# US 9,750,984 B2 · Golf balls having a multi-layered core with a thermoset rubber center

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- Number: US 9,750,984 B2
- Document ID: US9750984B2
- Status: Granted
- Kind: B2
- Application number: 15/205,132
- Filed: 2016-07-08
- Published: 2016-11-03
- Granted: 2017-09-05
- Earliest claimed: 2001-11-28
- Assignees: Acushnet Company
- Applicants: Acushnet Company
- Inventors: Michael J. Sullivan
- Web page: https://patentgrep.com/patent/US9750984B2

## CPC

- A63B 37/0076: {Multi-piece balls, i.e. having two or more intermediate layers}
- A63B 37/0003: {Golf balls}
- A63B 37/0027: {Polyurea}
- A63B 37/0031: {Hardness}
- A63B 37/0039: {characterised by the material}
- A63B 37/0043: {Hardness}
- A63B 37/0044: {Hardness gradient}
- A63B 37/0045: {Thickness}
- A63B 37/0051: {Materials other than polybutadienes; Constructional details}
- A63B 37/00621: {Centre hardness}
- A63B 37/00622: {Surface hardness}
- A63B 37/0063: {Hardness gradient}
- A63B 37/0064: {Diameter}
- A63B 37/0066: {Density; Specific gravity}
- A63B 37/0092: {Hardness distribution amongst different ball layers}
- A63B: APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT (apparatus for passive exercising, massage A61H)

## Abstract

Golf balls having a multi-layered solid core and multi-layered cover are provided. The center of the core is made of a thermoset rubber material and preferably has a positive hardness gradient. The intermediate core layer is made of a thermoset or thermoplastic composition. The outer core layer is made of a highly neutralized polymer composition. The inner cover is made of a thermoplastic composition, preferably an ethylene acid copolymer. The thermoplastic ethylene acid copolymer ionomer can have acid groups that are partially or highly neutralized. The outer cover is made of a composition comprising a polyurethane, polyurea, or copolymer or blend thereof. The finished ball has high resiliency and rebounding properties.

## Claims

### Claim 1

A golf ball consisting essentially of:
an inner core layer formed from a thermoset rubber composition and having a diameter of 1.100 inches to 1.400 inches, a center hardness (Hcenter material) of 50 Shore C or greater, and an outer surface hardness (Hcenter surface) of 65 Shore C or greater, wherein the Hcenter surface is greater than the Hcenter material to provide a positive hardness gradient;
an intermediate core layer formed from a thermoset or thermoplastic composition having a material hardness (Hintermediate core material) of 83 Shore C or greater and an outer surface hardness (Hintermediate core surface) of 85 Shore C or greater;
an outer core layer formed from a highly neutralized polymer composition and having a material hardness (Houter core material) of 70 Shore C or greater and an outer surface hardness (Houter core surface) of 70 Shore C or greater;
an inner cover layer formed from a thermoplastic composition having a material hardness (Hinner cover material) of 80 Shore C to 95 Shore C, the thermoplastic composition comprising an ethylene acid copolymer ionomer, wherein Hintermediate core material is greater than Hinner cover material; and
an outer cover layer formed from a composition comprising a material selected from the group consisting of polyurethanes, polyureas, and copolymers and blends thereof.

### Claim 2 (depends on 1)

The golf ball of claim 1, wherein the thermoplastic composition of the inner cover layer comprises a partially neutralized ethylene acid copolymer ionomer having acid groups such that the amount of neutralized acid groups is in the range of 30% to less than 80%.

### Claim 3 (depends on 1)

The golf ball of claim 1, wherein the thermoplastic composition of the inner cover layer comprises a highly neutralized ethylene acid copolymer ionomer having acid groups such that the amount of neutralized acid groups is 90% or greater.

### Claim 4 (depends on 1)

The golf ball of claim 1, wherein the thermoplastic composition of the inner cover layer comprises an ethylene acid copolymer ionomer having greater than 16% by weight of acid groups.

### Claim 5 (depends on 4)

The golf ball of claim 4, wherein the thermoplastic composition of the inner cover layer comprises a blend of ethylene acid copolymer ionomer having greater than 16% by weight of acid groups and maleic anhydride grafted ethylene-butylene copolymer.

### Claim 6 (depends on 1)

The golf ball of claim 1, wherein the thermoplastic composition of the inner cover layer further comprises additives selected from the group consisting of particulate fillers, coloring agents, fluorescent agents, whitening agents, UV light stabilizers, and plasticizers.

### Claim 7 (depends on 1)

The golf ball of claim 1, wherein the inner cover layer has a thickness in the range of 0.020 to 0.120 inches.

### Claim 8 (depends on 1)

The golf ball of claim 1, wherein the inner cover layer is formed from a thermoplastic composition comprising an ethylene acid copolymer ionomer having a material hardness (Hinner cover material) of 84 Shore C to 92 Shore C.

### Claim 9 (depends on 1)

The golf ball of claim 1, wherein the inner cover has an outer surface hardness (Hinner cover surface) of 80 Shore C to 95 Shore C.

### Claim 10 (depends on 1)

The golf ball of claim 1, wherein the intermediate core layer comprises a thermoset rubber composition.

### Claim 11 (depends on 1)

The golf ball of claim 1, wherein the intermediate core layer comprises a thermoplastic ethylene acid copolymer ionomer having acid groups such that the amount of neutralized acid groups is in the range of 30% to less than 80%.

### Claim 12 (depends on 1)

The golf ball of claim 1, wherein the intermediate core layer comprises a thermoplastic ethylene acid copolymer ionomer having acid groups such that the amount of neutralized acid groups is 90% or greater.

### Claim 13 (depends on 1)

The golf ball of claim 1, wherein the outer surface hardness of the intermediate core layer (Hintermediate core surface) is greater than the outer surface hardness of the outer core layer (Houter core surface).

### Claim 14 (depends on 1)

The golf ball of claim 1, wherein the material hardness of the intermediate core layer (Hintermediate core material) is greater than the material hardness of the outer core layer (Houter core material).