JP7342455B2 - Golf ball - Google Patents

Description

The present invention relates to a multi-piece solid golf ball that includes a core, an intermediate layer, an outermost layer, and a coating layer.

Dimples formed on the ball surface are an important component that improves the aerodynamic performance of the flight performance of the golf ball, and can also be a factor in determining the aesthetic appearance or design of the golf ball. Particularly in the case of colored balls, the impression given by the appearance of the ball is comprehensively determined by a combination of the shape of the dimples, the color of the ball, the glitter material, etc. Many color balls have a cover layer (outermost layer) containing a fluorescent coloring material or the like. Alternatively, there are golf balls having a coating film made by blending a glittering material such as a polarizing pigment with a coating resin such as a urethane-based coating.

Examples of technologies related to colored golf balls with transparent and glossy tones include JP-A No. 2012-105725 (Patent Document 1) and JP-A No. 2012-34776 (Patent Document 2). can do. However, these golf balls are colored golf balls that have a transparent and glossy tone, but such a ball appearance is susceptible to shadows and light reflection from the dimple shape. Issues that negatively impact play remain.

Also, in recent years, so-called matte color golf balls, which have a colored appearance but are so matte or lack luster that the contour shape of the dimples on the ball surface cannot be recognized, have become popular.

However, in conventional matte color golf balls, a matting agent such as silica is blended into a paint resin such as a urethane paint, mainly in the resin material of the coating film. Such golf balls appear to have no dimples and have a matte feel, but there are injection marks such as injection gate marks that occur during injection molding on the outermost layer of the cover layer, which is formed in one or more layers. It could be seen through, and no consideration was given to the composition or transmittance of the cover material in the middle layer or outermost layer.

In addition, colored golf balls often have a light-harvesting dye added to the resin material of the outermost layer of the cover layer to make the outermost layer colored. If there are many scratches, there is a problem in that the scratches on the surface of the cover become noticeable due to the color and the appearance of the ball becomes unimpressive.

Japanese Patent Application Publication No. 2012-105725 Japanese Patent Application Publication No. 2012-34776

The present invention was developed in view of the above circumstances, and it is difficult to see injection marks that occur during injection molding of the intermediate layer and the outermost cover layer in matte colored golf balls without gloss or luster, and prevents scratches on the cover surface. The purpose is to provide a golf ball that is inconspicuous and has a good appearance.

As a result of intensive studies to achieve the above object, the present inventors found that an intermediate layer is interposed between the core and the outermost layer, and the surface of the outermost layer is coated with a matte paint containing an inorganic filler. For matte color golf balls on which a coating film of Alternatively, by using a translucent resin material, the intermediate layer having a visible light transmittance in a specific range and the outermost layer are combined, and the synergistic effect of these layers does not impair the fluorescent coloring or matte feel. The inventors have discovered that it is possible to provide a golf ball that exhibits a desirable unique appearance by making it difficult to see the shadows of injection marks that occur during the molding of the intermediate layer and the outermost cover layer, and has led to the present invention. be.

Accordingly, the present invention provides the following golf ball.
1. A golf ball in which an intermediate layer is interposed between a core and an outermost layer, and a coating film is formed on the surface of the outermost layer, and the intermediate layer contains the following components (A) and (B). )Thermoplastic resin,
(B) It is formed from a resin composition containing a coloring agent consisting of a fluorescent dye or a fluorescent pigment, and the visible light transmittance of a 2 mm thick molded plate of the resin composition is in the range of 380 to 780 nm. The average value of each wavelength is 2.0 to 70.0%, and the outermost layer is formed of a transparent or translucent resin composition that does not contain a light-harvesting fluorescent dye, and A golf ball, wherein the coating film is formed from a urethane coating composition containing matte particles.
2. The thermoplastic resin of component (A) is the following components (a) and (b): (a) ethylene-α,β-unsaturated carboxylic acid copolymer and/or its metal salt; (b) ethylene-α,β-unsaturated The golf ball according to item 1 above, comprising any one of a saturated carboxylic acid-α,β unsaturated carboxylic acid ester copolymer and/or a metal salt thereof.
3. The golf ball according to item 1 or 2 above, wherein the amount of component (B) blended is 0.012 to 0.2 parts by mass per 100 parts by mass of component (A).
4. The resin composition for the intermediate layer further contains an inorganic filler or an organic filler as component (C), and the amount thereof is 0.01 to 1.0 parts by mass based on 100 parts by mass of component (A). 4. The golf ball according to any one of 1 to 3 above, which is
5. 5. The golf ball according to any one of 1 to 4 above, wherein a 2 mm thick plate-shaped molded resin composition used for the intermediate layer has a visible light transmittance of 3.0 to 60.0%.
6. 6. The golf ball according to any one of 1 to 5 above, wherein the base resin of the outermost layer is a polyurethane resin.
7. 7. The golf ball according to any one of 1 to 6 above, wherein a 2 mm thick plate-shaped molded resin composition used for the outermost layer has a visible light transmittance of 4.0 to 50.0%.
8. 8. The golf ball according to any one of 1 to 7 above, wherein the coating film has an average surface roughness Ra of 0.5 to 1.0 μm .
9. 9. The golf ball according to claim 1, wherein in the urethane coating composition for the coating film, the matte particles are silica.
10. 9. The golf ball according to 9 above, wherein the silica of the matte particles has an average primary particle diameter of 1.0 to 3.0 μm and a BET specific surface area of 200 to 400 m ² /g.

According to the golf ball of the present invention, the golf ball having dimples can provide an optical illusion effect that makes it appear as if there are no dimples, and can hide injection marks that occur during injection molding of the intermediate layer and the outermost cover layer. The cover has a good appearance with a matte color and no noticeable scratches on the surface.

The present invention will be explained in more detail below.
The golf ball of the present invention has a core, an intermediate layer, and an outermost layer from the inside.

The core can be formed using a known rubber material as a base material. As the base rubber, known base rubbers such as natural rubber or synthetic rubber can be used, and more specifically, polybutadiene, particularly cis-1,4-polybutadiene having at least 40% cis structure, can be used. Recommended for use. Further, in the base rubber, natural rubber, polyisoprene rubber, styrene-butadiene rubber, etc. can be used in combination with the above-mentioned polybutadiene, if desired. Further, polybutadiene can be synthesized using a Ziegler catalyst such as a titanium-based, cobalt-based, nickel-based, or neodymium-based catalyst, or a metal catalyst such as cobalt and nickel.

The base rubber mentioned above includes co-crosslinking agents such as unsaturated carboxylic acids and their metal salts, inorganic fillers such as zinc oxide, barium sulfate, and calcium carbonate, dicumyl peroxide and 1,1-bis(t-butyl Organic peroxides such as peroxy)cyclohexane and the like can be blended. Furthermore, if necessary, a commercially available anti-aging agent or the like may be appropriately added.

The core can be manufactured by vulcanizing and curing a rubber composition containing the components described above. For example, it is kneaded using a kneading machine such as a Banbury mixer or a roll, and compression molded or injection molded using a core mold, and the temperature is set at 100 to The molded product can be cured and produced by appropriately heating the molded product at 200° C., preferably 140 to 180° C., for 10 to 40 minutes.

At least two cover layers are formed around the core as members that cover the core. Among these cover layers, the outermost layer is the outermost layer, and one or more intermediate layers are formed between the outermost layer and the core.

At least one layer of the intermediate layer is formed from a resin composition containing the following (A) and (B).
(A) thermoplastic resin,
(B) Colorant consisting of fluorescent dye or fluorescent pigment The above components (A) and (B) will be explained below.

(A) Thermoplastic resin The above thermoplastic resin is not particularly limited, but includes resins conventionally employed as materials for golf balls, such as ionomer resins, polyester resins, polyurethane resins, polyamide resins, and polyolefins. Examples include resins, olefin thermoplastic elastomers, and styrene thermoplastic elastomers. Ionomer resins are particularly suitable, and specifically, (a) ethylene-α,β-unsaturated carboxylic acid copolymers and/or metal salts thereof, or (b) ethylene-α,β-unsaturated carboxylic acids. - It is preferable that it contains either component (a) or (b) of an α,β unsaturated carboxylic acid ester copolymer and/or a metal salt thereof.

Examples of the α,β unsaturated carboxylic acids of components (a) and (b) include acrylic acid, methacrylic acid, maleic acid, fumaric acid, etc., and in particular acrylic acid and methacrylic acid. is preferred. Further, as the α,β unsaturated carboxylic acid ester of the above component (b), lower alkyl esters of the above unsaturated carboxylic acids are suitable, and specifically, methyl methacrylate, ethyl methacrylate, propyl methacrylate , butyl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, and butyl acrylate (n-butyl acrylate, i-butyl acrylate) is particularly preferred.

The metal ion neutralized product of the above copolymer of the above components (a) and (b) is such that the acid groups of the above olefin-unsaturated carboxylic acid (-unsaturated carboxylic acid ester) copolymer are partially neutralized with metal ions. It can be obtained by neutralizing it. Examples of metal ions that neutralize acid groups include Na+, K+, Li+, Zn++, Cu++, Mg++, Ca++, Co++, Ni++, Pb++, etc. In particular, Na+, Li+, Zn++, Mg++, Ca++, etc. are preferably used. Such a neutralized product can be obtained by a known method. For example, for the copolymer, a formate, acetate, nitrate, carbonate, hydrogen carbonate, oxide, or hydroxide of the metal ion is added. Neutralized products can be obtained using compounds such as compounds and alkoxides.

As the components (a) and (b), known components can be used. For example, as a commercially available acid copolymer, Nuclel N1560, Nuclel N1214, Nuclel N1035, Nuclel AN4221C, Nuclel AN4311, Nuclel AN4318, Nuclel AN4319 (all manufactured by DuPont Mitsui Polychemicals), etc. can be mentioned. . In addition, examples of metal ion neutralized acid copolymers include Himilan 1554, 1557, 1601, 1605, 1706, AM7311, 1855, 1856, and AM7316 (all manufactured by Mitsui DuPont Polychemical Examples include Surlyn 7930, Surlyn 6320, Surlyn 8320, Surlyn 9320, and Surlyn 8120 (manufactured by DuPont).

The total amount of the thermoplastic resin as the component (A) is not particularly limited, and it should be blended in the total amount of the resin composition at 70% by mass or more, preferably at least 80% by mass, and more preferably at least 90% by mass. is recommended. If the above amount is insufficient, the desired effect of the present invention may not be obtained.

(B) Coloring agent consisting of fluorescent dye or fluorescent pigment The present invention is a colored ball that gives a dull and gentle impression to the surface of the ball. Therefore, the resin material of the intermediate layer contains (B) as the component. , a coloring agent consisting of a fluorescent dye or a fluorescent pigment is added. As this coloring agent, a known fluorescent dye or fluorescent pigment is suitably blended to color the intermediate layer. Here, examples include solvent yellow (dye), solvent orange (dye), anthraquinone (dye), phthalocyanine (dye), yellow fluorescent pigment, pink fluorescent pigment, and orange fluorescent pigment. For these, known commercially available products can be used.

In the present invention, it is preferable to use fluorescent colorants that have light-gathering properties. Here, a fluorescent colorant with light-gathering properties is a material that has the function of concentrating sunlight and converting it to a longer wavelength side as a fluorescent color. It is characterized by being guided to the dimple edge, condensing light, and being emitted in a concentrated state at the dimple edge, resulting in strong color development.

Examples of the above-mentioned light-harvesting fluorescent colorants include orange, pink, red, yellow, blue, and violet colorants, and commercially available products can be used in any of the coloring systems. For example, the product names "Lumogen F Yellow 083", "Lumogen F Orange 240", "Lumogen F Red 305", "Lumogen F Blue 650" (all manufactured by BASF), "Lumicolor Red", "Smart Color LP Green" ”, “Smart Color LP Yellow”, “Smart Color LP Orange” (all manufactured by Kashi no Moto Technology Co., Ltd.) and other light-harvesting fluorescent dyes can be employed.

The amount of component (B) to be blended is 0.001 to 0.2 parts by mass, preferably 0.005 to 0.1 parts by mass, per 100 parts by mass of component (A). If this amount is small, the fluorescence may become weak and the desired design may not be obtained. On the other hand, if the above-mentioned amount is increased, migration of the colorant, especially the dye, may occur, and there is a risk that objects that come into contact with the golf ball may be dyed.

(C) Inorganic filler or organic filler The resin composition of the above components (A) and (B) may further contain an inorganic filler or an organic filler as the component (C). The purpose of blending the inorganic and organic fillers is to appropriately prepare the resin composition in order to obtain a desired transmittance in the visible light region, as will be described later. However, in the present invention, component (C) is not an essential component.

When component (C) is an inorganic filler, examples thereof include, but are not limited to, zinc oxide, barium sulfate, calcium carbonate, titanium dioxide, and silica. Furthermore, by adding an inorganic filler, it becomes possible to impart translucency and adjust the color.

When component (C) is an organic filler, it is not particularly limited, but examples include crosslinked polymethyl methacrylate (crosslinked PMMA), crosslinked polybutyl methacrylate, crosslinked polyacrylate, crosslinked acrylic-styrene copolymer. Examples include fine particles of coalescence, melamine resin, polyurethane, and the like.

The amount of component (C) to be blended is 0.01 to 1.0 parts by mass, preferably 0.02 to 0.2 parts by mass or less, per 100 parts by mass of component (A). If this amount is too large, the concealment property becomes too high and the high-class design of the ball may be impaired, or the color may change significantly when it fades due to exposure to sunlight.

The resin composition can be obtained by mixing the above-mentioned components using various kneaders such as a kneading type (single-screw or) twin-screw extruder, Banbury, kneader, etc., for example.

Various additives can be blended into the resin composition as required, such as pigments, dispersants, antioxidants, light stabilizers, ultraviolet absorbers, lubricants, etc., as appropriate. .

The thickness of the intermediate layer is not particularly limited, but is preferably 0.5 mm or more, more preferably 0.7 mm or more, and the upper limit is preferably 1.7 mm or less, more preferably 1.4 mm or less. It is.

The hardness of the intermediate layer is not particularly limited, but is preferably 30 or more, more preferably 40 or more in terms of Shore D hardness, and the upper limit is preferably 75 or less, more preferably 70 Below, it can be more preferably set to 65 or less.

The visible light transmittance of a 2 mm thick molded plate of the resin composition is 2.0 to 70.0%, preferably 3.0 to 60%, as an average value for each wavelength in the 380 to 780 nm region. It is. Specifically, the measured value of visible light transmittance means the average of values measured in 1 nm increments in the 380 to 780 nm region using various UV-visible spectrophotometers. In order to obtain a matte ball appearance without gloss, it is necessary to prepare a resin composition that has a relatively strong fluorescent color and a certain degree of transparency, and as an indicator of this, the visible light transmittance of the above-mentioned intermediate layer is measured. It is specified that the value is within the range of values.

Next, the outermost layer will be explained.
The material hardness of the outermost layer is not particularly limited, but is preferably 25 to 57, more preferably 27 to 55, and still more preferably 29 to 53 in terms of Shore D hardness.

The thickness of the outermost layer is not particularly limited, but is preferably 0.3 to 1.5 mm, more preferably 0.4 to 1.2 mm, and still more preferably 0.5 to 1.0 mm.

There are no particular restrictions on the material for the outermost layer, and various thermoplastic resin materials and thermosetting materials can be suitably used. In particular, from the viewpoint of controllability during approach and abrasion resistance, it is preferable to use urethane resin.

As the urethane resin, in particular, thermoplastic polyurethane elastomers can be used, and specifically, for example, the product name "Pandex" manufactured by DIC Covestro Polymer Co., Ltd., and the product name "Pandex" manufactured by Dainichiseika Chemical Industry Co., Ltd. Examples include "Rezamin".

In order to finish the resin material of the outermost layer as a transparent or translucent layer, it is preferable that no coloring agent such as a light-harvesting fluorescent dye be added.

Note that the resin material of the outermost layer can be finished with a colored resin layer. In this case, various pigments can be appropriately added to the base resin such as the above-mentioned polyurethane resin within a range that does not impair the effects of the present invention.

The visible light transmittance of a 2 mm thick plate-shaped molded resin composition used for the outermost layer is preferably 4.0 to 50.0%, more preferably 10.0 to 40.0%. . By forming the outermost layer with a relatively low transmittance in this way, together with the above-mentioned intermediate layer material, it gives an optical illusion effect that makes it appear that there are no dimples, and also sufficiently suppresses injection marks that occur during injection molding. Can be hidden. Further, herein, a transmittance of 3.0 to 10.0% is defined as "semi-transparent", and a transmittance of more than 10.0% is defined as "transparent".

The golf ball formed by laminating the core, intermediate layer, and outermost layer described above can be manufactured by a conventional method such as a known injection molding method. For example, a vulcanized product mainly made of rubber material is placed as a core in a predetermined injection mold, an intermediate layer material is injected to obtain an intermediate spherical body, and then the spherical body is injected into another injection mold. A multi-piece golf ball can be obtained by placing the golf ball in a mold and injection molding the outermost layer material. Alternatively, the outermost layer can be laminated by coating the intermediate spherical body with the outermost layer. For example, the intermediate spherical body is wrapped with two half-cups that have been previously formed into a half-shell shape and molded under heat and pressure. be able to.

A large number of dimples of one or more types can be formed on the surface of the outermost layer, and the shape, diameter, depth, number, occupied surface area, etc. of the dimples are appropriately selected.

The present invention is a golf ball having a coating film, and the coating film is formed from a coating composition containing matte particles.

The coating composition is not particularly limited, but it is preferable to use a urethane coating. Since it is necessary to withstand the harsh usage conditions of golf balls, two-component curing urethane paints, particularly non-yellowing urethane paints, are preferred.

In the case of two-component curable urethane paints, various polyols such as saturated polyester polyols, acrylic polyols, and polycarbonate polyols are used as the main ingredient, and as the isocyanate, non-yellowing polyisocyanates such as hexamethylene diisocyanate, isophorone diisocyanate, It is preferable to use an adduct, a buret, an isocyanurate, or a mixture thereof such as hydrogenated xylylene diisocyanate.

Further, examples of the matte particles include silica particles, melamine particles, acrylic particles, and the like. Specific examples include silica, polymethyl methacrylate, polybutyl methacrylate, polystyrene, polybutyl acrylate, etc., and organic or inorganic materials may be used, with silica being particularly preferred.

The specific surface area of the matte particles is preferably 200 to 400 m 2 /g, more preferably 250 to ^{350 m 2 /} g in terms of BET specific surface area, from the viewpoint of extinction and coating properties.

Further, the average primary particle diameter of the matte particles is preferably 1.0 to 3.0 μm, more preferably 2.0 to 2.8 μm, from the viewpoint of spin performance and extinction property. If this value exceeds 3.0 μm, the ball surface will become rough, which may adversely affect the spin performance and reduce the performance. On the other hand, if this value is too small, the quenching effect may become small.

The blending amount of the above-mentioned matte particles can be preferably 5 to 10 parts by mass based on 100 parts by mass of the main component (total amount of resin component and solvent) of the coating composition for the coating film. If this amount is too large, the viscosity of the coating composition will increase and the coating workability will tend to deteriorate, and if it is too small, the light-quenching effect may be reduced.

The average roughness Ra of the surface of the coating film is preferably from 0.5 to 1.0 from the viewpoint of achieving both the amount of spin of the ball during approach and the extinction property. The surface roughness Ra of this coating film means the arithmetic mean roughness of JIS B0601 (1994).

Further, the reflectance of the above coating film measured by a gloss meter is 5.0 or less at an incident angle of 20°, 20.0 or less at an incident angle of 60°, and 40.0 or less at an incident angle of 85°. It is preferable that there be. In this way, a coating film whose reflectance is optimized so as to satisfy the numerical range described above can impart a matte effect. The reflectance was measured using the gloss meter described above using the measuring device used in the Examples described later, and was applied to an ABS resin plate coated with a thickness of 20 μm.

Ball specifications such as mass and diameter of the golf ball of the present invention can be appropriately set in accordance with the Rules of Golf.

EXAMPLES Hereinafter, the present invention will be specifically explained by showing examples and comparative examples, but the present invention is not limited to the following examples.

[Examples 1 to 15, Comparative Examples 1 to 20]
As shown in Table 1 below, solid cores for each example were created by vulcanization at 155° C. for 15 minutes using the following rubber composition common to all examples.

The details of the core material are as follows.
・“Polybutadiene” Manufactured by JSR, product name “BR01”
・“Barium sulfate” manufactured by Sakai Chemical Industry Co., Ltd. ・“Zinc oxide” manufactured by Sakai Chemical Industry Co., Ltd. ・“Zinc stearate” manufactured by NOF Corporation ・“2,2-methylenebis(4-methyl-6-tert-butylphenol)” Large Product name: Nocrack NS6 (anti-aging agent) manufactured by Uchishin Kagaku Kogyo Co., Ltd.
・“Zinc acrylate” manufactured by Nippon Shokubai Co., Ltd. ・“Dicumyl peroxide” Product name “Percyl D” manufactured by NOF (organic peroxide)
・“1,1-di(tert-butylperoxy)cyclohexane” NOF product name “Perhexa C-40” (organic peroxide)

Formation of cover layer (intermediate layer and outermost layer) Next, the core with a diameter of 38.65 mm obtained above was covered with an intermediate layer with a thickness of 1.2 mm shown in Table 2 below by an injection molding method. An intermediate layer coated sphere having a diameter (outer diameter) of 41.05 mm was manufactured.

Details in the above table are as follows.
・"Himilan 1605": Ionomer resin manufactured by Mitsui Dow Polychemicals ・"Himilan 1557": Ionomer resin manufactured by Mitsui Dow Polychemicals ・"Himilan 1706": Ionomer resin manufactured by Mitsui Dow Polychemicals Photofluorescent dye (1): Product name “Smart Color LP Yellow” manufactured by Kashi no Moto Technology Co., Ltd.
・Light-harvesting fluorescent dye (2): Product name “Smart Color LP Pink” manufactured by Kashi no Moto Technology Co., Ltd.
・Light-harvesting fluorescent dye (3): Product name “Lumicolor Red” manufactured by Kashi no Moto Technology Co., Ltd.
・Fluorescent dye: Product name “Sumiplast Yellow FL7G” manufactured by Sumika Chemtex
・Fluorescent brightener: Product name “Hakkol PY1800” manufactured by Showa Kagaku Kogyo Co., Ltd.
・Lubricant: Product name “Sunwax 161-P” manufactured by Sanyo Chemical Co., Ltd.

Next, the outermost layer material having a thickness of 0.8 mm shown in Table 3 below was coated around the intermediate layer coated sphere by injection molding to produce a three-piece golf ball having a ball diameter of 42.7 mm. At this time, common dimples were formed on the outermost layer surface of each Example and Comparative Example, although not particularly shown.

The description of the materials in Table 3 is the same as above. The thermoplastic urethane resin is an ether-type thermoplastic polyurethane (Shore D hardness: 35) manufactured by DICI Covestro Polymer Co., Ltd. under the trade name "Pandex".
The transparency (transparent/semi-transparent/opaque) of the resin composition was adjusted by appropriately adjusting the content of titanium dioxide as the component (C).

Next, a two-component curable urethane paint consisting of a main agent and a curing agent shown in Table 4 below was used to coat the surface of the outermost layer to a thickness of 15 μm.

Details of the above-mentioned main ingredient and curing agent are as shown in (i) to (iv) below.
(i) First, 140 parts by mass of trimethylolpropane, 95 parts by mass of ethylene glycol, 157 parts by mass of adipic acid, 1,4-cyclohexanedi 58 parts by mass of methanol was charged, the temperature was raised to 200 to 240°C while stirring, and the mixture was heated (reacted) for 5 hours. Thereafter, a "saturated polyester polyol" having an acid value of 4, a hydroxyl value of 170, and a weight average molecular weight (Mw) of 28,000 was obtained.
(ii) Next, the polyester polyol synthesized above was dissolved in butyl acetate to prepare a varnish with a nonvolatile content of 70% by mass.
(iii) 27.5 parts by mass of the above saturated polyester polyol solution was dissolved in butyl acetate (the nonvolatile content of this solution was 27.5% by mass), and silica ("Finesil X-" manufactured by Maruo Calcium Co., Ltd. 35'' (average primary particle diameter: 2.4 μm, BET specific surface area: 262 m ² /g) was mixed to form a main ingredient.
(iv) Next, as a curing agent, isocyanates shown in Table 4 are dissolved in an organic solvent and used. That is, HDI nurate ("Duranate TPA-100" manufactured by Asahi Kasei Corporation, NCO content 23.1% by mass, non-volatile content 100% by mass) and ethyl acetate as an organic solvent were mixed in the proportions shown in Table 4. and butyl acetate were added to prepare a resin composition for a paint.

Table 5 shows the material, outer diameter, amount of compressive deformation, etc. of each layer of the golf balls of the obtained Examples and Comparative Examples. The table also shows the transmittance of the intermediate layer and the outermost layer and the arithmetic mean roughness (Ra) of the coating film. Furthermore, the golf balls of each Example and Comparative Example were evaluated for appearance in two items by the following method. The results are also listed in Tables 5, 6, and 7.

Amount of compression deformation A core, intermediate layer coated sphere, or ball was placed on a steel plate, and the amount of deflection from the initial load of 98 N (10 kgf) to the final load of 1275 N (130 kgf) was measured. Note that the above deflection amounts are all measured values after the temperature was adjusted to 23.9°C.

Transmittance of intermediate layer and outermost layer The resin composition for the intermediate layer or the resin composition for the outermost layer was molded into a 2 mm sheet, and this was used as a sample using an ultraviolet-visible spectrophotometer "UV-1800" manufactured by Shimadzu Corporation. , the visible light transmittance was determined. The average values of the measured values in 1 nm increments in the region of 380 to 780 nm are listed in Tables 5 to 7.

Appearance 1
The visibility of the dimples on the golf balls of each example was visually evaluated based on the following criteria, and the scores are listed in Tables 5 to 7. A high score was evaluated as "good", and a score of 2 or less was evaluated as "bad".
<Evaluation criteria>
4 points: The dimple edge, which shows the outline of the dimple, is hardly visible. The difference in height between the bottom of the dimple and the edge of the dimple is almost invisible.
3 points: The dimple edge, which shows the outline of the dimple, appears blurred. The difference in height between the bottom of the dimple and the edge of the dimple appears blurred.
2 points: The dimple edge, which shows the outline of the dimple, is somewhat clearly visible. The difference in height between the bottom of the dimple and the edge of the dimple is somewhat clearly visible.
1 point: The dimple edge, which shows the outline of the dimple, is clearly visible. The bottom of the dimple and the edge of the dimple are clearly visible.

Appearance 2
When injection molding the outermost layer, the appearance of injection marks at the gate portion of the outermost layer was evaluated based on the following criteria. A high score was evaluated as "good", and a score of 1 or less was evaluated as "bad".
<Evaluation criteria>
4 points: No injection marks are visible.
3 points: Injection marks with an inner diameter of approximately 3 mm are visible.
2 points: Injection marks with an inner diameter of about 5 mm are visible.
1 point: Injection marks with an inner diameter of about 10 mm are visible.

Appearance 3
The "fluorescence" of the ball appearance was evaluated using the following criteria. A high score was evaluated as "good", and a score of 2 or less was evaluated as "bad".
<Evaluation criteria>
4 points: Fluorescent color development is sufficiently felt.
3 points: Fluorescent color is visible.
2 points: Only a small amount of fluorescent color is perceived.
1 point: No fluorescent color is perceived.

Appearance 4
The balls were kept warm at 23 degrees Celsius, and using a swing robot machine and a sand wedge club, each ball was hit five times at a head speed of 33 m/s, and the impact damage was visually evaluated using the following criteria. did.
<Evaluation criteria>
4 points: The impact damage is barely visible.
3 points: The impact damage is not very visible.
2 points: The impact damage is somewhat clearly visible.
1 point: The impact damage is clearly visible.

From the results in Tables 5, 6, and 7, the golf balls of Examples 1 to 15 all appear to have no dimples, have a matte feel, and have no visible injection marks that occur during molding of the outermost layer. The overall appearance of the ball is good.
On the other hand, in Comparative Example 1, the transmittance of the outermost layer was low, so the dimple bank and boundary were clearly visible, there was no fluorescent coloration, and the ball was not finished as a matte colored golf ball.
In Comparative Example 2, the transmittance of the outermost layer was low, so the dimple bank and boundary were clearly visible, there was no fluorescent coloration, and the golf ball was not finished in a matte colored golf ball.
In Comparative Example 3, the transmittance of the outermost layer was low, so the dimple bank and boundary were clearly visible, there was no fluorescent coloration, and the golf ball was not finished in a matte colored golf ball.
In Comparative Example 4, the transmittance of the outermost layer was low, so the dimple bank and boundary were clearly visible, there was no fluorescent coloration, and the golf ball was not finished in a matte colored golf ball.
In Comparative Example 5, the transmittance of the outermost layer was low, so the dimple bank and boundary were clearly visible, there was no fluorescent coloration, and the ball was not finished as a matte colored golf ball.
In Comparative Example 6, the transmittance of the outermost layer was low, so the dimple bank and boundary were clearly visible, there was no fluorescent coloration, and the golf ball was not finished in a matte colored golf ball.
In Comparative Example 7, the transmittance of the outermost layer was low, so the dimple bank and boundary were clearly visible, there was no fluorescent coloration, and the golf ball was not finished in a matte colored golf ball.
In Comparative Example 8, the transmittance of the intermediate layer was low, so there was no color development with fluorescence, and the golf ball was not finished in a matte colored golf ball.
In Comparative Example 9, the transmittance of the intermediate layer was low, so there was no color development with fluorescence, and the golf ball was not finished in a matte colored golf ball.
In Comparative Example 10, the transmittance of the outermost layer was low, so the dimple bank and boundary were clearly visible, there was no fluorescent coloration, and the ball was not finished as a matte colored golf ball.
In Comparative Example 11, since the transmittance of the intermediate layer was low, there was no coloration with slight fluorescence, and the golf ball was not finished in a matte colored golf ball.
In Comparative Example 12, since the transmittance of the intermediate layer was low, there was no color development with slight fluorescence, and the golf ball was not finished in a matte colored golf ball.
In Comparative Example 13, the transmittance of the outermost layer was low, so the dimple bank and boundary were clearly visible, there was no fluorescent coloration, and the ball was not finished as a matte colored golf ball.
In Comparative Example 14, since the intermediate layer had a high transmittance, there was no color development with fluorescence, and the golf ball was not finished as a matte colored golf ball.
In Comparative Example 15, since the intermediate layer had a high transmittance, there was no color development with fluorescence, and the golf ball was not finished in a matte colored golf ball.
In Comparative Example 16, since the intermediate layer had a high transmittance, there was no color development with fluorescence, and the golf ball was not finished in a matte colored golf ball.
In Comparative Example 17, since a fluorescent dye was used for the resin material of the outermost layer, scratches were somewhat noticeable.
In Comparative Example 18, since a fluorescent dye was used for the resin material of the outermost layer, scratches were noticeable.
In Comparative Example 19, since a fluorescent dye was used for the resin material of the outermost layer, scratches were somewhat noticeable.
In Comparative Example 20, since a fluorescent dye was used for the resin material of the outermost layer, scratches were noticeable.

Claims (10)

A golf ball in which an intermediate layer is interposed between a core and an outermost layer, and a coating film is formed on the surface of the outermost layer, and the intermediate layer contains the following components (A) and (B). )Thermoplastic resin,
(B) It is formed from a resin composition containing a coloring agent consisting of a fluorescent dye or a fluorescent pigment, and the visible light transmittance of a 2 mm thick molded plate of the resin composition is in the range of 380 to 780 nm. The average value of each wavelength is 2.0 to 70.0%, and the outermost layer is formed of a transparent or translucent resin composition that does not contain a light-harvesting fluorescent dye, and A golf ball, wherein the coating film is formed from a urethane coating composition containing matte particles. The thermoplastic resin of component (A) is the following components (a) and (b): (a) ethylene-α,β-unsaturated carboxylic acid copolymer and/or its metal salt; (b) ethylene-α,β-unsaturated The golf ball according to claim 1, comprising any one of a saturated carboxylic acid-α,β unsaturated carboxylic acid ester copolymer and/or a metal salt thereof. 3. The golf ball according to claim 1, wherein the amount of component (B) is 0.012 to 0.2 parts by mass based on 100 parts by mass of component (A). The resin composition for the intermediate layer further contains an inorganic filler or an organic filler as component (C), and the amount thereof is 0.01 to 1.0 parts by mass based on 100 parts by mass of component (A). 4. The golf ball according to claim 1, wherein the golf ball is: The golf ball according to any one of claims 1 to 4, wherein a 2 mm thick plate-shaped molded resin composition used for the intermediate layer has a visible light transmittance of 3.0 to 60.0%. The golf ball according to any one of claims 1 to 5, wherein the base resin of the outermost layer is a polyurethane resin. The golf ball according to any one of claims 1 to 6, wherein a 2 mm thick plate-shaped molded resin composition used for the outermost layer has a visible light transmittance of 4.0 to 50.0%. The golf ball according to any one of claims 1 to 7, wherein the coating film has a surface average roughness Ra of 0.5 to 1.0 μm . The golf ball according to any one of claims 1 to 8, wherein in the urethane coating composition for the coating film, the matte particles are silica. The golf ball according to claim 9, wherein the silica of the matte particles has an average primary particle diameter of 1.0 to 3.0 μm and a BET specific surface area of 200 to 400 m ² /g.