Method of strengthening hair fibers and protecting dyed hair color from fading or wash-out
Disclosed is a method of strengthening hair fibers using a hair composition comprising an amide and/or an alkyl ammonium carboxylate salt. The amide can be a monoamide and/or a bisamide. A method of protecting dyed hair color from fading or wash-out using the hair composition is also included.
1. A method of strengthening hair fibers comprising applying to hair a hair composition comprising reaction product of glucono delta-lactone and ethylene diamine wherein the reaction product is represented by Formula (III)
wherein R 1 ′-R 4 ′ are independently hydrogen
R 5 ′ and R 6 ′ are independently hydrogen
L is —CH2-CH2-.
2. The method of claim 1 , wherein the molar ratio of the lactone compound to the alkyl diamine compound ranges from about 5:1 to about 1:5.