Binder of vegetable origin， compositions comprising same and method for reducing the amount of petroleum-based bitumen

Disclosed is a binder of vegetable origin based on modified tall-oil pitch， modified vegetable resin and optionally oil. Also disclosed are leakproofing membrane compositions， soundproofing membrane compositions， liquid sealing system compositions， asphalt mix coating compositions， asphalt coating compositions， primer compositions， varnish compositions， mastic compositions， adhesive compositions or binder emulsion compositions which comprise said binder. In addition， a method is disclosed for reducing the amount of bitumen of petroleum origin in said compositions.