Golf ball
First Claim
1. A golf ball which comprises a core, a mid layer and a cover,said mid layer comprising 10 parts by weight or greater and 70 parts by weight or less of a thermoplastic elastomer containing a styrene block having a material hardness of less than 10, and 30 parts by weight or greater and 90 parts by weight or less of an ethylene-(meth)acrylic acid copolymer based ionomer resin having a material hardness of 50 or greater and 70 or less, per 100 parts by weight of the base polymer, wherein said mid layer has a shore D hardness of less than 40, and said mid layer has a thickness of equal to or less than 1.2 mm,said golf ball having three or more kinds of dimples, each having a different diameter, on the surface thereof,an occupation ratio of the total area of the dimples in the surface area of a phantom sphere being equal to or greater than 75%,a ratio Dx/Dn being equal to or greater than 1.30, wherein a mean diameter of the dimples having a diameter ranking in the top 10% of the diameters of all the dimples is defined as Dx and a mean diameter of the dimples having a diameter ranking in the bottom 10% of the diameters of all the dimples is defined as Dn, anda standard deviation η
- of diameters of all the dimples being equal to or less than 0.52.
4 Assignments
0 Petitions
Accused Products
Abstract
A golf ball 2 has a core, a mid layer and a cover. This mid layer comprises 10 parts by weight or greater and 70 parts by weight or less of a thermoplastic elastomer containing a styrene block having a material hardness of less than 10, and 30 parts by weight or greater and 90 parts by weight or less of an ethylene-(meth)acrylic acid copolymer based ionomer resin having a material hardness of 50 or greater and 70 or less. Hardness of this mid layer is less than 40, and the thickness is equal to or less than 1.2 mm. This golf ball 2 has seven kinds of dimples (A to G), each having a different diameter. When all the dimples are arranged in decreasing order of the diameter Di, ratio (Dx/Dn) of the mean diameter Dx of the dimples ranking in the top 10% to the mean diameter Dn of the dimples ranking in the bottom 10% is equal to or greater than 1.30. Standard deviation η of diameters of all the dimples is equal to or less than 0.52.
-
Citations
9 Claims
-
1. A golf ball which comprises a core, a mid layer and a cover,
said mid layer comprising 10 parts by weight or greater and 70 parts by weight or less of a thermoplastic elastomer containing a styrene block having a material hardness of less than 10, and 30 parts by weight or greater and 90 parts by weight or less of an ethylene-(meth)acrylic acid copolymer based ionomer resin having a material hardness of 50 or greater and 70 or less, per 100 parts by weight of the base polymer, wherein said mid layer has a shore D hardness of less than 40, and said mid layer has a thickness of equal to or less than 1.2 mm, said golf ball having three or more kinds of dimples, each having a different diameter, on the surface thereof, an occupation ratio of the total area of the dimples in the surface area of a phantom sphere being equal to or greater than 75%, a ratio Dx/Dn being equal to or greater than 1.30, wherein a mean diameter of the dimples having a diameter ranking in the top 10% of the diameters of all the dimples is defined as Dx and a mean diameter of the dimples having a diameter ranking in the bottom 10% of the diameters of all the dimples is defined as Dn, and a standard deviation η - of diameters of all the dimples being equal to or less than 0.52.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
Specification