Solvent resistant non-formaldehyde thermoset fluorescent pigment

Abstract

The present invention provides a novel, non-formaldehyde thermoset fluorescent pigment which is useful to color plastics, particularly flexible vinyl, which is solvent resistant, particularly to acetone. Moreover, the pigment does not bleed in plastics. The pigment comprises a polymer matrix and a fluorescent dye. The polymer matrix has a molecular weight of greater than about 330, preferably greater than about 1000. Embodiments which lack the water insoluble resin, have a molecular weight greater than about 330, preferably greater than about 500. The polymer matrix contains: from about 15 to 50 mole percent, preferably 30 to 40 mole percent, of a carboxylate functional oligomer; 30 to 80 mole percent, preferably 50 to 60 mole percent, of a metal ion; and 0 to 40 mole percent, preferably about 1 to 40 mole percent, more preferably from 1 to 30 mole percent, most preferably from about 3 to 10 mole percent of a water insoluble resin. In embodiments where no water insoluble resin is used, the metal is present from at least 51 mole percent. The oligomer comprises from about 10 to about 60 mole percent, preferably 20 to 35 mole percent of a first monomer, 40 to 90 mole percent, preferably 65 to 80 mole percent of second monomer. The weight average molecular weight of the oligomer is 330 to 2000, preferably about 560 to 600. The invention also relates to a novel method for producing the fluorescent pigments.