JP3424864B2 - Golf ball manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION The present invention relates to a golf ball.How to make
LawFor more details, feel at impact (feeling
Gol with excellent resilience, high repulsion performance and long flight distance
FubolManufacturing methodAbout. [0002] 2. Description of the Related Art In recent years, as a resin for golf ball covers,
For example, ionomer resins have been widely used (eg,
For example, JP-A-49-49727). This is Iono
It is said that the mer resin is excellent in repulsion performance and cut resistance
This is for the reason. However, it has the above-mentioned characteristics.
Because of the high rigidity of the ionomer resin,
-Golf balls that use resin for the cover
The drawback is that it makes a sound and the shot feeling becomes hard
is there. Various attempts have been made to improve the feel at impact.
Has been made. For example, JP-A-55-133440
The publication states that ionomer resins and ethylene-α-olefin
Ethylene-α-olefin in a mixture of ethylene copolymer rubbers
Proposal of a method to crosslink vinyl copolymer rubber with peroxide
However, peroxides also crosslink ionomer resins.
The shot feeling has not been improved. In addition, Japanese Unexamined Patent Publication
JP-79017 discloses an ionomer resin and a diene-based resin.
The rubber is mixed and the diene rubber is bridged in the ionomer resin.
A golf ball that has been bridged and used as a cover has been proposed.
However, no study has been made on the particle size of the rubber particles.
Simply mix ionomer resin and diene rubber
(Blend) Greater ball properties
The top is not obtained. [0005] SUMMARY OF THE INVENTION As described above,
Nomer resin and diene rubber are mixed, and diene rubber is
Dynamic cross-linking for golf ball covers
It is known that the ball properties are greatly improved
Not obtained. Accordingly, the present invention provides an ionomer resin
Softens the feel at impact without reducing the rebound performance of the
Excellent shot feeling, high rebound performance, and long flight distance
It is intended to provide a golf ball. [0007] Means for Solving the Problems The present inventors have developed an iono-electric device.
Of diene rubber dispersed in polymer resin
Improve the shot feeling without lowering the rebound performance
Based on the idea that it could be
After conducting various studies, it was dispersed in ionomer resin.
Diene rubber with cross-linking agentIn a particular wayDynamic frame
When bridging, the crosslinked rubber particles should have an average particle size of 10 μm or less.
It can be made into fine particles, and its dynamic crosslinking
And the average particle size is 10 μm or less in the ionomer resin.
The lower crosslinked diene rubber particles are dispersed and the resulting thermoplastic
The use of a conductive elastomer for the cover reduces the rebound performance.
Without softening the shot feeling, excellent shot feeling and high response
The present invention is to obtain a golf ball having a long flight distance with repelling performance.
Was completed. That is, the present invention provides a core and a coating on the core.
To have a coverI, As the base polymer of the cover,
Crosslinking agent for diene rubber dispersed in ionomer resin
Dynamic cross-linking, and average particle size in the ionomer resin
Heat-resistant in which crosslinked diene rubber particles having a diameter of 10 μm or less are dispersed
Use plastic elastomerGolf ball manufacturing method
What In the above dynamic cross-linking, stable
With the torque as 100, A = (weight of diene rubber) /
(Weight of ionomer resin + weight of diene rubber) and
Then, the ideal torque B at the time of dynamic crosslinking is calculated as B = 100 + (10 ×
In the case of A), the torque at the time of dynamic crosslinking is the ideal torque.
Dynamic cross-linking is terminated after the maximum value
EndGolf ballManufacturing methodAbout
You. [0009] As described above, the dispersion in the ionomer resin
The particle size of the crosslinked diene-based rubber particles
This increases the size of the continuous layer of ionomer resin,
The repellency of ionomer resin is prevented from deteriorating.
Fine crosslinked diene rubber particles in ionomer resin
Uniform dispersion plays a major role in shock absorption
It is thought that the hit feeling is softened. did
Therefore, as described above, fine cross-linking in the ionomer resin
Thermoplastic elastomer in which diene rubber particles are uniformly dispersed
Preparation of cover composition by using-as base polymer
The cover formed from the cover composition is coated on the core.
By overturning, excellent shot feeling and high rebound performance
So that a golf ball with a long flight distance can be obtained.
You. In the present invention, as the ionomer resin
Is, for example, an α-olefin and an α, β-unsaturated carboxylic acid.
Neutralization of a part of carboxylic acid of copolymer with acid with metal ion
Is used. As the above α-olefin
Is preferably, for example, ethylene, propylene, etc.
As the α, β-unsaturated carboxylic acid, for example, acrylic
Acid methacrylic acid is preferred. In addition, the carboxylic acid
Examples of metal ions that neutralize
On, potassium ion, alkali such as lithium ion
Metal ion, zinc ion, calcium ion, magnesi
Divalent metals such as uranium ions, copper ions and manganese ions
Trivalent gold such as ion, aluminum, neodymium ion
Group ions, but zinc ions are particularly
The on-agglomerate has a large bonding force and high repulsion performance and durability
It is preferable because it has both. Specific examples of the ionomer resin as described above
For example, Mitsui DuPont Polychemical Co., Ltd.
Himilan 1605 (trade name, sodium ion neutralization
Tylene-methacrylic acid copolymer-based ionomer resin), c
Imilan 1707 (trade name, sodium ion neutralized ethyl
Len-methacrylic acid copolymerized ionomer resin), high
Milan 1706 (trade name, zinc ion neutralized ethylene
Tacrylic acid copolymerized ionomer resin), Himilan A
M7315 (trade name, zinc ion neutralized ethylene-methacrylate
(Copolymer ionomer resin), Himilan AM7
317 (trade name, zinc ion neutralized ethylene-methacryl
Acid copolymerized ionomer resin), Himilan 1555
(Product name, sodium ion neutralized ethylene-methacryl
Acid copolymerized ionomer resin), Himilan 1557
(Product name, zinc ion neutralized ethylene-methacrylic acid copolymer
Combined ionomer resin), Exxon Chemical's eye
Otec 7010 (trade name, zinc ion neutralized ethylene-
Acrylic acid copolymerized ionomer resin), Iotek
8000 (trade name, sodium ion neutralized ethylene-A
Crylic acid copolymerized ionomer resin), manufactured by DuPont
Surlyn 7930 (trade name, lithium ion neutralized ethyl
-Methacrylic acid copolymer-based ionomer resin).
I can do it. Examples of the diene rubber include ethylene.
-Propylene-diene rubber (EPDM), butadiene
(BR), isoprene rubber (IR), styrene-buta
Diene rubber (SBR), nitrile-butadiene rubber (N
BR) and the like, and particularly ethylene-propylene
-Diene rubber, butadiene rubber, etc. obtained high repulsion performance
Is preferred. [0013] Diene system dispersed in ionomer resin
The amount of rubber is based on 100 parts by weight of the ionomer resin.
And 10 to 100 parts by weight of a diene rubber. Eye
The amount of the diene rubber dispersed in the onomer resin is within the above range.
If it is less than the box, the effect of improving the shot feeling is fully exhibited.
Diene resin that does not appear and is dispersed in ionomer resin
If the amount of the system exceeds the above range, the ionomer resin
There is a possibility that the resilience performance may decrease. As a crosslinking agent for dynamically crosslinking diene rubbers
Can be used as long as it is not a peroxide,
Oxime, Combination of sulfur and vulcanization accelerator, sulfur alone, vulcanization acceleration
Promoter alone is preferably used, especially oxime-based cross-linking.
Agents are preferred. As a specific example of this oxime-based crosslinking agent,
Is, for example, p-quinonedioxime, p, p'-benzo
Ilquinone dioxime and the like. Also, vulcanization
As an enhancer, for example, dibenzothiazyl disulphide
, N, N'-dicyclohexyl-2-benzothiazyl
Sulfemamide, hexamethylenetetramine, mel
Captobenzothiazole, tetramethylthiuram disul
Fido, tetraethyluram disulfide, tetrabuty
Preferred examples include ruthenium disulfide.
However, without being limited to these, rubber compounding is generally
Various vulcanization accelerators to be used
Can be. [0015] The amount of the cross-linking agent is
100 parts by weight of diene rubber in a mixture with diene rubber
0.2 to 10 parts by weight, preferably 1 to 5 parts by weight,
New If the amount of the crosslinking agent is less than the above range,
Insufficient cross-linking of the system rubber, thus absorbing impact
The effect of softening the feel at impact is not fully exhibited, and
If the amount of the crosslinking agent exceeds the above range, crosslinking of the rubber proceeds.
Only crosslinked diene rubber particles with too large diameter
The resilience performance of the ionomer resin is lost.
As a result, the rebound performance decreases and the flight distance decreases
There is a possibility that. The above ionomer resin and diene rubber
Fillers and chemicals commonly used in rubber compounding
(Additives, dispersants, stabilizers) and the like,
A white filler such as titanium dioxide may be blended. Further
Having an average particle size of 10 μm or less in the ionomer resin.
Thermoplastic elastomer with cross-linked diene rubber particles dispersed
Even if other resins are added within the range that does not impair the characteristics of
Good. However, when adding other resin like this,
The thermoplastic elastomer is mixed with other resins at 70
It preferably accounts for at least% by weight. In preparing the cover composition,
At least ionomer resin, diene
Kneader, Banbury, and extrusion of three types of rubber and crosslinking agent
Mix with a machine, roll, etc.
Dynamically crosslinks system rubber. The mixture of these three is ionoma
-Resin, diene rubber, crosslinking agent may be used in that order, or
The mixture mixed with a pre-roll may be subjected to dynamic crosslinking.
No. However, pre-mixing is performed below the activation temperature of the crosslinking agent.
There is a need. The temperature at which dynamic crosslinking is carried out depends on the activation temperature of the crosslinking agent.
Temperatures from 20 ° C below the temperature to 250 ° C are suitable.
For example, in the case of an oxime crosslinking agent, the activation temperature is generally
Since the temperature is about 180 ° C., the temperature during dynamic crosslinking is 1
A range from 60 to 250C is suitable. Also, sulfur and vulcanization
When using an accelerator together, the activation temperature is generally about 150 ° C.
Temperature, the temperature at the time of dynamic crosslinking is 130 to 25
A range of 0 ° C. is suitable. The temperature at the time of dynamic crosslinking is the above temperature
If it is lower, crosslinking of the diene rubber does not occur,
Alternatively, the progress of the crosslinking reaction is slow, resulting in poor production efficiency.
And the temperature during dynamic crosslinking is higher than 250 ° C
Causes deterioration of the diene rubber and softens the feel at impact
The effect or the like may not be sufficiently exhibited. Dynamic crosslinking is, DynamicStable torque before mechanical crosslinking
And the following ionomer resin and diene rubber
Let A be the ratio of At the time of dynamic crosslinkingIdeal torque BB = 100 + (10 × A)
WhenDefinitionWhen the dynamic crosslinkingTorque,Above ideal torqueK
BAfter satisfying the above conditions and taking the maximum value,
Finishes cross-linkingDo like.this is,Ionomer tree
In fatAverage particle size of crosslinked diene rubber particlesTo10 μm or less
ToTo do. In the present invention, the ionomer resin is dispersed in the ionomer resin.
The dispersed crosslinked diene rubber particles have an average particle size of 10 μm or less.
This is the average particle size of the crosslinked diene rubber particles.
When the diameter is larger than 10μm, it absorbs the impact at the time of hitting
The effect of softening the shot feeling is not fully exhibited, and
High repulsion due to reduced repulsion performance of ionomer resin
This is because a functional thermoplastic elastomer cannot be obtained. The crosslinked diene rubber particles have a small particle size.
The softer the shot feeling and the lower the rebound performance
Convenient to do, but too small
And the shock absorbing effect of the crosslinked diene rubber particles decreases.
The effect of improving the feel at impact disappears
In practice, those having an average particle diameter of 0.001 μm or more
preferable. The end of the dynamic crosslinking is determined by the torque value as described above.
Managed byButIn terms of time, the type and distribution of the crosslinking agent
Depends greatly on the amount of the compound,
~ 60 minutesso,For example, in the case of an oxime crosslinking agent, 3
About 60 minutes, 2 if sulfur and vulcanization accelerator are used together
In about 30 minutes, The dynamic crosslinking is properly terminatedYou. By the above-mentioned dynamic crosslinking, the ionomer resin
Crosslinked diene rubber particles having an average particle size of 10 μm or less are dispersed
Cover made of coated thermoplastic elastomer as base polymer
Is a solid golf ball core (solid core) and
Any of the cores for thread-wound golf balls (thread-wound cores)
It can also be applied to coatings. As a solid core, a one-layer core is
Of course, it may be a core having a multilayer structure of two or more layers,
For example, as a core for two-piece balls, butadiene
Acrylic acid, methacrylic acid to 100 parts by weight of rubber
Α, β-unsaturated carboxylic acids or metal salts thereof,
Functionality such as trimethylolpropane trimethacrylate
Vulcanizing agents (crosslinking agents) such as reactive monomers alone or in total
10-60 parts by weight, filled with zinc oxide, barium sulfate, etc.
10 to 30 parts by weight of the agent, such as dicumyl peroxide
0.5 to 5 parts by weight of peroxide, if necessary, further
A rubber composition containing 0.1 to 1 part by weight of an anti-aging agent
Less vulcanization (crosslinking), for example, a temperature of 140 to 170 ° C.
To form a spherical vulcanizate.
Can be used. The wound core is wound around the center and
Made of rubber thread, with liquid or rubber as the center
A shift can also be used. As a rubber center
For example, the same rubber composition as the solid core is added.
It is possible to use those obtained by
You. The rubber thread used may be any of those conventionally used.
It can be used, for example, with natural rubber or natural rubber
Anti-aging agent, vulcanization acceleration in mixture with synthetic polyisoprene
Vulcanization of a rubber composition containing a
Can be used. However, this
These solid cores and wound cores are just examples,
It is not limited only to these examples. The method of covering the core with the cover is not particularly limited.
Instead, it can be done in the usual way.
For example, the specific thermoplastic elastomer is a base polymer.
And a cover composition containing other necessary additives
The object is formed in advance into a half-shell
And wrap the core with two pieces at 100 to 170 ° C for 1 to 15
Press molding for a minute or cover composition directly to core
Injection molding on top and wrapping the core are adopted
You. The thickness of the cover is usually about 1 to 4 mm. Soshi
When molding the cover, if necessary,
The pull is formed, and the paint finish and stamp
It is applied as needed. Next, the structure of the golf ball of the present invention will be described.
This will be described with reference to the plane. FIG. 1 is a golf ball of the present invention.
FIG. 2 is a cross-sectional view schematically showing an example of
The ruf ball is a core 1 made of a vulcanized molded product of a rubber composition.
And a cover 2 that covers it.
Golf ball. The core 1 is called a solid core.
However, without being limited to a particular one, for example,
Addition of a rubber composition based on butadiene rubber as described above
A sulfur molded article is preferably used, and a cover 2 covering the
Using the specific thermoplastic elastomer as a base polymer
It was formed from a composition for a cover. And 2
a is a dimple provided on the cover 2. this
In the golf ball shown in FIG. 1, the core 1 has a single-layer rubber structure.
It consists of a vulcanized molded body of the composition, but instead
For example, vulcanization molding of a rubber composition mainly composed of butadiene rubber
More butadiene rubber around the inner core
Outer core consisting of a vulcanized molded product of rubber composition
It may be a solid core with a two-layer structure formed,
Thread rubber around the liquid or rubber center.
It may be a wound core formed by winding in a stretched state.
No. The dimples 2a are provided as needed.
Or the appropriate number and condition to obtain the desired characteristics.
And provided on the cover 2 of the golf ball.
Also, these golf balls may have a ball if necessary.
The surface is painted or marked. [0031] EXAMPLES Next, the present invention will be described in more detail with reference to Examples.
Will be described. However, the present invention is limited to only those examples.
It is not specified. Examples 1 to 3 and Comparative Examples 1 to 3 Through the following steps (1) to (3), Examples 1 to 3 and the ratio
Producing two-piece solid golf balls of Comparative Examples 1 to 3
Was. [0033]Making the core:BR01 [Product name, Japan
Butadiene rubber manufactured by Seimitsu Rubber Co., Ltd.]
25 parts by weight of zinc acrylate, 23 parts by weight of zinc oxide
And 1 part by weight of dicumyl peroxide.
The rubber composition was put in a mold and pressed at 155 ° C. for 30 minutes.
To form a core having a diameter of 38.5 mm. [0034]Preparation of cover composition:Ionomer tree
Fats, diene rubbers, and crosslinking agents
For Examples 1 to 3, the formulations shown in Table 1 were used.
The amounts of Comparative Examples 1 to 3 were as shown in Table 2,
Changing the ratio of diene rubber to ionomer resin
In Examples 1-3, dynamic crosslinking was performed, and in Comparative Examples 1-3,
Only kneaded. [0035]Ionomer resin: High Milan AM7315 [trade name, DuPont Mitsui
Mical Co., Ltd., zinc ion neutralized ethylene-methacryl
(Acid copolymerized ionomer resin)Diene rubber: Esplen 501A [trade name, manufactured by Sumitomo Chemical Co., Ltd.
Ethylene-propylene-diene rubber (EPDM)]Crosslinking agent: Barnock DGM [trade name, manufactured by NOF Corporation, p.
p'-benzoylquinone dioxime] The dynamic crosslinking in Examples 1 to 3 is shown in Table 1.
The compounding materials shown were spun with a Labo Plastomill manufactured by Toyo Seiki Co., Ltd.
Comparative Example 1 was carried out at 180 ° C. while kneading at 100 revolutions.
In the kneading in ~ 3, the compounding materials shown in Table 2 were used in the same manner as above.
100 rotations with Labo Plast Mill manufactured by Toyo Seiki Co., Ltd.
I went in. However, Comparative Examples 1 to 3 do not contain a crosslinking agent.
No dynamic crosslinking of the diene rubber occurs. The termination of the dynamic crosslinking in Examples 1 to 3
Satisfies the ideal torque ratio and reaches the maximum torque ratio
Comparative Examples 1 to 3
Kneading in each corresponding example is dynamically crosslinked
The kneading was carried out by the same method as the kneading time. The amount of each compounding material in the table is
It is based on parts by weight.
Ionomer resins and diene rubbers are indicated by trade names and crosslinked.
100 parts by weight of diene rubber (under rubber 100)
The amount (parts by weight) of the crosslinking agent with respect to parts is shown. [0039]Production of golf ball:For cover above
After pulverizing the composition to 3 to 5 mm, it is formed into a half shell
And wrap the core with two pieces at 160 ° C
By performing heat molding for 3 minutes, an outer diameter of 42.7 mm was obtained.
A two-piece solid golf ball was produced. The weight, coefficient of restitution, and resilience of the obtained golf ball
The flight distance was measured, and the shot feeling was evaluated. Coefficient of restitution
How to measure flight distance and how to evaluate shot feeling
It is as follows. [0041]How to measure the coefficient of restitution:Weight by air gun
Hit a 198g stainless steel cylinder at an initial speed of 35m / s
Out and hit the ball in front of it.
The cylinder and ball velocities are each controlled by two photocells.
And calculate the coefficient of restitution from each speed and weight.
Put out. The above measurement was performed for eight balls,
The average value was taken as the value of the coefficient of restitution. [0042]How to measure the flight distance:True Temper
Attach the No. 1 wood club to the Ing robot and head
Hit each of eight balls at a speed of 45 m / s.
Measure the distance to the drop point. Results are shown as their average
You. [0043]Evaluation method of shot feeling:5 golf players
Hit by Wood No. 1 club and hit by each person
The ball feeling is classified by the following seven-grade evaluation. HH: too hard H: Hard AH: A little hard but within good range A: Just good AS: A little soft but in good range S: Soft SS: Too soft The thermoplastic resin used for the cover is
The measurement of the particle size of the crosslinked diene rubber particles of the last
The procedure was as follows. First, the measurement sample was prepared using the above-described cover set.
After crushing the product to 3-5mm, pressurize at 160 ° C for 3 minutes
It was produced by heat molding into a sheet below. So
Then, the measurement of the particle size is performed using a scanning electron microscope (manufactured by JEOL).
T-220A) to take a backscattered electron image photograph,
Measure the vertical length of any 50 rubber particles, and
The numerical value obtained by the number average was used as the average particle size. Comparative Example 1
Nos. 3 to 3 have not been subjected to dynamic crosslinking, and are therefore ionomer resins.
And diene rubber form continuous layers, respectively.
Therefore, the particle size could not be measured. Formulation and behavior of the cover compositions of Examples 1-3
Rotation speed, ideal torque ratio, maximum torque ratio, bridging
Average particle size of diene rubber particles,
Table 1 shows the evaluation results of weight, coefficient of restitution, flight distance, and shot feeling.
Then, the composition of the cover composition of Comparative Examples 1 to 3, at the time of kneading
Number of revolutions, time, weight of golf ball obtained, repulsion
Table 2 shows the evaluation results of the number, flight distance, and shot feeling. [0047] [Table 1][0048] [Table 2] It is clear from the results shown in Tables 1 and 2.
As described above, the golf balls of Examples 1 to 3
Comparative Example 1 having the same composition (but not containing a crosslinking agent)
Higher coefficient of restitution, greater flight distance, and better shot feeling compared to ~ 3
Had been. Examples 4-5 and Comparative Examples 4-5 Example 4 differs from Example 1 in the type of diene rubber.
In 5, the composition for the cover was prepared by performing dynamic crosslinking,
In Examples 4 and 5, a cover composition was prepared only by kneading.
Using these cover compositions to produce golf balls,
Its properties were evaluated. Note that Examples 4 and 5 and Comparative Examples 4 and 5
The diene rubber used in 5 is as follows. [0052]Diene rubber: Esplen 301 [trade name, manufactured by Sumitomo Chemical Co., Ltd.
Tylene-propylene-diene rubber (EPDM)] Nodel 1470 [trade name, manufactured by Showa Denko KK, Echile
-Propylene-diene rubber (EPDM)] Table 3 shows the distribution of the cover compositions of Examples 4 and 5.
Rotation speed, ideal torque ratio, maximum torque during dynamic crosslinking
Ratio, average particle size of crosslinked diene rubber particles, resulting ball
Table 4 shows the properties of the cover compositions of Comparative Examples 4 and 5.
The number of revolutions and time during compounding and kneading, the characteristics of the obtained ball
Is shown. In addition, the core used, the display method in the table,
Cross-linking method, measurement and evaluation method of particle size and ball characteristics, etc.
Is the same as in the first embodiment. [0054] [Table 3] [0055] [Table 4]It is clear from the results shown in Tables 3 and 4.
Thus, the golf balls of Examples 4 to 5 are
Compared to golf balls, the coefficient of restitution and flight distance are longer,
The ball feeling was also excellent. Examples 6-7 and Comparative Examples 6-7 Butadiene rubber was used as the diene rubber, and its amount was varied.
In addition, in Examples 6 and 7, dynamic crosslinking was performed to
A product was prepared, and in Comparative Examples 6 and 7, for kneading only,
Preparing the compositions and using them for the cover composition
A ball was prepared and its characteristics were evaluated. In Examples 6 and 7 and Comparative Examples 6 and 7,
The diene rubbers used are as follows. [0059]Diene rubber: BR01 [trade name, manufactured by Nippon Synthetic Rubber Co., Ltd.
Tadiene rubber) Table 5 shows the distribution of the cover compositions of Examples 6 and 7.
Rotation speed, ideal torque ratio, maximum torque during dynamic crosslinking
Ratio, average particle size of crosslinked diene rubber particles, resulting ball
Table 6 shows the properties of the cover compositions of Comparative Examples 6 and 7 in Table 6.
The number of revolutions and time during compounding and kneading, the characteristics of the obtained ball
Is shown. In addition, the core used, the display method in the table,
Cross-linking method, measurement and evaluation method of particle size and ball characteristics, etc.
Is the same as in the first embodiment. [0061] [Table 5][0062] [Table 6] It is clear from the results shown in Tables 5 and 6.
As described above, the golf balls of Examples 6 and 7
Compared to golf balls, the coefficient of restitution and flight distance are longer,
The ball feeling was also excellent. Example 8 and Comparative Example 8 In Example 8, the rotational speed of the dynamic crosslinking was changed from that of Example 1.
(That is, change from 100 rpm to 150 rpm)
), Prepare a cover composition by performing dynamic crosslinking, and compare
Example 8 differs from Comparative Example 1 in that the number of revolutions during kneading was changed (sun
In other words, change from 100 rpm to 150 rpm), kneading
To prepare a cover composition,
Making a golf ball using the composition and evaluating its properties
did. Table 7 shows the composition of the cover composition of Example 8,
Rotational speed, ideal torque ratio, maximum torque ratio,
Average particle size of bridge diene rubber particles and properties of the obtained balls
And blending and kneading of the cover composition of Comparative Example 8
The number of turns, time, and characteristics of the obtained ball are shown. In addition, use
Core, labeling method in the table, dynamic crosslinking method, particle size
The ball characteristics measurement and evaluation method are the same as those described in the first embodiment.
Same as case. [0066] [Table 7] As shown in Table 7, the golf ball of Example 8
Of the golf ball of Comparative Example 8
The distance was great and the shot feeling was excellent. Further, the embodiment 8 is compared with the embodiment 1 described above.
Then, the average particle size of the crosslinked diene rubber particles is reduced from 6 μm.
2 μm, the coefficient of restitution, flight distance and
Had also improved. On the other hand, Comparative Example 8 and Comparative Example 1
Comparative Example 8 had a slightly smaller coefficient of restitution and a poorer shot feeling.
Had become. Examples 9 to 10 and Comparative Examples 9 to 11 In Examples 9 to 10, the amount of the crosslinking agent was changed from that in Example 1.
Preparation of cover composition by dynamic cross-linking
In Examples 9 to 10, the amount of the crosslinking agent was varied outside the present invention.
In order to prepare a cover composition by performing dynamic crosslinking,
Comparative Example 11 includes Himilan AM7315 [trade name, eye
Onomer resin) alone as a cover composition,
Then, a golf ball was manufactured and its characteristics were evaluated. Table 8 shows the compositions of the covers for Examples 9 to 10.
Formulation, rotation speed during dynamic crosslinking, ideal torque ratio, maximum torque
Ratio, average particle size of crosslinked diene rubber particles, resulting ball
Table 9 shows the compositions for covers of Comparative Examples 9 to 10.
Mix, rotation speed during dynamic crosslinking, ideal torque ratio, maximum torque
Ratio, average particle size of crosslinked diene rubber particles, and obtained
11 shows the characteristics of the ball and the ball characteristics of Comparative Example 11. In addition,
Core used, indication method in table, particle size and ball characteristics
The measurement and evaluation methods are the same as those in the first embodiment.
You. [0071] [Table 8][0072] [Table 9]It is clear from the results shown in Tables 8 and 9.
As described above, Examples 9 to 10 were more reactive than Comparative Examples 9 to 11.
The repulsion coefficient, the flight distance, and the shot feeling were excellent. [0074] As described above, according to the present invention, the hit ball
A golf ball with excellent feeling, high rebound performance, and long flight distance
Could be provided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view schematically showing one example of a golf ball according to the present invention. [Explanation of symbols] 1 core 2 cover

(56) References JP-A-4-359025 (JP, A) JP-A-6-7481 (JP, A) JP-A-6-54928 (JP, A) (58) Fields investigated (Int) .Cl. ⁷ , DB name) A63B 45/00 A63B 37/00 C08J 3/24

Claims (1)

(57) [Claims 1] have a cover covering the core and the core,
A thermoplastic elastomer in which a diene rubber dispersed in an ionomer resin is dynamically crosslinked with a crosslinking agent as a base polymer of the cover, and crosslinked diene rubber particles having an average particle size of 10 μm or less are dispersed in the ionomer resin. a method of manufacturing a golf ball Ru using <br/> the above in the dynamic crosslinking, before the dynamic crosslinking stable torque
Is 100, A = (weight of diene rubber) / (Io
Nomer resin weight + diene rubber weight)
The ideal torque B at the time of the bridge is B = 100 + (10 × A)
When the torque at the time of dynamic crosslinking is equal to or greater than the ideal torque B
The method for producing a golf ball , wherein the dynamic crosslinking is terminated after the maximum value is obtained .