Abstract: An object of the present invention is to provide a golf ball having excellent spin performance on approach shots under a wet condition and excellent spin performance on approach shots under a condition that there is grass between the golf ball and the club face.

Abstract: An object of the present invention is to provide a golf ball having improved spin performance on wedge shots under a wet condition such as rain by controlling the formulation of the paint film. The present invention provides a golf ball comprising a golf ball body and a paint film covering the golf ball body, wherein the paint film contains a base resin and a porous filler, and the porous filler contains SiO2 as a constituent in an amount of 50 mass % or more.

Abstract: A golf ball includes a spherical core and a cover positioned outside the core. The core has an inner layer and an outer layer positioned outside the inner layer. The inner layer is obtained by crosslinking a rubber composition. The rubber composition of the inner layer includes a butyl-based rubber as a base rubber. The inner layer has a diameter Di of not less than 10 mm and not greater than 34 mm. A difference (H2?H0) between a Shore C hardness H2 at a surface of the outer layer and a Shore C hardness H0 at a central point of the inner layer is less than 35. Preferably, the butyl-based rubber is a polymer including an isobutylene unit and an isoprene unit, and a derivative thereof.

Abstract: A golf ball 2 includes a main body 4 and a paint layer 6 positioned outside the main body 4. The main body 4 includes a spherical core 8, a mid layer 10 positioned outside the core 8, and a cover 12 positioned outside the mid layer 10. An indentation depth, measured when the paint layer 6 in a cross-section along a plane passing through a central point of the golf ball 2 is pressed by a force of 30 mgf in a direction perpendicular to the cross-section, is not less than 300 nm and not greater than 3000 nm. The paint layer 6 preferably has a thickness of not less than 5 ?m and not greater than 50 ?m.

Abstract: An object of the present invention is to provide a golf ball having improved spin performance on wedge shots under a wet condition such as rain by controlling the formulation of the paint film. The present invention provides a golf ball comprising a golf ball body and a paint film covering the golf ball body, wherein the paint film contains a base resin and a porous filler, and the porous filler contains SiO2 as a constituent in an amount of 50 mass % or more.

Abstract: An object of the present invention is to provide a golf ball having improved ball speed or aerodynamic performance on a rainy day or the like by controlling the formulation of the paint film. The present invention provides a golf ball comprising a golf ball body and a paint film covering the golf ball body, wherein a paint film surface of the golf ball has a water contact angle A1 of 70° or more and a water sliding angle B1 of less than 50°. The present invention also provides a golf ball comprising a golf ball body and a paint film covering the golf ball body, wherein when a sheet consisting of a slab formed from a composition constituting a golf ball body surface and a coating film formed by applying a paint constituting the paint film on the slab is prepared, a coating film surface of the sheet has a water contact angle A2 of 90° or more and a water sliding angle B2 of less than 52°.

Abstract: A golf ball 2 includes a core 4, an inner cover 6, a main cover 8, and an outer cover 10. S=Hs×Rc×0.05, M=Hm×Tm, I=Hi×Ti, O=Ho×To, and Q=(I+O)/2 that are calculated from a radius Rc 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 15?M?S?100, 0.25<Q/M?0.5, and 30<I?O.

Abstract: A golf ball 2 includes a main body 4 and a paint layer 6 positioned outside the main body 4. The main body 4 includes a spherical core 8, a mid layer 10 positioned outside the core 8, and a cover 12 positioned outside the mid layer 10. An indentation depth, measured when the paint layer 6 in a cross-section along a plane passing through a central point of the golf ball 2 is pressed by a force of 30 mgf in a direction perpendicular to the cross-section, is not less than 300 nm and not greater than 3000 nm. The paint layer 6 preferably has a thickness of not less than 5 ?m and not greater than 50 ?m.

Abstract: An object of the present invention is to provide a golf ball that can strike a good balance in approach performance under a rough condition and a wet condition while maintaining a flight distance on driver shots.

Abstract: An object of the present invention is to provide a golf ball having good spin performance on approach shots and good shot feeling as well as excellent stain resistance by precisely controlling physical properties of a paint film actually formed on a surface of a golf ball body. The present invention provides a golf ball comprising a golf ball body and a paint film formed on a surface of the golf ball body, wherein the paint film is such that a linear approximation curve obtained by a least square method has a slope in an absolute value ranging from 0.0001 to 0.0020 when a loss tangent tan ? thereof measured by a nanoindentation method is plotted as a vertical axis against a measuring frequency (Hz) as a horizontal axis, and that an elastic modulus thereof measured by a nanoindentation method ranges from 0.040 GPa to 0.600 GPa.

Abstract: A golf ball includes a spherical core and a cover positioned outside the core. The core has an inner layer and an outer layer positioned outside the inner layer. The inner layer is obtained by crosslinking a rubber composition. The rubber composition of the inner layer includes a butyl-based rubber as a base rubber. The inner layer has a diameter Di of not less than 10 mm and not greater than 34 mm. A difference (H2?H0) between a Shore C hardness H2 at a surface of the outer layer and a Shore C hardness H0 at a central point of the inner layer is less than 35. Preferably, the butyl-based rubber is a polymer including an isobutylene unit and an isoprene unit, and a derivative thereof.

Abstract: An object of the present invention is to provide a golf ball traveling a great distance on driver shots. The present invention provides a golf ball comprising a spherical core including an inner layer and an outer layer, wherein a difference (HX+1?HX?1) between a hardness (HX+1) at a point outwardly away in a radial direction from a boundary between the inner layer and the outer layer of the spherical core by 1 mm and a hardness (HX?1) at a point inwardly away in the radial direction from the boundary between the inner layer and the outer layer of the spherical core by 1 mm is 0 or more in Shore C hardness, a surface hardness (HX+Y) of the spherical core is more than 70 in Shore C hardness, an angle ? of a hardness gradient of the inner layer is 0° or more, and a difference (???) between the angle ? and an angle ? of a hardness gradient of the outer layer is 0° or more.

Abstract: An object of the present invention is to provide a golf ball that can strike a good balance in approach performance under a rough condition and a wet condition while maintaining a flight distance on driver shots.

Abstract: An object of the present invention is to provide a golf ball traveling a great flight distance on driver shots and an excellent shot feeling. The present invention provides a golf ball comprising a spherical core, an intermediate layer covering the spherical core, and a cover covering the intermediate layer, wherein a material hardness (Hm) of a resin composition constituting the intermediate layer ranges from 65 to 80 in Shore D hardness, a material hardness (Hc) of a resin composition constituting the cover ranges from 57 to 72 in Shore D hardness, a hardness difference (Hm?Hc) between the material hardness (Hm) and the material hardness (Hc) is more than 0, and the intermediate layer has a surface hardness satisfying a hardness difference (HmsC?HmsD) between a hardness thereof shown in Shore C hardness (HmsC) and a hardness thereof shown in Shore D hardness (HmsD) of 27 or less.

Abstract: A golf ball 2 includes a main body 4 and a paint layer 6 positioned outside the main body 4. The main body 4 includes a spherical core 8, a mid layer 10 positioned outside the core 8, and a cover 12 positioned outside the mid layer 10. An outer surface of the paint layer 6 forms a surface of the golf ball 2. A contact angle CAw with respect to water measured on the surface of the golf ball 2 is not less than 70 degrees. The paint layer 6 is preferably formed from a resin composition. A preferable resin composition includes a polyurethane as a base resin and includes a silicone compound and/or a fluorine compound. Another preferable resin composition includes a silicone compound and/or a fluorine compound as a base resin and includes no polyurethane.

Abstract: A golf ball 2 includes a core 4, a mid layer 6, and a cover 8. A difference DH in hardness between a surface and a central point of the core 4, a thickness Tm and a hardness Hm of the mid layer 6, a thickness Tc and a hardness Hc of the cover 8, and an amount of compressive deformation Sb of the golf ball 2 meet the following mathematical formulas (DH*Hm)/(Hc*Tc)>80 and ((Sb*Tc)/(Hc*Hm*Tm))*1000>0.75. A hardness Hc of the cover 8 is equal to or less than 40. A material of the cover 8 is a resin composition. The resin composition includes a polyurethane (A) and a polyrotaxane (B).

Abstract: A golf ball 2 includes an inner core 4, an outer core 6, a mid layer 8, and a cover 10. A diameter D1, a volume V1, a hardness H1o at a central point, and a boundary inside hardness H1in of the inner core 4; a volume V2, a boundary outside hardness H2out, and a surface hardness H2s of the outer core 6; a thickness Tm and a hardness Hm of the mid layer 8; and a thickness Tc and a hardness Hc of the cover 10 meet the following mathematical formulas (1) to (4): 1.0<V2/V1<7.0 (1); ?2<H2s?H2out<2 (2); 600<(H1o+H1in)*(D1/2)/2<1000 (3); 620<Tc*Hc*Hm/Tm<900 (4). The cover 10 includes a polyrotaxane.

Abstract: A golf ball 2 includes a core 4, a mid layer 6, and a cover 8. A hardness H75 at a point to which a distance from a central point of the core 4 is 75% of a radius of the core 4 is greater than a hardness H0 at the central point of the core 4. A difference D1=(H75?H0) is not less than 10.0 and not greater than 27.0 in Shore C hardness. A hardness Hs at a surface of the core 4 is greater than the hardness H75. A difference D2=(Hs?H75) is not less than 0 and not greater than 6.5 in Shore C hardness. The hardness H75 is less than a Shore C hardness HmC of the mid layer 6. A Shore D hardness HmD of the mid layer 6 is greater than a Shore D hardness Hc of the cover 8.

Abstract: A golf ball 2 includes a core 4, an inner cover 6, a main cover 8, and an outer cover 10. S=Hs×Rc×0.05, M=Hm×Tm, I=Hi×Ti, O=Ho×To, and Q=(I+O)/2 that are calculated from a radius Rc 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 15?M?S?100, 0.25<Q/M?0.5, and 30<I?O.

Abstract: An object of the present invention is to provide a golf ball travelling a great flight distance on driver shots, exhibiting an excellent spin performance on approach shots under a dry condition and a wet condition, and showing an excellent shot feeling and durability. The present invention provides a golf ball comprising a golf ball body having a spherical core, an intermediate layer and a cover, and a paint film composed of two or more layers, wherein a 10% elastic modulus difference (Min-Mout) between an innermost layer and an outermost layer of the paint film is 25 kgf/cm2 or more.