Method for marking liquid petroleum hydrocarbons

Abstract

A method for marking a liquid petroleum hydrocarbon; said method comprising adding to said liquid petroleum hydrocarbon at least one dye having an unsaturated cyclic nucleus comprising at least nine ring atoms, and having at least one (CN) 2 C═ substituent and at least one Ar—N═ substituent; wherein Ar is a substituted aryl group.

1 . A method for marking a liquid petroleum hydrocarbon; said method comprising adding to said liquid petroleum hydrocarbon at least one dye having an unsaturated cyclic nucleus comprising at least nine ring atoms, and having at least one (CN) 2 C═ substituent and at least one Ar—N═ substituent; wherein Ar is a substituted aryl group.  
     
     
         2 . The method of  claim 1  in which the unsaturated cyclic nucleus is selected from among  
       
         
           
           
               
               
           
         
       
       wherein Y is CH 2 , NR 13  or O; and R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12  and R 13  independently are selected from hydrogen, halo, cyano, nitro and organic functional groups.  
     
     
         3 . The method of  claim 2  in which the Ar—N═ substituent has formula  
       
         
           
           
               
               
           
         
       
       wherein X is amino, substituted amino, hydroxy or alkoxy; and R 1 , R 2 , R 3  and R 4  independently are selected from hydrogen, amino, hydroxy, halo and organic functional groups.  
     
     
         4 . The method of  claim 3  in which said at least one dye is selected from among  
       
         
           
           
               
               
           
         
       
       wherein Z represents O or C(CN) 2 .  
     
     
         5 . The method of  claim 4  in which R 1 , R 2 , R 3 , R 4  independently are hydrogen, alkyl, halo, amino, substituted amino, hydroxy or alkoxy; R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11  and R 12  independently are hydrogen, alkyl, halo, cyano or nitro; and X is NR 14 R 15 , wherein R 14  and R 15  independently are hydrogen or alkyl.  
     
     
         6 . The method of  claim 5  in which Z represents C(CN) 2 ; R 1  and R 3  are hydrogen; and R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11  and R 12  independently are hydrogen or alkyl.  
     
     
         7 . The method of  claim 1  in which said at least one dye has an absorption maximum in the range from 600 nm to 1000 nm.  
     
     
         8 . The method of  claim 7  in which each dye is present in an amount from 0.01 ppm to 2 ppm and has an absorption maximum from 700 nm to 1000 nm.  
     
     
         9 . The method of  claim 8  further comprising at least one dye having an absorption maximum from 500 nm to 700 nm.  
     
     
         10 . The method of  claim 8  in which at least two dyes are present, each of which has an absorption maximum from 700 nm to 1000 nm.