JPH09253236A - Thread-wound golf ball - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a golf ball in which improved response in striking the ball and controllability can be achieved and a sufficient striking distance can be provided and which can be easily manufactured. SOLUTION: This golf ball is composed of a solid center 1 comprising an inner part 1a and outer cover 1b, a thread-rubber layer 2, and a cover 3, and the inner part 1a has a Shore D hardness of 10-35 and a diameter of 18-28mm, and the cover 1b has a Shore D hardness of 36-63 and the difference in Shore D hardness between the part 1a and cover 1b is 5 or more, while the diameter of the center 1 is 29-39.5mm, whereby a load of 300-650kg is required to deform the ball by 10mm by compressing it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thread-wound golf ball in which thread rubber is wound around a solid center and the outer periphery of the thread is covered with a cover.

[0002]

2. Description of the Related Art A thread-wound golf ball is superior to a two-piece or three-piece solid golf ball in shot feeling and controllability, and is widely used by advanced golfers including professional golfers who place importance on these characteristics. However, since a wound golf ball is inferior to the two-piece and three-piece solid golf balls in terms of flight distance, it has an advantage of being excellent in shot feeling and controllability, and a thread-wound golf ball capable of obtaining a sufficient flight distance is desired. Has been.

There are two types of thread-wound golf balls, one using a solid center having a single structure made of rubber and the other using a liquid center in which a liquid is enclosed in a hollow rubber sphere. The solid center thread-wound golf ball has the advantage that the repulsion of the liquid center golf ball is reduced at low temperatures, but the performance is hardly reduced by temperature change.

Regarding this solid center thread wound golf ball, in Japanese Examined Patent Publication No. 4-25029, the diameter of the solid center is 28 to 32 mm and the hardness is JIS-A.
By setting the hardness to 70 to 80, the flight distance is improved. That is, by increasing the diameter of the solid center and thinning the rubber thread layer, the spin number of the ball at the time of a shot requiring a flight distance is reduced and a sufficient flight distance can be obtained.

[0005]

However, since the solid center is made soft in consideration of the influence on the shot feeling of the solid center having a large diameter, the resilience is lowered. Therefore, in order to suppress the decrease in resilience, it is necessary to wind the rubber thread with high tension,
There is a drawback that the rubber thread is easily broken during manufacturing, and defects frequently occur.

It is an object of the present invention to provide a thread-wound golf ball which is excellent in shot feeling and controllability, has a sufficient flight distance, and is easy to manufacture.

[0007]

In order to solve the above-mentioned problems, the present invention provides a thread wound golf ball in which a rubber thread is wound around a solid center and the outer periphery of which is covered with a cover. And its outer cover, and the inside has a Shore D hardness of 10 to 35 and a diameter of 1
8 to 28 mm, and the outer cover has a Shore D hardness of 36 to 6
3, the difference in Shore D hardness between the inside and the jacket is 5 or more, and the solid center has a diameter of 29 to 39.5.
3 mm to compress the ball and deform it by 10 mm
The hardness is set to require a load of 00 to 650 kg.

As shown in FIG. 1, the thread-wound golf ball of the present invention has a solid center 1 and a thread rubber layer 2 formed by winding a thread rubber around the solid center 1.
And a cover 3 that covers the rubber thread layer 2.

The solid center 1 is composed of an inner part 1a and an outer cover 1b, and has a diameter of 29 to 39.5 mm.
If the diameter of the solid center 1 is smaller than 29 mm, the rubber thread layer 2 becomes too thick and the spin number of the ball increases. On the other hand, if it is larger than 39.5 mm, the thread rubber layer 2 becomes too thin, and the shot feeling of the ball becomes poor.

The inner part 1a and the outer cover 1b are usually formed by using a rubber composition having a natural rubber and / or a synthetic rubber as a base material, and the inner part 1a has a Shore D hardness of 10 to 35 and a diameter of 18 to 28 mm. The outer cover 1b has a Shore D hardness of 36 to
63. If the hardness of the interior 1a is lower than the Shore D hardness of 10, the durability of the ball will be poor, and if it is higher than the Shore D hardness of 35, the shot feeling of the ball will be poor and the spin rate of the ball will be high. When the hardness of the jacket 1b is lower than the Shore D hardness 36, the resilience of the ball is lowered, and when the hardness is higher than the Shore D hardness 63, the shot feeling of the ball is deteriorated. The diameter of the interior 1a is
If it is less than 18 mm, the shot feeling of the ball will deteriorate, and 28
If it is larger than mm, the resilience of the ball decreases. In addition, the durability of the ball deteriorates.

The hardness difference between the inner part 1a and the outer cover 1b is
It is necessary that the Shore D hardness is 5 or more. If the hardness difference is less than 5, the shot feeling of the ball becomes poor and the resilience of the ball also deteriorates.

The rubber thread layer 2 is formed by winding rubber thread around the solid center 1. As the rubber thread, those conventionally used can be used, and it is preferable to wind the rubber thread so that the thickness of the rubber thread layer 2 is 0.5 to 5.0 mm. If the thickness of the rubber thread layer 2 is less than 0.5 mm, the shot feeling of the ball becomes poor, and if it is more than 5.0 mm, the spin number of the ball increases.

The cover 3 is formed by coating the thread rubber layer 2, and can be made of an ionomer resin or a mixture thereof, and has a thickness of 1.0 mm or more, particularly 1.0 to
It is preferably 2.2 mm. The thickness of the cover 3
If it is thinner than 1.0 mm, the durability (cut resistance) of the ball will be poor, and if it is thick, the shot feeling of the ball will be poor. If the cover 3 is hard, the shot feeling of the ball is poor and the controllability of the ball is also poor. Therefore, the Shore D hardness is 40 to 6
3 is preferable.

Further, in the present invention, the load required to compress the ball to deform it by 10 mm (hereinafter referred to as 10 mm compression load) is smaller than that of the conventional thread wound golf ball, and is in the range of 300 to 650 kg. Sometimes, a sufficient flight distance can be obtained. When the 10 mm compressive load of the ball is increased by winding the rubber thread with a high tension or the like, the spin number of the ball is increased and the flight distance cannot be obtained. That is, when shot with a golf club that requires a long flight distance, the ball is considerably deformed at impact, but a 10 mm compressive load is large,
A ball that has a relatively small amount of deformation at impact has a large number of spins, the trajectory is blown up from the middle, and the flight distance is not extended.

[0015]

EXAMPLES Examples 1 to 5 and Comparative Examples 1 and 2 Using the rubber composition for the inner portion 1a and outer casing 1b having the composition shown in Table 1, the solid center 1 having the dimensions, weights and Shore D hardness shown in Table 2 was used. Got Next, a rubber thread was wound around the obtained solid center 1 to form a rubber thread layer 2. The thread rubber layer 2 was coated with the resin composition for the cover 3 having the formulation shown in Table 1, and the thread rubber layer 2 was polished and coated to produce a thread wound golf ball. The thread-wound golf balls of Comparative Examples 1 and 2 are
The 10 mm compressive load on the ball is increased. Comparative Example 3 Comparative Example 3 is a conventional single layer solid center thread wound golf ball.

Regarding Examples 1 to 5 and Comparative Examples 1 to 3,
10mm compression load, spin number, carry, feel at impact Table 2
It was shown to.

As shown in Table 2, the thread wound golf balls of Examples 1 to 5 had a low spin rate and a carry of 175.
It was 2 to 175.9 m. Since the carry of the thread-wound golf ball of Comparative Example 3 is 173.3 m, the thread-wound golf balls of Examples 1 to 5 are superior in flight distance. In contrast to Examples 1 to 5, the thread-wound golf balls of Comparative Examples 1 and 2 have a large number of spins and a carry of 1.
The distance is 72.4 to 172.8 m, and the flight distance is not long.
The number of spins increased and the flight distance did not come out is 10 m
This is probably because the compressive load was large and the amount of ball deformation at impact was small.

Further, the thread-wound golf balls of Examples 1 to 5 were evaluated as having a good shot feeling. Comparing Example 1 and Example 5, the thread-wound golf ball of Example 1 having a soft cover 3 had an extremely good shot feeling.

[0019]

[Table 1]

In Table 1, Himilan 1605 is a sodium ion neutralized ionomer resin manufactured by Mitsui DuPont Polychemical Co., Ltd. and Himilan 1706.
Is a zinc ion neutralized ionomer resin manufactured by Mitsui DuPont Polychemical Co., Ltd.

[0021]

[Table 2]

In Table 2, the 10 mm compressive load is the load required to compress the golf ball to deform it by 10 mm, and the spin number and carry are the club head speed by the No. 1 wood club using the swing robot device. 40
It is measured by hitting at m / sec. The number of spins is
The value immediately after hitting. Further, the shot feeling is evaluated by an actual hit test by a male senior golfer, and is shown as “∘: extremely good, ◯: good, ×: bad”.

[0023]

The thread-wound golf ball of the present invention can optimally balance the spin number and the resilience of the ball within a range that does not deteriorate the shot feeling of the ball. The effect of possessing and obtaining a sufficient flight distance is achieved. Furthermore, it is not necessary to wrap the rubber thread with high tension during manufacturing,
It is possible to reduce the occurrence of defects due to rubber thread breakage and improve the yield.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a cross-sectional structure of a thread-wound golf ball of this example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Solid center 1a ... Inside 1b ... Outer sheath 2 ... Thread rubber layer 3 ... Cover

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Go Shimizu 5412 Shido, Shido Town, Okawa-gun, Kagawa Prefecture

Claims (3)

[Claims] 1. A thread-wound golf ball in which a rubber thread is wound around a solid center and the outer periphery of which is covered with a cover, wherein the solid center includes an inside and an outer cover, and the inside has a Shore D hardness of 10 ~ 35, diameter 18-28
mm, the jacket has a Shore D hardness of 36 to 63, the difference in Shore D hardness between the interior and the jacket is 5 or more, and the solid center has a diameter of 29 to 39.5 mm and compresses a ball. 300 to deform 10 mm
A thread-wound golf ball, which is set to a hardness that requires a load of 650 kg. 2. A thread-wound golf ball according to claim 1, wherein the thread rubber layer has a thickness of 0.5 to 5.0 mm. 3. The thread-wound golf ball according to claim 1, wherein the cover is formed of an ionomer resin or a mixture using the same, and has a Shore D hardness of 40 to 63 and a thickness of 1.0.
A thread-wound golf ball having a diameter of up to 2.2 mm.