Preparation Of Highly Absorptive Cationic Auxiliary For Leather Dyeing And Fat-liquoring

The previous auxiliaries for leather dyeing and fat-liquoring focused on problem in color fastness and "light color effect", with the function to improve the absorption of dyeing and fat-liquoring, which have been rarely reported to specialize in. The cationic auxiliary for leather dyeing and fat-liquoring were prepared, which can not only promote the absorption to reduce the pollution, but also to eliminate "light color effect" and guarantee the quality of leather.Highly absorptive cationic auxiliary for leather dyeing and fat-liquoring was synthesized with cationic vinyl monomer, acrylamide and acrylate, and application experiments were carried out, and the assay method to measure the content of dyeing was studied.When synthesizing the two-component auxiliary with cationic vinyl monomer and acrylamide, the effect on conversion of monomer and limiting viscosity of the polymer from chain-transfer agent, mass percent of monomer, temperature, pH were researched. The result shows, (1) the special chain-transfer agent favors to regulate the relative molecular weight of polymer, the more the dosage of it is, the lower the limiting viscosity of the polymer. (2) When increasing the dosage of the initiator, the limiting viscosity of polymer increases first, then decreases. When the mass percent is 0.35%, the limiting viscosity is highest. At the beginning of the reaction, the more the initiator is, the higher the limiting viscosity and conversion are. During the molecular balance, the less the initiator is, the higher the limiting viscosity is. Whenthe dosage of initiator exceeds some mass percent, the conversion is not affected from it. (3) When increasing the mass percent of monomer, the conversion increases first, then decreases. (4) When increasing reaction temperature, the limiting viscosity of polymer increases first. When it reaches 55 ℃, the conversion and the limiting viscosity are the highest, and if the temperature continues increasing, then it has no effect on conversion. At the beginning of the reaction, the higher the temperature is, the higher the conversion and limiting viscosity are. During molecular balance, the higher the temperature is, the lower the limiting viscosity is. (5) At the beginning of the reaction, the higher pH is, the higher the conversion is, but the final conversion is not the case.As regard to three-component highly absorptive cationic auxiliary for leather dyeing and fat-liquoring, the effect on conversion of monomer, limiting viscosity of polymer, the turbidity and absorption of the exhausted liquid from dyeing and fat-liquoring, the blackness and feeling of leather from monomer ratio(A), mass percent of monomer(B), dosage of initiator (C), temperature(D), time(E), pH value(F) were studied by orthogonal experiment, and the sequence are as follows, F >A>B>D>E>C, B>C>D>F>E>A, B>A, F>D>E>C, B>C> D>F>A>E, A>B>F>C> E>D, B>A>F, C> E>D, which set base for synthesis condition, e. g., how to balance the blackness and feeling of leather, the absorption of the exhausted liquid, and the conversion.The dyeing and fat-liquoring experiments show that within some scope of limiting viscosity, the auxiliary of less limiting viscosity is suitable for pig skin and sheep pelt, whose fiber are tightly knitted, while the auxiliary of higher one is suitable for buffalo hide, whose fiber is looser. When adopting the method of ' Sandwich' or pre-treating with auxiliary before dyeing and fat-liquoring, better absorption of dyeing and fat-liquoring and deep color effect are obtained, and the finished leather is tighter. So experiment scheme and dosage of auxiliary are chosen according to the concrete condition of crust and specific requirement of the product.Highly absorptive cationic auxiliary for leather dyeing and fat-liquoring wasscreened out, which can be practically industrialized.When dyeing and fat-liquoring, if the fat-liquoring is well absorbed, then the absorption in visible light area is low, while the absorption of dyeing is relatively high, so visible spectrometry can be used to measure the cont...