Coated metal effect pigments, method of production and use thereof

1 . A coated flaky metal effect pigment comprising a metal effect flake as substrate, wherein the substrate is selected from aluminum or aluminum alloys and including the following consecutive coating layers:

a) optionally a discontinuous or a continuous layer of Mo-oxide,

b1) an inorganic metal oxide layer comprising over 50% SiO 2 ,

c1) a hybrid layer comprising SiO 2 modified by a diphenyl silane, a phenyl silane or mixtures thereof,

or

c2) a hybrid layer comprising SiO 2 modified by a diphenyl silane, a phenyl silane or mixtures thereof, and

b2) an inorganic metal oxide layer comprising over 50% SiO 2 , wherein the layer c1) or c2) comprises SiO 2 modified by a diphenyl silane and the 29 Si NMR-MAS signal ratio of D-silanes to Q-silanes is in a range of 1.8% to 10.5%.

2 . A coated flaky metal effect pigment according to claim 1 , wherein the thickness of layer b1) or b2) is a least 15 nm.

3 . A coated flaky metal effect pigment according to claim 1 , wherein the 29 Si NMR-MAS signal ratio of T-silanes to Q-silanes is in a range of 0 to 3.0%.

4 . A coated flaky metal effect pigment according to claim 1 , wherein the hybrid layer c1) or c2) comprises diphenyl dimethoxy silane.

5 . A coated flaky metal effect pigment according to claim 1 , wherein the metal effect flake is an aluminum flake, which was produced by milling technology.

6 . A coated flaky metal effect pigment according to claim 1 , wherein the flaky metal effect pigment has a total amount of the sum of SiO 2 and of diphenyl silane in layers b1) and c1) or b2) and c2) of at least 95 wt.-%, based on the amount of the total coating.

7 . A coated flaky metal effect pigment according to claim 1 , further comprising a further top-coat of organofunctional silanes, titanates, aluminates or zirconates.

8 . A coating composition comprising a coated flaky metal effect pigment according to claim 1 and a carrier.

9 . A coated flaky metal effect pigment comprising a metal effect flake as substrate, wherein the substrate is selected from aluminum or aluminum alloys and including the following consecutive coating layers:

a) optionally a discontinuous or a continuous layer of Mo-oxide,

b1) an inorganic metal oxide layer comprising over 50% SiO 2 ,

c1) a hybrid layer comprising SiO 2 modified by a diphenyl silane, a phenyl silane or mixtures thereof,

or

c2) a hybrid layer comprising SiO 2 modified by a diphenyl silane, a phenyl silane or mixtures thereof, and

b2) an inorganic metal oxide layer comprising over 50% SiO 2 , wherein the characterization with 13 C-NMR-MAS spectroscopy yields signals attributable to diphenyl moieties of the D-silanes and optionally 13 C-NMR-MAS signals attributable to organic moieties connected with T-silanes and wherein the total amount of these 13 C-NMR signals is in a range of 80% to 100% of all 13 C-signals observed.

10 . A coated flaky metal effect pigment comprising a metal effect flake as substrate, wherein the substrate is selected from aluminum or aluminum alloys and including the following consecutive coating layers:

a) optionally a discontinuous or a continuous layer of Mo-oxide,

b1) an inorganic metal oxide layer comprising over 50% SiO 2 ,

c1) a hybrid layer comprising SiO 2 modified by a diphenyl silane, a phenyl silane or mixtures thereof,

or

c2) a hybrid layer comprising SiO 2 modified by a diphenyl silane, a phenyl silane or mixtures thereof, and

b2) an inorganic metal oxide layer comprising over 50% SiO 2 , wherein the total thickness of the coatings a), b) and c) is in a range of 30 to 60 nm.