Golf ball with heat resistant layer

Abstract

A golf ball comprising of an outer core layer, or an inner cover layer having heat resistant properties to facilitate compression molding of a thermosetting polybutadiene-comprising layer over at least one thermoplastic layer. The ball comprises a thermoplastic inner core or core layer comprising of a low vicat highly neutralized ionomer material having a low melting point of less than 100° C., and a Shore C surface hardness of less than 80 and a compression of less than 70, wherein an outer adjacent thermoset layer is placed around the inner core or core layer, the thermoset layer comprising comprising a peroxide that decomposes at low temperatures forming free radical initiators with short half lives, therein reducing the molding temperature of the high vicat layer and subsequently reducing the temperature and/or time the softer thermoplastic layer is exposed to the high heat.

1 . A golf ball comprising:
 a thermoplastic inner core comprising a partially or fully neutralized ionomer having a first vicat softening point temperature, the inner core having a surface hardness of less than 85 Shore C and a compression of less than 80;   a heat resistant thermoset layer encasing the inner core, the thermoset layer having a second vicat softening point temperature of at least 20° C. greater than the first; and comprising a peroxide that decomposes at low temperatures forming free radical initiators with short half lives; and   a cover layer,   wherein the free radical initiators have short half lives causing the molding temperature and time of the heat resistant layer to be reduced, therein restricting flow of the thermoplastic inner core into the thermoset layer.   
   
   
       2 . The golf ball according to  claim 1 , wherein the first vicat softening point temperature is 75° C. or less. 
   
   
       3 . The golf ball according to  claim 2 , wherein the second vicat softening ppint temperature is at least 50° C. greater than the first. 
   
   
       4 . The golf ball according to  claim 2 , wherein the second vicat softening ppint temperature is at least 100° C. greater than the first. 
   
   
       5 . The golf all according to  claim 1 , wherein the peroxide is 1,1-di(t-butylperoxy)cyclohexane, or 1,1-di(t-butylperoxy) -3,3,5-trimethylcyclohexane, or 1,1-di(t-amylperoxy)cyclohexane or tbutyl peroxy-(cis-3-carboxy)propenoate. 
   
   
       6 . The golf ball according to  claim 5 , wherein the peroxide has a half life of less than 10 minutes at 133° C. 
   
   
       7 . The golf ball according to  claim 1 , wherein the thermoplastic inner core has a diameter of about 1.00 inch or less. 
   
   
       8 . The golf ball according to  claim 1 , wherein the heat resistant thermoset layer comprises polyetheramides; polyetheresters; polyesteramides; thermoplastic urethanes; polyesters such as polybutylene terephthalate or polyethylene terephthalate or copolymers thereof; polycarbonates; polyamides; polypropylene; polyethylene; or mixtures thereof. 
   
   
       9 . The golf ball according to  claim 1 , wherein the thermoplastic inner core further comprises of dynamically vulcanized thermoplastic elastomers; suitable functionalized styrene-butadiene elastomers; thermoplastic polyetheresters; polyetheramides; thermoplastic polyesters; or mixtures thereof. 
   
   
       10 . The golf ball according to  claim 1 , wherein the heat resistant thermoset layer has a thickness of 0.050 inch or less. 
   
   
       11 . The golf ball according to  claim 1 , wherein the heat resistant thermoset layer has a thickness of 0.050 inch or less. 
   
   
       12 . The golf ball according to  claim 1 , wherein the cover layer comprises an ionomer, a polyurethane or a polyurea. 
   
   
       13 . The golf ball according to  claim 12 , wherein the ionomer, polyurethane or polyurea is a castable or reaction injection moldable thermosetting composition. 
   
   
       14 . A golf ball comprising:
 an inner core comprising a thermoset polybutadiene composition having a first hardness;   an intermediate core layer comprising a partially or fully neutralized ionomer having a first vicat softening point temperature and having a second hardness;   a heat resistant thermoset layer comprising a theroset material having a second vicat softening point temperature of at least 20° greater than the first and having a third hardness, the thermoset layer comprising a peroxide that decomposes at low temperatures forming free radical initiators with short half lives; and   a cover layer.   
   
   
       15 . The golf ball according to  claim 14 , wherein the intermediate layer has a first vicat softening point temperature of 75° C. or less. 
   
   
       16 . The golf ball according to  claim 14 , wherein the heat resistant layer has a second vicat softening point temperature of at least 50° C. greater than the first. 
   
   
       17 . The golf ball according to  claim 14 , wherein the heat resistant layer has a second vicat softening point temperature of at least 100° C. greater than the first. 
   
   
       18 . The golf ball according to  claim 14 , wherein the first hardness is less than the second hardness, the second hardness is less than the third hardness, and the fourth hardness is less than the third hardness. 
   
   
       19 . The golf all according to  claim 14 , wherein the peroxide is 1,1-di(t-butylperoxy)cyclohexane, or 1,1-di(t-butylperoxy)-3,3,5-trimethylcyclohexane, or 1,1-di(t-amylperoxy)cyclohexane or tbutyl peroxy-(cis-3-carboxy)propenoate. 
   
   
       20 . The golf ball according to  claim 19 , wherein the peroxide has a half life of less than 10 minutes at 133° C. 
   
   
       21 . The golf ball according to  claim 14 , wherein the cover layer comprises an ionomer, a polyurethane or a polyurea. 
   
   
       22 . The golf ball according to  claim 21 , wherein the ionomer, polyurethane or polyurea is a castable or reaction injection moldable thermosetting composition. 
   
   
       23 . The golf ball according to  claim 14 , wherein the cover layer has a Shore D hardness of less than 65. 
   
   
       24 . The golf ball according to  claim 14 , wherein the heat resistant thermoset layer comprises polyetheramides; polyetheresters; polyesteramides; thermoplastic urethanes; polyesters such as polybutylene terephthalate or polyethylene terephthalate or copolymers thereof; polycarbonates; polyamides; polypropylene; polyethylene; or mixtures thereof. 
   
   
       25 . The golf ball according to  claim 1 , wherein the intermediate core layer further comprises of dynamically vulcanized thermoplastic elastomers; suitable functionalized styrene-butadiene elastomers; thermoplastic polyetheresters; polyetheramides; thermoplastic polyesters; or mixtures thereof.