A golf ball with a core comprising polybutadiene and graphene is disclosed herein. The golf ball has a single core comprising polybutadiene and graphene. Alternatively, the golf ball has a dual core with an inner core comprising polybutadiene and graphene. Alternatively, the golf ball has a dual core with an outer core comprising polybutadiene and graphene.

A multi-piece solid golf ball for professional golfers and skilled amateurs in particular is endowed with an excellent distance, a soft yet good feel at impact and a good durability. In the ball, which includes a core, an envelope layer, an intermediate layer and a cover, the core has a hardness profile which satisfies specific conditions, the envelope layer has a thickness of from 0.3 to 1.2 mm, the intermediate layer has a thickness of from 0.3 to 1.2 mm, and the envelope and intermediate layers have a combined thickness from of 0.8 to 1.7 mm.

A golf ball includes a main body and a paint layer positioned outside the main body. The paint layer includes an inner layer and an outer layer positioned outside the inner layer. When an indentation depth (nm) is measured on a cross-section along a plane passing through a central point of the golf ball when a force of 30 mgf is applied to the cross-section in a direction perpendicular to the cross-section, an indentation depth Di on a cross-section of the inner layer is smaller than an indentation depth Do on a cross-section of the outer layer. A thickness To of the outer layer is larger than a thickness Ti of the inner layer.

In a golf ball having a core of one or more layer and a cover of one or more layer encasing the core, the core has a deflection when compressed under a specific load of at least 3.8 mm; at least an innermost portion of the core has a specific difference between maximum and minimum values in cross-sectional hardnesses (JIS-C) from a center to a surface thereof; and the center core is formed of a rubber composition that includes (a) a base rubber, (b) an ,-unsaturated carboxylic acid and/or metal salt thereof, (c) a diacyl peroxide and/or a peroxyester, and (d) a dialkyl peroxide and/or a peroxyketal. The golf ball has a low spin rate on driver shots by low head speed golfers, and thus achieves an improved distance, while minimizing any decrease in durability.

A golf ball with a center core comprising 1,4 polybutadiene with a cis content more than 50% and containing a metal salt of acrylate, wherein the 1,4 polybutadiene has 5 to 60 weight percent of a metal salt of acrylate, is disclosed herein. The metal salt of acrylate is preferably selected from zinc, magnesium, sodium, and calcium.

A golf ball with a core comprising polybutadiene and graphene, and a soft cover is disclosed herein. The golf ball has a dual core with an outer core comprising polybutadiene and graphene. The soft cover is preferably composed of a highly neutralized polymer, a first ionomer, a second ionomer, and an impact modifier.

In a multi-piece solid golf ball having a core, an intermediate layer encasing the core and a cover which encases the intermediate layer and has numerous dimples on an outside surface thereof, the intermediate layer is formed of a resin material, the cover is formed of a urethane resin material, the core has a diameter of at least 38.0 mm, the core has a deflection when compressed under a final load of 1,275 N (130 kgf) from an initial load of 98 N (10 kgf) of at least 3.9 mm, the core has a center and a surface such that the value obtained by subtracting the JIS-C hardness at the core center from the JIS-C hardness at the core surface is at least 15, the sphere obtained by encasing the core with the intermediate layer (intermediate layer-encased sphere) has a surface hardness on the Shore D hardness scale of at least 69, the ball has a surface hardness on the Shore D hardness scale of 62 or less, and the (intermediate layer thickness)/(core diameter) value is from 0.025 to 0.043, the (cover thickness)/(core diameter) value is from 0.014 to 0.027.

A method for manufacturing a golf ball having a core, an intermediate layer and a cover that is formed of a resin material composed primarily of a polyurethane resin and has a thickness of 0.1 mm to 0.7 mm by injection molding the cover using a vertically separating two-part injection mold having specific gate and support pin configurations. This method enables a relatively soft urethane resin cover that is thin and of high quality to be formed, and has a good golf ball productivity.

A method for forming a golf ball with a graphene core disclosed herein. The method includes mixing a graphene masterbatch material with a polybutadiene material to form a core mixture, wherein the graphene masterbatch material comprises graphene in an amount from 0.1 to 80.0 weight percent of the graphene masterbatch material mixed with a carrier polymer in an amount from 99.9 to 20 weight percent of the graphene masterbatch material.

A golf ball with a core comprising polybutadiene and graphene with an embedded IC is disclosed herein. The golf ball preferably has a single core comprising polybutadiene and graphene. Alternatively, the golf ball has a dual core with an inner core comprising polybutadiene and graphene. Alternatively, the golf ball has a dual core with an outer core comprising polybutadiene and graphene.