The invention concerns a compound containing calcium or magnesium acetylacetonate, at least partially coated with a compatible agent selected among alcohol's, carboxylic or sulphonic acids, or their derivatives, phosphates or titanates, beta-ketone compounds; said agents having at least a long chain radical; waxes; polyols; epoxidized vegetable oils; polysiloxane oils or resins or silanes. The invention also concerns the preparation of such a compound and the use of said compound as additive in formulations based on halogenated polymers.
