Development Of Micro-spherical Solvent Fluorescent Pigments

In this paper, a kind of micro sphere fluorescent pigment with high solvent resistancewas prepared by using two-approachs method, and the benzene substitutedmelamine-formaldehyde-melamine copolymer(BMFM) was employed as carrier resin. Inthe first approach: oligomer of BMFM was synthesized by controlling the kind of catalyzer,temperature and end-point of polymerization and modified by ammonia, which can reduceconcentration of dissociative formaldehyde and improve hydrophilicity of resin.Meanwhile the passivated HDI was composited with the oligomer of BMFM.In the second approach: Both the fluorescent pigment and oligomer of BMFM weredispersed in water and emulsified as micro sphere by controlling appropriate technic index.The primary solidification of emulsified mixture was carried out by being of proper acidcatalyzer and controlling speed of reaction. The product of primary solidification wasfiltered from solution and heated for improving solidification. Meanwhile the passivatedHDI was released and takes part in the solidification, that can reduce content of hydroxylgroup and amidogroup and improve the solvent resistance of resin. In the end, the microsphere fluorescent pigment with high solvent resistance was obtained.The effects of reaction condition contained -NH₂/HCHO ratio, the kind of catalyzer,temperature of emulsified process, concentration of ammonia, concentration of HDI, pHvalue and temperature of solidification for properties of fluorescent pigment wereinvestigated, sequentially, the best condition of preparation was obtained. The productpossess more advantages such as high temperature resistance, solvent resistance.