Preparation method of carboxyl-containing epoxy resin tanning agent

Abstract

A preparation method of a carboxyl-containing epoxy resin tanning agent comprises the steps: adding a sodium hydrogen sulfite aqueous solution into a reactor, then heating to 50-65 DEG C, dropwise adding allyl glycidyl ether, methacrylic acid and an ammonium persulfate aqueous solution with stirring, followed by carrying out a constant temperature reaction for 3-5 h at the temperature of 50-65 DEG C, finally, cooling to the room temperature, regulating the pH value of the obtained reaction system to 2.0-5.5, and thus obtaining the carboxyl-containing epoxy resin tanning agent. The preparation method of the tanning agent is simple and convenient in operation process; the tanning agent has a certain tanning effect and is combined with 3% of a chromium powder to tan sheep skin acid skin, the shrinkage temperature of crust leather after being tanned is allowed to reach about 110 DEG C, and the thickening rate is allowed to reach about 105%; and at the same time, compared with a 8% chromium powder traditional tanning method, the Cr2O3 content in waste liquid after chrome tanning is reduced by about 77.5%.

Description

technical field [0001] The invention belongs to the technical field of leather chemical synthesis, relates to a tanning agent used in the leather tanning process and a preparation method thereof, in particular to a preparation method of a carboxyl-containing epoxy resin tanning agent. Background technique [0002] In the tanning industry, chrome tanning agent is currently the most widely used and the largest amount of tanning agent due to its excellent leather performance, low cost and mature technology. However, chromium is a scarce resource. According to surveys, chromium resources are currently in short supply. At the same time, the absorption and utilization rate of chromium in bare leather in the traditional chrome tanning method is relatively low, only about 70%, and a large amount of unabsorbed chromium Compounds are discharged along with tannery wastewater, causing serious pollution to the environment. At present, tanning workers have begun to focus on research on c...

AI Technical Summary

Problems solved by technology

However, the research of epoxy resin tanning agents in the leather industry has been in a slow and almost stagnant state, mainly because the reaction time between epoxy resin and collagen is long (generally 3-5 days), the dosage is large, and the shrinkage temperature is relatively high. Low, in addition, R.J.Heath et al. believe that leather researchers lack a deep understanding of epoxy chemistry is also a reason for the slow development of epoxy resin tanning agents (Heath R.J., Di Y., Clara S., et al.Epoxide tannage: a way forward[J].Journal of the Society of Leather Technologists and Chemists,2005,89(5):186-193;Heath R.J.,Di Y.,Clara S.,et al.The optimization of epoxy-based tannage systems -an initial study[J].Journal of the Society of Leather Technologists and Chemists,2005,89(3):93-102)

[0004] Most of the traditional epoxy resins are solvent-based, which will release a large amount of organic pollutants during use, causing pollution to the environment; at the same time, the amount of organic solvents is large, and the price is much higher than that of water, which is extremely important in industrial production. Not advisable