Detergent composition for copolymer and detergent composition

PROBLEM TO BE SOLVED : To provide a copolymer for detergent compositions excellent in finger combing and sliding properties when washing and rinsing, and feels such as softness after drying.SOLUTION : The invention provides a copolymer for detergent compositions consisting of the copolymer having a unit from the formula (1), (2), and other ethylenic unsaturated monomer. [Ris H or methyl; Rto Rare an alkyl group and the like; Xis Halogen anion or monoalkyl sulfate ester anion; n is an integer of 1-10; Y is NH or O] [Ris H or methyl; Mis H, an alkyl metallic cation, or onium cations]