JP2677166B2 - Thread wound golf ball - Google Patents

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 which can provide good characteristics such as flight distance and feel.

[0002]

2. Description of the Related Art
The golf ball has a diameter of 42.6 according to R & A standards.
The weight is defined to be 7 mm or more and the weight is 45.93 g or less, and there is no regulation on the upper limit of the diameter and the lower limit of the weight.
Therefore, the diameter is 42.67 mm or more and the weight is 45.93.
Any golf ball having a weight of g or less is a golf ball conforming to the standard.

However, in general, a golf ball is so small that its diameter is not less than 42.67 mm and its weight is not more than 45.93 g in order to reduce air resistance during flight and improve flight performance. In the case of a thread-wound golf ball, the thread-wound core generally has an outer diameter of 26 to 32 mm and a weight of 17 to 22 g.
It is manufactured by coating a 2.0 mm cover resin.

However, while such a thread-wound golf ball has an excellent feel and controllability, it cannot provide a sufficient flight distance when hit by a powerless person, and also has a side spin when an off-center hit occurs. It has the drawback that extra spin is applied and the flight distance is impaired.

On the other hand, recently, many two-piece golf balls are on the market, and their characteristic is that the flight distance is larger than that of a thread-wound golf ball. This tendency is remarkable in the area where the head speed is slow,
According to the two-piece golf ball, a good flight distance can be obtained even by a relatively weak golfer.

However, the two-piece golf ball has a drawback that it is harder in hitting feeling than the thread-wound golf ball, and that the spin amount of the ball is extremely small, so that the ball is hard to stop on the green.

Therefore, golfers who have a slow head speed including a weak female golfer can have a good hit feeling and controllability like a wound golf ball and can obtain a flight distance like a two-piece ball. A ball is desired.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a thread-wound golf ball which provides an excellent flight distance and feel when hit by a particularly weak female golfer.

[0009]

Means and Actions for Solving the Problems As a result of intensive studies to achieve the above object, the present inventor has found that in a thread wound golf ball in which a thread wound core consisting of a center and a thread rubber layer is covered with a thread. The ionomer resin cover is coated to a thickness of 1 to 2.5 mm on the wound core formed so that the weight of the rubber layer becomes heavier than that of the center, preferably the weight difference is 0.1 to 15 g. By setting the outer diameter of the ball to be in the range of 42.9 to 46 mm, which is larger than that of the conventional large size ball,
It has been found that an increase in flight distance and an improvement in feel on impact can be achieved.

That is, in general, as the outer diameter increases, the air resistance increases and the flight distance decreases, but by increasing the amount of rubber thread with the increase in the outer diameter, the initial velocity is increased and the spin is decreased. It is effective to increase the flight distance by increasing the launch angle, and the resilience is excellent by increasing the ratio of the rubber thread layer. Therefore, the flight distance can be increased especially in the low head speed range. At the same time, the feel at impact can be significantly improved compared to a thread wound golf ball covered with a conventional ionomer cover, and by making it larger than a conventional golf ball, the ball does not sink into the grass easily and is easy to aim at. Since the inertia moment is large, it has been found that it is possible to give stability to rolling during putting, and the present invention has been completed. .

Therefore, according to the present invention, in a thread-wound golf ball in which a cover is applied to a thread-wound core consisting of a center and a thread-rubber layer, the ionomer is formed in the thread-wound core formed so that the weight of the thread-rubber layer becomes heavier than that of the center. A thread-wound golf ball comprising a resin cover covered with a thickness of 1 to 2.5 mm and having an outer diameter of the ball set to a range of 42.9 to 46 mm. Further, the present invention provides such a thread wound golf ball, wherein the weight difference between the center and the thread rubber layer is 0.1 to 15 g, and the outer diameter of the ball is 44 to 46 mm.
And a thread wound golf ball in which the weight difference between the center and the thread rubber layer is 1 to 10 g.

The present invention will be described in more detail below. The wound golf ball of the present invention has a center 1 as shown in FIG.
The thread winding core 3 having the thread rubber layer 2 formed on the outer periphery of the
In the thread-wound golf ball obtained by coating the above, the weight of the thread rubber layer 2 forming the thread-wound core 3 is set to be heavier than the weight of the center 1.

The center 1 may be either a solid center or a liquid center. Particularly, the solid center is preferably a solid core of rubber, and the liquid center is preferably a center made of a liquid core in which a vulcanized rubber bag is filled with a liquid. Used for.

The rubber used for the solid center is not particularly limited, but high-cis polybutadiene rubber having high resilience is preferable. Further, this solid center is obtained by kneading 1 to 3 parts by weight of peroxide and 100 parts by weight of high cis polybutadiene rubber and a desired amount of a weight adjusting agent with a Banbury mixer or a roll to obtain 10 at 155 to 165 ° C. It can be obtained by vulcanization molding for 25 minutes. As the vulcanizing agent in this case, not only the above-mentioned peroxide but also sulfur can be used. Further, as the weight adjusting agent, any of zinc white, barium sulfate, silica, calcium carbonate and the like may be used, or a combination thereof may be used.

On the other hand, the liquid center is obtained by filling water or a paste prepared by adding barium sulfate, a small amount of ethylene glycol or the like to water in a bag formed of a commonly used vulcanized rubber. be able to. The vulcanized rubber bag preferably has a thickness of 1.5 to 2.5 mm.

The center 1 is formed to be lighter in weight than the rubber thread layer 2, and its weight is not particularly limited, but is preferably 8 to 18 g, particularly 11 to 16 g. In this case, if the weight of the center 1 exceeds 18 g, it becomes difficult to construct a golf ball conforming to the standard weight. On the other hand, if the center weight is less than 8 g, the material of the center is extremely limited,
In reality, it may be difficult to form such a center. For example, in the case of forming a center having a diameter of about 26 mm, if the weight of the center is less than 8 g, the center material should have a specific gravity of less than 0.9. Has a specific gravity of 0.9 or more, and it is difficult to actually form such a center. The center 1 may have a diameter of 24 to 32 mm, especially 26 to 30 mm.

Next, the thread rubber layer 2 is attached to the center 1
It is formed by winding a rubber thread around the outer circumference of the core in a highly stretched state, and its weight is set to be heavier than the weight of the center 1. In this case, the weight of the rubber thread layer 2 is 16
It is preferable that the weight of the rubber thread layer 2 be less than 16 g, and the center 1 should have a weight of less than 16 g.
Is set to be lighter than the thread rubber layer 2, so the weight of the ball may be too light and the flight performance may be deteriorated. On the other hand, if it exceeds 26 g, a golf ball conforming to the standard weight may be formed. It will be difficult. Also, the thread rubber layer 2
Can have a thickness of 5 to 9 mm, especially 6 to 7 mm.
It can be set to ~ 43 mm. The thread rubber layer 2
As the thread rubber forming the golf ball, one known as a thread rubber for golf balls can be used.

The wound core 3 composed of the center 1 and the rubber thread layer 2 has the weight of the rubber thread layer 2 set to be larger than the weight of the center 1 as described above. The weight difference between 2 and the center 1 is 0.1-1
It is preferably 5 g, particularly 0.3 to 10 g. If the difference in weight is less than 0.1 g, the resilience may decrease, while if it exceeds 15 g, it may be difficult to produce balls satisfying the standard weight. When the outer diameter of the obtained ball is 44 to 46 mm, the weight difference is 1
It is preferably set to 10 to 10 g, whereby an increase in flight distance can be achieved more reliably.

The thread-wound golf ball of the present invention comprises the thread-wound core 3 obtained as described above and a cover 4 made of an ionomer resin having a thickness of 1 to 2.5 mm. In this case, if the thickness of the cover 4 is less than 1 mm, the cut resistance is insufficient, and the cover may be broken when hit by the top with an iron shot.
If it exceeds 5 mm, the cover becomes too thick and the feel becomes hard and the hit feeling is impaired. As the ionomer resin forming the cover 4, those generally used as golf ball covers can be used.
Although not limited, the Shore D hardness is particularly 52-
It is preferable to use those having 68 degrees, specifically, Surlyn 1557, Sai 1605, Sai 1555, Sai 1706.
Commercially available resins such as (made by DuPont) are exemplified, and these can be used alone or in combination of two or more kinds.

In the thread-wound golf ball thus obtained, the dimples are usually formed on the cover 4 at the same time as or after the ionomer resin cover 4 is coated on the thread-wound core 3. The geometrical arrangement is 8 With respect to a dimple pattern such as a tetrahedron or an icosahedron, any of a square type, a hexagon type, a pentagon type, a triangle type and the like may be adopted.

The thread wound golf ball of the present invention comprises the center 1, the thread rubber layer 2 and the cover 3, and the outer diameter of the ball is set in the range of 42.9 to 46 mm. In this case, if the outer diameter exceeds the upper limit of 46 mm, it may be difficult to keep the total weight within the standard weight. Although the total weight of the golf ball is not particularly limited, it is preferably 44.8 to 45.93 g.

The thread-wound golf ball of the present invention thus obtained is excellent in flight distance and feel even when hit by a weak user having a slow head speed. In addition, the ball is unlikely to sink into the turf, is easy to aim at, and has a large moment of inertia, which makes it possible to provide stability in rolling during putting.

[0023]

EXAMPLES Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. The outer diameter of a golf ball is the diameter of the ball when the ball is a true sphere, but it is extremely difficult to produce a ball that is normally a true sphere, and most golf balls have a small diameter. Since it is known that there is distortion, in the following examples and comparative examples, the outer diameter of the ball was measured at 5 points while avoiding the dimples, and the average value was taken.
The weight difference between the center and the rubber thread was calculated from the difference between the weight of the wound core of the ball and the weight of the center.

[Example 1] High-cis polybutadiene rubber / zinc white / zinc acrylate / barium sulfate / dicumyl peroxide = 100/10/10/77 / 1.5 (unit: parts by weight, the same applies hereinafter) Knead into a temperature of 160
A solid center was prepared by vulcanizing at 20 ° C. for 20 minutes. Obtained solid center, thread rubber (NR /
IR = 50/50), ionomer resin (Surlyn 17)
06 / same 1605 = 50/50) using a cover (Shore D hardness = 66 degrees), thread wound golf balls having the properties shown in Table 1 below were produced. The obtained golf ball has MOI (moment of inertia), coefficient of restitution, flight characteristics,
The hit feeling was evaluated. Table 1 shows the results. The flying characteristics and feel on impact were measured or evaluated by the following methods.

Flying Characteristic Test Using a swing robot manufactured by Trutemper Co., a carry (W1, loft angle: 11 °) was used to measure carry and total flying distance when hit with a head speed of 40 m / sec. The initial velocity, launch angle, and spin rate under these launch conditions were measured. Hitting sensation A professional golfer made a blindfold hit with W # 1 and evaluated the feeling at that time.

[Example 2] High-cis polybutadiene rubber / zinc white / zinc acrylate / barium sulfate / dicumyl peroxide = 100/10/10/33 / 1.5 were sufficiently kneaded, and the temperature was 160 ° C. A golf ball having the properties shown in Table 1 was prepared in the same manner as in Example 1 except that the solid center was prepared by vulcanizing for 20 minutes, and the ball performance was evaluated in the same manner. Table 1 shows the results.

[Example 3] High-cis polybutadiene rubber / zinc white / zinc acrylate / dicumyl peroxide =
Table 1 was prepared in the same manner as in Example 1 except that 100 / 5.5 / 10 / 1.5 were sufficiently kneaded and vulcanized at a temperature of 160 ° C. for 20 minutes to prepare a solid center.
A golf ball having the properties shown in was prepared, and the ball performance was evaluated in the same manner. Table 1 shows the results.

[Example 4] High-cis polybutadiene rubber / zinc white / zinc acrylate / barium sulfate / dicumyl peroxide = 100/5/10/5 / 1.5 were sufficiently kneaded at a temperature of 160 ° C. Golf balls having the properties shown in Table 1 were prepared in the same manner as in Example 1 except that the solid center was prepared by vulcanizing for 20 minutes, and the ball performance was evaluated in the same manner. Table 1 shows the results.

Example 5 Golf balls having the properties shown in Table 1 were prepared in the same manner as in Example 2 and the ball performance was evaluated in the same manner. Table 1 shows the results.

[Examples 6 and 7] As a center, natural rubber / zinc white / stearic acid / sulfur / vulcanization accelerator / antiaging agent = 100/35/2/2 / 1.5 / 1 was kneaded. A soft vulcanized rubber having a specific gravity of about 1.18 obtained with a thickness of about 2
mm sheet, molded into a pair of semi-vulcanized and hemispherical cups having a diameter of about 28 mm, and added barium sulfate, ethylene glycol, etc. to water to give a desired weight. A golf ball having the properties shown in Table 1 was produced in the same manner as in Example 1 except that a liquid center obtained by filling a cup, pressing a hemispherical cup, and vulcanizing in a mold was used. Similarly, the ball performance was evaluated. Table 1 shows the results.

[Comparative Examples 1 to 5] In the case of a thread wound golf ball whose center is heavier than rubber thread and whose outer diameter is less than 42.9 mm, the performance was evaluated in the same manner as in Example 1. Table 1 shows the results. The golf balls of Comparative Examples 2 and 3 are commercial products, and the weight of the rubber thread and the center weight were measured by dissecting the balls. In Comparative Examples 1 to 5, the center was a solid center, and in Comparative Example 4, the center was a liquid center.

[0032]

[Table 1]

From the results shown in Table 1, the thread-wound golf ball of the present invention is excellent in hitting feeling (feeling) and
It was confirmed that the coefficient of restitution was improved, the initial velocity at the time of hitting was improved, the launch angle was high, the spin was suppressed, the trajectory was close to the characteristics of a two-piece ball, and the flight distance was improved. Further, it is generally said that the wound ball of the solid center has a hard hit and is similar to a two-piece ball, but in the Examples, the result was that the soft feeling was good.

[0034]

As described above, the thread-wound golf ball of the present invention has a relatively large ball diameter of 42.9 to 46 mm and a large amount of thread rubber, and therefore has excellent resilience and an increased initial speed. In addition, the flight distance is increased by decreasing the spin and increasing the launch angle, a good flight distance can be obtained even for a golfer with a slow head speed, and the feel at the time of hitting is excellent, and the golf ball does not sink into the grass easily. It is also easy to hit.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example of a thread-wound golf ball of the present invention.

[Explanation of symbols]

 1 Center 2 Thread rubber layer 3 Thread winding core 4 Cover

Claims (3)

(57) [Claims] 1. A thread-wound golf ball comprising a thread-wound core consisting of a center and a thread-rubber layer, the cover being covered with an ionomer resin cover, the thread-wound core being formed so that the weight of the thread-rubber layer is heavier than that of the center. 1 to
A thread-wound golf ball having a thickness of 2.5 mm and an outer diameter of the ball set to a range of 42.9 to 46 mm. 2. The weight difference between the center and the rubber thread layer is 0.1.
The thread-wound golf ball of claim 1, which has a weight of 15 g. 3. The thread-wound golf ball according to claim 2, wherein the outer diameter of the ball is 44 to 46 mm, and the weight difference between the center and the rubber thread layer is 1 to 10 g.