Colloidal Properties of Copolymer-Encapsulated and Surface-Modified Pigment Dispersion and ITS Application in Inkjet Printing Inks

摘要

The copolymer-encapsulated pigment dispersion was prepared by phase separation technique with 2-[(2-Methoxy-4-nitrophenyl)azo]-N-(2-methoxyphenyl)-3-oxobutyramide (P. Y. 74) and copolymer of styrene and maleic acid (PSMA). The surface-modified pigment dispersion was prepared by milling method with P.Y.74 and dispersant of PSMA, and further the two dispersions were applied to formulate into pigment ink, respectively. The colloidal properties of these two dispersions were compared, and the printing performance of prepared inks was also investigated. The results showed that the particles in PSMA-encapsulated pigment dispersion were smaller than that of surface-modified pigment dispersion. The stability to NaCl concentration, pH value and temperature of PSMA-encapsulated dispersion was superior to surface-modified pigment dispersion. The apparent viscosity of PSMA-encapsulated pigment dispersion changed small, while changed greatly in surface-modified pigment dispersion with increasing the shear rate. Printing performance indicated that the PSMA-encapsulated pigment dispersion was more suitable to preparation of inkjet printing inks than that of surface-modified pigment dispersion.