Microcapsuled Pigment and its Application to Liquid Toner - Control of Negative Charge

摘要

Microcapsuled pigment is a submicron sized particle where the pigment is surrounded by polyurethane resins It is prepared by a novel process including pigment dispersion ana interfacial polymerization in hydrocarbon solvent(Fig.l)U). It can be applied to liquid toner however control technology of charge and resistivity is required .details of which haven't been clarified. In general , polar groups included in pigment and pigment dispersant have an influence on toner charge. Pigment dispersant containing long alkyl chain(Ci2) was used in place of the conventional polar agents (acid or basic) , to disperse phtHalocyanine blue , and had little influence on toner.charge. Acid polymer was added to the toner so that the toner can have negative charge. The effect of acid content and acidity on toner charge was examined. Furthermore polyacrylic charge director containing basic monomer was added to the solvent phase to increase toner charge and its effect on toner charge and resistivity was examined. For the evaluation of toner charge , electrodeposition method was adopted. The quantity of toner which deposited on the electrode was used as the linear measurement of toner charge.