Restorative material for antioxidant depleted polyolefin insulation
AssigneeBell Telephone Laboratories, Incorporated
InventorFrederick R. Wight, Jr.
Life of this patent
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Abstract
Materials and methods are shown for increasing the antioxidant protection of polyolefin insulation, such as low density polyethylene insulation on electrical conductors. The materials may be applied in the field to increase the service life of in-place cable. The material is typically applied by brushing or spraying a lacquer-based carrier containing the inventive stabilizer onto the insulation to be protected. The stabilizer migrates into the polyolefin insulation, typically increasing the service life of antioxidant depleted cable by several years.
Claims8
A method of protecting polyolefin insulation on an electrical conductor comprising the step of externally applying a protective material to said insulation, with said protective material comprising a stabilizer material that migrates into said insulation, the method characterized in that said stabilizer material comprises a first antioxidant selected from the group consisting of:
- tetrakis [methylene 3-(3',5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane;
- thio-diethyl-bis (3,5-di-tert-butyl-4-hydroxy hydrocinnamate);
- and octadecyl 3-(3',5'-di-tert-butyl-4'-hydroxyphenyl) propionate;
- and a second antioxidant consisting of:
- tris (3,5-di-tert-butyl-4-hydroxyphenyl) tricarbonamide;
- and a peroxide decomposer selected from the group consisting of:
- tetrakis (nonylphenyl) polypropyleneglycol 425 diphosphite, dilauryl thiodipropionate, and pentaerythritol hexyl thiodipropionate.
Dependencies are inferred from the claim text.