| abstract |
A fluorescent naphthalimide diester dye that is miscible or soluble in a variety of organic compounds such as, for example, mineral oil, polyalkylene glycols, polyolesters, motor oil, gear oil, synthetic oils, and polyalphaolefins, is provided. The fluorescent naphthalimide diester is useful as a tracer to detect leaks within a fluid systems such as, for example, refrigerant systems, transmission systems, and hydraulic systems. The fluorescent naphthalimide diester dye is comprised of a chromophore having the following structure:wherein: Z and Z' are the same or different, and are esters attached to saturated or unsaturated linear or branched hydrocarbon chains attached thereto, having from 8 to 24 carbon atoms in length, preferably from 12 to 22 carbon atoms in length, most preferably from 16 to 20 carbon atoms in length, and from 1 to 4 double bonds, most preferably 2 to 3 double bonds. R and R' are saturated, linear hydrocarbon chains, having from 2 to 10 carbon atoms in length, preferably from 2 to 8 carbon atoms in length, most preferably from 3 carbon atoms in length. Z and Z' are preferably fatty acids. The invention also relates to methods of making and using the fluorescent naphthalimide diester dye, as well as to fluorescent naphthalimide diester dye tracers. |