Golf ball compositions

Abstract

Disclosed herein are heterogeneous golf ball compositions comprising a matrix formed from a thermosetting or thermoplastic polymer composition and discrete particles dispersed within the matrix, and to the use of such heterogeneous compositions to form at least one core layer in multi-layer core golf balls.

What is claimed is: 
     
         1 . A golf ball comprising a core and a cover, wherein the core comprises:
 an inner core layer formed from a first thermoset composition and having a diameter of from 0.50 inches to 1.30 inches;   an intermediate core layer formed from a heterogeneous composition and having a thickness of from 0.01 inches to 0.20 inches; and   an outer core layer formed from a second thermoset composition and having a thickness of from 0.10 inches to 0.25 inches;   wherein the heterogeneous composition of the intermediate core layer comprises a matrix formed from a first thermoplastic composition and discrete particles of a second thermoplastic composition dispersed within the matrix, the second thermoplastic composition having a melting point above the processing temperature of the first thermoplastic composition.   
     
     
         2 . The golf ball of  claim 1 , wherein the discrete particles have a particle size of 0.037 mm or greater. 
     
     
         3 . The golf ball of  claim 1 , wherein the discrete particles are present in the heterogeneous composition in an amount of 10 wt % or greater, based on the total weight of the heterogeneous composition. 
     
     
         4 . The golf ball of  claim 1 , wherein the second thermoplastic composition has a specific gravity of 1.38 g/cm 3  or less. 
     
     
         5 . The golf ball of  claim 1 , wherein the first thermoplastic composition comprises from 0 wt % to 50 wt %, based on the total weight of the first thermoplastic composition, of an ionomer. 
     
     
         6 . A golf ball comprising a core and a cover, wherein the core comprises:
 an inner core layer formed from a first thermoset composition and having a diameter of from 0.50 inches to 1.30 inches;   an intermediate core layer formed from a heterogeneous composition and having a thickness of from 0.01 inches to 0.20 inches; and   an outer core layer formed from a second thermoset composition and having a thickness of from 0.10 inches to 0.25 inches;   wherein the heterogeneous composition of the intermediate core layer comprises a matrix formed from a thermoplastic composition and discrete particles of crosslinked rubber dispersed within the matrix, wherein the crosslinked rubber is selected from the group consisting of polybutadiene, polyisoprene, ethylene propylene rubber, styrene-butadiene rubber, styrenic block copolymer rubbers, butyl rubber, halobutyl rubber, polystyrene elastomers, polyethylene elastomers, polyurethane elastomers, polyurea elastomers, copolymers of isobutylene and para-alkylstyrene, halogenated copolymers of isobutylene and para-alkylstyrene, acrylonitrile butadiene rubber, polychloroprene, alkyl acrylate rubber, chlorinated isoprene rubber, acrylonitrile chlorinated isoprene rubber, polyalkenamer, and combinations of two or more thereof.   
     
     
         7 . The golf ball of  claim 6 , wherein the discrete particles have a particle size of from 0.074 mm to 2.38 mm. 
     
     
         8 . The golf ball of  claim 6 , wherein the discrete particles are present in the heterogeneous composition in an amount of from 10 wt % to 40 wt %, based on the total weight of the heterogeneous composition. 
     
     
         9 . The golf ball of  claim 6 , wherein the thermoplastic composition of the matrix comprises from 0 wt % to 50 wt %, based on the total weight of the thermoplastic composition, of an ionomer. 
     
     
         10 . The golf ball of  claim 6 , wherein the thermoplastic composition of the matrix comprises greater than 50 wt %, based on the total weight of the thermoplastic composition, of a non-ionomeric base resin selected from one or more E/X/Y-type acid copolymers of ethylene, an α,β-unsaturated carboxylic acid, and optionally a softening comonomer, 
     
     
         11 . A golf ball comprising a core and a cover, wherein the core comprises:
 an inner core layer formed from a first thermoset composition and having a diameter of from 0.50 inches to 1.30 inches;   an intermediate core layer formed from a thermoplastic composition and having a thickness of from 0.01 inches to 0.20 inches; and   an outer core layer formed from a second thermoset composition and having a thickness of from 0.10 inches to 0.25 inches;   wherein at least one of the first thermoset composition and the second thermoset composition is a heterogeneous composition, the heterogeneous composition comprising a matrix formed from a thermosetting polymer composition and discrete particles of a thermoplastic polymer composition dispersed within the matrix, the thermoplastic polymer composition having a melting point above the curing temperature of the thermosetting polymer composition.   
     
     
         12 . The golf ball of  claim 11 , wherein the discrete particles have a maximum particle size of 0.900 mm. 
     
     
         13 . The golf ball of  claim 11 , wherein the discrete particles are present in the heterogeneous composition in an amount of 20 wt % or greater, based on the total weight of the heterogeneous composition. 
     
     
         14 . The golf ball of  claim 11 , wherein first thermoset composition is a heterogeneous composition, and wherein the discrete particles are present in the heterogeneous composition in an amount of 40 wt % or greater, based on the total weight of the heterogeneous composition. 
     
     
         15 . The golf ball of  claim 14 , wherein the inner core layer has a zero hardness gradient, a positive hardness gradient of 4 Shore C or less, or a negative hardness gradient of 4 Shore C or less. 
     
     
         16 . The golf ball of  claim 11 , wherein the difference in the specific gravity of the thermosetting polymer composition and the specific gravity of the thermoplastic polymer composition of the discrete particles is at least 0.13 g/cm 3 . 
     
     
         17 . The golf ball of  claim 11 , wherein the thermoplastic polymer composition of the discrete particles is selected from the group consisting of non-ionomeric acid copolymers, polyether amides, polyester amides, polyimides, polystyrenes, polyethylenes, polypropylenes, rubber-toughened polyolefins, styrenic copolymers and styrenic block copolymers, dynamically vulcanized elastomers, ethylene vinyl acetates, ethylene (meth)acrylate based polymers, ethylene elastomers, propylene elastomers, ethylene propylene rubber, ethylene-propylene-diene rubber, polyvinyl chlorides, polytetrafluoroethylene, functionalized derivatives thereof, and combinations of two or more thereof. 
     
     
         18 . A golf ball comprising a core and a cover, wherein the core comprises:
 an inner core layer formed from a first thermoset composition and having a diameter of from 0.50 inches to 1.30 inches;   an intermediate core layer formed from a thermoplastic composition and having a thickness of from 0.01 inches to 0.20 inches; and   an outer core layer formed from a second thermoset composition and having a thickness of from 0.10 inches to 0.25 inches;   wherein at least one of the first thermoset composition and the second thermoset composition is a heterogeneous composition, the heterogeneous composition comprising a matrix formed from a thermosetting polymer composition and discrete particles dispersed within the matrix, the discrete particles being formed from a crosslinked rubber composition having a Shore D hardness of 65 or greater.   
     
     
         19 . The golf ball of  claim 18 , wherein the crosslinked rubber composition of the discrete particles has a Shore D hardness of 70 or greater. 
     
     
         20 . The golf ball of  claim 18 , wherein the crosslinked rubber composition of the discrete particles has a Shore D hardness of 90 or greater. 
     
     
         21 . The golf ball of  claim 18 , wherein the thermosetting polymer composition of the matrix is selected from the group consisting of ethylene propylene rubbers, ethylene-propylene-diene rubbers, styrene-butadiene rubbers, butyl rubbers, halobutyl rubbers, acrylonitrile butadiene rubbers, polychloroprenes, alkyl acrylate rubbers, chlorinated isoprene rubbers, acrylonitrile chlorinated isoprene rubbers, polyalkenamers, phenol formaldehydes, melamine formaldehydes, polyepoxides, polyimides, polysiloxanes, alkyds, polyisocyanurates, polycyanurates, polyacrylates, and combinations of two or more thereof. 
     
     
         22 . The golf ball of  claim 18 , wherein the discrete particles are present in the heterogeneous composition in an amount of 40 wt % or greater, based on the total weight of the heterogeneous composition. 
     
     
         23 . The golf ball of  claim 18 , wherein first thermoset composition is a heterogeneous composition, and wherein the discrete particles are present in the heterogeneous composition in an amount of 40 wt % or greater, based on the total weight of the heterogeneous composition. 
     
     
         24 . The golf ball of  claim 23 , wherein the inner core layer has a zero hardness gradient, a positive hardness gradient of 4 Shore C or less, or a negative hardness gradient of 4 Shore C or less.