# US 2010/0075779 A1 · Multi-layer core golf ball > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2010/0075779 A1 - Document ID: US20100075779A1 - Status: Published application - Kind: A1 - Application number: 12/629,581 - Filed: 2009-12-02 - Published: 2010-03-25 - Earliest claimed: 2008-01-10 - Assignees: Acushnet Company - Inventors: Michael J. Sullivan; Brian Comeau; Douglas S. Goguen - Web page: https://patentgrep.com/patent/US20100075779A1 ## CPC - A63B 37/0003: {Golf balls} - A63B 37/00621: {Centre hardness} - A63B 37/00622: {Surface hardness} - A63B 37/0076: {Multi-piece balls, i.e. having two or more intermediate layers} - A63B 37/0031: {Hardness} - A63B 37/0033: {Thickness} - A63B 37/0035: {Density; Specific gravity} - A63B 37/0045: {Thickness} - A63B 37/0047: {Density; Specific gravity} - A63B 37/0064: {Diameter} - A63B 37/0066: {Density; Specific gravity} - A63B: APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT (apparatus for passive exercising, massage A61H) ## Abstract Golf balls consisting of a multi-layer core and a cover are disclosed. The multi-layer core comprises a soft thermoset rubber center, a stiff thermoplastic intermediate core layer, and a thin thermoset rubber outer core layer. The maximum hardness of the core is a point or region located at a distance of from 0.1 mm to 8.0 mm measured radially inward from the outer surface of the core. The maximum core hardness is preferably at least 10% greater than the outer surface hardness of the core. ## Claims ### Claim 1 A golf ball comprising: a core consisting of: a center formed from a first diene rubber composition and having a diameter of from 1.000 inches to 1.580 inches, a center hardness of from 40 Shore C to 70 Shore C, and a surface hardness (SHcenter) of from 50 Shore C to 85 Shore C; an intermediate core layer formed from a thermoplastic composition and having a thickness of from 0.005 inches to 0.100 inches and an outer surface hardness of 60 Shore D or greater; and an outer core layer formed from a second diene rubber composition and having a thickness of from 0.010 inches to 0.100 inches and an outer surface hardness (SHouter) of 80 Shore C or greater; wherein SHouter is greater than SHcenter; wherein the core has a maximum hardness (SHpeak) located at a distance of from 0.25 mm to 5.00 mm measured radially inward from the outer surface of the core; and wherein SHpeak is 10% or more higher than SHouter; and a cover layer having a thickness of from 0.010 inches to 0.050 inches and formed from a composition having a material hardness of less than 60 Shore D. ### Claim 2 (depends on 1) The golf ball of claim 1, wherein SHpeak is 20% or more higher than SHouter. ### Claim 3 (depends on 1) The golf ball of claim 1, wherein SHpeak is located at a distance of from 0.50 mm to 5.00 mm measure radially inward from the outer surface of the core. ### Claim 4 (depends on 1) The golf ball of claim 1, wherein SHpeak is located at a distance of from 0.50 mm to 2.50 mm measure radially inward from the outer surface of the core. ### Claim 5 (depends on 1) The golf ball of claim 1, wherein SHpeak is 20% or more higher than SHouter, and wherein SHpeak is located at a distance of from 0.50 mm to 5.00 mm measure radially inward from the outer surface of the core. ### Claim 6 (depends on 1) The golf ball of claim 1, wherein the difference between SHouter and SHcenter is 5 Shore C units or greater. ### Claim 7 (depends on 1) The golf ball of claim 1, wherein the difference between SHouter and SHcenter is 10 Shore C units or greater. ### Claim 8 (depends on 1) The golf ball of claim 1, wherein the center has a positive hardness gradient wherein the difference between the center hardness and the surface hardness of the center is from 10 to 45. ### Claim 9 (depends on 1) The golf ball of claim 1, wherein the center has a diameter of from 1.300 inches to 1.490 inches, the intermediate core layer has a thickness of from 0.020 inches to 0.070 inches, and the outer core layer has a thickness of from 0.030 inches to 0.040 inches. ### Claim 10 (depends on 1) The golf ball of claim 1, wherein the surface hardness of the intermediate core layer is 65 Shore D or greater. ### Claim 11 (depends on 1) The golf ball of claim 1, wherein the surface hardness of the intermediate core layer is 70 Shore D or greater. ### Claim 12 (depends on 1) The golf ball of claim 1, wherein SHouter is 85 Shore C or greater. ### Claim 13 (depends on 1) The golf ball of claim 1, wherein the thermoplastic composition of the intermediate core layer is selected from the group consisting of partially- and fully-neutralized ionomers, and blends of two or more thereof. ### Claim 14 A golf ball comprising: a core consisting of: a center formed from a first diene rubber composition and having a diameter of from 1.400 inches to 1.550 inches, a center hardness of from 45 Shore C to 70 Shore C, and a surface hardness (SHcenter) of from 55 Shore C to 85 Shore C; an intermediate core layer formed from a thermoplastic composition and having a thickness of from 0.020 inches to 0.070 inches and an outer surface hardness of 65 Shore D or greater; and an outer core layer formed from a second diene rubber composition and having a thickness of from 0.020 inches to 0.050 inches and an outer surface hardness (SHouter) of 85 Shore C or greater; wherein SHouter is greater than SHcenter; wherein the core has a maximum hardness (SHpeak) located at a distance of from 0.50 mm to 5.00 mm measured radially inward from the outer surface of the core; and wherein SHpeak is 10% or more higher than SHouter; and a cover layer having a thickness of from 0.010 inches to 0.050 inches and formed from a composition having a material hardness of less than 60 Shore D, wherein the cover layer composition is selected from polyurethanes, polyureas, and polyurethane-urea hybrids. ### Claim 15 (depends on 14) The golf ball of claim 14, wherein SHpeak is 20% or more higher than SHouter. ### Claim 16 (depends on 14) The golf ball of claim 14, wherein SHpeak is located at a distance of from 0.50 mm to 2.50 surface mm measure radially inward from the outer surface of the core. ### Claim 17 (depends on 14) The golf ball of claim 14, wherein SHpeak is 20% or more higher than SHouter, and wherein SHpeak is located at a distance of from 0.50 mm to 2.50 mm measure radially inward from the outer surface of the core. ### Claim 18 (depends on 14) The golf ball of claim 14, wherein the difference between SHouter and SHcenter is 5 Shore C units or greater. ### Claim 19 (depends on 14) The golf ball of claim 14, wherein the difference between SHouter and SHcenter is 10 Shore C units or greater. ### Claim 20 (depends on 14) The golf ball of claim 14, wherein the center has a positive hardness gradient wherein the difference between the center hardness and the surface hardness of the center is from 10 to 45.