JP5450769B2 - Golf ball - Google Patents

Description

  The present invention relates to a golf ball.

  A mark is printed on the golf ball. The mark includes a brand and a ball number. Golfers can distinguish their balls from others by brand. Golfers can also identify their own balls from others by the ball number. The golfer approaches the ball and identifies the ball based on the mark. From a distance, identification based on the mark is difficult.

  The golf ball includes a core and a cover. A general golf ball is colored almost white. Coloring is achieved by dispersing a pigment in the cover. Coloring may be achieved by painting the surface of the cover.

  Golf balls may be colored blue, red, or the like. These golf balls are called “color balls”. In a color ball, a large amount of pigment is dispersed in a cover or a paint layer. Color balls can be easily distinguished from white balls. However, the color ball lacks luxury. Color balls are avoided by golfers.

  There are golf balls in which metal powder is dispersed in a cover. The metal powder imparts glitter to the golf ball. The metal powder contributes to discrimination. However, the metal powder impairs the brightness of the golf ball. Golf balls using metal powder are inferior in quality.

  Japanese Patent Application Laid-Open No. 6-170013 discloses a golf ball in which a cover or a paint layer includes composite particles. The composite particles are composed of mica and titanium oxide covering the mica. This golf ball has a brilliant and polarizing appearance. This golf ball can be distinguished from a normal golf ball.

  Japanese Patent Application Laid-Open No. 2000-254251 discloses a golf ball in which a pigment containing a liquid crystal polymer is dispersed in a paint layer. This pigment contributes to polarization. The appearance of this golf ball is unique. This golf ball can be distinguished from a normal golf ball.

  Japanese Patent Application Laid-Open No. 2004-166719 discloses a golf ball in which a paint layer includes glass flakes. This golf ball is excellent in glitter. This golf ball can be distinguished from a normal golf ball.

JP-A-6-170013 JP 2000-254251 A JP 2004-166719 A

  Mica is a natural mineral and contains many impurities. This impurity impairs the saturation of the golf ball. Mica is translucent, so the hiding power of mica is weak. Therefore, sufficient glitter is not exhibited. Furthermore, since mica is inferior in strength, it is easily damaged during kneading. The polarizing property is impaired due to the damage. The golf ball disclosed in JP-A-6-170013 is inferior in luxury.

  Pigments containing liquid crystal polymers change color significantly upon use. Moreover, discoloration is conspicuous due to the polarization of the pigment. The golf ball disclosed in JP 2000-254251 is inferior in weather resistance.

  The glass flake particles are large. When a paint containing glass flakes is applied, the glass flakes impair the smoothness of the paint layer. This paint layer is inferior in appearance. Furthermore, the glass flakes hinder the durability of the paint layer. The golf ball disclosed in Japanese Patent Application Laid-Open No. 2004-166719 is inferior in the sense of quality and durability of the paint layer.

  An object of the present invention is to provide a golf ball excellent in distinguishability, luxury feeling, weather resistance, and durability of a paint layer.

  The golf ball according to the present invention includes a core, a cover that covers the core, and a paint layer that covers the cover. The cover or paint layer includes composite particles having a core and a coat layer covering the core. The nucleus is made of a metal oxide. The coat layer contains titanium oxide.

  Preferably, the nucleus consists of aluminum oxide. Preferably, the composite particles are flaky.

  When the cover made of the resin composition includes composite particles, a preferable amount of the composite particles is 0.1 parts by mass or more and 15 parts by mass or less with respect to 100 parts by mass of the base resin of the resin composition.

  When the paint layer made of the resin composition includes composite particles, the preferable amount of the composite particles is 1 part by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the base resin of the resin composition.

  In this golf ball, the reflected light from the nucleus interferes with the reflected light from the coat layer. Due to this interference, glitter is imparted to the golf ball. Due to this glitter, distinctiveness and luxury are exhibited. Since the core is made of a metal oxide, this golf ball has excellent weather resistance. Even if the composite particles are used in the paint layer, the composite particles do not impair the durability of the paint layer.

FIG. 1 is a cross-sectional view showing a part of a golf ball according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view showing a part of the golf ball of FIG. FIG. 3 is a cross-sectional perspective view showing composite particles blended in the golf ball of FIG.

  Hereinafter, the present invention will be described in detail based on preferred embodiments with appropriate reference to the drawings.

  FIG. 1 is a schematic cross-sectional view showing a golf ball 2 according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view showing a part of the golf ball 2 of FIG. The golf ball 2 includes a spherical core 4, a cover 6 positioned outside the core 4, a mark layer 8, and a paint layer 10. The golf ball 2 has dimples 12 and lands 14 on the surface thereof. In FIG. 1, the mark layer 8 and the paint layer 10 are not shown. The golf ball 2 may include another paint layer between the cover 6 and the mark layer 8.

  The core 4 is formed by crosslinking a rubber composition. Examples of the base rubber of the rubber composition include polybutadiene, polyisoprene, styrene-butadiene copolymer, ethylene-propylene-diene copolymer, and natural rubber. Preferably, a co-crosslinking agent is used for crosslinking. Preferably, the rubber composition includes an organic peroxide. The core 4 may be composed of two or more layers.

  The cover 6 is made of a resin composition. A thermoplastic resin or a thermosetting resin can be used for the cover 6. Typical resins are ionomer resins and polyurethanes. The cover 6 may include a styrene elastomer, a polyamide elastomer, a polyester elastomer, and a polyolefin elastomer.

  A white colorant is added to the cover 6. A typical white colorant is titanium dioxide. The cover 6 having a desired color may be obtained by the combined use of titanium dioxide and another pigment. The amount of titanium dioxide is preferably 0.1 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the base resin.

  The resin composition of the cover 6 includes composite particles. FIG. 3 is a cross-sectional perspective view of the composite particle 16. The composite particle 16 includes a nucleus 18 and a coat layer 20. The nucleus 18 is made of a metal oxide. The coat layer 20 is made of titanium oxide. A part of the light beam that has entered the cover 6 is reflected by the coat layer 20. A part of the light beam that has entered the cover 6 passes through the coat layer 20 and is reflected by the core 18. The reflected light on the coat layer 20 interferes with the reflected light on the nucleus 18. Due to this interference, glitter is imparted to the golf ball 2. The appearance of the brilliant golf ball 2 is different from the appearance of a conventional golf ball. This golf ball 2 is excellent in distinguishability. Further, the golf ball 2 having brilliancy is excellent in luxury.

  As shown in FIG. 3, the composite particles 16 are flaky. In the flaky composite particles 16, the interference action is directional. The color of the composite particle 16 varies depending on the viewing angle. When the flaky composite particles 16 are dispersed, the golf ball 2 is imparted with polarization. The discriminability and high-class feeling of the golf ball 2 are achieved by this polarization property.

  The composite particles 16 in which the nuclei 18 are made of a metal oxide are difficult to discolor. The composite particles 16 do not hinder the weather resistance of the golf ball 2. Since the metal oxide is excellent in strength, the composite particles 16 do not hinder the durability of the paint layer 10. The composite particles 16 in which the nuclei 18 are made of a metal oxide are not easily damaged when the resin composition is kneaded. Sufficient polarization is imparted to the golf ball 2 by suppressing breakage. Furthermore, since the hiding power of the metal oxide is high, the discriminability is enhanced by the composite particles 16.

A preferable metal oxide of the nucleus 18 is exemplified by aluminum oxide (Al ₂ O ₃ ). Aluminum oxide provides sufficient glitter as compared with the case where aluminum is used. A high-class feeling of the golf ball 2 is achieved by the aluminum oxide. Moreover, aluminum oxide is excellent in strength.

  The coat layer 20 made of titanium oxide contributes to the glitter of the golf ball 2. Typically, titanium dioxide is used for the coat layer 20. The coat layer 20 may contain a small amount of pigment. When the coat layer 20 contains a substance other than titanium oxide, the ratio of titanium oxide in the coat layer 20 is 90% by mass or more, and further 95% by mass or more. The thickness of the coat layer 20 is preferably 0.1 μm or more and 10 μm or less.

  The particle size of the composite particles 16 is preferably 5 μm or more and 50 μm or less. The composite particles 16 having a particle size of 5 μm or more can achieve glitter and polarization. In this respect, the particle size is more preferably 10 μm or more. By using the composite particles 16 having a particle size of 50 μm or less, the weld line of the cover 6 is hardly noticeable. In this respect, the particle size is more preferably 30 μm or less. The particle size is a number average value measured by a light scattering particle counter “LA-910” manufactured by Horiba, Ltd.

  The amount of the composite particles 16 is preferably 0.1 parts by mass or more and 15 parts by mass or less with respect to 100 parts by mass of the base resin of the cover 6. When the composite particles 16 of 0.1 parts by mass or more are dispersed in the cover 6, excellent glitter is exhibited. In this respect, the amount is more preferably equal to or greater than 0.3 parts by weight, and particularly preferably equal to or greater than 0.5 parts by weight. In the cover 6 in which the amount is 15 parts by mass or less, a high-class feeling is achieved by high brightness. In this respect, the amount is more preferably equal to or less than 10 parts by weight, and particularly preferably equal to or less than 5 parts by weight.

  An appropriate amount of a filler such as barium sulfate, an antioxidant, an ultraviolet absorber, a light stabilizer, a fluorescent agent, and a fluorescent brightening agent is blended in the cover 6 as necessary. The cover 6 has a thickness of 0.1 mm to 3.5 mm.

  The mark layer 8 is made of an ink composition. This ink composition includes a base resin and a pigment. Specific examples of the base resin include epoxy resins, polyester polyols, polyether polyols, polyurethane polyols, and nitrocellulose. The color of the mark layer 8 is different from the color of the cover 6. The mark layer 8 displays the manufacturer name, brand, ball number, and the like.

  The mark layer 8 is formed by printing on the surface of the cover 6. Pad printing, engraving printing, ink jet printing, transfer film printing, and the like can be employed. From the viewpoint of productivity, pad printing is preferable.

  The paint layer 10 covers the cover 6 or the mark layer 8. The mark layer 8 is protected by the paint layer 10. The paint layer 10 is formed by applying a paint. Electrostatic coating, spray gun coating, brush coating, etc. can be employed. Examples of the base resin for the paint include polyurethane, epoxy resin, polyester, acrylic resin, cellulose resin, and the like. From the viewpoint of durability of the paint layer 10, a two-component curable polyurethane is preferable.

  A two-component curable polyurethane is obtained by a reaction between a main agent and a curing agent. A two-component curable polyurethane obtained by a reaction between a main component containing a polyol component and a curing agent containing a polyisocyanate (including a polyisocyanate derivative) is preferred.

  It is preferable that urethane polyol is used as the polyol component of the main agent. The urethane polyol has a urethane bond and at least two or more hydroxyl groups. Preferably, the urethane polyol has a hydroxyl group at its terminal. The urethane polyol can be obtained by reacting the polyol and the polyisocyanate 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.

  The polyol used for the production of the urethane polyol has a plurality of hydroxyl groups. A polyol having a weight average molecular weight of 50 to 2,000, particularly 100 to 1,000 is preferred. Examples of the low molecular weight polyol include diol and triol. Specific examples of the diol include ethylene glycol, diethylene glycol, triethylene glycol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol and 1,6-hexanediol. Specific examples of the triol include glycerin, trimethylolpropane, and hexanetriol. High molecular weight polyols include polyether polyols such as polyoxyethylene glycol (PEG), polyoxypropylene glycol (PPG) and polyoxytetramethylene glycol (PTMG); polyethylene adipate (PEA), polybutylene adipate (PBA) ) And polyhexamethylene adipate (PHMA); lactone polyester polyols such as poly-ε-caprolactone (PCL); polycarbonate polyols such as polyhexamethylene carbonate; and acrylic polyols. Two or more polyols may be used in combination.

The polyisocyanate used for the production of the urethane polyol has a plurality of isocyanate groups. Specific examples of the polyisocyanate include 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, a mixture of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate (TDI), and 4,4′-diphenylmethane diisocyanate (MDI). ), 1,5-naphthylene diisocyanate (NDI), 3,3′-vitrylene-4,4′-diisocyanate (TODI), xylylene diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI) and paraphenylene diisocyanate ( Aromatic polyisocyanates such as PPDI); 4,4′-dicyclohexylmethane diisocyanate (H ₁₂ MDI), hydrogenated xylylene diisocyanate (H ₆ XDI) and isophorone diisocyanate (IPDI) ); And aliphatic polyisocyanates such as hexamethylene diisocyanate (HDI). Two or more polyisocyanates may be used in combination. From the viewpoint of weather resistance, TMXDI, XDI, HDI, H ₆ XDI, IPDI and H ₁₂ MDI are preferred.

  A known catalyst can be used in the reaction of the polyol and the polyisocyanate for producing the urethane polyol. A typical catalyst is dibutyltin dilaurate.

  The ratio of the urethane bond contained in the urethane polyol is preferably from 0.1 mmol / g to 5 mmol / g. By the urethane polyol having this ratio of 0.1 mmol / g or more, the scratch resistance of the paint layer 10 can be achieved. With the urethane polyol having this ratio of 5 mmol / g or less, the followability of the paint layer 10 to the cover 6 can be achieved. In the paint layer 10 having excellent followability, cracks are less likely to occur when the golf ball 2 is repeatedly hit. By adjusting the molecular weight of the polyol used as a raw material, the ratio of urethane bonds can be set within the above range. The ratio of urethane bonds can be set within the above range also by adjusting the blending ratio of polyol and polyisocyanate.

  From the viewpoint that the time required for the reaction between the main agent and the curing agent is short, the weight average molecular weight of the urethane polyol is preferably 4000 or more, and more preferably 4500 or more. From the viewpoint of adhesion between the paint layer 10 and the cover 6, the weight average molecular weight is preferably 10,000 or less, and more preferably 9000 or less.

  From the viewpoint of adhesion between the paint layer 10 and the cover 6, the hydroxyl value (mgKOH / g) of the urethane polyol is preferably 15 or more, and more preferably 73 or more. From the viewpoint that the time required for the reaction between the main agent and the curing agent is short and from the viewpoint of suppressing cracks, the hydroxyl value is preferably 130 or less, more preferably 120 or less.

  The main agent may contain a polyol having no urethane bond together with the urethane polyol. The aforementioned polyol, which is a raw material for urethane polyol, can be used as the main agent. Polyols that are compatible with urethane polyols are preferred. From the viewpoint that the time required for the reaction between the main agent and the curing agent is short, the ratio of the urethane polyol in the main agent is preferably 50% by mass or more and more preferably 80% by mass or more in terms of solid content. Ideally this ratio is 100% by weight.

  The curing agent contains polyisocyanate or a derivative thereof. The aforementioned polyisocyanate, which is a raw material of urethane polyol, can be used as a curing agent.

  The paint of the paint layer 10 includes composite particles 16. The composite particles 16 are dispersed in the paint layer 10. An equivalent of the composite particles 16 included in the cover 6 can be used for the paint layer 10. The composite particles 16 of the paint layer 10 impart glitter and polarization to the golf ball 2. In this embodiment, composite particles 16 are blended in both the cover 6 and the paint layer 10. The composite particles 16 may be blended only in the cover 6. The composite particles 16 may be blended only in the paint layer 10.

  Also in the paint layer 10, the particle size of the composite particles 16 is preferably 5 μm or more and 50 μm or less. The composite particles 16 having a particle size of 5 μm or more can achieve glitter and polarization. In this respect, the particle size is more preferably 10 μm or more. The smoothness of the paint layer 10 can be achieved by the composite particles 16 having a particle size of 50 μm or less. In this respect, the particle size is more preferably 30 μm or less.

  The amount of the composite particles 16 in the paint layer 10 is preferably 1 part by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the base resin of the paint layer 10. When the composite particles 16 of 1 part by mass or more are dispersed in the paint layer 10, excellent glitter is exhibited. In this respect, the amount is more preferably equal to or greater than 3 parts by weight, and particularly preferably equal to or greater than 5 parts by weight. In the paint layer 10 in which the amount is 30 parts by mass or less, a high-quality feeling is achieved by high brightness. Moreover, in the paint layer 10 in which the amount is 30 parts by mass or less, the composite particles 16 do not hinder the durability of the paint layer 10. In this respect, the amount is more preferably equal to or less than 20 parts by weight, and particularly preferably equal to or less than 15 parts by weight.

  If necessary, additives such as antioxidants, ultraviolet absorbers, light stabilizers, fluorescent agents, and fluorescent brighteners are blended in appropriate amounts in the paint. The thickness of the paint layer 10 is 3 μm or more and 100 μm or less. Another paint layer may be provided outside the paint layer 10.

  Hereinafter, the effects of the present invention will be clarified by examples. However, the present invention should not be construed in a limited manner based on the description of the examples.

[Example 1]
100 parts by weight of polybutadiene (trade name “BR-730” from JSR), 25 parts by weight of zinc acrylate, 10 parts by weight of zinc oxide, 15 parts by weight of barium sulfate, 0.5 parts by weight of diphenyl disulfide ( Sumitomo Seika Co., Ltd.) and 0.8 part by weight of dicumyl peroxide (Nippon Yushi Co., Ltd.) were kneaded to obtain a rubber composition. This rubber composition was put into a mold composed of an upper mold and a lower mold each having a hemispherical cavity, and heated at 170 ° C. for 20 minutes to obtain a core having a diameter of 38.9 mm.

  45 parts by weight of sodium-neutralized ionomer resin (trade name “Surlin 8945” from DuPont), 45 parts by weight of zinc-neutralized ionomer resin (trade name “Surlin 9945” from DuPont), 10 parts by weight of styrene block The resin composition was obtained by kneading the contained thermoplastic elastomer (trade name “Lavalon SR04” manufactured by Mitsubishi Chemical Corporation) and 3 parts by mass of titanium dioxide with a twin-screw kneading extruder. The core was put into a final mold having a large number of pimples on the inner peripheral surface, and the resin composition was injected around the core by an injection molding method to form a cover having a thickness of 1.9 mm. A large number of dimples having a reversed pimple shape were formed on the cover. The cover color was white. The surface of this cover was polished.

  A clear paint based on a two-component curable polyurethane was prepared. The main component of this paint is a mixture of polyether polyol and polyester polyol. The hydroxyl value of this main agent is 82 mgKOH / g. The curing agent for this paint is hexamethylene diisocyanate. The NCO: OH equivalent ratio of this paint is 1.2: 1.0. This paint contains composite particles (Merck's trade name “Xirallic T60-20 WNT Sunbeam Gold”) whose core is made of aluminum oxide and whose coat layer is made of titanium oxide. The amount of the composite particles is 10 parts by mass with respect to 100 parts by mass of the base resin. The composite particles are flaky and have a particle size of 20 μm. This paint was applied to the cover with a spray gun. This paint was dried at a temperature of 40 ° C. for 120 minutes to obtain a paint layer having a thickness of about 10 μm. Thus, a golf ball of Example 1 having a diameter of 42.7 mm and a mass of about 45.4 g was obtained.

[Examples 2 to 5]
Golf balls of Examples 2 to 5 were obtained in the same manner as in Example 1 except that the amount of composite particles in the paint layer was as shown in Table 1 below.

[Comparative Example 1]
A golf ball of Comparative Example 1 was obtained in the same manner as in Example 1 except that the composite particles were not blended in the paint layer.

[Example 6 and Comparative Examples 2 to 5]
Golf balls of Example 6 and Comparative Examples 2 to 5 were obtained in the same manner as in Example 1 except that the composite particles shown in Table 1 below were blended in the paint layer. Details of each composite particle are as follows.
T60-20
Merck's product name "Xirallic T60-20 WNT Sunbeam Gold"
Core: Aluminum oxide, Coat layer: Titanium oxide, Particle size: 20 μm, Flakes
T60-25
Merck's product name "Xirallic T60-25 WNT Cosmic Turquoise"
Core: Aluminum oxide, Coat layer: Titanium oxide, Particle size: 20 μm, Flakes
Iriodin 201
Merck's product name "Iriodin 201"
Core: Mica, Coat layer: Titanium oxide, Particle size: 15 μm, Flakes
HC Jade
Wacker Chemical's trade name "Helicone HC Jade"
Liquid crystal polymer, particle size: 30μm
MC1080RG
Nippon Sheet Glass's product name "Metashine MC1080RG"
Core: glass flake, coat layer: titanium oxide, particle size: 80 μm
PM2010
Product name “ALOXAL PM2010” of ECKART
Aluminum flake, particle size: 20μm

[Example 7]
The amount of titanium dioxide in the cover is 0.2 parts by weight, 3 parts by weight of composite particles (Xirallic T60-20 WNT Sunbeam Gold mentioned above) are added to the cover, and no composite particles are added to the paint layer. Otherwise, a golf ball of Example 7 was obtained in the same manner as Example 1.

[Examples 8 to 11]
Golf balls of Examples 8 to 11 were obtained in the same manner as in Example 7 except that the amount of composite particles in the cover was as shown in Table 2 below.

[Example 12 and Comparative Examples 6 to 9]
Golf balls of Example 12 and Comparative Examples 6 to 9 were obtained in the same manner as Example 7 except that the composite particles shown in Table 2 below were blended in the cover.

[Example 13]
A golf ball of Example 13 was obtained in the same manner as in Example 7, except that 10 parts by mass of composite particles (the aforementioned “Xirallic T60-20 WNT Sunbeam Gold”) was added to the paint layer.

[Identity]
The golf balls of Examples 1 to 13 and Comparative Examples 2 to 9 were placed on the lawn together with the golf balls of Comparative Example 1, respectively. Ten golfers were visually observed from a point 5 m away from the ball to evaluate whether or not the golf ball of Comparative Example 1 could be identified. Based on the number of golfers that could be identified, the following ratings were assigned.
A: 9 or more B: 7 or more and 8 or less C: 4 or more and 6 or less D: 3 or less The results are shown in Tables 1 and 2 below.

[luxury]
The appearance of each golf ball was evaluated by 10 golfers. The following ratings were given based on the number of golfers rated as high-class.
A: 9 or more B: 7 or more and 8 or less C: 4 or more and 6 or less D: 3 or less The results are shown in Tables 1 and 2 below.

[Weatherability]
The indices L ^* , a ^* and b ^* of each golf ball in the CIELAB display system were measured with a color difference meter (“CR-221” manufactured by Minolta). The indices L ^* , a ^* and b ^* are calculated by the following mathematical formulas.
L ^* = 116 (Y / Yn) ¹ / 3-16
a ^* = 500 ((X / Xn) ¹ /3-(Y / Yn) ^1/3 )
b ^* = 200 ((Y / Yn) ¹ /3-(Z / Zn) ^1/3 )
In these mathematical formulas, X, Y, and Z are tristimulus values in the XYZ display system, and Xn, Yn, and Zn are tristimulus values on the perfect diffuse reflection surface. The CIELAB display system is a standard determined in 1976 by the International Commission on Illumination (CIE). In Japan, the CIELAB display system is adopted in “JIS Z 8729”. L ^* is a lightness index. a ^* and b ^* are indices that correlate with hue and saturation. The negative direction of a ^* is the green direction, and the positive direction is the red direction. The negative direction of b ^* is the blue direction, and the positive direction is the yellow direction. The golf ball was put into a sunshine weather meter, and the golf ball was irradiated with light for 120 hours. In addition, indices L ^* , a ^* and b ^* were measured. ΔE was calculated based on the following mathematical formula.
ΔE = ((ΔL ^* ) ² + (Δa ^* ) ² + (Δb ^* ) ² ) ^1/2
The results are shown in Tables 1 and 2 below.

[Durability of paint layer]
A driver was attached to the swing machine (Tsurtemper). Each golf ball was hit 150 times under the condition that the head speed was 45 m / sec. The golf ball was observed, and the following rating was performed based on the peel area ratio of the paint layer.
A: 0%
B: 1% or more and less than 5% C: 5% or more and less than 25% D: 25% or more The results are shown in Tables 1 and 2 below.

  As shown in Tables 1 and 2, the golf balls of the examples are excellent in all evaluation items. From this evaluation result, the superiority of the present invention is clear.

  The present invention can be applied to golf balls having various structures.

2 ... Golf ball 4 ... Core 6 ... Cover 8 ... Mark layer 10 ... Paint layer 16 ... Composite particles 18 ... Core 20 ... Coat layer

Claims (7)

A core, a cover covering the core, and a paint layer covering the cover;
The cover includes composite particles having a nucleus and a coat layer covering the nucleus,
This core is made of a metal oxide, this coat layer contains titanium oxide,
A golf ball in which the cover is made of a resin composition and includes 0.1 to 15 parts by mass of composite particles with respect to 100 parts by mass of a base resin of the resin composition.   The golf ball according to claim 1, wherein the core is made of aluminum oxide.   The golf ball according to claim 1, wherein the composite particles are flaky.   4. The golf ball according to claim 1, wherein the resin composition of the cover includes 0.3 to 10 parts by mass of composite particles with respect to 100 parts by mass of the base resin.   5. The golf ball according to claim 4, wherein the paint layer is made of a resin composition and includes 1 part by mass or more and 30 parts by mass or less of composite particles with respect to 100 parts by mass of the base resin of the resin composition.   The golf ball according to claim 1, wherein a particle size of the composite particles is 5 μm or more and 50 μm or less.   The golf ball according to claim 1, wherein the paint layer has a thickness of 3 μm to 100 μm.

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