JP4078071B2 - Golf ball - Google Patents

Description

【００６０】
（２） カバー用組成物の調製
表２に示すカバー用組成物を二軸混練押出機によりミキシングし、二軸押し出し機でシリンダー温度１８０℃で押し出した。押し出し温度は三元複合体のナイロンの融点以下であることが重要である。押出条件は、次の通りである。
【００６１】
スクリュー径：４５ｍｍ
スクリュー回転数：２００ｒｐｍ
スクリューＬ／Ｄ：３５
配合物は押出機のダイの位置で１９５〜２０５℃に加熱された。
【００６２】
上記カバー用組成物を用いて半球殻状のハーフシェルを射出成形し、これを２枚用いて上記のコアを包み、金型内で１５０℃でプレス熱圧縮成形し、冷却後、ゴルフボールを取り出した。その後、表面にペイントを塗装して、直径４２．８ｍｍ、質量４５．４ｇを有するゴルフボールを作製した。
【００６３】
【表２】

【００６４】
＜性能評価方法＞
得られたカバー組成物のスラブ片のショアＤ硬度、コア（ゴルフボール）の圧縮変形量、ゴルフボールの耐摩耗性及び耐擦過傷性を評価した。
【００６５】
（１） ショアＤ硬度
ＡＳＴＭ−Ｄ２２４０に準じて測定した。カバー用組成物から作成された厚さ約２ｍｍの熱プレス成形シートを２３℃で２週間保存後、スプリング式硬度計ショアＤ型を用いて３枚以上重ねて測定した。
【００６６】
（２） 圧縮変形量
ゴルフボール（またはソリッドコア）に初期荷重１０ｋｇから終荷重１３０ｋｇを負荷した時までの変形量（ｍｍ）を測定した。
【００６７】
（３） 耐摩耗性
ＡＳＴＭ Ｄ−１０４４に準拠して測定した。数字が小さい程、耐摩耗性に優れている。
【００６８】
（４） 耐擦過傷性
市販のピッチングウエッジをロボットマシーンに取り付け、ヘッドスピード３６ｍ／ｓでゴルフボールの２箇所を各１回打撃し、２箇所打撃部を観察し、３段階で評価した。
【００６９】
○： ボール表面に傷がわずかに残るがほとんど気にならない。
△： ボール表面に傷が区っきり残り若干毛羽立ちがみられる。
【００７０】
×： ボール表面がかなり削れ、毛羽立ちが目立つ。
【００７１】
【表３】

【００７２】
表３に実施例１〜実施例６および比較例１〜比較例３のゴルフボールの測定結果を示す。
【００７３】
＜評価結果＞
比較例１〜比較例３は、三元複合体を配合しないカバー組成物を用いており、いずれも耐擦過傷性、耐摩耗性がかなり劣っている。
【００７４】
実施例１〜４は、ポリウレタン系熱可塑性エラストマーに三元複合体を配合したカバー組成物であり、実施例５はポリアミド系熱可塑性エラストマーに三元複合体を配合したカバー組成物であり、実施例６はポリエステル系熱可塑性エラストマーに三元複合体を配合したカバー組成物である。いずれのゴルフボールも耐擦過傷性及び耐摩耗性に優れていることが認められる。
【００７５】
今回開示された実施の形態および実施例はすべての点で例示であって制限的なものではないと考えられるべきである。本発明の範囲は上記した説明ではなくて特許請求の範囲によって示され、特許請求の範囲と均等の意味および範囲内でのすべての変更が含まれることが意図される。
【００７６】
【発明の効果】
本発明のゴルフボールは、カバー組成物の樹脂成分としてポリウレタン系樹脂、ポリエステル系樹脂及びポリアミド系樹脂の群から選ばれた少なくとも、１種類に前記三元複合体を混合したため、反発性能等の諸特性を低下することなく耐擦過傷性及び耐摩耗性を向上することができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a golf ball having improved wear resistance and scratch resistance without sacrificing various characteristics such as resilience performance, spin performance, cut resistance, and feel at impact.
[0002]
[Prior art]
Conventionally, golf balls in which a thread wound layer is formed in a liquid center and covered with a balata cover have been widely used by advanced golfers and professional golfers because of their excellent shot feeling and controllability. However, since the structure of such a golf ball is complicated in manufacturing process and inferior in cut resistance, abrasion resistance and scratch resistance, development of various golf balls excellent in these characteristics is proceeding. It has been.
[0003]
For example, JP-A-59-91973 discloses a rubber containing at least 5 wt% of carbon fiber, silicon carbide fiber, boron fiber, or the like having a length of 0.1 mm or more in order to improve durability and feel at the time of impact. A golf ball having a solid core made of resin and having a diameter of 36.0 to 38 mm has been proposed.
[0004]
JP-A-62-64378 discloses a golf ball cover composition in which fine fibers having an amide group are blended with a cover material mainly composed of transpolyisoprene in order to improve resilience characteristics, spin performance and cut resistance. Things have been proposed.
[0005]
In JP-A-63-9461, as a cover material for maximizing the performance of a multi-dimple type golf ball, that is, the flight distance, 100 parts by mass of a cover material mainly composed of transpolyisoprene is used. A golf ball cover composition containing ˜42 parts by mass, 1 to 15 parts by mass of fine fibers having an amide group and 5 to 30 parts by mass of natural rubber has been proposed.
[0006]
JP-A-1-223980 discloses a thread-wound golf ball using a cover material in which inorganic single crystal fibers are blended in a trans-1,4-polyisoprene-based cover material in order to improve the flight distance of the ball. Proposed.
[0007]
Japanese Laid-Open Patent Publication No. 9-173504 discloses that a solid rubber center containing an oily substance and a soft cover material are used to improve the feel at impact and increase the spin rate with a short iron. In this technique, oil-resistant rubber and high-hardness ionomer resin are used outside the solid rubber center, so there is still room for improvement in resilience performance and feel at impact.
[0008]
Japanese Patent Application Laid-Open No. 10-137365 proposes a technique intended to improve resilience, durability, and cut resistance by blending fibrous aluminum borate whisker with thermoplastic resin or thermoplastic elastomer as the main material. . However, such a technique reduces the resilience performance of the cover material by blending the whisker.
[0009]
In JP-A-10-179802, the base resin of the cover is a styrene-butadiene-styrene block copolymer having a polybutadiene block containing an ionomer resin and an epoxy group, or a styrene having a polyisoprene block containing an epoxy group. A composition comprising a two-component heated mixture of isoprene-styrene block copolymer as a main component, the flexural rigidity of the composition constituting the cover is 50 to 300 MPa, and the Shore D hardness is 40 to 60. A golf ball is proposed. This technique is intended to improve the feel at impact, spin performance, and flight performance, but there is room for improvement in cut resistance.
[0010]
JP-A-10-225532 proposes a golf ball cover composition comprising a resin composition in which an aluminum borate whisker is blended with a resin material mainly composed of an ionomer resin in order to improve durability. .
[0011]
Japanese Patent No. 2676578 discloses an ethylene-unsaturated carboxylic acid copolymer as a cover material and an epoxy group, carboxyl group or acid anhydride group on the surface in order to improve soft feeling, durability and resilience. There has been proposed a composition comprising a core-shell polymer comprising a rubber-like polymer core (a) and a glass-like polymer shell (b).
[0012]
On the other hand, Journal of Japanese Rheological Society, Vol. 25 (1997) reports the development of a micro-dispersed ultrafine fiber reinforced composite prepared from a rubber / polyolefin / nylon ternary graft copolymer for use in the plastics field.
[0013]
These conventional techniques cannot comprehensively improve the resilience performance, spin performance, cut resistance, feeling, wear resistance, and scratch resistance.
[0014]
[Problems to be solved by the invention]
The present invention relates to a golf ball having excellent scratch resistance and wear resistance as well as various characteristics such as resilience performance, which are problems of conventional golf balls.
[0015]
[Means for Solving the Problems]
The present invention provides a golf ball comprising a core and a cover covering the core, wherein the cover includes at least one resin component selected from the group consisting of a polyurethane resin, a polyester resin, and a polyamide resin, and a rubber component. A golf ball comprising a composition obtained by mixing a ternary composite comprising a polyolefin component and a nylon component.
[0016]
The resin component is preferably a thermoplastic elastomer. And it is preferable that a cover is comprised with the composition which mixed 1-50 mass parts of said ternary composites with 100 mass parts of said resin components.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a golf ball comprising a core and a cover covering the core, wherein the cover includes at least one resin component selected from the group consisting of a polyurethane resin, a polyester resin, and a polyamide resin, and a rubber component. A golf ball comprising a composition obtained by mixing a ternary composite comprising a polyolefin component and a nylon component.
[0018]
<Resin component>
The resin component used in the cover composition of the present invention is to be interpreted in the broadest sense. The polyurethane-based resin includes a polyurethane-based thermoplastic resin and a polyurethane-based thermoplastic elastomer, and the polyester-based resin is a polyester-based thermoplastic resin. And a polyester-based thermoplastic elastomer, and the polyamide-based resin includes a polyamide-based thermoplastic resin and a polyamide-based thermoplastic elastomer.
[0019]
<Polyurethane resin>
The polyurethane-based resin includes a polyurethane-based thermoplastic elastomer and a polyurethane-based thermoplastic resin. Here, the polyurethane-based thermoplastic elastomer is composed of a hard segment of urethane structure and a soft segment of polyester or polyether. The product names are milactolan from Nippon Milactolan, Pandex from Dainippon Ink & Chemicals, Paraprene from Nippon Polyurethane Industry, Peresen from Dow Chemical Japan, Elastollan from BASF Polyurethane Elastomers, Esten and Esta from Kyowa Hakko Kogyo. Lock, Nippon Megtron's Iron Rubber, Dainichi Seika Kogyo's Rezamin P, Mitsui Nisso Urethane Hyprene, Nisshinbo Mobilon, Kuraray's Clamiron U, Asahi Glass's Eufine and Morsen, Sumitomo Bakelite's Sumiflex, Toyobo's Toyobo Urethane, Hokuto Chemical's Eagle Run, etc. The polyurethane-based thermoplastic resin broadly means a resin having a urethane bond in the molecular chain.
[0020]
<Polyester resin>
The polyester-based resin includes a polyester-based thermoplastic elastomer and a polyester-based thermoplastic resin. The polyester-based thermoplastic elastomer is composed of a hard segment having a polyester structure and a soft segment having a polyether or polyester. Product names include Toray DuPont's Hytrel and Toyobo's Perpren P.I. S, Dainippon Ink &Chemicals's Relax E, Nippon GE Plastics' Lomod, Mitsubishi Rayon's Diamond Alloy R, Sekisui Chemical's S-TPE, Nippon Zeon's ZTPE, Teijin's Nobellan, Nippon Synthetic Chemical's Flexomer, Miraclan's Liberan, Mitsubishi Chemical's Primalloy, etc. The polyester-based thermoplastic resin is a thermoplastic resin having a polyester bond in the molecule, such as polyethylene terephthalate.
[0021]
<Polyamide resin>
The polyamide-based resin includes a polyamide-based thermoplastic elastomer and a polyamide-based thermoplastic resin. The polyamide-based thermoplastic elastomer is composed of a polyamide hard segment and a polyether or polyester soft segment. Product names include Pebax from Toray, Daiamid PAE from Daicel Huls, Glais A from Dainippon Ink and Chemicals, Novamid PAE from Mitsubishi Engineering Plastics, UBE / PAE from Ube Industries, Ems There are Glolin ELX and Grillamide ELY from Japan, S-TPAE from Sekisui Chemical Co., Ltd. The polyamide-based thermoplastic resin is a thermoplastic resin having a polyamide bond in the molecular chain, and examples thereof include nylon 6, nylon 66, and nylon 11.
[0022]
<Mixing with olefinic thermoplastic resin>
The resin component of the cover of the present invention can be used by mixing with an ionomer resin, an olefin-based thermoplastic resin and / or an olefin-based thermoplastic elastomer (including a styrene-based elastomer). The mixing ratio is 50% by mass or less, preferably 20% by mass or less, based on the entire resin component.
[0023]
Here, the ionomer resin is, for example, a copolymer of an α-olefin and an α, β-unsaturated carboxylic acid having 3 to 8 carbon atoms, which is obtained by neutralizing at least a part of the carboxyl group with a metal ion. There are binary copolymers. And a terpolymer of an α-olefin, an α, β-unsaturated carboxylic acid having 3 to 8 carbon atoms and an α, β-unsaturated carboxylic acid ester having 2 to 22 carbon atoms, wherein at least one of the carboxyl groups. And those obtained by neutralizing the part with metal ions.
[0024]
As the olefinic thermoplastic resin, high density polyethylene, low density polyethylene, polystyrene, polypropylene, and the like can be used.
[0025]
In the present invention, the olefinic thermoplastic elastomer includes an olefin unit in a molecular chain and is a concept including a so-called styrene thermoplastic elastomer, and includes a block copolymer having a soft segment and a hard segment in the molecule. . A unit obtained from a conjugated diene compound as a soft segment, such as a butadiene block or an isoprene block. Here, as the conjugated diene compound, for example, one or two or more kinds can be selected from butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, etc., among which butadiene, isoprene, and these The combination of is preferable. As the component constituting the hard segment, one or more of ethylene, propylene, styrene and derivatives thereof such as α-methylstyrene, vinyltoluene, p-tert-butylstyrene, 1,1-diphenylethylene, etc. Is a unit such as a polyethylene block, a polypropylene block, a polystyrene block or the like obtained from the selected compound. In particular, polystyrene block units are preferred.
[0026]
Examples of the styrene-based thermoplastic elastomer include styrene-isoprene-butadiene-styrene block copolymer (SIBS structure), styrene-butadiene-styrene block copolymer (SBS structure), and hydrogenated double bond portion of the butadiene. Styrene-ethylene-butylene-styrene block copolymer (SEBS structure), styrene-isoprene-styrene block copolymer (SIS structure), styrene-ethylene-propylene-styrene block copolymer with hydrogenated isoprene double bond moiety Examples thereof include a coalescence (SEPS structure), a styrene-ethylene-ethylene-propylene-styrene copolymer (SEEPS structure), and a modified product thereof.
[0027]
The content of styrene (or a derivative thereof) in the SIBS structure, SBS structure, SEBS structure, SIS structure, SEPS structure, and SEEPS structure is preferably in the range of 10 to 50% by mass, particularly 15 to 45% by mass in the copolymer. When the amount is less than 10% by mass, the cover tends to be soft and the cut resistance tends to decrease. On the other hand, when the amount exceeds 50% by mass, the shot feeling and controllability cannot be sufficiently maintained.
[0028]
In the present invention, a part of the copolymer of the SIBS structure, SBS structure, SEBS structure, SIS structure, SEPS structure, and SEEPS structure is modified with a functional group selected from an epoxy group, a hydroxyl group, an acid anhydride, and a carboxyl group. Modified products can be used.
[0029]
<Ternary complex>
The ternary composite used in the present invention is composed of a rubber component, a polyolefin component, and a nylon component. These three components are chemically bonded to each other and are finely divided in a matrix made of rubber and polyolefin. A composite material in which nylon fibers are uniformly dispersed.
[0030]
Natural rubber, polyisoprene, ethylene-propylene-diene rubber (EPDM), nitrile-butadiene rubber (NBR), hydrogenated NBR (H-NBR), etc. as rubber components, kneaded with nylon, during reaction, and spinning It is limited to those in which gelation does not occur at high temperatures. In particular, ethylene-propylene-diene rubber (EPDM) is suitable.
[0031]
As the polyolefin component, low density polyethylene, high density polyethylene, and polypropylene are used, and polypropylene is particularly preferable.
[0032]
As the nylon component, nylon 6, nylon 66, nylon 11 and nylon 12 are used, and nylon 6 is particularly preferable. And these combination component ratio can be suitably adjusted according to the required characteristic of a golf ball cover material. This ternary composite was developed by Ube Industries, Ltd., and the trade name sold by Daiwa Polymer Co., Ltd. is known as SHP, and has the following grades depending on the composition ratio.
PA3060:
EPDM / PP / nylon 6 = 100/100/100
HA1060:
NR / HDPE / nylon 6 = 100/75/87
LA1060:
NR / LDPE / nylon 6 = 100/75/87
LA3080:
EPDM / LDPE / nylon 6 = 100/40/105
LA5060:
H-NBR / LDPE / nylon 6 = 100/100/100
Z040NB:
NBR / LDPE / nylon 6 = 100/75/75
Here, NR means natural rubber, HDPE means high density polyethylene, LDPE means low density polyethylene, NBR means acrylonitrile-butadiene rubber, and H-NBR means hydrogenated NBR. The composition ratio is shown in parts by mass.
[0033]
The average diameter of the nylon fibers used in the ternary composite is usually 10 μm or less, preferably in the range of 0.05 to 1 μm. In the matrix of the ternary composite, the polyolefin component (for example, HDPE) is continuous. Forming a phase.
[0034]
In order to produce a ternary composite (for example, SHP), it is usually produced by the following three steps.
(1) Kneading / reaction process of rubber component-polyolefin component.
[0035]
(2) Rubber component-polyolefin component-nylon kneading / reaction process.
(3) Spinning process First, rubber, polyolefin and a reactant are charged into a closed kneader to obtain a kneaded and reacted product. Here, a sea-island structure is formed in which polyolefin is the sea and rubber is the island. Next, the kneaded / reacted material and nylon are fed together with a reactant to a twin screw extruder to obtain a rubber-polyolefin-nylon ternary graft polymer, that is, a ternary composite. By adjusting the graft ratio, nylon is uniformly dispersed in the rubber-polyolefin matrix as, for example, 2 to 3 μm particles.
[0036]
Next, it is extruded from a nozzle installed at the tip of the twin screw extruder and taken out while drafting. By this spinning process, the nylon particles in the extrudate strand are deformed and converted into fibers. The nylon fiber diameter depends on the draft ratio, but is usually controlled to 0.2 to 0.3 μm in consideration of productivity. In these steps, since the polyolefin phase forms the sea, the tackiness is reduced and pelletization becomes possible.
[0037]
The ternary complex used in the present invention is described in Journal of the Japan Rheological Society, Vol. 25 (1997) pages 275 to 282, and the composition can be further adjusted.
[0038]
<Mixing of resin component and ternary composite>
In this invention, the compounding quantity of a ternary composite is the range of 1-50 mass parts with respect to 100 mass parts of said resin components. Preferably, it is 5 to 40 parts by mass, particularly 10 to 30 parts by mass. In this case, the reinforcing effect of the resin composition is affected by the content of nylon short fibers contained in the ternary composite. When the blending amount of the ternary composite is less than 1 part by mass, the reinforcing effect by the nylon short fibers is small, while when it exceeds 50 parts by mass, the hardness of the cover composition increases and the elastic modulus decreases.
[0039]
<Organic short fiber>
Although it is not essential for the cover composition of the present invention, organic short fibers such as nylon fibers, acrylic fibers, polyester fibers, aramid fibers, and the like can be used. In this case, the cut resistance can be improved without reducing the resilience performance.
[0040]
The length of the organic short fiber is 5 to 1000 μm, preferably 10 to 500 μm, and the diameter is 0.05 to 5 μm, preferably 0.1 to 1 μm. When the length of the organic short fiber is less than the above range, the strength in the bending direction is weak, the strength does not increase, and the cut resistance cannot be improved. Moreover, when the diameter of an organic short fiber is less than the said range, it only acts as a filler. On the other hand, when the length and diameter of the organic short fibers exceed the above ranges, the viscosity of the cover material increases and the moldability is impaired. In addition, the said organic short fiber is the concept containing the fiber finely cut | judged in the pulp form.
[0041]
The amount of the organic short fiber is in the range of 0.5 to 20 parts by mass with respect to 100 parts by mass of the resin component. When the amount is less than 0.5 part by mass, the effect of blending the organic short fibers is small. When the amount exceeds 20 parts by mass, the viscosity of the cover composition increases, the moldability deteriorates, and cracking easily occurs. In addition, when using short fiber reinforced rubber, rubber | gum is included in a polymer component and the compounding quantity of an organic short fiber is set to the said range.
[0042]
<Other ingredients>
In addition, the cover composition may include a filler such as barium sulfate, a colorant such as titanium dioxide, a dispersant, an anti-aging agent, an ultraviolet absorber, a light stabilizer, and a fluorescent material or fluorescent whitening as necessary. You may mix | blend an agent etc. in the range by which the desired characteristic by a golf ball cover is not impaired.
[0043]
<Hardness of cover>
Furthermore, the cover of the present invention has a Shore D hardness of 40 to 56, preferably 42 to 50, as measured with a slab specimen. If the Shore D hardness is less than 40, it becomes too soft and inferior in cut resistance. If the Shore D hardness exceeds 56, on the contrary, the shot feeling becomes harder and the spin amount at the time of impact becomes smaller. Here, the Shore D hardness is measured according to ASTM D-2240.
[0044]
<Method for producing cover composition>
In the cover composition of the present invention, resin components, that is, polyurethane resin, polyester resin, polyamide resin and the ternary composite (for example, SHP) are charged into a closed kneader and kneaded. At this time, the kneading temperature must be lower than the melting point of nylon of the ternary composite. If it is higher than the melting point of nylon, the fiber melts and the reinforcement by the fiber is lost. However, when the kneading temperature is lower than the temperature of the polyolefin, the ternary composite does not disperse in the rubber and remains as pellets. During this kneading, the phase transition between polyolefin and rubber occurs on the matrix side, and the polyolefin is finely dispersed in the rubber. Subsequently, the composition for a cover is obtained by adding and mixing another compounding agent.
[0045]
<Core composition>
Although the core of the golf ball of the present invention is composed of a crosslinked product of a rubber composition, the rubber component of the rubber composition is suitably based on a butadiene rubber having a cis-1,4-structure. Yes. However, in addition to the butadiene rubber, for example, natural rubber, styrene butadiene rubber, isoprene rubber, chloroprene rubber, butyl rubber, ethylene-propylene rubber, ethylene-propylene-diene rubber, acrylonitrile rubber and the like are 40 masses with respect to 100 mass parts of the rubber component. It may be blended with less than a part.
[0046]
In the rubber composition, an α, β-ethylenic unsaturated carboxylic acid such as acrylic acid or methacrylic acid and a metal oxide are reacted as a crosslinking agent during preparation of the rubber composition. A metal salt of a saturated carboxylic acid, or a metal salt of an α, β-ethylenically unsaturated carboxylic acid such as zinc acrylate or zinc methacrylate, a polyfunctional monomer, N, N′-phenylbismaleimide, sulfur Etc. are used as a crosslinking agent. In particular, a metal salt of an α, β-ethylenically unsaturated carboxylic acid is preferably used.
[0047]
For example, when using the metal salt of (alpha), (beta) -ethylenically unsaturated carboxylic acid, the compounding quantity has preferable 20-40 mass parts with respect to 100 mass parts of rubber components. On the other hand, when the α, β-ethylenically unsaturated carboxylic acid and the metal oxide are reacted during the preparation of the rubber composition, the blending amount is 15 to 30 parts by mass of the α, β-ethylenically unsaturated carboxylic acid, The metal oxide such as zinc oxide is preferably 15 to 35% by mass with respect to the α, β-ethylenically unsaturated carboxylic acid.
[0048]
As the filler used in the rubber composition, for example, one or more inorganic powders such as barium sulfate, calcium carbonate, clay, and zinc oxide can be used. The blending amount of these fillers is preferably in the range of 5 to 50 parts by mass with respect to 100 parts by mass of the rubber component. Further, for the purpose of improving workability and adjusting the hardness, a softening agent, liquid rubber, or the like may be appropriately blended, or an anti-aging agent may be blended as appropriate.
[0049]
As the crosslinking initiator, for example, organic peroxides such as dicumyl peroxide and 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane are used. These crosslinking initiators are blended in an amount of 0.1 to 5 parts by weight, particularly 0.3 to 3 parts by weight, based on 100 parts by weight of the rubber component.
[0050]
In the present invention, the core may be a single layer or a composite layer having different characteristics such as specific gravity and hardness. In this case, the composition of the core is not limited to the above description of the composition.
[0051]
<Compression deformation amount of core>
In the core of the present invention, the amount of compressive deformation when a load is applied from 10 kg to 130 kg is preferably in the range of 2.0 mm to 5.0 mm, particularly 2.5 mm to 4.0 mm. When the thickness is less than 2.0 mm, the feeling of hitting tends to deteriorate, while when it exceeds 5.0, the resilience is disadvantageous.
[0052]
<Manufacturing method of core>
And in preparation of a core, the above-mentioned compounding agent is mixed using a roll, a kneader, a banbari, etc., and 145 degreeC-200 degreeC under pressure using a metal mold | die, Preferably it is 150-175 degreeC for 10 minutes- Vulcanize for 40 minutes to make the core. Since the obtained core improves adhesion to the cover, an adhesive can be applied to the surface or the surface can be roughened.
[0053]
Here, the diameter of the wound core or the solid core is designed in the range of 36.8 to 41.4 mm, preferably 37.8 to 40.8 mm. If the thickness is less than 36.8 mm, the cover layer becomes thick and the resilience is lowered. On the other hand, if the thickness exceeds 41.4 mm, the cover layer becomes thin and molding becomes difficult.
[0054]
<Golf ball manufacturing method>
In the present invention, the cover can be formed into a core using a known method. The cover composition is formed in advance into a hemispherical half-shell, and the two cores are used to wrap the core and press molded at 130-170 ° C. for 1-5 minutes, or the cover composition is directly applied onto the core. A method of wrapping the core by injection molding may be used. The cover has a thickness of 0.7 to 3.0 mm, preferably 1.0 to 2.5 mm. If it is smaller than 0.7 mm, there is a drawback that the cover is liable to be cracked when it is repeatedly hit, and if it is larger than 3.0 mm, the shot feeling becomes worse. Furthermore, a large number of dimples are formed on the surface as necessary when molding the cover. The golf ball of the present invention is usually put on the market with a paint finish, a marking stamp, etc. in order to enhance aesthetics and increase commercial value.
[0055]
<Ball structure, dimensions, compression deformation>
In the golf ball of the present invention, a thread wound core, a single layer, or a multi-layer solid core is used as a core, and can be employed for either a thread wound ball or a solid ball.
[0056]
In the present invention, the cover may be a single layer, but may be configured as a multi-layer cover. The golf ball of the present invention is usually designed to have a ball mass of 45.00 to 45.93 g with a ball diameter of 42.67 to 43.00 mm.
[0057]
In the golf ball of the present invention, the amount of compressive deformation when a load is applied from 10 kg to 130 kg is in the range of 2.0 mm to 4.0 mm, preferably 2.5 mm to 3.5 m. When the thickness is less than 2.0 mm, the feeling of hitting tends to deteriorate. On the other hand, when it exceeds 4.0 mm, the feel at the time of hitting becomes soft and the resilience becomes disadvantageous.
[0058]
【Example】
Examples 1 to 6 and Comparative Examples 1 to 3
(1) Preparation of core As shown in Table 1, a rubber composition for cores containing butadiene rubber as a main component is kneaded and heated and molded in a mold at 170 ° C. for 15 minutes to form a spherical shape having a diameter of 41.2 mm. A solid core was produced. Table 1 shows the physical properties of the obtained solid core.
[0059]
[Table 1]

[0060]
(2) Preparation of cover composition The cover composition shown in Table 2 was mixed with a twin-screw kneading extruder and extruded at a cylinder temperature of 180 ° C with a twin-screw extruder. It is important that the extrusion temperature is below the melting point of the ternary composite nylon. Extrusion conditions are as follows.
[0061]
Screw diameter: 45mm
Screw rotation speed: 200rpm
Screw L / D: 35
The blend was heated to 195-205 ° C at the die of the extruder.
[0062]
The cover composition is used to injection-mold a hemispherical half-shell, and the two cores are used to wrap the core, followed by press hot compression molding at 150 ° C. in a mold, and after cooling, a golf ball is molded. I took it out. Thereafter, paint was applied to the surface to produce a golf ball having a diameter of 42.8 mm and a mass of 45.4 g.
[0063]
[Table 2]

[0064]
<Performance evaluation method>
The Shore D hardness of the slab piece of the obtained cover composition, the amount of compression deformation of the core (golf ball), the wear resistance and the scratch resistance of the golf ball were evaluated.
[0065]
(1) Shore D hardness Measured according to ASTM-D2240. A hot press-molded sheet having a thickness of about 2 mm prepared from the cover composition was stored at 23 ° C. for 2 weeks, and three or more sheets were measured using a spring type hardness meter Shore D type.
[0066]
(2) Compression Deformation Amount of deformation (mm) from when an initial load of 10 kg to a final load of 130 kg was applied to a golf ball (or solid core) was measured.
[0067]
(3) Wear resistance Measured according to ASTM D-1044. The smaller the number, the better the wear resistance.
[0068]
( 4 ) Scratch resistance A commercially available pitching wedge was attached to a robot machine, two golf balls were hit once each at a head speed of 36 m / s, the two hit portions were observed, and evaluated in three stages.
[0069]
○: Slight scratches remain on the ball surface, but it is hardly noticed.
Δ: Scratches remain on the surface of the ball and some fuzz is observed.
[0070]
X: The ball surface is considerably shaved and fuzz is conspicuous.
[0071]
[Table 3]

[0072]
Table 3 shows the measurement results of the golf balls of Examples 1 to 6 and Comparative Examples 1 to 3.
[0073]
<Evaluation results>
Comparative Examples 1 to 3 use a cover composition that does not contain a ternary composite, and all of them are considerably inferior in scuff resistance and wear resistance.
[0074]
Examples 1 to 4 are cover compositions in which a ternary composite is blended with a polyurethane-based thermoplastic elastomer, and Example 5 is a cover composition in which a ternary composite is blended with a polyamide-based thermoplastic elastomer. Example 6 is a cover composition in which a ternary composite is blended with a polyester-based thermoplastic elastomer. It is recognized that all golf balls are excellent in scratch resistance and wear resistance.
[0075]
It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
[0076]
【The invention's effect】
In the golf ball of the present invention, since the ternary composite is mixed with at least one selected from the group of polyurethane resin, polyester resin and polyamide resin as a resin component of the cover composition, various characteristics such as resilience performance are obtained. Scratch resistance and wear resistance can be improved without degrading the properties.

Claims (2)

A golf ball comprising a core and a cover covering the core, wherein the cover includes at least one resin component selected from the group consisting of polyurethane resin, polyester resin and polyamide resin, a rubber component, a polyolefin component, and nylon A golf ball comprising a ternary composite comprising components and a composition obtained by mixing 1 to 50 parts by mass of the ternary complex with 100 parts by mass of the resin component .   The golf ball according to claim 1, wherein the resin component is a thermoplastic elastomer.