# US 5,346,223 A · Thread wound golf ball

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- Number: US 5,346,223 A
- Document ID: US5346223A
- Status: Granted
- Kind: A
- Application number: 08/053,234
- Filed: 1993-04-28
- Granted: 1994-09-13
- Earliest claimed: 1992-04-28
- Assignees: Sumitomo Rubber Industries, Ltd.
- Inventors: Akihiko Hamada; Akira Kato
- Web page: https://patentgrep.com/patent/US5346223A

## CPC

- A63B 37/0003: {Golf balls}
- A63B 37/0052: {Liquid cores}
- A63B 37/0053: {Thread wound}
- A63B: APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT (apparatus for passive exercising, massage A61H)

## Abstract

The present invention provides a thread wound golf ball having excellent durability, heat resistance and impact resilience, which comprises a core, a thread rubber layer and an outer layer. A thread rubber constituting the thread rubber layer is obtained from a rubber latex blend containing a depolymerized high-cis polyisoprene rubber latex.

## Claims

### Claim 1

A thread wound golf ball comprising a core, a thread rubber layer formed on said core and a cover layer covering the thread rubber layer, the thread rubber constituting said thread rubber layer being obtained from a rubber latex blend comprising a depolymerized high-cis polyisoprene rubber latex.

### Claim 2 (depends on 1)

The thread wound golf ball according to claim 1 wherein said depolymerized high-cis polyisoprene latex has an adhesiveness of 25 to 300 g/2.5 cm.

### Claim 3 (depends on 1)

The thread wound golf ball according to claim 1 wherein said rubber latex blend comprises not less than 10% by weight of the depolymerized high-cis polyisoprene rubber latex.

### Claim 4 (depends on 1)

The thread wound golf ball according to claim 1 wherein said rubber latex blend comprises natural rubber latex, synthesized high-cis polyisoprene rubber latex, synthesized low-cis polyisoprene rubber or a mixture thereof, in addition to the depolymerized high-cis polyisoprene rubber latex.

### Claim 5 (depends on 1)

The thread wound golf ball according to claim 1 wherein said rubber latex blend further comprises vulcanizing agents, vulcanization accelerators, vulcanization auxiliaries, antioxidants, fillers and oils.

### Claim 6 (depends on 1)

The thread wound golf ball according to claim 1 wherein said thread rubber is prepared by coagulating said rubber latex blend with a coagulant to form a thin film and vulcanizing to form a vulcanized rubber sheet which is cut into pieces.

### Claim 7 (depends on 1)

The thread wound golf ball according to claim 1 wherein said core is made from rubber or liquid.

### Claim 8 (depends on 1)

The thread wound golf ball according to claim 1 wherein said cover is made from an ionomer resin or trans-polyisoprene.

### Claim 9 (depends on 1)

The thread wound golf ball according to claim 1 wherein said rubber layer has a thickness of 4 to 8 mm.