Study On The Improvement Of The Size Homogeneity Of Microcapsule Used In Carbonless Copy Paper

This thesis gave a detailed discussion in material structure, molecular weight and technical conditions of the process that producing microcapsule used in carbonless copy paper. This kind of microcapsule was made by chitosan as wall, dibutyl phthalate solution of crystal videt lactone as core. According to single cogulation process, the thesis determined the best ratio of core to wall, the emulsification condition, flocculation condition and solidification condition. Also, the thesis gave a comparative analysis for applying the final microcapsule product. First, in technical conditions of the process, this thesis gave a detailed discussion in all aspects including emulsification agents, flocculation agents, solidification agents and mixing speed, reaction temperature, pH and so on. Under these different experiment conditions, it was found the influence extent and function mechanisms of various reaction factors to the microcapsule particle size and distribution, determined the best craft condition by orthogonal experiment. Finally, experimental results proved that all kinds of indexes achieved domestic and overseas standards in the application performance of stability and showing color speed and so on. In addition, chitosan showed that its water solubility, film-making ability were better than unmodified chitosan through carboxyl methylation. It was also studied that the influence of carboxyl-methylation on the size of microcapsule distribution. During the depolymerization of chitosan through superwave, it was found that different superwave power can obtain chitosan with different molecular weight. The experiments indicated that chitosan with different molecular weight impacted on homogeneity and film-making ability of microcapsule. It was finally found that the size of microcapsule under the 200W ultrasonic action had the narrowest scope and showed thebest homogeneity.