Eva blend compositions suitable for RF welding applications
View Patent ↗Disclosed are films obtained from blends of ethylene copolymers with organic acid salt-modified potassium ionomeric copolymers. The films of the present invention can be welded using RF energy.
1. A film having a thickness of at least about 0.001 mil to about 25 mil that absorbs radio frequency energy consisting essentially of
A. a first component comprising a mixture of
1. at least one polymer selected from the group consisting of E/X/Y copolymers, ionomers of E/X/Y copolymers and mixtures thereof, where E is ethylene, X is a C 3 to C 8 α,β-ethylenically unsaturated carboxylic acid and Y is a comonomer selected from the group consisting of alkyl acrylates and alkyl methacrylates having alkyl groups of from one to eight carbon atoms, wherein said E/X/Y copolymers comprise from about 2-30 weight %, based on the weight of the E/X/Y copolymer, of copolymerized units of X and from about 0-40 weight %, based on the weight of the E/X/Y copolymer, of copolymerized units of Y, and
2. a material selected from the group consisting of organic carboxylic acids having from about 6 to about 38 carbon atoms, salts of said organic carboxylic acids and mixtures thereof;
wherein the combined carboxylic acid groups present in said polymer and said material of said first component are neutralized to a level of at least 70% by potassium ions; and
B. a second component in an amount of from 50-95 wt. %, based on the total weight of said first and second components, wherein i) said second component is different from said at least one polymer of said first component and ii) said second component is selected from the group consisting of ethylene vinyl acetate copolymers, ethylene copolymers having copolymerized epoxy-functionalized monomer units, ethylene carbon monoxide copolymers, ethylene vinyl alcohol copolymers and mixtures thereof.
2. The film of claim 1 wherein the second component is present in an amount of from about 70 to about 93 wt %, based on the total weight of the first and second components.
3. An article selected from the group consisting of film wraps, containers and lids, wherein said article comprises a film having a thickness of at least about 0.001 mil to about 25 mil comprising
A. a first component consisting essentially of a mixture of
1. at least one polymer selected from the group consisting of E/X/Y copolymers, ionomers of E/X/Y copolymers and mixtures thereof, where E is ethylene, X is a C 3 to C 8 α,β-ethylenically unsaturated carboxylic acid and Y is a comonomer selected from the group consisting of alkyl acrylates and alkyl methacrylates having alkyl groups of from one to eight carbon atoms, wherein said copolymers comprise from about 2-30 weight %, based on the weight of the E/X/Y copolymer, of copolymerized units of X and from about 0-40 weight %, based on the weight of the E/X/Y copolymer, of copolymerized units of Y, and
2. a material selected from the group consisting of organic carboxylic acids having from about 6 to about 38 carbon atoms, salts of said carboxylic acids and mixtures thereof;
wherein the combined carboxylic acid groups present in said polymer and said material of said first component are neutralized to a level of at least 70% by potassium ions; and
B. a second component in an amount of from 50-95 wt. %, based on the total weight of said first and second components, wherein i) said second component is different from said at least one polymer of said first component and ii) said second component is selected from the group consisting of ethylene vinyl acetate copolymers, ethylene copolymers having copolymerized epoxy-functionalized monomer units, ethylene carbon monoxide copolymers, ethylene vinyl alcohol copolymers and mixtures thereof.
4. The film of claim 1 wherein the first component comprises a mixture of a first ionomer of an E/X/Y copolymer and at least one additional ionomer of an E/X/Y copolymer that is different from said first ionomer.
5. The film of claim 1 wherein the second component is an ethylene vinyl acetate copolymer.
6. The film of claim 1 wherein the second component is an ethylene copolymer having copolymerized epoxy-functionalized monomer units.
7. The film of claim 1 wherein the second component is an ethylene carbon monoxide copolymer.
8. The film of claim 1 wherein the second component is an ethylene vinyl alcohol copolymer.
9. The film of claim 1 wherein the combined carboxylic acid groups present in said polymer and said material of said first component are neutralized solely by potassium ions.
10. A film wrap of claim 3 .
11. A film of claim 1 having a thickness of about 6 mil to about 12 mil.