Method of forming a golf ball core

A method of forming a golf ball core which comprises:

• combining a 1,4-cis-polybutadiene, a low temperature peroxide, a high temperature peroxide, and a crosslinking agent to provide a first mixture;
• forming the first mixture into a plurality of semi-ellipsoidal half-shells;
• subjecting the half-shells to a first heat curing at a first temperature between about 200° F. to 300° F. for about 30 seconds to 15 minutes to impart a rigidity sufficient to maintain the semi-ellipsoidal shape until the half-shells are assembled and subjected to a second heat curing, wherein at least about 50 weight percent of the high temperature peroxide remains after the first heat curing to initiate the second heat curing;
• providing a center;
• assembling at least two semi-ellipsoidal half-shells concentrically about the center to form a first mantle layer, wherein the first mantle layer and center together form the ball core;
• and
• subjecting the core to the second heat curing at a second temperature between about 310° F. to about 390° F. for about 5 to 25 minutes to further crosslink the shells, thereby forming a cured golf ball core.

A method of forming a golf ball core which comprises:

• combining about 35 to 80 weight percent 1,4-cis-polybutadiene, an amount of low temperature peroxide that reacts at a temperature of between about 210° F. to 290° F., a high temperature peroxide that reacts at a temperature of between about 320° F. to 380° F. and is present in an amount greater than the low temperature peroxide, and a crosslinking agent to provide a first mixture;
• forming the first mixture into a plurality of semi-ellipsoidal half-shells;
• subjecting the half-shells to a first heat curing at a first temperature between about 210° F. to 290° F. for about 1 to 15 minutes to impart a rigidity sufficient to maintain the semi-ellipsoidal shape until the half-shells are assembled and subjected to a second heat curing, wherein at least about 50 weight percent of the high temperature peroxide remains after the first heat curing to initiate the second heat curing;
• providing a center;
• assembling at least two semi-ellipsoidal half-shells concentrically about the center to form a first mantle layer, wherein the first mantle layer and center together form the ball core;
• and
• subjecting the core to the second heat curing at a second temperature between about 320° F. to 380° F. for about 5 to 25 minutes to further crosslink the shells, thereby forming a cured golf ball core.