THE EFFECT OF AKD ADSORBED ONTO CAUSTICIZED CALCIUM CARBONATE ON AKD SIZING EFFICIENCY

摘要

Causticized calcium carbonate(CCC)is used as a kind of paper filler instead of precipitated calcium carbonate(PCC),which comes from the green liquor causticizing process of alkali recovery system.There are many advantages to use CCC as paper filler,which not only saves resource and energy,but also can prevent secondary pollution and reduce the production cost of paper.Unfortunately,the application scope and dosage of CCC have been limited by low sizing efficiency of CCC-filled paper.In this research,the adsorption between CCC filler and alkyl ketene dimer(AKD)emulsion was studied,and the effective method to enhance AKD sizing efficiency of CCC-filled paper was found.It was proposed that the AKD sizing efficiency reduction of CCC-filled paper was resulted from the adsorption of AKD onto CCC,and the electrostatic interaction between AKD and CCC was the main reason for the adsorption,while physical adsorption played a role as assistance.It was found that controlling the electrostatic adsorption of AKD onto CCC was an effective method to improve the AKD sizing efficiency of CCC-filled paper.