A golf ball (2) includes a core (4), an inner cover (6), a main cover (8), and an outer cover (10). X=HcRc0.05, S=HsRc0.05, M=HmTm, I=HiTi, O=HoTo, and Q=(I+O)/2 that are calculated from a radius Rc of the core (4), a Shore C hardness Hc at a central point of the core (4), a Shore C hardness Hs at a surface of the core (4), a thickness Tm of the main cover (8), a Shore C hardness Hm of the main cover (8), a thickness Ti of the inner cover (6), a Shore C hardness Hi of the inner cover (6), a thickness To of the outer cover (10) and a Shore C hardness Ho of the outer cover (10), satisfy 15MS100, 0.25<Q/M<0.5, 10IO30, and Q/X<0.8.

A golf ball (2) includes a core (4), an inner cover (6), a main cover (8), and an outer cover (10). X=HcRc0.05, S=HsRc0.05, M=HmTm, I=HiTi, O=HoTo, and Q=(I+O)/2 that are calculated from a radius Rc of the core (4), a Shore C hardness Hc at a central point of the core (4), a Shore C hardness Hs at a surface of the core (4), a thickness Tm of the main cover (8), a Shore C hardness Hm of the main cover (8), a thickness Ti of the inner cover (6), a Shore C hardness Hi of the inner cover (6), a thickness To of the outer cover (10) and a Shore C hardness Ho of the outer cover (10), satisfy 15MS100, 0.25<Q/M<0.5, 10IO30, and Q/X0.8.

Golf ball incorporating at least one very thin moisture barrier film (monolayer film, bi-layer film or multi-layer film) comprising ethylene-based cycloolefin copolymer(s) and having a thickness of up to 0.009 inches as well as a normalized moisture vapor transmission rate (nMVTR) of less than about 5.0 g/(m.sup.2.Math.day). The ethylene-based cycloolefin copolymer-containing moisture barrier film is disposed about and adjacent to an outer surface of a subassembly and is surrounded by at least one outer layer having an nMVTR that is greater than that of the moisture barrier film. In particular embodiments, the nMVTR of the subassembly is also greater than that of the moisture barrier film.

Multi-piece golf balls having a multi-layered solid core and multi-layered cover are provided.

Golf ball incorporating at least one very thin moisture barrier film (monolayer film, bi-layer film or multi-layer film) comprising ethylene-based cycloolefin copolymer(s) and having a thickness of up to 0.009 inches as well as a normalized moisture vapor transmission rate (nMVTR) of less than about 5.0 g/(m.sup.2.Math.day). The ethylene-based cycloolefin copolymer-containing moisture barrier film is disposed about and adjacent to an outer surface of a subassembly and is surrounded by at least one outer layer having an nMVTR that is greater than that of the moisture barrier film. In particular embodiments, the nMVTR of the subassembly is also greater than that of the moisture barrier film.

Multi-piece golf balls having a multi-layered solid core and multi-layered cover are provided.

Golf ball comprising: a subassembly; a moisture barrier film layer having a continuous and substantially uniform thermoformed thickness of less than 0.020 inches and consisting of first and second heat-induced pre-form film half shells having first and second inner surfaces that are sized, shaped and contoured to receive and conformally and adhesively mate onto and about the subassembly such that the moisture barrier film layer has a normalized Moisture Vapor Transmission Rate (nMVTR) of less than 4.0 g/(m2.Math.day); and at least one outer layer disposed about an outer surface of the moisture barrier film layer that has an nMVTR greater than the nMVTR of the moisture barrier film layer. Alternatively, the thermoformed thickness is from about 0.003 inches to less than 0.020 inches; or 0.0035 inches to 0.010 inches; or from about 0.01 inches to less than 0.020 inches; or from greater than about 0.0035 inches to 0.005 inches.

In a multi-piece solid golf ball having a core, an envelope layer, an intermediate layer, and a cover with a plurality of dimples thereon, the core is a two-layer core consisting of an inner core layer and an outer core layer each formed primarily of a base rubber, the envelope layer, the intermediate layer and the cover layer are each composed of at least one layer and formed primarily of a synthetic resin material, and the initial velocities and surface hardnesses of the core, the envelope layer-encased sphere and the intermediate layer-encased sphere are designed within specific ranges. This golf ball satisfies at a very high level the flight and control performances expected for use by professional golfers and skilled amateurs, has the ability to move forward on a straight path particularly on full shots, and also has an excellent scuff resistance.

A golf ball includes a spherical core, a mid layer, an inner cover, and an outer cover. A hardness Hm of the mid layer is greater than a hardness Hinc of the inner cover which is greater than a hardness Houc of the outer cover. A difference (HmHouc) is greater than 25. A volume Vm of the mid layer is greater than a volume Vinc of the inner cover which is greater than a volume Vouc of the outer cover. A ratio [(Vm+Vinc+Vouc)/V] of a sum (Vm+Vinc+Vouc) relative to a volume V of an entirety of the golf ball is less than 0.30. A ratio (Vm/Vouc) is greater than 1.50. A product (Vm*Hm) and a product (Vouc*Houc) meet the following relationship: [(Vm*Hm)/(Vouc*Houc)]>3.0.

In a golf ball having a core, an outermost layer and an intermediate layer therebetween, the intermediate layer is formed of a thermoplastic resin composition that includes (A) an ionic olefin-methacrylic acid-unsaturated carboxylic acid ester copolymer, (B) a nonionic olefin-acrylic acid copolymer, (C) an organic acid or a metal salt thereof, and (D) a basic inorganic metal compound, and the outermost layer is formed of a thermoplastic resin composition that includes (a) a specific ionic olefin-unsaturated to carboxylic acid copolymer and (h) a specific ionic olefin-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer. The ratio (tan ) between the tensile storage modulus (E) and the tensile loss modulus (E) in a dynamic viscoelasticity test on the outermost layer-forming resin composition conducted under specific conditions is not more than 0.150. This combination of intermediate layer and outermost layer materials has is a large spin rate-lowering effect on the ball, enabling the ball to travel further.