Antidandruff composition for treating the hair and the scalp, based on a pyridinethione salt, an insoluble conditioner and an acrylic terpolymer

An antidandruff composition for treating the hair and the scalp, comprising in a cosmetically acceptable medium,

• at least one pyridinethione salt,
• at least one insoluble conditioner, and
• at least one acrylic terpolymer containing, in amounts based on the total weight of monomers constituting the terpolymer:
• acrylate monomer (a), in amount of 5% to 80% by weight and selected from the group consisting of a C1-C6 alkyl acrylate and a C1-C6 alkyl methacrylate;
• monomer (b), in an amount of 5% to 80% by weight and selected from the group consisting of a heterocyclic vinyl compound containing at least one nitrogen or sulphur atom, a (meth)acrylamide, a mono- and di(C1-C4) alkylamino (C1-C4) alkyl (meth)acrylate, and a mono- and di (C1-C4) alkylamino (C1-C4) alkyl (meth)acrylamide;
• and monomer (c), in an amount of 0.1% to 30% by weight and selected from the group consisting of:
• i) a urethane produced by reaction between a monoethylenic unsaturated isocyanate and a nonionic surfactant comprising a block copolymer of 1,2-butylene oxide and of ethylene oxide with a C1-4 alkoxy end;
• ii) a copolymerizable ethylenic unsaturated surfactant monomer obtained by condensation of a nonionic surfactant with an α,β-ethylenic unsaturated carboxylic acid or its anhydride;
• iii) an urea surfactant monomer produced by reacting a monoethylenic unsaturated monoisocyanate with a nonionic surfactant containing an amine function;
• iv) a (meth)allyl ether of formula CH2═CR1CH2OAmBnApR2 in which R1 denotes a hydrogen atom or a methyl group, A denotes a propylenoxy or butylenoxy group, B denotes ethylenoxy, n is equal to zero or denotes an integer less than or equal to 200, m and p denote zero or an integer less than n, and R2 is a hydrophobic group of at least 8 carbon atoms;
• and
• (v) a nonionic urethane monomer produced by reacting a monohydric nonionic surfactant with a monoethylenic unsaturated isocyanate.