CA2145783A1 - Thread wound golf ball - Google Patents
Thread wound golf ballInfo
- Publication number
- CA2145783A1 CA2145783A1 CA002145783A CA2145783A CA2145783A1 CA 2145783 A1 CA2145783 A1 CA 2145783A1 CA 002145783 A CA002145783 A CA 002145783A CA 2145783 A CA2145783 A CA 2145783A CA 2145783 A1 CA2145783 A1 CA 2145783A1
- Authority
- CA
- Canada
- Prior art keywords
- center
- golf ball
- weight
- thread
- parts
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
- A63B37/00—Solid balls; Rigid hollow balls; Marbles
- A63B37/0003—Golf balls
-
- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
- A63B37/00—Solid balls; Rigid hollow balls; Marbles
- A63B37/0003—Golf balls
- A63B37/0038—Intermediate layers, e.g. inner cover, outer core, mantle
- A63B37/0039—Intermediate layers, e.g. inner cover, outer core, mantle characterised by the material
-
- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
- A63B37/00—Solid balls; Rigid hollow balls; Marbles
- A63B37/0003—Golf balls
- A63B37/0004—Surface depressions or protrusions
-
- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
- A63B37/00—Solid balls; Rigid hollow balls; Marbles
- A63B37/0003—Golf balls
- A63B37/005—Cores
- A63B37/0051—Materials other than polybutadienes; Constructional details
-
- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
- A63B37/00—Solid balls; Rigid hollow balls; Marbles
- A63B37/0003—Golf balls
- A63B37/005—Cores
- A63B37/0051—Materials other than polybutadienes; Constructional details
- A63B37/0053—Thread wound
-
- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
- A63B37/00—Solid balls; Rigid hollow balls; Marbles
- A63B37/0003—Golf balls
- A63B37/005—Cores
- A63B37/006—Physical properties
- A63B37/0064—Diameter
-
- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
- A63B37/00—Solid balls; Rigid hollow balls; Marbles
- A63B37/0003—Golf balls
- A63B37/005—Cores
- A63B37/006—Physical properties
- A63B37/0065—Deflection or compression
-
- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
- A63B37/00—Solid balls; Rigid hollow balls; Marbles
- A63B37/0003—Golf balls
- A63B37/007—Characteristics of the ball as a whole
- A63B37/0072—Characteristics of the ball as a whole with a specified number of layers
- A63B37/0075—Three piece balls, i.e. cover, intermediate layer and core
-
- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
- A63B37/00—Solid balls; Rigid hollow balls; Marbles
- A63B37/0003—Golf balls
- A63B37/007—Characteristics of the ball as a whole
- A63B37/0077—Physical properties
- A63B37/0094—Rebound resilience
Abstract
The present invention provides a thread wound golf ball which keeps good hit feeling inherently holding in thread wound golf balls and attains long flying distance which is equal to that attained by the two-piece solid golf ball. The thread wound golf ball comprises a center composed of a vulcanized molded article of a rubber composition, a thread rubber layer formed on said center and a cover covering on said thread rubber layer, wherein said center has a diameter of 30 to 35 mm and a strain amount formed between an initial loading of 10 kg and a final loading of 30 kg is 1.2 to 2.5 mm.
Description
21 ~ S 783 THREAD WOUND GOLF BALL
FIELD OF THE INVENTION
The present invention relates to a thread wound golf ball.
More particularly, it relates to a thread wound golf ball which keeps good 5 hit feeling inherently present in thread wound golf balls and attains long flying distance.
BACKGROUND OF THE INVENTION
A thread wound golf ball is obtained by winding a thread rubber on a solid or liquid rubber center to form a thread rubber layer and 10 covering on the thread rubber layer with a cover material (e.g. ionomer, balata, etc.).
The thread wound golf ball is superior in hit feeling and control properties to a two-piece solid golf ball using a solid core.
However, it can not attain long flying distance because a spin amount is 15 large and a launch angle is small in comparison with the two-piece solid golf ball. Therefore, general amateur golfers tend to prefer the two-piece solid golf ball which attains long flying distance in comparison with the thread wound golf ball, and the two-piece solid golf ball have recently been put on the market, exclusively.
OBJECTS OF THE INVENTION
The present invention has been accomplished in order to solve a problem that the a conventional thread wound golf ball merely attains relatively short flying distance, and the main object of the present invention is to provide a thread wound golf ball which keeps good hit 21q~78~
-feeling inherently holding in thread wound golf balls and attains long flying distance which is equal to that attained by the two-piece solid golf ball.
This object as well as other objects and advantages of the present invention will become apparent to those skilled in the art from the 5 following description with reference to the accompanying drawing.
BRIEF EXPLANATION OF DRAWINGS
Fig. 1 is a schematic cross section illustrating one embodiment of a thread wound golf ball of the present invention.
SUMMARY OF THE INVENTION
According to the present invention, the above object has been accomplished by increasing a diameter of the center of the thread wound golf ball and making the center hard to control an amount of spin to be formed and increasing the launch angle to increase the flying distance.
That is, the present invention provides a thread wound golf 15 ball comprising a center composed of a vulcanized molded article of a rubber composition, a thread rubber layer formed on said center and a cover covering on said thread rubber layer, wherein said center has a diameter of 30 to 35 mm and a strain amount formed between an initial loading of 10 kg and a final loading of 30 kg is 1.2 to 2.5 mm.
DETAILED DESCRIPTION OF THE INVENTION
The center can be obtained, for example, by formulating 5 to 80 (preferably 15 to 50) parts by weight of a thermoplastic resin as a filler for adjusting hardness, 2 to 12 (preferably 8 to 10) parts by weight of sulfur, 1 to 4 (preferably 1 to 2) parts by weight of a vulcanization accelerator and 21~5783 10 to 150 (preferably 50 to 120) parts by weight of a weight adjustor and, if necessary, 3 to 10 (preferably 5 to 9) parts by weight of a vulcanization auxiliary, based on 100 parts by weight of a rubber, to give a rubber composition and subjecting the rubber composition to a vulcanization 5 molding.
In the present invention, the reason why large flying distance of the thread wound golf ball can be attained while maintaining good hit feeling by adjusting the diameter of the center at 30 to 35 mm and the strain amount formed between initial loading (10 kg) and final loading (30 10 kg) at 1.2 to 2.5 mm is not clear at present, but is considered as follows.
It is considered that, by adjusting the diameter of the center at 30 to 35 mm and the strain amount formed between initial loading (10 kg) and final loading (30 kg) at 1.2 to 2.5 mm, the deformation behavior of the golf ball at the time of hitting becomes similar to that of the two-piece solid 15 golf ball and, as a result, the amount of spin to be formed at the time of hitting is controlled and the launch angle becomes large, thereby increasing the flying distance.
Further, the reason why the thread wound golf ball can keep good hit feeling which is characteristics inherently holding in thread wound 20 golf balls regardless of improvement of the flying distance as described above is considered that the tension of the thread rubber layer is small in comparison with a conventional thread wound golf ball.
When the diameter of the center is smaller than 30 mm, the thread rubber layer becomes thick and, as a result, the launch angle 25 becomes small and the spin amount becomes large. On the other hand, when the diameter of the center is larger than 35 mm, the thread rubber layer becomes thin and the thread rubber has already been wound before - 4 21~783 the tension is formed so that a suitable hardness as the golf ball can not be obtained.
Further, when the strain amount of the center is larger than 2.5 mm under the above condition, the thread rubber must be wound tightly 5 so as to obtain a proper ball hardness. As a result, the tension of the thread rubber layer becomes large and the deformation at the time of hitting is not easily arisen, thereby obtaining no desired technical effects.
On the other hand, when the strain amount of the center is smaller than 1.2 mm under the above condition, the hit feeling becomes inferior.
Further, it is preferred that the height of rebound of the center is 120 cm or more, particularly 140 to 240 cm, when dropping it on a concrete board from the height of 254 cm. That is, the fact that the center has the large height of rebound shows that the impact resilience of the center is large, and when the center has the large impact resilience, the ball initial velocity at the time of hitting becomes large and, therefore, good flying performances can be obtained. On the other hand, when the height of rebound of the center is smaller than the above range, the ball initial velocity becomes small and, therefore, long flying distance can not be obtained easily.
As described above, the center is composed of the vulcanized molded article of the rubber composition obtained by formulating 5 to 80 (preferably 15 to 50) parts by weight of a thermoplastic resin as a filler for adjusting hardness, 2 to 12 (preferably 8 to 10) parts by weight of sulfur, 1 to 4 (preferably 1 to 2) parts by weight of a vulcanization accelerator and 10 to 150 (preferably 50 to 120) parts by weight of a weight adjustor and, if necessary, 3 to 10 (preferably 5 to 9) parts by weight of a vulcanization auxiliary, based on 100 parts by weight of a rubber. The 5 21~S783 -vulcanization is normally conducted by heating at 140 to 170C (preferably 150 to 160~C) under pressure for 5 to 30 minutes (preferably 10 to 20 minutes).
The rubber as the center is not specifically limited, and a 5 polybutadiene having high resilient performances (particularly high-cis polybutadiene) is preferred. It is preferred that high-cis polybutadiene or a rubber containing high-cis polybutadiene as a main component is used in the preparation of the rubber composition for the center.
The thermoplastic resin is not specifically limited, and there 10 can be preferably used high-molecular weight polyolefins such as high-styrene resin, high-molecular weight polyethylene, high-molecular weight polypropylene, etc., or a mixture thereof.
The above rubber composition for center differs from a conventional rubber composition for center in formulating the thermoplastic 15 resin as the filler for adjusting hardness.
The thermoplastic resin is used for adjusting the hardness of the center and the amount is, as described above, 5 to 80 parts by weight, preferably 15 to 50 parts by weight, based on 100 parts by weight of the rubber. When the amount of the thermoplastic resin is smaller than the 20 above range, the hardness of the center can not be sufficiently increased.
Therefore, the hardness becomes the same as that of a conventional center, thereby affording no desired effect. On the other hand, when the amount of the thermoplastic resin is larger than the above range, the hardness becomes too high and, therefore, the hit feeling becomes inferior 25 and the workability at the time of kneading of rubber also becomes inferior.
The amount of sulfur is, as described above, 2 to 12 parts by weight, preferably 8 to 10 parts by weight, based on 100 parts by weight of 21~783 the rubber. When the amount of sulfur is smaller than the above range, the vulcanization degree becomes low and, therefore, the desired hardness of the center can not be obtained easily. On the other hand, when the amount of sulfur is larger than the above range, the hardness of the center 5 becomes too high and, therefore, the desired effect can not be obtained.
Examples of the vulcanization auxiliary include metal oxides (e.g. zinc oxide, magnesium oxide, etc.) and higher fatty acids (e.g. stearic acid, palmitic acid, oleic acid, lauric acid, etc.). This vulcanization auxiliary is preferably used for conducting the vulcanization smoothly, but is not 10 necessarily required.
The vulcanization accelerator may be any one which can be used as the normal vulcanization accelerator of the sulfur vulcanization, and typical examples thereof include thiazole vulcanization accelerators such as 2-mercaptobenzothiazole, dibenzothiazyl disulfide, etc.; thiuram 15 vulcanization accelerators such as tetramethylthiuram monosulfide, tetramethylthiuram disulfide, etc.; sulfenamide vulcanization accelerators such as N-cyclohexyl-2-benzothiazyl sulfenamide, etc., but it is not limited to those described above.
The vulcanization auxiliary and vulcanization accelerator may 20 be formulated according to the amount of sulfur to be formulated. The amount of the vulcanization auxiliary is preferably 3 to 10 parts by weight, particularly 5 to 9 parts by weight, based on 100 parts by weight of the rubber, and the amount of the vulcanization accelerator is preferably 1 to 4 parts by weight, particularly 1 to 2 parts by weight, based on 100 parts by 25 weight of the rubber. When the amount of them is smaller than the above range, the vulcanization due to sulfur can not be sufficiently conducted. On the other hand, when the amount of them is larger than the above range, _ 7 the hardness of the center becomes too high, which results in deterioration of hit feeling.
Examples of the weight adjustor include barium sulfate, clay, calcium carbonate, silica filler and the like, and the amount is, as described above, preferably 10 to 150 parts by weight, particularly 50 to 120 parts by weight, based on 100 parts by weight of the rubber.
When the amount of the weight adjustor is smaller than the above range, the weight of the center becomes small and, the proper weight as the golf ball can not be obtained. On the other hand, when the 10 amount of the weight adjustor is larger than the above range, the weight of the center becomes large and, therefore, the ball weight exceeds the standard value.
To the rubber composition for center, antioxidants, etc. may be added, in addition to the above components.
The construction of the golf ball of the present invention will be explained with reference to the accompanying drawing. Fig. 1 is a schematic cross section illustrating one embodiment of the thread wound golf ball of the present invention. In Fig. 1, 1 is a center, 2 is a thread 5 rubber layer and 3 is a cover.
The center 1 is composed of a vulcanized molded article of a rubber composition and the diameter of the center is 30 to 35 mm. Further, the strain amount of the center, which is formed between initial loading (10 kg) and final loading (30 kg), is within a range of 1.2 to 2.5 mm.
The thread rubber layer 2 is formed by winding a thread rubber around the center 1, and a so-called thread wound core is composed of the center 1 and thread rubber layer 2 constitute.
As the thread rubber used for forming the thread rubber layer 2, there can be used the same thread rubber which has hitherto been used. For example, there c~an be used those obtained by vulcanizing a rubber composition wherein sulfur, a vulcanization auxiliary, a vulcanization accelerator, an antioxidant, etc. are formulated in a natural rubber, or a natural rubber and a synthetic polyisoprene.
The thread rubber layer 2 is covered with the cover 3 and 3a is a dimple provided on the cover 3 and, if necessary, a suitable number of dimples 3a may be provided according to the desired characteristics.
As the cover 3, there can be used both ionomer cover containing ionomer as a main material and balata cover, but the ionomer cover is preferred in view of increase in flying distance.
A method of covering the core with cover is not specifically limited, and the covering is conducted by a normal method. For example, there can be used a method comprising molding two half-shells having a Z1~57~3 _, g semispherical shape in advance, covering a core using them and subjecting to a pressure molding at 130 to 170C for 1 to 15 minutes, or a method comprising injection-molding a composition for cover directly on a core to cover the core. The thickness of the cover is normally about 1 to 4 mm. Then, a dimple may be optionally formed on the surface of the golf ball at the time of cover molding. Further, paint finishing, stamping, etc.
may be optionally provided after cover molding.
According to the present invention, there could be provided a thread wound golf ball which attains long flying distance while maintaining a good hit feeling as a characteristic of the thread wound golf ball, by increasing a diameter of the center and making the center hard in comparison with a conventional thread wound golf ball.
EXAM PLES
The following Examples and Comparative Examples further illustrate the present invention in detail but are not to be construed to limit the scope thereof.
Examples 1 to 5 and Comparative Examples 1 to 7 A rubber composition for center having a formulation shown in Tables 1 and 2, and the resulting rubber composition was charged in a mold for center and subjected to compression molding/vulcanization at 1 55C for 20 minutes to give a center, respectively.
The diameter, the JIS-A hardness (hardness measured by a JIS-A hardness tester), the strain amount, the height of rebound and the weight of the resulting center are shown in Tables 1 and 2.
The amount of the respective formulation amount to be formulated shown in Tables 1 and 2 is represented by parts by weight. The diameter, the JIS-A hardness (hardness measured by a JIS-A hardness Z~S783 tester), the strain amount, the height of rebound and the weight of the resulting center are shown in Tables 1, in addition to the composition of Examples 1 to 5. Those as to Comparative Examples 1 to 7 are shown in Table 2.
Further, the measuring method of the strain amount and height of rebound is as follows. The explanation of the formulation component will be described the back of Table 2.
Strain amount:
The strain amount formed between initial loading (10 kg) and final loading (30 kg) is measured.
Height of rebound:
The height of rebound of the center is measured when dropping it on a concrete board from the height of 254 cm.
Table 1 Example No.
BR11 3~1 100 100 100 100 100 Nippol 2007J ~2 30 30 30 40 0 MiperonXM-220 3~3 0 0 0 0 30 Sulfur 10 10 10 10 10 Vulcanization auxiliary39~4 7 7 7 7 7 Vulcanization accele,~ r3~5 1.5 1.5 1.5 1.5 1.5 Weightadjustor ~6 90 80 70 75 90 Center Diameter (mm) 30.3 31.3 32.4 32.3 31.2 JIS-A hardness 86 87 87 90 86 Strain amount (mm) 1.95 1.98 2.00 1.78 1.90 Height of rebound (cm)200 198 196 190 210 Weight (9) 20.4 22.1 23.2 23.2 22.1 21~578:~
Table 2 Comparative Example No.
BR11 ~1 100 100 100 100 100 100 100 Nippol2007J ~2 0 0 0 0 85 0 40 Sulfur 10 10 10 15 10 10 Vulcanization auxiliary 3~3 7 7 7 7 7 7 7 Vulcanization accelerator 3~4 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Weight adjustor ~5 83 70 65 65 90 33 77 Center Diameter (mm) 28.2 30.2 31.3 31.2 32.3 35.5 32.3 JIS-A hardness 76 75 74 85 99 73 84 - Strainamount(mm) 3.17 3.20 3.25 2.65 1.18 3.35 2.20 Heightofrebound(cm) 216 215 214 210 180 205 118 Weight(g) 17.5 20.5 22.0 22.0 23.2 29.1 23.1 ~1: Trade name, high-cis polybutadiene (amount of 1,4-cis-polybutadiene: 96%) manufactured by Nihon Gosei Gomu Co., Ltd.
~2: Trade name, high-styrene resin manufactured by Nihon Zeon Co., Ltd.
~3: Trade name, high-molecular weight polyethylene manufactured by Mitsui Petroleum Chemical Industries Co., Ltd.
FIELD OF THE INVENTION
The present invention relates to a thread wound golf ball.
More particularly, it relates to a thread wound golf ball which keeps good 5 hit feeling inherently present in thread wound golf balls and attains long flying distance.
BACKGROUND OF THE INVENTION
A thread wound golf ball is obtained by winding a thread rubber on a solid or liquid rubber center to form a thread rubber layer and 10 covering on the thread rubber layer with a cover material (e.g. ionomer, balata, etc.).
The thread wound golf ball is superior in hit feeling and control properties to a two-piece solid golf ball using a solid core.
However, it can not attain long flying distance because a spin amount is 15 large and a launch angle is small in comparison with the two-piece solid golf ball. Therefore, general amateur golfers tend to prefer the two-piece solid golf ball which attains long flying distance in comparison with the thread wound golf ball, and the two-piece solid golf ball have recently been put on the market, exclusively.
OBJECTS OF THE INVENTION
The present invention has been accomplished in order to solve a problem that the a conventional thread wound golf ball merely attains relatively short flying distance, and the main object of the present invention is to provide a thread wound golf ball which keeps good hit 21q~78~
-feeling inherently holding in thread wound golf balls and attains long flying distance which is equal to that attained by the two-piece solid golf ball.
This object as well as other objects and advantages of the present invention will become apparent to those skilled in the art from the 5 following description with reference to the accompanying drawing.
BRIEF EXPLANATION OF DRAWINGS
Fig. 1 is a schematic cross section illustrating one embodiment of a thread wound golf ball of the present invention.
SUMMARY OF THE INVENTION
According to the present invention, the above object has been accomplished by increasing a diameter of the center of the thread wound golf ball and making the center hard to control an amount of spin to be formed and increasing the launch angle to increase the flying distance.
That is, the present invention provides a thread wound golf 15 ball comprising a center composed of a vulcanized molded article of a rubber composition, a thread rubber layer formed on said center and a cover covering on said thread rubber layer, wherein said center has a diameter of 30 to 35 mm and a strain amount formed between an initial loading of 10 kg and a final loading of 30 kg is 1.2 to 2.5 mm.
DETAILED DESCRIPTION OF THE INVENTION
The center can be obtained, for example, by formulating 5 to 80 (preferably 15 to 50) parts by weight of a thermoplastic resin as a filler for adjusting hardness, 2 to 12 (preferably 8 to 10) parts by weight of sulfur, 1 to 4 (preferably 1 to 2) parts by weight of a vulcanization accelerator and 21~5783 10 to 150 (preferably 50 to 120) parts by weight of a weight adjustor and, if necessary, 3 to 10 (preferably 5 to 9) parts by weight of a vulcanization auxiliary, based on 100 parts by weight of a rubber, to give a rubber composition and subjecting the rubber composition to a vulcanization 5 molding.
In the present invention, the reason why large flying distance of the thread wound golf ball can be attained while maintaining good hit feeling by adjusting the diameter of the center at 30 to 35 mm and the strain amount formed between initial loading (10 kg) and final loading (30 10 kg) at 1.2 to 2.5 mm is not clear at present, but is considered as follows.
It is considered that, by adjusting the diameter of the center at 30 to 35 mm and the strain amount formed between initial loading (10 kg) and final loading (30 kg) at 1.2 to 2.5 mm, the deformation behavior of the golf ball at the time of hitting becomes similar to that of the two-piece solid 15 golf ball and, as a result, the amount of spin to be formed at the time of hitting is controlled and the launch angle becomes large, thereby increasing the flying distance.
Further, the reason why the thread wound golf ball can keep good hit feeling which is characteristics inherently holding in thread wound 20 golf balls regardless of improvement of the flying distance as described above is considered that the tension of the thread rubber layer is small in comparison with a conventional thread wound golf ball.
When the diameter of the center is smaller than 30 mm, the thread rubber layer becomes thick and, as a result, the launch angle 25 becomes small and the spin amount becomes large. On the other hand, when the diameter of the center is larger than 35 mm, the thread rubber layer becomes thin and the thread rubber has already been wound before - 4 21~783 the tension is formed so that a suitable hardness as the golf ball can not be obtained.
Further, when the strain amount of the center is larger than 2.5 mm under the above condition, the thread rubber must be wound tightly 5 so as to obtain a proper ball hardness. As a result, the tension of the thread rubber layer becomes large and the deformation at the time of hitting is not easily arisen, thereby obtaining no desired technical effects.
On the other hand, when the strain amount of the center is smaller than 1.2 mm under the above condition, the hit feeling becomes inferior.
Further, it is preferred that the height of rebound of the center is 120 cm or more, particularly 140 to 240 cm, when dropping it on a concrete board from the height of 254 cm. That is, the fact that the center has the large height of rebound shows that the impact resilience of the center is large, and when the center has the large impact resilience, the ball initial velocity at the time of hitting becomes large and, therefore, good flying performances can be obtained. On the other hand, when the height of rebound of the center is smaller than the above range, the ball initial velocity becomes small and, therefore, long flying distance can not be obtained easily.
As described above, the center is composed of the vulcanized molded article of the rubber composition obtained by formulating 5 to 80 (preferably 15 to 50) parts by weight of a thermoplastic resin as a filler for adjusting hardness, 2 to 12 (preferably 8 to 10) parts by weight of sulfur, 1 to 4 (preferably 1 to 2) parts by weight of a vulcanization accelerator and 10 to 150 (preferably 50 to 120) parts by weight of a weight adjustor and, if necessary, 3 to 10 (preferably 5 to 9) parts by weight of a vulcanization auxiliary, based on 100 parts by weight of a rubber. The 5 21~S783 -vulcanization is normally conducted by heating at 140 to 170C (preferably 150 to 160~C) under pressure for 5 to 30 minutes (preferably 10 to 20 minutes).
The rubber as the center is not specifically limited, and a 5 polybutadiene having high resilient performances (particularly high-cis polybutadiene) is preferred. It is preferred that high-cis polybutadiene or a rubber containing high-cis polybutadiene as a main component is used in the preparation of the rubber composition for the center.
The thermoplastic resin is not specifically limited, and there 10 can be preferably used high-molecular weight polyolefins such as high-styrene resin, high-molecular weight polyethylene, high-molecular weight polypropylene, etc., or a mixture thereof.
The above rubber composition for center differs from a conventional rubber composition for center in formulating the thermoplastic 15 resin as the filler for adjusting hardness.
The thermoplastic resin is used for adjusting the hardness of the center and the amount is, as described above, 5 to 80 parts by weight, preferably 15 to 50 parts by weight, based on 100 parts by weight of the rubber. When the amount of the thermoplastic resin is smaller than the 20 above range, the hardness of the center can not be sufficiently increased.
Therefore, the hardness becomes the same as that of a conventional center, thereby affording no desired effect. On the other hand, when the amount of the thermoplastic resin is larger than the above range, the hardness becomes too high and, therefore, the hit feeling becomes inferior 25 and the workability at the time of kneading of rubber also becomes inferior.
The amount of sulfur is, as described above, 2 to 12 parts by weight, preferably 8 to 10 parts by weight, based on 100 parts by weight of 21~783 the rubber. When the amount of sulfur is smaller than the above range, the vulcanization degree becomes low and, therefore, the desired hardness of the center can not be obtained easily. On the other hand, when the amount of sulfur is larger than the above range, the hardness of the center 5 becomes too high and, therefore, the desired effect can not be obtained.
Examples of the vulcanization auxiliary include metal oxides (e.g. zinc oxide, magnesium oxide, etc.) and higher fatty acids (e.g. stearic acid, palmitic acid, oleic acid, lauric acid, etc.). This vulcanization auxiliary is preferably used for conducting the vulcanization smoothly, but is not 10 necessarily required.
The vulcanization accelerator may be any one which can be used as the normal vulcanization accelerator of the sulfur vulcanization, and typical examples thereof include thiazole vulcanization accelerators such as 2-mercaptobenzothiazole, dibenzothiazyl disulfide, etc.; thiuram 15 vulcanization accelerators such as tetramethylthiuram monosulfide, tetramethylthiuram disulfide, etc.; sulfenamide vulcanization accelerators such as N-cyclohexyl-2-benzothiazyl sulfenamide, etc., but it is not limited to those described above.
The vulcanization auxiliary and vulcanization accelerator may 20 be formulated according to the amount of sulfur to be formulated. The amount of the vulcanization auxiliary is preferably 3 to 10 parts by weight, particularly 5 to 9 parts by weight, based on 100 parts by weight of the rubber, and the amount of the vulcanization accelerator is preferably 1 to 4 parts by weight, particularly 1 to 2 parts by weight, based on 100 parts by 25 weight of the rubber. When the amount of them is smaller than the above range, the vulcanization due to sulfur can not be sufficiently conducted. On the other hand, when the amount of them is larger than the above range, _ 7 the hardness of the center becomes too high, which results in deterioration of hit feeling.
Examples of the weight adjustor include barium sulfate, clay, calcium carbonate, silica filler and the like, and the amount is, as described above, preferably 10 to 150 parts by weight, particularly 50 to 120 parts by weight, based on 100 parts by weight of the rubber.
When the amount of the weight adjustor is smaller than the above range, the weight of the center becomes small and, the proper weight as the golf ball can not be obtained. On the other hand, when the 10 amount of the weight adjustor is larger than the above range, the weight of the center becomes large and, therefore, the ball weight exceeds the standard value.
To the rubber composition for center, antioxidants, etc. may be added, in addition to the above components.
The construction of the golf ball of the present invention will be explained with reference to the accompanying drawing. Fig. 1 is a schematic cross section illustrating one embodiment of the thread wound golf ball of the present invention. In Fig. 1, 1 is a center, 2 is a thread 5 rubber layer and 3 is a cover.
The center 1 is composed of a vulcanized molded article of a rubber composition and the diameter of the center is 30 to 35 mm. Further, the strain amount of the center, which is formed between initial loading (10 kg) and final loading (30 kg), is within a range of 1.2 to 2.5 mm.
The thread rubber layer 2 is formed by winding a thread rubber around the center 1, and a so-called thread wound core is composed of the center 1 and thread rubber layer 2 constitute.
As the thread rubber used for forming the thread rubber layer 2, there can be used the same thread rubber which has hitherto been used. For example, there c~an be used those obtained by vulcanizing a rubber composition wherein sulfur, a vulcanization auxiliary, a vulcanization accelerator, an antioxidant, etc. are formulated in a natural rubber, or a natural rubber and a synthetic polyisoprene.
The thread rubber layer 2 is covered with the cover 3 and 3a is a dimple provided on the cover 3 and, if necessary, a suitable number of dimples 3a may be provided according to the desired characteristics.
As the cover 3, there can be used both ionomer cover containing ionomer as a main material and balata cover, but the ionomer cover is preferred in view of increase in flying distance.
A method of covering the core with cover is not specifically limited, and the covering is conducted by a normal method. For example, there can be used a method comprising molding two half-shells having a Z1~57~3 _, g semispherical shape in advance, covering a core using them and subjecting to a pressure molding at 130 to 170C for 1 to 15 minutes, or a method comprising injection-molding a composition for cover directly on a core to cover the core. The thickness of the cover is normally about 1 to 4 mm. Then, a dimple may be optionally formed on the surface of the golf ball at the time of cover molding. Further, paint finishing, stamping, etc.
may be optionally provided after cover molding.
According to the present invention, there could be provided a thread wound golf ball which attains long flying distance while maintaining a good hit feeling as a characteristic of the thread wound golf ball, by increasing a diameter of the center and making the center hard in comparison with a conventional thread wound golf ball.
EXAM PLES
The following Examples and Comparative Examples further illustrate the present invention in detail but are not to be construed to limit the scope thereof.
Examples 1 to 5 and Comparative Examples 1 to 7 A rubber composition for center having a formulation shown in Tables 1 and 2, and the resulting rubber composition was charged in a mold for center and subjected to compression molding/vulcanization at 1 55C for 20 minutes to give a center, respectively.
The diameter, the JIS-A hardness (hardness measured by a JIS-A hardness tester), the strain amount, the height of rebound and the weight of the resulting center are shown in Tables 1 and 2.
The amount of the respective formulation amount to be formulated shown in Tables 1 and 2 is represented by parts by weight. The diameter, the JIS-A hardness (hardness measured by a JIS-A hardness Z~S783 tester), the strain amount, the height of rebound and the weight of the resulting center are shown in Tables 1, in addition to the composition of Examples 1 to 5. Those as to Comparative Examples 1 to 7 are shown in Table 2.
Further, the measuring method of the strain amount and height of rebound is as follows. The explanation of the formulation component will be described the back of Table 2.
Strain amount:
The strain amount formed between initial loading (10 kg) and final loading (30 kg) is measured.
Height of rebound:
The height of rebound of the center is measured when dropping it on a concrete board from the height of 254 cm.
Table 1 Example No.
BR11 3~1 100 100 100 100 100 Nippol 2007J ~2 30 30 30 40 0 MiperonXM-220 3~3 0 0 0 0 30 Sulfur 10 10 10 10 10 Vulcanization auxiliary39~4 7 7 7 7 7 Vulcanization accele,~ r3~5 1.5 1.5 1.5 1.5 1.5 Weightadjustor ~6 90 80 70 75 90 Center Diameter (mm) 30.3 31.3 32.4 32.3 31.2 JIS-A hardness 86 87 87 90 86 Strain amount (mm) 1.95 1.98 2.00 1.78 1.90 Height of rebound (cm)200 198 196 190 210 Weight (9) 20.4 22.1 23.2 23.2 22.1 21~578:~
Table 2 Comparative Example No.
BR11 ~1 100 100 100 100 100 100 100 Nippol2007J ~2 0 0 0 0 85 0 40 Sulfur 10 10 10 15 10 10 Vulcanization auxiliary 3~3 7 7 7 7 7 7 7 Vulcanization accelerator 3~4 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Weight adjustor ~5 83 70 65 65 90 33 77 Center Diameter (mm) 28.2 30.2 31.3 31.2 32.3 35.5 32.3 JIS-A hardness 76 75 74 85 99 73 84 - Strainamount(mm) 3.17 3.20 3.25 2.65 1.18 3.35 2.20 Heightofrebound(cm) 216 215 214 210 180 205 118 Weight(g) 17.5 20.5 22.0 22.0 23.2 29.1 23.1 ~1: Trade name, high-cis polybutadiene (amount of 1,4-cis-polybutadiene: 96%) manufactured by Nihon Gosei Gomu Co., Ltd.
~2: Trade name, high-styrene resin manufactured by Nihon Zeon Co., Ltd.
~3: Trade name, high-molecular weight polyethylene manufactured by Mitsui Petroleum Chemical Industries Co., Ltd.
3~4: 5 Parts by weight of zinc white, GINREI R (trade name, manufactured by Toho Aen Co., Ltd.) and 2 parts by weight of stearic acid (manufactured by Nihon Yushi Co., Ltd.) ~5: 0.25 Parts by weight of Noxxelar TT (trade name, tetramethylthiuram 21~578~
disulfide, manufactured by Ohuchi Shinko Kagaku Kogyo Co., Ltd.) and 1.25 parts by weight of Noxxelar CZ-G (trade name, N-cyclohexyl-2-benzothiazyl sulfenamide, manufactured by Ohuchi Shinko Kagaku Kogyo Co., Ltd.) 5 ~6: Barium sulfate (manufactured by Sakai Kagaku Kogyo Co., Ltd.
Next, a thread rubber comprising a natural rubber/low-cis synthetic polyisoprene (50:50, weight ratio) [Shell IR-309 (trade name), manufactured by Shell Kagaku Co., Ltd.] as the base rubber was wound around each center thus obtained as described above to form a thread 10 rubber layer, thereby preparing a thread wound core of 39.5 mm in outer diameter.
The above core was covered with pair of semispherical half-shells molded from the composition for cover, followed by subjecting to a press molding in a mold for ball at 150C for 3 minutes to give a thread 15 wound golf ball. The resulting golf ball was coated with a paint to finish a golf ball of 42.7 mm in outer diameter. The composition for cover is obtained by formulating 2 parts by weight of titanium dioxide in an ionomer mixture of Hi-milane 1605 (trade name) and Hi-milane 1706 (trade name) (50:50, weight ratio), which are ionomer neutralized with a sodium ion 20 manufactured by Mitsui Du Pont Polychemical Co., Ltd. and ionomer neutralized with a zinc ion manufactured by Mitsui Du Pont Polychemical Co., Ltd., respectively.
The weight, the compression, the flying performances and the hit feeling of the resulting golf ball were examined. The flying performances 25 were examined as to the case when hitting with a No. 1 wood club (flying performances 1) and the case when hitting with a No. 5 iron club (flying 214578~
performances 2).
The evaluation results of the weight, the compression, the flying performances 1 ) and 2) and the hit feeling of the golf balls of Examples 1 to 5 are shown in Table 3. Those of the golf balls of Comparative Examples 1 5 to 4 were shown in Table 4 and those of the golf balls of Comparative Examples 5 to 7 are shown in Table 5.
Further, the measuring method of the compression, flying performances 1 and flying performances 2 as well as the evaluation method of the hit feeling and the evaluation criteria are as follows.
1 0 Compression:
An initial load (10 kg) is applied on the golf ball, and then the load is gradually increased to the final load (130 kg). The amount of strain formed between initial loading and final loading of the golf ball is measured according to PGA system.
15 Flying performances 1:
A Swing robot manufactured by True Temper Co. is equipped with a No. 1 wood club and the golf ball is hit at a head speed of about 45 m/second to measure the flying performances 1. The spin amount is determined by taking a photograph of the golf ball to be hit. The carry is a 20 distance of the golf ball from the point where it was dropped. The total is atotal of the carry and a distance of the golf ball running from the point where it was dropped.
Flying performances 2:
A Swing robot manufactured by True Temper Co. is equipped 25 with a No. 5 iron club and the golf ball is hit at a head speed of about 38 m/second to measure the flying performances 2.
Evaluation method of hit feeling and evaluation criteria:
21~578~
The golf ball is practically hit with No. 1 wood club by 10 top professional golfers to evaluate the hit feeling. The evaluation criteria are as follows. The results shown in Tables 3 to 5 are based on the fact that not less than 8 out of 10 golfers evaluated with the same criterion.
5 0: Good hit feeling which is similar to that of a standard thread wound golf ball using a balata cover XH: Heavy and inferior XS: Soft and heavy feeling, inferior 16 21~57~
Table 3 Example No.
Ball Weight(g) 45.4 45 4 45 5 45 3 45 3 Compression 86 87 87 86 86 Flying performances 1 (No.1 wood club) Launch angle (degree) 11.2 11.3 11.4 11.5 11.4 Spin (rpm) 3150 3130 3080 3050 3120 Carry (yard) 227.0 227.3 228.0 228.2 227.2 Total (yard) 233.5 233.9 234.5 234.7 234.0 Flying performances 2 (No.5 iron club) Launch angle (degree) 14.7 14.8 15.0 15.2 14.9 Spin (rpm) 4800 4750 4730 4700 4730 Carry (yard) 187.3 187.5 187.9 188.0 187.6 Total (yard) 189.5 189.8 190.0 190.5 189.7 Hit feeling O O O O
21~S783 Table 4 Comparative Example No.
Ball Weight(g) 45.4 45.4 45-4 45 3 Compression 86 86 86 87 Flying performances 1 (No.1 wood club) Launch angle (degree) 10.7 11.0 10.9 11.1 Spin (rpm) 3400 3300 3310 3280 Carry (yard) 224.0 225.0 224.8 225.2 Total (yard) 229.5 230.2 230.0 230.4 Flying performances 2 (No.5 iron club) Launch angle (degree) 14.0 14.5 14.4 14.5 Spin (rpm) 5150 5020 5030 5000 Carry (yard) 184.3 185.0 184.8 185.2 Total (yard) 186.5 187.3 187.0 187.2 Hit feeling xH xH xH xH
~1~5~83 Table 5 Comparative Example No.
Ball Weight (9) 45.4 45.3 45.4 Compression 86 65 86 Flying performances 1 (No.1 wood club) Launch angle (degree) 11.2 11.5 11.0 Spin (rpm) 3320 3100 3350 Carry (yard) 225.5 223.5222.5 Total (yard) 230.5 229.0228.0 Flying performances 2 (No.5 iron club) Launch angle (degree) 14.3 15.0 14.1 Spin (rpm) 5030 4800 5100 Carry (yard) 184.7 184.0183.0 Total (yard) 187.1 187.5186.5 Hit feeling xH xS O
As is apparent from comparing the results shown in Tables 3, 4 and 5, regarding the golf balls of Examples 1 to 5, the spin amount was small and the launch angle was large and, further the flying distance was 5 large in comparison with the golf balls of Comparative Examples 1 to 7.
The flying distance (carry) due to the No. 1 wood club of a standard two-piece solid golf ball using a solid core is normally 225.0 to 235.0 yards 21~578~
and, therefore, it is understood that the flying distance of the golf balls of Examples 1 to 5 is large, which is equal to that of a two-piece solid golf ball. Further, in the evaluation of Examples 1 to 4 using the same thermoplastic resin, as the diameter of the center becomes larger and the 5 center becomes harder, the spin tends to become small and the launch angle tends to become large, which results in large flying distance.
To the contrary, regarding the golf balls of Comparative Examples 1 to 3 and 6, the center was soft and its strain amount was large and, therefore, large flying distance could not be attained. Also, 10 regarding the golf ball of Comparative Example 4, the strain amount of the center was large and, therefore, large flying distance could not be attained. Regarding the golf ball of Comparative Example 5, the center was too hard and its strain amount was small and, therefore, large flying distance could not be attained. Regarding the golf ball of Comparative 15 Example 7, the height of rebound was small and the impact resilient is insufficient and, therefore, the initial velocity became small, thereby attaining small flying distance.
Further, the golf balls of Comparative Examples 1 to 5 maintained a good hit feeling which is similar to that of a standard thread 20 wound golf ball using a balata cover, but some golf balls among the golf balls of Comparative Examples 1 to 6 were too hard or soft and, therefore, they were inferior.
disulfide, manufactured by Ohuchi Shinko Kagaku Kogyo Co., Ltd.) and 1.25 parts by weight of Noxxelar CZ-G (trade name, N-cyclohexyl-2-benzothiazyl sulfenamide, manufactured by Ohuchi Shinko Kagaku Kogyo Co., Ltd.) 5 ~6: Barium sulfate (manufactured by Sakai Kagaku Kogyo Co., Ltd.
Next, a thread rubber comprising a natural rubber/low-cis synthetic polyisoprene (50:50, weight ratio) [Shell IR-309 (trade name), manufactured by Shell Kagaku Co., Ltd.] as the base rubber was wound around each center thus obtained as described above to form a thread 10 rubber layer, thereby preparing a thread wound core of 39.5 mm in outer diameter.
The above core was covered with pair of semispherical half-shells molded from the composition for cover, followed by subjecting to a press molding in a mold for ball at 150C for 3 minutes to give a thread 15 wound golf ball. The resulting golf ball was coated with a paint to finish a golf ball of 42.7 mm in outer diameter. The composition for cover is obtained by formulating 2 parts by weight of titanium dioxide in an ionomer mixture of Hi-milane 1605 (trade name) and Hi-milane 1706 (trade name) (50:50, weight ratio), which are ionomer neutralized with a sodium ion 20 manufactured by Mitsui Du Pont Polychemical Co., Ltd. and ionomer neutralized with a zinc ion manufactured by Mitsui Du Pont Polychemical Co., Ltd., respectively.
The weight, the compression, the flying performances and the hit feeling of the resulting golf ball were examined. The flying performances 25 were examined as to the case when hitting with a No. 1 wood club (flying performances 1) and the case when hitting with a No. 5 iron club (flying 214578~
performances 2).
The evaluation results of the weight, the compression, the flying performances 1 ) and 2) and the hit feeling of the golf balls of Examples 1 to 5 are shown in Table 3. Those of the golf balls of Comparative Examples 1 5 to 4 were shown in Table 4 and those of the golf balls of Comparative Examples 5 to 7 are shown in Table 5.
Further, the measuring method of the compression, flying performances 1 and flying performances 2 as well as the evaluation method of the hit feeling and the evaluation criteria are as follows.
1 0 Compression:
An initial load (10 kg) is applied on the golf ball, and then the load is gradually increased to the final load (130 kg). The amount of strain formed between initial loading and final loading of the golf ball is measured according to PGA system.
15 Flying performances 1:
A Swing robot manufactured by True Temper Co. is equipped with a No. 1 wood club and the golf ball is hit at a head speed of about 45 m/second to measure the flying performances 1. The spin amount is determined by taking a photograph of the golf ball to be hit. The carry is a 20 distance of the golf ball from the point where it was dropped. The total is atotal of the carry and a distance of the golf ball running from the point where it was dropped.
Flying performances 2:
A Swing robot manufactured by True Temper Co. is equipped 25 with a No. 5 iron club and the golf ball is hit at a head speed of about 38 m/second to measure the flying performances 2.
Evaluation method of hit feeling and evaluation criteria:
21~578~
The golf ball is practically hit with No. 1 wood club by 10 top professional golfers to evaluate the hit feeling. The evaluation criteria are as follows. The results shown in Tables 3 to 5 are based on the fact that not less than 8 out of 10 golfers evaluated with the same criterion.
5 0: Good hit feeling which is similar to that of a standard thread wound golf ball using a balata cover XH: Heavy and inferior XS: Soft and heavy feeling, inferior 16 21~57~
Table 3 Example No.
Ball Weight(g) 45.4 45 4 45 5 45 3 45 3 Compression 86 87 87 86 86 Flying performances 1 (No.1 wood club) Launch angle (degree) 11.2 11.3 11.4 11.5 11.4 Spin (rpm) 3150 3130 3080 3050 3120 Carry (yard) 227.0 227.3 228.0 228.2 227.2 Total (yard) 233.5 233.9 234.5 234.7 234.0 Flying performances 2 (No.5 iron club) Launch angle (degree) 14.7 14.8 15.0 15.2 14.9 Spin (rpm) 4800 4750 4730 4700 4730 Carry (yard) 187.3 187.5 187.9 188.0 187.6 Total (yard) 189.5 189.8 190.0 190.5 189.7 Hit feeling O O O O
21~S783 Table 4 Comparative Example No.
Ball Weight(g) 45.4 45.4 45-4 45 3 Compression 86 86 86 87 Flying performances 1 (No.1 wood club) Launch angle (degree) 10.7 11.0 10.9 11.1 Spin (rpm) 3400 3300 3310 3280 Carry (yard) 224.0 225.0 224.8 225.2 Total (yard) 229.5 230.2 230.0 230.4 Flying performances 2 (No.5 iron club) Launch angle (degree) 14.0 14.5 14.4 14.5 Spin (rpm) 5150 5020 5030 5000 Carry (yard) 184.3 185.0 184.8 185.2 Total (yard) 186.5 187.3 187.0 187.2 Hit feeling xH xH xH xH
~1~5~83 Table 5 Comparative Example No.
Ball Weight (9) 45.4 45.3 45.4 Compression 86 65 86 Flying performances 1 (No.1 wood club) Launch angle (degree) 11.2 11.5 11.0 Spin (rpm) 3320 3100 3350 Carry (yard) 225.5 223.5222.5 Total (yard) 230.5 229.0228.0 Flying performances 2 (No.5 iron club) Launch angle (degree) 14.3 15.0 14.1 Spin (rpm) 5030 4800 5100 Carry (yard) 184.7 184.0183.0 Total (yard) 187.1 187.5186.5 Hit feeling xH xS O
As is apparent from comparing the results shown in Tables 3, 4 and 5, regarding the golf balls of Examples 1 to 5, the spin amount was small and the launch angle was large and, further the flying distance was 5 large in comparison with the golf balls of Comparative Examples 1 to 7.
The flying distance (carry) due to the No. 1 wood club of a standard two-piece solid golf ball using a solid core is normally 225.0 to 235.0 yards 21~578~
and, therefore, it is understood that the flying distance of the golf balls of Examples 1 to 5 is large, which is equal to that of a two-piece solid golf ball. Further, in the evaluation of Examples 1 to 4 using the same thermoplastic resin, as the diameter of the center becomes larger and the 5 center becomes harder, the spin tends to become small and the launch angle tends to become large, which results in large flying distance.
To the contrary, regarding the golf balls of Comparative Examples 1 to 3 and 6, the center was soft and its strain amount was large and, therefore, large flying distance could not be attained. Also, 10 regarding the golf ball of Comparative Example 4, the strain amount of the center was large and, therefore, large flying distance could not be attained. Regarding the golf ball of Comparative Example 5, the center was too hard and its strain amount was small and, therefore, large flying distance could not be attained. Regarding the golf ball of Comparative 15 Example 7, the height of rebound was small and the impact resilient is insufficient and, therefore, the initial velocity became small, thereby attaining small flying distance.
Further, the golf balls of Comparative Examples 1 to 5 maintained a good hit feeling which is similar to that of a standard thread 20 wound golf ball using a balata cover, but some golf balls among the golf balls of Comparative Examples 1 to 6 were too hard or soft and, therefore, they were inferior.
Claims (6)
1. A thread wound golf ball comprising a center composed of a vulcanized molded article of a rubber composition, a thread rubber layer formed on said center and a cover covering on said thread rubber layer, wherein said center has a diameter of 30 to 35 mm and a strain amount formed between an initial loading of 10 kg and a final loading of 30 kg is 1.2 to 2.5 mm.
2. The thread wound golf ball according to claim 1, wherein the center is a vulcanized molded article of a rubber composition comprising 100 parts by weight of a rubber and 5 to 80 parts by weight of a thermoplastic resin.
3. The thread wound golf ball according to claim 1, wherein the center is a vulcanized molded article of a rubber composition comprising 100 parts by weight of a rubber, 5 to 80 parts by weight of a thermoplastic resin, 2 to 12 parts by weight of sulfur, 1 to 4 parts by weight of a vulcanization accelerator and 10 to 150 parts by weight of a weight adjustor.
4. The thread wound golf ball according to any one of claims 1 to 3, wherein the rubber of the center is a high-cis polybutadiene or mainly conctains high-cis polybutadiene.
5. The thread wound golf ball according to any one of claim 2 or 3, wherein the thermoplastic resin is a high-styrene resin or a high-molecular weight polyolefin or a mixture thereof.
6. The thread wound golf ball according to claim 1, wherein the height of rebound of the center is 120 cm or more when dropping the center from the height of 254 cm.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP88014/1994 | 1994-03-31 | ||
| JP8801494 | 1994-03-31 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2145783A1 true CA2145783A1 (en) | 1995-10-01 |
Family
ID=13930996
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002145783A Abandoned CA2145783A1 (en) | 1994-03-31 | 1995-03-29 | Thread wound golf ball |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0674923B1 (en) |
| KR (1) | KR950031136A (en) |
| AU (1) | AU687511B2 (en) |
| CA (1) | CA2145783A1 (en) |
| DE (1) | DE69506930T2 (en) |
| TW (1) | TW323232B (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2299275B (en) * | 1995-03-31 | 1999-04-07 | Sumitomo Rubber Ind | Thread wound golf ball |
| JP3625231B2 (en) * | 1995-12-07 | 2005-03-02 | 住友ゴム工業株式会社 | Thread wound golf ball |
| JPH09248352A (en) * | 1996-03-15 | 1997-09-22 | Sumitomo Rubber Ind Ltd | Golf ball |
| JPH09271537A (en) * | 1996-04-04 | 1997-10-21 | Sumitomo Rubber Ind Ltd | Golf ball |
| AU714828B2 (en) * | 1996-04-04 | 2000-01-13 | Sumitomo Rubber Industries, Ltd. | Golf ball |
| US7244384B1 (en) | 1998-02-04 | 2007-07-17 | Taylormade-Adidas Golf Company | Method for manufacturing two and three piece golf balls constructed from polyurethane material |
| US7223181B2 (en) | 1998-02-04 | 2007-05-29 | Taylormade-Adidas Golf Company | Polyurethane material for two and three piece golf balls and method |
| US6196937B1 (en) | 1998-02-04 | 2001-03-06 | Sanjay M. Kuttappa | Three piece golf ball |
| US6719646B2 (en) | 2000-01-25 | 2004-04-13 | Dunlop Slazenger Sports | Polyurethane covered three-piece golf ball |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1520254A (en) * | 1974-12-30 | 1978-08-02 | Uniroyal Ltd | Golf balls |
| JPS59129072A (en) * | 1983-01-12 | 1984-07-25 | 住友ゴム工業株式会社 | Yarn wound golf ball |
| CA1230355A (en) * | 1983-10-24 | 1987-12-15 | William Gobush | Low trajectory long distance golf ball |
| JP3169287B2 (en) * | 1992-06-09 | 2001-05-21 | 住友ゴム工業株式会社 | Wound golf ball |
| JP2664857B2 (en) * | 1993-07-30 | 1997-10-22 | 住友ゴム工業株式会社 | Thread wound golf ball |
-
1995
- 1995-03-29 CA CA002145783A patent/CA2145783A1/en not_active Abandoned
- 1995-03-31 EP EP95302167A patent/EP0674923B1/en not_active Expired - Lifetime
- 1995-03-31 DE DE69506930T patent/DE69506930T2/en not_active Expired - Fee Related
- 1995-03-31 TW TW084103103A patent/TW323232B/zh active
- 1995-03-31 KR KR1019950007609A patent/KR950031136A/en not_active Application Discontinuation
- 1995-03-31 AU AU16202/95A patent/AU687511B2/en not_active Ceased
Also Published As
| Publication number | Publication date |
|---|---|
| AU687511B2 (en) | 1998-02-26 |
| DE69506930T2 (en) | 1999-05-27 |
| KR950031136A (en) | 1995-12-18 |
| DE69506930D1 (en) | 1999-02-11 |
| TW323232B (en) | 1997-12-21 |
| AU1620295A (en) | 1995-10-12 |
| EP0674923A1 (en) | 1995-10-04 |
| EP0674923B1 (en) | 1998-12-30 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |