Abstract: 1,4-Bis(2,4,6-trialkylanilino)anthraquinone wherein the alkyls on each anilino group are selected from the group consisting of methyl and ethyl and one of the three alkyls on each anilino group is different from the other two, e.g. 1,4-bis(2,6-diethyl-4-methylanilino)anthraquinone, is disclosed as an unusually effective blue dye suitable for use as a visual leak indicator in halocarbon refrigerants or in refrigeration liquids comprising a halocarbon refrigerant in admixture with a refrigeration oil.
Type:
Grant
Filed:
November 29, 1982
Date of Patent:
March 13, 1984
Assignee:
Racon Incorporated
Inventors:
Dale E. Stelz, Frank I. Carroll, Wilson M. Whaley
Abstract: Compounds of the class represented by 1,4-bis(2-methyl-6-ethylanilino)anthraquinone, 1,4-bis(2,6-dimethylanilino)anthraquinone, and 1,4-bis(2,4,6-trimethylanilino)anthraquinone are disclosed as being unusually stable blue dyes suitable for use as visual leak indicators in refrigerants; e.g., in halocarbon refrigerants, or in refrigeration liquids comprising a halocarbon refrigerant in admixture with a refrigeration oil.
Type:
Grant
Filed:
May 21, 1981
Date of Patent:
January 18, 1983
Assignee:
Racon Incorporated
Inventors:
Dale E. Stelz, Wilson M. Whaley, Frank I. Carroll