Golf ball and method of making same

Abstract

A golf ball according to the present invention is characterized by comprising: a core having an average diameter of 37 to 39 mm and having a first density; a cover layer having a thickness of 0.8 to 1.2 mm to surround the core and containing amorphous alloy powder having a second density; and an outer shell having a thickness of 1 to 1.4 mm to surround the cover layer and having a third density.

Description

Technical Field

[0001] This invention relates to a golf ball containing amorphous alloy powder. Background Technology

[0002] A golf ball is the ball used in golf. The generally accepted specifications for a golf ball are a weight of less than 45.93g and a diameter of more than 42.67mm. This is because increasing the weight or decreasing the size of a golf ball increases the amount of movement or reduces air resistance. Therefore, depending on the user's needs, some golf balls can be reduced in size and increased in weight, and are used as non-standard golf balls.

[0003] This type of golf ball consists of a core and an outer layer of two to three or more layers covering the core. The materials of the core and the outer layers surrounding it are the main factors determining the golf ball's bounce, flight distance, and other characteristics.

[0004] At this point, a golf ball is generally composed of a highly elastic core made of polybutadiene rubber and an outer shell made of polyurethane or ionomer plastic. There is also an intermediate layer between the core and the outer shell, which is called the outer core or inner shell.

[0005] In other words, the core is a highly elastic material that determines the flight distance of a golf ball, the outer shell serves as a protective layer to prevent wear and tear, and the middle layer can be made of various materials to improve spin or flight distance depending on the material of the outer shell. For example, when the outer shell is made of a highly elastic material, a material that increases rigidity can be used as the middle layer; when the outer shell is made of a highly rigid material, a material that increases elasticity can be used as the middle layer.

[0006] However, when the intermediate layer uses opposite materials based solely on elasticity or stiffness, it may have adverse effects on the overall density balance or moment of inertia design of the golf ball.

[0007] In addition, existing golf balls are designed with a focus on the distance or amount of spin during the swing, so there are almost no golf balls developed that show an advantage when chipping or putting.

[0008] Existing technical documents

[0009] Patent documents

[0010] (Patent Document) Korean Patent Publication No. 20010000252 (January 5, 2001) Summary of the Invention

[0011] The technical problem to be solved

[0012] According to one aspect of the present invention, a golf ball and a method of manufacturing the same can be provided, which effectively converts the impact energy transmitted to the golf ball into kinetic energy, minimizes the loss of flight distance, and makes the glide range short and the conversion speed of front spin very fast during putting.

[0013] Technical solution

[0014] According to one aspect of the invention, a golf ball may include: a core having an average diameter of 37 to 39 mm and having a first density; a cover layer having a thickness of 0.8 to 1.2 mm to surround the core and comprising amorphous alloy powder and having a second density; and a shell having a thickness of 1 to 1.4 mm to surround the cover layer and having a third density.

[0015] The second density may be lower than the first density and the third density.

[0016] The first density can be 1.10 to 1.20 g / cm³. 3 The second density can be 0.95–1.15 g / cm³. 3 The third density can be 1.05–1.15 g / cm³. 3 .

[0017] The density of the amorphous alloy powder can be 6-8 g / cm³. 3 .

[0018] Based on the weight of the coating layer, the content of the amorphous alloy powder in the coating layer is 12-16 wt%.

[0019] The average particle size of the amorphous alloy powder can be 10 μm to 50 μm.

[0020] The elastic modulus of the core, the covering layer, and the outer shell can decrease sequentially.

[0021] According to another aspect of the present invention, a method for manufacturing a golf ball may include: a core forming step, preparing a rubber mixture for the core, pressing and polishing the rubber mixture for the core to produce a core with an average diameter of 37-39 mm and having a first density; a cover layer forming step, mixing amorphous alloy powder into a resin for cover layer forming to prepare a resin mixture for cover layer forming, injection molding the resin mixture for cover layer forming to surround the core, and then polishing to form a cover layer with a thickness of 0.8-1.2 mm and having a second density; and a shell forming step, mixing additives into a resin for shell forming to prepare a mixture for shell forming, casting the resin mixture for shell forming to surround the cover layer to form a shell with a thickness of 1-1.4 mm and having a third density.

[0022] The second density may be lower than the first density and the third density.

[0023] The first density can be 1.10 to 1.20 g / cm³. 3 The second density can be 0.95–1.15 g / cm³, and the third density can be 1.05–1.15 g / cm³. 3 .

[0024] The density of the amorphous alloy powder can be 6-8 g / cm³. 3 The average particle size of the amorphous alloy powder can be 10μm to 50μm, and the content of the amorphous alloy powder in the resin mixture for the coating layer is 12 to 16 wt%, based on the weight of the resin mixture for the coating layer.

[0025] Invention Effects

[0026] According to one aspect of the present invention, a golf ball with improved flight distance characteristics and an effective method of manufacturing the same may be provided.

[0027] The technical effects of the present invention are not limited to the above description, and can also be understood to include the concepts that can be inferred by those skilled in the art from the following description. Attached Figure Description

[0028] Figure 1 This is a partial cross-sectional view of a golf ball according to an embodiment of the present invention. Detailed Implementation

[0029] This invention relates to a golf ball and a method for manufacturing the same. Preferred embodiments of the invention will be described below. The embodiments of the invention can be modified in various other forms, and the scope of the invention is not limited to the embodiments described below. These embodiments are provided to further illustrate the invention in detail to those skilled in the art.

[0030] In the following description, a golf ball according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0031] Figure 1 This is a partial cross-sectional view of a golf ball according to an embodiment of the present invention.

[0032] According to one aspect of the invention, a golf ball may include a shell 10, a cover layer 20, and a core 30.

[0033] The core 30 may be located at the inner center of the golf ball according to the invention, and may be configured as a sphere with a constant radius. That is, the core 30 is the innermost structural layer containing the center of the golf ball, and may be configured as a sphere with an average diameter of 37 to 39 mm, and may be made of an elastic rubber material.

[0034] There are no particular restrictions on the method for measuring the average diameter; methods conventionally used by those skilled in the art can be used. For example, a golf ball can be cut so that its center lies in a cross-section. It is assumed that two or more arbitrary straight lines pass through the center of the golf ball in the cross-section, and measurements are taken to calculate the average diameter of the core.

[0035] To ensure the elasticity of the golf ball, the average diameter of the core is preferably 37mm or more. However, when the core diameter is too large, the performance of the golf ball may decrease due to limitations in the thickness and density settings of the overlay and shell; therefore, the average core diameter can be limited to 39mm or less.

[0036] At this point, there are no particular restrictions on the rubber material used as the core material 30 of an existing golf ball, and any material can be used. For example, natural rubber, synthetic rubber, and mixtures thereof can be used, with polybutadiene rubber being preferred, and cis-1,4-butadiene rubber having more than 40% cis bonds being more preferred.

[0037] In addition, when polybutadiene rubber is used as a rubber material, at least one of the following can be mixed with polybutadiene rubber: natural rubber, polyisoprene rubber, styrene-butadiene rubber, chloroprene rubber, and ethylene propylene diene monomer (EPDM).

[0038] On the other hand, when polybutadiene rubber is used as the rubber material, the density of polybutadiene is 0.91 g / cm³. 3 Therefore, fillers can be used in rubber materials to adjust the density. Commonly used fillers can be used in this invention. The adjusted density of the core (first density) is preferably 1.10–1.20 g / cm³. 3 .

[0039] In terms of ensuring increased flight distance by maintaining the elastic modulus, the density of the sphere core is preferably 1.10 g / cm³. 3 That's all. However, when the core density is too high, the overall moment of inertia (MOI) of the golf ball weakens and the spin increases, which can actually reduce the total flight distance of the golf ball. Therefore, it is preferable to limit the core density to 1.20 g / cm³. 3 The following range.

[0040] Additional additives, such as crosslinking agents and antioxidants, which are commonly used in the core, can also be used without limitation.

[0041] A capping layer 20 is formed on the outer surface of the spherical core 30 and has a thickness of 0.8 to 1.2 mm. The polymer used for the capping layer 20 can be a highly elastic ionomer resin or a polyester elastomer resin, and fillers can be added to adjust the density of the capping layer.

[0042] For example, DuPont's SURLYN can be used as the highly elastic ionomer resin, and Kolon Plastics' Kope can be used as the polyester elastomer resin. In this invention, to facilitate adjustment of the density of the capping layer 20, either the ionomer resin or the polyester elastomer resin can be used. The density of the ionomer resin can be 1.0 g / cm³. 3 The density of the polyester elastomer can be 1.15 g / cm³. 3 above.

[0043] Amorphous alloy powder is formed by mixing it into the polymer of the coating layer. The elastic modulus of the coating layer increases by mixing amorphous alloy powder, thereby increasing its ability to convert impact energy into kinetic energy.

[0044] At this point, the amorphous alloy powder has a concentration of 6–8 g / cm³. 3 The amorphous alloy powder contains 12-16 wt% of the powder in the capping layer, with an average particle size of 10 μm-50 μm. More preferably, it can be 20-30 μm. To ensure the elastic modulus of the capping layer, the density of the amorphous alloy powder is preferably 6 g / cm³. 3 Preferably, the amorphous alloy powder is included in the coating layer in the range of 12 wt% or more based on the total weight of the coating layer. However, if the density of the amorphous alloy powder is too high or if too much amorphous alloy powder and coating layer are added, the elastic modulus of the coating layer becomes higher than that of the core, thus offsetting the effect of increased flight distance. Alternatively, the amorphous alloy powder may not be uniformly dispersed in the polymer during the manufacture of the coating layer. Therefore, the density of the amorphous alloy powder is preferably 8 g / cm³. 3 Preferably, based on the total weight of the coating, the amorphous alloy powder is included in the coating in the range of less than 16 wt%.

[0045] Regarding the uniform dispersion of amorphous alloy powder, a smaller average particle size is more advantageous. However, when the average particle size of the amorphous alloy powder is too small, the increase in elastic modulus is not significant compared to the amount of amorphous alloy powder added. Therefore, it is preferable for the amorphous alloy powder to have an average particle size of 10 mm or more. On the other hand, when the average particle size of the amorphous alloy powder is too large, irregular elasticity may occur due to the non-uniform dispersion of the amorphous alloy powder, which may degrade the overall performance of the golf ball. Therefore, the average particle size of the amorphous alloy powder can be limited to below 50 μm.

[0046] In this invention, there are no particular restrictions on the composition of the amorphous alloy powder, but iron-based amorphous alloy powder containing iron is preferred.

[0047] The composition of the amorphous alloy powder is not limited, but preferably includes iron to increase strength, chromium or molybdenum for corrosion resistance, and preferably includes carbon, boron, etc. to enhance the amorphous formation properties. For example, based on 100 parts by weight of iron, a powder containing 25.4 to 55.3 parts by weight of chromium and 35.6 to 84.2 parts by weight of molybdenum can be used.

[0048] The density of the capping layer (second density) is preferably 0.95–1.15 g / cm³. 3 The thickness of the overlay is preferably 0.8–1.2 mm. The overlay thickness can refer to the average thickness measured at multiple points along the cross-section of the golf ball. Since the density of the overlay is lower than that of the core or outer shell, it serves to balance the overall density. To ensure increased flight distance while maintaining a high modulus of elasticity, the density of the overlay is preferably 0.95 g / cm³. 3 The thickness of the coating layer is preferably 1.2 mm or less. On the other hand, according to the inventors' research, it has been confirmed that the lower the density of the coating layer containing amorphous alloy powder and the thicker the coating layer, the shorter the length of the golf ball's glide during putting. That is, the present invention limits the density of the coating layer to 1.15 g / cm³. 3 The following range limits the thickness of the overlay to 0.8mm or more, thus effectively ensuring the rolling characteristics of the golf ball in the set direction during putting.

[0049] Therefore, fillers can be used to adjust the density of the capping layer 20, but in some cases, the aforementioned amorphous alloy powder can also serve as a filler.

[0050] A shell 10 with a thickness of 1 mm to 1.4 mm can be formed on the outer surface of the cover layer 20. The thickness of the shell can also refer to the average thickness of the shell measured at multiple points in the cross-section of the golf ball. Dimples can be formed on the surface of the shell 10.

[0051] Depending on the hardness characteristics of the ball to be manufactured, the outer shell can be made of ionomer or polyurethane resin, and can include fillers and pigments.

[0052] The density of the outer shell (third density) can be 1.05–1.15 g / cm³. 3 Preferably, to ensure durability and elastic modulus, the density of the outer shell is 1.05 g / cm³. 3 On the other hand, when the density of the outer shell is too high, the elasticity of the core is offset, which actually shortens the flight distance of the golf ball. Therefore, the density of the outer shell is preferably 1.15 g / cm³. 3 Furthermore, to optimize the elastic modulus, spin, and glide range of the golf ball, the third density of the outer shell is preferably equal to or lower than the first density of the core, and the third density of the outer shell is preferably higher than the second density of the overlay. Additionally, to optimize the elastic modulus, spin, and glide range of the golf ball, the elastic modulus of the outer shell is preferably lower than the elastic modulus of the core and the overlay.

[0053] In terms of ensuring durability and modulus of elasticity, the thickness of the outer shell is preferably 1 mm or more. On the other hand, when the outer shell is too thick, the ratio of the cover layer to the core in the golf ball decreases, which not only fails to ensure the required modulus of elasticity but also increases the slip range. Therefore, the thickness of the outer shell is preferably in the range of 1.4 mm or less.

[0054] According to another aspect of the present invention, a method for manufacturing a golf ball includes a core forming step, a cover forming step, and a shell forming step.

[0055] The core forming process involves mixing butadiene, fillers, and antioxidants in a kneader and roller mill to prepare a rubber compound for the core, followed by pressing and polishing the rubber compound to manufacture the golf ball core. Cores produced through pressing and polishing meet a strength of 1.10–1.20 g / cm³. 3 The density (first density) and the average diameter of 37–39 mm.

[0056] The capping layer forming step involves mixing an amorphous alloy powder with an ionomer resin or polyester elastomer resin (used as the capping layer forming resin) to prepare a capping layer resin mixture. This mixture is then injection molded to surround the spherical core, followed by polishing to form the capping layer. The amorphous alloy powder used in the capping layer forming step can be an amorphous alloy powder having the aforementioned particle size and physical properties. The capping layer after injection molding and polishing can meet the requirements of 0.95–1.15 g / cm³. 3 The density (second density) and the thickness of 0.8 to 1.2 mm.

[0057] The shell forming step involves preparing a shell forming mixture by mixing additives into an ionomer resin or polyurethane resin, which serves as the shell forming resin, and then casting or injection molding the shell forming resin mixture to surround the cover layer.

[0058] Next, the wrinkles in the shell are trimmed and surface-treated to form a coating. Then, it is marked using a printing press and undergoes quality checks to produce the golf ball. In the final manufactured golf ball, the shell density (third density) can meet the requirement of 1.05–1.15 g / cm³. 3 The thickness of the outer shell can be within the range of 1 to 1.4 mm.

[0059] Figure label:

[0060] 10: Outer shell

[0061] 20: Covering layer

[0062] 30: Core

[0063] Implementation

[0064] The golf ball of the present invention is described in more detail below by way of examples. The examples below are provided to illustrate the invention in more detail, and it should be noted that the scope of the invention is not limited to the matters described in the following examples.

[0065] [Example]

[0066] After uniformly mixing polybutadiene rubber, filler, and antioxidant in a kneader and roller mill to prepare a rubber compound for golf ball cores, the rubber compound for cores is pressed and ground to manufacture golf ball cores with the diameters and densities shown in Table 1. The density of the core is controlled by adjusting the amount of filler added.

[0067] Next, ionomer resin, filler, and amorphous alloy powder were added to prepare a resin composition for the capping layer. The composition was then injection molded and polished to form a capping layer with the thicknesses shown in Table 1. The amorphous alloy powder, based on 100 parts by weight of iron, contained 25.4–55.3 parts by weight of chromium and 35.6–84.2 parts by weight of molybdenum. Amorphous alloy powder containing trace amounts of boron or carbon was also used, and the average particle size of the amorphous alloy powder was controlled to approximately 30 μm before being added to the resin composition. In the case of No. 10, a density of 5 g / cm³ was used. 3 The amorphous alloy powder slightly reduced the density of the coating. In the case of No. 11, by using a density of 9 g / cm³... 3 The amorphous alloy powder slightly increased the density of the coating. The remaining golf ball used a density of 7 g / cm³. 3 The amorphous alloy powder was used to manufacture the coating layer. The amorphous alloy powder was added to the resin composition for the coating layer to a weight of 14 wt% based on the weight fraction of the resin composition for the coating layer.

[0068] Next, a resin mixture for the shell is prepared using ionomers and additives. The resin mixture is then cast and polished to surround the outer surface of the covering layer, including the spherical core, thereby forming a shell with the thickness and density shown in Table 1. The density of the shell is controlled by adjusting the amount of filler added.

[0069] Table 1

[0070]

[0071]

[0072] Using the same swing robot from Golf Laboratories used in R&A and USG, a golf ball swing distance test was conducted under the conditions provided in Table 1 (simulating clubhead speed of 100 MPH). The ball speed (MPH), launch angle (Launch Angle), total spin (RPM), flight distance (Carry, m), and total distance (Total, m) of each golf ball were measured, and the results are recorded in Table 2.

[0073] In addition, additional tests were conducted using a putter swing robot on putting tests of golf balls provided under the conditions in Table 1 (simulating a putting speed of 3 MPH). The skid distance (Skid, m) from the point of impact of each golf ball to the point where it transitions from backspin to forwardspin after passing through the backspin zone was measured and recorded in Table 2.

[0074] Table 2

[0075]

[0076]

[0077] Based on Tables 1 and 2, it can be confirmed that the inventive embodiments that satisfy the thickness and density of the core, cover layer, and shell as defined by the present invention accelerate the ball speed, which is the main factor determining the flight distance of a golf ball, and reduce the amount of spin, thereby simultaneously satisfying a total distance of more than 240m and a glide distance of less than 0.7m. Conversely, comparative examples that do not satisfy any of the thickness and density of the core, cover layer, and shell as defined by the present invention cannot satisfy a total distance of more than 240m and a glide distance of less than 0.7m.

[0078] Therefore, according to one aspect of the present invention, a golf ball and a method for manufacturing the same can be provided, which improves flight distance characteristics while effectively improving accuracy during putting.

[0079] Although the present invention has been described in detail through the above embodiments, other types of embodiments are also possible. Therefore, the technical concept and scope of the following claims are not limited to the embodiments.

Claims

1. A golf ball, characterized in that, include: The spherical core has an average diameter of 37–39 mm and possesses a first density; A capping layer, having a thickness of 0.8–1.2 mm, surrounds the spherical core and comprises amorphous alloy powder having a second density; and The outer shell has a thickness of 1–1.4 mm to surround the covering layer and has a third density. The density of the amorphous alloy powder is 6–8 g / cm³. 3 , Based on the weight of the capping layer, the content of the amorphous alloy powder in the capping layer is 12-16 wt%. The average particle size of the amorphous alloy powder is 10 μm to 50 μm.

2. The golf ball according to claim 1, wherein, The second density is lower than the first density and the third density.

3. The golf ball according to claim 1, wherein, The first density is 1.10–1.20 g / cm³. 3 The second density is 0.95–1.15 g / cm³. 3 The third density is 1.05–1.15 g / cm³. 3 .

4. The golf ball according to claim 1, wherein, The elastic modulus of the core, the covering layer, and the outer shell decreases sequentially.

5. A method for manufacturing a golf ball, comprising: The core forming step involves preparing a rubber mixture for the core, pressing and polishing the rubber mixture to produce a core with an average diameter of 37-39 mm and a first density. The coating layer forming step involves mixing amorphous alloy powder into a resin for coating layer formation to prepare a resin mixture for coating layer formation, injection molding the resin mixture for coating layer formation to surround the sphere core, and then polishing to form a coating layer with a thickness of 0.8 to 1.2 mm and a second density. as well as The shell forming step involves mixing additives into a shell-forming resin to prepare a shell-forming mixture, and then casting the shell-forming resin mixture to surround the covering layer, forming a shell with a thickness of 1–1.4 mm and a third density. The density of the amorphous alloy powder is 6–8 g / cm³. 3 , The amorphous alloy powder has an average particle size of 10 μm to 50 μm. Based on the weight of the resin mixture for the coating layer, the content of the amorphous alloy powder in the resin mixture for the coating layer is 12 to 16 wt%.

6. The method for manufacturing a golf ball according to claim 5, wherein, The second density is lower than the first density and the third density.

7. The method for manufacturing a golf ball according to claim 5, wherein, The first density is 1.10–1.20 g / cm³. 3 The second density is 0.95–1.15 g / cm³. 3 The third density is 1.05–1.15 g / cm³. 3 .

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