Abstract: An object of the present invention is to improve the durability of the golf ball without substantially lowering the spin performance. The present invention provides a golf ball comprising a spherical core and a cover covering the spherical core, wherein the cover contains: (A) a base resin component, and (B) resin fine particles containing a polyrotaxane component having a cyclodextrin, a linear molecule penetrating the cyclic structure of the cyclodextrin in a skewering manner, and blocking groups located at both terminals of the linear molecule to prevent disassociation of the cyclodextrin, wherein at least a part of hydroxyl groups of the cyclodextrin is modified with a caprolactone chain via a —O—C3H6—O— group.

Abstract: An object of the present invention is to provide a golf ball having excellent shot feeling and durability. The present invention provides a golf ball comprising a constituent member containing a crosslinked rubber component and resin fine particles, wherein the resin fine particles contain a polyrotaxane component having a cyclodextrin, a linear molecule piercing through the cyclic structure of the cyclodextrin, and blocking groups located at both terminals of the linear molecule to prevent disassociation of the cyclodextrin, wherein at least a part of hydroxyl groups of the cyclodextrin is modified with a caprolactone chain via a —O—C3H6—O— group.

Abstract: A golf ball strikes a good balance between the durability and the shot feeling, and includes a spherical core and at least one cover disposed outside the spherical core. At least one layer of the cover contains (A) a base resin and (B) a resin fine particle, (A) the base resin contains an ionomer resin, and (B) the resin fine particles contain a polyrotaxane component having a cyclodextrin, a linear molecule penetrating the cyclic structure of the cyclodextrin in a skewering manner, and blocking groups located at both terminals of the linear molecule to prevent disassociation of the cyclodextrin wherein at least a part of hydroxyl groups of the cyclodextrin is modified with a caprolactone chain via a —O—C3H6—O— group.

Abstract: 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.

Abstract: A golf ball 2 includes a main body 4 and a paint layer 6 positioned outside the main body 4. The paint layer 6 includes an inner layer 14 and an outer layer 16 positioned outside the inner layer 14. When an indentation depth (nm) is measured on a cross-section along a plane passing through a central point of the golf ball 2 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 14 is smaller than an indentation depth Do on a cross-section of the outer layer 16. A thickness To of the outer layer 16 is smaller than a thickness Ti of the inner layer 14.

Abstract: An object of the present invention is to provide a novel rotaxane and a polyurethane using the same. The present invention provides a rotaxane having a crown ether and a chain molecule piercing through the cyclic structure of the crown ether, wherein a hydroxyl group exists at one terminal of the chain molecule, and a hydroxyl group bonds to the cyclic structure of the crown ether. The present invention further provides a polyurethane using the rotaxane as a polyol component.

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: An object of the present invention is to provide a golf ball exhibiting good shot feeling and excellent resilience. The present invention provides a golf ball comprising a spherical core and one or more cover layers disposed outside the spherical core, wherein at least one layer of the cover layers contains: (A) a base resin containing (a-1) an ionomer resin and having a material hardness of 59 or more in Shore D hardness; and (B) a polyrotaxane having a cyclodextrin with at least a part of hydroxyl groups of the cyclodextrin being modified with a caprolactone chain having a carboxyl group at a terminal of the caprolactone chain, a linear molecule piercing through a cyclic structure of the cyclodextrin, and blocking groups located at both terminals of the linear molecule to prevent disassociation of the cyclodextrin.

Abstract: An object of the present invention is to provide a golf ball having excellent shot feeling and resilience as well as improved durability and abrasion resistance. The present invention provides a golf ball comprising a spherical core and one or more cover layers disposed outside the spherical core, wherein at least one layer of the cover layers contains: (A) a base resin containing (a-1) an ionomer resin and having a material hardness of 58 or less in Shore D hardness; and (B) a polyrotaxane having a cyclodextrin with at least a part of hydroxyl groups thereof being modified with a caprolactone chain having a carboxyl group at a terminal of the caprolactone chain, a linear molecule piercing through a cyclic structure of the cyclodextrin, and blocking groups located at both terminals of the linear molecule to prevent disassociation of the cyclodextrin.

Abstract: An object of the present invention is to provide a golf ball exhibiting good shot feeling and excellent resilience. The present invention provides a golf ball comprising a spherical core and one or more cover layers disposed outside the spherical core, wherein at least one layer of the cover layers contains: (A) a base resin containing (a-1) an ionomer resin and having a material hardness of 59 or more in Shore D hardness; and (B) a polyrotaxane having a cyclodextrin with at least a part of hydroxyl groups of the cyclodextrin being modified with a caprolactone chain via —O—C3H6—O— group, a linear molecule piercing through a cyclic structure of the cyclodextrin, and blocking groups located at both terminals of the linear molecule to prevent disassociation of the cyclodextrin.

Abstract: An object of the present invention is to provide a golf ball having excellent shot feeling and resilience as well as improved durability and abrasion resistance. The present invention provides a golf ball comprising a spherical core and one or more cover layers disposed outside the spherical core, wherein at least one layer of the cover layers contains: (A) a base resin containing (a-1) an ionomer resin and having a material hardness of 58 or less in Shore D hardness; and (B) a polyrotaxane having a cyclodextrin with at least a part of hydroxyl groups thereof being modified with a caprolactone chain via —O—C3H6—O— group, a linear molecule piercing through a cyclic structure of the cyclodextrin, and blocking groups located at both terminals of the linear molecule to prevent disassociation of the cyclodextrin.

Abstract: An object of the present invention is to provide a golf ball having excellent abrasion resistance and spin performance on driver shots. The present invention provides a golf ball having a spherical core and a cover covering the spherical core, wherein the cover contains a polyurethane, wherein the polyurethane comprises, as a constituent component, (A) a polyisocyanate component and (B) a polyol component containing (b1) a polyrotaxane, and wherein (b1) the polyrotaxane has a cyclodextrin, a linear molecule piercing through the cyclic structure of the cyclodextrin, and a blocking group located at both terminals of the linear molecule to prevent disassociation of the cyclodextrin, and at least a part of hydroxyl groups of the cyclodextrin is modified with a caprolactone chain via —O—C3H6—O— group.

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 travelling a great flight distance on driver shots, having enhanced controllability on approach shots under a wet condition, and being excellent in stain resistance and shot feeling. The present invention provides a golf ball comprising a golf ball body having a cover, and a paint film covering the golf ball body, wherein a 10% elastic modulus of the paint film is 75 kgf/cm2 or less, a storage modulus (E?150) at 150° C. of the paint film obtained by measuring dynamic viscoelasticity of the paint film is 1.0×107 Pa or more, an indentation depth of the paint film measured with a nanoindenter in a state that the paint film is formed on the surface of the golf ball body is 1250 nm or more, and a material hardness of the cover is 50 or more in Shore D hardness.

Abstract: An object of the present invention is to provide a golf ball having enhanced controllability on approach shots from the rough and excellent stain resistance and shot feeling. The present invention provides a golf ball comprising a golf ball body having a cover, and a paint film covering the golf ball body, wherein a 10% elastic modulus of the paint film is 75 kgf/cm2 or less, a storage modulus (E?150) at 150° C. of the paint film obtained by measuring dynamic viscoelasticity of the paint film is 1.0×107 Pa or more, an indentation depth of the paint film measured under a specific measuring condition in a state that the paint film is formed on the surface of the golf ball body is 1250 nm or more, and a material hardness of the cover is less than 50 in Shore D hardness.

Abstract: An object of the present invention is to provide a golf ball having excellent abrasion resistance and spin performance on driver shots. The present invention provides a golf ball having a spherical core and a cover covering the spherical core, wherein the cover contains a polyurethane, wherein the polyurethane comprises, as a constituent component, (A) a polyisocyanate component and (B) a polyol component containing (b1) a polyrotaxane, and wherein (b1) the polyrotaxane has a cyclodextrin, a linear molecule piercing through the cyclic structure of the cyclodextrin, and a blocking group located at both terminals of the linear molecule to prevent disassociation of the cyclodextrin, and at least a part of hydroxyl groups of the cyclodextrin is modified with a caprolactone chain via —O—C3H6—O— group.

Abstract: A golf ball 2 includes a main body 4 and a paint layer 6 positioned outside the main body 4. The paint layer 6 includes an inner layer 14 and an outer layer 16 positioned outside the inner layer 14. When an indentation depth (nm) is measured on a cross-section along a plane passing through a central point of the golf ball 2 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 14 is smaller than an indentation depth Do on a cross-section of the outer layer 16. A thickness To of the outer layer 16 is smaller than a thickness Ti of the inner layer 14.

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.