Abstract: Provided are a leave-on hair cosmetic composition, containing the following components (A), (B) and (C): (A) an organic dicarboxylic acid or salt thereof, (B) an organic solvent selected from aromatic alcohols, N-alkylpyrrolidones, alkylene carbonates, polypropylene glycols having a number average molecular weight of from 100 to 1000, lactones and cyclic ketones, and (C) an organopolysiloxane having an organopolysiloxane segment and a poly(N-acylalkyleneimine) segment having a recurring unit represented by the following formula (1): (wherein, R1: H, C1-22 alkyl, cycloalkyl, aralkyl or aryl, and n: 2 or 3), wherein the latter segment has been bonded to at least one silicon atom of the former segment via a hetero-atom-containing alkylene group; having the organopolysiloxane segment and the poly(N-acylalkyleneimine)segment at a weight ratio of from 98/2 to 40/60; and having a weight average molecular weight of from 50,000 to 500,000; and a hair treating method with the composition.

Abstract: Provided are a leave-on hair cosmetic composition, containing the following components (A), (B) and (C): (A) an organic dicarboxylic acid or salt thereof, (B) an organic solvent selected from aromatic alcohols, N-alkylpyrrolidones, alkylene carbonates, polypropylene glycols having a number average molecular weight of from 100 to 1000, lactones and cyclic ketones, and (C) an organopolysiloxane having an organopolysiloxane segment and a poly(N-acylalkyleneimine) segment having a recurring unit represented by the following formula (1): (wherein, R1:H, C1-22 alkyl, cycloalkyl, aralkyl or aryl, and n: 2 or 3), wherein the latter segment has been bonded to at least one silicon atom of the former segment via a hetero-atom-containing alkylene group; having the organopolysiloxane segment and the poly(N-acylalkyleneimine)segment at a weight ratio of from 98/2 to 40/60; and having a weight average molecular weight of from 50,000 to 500,000; and a hair treating method with the composition.