A coating composition comprising: at least one polyacrylimide polymer (A)] comprising recurring units of formula (I), and further comprising recurring units complying with one or more of the following structures: J, JJ, JJJ, wherein R1, R2, R4, R5, R6, R7, equal to or different from each other are independently H or C1-20 alkyl group, R3 and R8, equal to or different from each other, are independently H, alkyl, cycloalkyl, alkaryl, aryl, heterocyclic C1-36 group, wherein said polymer (A) possesses an imidization degree of less than 80%; a liquid medium; and at least one vinylidene fluoride polymer (F) at least partially dissolved and/or at least partially dispersed in said liquid medium, wherein the amount of polymer (F) ranges from 50 to 90% wt. with respect to the total weight of polymer (A) and polymer (F).