JP4835195B2 - Rubber composition for golf ball and golf ball - Google Patents

Description

  The present invention relates to a rubber composition for a golf ball and a golf ball. More specifically, the present invention relates to a rubber composition that gives a golf ball excellent in manufacturing workability and good rebound resilience, and a golf ball obtained from the composition.

Golf balls are roughly classified into solid golf balls and thread wound golf balls. For solid golf balls, a one-piece solid golf ball made of a cross-linked product obtained by integrally molding a rubber composition, or a two-piece or more multi-piece solid in which a solid core having a layer structure made of a cross-linked product of a hard rubber composition is covered. There is a golf ball.
Among these solid golf balls, multi-piece solid golf balls are particularly popular in round golf balls in recent years because of their excellent flight distance. However, this multi-piece solid golf ball has a drawback that the shot feeling is harder than that of a wound golf ball. Therefore, attempts have been made to improve the feel at impact of the multi-piece solid golf ball by increasing the collapse at the time of hitting by making the core softer and softer toward the center. However, by making the core soft, the flight distance (rebound resilience) decreases. Therefore, the appearance of a multi-piece solid golf ball having excellent rebound resilience even with the same core hardness is desired.

  Conventionally, the core of a multi-piece solid golf ball and the core (solid center) of a one-piece golf ball have a 1,4-cis bond content of 80 mol% or more synthesized using a nickel-based catalyst or a cobalt-based catalyst. Since the rubber composition containing the polybutadiene which has has high resilience, it is used suitably. In addition, it is known that polybutadiene synthesized using a rare earth element-based catalyst can be used for similar applications.

  For example, in Patent Document 1, Patent Document 2, Patent Document 3, Patent Document 4, Patent Document 5, Patent Document 6, and Patent Document 7, a rubber composition using rare earth element-based polybutadiene is suitable for golf ball applications. It is disclosed. However, sufficient performance is not obtained with respect to the resilience performance of the obtained golf ball. Also, sufficient performance is not obtained in terms of manufacturing workability.

  Patent Document 8 discloses the use of polybutadiene modified with a compound having an alkoxysilyl group as a rubber composition for a golf ball. However, manufacturing workability is not sufficient, and there is still room for further improvement with respect to resilience performance.

Japanese Patent Publication No. 3-59931 Japanese Patent Publication No. 6-80123 Japanese Patent No. 2678240 JP-A-6-79018 JP 7-268132 A JP 11-319148 A JP 11-164912 A JP 2002-293996 A

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a rubber composition for a golf ball that is excellent in manufacturing workability and has a large rebound resilience when used for a golf ball. It is to provide a used golf ball.

According to the present invention, the step of performing a modification reaction using an alkoxysilane compound on the active terminal of polybutadiene having an active terminal having a vinyl content of less than 10% and a cis 1,4-bond content of 75% or more. And a step of performing a condensation reaction of the alkoxysilane compound (residue) in the presence of a condensation accelerator comprising a compound containing at least one element of titanium (Ti), zirconium (Zr), and bismuth (Bi). 5 to 80 parts by mass of an inorganic filler, and α, β-ethylenically unsaturated carboxylic acid, α, β-ethylenic, relative to 100 parts by mass of the rubber component containing 30 to 100% by mass of the obtained modified polybutadiene Provided is a rubber composition for a golf ball containing 10 to 50 parts by mass of a crosslinking agent selected from monovalent or divalent metal salts of unsaturated carboxylic acids.

  The modified polybutadiene in the present invention is preferably obtained by adding a step of adding an alkoxysilane compound.

Is Raniwa, compound constituting the condensation accelerator is an alkoxide, more preferably a carboxylic acid salt, or acetylacetonato complex salt.

The alkoxysilane compound is preferably an alkoxysilane compound containing at least one functional group selected from the following (a) to (c).
(A); epoxy group (b); isocyanate group (c); carboxyl group

In the production method of the present invention, an alkoxysilane compound containing at least one functional group selected from the following (d) to (f) is further added during the modification reaction in which the alkoxysilane compound is reacted. Is desirable.
(D); amino group (e); imino group (f); mercapto group

The polybutadiene having an active terminal used in the present invention is preferably one obtained by polymerizing 1,3-butadiene using a catalyst having the following components (g) to (i) as main components.
(G) component; a rare earth element-containing compound corresponding to atomic numbers 57 to 71 in the periodic table, or a reaction product of these compounds with a Lewis base (h) component; alumoxane and / or AlR ¹ R ² R ³ (wherein , R ¹ and R ² are the same or different and are a hydrocarbon group or hydrogen atom having 1 to 10 carbon atoms, R ³ is a hydrocarbon group having 1 to 10 carbon atoms, provided that R ³ is the above R ¹ or R ² An organoaluminum compound corresponding to (may be the same as or different from) (i) component; halogen-containing compound

  In the present invention, among the rubber components, rubber components other than the modified polybutadiene are natural rubber, synthetic isoprene rubber, butadiene rubber, styrene-butadiene rubber, ethylene-α-olefin copolymer rubber, ethylene-α-olefin-diene copolymer. A material comprising at least one selected from the group consisting of polymerized rubber, acrylonitrile-butadiene copolymer rubber, chloroprene rubber, and halogenated butyl rubber (however, modified polybutadiene + other rubber = 100% by mass) is preferably used.

The inorganic filler is preferably one or more of zinc oxide, barium sulfate, and silica.
Moreover, it is necessary to contain 10-50 mass parts of crosslinking agents with respect to 100 mass parts of said rubber components, and also 0.1-10 mass parts of organic peroxides with respect to 100 mass parts of said rubber components. It is preferable to contain.

  Furthermore, according to the present invention, there is provided a golf ball obtained by crosslinking and molding the rubber composition for a golf ball described above containing 5 to 100% by mass.

  According to the present invention, when used as a golf ball, there is an excellent effect that it is possible to provide a rubber composition for a golf ball having excellent manufacturing workability and high rebound resilience, and a golf ball using the same.

Hereinafter, although embodiment of this invention is described in detail, this invention is not limited to these embodiment.
In the rubber composition for a golf ball of the present invention, as a rubber component, an alkoxy group is bonded to the active terminal of polybutadiene having an active terminal having a vinyl content of less than 10% and a cis 1,4-bond content of 75% or more. 30 to 100% by mass of modified polybutadiene obtained by a step of performing a modification reaction using a silane compound and a step of performing a condensation reaction of an alkoxysilane compound (residue) in the presence of a condensation accelerator is contained.

  The condensation accelerator is usually added before the condensation reaction after the alkoxysilane compound is added to the active terminal of the polybutadiene and subjected to a modification reaction, but before the addition of the alkoxysilane compound (before the modification reaction), A condensation reaction may be performed after the modification reaction by adding an alkoxysilane compound.

  The polybutadiene having an active terminal and having a vinyl content of less than 10% and a cis 1,4-bond content of 75% or more can be carried out using a solvent or without a solvent. The polymerization solvent is an inert organic solvent, for example, a saturated aliphatic hydrocarbon having 4 to 10 carbon atoms such as butane, pentane, hexane or heptane, or a saturated alicyclic having 6 to 20 carbon atoms such as cyclopentane or cyclohexane. Hydrocarbons, monoolefins such as 1-butene, 2-butene, aromatic hydrocarbons such as benzene, toluene, xylene, methylene chloride, chloroform, carbon tetrachloride, trichloroethylene, perchloroethylene, 1,2-dichloroethane, Halogenated hydrocarbons such as chlorobenzene, bromobenzene, chlorotoluene and the like can be mentioned.

The polybutadiene having an active end in the present invention is usually obtained at a polymerization temperature of -30 ° C to + 200 ° C, preferably 0 to + 150 ° C. Moreover, there is no restriction | limiting in particular about the form of a polymerization reaction, You may carry out using a batch type reactor, and you may carry out by a continuous type using apparatuses, such as a multistage continuous type reactor.
In addition, when using a polymerization solvent, the monomer concentration in this solvent is 5-50 mass% normally, Preferably it is 7-35 mass%.
In addition, in order to produce a polymer and not to deactivate a polymer having an active terminal, consideration is given to minimize the incorporation of a deactivating compound such as oxygen, water or carbon dioxide into the polymerization system. is required.

  Examples of the conjugated diene compound as the polymerization monomer in the present invention include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, myrcene and the like. 1,3-butadiene, isoprene, and 2,3-dimethyl-1,3-butadiene are preferred. These conjugated diene compounds can be used singly or in combination of two or more. When two or more of these are used in combination, a copolymer is obtained.

The above-mentioned polybutadiene having an active end is not particularly limited and can be polymerized using a known one, but the polymerization catalyst is selected from the following components (g), (h), and (i). A combination of at least one compound is preferred. That is,
(G) component;
The component (g) is a rare earth element-containing compound corresponding to atomic numbers 57 to 71 in the periodic table or a compound obtained from a reaction of these compounds with a Lewis base.
Preferred elements are neodymium, praseodymium, cerium, lanthanum, gadolinium, etc., or mixtures thereof, more preferably neodymium.
The rare earth element-containing compound of the present invention is a carboxylate, alkoxide, β-diketone complex, phosphate or phosphite.

The carboxylate of the rare earth element is represented by the general formula (R ⁴ —CO ₂ ) ₃ M (wherein M is a rare earth element corresponding to atomic numbers 57 to 71 in the periodic table), and R ⁴ is the number of carbon atoms. 1 to 20 hydrocarbon group, preferably a saturated or unsaturated alkyl group, linear, branched or cyclic, and a carboxyl group bonded to a primary, secondary or tertiary carbon atom is doing. Specifically, octanoic acid, 2-ethylhexanoic acid, oleic acid, stearic acid, benzoic acid, naphthenic acid, versatic acid [trade name of Shell Chemical Co., Ltd., the carboxyl group bonded to the tertiary carbon atom And salts of 2-ethylhexanoic acid, naphthenic acid, and versatic acid are preferable.

The alkoxide of the rare earth element is a general formula (R ⁵ O) ₃ M (M is a rare earth element corresponding to atomic numbers 57 to 71 in the periodic table), and R ⁵ is a hydrocarbon group having 1 to 20 carbon atoms. And is preferably a saturated or unsaturated alkyl group and is a long chain, branched or cyclic group, and the carboxyl group is bonded to a primary, secondary or tertiary carbon atom. Examples of the alkoxy group represented by R ⁵ O include alkoxy groups such as 2-ethylhexyl, oleyl, stearyl, phenyl and benzyl. Of these, preferred are 2-ethylhexyl and benzyl alkoxy groups.

  Examples of the rare earth element β-diketone complex include rare earth elements such as acetylacetone, benzoylacetone, propionylacetone, valerylacetone, and ethylacetylacetone complex. Among these, an acetylacetone complex and an ethylacetylacetone complex are preferable.

As rare earth element phosphates or phosphites, rare earth elements bis (2-ethylhexyl) phosphate, bis (1-methylheptyl) phosphate, bis (p-nonylphenyl) phosphate, bisphosphate (Polyethylene glycol-p-nonylphenyl), phosphoric acid (1-methylheptyl) (2-ethylhexyl), phosphoric acid (2-ethylhexyl) (p-nonylphenyl), 2-ethylhexylphosphonic acid mono-2-ethylhexyl, 2 -Ethylhexylphosphonic acid mono-p-nonylphenyl, bis (2-ethylhexyl) phosphinic acid, bis (1-methylheptyl) phosphinic acid, bis (p-nonylphenyl) phosphinic acid, (1-methylheptyl) (2-ethylhexyl) ) Phosphinic acid, (2-ethylhexyl) (p-nonylphenyl) phosphinic acid Examples of these salts include, and preferred examples include bis (2-ethylhexyl) phosphate, bis (1-methylheptyl) phosphate, mono-2-ethylhexyl 2-ethylhexylphosphonate, and bis (2-ethylhexyl) phosphinic acid. Salt.
Among the examples, neodymium phosphate or neodymium carboxylate is particularly preferable, and carboxylates such as neodymium 2-ethylhexanoate and neodymium versatate are most preferable.

The Lewis base used to easily solubilize the rare earth element-containing compound in the solvent is 0 to 30 mol, preferably 1 to 10 mol, as a mixture of both, per 1 mol of the rare earth metal compound. Or a product obtained by reacting both in advance.
Here, examples of the Lewis base include acetylacetone, tetrahydrofuran, pyridine, N, N-dimethylformamide, thiophene, diphenyl ether, triethylamine, an organic phosphorus compound, and a monovalent or divalent alcohol.
The above (g) component can be used individually by 1 type, or can also be used in combination of 2 or more type.

(H) component;
As the component (h), alumoxane and / or AlR ¹ R ² R ³ (wherein R ¹ and R ² are the same or different, a hydrocarbon group or hydrogen atom having 1 to 10 carbon atoms, and R ³ has 1 carbon atom) 10 to 10 hydrocarbon groups, wherein R ³ may be the same as or different from R ¹ or R ² above, and a plurality of them can be used simultaneously.

  The alumoxane used in the catalyst of the present invention is a compound having a structure represented by the following formula (I) or formula (II). In addition, Fine Chemicals, 23, (9), 5 (1994), J. Am. Am. Chem. Soc. 115, 4971 (1993); Am. Chem. Soc. 117, 6465 (1995).

(In the formula, each R ⁶ is the same or different and is a hydrocarbon group having 1 to 20 carbon atoms, and n is an integer of 2 or more.)
In the alumoxane represented by the formula (I) or formula (II), the hydrocarbon group represented by R ⁶ includes methyl, ethyl, propyl, butyl, isobutyl, t-butyl, hexyl, isohexyl, octyl, isooctyl group Among them, preferred are methyl, ethyl, isobutyl and t-butyl groups, and particularly preferred is a methyl group. N is 2 or more, preferably an integer of 4 to 100.

Specific examples of the alumoxane include methylalumoxane, ethylalumoxane, n-propylalumoxane, n-butylalumoxane, isobutylalumoxane, t-butylalumoxane, hexylalumoxane, isohexylalumoxane and the like.
Any known technique may be used for the production of alumoxane. For example, trialkylaluminum or dialkylaluminum monochloride is added to an organic solvent such as benzene, toluene, xylene, and water, water vapor, steam-containing nitrogen gas, Or it can manufacture by adding the salt which has crystal water, such as copper sulfate pentahydrate and aluminum sulfate 16 hydrate, and making it react.
Alumoxane can be used alone or in combination of two or more.

AlR ¹ R ² R ^3, which is the other component (h) used in the catalyst of the present invention, wherein R ¹ and R ² are the same or different and each represents a hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom, Examples of the organoaluminum compound corresponding to R ³ is a hydrocarbon group having 1 to 10 carbon atoms (wherein R ³ may be the same as or different from R ¹ or R ² ), for example, trimethylaluminum, triethyl Aluminum, tri-n-propylaluminum, triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-t-butylaluminum, tripentylaluminum, trihexylaluminum, tricyclohexylaluminum, trioctylaluminum, diethyl hydride Aluminum, hydrogenated di-n-propylaluminum Di-n-butylaluminum hydride, diisobutylaluminum hydride, dihexylaluminum hydride, diisohexylaluminum hydride, dioctylaluminum hydride, diisooctylaluminum hydride, ethylaluminum dihydride, n-propylaluminum Examples include hydride and isobutylaluminum dihydride, and triethylaluminum, triisobutylaluminum, diethylaluminum hydride, and diisobutylaluminum hydride are preferable.
The organoaluminum compound as component (h) of the present invention can be used alone or in combination of two or more.

(I) component;
The component (i) used in the catalyst of the present invention is a halogen-containing compound, preferably a reaction product of a metal halide and a Lewis base, diethylaluminum chloride, silicon tetrachloride, trimethylchlorosilane, methyldichlorosilane, dimethyl Examples include dichlorosilane, methyltrichlorosilane, ethylaluminum dichloride, ethylaluminum sesquichloride, tin tetrachloride, tin trichloride, phosphorus trichloride, benzoyl chloride, t-butyl chloride, and the like.

  Here, as the metal halide, beryllium chloride, beryllium bromide, beryllium iodide, magnesium chloride, magnesium bromide, magnesium iodide, calcium chloride, calcium bromide, calcium iodide, barium chloride, barium bromide, Barium iodide, zinc chloride, zinc bromide, zinc iodide, cadmium chloride, cadmium bromide, cadmium iodide, mercury chloride, mercury bromide, mercury iodide, manganese chloride, manganese bromide, manganese iodide, rhenium chloride , Rhenium bromide, rhenium iodide, copper chloride, copper iodide, silver chloride, silver bromide, silver iodide, gold chloride, gold iodide, gold bromide, etc., preferably magnesium chloride, calcium chloride , Barium chloride, manganese chloride, zinc chloride, copper chloride, particularly preferably magnesium chloride, manganic chloride , Zinc chloride, copper chloride.

  Moreover, as a Lewis base made to react in order to produce | generate a reaction material with said metal halide, a phosphorus compound, a carbonyl compound, a nitrogen compound, an ether compound, alcohol, etc. are preferable. Specifically, tributyl phosphate, tri-2-ethylhexyl phosphate, triphenyl phosphate, tricresyl phosphate, triethylphosphine, tributylphosphine, triphenylphosphine, diethylphosphinoethane, diphenylphosphinoethane, acetylacetone, benzoylacetone , Propionitrile acetone, valeryl acetone, ethyl acetylacetone, methyl acetoacetate, ethyl acetoacetate, phenyl acetoacetate, dimethyl malonate, diethyl malonate, diphenyl malonate, acetic acid, octanoic acid, 2-ethylhexanoic acid, oleic acid , Stearic acid, benzoic acid, naphthenic acid, versatic acid (trade names manufactured by Shell Chemical Co., which is a carboxylic acid having a carboxyl group bonded to a tertiary carbon atom), triethylamine, N, N— Examples include methylacetamide, tetrahydrofuran, diphenyl ether, 2-ethylhexyl alcohol, oleyl alcohol, stearyl alcohol, phenol, benzyl alcohol, 1-decanol, lauryl alcohol, preferably tri-2-ethylhexyl phosphate, tricresyl phosphate, acetylacetone 2-ethylhexanoic acid, versatic acid, 2-ethylhexyl alcohol, 1-decanol, lauryl alcohol.

  The above Lewis base is reacted at a ratio of 0.01 to 30 mol, preferably 0.5 to 10 mol, per 1 mol of the metal halide. When the reaction product with the Lewis base is used, the metal remaining in the polymer can be reduced.

The amount or composition ratio of each component of the catalyst used in the present invention is set to various values depending on the purpose or necessity.
Of these, the component (g) is preferably used in an amount of 0.00001 to 1.0 mmol with respect to 100 g of the conjugated diene compound. If it is less than 0.00001 mmol, the polymerization activity is low, which is not preferable. On the other hand, if it exceeds 1.0 mmol, the catalyst concentration becomes high and a decatching step is required, which is not preferable. It is particularly preferable to use an amount of 0.0001 to 0.5 mmol.

Moreover, generally the usage-amount of (h) component can be represented by the molar ratio of Al with respect to (g) component, (g) component to (h) component is 1: 1-1: 500, Preferably it is 1: 3. ˜1: 250, more preferably 1: 5 to 1: 200.
Furthermore, the ratio of (g) component and (i) component is 1: 0.1-1: 30 by mole ratio, Preferably it is 1: 0.2-1: 15.
Outside the range of these catalyst amounts or component ratios, it is not preferable because it does not act as a highly active catalyst or requires a decontacting step. In addition to the above components (g) to (i), a polymerization reaction may be carried out in the presence of hydrogen gas for the purpose of adjusting the molecular weight of the polymer.

  As a catalyst component, in addition to the above components (g) to (i), a conjugated diene compound and / or a non-conjugated diene compound is optionally added in an amount of 0 to 1, per mole of the component (g). You may use it in the ratio of 000 mol. As the conjugated diene compound used for the production of the catalyst, 1,3-butadiene, isoprene and the like can be used as in the case of the monomer for polymerization. Examples of the non-conjugated diene compound include divinylbenzene, diisopropenylbenzene, triisopropenylbenzene, 1,4-vinylhexadiene, and ethylidene norbornene. A conjugated diene compound as a catalyst component is not essential, but when used in combination, there is an advantage that the catalytic activity is further improved.

  The catalyst production in the present invention is, for example, by reacting the components (g) to (i) dissolved in a solvent and, if necessary, a conjugated diene compound and / or a non-conjugated diene compound. In that case, the addition order of each component may be arbitrary. These components are preferably mixed, reacted and aged in advance from the viewpoint of improving the polymerization activity and shortening the polymerization initiation induction period. Here, the aging temperature is 0 to 100 ° C, preferably 20 to 80 ° C. If the temperature is lower than 0 ° C, aging is not sufficiently performed. On the other hand, if the temperature exceeds 100 ° C, the catalytic activity is lowered and the molecular weight distribution is widened. The aging time is not particularly limited, and can be contacted in the line before being added to the polymerization reaction tank. Usually, 0.5 minutes or more is sufficient, and stable for several days.

The polybutadiene having active ends described above has a vinyl content of less than 10%, preferably less than 5%, more preferably less than 2%, and a cis 1,4-bond content of 75% or more, preferably 85% or more. Preferably it is 90 to 99.9%. Moreover, as for this polybutadiene, ratio (Mw / Mn) of the weight average molecular weight (Mw) and number average molecular weight (Mn) measured by the gel permeation chromatography has preferable 1.01-5, More preferably, 1 .01-4.
When the vinyl content of the polybutadiene is 10% or more, or the cis 1,4-bond content is less than 75%, the rebound resilience when the composition is a golf ball is inferior. Even if Mw / Mn exceeds 5, the rebound resilience when the composition is a golf ball is inferior.
Here, the vinyl content and / or cis 1,4-bond content can be easily controlled by controlling the polymerization temperature, and Mw / Mn can be easily controlled by controlling the molar ratio of the above components (g) to (i). Can be adjusted.

The Mooney viscosity (ML _{1 + 4,} 100 ° C.) at 100 ° C. of the polybutadiene having active ends described above is preferably in the range of 5 to 50, more preferably 10 to 40. If it is less than 5, it tends to be inferior in rebound resilience when the composition is made into a golf ball. On the other hand, if it exceeds 50, the production workability when the modified polybutadiene after the modification and condensation reaction is used is used as the composition. Inferior.
This Mooney viscosity can be easily adjusted by controlling the molar ratio of the components (g) to (i).

In the present invention, first, an alkoxysilane compound is reacted at the active terminal of polybutadiene having a vinyl content of less than 10% and a cis 1,4-bond content of 75% or more obtained as described above. A denaturing reaction is performed. The alkoxysilane compound (hereinafter also referred to as “modifier”) used in the modification reaction is not particularly limited, and examples thereof include (a): an epoxy group, (b): an isocyanate group, and (c). It is preferable to use an alkoxysilane compound containing at least one functional group selected from carboxyl groups. The alkoxysilane compound may be a partial condensate or a mixture of the alkoxysilane compound and the partial condensate.
Here, the partial condensate means a product in which a part (not all) of SiOR of the alkoxysilane compound is bonded to SiOSi by condensation.
In the above modification reaction, it is preferable that the polymer to be used has at least 10% of the polymer chain having a living property.

  Specific examples of the alkoxysilane compound used for the reaction with the active terminal of the polymer include 2-glycidoxyethyltrimethoxysilane, 2-glycidoxyethyltriethoxysilane, (2 -Glycidoxyethyl) methyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, (3-glycidoxypropyl) methyldimethoxysilane, 2- (3,4-epoxy Preferred examples include (cyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane, and 2- (3,4-epoxycyclohexyl) ethyl (methyl) dimethoxysilane. Among these, , Especially 3-glycidoxypropyl Trimethoxysilane and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane are preferable.

  Examples of the isocyanate group-containing alkoxysilane compound include 3-isocyanatepropyltrimethoxysilane, 3-isocyanatepropyltriethoxysilane, 3-isocyanatepropylmethyldiethoxysilane, 3-isocyanatepropyltriisopropoxysilane, and the like. Of these, 3-isocyanatopropyltrimethoxysilane is particularly preferable.

Further, as the carboxyl group-containing alkoxysilane compound, 3-methacryloyloxypropyltriethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane, 3-methacryloyloxypropyltriisosilane Examples thereof include propoxysilane, and among these, 3-methacryloyloxypropyltrimethoxysilane is particularly preferable.
These alkoxysilane compounds may be used individually by 1 type, and may be used in combination of 2 or more type. Moreover, the partial condensate of an alkoxysilane compound mentioned above can also be used.

In the modification reaction with the modifying agent, the amount of the alkoxysilane compound used is preferably 0.01 to 200, more preferably 0.1 to 150, in molar ratio to the component (g). If it is less than 0.01, the progress of the modification reaction is not sufficient, the dispersibility of the filler is not sufficiently improved, and the rebound resilience when the composition is a golf ball is poor. On the other hand, even if it is used in excess of 200, the modification reaction is saturated, which is not economical.
The method for adding the modifier is not particularly limited, and examples thereof include a batch addition method, a division addition method, and a continuous addition method. preferable.

The modification reaction in the present invention is preferably performed by a solution reaction (a solution containing an unreacted monomer used at the time of polymerization may be used).
There is no restriction | limiting in particular about the form of denaturation reaction, You may carry out using a batch type reactor, and you may carry out by a continuous type using apparatuses, such as a multistage continuous type reactor and an in-line mixer. In addition, it is important to carry out the modification reaction after completion of the polymerization reaction and before performing various operations necessary for solvent removal treatment, water treatment, heat treatment, polymer isolation, and the like.

As the temperature of the modification reaction, the polymerization temperature of polybutadiene can be used as it is. Specifically, a preferable range is 20 ° C to 100 ° C. More preferably, it is 40-90 degreeC. If the temperature is low, the viscosity of the polymer tends to increase, and if the temperature is high, the polymerization active terminal tends to be deactivated.
The modification reaction time is usually 5 minutes to 5 hours, preferably 15 minutes to 1 hour.
In the present invention, during this modification reaction, a known antiaging agent or reaction terminator can be added, if desired, in the step after introducing the alkoxysilane compound residue into the active terminal of the polymer.

  In the present invention, it is preferable to further add an alkoxysilane compound. Further, the alkoxysilane compound to be added is preferably an alkoxysilane compound having a functional group (hereinafter referred to as “functional group introducing agent”) from the viewpoint of rebound resilience when the composition is a golf ball. The addition time is a step after introducing the alkoxysilane compound residue into the active terminal of the polymer, and it is preferable to add it before the start of the condensation reaction. When added after the start of the condensation reaction, the functional group introduction agent may not be uniformly dispersed and the catalyst performance may be lowered. The timing of addition of the functional group introducing agent is preferably 5 minutes to 5 hours after the start of the modification reaction, particularly 15 minutes to 1 hour after the start of the modification reaction.

Here, since the functional group introducing agent generally does not substantially react directly with the active end and remains unreacted in the reaction system, the alkoxysilane compound introduced into the active end remains in the condensation reaction step. Consumed in the condensation reaction with the group.
As the functional group introducing agent to be newly added, there are alkoxysilane compounds containing at least one functional group selected from (d); amino group, (e); imino group, and (f); mercapto group. preferable. The alkoxysilane compound used as the functional group introducing agent may be a partial condensate or a mixture of the alkoxysilane compound and the partial condensate.

  Specific examples of newly added functional group introducing agents include 3-dimethylaminopropyl (triethoxy) silane, 3-dimethylaminopropyl (trimethoxy) silane, 3-diethylaminopropyl (triethoxy) as amino group-containing alkoxysilane compounds. Silane, 3-diethylaminopropyl (trimethoxy) silane, 2-dimethylaminoethyl (triethoxy) silane, 2-dimethylaminoethyl (trimethoxy) silane, 3-dimethylaminopropyl (diethoxy) methylsilane, 3-dibutylaminopropyl (triethoxy) silane 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, aminophenyltrimethoxysilane, aminophenyltriethoxysilane, 3- (N-methylamino) propylto Examples include methoxysilane, 3- (N-methylamino) propyltriethoxysilane, among which 3-diethylaminopropyl (triethoxy) silane, 3-dimethylaminopropyl (triethoxy) silane, 3-amino Propyltriethoxysilane is preferred.

  Further, as imino group-containing alkoxysilane compounds, 3- (1-hexamethyleneimino) propyl (triethoxy) silane, 3- (1-hexamethyleneimino) propyl (trimethoxy) silane, (1-hexamethyleneimino) methyl (trimethoxy) ) Silane, (1-hexamethyleneimino) methyl (triethoxy) silane, 2- (1-hexamethyleneimino) ethyl (triethoxy) silane, 2- (1-hexamethyleneimino) ethyl (trimethoxy) silane, 3- (1 -Pyrrolidinyl) propyl (triethoxy) silane, 3- (1-pyrrolidinyl) propyl (trimethoxy) silane, 3- (1-heptamethyleneimino) propyl (triethoxy) silane, 3- (1-dodecamethyleneimino) propyl (triethoxy) Silane, 3- (1- Xamethyleneimino) propyl (diethoxy) methylsilane, 3- (1-hexamethyleneimino) propyl (diethoxy) ethylsilane, and N- (1,3-dimethylbutylidene) -3- (triethoxysilyl) -1-propane Amine, N- (1-methylethylidene) -3- (triethoxysilyl) -1-propanamine, N-ethylidene-3- (triethoxysilyl) -1-propanamine, N- (1-methylpropylidene) -3- (triethoxysilyl) -1-propanamine, N- (4-N, N-dimethylaminobenzylidene) -3- (triethoxysilyl) -1-propanamine, N- (cyclohexylidene) -3 -(Triethoxysilyl) -1-propanamine and the trimethoates corresponding to these triethoxysilyl compounds Sisilyl compound, methyldiethoxysilyl compound, ethyldiethoxysilyl compound, methyldimethoxysilyl compound, or ethyldimethoxysilyl compound, 1- [3- (triethoxysilyl) propyl] -4,5-dihydroimidazole, 1- [3- (trimethoxysilyl) propyl] -4,5-dihydroimidazole, 3- [10- (triethoxysilyl) decyl] -4-oxazoline, 3- (1-hexamethyleneimino) propyl (triethoxy) silane, (1-hexamethyleneimino) methyl (trimethoxy) silane, N- (3-triethoxysilylpropyl) -4,5-dihydroimidazole, N- (3-isopropoxysilylpropyl) -4,5-dihydroimidazole, N -(3-Methyldiethoxysilylpropyl) -4,5- Dihydroimidazole and the like can be preferably exemplified, among which 3- (1-hexamethyleneimino) propyl (triethoxy) silane, N- (1-methylpropylidene) -3- (triethoxysilyl)- 1-propanamine, N- (1,3-dimethylbutylidene) -3- (triethoxysilyl) -1-propanamine, 3- (1-hexamethyleneimino) propyl (triethoxy) silane, (1-hexamethylene Imino) methyl (trimethoxy) silane, 1- [3- (triethoxysilyl) propyl] -4,5-dihydroimidazole, 1- [3- (trimethoxysilyl) propyl] -4,5-dihydroimidazole, N- (3-Triethoxysilylpropyl) -4,5-dihydroimidazole is preferred.

Further, as mercapto group-containing alkoxysilane compounds, 3-mercaptopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, 2-mercaptoethyltrimethoxysilane, 3-mercaptopropyl (diethoxy) methylsilane , 3-mercaptopropyl (monoethoxy) dimethylsilane, mercaptophenyltrimethoxysilane, mercaptophenyltriethoxysilane, and the like, among which 3-mercaptopropyltriethoxysilane is preferable.
These functional group introducing agents may be used alone or in combination of two or more.

  In the modification method of the present invention, when a functional group-containing alkoxysilane compound is used as the functional group introducing agent, a polymer having an active end, and a substantially stoichiometric amount of the alkoxysilane compound added to the reaction system, Reaction, an alkoxysilyl group is introduced into substantially all of the terminals (modification reaction), and addition of an alkoxysilane compound introduces more alkoxysilane compound residues than the equivalent of the active terminal. The

  The condensation reaction between alkoxysilyl groups occurs between free alkoxysilane (residual or newly added) and the alkoxysilyl group at the end of the polymer, and in some cases between the alkoxysilyl groups at the end of the polymer. Is preferred, and reaction between free alkoxysilanes is unnecessary. Therefore, when an alkoxysilane compound is newly added, it is preferable from the viewpoint of efficiency that the hydrolyzability of the alkoxysilyl group does not exceed the hydrolyzability of the alkoxysilyl group at the end of the polymer. For example, a highly hydrolyzable trimethoxysilyl group-containing compound is used for the alkoxysilane compound used for the reaction with the active terminal of the polymer, and an alkoxysilyl compound having a lower hydrolyzability than the newly added alkoxysilane compound. A combination using a compound containing a group (for example, a triethoxysilyl group) is preferable. On the contrary, for example, it is included in the scope of the present invention that the alkoxysilane compound used for the reaction with the active terminal of the polymer contains a triethoxysilyl group and the newly added alkoxysilane compound contains a trimethoxysilyl group. However, it is not preferable from the viewpoint of reaction efficiency.

  The usage-amount of the said functional group containing alkoxysilane compound used as a functional group introducing agent is 0.01-200 by molar ratio with respect to the said (g) component, More preferably, it is 0.1-150. If it is less than 0.01, the progress of the condensation reaction is not sufficient, the dispersibility of the filler is not sufficiently improved, and the rebound resilience when the composition is a golf ball is poor. On the other hand, even if it exceeds 200, the condensation reaction is saturated, which is not economically preferable.

In the present invention, a condensation accelerator is used to accelerate the condensation reaction of the alkoxysilane compound (and the functional group-containing alkoxysilane compound that may be used as a functional group introducing agent) used as the modifier.
The condensation accelerator used here can be added before the modification reaction, but it is preferable to add it after the modification reaction and before the start of the condensation reaction. When added before the modification reaction, a direct reaction with the active terminal may occur, and an alkoxysilyl group may not be introduced into the active terminal. Moreover, when it adds after a condensation reaction start, a condensation promoter may not disperse | distribute uniformly but a catalyst performance may fall. The addition time of the condensation accelerator is usually 5 minutes to 5 hours after the start of the modification reaction, preferably 15 minutes to 1 hour after the start of the modification reaction.

Condensation accelerator used in the present invention, titanium (Ti), a compound containing at least one element selected from zirconium (Zr), bismuth (Bi), the compound constituting the condensation accelerator is an alkoxide, a carboxylic acid A salt or an acetylacetonate complex salt is particularly preferable.

Specific examples of the condensation accelerator include tetramethoxytitanium, tetraethoxytitanium, tetran-propoxytitanium, tetrai-propoxytitanium, tetran-butoxytitanium, tetran-butoxytitanium oligomer, tetrasec-butoxytitanium, Tetra-tert-butoxytitanium, tetra (2-ethylhexyl) titanium, bis (octanediolate) bis (2-ethylhexyl) titanium, tetra (octanediolate) titanium, titanium lactate, titanium dipropoxybis (triethanolaminate), Titanium dibutoxybis (triethanolamate), Titanium tributoxy systemate, Titanium tripropoxy systemate, Titanium tripropoxyacetate Ruacetonate, Titanium dipropoxybis (acetylacetonate), Titanium tripropoxyethylacetoacetate, Titanium propoxyacetylacetonate bis (ethylacetoacetate), Titanium tributoxyacetylacetonate, Titanium dibutoxybis (acetylacetonate), Titanium tri Butoxyethyl acetoacetate, titanium butoxyacetylacetonate bis (ethyl acetoacetate), titanium tetrakis (acetylacetonate), titanium diacetylacetonate bis (ethylacetoacetate), bis (2-ethylhexanoate) titanium oxide, bis ( Laurate) Titanium oxide, Bis (naphthate) Titanium oxide, Bis (stearate) Nium oxide, bis (oleate) titanium oxide, bis (linoleate) titanium oxide, tetrakis (2-ethylhexanoate) titanium, tetrakis (laurate) titanium, tetrakis (naphthate) titanium, tetrakis (stearate) titanium, tetrakis (oleate) ) Titanium, tetrakis (linoleate) titanium, tris (2-ethylhexanoate) bismuth, tris (laurate) bismuth, tris (naphthate) bismuth, tris (stearate) bismuth, tris (oleate) bismuth, tris (linoleate) bismuth , Tetraethoxyzirconium, tetra-n-propoxyzirconium, tetra-i-propoxyzirconium, tetra-n-butoxyzirconium, tetra-sec -Butoxyzirconium, tetra-tert-butoxyzirconium, tetra (2-ethylhexyl) zirconium, zirconium tributoxy systemate, zirconium tributoxyacetylacetonate, zirconium dibutoxybis (acetylacetonate), zirconium tributoxyethylacetoacetate, zirconium butoxy Acetylacetonate bis (ethylacetoacetate), zirconium tetrakis (acetylacetonate), zirconium diacetylacetonate bis (ethylacetoacetate), bis (2-ethylhexanoate) zirconium oxide, bis (laurate) zirconium oxide, bis ( Naphthate) zirconium oxide, bis (stearate) zirconium oxide, bis (o Ate) zirconium oxide, bis (linoleate) zirconium oxide, tetrakis (2-ethylhexanoate) zirconium, tetrakis (laurate) zirconium, tetrakis (naphthate) zirconium, tetrakis (stearate) zirconium, tetrakis (oleate) zirconium, tetrakis ( linoleate) zirconium can be given beam, etc., and among these, tris (2-ethylhexanoate) bismuth, tetra-n- propoxy zirconium, tetra-n- butoxy zirconium, bis (2-ethylhexanoate) zirconium oxide, bis (oleate) zirconium oxide, di benzalkonium tetrakis (acetylacetonate) are preferred.

  The amount of the condensation accelerator used is preferably such that the number of moles of the compound is from 0.1 to 10 as the molar ratio to the total amount of alkoxysilyl groups present in the reaction system, particularly from 0.5 to 5. preferable. If it is less than 0.1, the condensation reaction does not proceed sufficiently. On the other hand, even if it is used in excess of 10, the effect as a condensation accelerator is saturated, which is economically undesirable.

The condensation reaction in the present invention is carried out in an aqueous solution, and the temperature during the condensation reaction is preferably 85 to 180 ° C, more preferably 100 to 170 ° C, particularly preferably 110 to 150 ° C, and the pH of the aqueous solution is preferably 9 to 14 More preferably, it is 10-12.
When the temperature during the condensation reaction is less than 85 ° C., the condensation reaction proceeds slowly and the condensation reaction cannot be completed, so that the resulting modified polybutadiene undergoes a change over time, which poses a quality problem. On the other hand, if it exceeds 180 ° C., the aging reaction of the polymer proceeds and the physical properties are lowered, which is not preferable.

  Similarly, when the pH of the aqueous solution at the time of the condensation reaction is less than 9, the progress of the condensation reaction is slow and the condensation reaction cannot be completed. Become. On the other hand, when the pH of the aqueous solution at the time of the condensation reaction exceeds 14, a large amount of alkali-derived components remain in the modified polybutadiene after isolation, making it difficult to remove.

The condensation reaction time is usually about 5 minutes to 10 hours, preferably about 15 minutes to 5 hours. If it is less than 5 minutes, the condensation reaction is not completed. On the other hand, if it exceeds 10 hours, the condensation reaction is saturated, which is not preferable.
In addition, the pressure of the reaction system at the time of condensation reaction is 0.01-20 Mpa normally, Preferably it is 0.05-10 Mpa.
There is no restriction | limiting in particular about the form of a condensation reaction, You may carry out by a continuous type using apparatuses, such as a batch type reactor and a multistage continuous reactor. Moreover, you may perform this condensation reaction and a desolvent simultaneously.
After the condensation treatment as described above, a conventionally known post-treatment can be performed to obtain the desired modified polybutadiene.

The Mooney viscosity (ML _{1 + 4,} 100 ° C.) of the modified polybutadiene in the present invention is preferably 10 to 150, more preferably _{15 to} 100. If the Mooney viscosity is low, the rebound resilience when the composition is used as a golf ball tends to be inferior. On the other hand, if the Mooney viscosity is high, the manufacturing workability when the composition is used is poor.

  In the rubber composition of this invention, it is preferable to contain 30-100 mass% of said modified polybutadiene as a rubber component. If this amount is less than 30% by mass, it is difficult to obtain a rubber composition having desired physical properties, and the object of the present invention may not be achieved. The more preferable content of the modified polybutadiene in the rubber component is 40% by mass or more, and particularly preferably 50% by mass or more.

  This modified polybutadiene may be used alone or in combination of two or more. Other rubber components used in combination with the modified polybutadiene include natural rubber, synthetic isoprene rubber, butadiene rubber, styrene-butadiene rubber, ethylene-α-olefin copolymer rubber, ethylene-α-olefin-diene copolymer rubber. , Acrylonitrile-butadiene copolymer rubber, chloroprene rubber, halogenated butyl rubber, and mixtures thereof. Further, some of them may have a branched structure by using a polyfunctional type, for example, a modifier such as tin tetrachloride or silicon tetrachloride.

In the rubber composition of the present invention, with respect to 100 parts by mass of the rubber component, 5 to 80 parts by weight of an inorganic filler, and a crosslinking agent together containing 10 to 50 parts by weight, organic peroxide 0.1 It is preferable to contain 10 mass parts.

The crosslinking agent functions to promote crosslinking of the rubber component while being polymerized by radicals generated by the decomposition of an organic peroxide described below that functions as a radical initiator.
Examples of the crosslinking agent blended in the rubber composition of the present invention include α, β-ethylenically unsaturated carboxylic acid and monovalent or divalent metal salt of α, β-ethylenically unsaturated carboxylic acid. In terms of
(I) Acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, sorbic acid, tiglic acid, cinnamic acid, and aconitic acid (ii) Zn acrylate, Zn diacrylate, Zn methacrylate, dimethacryl Zn, Mg, Ca, Ba, and Na of the unsaturated acid of (i) above, such as acid Zn, Zn itaconate, Mg acrylate, Mg diacrylate, Mg methacrylate, Mg dimethacrylate, Mg itaconate, etc. Each salt etc. can be mentioned, These can be used individually by 1 type or in combination of 2 or more types.
In addition, the metal salt of the α, β-ethylenically unsaturated carboxylic acid is contained in a rubber composition in which a metal oxide such as zinc oxide is previously kneaded in addition to the usual method of mixing with the base rubber as it is. An α, β-ethylenically unsaturated carboxylic acid such as acrylic acid or methacrylic acid is added and kneaded, and the α, β-ethylenically unsaturated carboxylic acid and the metal oxide are reacted in the rubber composition to obtain α, It may be a metal salt of β-ethylenically unsaturated carboxylic acid. Moreover, a crosslinking agent can be used individually by 1 type or in combination of 2 or more types.
The compounding quantity of a crosslinking agent is 10-50 mass parts with respect to 100 mass parts of rubber components, Preferably it is 10-40 mass parts. If it is less than 10 parts by mass, the rebound resilience as a solid golf ball will be reduced. On the other hand, if it exceeds 50 parts by mass, it will be too hard and the workability will be poor.

The inorganic filler reinforces the cross-linked rubber to improve the strength, and can adjust the weight of the solid golf ball depending on the blending amount.
Specific examples of the inorganic filler include zinc oxide, barium sulfate, silica, alumina, aluminum sulfate, calcium carbonate, aluminum silicate, and magnesium silicate. Of these, use of zinc oxide, barium sulfate, and silica is preferable. These inorganic fillers can be used alone or in combination of two or more.
The compounding quantity of an inorganic filler is 5-80 mass parts with respect to 100 mass parts of rubber components, Preferably it is 5-70 mass parts. If it is less than 5 parts by mass, the resulting solid golf ball becomes too light, while if it exceeds 80 parts by mass, the resulting solid golf ball becomes too heavy.

The organic peroxide acts as an initiator for the rubber component and the crosslinking reaction, grafting reaction, polymerization reaction and the like of the crosslinking agent.
Preferable specific examples of the organic peroxide include, for example, dicumyl peroxide, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di -(T-butylperoxy) hexane, 1,3-bis (t-butylperoxy-isopropyl) benzene and the like can be mentioned.
The compounding quantity of an organic peroxide is 0.1-10 mass parts with respect to 100 mass parts of rubber components, Preferably it is 0.2-5 mass parts. If the amount is less than 0.1 parts by mass, the rebound resilience is lowered due to being too soft.

  In addition to the rubber component, inorganic filler, cross-linking agent, and organic peroxide, the rubber composition of the present invention contains a cross-linking aid such as zinc oxide; a lubricant such as stearic acid; an antioxidant, if desired. May be.

A representative example of a solid golf ball produced by crosslinking and molding from the rubber composition of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic cross-sectional view showing a one-piece solid golf ball. In FIG. 1, 1 is a main body portion and 1a is a dimple. The main body portion 1 is made of rubber (that is, rubber made of a crosslinked molded body of the rubber composition of the present invention).
FIG. 2 is a schematic cross-sectional view showing a two-piece solid golf ball. Reference numeral 11 denotes a core, and 12 denotes a cover. The cover 12 covers the core 11. And 12a is a dimple. The core 11 is made of rubber.
FIG. 3 is a schematic cross-sectional view showing a three-piece solid golf ball, in which 21 is an inner layer core, 22 is an outer layer core, 23 is a cover, and 23a is a dimple. In this three-piece solid golf ball, the inner layer core 21 and the outer layer core 22 constitute a solid core. The inner layer core 21 or the outer layer core 22 or both the inner layer core 21 and the outer layer core 22 are made of rubber. In addition, the density of the outer layer core 22 of the three-piece solid golf ball is preferably higher than that of the inner layer core 21 in terms of flight distance and rotational speed retention. For example, the outer layer core 22 can be blended with a filler having a high specific gravity such as W ₂ O ₅ and the inner layer core 21 can be blended with a filler having a low specific gravity such as ZnO ₂ as described above.

Next, a method for producing a solid golf ball using the rubber composition of the present invention will be described. First, the main body portion of the one-piece solid golf ball, the core of the two-piece solid golf ball, and the inner layer core of the three-piece solid golf ball are each subjected to crosslinking molding by pressing the rubber composition of the present invention into a predetermined mold. . The crosslinking conditions are preferably 130 to 180 ° C. and 10 to 50 minutes. The temperature at the time of this cross-linking molding may be changed in two or more steps.
In the three-piece solid golf ball, a two-layer structure is formed by sticking a sheet of the rubber composition for the outer layer core to a desired thickness on the outer side of the inner layer core obtained as described above, and crosslinking with a press. A solid core can be formed. In the three-piece solid golf ball, any of the rubber compositions used for the inner layer core and the outer layer core may be the rubber composition of the present invention, but both are preferably the rubber composition of the present invention. .

Covers for two-piece solid golf balls and three-piece solid golf balls are for covers in which an inorganic white pigment such as titanium dioxide and additives such as light stabilizers are appropriately blended with resin components mainly composed of ionomer resin. Formed by coating the core with the composition. In the coating, an injection molding method is usually employed, but is not limited thereto.
In addition, in a one-piece solid golf ball, a desired dimple is formed as necessary when forming a main body portion, and in a two-piece solid golf ball or a three-piece solid golf ball, when forming a cover.
The four-piece solid golf ball can be produced from the rubber composition of the present invention in the same manner as the three-piece solid golf ball.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples of the present invention. However, the present invention is not limited to the following examples.
In Examples, parts and% are based on mass unless otherwise specified.
In addition, various measurements in the examples were based on the following methods.

Mooney viscosity (ML _{1 + 4} , 100 ° C.):
Preheating was performed for 1 minute, measuring time of 4 minutes, and temperature of 100 ° C.
Mooney viscosity (ML _{1 + 4} , 125 ° C.):
Preheating was performed for 1 minute, measurement time of 4 minutes, and temperature of 125 ° C.
Microstructure (cis 1,4-bond content, 1,2-vinyl bond content):
It calculated | required by the infrared method (Morello method).
Molecular weight distribution (Mw / Mn):
Measurement was performed under the following conditions using a differential refractometer as a detector using HLC-8120GPC manufactured by Tosoh Corporation.
Column: manufactured by Tosoh Corporation, column GMHHXL
Mobile phase: tetrahydrofuran

Synthesis Example 1 (Production of Modified Polymer A)
A nitrogen-substituted 5 L autoclave was charged with 2.4 kg of cyclohexane and 300 g of 1,3-butadiene under nitrogen. In addition, as a catalyst component, neodymium versatate (0.09 mmol) in cyclohexane, methylalumoxane (hereinafter also referred to as “MAO”) (1.8 mmol) in toluene, diisobutylaluminum hydride (hereinafter also referred to as “DIBAH”). ) (5.0 mmol) and a solution of diethylaluminum chloride (0.18 mmol) in toluene and 1,3-butadiene (4.5 mmol) at 50 ° C. for 30 minutes, and a polymerization was performed at 80 ° C. for 60 minutes. went. The reaction conversion of 1,3-butadiene was almost 100%. 200 g of this polymer solution was extracted, a methanol solution containing 1.5 g of 2,4-di-tert-butyl-p-cresol was added, the polymerization was stopped, the solvent was removed by steam stripping, and a roll at 110 ° C. Was dried to obtain a pre-modified polymer. The results of the polymerization reaction are shown in Table 1.

Further, the remaining polymer solution was kept at a temperature of 60 ° C., and a toluene solution of 3-glycidoxypropyltrimethoxysilane (hereinafter also referred to as “GPMOS”) (4.5 mmol) was added and reacted for 30 minutes. Subsequently, a toluene solution of tetraisopropyl titanate (hereinafter also referred to as “IPOTi”) (13.5 mmol) was added and mixed for 30 minutes. Thereafter, a methanol solution containing 1.5 g of 2,4-di-tert-butyl-p-cresol was added to obtain 2.5 kg of a modified polymer solution.
Next, the modified polymer solution is added to 20 L of an aqueous solution adjusted to pH 10 with sodium hydroxide, subjected to a condensation reaction with solvent removal at 110 ° C. for 2 hours, and dried with a roll at 110 ° C. to obtain a modified polymer. Obtained. Table 1 shows the modification and condensation conditions and the results of the reaction.

Synthesis Example 2 (Production of modified polymer B)
A modified polymer was obtained by the same charging composition and polymerization method as in Synthesis Example 1 except that IPOTi was replaced with tetra 2-ethylhexyl titanate (hereinafter also referred to as “EHOTi”) in Synthesis Example 1. Table 1 shows the modification and condensation conditions and the results of the reaction.

Synthesis Example 3 (Production of Modified Polymer C)
A modified polymer was obtained by the same charging composition and polymerization method as in Synthesis Example 1 except that IPOTi was replaced with tris (2-ethylhexanoate) bismuth (hereinafter also referred to as “EHABi”) in Synthesis Example 1. . Table 1 shows the modification and condensation conditions and the results of the reaction.

Synthesis Example 4 (Production of modified polymer D)
A modified polymer was obtained by the same charging composition and polymerization method as in Synthesis Example 1 except that IPOTi was replaced with tetra-n-propoxyzirconium (hereinafter also referred to as “NPOZr”) in Synthesis Example 1. Table 1 shows the modification and condensation conditions and the results of the reaction.

Synthesis Example 5 (Production of Modified Polymer E)
In Synthesis Example 1, GPMOS was replaced with 3-isocyanatopropyltriethoxysilane (hereinafter also referred to as “IPEOS”), and IPOTi was replaced with bis (2-ethylhexanoate) zirconium oxide (hereinafter also referred to as “EHAZrO”). A modified polymer was obtained by the same charging composition and polymerization method as in Synthesis Example 1. Table 1 shows the modification and condensation conditions and the results of the reaction.

Synthesis Comparative Example 5 (Production of Modified Polymer F)
A modified polymer was obtained by the same charging composition and polymerization method as in Synthesis Example 1 except that IPOTi was replaced with tris (2-ethylhexanoate) aluminum (hereinafter also referred to as “EHAAl”) in Synthesis Example 1. . Table 1 shows the modification and condensation conditions and the results of the reaction.

Synthesis Example 6 (Production of Modified Polymer G)
A modified polymer was obtained by the same charging composition and polymerization method as in Synthesis Example 1 except that IPOTi was replaced with zirconium tetrakis (acetylacetonate) (hereinafter also referred to as “ZrAC”) in Synthesis Example 1. Table 1 shows the modification and condensation conditions and the results of the reaction.

Synthesis Comparative Example 6 (Production of Modified Polymer H)
A modified polymer was obtained by the same charging composition and polymerization method as in Synthesis Example 1 except that IPOTi was replaced with bis (2-ethylhexanoate) tin (hereinafter also referred to as “BEHAT”) in Synthesis Example 1. . Table 1 shows the modification and condensation conditions and the results of the reaction.

Synthesis Example 7 (Production of Modified Polymer I)
A nitrogen-substituted 5 L autoclave was charged with 2.4 kg of cyclohexane and 300 g of 1,3-butadiene under nitrogen. As a catalyst component, a solution of neodymium versatate (0.09 mmol) in cyclohexane, MAO (1.8 mmol) in toluene, DIBAH (5.0 mmol) and diethylaluminum chloride (0.18 mmol) in toluene and 1, A catalyst in which 3-butadiene (4.5 mmol) was reacted and aged at 50 ° C. for 30 minutes was charged, and polymerization was performed at 80 ° C. for 60 minutes. The reaction conversion of 1,3-butadiene was almost 100%. 200 g of this polymer solution was extracted, a methanol solution containing 1.5 g of 2,4-di-tert-butyl-p-cresol was added, the polymerization was stopped, the solvent was removed by steam stripping, and a roll at 110 ° C. Was dried to obtain a pre-modified polymer. The results of the polymerization reaction are shown in Table 1.

Further, the remaining polymer solution was kept at a temperature of 60 ° C., and a toluene solution of GPMOS (4.5 mmol) was added and reacted for 30 minutes. Subsequently, 3-aminopropyltriethoxysilane (hereinafter also referred to as “APEOS”) (13.5 mmol) was added and mixed for 30 minutes. Furthermore, a toluene solution of IPOTi (13.5 mmol) was added and mixed for 30 minutes. Thereafter, a methanol solution containing 1.5 g of 2,4-di-tert-butyl-p-cresol was added to obtain 2.5 kg of a modified polymer solution.
Next, the modified polymer solution is added to 20 L of an aqueous solution adjusted to pH 10 with sodium hydroxide, subjected to a condensation reaction with solvent removal at 110 ° C. for 2 hours, and dried with a roll at 110 ° C. to obtain a modified polymer. Obtained. Table 1 shows the modification and condensation conditions and the results of the reaction.

Synthesis Example 8 (Production of Modified Polymer J)
The same as Example 1 except that the toluene solution of APEOS in Example 7 was replaced with a toluene solution of N- (3-triethoxysilylpropyl) -4,5-dihydroimidazole (hereinafter also referred to as “EOSDI”). A modified polymer was obtained by the charged composition and polymerization method. Table 1 shows the modification and condensation conditions and the results of the reaction.

Synthesis Example 9 (Production of modified polymer K)
Modified polymer by the same charging composition and polymerization method as in Example 1 except that the toluene solution of APEOS in Example 7 was replaced with a toluene solution of 3-mercaptopropyltriethoxysilane (hereinafter also referred to as “MPEOS”). Got. Table 1 shows the modification and condensation conditions and the results of the reaction.

Synthetic Comparative Example 1 (Production of Modified Polymer L)
A modified polymer was obtained by the same composition and polymerization method as in Synthesis Example 1 except that IPOTi was not added in Synthesis Example 1. Table 1 shows the modification and condensation conditions and the results of the reaction.

Synthetic Comparative Example 2 (Production of Modified Polymer M)
In Synthesis Example 8 , a modified polymer was obtained by the same charging composition and polymerization method as in Synthesis Example 8 except that IPOTi was not added. Table 1 shows the modification and condensation conditions and the results of the reaction.

Synthesis Comparative Example 3 (Production of polymer N)
A nitrogen-substituted 5 L autoclave was charged with 2.4 kg of cyclohexane and 300 g of 1,3-butadiene under nitrogen. As a catalyst component, a solution of neodymium versatate (0.09 mmol) in cyclohexane, MAO (1.8 mmol) in toluene, DIBAH (5.0 mmol) and diethylaluminum chloride (0.18 mmol) in toluene and 1, A catalyst in which 3-butadiene (4.5 mmol) was reacted and aged at 50 ° C. for 30 minutes was charged, and polymerization was performed at 80 ° C. for 60 minutes. The reaction conversion of 1,3-butadiene was almost 100%. 200 g of this polymer solution was extracted, a methanol solution containing 1.5 g of 2,4-di-tert-butyl-p-cresol was added, the polymerization was stopped, the solvent was removed by steam stripping, and a roll at 110 ° C. Was dried to obtain a pre-modified polymer. The results of the polymerization reaction are shown in Table 1.
Further, a methanol solution containing 1.5 g of 2,4-di-tert-butyl-p-cresol was added to the remaining polymer solution to terminate the polymerization, and subsequently, a toluene solution of IPOTi (13.5 mmol). And mixed for 30 minutes to obtain 2.5 kg of polymer solution.
Next, the above polymer solution was added to 20 L of an aqueous solution adjusted to pH 10 with sodium hydroxide, and the solvent was removed at 110 ° C. for 2 hours, followed by drying with a roll at 110 ° C. to obtain a polymer. The analysis results of the polymer are shown in Table 1.

Synthesis Comparative Example 4 (Production of Polymer O)
In Synthesis Comparative Example 3, a modified polymer was obtained by the same charging composition and polymerization method as in Synthesis Comparative Example 3 except that IPOTi was not added. Table 1 shows the modification and condensation conditions and the results of the reaction.

  BR01, BR03, BR11, BR18 in Table 1 are unmodified polybutadiene rubbers that do not use a modifier.

Example 1
25 parts by mass of zinc diacrylate, 22 parts by mass of zinc oxide, 1.8 parts by mass of dicumyl peroxide, and 0.5 parts by mass of antioxidant are added to 100 parts by mass of the modified polymer A obtained in Synthesis Example 1. The mixture was kneaded for 15 minutes with a kneader at 50 ° C. and 50 rpm.

In order to compare manufacturing workability, a rollability test was performed with a 6-inch roll to evaluate roll workability. The results are shown in Table 2.
Roll processability:
Condition of winding test: temperature 70 ° C., nip width 1.4 mm, rotation speed 20 rpm / 24 rpm.
Here, evaluation of roll workability was calculated | required as follows. The roll processability is better as the numerical value is larger (the evaluations in Tables 3 and 4 are the same).
5; The roll is wound neatly and the surface is smooth.
4; It rolls around a roll and there is no roughness on the surface.
3; Although it winds around a roll, it has a rough surface.
2; It winds around the roll, but the surface has holes and dirty.
1; It does not wind around a roll.

Moreover, in order to compare extrusion workability | operativity, the extrusion test by the flow tester described in the Journal of Japan Rubber Association, volume 76, P441, (2005) was done, and the fluidity | liquidity was evaluated. The results are shown in Table 2.
Extrusion workability:
Using a flow tester manufactured by Shimadzu Corporation, extrusion was performed under the conditions of a load of 50 kg, a nozzle of 2 × 2 m / m, a residual heat of 180 Sec, and 60 ° C., and their fluidity was compared. The results are shown as an index with the measured value of Comparative Example 4 as 100. In addition, fluidity | liquidity is so favorable that a numerical value is large.

Next, the obtained rubber composition was subjected to pressure-crosslinking molding at 150 ° C. for 30 minutes, and the rebound resilience was measured at a low temperature (−20 ° C.) described in Journal of Japan Rubber Association, Vol. 76, P441, (2005). Evaluation was performed using tan δ measured in (1). The results are shown in Table 2.
Rebound resilience:
Using a dynamic spectrometer manufactured by Rheometrics, Inc., measurement was performed at a tensile dynamic strain of 0.1%, a frequency of 15 Hz, and −20 ° C. The results are shown as an index with the measured values of Comparative Examples 7 , 17 , and 24 as 100. The rebound resilience is better as the value is larger.

Examples 2 to 9 and Comparative Examples 1 to 10
A rubber composition was prepared in the same manner as in Example 1 except that the modified polymer shown in Table 2 was used, and roll processability, extrusion workability, and rebound resilience were measured. The results are shown in Table 2. From Table 2, the roll processability of Examples 1 9 balanced extrusion workability and impact resilience, found to be excellent as compared with Comparative Examples 1-10.

Examples 10 to 13 and Comparative Examples 11 to 17
According to the formulation shown in Table 3, a rubber composition was prepared by kneading for 15 minutes in a kneader at 50 ° C. and 50 rpm. Here, roll processability, extrusion workability, and rebound resilience were measured in the same manner as described in Example 1. The results are shown in Table 3.

From Table 3, it can be seen that the balance of roll processability, extrusion workability, and rebound resilience of Examples 10 to 13 is superior to Comparative Examples 11 to 17 . Further, from the comparison between Examples 10 and 11 and Comparative Example 15 and Examples 12 and 13 and Comparative Example 16 , it is important to use the modified polymer of the present application within the scope of the present application as the rubber component content. I understand.

Examples 14-17 and Comparative Examples 18-24
According to the formulation shown in Table 4, a rubber composition was prepared by kneading for 15 minutes in a kneader at 50 ° C. and 50 rpm. Here, roll processability, extrusion workability, and rebound resilience were measured in the same manner as described in Example 1. The results are shown in Table 4.

From Table 4, the roll processability of Examples 14-17, the balance of the extrusion workability and impact resilience, found to be excellent as compared with Comparative Examples 18-24. Further, from the comparison between Examples 14 and 15 and Comparative Example 22 , Examples 16 and 17 and Comparative Example 23 , it is important to use the modified polymer of the present application within the scope of the present application as the rubber component content. I understand.

In Table 1, * 1 to * 4 are as follows.
* 1 Ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) * 2 GPMOS; 3-glycidoxypropyltrimethoxysilane IPEOS; 3-isocyanatopropyltriethoxysilane APEOS; 3-aminopropyltriethoxysilane EOSDI N- (3-triethoxysilylpropyl) -4,5-dihydroimidazole MPEOS; 3-mercaptopropyltriethoxysilane IPOTi; tetraisopropyl titanate EHOTi; tetra-2-ethylhexyl titanate EHABi; tris (2-ethylhexanoate) Bismuth NPOZr; Dibutyltin dilaurate tetra n-propoxyzirconium EHAZrO; Bis (2-ethylhexanoate) zirconium oxide EHAAl; Tris (2-ethylhexyl) Noeto) aluminum ZrAC; zirconium tetrakis (acetylacetonate)
EHASn: bis (2-ethylhexanoate) tin * 3 BR01: manufactured by JSR, polybutadiene rubber BR03: manufactured by JSR, polybutadiene rubber BR11: manufactured by JSR, polybutadiene rubber BR18: manufactured by JSR, polybutadiene rubber * 4 Polymerization stop Then add IPOTi and mix

In Table 2, * 1 to * 2 are as follows.
* 1 Antioxidant: Yoshinox 425, manufactured by Yoshitomi Pharmaceutical Co., Ltd.
* 2 An index with Comparative Example 7 as 100, the higher the value, the better.

In Table 3, * 1 to * 2 are as follows.
* 1 Antioxidant: Yoshinox 425, manufactured by Yoshitomi Pharmaceutical Co., Ltd.
* 2 An index with Comparative Example 17 as 100, the higher the value, the better.

In Table 4, * 1 to * 2 are as follows.
* 1 Antioxidant: Yoshinox 425, manufactured by Yoshitomi Pharmaceutical Co., Ltd.
* 2 An index with Comparative Example 24 set to 100, the higher the value, the better.

  The golf ball obtained from the rubber composition for a golf ball of the present invention has excellent workability, large rebound resilience, and excellent industrial utility value.

It is a schematic sectional drawing which shows an example of a one-piece solid golf ball. It is a schematic sectional drawing which shows an example of a two-piece solid golf ball. It is a schematic sectional drawing which shows an example of a three-piece solid golf ball.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Body part 1a, 2a, 3a Dimple 11 Core 21 Inner layer core 22 Outer layer core 12, 23 Cover

Claims (9)

A step of performing a modification reaction using an alkoxysilane compound on the active terminal of polybutadiene having an active terminal having a vinyl content of less than 10% and a cis 1,4-bond content of 75% or more; and titanium (Ti) Modified polybutadiene obtained by the step of conducting a condensation reaction of an alkoxysilane compound (residue) in the presence of a condensation accelerator comprising a compound containing at least one element of zirconium (Zr) and bismuth (Bi) 5 to 80 parts by mass of an inorganic filler and 1 of α, β-ethylenically unsaturated carboxylic acid and α, β-ethylenically unsaturated carboxylic acid with respect to 100 parts by mass of the rubber component contained in 30 to 100% by mass A golf ball rubber composition comprising 10 to 50 parts by mass of a crosslinking agent selected from a valent or divalent metal salt.   The rubber composition for a golf ball according to claim 1, wherein the modified polybutadiene is obtained by adding a step of further adding an alkoxysilane compound. 3. The golf ball according to claim 1, wherein the alkoxysilane compound used in the step of performing the modification reaction is an alkoxysilane compound containing at least one functional group selected from the following (a) to (c). Rubber composition.
(A); epoxy group (b); isocyanate group (c); carboxyl group 4. The rubber composition for a golf ball according to claim 2, wherein the further added alkoxysilane compound is an alkoxysilane compound containing at least one functional group selected from the following (d) to (f): .
(D); amino group (e); imino group (f); mercapto group The polybutadiene having the active terminal is obtained by polymerizing 1,3-butadiene using a catalyst mainly comprising the following components (g) to (i): The rubber composition for golf balls described.
(G) component; a rare earth element-containing compound corresponding to atomic numbers 57 to 71 in the periodic table, or a reaction product of these compounds with a Lewis base (h) component; alumoxane and / or AlR ¹ R ² R ³ (wherein , R ¹ and R ² are the same or different and are a hydrocarbon group or hydrogen atom having 1 to 10 carbon atoms, R ³ is a hydrocarbon group having 1 to 10 carbon atoms, provided that R ³ is the above R ¹ or R ² An organoaluminum compound corresponding to (may be the same as or different from) (i) component; halogen-containing compound   Among the rubber components, rubber components other than modified polybutadiene are natural rubber, synthetic isoprene rubber, butadiene rubber, styrene-butadiene rubber, ethylene-α-olefin copolymer rubber, ethylene-α-olefin-diene copolymer rubber, acrylonitrile. The rubber composition for a golf ball according to any one of claims 1 to 5, which is at least one selected from the group consisting of a butadiene copolymer rubber, a chloroprene rubber and a halogenated butyl rubber.   The rubber composition for a golf ball according to any one of claims 1 to 6, wherein the inorganic filler is one or more of zinc oxide, barium sulfate, and silica.   The rubber composition for golf balls according to any one of claims 1 to 7, comprising 0.1 to 10 parts by mass of an organic peroxide with respect to 100 parts by mass of the rubber component.   A golf ball obtained by crosslinking and molding the rubber composition for a golf ball according to claim 1, containing 5 to 100% by mass.

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