'PEARLESCENT PIGMENT WITH MODIFIED DENSITY OF SURFACE CAPPING FUNCTIONAL GROUPS, PROCESS FOR PRODUCING THE SAME, AND MIXTURES AND COMPOSITIONS THEREOF'

摘要

Inorganic pigments, particularly pearlescent pigments, with improved weathering stability in organic substrates and excellent dispersability and adhesion in coatings comprise a first protective layer comprising metal oxide and/or metal hydroxide of the metals Al, Ce, Zr, W, Mo or the combinations of the same, a second protective layer comprising silicates and/or Si02, and a multifunctional organic capping layer adhered to the second layer, which capping layer is prepared by addition of one or more organic coupling agents, in particular, organo silane coupling agents, substituted with a reactive functional group, for example, a primary amine, and which reactive group is partially or completely modified with a bis-reactive agent, for example, a dialdehyde or diketone, while the organic coupling agent is either hydrogen bonded to the second protective layer or is bound to the second layer by means of oxygen atom, resulting in a pigment capping layer with a modified density of surface capping (PMDSC). Mixed pigments comprising blended mixtures of the pigments with unmodified density of surface capping (PUDSC) and modified surface capping layers (PMDSC"s) are also provided