Process for cleaning metal surfaces of poly(arylene sulfide) deposits
AssigneePhillips Petroleum Company
InventorsRonald D. Mathis, Jerry O. Reed
Life of this patent
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Abstract
A process for the removal of poly(arylene sulfide) deposits is provided which comprises contacting said deposits with a solution comprising an alkali metal hydrosulfide in a lactam. In addition, a process for the cleaning of metal parts having poly(arylene sulfide) deposits is provided by contacting the metal parts in the manner as described immediately above, contacting the metal part with a lower alkyl alcohol, washing said metal part with water, drying said metal part, contacting the dried part with concentrated HNO.sub.3 followed by water washing and drying.
Claims10
A process for the removal of poly(arylene sulfide) deposits from metal surfaces comprising contacting said deposits with a cleaning solution, consisting essentially of at least one alkali metal hydrosulfide in a lactam of the general formula ##STR2## where R is hydrogen or an alkyl radical having from 1 to 5 carbon atoms and n is an integer from 5 to 7 at a temperature and for a time sufficient to remove said deposits.
A process for cleaning metal surfaces having poly(arylene sulfide) deposits thereon comprising:
- (a) contacting said metal parts with a cleaning solution, consisting essentially of at least one alkali metal hydrosulfide in a lactam of the general formula ##STR3## where R is hydrogen or an alkyl radical having from 1 to 5 carbon atoms and n is an integer from 5 to 7 at a temperature and for a time sufficient to remove said deposits;
- (b) thereafter contacting the metal part with a lower alkyl alcohol;
- (c) washing the metal part with water;
- (d) drying the metal part;
- and
- (e) contacting the dried metal part with concentrated HNO.sub.3 followed by water washing and drying.
Dependencies are inferred from the claim text.