Dual core golf balls having reduced driver spin
Dual component cores having positive hardness and compression gradients and golf balls including these cores are disclosed. The hardness, compression, and diameter relationships in the core assemblage components help to reduce the spin rate of the ball off the driver while still providing desirable performance characteristics in and around the green.
1. A golf ball, comprising:
a core assemblage comprising:
a center having a geometric center hardness H 1 and a surface hardness H 2 , a diameter D 1 , and a SCDI compression C 1 ranging from about 120 to about 160 SCDI, wherein H 1 is about 50 percent to about 85 percent of H 2 ; and
an outer core layer disposed about the inner core layer and having a surface hardness H 3 , a diameter D 2 , wherein the core assemblage has a SCDI compression C 2 ranging from about 200 to about 240 SCDI, and wherein H 2 is about 70 percent to about 98 percent of H 3 and C 1 is about 60 percent to about 75 percent of C 2 ;
a layer disposed about the core assemblage; and
a cover layer disposed about the layer.
2. The golf ball of claim 1 , wherein the center comprises a first rubber formulation comprising a first amount of co-agent and the outer core layer comprises a second rubber formulation comprising a second amount of co-agent.
3. The golf ball of claim 2 , wherein the first amount of co-agent is about 50 to about 80 percent of the second amount of co-agent.
4. The golf ball of claim 2 , wherein each of the first and second rubber formulations comprise polybutadiene rubber, butyl rubber, or a blend thereof.
5. The golf ball of claim 1 , wherein D 1 is about 70 percent to 90 percent of D 2 .
6. The golf ball of claim 1 , wherein the cover layer has a thickness in the range of about 0.010 to about 0.080 inches.
7. The golf ball of claim 1 , wherein the cover layer comprises a material selected from the group consisting of polyurethanes, polyureas, and hybrids, copolymers, and blends thereof.
8. The golf ball of claim 1 , wherein the layer comprises an ionomer material.
9. The golf ball of claim 1 , wherein H 1 is in the range of about 50 to about 60 Shore C, H 2 is in the range of about 70 to about 90 Shore C, and H 3 is in the range of about 80 to about 100 Shore C to provide a positive hardness gradient from the center to the outer core layer.
10. A golf ball, comprising:
a core assemblage comprising:
a center having a geometric center hardness H 1 , a surface hardness H 2 , a diameter D 1 , and a SCDI compression C 1 ranging from about 120 to about 160 SCDI; and
an outer core layer disposed about the center and having a surface hardness H 3 , a diameter D 2 , wherein the core assemblage has a SCDI compression C 2 ranging from about 200 to about 240 SCDI,
0
.
3
5
≤
H
1
H
3
C
2
C
1
≤
0.55
,
and wherein C 1 is about 60 percent to about 75 percent of C 2 ;
a layer disposed about the core assemblage to form an intermediate ball; and
a cover layer disposed about the intermediate ball.
11. The golf ball of claim 10 , wherein H 1 is in the range of about 50 to about 60 Shore C, H 2 is in the range of about 70 to about 90 Shore C, and H 3 is in the range of about 80 to about 100 Shore C to provide a positive hardness gradient from the center to the outer core layer.
12. The golf ball of claim 10 , wherein
0
.
3
5
≤
H
2
H
3
C
2
C
1
≤
0.7
5
.
13. The golf ball of claim 10 , wherein the center comprises a first rubber formulation comprising a first amount of co-agent and the outer core layer comprises a second rubber formulation comprising a second amount of co-agent.
14. The golf ball of claim 13 , wherein the first amount of co-agent is about 60 to about 80 percent of the second amount of co-agent.
15. A golf ball, comprising:
a core assemblage comprising:
a center having a geometric center hardness H 1 , a surface hardness H 1 , a diameter D 1 , and a SCDI compression C 1 ranging from about 120 to about 160 SCDI; and
an outer core layer disposed about the center and having a surface hardness H 3 , a diameter D 2 , wherein the core assemblage has a SCDI compression C 2 ranging from about 200 to about 240 SCDI, wherein H 1 is in the range of about 60 to about 80 Shore C, H 2 is in the range of about 70 to about 90 Shore C, and H 3 is in the range of about 80 to about 100 Shore C to provide a positive hardness gradient from the center to the outer core layer, and wherein C 1 is about 60 percent to about 75 percent of C 2 ;
an intermediate layer disposed about the core assemblage to form an intermediate ball; and
a cover layer disposed about the intermediate ball.
16. The golf ball of claim 15 , wherein the cover layer comprises a material selected from the group consisting of polyurethanes, polyureas, and hybrids, copolymers, and blends thereof.
17. The golf ball of claim 15 , wherein the intermediate layer comprises an ionomer material.
18. The golf ball of claim 13 , wherein the first amount of co-agent is about 25 to about 90 percent of the second amount of co-agent.
19. The golf ball of claim 1 , wherein C 1 is about 60 percent to about 70 percent of C 2 .
20. The golf ball of claim 15 , wherein C 1 is about 60 percent to about 70 percent of C 2 .