Golf ball having a cover layer with a purposed hardness gradient
View Patent ↗Compositions for golf balls that include polyurethane and/or polyurea linkages and that are crosslinked in the soft segments of the polymer backbone to improve the crosslink density and effect a hardness gradient throughout the molded article.
1. A golf ball comprising a core and a cover, wherein the cover comprises a single layer formed from the reaction product of:
a conjugated diene comprising a plurality of terminal ends comprising amino groups;
an isocyanate-containing component; and
a curative blend comprising:
an amine-terminated curing agent;
a hydroxy-terminated curing agent, wherein at least one of the amine-terminated curing agent and hydroxy-terminated curing agent comprises at least three functional groups; and
an organic peroxide;
wherein the cover has a first hardness at an interior location on the layer at least about 10 percent less than a second hardness at an exterior location on the layer.
2. The golf ball of claim 1 , wherein the conjugated diene comprises a polybutadiene.
3. The golf ball of claim 2 , wherein the plurality of terminal ends comprise primary amino groups, secondary amino groups, or a combination thereof.
4. The golf ball of claim 1 , wherein the first hardness is at least about 12 percent less than the second hardness.
5. The golf ball of claim 1 , wherein the first hardness is about 20 percent to about 35 percent less than the second hardness.
6. The golf ball of claim 1 , wherein the curative blend further comprises a photoinitiator.
7. The golf ball of claim 1 , wherein the amine-terminated curing agent is selected from the group consisting of dipropylene triamine, diethylene triamine, propylene oxide based triamine, and combinations thereof.