Rotomolding composition
AssigneeNOVA Chemicals (International) S.A.
InventorsCarmine D'Agostino, Gilbert Arnould
Life of this patent
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Abstract
A polyethylene composition suitable for rotomolding and comprising a blend of a stabilized polyethylene, and optionally substantially non-stabilized polyethylene, with a recycled polymer (PCR), is described. By using a PCR with a higher density and lower melt flow as compared to the stabilized polyethylene, a higher portion of the recycled polymer is present on the interior surface the rotomolded part. Oxidation of the recycled polymer results in formation of oxidized species, such as carbonyl groups, on the interior surface of the part, which along with higher surface roughness enhances adhesion between the interior surface and coatings or fillings, such as polyurethane, used to provide a layer of insulation or improve structural strength or buoyancy.
Claims20
A polyethylene composition comprising:
- a) from 85 to 99 wt % of a stabilized polyethylene having a melt index, I2, as measured by ASTM D 1238 at 190° C. using a 2.16 kg load, of from 0.5 to 10 g/10 min;
- a density as measured by ASTM D792 of from 0.920 to 0.950 g/cc;
- and
- b) from 15 to 1 wt % of a recycled polymer having a recycled polymer density greater than the density of the stabilized polyethylene, and a recycled polymer melt index, I2, of less than 1 g/10 min.
A polyethylene composition comprising:
- a) a stabilized polyethylene having a melt index, I2, as measured by ASTM D123 8 at 190° C. using a 2.16 kg load, of from 0.5 to 10 grams/10 minutes;
- a density as measured by ASTM D792 of from 0.920 to 0.950 g/cc;
- b) a substantially non-stabilized polyethylene having i) a high load melt index, I21, as measured by ASTM D1238 at 190° C. using a 21.6 kg load, of from 2 to 20 grams/10 minutes;
- ii) a density of from 0.950 to 0.965 g/cc as measured by ASTM D792;
- and iii) an average particle size of from 500 to 3000 microns;
- and
- c) a recycled polymer having a recycled polymer density greater than the density of the stabilized polyethylene, and a recycled polymer melt index, I2, of less than 1 g/10 min.
Dependencies are inferred from the claim text.