Patent ID: 7803198

Claim:
A hair dye comprising 0.1 to 3.0% by weight of at least one of aqueous acid dyes and a resin comprising a terpolymer constituted from a vinyl cyclic amide represented by following Formula (I), an acrylic acid derivative represented by following Formula (II) and a quaternary derivative of acrylic acid represented by following Formula (III), wherein a content of the resin is 0.1 to 2.5% by weight in terms of a solid content; and the hair dye further comprises 1.0 to 20% by weight of a hair dyeing auxiliary agent, 20 to 60% by weight of a lower alcohol and 20 to 60% by weight of water and has a pH of 2 to 4: (in Formula (I), n is an integer of 3 to 6, and R represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms); (in Formula (II), P is an oxygen atom or NR 2 ; R 1 , R 2 , R 3 and R 4 each are a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and they may be the same or different; and R 5 represents an alkylalkylene group having 2 to 16 carbon atoms); (in Formula (III), P is an oxygen atom or NR 2 ; R 1 , R 2 , R 3 and R 4 each are a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and they may be the same or different; R 5 represents an alkylalkylene group having 2 to 16 carbon atoms; R 6 is an alkyl group having 9 to 24 carbon atoms; and M represents a halide, tosylate or phosphoric acid anion).