Importance

Loading Importance Indicators...

Abstract

The invention covers a fine-particle, brilliant and strongly hiding rutile-based pigment that is devoid of any metal or reactive metal compounds relevant to mill abrasion detectable by application technology but whose particle-size in terms of particle diameters ranges from 50 to 1000 nm, for mono-, bi-, tri- or oligo-modal size distribution and a primary maximum ranges from 230 to 400 nm, wherein optionally for a bi- or poly-modal frequency distribution, a secondary maximum is less than 25% of the primary maximum between 400 and 1000 nm. The process for producing said pigment comprises treating an inorganic mixed-phase rutile structured oxide pigment by high-speed grinding in suspension in a ball grinding mill provided with a mechanically and chemically resistant coating until said particle-size and a substantially isometric rounded particle shape are attained. The invention optionally provides for viscosity adjustment and surface conditioning of the pigment. The inventive pigment differs from prior art by improved gloss, low whiteness or reduced whitening, relatively high hue saturation, by extremely high hiding power which had been unattainable in said class of products up to now and exhibits a low photoactivity with respect to known fine-particle rutiles. In practice neither abrasivity nor interaction of possible grinding residues with an application matrix are observed.

Loading the Abstract Image...

First Claim