JPH1176458A - Golf ball - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a golf ball having good spin characteristic while good repulsion is secured by increasing the inertia moment of the golf ball without damaging the physical property of rubber or synthetic resin which is the base material of a layer for forming the golf ball. SOLUTION: A metal layer 6 is provided between a core 4 and a cover 8, between an inner core and an outer core, or between an inner layer cover and an outer layer cover. The distance (a) between the center of the core 4 or the inner core and the inner surface of the metal layer 6 is 17 mm or more, and the weight of the metal layer 6 is 0.2-4.0 g. As metal for forming the metal layer 6, nickel is preferable. Further it is suitable to form the metal layer by a plating method.

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 large moment of inertia and excellent spin characteristics.

[0002]

2. Description of the Related Art In order to increase the moment of inertia of a golf ball during flight, a large amount of a weight adjusting agent such as a metal powder or a metal oxide powder is added to a rubber layer or a synthetic resin layer near the surface of the golf ball. It is known to increase the specific gravity of this layer by adding it (Japanese Patent Laid-Open No. 60-53164).
JP-A-60-210272, JP-A-61-290
No. 969).

[0003]

However, when a large amount of a weight adjusting agent such as a metal powder and a metal oxide powder is added to a rubber layer or a synthetic resin layer, the addition of a large amount of the weight adjusting agent causes Rubber or synthetic resin as a base material of the rubber layer or synthetic resin layer is likely to be hard and brittle in mechanical properties. In addition, when a weight adjuster is added to rubber or synthetic resin, the resilience of rubber or synthetic resin tends to be lower than when not added, and this tendency becomes more pronounced as the amount of weight adjuster added increases. . Therefore, in the conventional golf ball described above, there is a limit to the amount of the weight adjuster that can be added to the rubber layer or the synthetic resin layer existing near the surface of the golf ball without impairing the physical properties of the base material rubber or the synthetic resin. Therefore, a sufficient effect of increasing the moment of inertia could not be obtained.

The present invention has been made in view of the above circumstances, and increases the moment of inertia without impairing the physical properties of rubber or synthetic resin as a base material of a layer constituting a golf ball. It is an object of the present invention to provide a golf ball capable of obtaining excellent spin characteristics while securing the golf ball.

[0005]

The present invention provides the following first invention to third invention to achieve the above object. First invention: a metal layer is provided between the core and the cover, the distance between the center of the core and the inner surface of the metal layer is 17 mm or more, and the weight of the metal layer is 0.2 to 4. A golf ball weighing 0 g. Second invention: a metal layer is provided between the inner core and the outer core, the distance between the center of the inner core and the inner surface of the metal layer is 17 mm or more, and the weight of the metal layer is 0.2 A golf ball weighing 4.0 g. Third invention: a metal layer is provided between the inner cover and the outer cover, and the distance between the center of the core and the inner surface of the metal layer is 1
7 mm or more, and the weight of the metal layer is 0.2 to
A golf ball weighing 4.0 g.

[0006] The golf ball of the present invention is provided between a core and a cover (first invention), between an inner core and an outer core (second invention), or between an inner cover and an outer cover (third invention). ) Is provided with a metal layer, and the distance between the center of the core or the inner core and the inner surface of the metal layer is 17 mm.
With the above, a large amount of weight is distributed near the surface of the golf ball to increase the moment of inertia. Therefore, in the present invention, the moment of inertia is increased without adding a weight adjusting agent such as a metal powder and a metal oxide powder to the rubber layer or the synthetic resin layer constituting the golf ball in such a large amount that the physical properties are impaired. Therefore, the resilience of the rubber layer and the synthetic resin layer is not impaired. Also,
By selecting the weight of the metal layer, the degree of increase in the moment of inertia can be adjusted widely. for that reason,
In the golf ball of the present invention, the moment of inertia can be increased to a desired degree while securing good resilience.

Hereinafter, the present invention will be described in more detail. In the present invention, the ball of the first invention has a core and a cover, the ball of the second invention has a core and a cover comprising an inner core and an outer core, and the ball of the third invention has a core, an inner cover and And a cover made of an outer layer cover. In this case, the material of the core according to the first and third inventions and the material of the inner core and the outer core according to the second invention are not limited. For example, vulcanization mainly containing polybutadiene rubber, polyisoprene rubber, natural rubber, silicone rubber, etc. Although rubber can be used, it is particularly preferable to use vulcanized rubber containing polybutadiene rubber as a main component. The above-described core, inner core, and outer core may each have a single-layer structure made of one kind of material, or may have a multilayer structure of two or more layers in which layers made of different kinds of materials are stacked.

The materials of the cover according to the first and second inventions and the inner cover and the outer cover according to the third invention are not limited. For example, ionomer resins, urethane resins, polyester resins, polyurethane resins and polyester resins. Those selected from a mixture with a resin can be used. The above-described cover, inner cover and outer cover may each have a single-layer structure made of one kind of material, or may have a multilayer structure of two or more layers in which layers made of different materials are stacked.

In the first to third inventions, a metal layer is provided at each of the above-described portions. In this case, the material of the metal layer is not limited, for example, nickel, aluminum, copper, lead, zinc,
Although a material selected from tin, gold, silver, platinum and the like can be used, it is particularly preferable to use nickel in consideration of the production cost and specific gravity.

In the first to third inventions, examples of a method for providing a metal layer at the above-mentioned portion include the following methods, but are not limited thereto. A method of forming a metal layer on the surface of the first invention core, and then covering the core with a cover by compression molding or injection molding. A method of forming a metal layer on the inner surface of a hemispherical cup-shaped cover molding material, and then covering the core with a cover by compression molding using the cover molding material. A method in which a metal layer is formed on a surface of a core, a metal layer is formed on an inner surface of a cover molding material having a hemispherical cup shape, and the cover is coated on the core by compression molding using the cover molding material.

Second invention A method of forming a metal layer on the surface of the inner core, and then coating the inner core with an outer core by compression molding or the like. A method of forming a metal layer on an inner surface of a hemispherical cup-shaped outer core molding material, and then covering the inner core with the outer core by compression molding. A method in which a metal layer is formed on a surface of an inner core, and a metal layer is formed on an inner surface of a hemispherical cup-shaped outer core molding material, and then the inner core is covered with the outer core by compression molding.

[0012] The third invention is a method of coating the core with an inner cover, further forming a metal layer on the surface of the inner cover, and then covering the inner cover with an outer cover by compression molding or injection molding. After covering the core with the inner layer cover and forming a metal layer on the inner surface of the hemispherical cup-shaped outer layer cover molding material,
A method of covering the outer cover with the inner cover by compression molding using the outer cover molding material. After covering the core with the inner layer cover and forming a metal layer on the surface of the inner layer cover, and forming a metal layer on the inner surface of the hemispherical cup-shaped outer layer cover molding material, compression molding is performed using this outer layer cover molding material. Covering the outer cover with the inner cover.

Examples of the method for forming the metal layer include a plating method, a vacuum evaporation method, a sputtering method, and a chemical vapor deposition method. The method is particularly preferred. When a metal layer having a uniform thickness is formed by a plating method, eccentric rotation of the ball can be prevented. That is, in order to increase the moment of inertia, for example, when trying to form a layer made of a material having a high specific gravity in the vicinity of the surface of the golf ball,
When the thickness of the layer made of the high specific gravity material varies, the eccentric rotation of the ball occurs and the flying performance is reduced,
Such a problem can be solved by forming a metal layer having a uniform thickness by plating.

When a metal layer is formed by a plating method,
For example, after a surface to be plated (for example, the surface of a core) is imparted with conductivity in advance by vacuum deposition, conductive coating, electroless plating, or the like, a plating process such as electrolytic plating or electroless plating is further performed on the surface to be plated. An application method can be adopted. However, in terms of the high precision of the thickness of the plating layer and the high adhesion of the plating layer to the surface to be plated, after the conductivity is imparted to the surface to be plated by electroless plating, the surface A method of performing plating or electrolytic plating is particularly preferable.

In the present invention, the distance between the center of the core or the inner core and the inner surface of the metal layer is set to 17 mm or more. If this distance is less than 17 mm, a sufficient effect of increasing the moment of inertia cannot be obtained. A more preferred range of the distance between the center of the core or the inner core and the inner surface of the metal layer is 18.0 to 19.5 mm, particularly 19.0 mm.
１９19.5 mm. If the distance exceeds 20 mm, the resilience of the ball may be reduced, and the durability may be reduced.

In the present invention, the weight of the metal layer is set at 0.2
To 4.0 g. If the weight of the metal layer is less than 0.2 g, a sufficient effect of increasing the moment of inertia cannot be obtained,
If it is larger than 4.0 g, the resilience of the golf ball may be reduced due to the metal layer. The weight of the metal layer can be appropriately selected from the above range according to the desired degree of moment of inertia, but usually, the more preferable range of the weight of the metal layer is 1.0 to 4.0 g, particularly 2.0 g. Ｇ3.5 g.

Further, the weight of the portion inside the metal layer, that is, the weight of the core in the first invention, the weight of the inner core in the second invention, and the total weight of the core and the inner layer cover in the third invention are 25.0 to 35. 0.0 g, the weight of the portion outside the metal layer, that is, the weight of the cover in the first invention, the total weight of the outer core and the cover in the second invention, and the weight of the outer layer cover in the third invention are 5.0 to 5.0.
It is preferably 15.0 g. If the weight of each of the above-mentioned portions is out of the above-mentioned range, a sufficient moment of inertia increasing effect may not be obtained. A more preferred range for the weight of the portion inside the metal layer is 31.0.
A more preferable range of the weight of the portion outside the metal layer is 8.0 to 12.0 g. The weight adjustment of each layer described above can be performed, for example, by adjusting the specific gravity of each layer according to the amount of the weight adjuster added to the rubber or synthetic resin constituting each layer.

The golf ball of the present invention can be manufactured by subjecting the cover to a finishing treatment such as painting and mark stamping as necessary after molding. In this case, the size and weight of the golf ball of the present invention comply with the golf rules, and the diameter is 42.67 mm or more and the weight is 45.9.
It can be formed to 3 g or less.

[0019]

FIG. 1 is a sectional view showing an embodiment of a golf ball according to the first invention. The golf ball 2 shown in FIG. 1 is manufactured by forming a metal layer 6 on the surface of a core 4 and covering the metal layer 6 with a cover 8. The distance a between the center of the core 4 and the inner surface of the metal layer 6 is 17 mm or more, and the weight of the metal layer 6 is 0.2 mm.
It is set to 4.0 g.

The golf ball 2 of this embodiment can be manufactured, for example, by the following procedure, but is not limited to this. (1) After a core 4 made of vulcanized rubber is produced by compression molding, a metal layer 6 is formed on the surface of the core 4 by a plating method. (2) The cover 8 is formed on the metal layer 6 by compression molding or injection molding.
To form dimples.

FIG. 2 is a sectional view showing an embodiment of the golf ball according to the second invention. In the golf ball 12 shown in FIG. 2, the metal layer 6 is formed on the surface of the inner core 14,
Further, the core 18 is formed by molding the outer core 16 on the surface of the metal layer 6, and then the core 18 is covered with the cover 8. The distance a between the center of the inner core 14 and the inner surface of the metal layer 6 is set to 17 mm or more, and the weight of the metal layer 6 is set to 0.2 to 4.0 g.

The golf ball 12 of this embodiment can be manufactured by, for example, the following procedure, but is not limited to this. (A) After the inner core 14 made of vulcanized rubber is produced by compression molding, the metal layer 6 is formed on the surface of the inner core 14 by plating. (B) Two hemispherical cup bodies for molding an outer core made of unvulcanized rubber are primarily vulcanized (semi-vulcanized), and then covered on the inner core 14 having the metal layer 6, and further heated and compressed to form a hemispherical cup body. By performing secondary vulcanization (full vulcanization) and joining the hemispherical cups, a core 18 having the metal layer 6 provided between the inner core 14 and the outer core 16 is manufactured. (C) The cover 8 is formed on the core 18 by compression molding or injection molding.
To form dimples.

FIG. 3 is a sectional view showing an embodiment of the golf ball according to the third invention. The golf ball 22 shown in FIG. 3 is manufactured by covering the core 4 with the inner cover 24, forming the metal layer 6 on the surface of the inner cover 24, and further covering the metal layer 6 with the outer cover 26. is there. Further, the distance a between the center of the core 4 and the inner surface of the metal layer 6 is 17 mm or more, and the weight of the metal layer 6 is 0.2 to 4.0.
g.

The golf ball 22 of this embodiment can be manufactured by, for example, the following procedure, but is not limited to this. (a) After the core 4 made of vulcanized rubber is produced by compression molding, the core 4 is covered with the outer layer cover 24 by compression molding or injection molding. (b) The metal layer 6 is formed on the surface of the outer cover 24 by plating.
To form (c) The metal layer 6 is covered with the outer layer cover 26 by compression molding or injection molding to form dimples.

[0025]

EXAMPLES Examples 1-4 and Comparative Examples 1-3 shown in Table 1
Was manufactured. Examples 1 and 2 are balls of the first invention, and Examples 3 and 4 are balls of the third invention. The balls of Examples 1 and 2 and Comparative Example 1 were manufactured according to the procedures (1) and (2), and the balls of Examples 3 and 4 were manufactured according to the procedures (a) to (c). The ball of Comparative Example 2 was manufactured in the same procedure as in the above (1) and (2) except that the metal layer was not formed. The ball of Comparative Example 3 was manufactured in the same manner as in (a) except that the metal layer was not formed.
To (c). The metal layer was formed by imparting conductivity to the surface of the core or the inner layer cover by electroless nickel plating, and then applying electroless nickel plating to the surface of the core or the inner layer cover.

The base rubbers in Table 1 are polybutadiene rubbers JSR BR01 and BR11 manufactured by Nippon Synthetic Rubber Co., Ltd.
Were mixed at a weight ratio of 50:50, dicumyl peroxide (Park Mill D manufactured by NOF Corporation) was used as a vulcanizing agent, and zinc acrylate was used as a curing agent. The cover of the balls of Examples 1 and 2 and Comparative Examples 1 and 2 and the outer layer cover of the balls of Examples 3 and 4 and Comparative Example 3 were made of DuPont's Surlyn 8120 which is an ionomer resin and Mitsui's.
Dupont Polychemical's High Milan 1557 and 18
And 55 were blended at a weight ratio of 50:20:30. The inner layer covers of the balls of Examples 3 and 4 and Comparative Example 3 are polyester elastomers,
Molding was performed using Hytrel H4047 manufactured by DuPont.
In addition, these covers, inner layer cover and outer layer cover,
All were formed by injection molding.

[0027]

[Table 1]

The golf balls of the examples and comparative examples were measured for the moment of inertia and also subjected to a flying test. The measurement and test were performed as follows.

[Measurement of moment of inertia] INERTIA DYNAMI
Moment of inertia measuring device manufactured by CS INC. (M01-005)
The measurement was performed using. The moment of inertia of the golf ball was calculated from the difference between the period of the vibration when the golf ball was placed on the jig of this measuring machine and the period of the vibration when the ball was not placed.

[Flying test] The following values were measured using a hitting tester.・ Head speed 50m / s by No.1 wood (W1)
Initial speed when hitting with (HS50) ・ Head speed 40m / s by No.1 wood (W1)
(HS40) Spin amount when hitting ・ Head speed 45m / s by No.1 wood (W1)
Spin rate when hitting with (HS45) ・ Head speed 19m by sand wedge (SW)
/ S (HS19) Spin amount when hitting ・ Head speed 25m by sand wedge (SW)
/ S (HS25) Spin amount when hitting

The results are shown in Table 1. From Table 1, the following is found. (I) In the golf ball of Comparative Example 2 which is a conventional two-piece ball, the golf balls of Examples 1 and 2 of the present invention in which a metal layer is provided between a core and a cover have a higher moment of inertia than the ball of Comparative Example 2. Is getting bigger. From this, according to the first invention, the moment of inertia of the conventional two-piece ball is increased without substantially lowering the initial velocity,
It can be seen that low spin can be achieved by hitting No. 1 wood and high spin can be achieved by hitting sand wedge. (II) The golf ball of Comparative Example 3, which is a conventional double spin cover type ball using a polyester elastomer for the inner layer cover, wherein the metal layer is provided between the inner layer cover and the outer layer cover. The golf ball of the present invention has a larger moment of inertia than the ball of Comparative Example 3. From this, according to the third invention, the moment of inertia of the conventional double spin cover type ball is increased without substantially lowering the initial velocity, the spin is reduced by hitting the first wood, and the sand wedge is hit. It can be understood that the high spin of can be achieved. (III) The ball of Comparative Example 1 in which the weight of the metal layer is larger than 4 g has an increased moment of inertia, but the resilience deteriorates due to the presence of the metal layer, and is smaller than the ball of Comparative Example 2 which is a conventional two-piece ball. The initial speed has decreased.

[0032]

According to the present invention, the moment of inertia can be increased without impairing the physical properties of the rubber or synthetic resin which is the base material of the layer constituting the golf ball, and therefore, good resilience and excellent spin can be obtained. A golf ball having characteristics can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a golf ball according to a first invention.

FIG. 2 is a sectional view showing an example of a golf ball according to a second invention.

FIG. 3 is a sectional view showing an example of a golf ball according to a third invention.

[Explanation of symbols]

 2 Golf ball 4 Core 6 Metal layer 8 Cover 12 Golf ball 14 Inner core 16 Outer core 22 Golf ball 24 Inner layer cover 26 Outer layer cover

Claims (5)

[Claims] 1. A metal layer is provided between a core and a cover, and a distance between a center of the core and an inner surface of the metal layer is 17 mm.
As described above, the weight of the metal layer is 0.2 to 4.0 g.
A golf ball, characterized in that: 2. A metal layer is provided between the inner core and the outer core, the distance between the center of the inner core and the inner surface of the metal layer is 17 mm or more, and the weight of the metal layer is 0.1 mm. A golf ball weighing 2 to 4.0 g. 3. A metal layer is provided between the inner cover and the outer cover, the distance between the center of the core and the inner surface of the metal layer is 17 mm or more, and the weight of the metal layer is 0.2 mm.
A golf ball weighing 4.0 g. 4. The method according to claim 1, wherein the metal layer is made of nickel.
Or the golf ball of 3. 5. The golf ball according to claim 1, wherein the metal layer is formed by a plating method.