the fourth layer corresponds to the B layer. Needless to say, the Shore D hardness of the remaining layer is lower than that of the second layer 18b and the fourth layer.

[0038]

EXAMPLES Examples 1 to 7 and Comparative Examples 1 to 3 Polybutadiene, zinc acrylate, zinc oxide, an antioxidant, and dicumyl peroxide were added in a ratio of 100: 27: 70: 0.5: 1.
5 (weight ratio, the same applies hereinafter), and this mixture was compression-molded while heating to prepare an inner layer 16 having a rubber composition of the above-mentioned components and ratio and having a diameter of 25.0 mm.

Next, Hytrel 4047 (trade name, thermoplastic polyester elastomer manufactured by Toray DuPont)
And a Pebax 3533 (trade name, a thermoplastic polyamide elastomer manufactured by Atochem) in a ratio of 50:50 and injection-molded on the surface of the inner layer 16 to form a thermoplastic elastomer having a thickness of 1.5 mm. One layer 18a was produced.

Next, the same component as that of the inner layer 16 is 100: 3
The rubber composition blended at 4: 7: 0.5: 1.5 is the first rubber composition.
After coating the layer 18a, it is compression molded to a thickness of 4.2 m.
m second layer 18b was produced.

Next, Pebax 3533 and Himilan 1
605 (trade name, sodium ion neutralized ionomer resin of ethylene-methacrylic acid copolymer manufactured by Du Pont-Mitsui Polychemicals Co., Ltd.) and an elastomer / resin composition compounded at 70:30 on the surface of the second layer 18b. To form an outer layer 20 having a thickness of 1.3 mm.

Finally, a heat treatment was carried out in which Himilan 1605 and Himilan 1706 (trade name, ionized ionomer resin of zinc ion neutralized ethylene-methacrylic acid copolymer manufactured by DuPont Mitsui Polychemicals) were mixed at a ratio of 50:50. A plastic resin was injection-molded on the surface of the outer layer 20 to produce a cover 14 having a thickness of 1.9 mm to obtain a multi-piece solid golf ball 10 having a five-layer structure. Example 1
And

The Shore D hardness of each of the layers 16, 18a, 18b, 20 and the cover 14 is 52, 3 respectively.
8, 56, 41 and 70.

Further, a multi-piece solid golf ball 10 having a five-layer structure was obtained according to Example 1, except that the components and proportions were as shown in FIG. These were used in Example 2
To 6. In FIG. 3, Hytrel 4767 is used.
And Hytrel 3078 are trade names of thermoplastic polyester elastomers manufactured by Dupont Toray. Also,
Surlyn 8542 is a magnesium ion neutralized ionomer resin of ethylene-methacrylic acid-acrylate terpolymer manufactured by DuPont, and Dumilan C15
50 is a partially saponified resin of a modified ethylene-vinyl acetate copolymer manufactured by Takeda Pharmaceutical Company.

Further, in the same manner as in Example 1, the inner layer 16 having the components and ratios shown in FIG.
a, an intermediate layer 1 composed of a second layer 18b and a third layer 18c
8 and the outer core 20 have a solid core 32
4 to produce a multi-piece solid golf ball 30. This is Example 7.

The solid core 12 in the multi-piece solid golf balls 10 and 30 of Examples 1 to 7
FIG. 4 also shows the Shore D hardness and thickness of each of the 32 layers 16, 18a, 18c, 18b, and 20, and the cover 14, and the diameter of the entire golf ball.

For comparison, a two-piece solid golf ball was manufactured by forming the solid core into a single layer structure composed of a rubber composition having the components and proportions shown in FIG. 3 and covering the solid core with a cover. That is, the two-piece solid golf ball does not include the mid layer 18 and the outer layer 20. This is referred to as Comparative Example 1.

Further, a multi-piece solid golf having a second layer and a layer other than the inner layer located inside three layers counted from the second layer, that is, one of the first layer and the outer layer has a Shore D hardness of more than 50. Balls were manufactured. These are referred to as Comparative Examples 2 and 3, respectively.

The materials for forming the layers of the solid core and the cover in the golf balls of Comparative Examples 1 to 3 and their proportions are shown in FIG. 3, and the Shore D hardness and thickness are shown in FIG.

The initial speeds of the golf balls of Examples 1 to 7 and Comparative Examples 1 to 3 were measured according to the initial speed test method specified by the American Golf Association. The higher the initial velocity, the higher the resilience, and therefore, the golf ball that is superior in flight distance performance. The results are also shown in FIG.

It is apparent from FIG. 4 that all of the multi-piece solid golf balls 10 and 30 of Examples 1 to 7 have approximately the same flight distance performance as the two-piece solid golf ball of Comparative Example 1.

Each of the solid golf balls of Examples 1 to 7 and Comparative Examples 1 to 3 was hit by a senior male golfer, and the shot feeling at that time was evaluated. In FIG. 4, the results are shown with "O" when the shot feeling is soft and "X" when hard.

As will be understood from FIG.
In the multi-piece solid golf balls 10 and 30, soft hit feeling was obtained. On the other hand, the two-piece solid golf balls of Comparative Example 1 and the multi-piece solid golf balls of Comparative Examples 2 and 3 were hard to hit.
The reason is that both the solid core and the cover are hard in Comparative Example 1, and the second core in Comparative Examples 2 and 3.
This is probably because the Shore D hardness of the layers other than the layer and the inner layer exceeds 50.

[0054]

As described above, the multi-piece solid golf ball according to the present invention has excellent flight distance performance. Moreover, when hitting the multi-piece solid golf ball, a softer hit feeling can be obtained as compared with the multi-piece solid golf ball according to the prior art.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a multi-piece solid golf ball according to a first embodiment of the present invention.

FIG. 2 is a schematic sectional view of a multi-piece solid golf ball according to a second embodiment of the present invention.

FIG. 3 is a table showing the materials forming the solid core and the cover in the golf balls of Examples 1 to 7 and Comparative Examples 1 to 3 and their ratios.

FIG. 4 is a chart showing Shore D hardness and thickness, initial velocity and shot feeling of solid cores and covers in golf balls of Examples 1 to 7 and Comparative Examples 1 to 3.

[Explanation of symbols]

 10, 30: multi-piece solid golf ball 12, 32: solid core 14: cover 16: inner layer 18: middle layer 18a: first layer 18b: second layer 18c: third layer 20: outer layer

Continued on the front page (72) Inventor Yoji Watanabe 5412 Shisato-cho, Shido-cho, Okawa-gun, Kagawa Prefecture Inside Casco Co., Ltd.

Claims (3)

[Claims] 1. A solid core comprising an inner layer, an intermediate layer covering the inner layer and comprising at least two layers, and an outer layer covering an outermost intermediate layer located on the outermost side of the intermediate layer; and covering the outer layer. And a cover having a higher Shore D hardness than the outer layer. The outermost intermediate layer has a Shore D hardness of 40 to 65, and is located inside the outermost intermediate layer and the outermost intermediate layer. A layer B having a Shore D hardness of 20 to 50 and a Shore D hardness lower than the outermost intermediate layer and the A layer is interposed between the layer A having a Shore D hardness of 35 to 65. The outermost intermediate layer, the layer constituting the remaining solid core excluding the layer A and the layer B has a Shore D hardness of 20 to
50. The multi-piece solid golf ball according to claim 1, wherein the difference between the outermost intermediate layer and the A layer is lower than that of the outermost intermediate layer and the A layer, and the difference in Shore D hardness between adjacent layers is 5 or more. 2. The multi-piece solid golf ball according to claim 1, wherein said outermost intermediate layer has a thickness of 1.0 to 1.0.
6.0 mm, and the thickness of the outer layer is 1.0 to 3.0.
A multi-piece solid golf ball having a diameter of 0 mm. 3. The multi-piece solid golf ball according to claim 1, wherein at least one of the layers constituting said solid core is formed of a material containing a thermoplastic elastomer. Solid golf ball.