Patent No. U.S. 7,273,842 B1
Rohm and Haas Co. has been granted a patent for a colorant composition comprised of at least one chromophore, polymeric nanoparticles (PNPs), a locking agent, and 0.01-50% weight based on the weight of the PNPs, of a PNP coacervation aid; wherein the PNPs comprise, as polymerized units, at least one multi-ethylenically unsaturated monomer; wherein the PNPs have a mean diameter in the range of from 1-50 nanometers, an acid value in the range of from 0-700 mg KOH/g PNP solids, an amine value in the range of from 0-250, a hydroxyl number in the range of from 0-250 mg KOH/g PNP solids, and contain at least 2% of a polarizable group, and wherein the colorant composition provides improved colorant stability, improved colorant acceptance into paint and coatings, improved compatibility of