A kind of preparation method of environment-friendly aldehyde acid leather tanning agent

Abstract

The invention discloses a preparation method of an environment-friendly aldehyde acid leather tanning agent, and belongs to the technical field of leather tanning agents. The method comprises the steps that (1) alkali is added into 40-50 wt% of glyoxylic acid to adjust the pH value to range from 7 to 8, and standing is achieved for standby application; (2) alkali is added into 40-50 wt% of glutaraldehyde to adjust the pH value to range from 7 to 8; and (3) a reaction solution obtained in the step (2) is slowly added into a reaction solution obtained in the step (1), water is added to adjust the solid content of a solution system to range from 30% to 35%, reacting is carried out for 1.5 h to 3.0 h under the condition with the temperature ranging from 80 DEG C to 95 DEG C to obtain a product, and the molar ratio of the glyoxylic acid to the glutaraldehyde is (2.5-3.5):1. By means of the method, the glutaraldehyde is modified through the glyoxylic acid, sodium glyoxylate is made to be excessive to the greatest extent, leather can be prevented from being yellowed, the shrinkage temperature of the treated leather is larger than 90 DEG C, and the thickening rate is larger than 20%.

Description

technical field [0001] The invention belongs to the technical field of leather tanning agents, and in particular relates to a preparation method of an environment-friendly aldehyde acid leather tanning agent, in particular to a preparation method of an environment-friendly leather tanning agent modified with glyoxylic acid glutaraldehyde. Background technique [0002] Leather refers to the denatured and non-perishable animal skin obtained through physical and chemical processing such as depilation and tanning. Compared with animal hides, the leather produced through a series of processing techniques has the advantages of non-perishability, moisture and heat resistance, water resistance and extensibility. Therefore, improving the leather processing techniques to meet the needs of various industries is the need of the market. It is also a need to improve human living standards. [0003] Tanning is an important link in the whole leather processing process, which is the process...

AI Technical Summary

Problems solved by technology

[0008] (1) It can only be used as a pre-tanning agent. After the pre-tanning treatment, it is still necessary to use chrome tanning agent for chrome tanning, which cannot solve the problem of chrome pollution;

[0009] (2) The problem of the yellowish color of the finished product of glutaraldehyde tanning is not solved;

[0010] (3) The problem of substandard thickening rate of finished products tanned with glutaraldehyde was not solved;

[0011] (4) The product preparation method is complicated and the conditions are harsh, and it needs to be carried out under the protection of nitrogen. At the same time, it needs to be distilled or refluxed to remove water, and it is also necessary to add water and acid to adjust the pH value and solid content;

[0012] (5) The product has a strong pungent smell, and the user experience is not good;

[0013] (6) Carcinogens such as benzene are used in the production process, polluting the environment and endangering human health