A composition is provided which is coextrudable with vinylidene polyfluoride permitting it to adhere to incompatible polymeric resins, the composition which has a base of an alkyl polymethacrylate and a thermoplastic polymer is comprised of:from 27 to 50 parts by weight of an alkyl polymethacrylate; andfrom 73 to 50 parts by weight of an additive itself constituted for 100 portions by weight of additive of:from 35 to 50 parts by weight of PVDF, andfrom 65 to 50 parts by weight of acrylic or methacrylic elastomer.This composition serves to produce vinylidene polyfluoride compounds capable of coating polymers which are non-compatible with vinylidene polyfluoride. When used as an adhesion agent, one can obtain by coextrusion, compounds of vinylidene polyfluoride and polymers non-compatible with the vinylidene polyfluoride.