Thiobis phenolic antioxidant/polyethylene glycol blends
AssigneeUnion Carbide Chemicals & Plastics Technology Corporation
InventorsAntoni Adamczyk, Daniel Emley, Neil W. Dunchus, Jeffrey M. Cogen, Susan Song
Life of this patent
Estimating the term…
Abstract
Thiobis phenolic antioxidants are efficiently dry or melt blended with a tree-resistant, crosslinkable polyethylene by first forming a blend, preferably a dry blend, of the antioxidant with a polyalkylene glycol (PAG), and then mixing the blend with the polyethylene. The incorporation of thiobis phenolic antioxidant and PAG blend into polyethylene provides the PE with high oxidative induction time (OIT) which is a measure of the oxidative stability of the PE.
Claims15
A process of preparing a mixture consisting essentially of:
- A. at least one thiobis phenolic antioxidant, selected from the group consisting of 2,2′-thiobis(6-t-butyl-4-methylphenol);
- 4,4′-thiobis(2-methyl-6-t-butylphenol);
- 2,2′-thiobis 4-octylphenol;
- and 4,4′-thiobis-(2-t-butyl-5-methyl-phenol) (TBM6),
- B. at least one polyalkylene glycol (PAG) of a weight average molecular weight of at least 10,000,
- in which the thiobis phenolic antioxidant and PAG are present at a thiobis phenolic antioxidant to PAG weight ratio from 0.1:1 to 2:1,
- the process comprising the steps of dissolving the PAG and thiobis phenolic antioxidant in a halogenated hydrocarbon, and then removing the halogenated hydrocarbon by evaporation.
A method of mixing a solid thiobis phenolic antioxidant with polyethylene, the method comprising the steps of (A) dissolving thiobis phenolic antioxidant and polyalkylene glycol (PAG) in a common solvent to form a blend, (B) removing the solvent from the blend, and (C) mixing the blend with polyethylene.
Dependencies are inferred from the claim text.