Stearic-modified ionomers for golf balls
AssigneeE. I. Du Pont de Nemours and Company
InventorJohn Chu Chen
Life of this patent
Estimating the term…
Abstract
Ethylene/(meth)acrylic acid ionomers which have been modified with relatively low levels of a stearic acid moiety, particularly metal stearates and especially calcium stearate have improved resilience for a given level of hardness or PGA Compression values. The improvement is seen in bulk material when measurements are made on solid neat spheres. When used as cover material, the improvement is more manifest for softer material, and is less, or disappears, for typical mixed metal ionomer hard covers. The stearic-modified ionomers or ionomer blends are especially useful when the ionomer is formulated for use as a golf ball core, center, one-piece ball and as a soft golf ball cover. For covers, softer ionomer compositions will show an improvement.
Claims6
A golf ball having a core and a cover, or a wound center and a cover, the core or center comprising;
- (i) an ionomeric polymer containing
- a) ethylene,
- b) from 5 to 25 weight percent (meth)acrylic acid,
- c) from 0 to 40 weight percent of a 1 to 8C-alkyl, alkyl acrylate, the acid groups neutralized to between 10 and 90 percent with zinc, sodium, lithium, calcium, magnesium ions and a mixture of any of these, and
- (ii) from 5 to 45 weight percent, based on (i) plus (ii), of a metal stearate, the metal selected from the group consisting of calcium, sodium, zinc, lithium, magnesium and barium or a mixture of said metal stearates.
A one-piece golf ball comprising,
- (i) an ionomeric polymer derived from an acid copolymer containing
- a) ethylene,
- b) from 5 to 25 weight percent (meth)acrylic acid,
- c) from 0 to 40 weight percent of a 1 to 8C-alkyl acrylate, the ionomeric polymer formed by partial neutralization of the acid copolymer with metal ions selected from the group consisting of lithium, calcium, sodium, zinc and magnesium and a mixture of any of these, the neutralization level being from 10 to 90 percent, and
- (ii) from 5 to 45 weight percent, based on (i) plus (ii), of a metal stearate, the metal selected from the group consisting of calcium, sodium, zinc, lithium, barium and magnesium or a mixture of said metal stearates.
Dependencies are inferred from the claim text.