Golf ball and method of manufacture

Patent metadata

Field	Value
Publication number	US-11577128-B2
Application number	US-202017124567-A
Country	US
Kind code	B2
Filing date	Dec 17, 2020
Priority date	Dec 20, 2019
Publication date	Feb 14, 2023
Grant date	Feb 14, 2023

Abstract

In a golf ball having a core composed of one or more layer, the outermost layer of the core is formed of a rubber composition containing an α,β-unsaturated metal carboxylate, and an envelope layer directly encasing the core is formed of a resin composition containing a thermoplastic resin having a structure that includes α,β-ethylenically unsaturated carboxylic acid copolymerization units. The infrared absorption spectra at surface sites on the outermost layer of the core, as measured by ATR FT-IR spectroscopy, satisfy a specific condition. The ball has an enhanced adhesion between the rubber-based core and the adjacent cover layer that is formed of an ionomer resin or other α,β-ethylenically unsaturated carboxylic acid copolymer-containing resin material.

First claim

The invention claimed is:

1. A method for producing a golf ball having a core composed of one or more layer, which method comprises the steps of:
forming an outermost layer of the core with a rubber composition containing a base rubber and an α,β-unsaturated metal carboxylate;
surface-treating the core outermost layer by bringing an acid-containing solution into contact with a surface of the outermost layer; and
forming an envelope layer by molding, over the surface-treated outermost layer of the core, a resin composition containing a thermoplastic resin having a structure that includes α,β-ethylenically unsaturated carboxylic acid copolymerization units;
wherein the acid-containing solution consists of aqueous hydrochloric acid solution.

2. The method of claim 1 , wherein the acid-containing solution, when brought into contact with the surface of the core outermost layer, has an acid concentration of at least 0.05 mol/L.

3. The method of claim 1 , wherein the surface of the acid-containing solution is brought into contact with the core outermost layer by dipping the core in the acid-containing solution.

4. The method of claim 1 , wherein when the infrared absorption spectra at surface sites on the surface-treated outermost layer of the core are measured by attenuated total reflectance Fourier transform infrared (ATR FT-IR) spectroscopy, letting A be the absorbance peak height near a wave number of 1700±40 cm −1 (height of absorbance peak attributed to carboxylic acid) and B be the absorbance peak height near a wave number of 1550±40 cm −1 (height of absorbance peak attributed to metal carboxylate), the value expressed as A/(A+B) at some or all of the surface sites is at least 0.4.

5. A method for producing a golf ball having a core composed of one or more layer, which method comprises the steps of:
forming an outermost layer of the core with a rubber composition containing a base rubber and an α,β-unsaturated metal carboxylate;
surface-treating the core outermost layer by bringing an acid-containing solution into contact with a surface of the outermost layer; and
forming an envelope layer by molding, over the surface-treated outermost layer of the core, a resin composition containing a thermoplastic resin having a structure that includes α,β-ethylenically unsaturated carboxylic acid copolymerization units;
wherein the acid-containing solution consists of an alcohol.

6. The method of claim 5 , wherein the acid-containing solution, when brought into contact with the surface of the core outermost layer, has an acid concentration of at least 0.05 mol/L.

7. The method of claim 5 , wherein the surface of the acid-containing solution is brought into contact with the core outermost layer by dipping the core in the acid-containing solution.

8. The method of claim 5 , wherein when the infrared absorption spectra at surface sites on the surface-treated outermost layer of the core are measured by attenuated total reflectance Fourier transform infrared (ATR FT-IR) spectroscopy, letting A be the absorbance peak height near a wave number of 1700±40 cm −1 (height of absorbance peak attributed to carboxylic acid) and B be the absorbance peak height near a wave number of 1550±40 cm −1 (height of absorbance peak attributed to metal carboxylate), the value expressed as A/(A+B) at some or all of the surface sites is at least 0.4.

9. A method for producing a golf ball having a core composed of one or more layer, which method comprises the steps of:
forming an outermost layer of the core with a rubber composition containing a base rubber and an α,β-unsaturated metal carboxylate;
surface-treating the core outermost layer by bringing an acid-containing solution into contact with a surface of the outermost layer; and
forming an envelope layer by molding, over the surface-treated outermost layer of the core, a resin composition containing a thermoplastic resin having a structure that includes α,β-ethylenically unsaturated carboxylic acid copolymerization units,
wherein the acid-containing solution consists of a hydrochloric acid and an alcohol.

10. The method of claim 9 , wherein the acid-containing solution, when brought into contact with the surface of the core outermost layer, has an acid concentration of at least 0.05 mol/L.

11. The method of claim 9 , wherein the surface of the acid-containing solution is brought into contact with the core outermost layer by dipping the core in the acid-containing solution.

12. The method of claim 9 , wherein the acid-containing solution consists of a hydrochloric acid and 2-propanol.

13. The method of claim 9 , wherein when the infrared absorption spectra at surface sites on the surface-treated outermost layer of the core are measured by attenuated total reflectance Fourier transform infrared (ATR FT-IR) spectroscopy, letting A be the absorbance peak height near a wave number of 1700±40 cm-1 (height of absorbance peak attributed to carboxylic acid) and B be the absorbance peak height near a wave number of 1550±40 cm-1 (height of absorbance peak attributed to metal carboxylate), the value expressed as A/(A+B) at some or all of the surface sites is at least 0.4.

Assignees

• Bridgestone Sports Co Ltd

Inventors

• Shindo Jun

Classifications

• A63B45/00

  Apparatus or methods for manufacturing balls (working of plastics or substances in a plastic state B29) · CPC title

• A63B37/0039

  characterised by the material · CPC title

• A63B37/0063

  Hardness gradient · CPC title

• A63B37/0076

  Multi-piece balls, i.e. having two or more intermediate layers · CPC title

• A63B37/0075 Primary

  Three piece balls, i.e. cover, intermediate layer and core · CPC title