JP6613572B2 - Golf ball manufacturing method - Google Patents

Description

  The present invention relates to a golf ball having at least one core and at least one cover, and more specifically, a golf ball capable of improving adhesion between each layer and improving cracking durability at the time of hitting, and the golf ball thereof It relates to a manufacturing method.

  In recent years, solid golf balls having a multi-layer structure more than three-pieces have been widely used, and four-piece solids in which three or more covers such as an envelope layer, an intermediate layer, and an outermost layer are covered on the core have come into circulation. Yes. These multi-layer golf balls are usually formed by sequentially injection-molding a synthetic resin cover material around the core and laminating the layers on the core. Further, since there is a possibility that various physical properties of the ball such as hit feeling and cracking durability may be lowered, it is desired to improve the adhesion between the layers.

  As a technique for improving the adhesion between the layers of the golf ball, for example, a technique described in the following patent publication is proposed.

  Japanese Patent Laid-Open No. 10-179795 proposes a technique for forming an adhesive layer on an intermediate layer. Japanese Patent Application Laid-Open No. 11-137726 proposes a technique in which an adhesive is blended with a cover material mainly composed of a thermoplastic resin. Japanese Unexamined Patent Publication No. 2003-339912 proposes a technique in which the inner layer surface of the inner and outer layer covers is acid cleaned to improve the adhesion between the inner layer and the non-ionomer resin such as polyurethane elastomer. Has been. Japanese Patent Application Laid-Open No. 2009-131631 discloses that the surface of a rubber core is treated with a solution containing a halogenated isocyanuric acid and / or a metal salt thereof for the purpose of improving the adhesion between the rubber core and the urethane cover. After that, a golf ball manufacturing method including covering a cover material has been proposed.

  However, even in the above-described various proposals, the adhesion is still insufficient depending on the material of each layer. In particular, the adhesion between the rubber core and the ionomer resin material is insufficient, and this decrease in adhesion has adversely affected various physical properties of the golf ball.

Japanese Patent Application Laid-Open No. 10-179795 JP 11-137726 A JP 2003-339912 A JP 2009-131631 A

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a golf ball that can improve the adhesion between the layers and improve the physical properties of the golf ball, in particular, the durability to cracking at impact. .

  As a result of intensive studies to achieve the above object, the inventors of the present invention have prepared a multilayer golf ball having a core and one or more covers covering the core, and the core surface includes a solution containing a butyl rubber ionomer. After the treatment with the above, it was found that by covering the cover material, the adhesion between the core surface and the cover can be improved and the hitting durability can be improved. In particular, the core surface can be finely rugged by normal polishing, but the solution containing the butyl rubber ionomer can enter the rugged surface and improve the adhesion to the envelope layer or intermediate layer covering the core surface. In addition, the adhesion may be improved by the interaction between the rubber component of the butyl rubber ionomer and the rubber component of the core layer and the interaction between the ionic component of the butyl rubber ionomer and the ionic component of the ionomer resin material. With regard to such operational effects, it has been found that the adhesion effect is particularly remarkable when water is added to the core formulation, and the present invention has been made.

Accordingly, the present invention provides the following golf ball manufacturing method .
1. In a method for producing a golf ball comprising at least one core and at least one cover, a treatment solution in which a butyl rubber ionomer is dissolved in a solvent is prepared, and the treatment solution is added to at least one layer of the golf ball member ( By applying to the “treatment solution target layer”), a skin layer made of the treatment solution is formed on the surface of the treatment solution target layer, and the thickness of the skin layer is 1 to 5.6 μm. Then, the rubber layer, the resin layer, or the paint layer is coated on the adjacent outer layer, and the treatment solution target layer and the outer layer adjacent to the layer through the skin layer. A golf ball manufacturing method comprising adjusting an adhesive strength to be 1.37 N / 4 mm or more.
2. 2. The method for producing a golf ball according to 1 above, wherein the butyl rubber ionomer is produced from a halogenated butyl rubber reacted with a nitrogen-based or phosphorus-based nucleophile.
3. 3. The method for producing a golf ball according to 1 or 2 , wherein the butyl rubber ionomer treatment solution is applied to at least one layer (treatment solution target layer) of the golf ball member by an immersion method.
4). 4. The golf ball manufacturing method according to 3 above, wherein the immersion treatment is performed at room temperature.
5. 5. The method for producing a golf ball according to any one of 1 to 4, wherein the solvent of the butyl rubber ionomer treatment solution contains isooctane, benzene, toluene, or chloroform.
6). The treatment solution target layer includes the following components (A) to (C):
(A) Base rubber (B) Organic peroxide (C) The rubber composition according to any one of 1 to 5 above, which is formed from a heat-molded rubber composition containing water and / or a monocarboxylic acid metal salt. Golf ball manufacturing method.
7). 7. The method for producing a golf ball according to 6 above, wherein the component (C) is water and the amount of water is 0.1 to 5 parts by mass with respect to 100 parts by mass of the base rubber (A).

  According to the golf ball and the manufacturing method thereof of the present invention, the adhesion between the layers can be improved, and the cracking durability when the golf ball is hit can be improved.

It is explanatory drawing of the sampling method of the test piece for adhesive strength measurement at the time of measuring the adhesive strength of a core and a surrounding layer.

Hereinafter, the present invention will be described in more detail.
The golf ball of the present invention includes at least one core and at least one cover.

  About the said core, it can form using a well-known rubber composition, Although it does not restrict | limit in particular, The rubber composition of the following mixing | blending can be illustrated as a suitable thing.

  As a material for forming the core, a rubber material can be used as a main material. For example, the base rubber can be formed using a rubber composition containing a co-crosslinking agent, an organic peroxide, an inert filler, sulfur, an antioxidant, an organic sulfur compound, and the like.

  The base rubber of the rubber composition is preferably one using polybutadiene. As this polybutadiene, a polymer having a cis-1,4-bond of preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 95% by mass or more is preferably used in the polymer chain. it can. If there are too few cis-1,4-bonds in the bonds in the molecule, the resilience may decrease. The content of 1,2-vinyl bond contained in the polybutadiene is preferably 2% by mass or less, more preferably 1.7% by mass or less, and further preferably 1.5% by mass or less in the polymer chain. is there. If the content of 1,2-vinyl bond is too large, the resilience may be lowered.

  From the viewpoint of obtaining a vulcanized molded product of a rubber composition having good resilience, the polybutadiene is preferably blended with a rare earth element-based catalyst or a Group VIII metal compound catalyst. It is preferably synthesized with a system catalyst.

  In addition to the polybutadiene, other rubber components can be blended with the rubber composition as long as the effects of the present invention are not impaired. Examples of the rubber component other than the polybutadiene include polybutadiene other than the polybutadiene, and other diene rubbers such as styrene butadiene rubber, natural rubber, isoprene rubber, and ethylene propylene diene rubber.

  Examples of the co-crosslinking agent include unsaturated carboxylic acids and unsaturated carboxylic acid metal salts. Specific examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, maleic acid, and fumaric acid. Acrylic acid and methacrylic acid are particularly preferably used. Although it does not specifically limit as a metal salt of unsaturated carboxylic acid, For example, what neutralized the said unsaturated carboxylic acid with the desired metal ion is mentioned. Specific examples include zinc salts such as methacrylic acid and acrylic acid, magnesium salts, and the like. In particular, zinc acrylate is preferably used.

  The unsaturated carboxylic acid and / or metal salt thereof is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and still more preferably 15 parts by mass or more with respect to 100 parts by mass of the base rubber. The upper limit of the amount is preferably 60 parts by mass or less, more preferably 50 parts by mass or less, still more preferably 40 parts by mass or less, and most preferably 30 parts by mass or less. If the blending amount is too large, it may become too hard and unbearable feel may occur, and if the blending amount is too small, the resilience may decrease.

  Commercially available products can be used as the organic peroxide, for example, trade names “Park Mill D”, “Perhexa 3M”, “Perhexa C-40”, “Nyper BW”, “Parroyl L”, etc. Oil Company) or Luperco 231XL (Atchem Corporation) can be exemplified. These are preferably used alone.

  The organic peroxide is preferably 0.1 parts by mass or more, more preferably 0.3 parts by mass or more, still more preferably 0.5 parts by mass or more, and most preferably 0, with respect to 100 parts by mass of the base rubber. The upper limit of the amount is preferably 5 parts by mass or less, more preferably 4 parts by mass or less, still more preferably 3 parts by mass or less, and most preferably 2 parts by mass or less. it can. If the blending amount is too large or too small, it may not be possible to obtain suitable feel, durability and resilience.

  As the inert filler, for example, zinc oxide, barium sulfate, calcium carbonate and the like can be suitably used. These may be used individually by 1 type and may use 2 or more types together.

  The compounding amount of the inert filler is preferably 1 part by mass or more, more preferably 5 parts by mass or more with respect to 100 parts by mass of the base rubber, and the upper limit of the compounding amount is preferably 100 parts by mass or less. More preferably, it is 80 mass parts or less, More preferably, it can be 60 mass parts or less. If the amount is too large or too small, it may not be possible to obtain an appropriate weight and suitable resilience.

  Furthermore, an anti-aging agent can be blended as needed. For example, commercially available products are Nocrack NS-6, NS-30, 200 (Ouchi Shinsei Chemical Co., Ltd.), Yoshinox 425 (Yoshitomi Pharmaceutical Co., Ltd.) Manufactured) and the like. These may be used individually by 1 type and may use 2 or more types together.

  The blending amount of the anti-aging agent can be more than 0, preferably 0.05 parts by mass or more, particularly 0.1 parts by mass or more with respect to 100 parts by mass of the base rubber. The upper limit of the blending amount is not particularly limited, but is preferably 3 parts by mass or less, more preferably 2 parts by mass or less, still more preferably 1 part by mass or less, and most preferably 0.5 parts with respect to 100 parts by mass of the base rubber. It can be below mass parts. If the amount is too large or too small, an appropriate core hardness gradient may not be obtained, and a suitable resilience, durability, and low spin effect during full shot may not be obtained.

  Moreover, an organic sulfur compound can be mix | blended with the said rubber composition for the purpose of the resilience improvement of a core as needed. When blending an organic sulfur compound, the blending amount is preferably 0.05 parts by weight or more, more preferably 0.1 parts by weight or more, and the upper limit of the blending amount is preferably 100 parts by weight of the base rubber. The amount can be 5 parts by mass or less, more preferably 4 parts by mass or less, and still more preferably 2 parts by mass or less. If the amount of the organic sulfur compound is too small, the effect of improving the resilience of the core may not be sufficiently obtained. Conversely, if the amount is too large, the hardness of the core becomes too soft, and the feeling is reduced. It becomes worse and the durability to cracking may be worsened when repeatedly hit.

Further, as the above-mentioned core, the following components (A) to (C) (A) base rubber (B) organic peroxide (C) water and / or monocarboxylic acid metal salt are blended as essential components. It can be formed by hot molding of a rubber composition.
As will be described later, the present invention has a layer containing a butyl rubber ionomer, and one layer adjacent to this layer is a thermoformed product of a rubber composition in which the above components (A) to (C) are blended. It is suitable that it is formed by.

  That is, by thermoforming a rubber composition containing (A) a base rubber, (B) an organic peroxide, and (C) components (A) to (C) of water and / or a metal salt of a monocarboxylic acid. By forming the core, it is possible to appropriately control the difference in crosslink density between the center of the core and the surface, or the dynamic viscoelastic properties of the core center, and as a golf ball, achieve low spin, Further, it is possible to provide a golf ball having good durability and having little change in resilience even when used for a long period of time.

  And decomposition | disassembly of the organic peroxide in a core mixing | blending can be accelerated | stimulated by mix | blending water (material containing water) directly with a core material. Moreover, it is known that the decomposition efficiency of the organic peroxide in the core rubber composition changes depending on the temperature, and the decomposition efficiency increases as the temperature rises higher than a certain temperature. If the temperature is too high, the amount of radicals decomposed will increase too much, resulting in recombination and inactivation between radicals. As a result, radicals that effectively work for crosslinking are reduced. Here, when decomposition heat is generated by the decomposition of the organic peroxide during core vulcanization, the temperature near the core surface is maintained at about the same level as the temperature of the vulcanization mold, but the area near the core center is outside. Since the heat of decomposition of the organic peroxide decomposed from is accumulated, it becomes considerably higher than the mold temperature. When water (a material containing water) is blended directly into the core, water has a function of promoting the decomposition of the organic peroxide, so that the radical reaction as described above can be changed at the core center and the core surface. it can. That is, the decomposition of the organic peroxide is further promoted in the vicinity of the core center, and the radical inactivation is further promoted to further reduce the amount of effective radicals. In addition, cores having different dynamic viscoelastic properties at the center of the core can be obtained.

  In addition, when it replaces with said water and a zinc monoacrylate is used, water generate | occur | produces from a zinc monoacrylate by the heat | fever during kneading | mixing of a compounding material. As a result, the same effect as when water is blended can be obtained.

  About the base rubber of said (A) component and (B) organic peroxide, the thing similar to the base rubber and organic peroxide mentioned above can be used conveniently.

  There is no restriction | limiting in particular about the water of the said (C) component, Although distilled water or tap water may be sufficient, Especially using distilled water which does not contain an impurity is employ | adopted suitably. The amount of water is preferably 0.1 parts by mass or more, more preferably 0.3 parts by mass or more, and preferably 5 parts by mass or less, with respect to 100 parts by mass of the base rubber. More preferably, it is 4 parts by mass or less.

  Moreover, it is preferable that the water content in the rubber composition before vulcanization is 1000 ppm or more by blending an appropriate amount of the above water, and more preferably 1500 ppm or more. As an upper limit, Preferably it is 8500 ppm or less, More preferably, it is 8000 ppm or less. If the water content of the rubber composition is too small, it may be difficult to obtain an appropriate crosslinking density and Tan δ, and it may be difficult to mold a golf ball with low energy loss and low spin. . When the water content of the rubber composition is too large, the core becomes too soft and it may be difficult to obtain an appropriate initial core speed.

Although it is possible to add water directly to the rubber composition, the following methods (i) to (iii) can be employed.
(I) Method of applying mist-like water to all or part of rubber composition (compounding material) by steam or ultrasonic wave (ii) Method of immersing all or part of rubber composition in water (iii) Rubber composition A method in which all or part of the object is left in a high humidity environment for a certain period of time in a humidity-controllable place such as a humidity chamber. Although not limited, it is preferable that the humidity is 40 to 100%.

  Moreover, water can be processed into a jelly form and blended with the rubber composition. Alternatively, a material in which water is previously supported on a filler, unvulcanized rubber, rubber powder or the like can be used and blended with the rubber composition. Since such an aspect is more workable than directly adding water, the production efficiency of the golf ball can be improved. The type of material containing a predetermined amount of water is not particularly limited, but examples include sufficiently filled water, unvulcanized rubber, rubber powder, etc., particularly impairing durability and resilience. It is preferred to use materials without The moisture content of the material is preferably 3% by mass or more, more preferably 5% by mass or more, and further preferably 10% by mass or more, and the upper limit is preferably 99% by mass or less, more preferably 95% by mass. % Or less.

Moreover, in this invention, a monocarboxylic acid metal salt is employable instead of said water. The monocarboxylic acid metal salt is presumed that the carboxylic acid is coordinated to the metal. For example, two carboxylic acid molecules such as zinc diacrylate represented by [CH ₂ ═CHCOO] ₂ Zn A distinction is made from dicarboxylic acid metal salts which are bonded to one metal atom. Since the monocarboxylic acid metal salt brings water into the rubber composition by performing a dehydration condensation reaction, the same effect as the above water can be obtained. In addition, since the monocarboxylic acid metal salt can be blended in the rubber composition as a powder, the work process can be simplified and it can be easily dispersed uniformly in the rubber composition. In order to perform the above reaction effectively, it is necessary to be a mono salt. The compounding amount of the monocarboxylic acid metal salt is preferably 1 part by mass or more, and more preferably 3 parts by mass or more with respect to 100 parts by mass of the base rubber. As an upper limit, the compounding amount of the monocarboxylic acid metal salt is preferably 60 parts by mass or less, and more preferably 50 parts by mass or less. If the amount of the monocarboxylic acid metal salt is too small, it is difficult to obtain an appropriate crosslinking density and Tan δ, and the low spin effect of the golf ball may not be sufficiently obtained. Further, when the amount is too large, the core becomes too hard, and it may be difficult to maintain an appropriate feel.

  As the carboxylic acid, acrylic acid, methacrylic acid, maleic acid, fumaric acid, stearic acid and the like can be used. Examples of the substitution metal include Na, K, Li, Zn, Cu, Mg, Ca, Co, Ni, and Pb. Zn is preferably used. Specific examples include zinc monoacrylate and zinc monomethacrylate, and it is particularly preferable to use zinc monoacrylate.

  The rubber composition containing each of the above components is prepared by kneading using an ordinary kneading machine such as a Banbury mixer or roll. Moreover, what is necessary is just to shape | mold by compression molding or injection molding etc. using a predetermined mold for core formation, when shape | molding a core using this rubber composition. About the obtained molded object, it heat-hardens on temperature conditions sufficient for the organic peroxide and co-crosslinking agent which were mix | blended with the rubber composition to act, and it is set as the core which has predetermined | prescribed hardness distribution. In this case, the vulcanization conditions are not particularly limited, but are usually about 130 to 170 ° C., particularly 150 to 160 ° C. for 10 to 40 minutes, particularly 12 to 20 minutes.

  Next, the cover used for the golf ball of the present invention will be described. The cover is a member that covers the core and has at least one layer, and examples thereof include a two-layer cover and a three-layer cover. In the case of a two-layer cover, each layer may be referred to as an intermediate layer on the inside and an outermost layer on the outside. In the case of a three-layer cover, each layer may be referred to as an envelope layer, an intermediate layer, and an outermost layer in order from the inside.

  As the resin material for forming the cover, known resins can be used and are not particularly limited. However, ionomer resins, thermoplastic elastomers such as urethane, amide, ester, olefin, and styrene are available. 1 type (s) or 2 or more types selected from the group which consists of can be used.

  There is no restriction | limiting in particular as said ionomer resin, A well-known thing can be used. Commercially available products can be used as the ionomer resin, and examples thereof include H1706, H1605, H1557, H1601, AM7329, AM7317, and AM7318 manufactured by Mitsui DuPont Polychemical Co., Ltd.

  Examples of the thermoplastic elastomer include thermoplastic elastomers such as a polyester elastomer, a polyamide elastomer, and a polyurethane elastomer, and a polyurethane elastomer is particularly preferably used.

  The polyurethane elastomer is not particularly limited as long as it is an elastomer mainly composed of polyurethane, but from a polymer polyol compound constituting a soft segment, a diisocyanate constituting a hard segment, and a monomolecular chain extender. It is preferable to be configured.

  Although it does not restrict | limit especially as a high molecular polyol compound, For example, a polyester-type polyol, a polyether-type polyol etc. are mentioned, From a viewpoint of rebound resilience or a low-temperature characteristic, a polyether type is used preferably. Examples of the polyether-based polyol include polytetramethylene glycol and polypropylene glycol, and polytetramethylene glycol is particularly preferably used. Moreover, these number average molecular weights become like this. Preferably it is 1000-5000, More preferably, it is 1500-3000.

  The diisocyanate is not particularly limited. For example, aromatic diisocyanates such as 4,4′-diphenylmethane diisocyanate, 2,4-toluene diisocyanate, and 2,6-toluene diisocyanate, and aliphatics such as hexamethylene diisocyanate. Diisocyanate is mentioned. In the present invention, 4,4'-diphenylmethane diisocyanate is preferably used from the viewpoint of reaction stability with the isocyanate mixture when an isocyanate mixture described later is blended.

  Although it does not restrict | limit especially as a monomolecular chain extender, A normal polyhydric alcohol and amines can be used, for example, 1, 4- butylene glycol, 1, 2- ethylene glycol, 1, 3- propylene glycol, 1 , 3-butanediol, 1,6-hexylene glycol, 2,2-dimethyl-1,3-propanediol, 1,3-butylene glycol, dicyclohexylmethylmethanediamine (hydrogenated MDA), isophoronediamine (IPDA), etc. Is mentioned. These chain extenders preferably have an average molecular weight of 20 to 15000.

  As such a polyurethane elastomer, a commercially available product can be used. For example, Pandex T7298, TR3080, T8230, T8290, T8295, T8260 (manufactured by DIC Bayer Polymer Co., Ltd.), Resamine 2593, 2597 ( Dainichi Seika Kogyo Co., Ltd.). These may be used individually by 1 type and may use 2 or more types together.

Moreover, as a material which forms the said cover, the following (A)-(D) component,
(A-1) a metal ion neutralized product of an olefin-unsaturated carboxylic acid binary random copolymer and / or an olefin-unsaturated carboxylic acid binary random copolymer;
(A-2) Metal ion neutralized product of olefin-unsaturated carboxylic acid-unsaturated carboxylic acid ternary random copolymer and / or olefin-unsaturated carboxylic acid-unsaturated carboxylic acid ternary random copolymer (A) a base resin blended so that the mass ratio is 100: 0 to 0: 100,
(B) With respect to 100 parts by mass of a resin component blended with a non-ionomer thermoplastic elastomer in a mass ratio of 100: 0 to 50:50,
(C) a fatty acid having a molecular weight of 228 to 1500 and / or a derivative thereof, 5 to 120 parts by mass,
(D) A resin composition comprising 0.1 to 17 parts by mass of a basic inorganic metal compound capable of neutralizing an unneutralized acid group in component (A) and component (C) as an essential component. It can be illustrated.

  As will be described later, the present invention is characterized by having a layer containing a butyl rubber ionomer. However, from the viewpoint that the desired effect of the present invention can be sufficiently exerted, 1 adjacent to the layer containing the butyl rubber ionomer is provided. The layer is preferably a resin material in which the above components (A) and (B) are blended. More preferably, a resin material in which all the components (A), (B), (C) and (D) are blended is employed.

  As the components (A) to (D), for example, the resin material (A) to (D) components described in JP2011-120898A can be suitably used.

  In addition, various additives can be blended in the material for forming the cover, if necessary. For example, pigments, dispersants, antioxidants, light-resistant stabilizers, ultraviolet absorbers, release agents, and the like are appropriately used. Can be blended.

  A known method can be used as a method for forming each layer of the cover, and is not particularly limited. For example, a core prepared in advance or a coated sphere coated with each layer is placed in a mold, and A method of injection molding the resin material prepared in (1) can be employed. A paint layer can be provided on the surface of the outermost layer of the cover.

In the present invention, at least one of the golf ball members contains a butyl rubber ionomer. The butyl rubber ionomer, for example, can be used following the butyl rubber ionomer described in JP 2008-156 6 06 JP.

  The content of the butyl rubber ionomer contained in the golf ball member is not particularly limited, but is 1 to 100% by mass, preferably 5% by mass or more, more preferably 20% by mass or more, based on the total weight of the layer. More preferably, it is 80 mass% or more. When this compounding quantity decreases, there exists a possibility that adhesiveness with the layer to adhere | attach may fall.

  Butyl rubber ionomers are prepared from halogenated butyl rubber polymers. Butyl rubber polymers are usually derived from at least one isoolefin monomer, at least one polyolefin monomer, and a further copolymerizable monomer.

  The butyl rubber polymer is not limited to a specific isoolefin. However, isoolefins having in the range of 4-16 carbon atoms, preferably in the range of 4-7, such as isobutene, 2-methyl-1-butene, 3-methyl-1-butene, 2- Methyl-2-butene and mixtures thereof are preferred. Isobutene is more preferred.

  The butyl rubber polymer is not limited to a specific polyolefin. Polyvalent olefins copolymerizable with isoolefins can be used. However, polyvalent olefins having in the range of 4 to 14 carbon atoms such as isoprene, butadiene, 2-methylbutadiene, 2,4-dimethylbutadiene, 3-methyl-1,3-pentadiene, 2,4-hexadiene 2-methyl-1,5-hexadiene, 2,5-dimethyl-2,4-hexadiene, 2-methyl-1,4-pentadiene, 2-methyl-1,6-heptadiene, cyclopentadiene, cyclohexadiene, and Mixtures of these, preferably conjugated dienes are used. More preferably, isoprene is used.

  As an optional monomer, a monomer copolymerizable with isoolefin and / or diene can be used. Preferably α-methyl styrene, p-methyl styrene, chlorostyrene, and other styrene derivatives may also be used.

  In one embodiment, the butyl rubber ionomer is prepared from a butyl rubber polymer having 1.5 to 2.2 mole percent polyolefin monomer. In other embodiments, it is either pre-prepared from a butyl rubber polymer with a higher polyolefin content (eg, greater than 2.5 mol%).

  The butyl rubber polymer can then be subjected to a halogenation step to produce a halobutyl polymer. Bromination or chlorination is described, for example, in rubber technology, 3rd edition, edited by Maurice Morton, Kluwer Academic Publishers, pages 297-300 and further references cited therein. Can be carried out according to the procedure.

  In the halogenation, part or all of the polyvalent olefin contained in the butyl polymer is converted into an allyl halide. Accordingly, the allylic halide in the halobutyl polymer is a repeating unit derived from a polyolefin monomer originally present in the butyl polymer. The total amount of allyl halide contained in the halobutyl polymer cannot exceed the initial content of the polyvalent olefin in the base butyl polymer.

（式中、
Ａは、窒素またはリンであり、
Ｒ₁、Ｒ₂、およびＲ₃は、直鎖または分岐のＣ₁〜Ｃ₁₈アルキル置換基、単環であるかもしくはＣ₄〜Ｃ₈縮合環から構成されるアリール置換基、ならびに／またはヘテロ原子（例えば、Ｂ、Ｎ、Ｏ、Ｓｉ、Ｐ、およびＳから選択される原子）からなる群から選択される）に従う、少なくとも１種の窒素またはリン含有求核剤と反応させることができる。 The allylic halide moiety of the halobutyl polymer is then represented by the following formula:

(Where
A is nitrogen or phosphorus;
R ₁ , R ₂ , and R ₃ are linear or branched C ₁ -C ₁₈ alkyl substituents, aryl substituents that are monocyclic or composed of C ₄ -C ₈ fused rings, and / or hetero Can be reacted with at least one nitrogen- or phosphorus-containing nucleophile according to an atom (for example selected from the group consisting of B, N, O, Si, P, and S).

  In general, a suitable nucleophile will contain at least one nitrogen or phosphorus center with a lone pair of electrons available both electronically and sterically when participating in a nucleophilic substitution reaction. Suitable nucleophiles include trimethylamine, triethylamine, trimethylphosphine, triethylphosphine.

  The amount of nucleophile that is subjected to the reaction with butyl rubber is 0.1 to 5 molar equivalents, more preferably 0.2 to 4 based on the total molar amount of allyl halide present in the halobutyl polymer. The molar equivalent may be within a range of 0.3 to 3 molar equivalents.

  Since the nucleophile reacts with the allylic halide group of the halobutyl polymer, the resulting ionomeric moiety is a repeating unit derived from the allylic halide. Therefore, the total content of ionomeric moieties in the butyl ionomer cannot exceed the initial amount of allylic halide in the halobutyl polymer. On the other hand, residual allyl halides and / or residual polyolefins may be present. The resulting halobutyl-based ionomer preferably has at least 0.1 mol%, preferably at least 0.2 mol%, more preferably at least 0.3 mol% ionomer moieties. The residual allylic halide may be present in an amount from 0.1 mol% up to an amount not exceeding the original allylic halide content of the halobutyl polymer used to make the butyl ionomer. The residual polyolefin may be present in an amount from 0.1 mol% up to an amount that does not exceed the original polyolefin content of the butyl polymer used to make the halobutyl polymer. Typically, the residual polyolefin content of the ionomer is at least 0.4 mol%, preferably at least 1.0 mol%, and most preferably at least 3.0 mol%.

  The butyl rubber ionomer can be dissolved in an organic solvent and used as a butyl rubber ionomer solution. In this case, the content of butyl rubber ionomer in the solution is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and further preferably 1.0% by mass or more. If the content is too small, the effect of improving the adhesion treatment to the core surface or the like cannot be expected, and the impact durability may be inferior. As an upper limit, it is 20 mass% or less, Preferably it is 10 mass% or less, More preferably, it is 5 mass% or less. When there is too much said content, it may not fully melt | dissolve in an organic solvent.

  Examples of the organic solvent include hexane, cyclohexane, isooctane, dichloromethane, chloroform, tetrachloroethane, trichloroethylene, benzene, toluene, ethylbenzene, dichlorobenzene, and chlorotoluene. Particularly preferred are those containing isooctane, benzene, toluene or chloroform.

  The above butyl rubber ionomer solution can contain one or more fillers (for example, silica, silicate, clay, bentonite, vermiculite, nontronite, beidellite, vorconsky stone, hectorite, saponite. Inorganic particles selected from the group consisting of laponite, sauconite, layered polysilicate, kenyaite, ladykite, gypsum, alumina, titanium dioxide, talc and the like, and mixtures thereof can be used.

Moreover, the following are also mentioned as an example of another suitable filler.
(1) Highly dispersible silica produced by precipitation of a silicate solution or flame hydrolysis of silicon halide, having a specific surface area (BET specific surface area) of 50 to 1000 m ² / g, preferably 20 to 400 m ² / g, (2) Aluminum silicate and alkaline earth metal silicate (3) Magnesium silicate or calcium silicate having a BET specific surface area of 20 to 400 m ² / g and a main particle size of 10 to 400 nm (4) Kaolin and other natural silicas (5) Natural clays such as montmorillonite and other natural clays (6) Glass fibers and glass fiber products (7) Zinc oxide, calcium oxide, magnesium oxide, aluminum oxide, magnesium carbonate, carbonic acid Calcium, zinc carbonate, aluminum hydroxide and Metal oxides such as magnesium oxide, metal carbonate or metal hydroxide

  About content of the filler (filler) contained in the said butyl rubber ionomer solution, it can adjust suitably in the range which does not inhibit the effect of this invention. Specifically, the inorganic filler is preferably contained in an amount of 0.1 to 30% by mass with respect to the total weight of the layer.

  As a method for treating the butyl rubber ionomer solution, a method of applying the butyl rubber ionomer solution to the surface of the core or each layer by brushing or spraying, or a method of immersing a sphere coated with the core or each layer in the treatment solution of the butyl rubber ionomer solution In particular, the dipping method is preferably used from the viewpoints of productivity and adhesion efficiency to the core surface.

  Although there is no restriction | limiting in particular about the thickness of the layer containing the said butyl rubber ionomer, It is suitable that it is the range of 1 micrometer-100 micrometers. Although depending on the treatment of the butyl rubber ionomer solution, a thin layer (skin layer) containing butyl rubber ionomer can be formed on the surface of the sphere coated with the core and each layer. The thickness of the thin layer is preferably 1 μm or more, more preferably 2 μm or more, further preferably 3 μm or more, and the upper limit is 100 μm or less, preferably 50 μm or less, more preferably 20 μm or less.

  Further, as a post-process, it is possible to appropriately provide a drying process for sufficiently drying the thin layer (skin layer) described above.

  In the present invention, as described above, the surface of the sphere coated with the core or each layer is treated with a butyl rubber ionomer solution to improve the adhesion between these layers. It can be preferably 1.18 N / 4 mm or more, particularly preferably 1.37 N / 4 mm or more, by a method for measuring adhesive strength described later.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not restrict | limited to the following Example.

[Examples 1-3, Comparative Examples 1-3]
Formation of Core After preparing the rubber composition shown in Table 1, a core was prepared by vulcanization molding under vulcanization conditions of 157 ° C. for 15 minutes.

The details of the rubber composition described in Table 1 are as follows.
Polybutadiene rubber I: “BR01” manufactured by JSR
Polybutadiene rubber II: “BR51” manufactured by JSR
Zinc acrylate: Zinc oxide manufactured by Nippon Distillation Industry Co., Ltd .: Barium sulfate manufactured by Sakai Chemical Industry Co., Ltd. Sakai Chemical Industry Co., Ltd. “Precipitated barium sulfate 100”
Anti-aging agent: “NOCRAK NS-6” manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.
Organic peroxides: NOF Corporation "Park Mill D", Dicumyl peroxide

  Next, in Examples 1 to 3, the treatment solution of the butyl rubber ionomer solution having the composition shown in Table 3 was immersed on the core surface at the immersion time shown in Table 3 at room temperature (27 ° C.), and then sufficiently dried. It was. In Comparative Example 3, a butyl rubber solution was used as the treatment solution instead of the butyl rubber ionomer solution.

[Core skin layer]
(1) Butyl rubber ionomer solution A butyl rubber ionomer was added to a chloroform solution, and stirred at room temperature for 3 hours to dissolve.
-Butyl rubber ionomer: manufactured by LANXESS Corporation-Chloroform: "chloroform special grade" manufactured by Kanto Chemical Co., Inc. (2) Butyl rubber solution Butyl rubber was added to the chloroform liquid and stirred at room temperature for 3 hours to dissolve.
・ Butyl rubber: “Butyl365” manufactured by JSR ・ Chloroform: “Chloroform special grade” manufactured by Kanto Chemical

  Next, the resin composition shown in Table 2 is used to produce a multi-piece solid golf ball by sequentially coating the surrounding surface, intermediate layer, and outermost layer around the core surface (and skin layer) by injection molding. did.

The details of the resin composition described in Table 2 are as follows.
・ HPF1000: DuPont Ionomer ・ High Milan: Mitsui DuPont Polychemical Ionomer ・ T-8283, T-8290: DIC Bayer Polymer brand name “Pandex”, MDI-PTMG type thermoplastic polyurethane ・ Polyethylene Wax: Trade name “Sun Wax 161P” (manufactured by Sanyo Kasei Co., Ltd.)

The obtained golf balls were evaluated for adhesion strength and impact durability by the following methods. The results are shown in Table 3.

Adhesive strength In FIG. 1, two parallel cuts 11 and 12 with an interval of 4.0 mm that penetrate the envelope layer 2 in a state where the envelope layer was covered were made, and the envelope layers at both ends were peeled off. Next, after the cut 13 crossing the two cuts 11 and 12 at a right angle is inserted so as to penetrate the envelope layer 2, the core portion 1 is fixed, and the cut portion of the envelope layer 2 is pulled to bond strength. Was measured. The measurement method is an Instron testing machine, based on JIS K6256 “Adhesion test method for vulcanized rubber and thermoplastic rubber”, the above test piece is used for the test piece, and the moving speed of the gripping tool is 50 mm / min. The tensile strength was measured every 0.1 mm. The average of the tensile strengths of the three test pieces excluding the first 1/4 and the last 1/4 of all measurement points was defined as the adhesive strength (unit: N).

By ADC Ball COR Durability Tester of durability to impact the United States Automated Design Corporation, Ltd., to evaluate the durability of the ball. This test machine has a function of causing a golf ball to be blown with air pressure and then continuously colliding with two metal plates installed in parallel. The incident speed on the metal plate was 43 m / s. The number of firings required to break the golf ball was measured. The index when the average value (n = 5) of the number of times the ball of Example 3 started to crack was set to 100 (reference value) was obtained, and the results of evaluation based on the following criteria were shown.
○: 95 or more ×: less than 95

The following is considered from the experimental results in Table 3 above.
Comparative Example 1 is an example of a four-layer golf ball in which the core surface was not treated at all. Compared with Examples 1 and 2, the adhesive strength was low and durability by repeated hitting was low.
Comparative Example 2 is an example of a four-layer golf ball in which the core surface was not treated at all. Compared with Example 3, the adhesive strength was low, and durability by repeated hitting was low.
Comparative Example 3 is an example of a four-layer golf ball in which the core surface is dipped with a butyl rubber solution. Compared to Example 3, the adhesive strength is low and durability by repeated hitting is low.
On the other hand, as shown in Table 3, Examples 1 to 3 show that the adhesive strength between the core surface and the envelope layer is improved, and as a result, the durability by repeated impacts is remarkably improved.

Claims (7)

  In a method for producing a golf ball comprising at least one core and at least one cover, a treatment solution in which a butyl rubber ionomer is dissolved in a solvent is prepared, and the treatment solution is added to at least one layer of the golf ball member ( By applying to the “treatment solution target layer”), a skin layer made of the treatment solution is formed on the surface of the treatment solution target layer, and the thickness of the skin layer is 1 to 5.6 μm. Then, the rubber layer, the resin layer, or the paint layer is coated on the adjacent outer layer, and the treatment solution target layer and the outer layer adjacent to the layer through the skin layer. A golf ball manufacturing method comprising adjusting an adhesive strength to be 1.37 N / 4 mm or more. The butyl rubber ionomer, the manufacturing method of the golf ball of claim 1, wherein made from nitrogen-based or halogenated butyl rubber is reacted with phosphorus nucleophile. The butyl rubber ionomer treatment solution, by dipping method, a manufacturing method according to claim 1 or 2 golf ball according subjected to at least one layer (treatment solution subject layer) of the golf ball member. The golf ball manufacturing method according to claim 3 , wherein the immersion treatment is performed at room temperature. The solvent of butyl rubber ionomer treatment solution isooctane, benzene, toluene, or any one golf ball manufacturing method of according to claims 1 to 4 is intended to include chloroform. The treatment solution target layer includes the following components (A) to (C):
(A) a base rubber (B) an organic peroxide (C) water and / or any one of claims 1 to 5, the monocarboxylic acid metal salt is formed by heating the molded product of the rubber composition obtained by blending A method for producing the golf ball according to claim. The method for producing a golf ball according to claim 6 , wherein the component (C) is water, and the amount of water is 0.1 to 5 parts by mass with respect to 100 parts by mass of the base rubber (A).

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