Golf balls with soft, resilient bimodal ionomeric covers
View Patent ↗Disclosed are golf balls having soft, resilient bimodal ionomeric covers with improved softness and scuff resistance and methods for their preparation. The soft, resilient bimodal ionomeric covers comprise at least partially neutralized mixtures of carboxylate functionalized terpolymers (molecular weight between about 80,000 and 500,000) with carboxylate functionalized ethylene low copolymers (molecular weight between about 2,000 and 30,000).
1. A composition comprising a bimodal composition consisting essentially of:
(a) one or more E/X/Y terpolymers, wherein E represents copolymerized residues of ethylene, X represents copolymerized residues of a C3 to C8, α,β-ethylenically unsaturated carboxylic acid, and Y represents copolymerized residues of a softening comonomer selected from the group consisting of alkyl acrylates and alkyl methacrylates wherein the alkyl groups have from 1-8 carbon atoms, wherein the level of X is about 2 to 30 wt % and the level of Y is 0 to about 35 wt %, based on the total weight of the E/X/Y copolymer, and wherein the molecular weight (Mw) of the E/X/Y copolymer is in the range of 80,000 to 500,000; and
one or more E/X bipolymers, wherein E represents copolymerized residues of ethylene, X represents copolymerized residues of a C3 to C8, α,β-ethylenically unsaturated carboxylic acid, wherein the level of X is about 2 to 30 wt %, based on the total weight of the E/X bipolymer, and wherein the molecular weight (Mw) of the E/X bipolymer is in the range of 80,000 to 500,000;
(b) one or more E/(M)AA copolymers comprising 3 to 25 wt % of copolymerized residues of (M)AA based on the total weight of the E/(M)AA copolymer, wherein the molecular weight (Mw) of the E/(M)AA copolymer is in the range of 2,000 and 30,000; and
wherein the acid residues of (a) and of (b) are at least partially neutralized.
2. The composition of claim 1 , wherein the polydispersity (Mw/Mn) of each of the E/X/Y terpolymers and each of the E/X bipolymers ranges from about 1 to about 15.
3. The composition of claim 2 , wherein the polydispersity (Mw/Mn) of each of the E/X/Y terpolymers and each of the E/X bipolymers ranges from 5.1 to 11.5.
4. The composition of claim 1 , wherein the one or more E/(M)AA copolymers are present at a level of about 5 to about 50 wt %, based on the total weight of (a) and (b).
5. The composition of claim 1 wherein X represents copolymerized units of acrylic acid or methacrylic acid; and wherein Y represents copolymerized units of an alkyl acrylate.
6. The composition of claim 5 wherein the level of X in the E/X/Y terpolymer is 5 to 25 wt %.
7. The composition of claim 5 , wherein the level of X in the E/X/Y terpolymer is 8 to 20 wt %.
8. The composition of claim 5 wherein the level of Y in the E/X/Y terpolymer is 3 to 25 wt %.
9. The composition of claim 5 wherein the level of Y in the E/X/Y terpolymer is 10 to 25 wt %.
10. The composition of claim 5 wherein Y represents copolymerized residues of n-butyl acrylate.
11. The composition of claim 5 wherein X represents copolymerized residues of acrylic acid.
12. The composition of claim 5 wherein X represents copolymerized residues of methacrylic acid.
13. The composition of claim 1 wherein the level of X in the E/X bipolymer is 5 to 25 wt %.
14. The composition of claim 1 wherein the level of X in the E/X bipolymer is 4 to 15 wt %.
15. The composition of claim 1 wherein the level of X in the E/X bipolymer is 4 to 11 wt %.
16. The composition of claim 13 wherein X represents copolymerized residues of methacrylic acid.
17. The composition of claim 1 , wherein about 40 to about 100% of the acid residues of (a) and of (b) are neutralized.
18. The composition of claim 1 , wherein the acid residues of (a) and of (b) are at least partially neutralized to include zinc cations.
19. The composition of claim 1 , further comprising one or more optical brighteners, surfactants or processing aids.
20. The composition of claim 1 , further comprising up to 100 parts by weight of one or more organic acid salts, up to 200 parts by weight of one or more thermoplastic elastomers, or up to 170 parts by weight of one or more fillers, based on 100 parts by weight of the bimodal composition.
21. A golf ball comprising the composition of claim 1 .
22. The golf ball of claim 16 wherein the composition is used in the cover of the ball.
23. An injection molded article, a film, a protective coating, flooring or an article of footwear comprising the composition of claim 1 .