Thermally self-cross-linkable ethylene/vinyl acetate copolymers

Claim 2

A thermally self-cross-linkable ethylene/vinyl acetate copolymer consisting essentially of the following monomer units: a. from 5 to 50% by weight of ethylene, b. from 30 to 87% by weight of vinyl acetate, c. from 2 to 10% by weight of mono-olefinically unsaturated compound capable of copolymerizing and containing an N-methylol group selected from the group consisting of N-methylol acrylamide, N-methylol methacrylamide, lower alkanol ethers thereof, and mixtures thereof, d. from 5 to 20% by weight of an acryl compound selected from the group consisting of alkyl acrylate and alkyl methacrylate where alkyl has from 1 to 10 carbon atoms, e. from 0.5 to 3% by weight of an unsaturated acid selected from the group consisting of alkenoic acids having from 3 to 6 carbon atoms and alkenedioic acids having from 4 to 6 carbon atoms, and f. from 0 to 1% by weight of a poly-olefinically-unsaturated monomer copolymerizable with vinyl acetate and ethylene, said copolymer having a glass transition temperature of between -40° and +10° C.

Claim 3

The ethylene/vinyl acetate copolymer of claim 1 wherein said component (f) is from 0.001 to 1% by weight.

Claim 4

The ethylene/vinyl acetate copolymer of claim 2 wherein said component (d) is from 8 to 15% by weight.

Claim 5

The ethylene/vinyl acetate copolymer of claim 1 wherein said component (f) is from 0.01 to 1% by weight of allyl acrylate.

Claim 6

The ethylene/vinyl acetate copolymer of claim 1 wherein said component (f) is from 0.01 to 1% by weight of allyl methacrylate.

Claim 7

A process for the production of the thermally self-cross-linkable ethylene/vinyl acetate copolymer of claim 1 consisting essentially of the steps of copolymerizing a monomer mixture of a. ethylene in an amount sufficient to give from 5 to 50% by weight of monomer units in the final copolymer, b. from 30 to 87% by weight of vinyl acetate, c. from 2 to 10% by weight of a mono-olefinically unsaturated compound capable of copolymerizing and containing an N-methylol group selected from the group consisting of N-methylol acrylamide, N-methylol methacrylamide, lower alkanol ethers thereof, and mixtures thereof, d. from 5 to 20% by weight of an acryl compound selected from the group consisting of alkyl acrylate and alkyl methacrylate where alkyl has from 1 to 10 carbon atoms, e. from 0.5 to 3% by weight of an unsaturated acid selected from the group consisting of alkenoic acids having from 3 to 6 carbon atoms and alkenedioic acids having from 4 to 6 carbon atoms, and f. from 0 to 1% by weight or a poly-olefinically-unsaturated monomer copolymerizable with vinyl acetate and ethylene, in an aqueous system in the presence of emulsifiers and free-radical-forming polymerization catalysts under an ethylene pressure of from 10 to 100 atmospheres guage at a temperature and for a time sufficient to effect copolymerization, and recovering said thermally self-cross-linkable ethylene/vinyl acetate copolymer having a glass transition temperature of between -40° C and +10° C.

Claim 8

The process of claim 6 wherein said ethylene pressure is from 20 to 80 atmospheres gauge.

Claim 9

The process of claim 6 wherein said component (f) is from 0.001 to 1% by weight.

Claim 10

The process of claim 6 wherein said copolymerizing step is conducted at such a rate that only from 4 to 10% by weight of said components (b) and (d) are present as monomers.

Claim 11

A process for producing ethylene/vinyl acetate copolymer films, coatings or bindings consisting essentially of the steps of forming a film, coating or binding of the thermally self-cross-linkable ethylene/vinyl acetate copolymer of claim 1 and heating said film from 110° to 170° C for a period sufficient to effect cross-linking.