JP2015213677A - Grip for golf club and golf club - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grip for a golf club that is excellent in grip performance in wet condition and wear resistance.SOLUTION: A grip 1 for a golf club is formed of a rubber composition including a substrate rubber and a crosslinking agent, where the substrate rubber includes a carboxy-modified acrylonitrile - butadiene rubber.

Description

  The present invention relates to a golf club grip, and more particularly to a grip excellent in wear resistance.

  Rubber grips are often used as grips attached to golf clubs. As such a rubber grip, for example, in Patent Document 1, acrylonitrile-butadiene rubber having a glass transition point of −40 ° C. or higher and −13 ° C. or lower is used as a base polymer, and the total amount of the base polymer of the acrylonitrile-butadiene rubber is used. The rubber composition is formed by crosslinking at a ratio of 45% by mass or more, the initial strain is 10%, the amplitude is ± 2%, the frequency is 10 Hz, and the starting temperature is −100 ° C. The peak temperature of the loss coefficient curve measured by a viscoelastic spectrometer under the conditions that the end temperature is 100 ° C., the rate of temperature increase is 3 ° C./min, and the deformation mode is tensile is −29 ° C. Is described (see Patent Document 1 (Claim 4)).

Japanese Patent No. 3701220

  An object of the present invention is to provide a golf club grip excellent in grip performance and wear resistance when wet.

  The golf club grip of the present invention that has solved the above problems is formed from a rubber composition containing a base rubber and a crosslinking agent, and the base rubber is a carboxy-modified acrylonitrile- It contains butadiene rubber. By using carboxy-modified acrylonitrile-butadiene rubber as the base rubber, the wear resistance can be improved while maintaining the grip performance when wet in the same level as that of acrylonitrile-butadiene rubber.

  The content of the carboxy group-containing monomer of the carboxy-modified acrylonitrile-butadiene rubber is preferably 1.0% by mass to 8.0% by mass, and more preferably 3.5% by mass to 8.0% by mass. The acrylonitrile content of the carboxy-modified acrylonitrile-butadiene rubber is preferably 26% by mass to 34% by mass.

  The present invention also includes a golf club comprising a shaft, a head attached to one end of the shaft, and a grip attached to the other end of the shaft, wherein the grip is the grip for the golf club.

  According to the present invention, a grip for a golf club having excellent grip performance and wear resistance when wet can be obtained.

It is a perspective view which shows an example of the grip for golf clubs of this invention. It is a perspective view which shows an example of the golf club of this invention.

  The golf club grip of the present invention is molded from a rubber composition containing a base rubber and a crosslinking agent. In the present invention, carboxy-modified acrylonitrile-butadiene rubber is used as the base rubber. By using carboxy-modified acrylonitrile-butadiene rubber, the wear resistance of the grip can be improved while maintaining the grip performance when wet.

  The rubber composition used for the golf club grip of the present invention will be described. The rubber composition contains a base rubber containing a carboxy-modified acrylonitrile-butadiene rubber and a crosslinking agent. The carboxy-modified acrylonitrile-butadiene rubber is a copolymer of a monomer having a carboxy group, acrylonitrile, and butadiene. Examples of the monomer having a carboxy group include acrylic acid, methacrylic acid, fumaric acid, maleic acid and the like.

  The acrylonitrile content in the carboxy-modified acrylonitrile-butadiene rubber is preferably 15% by mass or more, more preferably 18% by mass or more, further preferably 21% by mass or more, and preferably 50% by mass or less, more preferably 45%. It is at most 40% by mass, more preferably at most 40% by mass. When the acrylonitrile content is 15% by mass or more, the wear resistance is good, and when the acrylonitrile content is 50% by mass or less, the grip feeling in cold or winter is good.

  The content of the carboxy group-containing monomer of the carboxy-modified acrylonitrile-butadiene rubber is preferably 1.0% by mass or more, more preferably 2.0% by mass or more, and further preferably 3.5% by mass or more. Yes, 30 mass% or less is preferable, More preferably, it is 25 mass% or less, More preferably, it is 20 mass% or less. If the content of the monomer containing a carboxy group is 1.0% by mass or more, the wear resistance is better, and if it is 30% by mass or less, the grip feel in cold or winter is good.

  The carboxy group content of the carboxy-modified acrylonitrile-butadiene rubber is preferably 1.0% by mass or more, more preferably 2.0% by mass or more, still more preferably 3.5% by mass or more, and 30% by mass or less. More preferably, it is 25 mass% or less, More preferably, it is 20 mass% or less. If the carboxy group content is 1.0% by mass or more, the wear resistance is better, and if it is 30% by mass or less, the grip feeling in cold or winter is good.

  As the carboxy-modified acrylonitrile-butadiene rubber, a hydrogenated carboxy-modified acrylonitrile-butadiene rubber in which some double bonds in the molecule are hydrogenated may be used. In this case, the double bond content of the hydrogenated carboxy-modified acrylonitrile-butadiene rubber is preferably 0.09 mmol / g or more, more preferably 0.2 mmol / g or more, and preferably 2.5 mmol / g or less, More preferably, it is 2.0 mmol / g or less, More preferably, it is 1.5 mmol / g or less. If the double bond content is 0.09 mmol / g or more, it becomes easy to vulcanize at the time of molding, and if it is 2.5 mmol / g or less, a decrease in weather resistance can be suppressed. The double bond content can be adjusted by the butadiene content in the copolymer and the amount of hydrogen added to the copolymer.

  A commercially available product can be used as the carboxy-modified acrylonitrile-butadiene rubber. Examples of such carboxy-modified acrylonitrile-butadiene rubber include, for example, Krynac (registered trademark) X146, Krynac X160, Krynac X740, Krynac X750, commercially available from LANXESS, and Zetpol (registered trademark), commercially available from ZEON. 1072J, Zetpol DN631, Zetpol NX775. Examples of the hydrogenated carboxy-modified acrylonitrile-butadiene rubber include Therban (registered trademark) XT KA 8889VP commercially available from LANXESS.

  The base rubber may contain a rubber component other than carboxy-modified acrylonitrile-butadiene rubber. Other rubber components include acrylonitrile-butadiene rubber, hydrogenated acrylonitrile-butadiene rubber, isoprene rubber, butadiene rubber, styrene-butadiene rubber, ethylene-propylene-diene rubber, chloroprene rubber, butyl rubber, acrylic rubber, urethane rubber, epichlorohydrin rubber, Examples include polysulfide rubber and natural rubber. The content of the carboxy-modified acrylonitrile-butadiene rubber in the base rubber is preferably 60% by mass or more, more preferably 70% by mass or more, and further preferably 80% by mass or more. It is also preferable to use only carboxy-modified acrylonitrile-butadiene rubber as the base rubber.

  As said crosslinking agent, a sulfur type crosslinking agent and an organic peroxide can be used. Examples of the sulfur-based crosslinking agent include elemental sulfur and a sulfur donor type compound. Examples of the elemental sulfur include powdered sulfur, precipitated sulfur, colloidal sulfur, and insoluble sulfur. Examples of the sulfur donor type compound include 4,4'-dithiobismorpholine. Examples of the organic peroxide include dicumyl peroxide, α, α′-bis (t-butylperoxy-m-diisopropyl) benzene, 2,5-dimethyl-2,5-di (t-butylperoxy). Examples include hexane and 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane. The said crosslinking agent may be used independently and may use 2 or more types together. As the crosslinking agent, a sulfur-based crosslinking agent is preferable, and elemental sulfur is more preferable. The amount of the crosslinking agent used is preferably 0.2 parts by mass or more, more preferably 0.4 parts by mass or more, and still more preferably 0.6 parts by mass or more with respect to 100 parts by mass of the base rubber. 0.0 parts by mass or less is preferable, more preferably 3.5 parts by mass or less, and still more preferably 3.0 parts by mass or less.

  The rubber composition preferably contains a metal compound in addition to the base rubber and the crosslinking agent. By containing a metal compound, a metal bridge | crosslinking can be formed in the carboxy group which carboxy modified acrylonitrile-butadiene rubber has. Examples of the metal compound include metal oxides, metal peroxides, metal hydroxides, and metal carbonates. Examples of the metal oxide include zinc oxide, magnesium oxide, calcium oxide, copper oxide, and lead oxide. Examples of the metal peroxide include zinc peroxide, chromium peroxide, magnesium peroxide, and calcium peroxide. Examples of the metal hydroxide include magnesium hydroxide, zinc hydroxide, calcium hydroxide, sodium hydroxide, lithium hydroxide, potassium hydroxide, and copper hydroxide. Examples of the metal carbonate include magnesium carbonate, zinc carbonate, calcium carbonate, sodium carbonate, lithium carbonate, and potassium carbonate. The metal compound is preferably a divalent metal compound, more preferably a zinc compound. These metal compounds may be used alone or in combination of two or more.

  The amount of the metal compound used is preferably 0.5 parts by mass or more, more preferably 0.6 parts by mass or more, and still more preferably 0.7 parts by mass or more with respect to 100 parts by mass of the base rubber. 0.0 parts by mass or less is preferable, more preferably 9.5 parts by mass or less, and still more preferably 9.0 parts by mass or less.

  The rubber composition preferably further contains a vulcanization accelerator and a vulcanization activator.

  Examples of the vulcanization accelerator include thiurams such as tetramethylthiuram disulfide, tetramethylthiuram monosulfide and dipentamethylenethiuram tetrasulfide; guanidines such as diphenylguanidine; dithiocarbamates such as zinc dibutyldithiocarbamate; trimethylthio Thioureas such as urea and N, N′-diethylthiourea; thiazoles such as mercaptobenzothiazole and benzothiazole disulfide; sulfenamides such as N-cyclohexyl-2-benzothiazolylsulfenamide; These vulcanization accelerators may be used alone or in combination of two or more.

  The amount of the vulcanization accelerator used is preferably 0.4 parts by mass or more, more preferably 0.8 parts by mass or more, and further preferably 1.2 parts by mass or more with respect to 100 parts by mass of the base rubber. 8.0 parts by mass or less, preferably 7.0 parts by mass or less, and more preferably 6.0 parts by mass or less.

  Examples of the vulcanization activator include metal oxides, metal peroxides, and fatty acids. Examples of the fatty acid include stearic acid, oleic acid, and palmitic acid. These vulcanization activators may be used alone or in combination of two or more.

  The amount of the vulcanization activator used is preferably 0.5 parts by mass or more, more preferably 0.6 parts by mass or more, and further preferably 0.7 parts by mass or more with respect to 100 parts by mass of the base rubber. 10.0 mass parts or less are preferable, More preferably, it is 9.5 mass parts or less, More preferably, it is 9.0 mass parts or less.

  The rubber composition may further contain a reinforcing material, an anti-aging agent, a softening agent, a colorant, and the like as necessary.

  Examples of the reinforcing material include carbon black and silica. The amount of the reinforcing material used is preferably 2.0 parts by mass or more, more preferably 3.0 parts by mass or more, still more preferably 4.0 parts by mass or more, with respect to 100 parts by mass of the base rubber. The amount is preferably not more than part by mass, more preferably not more than 45 parts by mass, still more preferably not more than 40 parts by mass.

  Examples of the antiaging agent include imidazoles, amines, phenols and the like. Examples of the imidazoles include nickel dibutyldithiocarbamate, 2-mercaptobenzimidazole, zinc salt of 2-mercaptobenzimidazole, and the like. Examples of amines include phenyl-α-naphthylamine. Examples of phenols include 2,6-di-tert-butyl-4-methylphenol. These antioxidants may be used alone or in combination of two or more. The amount of the anti-aging agent used is preferably 0.2 parts by mass or more, more preferably 0.3 parts by mass or more, further preferably 0.4 parts by mass or more, with respect to 100 parts by mass of the base rubber. The amount is preferably 5.0 parts by mass or less, more preferably 4.8 parts by mass or less, and still more preferably 4.6 parts by mass or less.

  Examples of the softener include mineral oil and plasticizer. Examples of the mineral oil include paraffin oil, naphthenic oil, and aromatic oil. Examples of the plasticizer include dioctyl phthalate, dibutyl phthalate, dioctyl separate, dioctyl adipate, and the like.

  The rubber composition can be prepared by a conventionally known method. For example, it can be prepared by kneading each raw material using a kneader such as a Banbury mixer, a kneader, or an open roll. The temperature during kneading (material temperature) is preferably 90 ° C to 160 ° C.

  The shape of the golf club grip of the present invention is not particularly limited, and a conventionally known shape can be employed. Examples of the shape of the grip include a shape having a cylindrical portion into which a shaft is inserted and a cap portion integrally formed so as to cover the opening at the rear end of the cylindrical portion. The thickness of the cylindrical portion may be constant in the axial direction, or may be formed so as to gradually increase from the front end portion toward the rear end portion. Moreover, you may form so that the thickness of a cylindrical part may become fixed to radial direction, and you may provide a protruding item | line part (what is called a back line) in part. Moreover, you may provide a groove | channel in the surface of a cylindrical part. The groove suppresses the formation of a water film between the golfer's hand and the grip, and the grip performance in a wet state is further improved. Furthermore, a reinforcing cord may be provided in the grip from the viewpoint of the slip prevention performance and wear resistance of the grip.

  A golf club grip is obtained by molding the rubber composition in a mold. Examples of the molding method include press molding and injection molding. When employing press molding, the mold temperature is preferably 140 ° C. to 200 ° C., the molding time is preferably 5 minutes to 45 minutes, and the molding pressure is preferably 0.1 MPa to 100 MPa.

  The golf club of the present invention includes a shaft, a head attached to one end of the shaft, and a grip attached to the other end of the shaft, and the grip is molded from the rubber composition. The shaft can be made of stainless steel or carbon fiber reinforced resin. Examples of the head include a wood type, a utility type, and an iron type. The material constituting the head is not particularly limited, and examples thereof include titanium, titanium alloy, carbon fiber reinforced plastic, stainless steel, maraging steel, and soft iron.

  Hereinafter, a golf club grip and a golf club of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing an example of a golf club grip of the present invention. The grip 1 includes a cylindrical portion 1a into which a shaft is inserted and a cap portion 1b integrally formed so as to cover an opening at the rear end of the cylindrical portion. The thickness of the cylindrical portion 1a is formed so as to gradually increase from the front end portion toward the rear end portion.

  FIG. 2 is a perspective view showing an example of the golf club of the present invention. The golf club 2 includes a shaft 3, a head 4 attached to one end of the shaft 3, and a grip 1 attached to the other end of the shaft 3. The rear end of the shaft 3 is fitted into the cylindrical portion 1 a of the grip 1.

  The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to the following examples, and may be appropriately modified and implemented within a range that can meet the purpose described above and below. All of which are within the scope of the present invention.

[Evaluation method]
(1) Acrylonitrile content The acrylonitrile content was measured according to ISO 24698-1 (2008).

(2) Content of monomer containing carboxy group 1 g of hydrogenated acrylonitrile-butadiene rubber was weighed and dissolved in 50 ml of chloroform, and thymol blue indicator was added dropwise thereto. While stirring this solution, 0.05 mol / L methanol solution of sodium hydroxide was added dropwise, and the amount of dropwise addition (Vml) until the first color change was recorded. For 50 ml of chloroform that does not contain hydrogenated acrylonitrile-butadiene rubber as a blank, 0.05 mol / L methanol solution of sodium hydroxide is dropped with thymol blue as an indicator, and the amount of dripping until the first color change (Bml) is recorded. did. The content rate of the monomer containing a carboxy group was calculated by the following formula.
Carboxy group-containing monomer content = {0.05 × (V−B) × PM} / 10
(In formula, V: Sodium hydroxide solution dropping amount (ml) of test solution, B: Blank sodium hydroxide solution dropping amount (ml), PM: Molecular weight of carboxy group-containing monomer, X: Carboxy group-containing monomer Valence of the monomer

(3) Double bond content (mmol / g)
The double bond content was calculated from the butadiene content (% by mass) and the residual double bond content (%) in the copolymer. The residual double bond amount is the mass ratio of the double bond in the copolymer before hydrogenation to the double bond in the copolymer after hydrogenation (double bond amount after hydrogenation / hydrogenation). The previous double bond amount) and can be measured by infrared spectroscopy. The butadiene content in the copolymer can be obtained by reducing the acrylonitrile content (mass%) and the content (mass%) of the monomer containing a carboxy group from 100.
Double bond amount = {butadiene content / 45} × residual double bond amount × 10

(4) Abrasion resistance Abrasion resistance was evaluated using a Gakushin type wear tester (manufactured by Suga Test Instruments Co., Ltd., FR-2). Specifically, a sheet having a thickness of 2 mm was produced by press molding (molding temperature 160 ° C., molding time 15 minutes) using the rubber composition. This sheet was punched into a rectangular shape having a length of 130 mm and a width of 35 mm to produce a test piece, and was fixed to the test piece base. Sandpaper (counter No. 240) was attached to the tip of the friction element and rubbed back and forth 500 times at a speed of 30 reciprocations per minute between the central part of the test piece 100 mm with a load of 2N. Then, abrasion resistance was evaluated by the mass change before and after the test of the test piece. In addition, the wear resistance is the grip no. The wear resistance of 1 is taken as 100, and the value is shown as an index value.

(5) Grip performance when wet A golf club was manufactured by attaching a grip to a shaft. Water was applied to this grip to make it wet, and this golf club was used by 10 golfers to evaluate the anti-slip performance in five stages from “1” to “5”. “5” was the least prone to slip and “1” was the most probable. The average evaluation value of 10 golfers of each grip was obtained, and the grip No. The anti-slip performance of 1 is taken as 100, and is shown as an indexed value.

[Grip production]
Each raw material was kneaded with a Banbury mixer (material temperature 150 ° C.) with the formulation shown in Table 1 to prepare a rubber composition. The obtained rubber composition was put into a mold having a groove pattern on the cavity surface. Then, heat treatment was performed at a mold temperature of 160 ° C. and a heating time of 15 minutes to obtain a golf grip.

  The evaluation results of each grip are shown in Table 1.

ＮＢＲ：アクリロニトリル−ブタジエンゴム（ランクセス社製、Ｋｒｙｎａｃ（登録商標） ３３４５Ｆ（アクリロニトリル含有率３３．０質量％））
ＸＮＢＲ１：カルボキシ変性アクリロニトリル−ブタジエンゴム（ランクセス社製、Ｋｒｙｎａｃ Ｘ１４６（アクリロニトリル含有率３２．５質量％））
ＸＮＢＲ２：カルボキシ変性アクリロニトリル−ブタジエンゴム（ランクセス社製、Ｋｒｙｎａｃ Ｘ７５０（アクリロニトリル含有率２７．０質量％））
ＨＸＮＢＲ：水素添加カルボキシ変性アクリロニトリル−ブタジエンゴム（ランクセス社製、Ｔｈｅｒｂａｎ（登録商標） ＸＴ ＶＰＫＡ ８８８９（アクリロニトリル含有率３３．０質量％、残存二重結合量３．５％））
硫黄：鶴見化学工業社製、５％油入微粉硫黄（２００メッシュ）
ＴＭＴＤ：テトラメチルチウラムジスルフィド（大内新興化学工業社製、ノクセラー（登録商標）ＴＴ−Ｐ）
酸化亜鉛：東邦亜鉛社製、銀嶺Ｒ
過酸化亜鉛：シグマアルドリッチ社製
ステアリン酸：日油社製、ビーズステアリン酸つばき
カーボンブラック：東海カーボン社製、シーストＳＯ（ＦＥＦ）
ＮＤＩＢＣ：ジブチルジチオカルバミン酸ニッケル（大内新興化学工業社製、ノクラック（登録商標）ＮＢＣ）

NBR: Acrylonitrile-butadiene rubber (manufactured by LANXESS, Krynac (registered trademark) 3345F (acrylonitrile content 33.0% by mass))
XNBR1: Carboxy-modified acrylonitrile-butadiene rubber (manufactured by LANXESS, Krynac X146 (acrylonitrile content 32.5% by mass))
XNBR2: carboxy-modified acrylonitrile-butadiene rubber (manufactured by LANXESS, Krynac X750 (acrylonitrile content 27.0% by mass))
HXNBR: Hydrogenated carboxy-modified acrylonitrile-butadiene rubber (manufactured by LANXESS, Therban (registered trademark) XT VPKA 8889 (acrylonitrile content 33.0% by mass, residual double bond content 3.5%))
Sulfur: Tsurumi Chemical Co., Ltd., 5% oil-filled fine sulfur (200 mesh)
TMTD: Tetramethylthiuram disulfide (Ouchi Shinsei Chemical Industry Co., Ltd., Noxeller (registered trademark) TT-P)
Zinc oxide: manufactured by Toho Zinc Co., Ltd.
Zinc peroxide: Sigma-Aldrich stearic acid: NOF Corporation, bead stearic acid Tsubaki carbon black: Tokai Carbon Co., SEAST SO (FEF)
NDIBC: nickel dibutyldithiocarbamate (manufactured by Ouchi Shinko Chemical Industry Co., Ltd., NOCRACK (registered trademark) NBC)

  Grip No. Nos. 1 to 3 use acrylonitrile-butadiene rubber as the base rubber and change the amount of carbon black used. When these wear resistances are compared, grip no. 2 (10 parts by mass of carbon black) is Grip No. Although the wear resistance is higher than that of Grip No. 1, grip no. 3 (30 parts by mass of carbon black) is Grip No. Wear resistance is inferior to 2. Grip No. 4 to 6 are cases where carboxy-modified acrylonitrile-butadiene rubber is used as the base rubber. These grip Nos. 5 and 6 wear resistance and grip No. Comparing the tensile strengths of 1 to 3, it can be seen that the use of carboxy-modified acrylonitrile-butadiene rubber has a greater effect of improving wear resistance than increasing the amount of carbon black used.

1: Grip, 2: Golf club, 3: Shaft, 4: Head

Claims (5)

Molded from a rubber composition containing a base rubber and a crosslinking agent,
The golf club grip, wherein the base rubber contains a carboxy-modified acrylonitrile-butadiene rubber.   2. The golf club grip according to claim 1, wherein the content of the monomer containing a carboxy group in the carboxy-modified acrylonitrile-butadiene rubber is 1.0 mass% to 8.0 mass%.   The grip for a golf club according to claim 2, wherein the content of the monomer containing a carboxy group in the carboxy-modified acrylonitrile-butadiene rubber is 3.5 mass% to 8.0 mass%.   The golf club grip according to any one of claims 1 to 3, wherein the carboxy-modified acrylonitrile-butadiene rubber has an acrylonitrile content of 26 mass% to 34 mass%. A shaft, a head attached to one end of the shaft, and a grip attached to the other end of the shaft;
The golf club according to claim 1, wherein the grip is a grip for a golf club according to claim 1.

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