Product and process for reducing block and increasing slip of linear low density ethylene copolymer films
AssigneeThe Dow Chemical Company
InventorsOsborne K. McKinney, David P. Flores
Life of this patent
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Abstract
Extrusion-cast films of high molecular weight, linear low density ethylene copolymers which inherently have high block and low slip characteristics are compounded with a minor amount of a secondary fatty acid amide and a finely-divided natural inorganic, e.g., silica, before being extrusion-cast as a thin film, the additives serving to substantially reduce the block and increase the slip characteristics of the film.
Claims14
A process for reducing block, and increasing slip, of extrusion-cast films of linear low density ethylene copolymers which inherently exhibit high block and low slip, said process comprising
- incorporating into the said copolymer, prior to extrusion-casting into films, an effective amount in the range of about 0.05 to about 1.5 weight percent of at least one secondary fatty acid amide and about 0.02 to about 2 weight percent of finely-divided natural mineral, and
- extrusion-casting the mixture into a thin film,
- wherein the linear low density ethylene copolymer comprises ethylene copolymerized with a sufficient amount of at least one alpha, beta-ethylenically unsaturated alkene having from 3 to 12 carbons, to provide a copolymer having a density in the range of about 0.90 to about 0.94 gms. cc,
- said copolymers having a melt index in the range of about 0.1 gm./10 min. as measured by ASTM-D-1238(E) to about 20 gms./10 min. as measured by ASTM-D-1238(D).
A process for reducing block, and increasing slip, of extrusion-cast films of linear low density ethylene copolymers which inherently exhibit high block and low slip, said process comprising
- incorporating into the said copolymer, prior to extrusion-casting into films, an effective amount, in the range of about 0.05 to about 1.5 weight percent, of at least one secondary fatty acid amide and about 0.02 to about 2 weight percent of finely-divided natural mineral, and
- extrusion-casting the mixture into a thin film,
- wherein said copolymer comprises ethylene copolymerized with a sufficient amount of at least one alpha, beta-ethylenically unsaturated alkene, having from 4 to 8 carbon atoms, to provide a copolymer having a density in the range of about 0.90 to about 0.94 gms/cc,
- wherein said secondary fatty acid amide comprises at least one conforming essentially to the empirical formula R--CO--NH--R', where R and R' represent, independently, moieties selected from the group of fatty acids comprising erucyl, linoleyl, linolenyl, arachidonyl, palmitoleyl, elaidyl, vaccenyl, behenyl, arachidyl, stearyl, palmityl, lignoceryl, and oleyl, and
- wherein said finely-divided natural mineral comprises at least one of the group comprising silica, diatomaceous earth, talc, limestone, and clay.
Dependencies are inferred from the claim text.