Patent ID: 9701844
Date: 2017-07-11
CPC Classifications: C01P,C09C

Claim:
1. A process for preparing a coloured effect pigment having an aluminum-based substrate particle and an iron oxide or titanium oxide layer, the process comprising: (i) coating aluminium-based substrate particles in a liquid aqueous coating medium with at least one metal oxide layer comprising at least one of a titanium oxide and an iron oxide, (ii) adding a particulate inorganic non-metallic material to the liquid aqueous coating medium to obtain a mixture of the coated aluminium-based substrate particles and the particulate inorganic non-metallic material in the liquid aqueous coating medium, (iii) separating the particulate mixture of the coated aluminium-based substrate particles and the particulate inorganic non-metallic material from the liquid aqueous coating medium, and (iv) thermally drying the separated particulate mixture to obtain the coloured effect pigment as a dry material.