Abstract: It has been unexpectedly discovered that cis-1,4-polybutadiene that is synthesized utilizing Zeigler-Natta catalyst systems has superior characteristics for utilization in solid golf ball cores if the polymerization is terminated utilizing a carboxylic acid of the structural formula RCOOH, wherein R represents an alkyl group containing from 1 to about 30 carbon atoms.

Abstract: This invention is based upon the unexpected discovery that cis-1,4-polybutadiene that is synthesized utilizing organometallic catalyst systems has superior characteristics for utilization in solid golf ball cores if the polymerization is terminated utilizing a carboxylic acid of the structural formula RCOOH, wherein R represents an alkyl group containing from 1 to about 30 carbon atoms. This invention more specifically relates to a golf ball which is comprised of a solid core and a resin cover, wherein the solid core is comprised of cis-1,4-polybutadiene rubber which is made by polymerizing 1,3-butadiene in the presence of an organometallic catalyst system wherein the polymerization is short-stopped with a carboxylic acid of the structural formula RCOOH, wherein R represents an alkyl group containing from 1 to about 30 carbon atoms.