关键词: 超细纤维合成革, 水性聚氨酯, 含浸, 甲苯减量, 柔软丰满

Abstract: Combined with the requirements of polyurethane impregnation and toluene-reduction process in the manufacture of microfiber synthetic leather, according to the relationship among the structure of water-based polyurethane and the resistance to toluene, the aromatic polyisocyanate and solvent-resistant polyol are used as the main raw materials to synthesize a series of microfiber impregnated water-based polyurethanes(WPU). The toluene-resistant and other properties of WPU films were investigated by the mechanical properties testing, dynamic thermal mechanical analysis （DMA）, differential scanning calorimeter （DSC）, respectively. Then the waterborne polyurethane was applied in impregnation and toluene-reduction process and the impregnating effect, involving the de-weighting ratio, thickness and softness of resultant base, and its surface and cross section structure were investigated in detail. Finally, by adjusting the impregnation and solidification methods, the influence of the impregnation-solidification process on the final performance of the superfiber base was also investigated .The results show that the toluene-resistance of WPU is related to its polarity and crosslinking degree, PBA is better than that of PTMG, especially, when the mass ratio of PBA: PTMG is controlled at 1∶1, the comprehensive performance of the waterborne polyurethane is acceptable and the resultant base is soft and fullness. Increasing the numbers of impregnation, changing the composition of the impregnating slurry, and employing the wet coagulation process can effectively improve the thickness or softness of the microfiber base. Solvent-based polyurethane is replaced by waterborne polyurethane, which can reduce the use of organic solvents and emissions and reduce the environmental pollution.

Key words: microfiber synthetic leather, waterborne polyurethane, impregnation, toluene de-weighting, softness and fullness