Specific nanostructured material, as a protective coating for metal surfaces.

Nanostructured material (A) comprises at least an elementary nanoblock made of silica, alumina, zirconia, titanium oxide or cerium (IV), and functionalized with at least two functionalizing agents (I), (II), and (III). Nanostructured material (A) comprises at least an elementary nanoblock made of silica, alumina, zirconia, titanium oxide or cerium (IV), and functionalized with at least two functionalizing agents of formulae (Z 4-xSi((R1a) p-F1) x) (I), (Z 4-x-y(F1a-(R1a) p) ySi((R1a) p-F1) x) (II), and (Z n-ma-mb(F1a-L) maM(L-F1) mb) (III). Z : halo or -OR; R : 1-4C alkyl; x, y : 1-3; R1a : organic spacer group comprising 1-4C alkaline, 2-4C alkenylene, or 6-10C arylene; p : 0-1; F1 : 1-4C alkyl, 2-4C alkenyl, 2-4C alkynyl, 6-10C aryl, methacryl or methacryloxy(1-10C alkyl), epoxyalkyl or epoxyalkoxyalkyl (where the alkyl comprises 1-10C and alkoxy comprises 1-10C), 2-10C halo alkyl, 2-10C perhaloalkyl, 2-10C mercaptoalkyl, 2-10C aminoalkyl, amino(2-10C)amino(2-10C alkyl), di(2-10C alkylene)triamino(2-10C alkyl) or imidazolyl(2-10C alkyl); F1a, L : monodentate or polydentate ligand complex, preferably polydentate; M : Al(III), Ce(III), Ce(IV), Zr(IV), Ti(IV), Sn(IV), Nb(V), V(V), Ta(V), Hf(V), or a rare earth comprising Y(III), La(III) or Eu(III); n : state of coordination of atom (M); m : number of coordination bond between L and M; and a, b : integers of ma+mb= n. Provided that 4-x>= 1 for (I) and 4-x-y>= 0 for (II). Independent claims are included for : (1) a process of preparing (A), comprising : (a) preparing elementary nanoblocks by a hydrolytic or non-hydrolytic process from at least a metallic alkoxide or metal halide; (b)functionalizing the elementary nanoblocks using the functionalizing agent; (c) preparing an organic/inorganic hybrid matrix by sol-gel, from the metal alkoxide, where the preparation by sol-gel being in the presence of a solvent, and optionally a catalyst; and (d) mixing the functionalized elementary nanoblocks and the matrix; (2) an article comprising metal substrate and at least a surface consisting of at least (A); and (3) a process for preparing the article, comprising soaking (A) in a bath, and depositing on substrate by rotation, spraying, laminate coating or brush.