Patent ID: 8197591

Claim:
A pearlescent pigment comprising a metal oxide-containing, platelet-shaped substrate and with a first and a second protective layer, wherein the metal oxide has a refractive index greater than 1.8, wherein a) the first protective layer comprises at least one metal oxide selected from the group consisting of cerium oxide, hydrated cerium oxide, cerium hydroxide and mixtures thereof, b) the second protective layer is comprised substantially of SiO 2 , wherein the second protective layer is disposed on top of the first protective layer, and between the first and second protective layers there are optionally disposed at least one metal oxide layer composed of a metal oxide that differs from the metal oxide contained in both the first protective layer and the second protective layer, wherein c) the second protective layer has an organochemical aftercoat and the organochemical aftercoat comprises at least one α-silane bonded to the second protective layer by means of at least one oxygen atom, said α-silane having the formula —O (4-n-m —Si(—R 1 ) m (—CH 2 —Y) n (I) in which 1≦n+m≦3; m=0 to 2; n=1 to 3 and R 1 is a hydrogen atom or an Si—C-bonded C 1 -C 20 -hydrocarbon radical or a C 1 -C 15 -hydrocarbonoxy radical, in which in each case one or more methylene units not adjacent to one another can be replaced by the groups —O—, —CO—, —COO—, —OCO—, or —OCOO—, —S—, or —NR x and in which one or more methine units not adjacent to one another can be replaced by the groups —N═, —N═N—, or —P═, wherein R 1 can independently be the same or different, R x can be a hydrogen atom or a linear, branched and/or cyclic C 1 -C 15 -hydrocarbon radical or aryl radical, and Y is a functional binding group reactive with a binder system, and wherein the organochemical aftercoat comprises no silane not having a functional binding group.