Study On Preparation Procedure And Modification Of Cationic Dispersed Rosin

Sizing agent is an important and indispensable raw material in paper industry, especially the rosin sizing agent. Cationic dispersed rosin size, for its good compatibility, is becoming more and more widely used in paper sizing.In this paper, the modification and preparation of the cationic dispersed rosin size were studied. Maleic anhydride and inorganic salt were used to modify the rosin (strength rosin) while the polyamines macromolecular emulsifier was synthesized by diethylenetriamine, adipic acid, epichlorohydrin. Finally, the cationic rosin emulsion was obtained by three steps:mixed the macromolecular emulsifier and strength rosin with a certain ratio; pre-emulsifying; and high-pressure homogenizing. The optimum reaction conditions were decided by investigating the ratio of reactants, reaction temperature, reaction time, intermediate viscosity. Also the product performance, application and stability of cationic rosin size were discussed, respectively. In order to solve the problem of cationic rosin production process is prone to a large number of bubbles, and developed a new type of silicone defoamer, And to explore the defoamer performance improvement and its application, through the above research the following conclusiongs:(1) Strength rosin was prepared by modifying the rosin with maleic anhydride and inorganic salt. For the purpose of cationic dispersed rosin size which prepared from strength rosin using in cup paper and liquid packaging paper，the softening point of the strength rosin must be95～100℃For this purpose, we studied and determined the optimum reaction conditions:the mass ratio of rosin, maleic anhydride and inorganic salt was1000:10:1,reaction time was3h, reaction temperature was180℃.(2) Using diethylenetriamine and adipic acid, polyamine macromolecular emulsifier intermediate was prepared successfully in the reaction conditions:the mass ratio of diethylenetriamine and adipic acid was1:1, reaction temperature was180℃, reaction time was8h. The effect of intermediate viscosity in emulsifier syntheses was investigated. Result shows that intermediate viscosity for100-500mpa·s.(3) Intermediates and epichlorohydrin in the mass ratio of3:1, the reaction temperature of70℃, polyamines macromolecular emulsifier was prepared with viscosity of20-30mpa·s.(4) Mixing the macromolecular emulsifier and strength rosin with a certain ratio2:1, cationic dispersed rosin size emulsion obtained by high-pressure homogenization. (5) The product pilot program and production conditions of cationic dispersed rosin size was established according to the small test data, and their capital investment, production unit cost were also estimated, RMB2,712million and RMB5203.2, respectively.(6) In order to solve the problem of cationic rosin production process is prone to a large number of bubbles, and developed a new type of silicone defoamer.Adding mineral oil, polyether, aliphatic alcohol and modified silicone (X-1, X-2and X-3) to common silicone defoamer, we prepared a series of papermaking specialized silicone defoamers with new performance.The effects of types and quantity of modifying agents on the performance of defoamers were studied, such as physicochemical properties, stability and antifoam ability. The results show that adding modifying agents had few effect on silicone defoamers physicochemical properties and stable centrifugally homogeneity in3000rpm, but significantly improve their antifoam ability, which only3.0%of the mineral oil, polyether and aliphatic alcohol modification can double enhance the antifoam ability of defoamer to detergent in comparison with black liquor foam. Modified silicone can greatly increase the antifoam performance to not only detergent foam but also black liquor foam, especially X-2and X-3. Finally, Choosing5.0%of silicone X-3as the optimized test conditions, the product’s advantage is remarkable in paper mills compared with other silicone defoamers.