Golf ball
AssigneeBridgestone Sports Co., Ltd.
InventorsMasanobu KUWAHARA, Hirotaka SHINOHARA, Daichi MIZUTANI
Life of this patent
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Abstract
A golf ball includes at least one intermediate layer formed between a core and a cover, wherein a standard deviation of a specific gravity of each layer of the core, the intermediate layer, the cover is within 0.07, and the cover is formed of a resin composition that includes the following components (I) and (II): (I) polyurethane (II) (meth)acrylic block copolymer, and the cover satisfies the following condition (1): 0.1 ≤ VR L × V R H ≤ 0 . 2 6 ( 1 ) [in the above condition, VRL represents a viscosity at 210° C. and a viscosity at 200° C. at a predetermined shear rate, and VRH represents a ratio between a viscosity η3 at 230° C. and a viscosity at 220° C. at the predetermined shear rate].
Claims15
A golf ball comprising at least one intermediate layer formed between a core and a cover, wherein a standard deviation of a specific gravity of each layer of the core, the intermediate layer, and the cover is within 0.07, the cover is formed of a resin composition that includes the following components (I) and (II):
- (I) polyurethane
- (II) (meth)acrylic block copolymer,
- and the cover satisfies the following condition (1):
- 0.1
- ≤
- VR
- L
- ×
- V
-
- R
- H
- ≤
- 0
- .
- 2
-
- 6
- (
- 1
- )
- [in the above condition, VRL represents a ratio (η1/η0) of a viscosity η1 (dPa·s) at 210° C. and a viscosity η0 (dPa·s) at 200° C. at a shear rate of 1,216 (1/sec), and VRH represents a ratio (η3/η2) of a viscosity η3 (dPa·s) at 230° C. and a viscosity η2 (dPa·s) at 220° C. at the shear rate of 1,216 (1/sec)].
Dependencies are inferred from the claim text.