Formulations Having Benzoate Dye Carriers for Meta-Aramid Articles

Abstract

Glycol ether benzoates, glycol benzoates and methyl benzoate facilitate the dyeing of the meta-aramid article, e.g., fibers, at or near neutral pH. The addition of an anionic surfactant, such as sodium lauryl sulfate, enhances the performance of the benzoates.

1 . An aqueous dye formulation comprising:
 A. A cationic dye;   B. At least one of a glycol ether benzoate and glycol benzoate;   C. Water; and   D. Optionally, an anionic surfactant.   
     
     
         2 . The dye formulation of  claim 1  having a pH of 6-8. 
     
     
         3 . The dye formulation of  claim 1  in which the glycol ether benzoate is of the formula
   R 1 —O—(CH 2 CH(R 2 O) n —R 3  
 
 
       in which R 1  is a C 1-10  alkyl group, phenyl or benzyl, R 2  is either hydrogen, methyl or ethyl, R 3 — is C═C—C 6 H 5  from benzoic acid, and n=1-3. 
     
     
         4 . The dye formulation of  claim 3  in which the dye is present in an amount of 0.05 to 5 wt %, the at least one of a glycol ether benzoate and glycol benzoate is present in an amount of 3 to 6 wt %, and the water is de-ionized. 
     
     
         5 . The dye formulation of  claim 4  in which the glycol ether benzoate is at least one of 1-methoxy-2-propylbenzoate, 2-propoxyethyl benzoate, 2-butoxyethyl benzoate, 2-(2-phenoxyethoxy)ethyl benzoate and 2-(2-phnoxy-1-methylethoxy)-1-methylethoxy benzoate; and the glycol benzoate is at least one of a diethylene glycol mono- and dibenzoates, dipropylene glycol mono- and dibenzoates, triethylene glycol benzoates and trimethylene glycol dibenzoate. 
     
     
         6 . The dye formulation of  claim 5  in which the anionic surfactant is present in an amount of 1-4 wt %. 
     
     
         7 . The dye formulation of  claim 6  in which the anionic surfactant is a linear alkyl sulfonate. 
     
     
         8 . A method of dyeing a meta-aramid article, the method comprising the step of contacting the meta-aramid article with a dye formulation comprising:
 A. A cationic dye;   B. At least one of a glycol ether benzoate and glycol benzoate;   C. Water; and   D. Optionally, an anionic surfactant;   
       the dye formulation having a pH of 6-8. 
     
     
         9 . The method of  claim 8  in which the article is immersed in a bath of the dye formulation. 
     
     
         10 . . A meta-aramid article dyed by the method of  claim 8 . 
     
     
         11 . . The article of  claim 10  in the form of a fiber.