JP2003206376A - Golf ball material and golf ball using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a golf ball material having excellent flowability, impact resilience, abrasion resistance, durability, and continuous productivity, and a golf ball which excels in controllability, a feeling of striking a ball, and durability. <P>SOLUTION: The golf ball material can be obtained by supplying, based on 100 pts.wt. sum of (A) an ionomer of an ethylene-unsaturated carboxylic acid copolymer and (B) a peroxide crosslinkable material, (A) 55-99 pts.wt. ionomer of an ethylene-unsaturated carboxylic acid copolymer and (B) 45-1 pt.wt. peroxide crosslinkable material to an extruder, and dynamically heat treating the components (A) and (B) in the presence of a peroxide (C). It is preferred that the content of the constituting unit to be derived from the unsaturated carboxylic acid of the ethylene-unsaturated carboxylic acid copolymer constituting this ionomer (A) of an ethylene-unsaturated carboxylic acid copolymer is 10-30 wt.% and, simultaneously, the melt flow rate (ASTM D 1238, at 190°C under a load of 2.16 kg) of the above component (A) is 0.1-50 g/10 min. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a golf ball material and a golf ball using the same. More specifically, the present invention relates to a golf ball material which is excellent in impact resilience, abrasion resistance, durability, controllability, shot feeling, durability and the like, and a golf ball using the same.

[0002]

BACKGROUND OF THE INVENTION Conventionally, various ionomers have been proposed and widely used as a skin material for golf balls because of their excellent durability. Generally, the harder the ionomer is, the more excellent the impact resilience becomes. Therefore, the hard ionomer has been exclusively used for increasing the flight distance of the golf ball. However, a golf ball using a hard ionomer as a skin material has a problem that dissatisfaction remains in terms of controllability and shot feeling, and attempts to improve the above problems by blending a hard ionomer with a flexible material. Attempts have been made to do so.

As such an attempt, for example, a method of blending a hard ionomer with a soft ionomer is disclosed (see Non-Patent Document 1 and Patent Document 1). Also, for hard ionomer, EPR (ethylene / propylene copolymer rubber), SEBS (styrene / ethylene / butylene /
A method of blending a maleic anhydride-modified product of a thermoplastic rubber such as styrene block copolymer) or EVA (ethylene / vinyl acetate copolymer) is disclosed (see Patent Document 2). However, although the controllability of the golf ball is improved by adding these soft materials to the hard ionomer, new problems may occur. For example, there has been a problem that the excellent impact resilience of the hard ionomer is impaired, or the durability is lowered and the ball is repeatedly struck and easily cracked or cracked.

Further, techniques for dynamically cross-linking an ionomer and a rubber component to obtain a golf ball material have been disclosed. When these techniques are used, a partially cross-linked product is obtained by using an extruder. However, a method using a roll is generally proposed (see Patent Documents 3, 4, and 5). However, since the ionomer having metal adhesiveness is inferior in roll processability, it is difficult to continuously produce a stable golf ball material.

In view of such a situation, the present inventors have considered
As a result of studying the ionomer / rubber partially crosslinked product that can be continuously produced by the extruder, it is possible to continuously produce by the extruder by using the ionomer of the specific ethylene / unsaturated carboxylic acid copolymer as the ionomer component. The inventors have found that a golf ball material having excellent fluidity, impact resilience, abrasion resistance, and durability can be obtained, and have completed the present invention.

[0006]

[Non-Patent Document 1] Research Disclosure 27 103 (Novemb
er 1986)

[Patent Document 1] Japanese Patent Laid-Open No. 1-308577

[Patent Document 2] US Pat. No. 5,098,105

[Patent Document 3] JP-A-55-133440

[Patent Document 4] Japanese Patent Publication No. 45-25983

[Patent Document 5] Japanese Patent Publication No. 47-9378

[0007]

OBJECTS OF THE INVENTION It is an object of the present invention to provide a golf ball material excellent in impact resilience, abrasion resistance, durability and the like. Another object of the present invention is to provide a golf ball having excellent controllability, shot feeling, and durability.

[0008]

SUMMARY OF THE INVENTION The golf ball material according to the present invention is an ionomer (A) of an ethylene / unsaturated carboxylic acid copolymer.
The amount of the ionomer (A) of the ethylene / unsaturated carboxylic acid copolymer is 55 to 99 parts by weight based on 100 parts by weight of the total amount of the epoxy crosslinkable material (B) and the peroxide crosslinkable material (B). ) Is supplied to the extruder in an amount of 45 to 1 part by weight, and is dynamically heat-treated in the presence of peroxide (C).

In the golf ball material according to the present invention, the structure derived from the unsaturated carboxylic acid of the ethylene / unsaturated carboxylic acid copolymer constituting the ionomer (A) of the ethylene / unsaturated carboxylic acid copolymer. The unit content is 10 to 30% by weight, and the ionomer (A) of the ethylene / unsaturated carboxylic acid copolymer has a melt flow rate (ASTM D 1238, 190 ° C., 2.16 kg load) of 0.1. It is preferably 50 g / 10 minutes.

In the golf ball material according to the present invention, the ionomer (A) of the ethylene / unsaturated carboxylic acid copolymer is an ionomer of a binary copolymer of ethylene and unsaturated carboxylic acid. , Ingredient (A) 10
Melt flow rate (ASTM D 1238, 190 ° C, 2.16 kg load) when 0.1 part by weight of peroxide (C) was added to 0 part by weight and kneaded at 200 ° C for 5 minutes
It is preferable that the ionomer of the ethylene / unsaturated carboxylic acid copolymer has a reduction rate of 50% or less.

In the golf ball material according to the present invention, the peroxide crosslinkable material (B) is a resin or rubber having an unsaturated carbon-carbon bond, a resin or rubber having a structural unit derived from vinyl acetate, Alternatively, it is preferably a resin or rubber having a structural unit derived from a (meth) acrylic acid ester. The melt flow rate of the golf ball material according to the present invention (JIS
K 6760, 190 ° C, 2.16kg load) 0.2-20g / 1
It is preferably 0 minutes.

In the present invention, the extruder is a twin-screw extruder, L / D is 30 or more, residence time can be 1 minute or more, and the temperature of the reaction zone is set in the range of 180 to 240 ° C. It is preferably an extruder that can be used. The golf ball material according to the present invention has a Taber wear test (wear wheel:
H-22 / 1kg load), wear wheel 100
The Taber abrasion amount after 0 rotation is preferably 150 mg or less.

The golf ball material according to the present invention preferably has a breaking strength of 15 MPa or more when subjected to a tensile test (JIS K 6760 No. 3 test) at a tensile speed of 200 mm / min. The golf ball material according to the present invention,
It is preferable that the Shore D hardness (JIS K 7215) is 40 to 65 and the impact resilience (JIS K 6301 compliant) is 60% or more.

The golf ball material according to the present invention preferably has a bending rigidity (Olsen's formula (JIS K 7106)) of 100 MPa or more. The golf ball according to the present invention,
The golf ball material is contained in any or all of a skin material, an intermediate layer, and a core material.

[0015]

DETAILED DESCRIPTION OF THE INVENTION The golf ball material according to the present invention will be specifically described below. The golf ball material according to the present invention has an ethylene / unsaturated carboxylic acid copolymer based on 100 parts by weight of the total amount of the ionomer (A) of the ethylene / unsaturated carboxylic acid copolymer and the peroxide crosslinkable material (B). The combined ionomer (A) was supplied to the extruder in an amount of 55 to 99 parts by weight and the peroxide crosslinkable material (B) in an amount of 45 to 1 parts by weight, and the mixture was mixed in the presence of the peroxide (C). It can be obtained by heat treatment.

First, each component will be specifically described. (A) Iono of ethylene / unsaturated carboxylic acid copolymer
Mer ionomer of ethylene-unsaturated carboxylic acid copolymer used in the present invention (A) an acid group of the ethylene-unsaturated carboxylic acid copolymer as the base polymer of the ionomer, for example, a metal part of the carboxylate ion It is a thermoplastic resin neutralized by.

First, the ethylene / unsaturated carboxylic acid copolymer constituting the ionomer (A) will be described. The ethylene / unsaturated carboxylic acid copolymer serving as the base polymer of the ionomer (A) is a copolymer containing ethylene and an unsaturated carboxylic acid, and if necessary, in addition to ethylene and the unsaturated carboxylic acid, a small amount. , For example 0
It may contain 20% by weight of other monomer components, for example, unsaturated carboxylic acid ester such as methyl (meth) acrylate, ethyl (meth) acrylate, etc., but it is preferable to use ethylene and unsaturated carboxylic acid. It is desirable to be a terpolymer.

The unsaturated carboxylic acid to be copolymerized with ethylene is specifically one having 3 to 8 carbon atoms such as acrylic acid, methacrylic acid, ethacrylic acid, maleic acid, fumaric acid and maleic anhydride. Mention may be made of α, β-unsaturated carboxylic acids. Of these, acrylic acid and methacrylic acid are preferred. Specific examples of the binary copolymer of ethylene and unsaturated carboxylic acid include ethylene / acrylic acid copolymer, ethylene / methacrylic acid copolymer, ethylene / ethacrylic acid copolymer, ethylene / maleic acid copolymer. Examples thereof include polymers, ethylene / fumaric acid copolymers and ethylene / maleic anhydride copolymers. Among these, ethylene / acrylic acid copolymer and ethylene / methacrylic acid copolymer are preferable.

The content of the structural unit derived from ethylene in the ethylene / unsaturated carboxylic acid copolymer (hereinafter, also referred to as the content of ethylene unit) is preferably 70.
To 90% by weight, more preferably 75 to 88% by weight, and the content of the structural unit derived from an unsaturated carboxylic acid (hereinafter, also referred to as unsaturated carboxylic acid unit content) is preferably 10 to 30% by weight. And more preferably 1
It is preferably 2 to 25% by weight. Such a copolymer can be obtained by radical-copolymerizing each component under high temperature and high pressure as in the case of high-pressure polyethylene.

An ionomer (A) of an ethylene / unsaturated carboxylic acid copolymer using an ethylene / unsaturated carboxylic acid copolymer having an unsaturated carboxylic acid unit content within the above range is crosslinked with a peroxide (C). Is less likely to occur, and blending with the peroxide crosslinkable resin (B) and dynamic crosslink extrusion can be performed. When an ionomer using an ethylene / unsaturated carboxylic acid copolymer having an unsaturated carboxylic acid unit content other than the above range is used, dynamic cross-linking extrusion becomes unstable, and a desired golf ball material can be obtained. Sometimes you can't.

The ethylene / unsaturated carboxylic acid copolymer
Ions that neutralize acid groups such as carboxyl groups
As a metal ion having a valence of 1 to 3, especially
Groups I, II, III, IV A and VII in the Periodic Table of the Elements
Is preferably a metal ion having a valence of 1 to 3,
Physically, Na⁺, K⁺, Li⁺, Cs⁺, Ag⁺, Hg⁺,
Cu⁺, Be⁺⁺, Mg⁺⁺, Ca⁺⁺, Sr⁺⁺, Ba⁺⁺, C
u⁺⁺, Cd⁺⁺, Hg⁺⁺, Sn⁺⁺, Pb⁺⁺, Fe⁺⁺, Co
⁺⁺, Ni⁺⁺, Zn⁺⁺, Al⁺⁺⁺, Sc⁺⁺⁺, Fe ⁺⁺⁺, Y
⁺⁺⁺And so on. Two or more of these metal ions
It does not matter even if it is a mixed ingredient of
It may be a mixed component with muion. these
Among the metal ions of⁺⁺, Na⁺Is preferred
Yes.

The ionomer (A) of the ethylene / unsaturated carboxylic acid copolymer is obtained by neutralizing a part of the carboxyl groups of the ethylene / unsaturated carboxylic acid copolymer with the above metal ion. be able to. Specifically, a part of the carboxyl groups of the ethylene / unsaturated carboxylic acid copolymer, usually more than 0 mol% and 90 mol% or less, preferably more than 0 mol% and 85 mol% or less, It is desirable to neutralize 10 to 80 mol% with metal ions.

Further, the melt flow rate (ASTM D 1238, 190 ° C., 2.16 kg load) of the ionomer (A) of the ethylene / unsaturated carboxylic acid copolymer is usually 0.1 to 0.1%.
50 g / 10 minutes, preferably 0.15-35 g / 10
Min, more preferably 0.2 to 30 g / 10 min. The ionomer (A) of the ethylene / unsaturated carboxylic acid copolymer is the ionomer of the above-mentioned binary copolymer of ethylene and unsaturated carboxylic acid, and is based on 100 parts by weight of the component (A). When 0.1 part by weight of peroxide (C) was added and kneading was performed at 200 ° C. for 5 minutes, the melt flow rate (ASTM D 1
238, 190 ℃, 2.16kg load) reduction rate is preferably 50%
The ionomer of an ethylene / unsaturated carboxylic acid copolymer having a ratio of 40% or less is more preferable. Since the ionomer (A) of the ethylene / unsaturated carboxylic acid copolymer having a decrease rate of the melt flow rate not more than the above value is unlikely to be crosslinked by the peroxide (C), it is blended with the peroxide crosslinkable resin (B). And dynamic cross-linking extrusion can be performed efficiently.

The ionomer of the component (A), that is, the ethylene / unsaturated carboxylic acid copolymer is preferably 5 parts by weight per 100 parts by weight of the total amount of the components (A) and (B).
5 to 99 parts by weight, more preferably 60 to 95 parts by weight,
Particularly preferably, it is used in an amount of 65 to 90 parts by weight. When the component (A) is used in an amount within the above range, a golf ball material having excellent fluidity can be obtained, and a molded product having excellent mechanical strength characteristics and flexibility can be prepared.

Peroxide Crosslinkable Material (B) The peroxide crosslinkable material (B) used in the present invention has, for example, a resin or rubber having an unsaturated carbon-carbon bond, or a structural unit derived from vinyl acetate. Examples thereof include resins or rubbers, or resins or rubbers having a structural unit derived from (meth) acrylic acid ester.

Specific examples of the resin or rubber having an unsaturated carbon-carbon bond include ethylene and 3 carbon atoms.
~ 20 ethylene-α-copolymerized with α-olefin
Olefin copolymer synthetic rubber, ethylene and 3 carbon atoms
To .alpha.-olefin-polyene copolymer rubber copolymerized with .about.20 .alpha.-olefin and polyene such as diene, ethylene-butadiene copolymer rubber and other substantially amorphous elastic copolymer, natural Rubber (NR), isoprene rubber (IR), butadiene rubber (BR), styrene-butadiene rubber (SBR), butyl rubber (IIR), chloroprene rubber (CR), nitrile rubber (NBR), vinylmethyl silicone rubber (VMQ), etc. Is mentioned.
Among these, ethylene / α-olefin / polyene copolymer rubber and butadiene rubber (BR) are preferably used.

3 to 2 carbon atoms to be copolymerized with ethylene
Specific examples of the α-olefin of 0 include propylene, 1-butene, 1-pentene, 1-hexene, and 2-methyl-1-.
Propene, 3-methyl-1-pentene, 4-methyl-1-pentene, 5-methyl-1-hexene, 1-octene, 1-decene, 1-
Eikosen etc. are mentioned. Examples of the polyene include dicyclopentadiene, 1,4-hexadiene, dicyclooctadiene, methylene-norbornene,
Examples include non-conjugated dienes such as ethylidene-norbornene.

In the present invention, the above ethylene / α-
Among olefin / polyene copolymer rubbers, the molar ratio of ethylene component unit to α-olefin component unit (ethylene component unit / α-olefin component unit) is about 50/50.
To 95/5, preferably about 55/45 to 85/15, and the content of non-conjugated polyene is 5 to 50, preferably 10 to 40 ethylene / α-olefin / non-conjugated in terms of iodine value. Diene copolymer rubber is preferred. Also,
This copolymer rubber has a Mooney viscosity ML1 + 4 (100
It is desirable that the temperature (C) is about 10 to 200, preferably about 12 to 150. Among the ethylene / α-olefin / non-conjugated diene copolymer rubbers, the ethylene / propylene / non-conjugated diene copolymer rubber (EPDM) is particularly preferably used.

In the present invention, butadiene rubber (BR) is also used.
Is also particularly preferably used. Specific examples of the resin or rubber having a structural unit derived from vinyl acetate include ethylene / vinyl acetate copolymer (EVA), polyvinyl acetate, ethylene / vinyl acetate / carbon monoxide copolymer and the like. To be The content of the structural unit derived from vinyl acetate in the vinyl acetate group-containing resin or rubber is usually 12 to 60% by weight, preferably 15 to 50% by weight. Among resins or rubbers containing a structural unit derived from vinyl acetate, ethylene / vinyl acetate copolymer (EVA) is preferable, and among them, the content of the structural unit derived from vinyl acetate is 12 to 60% by weight, Especially, EVA of 15 to 50% by weight is preferable.

Specific examples of the resin or rubber having a structural unit derived from (meth) acrylic acid ester include methyl poly (meth) acrylate, ethyl poly (meth) acrylate, and poly (meth) acrylic acid. Butyl, ethylene / methyl (meth) acrylate copolymer, ethylene /
Examples thereof include ethyl (meth) acrylate copolymer, ethylene / n-butyl acrylate (n-butyl) copolymer, and ethylene / isobutyl (meth) acrylate copolymer.
Further, it may be a terpolymer of ethylene / (meth) acrylic acid ester copolymer / reactive monomer.

Here, as the reactive monomer, acrylic acid, methacrylic acid; maleic acid monoesters such as monomethyl maleate, monoethyl maleate and isopropyl maleate; unsaturated monocarboxylic acids such as glycidyl acrylate and glycidyl methacrylate. Examples thereof include glycidyl acid. The peroxide crosslinkable material (B) as described above is preferably 45 to 1 part by weight, more preferably 40 to 5 parts by weight, based on 100 parts by weight of the total amount of the component (A) and the component (B). It is particularly preferably used in an amount of 35 to 10 parts by weight. When the peroxide crosslinkable material (B) is used in an amount within the above range, a golf ball material having excellent fluidity can be obtained and a molded article having excellent flexibility can be prepared.

Peroxide (C) Examples of the peroxide (C) used in the present invention include organic peroxides and inorganic peroxides (eg KMnO ₄ ). Among them, organic peroxide is preferably used. Specific examples of the organic peroxide include dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane, and 2,5-dimethyl-2,5. -Di- (tert-butylperoxy) hexyne-3,1,3-bis (tert-butylperoxyisopropyl) benzene, 1,1-bis (tert-
Butylperoxy) -3,3,5-trimethylcyclohexane, n-butyl-4,4-bis (tert-butylperoxy) valerate, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, tert-butyl Examples thereof include peroxybenzoate, tert-butylperoxyisopropyl carbonate, diacetyl peroxide, lauroyl peroxide, tert-butylcumyl peroxide and the like.

Among these, 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane and 2,5-dimethyl-2,5-di-from the viewpoint of odor and scorch stability. (Tert-Butylperoxy) hexyne-3,1,3-bis (tert-butylperoxyisopropyl) benzene, 1,1-bis (tert-butylperoxy) -3,3,5-trimethylcyclohexane, n-
Butyl-4,4-bis (tert-butylperoxy) valerate and the like are preferable, and above all, 2,5-dimethyl-2,5-di-
(Tert-Butylperoxy) hexane is more preferred.

In the present invention, the peroxide (C) such as organic peroxide is the component (A) and the component (B).
Is preferably 0.001 per 100 parts by weight of
It is used in an amount of ˜4.0 parts by weight, more preferably 0.01 to 3.5 parts by weight, particularly preferably 0.02 to 2.5 parts by weight. When the peroxide (C) is used in an amount within the above range, a golf ball material having excellent fluidity can be obtained, and a molded product having excellent tensile strength characteristics and flexibility can be prepared.

Further, in the present invention, a crosslinking aid can be used. Specific examples of the cross-linking aid include p
-Quinone dioximes, quinone oximes such as p, p-dibenzoylquinone oximes, (meth) acrylates such as lauryl (meth) acrylate and ethylene glycol acrylate; aryls such as diaryl fumarate and triaryl cyanurate; maleimides , Maleimides such as phenylmaleimide; maleic anhydride,
Itaconic acid, divinylbenzene, vinyltoluene,
1,2-polybutadiene etc. can be mentioned.

The cross-linking aid includes the component (A) and the component (B).
Is preferably 0.001 per 100 parts by weight of
~ 5 parts by weight, more preferably 0.01 to 4 parts by weight. Other Components In addition to the above-mentioned components (A), (B) and (C) during the preparation of the golf ball material according to the present invention or after the preparation, if necessary, conventionally known filling Agent,
Additives such as mineral oil type softeners, antioxidants, heat resistance stabilizers, weather resistance stabilizers, light stabilizers, lubricants, and ultraviolet absorbers can be added within the range not impairing the object of the present invention.

Examples of the filler include carbon black, talc, clay, calcium carbonate, ground calcium carbonate, zinc oxide, titanium oxide, kaolin, diatomaceous earth,
Examples thereof include silica, alumina, asbestos, graphite and glass fiber. Examples of the mineral oil-based softening agent include paraffin-based or naphthene-based process oils, which are used in the range of 0 to 20 parts by weight based on 100 parts by weight of the total amount of the components (A) and (B). Preferably.

Examples of the antioxidant include phenyl-
Examples include α-naphthylamine, 2,6-di-t-butylphenol, tetrakis [methylene (3,5-di-t-butyl-4-hydroxyphenyl) propionate] and the like. Golf Ball Material The golf ball material according to the present invention comprises a total amount of the ionomer (A) of the ethylene / unsaturated carboxylic acid copolymer and the peroxide crosslinkable material (B) of 10
Extruder in an amount of 55 to 99 parts by weight of the ionomer (A) of the ethylene / unsaturated carboxylic acid copolymer and 45 to 1 parts by weight of the peroxide crosslinkable material (B) based on 0 parts by weight. Supply to
It can be obtained by dynamically heat-treating (dynamically crosslinking) in the presence of peroxide (C).

The above-mentioned "dynamically heat-treating" means that the above components are kneaded in a molten state, and the crosslinking reaction is highly performed in a state where the component (B) is dispersed in the component (A). . A twin-screw extruder is preferably used as the extruder used for this kneading. The extrusion conditions (or kneading conditions) are
It is as follows. That is, a twin-screw extruder that has an L / D of 30 or more and a residence time of 1 minute or more is used, and as the extrusion condition, the temperature of the reaction zone is preferably 180 to
It is desirable to set in the range of 240 ° C.

The above kneading is preferably carried out in an atmosphere of an inert gas such as nitrogen gas or carbon dioxide gas. The golf ball material according to the present invention has a melt flow rate (MF
R: JIS K 6760, 190 ° C, 2.16 kg load) is 0.2 to 20
g / 10 minutes, preferably 0.3 to 18 g / 10 minutes, and more preferably 0.5 to 15 g / 10 minutes.

Further, the golf ball material according to the present invention is
When a Taber abrasion test (wear wheel: H-22 / 1 kg load) is performed, the Taber abrasion amount after 1000 rotations of the wear wheel is 150 mg or less, preferably 145 mg or less, and more preferably 140 mg or less. Further, the golf ball material according to the present invention has a tensile speed of 20.
When the tensile test (JIS K 6760 No. 3 test) is performed at 0 mm / min, the breaking strength is 15 MPa or more, preferably 15 to 45 MPa. The tensile elongation at break at this time is 300% or more, preferably 30%.
It is desirable to be 0 to 600%.

Further, the golf ball material according to the present invention is
Shore D hardness (JIS K 7215) is 40 to 65, preferably 41 to 63, and impact resilience (JIS K 6301 compliant) is 60%
Above, it is desirable to be 60 to 75%.
Further, the golf ball material according to the present invention has a flexural rigidity (Olsen's formula) (JIS K7106) of 100 MPa or more, preferably 110 to 350 MPa.

Golf Ball The golf ball material described above can be used as a skin material, an intermediate layer, or a core material of a golf ball such as a wound ball or a solid ball. Solid balls include one-piece balls or two-piece balls, as well as multi-piece balls such as three-piece and four-piece balls.

The golf ball material according to the present invention achieves a low hardness of Shore D hardness of 40 to 65, has a high impact resilience of 60% or more (according to JIS K 6301), and further has abrasion resistance. Since it is excellent in durability and durability,
By using this golf ball material for any or all of the skin material, the intermediate layer, and the core material of the golf ball, a golf ball excellent in controllability, shot feeling, and durability can be obtained.

[0045]

INDUSTRIAL APPLICABILITY According to the present invention, by using an ionomer of a specific ethylene / unsaturated carboxylic acid copolymer as an ionomer component, excellent fluidity, impact resilience, abrasion resistance, durability and continuous production can be obtained. A golf ball material having properties can be provided. Further, a golf ball containing this golf ball material as a skin material and / or a core material is excellent in controllability, shot feeling and durability.

[0046]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. The ionomer, EPDM, butadiene rubber, EVA, and peroxide of the ethylene / unsaturated carboxylic acid copolymer used in Examples and Comparative Examples are as follows. Ethylene / unsaturated carboxylic acid copolymer ionomer (1) Ethylene / methacrylic acid copolymer ionomer (A-1) Methacrylic acid unit content: 15 wt% Zn content: Amount to neutralize 30 mol% of methacrylic acid Na content: Amount for neutralizing 15 mol% of methacrylic acid MFR (ASTM D 1238, 190 ° C, 2.16 kg load): 1.7 g
/ 10 minutes MFR reduction rate (measured by the method described above. The same applies hereinafter): 2
0% (2) Ionomer (A-2) of ethylene / methacrylic acid copolymer Content of methacrylic acid unit: 20% by weight Zn content: Amount for neutralizing 30 mol% of methacrylic acid MFR (ASTM D 1238, 190 ° C, 2.16kg load): 1.0g
/ 10 minutes MFR reduction rate (measured by the method described above; the same applies hereinafter): 1
0% (3) Ionomer of ethylene / methacrylic acid copolymer (A-3) Methacrylic acid unit content: 15% by weight Na content: Amount for neutralizing 54 mol% of methacrylic acid MFR (ASTM D 1238, 190 ° C, 2.16kg load): 0.9g
/ 10 minutes MFR reduction rate: 15% (4) Ionomer (A-4) of ethylene / methacrylic acid copolymer Methacrylic acid unit content: 15 wt% Zn content: Amount to neutralize 60 mol% of methacrylic acid MFR ( ASTM D 1238, 190 ℃, 2.16kg load): 0.9g
/ 10 minutes MFR reduction rate: 35% (5) Ionomer (A-5) of ethylene / methacrylic acid copolymer Methacrylic acid unit content: 9 wt% Zn content: Amount to neutralize 18 mol% of methacrylic acid MFR ( ASTM D 1238, 190 ℃, 2.16kg load): 5.5g
/ 10 minutes MFR reduction rate: 63% EPDM, butadiene rubber, EVA (1) EPDM (B-1) Trade name Mitsui EPT3106P, Mitsui Chemicals, Inc. Mooney viscosity ML1 + 4 (100 ° C): 15 (2) Butadiene Rubber (B-2) Brand name BR01, made by JSR Corporation 1,4-cis butadiene rubber cis 1,4 bond: 96% Mooney viscosity ML1 + 4 (100 ° C): 44 (3) EVA (B-3) Vinyl acetate unit content: 46% by weight MFR (ASTM D 1238, 190 ° C, 2.16 kg load): 1.0 g
/ 10 minutes (4) EPDM (B-4) Trade name Mitsui EPT3072E, Mitsui Chemicals Co., Ltd. Mooney viscosity ML1 + 4 (100 ° C.): 70 peroxide (1) peroxide (C-1) Trade name Lupasol 101 , Atochem Yoshitomi Co., Ltd. 2,
5-Dimethyl-2,5-di- (tert-butylperoxy) hexane

[0047]

Example 1 80 parts by weight of the ionomer (A-1) of the ethylene / methacrylic acid copolymer and the EPDM (B
-1) 20 parts by weight and the peroxide (C-1)
0.1 part by weight was premixed in a Henschel mixer for 60 seconds and the mixture was mixed with a pelletizer for 30 mm.
φ twin-screw extruder [manufactured by Ikegai Corp., product number PCM30-35
-3V-1SF] by a predetermined amount with a quantitative feeder, melt-kneaded under the following extrusion conditions (or melt-kneading conditions), and granulated to obtain pellets.

The extrusion conditions for the above twin-screw extruder are as follows. L / D: 35 barrel temperature (° C); C1 (120), C2 (160), C3 (160), C4-C9 (200),
A (200), D (200) Screw rotation speed: 150 rpm Extrusion amount: 6 kg / h Residence time: 90 seconds Mixing zone temperature: 200 ° C. The obtained golf ball material is MFR (JIS K6760, 190).
C., 2.16 kg load) was 1.5 g / 10 minutes.

Next, the obtained pellets were press-molded by a press-molding machine set at 200 ° C. to prepare a 150 mm square sheet. The flexural rigidity, hardness, tensile strength at break at break, elongation at tensile break, wear amount, and impact resilience of the obtained press sheet were measured according to the following methods. The results are shown in Table 1. (1) Bending Rigidity (Olsen's Equation) The bending rigidity (Olzen's equation) was measured according to JIS K7106. (2) Hardness (Shore D) The hardness (Shore D) was measured according to JIS K7215. (3) Tensile strength at break and elongation at break Tensile strength at break and elongation at break are measured according to JIS K6.
According to 760, a tensile test was performed at a tensile speed of 200 mm / min for measurement. (4) Abrasion amount A Taber abrasion test was performed to measure the weight of the test piece after the abrasion wheel (H-22 / 1 kg load) was rotated 1000 times, and the abrasion amount was measured from the weight before and after the test. (5) Impact resilience The impact resilience was measured according to JIS K6301.

[0050]

Example 2 In Example 1, the peroxide (C-
Example 1 was repeated except that 1) was changed to 0.025 parts by weight. The results are shown in Table 1.

[0051]

Example 3 Example 1 was repeated except that the butadiene rubber (B-2) was used instead of the EPDM (B-1). The results are shown in Table 1.

[0052]

Example 4 Example 1 was repeated except that the EVA (B-3) was used in place of the EPDM (B-1). The results are shown in Table 1.

[0053]

[Example 5] The same procedure as in Example 1 was carried out except that the above EPDM (B-4) was used in place of the EPDM (B-1). The results are shown in Table 1.

[0054]

Example 6 In Example 1, instead of the ionomer (A-1) of the ethylene / methacrylic acid copolymer, the ionomer (A- of the ethylene / methacrylic acid copolymer was used.
Example 1 was repeated except that 2) was used. The results are shown in Table 1.

[0055]

Example 7 In Example 1, instead of the ionomer (A-1) of the ethylene / methacrylic acid copolymer, the ionomer (A- of the ethylene / methacrylic acid copolymer was used.
Example 1 was repeated except that 3) was used. The results are shown in Table 1.

[0056]

Example 8 In Example 1, instead of the ethylene / methacrylic acid copolymer ionomer (A-1), the ethylene / methacrylic acid copolymer ionomer (A-
The same procedure as in Example 1 was performed except that 4) was used. The results are shown in Table 1.

[0057]

Example 9 The ionomer (A-1) and EPDM of ethylene / methacrylic acid copolymer in Example 1 were used.
The same procedure as in Example 1 was performed except that the blending amount of (B-1) was changed to 60 parts by weight and 40 parts by weight, respectively. The results are shown in Table 1.

[0058]

Comparative Example 1 In Example 1, the peroxide (C-
Example 1 was repeated except that the compounding amount of 1) was set to 0. The results are shown in Table 2.

[0059]

Comparative Example 2 In Example 8, the peroxide (C-
The same procedure as in Example 8 was carried out except that the compounding amount in 1) was set to 0. The results are shown in Table 2.

[0060]

Comparative Example 3 In Example 1, instead of the ionomer (A-1) of the ethylene / methacrylic acid copolymer, the ionomer (A- of the ethylene / methacrylic acid copolymer was used.
Example 1 was repeated except that 5) was used. The results are shown in Table 2.

[0061]

[Comparative Example 4] In Example 1, the blending amount of the ionomer (A-1) of the ethylene / methacrylic acid copolymer was 100.
Example 1 was repeated except that the blending amounts of EPDM (B-1) and peroxide (C-1) were changed to 0 parts by weight. The results are shown in Table 2.

[0062]

Comparative Example 5 In Comparative Example 4, instead of the ionomer (A-1) of the ethylene / methacrylic acid copolymer, the ionomer (A- of the ethylene / methacrylic acid copolymer was used.
The same procedure as in Comparative Example 4 was performed except that 2) was used. The results are shown in Table 2.

[0063]

Comparative Example 6 In Comparative Example 4, the ionomer (A-) of the ethylene / methacrylic acid copolymer was used instead of the ionomer (A-1) of the ethylene / methacrylic acid copolymer.
The same procedure as in Comparative Example 4 was performed except that 3) was used. The results are shown in Table 2.

[0064]

Comparative Example 7 In Comparative Example 4, the ionomer (A-) of the ethylene / methacrylic acid copolymer was used instead of the ionomer (A-1) of the ethylene / methacrylic acid copolymer.
The same procedure as in Comparative Example 4 was performed except that 4) was used. The results are shown in Table 2.

[0065]

[Table 1]

[0066]

[Table 2]

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08K 5/14 C08K 5/14 // (C08L 23/26 C08L 101: 00 101: 00) F term (reference) ) 4F070 AA13 AB01 AB09 AB11 AB24 AC56 AC73 AC75 AE08 AE30 FA03 FB06 FB08 FC06 GA05 GA07 GB02 GB08 GB09 GC01 4J002 AA012 AC002 AC012 AC032 AC062 AC072 AC082 AC092 5060EK029 BB052 BB2 BB2 BB2 BB2 BB2312

Claims (11)

[Claims] 1. An ionomer (A) of an ethylene / unsaturated carboxylic acid copolymer and a peroxide crosslinkable material (B).
The amount of the ionomer (A) of the ethylene / unsaturated carboxylic acid copolymer is 55 to 99 parts by weight, and the amount of the peroxide crosslinkable material (B) is 45 to 1 parts by weight based on 100 parts by weight of the total amount of A golf ball material obtained by dynamically heat-treating it in the presence of a peroxide (C). 2. The content of the structural unit derived from the unsaturated carboxylic acid of the ethylene / unsaturated carboxylic acid copolymer constituting the ionomer (A) of the ethylene / unsaturated carboxylic acid copolymer is 10 to 30% by weight. %, And the ionomer (A) of the ethylene / unsaturated carboxylic acid copolymer
2. The golf ball material according to claim 1, wherein the melt flow rate (ASTM D 1238, 190 ° C., 2.16 kg load) is 0.1 to 50 g / 10 minutes. 3. The ionomer (A) of the ethylene / unsaturated carboxylic acid copolymer is an ionomer of a binary copolymer of ethylene and an unsaturated carboxylic acid, and is based on 100 parts by weight of the component (A). Then, when the peroxide (C) was added in an amount of 0.1 part by weight and kneaded at 200 ° C. for 5 minutes, the melt flow rate (ASTM D 1238, 190 ° C., 2.
The golf ball material according to claim 1 or 2, which is an ionomer of an ethylene / unsaturated carboxylic acid copolymer having a reduction rate of 50% or less under a load of 16 kg. 4. The peroxide-crosslinkable material (B)
Is a resin or rubber having an unsaturated carbon-carbon bond,
The resin or rubber having a structural unit derived from vinyl acetate, or the resin or rubber having a structural unit derived from a (meth) acrylic acid ester, according to any one of claims 1 to 3. Golf ball material. 5. Melt flow rate (JIS K 6760, 190
The golf ball material according to claim 1, wherein the golf ball material has a temperature of 2.16 kg) of 0.2 to 20 g / 10 minutes. 6. The extruder is a twin-screw extruder, L / D
Is 30 or more, the residence time can be 1 minute or more, and the temperature of the reaction zone can be set in the range of 180 to 240 ° C. The extruder according to claim 1. Golf ball material. 7. A Taber abrasion test (abrasion wheel: H-22 /
The golf ball material according to any one of claims 1 to 6, wherein the amount of Taber abrasion after 1000 rotations of the abrasion wheel is 150 mg or less when a load of 1 kg is applied. 8. The tensile strength at break is 15 MPa or more when a tensile test (JIS K 6760 No. 3 test) is performed at a tensile speed of 200 mm / min.
The golf ball material according to any one of 1. 9. Shore D hardness (JIS K 7215) is 40 to 6
The golf ball material according to any one of claims 1 to 8, wherein the golf ball material has a rebound resilience (JIS K 6301 compliant) of 60% or more. 10. Flexural rigidity (Olsen formula (JIS K 710
The golf ball material according to any one of claims 1 to 9, wherein 6)) is 100 MPa or more. 11. A golf ball comprising the golf ball material according to claim 1 in any or all of a skin material, an intermediate layer and a core material.