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US 10,766,986 B2Granted
Acid resistant polyethylene containers
AssigneeNOVA Chemicals (International) S.A.
InventorsHenry Hay, Derek Wasylenko, Tony Tikuisis, Gilbert Arnould
Life of this patent
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Abstract
Rotomolded polyethylene containers that are used to store sulfuric acid can become discolored on the interior surface which is in contact with the acid. This problem may be mitigated by the use of an additive package that contains two primary antioxidants.
Claims8
A method for improving the discoloration resistance of a rotational molded polyethylene container that is contacted with concentrated sulfuric acid, said method comprising the steps of
- 1) providing a stabilized ethylene copolymer composition, wherein said stabilized ethylene copolymer composition contains an additive package comprising
- A.1) a hindered phenolic primary antioxidant;
- A.2) a hydroxylamine primary antioxidant;
- B) a phosphite secondary antioxidant;
- C) a hindered amine light stabilizer;
- and
- 2) subjecting said stabilized ethylene copolymer composition to rotational molding conditions to produce a rotational molded polyethylene container;
- and
- 3) contacting said rotational molded polyethylene container with concentrated sulfuric acid to produce an acid contacted container;
- wherein said acid contacted container has improved color in comparison to a control acid contacted container that is prepared using an additive package that does not contain any of said hydroxylamine primary antioxidant.
7 more elements
Dependencies are inferred from the claim text.