I’m working with a new pigment, Pyrrole Red PR 254. It resists wetting, so I added a bit of alcohol to disperse and convert it to a paste. Usually once a pigment has successulfy dispersed in water, and it dries out, adding more water readily rewets it. However when the Pyrrole paste dried out, adding more water didn’t reconvert it to a paste; I had to add more alcohol. I’m interested in this, as well as any other comments on Pyrrole Red, which is new to me.
Thanks, Koo Schadler
We have yet to do significant testing of diketo-pyrrolo-pyrrole (DPP) (PR 254) pigments, but in my research I noted that most acrylic dispersants do not disperse and stabilize this pigment effectively except for coppolymers modified with special aromatic acidic anchoring groups. This may be related to the effect you see of poor wetting by water.