POLYAMIDE COMPOSITIONS CONTAINING PLASTICIZERS FOR USE IN MAKING GOLF BALLS
Multi-layered golf balls having at least one layer made of a polyamide composition containing a polyamide polymer and plasticizer are provided. The plasticizers help reduce the glass transition temperature (Tg) of the composition and various plasticizers may be used. For example, the composition may include ethyl oleate or propylene carbonate as a plasticizer. Transparent polyamides, for example, polyether-amide block copolymers, preferably are used in the composition. The golf ball includes a core having at least one layer and a cover having at least one layer. The polyamide composition may be used to form any core, cover, or other layer in the golf ball. In one version, the polyamide composition is used to form the inner cover layer.
1 . A golf ball, comprising:
a) dual core comprising an inner core and outer core layer, the inner core having an outer surface and geometric center and the outer core layer having an outer surface and inner surface; the inner core comprising a rubber composition and the outer core layer comprising a polyamide composition, the polyamide composition comprising:
i) about 40 to about 99% by weight polyamide; and
ii) about 1 to about 60% by weight of a plasticizer,
wherein the center of the inner core and surface of the outer core layer each has a hardness, and the surface hardness of the outer core layer is greater than the center hardness of the inner core; and
b) a cover having at least one layer disposed about the core.
2 . The golf ball of claim 1 , wherein the polyamide is selected from the group consisting of polyether-amide block polymers, polyamide 6; polyamide 6,6; polyamide 6,10; polyamide 6,12; polyamide 11; polyamide 12; polyamide 6,9; and polyamide 4,6, and copolymers and blends thereof.
3 . The golf ball of claim 1 , wherein the polyamide is a transparent polyamide.
4 . The golf ball of claim 3 , wherein the transparent polyamide is a transparent polyether-amide block copolymer.
5 . The golf ball of claim 3 , wherein the transparent polyamide has a glass transition temperature in the range of about 75° to about 160° C.
6 . The golf ball of claim 3 , wherein the transparent polyamide has a Charpy notched impact-resistance of at least about 15 kJ/m 2 at 23° C.
7 . The golf ball of claim 3 , wherein the transparent polyamide has a ratio of Charpy notched impact-resistance measured at 23° C. to Charpy notched impact-resistance measured at −30° C. of at least about 2.0 to 1.0.
8 . The golf ball of claim 3 , wherein the transparent polyamide has a transparency of at least about 85%.
9 . The golf ball of claim 1 , wherein the polyamide composition comprises a blend of transparent polyamides and non-transparent polyamides.
10 . The golf ball of claim 1 , wherein the plasticizer is selected from the group consisting of N-butylbenzenesulfonamide (BBSA); N-ethylbenzenesulfonamide (EBSA); N-propylbenzenesulfonamide (PBSA); N-butyl-N-dodecylbenzenesulfonamide (BDBSA); N,N-dimethylbenzenesulfonamide (DMBSA); p-methylbenzenesulfonamide; o,p-toluene sulfonamide; p-toluene sulfonamide; 2-ethylhexyl-4-hydroxybenzoate; hexadecyl-4-hydroxybenzoate; 1-butyl-4-hydroxybenzoate; dioctyl phthalate; diisodecyl phthalate; di-(2-ethylhexyl)adipate; and tri-(2-ethylhexyl)phosphate, propylene carbonate, an alkyl or aryl fatty acid ester.
11 . The golf ball of claim 1 , wherein the plasticizer is ethyl oleate or propylene carbonate.
12 . The golf ball of claim 1 , wherein the polyamide composition further comprises an acid anhydride-modified polyolefin.
13 . The golf ball of claim 1 , wherein the acid anhydride-modified polyolefin is an ethylene-based copolymer and the acid anhydride used to modify the ethylene-based copolymer is selected from the group consisting of maleic, fumaric, nadic, itaconic, and clorendic acid anhydrides, and substituted derivatives thereof.
14 . A molded sphere comprising a polyamide composition of about 40 to about 99% by weight polyamide polymer and about 1 to about 60% by weight plasticizer, wherein the sphere has a Coefficient of Restitution of at least about 0.600; a DCM Compression of no greater than about 80; and Shore D surface hardness of no greater than about 60.
15 . The molded sphere of claim 14 , wherein the sphere has a Coefficient of Restitution of at least about 0.640; a DCM Compression in the range of about 10 to about 60; and Shore D surface hardness in the range of about 25 to about 75.
16 . A molded sphere comprising a polyamide composition of about 40 to about 99% by weight polyamide polymer and about 1 to about 60% by weight plasticizer, wherein the sphere has a Coefficient of Restitution of at least about 0.750; a DCM Compression of no greater than about 100; and Shore D surface hardness of no greater than about 80.
17 . The golf ball of claim 1 , wherein the center hardness of the inner core is about 15 Shore D or greater and the surface hardness of the outer core is about 40 Shore D or greater, the surface hardness of the outer core layer being greater than the center hardness of the inner core.
18 . The golf ball of claim 1 , wherein the cover is a single layer having a thickness of about 0.015 to about 0.090 inches and is formed from a thermoplastic or thermoset material.
19 . The golf ball of claim 1 , wherein the cover comprises two or more layers and has an overall thickness of about 0.020 to about 0.160 inches and wherein each cover layer is formed from a thermoplastic or thermoset material.
20 . A golf ball, comprising:
a) dual core comprising an inner core and outer core layer, the inner core having an outer surface and geometric center and the outer core layer having an outer surface and inner surface; the inner core comprising a polyamide composition and the outer core layer comprising a rubber composition, the polyamide composition comprising:
i) about 40 to about 99% by weight polyamide; and
ii) about 1 to about 60% by weight of a plasticizer,
wherein the center of the inner core and surface of the outer core layer each has a hardness, and the surface hardness of the outer core layer is greater than the center hardness of the inner core; and
b) a cover having at least one layer disposed about the core.
21 . The golf ball of claim 20 , wherein the polyamide is selected from the group consisting of polyether-amide block polymers, polyamide 6; polyamide 6,6; polyamide 6,10; polyamide 6,12; polyamide 11; polyamide 12; polyamide 6,9; and polyamide 4,6, and copolymers and blends thereof.
22 . The golf ball of claim 20 , wherein the polyamide is a transparent polyamide.
23 . The golf ball of claim 20 , wherein the plasticizer is selected from the group consisting of N-butylbenzenesulfonamide (BBSA); N-ethylbenzenesulfonamide (EBSA); N-propylbenzenesulfonamide (PBSA); N-butyl-N-dodecylbenzenesulfonamide (BDBSA); N,N-dimethylbenzenesulfonamide (DMBSA); p-methylbenzenesulfonamide; o,p-toluene sulfonamide; p-toluene sulfonamide; 2-ethylhexyl-4-hydroxybenzoate; hexadecyl-4-hydroxybenzoate; 1-butyl-4-hydroxybenzoate; dioctyl phthalate; diisodecyl phthalate; di-(2-ethylhexyl)adipate; and tri-(2-ethylhexyl)phosphate, propylene carbonate, an alkyl or aryl fatty acid ester.
24 . The golf ball of claim 1 , wherein the plasticizer is propylene carbonate.