Preparation method of fatty alcohol ether modified styrene-maleic anhydride tanning agent

Abstract

The invention relates to a preparation method of a fatty alcohol ether modified styrene-maleic anhydride (SMA) tanning agent. The method comprises the following steps: adding SMA copolymer, fatty alcohol ether and catalyst in a reactor provided with a condensing device, adding organic solvent to react, measuring the hydroxyl value of the reaction system to ensure that the hydroxyl value is less than 10mgKOH / g according to the total amount of the reactant, removing solvent through reduced pressure distillation, neutralizing with alkaline solution, and adjusting the solid content of the productto obtain SMA fatty alcohol ether monoester salt. The tanning agent prepared by the method can maintain the filling property of the SMA tanning agent and improve the defect that the flexibility of the crust leather is poor after retanned by using the SMA tanning agent. Meanwhile, the modified SMA tanning agent has good emulsifying dispersity, is easy to emulsify and has excellent retanning and fatliquoring properties; and the retanned crust leather is plumpy and soft, and has good elasticity and higher thickening rate, tensile strength and tear strength.

Description

technical field [0001] The invention relates to the technical field of leather chemical production, in particular to a preparation method of fatty alcohol ether modified SMA tanning agent. Background technique [0002] The sodium salt after hydrolysis and neutralization of SMA (SMA-Na for short) can be used in the retanning process in the leather industry. Fine grain, clear pores, plump leather body, can improve the grade of finished leather, especially suitable for white leather and light-colored leather. At the same time, it has a certain absorption and fixation effect on chromium, which can reduce the chromium content in the waste chromium solution. Therefore, SMA-Na has been widely used in the leather industry. [0003] The disadvantage of SMA-Na as a leather retanning agent is that when the amount is large, the finished leather feels hard. At the same time, because the tanning agent contains a large number of carboxyl groups, it has a repulsive effect on negatively c...

AI Technical Summary

Problems solved by technology

[0006] In order to overcome the above-mentioned shortcoming of prior art, the purpose of the present invention is to provide a kind of preparation method of fatty alcohol ether modified SMA tanning agent, the prepared tanning agent has not only kept the inherent filling performance of SMA tanning agent, but also improves the re-combination of SMA tanning agent. The shortcoming of insufficient softness of crust leather after tanning, at the same time, the modified SMA tanning agent has good emulsification dispersion, easy emulsification, excellent retanning and fatliquoring performance, and the body of retanned crust leather is plump, soft and Good elasticity, increased thickness, tensile strength and tear strength