Rubber composition for billiard tip and billiard tip

Abstract

To provide a novel material for forming a billiard tip that is composed of a material other than natural leather and exhibits good feel at the time of hitting.SOLUTION: A rubber composition for a billiard tip according to the present invention comprises: (a) a base rubber; (b) a co-crosslinking agent; (c) a crosslinking agent; and (d) a terpene resin. Based on 100 pts.mass of the base rubber (a), the content of the terpene resin (d) is 1 to 23 pts.mass.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a rubber composition for billiard taps and a billiard tap. [Background technology]

[0002] Billiards can be broadly divided into pocket billiards and carom billiards. Pocket billiards is a game in which the player hits a predetermined target ball with the cue ball, and the target ball goes into the pocket. Carom billiards is a game in which the player uses a table without pockets and tries to hit two or more target balls with one shot.

[0003] Advanced players control the point where the cue ball is struck and, for example, can apply backspin to bring the cue ball back or follow spin to roll the cue ball, thereby controlling the movement of the cue ball.

[0004] A billiard tap is attached to the tip of the cue stick used to strike the cue ball in billiards. The billiard tap is the part that comes into contact with the cue ball when it is struck, and is an extremely important part for controlling the ball. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2010-227189 A Summary of the Invention [Problem to be solved by the invention]

[0006] Conventional billiard taps are made by forming natural animal leather such as cow or pig into a cylindrical shape. For example, there are some that are made by laminating multiple layers of pig leather and bonding each layer with an adhesive to form a cylindrical shape. However, there are individual differences between animals, and the texture and hardness of natural leather are not uniform. Therefore, billiard taps made from natural leather have a large variation in quality. Even if billiard taps are made by cutting out only the good quality parts from natural leather, the quality still varies. If the quality of billiard taps is not uniform, it becomes difficult for players to control the ball. In addition, there are concerns about the environmental impact of using animal skin.

[0007] The present invention has been made in consideration of the above circumstances, and has an object to provide a new material for forming a new billiard tap that is made of a material other than natural leather and that provides a good hitting feel.Another object of the present invention is to provide a new billiard tap that is made of a material other than natural leather and that provides a good hitting feel. [Means for solving the problem]

[0008] The rubber composition for billiard taps of the present invention, which has been able to solve the above problems, is characterized in that it contains (a) a base rubber, (b) a co-crosslinking agent, (c) a crosslinking agent, and (d) a terpene resin, and the content of the (d) terpene resin is 1 part by mass to 23 parts by mass per 100 parts by mass of the (a) base rubber. Effect of the Invention

[0009] The billiard taps obtained from the rubber composition for billiard taps of the present invention do not use natural leather, and therefore have little variation in quality. Furthermore, the billiard taps of the present invention have a good shot feeling. [Brief description of the drawings]

[0010] [Figure 1] 1 is an explanatory diagram showing a billiard tap according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The rubber composition for billiard taps of the present invention contains (a) a base rubber, (b) a co-crosslinking agent, (c) a crosslinking agent, and (d) a terpene resin, and is characterized in that the content of the (d) terpene resin is 1 part by mass to 23 parts by mass per 100 parts by mass of the (a) base rubber.

[0012] [(a) Base rubber] (a) Examples of the base rubber include butyl rubber, isoprene rubber, polybutadiene rubber, styrene butadiene rubber, natural rubber, nitrile rubber such as chloroprene rubber and acrylonitrile butadiene rubber, hydrogenated nitrile rubber, norbornene rubber, ethylene propylene rubber, ethylene-propylene-diene rubber, acrylic rubber, ethylene-acrylate rubber, fluororubber, chlorosulfonated polyethylene rubber, epichlorohydrin rubber, silicone rubber, urethane rubber, polysulfide rubber, phosphanzene rubber, and 1,2-polybutadiene. These may be used alone or in combination of two or more.

[0013] Among these, (a) the base rubber is preferably polybutadiene and / or styrene-butadiene rubber.

[0014] The polybutadiene rubber is more preferably a high-cis polybutadiene rubber, which has cis-1,4-bonds, which are advantageous in terms of resilience, in an amount of 40% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more.

[0015] From the viewpoint of improving resilience, the content of high-cis polybutadiene in 100% by mass of (a) base rubber is preferably 60% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more. It is also preferable that (a) base rubber consists solely of high-cis polybutadiene.

[0016] The high-cis polybutadiene preferably has a 1,2-vinyl bond content of 2.0% by mass or less, more preferably 1.7% by mass or less, and further preferably 1.5% by mass or less. If the 1,2-vinyl bond content is too high, the resilience may decrease.

[0017] The high-cis polybutadiene is preferably one synthesized using a rare earth element catalyst. In particular, the use of a neodymium-based catalyst using a neodymium compound, which is a lanthanum series rare earth element compound, is preferred because it can produce a polybutadiene rubber having a high content of 1,4-cis bonds and a low content of 1,2-vinyl bonds with excellent polymerization activity.

[0018] The high cis polybutadiene has a Mooney viscosity (ML 1+4 (100°C)) is preferably 30 or more, more preferably 32 or more, even more preferably 35 or more, and is preferably 140 or less, more preferably 120 or less, even more preferably 100 or less, and most preferably 55 or less. The Mooney viscosity (ML 1+4 (100°C) is a value measured in accordance with JIS K6300 using an L rotor with a preheating time of 1 minute, rotor rotation time of 4 minutes, and at 100°C.

[0019] The high cis polybutadiene preferably has a molecular weight distribution Mw / Mn (Mw: weight average molecular weight, Mn: number average molecular weight) of 2.0 or more, more preferably 2.2 or more, even more preferably 2.4 or more, most preferably 2.6 or more, and preferably 6.0 or less, more preferably 5.0 or less, even more preferably 4.0 or less, and most preferably 3.0 or less. If the molecular weight distribution (Mw / Mn) of the high cis polybutadiene is too small, the workability may decrease, and if it is too large, the resilience may decrease. The molecular weight distribution is measured by gel permeation chromatography (manufactured by Tosoh Corporation, "HLC-8120GPC") using a differential refractometer as a detector under the conditions of column: GMHHXL (manufactured by Tosoh Corporation), column temperature: 40°C, and mobile phase: tetrahydrofuran, and calculated as a standard polystyrene equivalent value.

[0020] Styrene butadiene rubber (SBR) is a copolymer of styrene and 1,3-butadiene, and any of various crosslinkable SBRs can be used. The SBR may be used alone or in combination of two or more. Examples of the SBR include those obtained by emulsion polymerization and those obtained by solution polymerization, and those obtained by emulsion polymerization are preferred.

[0021] The SBR may be of the oil-extended type, in which flexibility is adjusted by adding an extender oil, or of the non-oil-extended type, in which no extender oil is added, but the non-oil-extended SBR is preferred. The SBR is in a solid state at 23°C.

[0022] As the SBR, any of high styrene type, medium styrene type, and low styrene type SBRs classified according to the styrene content can be used. The styrene content of the SBR is preferably 15% by mass or more, more preferably 20% by mass or more, and is preferably 45% by mass or less, more preferably 35% by mass or less.

[0023] The Mooney viscosity (ML 1+4 (100°C)) is preferably 35 or more, more preferably 45 or more, and is preferably 60 or less, more preferably 58 or less. 1+4 (100°C) is the value measured in accordance with JIS K6300-1 (2013) using an L rotor with a preheating time of 1 minute, rotor rotation time of 4 minutes, and at 100°C.

[0024] [(b) Co-crosslinking agent] The (b) co-crosslinking agent has the effect of crosslinking rubber molecules by graft polymerization with the base rubber molecular chains. The (b) co-crosslinking agent preferably contains an α,β-unsaturated carboxylic acid having 3 to 8 carbon atoms and / or a metal salt thereof.

[0025] Examples of the α,β-unsaturated carboxylic acid having 3 to 8 carbon atoms include acrylic acid, methacrylic acid, fumaric acid, maleic acid, and crotonic acid.

[0026] Examples of the metal constituting the metal salt of the α,β-unsaturated carboxylic acid having 3 to 8 carbon atoms include monovalent metal ions such as sodium, potassium, and lithium; divalent metal ions such as magnesium, calcium, zinc, barium, and cadmium; trivalent metal ions such as aluminum; and other ions such as tin and zirconium. The metal components can be used alone or in a mixture of two or more kinds. Among these, divalent metals such as magnesium, calcium, zinc, barium, and cadmium are preferable as the metal components. This is because the use of a divalent metal salt of the α,β-unsaturated carboxylic acid having 3 to 8 carbon atoms makes it easier for metal crosslinks to form between rubber molecules. The α,β-unsaturated carboxylic acid having 3 to 8 carbon atoms and / or its metal salt may be used alone or in a combination of two or more kinds.

[0027] In the present invention, as the (b) co-crosslinking agent, it is preferable to use acrylic acid or a metal salt thereof, or methacrylic acid or a metal salt thereof, it is more preferable to use a metal salt of methacrylic acid, and it is even more preferable to use zinc methacrylate.

[0028] The content of the (b) co-crosslinking agent, relative to 100 parts by mass of the (a) base rubber, is preferably 70 parts by mass or more, more preferably 75 parts by mass or more, and even more preferably 80 parts by mass or more, and is preferably 120 parts by mass or less, more preferably 110 parts by mass or less, and even more preferably 100 parts by mass or less.

[0029] The (c) crosslinking agent is blended to crosslink the (a) base rubber component. The (c) crosslinking agent is not particularly limited, and examples thereof include sulfur, organic peroxides, and triazine derivatives, which may be used alone or in combination of two or more.

[0030] Examples of sulfur used as a crosslinking agent include powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, highly dispersible sulfur, soluble sulfur, etc. Commercially available products include those from Tsurumi Chemical Industry Co., Ltd., Karuizawa Sulfur Co., Ltd., Shikoku Chemical Industry Co., Ltd., Flexis, Nippon Kanzuri Kogyo Co., Ltd., Hosoi Chemical Industry Co., Ltd., etc. These may be used alone or in combination of two or more kinds.

[0031] Specific examples of the organic peroxide include dialkyl peroxide, peroxy ester, peroxy ketal, and hydroperoxide. Examples of the dialkyl peroxide include di(2-t-butylperoxyisopropyl)benzene, dicumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, t-butylcumyl peroxy, di-t-hexyl peroxy, di-t-butyl peroxy, and 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3. Examples of the peroxy ester include t-butyl peroxy maleate, t-butyl peroxy-3,3,5-trimethylcyclohexanoate, t-butyl peroxy laurate, t-butyl peroxy isopropyl monocarbonate, t-hexyl peroxy benzoate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, t-butyl peroxy acetate, and t-butyl peroxy benzoate. Examples of peroxyketals include 1,1-di(t-hexylperoxy)-3,3,5-trimethylcyclohexane, 1,1-di(t-hexylperoxy)cyclohexane, 1,1-di(t-butylperoxy)-2-methylcyclohexane, 1,1-di(t-butylperoxy)cyclohexane, 2,2-di(t-butylperoxy)butane, n-butyl-4,4-di(t-butylperoxy)valerate, and 2,2-di(4,4-di(t-butylperoxy)cyclohexyl)propane. Examples of hydroperoxides include p-menthane hydroperoxide and diisopropylbenzene hydroperoxide. These organic peroxides may be used alone or in combination of two or more.

[0032] As the (c) crosslinking agent used in the rubber composition of the present invention, an organic peroxide is suitable. Specific examples of the organic peroxide include dicumyl peroxide, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, and di-t-butyl peroxide. Among these, dicumyl peroxide is preferably used.

[0033] The content of the (c) crosslinking agent is preferably 0.5 parts by mass or more, more preferably 1.0 parts by mass or more, and even more preferably 1.5 parts by mass or more, and is preferably 5.5 parts by mass or less, more preferably 5.0 parts by mass or less, and even more preferably 4.5 parts by mass or less, based on 100 parts by mass of the base rubber. If the content of the (c) crosslinking agent is within the above range, the physical properties of the produced tip are just right and the hitting feel is good.

[0034] [(d) Terpene resin] The terpene resin used in the present invention is not particularly limited as long as it is a polymer containing a terpene compound as a constituent component. The terpene resin is preferably at least one selected from the group consisting of a terpene polymer, a terpene-phenol copolymer, a terpene-styrene copolymer, a terpene-phenol-styrene copolymer, a hydrogenated terpene-phenol copolymer, a hydrogenated terpene-styrene copolymer, and a hydrogenated terpene-phenol-styrene copolymer.

[0035] The terpene polymer is a homopolymer obtained by polymerizing a terpene compound. The terpene compound is (C5H8) n The hydrocarbons and their oxygen-containing derivatives represented by the composition 10 H 16 ), sesquiterpenes (C 15 H 24 ), diterpenes (C 20 H 32) are compounds having a basic skeleton of terpene classified as one of the following compounds. Examples of the terpene compounds include α-pinene, β-pinene, dipentene, limonene, myrcene, alloocimene, ocimene, α-phellandrene, α-terpinene, γ-terpinene, terpinolene, 1,8-cineole, 1,4-cineole, α-terpineol, β-terpineol, γ-terpineol, and the like. The terpene compounds can be used alone or in combination of two or more kinds.

[0036] The terpene polymer can be obtained by, for example, polymerizing the terpene compound. Examples of the terpene polymer include an α-pinene polymer, a β-pinene polymer, a limonene polymer, a dipentene polymer, and a β-pinene / limonene polymer.

[0037] Terpene-phenol copolymers (sometimes referred to as "terpene phenol resins") are, for example, copolymers of the above-mentioned terpene compounds and phenolic compounds. Examples of the above-mentioned phenolic compounds include phenol, cresol, xylenol, catechol, resorcinol, hydroquinone, and bisphenol A. As the terpene-phenol copolymers, copolymers of terpene compounds and phenols are preferred.

[0038] The acid value of the terpene-phenol copolymer is preferably 10 mgKOH / g or more, more preferably 35 mgKOH / g or more, and even more preferably 60 mgKOH / g or more. The acid value of the terpene-phenol copolymer is preferably 300 mgKOH / g or less, more preferably 250 mgKOH / g or less, even more preferably 200 mgKOH / g or less, particularly preferably 150 mgKOH / g or less, and most preferably 90 mgKOH / g or less. In the present invention, the acid value of the terpene-phenol copolymer is the amount of potassium hydroxide required to neutralize the acid contained in 1 g of the terpene-phenol copolymer, expressed in milligrams, and is a value measured by potentiometric titration (JIS K 0070:1992).

[0039] The hydroxyl value of the terpene-phenol copolymer is preferably 30 mgKOH / g or more, more preferably 50 mgKOH / g or more. The hydroxyl value of the terpene-phenol copolymer is preferably 150 mgKOH / g or less, more preferably 100 mgKOH / g or less. In this specification, the hydroxyl value is the amount of potassium hydroxide required to neutralize the acetic acid bonded to the hydroxyl group when acetylating 1 g of resin, expressed in milligrams, and is a value measured by potentiometric titration (JIS K 0070:1992).

[0040] The terpene-styrene copolymer is, for example, a copolymer of the terpene compound and a styrene-based compound. Examples of the styrene-based compound include styrene and α-methylstyrene. The terpene-styrene copolymer is preferably a copolymer of the terpene compound and α-methylstyrene.

[0041] The terpene-phenol-styrene copolymer is, for example, a copolymer of the terpene compound, the phenolic compound, and the styrene compound. The terpene-phenol-styrene copolymer is preferably a copolymer of the terpene compound, phenol, and α-methylstyrene.

[0042] A hydrogenated terpene-phenol copolymer is obtained by hydrogenating the terpene-phenol copolymer. A hydrogenated terpene-styrene copolymer is obtained by hydrogenating the terpene-styrene copolymer. A hydrogenated terpene-phenol-styrene copolymer is obtained by hydrogenating the terpene-phenol-styrene copolymer.

[0043] (d) The terpene resin is preferably at least one selected from the compounds having structures represented by the following formulas (1) to (4).

[0044] [ka] [ka] [ka] [ka]

[0045] [In formulas (1) to (4), R 1 and R 2 each independently represents a divalent residue of a phenolic compound and / or a styrene compound; m 1 ~m 4 Each independently represents a natural number from 1 to 30, 1 ~n 2 each independently represents a natural number from 1 to 20.

[0046] The compounds having the structures represented by the formulas (1) to (4) all have a structure derived from pinene in the molecule.

[0047] A compound having a structure represented by formula (1) has a structural portion derived from α-pinene and R bonded to the structural portion derived from α-pinene. 1 R 1 is preferably a divalent residue in which two hydrogen atoms have been removed from a benzene ring of a phenolic compound and / or a styrene compound. Examples of compounds having a structure represented by formula (1) include copolymers of α-pinene and a phenolic compound and / or a styrene compound.

[0048] Examples of the phenol-based compounds include phenol, cresol, xylenol, catechol, resorcin, hydroquinone, and bisphenol A. Examples of the styrene-based compounds include styrene and α-methylstyrene.

[0049] In formula (1), m1 represents the degree of polymerization of the structural unit derived from α-pinene, and is preferably a natural number of 1 to 30. 1 is preferably 1 or more, more preferably 2 or more, and even more preferably 3 or more; and is preferably 30 or less, more preferably 25 or less, and even more preferably 20 or less.

[0050] In formula (1), n 1 is a structural part derived from α-pinene and R bound to this structural part derived from α-pinene. 1 It is preferable that n is a natural number of 1 to 20. 1 is preferably 1 or more, more preferably 2 or more, and even more preferably 3 or more; and is preferably 20 or less, more preferably 18 or less, and even more preferably 15 or less.

[0051] A compound having a structure represented by formula (2) has a structural part derived from β-pinene in the molecule and R 2 The compound having the structure represented by formula (2) is, for example, a copolymer of β-pinene with a phenolic compound and / or a styrene compound. 2 is a divalent residue formed by removing two hydrogen atoms from the benzene ring of a phenolic compound and / or a styrene compound.

[0052] Examples of the phenol-based compounds include phenol, cresol, xylenol, catechol, resorcin, hydroquinone, and bisphenol A. Examples of the styrene-based compounds include styrene and α-methylstyrene.

[0053] In formula (2), m 2 represents the degree of polymerization of the structural unit derived from β-pinene, and is preferably a natural number of 1 to 30. 2 is preferably 1 or more, more preferably 2 or more, and even more preferably 3 or more; and is preferably 30 or less, more preferably 25 or less, and even more preferably 20 or less.

[0054] In formula (2), n 2 is a structural part derived from β-pinene and R bound to this structural part. 2 It is preferable that n is a natural number of 1 to 20. 2 is preferably 1 or more, more preferably 2 or more, and even more preferably 3 or more; and is preferably 20 or less, more preferably 18 or less, and even more preferably 15 or less.

[0055] The compound having a structure represented by formula (3) is a polymer having structural units derived from α-pinene, and more preferably a polymer having only structural units derived from α-pinene.

[0056] In formula (3), m 3 represents the degree of polymerization of the structural unit derived from α-pinene, and is preferably a natural number of 1 to 30. 3 is preferably 1 or more, more preferably 2 or more, and even more preferably 3 or more; and is preferably 30 or less, more preferably 25 or less, and even more preferably 20 or less.

[0057] The compound having the structure represented by formula (4) is a β-pinene polymer having structural units derived from β-pinene in the molecule, and is more preferably a polymer having only structural units derived from β-pinene.

[0058] In formula (4), m 4 represents the degree of polymerization of the structural unit derived from β-pinene, and is preferably a natural number of 1 to 30. 4 is preferably 1 or more, more preferably 2 or more, and even more preferably 3 or more; and is preferably 30 or less, more preferably 25 or less, and even more preferably 20 or less.

[0059] The terpene resin (d) preferably contains at least one selected from the group consisting of α-pinene-phenol copolymer, α-pinene-α-methylstyrene copolymer, α-pinene-α-methylstyrene-phenol copolymer, β-pinene-phenol copolymer, β-pinene-α-methylstyrene copolymer, and β-pinene-α-methylstyrene-phenol copolymer. As the terpene resin (d), these copolymers may be used alone or in combination of two or more.

[0060] The softening point of the (d) terpene resin is preferably 60° C. or higher, more preferably 80° C. or higher, and even more preferably 100° C. or higher, and is preferably 150° C. or lower, more preferably 130° C. or lower, and even more preferably 120° C. or lower. By using the (d) terpene resin having a softening point within the above range, the resin dispersibility during rubber kneading is improved. The softening point of the (d) terpene resin is the temperature at which the ball drops when the softening point as defined in JIS K 6220-1:2001 is measured using a ring and ball softening point measuring device.

[0061] As the (d) terpene resin, commercially available products can be used, for example, Sylvares TP2019, Sylvares TP7042, Sylvares TR7115, Sylvares TR7125, and Sylvatraxx6720 manufactured by KRATON Corporation; YS Resin PX1150 and YS Resin PX1250 manufactured by Yasuhara Chemical Co., Ltd.

[0062] The content of the (d) terpene resin is preferably 1 part by mass or more, more preferably 5 parts by mass or more, even more preferably 10 parts by mass or more, and is preferably 23 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less, per 100 parts by mass of the (a) base rubber. If the content of the (d) component is within the above range, the balance between the resilience modulus and Shore D hardness is good, and the hitting feel is improved. This is because:

[0063] [(e) Filler] The rubber composition of the present invention preferably contains a filler. Examples of the filler include inorganic fillers such as silica, carbon black, zinc oxide, titanium oxide, barium sulfate, calcium carbonate, magnesium oxide, tungsten powder, molybdenum powder, aluminum hydroxide, alumina (aluminum oxide), clay, talc, and mica. Titanium oxide is particularly preferred as the filler.

[0064] The silica is not particularly limited, and for example, silica prepared by a dry method (anhydrous silica) or silica prepared by a wet method (hydrated silica) can be used. Among them, hydrated silica prepared by a wet method is preferable because it has a large number of silanol groups. As the silica, for example, those manufactured and sold by Evonik Degussa, Solvay, Tosoh Silica Co., Ltd., Tokuyama Corporation, etc. can be used. These silicas may be used alone or in combination of two or more.

[0065] The silica is preferably used in combination with a silane coupling agent. Examples of the silane coupling agent include sulfide-based silane coupling agents such as bis(3-triethoxysilylpropyl) disulfide and bis(3-triethoxysilylpropyl) tetrasulfide; mercapto-based silane coupling agents such as 3-mercaptopropyltrimethoxysilane, NXT-Z100, NXT-Z45, and NXT manufactured by Momentive; vinyl-based silane coupling agents such as vinyltriethoxysilane and vinyltrimethoxysilane; 3-aminopropyltriethoxysilane and 3-aminopropyltriethoxysilane; Examples of the silane coupling agents include amino-based silane coupling agents such as methoxysilane and 3-(2-aminoethyl)aminopropyltriethoxysilane; glycidoxy-based silane coupling agents such as γ-glycidoxypropyltriethoxysilane and γ-glycidoxypropyltrimethoxysilane; nitro-based silane coupling agents such as 3-nitropropyltrimethoxysilane and 3-nitropropyltriethoxysilane; chloro-based silane coupling agents such as 3-chloropropyltrimethoxysilane and 3-chloropropyltriethoxysilane; etc. These silane coupling agents may be used alone or in combination of two or more.

[0066] When containing silane coupling agent, the content of silane coupling agent is preferably 1 part by mass or more, more preferably 3 parts by mass or more, even more preferably 5 parts by mass or more, and particularly preferably 8 parts by mass or more, based on 100 parts by mass of silica. Also, the content of the silane coupling agent is preferably 25 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less, based on 100 parts by mass of silica.

[0067] Examples of the clay include calcined clay and kaolin clay. Specific examples of the clay include SILLITIN (registered trademark) Z manufactured by HOFFMANN MINERAL, SATINTONE (registered trademark) W manufactured by ENGELHARD, NN kaolin clay manufactured by Tsuchiya Kaolin Kogyo Co., Ltd., and PoleStar 200R manufactured by Imerys Specialties Japan.

[0068] Specific examples of the talc include Hitron A manufactured by Takehara Chemical Industry Co., Ltd., MICRO ACE (registered trademark) K-1 manufactured by Nippon Talc Co., Ltd., and Mistron (registered trademark) Vapor manufactured by Imerys Specialties Japan.

[0069] Carbon black may be any of those commonly used in the rubber industry, such as N134, N110, N220, N234, N219, N339, N330, N326, N351, N550, and N762. Commercially available products include those from Asahi Carbon Co., Ltd., Cabot Japan Co., Ltd., Tokai Carbon Co., Ltd., Mitsubishi Chemical Corporation, Lion Corporation, Shin-Nichika Carbon Co., Ltd., Columbia Carbon Co., Ltd., and the like. These may be used alone or in combination of two or more.

[0070] The amount of the filler is preferably 30 parts by mass or more, more preferably 40 parts by mass or more, and even more preferably 50 parts by mass or more, and is preferably 100 parts by mass or less, more preferably 90 parts by mass or less, and even more preferably 80 parts by mass or less, per 100 parts by mass of the (a) base rubber. If the amount of the filler is 30 parts by mass or more, the hitting feel is soft, and if it is 100 parts by mass or less, the hitting feel is hard.

[0071] The rubber composition may contain a vulcanization accelerator. Examples of the vulcanization accelerator include thiazole-based vulcanization accelerators such as 2-mercaptobenzothiazole and di-2-benzothiazolyl disulfide; dithiocarbamate-based accelerators such as zinc dimethyldithiocarbamate; thiuram-based vulcanization accelerators such as tetramethylthiuram disulfide (TMTD), tetrabenzylthiuram disulfide (TBzTD), and tetrakis(2-ethylhexyl)thiuram disulfide (TOT-N); sulfenamide-based vulcanization accelerators such as N-cyclohexyl-2-benzothiazylsulfenamide (CBS), N-tert-butyl-2-benzothiazolylsulfenamide (TBBS), N-oxyethylene-2-benzothiazolesulfenamide, and N,N'-diisopropyl-2-benzothiazolesulfenamide; and guanidine-based vulcanization accelerators such as diphenylguanidine, di-orthotolylguanidine, and orthotolylbiguanidine. As commercially available products, products from Sumitomo Chemical Co., Ltd., Ouchi Shinko Chemical Industry Co., Ltd., etc. can be used. These may be used alone or in combination of two or more kinds.

[0072] The rubber composition may contain additives such as pigments, oils, waxes, peptizers, softeners, and antioxidants, as required.

[0073] Examples of the oil include process oil, vegetable oil, and mixtures thereof. Examples of the process oil include paraffin-based process oil, aromatic process oil, naphthenic process oil, and the like. Examples of the vegetable oil include castor oil, cottonseed oil, linseed oil, rapeseed oil, soybean oil, palm oil, coconut oil, peanut oil, rosin, pine oil, pine tar, tall oil, corn oil, rice oil, safflower oil, sesame oil, olive oil, sunflower oil, palm kernel oil, camellia oil, jojoba oil, macadamia nut oil, and tung oil. These may be used alone or in combination of two or more.

[0074] The wax is not particularly limited, and examples thereof include petroleum waxes such as paraffin wax and microcrystalline wax, natural waxes such as vegetable wax and animal wax, synthetic waxes such as polymers of ethylene, propylene, etc. These may be used alone or in combination of two or more.

[0075] Examples of the antioxidant include naphthylamine-based antioxidants such as phenyl-α-naphthylamine; diphenylamine-based antioxidants such as octylated diphenylamine and 4,4'-bis(α,α'-dimethylbenzyl)diphenylamine; N-isopropyl-N'-phenyl-p-phenylenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, and N,N'-di-2-naphthyl-p-phenylenediamine. Examples of the antioxidants include p-phenylenediamine antioxidants such as p-phenylenediamine, quinoline antioxidants such as polymers of 2,2,4-trimethyl-1,2-dihydroquinoline, monophenol antioxidants such as 2,6-di-t-butyl-4-methylphenol and styrenated phenol, and bis-, tris-, and polyphenol antioxidants such as tetrakis-[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane. These antioxidants may be used alone or in combination of two or more.

[0076] The content of the peptizing agent is preferably 0.1 part by mass or more and 5 parts by mass or less per 100 parts by mass of the (a) base rubber.

[0077] The rubber composition is obtained by mixing and kneading (a) base rubber, (b) co-crosslinking agent, (c) crosslinking agent, (d) terpene resin, and other components as necessary. The kneading method is not particularly limited, and may be performed using a known kneading machine such as a kneading roll, a Banbury mixer, or a kneader.

[0078] The billiard tap of the present invention is preferably obtained by curing the kneaded rubber composition. The billiard tap of the present invention can be obtained, for example, by molding the kneaded rubber composition in a mold. The molding temperature is preferably 120°C or higher, more preferably 150°C or higher, even more preferably 160°C or higher, and preferably 170°C or lower. The molding pressure is preferably 2.9 MPa to 11.8 MPa. The molding time is preferably 10 minutes to 60 minutes.

[0079] The billiard tap of the present invention is preferably integrally molded into a predetermined shape from a rubber composition.

[0080] The billiard tap of the present invention is preferably formed into a cylindrical shape. The diameter of the cylindrical molded body is, for example, preferably 13 mm or more, more preferably 13.5 mm or more, even more preferably 14 mm or more, preferably 16 mm or less, more preferably 15 mm or less, and even more preferably 14.5 mm or less.

[0081] The height of the cylindrical molded body is preferably 4 mm or more, more preferably 5 mm or more, and even more preferably 6 mm or more, and is preferably 14 mm or less, more preferably 10 mm or less, and even more preferably 8 mm or less.

[0082] After the cylindrical billiard tap is attached to the billiard cue, the contact surface with the ball is preferably processed into a spherical shape. FIG. 1 is an explanatory diagram for explaining the billiard tap of the present invention, and is an enlarged view of the tip portion of the billiard cue. Billiard cue 1 has a shaft 2 and a butt (not shown). A resin reinforcing part called a tip point 3 is provided at the tip of the tip point 3. Billiard tap 4 of the present invention is attached to the tip of the tip point 3.

[0083] The Lupke resilience of the billiard tap of the present invention is preferably 50% or less, more preferably 48% or less, even more preferably 45% or less, preferably 30% or more, more preferably 35% or more, and even more preferably 40% or more. If the Lupke resilience of the billiard tap is within the above range, the force is transmitted to the ball better.

[0084] The Shore D hardness of the billiard tap of the present invention is preferably 60 or more, more preferably 62 or more, even more preferably 65 or more, and is preferably 80 or less, more preferably 78 or less, and even more preferably 75 or less. If the Shore D hardness of the billiard tap is within the above range, the hitting feeling when hitting is improved. EXAMPLES

[0085] The present invention will be described in detail below with reference to examples. However, the present invention is not limited to the following examples, and all modifications and embodiments that do not deviate from the spirit of the present invention are included within the scope of the present invention.

[0086] [Evaluation method] [Shore D hardness] Using a billiard tap (diameter 14.0 mm, height 7.0 mm) molded into a cylindrical shape, measurements were made using an automatic rubber hardness tester Model P1 manufactured by Kobunshi Keiki Co., Ltd., equipped with a spring-type Shore D hardness tester specified in ASTM-D2240.

[0087] [Lupke type rebound resilience] The impact resilience test was performed on a cylindrical billiard tap (diameter 14.0 mm, height 7.0 mm) in accordance with JIS K6255 (2013). The test specimen was stored at a temperature of 23±2°C and a relative humidity of 50±5%. The impact resilience of the prepared test specimen was measured using a Lübke type impact resilience test measuring device (manufactured by Ueshima Seisakusho Co., Ltd.). The position of the tip of the device was adjusted so that it hit the center of the upper surface of the billiard tap, and the flat part of the test specimen was supported by a mechanical fixing method. The measurement conditions were a temperature of 23°C, a relative humidity of 50%, an impact end diameter of 12.50±0.05 mm, an impact mass of 0.35±0.01 kg, and an impact speed of 1.4±0.01 m / s.

[0088] [Feel] The manufactured billiard taps were attached to billiard cues and hit tests were conducted by professional and amateur players, who were then asked to evaluate the feeling of the taps when hitting the billiards, based on the following criteria. The most common evaluation was the feel of the taps when hitting the ball. Evaluation criteria 〇: The feeling is good. △: Normal. ×: Feeling bad.

[0089] [Making billiard taps] The rubber composition shown in Table 1 was kneaded with a kneading roll, and then hot-pressed in a cylindrical mold at 170°C for 20 minutes under a pressure of 10 MPa to obtain a cylindrical billiard tap with a diameter of 14.0 mm and a height of 7.0 mm. The evaluation results of the resulting billiard tap are also shown in Table 1.

[0090] [Table 1]

[0091] The materials used in Table 1 are as follows: Styrene butadiene rubber: "Nipol (registered trademark) 1502" manufactured by Zeon Corporation (non-oil-extended emulsion-polymerized styrene butadiene rubber, bound styrene content: 23.5% by mass, Mooney viscosity ML 1+4(100℃) 52.0) Zinc methacrylate: San-Ester "SK-30" manufactured by Sanshin Chemical Industry Co., Ltd. Dicumyl peroxide: NOF Corporation, "Percumyl (registered trademark) D" Terpene resin 1: YS Polystar T130 manufactured by Yasuhara Chemical Co., Ltd., terpene phenol resin (softening point 130±5℃) Terpene resin 2: YS Resin TO125 manufactured by Yasuhara Chemical Co., Ltd. (aromatic modified terpene resin, softening point: 125±5°C) Titanium oxide: CR60 (Ishihara Sangyo Kaisha, Ltd.)

[0092] The results in Table 1 show that the billiard tap of the present invention formed from a rubber composition for billiard taps containing (a) base rubber, (b) co-crosslinking agent, (c) crosslinking agent, and (d) terpene resin, in which the content of (d) terpene resin is 1 part by mass to 23 parts by mass per 100 parts by mass of (a) base rubber, has an excellent shot feel. [Industrial Applicability]

[0093] The present invention is suitable as a billiard tap.

[0094] A preferred embodiment (1) of the present invention is a rubber composition for billiard taps, comprising (a) a base rubber, (b) a co-crosslinking agent, (c) a crosslinking agent, and (d) a terpene resin, wherein the content of the (d) terpene resin is 1 part by mass to 23 parts by mass per 100 parts by mass of the (a) base rubber.

[0095] A preferred embodiment (2) of the present invention is the rubber composition for billiard taps of embodiment (1), wherein (d) the terpene resin is at least one selected from the group consisting of a terpene polymer, a terpene-phenol copolymer, a terpene-styrene copolymer, a terpene-phenol-styrene copolymer, a hydrogenated terpene-phenol copolymer, a hydrogenated terpene-styrene copolymer, and a hydrogenated terpene-phenol-styrene copolymer.

[0096] A preferred embodiment (3) of the present invention is the rubber composition for billiard taps of the embodiment (1), further comprising (e) a filler.

[0097] A preferred embodiment (4) of the present invention is the rubber composition for billiard taps according to the embodiment (3), wherein (e) the filler contains titanium oxide.

[0098] A preferred embodiment (5) of the present invention is the rubber composition for billiard taps according to embodiment (3), which contains 30 to 100 parts by mass of (e) a filler per 100 parts by mass of the (a) base rubber.

[0099] A preferred embodiment (6) of the present invention is the rubber composition for billiard taps according to embodiment (1), which contains 70 to 120 parts by mass of (b) a co-crosslinking agent per 100 parts by mass of (a) the base rubber.

[0100] A preferred embodiment (7) of the present invention is a billiard tap characterized by being formed from the rubber composition for billiard taps according to any one of the above embodiments (1) to (6).

Claims

1. A rubber composition for billiard taps, comprising: (a) a base rubber; (b) a co-crosslinking agent; (c) a crosslinking agent; and (d) a terpene resin, wherein the content of the terpene resin (d) is 1 part by mass to 23 parts by mass per 100 parts by mass of the base rubber (a).

2. (d) The rubber composition for billiard taps according to claim 1, wherein the terpene resin is at least one selected from the group consisting of terpene polymers, terpene-phenol copolymers, terpene-styrene copolymers, terpene-phenol-styrene copolymers, hydrogenated terpene-phenol copolymers, hydrogenated terpene-styrene copolymers, and hydrogenated terpene-phenol-styrene copolymers.

3. The rubber composition for billiard taps according to claim 1, further comprising (e) a filler.

4. 4. The rubber composition for billiard taps according to claim 3, wherein the filler (e) contains titanium oxide.

5. 4. The rubber composition for billiard taps according to claim 3, comprising 30 to 100 parts by mass of the filler (e) per 100 parts by mass of the base rubber (a).

6. 2. The rubber composition for billiard taps according to claim 1, comprising 70 to 120 parts by mass of (b) the co-crosslinking agent per 100 parts by mass of (a) the base rubber.

7. A billiard tap formed from the rubber composition for billiard taps according to any one of claims 1 to 6.

Images