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US 7,115,164 B2Granted
Preparation of yellow pigments
AssigneeSun Chemical Corporation
InventorsGeorge H. Robertson, Edward H. Sung, Veronica L. Chambers
Life of this patent
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Abstract
A process for the manufacture of a transparent Pigment Yellow 155 or transparent Pigment Yellow 180 is disclosed, said process includes grinding particles of said pigment in the presence of a grinding agent until said particles achieve a surface area of at least about 40 m2/g.
Claims16
A process for the manufacture of a transparent Pigment Yellow 155 or transparent Pigment Yellow 180, said process comprising:
- (a) grinding particles of said pigment in the presence of a grinding agent until said particles achieve a surface area of at least about 40 m2/g;
- and (b) isolating said pigment by a process which comprises:
- (i) preparing an aqueous slurry of the ground pigment;
- (ii) filtering said slurry resulting in a filter cake containing particles of transparent pigment;
- and
- (iii) either (i) flushing the pigment from the filter cake;
- or (ii) drying the filter cake optionally followed by grinding.
4 more elements
Dependencies are inferred from the claim text.