| abstract |
Golf ball comprising core, cover, and optional intermediate layer(s) has the core and/or intermediate layer(s) made by crosslinking a rubber composition including at least (a) 100 parts by weight polybutadiene having 85% to 100% cis-1,4 bond content; (b) about 10 to about 50 parts by weight of (i) a zinc, magnesium, or calcium salt of a first carboxylic acid with least two ethylenically unsaturated bonds and (ii) a zinc, magnesium, or calcium salt of a second carboxylic acid with one ethylenically unsaturated bond that is α,β to a carbonyl of a carboxyl group, wherein (b)(i) is about 50% by weight to 100% by weight of the combination of (b)(i) and (b)(ii); (c) a free radical initiator; and (d) an inorganic zinc, magnesium, or calcium compound. Further disclosed is a method of making this golf ball by molding and crosslinking the rubber composition to make the core or intermediate layer(s). |