JP2017118950A - Golf ball - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a golf ball that excels in molding efficiency of the cover, that has a clear-colored border line which is favorably usable as an indicator for a striking direction, and that also has superior fashionability and visibility.SOLUTION: The outermost layer 22 of the core 12 of the golf ball 10 is provided with two hemispherical parts 24, 26 which are formed with a rubber composition and which have mutually different color tones. Also, the border between the hemispherical parts 24, 26 as the color border line is prepared along the great circle of the outermost layer 22 of the core 12. At least one of the hemispherical parts 24, 26 contains a fluorescent coloring agent or a luminous agent. The cover 14 is formed with a transparent or a translucent thermoplastic resin composition. At least one layer of the cover 14 contains at least one of fluorescent brightener, fluorescent coloring agent, and luminous agent.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a golf ball having a unique appearance color tone, high fashionability, excellent color variation, and good visibility.

  The color tone of the appearance of a golf ball is usually composed of only a single color of white, but recently, instead of this white color, the color tone of fluorescent colors such as yellow, orange, pink, red, blue, etc. A ball made of is commercially available. These fluorescent balls are more fashionable than white balls, and when used on a golf course, for example, it is easier for the player to determine the ball's flight direction and fall point even from a distance. Is possible. Furthermore, it has been confirmed that the color is effective on the optic nerve of the player, which makes it easier for the player to concentrate psychologically and settle down when hitting the ball.

  For the reasons mentioned above, fluorescent colored balls are preferred for women who place importance on fashion, elderly people who have lost their eyesight, and those who can feel psychological effects. Is still limited.

  Therefore, in order to further expand the user base, the appearance of the golf ball has two different colors, and the boundary between these colors is a two-tone color provided along the great circle (equatorial line) of the golf ball. It has been tried. In this case, for example, when a player performs a tee shot or putting, the golf ball is placed so as to be held using a color boundary line as an indicator of the launch direction, thereby making it easier to launch the golf ball in the target direction. Can do.

  A two-tone golf ball is usually produced by using a two-tone color cover that covers the core of the golf ball as disclosed in Patent Document 1. Such a cover is formed by heat-pressing two hemispherical shells made of thermoplastic resins colored in different colors.

JP-A-63-038476

  As described above, when a two-tone cover is obtained, it is necessary to obtain two hemispherical shells having different color tones in advance and to perform heat and pressure molding in a state where each hemispherical shell is accurately positioned with respect to the mold. Therefore, through these steps, the molding efficiency of the two-tone cover is significantly lower than the molding efficiency of a single color cover or the like obtained by injection molding.

  Further, in the two-tone cover, high accuracy is required for positioning the hemispherical shell with respect to the mold, and if the positioning is not performed accurately, there is a concern that the color boundary line may be unclear. It becomes difficult to use an unclear color boundary line as an indicator of the launch direction.

  The present invention has been made in order to solve the above-mentioned problems, and is easily provided with a clear color boundary line that is excellent in the molding efficiency of the cover and can be used well as an indicator of the launch direction. An object is to provide a golf ball having excellent visibility.

  In order to achieve the above object, the present invention provides a golf ball comprising a core having at least one layer and a cover having at least one layer, wherein the outermost layers of the core are formed from a rubber composition. Two hemispherical portions having different tones are provided, and a boundary between the hemispherical portions is provided as a color boundary line along a great circle of the outermost layer of the core, and at least one of the hemispherical portions is a fluorescent colorant Or a brightening agent, wherein the cover is formed of a transparent or translucent thermoplastic resin composition, and at least one layer of the cover contains any of a brightening agent, a fluorescent coloring agent, and a brightening agent. Features.

  In this golf ball, since the cover covering the core is transparent or translucent, the color tone of the outermost layer of the core via the cover is visually recognized as the color tone of the appearance of the golf ball. That is, the color tone of the appearance of the golf ball can be set according to the color tone of the two hemispherical portions of the outermost layer of the core. Further, the boundary between the hemispherical portions formed along the great circle of the outermost layer of the core can be used as the boundary line of the color of the golf ball. Here, the great circle means an intersection circle when the split plane passes through the center of the sphere, and the so-called equatorial line of the golf ball is included in the great circle.

  Accordingly, since it is not necessary to provide a color boundary line on the cover, the cover can be obtained easily and efficiently by injection molding or the like, not by heat and pressure molding. Further, the boundary line of the color of the golf ball, which is the boundary between the hemispherical parts made of the rubber composition, can be easily and clearly provided without going through complicated steps such as advanced positioning.

  Furthermore, since at least one of the hemispherical parts contains a fluorescent colorant or a brightening agent, and at least one layer of the cover contains any one of a fluorescent whitening agent, a fluorescent colorant, and a brightening agent, the fashionability and visibility of the golf ball are improved. It can be improved satisfactorily. Further, the color tone of the appearance of the golf ball can also be adjusted by the color tone of the transparent or translucent cover as the color tone of the outermost layer of the core visually recognized through the cover. This gives a richer color variation to the color tone of the appearance of the golf ball.

  As described above, according to the present invention, a golf ball having excellent cover molding efficiency, easily provided with a clear color boundary line that can be favorably used as an index of launch direction, and excellent in fashionability and visibility. Is provided.

  In the above golf ball, at least one of the hemispherical parts includes a fluorescent pigment in a blending amount of 0.5 to 5.0 parts by weight when the base rubber of the rubber composition is 100 parts by weight, At least one layer of the cover may contain a fluorescent brightening agent or a fluorescent dye in a blending amount of 0.001 to 3.0 parts by weight when the base resin of the thermoplastic resin composition is 100 parts by weight. preferable. In this case, since the color tone of the appearance of the golf ball becomes clear due to the fluorescent agent, the fashionability is improved and the player can more easily recognize the golf ball visually.

  In the above golf ball, at least one layer of the cover includes a brightening agent in which glass flakes or silicon dioxide is coated with a metal or a metal oxide, and the blending amount of the brightening agent is based on the thermoplastic resin composition. When the material resin is 100 parts by weight, it is preferably 0.05 to 5.0 parts by weight. In this case, since the brightening agent reflects light such as sunlight well, it is possible to further improve fashionability and visibility.

  In the golf ball described above, it is preferable that the cover has two layers including an inner layer and an outer layer, the inner layer includes a brightening agent, and the outer layer includes a fluorescent dye. In this case, the fashionability and visibility of the golf ball can be effectively improved by both the brightening agent and the fluorescent dye.

  In the above golf ball, it is preferable that a yellow fluorescent dye is contained in the outer layer of the cover. In this case, for example, it is particularly effective to make it easy to distinguish a lawn that has withered in winter and a golf ball, and to make the golf ball easy to see in weather such as fog and rain.

  According to the present invention, the color tone of the outermost layer of the core through the transparent or translucent cover is visually recognized as the color tone of the appearance of the golf ball. The outermost layer of the core has two hemispherical portions formed from a rubber composition and having different colors. For this reason, the boundary between hemispherical portions is clearly provided along the great circle of the outermost layer of the core as a color boundary line. That is, with this golf ball, a cover can be efficiently obtained by injection molding or the like. In addition, it is possible to easily provide a clear color boundary line that can be satisfactorily used as an index of the launch direction.

  Further, in this golf ball, at least one of the hemispherical portions contains a fluorescent colorant or a brightening agent, and at least one layer of the cover contains any one of a fluorescent brightening agent, a fluorescent colorant, and a brightening agent. Excellent in color and color variation.

1 is a schematic partial cross-sectional view of a golf ball according to an embodiment of the present invention. It is a chart showing the raw material of each core in the golf ball of Examples 1-7, and its compounding quantity. It is a chart showing the raw material of the cover in the golf ball of Examples 1-7 and its compounding quantity, and the color tone of the cover in the golf ball of Comparative Examples 1 and 2. It is a table | surface showing the evaluation result of the color tone of the external appearance in the golf ball of Examples 1-7 and Comparative Examples 1 and 2, fashionability, visibility, the ease of holding at the time of an address, and the ease of a stroke.

  Hereinafter, preferred embodiments of the golf ball according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic partial cross-sectional view of a golf ball 10 according to the present embodiment. As shown in FIG. 1, the golf ball 10 includes a core 12 and a cover 14 that covers the core 12.

  The core 12 is formed from a rubber composition such as natural rubber or synthetic rubber, and has two layers, an inner layer core 20 and an outer layer core 22. Preferable examples of the rubber composition include polybutadiene rubber as a base rubber, zinc acrylate which is a metal salt of α, β-unsaturated carboxylic acid, dicumyl peroxide which is an organic peroxide, and oxidation which is a filler. The rubber composition which mix | blended zinc etc. is mentioned. The inner layer core 20 and the outer layer core 22 may be formed from the same rubber composition or from different rubber compositions.

  The inner layer core 20 has a spherical shape and is covered with the outer layer core 22. That is, in this case, the outer layer core 22 is the outermost layer of the core 12. The outer core layer 22 has a first hemispherical portion 24 and a second hemispherical portion 26 formed in a hollow hemispherical shape, and each of the first hemispherical portion 24 and the second hemispherical portion 26 covers the inner layer core 20. To make a sphere. In addition, at least one of the first hemispherical portion 24 and the second hemispherical portion 26 is mixed with a fluorescent colorant or a brightening agent having desired coloring characteristics in the above rubber composition. Accordingly, the first hemisphere portion 24 and the second hemisphere portion 26 are set to different color tones. That is, a color boundary line along the great circle of the outer core 22 is formed at the boundary between the first hemisphere portion 24 and the second hemisphere portion 26.

  From the viewpoint of further improving the fashionability and visibility of the golf ball 10, it is preferable that at least one of the first hemispherical portion 24 or the second hemispherical portion 26 contains a fluorescent pigment. In this case, the preferable addition amount of the fluorescent pigment is 0.5 to 5.0 parts by weight with respect to 100 parts by weight of the base rubber of the rubber composition.

  The cover 14 is formed of a transparent or translucent thermoplastic resin composition, and has two layers of an inner layer cover 30 and an outer layer cover 32 that covers the inner layer cover 30. Preferable examples of the thermoplastic resin composition include an ionomer resin, and the inner layer cover 30 and the outer layer cover 32 are formed from the same thermoplastic resin composition, but are formed from different thermoplastic resin compositions. Also good.

  At least one of the inner layer cover 30 and the outer layer cover 32 includes any one of a fluorescent brightening agent, a fluorescent colorant, and a brightening agent. Among these, when at least one of the inner layer cover 30 and the outer layer cover 32 includes a fluorescent whitening agent or a fluorescent dye, a suitable addition amount of the fluorescent whitening agent or the fluorescent dye is the base resin 100 of the thermoplastic resin composition. 0.001 to 3.0 parts by weight with respect to parts by weight. In this case, the color tone of the golf ball 10 can be made clearer.

  When at least one of the inner layer cover 30 and the outer layer cover 32 contains a brightening agent, specific examples of the brightening agent are formed by coating the surface of glass flakes or silicon dioxide (silica) with a metal or metal oxide. And the like. A suitable addition amount of the brightening agent is 0.05 to 5.0 parts by weight with respect to 100 parts by weight of the base resin of the thermoplastic resin composition. In this case, the brightening agent reflects light such as sunlight well.

  Further, when the inner layer cover 30 includes a brightening agent and the outer layer cover 32 includes a fluorescent dye, both the brightening agent and the fluorescent dye can effectively improve the fashionability and visibility of the golf ball 10. preferable. In particular, when the outer cover 32 includes a yellow fluorescent dye, it is easy to distinguish the golf ball 10 from a lawn that has withered in winter, or to make the golf ball 10 easy to see in weather such as fog or rain. Will also be possible.

  From the above, in the golf ball 10 according to the present embodiment, the cover 14 covering the core 12 is transparent or translucent, so that the color tone of the outer core 22 via the cover 14 is visually recognized as the color tone of the golf ball 10. The Specifically, a color boundary line that is a boundary between the first hemisphere portion 24 and the second hemisphere portion 26 is visually recognized as a color boundary line L along the great circle of the golf ball 10 through the cover 14. That is, in the golf ball 10, the hemisphere on one side having the color boundary line L as a boundary shows the same color tone a as the first hemisphere part 24 through the cover 14, and the hemisphere on the other side through the cover 14. A color tone b similar to that of the second hemisphere 26 is shown.

  In this way, even if the color tone of the appearance of the golf ball 10 is two-tone, it is not necessary to provide a color boundary line on the cover 14, and therefore the cover 14 can be easily and efficiently formed by injection molding or the like, not by heat and pressure molding. Can be obtained. In addition, the boundary line L of the color of the golf ball 10 can be easily and clearly provided as a boundary between the first hemisphere portion 24 and the second hemisphere portion 26 made of the rubber composition.

  Further, at least one of the first hemispherical portion 24 and the second hemispherical portion 26 includes a fluorescent colorant or a brightening agent, and at least one of the inner layer cover 30 and the outer layer cover 32 is any of a brightening agent, a fluorescent coloring agent, and a brightening agent. Including Thereby, the fashionability and visibility of the golf ball 10 can be improved satisfactorily.

  Further, by further adjusting the color tone of the transparent or translucent cover 14, the color tone of the appearance of the golf ball 10 can be adjusted by both the cover 14 and the outer layer core 22. For this reason, a richer color variation can be given to the color tone of the appearance of the golf ball 10.

  As a result, the golf ball 10 is provided that has an excellent molding efficiency of the cover 14, is easily provided with a clear color boundary L that can be satisfactorily used as an indicator of the launch direction, and is excellent in fashionability and visibility. The

  The present invention is not particularly limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.

  For example, in the golf ball 10 according to the above embodiment, the core 12 is composed of a total of two layers of the inner layer core 20 and the outer layer core 22, and the cover 14 is composed of a total of two layers of the inner layer cover 30 and the outer layer cover 32. However, it is not particularly limited to these. Each of the core 12 and the cover 14 may be a single layer, or may be three or more layers. In addition, in the core which consists of one layer, you may have a solid hemispherical 1st hemisphere part and a 2nd hemisphere part. In the core composed of three or more layers, at least the outermost layer may have a hollow hemispherical first hemisphere portion and a second hemisphere portion. The material of the core 12 excluding the outermost layer is not limited to the rubber composition, and a so-called thread wound core may be adopted. Further, the core may be coated without impairing the color with a paint layer containing a fluorescent brightening agent or a brightening agent.

  First, the inner layer core was produced based on the raw material and compounding quantity of the core shown in FIG. That is, using polybutadiene as a base rubber, 11.0 parts by weight of zinc acrylate, 12.0 parts by weight of zinc oxide, 0.3 part by weight of an antioxidant, and calcium carbonate (100 parts by weight of polybutadiene) A rubber composition for an inner layer core was obtained by mixing 32.0 parts by weight of Ca), 19.0 parts by weight of barium sulfate (Ba), and 1.3 parts by weight of dicumyl peroxide. This rubber composition was molded into a spherical shape having a diameter of 25.0 mm to produce an inner layer core.

  Next, the outer layer core was produced based on the raw material and compounding quantity of the core shown in FIG. That is, using polybutadiene as a base rubber, 35.0 parts by weight of zinc acrylate, 8.0 parts by weight of zinc oxide, 0.4 parts by weight of antioxidant, and dicumyl peroxide with respect to 100 parts by weight of polybutadiene Is mixed with 1.8 parts by weight of FX-305 (trade name of a yellow fluorescent pigment made by Sinloihi Co., Ltd.) as a fluorescent colorant at a blending amount of 3.0 parts by weight to obtain a rubber composition for the first hemisphere part. It was. The second hemispherical part is the same as the rubber composition for the first hemispherical part, except that FX-307 (trade name of pink fluorescent pigment made by Sinlohi) is used as the fluorescent colorant at 3.0 parts by weight. A rubber composition was obtained.

  Each of these rubber compositions was preformed in a mold to obtain two first and second hemispherical portions having different color tones. That is, a first hemisphere portion made of yellow fluorescent color and a second hemisphere portion made of pink fluorescent color were obtained. By covering the inner layer core with these first and second hemispherical parts, the inner layer core and the outer layer core have two layers, and a color boundary line is formed along the great circle. The core of was produced.

  Next, a cover was produced based on the raw material and the amount of the cover shown in FIG. That is, High Milan 1855 (trade name of thermoplastic resin manufactured by Mitsui DuPont Polychemical Co., Ltd., 1855 in FIG. 3) and SURLYN1856 (trade name of thermoplastic resin manufactured by EI Dupont de Nemours & Company, Inc. 1856) in No. 3 were mixed at a ratio of 50.0 parts by weight to 50.0 parts by weight, respectively, to obtain a base resin. Obtained by mixing HOTALUX KS-N (trade name of fluorescent whitening agent manufactured by Clariant Japan Co., Ltd., KS-N in FIG. 3) in an amount of 0.01 parts by weight with respect to 100 parts by weight of the base resin. The transparent thermoplastic resin composition was injection molded on the outer periphery of the core to produce a transparent cover. Thus, the golf ball of Example 1 was obtained by covering the two-layer core with the one-layer cover. That is, the color tone of the appearance of the golf ball of Example 1 is a two-tone color of yellow fluorescent color and pink fluorescent color through a transparent cover.

  As shown in FIG. 2, Example 1 except that the colorant added to the rubber composition for the second hemispherical part was 5.0 parts by weight of FA-48 (trade name of blue fluorescent pigment manufactured by Sinloich). The golf ball of Example 2 was obtained in the same manner as the golf ball. That is, the color tone of the appearance of the golf ball of Example 2 is a two-tone color of yellow fluorescent color and blue fluorescent color through a transparent cover.

  As shown in FIG. 2, as a colorant added to the rubber composition for the first hemisphere part, FX-303 (trade name of a red fluorescent pigment manufactured by Sinloihi) was set to 5.0 parts by weight. Further, as a colorant added to the rubber composition for the second hemisphere part, CR-60-2 (trade name of titanium oxide manufactured by Ishihara Sangyo Co., Ltd., titanium oxide in FIG. 2) was 3.0 parts by weight. Otherwise, the golf ball of Example 3 was obtained in the same manner as the golf ball of Example 1. That is, the color tone of the appearance of the golf ball of Example 3 is a two-tone color of red fluorescent color and white via a transparent cover.

  As shown in FIG. 2, as a colorant added to the rubber composition for the first hemisphere, FX-306 (trade name of orange fluorescent pigment manufactured by Sinloihi) was 3.0 parts by weight. Moreover, as a coloring agent added to the rubber composition for 2nd hemisphere parts, FA-202 (brand name of the green fluorescent pigment made from Sinloihi) was 3.0 weight part. Otherwise, the golf ball of Example 4 was obtained in the same manner as the golf ball of Example 1. That is, the color tone of the appearance of the golf ball of Example 4 is a two-tone color of an orange fluorescent color and a green fluorescent color through a transparent cover.

  Based on FIG. 2, 17.5 parts by weight of zinc acrylate, 12.3 parts by weight of zinc oxide, 0.3 parts by weight of anti-aging agent and 0.3 parts by weight of calcium carbonate with respect to 100 parts by weight of polybutadiene as the base rubber. A rubber composition for an inner core was obtained by mixing 26.8 parts by weight, 19.0 parts by weight of barium sulfate, and 1.3 parts by weight of dicumyl peroxide. This rubber composition was molded into a spherical shape having a diameter of 25.0 mm to produce an inner layer core.

  Next, based on 100 parts by weight of polybutadiene as the base rubber, 28.1 parts by weight of zinc acrylate, 14.3 parts by weight of zinc oxide, 0.4 parts by weight of anti-aging agent based on FIG. A rubber composition for the first hemisphere part was obtained by mixing 1.2 parts by weight of dicumyl peroxide and 3.0 parts by weight of FX-305 as a fluorescent colorant. Moreover, the rubber composition for 2nd hemisphere parts was obtained similarly to the rubber composition for 1st hemisphere parts except having set said FX-307 as 3.0 weight part as a fluorescent colorant.

  The rubber compositions for the first hemisphere part and the second hemisphere part were respectively pre-molded in a mold to obtain two first hemisphere parts and second hemisphere parts having different color tones. Then, the inner layer core is covered with the first hemisphere portion and the second hemisphere portion, so that the inner layer core and the outer layer core have two layers, and a color boundary line is formed along the great circle. The core of was produced.

  Next, based on FIG. 3, HiMilan 1605 and HiMilan 1706 (both trade names of thermoplastic resins made by Mitsui DuPont Polychemical Co., Ltd., 1605 and 1706 in FIG. 3) are respectively 50.0 parts by weight and 50.0 parts by weight. The base resin was mixed at a ratio of Obtained by mixing Metashine MC-5090RY (trade name of a brightening agent manufactured by Nippon Sheet Glass Co., Ltd., MC-5090RY in FIG. 3) at a blending amount of 0.5 parts by weight with respect to 100 parts by weight of the base resin. The thermoplastic resin composition was injection molded on the outer periphery of the core to create an inner layer cover.

  Next, based on FIG. 3, the above-mentioned HiMilan 1855 and SURLYN1856 were mixed at a ratio of 50.0 parts by weight to 50.0 parts by weight, respectively, to obtain a base resin. Heat in which Sumiplast FL-7G (trade name of yellow fluorescent dye manufactured by Sumika Chemtech Co., Ltd., FL-7G in FIG. 3) was mixed in an amount of 0.05 part by weight with respect to 100 parts by weight of the base resin. The plastic resin composition was injection molded on the outer periphery of the inner layer cover to produce a translucent outer layer cover containing a yellow fluorescent color. Thus, the golf ball of Example 5 was obtained by covering the two-layer core with the two-layer cover. That is, the color tone of the appearance of the golf ball of Example 5 includes yellow fluorescent color and orange fluorescent color through a translucent outer layer cover including yellow fluorescent color and a transparent inner layer cover including brightener. The two-tone color.

  As shown in FIG.2 and FIG.3, it is the same as that of the golf ball of Example 5 except having made said FA-202 into 3.0 weight part as a coloring agent added to the rubber composition for 2nd hemisphere parts. A golf ball of Example 6 was obtained. That is, the color tone of the appearance of the golf ball of Example 6 includes yellow fluorescent color and green fluorescent color through a translucent outer layer cover including yellow fluorescent color and a transparent inner layer cover including brightener. The two-tone color.

  As shown in FIGS. 2 and 3, the golf ball of Example 6 is the same as the golf ball of Example 6 except that 3.0 parts by weight of FX-307 is used as the colorant added to the rubber composition for the first hemisphere. A golf ball of Example 7 was obtained. That is, the color tone of the appearance of the golf ball of Example 7 is orange fluorescent color and green fluorescent color through a translucent outer layer cover containing a yellow fluorescent color and a transparent inner layer cover containing a brightening agent. It is a two-tone color.

  For comparison, a conventional golf ball in which the color of the appearance was white by coloring the cover white was referred to as Comparative Example 1. A comparative example of a conventional golf ball having a two-tone color of yellow and white in appearance by having a cover that is heat-pressed so that a color boundary line is formed along the great circle of the cover 2.

  For each of the golf balls of Examples 1 to 7 and Comparative Examples 1 and 2, the following seven evaluations were performed, and the results are shown in FIG. In these evaluations, it was determined that the golf ball of Comparative Example 1 exhibited a conventional standard, and when it was superior to the golf ball of Comparative Example 1, it was superior to the conventional one. Further, in FIG. 4, the case of the conventional evaluation is indicated by Δ, the case of being superior to the conventional evaluation is indicated by ◯, and the case of being superior to the conventional evaluation is indicated by ◎.

  First, the fashionability of the appearance was evaluated. As a result, it was evaluated that the golf balls of Examples 1 to 7 were much more fashionable than the conventional golf balls.

  Next, the golf balls of Examples 1 to 7 and Comparative Examples 1 and 2 were placed on an outdoor green, and the golf balls were respectively separated from a point 10 yards away, a point 50 yards away and a point 200 yards away. Visibility was evaluated by judging whether or not the ball was easily recognized. As a result, when judged from a point 10 yards away, the golf balls of Examples 1 to 7 were evaluated to be very excellent in visibility than before.

  When judged from a point 50 yards away, each of the golf balls of Examples 1 to 7 was evaluated to be very excellent in visibility than before. On the other hand, the golf ball of Comparative Example 2 was evaluated as having conventional visibility.

  When judged from a point 200 yards away, each of the golf balls of Examples 5 to 7 is evaluated to be very excellent in visibility than before, and each of the golf balls of Examples 1 to 4 is visually recognized than before. It was evaluated as having excellent properties. On the other hand, the golf ball of Comparative Example 2 was evaluated as having conventional visibility.

  Next, we evaluated the ease of holding at addressing by the driver and the ease of stroke. As a result, each golf ball of Examples 1 to 7 was evaluated to be very easy to hold as compared with the conventional golf balls. About the ease of a stroke, each golf ball of Examples 1-7 was evaluated that it was easier to stroke than before.

  Next, the ease of holding at the time of addressing by the putter and the ease of stroke were evaluated. As a result, it was evaluated that the golf balls of Examples 1 to 7 were much easier to hold at the time of addressing than before and very easy to stroke.

  From the above, it is clear that the golf balls of Examples 1 to 7 are superior in fashionability and visibility as compared with conventional golf balls, and are easy to hold at the time of addressing and easy to stroke.

DESCRIPTION OF SYMBOLS 10 ... Golf ball 12 ... Core 14 ... Cover 20 ... Inner layer core 22 ... Outer layer core 24 ... 1st hemisphere part 26 ... 2nd hemisphere part 30 ... Inner layer cover 32 ... Outer layer cover L ... Borderline a, b ... Color tone

Claims (5)

In a golf ball comprising a core having at least one layer and a cover having at least one layer,
The outermost layer of the core has two hemispherical portions of different colors formed from a rubber composition, and the boundary between the hemispherical portions is a color boundary line along the great circle of the outermost layer of the core. Provided,
At least one of the hemispherical parts includes a fluorescent colorant or a brightening agent,
The cover is formed from a transparent or translucent thermoplastic resin composition,
At least one layer of the cover includes at least one of a fluorescent brightener, a fluorescent colorant, and a brightening agent. The golf ball according to claim 1,
At least one of the hemispherical parts includes a fluorescent pigment in a blending amount of 0.5 to 5.0 parts by weight, when the base rubber of the rubber composition is 100 parts by weight,
At least one layer of the cover includes a fluorescent brightening agent or a fluorescent dye in a blending amount of 0.001 to 3.0 parts by weight when the base resin of the thermoplastic resin composition is 100 parts by weight. A golf ball characterized by In the golf ball according to claim 1 or 2,
At least one layer of the cover includes a brightening agent in which glass flakes or silicon dioxide is coated with a metal or metal oxide, and the blending amount of the brightening agent is 100 parts by weight of the base resin of the thermoplastic resin composition. The golf ball is 0.05 to 5.0 parts by weight. The golf ball according to any one of claims 1 to 3,
A golf ball characterized in that the cover is composed of two layers comprising an inner layer and an outer layer, the inner layer contains a brightening agent, and the outer layer contains a fluorescent dye. The golf ball according to claim 4.
A golf ball comprising an outer layer of the cover containing a yellow fluorescent dye.

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