WO2020009887A1

WO2020009887A1 - Graphene core for a golf ball with a soft cover

Info

Publication number: WO2020009887A1
Application number: PCT/US2019/039427
Authority: WO
Inventors: Petra Petrich; Bartels DAVID; Hong G. JEON; Carl Brown
Original assignee: Callaway Golf Company
Priority date: 2018-07-02
Filing date: 2019-06-27
Publication date: 2020-01-09
Also published as: JP2021509069A; KR102523415B1; JP2023016834A; CN112867758A; KR20210023866A; CN112867758B; JP7212692B2

Abstract

A golf ball (10) with a core (12) comprising polybutadiene and graphene, and a soft cover (16) is disclosed herein. The golf ball (10) has a dual core (12) with an outer core (l2b) comprising polybutadiene and graphene. The soft cover (16) is preferably composed of a highly neutralized polymer, a first ionomer, a second ionomer, and an impact modifier.

Description

Graphene Core For A Golf Ball With A Soft Cover

Technical Field

[0001] The present invention generally relates to the use of graphene in layers of a golf ball, and more particularly to a golf ball with a graphene core and a soft cover.

Background Art

[0002] Typical process of synthesizing exfoliated graphite (individual sheets of exfoliated graphite are also known as graphene or graphene nanoplatelets) includes reacting graphite with acids such as nitric and or sulfuric acid followed by heat treatment and chemical reduction. Exfoliated graphite is a two dimensional planar sheet made of SP²-hybridized carbon. Graphene (individual sheets of reduced exfoliated graphite) sheets are typically few nanometers thick and few microns wide (aspect ratio of >1000). This high aspect ratio of graphene coupled with their high tensile strength (tensile strength in GPa compared to MPa for polymers) can lead to polymeric composite materials with very high tensile and flexural properties.

Graphene’s unusually high thermal conductivity (-3000 W/mk compared to <1 W/mk for typical thermoplastic polymers; can be utilized in making thermally conductive composite materials. For thermally cured elastomeric products, this high thermal conductivity can mean shorter, more uniform curing cycles that can lead to higher production volumes.

[0003] Various examples of exfoliated graphite (also called graphene) based

composites can be found in literature. Wang et al. describe expanded graphite polyethylene composite for electromagnetic radiation interference (EMI) shielding applications.

[0004] EiS Patent 4946892 describes synthesis of exfoliated graphene based

composite by compression molding graphite with polyimide resin under high heat (200 C) and pressure (80 kPa).

[0005] Shioyama describes synthesis of polyisoprene and polystyrene based

composite materials by in-situ polymerization of styrene and isoprene monomers in presence of exfoliated graphite.

[0006] US Patent 5776372 describes an electrically conductive nanocomposite made with expanded graphite and various polymers such as polypropylene,

polytetrafluoroethylene, and phenolic resin. Pan et al. describe synthesis of nylon-6 expanded graphite nanocomposite by polymerization of e-caprolactam in presence of expanded graphite.

[0007] Chen et al. describe in-situ polymerization of methyl methacrylate in presence of expanded graphite to obtain an electrically conductive nanocomposite.

[0008] Xiao et al. describe making exfoliated graphite composite with improved

thermal stability by in-situ polymerization of styrene in presence of exfoliated graphene.

[0009] The prior art fails to even recognize this problem.

Summary of the Invention

[0010] The primary purpose of the present invention is to improve durability of golf ball core by incorporation of graphene in the core to improve the impact strength of the ball, and to have a soft cover. This benefit can be seen in either a ball with single piece core, or a dual core with an outer core firmer than the inner core. Improved durability of the core by using graphene can result in higher mean time to fail (MTTF) upon repeated impact in a high speed testing device, or with a golf club in normal play.

[0011] Another objective is to improve aging properties due to the incorporation of graphene in the core for better retention of compression and COR over time.

[0012] One aspect of the present invention is a golf ball comprising an inner core, an outer core and a cover layer. The cover layer is disposed over the outer core, and the cover layer is composed of 5 to 45 wt% of a highly neutralized polymer, 5 to 45 wt% of a first ionomer, 5 to 45 wt% of a second ionomer, 5 to 45 wt% of a third ionomer, 5 to 30 wt% of a masterbatch comprising from 15 to 40 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch. The core comprising the inner core and the outer core has a compression value ranging from 40 to 55. The golf ball has a diameter of at least 1.68 inches, a mass lower than 45.93 grams, and a COR of at least 0.790.

[0013] In a more preferred embodiment, outer core comprise graphene material

ranging from 0.4 to 2.5 weight percent of the outer core. In an even more preferred embodiment, the graphene material ranges from 0.6 to 1.5 weight percent of the outer core.

[0014] Another aspect of the present invention is a golf ball comprising an inner core, an outer core, and a cover layer. The inner core comprises a polybutadiene material. The outer core comprises polybutadiene material and a graphene material in an amount ranging from 0.1 to 5.0 weight percent of the outer core, wherein the outer core has a flexural modulus ranging from 80MPa to 95MPa. The cover layer is disposed over the outer core. The cover layer comprises 5 to 45 wt% of a highly neutralized polymer, 5 to 45 wt% of a first ionomer, 5 to 45 wt% of a second ionomer, 5 to 45 wt% of a third ionomer, 5 to 30 wt% of a masterbatch comprising from 15 to 40 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch. A dual core comprises the inner core and the outer core has a compression value ranging from 40 to 55. The golf ball has a diameter of at least 1.68 inches, a mass lower than 45.93 grams, and a COR of at least 0.790.

[0015] Yet another aspect of the present invention is a golf ball comprising a dual core composed of an inner core and an outer core, and a cover layer. The inner core comprises a polybutadiene and a graphene material in an amount ranging from 0.1 to 5.0 weight percent of the inner core. The outer core comprises a polybutadiene and a graphene material in an amount ranging from 0.1 to 5.0 weight percent of the outer core. The outer core has a flexural modulus ranging from 80MPa to 95MPa. The cover layer is disposed over the outer core. The cover layer comprises 5 to 45 wt% of a highly neutralized polymer, 5 to 45 wt% of a first ionomer, 5 to 45 wt% of a second ionomer, 5 to 45 wt% of a third ionomer, 5 to 30 wt% of a masterbatch comprising from 15 to 40 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch. The cover layer has a thickness ranging from 0.025 inch to 0.055 inch. The dual core has a compression value ranging from 40 to 55.

[0016] Yet another aspect of the present invention is a golf ball comprising a dual core composed of an inner core and an outer core, and a mantle layer and a cover layer. The inner core comprises a polybutadiene and a graphene material in an amount ranging from 0.1 to 5.0 weight percent of the inner core. The outer core comprises a polybutadiene and a graphene material in an amount ranging from 0.1 to 5.0 weight percent of the outer core. The outer core has a flexural modulus ranging from 80MPa to 95MPa. The cover layer is disposed over the mantle layer. The cover layer comprises 5 to 45 wt% of a highly neutralized polymer, 5 to 45 wt% of a first ionomer, 5 to 45 wt% of a second ionomer, 5 to 45 wt% of a third ionomer, 5 to 30 wt% of a masterbatch comprising from 15 to 40 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch. The cover layer has a thickness ranging from 0.025 inch to 0.055 inch. The cover layer has a Shore D hardness ranging from 35 to 60.

The dual core has a compression value ranging from 40 to 55.

Brief Description of the Drawings

[0017] FIG. 1 is an exploded partial cut-away view of a golf ball.

[0018] FIG. 2 is an exploded partial view of a golf ball.

[0019] FIG. 3 is an exploded partial cut-away view of a golf ball.

[0020] FIG. 4 is top perspective view of a golf ball.

[0021] FIG. 5 is a cross-sectional view of a core component of a golf ball.

[0022] FIG. 6 is a cross-sectional view of a core component and a mantle component of a golf ball.

[0023] FIG. 7 is a cross-sectional view of an inner core layer, an outer core layer, an inner mantle layer, an outer mantle layer and a cover layer of a golf ball.

[0024] FIG. 7A is a cross-sectional view of an inner core layer, an intermediate core layer, an outer core layer, a mantle layer and a cover layer of a golf ball.

[0025] FIG. 8 is a cross-sectional view of an inner core layer under a 100 kilogram load.

[0026] FIG. 9 is a cross-sectional view of a core under a 100 kilogram load. [0027] FIG. 10 is a cross-sectional view of a core component and a mantle component of a golf ball.

[0028] FIG. 11 is a cross-sectional view of a core component, the mantle component and a cover layer of a golf ball.

[0029] FIG. 12 is an exploded partial cut-away view of a four-piece golf ball

[0030] FIG. 13 is an exploded partial cut-away view of a three-piece golf ball

[0031] FIG. 14 is an exploded partial cut-away view of a two-piece golf ball

[0032] FIG. 15 is a cross-sectional view of a two-piece golf ball

[0033] FIG. 16 is a cross-sectional view of a three-piece golf ball

[0034] FIG. 17 is an exploded partial cut-away view of a three-piece golf ball

[0035] FIG. 18 is a cross-sectional view of a three-piece golf ball with a dual core and a cover.

[0036] FIG. 19 is a cross-sectional view of a three-piece golf ball with a core , mantle and cover.

[0037] FIG. 20 is a cross-sectional view of a four-piece golf ball with a dual core, mantle layer and a cover.

[0038] FIG. 21 is a cross-sectional view of a four-piece golf ball with a core, dual mantle layers and a cover.

[0039] FIG. 22 is a graph of durability testing of outer cores using PTM at l75fps.

[0040] FIG. 23 is a graph of durability testing of dual cores using PTM at l75fps.

[0041] FIG. 24 is a graph of durability testing of dual cores using PTM at l75fps.

[0042] FIG. 25 is a graph of durability testing of dual cores using PTM at l75fps.

[0043] FIG. 26 is an illustration of graphene.

[0044] FIG. 27 is a graph of durability testing of dual cores using PTM at l75fps.

[0045] FIG. 28 is a durability plot (MTTF) vs average surface area of graphene.

[0046] FIG. 29 is a graph of temperature of an outer core of a dual core as a function of cure time.

Best Mode(s) For Carrying Out The Invention

[0047] One objective of the present invention is to improve durability of golf ball core by incorporation of graphene in either the core the impact strength of the ball. This benefit can be seen in either a ball designed to have a low compression single piece core, or a dual core with an outer core firmer than the inner core. Improved durability of the core or mantle composition by using graphene can result in higher mean time to fail (MTTF) upon repeated impact in a high speed testing device, or with a golf club in normal play.

[0048] Another objective of the present invention is to improve aging properties due to the incorporation of graphene in either the core or mantle layer for better retention of compression and COR over time.

[0049] In a preferred embodiment, a golf ball comprises a core with a cover layer composed of 5 to 45 wt% of a highly neutralized polymer, 5 to 45 wt% of a first ionomer, 5 to 45 wt% of a second ionomer, 5 to 45 wt% of a third ionomer, 5 to 30 wt% of a masterbatch comprising from 15 to 40 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch. In an alternative embodiment, the cover layer 16 is composed of 30 to 40 wt% of a highly neutralized polymer (“HNP”), 10 to 20 wt% of a first ionomer; 10 to 20 wt% of a second ionomer, 15 to 25 wt% of a masterbatch comprising from 20 to 50 wt% of an impact modifier, and 5 to 15 wt% of a color masterbatch. In yet another alternative embodiment, the cover layer is composed of 35 to 45 wt% of a highly neutralized polymer (“HNP”), 10 to 20 wt% of a first ionomer; 10 to 20 wt% of a second ionomer, 15 to 25 wt% of a masterbatch comprising from 20 to 50 wt% of an impact modifier, and 5 to 15 wt% of a color masterbatch. In yet another alternative embodiment, the cover layer is composed of 10 to 30 wt% of a highly neutralized polymer, 10 to 30 wt% of a first ionomer, 10 to 30 wt% of a second ionomer, 10 to 30 wt% of a third ionomer, 15 to 25 wt% of a masterbatch comprising from 15 to 30 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch. In yet another alternative embodiment, the cover layer composed of 10 to 30 wt% of a highly neutralized polymer, 10 to 90 wt% of a first ionomer, 0 to 30 wt% of a second ionomer, 0 to 30 wt% of a third ionomer, 15 to 25 wt% of a masterbatch comprising from 15 to 30 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch.

[0050] A preferred HNP is HPF 2000 available from DuPont Chemical. Another preferred HNP is HPF 1000, also available from DuPont. Yet another alternative HNP is AD1035, also available from DuPont. Yet another alternative HNP is AD1172, also available from DuPont.

[0051] A preferred ionomer material is SURLYN® 9150, available from DuPont.

SURLYN 9150 is an ethyl ene/methacrylic acid copolymer with partial neutralization of the acid groups with zinc ions. Another preferred ionomer material is SURLYN® 8150, also available from DuPont. SURLYN 8150 is an ethyl ene/methacrylic acid copolymer with partial neutralization of the acid groups with sodium ions. Yet another preferred ionomer material is SURLYN® AD 1022, also available from DuPont.

[0052] An alternative ionomer material is SURLYN® 9945, available from DuPont.

An alternative ionomer material is SURLYN® 8945, available from DuPont.

[0053] The impact modifier is at least one of acrylonitrile-butadiene-styrene polymer (ABS), methyl methacrylate-butadiene-styrene polymer (MBS) impact-property modifiers for poly(vinyl chloride), and acrylic/methacrylic core-shell modifiers for polycarbonate.

[0054] Polybutadiene based cores were made using following materials.

Corresponding levels (by % wt) is mentioned next to each material: Polybutadiene with more than 60% l,4-cis structure-(40-90%); Polyisoprene-(l-30%); Zinc diacrylate- (10-50%); Zinc oxide-(l-30%); Zinc stearate-(l-20%); Peroxide initiator- (0.1-10%); Zinc pentachlorothiophenol-(0-l0%); Color-(0-l0%); Barium sulfate-(0- 20%); Graphene A (0.0l-6%)-is available from various suppliers such as Cheap Tubes Inc., Ad-Nano Technologies Private Limited, MKnano, XG Sciences Inc., Angstron Materials Inc. (graphene A may have an average surface area between 15- 50 m²/g); Graphene B (0.0l-6%)-is available from various suppliers such as Cheap Tubes Inc., Ad-Nano Technologies Private Limited, MKnano, XG Sciences Inc., Angstron Materials Inc. (graphene B may have an average surface area between 300- 400 m²/g); Graphene C (0.0l-6%)-is available from various suppliers such as Cheap Tubes Inc., Ad-Nano Technologies Private Limited, MKnano, XG Sciences Inc., Angstron Materials Inc. (graphene C has a higher surface average than either graphene A or graphene B, and graphene C may have an average surface area between 400-800 m²/g); Graphene masterbatch(a masterbatch of 90-99%

polybutadiene or polyisoprene and 1-10% graphene)-(0.l-50%)-custom compounding can be done with the help of various suppliers such as Preferred Compounding Corp, Dyna-Mix, Alttran, Callaway (in house compounding).

[0055] Four different single cores (formula 1 to 4) were made as shown in recipe in Table 1. Control group (formula 1) had no graphene

[0056] Table 1. Recipe of solid core (graphene)

[0057] Compression is measured by applying a 200 pound load to the core and measuring its deflection, in inches. Compression = 180 - (deflection *1000).

[0058] Durability testing of solid cores

[0059] Cores were shot at 150 fps in a pneumatic testing machine (PTM).

[0060] For each formula mentioned in Table 1, twelve cores were tested. The number of shots after which each core cracked was recorded for each core, and the cracked core was removed from the remainder of the test. The data was reported using a Weibull plot, and the mean time to fail was reported as shown in Table 1. As seen in FIG. 20, graphene modified cores endured more shots before failure compared to cores with no graphene. It is reasonable to assume that the durability of a golf ball having a single piece core of this design will also experience a dramatic increase in crack durability based on this improvement to the core.

[0061] In this study graphene A was introduced to the outer core in a dual core construction. Dual cores were made by compression molding two outer core halves around an already molded inner core having a diameter of approximately 0.940” and a soft compression of approximately 0.200 inches of deflection under a 200lb load. Curing of the inner and outer core was done at temperatures ranging between 150-400 °F for times ranging from 1-30 minutes. After molding, the dual cores were spherically ground to approximately 1.554” prior to testing.

[0062] Table 2 and 3 give details of recipe of inner and outer cores. Components from these recipes were mixed in an internal mixer. Optionally, additional mixing was done using a two roll mill.

[0063] Compression of the outer core is measured by first making a full size core separately, measuring its compression, and then molding two halves around the inner core to complete the dual core.

[0064] Compression differential describes the difference between the outer core

compression (as molded independently) and inner core compression. A higher compression differential is more susceptible to crack durability upon impact. [0065] Table 2. Inner core recipe

[0066] Table 3. Outer core recipe of dual core

Properties of outer core

[0067] Compression is measured by applying a 200 pound load to the core and

measuring its deflection, in inches. Compression = 180 - (deflection *1000) Durability testing of dual cores

[0068] Cores were shot at 175 fps in a pneumatic testing machine (PTM).

[0069] For each formula mentioned in Table 3, twelve cores were tested. The number of shots after which each core cracked was recorded for each core, and the cracked core was removed from the remainder of the test. The data was reported using a

Weibull plot, and the mean time to fail was reported as shown in Table 3. As seen in FIG. 21, graphene modified cores endured more shots before failure compared to cores with no graphene. It is reasonable to assume that the durability of a golf ball having a dual core of this design will also experience a dramatic increase in crack durability based on this improvement to the dual core.

[0070] Dual cores with Graphene-C in outer core only

[0071] In this study Graphene-C (0.01-6%, available from various suppliers such as Cheap Tubes Inc., Ad-Nano Technologies Private Limited, MKnano, XG Sciences Inc., Angstron Materials Inc., and has an average surface area between 400-800 m²/g) was introduced to the outer core in a dual core construction. Dual cores were made by compression molding two outer core halves around an already molded inner core having a diameter of approximately 0.940” and a soft compression of approximately 0.200 inches of deflection under a 200lb load. Curing of the inner and outer core was done at temperatures ranging between 150-400 F for times ranging from 1-30 minutes. After molding, the dual cores were spherically ground to approximately 1.554” prior to testing.

[0072] Tables 4 and 5 give details of recipe of inner and outer cores. Components from these recipes were mixed in an internal mixer. Optionally, additional mixing was done using a two roll mill.

[0073] Compression of the outer core is measured by first making a full size core separately, measuring its compression, and then molding two halves around the inner core to complete the dual core. Compression differential describes the difference between the outer core compression (as molded independently) and inner core compression. A higher compression differential is more susceptible to crack durability upon impact.

[0074] Table 4. Inner core recipe

[0075]

[0076] Table 4

[0077] Table 5. Outer recipe of dual core [00781 Table 5 [0079] Compression is measured by applying a 200 pound load to the core and measuring its deflection, in inches. Compression = 180 - (deflection *1000).

[0080] Cores were shot at 175 fps in a pneumatic testing machine (PTM).

[0081] For each formula mentioned in Table 5, twelve cores were tested. The number of shots after which each core cracked was recorded for each core, and the cracked core was removed from the remainder of the test. The data was reported using a Weibull plot, and the mean time to fail was reported as shown in Table 5. Testing was stopped after 100 shots. As shown in FIG. 22, graphene modified cores endured more shots before failure compared to cores with no graphene. It is reasonable to assume that the durability of a golf ball having a dual core of this design will also experience a dramatic increase in crack durability based on this improvement to the dual core.

It’s reasonable to assume that the addition of graphene in the inner core could provide a durability enhancement to the overall golf ball, but this study only focused on the outer core.

[0082] Dual cores with graphene A in the inner core and the outer core.

[0083] In this study graphene A was introduced to the inner and outer core in a dual core construction. Table 6 gives details of recipe of inner and outer cores of these dual cores. Components from these recipes were mixed in an internal mixer. Optionally, additional mixing was done using a two roll mill. Dual cores were made by compression molding two outer core halves around an already molded inner core having a diameter of approximately 0.940” and a soft compression of approximately 0.200 inches of deflection under a 200lb load. Curing of the inner and outer core was done at temperatures ranging between 150-400 F for times ranging from 1-30 minutes. After molding, the dual cores were spherically ground to approximately 1.554” prior to testing.

[0084] Compression of the outer core was measured by first making a full size core separately, measuring its compression, and then molding two halves around the inner core to complete the dual core.

[0085] Table 6. Dual core recipes with graphene A in the inner core and the outer core

Table 6 [0086] Compression is measured by applying a 200 pound load to the core and measuring its deflection, in inches. Compression = 180 - (deflection *1000).

[0087] For each formula mentioned in Table 6, twelve cores were tested. The number of shots after which each core cracked was recorded for each core, and the cracked core was removed from the remainder of the test. The data was reported using a Weibull plot, and the mean time to fail was reported as shown in Table 6. As seen in FIG. 23, graphene modified cores endured more shots before failure compared to cores with no graphene. The best durability was observed for balls which had graphene in inner and outer cores. It is reasonable to assume that the durability of a golf ball having a dual core of this design will also experience a dramatic increase in crack durability based on this improvement to the dual core. It’s reasonable to assume that the addition of graphene in the inner core could provide a durability enhancement to the overall golf ball, but this study only focused on the outer core.

[0088] Dual Cores With Graphene B In The Outer Core Only

[0089] In this study Graphene-B was introduced to the outer core in a dual core

construction. Dual cores were made by compression molding two outer core halves around an already molded inner core having a diameter of approximately 0.940” and a soft compression of approximately 0.200 inches of deflection under a 200lb load. Curing of the inner and outer core was done at temperatures ranging between 150-400 F for times ranging from 1-30 minutes. After molding, the dual cores were spherically ground to approximately 1.554” prior to testing.

[0090] Tables 7 and 8 give details of recipe of inner and outer cores. Components from these recipes were mixed in an internal mixer. Optionally, additional mixing was done using a two roll mill.

[0091] Compression of the outer core is measured by first making a full size core separately, measuring its compression, and then molding two halves around the inner core to complete the dual core. Compression differential describes the difference between the outer core compression (as molded independently) and inner core compression. A higher compression differential is more susceptible to crack durability upon impact.

[ 0092 ] Table 7. Inner Core Recipe [ 0093 ] Table 8. Outer Core Recipe Of Dual Core

Table 8

[ 0094 ] The compression of Formula 17 is 64.3, the compression of Formula 18 is 68.0, and the compression of Formula 19 is 67.1. The compression of a dual core built from the inner core and the outer core is 42.1 for Formula 17, 45.8 for Formula 18 and 48.7 for Formula 19. Compression is measured by applying a 200 pound load to the core and measuring its deflection, in inches. Compression = 180 - (deflection *1000). [ 0095 ] Cores were shot at 175 fps in a pneumatic testing machine (PTM). For each formula mentioned in Table 8, twelve cores were tested. The number of shots after which each core cracked was recorded for each core, and the cracked core was removed from the remainder of the test. The data was reported using a Weibull plot, and the mean time to fail was reported as shown in Table 8. Testing was stopped after 100 shots. As seen in FIG. 25, graphene modified cores endured more shots before failure compared to cores with no graphene. It is reasonable to assume that the durability of a golf ball having a dual core of this design will also experience a dramatic increase in crack durability based on this improvement to the dual core. It’s reasonable to assume that the addition of graphene in the inner core could provide a durability enhancement to the overall golf ball, but this study only focused on the outer core.

[ 0096 ] As seen in FIG. 26, as the average surface area of graphene nanoplatelet

increases, mean time to fail (MTTF) or durability increases. For the same concentration of graphene, nanoplatelet that has higher average surface area lasts longer in a typical durability test.

[ 0097 ] To test if graphene helps reduce the time required to cure a given rubber core, temperature/time experiment was conducted. Controlled cores had no graphene whereas modified cores contained 1.6% graphene in an outer core. Inner cores did not have any graphene. A thermocouple was attached to an outer core of the dual core. Temperature of outer core was recorded while curing the dual core. Temperature inside outer core of a dual core was recorded as a function of time as shown in FIG. 27. As seen in FIG. 27, cores that contain graphene achieve a maximum temperature sooner than cores that do not contain graphene. This can be attributed to a higher thermal conductivity of graphene that causes the outer core to reach higher temperature faster than cores that do not have any graphene .

[ 0098 ] Novelty of this process: Durability of the dual core with a high compression

differential is greatly enhanced by incorporation of graphene in inner and outer core.

The graphene reinforcement to the inner and outer core helps resist the high stresses experienced by the core when struck at high club speeds. Addition of graphene to the core recipe is very simple and it can be dispersed into the polybutadiene mixture during two roll milling process. Due to high thermal conductivity of graphene, overall thermal conductivity of cores can be increased with incorporation of graphene. With higher thermal conductivity of graphene reinforced cores, curing cycles can be made shorter. Shorter curing cycles can lead to higher output in production. Optionally, graphene can be introduced as a masterbatch in polybutadiene or polyisoprene, making its dispersion into polybutadiene rubber much easier and dust free.

[0099] As our experiment has shown, incorporating graphene into the inner and outer core recipe reinforces the strength of the outer core and provides greater crack durability protection in the design of a dual core golf ball, which is more susceptible to crack durability failures if the outer core is much firmer than the soft inner core.

[00100] In general, this is applicable when the inner core is softer than the outer core.

More specifically, when the inner core has more than 0.200” deflection under a 200lb load, and the dual core is 40 compression or greater.

[00101] This is particularly crucial if the ball is a 4-piece construction with a single mantle layer with thickness less than 0.050”, or more specifically thinner than 0.040”, with 0.036” being the target in this study.

[00102] FIGS. 3-7 illustrate a five piece golf ball 10 comprising an inner core l2a, an outer core l2b, an inner mantle l4a, an outer mantle l4b, and a cover layer 16 composed of 5 to 45 wt% of a highly neutralized polymer, 5 to 45 wt% of a first ionomer, 5 to 45 wt% of a second ionomer, 5 to 45 wt% of a third ionomer, 5 to 30 wt% of a masterbatch comprising from 15 to 40 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch. In an alternative embodiment, the cover layer 16 is composed of 30 to 40 wt% of a highly neutralized polymer (“HNP”), 10 to 20 wt% of a first ionomer; 10 to 20 wt% of a second ionomer, 15 to 25 wt% of a masterbatch comprising from 20 to 50 wt% of an impact modifier, and 5 to 15 wt% of a color masterbatch. In yet another alternative embodiment, the cover layer is composed of 35 to 45 wt% of a highly neutralized polymer (“HNP”), 10 to 20 wt% of a first ionomer;

10 to 20 wt% of a second ionomer, 15 to 25 wt% of a masterbatch comprising from 20 to 50 wt% of an impact modifier, and 5 to 15 wt% of a color masterbatch. In yet another alternative embodiment, the cover layer is composed of 10 to 30 wt% of a highly neutralized polymer, 10 to 30 wt% of a first ionomer, 10 to 30 wt% of a second ionomer, 10 to 30 wt% of a third ionomer, 15 to 25 wt% of a masterbatch comprising from 15 to 30 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch. In yet another alternative embodiment, the cover layer is composed of 10 to 30 wt% of a highly neutralized polymer, 10 to 90 wt% of a first ionomer, 0 to 30 wt% of a second ionomer, 0 to 30 wt% of a third ionomer, 15 to 25 wt% of a masterbatch comprising from 15 to 30 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch.

The inner core l2a comprises polybutadiene mixture comprising 0.4 to 2.5 weight percent of a graphene.

[00103] FIG. 7A illustrates a five piece golf ball 10 comprising an inner core l2a, an intermediate core l2b, an outer core l2c, a mantle 14, and a cover layer 16 composed of 5 to 45 wt% of a highly neutralized polymer, 5 to 45 wt% of a first ionomer, 5 to 45 wt% of a second ionomer, 5 to 45 wt% of a third ionomer, 5 to 30 wt% of a masterbatch comprising from 15 to 40 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch. In an alternative embodiment, the cover layer 16 is composed of 30 to 40 wt% of a highly neutralized polymer (“HNP”), 10 to 20 wt% of a first ionomer; 10 to 20 wt% of a second ionomer, 15 to 25 wt% of a masterbatch comprising from 20 to 50 wt% of an impact modifier, and 5 to 15 wt% of a color masterbatch. In yet another alternative embodiment, the cover layer is composed of 35 to 45 wt% of a highly neutralized polymer (“HNP”), 10 to 20 wt% of a first ionomer; 10 to 20 wt% of a second ionomer, 15 to 25 wt% of a masterbatch comprising from 20 to 50 wt% of an impact modifier, and 5 to 15 wt% of a color masterbatch. In yet another alternative embodiment, the cover layer is composed of 10 to 30 wt% of a highly neutralized polymer, 10 to 30 wt% of a first ionomer, 10 to 30 wt% of a second ionomer, 10 to 30 wt% of a third ionomer, 15 to 25 wt% of a masterbatch comprising from 15 to 30 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch. In yet another alternative embodiment, the cover layer is composed of 10 to 30 wt% of a highly neutralized polymer, 10 to 90 wt% of a first ionomer, 0 to 30 wt% of a second ionomer, 0 to 30 wt% of a third ionomer, 15 to 25 wt% of a masterbatch comprising from 15 to 30 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch.

The intermediate core l2b comprises polybutadiene mixture comprising 0.4 to 2.5 weight percent of a graphene.

[00104] FIGS. 10 and 11 illustrate a six piece golf ball 10 comprising an inner core l2a, an intermediate core l2b, an outer core l2c, an inner mantle l4a, an outer mantle l4b, and a cover layer 16 composed of 5 to 45 wt% of a highly neutralized polymer, 5 to 45 wt% of a first ionomer, 5 to 45 wt% of a second ionomer, 5 to 45 wt% of a third ionomer, 5 to 30 wt% of a masterbatch comprising from 15 to 40 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch. In an alternative embodiment, the cover layer 16 is composed of 30 to 40 wt% of a highly neutralized polymer (“HNP”), 10 to 20 wt% of a first ionomer; 10 to 20 wt% of a second ionomer, 15 to 25 wt% of a masterbatch comprising from 20 to 50 wt% of an impact modifier, and 5 to 15 wt% of a color masterbatch. In yet another alternative embodiment, the cover layer is composed of 35 to 45 wt% of a highly neutralized polymer (“HNP”), 10 to 20 wt% of a first ionomer; 10 to 20 wt% of a second ionomer, 15 to 25 wt% of a masterbatch comprising from 20 to 50 wt% of an impact modifier, and 5 to 15 wt% of a color masterbatch. In yet another alternative embodiment, the cover layer is composed of 10 to 30 wt% of a highly neutralized polymer, 10 to 30 wt% of a first ionomer, 10 to 30 wt% of a second ionomer, 10 to 30 wt% of a third ionomer, 15 to 25 wt% of a masterbatch comprising from 15 to 30 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch. In yet another alternative embodiment, the cover layer is composed of 10 to 30 wt% of a highly neutralized polymer, 10 to 90 wt% of a first ionomer, 0 to 30 wt% of a second ionomer, 0 to 30 wt% of a third ionomer, 15 to 25 wt% of a masterbatch comprising from 15 to 30 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch. The inner core l2a comprises polybutadiene mixture comprising 0.4 to 2.5 weight percent of a graphene.

[00105] FIG. 12 illustrates a four piece golf ball comprising a dual core, a boundary layer and a cover layer composed of 5 to 45 wt% of a highly neutralized polymer, 5 to 45 wt% of a first ionomer, 5 to 45 wt% of a second ionomer, 5 to 45 wt% of a third ionomer, 5 to 30 wt% of a masterbatch comprising from 15 to 40 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch. In an alternative embodiment, the cover layer is composed of 30 to 40 wt% of a highly neutralized polymer (“HNP”), 10 to 20 wt% of a first ionomer; 10 to 20 wt% of a second ionomer, 15 to 25 wt% of a masterbatch comprising from 20 to 50 wt% of an impact modifier, and 5 to 15 wt% of a color masterbatch. In yet another alternative embodiment, the cover layer is composed of 35 to 45 wt% of a highly neutralized polymer (“HNP”), 10 to 20 wt% of a first ionomer; 10 to 20 wt% of a second ionomer, 15 to 25 wt% of a masterbatch comprising from 20 to 50 wt% of an impact modifier, and 5 to 15 wt% of a color masterbatch. In yet another alternative embodiment, the cover layer is composed of 10 to 30 wt% of a highly neutralized polymer, 10 to 30 wt% of a first ionomer, 10 to 30 wt% of a second ionomer, 10 to 30 wt% of a third ionomer, 15 to 25 wt% of a masterbatch comprising from 15 to 30 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch. In yet another alternative embodiment, the cover layer is composed of 10 to 30 wt% of a highly neutralized polymer, 10 to 90 wt% of a first ionomer, 0 to 30 wt% of a second ionomer, 0 to 30 wt% of a third ionomer, 15 to 25 wt% of a masterbatch comprising from 15 to 30 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch. The outer core comprises polybutadiene mixture comprising 0.4 to 2.5 weight percent of a graphene.

[00106] FIG. 13 illustrates a three piece golf ball comprising a core, a boundary layer and a cover layer composed of 5 to 45 wt% of a highly neutralized polymer, 5 to 45 wt% of a first ionomer, 5 to 45 wt% of a second ionomer, 5 to 45 wt% of a third ionomer, 5 to 30 wt% of a masterbatch comprising from 15 to 40 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch. In an alternative embodiment, the cover layer is composed of 30 to 40 wt% of a highly neutralized polymer (“HNP”), 10 to 20 wt% of a first ionomer; 10 to 20 wt% of a second ionomer, 15 to 25 wt% of a masterbatch comprising from 20 to 50 wt% of an impact modifier, and 5 to 15 wt% of a color masterbatch. In yet another alternative embodiment, the cover layer is composed of 35 to 45 wt% of a highly neutralized polymer (“HNP”), 10 to 20 wt% of a first ionomer; 10 to 20 wt% of a second ionomer, 15 to 25 wt% of a masterbatch comprising from 20 to 50 wt% of an impact modifier, and 5 to 15 wt% of a color masterbatch. In yet another alternative embodiment, the cover layer is composed of 10 to 30 wt% of a highly neutralized polymer, 10 to 30 wt% of a first ionomer, 10 to 30 wt% of a second ionomer, 10 to 30 wt% of a third ionomer, 15 to 25 wt% of a masterbatch comprising from 15 to 30 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch. In yet another alternative embodiment, the cover layer is composed of 10 to 30 wt% of a highly neutralized polymer, 10 to 90 wt% of a first ionomer, 0 to 30 wt% of a second ionomer, 0 to 30 wt% of a third ionomer, 15 to 25 wt% of a masterbatch comprising from 15 to 30 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch. The core comprises polybutadiene mixture comprising 0.4 to 2.5 weight percent of a graphene.

[00107] FIGS. 14 and 15 illustrate a two piece golf ball 20 with a core 25 and a cover layer 30 composed of 5 to 45 wt% of a highly neutralized polymer, 5 to 45 wt% of a first ionomer, 5 to 45 wt% of a second ionomer, 5 to 45 wt% of a third ionomer, 5 to 30 wt% of a masterbatch comprising from 15 to 40 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch. In an alternative embodiment, the cover layer 30 is composed of 30 to 40 wt% of a highly neutralized polymer (“HNP”), 10 to 20 wt% of a first ionomer; 10 to 20 wt% of a second ionomer, 15 to 25 wt% of a masterbatch comprising from 20 to 50 wt% of an impact modifier, and 5 to 15 wt% of a color masterbatch. In yet another alternative embodiment, the cover layer is composed of 35 to 45 wt% of a highly neutralized polymer (“HNP”), 10 to 20 wt% of a first ionomer; 10 to 20 wt% of a second ionomer, 15 to 25 wt% of a masterbatch comprising from 20 to 50 wt% of an impact modifier, and 5 to 15 wt% of a color masterbatch. In yet another alternative embodiment, the cover layer is composed of 10 to 30 wt% of a highly neutralized polymer, 10 to 30 wt% of a first ionomer, 10 to 30 wt% of a second ionomer, 10 to 30 wt% of a third ionomer, 15 to 25 wt% of a masterbatch comprising from 15 to 30 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch. In yet another alternative embodiment, the cover layer is composed of 10 to 30 wt% of a highly neutralized polymer, 10 to 90 wt% of a first ionomer, 0 to 30 wt% of a second ionomer, 0 to 30 wt% of a third ionomer, 15 to 25 wt% of a masterbatch comprising from 15 to 30 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch. The core comprises polybutadiene mixture comprising 0.4 to 2.5 weight percent of a graphene.

[00108] FIGS. 16 and 17 illustrate a three-piece golf ball 5 comprising a core 10, a mantle layer 14 and a cover layer 16 composed of 5 to 45 wt% of a highly neutralized polymer, 5 to 45 wt% of a first ionomer, 5 to 45 wt% of a second ionomer, 5 to 45 wt% of a third ionomer, 5 to 30 wt% of a masterbatch comprising from 15 to 40 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch, with dimples 18, wherein the core comprises 0.4 to 2.5 weight percent of a graphene. In an alternative embodiment, the cover layer 16 is composed of 30 to 40 wt% of a highly neutralized polymer (“HNP”), 10 to 20 wt% of a first ionomer; 10 to 20 wt% of a second ionomer, 15 to 25 wt% of a masterbatch comprising from 20 to 50 wt% of an impact modifier, and 5 to 15 wt% of a color masterbatch. In yet another alternative embodiment, the cover layer is composed of 35 to 45 wt% of a highly neutralized polymer (“HNP”), 10 to 20 wt% of a first ionomer; 10 to 20 wt% of a second ionomer, 15 to 25 wt% of a masterbatch comprising from 20 to 50 wt% of an impact modifier, and 5 to 15 wt% of a color masterbatch. In yet another alternative embodiment, the cover layer is composed of 10 to 30 wt% of a highly neutralized polymer, 10 to 30 wt% of a first ionomer, 10 to 30 wt% of a second ionomer, 10 to 30 wt% of a third ionomer, 15 to 25 wt% of a masterbatch comprising from 15 to 30 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch. In yet another alternative embodiment, the cover layer is composed of 10 to 30 wt% of a highly neutralized polymer, 10 to 90 wt% of a first ionomer, 0 to 30 wt% of a second ionomer, 0 to 30 wt% of a third ionomer, 15 to 25 wt% of a masterbatch comprising from 15 to 30 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch.

[00109] FIG. 18 illustrates a dual core three piece golf ball 35 comprising an inner core 30, and outer core 32 and a cover layer 34 composed of 5 to 45 wt% of a highly neutralized polymer, 5 to 45 wt% of a first ionomer, 5 to 45 wt% of a second ionomer, 5 to 45 wt% of a third ionomer, 5 to 30 wt% of a masterbatch comprising from 15 to 40 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch, wherein the core comprises 0.4 to 2.5 weight percent of a graphene. In an alternative embodiment, the cover layer 34 is composed of 30 to 40 wt% of a highly neutralized polymer (“HNP”), 10 to 20 wt% of a first ionomer; 10 to 20 wt% of a second ionomer, 15 to 25 wt% of a masterbatch comprising from 20 to 50 wt% of an impact modifier, and 5 to 15 wt% of a color masterbatch. In yet another alternative embodiment, the cover layer is composed of 35 to 45 wt% of a highly neutralized polymer (“HNP”), 10 to 20 wt% of a first ionomer; 10 to 20 wt% of a second ionomer, 15 to 25 wt% of a masterbatch comprising from 20 to 50 wt% of an impact modifier, and 5 to 15 wt% of a color masterbatch. In yet another alternative embodiment, the cover layer is composed of 10 to 30 wt% of a highly neutralized polymer, 10 to 30 wt% of a first ionomer, 10 to 30 wt% of a second ionomer, 10 to 30 wt% of a third ionomer, 15 to 25 wt% of a masterbatch comprising from 15 to 30 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch. In yet another alternative embodiment, the cover layer is composed of 10 to 30 wt% of a highly neutralized polymer, 10 to 90 wt% of a first ionomer, 0 to 30 wt% of a second ionomer, 0 to 30 wt% of a third ionomer, 15 to 25 wt% of a masterbatch comprising from 15 to 30 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch.

[00110] FIG. 19 illustrates a three piece golf ball 45 comprising a core 40, a mantle layer 42 and a cover layer 44 composed of 5 to 45 wt% of a highly neutralized polymer, 5 to 45 wt% of a first ionomer, 5 to 45 wt% of a second ionomer, 5 to 45 wt% of a third ionomer, 5 to 30 wt% of a masterbatch comprising from 15 to 40 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch, wherein the core comprises 0.4 to 2.5 weight percent of a graphene. In an alternative embodiment, the cover layer 44 is composed of 30 to 40 wt% of a highly neutralized polymer (“HNP”), 10 to 20 wt% of a first ionomer; 10 to 20 wt% of a second ionomer, 15 to 25 wt% of a masterbatch comprising from 20 to 50 wt% of an impact modifier, and 5 to 15 wt% of a color masterbatch. In yet another alternative embodiment, the cover layer is composed of 35 to 45 wt% of a highly neutralized polymer (“HNP”), 10 to 20 wt% of a first ionomer; 10 to 20 wt% of a second ionomer, 15 to 25 wt% of a masterbatch comprising from 20 to 50 wt% of an impact modifier, and 5 to 15 wt% of a color masterbatch. In yet another alternative embodiment, the cover layer is composed of 10 to 30 wt% of a highly neutralized polymer, 10 to 30 wt% of a first ionomer, 10 to 30 wt% of a second ionomer, 10 to 30 wt% of a third ionomer, 15 to 25 wt% of a masterbatch comprising from 15 to 30 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch. In yet another alternative embodiment, the cover layer is composed of 10 to 30 wt% of a highly neutralized polymer, 10 to 90 wt% of a first ionomer, 0 to 30 wt% of a second ionomer, 0 to 30 wt% of a third ionomer, 15 to 25 wt% of a masterbatch comprising from 15 to 30 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch.

[00111] FIG. 20 illustrates a dual core four piece golf ball 55 comprising an inner core 50, an outer core 52, a mantle layer 54 and a cover layer 56 composed of 5 to 45 wt% of a highly neutralized polymer, 5 to 45 wt% of a first ionomer, 5 to 45 wt% of a second ionomer, 5 to 45 wt% of a third ionomer, 5 to 30 wt% of a masterbatch comprising from 15 to 40 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch, wherein the core comprises 0.4 to 2.5 weight percent of a graphene. In an alternative embodiment, the cover layer 56 is composed of 30 to 40 wt% of a highly neutralized polymer (“HNP”), 10 to 20 wt% of a first ionomer; 10 to 20 wt% of a second ionomer, 15 to 25 wt% of a masterbatch comprising from 20 to 50 wt% of an impact modifier, and 5 to 15 wt% of a color masterbatch. In yet another alternative embodiment, the cover layer is composed of 35 to 45 wt% of a highly neutralized polymer (“HNP”), 10 to 20 wt% of a first ionomer; 10 to 20 wt% of a second ionomer, 15 to 25 wt% of a masterbatch comprising from 20 to 50 wt% of an impact modifier, and 5 to 15 wt% of a color masterbatch. In yet another alternative embodiment, the cover layer is composed of 10 to 30 wt% of a highly neutralized polymer, 10 to 30 wt% of a first ionomer, 10 to 30 wt% of a second ionomer, 10 to 30 wt% of a third ionomer, 15 to 25 wt% of a masterbatch comprising from 15 to 30 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch. In yet another alternative embodiment, the cover layer is composed of 10 to 30 wt% of a highly neutralized polymer, 10 to 90 wt% of a first ionomer, 0 to 30 wt% of a second ionomer, 0 to 30 wt% of a third ionomer, 15 to 25 wt% of a masterbatch comprising from 15 to 30 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch. [00112] FIG. 21 illustrates a four piece golf ball 65 comprising a core 60, an inner mantle 62, an outer mantle 64 and a cover layer 66 composed of 5 to 45 wt% of a highly neutralized polymer, 5 to 45 wt% of a first ionomer, 5 to 45 wt% of a second ionomer, 5 to 45 wt% of a third ionomer, 5 to 30 wt% of a masterbatch comprising from 15 to 40 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch, wherein the core comprises 0.4 to 2.5 weight percent of a graphene. In an alternative embodiment, the cover layer 66 is composed of 30 to 40 wt% of a highly neutralized polymer (“HNP”), 10 to 20 wt% of a first ionomer; 10 to 20 wt% of a second ionomer, 15 to 25 wt% of a masterbatch comprising from 20 to 50 wt% of an impact modifier, and 5 to 15 wt% of a color masterbatch. In yet another alternative embodiment, the cover layer is composed of 35 to 45 wt% of a highly neutralized polymer (“HNP”), 10 to 20 wt% of a first ionomer; 10 to 20 wt% of a second ionomer, 15 to 25 wt% of a masterbatch comprising from 20 to 50 wt% of an impact modifier, and 5 to 15 wt% of a color masterbatch. In yet another alternative embodiment, the cover layer is composed of 10 to 30 wt% of a highly neutralized polymer, 10 to 30 wt% of a first ionomer, 10 to 30 wt% of a second ionomer, 10 to 30 wt% of a third ionomer, 15 to 25 wt% of a masterbatch comprising from 15 to 30 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch. In yet another alternative embodiment, the cover layer is composed of 10 to 30 wt% of a highly neutralized polymer, 10 to 90 wt% of a first ionomer, 0 to 30 wt% of a second ionomer, 0 to 30 wt% of a third ionomer, 15 to 25 wt% of a masterbatch comprising from 15 to 30 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch.

[00113] The optional mantle component is preferably composed of the inner mantle layer and the outer mantle layer. The mantle component preferably has a thickness ranging from 0.05 inch to 0.15 inch, and more preferably from 0.06 inch to 0.08 inch. The outer mantle layer is preferably composed of a blend of ionomer materials. One preferred embodiment comprises SURLYN 9150 material, SURLYN 8940 material, a SURLYN AD 1022 material, and a masterbatch. The SURLYN 9150 material is preferably present in an amount ranging from 20 to 45 weight percent of the cover, and more preferably 30 to 40 weight percent. The SURLYN 8945 is preferably present in an amount ranging from 15 to 35 weight percent of the cover, more preferably 20 to 30 weight percent, and most preferably 26 weight percent. The SURLYN 9945 is preferably present in an amount ranging from 30 to 50 weight percent of the cover, more preferably 35 to 45 weight percent, and most preferably 41 weight percent. The SURLYN 8940 is preferably present in an amount ranging from 5 to 15 weight percent of the cover, more preferably 7 to 12 weight percent, and most preferably 10 weight percent.

[00114] SURLYN 8320, from DuPont, is a very-low modulus ethylene/methacrylic acid copolymer with partial neutralization of the acid groups with sodium ions.

SURLYN 8945, also from DuPont, is a high acid ethylene/methacrylic acid copolymer with partial neutralization of the acid groups with sodium ions. SURLYN 9945, also from DuPont, is a high acid ethylene/methacrylic acid copolymer with partial neutralization of the acid groups with zinc ions. SURLYN 8940, also from DuPont, is an ethylene/methacrylic acid copolymer with partial neutralization of the acid groups with sodium ions.

[00115] An embodiment with an inner mantle has the inner mantle layer preferably composed of a blend of ionomers, preferably comprising a terpolymer and at least two high acid (greater than 18 weight percent) ionomers neutralized with sodium, zinc, magnesium, or other metal ions. The material for the inner mantle layer preferably has a Shore D plaque hardness ranging preferably from 35 to 77, more preferably from 36 to 44, a most preferably approximately 40. The thickness of the outer mantle layer preferably ranges from 0.025 inch to 0.050 inch, and is more preferably approximately 0.037 inch. The mass of an insert including the dual core and the inner mantle layer preferably ranges from 32 grams to 40 grams, more preferably from 34 to 38 grams, and is most preferably approximately 36 grams. The inner mantle layer is alternatively composed of a HPF material available from DuPont.

[00116] An embodiment with an outer mantle has the outer mantle layer preferably composed of a blend of ionomers, preferably comprising at least two high acid (greater than 18 weight percent) ionomers neutralized with sodium, zinc, or other metal ions. The blend of ionomers also preferably includes a masterbatch. The material of the outer mantle layer preferably has a Shore D plaque hardness ranging preferably from 55 to 75, more preferably from 65 to 71, and most preferably approximately 67. The thickness of the outer mantle layer preferably ranges from 0.025 inch to 0.040 inch, and is more preferably approximately 0.030 inch. The mass of the entire insert including the core, the inner mantle layer and the outer mantle layer preferably ranges from 38 grams to 43 grams, more preferably from 39 to 41 grams, and is most preferably approximately 41 grams.

[00117] In an alternative embodiment, the inner mantle layer is preferably composed of a blend of ionomers, preferably comprising at least two high acid (greater than 18 weight percent) ionomers neutralized with sodium, zinc, or other metal ions. The blend of ionomers also preferably includes a masterbatch. In this embodiment, the material of the inner mantle layer has a Shore D plaque hardness ranging preferably from 55 to 75, more preferably from 65 to 71, and most preferably approximately 67. The thickness of the outer mantle layer preferably ranges from 0.025 inch to 0.040 inch, and is more preferably approximately 0.030 inch. Also in this embodiment, the outer mantle layer l4b is composed of a blend of ionomers, preferably comprising a terpolymer and at least two high acid (greater than 18 weight percent) ionomers neutralized with sodium, zinc, magnesium, or other metal ions. In this embodiment, the material for the outer mantle layer l4b preferably has a Shore D plaque hardness ranging preferably from 35 to 77, more preferably from 36 to 44, a most preferably approximately 40. The thickness of the outer mantle layer preferably ranges from 0.025 inch to 0.100 inch, and more preferably ranges from 0.070 inch to 0.090 inch.

[00118] In yet another embodiment wherein the inner mantle layer is thicker than the outer mantle layer and the outer mantle layer is harder than the inner mantle layer, the inner mantle layer is composed of a blend of ionomers, preferably comprising a terpolymer and at least two high acid (greater than 18 weight percent) ionomers neutralized with sodium, zinc, magnesium, or other metal ions. In this embodiment, the material for the inner mantle layer has a Shore D plaque hardness ranging preferably from 30 to 77, more preferably from 30 to 50, and most preferably approximately 40. In this embodiment, the material for the outer mantle layer has a Shore D plaque hardness ranging preferably from 40 to 77, more preferably from 50 to 71, and most preferably approximately 67. In this embodiment, the thickness of the inner mantle layer preferably ranges from 0.030 inch to 0.090 inch, and the thickness of the outer mantle layer ranges from 0.025 inch to 0.070 inch.

[00119] Preferably the inner core has a diameter ranging from 0.75 inch to 1.20 inches, more preferably from 0.85 inch to 1.05 inch, and most preferably approximately 0.95 inch. Preferably the inner core l2a has a Shore D hardness ranging from 20 to 50, more preferably from 25 to 40, and most preferably approximately 35. Preferably the inner core has a mass ranging from 5 grams to 15 grams, 7 grams to 10 grams and most preferably approximately 8 grams.

[00120] Preferably the outer core has a diameter ranging from 1.25 inch to 1.55 inches, more preferably from 1.40 inch to 1.5 inch, and most preferably approximately 1.5 inch. Preferably the outer core has a Shore D surface hardness ranging from 40 to 65, more preferably from 50 to 60, and most preferably approximately 56. Preferably the outer core is formed from a polybutadiene, zinc diacrylate, zinc oxide, zinc stearate, a peptizer and peroxide. Preferably the combined inner core and outer core have a mass ranging from 25 grams to 35 grams, 30 grams to 34 grams and most preferably approximately 32 grams.

[00121] Preferably the inner core has a deflection of at least 0.230 inch under a load of 220 pounds, and the core has a deflection of at least 0.080 inch under a load of 200 pounds. As shown in FIGS. 8 and 9, a mass 50 is loaded onto an inner core and a core. As shown in FIGS. 8 and 9, the mass is 100 kilograms, approximately 220 pounds. Under a load of 100 kilograms, the inner core preferably has a deflection from 0.230 inch to 0.300 inch. Under a load of 100 kilograms, preferably the core has a deflection of 0.08 inch to 0.150 inch. Alternatively, the load is 200 pounds

(approximately 90 kilograms), and the deflection of the core 12 is at least 0.080 inch. Further, a compressive deformation from a beginning load of 10 kilograms to an ending load of 130 kilograms for the inner core ranges from 4millimeters to 7 millimeters and more preferably from 5 millimeters to 6.5 millimeters. The dual core deflection differential allows for low spin off the tee to provide greater distance, and high spin on approach shots.

[00122] In an alternative embodiment of the golf ball shown in FIG. 7A, the golf ball

10 comprises an inner core l2a, an intermediate core l2b, an outer core l2b, a mantle 14 and a cover 16. The golf ball 10 preferably has a diameter of at least 1.68 inches, a mass ranging from 45 grams to 47 grams, a COR of at least 0.79, a deformation under a 100 kilogram loading of at least 0.07mm.

[00123] In a preferred embodiment, a golf ball comprises a dual core and a cover layer composed of 5 to 45 wt% of a highly neutralized polymer, 5 to 45 wt% of a first ionomer, 5 to 45 wt% of a second ionomer, 5 to 45 wt% of a third ionomer, 5 to 30 wt% of a masterbatch comprising from 15 to 40 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch. The cover preferably has a hardness ranging from 30 to 60 Shore D, more preferably 45 to 55 Shore D. The inner core preferably has a diameter ranging from 1.1 to 1.5 inches, and most preferably 1.25 inches. The dual core (consisting of the inner core and outer core) preferably has a diameter of 1.55 inches to 1.65 inches, and most preferably 1.59 inches to 1.6 inches. The golf ball preferably has a diameter of at least 1.68 inches. The golf ball preferably has a mass lower than 45.93 grams, and preferably ranging from 45.0 to 45.93 grams. The golf ball preferably has a COR of at least 0.790. The golf ball preferably has an INSTRON compression ranging from 0.10 to 0.13 inches.

[00124] As used herein, "Shore D hardness" of the golf ball layers is measured

generally in accordance with ASTM D-2240 type D, except the measurements may be made on the curved surface of a component of the golf ball, rather than on a plaque.

If measured on the ball, the measurement will indicate that the measurement was made on the ball. In referring to a hardness of a material of a layer of the golf ball, the measurement will be made on a plaque in accordance with ASTM D-2240.

Furthermore, the Shore D hardness of the cover is measured while the cover remains over the mantles and cores. When a hardness measurement is made on the golf ball, the Shore D hardness is preferably measured at a land area of the cover.

[00125] As used herein, "Shore A hardness" of a cover is measured generally in

accordance with ASTM D-2240 type A, except the measurements may be made on the curved surface of a component of the golf ball, rather than on a plaque. If measured on the ball, the measurement will indicate that the measurement was made on the ball. In referring to a hardness of a material of a layer of the golf ball, the measurement will be made on a plaque in accordance with ASTM D-2240.

Furthermore, the Shore A hardness of the cover is measured while the cover remains over the mantles and cores. When a hardness measurement is made on the golf ball, Shore A hardness is preferably measured at a land area of the cover

[00126] The resilience or coefficient of restitution (COR) of a golf ball is the constant "e," which is the ratio of the relative velocity of an elastic sphere after direct impact to that before impact. As a result, the COR ("e") can vary from 0 to 1, with 1 being equivalent to a perfectly or completely elastic collision and 0 being equivalent to a perfectly or completely inelastic collision.

[00127] COR, along with additional factors such as club head speed, club head mass, ball weight, ball size and density, spin rate, angle of trajectory and surface

configuration as well as environmental conditions (e.g. temperature, moisture, atmospheric pressure, wind, etc.) generally determine the distance a ball will travel when hit. Along this line, the distance a golf ball will travel under controlled environmental conditions is a function of the speed and mass of the club and size, density and resilience (COR) of the ball and other factors. The initial velocity of the club, the mass of the club and the angle of the ball's departure are essentially provided by the golfer upon striking. Since club head speed, club head mass, the angle of trajectory and environmental conditions are not determinants controllable by golf ball producers and the ball size and weight are set by the U.S.G.A., these are not factors of concern among golf ball manufacturers. The factors or determinants of interest with respect to improved distance are generally the COR and the surface configuration of the ball.

[00128] The coefficient of restitution is the ratio of the outgoing velocity to the

incoming velocity. In the examples of this application, the coefficient of restitution of a golf ball was measured by propelling a ball horizontally at a speed of 125 +/- 5 feet per second (fps) and corrected to 125 fps against a generally vertical, hard, flat steel plate and measuring the ball's incoming and outgoing velocity electronically. Speeds were measured with a pair of ballistic screens, which provide a timing pulse when an object passes through them. The screens were separated by 36 inches and are located 25.25 inches and 61.25 inches from the rebound wall. The ball speed was measured by timing the pulses from screen 1 to screen 2 on the way into the rebound wall (as the average speed of the ball over 36 inches), and then the exit speed was timed from screen 2 to screen 1 over the same distance. The rebound wall was tilted 2 degrees from a vertical plane to allow the ball to rebound slightly downward in order to miss the edge of the cannon that fired it. The rebound wall is solid steel.

[00129] As indicated above, the incoming speed should be 125 ±5 fps but corrected to 125 fps. The correlation between COR and forward or incoming speed has been studied and a correction has been made over the ±5 fps range so that the COR is reported as if the ball had an incoming speed of exactly 125.0 fps.

[00130] The measurements for deflection, compression, hardness, and the like are preferably performed on a finished golf ball as opposed to performing the

measurement on each layer during manufacturing.

[00131] Preferably, in a five layer golf ball comprising an inner core, an outer core, an inner mantle layer, an outer mantle layer and a cover, the hardness/compression of layers involve an inner core with the greatest deflection (lowest hardness), an outer core (combined with the inner core) with a deflection less than the inner core, an inner mantle layer with a hardness less than the hardness of the combined outer core and inner core, an outer mantle layer with the hardness layer of the golf ball, and a cover with a hardness less than the hardness of the outer mantle layer. These measurements are preferably made on a finished golf ball that has been tom down for the

measurements.

Claims

1. A golf ball comprising:

an inner core comprising a polybutadiene material;

an outer core comprising polybutadiene material and a graphene material; and

a cover layer disposed over the outer core, the cover layer comprising 5 to 45 wt% of a highly neutralized polymer, 5 to 45 wt% of a first ionomer, 5 to 45 wt% of a second ionomer, 5 to 45 wt% of a third ionomer, 5 to 30 wt% of a masterbatch comprising from 15 to 40 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch;

wherein the golf ball has a diameter of at least 1.68 inches, a mass lower than 45.93 grams, and a COR of at least 0.790.

2. A golf ball comprising:

an inner core comprising a polybutadiene material;

an outer core comprising polybutadiene material and a graphene material in an amount ranging from 0.1 to 5.0 weight percent of the outer core, wherein the outer core has a flexural modulus ranging from 80MPa to 95MPa; and a cover layer disposed over the outer core, the cover layer comprising 30 to 40 wt% of a highly neutralized polymer, 10 to 20 wt% of a first ionomer, 10 to 20 wt% of a second ionomer, 15 to 25 wt% of a masterbatch comprising from 20 to 50 wt% of an impact modifier, and 5 to 15 wt% of a color masterbatch;

wherein a dual core comprising the inner core and the outer core has a compression value ranging from 40 to 55.

3. A golf ball comprising:

an inner core comprising a polybutadiene material;

an outer core comprising polybutadiene material and a graphene material; and

a cover layer disposed over the outer core, the cover layer comprising 30 to 40 wt% of a highly neutralized polymer, 10 to 20 wt% of a first ionomer, 10 to 20 wt% of a second ionomer, 15 to 25 wt% of a masterbatch comprising from 20 to 50 wt% of an impact modifier, and 5 to 15 wt% of a color masterbatch;

4. A golf ball comprising:

an inner core comprising a polybutadiene material;

an outer core comprising polybutadiene material; and

a cover layer disposed over the outer core, the cover layer comprising 10 to 30 wt% of a highly neutralized polymer, 10 to 90 wt% of a first ionomer, 0 to 30 wt% of a second ionomer, 0 to 30 wt% of a third ionomer, 15 to 25 wt% of a masterbatch comprising from 15 to 30 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch;

5. The golf ball according to any of claims 1, 2, 3 and 4 wherein the graphene material ranges from 0.4 to 2.5 weight percent of the outer core.

6. The golf ball according to any of claims 1, 2, 3 and 4 wherein the graphene material ranges from 0.6 to 1.5 weight percent of the outer core.

7. The golf ball according to any of claims 1, 2, 3 and 4 wherein the impact modifier is at least one of methyl methacrylate-butadiene-styrene polymer (MBS) impact-property modifiers for poly(vinyl chloride), and acrylic/methacrylic core-shell modifiers for polycarbonate.

8. The golf ball according to any of claims 1, 2, 3 and 4 wherein the graphene material has a surface area ranging from 400m²/g to 800m²/g.

9. The golf ball according to any of claims 1, 2, 3 and 4 wherein the cover layer has a Shore D hardness ranging from 35 to 60.

10. The golf ball according to any of claims 1, 2, 3 and 4 wherein the outer core has a tensile modulus ranging from 8MPa to lOMPa.

11. A golf ball comprising:

an inner core comprising a polybutadiene and a graphene material; an outer core comprising a polybutadiene and a graphene material; and a cover layer disposed over the outer core, the cover layer comprising 5 to 45 wt% of a highly neutralized polymer, 5 to 45 wt% of a first ionomer, 5 to 45 wt% of a second ionomer, 5 to 45 wt% of a third ionomer, 5 to 30 wt% of a masterbatch comprising from 15 to 40 wt% of an impact modifier, and 1 to 10 wt% of a color masterbatch;

12. The golf ball according to claim 11 wherein the impact modifier is at least one of methyl methacrylate-butadiene-styrene polymer (MBS) impact-property modifiers for poly(vinyl chloride), and acrylic/methacrylic core-shell modifiers for polycarbonate.