A two-part hair dye comprising a first preparation containing an alkali agent, a second preparation containing hydrogen peroxide, and a non-aerosol foamer container, wherein the first preparation contains the components (A) to (C) mentioned below, the ratio of the mass of the component (A) to the mass of the component (B) (i.e., an (A)/(B) ratio) in the first preparation is 0.3 or less, and the viscosity of the mixed solution is 1 to 300 mPa·s or more. (A): 0.9 to 1.7 mass% of resorcin. (B): a polyoxyalkylene-type nonionic surfactant. (C): a polymer or copolymer having a molar fraction of a diallyl dimethyl quaternary ammonium salt monomer of 70% or more.本發明提供一種二劑式染毛劑,其包含:含有鹼劑之第1劑、含有過氧化氫之第2劑、及非氣溶膠發泡容器;並且於第1劑中含有以下之成分(A)~(C),第1劑中之成分(A)與成分(B)之質量比(A)/(B)為0.3以下,混合液之黏度為1~300 mPa‧s。(A):間苯二酚0.9~1.7質量%(B):聚氧伸烷基型非離子界面活性劑(C):二烯丙基二甲基四級銨鹽單體之莫耳分率為70%以上之聚合物或共聚物
