Multi-piece solid golf ball
AssigneeBridgestone Sports Co., Ltd.
InventorsHideo Watanabe, Rinya Takesue
Life of this patent
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Abstract
A multi-piece solid golf ball includes a core, at least one mantle layer enclosing the core, and a cover that is made primarily of a thermoplastic polyurethane composition. The cover and the mantle layer have a difference in Shore D hardness therebetween such that −8≦[(cover hardness)−(mantle layer hardness)]≦5. The cover and the core have a difference in Shore D hardness therebetween such that 5≦[(cover hardness)−(average core hardness)]≦25. The core has an average Shore D hardness of 30 to 50, and the cover has a Shore D hardness of at least 52. The ball has an initial velocity of at least 76.4 m/s.
Claims22
A multi-piece solid golf ball comprising a core, at least one mantle layer enclosing the core, and a cover;
- wherein
- the cover is made primarily of a thermoplastic polyurethane composition,
- the cover and the mantle layer have a difference in Shore D hardness therebetween such that −8≦[(cover hardness)−(mantle layer hardness)]≦5,
- the cover and the core have a difference in Shore D hardness therebetween such that 5≦[(cover hardness)−(average core hardness)]≦25,
- the core has an average Shore D hardness of 30 to 50,
- the cover has a Shore D hardness of at least 52, and
- the ball has an initial velocity of at least 76.4 m/s,
- wherein the thermoplastic polyurethane composition includes (A) a thermoplastic polyurethane and (B) an isocyanate mixture prepared by dispersing (b-1) a compound having as functional groups at least two isocyanate groups per molecule in (b-2) a thermoplastic resin that is substantially non-reactive with isocyanate.
A multi-piece solid golf ball comprising a core, at least one mantle layer enclosing the core, and a cover;
- wherein
- the cover is made primarily of a thermoplastic polyurethane composition,
- the cover and the mantle layer have a difference in Shore D hardness therebetween such that −8≦[(cover hardness)−(mantle layer hardness)]≦5,
- the cover and the core have a difference in Shore D hardness therebetween such that 5≦[(cover hardness)−(average core hardness)]≦25,
- the core has an average Shore D hardness of 30 to 50,
- the cover has a Shore D hardness of at least 52, and
- the ball has an initial velocity of at least 76.4 m/s,
- wherein the mantle layer is composed primarily of a mixture prepared from a base resin of
- (C) an ionomer resin component containing,
- (c-1) an olefin/unsaturated carboxylic acid random bipolymer and/or a metal ion neutralization product of an olefin/unsaturated carboxylic acid random bipolymer, and
- (c-2) an olefin/unsaturated carboxylic acid/unsaturated carboxylic acid ester random terpolymer and/or a metal ion neutralization product of an olefin/unsaturated carboxylic acid/unsaturated carboxylic acid ester random terpolymer in a weight ratio (c-1)/(c-2) of 100/0 to 25/75, and
- (D) a non-ionomer thermoplastic elastomer in a weight ratio C/D of 100/0 to 50/50, to which base resin is added:
- (E) a fatty acid having a molecular weight of 280 to 1,500 or a derivative thereof, and
- (F) a basic metal compound such as to satisfy the respective weight ratios (C+D)/E=100/5 to 100/80 and (C+D)/F=100/0.1 to 100/10.
Dependencies are inferred from the claim text.