JP3625326B2 - Golf ball - Google Patents

Description

【００５８】
【表２】

【００５９】
表１に示す結果から明らかなように、実施例１〜４は、飛距離が大きく、かつ良好な打球感を有していた。これは、アイオノマー樹脂のハイミラン１６０５（商品名）に対して、アイオノマー樹脂と相溶し得る部分を有するジエン系ゴムであるＡＮ−ＰＢ（商品名）を混合（ブレンド）し、かつ動的架橋したことによるものである。
【００６０】
これに対し、カバーの樹脂成分としてアイオノマー樹脂のみを用いた比較例１は、表２に示すように、打球感が硬くて悪かった。また、アイオノマー樹脂にアイオノマー樹脂と相溶し得る部分を有するジエン系ゴムをブレンドすることなく、通常のジエン系ゴムをブレンドしただけで動的架橋もしていない比較例２は、飛距離が低下し、また打球感がやわらかすぎて、悪くなっていた。
【００６１】
上記のように比較例２の特性が実施例１〜４に比べて悪かったのは、カバー用組成物におけるアイオノマー樹脂中のゴム粒子の平均粒子径からも判断できる。すなわち、表１〜２に示すゴム粒子の平均粒子径の対比から明らかなように、比較例２のゴム粒子の平均粒子径は実施例１〜４のゴム粒子の平均粒子径より大きく、その結果、上記のように飛距離が低下するなど、特性が悪くなったものと考えられる。これに対し、実施例１〜４が反撥性能の低下を招くことなく、打球感を良好にすることができたのは、前記のようなアイオノマー樹脂と相溶し得る部分を有するジエン系ゴムであるＡＮ−ＰＢのブレンドと動的架橋により、アイオノマー樹脂中に分散するゴム粒子の粒子径を小さくすることができたことによるものと考えられる。
【００６２】
また、アイオノマー樹脂と相溶し得る部分を有するジエン系ゴムであるＡＮ−ＰＢ（商品名）をアイオノマー樹脂にブレンドしても動的架橋をしなかった比較例３は、ゴム粒子の粒子径が充分に小さくならず、飛距離が小さく、かつ打球感もやわらかく適正さを欠いていた。
【００６３】
また、アイオノマー樹脂と相溶し得る部分を有するジエン系ゴムであるＡＮ−ＰＢ（商品名）のブレンド量が多かった比較例４も、飛距離が小さく、打球感もやわらかすぎて悪くなっていた。
【００６４】
【発明の効果】
以上説明したように、本発明は、打球感が良好で、かつ高反撥性能で、飛距離が大きいゴルフボールを提供することができた。
【図面の簡単な説明】
【図１】本発明に係るゴルフボールの一例を模式的に示す断面図である。
【符号の説明】
１ コア
１ａ センター
１ｂ 糸ゴム層
２ カバー[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a golf ball, and more particularly to a golf ball having a good feel at impact (feeling upon hitting), high rebound performance, and a large flight distance.
[0002]
[Prior art]
In recent years, ionomer resins have been widely used as resin for golf ball covers (for example, Japanese Patent Application Laid-Open No. 49-49727). This is because the ionomer resin is excellent in rebound performance and cut resistance.
[0003]
However, since the ionomer resin has high rigidity, a golf ball using the ionomer resin as a cover has a problem that the shot feeling is hard and bad.
[0004]
Therefore, various attempts have been made to improve the feel at impact by mixing (blending) rubber with ionomer resin, but sufficient results have not yet been achieved.
[0005]
For example, Japanese Patent Application Laid-Open No. 55-133440 has proposed a method of crosslinking a mixture of an ionomer resin and an ethylene-α-olefin copolymer rubber with a peroxide. In this case, since the ionomer resin is also cross-linked, the feel at impact cannot be sufficiently improved.
[0006]
Japanese Patent Laid-Open No. 6-79017 proposes a method of mixing an ionomer resin and a diene rubber and crosslinking the diene rubber in the mixture. However, the crosslinking speed and the crosslinked rubber particle diameter are considered. (I.e., since no compatibilization has been determined), the diene rubber may take a continuous layer in the ionomer resin, and therefore, in terms of workability, such as roughening during surface treatment. There were many disadvantages.
[0007]
[Problems to be solved by the invention]
As described above, in golf balls using an ionomer resin as a cover material, various attempts have been made to improve the feel at impact, but they cannot sufficiently improve the feel at impact or work. There was a problem such as causing a decline in sex.
[0008]
Accordingly, the present invention provides a golf ball having a good shot feeling, a good shot feeling, a high rebound performance, and a large flight distance without deteriorating workability and the high rebound performance of the ionomer resin. For the purpose.
[0009]
[Means for Solving the Problems]
As a result of intensive studies to achieve the above object, the inventors of the present invention have found that the dynamics of a mixture containing at least two components of an ionomer resin and a diene rubber having a portion compatible with the ionomer resin in a specific ratio. When the cover is made of a cross-linked product, the feel at impact can be made soft without deteriorating the workability and the resilience performance of the ionomer resin, the feel at impact is good, and the rebound performance is high. It was found that a large golf ball can be easily obtained, and the present invention has been completed.
[0010]
The present invention will be described in more detail. The inventors previously combined the high rebound performance based on the ionomer resin and the flexibility based on the diene rubber by dynamically crosslinking the diene rubber in the ionomer resin. A cover composition capable of providing a golf ball having a large flight distance and a soft feel at impact was provided. It was also found that among them, the smaller the particle size of the dynamically crosslinked diene rubber, the more golf balls with a soft feel at impact and excellent rebound performance.
[0011]
However, it has also been found that there is a limit in reducing the particle size of the diene rubber simply by dynamic crosslinking. In addition, when the particle size of the diene rubber is large, surface roughening occurs during surface treatment such as paint pretreatment at the time of golf ball production, and work for repairing the roughened portion is required. In addition, the adhesiveness of the paint also deteriorates, and it has been found that it is preferable that the particle diameter of the diene rubber is small also in these aspects.
[0012]
However, in the present invention, the ionomer resin and the diene rubber having a portion compatible with the ionomer resin are mixed to make them compatible in a fine particle state, and the mixture is subjected to dynamic crosslinking. As a result, the diene rubber having a part compatible with the ionomer resin is dynamically cross-linked, so that the rubber particles dispersed in the ionomer resin are further refined, thereby eliminating surface roughness during molding. As a result, a decrease in workability is suppressed, and a golf ball having a soft feel at impact, a high repulsion performance and a long flight distance can be obtained.
[0013]
In the present invention, the mixing ratio of the ionomer resin and the diene rubber having a portion compatible with the ionomer resin is 40:60 to 99: 1 by weight.
[0014]
When the mixing ratio of the ionomer resin is less than the above range, the high repulsion performance of the ionomer resin is impaired and the flight distance is reduced, and when the mixing ratio of the ionomer resin is higher than the above range, the properties of the ionomer resin become strong. Therefore, there is a possibility that the feel at impact cannot be improved. The mixing ratio of the ionomer resin and the diene rubber having a portion compatible with the ionomer resin is particularly preferably 50:50 to 95: 5 by weight.
[0015]
The diene rubber having a part compatible with the ionomer resin is for softening the shot feeling without reducing the high repulsion performance of the ionomer resin, but some of it is a normal diene rubber. It may be. However, when this ordinary diene rubber is used in combination with a diene rubber having a portion compatible with an ionomer resin, the diene rubber having a portion compatible with the ionomer resin and the ionomer resin and a normal diene rubber The diene rubber having a portion compatible with the ionomer resin is required to be 1% by weight or more, and particularly preferably 5% by weight or more.
[0016]
Next, the diene rubber having a portion compatible with the ionomer resin and the ionomer resin will be described in detail.
[0017]
Examples of the ionomer resin include Himiran 1605 (trade name, sodium ion neutralized ethylene-methacrylic acid copolymer ionomer resin) manufactured by Mitsui DuPont Polychemical Co., Ltd., Himiran 1707 (trade name, sodium ion neutralized ethylene-methacrylic acid). Acid copolymer ionomer resin), Himiran 1706 (trade name, zinc ion neutralized ethylene-methacrylic acid copolymer ionomer resin), Himiran AM7315 (trade name, zinc ion neutralized ethylene-methacrylic acid copolymer ionomer resin), Himiran AM7317 (trade name, zinc ion neutralized ethylene-methacrylic acid copolymer ionomer resin), Himiran 1555 (trade name, sodium ion neutralized ethylene-methacrylic acid copolymer ionomer resin), Himira 1557 (trade name, zinc ion neutralized ethylene-methacrylic acid copolymer ionomer resin), Iontech 7010 (trade name, zinc ion neutralized ethylene-acrylic acid copolymer ionomer resin), Iotech 8000 (product) Name, sodium ion neutralized ethylene-acrylic acid copolymer ionomer resin), Surlyn 7930 (trade name, lithium ion neutralized ethylene-methacrylic acid copolymer ionomer resin) manufactured by DuPont, Surlyn 8511 (trade name, zinc ion) Neutralized ethylene-methacrylic acid copolymer ionomer resin), Surlyn 8512 (trade name, sodium ion neutralized ethylene-methacrylic acid copolymer ionomer resin), and the like. However, these are examples, and are not limited to these.
[0018]
Examples of the diene rubber used as the base in the diene rubber having a portion compatible with the ionomer resin include, for example, ethylene propylene diene rubber (EPDM), butadiene rubber (BR), isoprene rubber (IR), and styrene butadiene rubber. (SBR), acrylonitrile butadiene rubber (NBR) and the like.
[0019]
In the present invention, the fact that the diene rubber having a portion compatible with the ionomer resin is compatible with the ionomer resin means that it is compatible with the ionomer resin or reacts with a residual carboxyl group in the ionomer resin. It means having a functional group that can.
[0020]
Good compatibility in the above means that the diene rubber having a portion compatible with the ionomer resin is dispersed as fine particles in the ionomer resin, each 10 μm when observed microscopically with an electron microscope or the like. The following fine particles are dispersed, and it is particularly preferable that the fine particles are dispersed as 2 μm or less.
[0021]
As an ionomer resin having good compatibility with the above ionomer resin, since the main chain of the ionomer resin is ethylene, an ethylene-based polymer is suitable. From such a viewpoint, ethylene propylene diene rubber, butadiene rubber and the like are preferable. .
[0022]
On the other hand, examples of the moiety capable of reacting with the residual carboxyl group in the ionomer resin include maleic anhydride, oxazoline group, epoxy group, glycidyl group and the like bonded to the diene rubber, and the carboxyl group in such ionomer resin Examples of the diene rubber having a reactable portion include a diene rubber having maleic anhydride as one constituent, a diene rubber having an oxazoline group as one constituent, and a diene rubber having an epoxy group as one constituent. Or a diene rubber containing a glycidyl group as one constituent component.
[0023]
Examples of the diene rubber having maleic anhydride as one component include those obtained by adding maleic anhydride to the main chain of the diene rubber and those obtained by copolymerizing maleic anhydride with the main chain of the diene rubber. It is done. Specific examples of such a diene rubber having maleic anhydride as a constituent component include, for example, maleic anhydride butadiene rubber, maleic anhydride ethylene propylene rubber, maleic anhydride ethylene propylene diene rubber and the like. In the diene rubber containing maleic anhydride as a constituent component, the maleic anhydride reacts with the residual carboxyl group of the ionomer resin.
[0024]
Examples of the diene rubber having an oxazoline group as a constituent component include those obtained by adding an oxazoline group to the main chain of the diene rubber, and those obtained by copolymerizing the oxazoline group with the main chain of the diene rubber. In the diene rubber having one of these oxazoline groups as a constituent component, the oxazoline group reacts with the remaining carboxyl group of the ionomer resin.
[0025]
Examples of the diene rubber having an epoxy group as a constituent component include those obtained by adding an epoxy-containing group to the main chain of the diene rubber, and those obtained by copolymerizing the epoxy-containing group with the main chain of the diene rubber. Specific examples include epoxidized EPDM (epoxidized ethylene propylene diene rubber) and epoxidized SBS (epoxidized styrene-butadiene-styrene copolymer). And the diene rubber which uses these epoxy groups as one structural component, the epoxy group reacts with the residual carboxyl group of ionomer resin.
[0026]
Examples of the diene rubber having a glycidyl group as a constituent component include diene rubbers having a glycidyl methacrylate group, a glycidyl acrylate group, an allyl glycidyl ether group, a butene carboxylic acid ester group, and the like. In the diene rubber having one of these glycidyl groups as a constituent component, the glycidyl group reacts with the residual carboxyl group of the ionomer resin. Two or more diene rubbers having a portion compatible with these ionomer resins may be used in combination.
[0027]
Examples of the crosslinking agent for performing dynamic crosslinking include rubber vulcanizing agents, vulcanization accelerators, resin crosslinking agents, and the like, and one or a combination of two or more of them can be used.
[0028]
Specific examples of the crosslinking agent include, for example, p-benzoylquinone dioxime, p, p'-dibenzoylquinone dioxime, 4,4'-dithio-bis-dimorpholine, alkylphenol-formaldehyde, brominated-alkylphenol. -Formaldehyde, phenolic resin, coumarone resin, dibenzothiazyl disulfide, N, N'-dicyclohexyl-2-benzothiazylsulfenamide, hexamethylenetetramine, mercaptobenzothiazole, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutyl Preferred examples include thidium disulfide, but the present invention is not limited to these, and various types can be used as long as they are vulcanizing agents and vulcanization accelerators used in normal rubber compounding.
[0029]
Dynamic cross-linking refers to a method of cross-linking rubber in the sea of resin by putting resin, uncross-linked rubber and cross-linking agent into a kneader and mixing at a temperature higher than the reaction temperature of the cross-linking agent. Since rupture and crosslinking occur at the same time, the refined rubber particles can be dispersed in the resin, and a material having both the properties of the resin and rubber can be obtained. As described above, the dynamic cross-linking does not require an independent cross-linking operation, and the obtained material can be reused when heated.
[0030]
The mixing method is not particularly limited, and for example, a mixing method using a closed kneader such as a kneader or an open kneader such as a roll can be adopted. However, in consideration of continuous productivity, mixing using an extruder The method is suitable. Moreover, you may mix the same substance by several or more types of kneading | mixing methods at the time of the said mixing.
[0031]
The cover composition contains at least an ionomer resin, a diene rubber having a portion compatible with the ionomer resin (which may include a part of a normal diene rubber), and a crosslinking agent. In addition, pigments such as titanium dioxide and barium sulfate, and other additives such as stabilizers, dispersants, ultraviolet absorbers, and light stabilizers are appropriately mixed.
[0032]
The dynamic crosslinking is performed during mixing as described above, and the temperature for performing the dynamic crosslinking is suitably from 20 ° C. to 250 ° C. lower than the activation temperature of the crosslinking agent. For example, in the case of an oxime-based crosslinking agent, the activation temperature is generally about 180 ° C., and therefore the temperature during dynamic crosslinking is suitably in the range of 160 to 250 ° C. In the case of an aldehyde-based crosslinking agent, the activation temperature is generally about 120 to 140 ° C., and therefore the temperature during dynamic crosslinking is suitably in the range of 100 to 250 ° C. Further, when sulfur and a vulcanization accelerator are used in combination, the activation temperature is generally about 150 ° C., and therefore the temperature during dynamic crosslinking is suitably in the range of 130 to 250 ° C. If the temperature at the time of dynamic crosslinking is lower than the above temperature, there is a risk that production efficiency may be deteriorated because crosslinking of a diene rubber having a portion compatible with the ionomer resin does not occur or the progress of the crosslinking reaction is slow. In addition, when the temperature during dynamic crosslinking is higher than 250 ° C., the diene rubber having a portion compatible with the ionomer resin is deteriorated, and the effect of softening the feel at impact is not sufficiently exhibited. There is a fear. However, the temperature at the time of the dynamic crosslinking is merely an example, and is not necessarily limited thereto.
[0033]
When performing dynamic cross-linking, it is preferable that the torque once increased by cross-linking of a diene rubber or the like having a portion compatible with the ionomer resin is decreased, and the dynamic cross-linking is terminated immediately before stabilization or immediately after stabilization. As described above, it is appropriate to manage the end of the dynamic cross-linking by the torque value. However, in terms of time, although it varies greatly depending on the type of the cross-linking agent, the blending, the amount of the blending, etc., it is usually 1-60. For example, it is about 3 to 60 minutes in the case of an oxime-based crosslinking agent, 2 to 40 minutes in the case of an aldehyde-based crosslinking agent, and 2 to 30 minutes when sulfur and a vulcanization accelerator are used in combination. Degree.
[0034]
A cover composition comprising a dynamic cross-linked product of a mixture containing at least two components of the above ionomer resin and a diene rubber having a portion compatible with the ionomer resin includes a solid golf ball core (solid core), and thread wound golf. It can be used to coat any core of a ball core (pound core).
[0035]
The solid core may be a single-layered core or a multilayered core of two or more layers. For example, as a two-piece ball core, acrylic acid, methacrylic acid, etc. with respect to 100 parts by weight of polybutadiene 10 to 60 parts by weight of a cross-linking agent (vulcanizing agent) composed of a α, β-monoethylenically unsaturated carboxylic acid or a metal salt thereof or a functional monomer such as trimethylolpropane trimethacrylate alone or in total 3 to 30 parts by weight of a filler such as zinc and barium sulfate and 0.5 to 5 parts by weight of a peroxide such as dicumyl peroxide are added, and if necessary, an antioxidant is further added to 0.1 to 1 part by weight. Partly compounded rubber composition is heat-compressed by press crosslinking (vulcanization), for example, at a temperature of 140 to 170 ° C. for 10 to 40 minutes to form a spherical crosslinked (vulcanized) product. What was obtained by these can be used.
[0036]
The wound core is composed of a center and a thread rubber wound around the center, and either a liquid system or a rubber system can be used as the center. As the rubber center, for example, one obtained by crosslinking (vulcanizing) the same rubber composition as that of the solid core can be used.
[0037]
As the rubber thread, those conventionally used can be used. For example, rubber in which natural rubber or a mixture of natural rubber and synthetic polyisoprene is blended with an anti-aging agent, a crosslinking (vulcanization) accelerator, sulfur and the like. What was obtained by bridge | crosslinking (vulcanizing | curing) a composition can be used. However, these solid cores and thread wound cores are merely examples, and are not limited to these examples.
[0038]
The method of covering the core with the cover is not limited to obtaining, and can be performed by a normal method. For example, the cover composition composed of the specific dynamic cross-linked product is formed into a half-shell half shell in advance, and the two cores are used to wrap the core, followed by pressure molding at 100 to 170 ° C. for 1 to 15 minutes. Alternatively, a method in which the cover composition is directly injection-molded on the core and the core is wrapped is employed. The thickness of the cover is usually about 1 to 4 mm. When forming the cover, dimples are formed on the ball surface as necessary, and paint finishing, stamping, and the like are also performed as necessary.
[0039]
Next, the structure of the golf ball of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view schematically showing an example of the golf ball of the present invention. The golf ball shown in FIG. 1 is a thread wound golf ball. In FIG. 1, 1 is composed of a center 1a and a thread rubber layer 1b. A core, 2 is a cover, and 2a is a dimple.
[0040]
The thread rubber for forming the center 1a and the thread rubber layer 1b is not limited to a specific one but can be the same as the conventional one. The center 1a can be either liquid or rubber. The thread rubber layer 1b may be formed by winding a thread rubber around the center 1a in a stretched state, thereby forming a core 1 called a thread wound core.
[0041]
The cover 2 covers the core 1 and is formed from a cover composition made of the specific dynamic cross-linked product. Reference numeral 2a denotes a dimple provided on the cover 2. In the golf ball shown in FIG. 1, the core 1 is formed of a thread wound core. Instead, for example, a solid core made of a crosslinked (vulcanized) molded body of a rubber composition mainly composed of butadiene rubber or the like is used. You can also.
[0042]
The dimples 2a are provided on the cover 2 of the golf ball in a suitable number and manner so that desired characteristics can be obtained as needed, and these golf balls are provided as needed. The ball surface is painted and marked.
[0043]
DETAILED DESCRIPTION OF THE INVENTION
Next, the present invention will be described more specifically with reference to examples. However, this invention is not limited only to those Examples.
[0044]
Examples 1-4 and Comparative Examples 1-4
The golf balls of Examples 1 to 4 and Comparative Examples 1 to 4 were produced through the following steps (1) to (3).
[0045]
(1) Core production:
A thread-wound core having an outer diameter of 38.5 mm is formed by wrapping thread rubber in a stretched state around a liquid center formed by sealing water into a rubber bag made of vulcanized natural rubber and forming it into a spherical shape. Was made.
[0046]
(2) Preparation of cover composition:
As the ionomer resin, the diene rubber having a portion compatible with the ionomer resin, the normal diene rubber, and the cross-linking agent, the following are used, and Examples 1 to 4 are mixed in the formulation shown in Table 1. Then, the composition for the cover is prepared by dynamically crosslinking together, and the composition for the cover is prepared by mixing in the composition described in Table 2 for Comparative Examples 1 to 3, and the composition described in Table 2 for the Comparative Example 4 The composition for a cover was prepared by performing dynamic crosslinking while mixing. In addition, the said mixing was performed at each zone temperature = 165-225 degreeC using the twin-screw extruder (screw diameter 45mm, L / D = 25). However, each component was preliminarily mixed with an open roll in advance, and the mixture was supplied to the extruder. The time required for dynamic crosslinking is 5 minutes in all cases, and the blending amount of each component in the table is parts by weight.
[0047]
Ionomer resin:
High Milan 1605 [trade name, manufactured by Mitsui DuPont Polychemical Co., Ltd., sodium ion neutralized ethylene-methacrylic acid copolymer ionomer resin]
[0048]
Diene rubber having a part compatible with ionomer resin:
AN-PB [trade name, manufactured by Nippon Soda Co., Ltd., maleated butadiene rubber]
[0049]
Diene rubber:
Esplene 505A [trade name, manufactured by Sumitomo Chemical Co., Ltd., ethylene propylene diene rubber]
[0050]
Cross-linking agent:
Tactrol 250 [trade name, manufactured by Taoka Chemical Industry Co., Ltd., brominated-alkylphenol-formaldehyde]
[0051]
(3) Production of golf ball:
The cover composition of (2) above is formed into a pellet, a half shell is formed using the pellet cover composition, and two of them are used to wrap the core of (1) above at 150 ° C. Eight types of thread-wound golf balls having an outer diameter of 42.7 mm and a weight of 45.1 to 45.3 g were produced by thermoforming for 2 minutes.
[0052]
The flight distance of the obtained golf ball was measured and the feel at impact was evaluated. Moreover, the particle diameter of the dispersed rubber particles in the ionomer resin in the cover composition was measured. The method for measuring the particle diameter of the rubber particles, the flight distance of the golf ball, and the method for evaluating the feel at impact are as follows.
[0053]
Method for measuring the particle size of rubber particles and calculating the average particle size
First, a sample for measurement was prepared by forming the cover composition of the above (2) into a pellet and heat-molding the pellet-like cover composition into a sheet under pressure at 160 ° C. for 3 minutes. Then, the sample surface is cut smoothly with a microtome, and using a scanning electron microscope (T-220A manufactured by JEOL), OsO₄The backscattered electron image photograph of the dyed sample was taken, the length in the vertical direction of the 60 arbitrary rubber particles was measured, and the numerical value of the number average was taken as the average particle diameter.
[0054]
Flight distance measurement method:
A wood No. 1 club is attached to a swing robot manufactured by True Temper, and each ball is hit at a head speed of 45 m / s, and the distance to the drop point is measured. A result is shown by the average value.
[0055]
Evaluation method of shot feeling:
A golf player hits a ball with a wood No. 1 club and classifies the feeling of hitting felt by each of the golf players according to the following seven-step evaluation.
HH: Too hard and bad.
H: Hard.
AH: Slightly hard but in good range.
A: Just right.
AS: Slightly soft but in good range.
S: Soft.
SS: Too soft and bad.
[0056]
Table 1 shows the composition of the cover compositions of Examples 1 to 4, the average particle diameter of the rubber particles, the flight distance of the obtained golf ball, and the evaluation results of the shot feeling, and Table 2 shows the covers of Comparative Examples 1 to 4 The evaluation results of the composition of the composition for use, the average particle diameter of the rubber particles, the flight distance of the obtained golf ball, and the shot feeling are shown.
[0057]
[Table 1]

[0058]
[Table 2]

[0059]
As is clear from the results shown in Table 1, Examples 1 to 4 had a great flight distance and a good feel at impact. This is made by mixing (blending) AN-PB (trade name), which is a diene rubber having a portion compatible with the ionomer resin, and dynamically cross-linking with Himiran 1605 (trade name) of the ionomer resin. It is because.
[0060]
On the other hand, as shown in Table 2, Comparative Example 1 using only the ionomer resin as the resin component of the cover was hard and bad. Further, Comparative Example 2 in which ordinary diene rubber is blended without dynamic crosslinking without blending the ionomer resin with a diene rubber having a portion compatible with the ionomer resin has a reduced flight distance. Also, the shot feeling was too soft and worse.
[0061]
The reason why the characteristics of Comparative Example 2 were worse as compared with Examples 1 to 4 as described above can also be judged from the average particle diameter of rubber particles in the ionomer resin in the cover composition. That is, as apparent from the comparison of the average particle diameter of the rubber particles shown in Tables 1 and 2, the average particle diameter of the rubber particles of Comparative Example 2 is larger than the average particle diameter of the rubber particles of Examples 1 to 4, and as a result. It is considered that the characteristics deteriorated, such as a decrease in flight distance as described above. On the other hand, the diene rubber having a portion compatible with the ionomer resin as described above was able to improve the shot feeling without causing a drop in the rebound performance of Examples 1 to 4. It is considered that the particle diameter of the rubber particles dispersed in the ionomer resin could be reduced by a certain AN-PB blend and dynamic crosslinking.
[0062]
Further, Comparative Example 3 in which AN-PB (trade name), which is a diene rubber having a portion compatible with the ionomer resin, was blended with the ionomer resin and did not undergo dynamic crosslinking had a particle size of rubber particles. It was not sufficiently small, the flight distance was small, and the shot feeling was soft and lacked appropriateness.
[0063]
Further, Comparative Example 4 in which the blend amount of AN-PB (trade name), which is a diene rubber having a portion compatible with the ionomer resin, was large, and the flying distance was small, and the shot feeling was too soft, which was worse. .
[0064]
【The invention's effect】
As described above, the present invention can provide a golf ball having a good shot feeling, a high rebound performance, and a long flight distance.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view schematically showing an example of a golf ball according to the present invention.
[Explanation of symbols]
1 core
1a Center
1b Rubber thread layer
2 Cover

Claims (6)

A golf ball having a core and a cover, wherein the cover includes at least two components of (1) an ionomer resin and (2) a diene rubber having a portion compatible with the ionomer resin, and (1) an ionomer resin. and (2) the ionomer resin and the mixing ratio by weight of the diene rubber having a moiety capable of compatible 40: 60-99: 1 and a mixture Ri Do from the dynamic crosslinked product, and in the cover (2) a golf ball having a diene rubber having a moiety capable of compatible with the ionomer resin is formed by dynamic crosslinking, characterized by Oh Rukoto at 10μm or less fine particles with an average particle size. The cover of the diene rubber with respect to 100 parts by weight of the diene rubber in the mixture containing at least two components of (1) an ionomer resin and (2) a diene rubber having a portion compatible with the ionomer resin. The golf ball according to claim 1, comprising a dynamic cross-linked product obtained by mixing 0.1 to 30 parts by weight of a cross-linking agent and dynamically cross-linking at least a part of the diene rubber. 3. The golf ball according to claim 1, wherein the diene rubber having a portion compatible with the ionomer resin is a diene rubber having maleic anhydride as a constituent component. 3. The golf ball according to claim 1, wherein the diene rubber having a portion compatible with an ionomer resin is a diene rubber having an oxazoline group as one constituent component. 3. The golf ball according to claim 1, wherein the diene rubber having a portion compatible with an ionomer resin is a diene rubber having an epoxy group as a constituent component. 3. The golf ball according to claim 1, wherein the diene rubber having a portion compatible with an ionomer resin is a diene rubber having a glycidyl group as one constituent component.

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