High speed extrusion coating with ethylene copolymers
AssigneeExxon Research & Engineering Co.
InventorDirk J. M. Michiels
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Abstract
Extrusion coating with high line speeds of up to 600 mpm may be achieved without sacrificing the adhesion of the coating to the substrate by using an ethylene copolymer with up to 3% by weight copolymer, preferably 0.5 to 2.5% by weight VA, as the coating polymer. The extrusion temperature is in the region of incipient degradation, but maintained below the level which gives undesired degradation leading to odor or discoloration.
Claims9
A method of extrusion coating a substrate with a layer of a low density ethylene copolymer comprising extruding a layer consisting essentially of low density ethylene copolymer containing less than 3% by weight of a comonomer selected from vinyl esters, acrylic acids, or methacrylic acids, acrylates or methacrylates and unsaturated alcohols from an extruder onto the substrate at a temperature in the range of T.sub.D .+-.15.degree. C. where T.sub.D is the degradation temperature in .degree.C. of the copolymer, defined as the minimum temperature at which chemical breakdown occurs with the extruder operating at minimum output.
A method of forming a composite comprising coextruding onto a paper substrate a layer of a low density ethylene copolymer from an extruder onto the substrate at a temperature in the range of T.sub.D .+-.15.degree. C. where T.sub.D is the degradation temperature in .degree.C. of the copolymer, defined as the minimum temperature at which chemical breakdown occurs with the extruder operating at minimum output, said ethylene copolymer containing less than 3% by weight of a comonomer selected from vinyl esters, acrylic acids or methacrylic acids, acrylates or methylacrylates and unsaturated alcohols.
Dependencies are inferred from the claim text.