Castable polyurea compositions for golf ball covers

Abstract

Disclosed herein is a golf ball having improved cut and shear resistance. Such gold balls comprise a core, an inner cover layer, and an outer cover layer, the outer cover layer being formed from a polyurea or poly(urea-co-urethane) comprising: 1) a polyurea prepolymer comprising: the reaction product of at least one first polyisocyanate, wherein the polyisocyanate has a reactivity greater than that of 4,4′-methylene bis(cyclohexyl) isocyanate and a functionality of 1.7 to 2.3, and at least one amine-terminated compound, wherein the amine-terminated compound is selected from the group consisting of amine-terminated hydrocarbons, amine-terminated polyethers, amine-terminated polyesters, amine-terminated polycaprolactones, amine-terminated polycarbonates, amine-terminated polyamides, and mixtures thereof; and at least one second polyisocyanate with a vapor pressure lower than 0.01 mm Hg at 20° C.; and 2) at least one curing agent comprising amine or hydroxyl functional curatives.

1 . A golf ball comprising a core and a cover, said cover comprising a polyurea elastomer comprising the reaction product of
 at least one amine curing agent with a polyisocyanate composition wherein the isocyanate composition comprises
 an isocyanate terminated prepolymer comprising at least one first polyisocyanate with a reactivity greater than that of 4,4′-methylene bis(cyclohexyl) isocyanate and functionality of 1.7 to 2.3 and 
 at least one amine-terminated compound having a molecular weight greater than 1000 selected from the group consisting of amine-terminated hydrocarbons, amine-terminated polyethers, amine-terminated polyesters, amine-terminated polycaprolactones, amine-terminated polycarbonates, amine-terminated polyamides, and mixtures thereof; and 
   at least one second polyisocyanate with a vapor pressure lower than 0.01 mmHg at 20° C.   
     
     
         2 . A golf ball comprising a core and a cover, said cover comprising a polyurethane-co-urea) elastomer comprising the reaction product of a hydroxyl curing agent with a polyisocyanate composition wherein the isocyanate composition is
 an isocyanate terminated prepolymer comprising at least one first polyisocyanate with a reactivity greater than that of 4,4′-methylene bis(cyclohexyl) isocyanate and functionality of 1.7 to 2.2 and at least one amine-terminated compound having a molecular weight greater than 1000 selected from the group consisting of amine-terminated hydrocarbons, amine-terminated polyethers, amine-terminated polyesters, amine-terminated polycaprolactones, amine-terminated polycarbonates, amine-terminated polyamides, and mixtures thereof; and   at least one second polyisocyanate with a vapor pressure lower than 0.01 mmHg at 20° C.   
     
     
         3 . (canceled) 
     
     
         4 . (canceled) 
     
     
         5 . The golf ball of  claim 1  wherein the weight ratio of prepolymer to the second isocyanate is from 10:90 to 98:2. 
     
     
         6 . The golf ball of  claim 3  wherein the first polyisocyanate has a reactivity of greater than that of isophorone diisocyanate. 
     
     
         7 . The golf ball of  claim 1  wherein the amine-terminated compound comprises primary amines, secondary amines, triamines, or combinations thereof. 
     
     
         8 . (canceled) 
     
     
         9 . The golf ball of  claim 1  wherein the cover has a Shore D harness of 40 to 60. 
     
     
         10 . (canceled) 
     
     
         11 . The golf ball of  claim 1  wherein the cover has a resilience greater than 40% measured by Bashore rebound. 
     
     
         12 . The golf ball of  claim 1  wherein the amine-terminated curing agent is an alkylated aromatic diamine or alkylated methylene dianiline. 
     
     
         13 . The golf ball of  claim 1  where the first polyisocyanate is an aromatic isocyanate and the second polyisocyanate is an aromatic isocyanate. 
     
     
         14 . (canceled) 
     
     
         15 . (canceled) 
     
     
         16 . (canceled) 
     
     
         17 . The golf ball  claim 1  to where the first polyisocyanate is an aromatic polyisocyanate and the second polyisocyanate is a dimer, trimer or a mixture thereof of an aliphatic polyisocyanate. 
     
     
         18 . The golf ball of  claim 1  to wherein the first polyisocyanate is an aliphatic isocyanate and the second polyisocyanate is an aromatic isocyanate. 
     
     
         19 . The golf ball of  claim 2  wherein the weight ratio of prepolymer to the second isocyanate is from 10:90 to 98:2. 
     
     
         20 . The golf ball of  claim 12  wherein the first polyisocyanate has a reactivity of greater than that of isophorone diisocyanate. 
     
     
         21 . The golf ball of  claim 2  wherein the amine-terminated compound comprises primary amines, secondary amines, triamines, or combinations thereof. 
     
     
         22 . The golf ball of  claim 2  wherein the cover has a Shore D harness of 40 to 60. 
     
     
         23 . The golf ball of  claim 2  wherein the cover has a resilience greater than 40% measured by Bashore rebound. 
     
     
         24 . The golf ball of  claim 2  wherein the amine-terminated curing agent is an alkylated aromatic diamine or alkylated methylene dianiline. 
     
     
         25 . The golf ball of  claim 2  where the first polyisocyanate is an aromatic isocyanate and the second polyisocyanate is an aromatic isocyanate. 
     
     
         26 . The golf ball of golf ball of  claim 2  wherein the first polyisocyanate is an aromatic polyisocyanate and the second polyisocyanate is a dimer, trimer or a mixture thereof of an aliphatic polyisocyanate. 
     
     
         27 . The golf ball of  claim 2  wherein the first polyisocyanate is an aliphatic isocyanate and the second polyisocyanate is an aromatic isocyanate.