A method of forming a golf ball is disclosed herein. The method includes injecting a cover mixture into a mold to form a cover mixture comprising a thermoplastic polyurethane resin and a polyahl, subjecting the golf ball to a polyisocyanated solution to create a golf ball with a polyisocyanated cover, and heating the golf ball or polyisocyanated cover to remove a solvent component of the polyisocyanated solution and promote the reaction of the polyisocyanate with the cover mixture and polyahl.

A golf ball and a method of forming a golf ball is disclosed herein. The golf ball includes an alignment aid or feature that is integrally formed with a core body of the golf ball. A cover is provided that allows the alignment aid to be visible from an exterior of the golf ball. The alignment aid can be formed as central spherical segment that fuses two spherical cap portions with each other to form the core body. Different material selections can be made for the spherical cap portions and the central spherical segment that can further provide variation in performance characteristics of the golf ball.

The present invention relates to the use of a mono (meth)acrylate ester in a golf ball layer. The mono (meth)acrylate ester may be added to one or more portions of a golf ball including a core, intermediate, or cover layer. For example, in one embodiment, the mono (meth)acrylate ester may be blended with a polybutadiene rubber material. In another embodiment, the mono (meth)acrylate ester of the present invention may be blended with an ionomer. In some embodiments, the mono (meth)acrylate ester may be blended with a formulation including both a polybutadiene rubber component and an ionomer.

Golf ball comprising a core having a hardness gradient and an outer cover layer having a microhardness gradient and being formed from a thermoset polyurethane material throughout, and having: i) a treated region that is contacted with a thermoset polyurethane microhardness-increasing solution consisting of an isocyanate portion and at least one non-aqueous solvent; and ii) an untreated region that is not contacted with the thermoset polyurethane microhardness-increasing solution. The treated region comprises the isocyanate portion, whereas the untreated region does not comprise the isocyanate portion. Treated region has a microhardness M.sub.1 that is greater than microhardness M.sub.2 of untreated region to define the outer cover layer positive microhardness gradient M=M.sub.1M.sub.2. The treated region may have a depth Dtr that extends inward from the cover outer surface and in some embodiments is less than a thickness of the untreated region. Treated region may alternatively extend from the inner surface toward outer surface.

Golf ball comprising a positive hardness gradient core and an outer cover layer having a microhardness gradient and being formed from a thermoset polyurethane material throughout, and having: i) a treated region that is contacted with a thermoset polyurethane microhardness-increasing solution consisting of an isocyanate portion and at least one non-aqueous solvent; and ii) an untreated region that is not contacted with the thermoset polyurethane microhardness-increasing solution. The treated region comprises the isocyanate portion, whereas the untreated region does not comprise the isocyanate portion. Treated region has a microhardness M.sub.1 that is greater than microhardness M.sub.2 of untreated region to define the outer cover layer positive microhardness gradient M=M.sub.1M.sub.2. The treated region may have a depth Dtr that extends inward from the cover outer surface and in some embodiments is less than a thickness of the untreated region. Treated region may alternatively extend from the inner surface toward outer surface.

Golf balls having a multi-layered core made of a foamed composition are provided. The core assembly preferably includes a foam inner core (center) and surrounding outer core layer. Preferably, a viscoelastic polyurethane foam composition is used to form the inner core. The foam composition has shape-memory properties. The core has good durability and thermal stability. In other instances, the viscoelastic polyurethane foam composition can be used to make the outer core layer. The core layers can have different hardness gradients and specific gravity values. The ball further includes a cover that can be multi-layered.

A golf ball with a center core comprising polybutadiene and a carbon nanotube material in an amount ranging from 0.4 to 2.5 weight percent of the center core is disclosed herein. Alternatively, the golf ball has a mantle layer with a blend of ionomer materials and a carbon nanotube material in an amount ranging from 0.2 to 2.5 weight percent of the mantle layer.

An ultra-low compression golf ball is disclosed herein. The core preferably has a PGA compression less than 30. The mantle layer and cover have approximately the same thickness. The cover comprises a thermoplastic polyurethane material and has a specific gravity greater than the core and mantle layer. The golf ball has a PGA compression less than 75 and a COR of at least 0.780.

Golf balls having a multi-layered core made of a foamed composition are provided. The core preferably has a foam inner core (center) and surrounding thermoset or thermoplastic outer core layer. Preferably, a polyurethane foam composition is used to form the foam center. The foam inner core preferably includes a fully-foamed center region and a partially or completely-collapsed foam outer region. The hardness of the fully-foamed region is different than the hardness of the collapsed foam region. Non-foamed thermoset or thermoplastic materials such as polybutadiene rubbers or ethylene acid copolymer ionomer may be used to form the outer core layer. The ball further includes a cover that may be multi-layered. The foam cores have good resiliency.

A golf ball includes a core having an outer surface, a geometric center, and a soft transition region adjacent to the outer surface. The soft transition region has a thickness of about 4 mm or less and includes about 2 to 10 percent of a trans-polybutadiene isomer. An outer cover layer has a hardness of about 50 Shore M or greater. The core outer surface hardness is greater than the hardness at the geometric center to define a positive hardness gradient of about 10 to 48 Shore C. The core has a secondary gradient quotient, GQ, of 1.5 to 7.25, GQ being defined by the equation: $\frac{G^{}+T}{10\mathrm{COR}}$
where G is the positive hardness gradient in Shore C, T is the percent trans-polybutadiene isomer at the core outer surface, and COR is the coefficient of restitution of the core measured at an incoming velocity of 125 ft/s.