Ionomers having improved low temperature properties

Claim 2

Ionic copolymer of ethylene, unsaturated carboxylic acid and at least one softening comonomer that is characterized by being copolymerizable with ethylene and forming a homopolymer that has low glass transition temperature, said ionic copolymer having improved low temperature properties, wherein the unsaturated carboxylic acid is selected from the group consisting of acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, and half esters of maleic, fumaric and itaconic i acids, said copolymer containing from about 10 to about 87% by weight of ethylene, from about 3 to about 30% by weight of unsaturated acid and from about 10 to about 60% by weight of said softening comonomer, said copolymer having from about 3 to about 90% of the carboxylic acid groups ionized by neutralization with metal ion'selected from groups Ia, Ib, IIa, IIb, IIIa, IVa, VIb and VIII of the Periodic Table of Elements, said copolymer being characterized by a low level of chain branching of up to about 2.8 chain branches/1000 backbone methylene units.

Claim 3

The ionic copolymer of Claim 1 wherein said softening comonomer is selected from the group consisting of alkyl esters of acrylic acid, alkyl vinyl ethers, vinyl esters and vinyl siloxanes.

Claim 4

The ionomer of Claim 1 or 2 wherein said metal ion is selected from the group consisting of sodium, potassium, zinc, calcium, magnesium, lithium, aluminum, nickel, and chromium. 1 , 2 , or

Claim 5

The ionomer of Claim/3 wherein said softening comonomer is selected from the group consisting of alkyl esters of acrylic acid and alkyl vinyl ethers wherein the alkyl group of said acrylic acid ester is selected from the group consisting of n -propyl, n-butyl, n-octyl, 2-ethylhexyl and 2-methoxyethyl and the alkyl group of said ether is selected from the group consisting of n-butyl, n-hexyl, 2-ethylhexyl and 2-methoxyethyl.

Claim 6

The ionomer of any one of claims 1 to 4 wherein the ionomer is direct copolymer, said unsaturated acid is selected from the group consisting of acrylic acid and methacrylic acid, said softening comonomer is selected from the group consisting of alkyl esters of acrylic acid and alkyl vinyl ethers and said alkyl ester is selected from the group consisting of n-butyl acrylate, 2-ethylhexyl acrylate and 2-methoxyethyl acrylate, and said alkyl vinyl ether is selected from the group consisting of n-butyl vinyl ether and n-hexyl vinyl ether.

Claim 7

The ionomer of Claim 5 wherein said ethylene is present in an amount of from about 60 to about 75% by weight, said unsaturated acid is present in an amount of from about 5 to about 15% by weight, said alkyl ester is present in an amount of from about 15 to about 25% by weight and said alkyl vinyl ether is present in an amount of from about 10 to about 30% by weight.

Claim 8

The ionomer of any one of Claims 1 to 6 wherein said copolymer has from about 35 to about 75% of the carboxylic acid groups ionized by neutralization with metal ion selected from the group consisting of sodium, potassium, zinc, calcium and magnesium.

Claim 9

anyone of to 4 8. The ionomer of any one of Claims 1 to 4 wherein the ionomer is a graft copolymer.

Claim 10

An improved process of preparing ionic copolymers having improved low temperature properties, said process being selected from the group consisting of direct copolymerization and graft copolymerization wherein (A) said direct copolymerization comprises polymerizing ethylene, unsaturated carboxylic acid and at least one comonomer in the presence of free radical polymerization initiator at elevated temperatures followed by neutralization of the carboxylic acid groups of the resultant direct copolymer with metal ions, and (B) said graft copolymerization comprises polymerizing ethylene and at least one comonomer in the presence of free radical polymerization initiator at elevated temperatures and grafting unsaturated carboxylic acid or anhydride onto the ethylene/comonomer polymer backbone followed by neutralization of the carboxylic acid groups of the resultant graft copolymer with metal ions, the improvement comprising selecting said comonomer from the group consisting of softening comonomers that are characterized by being copolymerizable with ethylene and forming a homopolymer that has low glass transition temperature, and selecting the unsaturated acid from the group consisting of acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid and half esters of maleic, fumaric and itaconic acid, said copolymer containing from about 10 to about 87% by weight of ethylene, from about 3 to about 30% by weight of acid, and from about 10 to about 60% by weight of softening comonomer, the polymerization temperature being from about 100 to about 200°C, from about 3 to about 90% of the carboxylic acid groups of the copolymer being neutralized with metal ions selected from groups Ia, Ib, IIa, IIb, IIIa, IVa, VI b and VIII of the Periodic Table.

Claim 11

An improved process of preparing ionic copolymers having improved low temperature properties, said process being selected from the group consisting of direct copolymerization and graft copolymerization wherein (A) said direct copolymerization comprises polymerizing ethylene, unsaturated carboxylic acid and at least one comonomer in the presence of free radical polymerization initiator at elevated temperatures followed by neutralization of the carboxylic acid groups of the resultant direct copolymer with metal ions, and (B) said graft copolymerization comprises polymerizing ethylene and at least one comonomer in the presence of free radical polymerization initiator at elevated temperatures and grafting unsaturated carboxylic acid or anhydride onto the ethylene/comonomer polymer backbone followed by neutralization of the carboxylic acid groups of the resultant graft copolymer with metal ions, the improvement comprising selecting said comonomer from the group consisting of softening comonomers that are characterized by being copolymerizable with ethylene and forming a homopolymer that has low glass transition temperature, and selecting the unsaturated acid from the group consisting of acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid and half esters of maleic, fumaric and itaconic acid, said copolymer containing from about 10 to about 87% by weight of ethylene, from about 3 to about 30% by weight of acid, and from about 10 to about 60% by weight of softening comonomer, the polymerization temperature being from about 100 to about 200°C, from about 3 to about 90% of the carboxylic acid groups of the copolymer being neutralized with metal ions selected from groups Ia, Ib, IIa, IIb, IIIa, IVa, VI b and VIII of the Periodic Table.

Claim 12

The process of Claim 9 wherein said softening comonomer is selected from the group consisting of alkyl esters of acrylic acid, alkyl vinyl ethers, vinyl esters and vinyl siloxanes.

Claim 13

The process of Claim 9 or 10 wherein said metal ion is selected from the group consisting of sodium, potassium, zinc, calcium, magnesium, lithium, aluminum, nickel, and chromium.

Claim 14

The process of Claim 9, 10 or 11 wherein said softening comonomer is selected from the group consisting of alkyl esters of acrylic acid and alkyl vinyl ethers wherein the alkyl group of said acrylic acid ester is selected from the group consisting of n-propyl, n-butyl, n-octyl, 2-ethylhexyl and 2-methoxyethyl and the alkyl group of said ether is selected from the group consisting of n-butyl, n-hexyl, 2- ethylhexyl and 2 -methoxyethyl.

Claim 15

The improved processa of any one of claims 9 to 12 wherein the process is direct copolymerization, said unsaturated acid is selected from the group consisting of acrylic acid and methacrylic acid, said softening comonomer is selected from the group consisting of alkyl esters of acrylic acid and alkyl vinyl ethers and said alkyl ester is selected from the group consisting of n-butyl acrylate, 2-ethylhexyl acrylate and 2-methoxyethyl acrylate, and said alkyl vinyl ether is selected from the group consisting of n-butyl vinyl ether and n-hexyl vinyl ether. anyone of 9 to

Claim 16

The improved process of any one of Claims 9 to 13 wherein the polymerization temperature is from about 140 to about 160°C and the polymerization pressure is from about 140 mPa (20,000 psi) to about 350 mPa (50,000 psi). any one of 9 to

Claim 17

The improved process of any one of Claims 9 to 13 wherein the polymerization temperature is from about 130 to about 145°C and the polymerization pressure is from about 140 mPa (20,000 psi) to about 350 mPa (50,000 psi). any one of

Claim 18

The improved process of/Claims 9 to 15 wherein said ethylene is present in an amount of from about 65 to about 80% by weight, said unsaturated acid is present in an amount of from about 5 to about 15% by weight, said alkyl ester is present in an amount of from about 10 to about 25% by weight and said alkyl vinyl ether is present in an amount of from about 10 to about 30 % by weight. any one of

Claim 19

The improved process of/Claims 9 to 16 wherein said copolymer has from about 35 to about 75% of the carboxylic acid groups ionized by neutralization with metal ion selected from the group consisting of sodium, potassium, zinc, calcium and - magnesium. any one of to 12

Claim 20

The improved process of/Claims9/wherein the process is graft copolymerization.

Claim 21

A thermoplastic blend of the improved anyone of to 8 ionomer of any one Claims 1to 8 with material selected from the group consisting of nylon, polypropylene, propylene-ethylene copolymer, linear polyethylene, and ethylene/unsaturated carboxylic acid copolymer.

Claim 22

20 . A golf ball comprising a core and a cover, wherein said cover comprises the ionic copolymer of any one of Claims 1 to 8.