Castable hydrophobic polyurea compositions for use in golf balls
View Patent ↗Compositions for golf balls that are formed from the reaction product of an isocyanate-containing component and an amine-terminated component having an unsaturated backbone, which is cured with a curing agent. In particular, the compositions of the invention may be formed from a prepolymer having urea linkages and at least one carbon-carbon double bond in the backbone that is cured with an amine-terminated component resulting in golf balls having weight gain comparable to ionomers and less loss of COR as compared to ionomers and conventional polyurethanes after submersion in water.
1. A golf ball comprising a core and a cover, wherein the cover is formed from a composition comprising:
a prepolymer comprising the reaction product of an isocyanate-containing component and a first isocyanate-reactive component, wherein the first isocyanate-reactive component comprises a conjugated diene hydrocarbon backbone comprising a primary amino group at first terminal end of the backbone and a secondary amino group at second terminal end of the backbone; and
a curative blend comprising an amine-terminated component, a hydroxy-terminated component comprising at least three functional groups, and a free radical source.
2. The golf ball of claim 1 , wherein the isocyanate-containing component comprises at least two isocyanate groups.
3. The golf ball of claim 1 , wherein the amine-terminated component is selected from the group consisting of propylene oxide-based triamine, dipropylene triamine, diethylene triamine, and combinations thereof.
4. A golf ball comprising:
a core; and
a cover formed from a composition comprising:
a prepolymer comprising:
a polymer backbone comprising a conjugated diene and urea linkages; and
a plurality of terminal ends comprising isocyanate groups;
a curative blend comprising a first curative comprising amino groups capable of reacting with the isocyanate groups in the prepolymer, a second curative comprising an isocyanate-reactive component comprising at least three hydroxyl-functional groups, and a free radical. source capable of crosslinking unsaturated segments in the prepolymer.
5. The golf ball of claim 4 , wherein the polymer backbone comprises polybutadiene.
6. The golf ball of claim 4 , wherein the prepolymer consists essentially of urea linkages.
7. The golf ball of claim 4 , wherein the first curative is selected from the group consisting of propylene oxide-based triamine, dipropylene triamine, diethylene triamine, and combinations thereof.
8. A golf ball comprising a core and a cover, wherein the cover is formed from a composition comprising:
a prepolymer comprising the reaction product of diisocyanate and a polybutadiene comprising amino groups at the terminal ends, wherein the prepolymer has a first crosslinking density; and
a curative blend comprising:
a first curing agent comprising primary amino groups, secondary amino groups, or a combination thereof,
a second curing agent comprising a component with at least three hydroxy functional groups, wherein reaction between the prepolymer and the first and second curing agents results in an intermediate polymer having a second crosslinking density greater than the first crosslinking density; and
a free radical source capable of reacting unsaturated segments in the prepolymer, wherein the composition has a third crosslinking density greater than the second crosslinking density.
9. The golf ball of claim 8 , wherein the polybutadiene comprises primary amino groups at the terminal ends.
10. The golf ball of claim 8 , wherein the polybutadiene comprises secondary amino groups at the terminal ends.
11. The golf ball of claim 8 , wherein the polybutadiene comprises a primary amino group at one terminal end and secondary amino group at the other terminal end.
12. The golf ball of claim 8 , wherein the first curing agent comprises secondary amino groups.
13. The golf ball of claim 8 , wherein the first curing agent is selected from the group consisting of propylene oxide-base triamine, diproplene triamine, diethylene triamine, and combinations thereof.