Molded polymer material and golf ball
AssigneeBridgestone Sports Co., Ltd.
InventorsJun SHINDO, Atsushi Nanba
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Abstract
The invention provides a molded polymer material which is obtained by subjecting a polymer composition that includes (A) at least one polymer containing α,β-ethylenically unsaturated carboxylic acid, (B) at least one diene polymer, (C) at least one metal cation source, and (D) at least one organic peroxide, and has a chemical structure arrived at by neutralizing some or all of the carboxyl groups in component A with component C in the presence of component B, to molding and crosslinking under the influence of radicals generated by decomposing component D. The molded polymer material has a high resilience, a high hardness and a good durability, making it well-suited for use in golf balls.
Claims36
A molded polymer material obtained from a polymer composition comprising:
- (A) at least one polymer containing α, β-ethylenically unsaturated carboxylic acid,
- (B) at least one diene polymer, which is a polybutadiene synthesized with a lanthanide series catalyst and having a cis-1,4 bond content of at least 60%, a 1,2-vinyl bond content of not more than 4%, a Mooney viscosity (ML1+4 (100° C.)) of 35 to 65, a weight-average molecular weight (Mw) of 450,000 to 850,000, and a weight-average molecular weight (Mw) to number-average molecular weight (Mn) ratio of 5 or less;
- (C) at least one metal cation source,
- (D) at least one organic peroxide, and
- (E) a metal salt of an α, β-ethylenically unsaturated carboxylic acid monomer;
- wherein the molded polymer material is obtained by:
- (i) mixing components A and B;
- and
- (ii) adding component C to the resulting mixture, thereby neutralizing some or all of the carboxyl groups in component A with component C in the presence of component B.
A golf ball which is a one-piece golf ball or a multi-layer golf ball that includes a core and one or more cover layer enclosing the core, comprising at least one member selected from among the one-piece golf ball, the core and the one or more cover layer which is formed of a molded polymer material obtained from a polymer composition comprising:
- (A) at least one polymer containing an α, β-ethylenically unsaturated carboxylic acid,
- (B) at least one diene polymer, which is a polybutadiene synthesized with a lanthanide series catalyst and having a cis-1,4 bond content of at least 60%, a 1,2-vinyl bond content of not more than 4%, a Mooney viscosity (ML1+4 (100° C.)) of 35 to 65, a weight-average molecular weight (Mw) of 450,000 to 850,000, and a weight-average molecular weight (Mw) to number-average molecular weight (Mn) ratio of 5 or less;
- (C) at least one metal cation source,
- (D) at least one organic peroxide, and
- (E) a metal salt of an α, β-ethylenically unsaturated carboxylic acid monomer;
- wherein the molded polymer material is obtained by:
- (i) mixing components A and B;
- and
- (ii) adding component C to the resulting mixture, thereby neutralizing some or all of the carboxyl groups in component A with component C in the presence of component B.
Dependencies are inferred from the claim text.