Synthesis And Application Of Water-borne Polyurethane Surface Sizing Agent

In this paper, use"self-emulsifying"method to Synthesis of epoxy modified polyurethane sizing agent, and this experimental method is designed on the basis of the DOE model of Minitab software. The content and the results of the study are as follows:1. In the exploration of the synthesis process, the synthesis of epoxy modified anionic polyurethane with dimethylol prop ionic acid (DMPA) for hydrophilic chain extenders; choose a value of 0.43 of biphenyl A epoxy-based E-44 modified epoxy; epoxy resin E-44 joined the manner graft copolymer, the first reaction by adding a certain time and then adding DMPA epoxy resin E-44; choose triethylamine as a salt agent.2. By DOE in two levels factorial design method to study the affections of the amount of raw materials on the emulsion particle size, Cobb value and strength of the printing paper surface. Through the study found that R value, DMPA usage and E-44 are the main factors which affected the particle size and the strength of the printing paper surface; R value, DMPA usage, E-44 usage and the Neutralization degree of is the main factor affecting Cobb value. Minor factor in the level set as follows: DEG usage amount is 4%, the neutralization degree is 100%.3. Conduct a level determined optimum design based on the selected main factors which effect key indicators. Obtained by optimizing the experimental water-based epoxy modified polyurethane synthesis is: an R value is 2.6, DMPA using amount is 8%, E-44 using amount is 8%, EDG using amount is 4% and neutralization degree of 100%.4. In the applications of Synthetic surface sizing, The conclusion of the research is: when the using amount of synthetic sizing agent were 0.9g/m~2, 1.2g/m~2 and1.5g/m~2 ,compared with the base paper, the Cobb values reduced by 24.51%, 37.18% and 49.56% respectively, and the printing paper surface strength increased by 37.97%, 61.18% and 64.97% respectively. Oxidized starch and polymer surface sizing compound in different proportions of each for the surface sizing, the best ratio is: oxidized starch: E-WPU = 92:8.