Abstract A liquid composition having high dielectric strength and oxidation resistance for use as a transformer oil and for other purposes in which an electrically insulating liquid is required, the composition consisting essentially of an alkylaryl hydrocarbon (i.e., dodecylbenzene) and 10 to 1,000 parts per million (ppm) of an antioxidizer from the group of phenolic and naphtholic compounds and their nuclear-substitution products, especially alkyl-substituted cresols, phenols and aminophenols, preferably di-tertiarybutyl-paracresol and 2,4-dimethyl-6tertiarybutylphenol. The basic hydrocarbon is preferably the alkylbenzene obtained by alkylation of benzene with alkyl groups derived from polymerization of propylene (i.e., propylene tetramer).
The composition defined in claim 1 wherein said alkylbenzene has an alkyl group formed by polymerization of propylene, said composition having a minimum dielectric strength of about 40 KV and a neutralization number no greater than 0.1 mg KOH/g after 28 days of tests in accordance with German Industrial Standard DIN 51554 or ASTM Standards D 1904-61T and D 974-64.
Claim 2
Dependent Claim
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The composition defined in claim 2 wherein said alkylbenzene is dodecylbenzene and said stabilizer iS present in an amount ranging from 10 to 1,000 parts per million.
Claim 3
Dependent Claim
20 words
The composition defined in claim 3 wherein said stabilizer is present in an amount of about 50 parts per million.