JP3543629B2 - Multi-piece solid golf ball - Google Patents

Description

＊１：「ハイトレル」東レ・デュポン社製ポリエステル系エラストマー
＊２：「プリマロイ」三菱化学工業（株）製ポリエステル系エラストマーを主成分とするアロイ材料
＊３：「ペバックス」アトケム社製ポリアミド系エラストマー
＊４：「パンデックス」大日本インキ化学工業（株）製ポリウレタン系エラストマー
＊５：「ハイミラン」三井・デュポンポリケミカル社製アイオノマー樹脂
＊６：「サーリン」デュポン社製アイオノマー樹脂
【００５１】
【表２】

【００５２】
表２の結果から明らかなように、比較例１は一般的なツーピースソリッドゴルフボールであり、飛距離は比較的良好であるが、ドライバーとパターの打感がともに硬く劣るものである。
【００５３】
比較例２は特開平９−３１３６４３号公報と同様のスリーピースソリッドゴルフボールであり、飛距離がやや低下する上に、ドライバーとパターの打感がともにやや硬く劣るものである。
【００５４】
比較例３は特開平１０−１２７８１９号公報と同様のフォーピースソリッドゴルフボールであるが、各層の硬度や厚さが適当なものではなく、各層の界面でエネルギーロスが生じ、このため飛距離が著しく劣る上に、小変形打撃時（パター）での打感が硬いものである。
【００５５】
これに対して実施例１〜５のボールは、エネルギーロスのないボール構造を有するために反発性に優れ、飛距離が増大すると共に、ドライバーでもパターでも非常に軟らかく良好な打感が得られるものである。
【図面の簡単な説明】
【図１】本発明の一実施例に係るマルチピースソリッドゴルフボールの断面図である。
【符号の説明】
１ ソリッドコア
２ 包囲層
３ 中間層
４ カバー
Ｇ ゴルフボール[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a multi-piece solid golf ball having at least a four-layer structure including a solid core, an envelope layer, an intermediate layer, and a cover. The multi-piece solid golf ball has excellent resilience (flying performance) and is very soft and has a good feel. The present invention relates to a piece solid golf ball.
[0002]
Problems to be solved by the prior art and the invention
Conventionally, solid golf balls, such as two-piece golf balls, which have been proposed in many cases, have a ballistic trajectory called a so-called rod ball for both driver shots and iron shots as compared to thread-wound golf balls, and due to their structural characteristics that are less likely to be spun, This has the advantage that the total flight distance increases due to the increase in the number of shots.
[0003]
On the other hand, solid golf balls tend to be harder to stop on the green and have less controllability than thread-wound golf balls because they are less likely to spin on irons than on thread-wound golf balls.
[0004]
On the other hand, a golf ball is required to have a feeling of impact at the time of hitting along with an increase in flight distance, and without this, the commercial value is impaired. In general, thread-wound golf balls have structural characteristics that are very soft and provide good hit feeling as compared with solid golf balls.
[0005]
For this reason, in a two-piece solid golf ball composed of a core and a cover, it is generally practiced to soften the ball structure in order to achieve a soft feel at the time of hitting, but a ball that sufficiently satisfies the demand has been obtained. Numerous three-piece solid golf balls with an intermediate layer between the core and the cover have been proposed, but these proposals also combine the flight distance of a two-piece solid golf ball with the feel of a thread-wound golf ball. It was extremely difficult to obtain a good golf ball.
[0006]
Recently, a multi-piece solid golf ball having a four-layer structure or more has been proposed (JP-A-9-266959, JP-A-10-127818, JP-A-10-127819, etc.).
[0007]
These proposals provide a four-layer solid golf ball having a solid core having a three-layer structure of an inner layer, an intermediate layer, and a cover layer, and a cover covering the solid core, and providing a hardness difference between these layers. Thus, the hit feeling and controllability are improved.
[0008]
However, if the hardness difference between the layers is large or if the thickness or material of each layer is not appropriate, the amount of deformation at the time of impact greatly differs between the layers, so that energy loss occurs at the interface of each layer and the resilience decreases, As a result, there is a problem that the flight distance is reduced and the durability at the time of continuous impact is also deteriorated.
[0009]
In particular, when the material of the adjacent layers is different and the adhesiveness thereof is low, the tendency is remarkable, and when the hardness difference between the adjacent layers is reduced, the effect of improving the hit feeling is rather impaired. There is.
[0010]
The present invention has been made in view of the above circumstances, and has a solid core, a surrounding layer covering the core, at least one intermediate layer covering the surrounding layer, and at least one cover covering the intermediate layer. It is an object of the present invention to provide a multi-piece solid golf ball having a very soft and good feel while maintaining excellent flight performance of the solid golf ball.
[0011]
Means for Solving the Problems and Embodiments of the Invention
The present inventor has conducted intensive studies to achieve the above object, and as a result, in a multi-piece solid golf ball having at least a four-layer structure including a solid core, a surrounding layer, an intermediate layer, and a cover, the hardness and thickness of each layer, By adjusting the rate of change of the amount of deformation of each material before and after covering each layer so as to satisfy a certain range, it is excellent in resilience, controllability, and very soft and good hit feeling It has been found that a multi-piece solid golf ball having the same can be obtained.
[0012]
That is, a solid core, a surrounding layer mainly composed of a thermoplastic resin covering the core, at least one intermediate layer covering the surrounding layer, and at least one cover covering the intermediate layer are provided. In the multi-piece solid golf ball, (1) the Shore D hardness of the surrounding layer and the intermediate layer is 10 to 50, the Shore D hardness of the cover is 50 to 65, and the Shore D hardness of the surrounding layer and the intermediate layer and the cover And the Shore D hardness of the surrounding layer ≦ the Shore D hardness of the intermediate layer ≦ the Shore D hardness of the cover, that is, the cover, the intermediate layer and the surrounding layer are softer toward the inner side. By forming so that energy loss due to deformation at the time of impact can be suppressed as small as possible, resilience is improved, and (2) 100 k of solid core The amount of deformation A (mm) under load is 5.0 to 6.8 mm, and the solid core is covered with a surrounding layer having a thickness of 0.5 to 4.0 mm at a load of 100 kg. Of a spherical body having an intermediate layer having a thickness of 0.5 to 4.0 mm around a surrounding layer having a deformation amount B (mm) of 2.3 to 7.0 mm under a load of 100 kg, C (Mm) is 2.3 to 6.5 mm, and the deformation amount D (mm) of the entire ball covered with a cover having a thickness of 1.0 to 3.5 mm around the intermediate layer under a load of 100 kg is 2 0.3 to 6.0 mm and satisfy the following relationships: 0.98 ≦ B / A ≦ 1.01, 0.96 ≦ C / B ≦ 0.98, 0.79 ≦ D / C ≦ 0.83, respectively. Thus, the change rate (B / A, C) of the deformation amount of each spherical body before and after each layer is covered B, D / C) can be set to a value close to 1, energy loss on each layer surface at the time of impact can be minimized, and reduction in resilience can be suppressed, more preferably. (3) By forming the surrounding layer and the intermediate layer using the same type of thermoplastic resin as the main material, the adhesion between the surrounding layer and the intermediate layer is improved, and the resilience is excellent. The present inventors have found that 3) acts synergistically to obtain a multi-piece solid golf ball having excellent flying performance and a very soft and good hit feeling, which has never been achieved before, and completed the present invention.
[0013]
Therefore, the present invention
(1) A solid core, an envelope layer mainly composed of a thermoplastic resin covering the core, at least one intermediate layer covering the envelope layer, and at least one cover covering the intermediate layer. In the multi-piece solid golf ball, the Shore D hardness of the surrounding layer and the intermediate layer is 10 to 50, the Shore D hardness of the cover is 50 to 65, and the Shore D hardness of the surrounding layer and the intermediate layer and the cover The Shore D hardness satisfies the relationship of Shore D hardness of the surrounding layer ≤ Shore D hardness of the intermediate layer ≤ Shore D hardness of the cover, and the diameter of the solid core is 25.7 to 37.7 mm; The amount of deformation A (mm) under load of 5.0 to 6.8 mm, and a spherical body having a solid core and a surrounding layer having a thickness of 0.5 to 4.0 mm coated around the solid core 1 Deformation amount B (mm) under a load of 0 kg is 2.3 to 7.0 mm, and a spherical body coated with an intermediate layer having a thickness of 0.5 to 4.0 mm around the surrounding layer is subjected to a load of 100 kg. A deformation amount C (mm) of 2.3 to 6.5 mm, and a deformation amount D (at the time of a load of 100 kg) of the entire ball covered with a cover having a thickness of 1.0 to 3.5 mm around the intermediate layer. mm) is 2.3 to 6.0 mm, and 0.98 ≦ B / A ≦ 1.01, 0.96 ≦ C / B ≦ 0.98, 0.79 ≦ D / C ≦ 0.83, respectively. Multi-piece solid golf ball, characterized by satisfying the relationship of
(2) The multi-piece solid golf ball according to (1), wherein the total thickness of the surrounding layer and the intermediate layer is 2.0 to 5.0 mm, and (3) the same type of thermoplastic resin as the surrounding layer and the intermediate layer. The multi-piece solid golf ball according to (1) or (2), which is formed mainly from
[0014]
Hereinafter, the present invention will be described in more detail. As shown in FIG. 1, a multi-piece golf ball G of the present invention comprises a solid core 1, an envelope layer 2 covering the core 1, and an envelope layer 2 covering the core 1. And at least one cover 4 that covers the intermediate layer 3.
[0015]
The solid core 1 can be formed from a rubber composition mainly composed of a base rubber mainly composed of polybutadiene rubber, polyisoprene rubber, natural rubber, and silicone rubber. Is preferably a polybutadiene rubber. As the polybutadiene rubber, cis-1,4-polybutadiene having a cis structure of at least 40% or more is preferable. In addition, in the base rubber, natural rubber, polyisoprene rubber, styrene butadiene rubber, and the like can be appropriately blended with the polybutadiene, if desired. However, by increasing the polybutadiene rubber component, the resilience of the golf ball is improved. Therefore, the rubber component other than polybutadiene is preferably not more than 10 parts by weight based on 100 parts by weight of polybutadiene.
[0016]
The rubber composition may contain, in addition to the rubber component, a crosslinking agent such as zinc salts of unsaturated fatty acids such as zinc methacrylate and zinc acrylate, and magnesium salts and ester compounds such as trimethylpropane methacrylate. Zinc acrylate can be suitably used because of its height. The amount of the crosslinking agent is preferably 10 to 40 parts by weight based on 100 parts by weight of the base rubber.
[0017]
In addition, a vulcanizing agent such as dicumyl peroxide is usually compounded in the rubber composition, and the compounding amount of the vulcanizing agent is 0.1 to 5 parts by weight based on 100 parts by weight of the base rubber. can do.
[0018]
The rubber composition may further contain, if necessary, an antioxidant or a filler for adjusting specific gravity, such as zinc oxide or barium sulfate. The amount of these fillers is 100 wt. 0 to 130 parts by weight per part.
[0019]
Preferred embodiments of the rubber composition for a core according to the present invention are as follows.
[0020]
Cis-1,4-polybutadiene 100 parts by weight Zinc oxide 0 to 50 parts by weight Zinc acrylate 10 to 40 parts by weight Barium sulfate 0 to 50 parts by weight Peroxide 0.1 to 5.0 parts by weight Antioxidant Appropriate vulcanization conditions : Vulcanization is preferably performed at 150 ± 10 ° C. for 5 to 20 minutes.
[0021]
The rubber composition for a core is kneaded using a usual kneader (for example, a Banbury mixer, a kneader, a roll, or the like), and the obtained compound is formed by injection molding or compression molding using a core mold. .
[0022]
The solid core thus obtained has a diameter of 25.7 to 37.7 mm, preferably 28 to 37 mm.
[0023]
The amount of deformation A (mm) of the core under a load of 100 kg is 5.0 to 6.8 mm, and preferably 5.0 to 6.5 mm. If the amount of deformation is less than 5.0 mm, the feel when hitting a large deformation such as a driver shot may be hard, and if it exceeds 6.8 mm, the resilience is reduced and good flight performance cannot be obtained.
[0024]
The core may have a single-layer structure made of one kind of material, or may have a multi-layer structure made up of two or more layers made of different kinds of materials.
[0025]
In the present invention, the surrounding layer 2 is formed around the core 1. The surrounding layer 2 is formed mainly of a thermoplastic resin, and examples thereof include an ionomer resin, a polyester-based elastomer, a polyamide-based elastomer, a styrene-based elastomer, a polyurethane-based elastomer, an olefin-based elastomer, and a mixture thereof. Thermoplastic polyester-based elastomers and polyurethane-based elastomers having good resilience at a hardness of are preferred. Specifically, commercially available products such as "Hytrel" (manufactured by Dupont Toray), "Pandex" (manufactured by Dainippon Ink and Chemicals), and "Primalloy" (manufactured by Mitsubishi Chemical Corporation) can be used. it can.
[0026]
In addition, an antioxidant, a dispersant such as metal soap, or the like can be added to the surrounding layer composition as needed, and the surrounding layer may be formed of a plurality of layers made of different materials.
[0027]
The method for coating the surrounding layer around the core is not particularly limited, and ordinary injection molding or compression molding can be employed.
[0028]
The thickness of the envelope layer formed in this way is 0.5 to 4.0 mm, preferably 0.7 to 3.5 mm, and its Shore D hardness is 10 to 50, preferably 15 to 47.
[0029]
The amount of deformation B (mm) under a load of 100 kg of the spherical body formed by coating the core with the surrounding layer is 2.3 to 7.0 mm, preferably 2.5 to 6.5 mm.
[0030]
Next, at least one, preferably one or two intermediate layers 3 are formed around the surrounding layer 2. It is preferable that the intermediate layer 3 is formed mainly of the same type of thermoplastic resin as the surrounding layer. By forming the surrounding layer and the intermediate layer from the same type of material, the adhesion between the two becomes high. Durability and resilience are improved. In addition, a UV absorber, an antioxidant, a dispersant such as metal soap, and the like can be added to the intermediate layer material as needed.
[0031]
The method of coating the intermediate layer around the surrounding layer is not particularly limited, and ordinary injection molding or compression molding can be employed.
[0032]
The thickness of the intermediate layer formed in this manner is 0.5 to 4.0 mm, preferably 0.7 to 3.5 mm, and the total thickness of the surrounding layer and the intermediate layer is preferably 2.0 to 4.0. It is 5.0 mm, more preferably 2.0 to 4.5 mm. If the total thickness of the surrounding layer and the intermediate layer is smaller than the above range, the effect of improving the feel may be reduced. On the other hand, if the total thickness is larger than the above range, the resilience may be reduced.
[0033]
Further, the Shore D hardness of the intermediate layer is 10 to 50, preferably 15 to 47. When the intermediate layer is a multilayer, the Shore D hardness of each layer falls within the above hardness range.
[0034]
Here, the deformation amount C (mm) under a load of 100 kg of the spherical body in which the intermediate layer is coated around the surrounding layer is 2.3 to 6.5 mm, preferably 2.5 to 6.0 mm. The cover 4 can be formed using a usual thermoplastic resin as a main material, and examples thereof include an ionomer resin, a polyester-based elastomer, a polyamide-based elastomer, a styrene-based elastomer, a polyurethane-based elastomer, an olefin-based elastomer, and a mixture thereof. However, it is particularly preferable to use an ionomer resin as a main material, and specific examples thereof include “HIMILAN” (manufactured by DuPont-Mitsui Polychemicals) and “Surlyn” (manufactured by DuPont). In addition, titanium dioxide for coloring, and a dispersant such as a UV absorber, an antioxidant, and a metal soap can also be added to the cover material, if necessary.
[0035]
This cover can be formed in at least one layer, preferably one layer or two layers. The method of covering this cover is not particularly limited, and ordinary injection molding or compression molding can be employed.
[0036]
The cover thus formed has a thickness of 1.0 to 3.5 mm, preferably 1.0 to 3.0 mm, and a Shore D hardness of 50 to 65.
[0037]
Here, the deformation amount D (mm) under a load of 100 kg of a spherical body (that is, the whole ball) having a cover formed around the intermediate layer is 2.3 to 6.0 mm, preferably 2.5 to 5. 5 mm.
[0038]
In the present invention, it is necessary that the Shore D hardness of the surrounding layer, the intermediate layer and the cover satisfy the relationship of Shore D hardness of the surrounding layer ≦ Shore D hardness of the intermediate layer ≦ Shore D hardness of the cover. Preferably, the Shore D hardness of the surrounding layer is 3 to 30 lower than the Shore D hardness of the intermediate layer, and the Shore D hardness of the intermediate layer is 5 to 35 lower than the Shore D hardness of the cover.
[0039]
As described above, each layer constituting the ball satisfies the above-mentioned range of Shore D hardness, that is, the cover, the intermediate layer, and the surrounding layer are formed so as to become softer toward the inside, so that energy loss due to deformation at impact can be reduced. It can be kept as small as possible, the resilience is improved, and the flight distance is increased.
[0040]
Further, in the present invention, the change rates (B / A, C / B, D / C) of the deformation amounts A to D under a load of 100 kg of each spherical body before and after covering each layer are set to values close to 1. Set to be.
[0041]
That is, the deformation amount A (mm) of the solid core under a load of 100 kg, the deformation amount B (mm) of a spherical body having the surrounding layer coated around the solid core under a load of 100 kg, and an intermediate amount around the surrounding layer. It is necessary that the deformation amount C (mm) of the spherical body coated with the layer under a load of 100 kg and the deformation amount D (mm) of the entire ball under a load of 100 kg satisfy the following relationship.
[0042]
0.98 ≦ B / A ≦ 1.01,
0.96 ≦ C / B ≦ 0.98,
0.79 ≦ D / C ≦ 0.83,
If the rate of change of the deformation amount of each of these spherical bodies deviates from the above relationship, the deformation amount at the time of impact greatly differs between each layer, energy loss occurs at the interface of each layer, resilience decreases, and flight distance is increased. You can't do that.
[0043]
The multi-piece solid golf ball of the present invention has the above structure, and adjusts the material between layers, hardness, thickness, the rate of change of the deformation amount of each spherical body before and after covering each layer, and the like to an optimum one. As a result, it is possible to form a ball structure with less energy loss, and to have excellent flight performance due to the improved resilience, and very soft hitting both when hitting a large deformation (driver) and when hitting a small deformation (putter). It has a feeling.
[0044]
The golf ball of the present invention has a large number of dimples formed on the surface thereof, and the surface can be subjected to finishing treatment such as painting and stamping as necessary. Further, the ball diameter and weight can be formed to a diameter of not less than 42.67 mm and a weight of not more than 45.93 g according to the R & A golf rules.
[0045]
【The invention's effect】
According to the present invention, a multi-piece solid golf ball having both excellent flight performance and a very soft feel is obtained.
[0046]
【Example】
Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. The amounts in Table 1 are all parts by weight.
[0047]
(Examples, Comparative Examples)
Examples 1 to 5 and Comparative Examples 1 to 3 were obtained by kneading the core rubber composition having the compounding formulation shown in Table 1 with a kneader and vulcanizing it at a temperature of 155 ° C. for about 15 minutes in a core mold. Created a solid core.
[0048]
The surrounding core material, the intermediate layer material, and the cover material shown in Table 1 were respectively formed around the obtained core by injection molding to obtain solid golf balls having a four-layer structure of Examples 1 to 5 and Comparative Example 3. Created. Comparative Example 1 is a two-piece golf ball having a core and a cover without an envelope layer and an intermediate layer, and Comparative Example 2 is a three-piece golf ball without an envelope layer.
[0049]
Next, the properties of the obtained golf ball were evaluated by the methods shown below. Table 2 shows the results. The solid core hardness A, the hardness B of the spherical body with the surrounding layer coated around the core, the hardness C of the spherical body with the intermediate layer coated around the surrounding layer, and the ball hardness D were obtained by coating each layer in the molding process. The measurement was performed in each state.
Solid core hardness A
It was represented by the amount of deformation (mm) when a load of 100 kg was applied to the core.
Hardness B of spherical body with surrounding layer coated around core
The deformation amount (mm) when a load of 100 kg was applied to the spherical body in which the surrounding layer was coated around the core was expressed.
Hardness C of a spherical body with an intermediate layer coated around the surrounding layer
The deformation amount (mm) when a load of 100 kg was applied to the spherical body in which the intermediate layer was coated around the surrounding layer was expressed.
Ball hardness D
It was represented by the amount of deformation (mm) when a load of 100 kg was applied to the ball.
Flying performance At a head speed of 45 m / sec (HS45), the club was actually hit with a driver ("PRO230Titan loft 10 degrees" (Bridgestone Sports Co., Ltd.)) by a swing robot manufactured by Miyama Co., Ltd. Carry and total flight distance were measured.
Feel of hitting Five professional golfers evaluated the feeling of hitting with a driver and a putter as a club based on the following criteria.
◎: very soft ○: soft △: normal ×: hard
[Table 1]

* 1: "Hytrel" polyester elastomer manufactured by Toray DuPont * 2: "Primalloy" alloy material containing polyester elastomer manufactured by Mitsubishi Chemical Corporation * 3: "Pebax" polyamide elastomer manufactured by Atochem * 4: "Pandex" polyurethane elastomer manufactured by Dainippon Ink and Chemicals, Inc. * 5: "Himilan" ionomer resin manufactured by Mitsui / Dupont Polychemicals * 6: "Surlyn" ionomer resin manufactured by DuPont
[Table 2]

[0052]
As is evident from the results in Table 2, Comparative Example 1 is a general two-piece solid golf ball, which has a relatively good flight distance, but is hard and inferior in both the driver and the putter feel.
[0053]
Comparative Example 2 is a three-piece solid golf ball similar to that of Japanese Patent Application Laid-Open No. 9-313643, in which the flight distance is slightly reduced, and the hit feeling of both the driver and the putter is slightly hard and inferior.
[0054]
Comparative Example 3 is a four-piece solid golf ball similar to Japanese Patent Application Laid-Open No. 10-127819, but the hardness and thickness of each layer are not appropriate, and energy loss occurs at the interface between the layers. In addition to being extremely inferior, the ball has a hard feel when hitting with a small deformation (putter).
[0055]
On the other hand, the balls of Examples 1 to 5 are excellent in resilience due to having a ball structure with no energy loss, increase the flight distance, and are very soft even with a driver or a putter, so that a good hit feeling can be obtained. It is.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a multi-piece solid golf ball according to one embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Solid core 2 Surrounding layer 3 Intermediate layer 4 Cover G Golf ball

Claims (3)

A multi-piece comprising a solid core, a surrounding layer mainly composed of a thermoplastic resin covering the core, at least one intermediate layer covering the surrounding layer, and at least one cover covering the intermediate layer. In the solid golf ball, the Shore D hardness of the surrounding layer and the intermediate layer is 10 to 50, the Shore D hardness of the cover is 50 to 65, and the Shore D hardness of the surrounding layer and the intermediate layer and the Shore D hardness of the cover. Satisfy the relationship of Shore D hardness of the surrounding layer ≦ Shore D hardness of the intermediate layer ≦ Shore D hardness of the cover, and the diameter of the solid core is 25.7 to 37.7 mm, and the solid core is loaded with a load of 100 kg. Of a spherical body having a deformation amount A (mm) of 5.0 to 6.8 mm and a surrounding layer having a thickness of 0.5 to 4.0 mm coated around the solid core. The amount of deformation B (mm) under load is 2.3 to 7.0 mm, and the spherical body coated with an intermediate layer having a thickness of 0.5 to 4.0 mm around the surrounding layer at 100 kg load The deformation amount C (mm) is 2.3 to 6.5 mm, and the deformation amount D (mm) of the entire ball covered with a cover having a thickness of 1.0 to 3.5 mm around the intermediate layer is 100 kg. ) Is 2.3 to 6.0 mm and 0.98 ≦ B / A ≦ 1.01, 0.96 ≦ C / B ≦ 0.98, and 0.79 ≦ D / C ≦ 0.83, respectively. A multi-piece solid golf ball that satisfies the relationship. 2. The multi-piece solid golf ball according to claim 1, wherein the total thickness of the surrounding layer and the intermediate layer is 2.0 to 5.0 mm. 3. The multi-piece solid golf ball according to claim 1, wherein the surrounding layer and the intermediate layer are formed mainly of the same thermoplastic resin.

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