Abstract: The neodymium catalyst system prepared by the technique of this invention can be used in the polymerization of isoprene monomer into polyisoprene rubber that is clear (transparent) and of high purity. This invention more specifically discloses a process for the synthesis of polyisoprene rubber which comprises polymerizing isoprene monomer in the presence of a neodymium catalyst system, wherein the neodymium catalyst system is prepared by (1) reacting a neodymium carboxylate with an organoaluminum compound in the presence of isoprene for a period of about 10 minutes to about 30 minutes to produce neodymium-aluminum catalyst component, and (2) subsequently reacting the neodymium-aluminum catalyst component with a dialkyl aluminum chloride for a period of at least 30 minutes to produce the neodymium catalyst system.

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: The neodymium catalyst system prepared by the technique of this invention can be used in the polymerization of isoprene monomer into polyisoprene rubber that is clear (transparent) and of high purity. This invention more specifically discloses a process for the synthesis of polyisoprene rubber which comprises polymerizing isoprene monomer in the presence of a neodymium catalyst system, wherein the neodymium catalyst system is prepared by (1) reacting a neodymium carboxylate with an organoaluminum compound in the presence of isoprene for a period of about 10 minutes to about 30 minutes to produce neodymium-aluminum catalyst component, and (2) subsequently reacting the neodymium-aluminum catalyst component with a dialkyl aluminum chloride for a period of at least 30 minutes to produce the neodymium catalyst system.

Abstract: The production of a protein free synthetic polyisoprene which has both low levels of chemical impurities and good physical properties has yet to be realized. It has now been envisioned that the use of neodymium catalyzed polyisoprene will offer the combined advantages of both a clean, as well as, high cis-1,4 polymer. Synthesis of polyisoprene rubber using a neodymium based catalyst system is described. Characterization of the material shows the absence of an ultra high molecular weight fraction and the presence of very high cis-1,4-microstructure. Gum stock and black filled compound studies comparing neodymium polyisoprene with natural rubber, titanium polyisoprene, and lithium polyisoprene have been performed. Results indicate that polyisoprene rubber synthesized using a neodymium catalyst. system (Nd—PI) has similar stress-strain and tear properties as synthetic titanium polyisoprene.

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.

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 fatty alcohol of the structural formula ROH, wherein R represents an alkyl group containing from 2 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 fatty alcohol of the structural formula ROH, wherein R represents an alkyl group containing from 2 to about 30 carbon atoms.