Abstract: The z potential of carbon black MA-100 adsorbed dispersants with different structures and its dispersing stability under different pH values were analyzed, and the storage stability and writing properties of gel ink that was prepared with carbon black paste were studied. The results show that the anionic polymer dispersant ammonium salt of styrene-maleate copolymer (SMA-NH4) has the best dispersing stability to carbon black MA-100 with the sedimentation rate of 17 mm/min, followed by the nonionic dispersant polyvinyl pyrrolidone with 30 mm/min, and the anionic dispersant methylenebis naphthalene sulfonate falls into the last position with 218 mm/min. In aqueous systems, pH value can change not only the ionization degree of SMA-NH4, but also the configuration of polymer chains on the carbon black surface. The z potential of carbon black is -45.7 mV at pH value of 8, so the molecular chains of the polymer fully stretch, leading to that improvement of SMA-NH4 steric resistance, the gel ink prepared with this dispersant shows good storage stability and writing properties.

Key words: carbon black, dispersant, dispersion stability, copolymer, ink, adsorption

摘要： 在不同pH值下分析了吸附不同结构分散剂的炭黑MA-100的z电势和分散稳定性，考察了炭黑所制色浆配制的中性墨水的存储稳定性和书写性能. 结果表明，阴离子型聚合物分散剂聚苯乙烯马来酸酐共聚铵盐(SMA-NH4)对炭黑的稳定效果最好，沉降速率为17 mm/min，非离子型高分子分散剂聚乙烯吡咯烷酮次之，沉降速率为30 mm/min，阴离子型分散剂亚甲基二萘磺酸钠效果最差，沉降速率为218 mm/min. 水性分散体系中pH值不仅能改变SMA-NH4的电离程度，而且能改变其聚合物链在炭黑表面的构型，pH值为8时SMA-NH4为炭黑提供的z电势最高，为-45.7 mV，使聚合物的分子链段充分舒展，提高了SMA-NH4的空间位阻，其所制色浆配制的中性墨水具有良好的存储稳定性和书写性能.

关键词: 炭黑, 分散剂, 稳定性, 共聚合物, 墨水, 吸附