Study On Water-borne Diallyl Phthalate Resin Impregnated Paper

DAP(diallyl phthalate)is desirable for surface decoration of wood-based panels. However, traditionally the DAP resin is solubilized in organic solvent to impregnate paper, which needs so much organic solvent that it seriously hinders the application of DAP resin on decorative boards. To avoid the said defects, this paper adopted DAP emulsion impregnating instead of solution one.Firstly, DAP was polymerized in alcohol to certain ratio and degree. The study showed that AIBN excels BPO in initiation effect. In addition, it was found that DAP polymerization is prone to self -stagnate as well as cross-link and the result of this competition depends on the reaction temperature. Proper condition of DAP polymerization is confirmed as follows: DAP: alcohol: AIBN=100:30:2 reacting under 80℃for 4～5h. After this process, the polymerization ratio reaches over 40% and the prepared prepolymer is soluble and meltable with the potential of further cross-linking.Secondly, the DAP resin solution was emulsified. By comparing the stability of different emulsion formulation, it was shown that the formulation of resin(including unreacted monomer):H2O:SLDS:OP-10: PVA1788=100: 70: 1.33: 0.67: 0.5 makes the best emulsion stability. The research also showed that emulsion particles can be grinded up into smaller ones by latex mill so as to improve the emulsion stability. The proper grinding technology is 5000r/min for 3～4minutes.Having prepared stable DAP resin emulsion, the paper was impregnated, dried and hot pressed into decorative board. By analyzing large amount of data, it was found that drying temperature and time have significant effect on resin content and pre-curing ratio of impregnated paper, among which temperature exerts greater effect. The paper was dried under 110℃for 30 minutes, supposed to get a resin content of 180% as well as a pre-curing ratio of 50%.On the basis of an appropriate drying process, we made a primary research on the effect of parameters of hot pressing on the tensile strength of decorative board. The results suggested that it is proper to set the hot-pressing temperature between 130～150℃, pressure at about 0.2MPa and time at 20minutes or so. After that, by an orthogonal design program the optimal hot-pressing process was confirmed as follows: temperature of 140℃, pressure of 0.2 MPa and time of 30minutes.