Multi-piece solid golf ball

• US 7,201,671 B2
• Filed: 01/05/2006
• Issued: 04/10/2007
• Est. Priority Date: 01/28/2004
• Status: Active Grant

• Current Assignee: Bridgestone Sports Co Limited (Bridgestone Corporation)
• Original Assignee: Bridgestone Sports Co Limited (Bridgestone Corporation)
• Inventors: Watanabe, Hideo, Hayashi, Junji, Takesue, Rinya, Kasashima, Atsuki
• Primary Examiner(s): Trimiew; Raeann
• Application Number:
  US11/325,461
• Publication Number:
  US 20060116221A1
• Time in Patent Office: 460 Days
• Field of Search: 473/373, 473/374, 473/378, 473/377, 473/376
• US Class Current: 473/374
• CPC Class Codes: A63B 37/0003 Golf balls
• CPC Class Codes: A63B 37/0031 Hardness
• CPC Class Codes: A63B 37/0033 Thickness
• CPC Class Codes: A63B 37/0036 Melt flow rate [MFR]
• CPC Class Codes: A63B 37/0039 characterised by the material
• CPC Class Codes: A63B 37/0043 Hardness
• CPC Class Codes: A63B 37/0045 Thickness
• CPC Class Codes: A63B 37/0046 Deflection or compression
• CPC Class Codes: A63B 37/0062 Hardness
• CPC Class Codes: A63B 37/0064 Diameter
• CPC Class Codes: A63B 37/0068 Initial velocity

Abstract

A multi-piece solid golf ball exhibits a good profile of rebound, feel and durability suited for low head speed amateur players when it satisfies the requirements that (Shore D hardness of the cover)−(Shore D hardness of the intermediate layer)>0, (initial velocity (in m/s) of the core enclosed with the intermediate layer)−(initial velocity (in m/s) of the core)>−0.2, 0.90≦(Deflection amount of the core enclosed with the intermediate layer)/(Deflection amount of the core)≦1.00, the total of the thickness of the intermediate layer and the thickness of the cover is up to 3.0 mm, and the ball has a coefficient of lift (CL) when hit of at least 0.165 at a Reynolds number of 70,000 and a spin rate of 2,000 rpm, and a coefficient of drag (CD) when hit of not more than 0.230 at a Reynolds number of 180,000 and a spin rate of 2,520 rpm.

Claims

1. A multi-piece solid golf ball comprising a core, an intermediate layer enclosing the core to form a sphere, and a cover enclosing the intermediate layer, and numerous dimples formed on a surface of the cover, wherein each component has a Shore D hardness, a Deflection amount, an initial velocity (in m/s) and a thickness (in mm), the Deflection amount being defined as an amount of deflection (in mm) under load of a spherical body incurred when the load is increased from an initial value of 98 N (10 kgf) to a final value of 1275 N (130 kgf), and the ball satisfies the following requirements (1) to (4):

(1) (Shore D hardness of the cover)−

(Shore D hardness of the intermediate layer)>

0,

(2) (initial velocity of the sphere)−

(initial velocity of the core)>

−

0.2,

(3) 0.90≦

(Deflection amount of the sphere)/(Deflection amount of the core)≦

1.00,

(4) the total of the thickness of the intermediate layer and the thickness of the cover is up to 3.0 mm,

and the ball has a coefficient of lift (CL) when hit of at least 0.165 at a Reynolds number of 70,000 and a spin rate of 2,000 rpm, and a coefficient of drag (CD) when hit of not more than 0.230 at a Reynolds number of 180,000 and a spin rate of 2,520 rpm.

2. The multi-piece solid golf ball of claim 1 wherein the total number of the dimples is at least 300 and not more than 380.

3. The multi-piece solid golf ball of claim 1 wherein the total number of the dimples is at least 320 and not more than 358.

4. The multi-piece solid golf ball of claim 1 wherein the total number of the dimples is at least 325 and not more than 340.

5. The multi-piece solid golf ball of claim 1 which further satisfies the following requirements (5) to (9):

(5) the thickness of the cover is from 0.5 mm to 2.0 mm,

(6) the Shore D hardness of the cover is from 55 to 7,

(7) the thickness of the intermediate layer is from 0.5 mm to 1.6 mm,

(8) the Shore D hardness of the intermediate layer is from 40 to 60, and

(9) the golf ball has an initial velocity of at least 76.5 m/s.

6. The multi-piece solid golf ball of claim 1 which further satisfies the following requirement (10):

(10) the cover has a melt flow rate of at least 2 g/10 min.

7. The multi-piece solid golf ball of claim 1 which further satisfies the following requirement (11):

(11) 0.85≦

(Deflection amount of the golf ball)/(Deflection amount of the sphere)≦

0.95.

8. The multi-piece solid golf ball of claim 1 wherein said intermediate layer comprises

(A) an ionomer resin comprising

(a-1) an olefin/unsaturated carboxylic acid binary random copolymer and/or a metal ion neutralized product thereof and

(a-2) an olefin/unsaturated carboxylic acid/unsaturated carboxylic acid ester ternary random copolymer and/or a metal ion neutralized product thereof in a weight ratio (a-1)/(a-2) between 100/0 and 0/100, and

(B) a non-ionomeric thermoplastic elastomer in a weight ratio A/B between 100/0 and 50/50.

9. The multi-piece solid golf ball of claim 8 wherein said intermediate layer is made of a mixture comprisingparts by weight of a resin component comprising the ionomer resin (A) and the non-ionomeric thermoplastic elastomer (B) in a weight ratio A/B between 100/0 and 50/50,

(C) 5 to 80 parts by weight of an organic fatty acid and/or a derivative thereof having a molecular weight of 280 to 1,500, and

(D) 0.1 to 10 parts by weight of a basic inorganic metal compound capable of neutralizing un-neutralized acid groups in said resin component and component (C).