JP2007319432A - Golf ball - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a golf ball with excellent brightness and with a coating film excellent in durability. <P>SOLUTION: The golf ball comprises a golf ball body and the coating film covering the golf ball body. The golf ball body and/or coating film includes a photochromic laminated body 1 with laminated polymer layers 3 with different refractive indexes. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an improvement in the appearance of a golf ball, and more particularly to a technique for imparting glitter to a golf ball.

  Although golf balls are usually white, there is an increasing demand for golf balls that have a high-class feeling or a personalized appearance. In response to such demands, golf balls have been proposed in which glitter is imparted to golf balls.

  For example, Patent Document 1 discloses a golf ball provided with a mark formed on the surface of a golf ball main body and a transparent coating layer that covers the mark, and the transparent coating layer includes a base resin, A golf ball comprising a glittering material coated with a metal oxide on the surface of glass flakes and coated with a mark having a color tone satisfying L ≦ 40 when expressed in the Lab system Proposed. Since the glittering material is contained in the transparent coating layer covering the mark, it is possible to impart glitter to the golf ball without reducing the durability of the mark or the coating film itself.

In Patent Document 2, in a golf ball comprising a core and two or more layers covering the core, the base material of the outermost layer cover of the cover is a thermoplastic resin, and 100 parts by mass of the thermoplastic resin. While containing 0.2 to 5 parts by mass of the cholesteric liquid crystal polymer, the base material of the inner cover adjacent to the outermost layer cover is a thermoplastic resin, and titanium oxide is 1 part by mass or less with respect to 100 parts by mass of the thermoplastic resin. A golf ball characterized by containing a fluorescent pigment in an amount of 1 part by mass or less is disclosed.
JP 2004-166719 A JP-A-2005-52510

  The technique disclosed in Patent Document 1 can provide a golf ball having a unique appearance by imparting glitter without reducing the durability of the mark or coating film. Therefore, there has been a problem that the glittering material settles in the composition for forming a transparent coating layer. Further, when an anti-settling agent is added in order to prevent the glittering material from settling, a new problem has arisen in that the durability of the formed mark and coating film is lowered.

  In Patent Document 2, a glittering material of a liquid crystal polymer is used. However, since the glittering material of a liquid crystal polymer has a spiral structure, the pitch width may change depending on the temperature and the glitter may be reduced. is there. Further, when a liquid crystal polymer glittering material is used, the durability of the cover tends to decrease.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a golf ball having excellent glitter. Furthermore, an object of the present invention is to provide a golf ball having a coating film and a cover that have excellent glitter and excellent durability.

  The golf ball of the present invention that has solved the above problems is a golf ball having a golf ball main body and a coating film covering the golf ball main body, wherein the golf ball main body and / or the coating film comprises: It contains a photochromic laminate formed by laminating polymer layers having different refractive indexes.

  The photochromic laminate used in the present invention develops color due to the light interference action due to its fine multilayer structure (hereinafter sometimes simply referred to as “structural color development”). Utilizing such properties, the golf ball main body or the coating film covering the golf ball main body contains the photochromic laminate so that the golf ball has a glitter (color tone such as metallic luster). Can be granted. Furthermore, since a golf ball having a slightly different color appearance depending on the viewing angle can be obtained, a golf ball having a personalized appearance can be manufactured. For example, when the golf ball main body has a core and a cover, it is also a preferable aspect that the cover contains the photochromic laminate.

  The photochromic laminate is preferably one in which two types of polymer layers having different refractive indexes are alternately laminated, and more preferably five or more polymer layers having different refractive indexes are laminated. The thickness of the polymer layers having different refractive indexes is preferably, for example, 50 nm to 500 nm.

  Since the photochromic laminate used in the present invention is made of a polymer material having a low specific gravity, when it is contained in a coating film, the dispersibility in the coating film forming composition is improved. As a result, sedimentation is suppressed as compared with the case of using metallic powder or an inorganic mineral-based glittering material. The content of the photochromic laminate in the coating film is preferably 0.01 to 50 parts by mass with respect to 100 parts by mass of the base resin.

  According to the present invention, it is possible to provide a golf ball having excellent glitter. Furthermore, a golf ball having excellent durability of the coating film and the cover can be obtained. In addition, when the coating film is formed on the golf ball, since the precipitation of the photochromic laminate contained in the coating film forming composition can be suppressed, the quality of the golf ball can be stabilized.

  The golf ball of the present invention is a golf ball having a golf ball main body and a coating film covering the golf ball main body, wherein the golf ball main body and / or the coating film is formed by laminating polymer layers having different refractive indexes. It contains the photochromic laminated body formed.

  First, the photochromic laminate used in the present invention will be described. In the present invention, a photochromic laminate obtained by laminating polymer layers having different refractive indexes (hereinafter sometimes simply referred to as “photochromic laminate”) is contained. The photochromic laminate is formed by laminating polymer layers having different refractive indexes, and preferably by alternately laminating two types of polymer layers having different refractive indexes. FIG. 1 is an explanatory view schematically illustrating a cross-sectional structure of a photochromic laminate used in the present invention. In FIG. 1, a polymer layer 2 and polymer layers 3 having different refractive indexes are alternately laminated on the photochromic laminate 1. FIG. 2 is an explanatory view schematically illustrating another example of the cross-sectional structure of the photochromic laminate used in the present invention, in which a laminate portion 4 in which two types of polymer layers having different refractive indexes are laminated is shown. In this embodiment, the transparent polymer 5 is coated.

  The photochromic laminate used in the present invention is considered to exhibit excellent glitter by the following mechanism. That is, incident light that has entered the photochromic laminate from the outside is reflected on the surface of the laminate or the interface of the multilayer structure, and these reflected lights interfere. Since polymers with different refractive indexes are laminated, the reflected light of a specific color is intensified according to the angle of the reflected light, the thickness of the polymer layer, the number of laminated layers, etc., and it looks subtle depending on the viewing angle. Different metallic luster is obtained.

  The thickness of the polymer layer constituting the photochromic laminate is 50 nm or more, more preferably 100 nm or more, further preferably 150 nm or more, 500 nm or less, more preferably 400 nm or less, and further preferably 300 nm or less. It is preferable that This is because, when the thickness of the polymer layer is within the above range, the photochromic laminate is structurally colored, and it is easy to impart glitter to the mark. The number of polymer layers of the photochromic laminate is preferably 5 or more, more preferably 15 or more, preferably 100 or less, and more preferably 80 or less. This is because by setting the number of polymer layers to be within the above range, the photochromic laminate is structurally colored and easily imparts glitter to the mark.

  As the polymer constituting the photochromic laminate, polymers having different refractive indexes may be used, and two types of polymers having different refractive indexes are more preferably used. Examples of the polymer include polyester, polyamide, polycarbonate, polystyrene, silicone resin, polyvinyl acetal, polymethyl methacrylate, polyether sulfone, polyurethane, cellulose resin, acetal resin, fluororesin, and epoxy resin. The two polymers having different refractive indexes are preferably a combination having a difference in refractive index. In general, the refractive index of a polymer is in the range of 1.30 to 1.82, and in general-purpose polymers, it is in the range of 1.35 to 1.75. Among these, when the refractive index of the polymer on the high refractive index side is n1 and the refractive index of the polymer on the low refractive index side is n2, the ratio n1 / n2 of the refractive indexes of both polymers is 1.1 to 1.4. You can choose one that falls within the range. Specifically, the combination of polyester, polyamide, polyolefin, etc. is mentioned, More preferably, polyester and polyamide are suitable. In addition, the measuring method of the refractive index of a polymer can be measured according to JISK7105.

  In the photochromic laminate used in the present invention, the durability of the laminate can be further improved by coating the laminate where the polymer layers having different refractive indexes are laminated with a transparent polymer (FIG. 2). reference). As the transparent polymer, it is preferable to use any of the polymers used in the laminated part, and among the polymers used in the laminated part, a polymer having a higher melting point is used. Is a preferred embodiment. FIG. 3 shows an embodiment of a photochromic laminate in which the material of the polymer layer 3 used for the laminate and the transparent polymer 5 covering the laminate are the same. The thickness of the transparent polymer is 0.1 μm or more, more preferably 0.5 μm or more, further preferably 2 μm or more, and is 15 μm or less, more preferably 10 μm or less, and further preferably 7 μm or less. This is because if the thickness of the transparent polymer is out of the above range, the glitter may be lowered. In addition, the thickness of a transparent polymer shall point out the average value of the maximum thickness of the laminated part 4 in FIG.

  The photochromic laminate used in the present invention has an average particle size (median particle size distribution (median)) of 10 μm or more, more preferably 50 μm or more, more preferably 70 μm or more, and 2,000 μm or less. More preferably, it is 1,500 μm or less, and more preferably 1,000 μm or less. When the average particle size of the photochromic laminate is less than 10 μm, the glitter is weak, and when it is more than 2,000 μm, the durability is lowered (the coating film is easily peeled off by impact).

  The photochromic laminate has an average thickness of 1 μm or more, more preferably 5 μm or more, further preferably 10 μm or more, and 50 μm or less, more preferably 40 μm or less, and even more preferably 30 μm or less. desirable. When the average thickness of the photochromic laminate is less than 1 μm, the glitter is weak, and when it is more than 50 μm, the durability of the resulting coating film may be lowered.

  The photochromic laminate preferably has a refractive index in the visible light region of 1.0 or more, more preferably 1.2 or more, preferably 2.0 or less, and more preferably 1.8 or less. The specific gravity of the photochromic laminate is preferably 0.90 or more, more preferably 0.95 or more, preferably 1.60 or less, and more preferably 1.4 or less. This is because if the specific gravity is too small or too large, the photochromic laminate is easily separated from the coating film forming composition.

  Specific examples of the photochromic laminate used in the present invention include, for example, “Morphoton VM40C75” and “Morphoton RM40C75” manufactured by Teijin Fibers Limited.

  The golf ball of the present invention is a golf ball having a golf ball main body and a coating film covering the golf ball main body, wherein the golf ball main body and / or the coating film is formed by laminating polymer layers having different refractive indexes. And a photochromic laminate. That is, the golf ball body or the coating film that covers the golf ball body contains the photochromic laminate to obtain a golf ball having glitter. Specific embodiments include an embodiment in which only a golf ball body contains the photochromic laminate, an embodiment in which only a coating film covering the golf ball body contains the photochromic laminate, a golf ball body and the golf An example in which both of the coating films covering the ball body contain the photochromic laminate.

  Hereinafter, the coating film containing the photochromic laminate will be described. The coating film should just be provided so that a golf ball main body may be coat | covered. The coating film may be a so-called clear paint layer that contains a base resin and the photochromic laminate, and does not contain other pigments, or the base resin and the photochromic laminate. And so-called enamel paint layers containing other pigments.

  The base resin of the coating film is not particularly limited, and an acrylic resin, an epoxy resin, a urethane resin, a polyester resin, a cellulose resin, or the like can be used, but it is preferable to use a two-component curable urethane resin described later. . This is because when a two-component curable urethane resin is used, a coating film having further excellent durability can be obtained.

  The two-component curable urethane resin is a urethane resin obtained by reacting and curing a main agent and a curing agent, and examples thereof include those obtained by curing a main component containing a polyol component with a polyisocyanate compound and a derivative thereof.

The main component containing the polyol component preferably further contains the specific urethane polyol as shown below. Urethane polyol is synthesized by a reaction between a polyisocyanate compound and a polyol. The polyisocyanate compound used for the synthesis is not particularly limited as long as it has two or more isocyanate groups. For example, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 2,4-toluene diisocyanate, Mixture of 6-toluene diisocyanate (TDI), 4,4′-diphenylmethane diisocyanate (MDI), 1,5-naphthylene diisocyanate (NDI), 3,3′-vitrylene-4,4′-diisocyanate (TODI), xylylene range diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), aromatic polyisocyanates such as p-phenylene diisocyanate (PPDI); 4,4'-dicyclohexylmethane diisocyanate _(H 12 MDI), hydrogenated Kishirire Diisocyanate _(H 6 XDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IIPDI), 1 or a mixture of two or more of the alicyclic polyisocyanate, or an aliphatic polyisocyanate such as norbornene diisocyanate (NBDI) are Can be mentioned. Of these, non-yellowing polyisocyanates (TMXDI, XDI, HDI, H ₆ XDI, IPDI, H ₁₂ MDI, NBDI, etc.) are preferably used from the viewpoint of weather resistance. In addition, the said polyisocyanate compound can also be used as a hardening | curing agent for hardening a urethane polyol.

  The polyol used for the production of the urethane polyol is not particularly limited as long as it has a plurality of hydroxyl groups, and examples thereof include a low molecular weight polyol and a high molecular weight polyol. Examples of the low molecular weight polyol include diols such as ethylene glycol, diethylene glycol, triethylene glycol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol; glycerin, trimethylol Examples include triols such as propane and hexanetriol. High molecular weight polyols include polyether polyols such as polyoxyethylene glycol (PEG), polyoxypropylene glycol (PPG), polyoxytetramethylene glycol (PTMG); polyethylene adipate (PEA), polybutylene adipate (PBA) ), A polycondensed polyester polyol such as polyhexamethylene adipate (PHMA); a lactone polyester polyol such as poly-ε-caprolactone (PCL); a polycarbonate polyol such as polyhexamethylene carbonate; and an acrylic polyol. Among the above polyols, those having a weight average molecular weight of 50 to 2,000, particularly about 100 to 1,000 are preferably used. In addition, you may use these polyols 1 type or in mixture of 2 or more types.

  The urethane polyol is a polyol having a hydroxyl group at the terminal by reacting the polyisocyanate compound with the polyol to form a urethane bond. Here, the ratio of the urethane bond in the urethane polyol is preferably 0.1 to 5 mmol / g with respect to 1 g of the urethane polyol. This is because the urethane bond ratio is related to the rigidity of the coating film to be formed, and if it is less than 0.1 mmol / g, the urethane concentration in the coating film to be formed is low, resulting in insufficient scratch resistance. On the other hand, if it exceeds 5 mmol / g, the coating film becomes too hard, the followability to the deformation of the golf ball body is lowered, and cracking is likely to occur.

  The weight average molecular weight of the urethane polyol is 4,000 or more, preferably 4,500 or more and less than 10,000, preferably 9,000 or less. This is because if it is less than 4,000, drying takes time and workability and productivity are lowered. On the other hand, a high molecular weight urethane polyol of 10,000 or more has a relatively small hydroxyl value of the urethane polyol, and the reaction amount after coating is reduced, resulting in a decrease in adhesion to the base. Moreover, if the weight average molecular weight is 9,000 or less, a dense coating film (or clear paint layer) can be formed with little decrease in adhesion even in a wet state.

  The hydroxyl value of the urethane polyol is preferably 15 mgKOH / g or more, particularly 73 mgKOH / g or more, and 130 mgKOH / g or less, particularly preferably 120 mgKOH / g or less. If the amount is less than 15 mgKOH / g, the amount of reaction with the curing agent is insufficient, so that it is difficult to obtain adhesion strength with the ball body. On the other hand, if it exceeds 130 mgKOH / g, it takes time for the reaction with the curing agent, the drying time becomes longer, the productivity is lowered, and cracking is likely to occur at the time of impact.

  The urethane polyol as described above is obtained by reacting a polyol and a polyisocyanate compound as raw materials at a ratio such that the hydroxyl group of the polyol component is excessive in molar ratio with respect to the isocyanate group of the polyisocyanate compound. It is done. In the above reaction, a known catalyst (such as dibutyltin dilaurate) can be used for the solvent or urethanization reaction. The urethane bond ratio can be adjusted by adjusting the molecular weight of the polyol used as a raw material, the blending ratio of the polyol and the polyisocyanate compound, and the like.

  The polyol component constituting the main agent is preferably the specific urethane polyol itself, that is, the main agent is substantially the specific urethane polyol, but is compatible with the urethane polyol in addition to the urethane polyol. A polyol having no urethane bond may be contained. The polyol having no urethane bond in this case is not particularly limited, and the above-described raw material polyol for urethane polyol synthesis can be used. When the main agent contains a polyol having no urethane bond, the content of the urethane polyol in the main agent is preferably 50% by mass or more, more preferably 80% by mass or more. This is because when the content of the urethane polyol in the main agent is less than 50% by mass, the content of the urethane polyol is relatively decreased, and thus the drying time becomes longer.

  The content of the photochromic laminate in the coating film is not particularly limited, but is 0.01 parts by mass or more, more preferably 0.05 parts by mass or more with respect to 100 parts by mass of the base resin. The photochromic laminate is more preferably 0.1 parts by mass or more and 50 parts by mass or less, more preferably 45 parts by mass or less, and further preferably 25 parts by mass or less. This is because when the content of the photochromic laminate is less than the lower limit, the glitter is insufficient, and when it exceeds the upper limit, durability due to impact tends to decrease.

  In addition to the base resin, the coating film may further contain an ultraviolet absorber, an antioxidant, a light stabilizer, a fluorescent whitening agent, an antiblocking agent, a pigment, and the like that can be generally contained in golf paints. An agent may be included.

  A mark is usually formed on the surface of the golf ball body. The mark formed on the surface of the golf ball main body can be formed using what is usually used as a golf ball mark ink composition, and includes pigments, solvents, base resins, and other additives. The thing to contain can be mentioned. The base resin of the mark ink composition is not particularly limited, and examples thereof include polyester, epoxy resin, nitrified cotton, acrylic resin, vinyl chloride-vinyl acetate copolymer, polyurethane, polyamide, etc. Epoxy resin, polyester, nitrified cotton and the like are preferable. When using an epoxy resin as the base resin, it is preferable to use, for example, a polyisocyanate such as hexamethylene diisocyanate, isophorone diisocyanate, or tolylene diisocyanate as a curing agent. The solvent for the mark ink composition is not particularly limited, and examples thereof include cyclohexanone, acetylacetone, propylene glycol monomethyl ether acetate, methoxymethyl butyl acetate, ethyl acetate, aromatic hydrocarbon, and a mixed solvent of two or more thereof. It is done. Examples of the other additives include a matting agent and an antifoaming agent. As the matting agent, colloidal silica, low density polyethylene particles, medium density polyethylene particles, and the like can be used. As the antifoaming agent, methylsiloxane or the like can be used.

  The structure of the golf ball of the present invention is not particularly limited, and may be a one-piece golf ball, a two-piece golf ball, a multi-piece golf ball higher than a three-piece golf ball, or a thread wound golf ball. This is because the present invention can be preferably applied in any case. In particular, in the case of a golf ball having a core and a cover, the golf ball can be provided with glitter by including the above-described photochromic laminate in the outermost layer cover.

  The resin component of the cover composition forming the cover is not particularly limited, and examples thereof include polyurethane, ionomer resin, polyamide, polyester, or a mixture thereof. In particular, the main component of the resin component is preferably a polyurethane or ionomer resin, and the content of the polyurethane or ionomer resin is 50% by mass or more, more preferably 70% by mass or more, and still more preferably 90% by mass. It is preferable to contain above. Furthermore, it is also a preferable aspect that the resin component is substantially made only of polyurethane or ionomer resin. This is because if a polyurethane or ionomer resin is employed as the resin component of the cover composition, a cover with excellent durability can be obtained.

  The polyurethane that can be used as the resin component of the cover composition is not particularly limited as long as it has a plurality of urethane bonds in the molecule. For example, by reacting a polyisocyanate and a polyol, the urethane bond becomes a molecule. The product formed inside is obtained by further reacting with a polyamine or the like, if necessary. Examples of the polyurethane include thermoplastic polyurethane and thermosetting (two-component curing type) polyurethane.

The polyurethane generally contains a polyisocyanate component and a polyol component, and further contains a polyamine component as necessary. The polyisocyanate component is not particularly limited as long as it has two or more isocyanate groups. For example, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 2,4-toluene diisocyanate, and 2,6-toluene. Mixtures of diisocyanates (TDI), 4,4′-diphenylmethane diisocyanate (MDI), 1,5-naphthylene diisocyanate (NDI), 3,3′-bitrylene-4,4′-diisocyanate (TODI), xylylene diisocyanate ( XDI), tetramethyl xylylene diisocyanate (TMXDI), aromatic polyisocyanates such as p-phenylene diisocyanate (PPDI); 4,4'-dicyclohexylmethane diisocyanate _(H 12 MDI), hydrogenated xylylene diisocyanate Over preparative _(H 6 XDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), 1 kind of cycloaliphatic polyisocyanates or aliphatic polyisocyanates such as norbornene diisocyanate (NBDI), or, two or more And so on.

From the viewpoint of improving the scratch resistance, it is preferable to use an aromatic polyisocyanate as the polyisocyanate component of the polyurethane. By using the aromatic polyisocyanate, the mechanical properties of the resulting polyurethane are improved, and a cover having excellent scratch resistance can be obtained. From the viewpoint of improving weather resistance, non-yellowing polyisocyanates (TMXDI, XDI, HDI, H ₆ XDI, IPDI, H ₁₂ MDI, NBDI, etc.) may be used as the polyisocyanate component of polyurethane. Preferably, more preferably 4,4′-dicyclohexylmethane diisocyanate (H ₁₂ MDI) is used. This is because 4,4′-dicyclohexylmethane diisocyanate (H ₁₂ MDI) has a rigid structure, the mechanical properties of the resulting polyurethane are improved, and a cover having excellent scratch resistance can be obtained.

  The polyol component constituting the polyurethane is not particularly limited as long as it has a plurality of hydroxyl groups, and examples thereof include a low molecular weight polyol and a high molecular weight polyol. Examples of the low molecular weight polyol include diols such as ethylene glycol, diethylene glycol, triethylene glycol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol; glycerin, trimethylol Examples include triols such as propane and hexanetriol. Examples of the high molecular weight polyol include polyether polyols such as polyoxyethylene glycol (PEG), polyoxypropylene glycol (PPG), and polyoxytetramethylene glycol (PTMG); polyethylene adipate (PEA), polybutylene adipate (PBA), condensation-type polyester polyols such as polyhexamethylene adipate (PHMA); lactone-type polyester polyols such as poly-ε-caprolactone (PCL); polycarbonate polyols such as polyhexamethylene carbonate; and acrylic polyols A mixture of at least two of the above-described polyols may be used.

  Although the average molecular weight of a high molecular weight polyol is not specifically limited, For example, it is preferable that it is 400 or more, More preferably, it is 1000 or more. This is because if the average molecular weight of the high molecular weight polyol becomes too small, the resulting polyurethane becomes hard and the feel at impact of the golf ball decreases. The upper limit of the average molecular weight of the high molecular weight polyol is not particularly limited, but is 10,000 or less, more preferably 8000 or less.

  Moreover, the polyamine which comprises the said polyurethane as needed is not specifically limited if it has at least 2 or more amino groups. Examples of the polyamine include aliphatic polyamines such as ethylenediamine, propylenediamine, butylenediamine and hexamethylenediamine, alicyclic polyamines such as isophoronediamine and piperazine, and aromatic polyamines.

  The aromatic polyamine is not particularly limited as long as at least two amino groups are directly or indirectly bonded to the aromatic ring. Here, being indirectly bonded means that the amino group is bonded to the aromatic ring via, for example, a lower alkylene group. The aromatic polyamine may be, for example, a monocyclic aromatic polyamine in which two or more amino groups are bonded to one aromatic ring, or an amino in which at least one amino group is bonded to one aromatic ring. It may be a polycyclic aromatic polyamine containing two or more phenyl groups.

  Examples of the monocyclic aromatic polyamine include a type in which an amino group such as phenylenediamine, toluenediamine, diethyltoluenediamine, and dimethylthiotoluenediamine is directly bonded to an aromatic ring; and an amino group such as xylylenediamine. Examples include a type bonded to an aromatic ring via a lower alkylene group. The polycyclic aromatic polyamine may be poly (aminobenzene) in which at least two aminophenyl groups are directly bonded, or at least two aminophenyl groups intervene with a lower alkylene group or an alkylene oxide group. May be combined. Of these, diaminodiphenylalkanes in which two aminophenyl groups are bonded via a lower alkylene group are preferred, and 4,4′-diaminodiphenylmethane and its derivatives are particularly preferred.

  In the present invention, it is one of preferred embodiments to use a thermoplastic polyurethane as the resin component of the cover composition, and it is more preferable to use a thermoplastic polyurethane elastomer. The thermoplastic polyurethane elastomer is a polyurethane exhibiting so-called rubber elasticity, and a cover having high resilience can be obtained by using the thermoplastic polyurethane elastomer. The thermoplastic polyurethane elastomer is not particularly limited as long as it can form a cover by, for example, injection molding or compression molding. “Elastolan XNY90A” and “Elastolan XNY97A” commercially available from BASF Japan Ltd. "Elastolan XNY585" can be used.

Moreover, in this invention, it is also a preferable aspect to use a thermosetting polyurethane as a resin component of the composition for covers. Since thermosetting polyurethane can generate many three-dimensional crosslinking points, a cover having excellent durability can be obtained. Examples of the thermosetting polyurethane include a type in which an isocyanate group-terminated urethane prepolymer is cured with a curing agent such as polyamine or polyol, or a hydroxyl group or amino group-terminated urethane prepolymer is cured with a curing agent such as polyisocyanate. List types. The polyamine, polyol, and polyisocyanate used as the curing agent can be appropriately selected from those described above. Among these, as the thermosetting polyurethane, those obtained by curing an isocyanate group-terminated urethane prepolymer with a polyamine are preferable. In this case, the molar ratio (NH ₂ / NCO) of the curing agent amino group to the isocyanate group of the urethane prepolymer is 0.70 or more, more preferably 0.80 or more, and further preferably 0.85 or more. It is desirable to set it to 20 or less, more preferably 1.05 or less, and still more preferably 1.00 or less. If it is less than 0.70, the amount of the isocyanate group-terminated urethane prepolymer with respect to the polyamine becomes excessive, and the formation reaction of allophanate crosslinking and burette crosslinking is likely to occur, and the flexibility of the finally obtained polyurethane becomes insufficient. On the other hand, if it exceeds 1.20, the isocyanate group is insufficient, so that allophanate and burette cross-linking reactions are difficult to occur. As a result, the number of three-dimensional cross-linking points becomes too small, and the thermosetting polyurethane finally obtained has a high strength. There is a tendency to decrease.

  In the present invention, it is also a preferable aspect to use an ionomer resin as the resin component of the cover composition. Examples of the ionomer resin include those obtained by neutralizing at least a part of carboxyl groups in a copolymer of ethylene and an α, β-unsaturated carboxylic acid with metal ions, or ethylene and an α, β-unsaturated carboxylic acid. The thing which neutralized at least one part of the carboxyl group in the ternary copolymer of an acid and (alpha), (beta)-unsaturated carboxylic acid ester with a metal ion can be mentioned. Examples of the α, β-unsaturated carboxylic acid include acrylic acid, methacrylic acid, fumaric acid, maleic acid, and crotonic acid, and acrylic acid or methacrylic acid is particularly preferable. As the α, β-unsaturated carboxylic acid ester, for example, methyl, ethyl, propyl, n-butyl, isobutyl ester, etc. such as acrylic acid, methacrylic acid, fumaric acid, maleic acid, etc. are used. Methacrylic acid esters are preferred. Copolymers of ethylene and α, β-unsaturated carboxylic acid, and carboxylic acid groups in the terpolymer of ethylene, α, β-unsaturated carboxylic acid and α, β-unsaturated carboxylic acid ester. Examples of metal ions that neutralize at least a part include alkali metal ions such as sodium, potassium, and lithium; divalent metal ions such as magnesium, calcium, zinc, barium, and cadmium; trivalent metal ions such as aluminum; tin Other ions such as zirconium and the like can be mentioned, and sodium, zinc and magnesium ions are particularly preferably used from the viewpoint of resilience and durability.

  Specific examples of the ionomer resin include Himiran 1555, 1557, 1605, 1652, 1702, 1705, 1706, 1707, 1855, 1856 (manufactured by Mitsui Dupont Polychemical), Surlyn 8945, Surlyn 9945, Surlyn AD8511, Surlyn AD8512, Examples include Surlyn AD8542 (manufactured by DuPont), IOTEK 7010, 8000 (manufactured by Exxon), and the like. As these ionomer resins, those exemplified above may be used alone or as a mixture of two or more.

  As a resin component of the cover composition in the present invention, it is also a preferable aspect to use a thermoplastic elastomer in addition to the base resin such as the thermoplastic polyurethane or the ionomer resin.

  Specific examples of the thermoplastic elastomer include thermoplastic polyamide elastomer commercially available from Arkema Co., Ltd. under the trade name “Pebax (eg,“ Pebax 2533 ”), and trade name“ Hytrel ”from Toray DuPont Co., Ltd. (For example, "Hytrel 3548", "Hytrel 4047") ", a thermoplastic polyester elastomer marketed by Mitsubishi Chemical Co., Ltd., a thermoplastic polystyrene elastomer marketed by the brand name" Lavalon ", a product from BASF Japan The thermoplastic polyurethane elastomer etc. which are marketed by the name "Elastollan" (for example, "Elastollan ET880") etc. are mentioned, Among these, a thermoplastic polystyrene elastomer is preferable. Examples of the thermoplastic polystyrene elastomer include a polystyrene-diene block copolymer having a polystyrene block component as a hard segment and a diene block component such as polybutadiene, isoprene, hydrogenated polybutadiene, and hydrogenated polyisoprene as a soft segment. be able to. The polystyrene-diene block copolymer has a double bond derived from a conjugated diene compound of a block copolymer or a partially hydrogenated block copolymer. Examples of the polystyrene-diene block copolymer include a block copolymer having an SBS (styrene-butadiene-styrene) structure having a polybutadiene block, or a block copolymer having an SIS (styrene-isoprene-styrene) structure. Is mentioned. The blending amount of the thermoplastic elastomer is preferably 1 to 60 parts by mass, more preferably 1 to 35 parts by mass with respect to 100 parts by mass of the base resin.

  When the photochromic laminate is contained in the cover, the content of the photochromic laminate in the cover composition is 0.001 part by mass or more, more preferably 0.001 part by mass with respect to 100 parts by mass of the resin component. 002 parts by mass or more, more preferably 0.003 parts by mass or more, 5 parts by mass or less, more preferably 1 part by mass or less, and further preferably 0.1 parts by mass or less. This is because, if the content of the photochromic laminate exceeds 5 parts by mass, a weld line appears clearly after molding, and the durability may be lowered. Further, when the content of the photochromic laminate is less than 0.001 part by mass, sufficient glitter cannot be obtained.

  In addition to the photochromic laminate, it is also preferable to add a normal pigment to the cover. This is because covers having various color tones and radiance can be obtained. The content of the pigment in the cover composition is 0.01 parts by mass or more, more preferably 0.02 parts by mass or more, and further preferably 0.03 parts by mass or more with respect to 100 parts by mass of the resin component. 1 part by mass or less, more preferably 0.5 part by mass or less, and still more preferably 0.1 part by mass or less. This is because if the pigment content exceeds 1 part by mass, the durability of the cover may decrease. Further, when the pigment content is less than 0.01 parts by mass, the desired color tone is not clear.

The pigment may be either an organic pigment or an inorganic pigment. Examples of the pigment include black pigments such as carbon black; white pigments such as titanium oxide; blue pigments such as ultramarine, cobalt blue, and phthalocyanine blue; purple pigments such as anthraquinone violet, dioxane violet, and methyl violet; titanium yellow Yellow pigments such as (20TiO ₂ —NiO—Sb ₂ O ₃ ), risurge (PbO), yellow lead (PbCrO ₄ ), yellow iron oxide (FeO (OH)), cadmium yellow, pigment yellow-1, and pigment yellow-12 Red pigments such as bengara (Fe ₂ O ₃ ), red lead (Pb ₃ O ₄ ), molybden red, cadmium red, pigment red-3, pigment red-57, and pigment orange-13. These pigments can be used alone or in admixture of two or more.

  The cover composition in the present invention further includes a specific gravity adjuster such as calcium carbonate and barium sulfate, a dispersant, an anti-aging agent, an ultraviolet absorber, a light stabilizer, a fluorescent material, or a fluorescent brightening agent, and the like. You may contain in the range which does not impair.

  In the present invention, the thickness of the cover is not particularly limited, but is 0.3 mm or more, more preferably 0.5 mm or more, still more preferably 0.8 mm or more, preferably 2.3 mm or less. 0.0 mm or less is more preferable, and 1.6 mm or less is more preferable. This is because if it is less than 0.3 mm, it may be difficult to form a cover or an intermediate layer. This is because if the thickness exceeds 2.3 mm, the cover becomes too thick, and the resilience of the resulting golf ball may decrease.

  Next, although the method of manufacturing the golf ball of the present invention will be described taking an example of a two-piece golf ball as an example, the present invention is not limited to such a manufacturing method and two-piece golf ball. As the core of the two-piece golf ball, a conventionally known core can be used. For example, a core rubber composition containing a base rubber, a crosslinking initiator, a co-crosslinking agent, a filler, an anti-aging agent, etc. Obtained by hot pressing. As the base rubber, natural rubber and / or synthetic rubber can be used. For example, polybutadiene rubber, natural rubber, polyisoprene rubber, styrene polybutadiene rubber, ethylene-propylene-diene rubber (EPDM) and the like can be used. Among these, it is particularly preferable to use a high-cis polybutadiene having a cis bond advantageous for repulsion of 40% or more, preferably 70% or more, more preferably 90% or more.

  As the crosslinking initiator, an organic peroxide can be suitably used. Examples of the organic peroxide include dicumyl peroxide, 1,1-bis (t-butylperoxy) -3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di (t-butyl). Peroxy) Organic peroxides such as hexane and di-t-butyl peroxide are exemplified, and among them, dicumyl peroxide is preferably used. The compounding amount of the organic peroxide is 0.3 parts by mass or more, more preferably 0.4 parts by mass or more and 5 parts by mass or less, more preferably 3 parts by mass with respect to 100 parts by mass of the base rubber. The following is desirable. If the amount is less than 0.3 parts by mass, the core tends to be too soft and the resilience tends to decrease. If the amount exceeds 5 parts by mass, the core becomes too hard and the feel at impact is reduced.

  As the co-crosslinking agent, an α, β-unsaturated carboxylic acid having 3 to 8 carbon atoms or a metal salt thereof can be used. Examples of the metal constituting the metal salt include zinc, magnesium, calcium, aluminum, and sodium, and zinc is preferably used because of its high resilience. Preferable examples of the α, β-unsaturated carboxylic acid or a metal salt thereof include acrylic acid, methacrylic acid, zinc acrylate, and zinc methacrylate.

  The amount of the co-crosslinking agent used is 10 parts by mass or more, more preferably 15 parts by mass or more, still more preferably 20 parts by mass or more, and more preferably 55 parts by mass or less, relative to 100 parts by mass of the base rubber. Is preferably 50 parts by mass or less, more preferably 48 parts by mass or less. When the amount of co-crosslinking agent used is less than 10 parts by mass, the amount of organic peroxide used must be increased in order to obtain an appropriate hardness, and the resilience tends to decrease. On the other hand, when the usage-amount of a co-crosslinking agent exceeds 55 mass parts, a core may become hard too much and there exists a possibility that a shot feeling may fall.

  The filler may be any material that is usually blended into the core of a golf ball, and includes inorganic salts (specifically, zinc oxide, barium sulfate, calcium carbonate, etc.), high specific gravity metal powder (eg, tungsten powder, molybdenum). Powders and the like) and mixtures thereof. The blending amount of the filler is 0.5 parts by mass or more, preferably 1 part by mass or more, and 30 parts by mass or less, preferably 20 parts by mass or less with respect to 100 parts by mass of the base rubber. desirable. When the amount is less than 0.5 parts by mass, it is difficult to adjust the specific gravity and an appropriate weight cannot be obtained.

  In addition to the base rubber, co-crosslinking agent, organic peroxide, and filler, the core rubber composition further contains an organic sulfur compound, an antioxidant, a peptizer, or the like as appropriate. be able to. The blending amount of the anti-aging agent is preferably 0.1 parts by mass or more and 1 part by mass or less with respect to 100 parts by mass of the base rubber. Moreover, it is preferable that a peptizer is 0.1 to 5 mass parts with respect to 100 mass parts of base rubber.

  The core can be obtained by mixing, kneading and molding the above-described rubber composition for a core in a mold. The conditions at this time are not particularly limited, but are usually 130 to 180 ° C. and a pressure of 2.9 to 11.8 MPa for 10 to 40 minutes.

  The above-mentioned cover composition is coated on the core obtained as described above to produce a golf ball body. As a method for molding the cover, for example, a method in which the cover composition is directly injection-molded onto the core, or a cover composition is molded in advance into a hemispherical half shell and the core is wrapped with two half shells. The method of heat-pressing etc. can be mentioned. Further, when a golf ball body is manufactured by covering a cover, a depression called dimple is usually formed on the surface. Further, the surface of the golf ball body may be subjected to a polishing process such as a sand blasting process, if necessary, in order to improve adhesion to a mark or a coating film.

  After the golf ball body is produced, a coating film is formed on the surface of the golf ball body (a mark is also formed if necessary). The coating film is formed by coating a coating film-forming composition containing the base resin and the photochromic laminate so as to cover the golf ball body and drying (or curing). The coating method of the coating film forming composition is not particularly limited, and can be applied to the golf ball main body using, for example, an air spray gun, electrostatic coating, or the like.

  Next, the coating film-forming composition applied to the surface of the golf ball can be treated, for example, at a temperature of 30 ° C. to 60 ° C. for about 1 to 6 hours to form a coating film. The film thickness of the coating film is not particularly limited, but is desirably 5 μm or more, more preferably 7 μm or more and 25 μm or less, and more preferably 18 μm or less. This is because if the film thickness is less than 5 μm, the coating film tends to wear and disappear due to continuous use, and if the film thickness exceeds 25 μm, the dimple effect decreases and the flight performance of the golf ball decreases.

  The coating film preferably has a single layer structure. A single-layer structure can simplify the painting process. In particular, according to the present invention, excellent physical properties (durability) are exhibited even in a single layer structure. The coating film is preferably an outermost clear paint layer.

  In the above-described manufacturing method, the embodiment of the two-piece golf ball has been described as an example. For example, in the case of a thread-wound golf ball, a thread-wound core may be used. At least one or more intermediate layers can be provided therebetween. The thread winding core includes a center and a thread rubber layer formed by winding a thread rubber around the center in a stretched state, and a conventionally known one can be used. As the center, either a liquid system (liquid center) or a rubber system (solid center) may be used. The thread rubber wound around the center can be the same as that conventionally used for the thread wound layer of a thread wound golf ball, for example, natural rubber or natural rubber and synthetic polyisoprene with sulfur, You may use what was obtained by vulcanizing | curing the rubber composition which mix | blended the vulcanization | cure adjuvant, the vulcanization accelerator, anti-aging agent, etc. The thread rubber is stretched about 10 times on the center and wound to form a thread wound core.

  In addition, as an intermediate layer of a three-piece or more multi-piece golf ball, for example, a thermoplastic resin such as polyurethane resin, ionomer resin, nylon or polyethylene; heat such as polystyrene elastomer, polyolefin elastomer, polyurethane elastomer, polyester elastomer Examples thereof include plastic elastomers. Here, as the ionomer resin, for example, a resin obtained by neutralizing at least a part of a carboxyl group in a copolymer of ethylene and an α, β-unsaturated carboxylic acid with a metal ion, or ethylene and an α, β-unsaturated resin. What neutralized at least one part of the carboxyl group in the ternary copolymer of saturated carboxylic acid and (alpha), (beta)-unsaturated carboxylic acid ester with a metal ion is mentioned. The intermediate layer may further contain a specific gravity adjusting agent such as barium sulfate or tungsten, an anti-aging agent, or a pigment.

  Hereinafter, the present invention will be described in detail by way of examples. However, the present invention is not limited to the following examples, and all modifications and embodiments without departing from the gist of the present invention are not limited thereto. Included in range.

[Evaluation methods]
(1) Precipitation property of glittering material 45 g of the prepared composition for forming a coating film is put in a transparent plastic container (screw bottle) and allowed to stand at 25 ° C. for 12 hours, and the presence or absence of sedimentation of the glittering material is visually observed. did.
Evaluation result present: Sedimentation was observed.
No: No sedimentation was observed.

(2) Brightness The golf ball on which the mark was formed was visually observed, and the glitter was evaluated based on the following evaluation criteria.
(Double-circle): A very clear glitter is recognized.
○: A clear glitter is recognized.
(Triangle | delta): Glossiness is recognized slightly.
X: Brightness is not recognized.

(3) Durability of coating film A driver (1W) is attached to a swing robot manufactured by Trutemper, and a golf ball is repeatedly hit 100 times at a head speed of 45 m / s, and the mark and the degree of peeling of the coating film are observed. Evaluation was made based on the following criteria.
A: Neither mark nor coating film was peeled off.
○: Peeling less than 1 mm ² occurred in either the mark or the coating film.
Δ: Peeling of less than 1 to 4 mm ² occurred in either the mark or the coating film.
X: Peeling of 4 mm ² or more occurred in either the mark or the coating film.

  In addition, since durability will reduce glossiness and visibility even if any layer of a mark and a coating film peels, it was set as comprehensive evaluation of all the layers.

(4) Durability of the cover A metal head # W1 driver is attached to a swing robot manufactured by Trutemper, and each golf ball is repeatedly hit at a head speed of 45 m / sec to measure the number of hits until the golf ball breaks. did. The durability of each golf ball is determined according to the golf ball no. The number of hits for each golf ball is shown as an index value with the number of hits of 1 as 100. The larger the indexed value, the more excellent the golf ball is.

[Production of golf ball body]
(1) Production of core A rubber composition for a core having the composition shown in Table 1 is kneaded and heated and pressed at 160 ° C. for 13 minutes in an upper and lower mold having hemispherical cavities to obtain a spherical core having a diameter of 39.3 mm. It was.

Polybutadiene rubber: BR11 manufactured by JSR Corporation
Zinc acrylate: ZNDA-90S manufactured by Nippon Distillation Co., Ltd.
Zinc oxide: Toho Zinc Co., Ltd.
Calcium carbonate: Bihoku powdering Co., Ltd.
Dicumyl peroxide: Park Mill D manufactured by NOF Corporation

(2) Preparation of composition for cover (intermediate layer) Using the compounding materials shown in Tables 2 and 3, mixing with a twin-screw kneading type extruder, each of the pellet-shaped cover (intermediate layer) composition Prepared. The extrusion conditions were a screw diameter of 45 mm, a screw rotation speed of 200 rpm, and a screw L / D = 35, and the blend was heated to 160-230 ° C. at the die position of the extruder.

(3) Production of golf ball body Intermediate layer and / or cover layer covering said core by direct injection molding the cover (intermediate layer) composition obtained above onto the core obtained as described above. A two-piece (or three-piece) golf ball body having a diameter of 42.7 mm was produced. The upper and lower molds for molding a cover have hemispherical cavities, are provided with dimples, and also serve as hold pins in which a part of the dimples can advance and retreat. The hold pin is protruded, the core is inserted and then held, and a resin heated to 210 ° C. is injected into a mold clamped at a pressure of 80 tons in 0.3 seconds, cooled for 30 seconds, and the mold is opened to open a golf ball Was taken out.

Ionomer resin ¹⁾ : High Milan 1605 / High Milan 1706 = 50/50
Ionomer resin ²⁾ : High Milan 1605 / High Milan 1706 / High Milan 1707 = 40/30/30
High Milan 1605: Sodium ion neutralized ethylene-methacrylic acid copolymer ionomer resin manufactured by Mitsui DuPont Polychemical Co., Ltd. High Milan 1706: Zinc ion neutralized ethylene-methacrylic acid copolymer ionomer resin manufactured by Mitsui DuPont Polychemical Co., Ltd. High Milan 1707: Sodium ion neutralized ethylene-methacrylic acid copolymer ionomer resin photochromic laminate manufactured by Mitsui DuPont Polychemical Co., Ltd. 1: Morphone VM40C75 manufactured by Teijin Fibers Limited, average particle diameter 75 μm, average thickness 10 μm
Photochromic laminate 2: Morphopine RM40C75 manufactured by Teijin Fibers Limited, average particle diameter 75 μm, average thickness 10 μm
Luminous material 1: Iriodin 100 manufactured by MERCK Co., Ltd .: Pearl pigment (mica coated with titanium oxide)
Cholesteric liquid crystal polymer: Heckerone HC Jade made by Wacker Chemie
Anti-settling agent: Aerosil manufactured by Nippon Aerosil Co., Ltd.

[Mark and coating formation]
Using the mark forming ink composition shown in Table 4, a mark “X” having a width of 8 mm × a height of 8 mm × a line width of 2 mm is pad-printed on the surface of the golf ball body, and then the golf ball body is covered. The coating film-forming composition shown in 4 was applied with an air gun and dried in an oven at 40 ° C. for 4 hours to produce a golf ball. The composition for forming a coating film was prepared as follows.

[Preparation of coating film forming composition]
1) Main agent: urethane polyol 60 parts by mass of PTMG250 (manufactured by BASF: polyoxytetramethylene glycol, molecular weight 250) and 54 parts by mass of 550 U (manufactured by Sumika Bayer Urethane: branched polyol having a molecular weight of 550) 120 parts by mass of solvent It was dissolved in (toluene and methyl ethyl ketone), and dibutyltin dilaurate was added to this so that it might become 0.1 mass% with respect to the whole main ingredient. While maintaining this polyol at 80 ° C., 66 parts by mass of isophorone diisocyanate was added dropwise to prepare urethane polyol (solid content 60% by mass, hydroxyl value 75 mgKOH / g, weight average molecular weight 7808).
2) Hardener: Isophorone diisocyanate (Suika Bayer Urethane)
3) Mixing ratio: NCO of curing agent / OH of main agent = 1.2 (molar ratio)
4) As shown in Tables 2 and 3, the photochromic laminate was added to 100 parts by mass of the two-component curable urethane resin component to prepare a coating film forming composition.

  Table 2 and Table 3 show the results of evaluating the glitter, sedimentation and durability of the obtained golf ball. In Table 2 and Table 3, golf ball No. 1-No. Reference numeral 16 denotes a case where the golf ball main body or at least one of the coating films covering the golf ball main body contains a photochromic laminate formed by laminating polymer layers having different refractive indexes. In any case, it can be seen that a golf ball excellent in glitter is obtained. In addition, even when the photochromic laminate is included in the coating film, the coating film forming composition does not show the precipitation of the glittering material, and a golf ball having excellent glitter and durability is obtained. It was.

  Golf ball no. No. 18 is a case where a conventional glittering material was blended in the coating film, and precipitation of the glittering material was observed in the coating film forming composition. Golf ball no. 19 is a golf ball No. 19; In this case, the anti-settling agent was added to No. 18, but the durability of the coating film was decreased. Golf ball no. 20 and no. 21 is a case where a cholesteric liquid crystal polymer was blended in the cover, but the durability (adhesion) of the cover was lowered. In addition, the brightness was slightly inferior. Golf ball no. No. 17 was a case where no glittering material was used, and no mark having glitter was obtained.

  The present invention provides a golf ball having glitter.

Explanatory drawing which shows typically the photochromic laminated body used by this invention. Explanatory drawing which shows typically another example of the photochromic laminated body used by this invention. Explanatory drawing which shows typically another example of the photochromic laminated body used by this invention.

Explanation of symbols

1: photochromic laminate, 2: polymer layer, 3: polymer layer having different refractive index, 4: laminate part, 5: transparent polymer

Claims (9)

  A golf ball having a golf ball main body and a coating film covering the golf ball main body, wherein the golf ball main body and / or the coating film is formed by laminating polymer layers having different refractive indexes. A golf ball comprising a body.   The golf ball according to claim 1, wherein the coating film contains 0.01 to 50 parts by mass of the photochromic laminate with respect to 100 parts by mass of the base resin.   3. The golf ball body according to claim 1, wherein the golf ball main body has a core and a cover, and the cover contains a photochromic laminate formed by laminating polymer layers having different refractive indexes. Golf ball.   The golf ball according to claim 1, wherein the photochromic laminate is obtained by alternately laminating two types of polymer layers having different refractive indexes.   The golf ball according to claim 1, wherein the polymer layers having different refractive indexes have a thickness of 50 nm to 500 nm.   The golf ball according to claim 1, wherein the photochromic laminate is obtained by laminating five or more polymer layers having different refractive indexes.   The photochromic laminate has a refractive index in the visible light region of 1.0 to 2.0 and a specific gravity of 0.90 to 1.60. Golf ball.   The golf ball according to claim 1, wherein the photochromic laminate has an average particle size of 10 μm to 2,000 μm.   The golf ball according to claim 1, wherein the polymers having different refractive indexes are polyester and polyamide.