Preparation method of acrylic acid retanning agents

Abstract

The invention provides a preparation method of acrylic acid retanning agents, which comprises the following steps: adding 1500 to 1620 kg of acrylic acid into an overhead tank 1; carrying out polyreaction; adding 150 to 160 kg of chain transfer agents into an overhead tank 2; adding 180 kg of triggering agent solution containing 16 to 20 kg of triggering agents into an overhead tank 3; adding 60 to 80 kg of oxidizing agent solution with the content of 50 percent into an overhead tank 4; adding 20 kg of regulating agent solution containing 1.8 to 1.9 kg of regulating agents into an overhead tank 5; adding 500 to 600 kg of water into a reaction kettle; adding 16 to 20 kg of pH buffer solution; then, heating materials in the reaction kettle to a temperature between 98 and 102 DEG C; simultaneously opening condenser circulation water; at the time, simultaneously beginning to add the acrylic acid, the chain transfer agents and the triggering agents with the material adding time between 4 and 5 hours; controlling the temperature between 98 and 102 DEG C in the period; cooling the materials in the reaction kettle to 80 to 85 DEG C after the material addition is completed; adding the regulating agent solution; continuously carrying out reaction for 1 to 2 hours at 80 to 85 DEG C; then, adding 690 to 700 kg of 30 percent sodium hydroxide solution and simultaneously adding 250 kg of water; regulating the pH value to 4 to 4.5 for continuous reaction for 30 min; raising the temperature in the reaction kettle to 100 DEG C; adding the oxidizing agent solution in 1 to 1.5 hours; preserving the temperature for 2 to 4 hours at 100 DEG C after the addition; lowering down the temperature to 55 to 60 DEG C; adding 1800 to 2000 kg of water to regulate the content to the specified content; and carrying out mixing for 30 min at 55 to 60 DEG C.

Description

technical field [0001] The present invention relates to a kind of preparation method of retanning agent for tanning, more specifically, what the present invention relates to is the preparation method of a kind of acrylic acid retanning agent for tanning. Background technique [0002] Retanning is an important and indispensable process in the process of leather making, known as the "golden touch" of leather making. Retanning can improve the fullness and firmness of the leather, reduce the difference in parts, etc., and is also conducive to the operation of the subsequent finishing process. Acrylic polymer retanning agent has good water dispersion and good binding ability with leather, strong filling effect, obvious thickening effect on leather, and can also endow leather with good softness, fullness and elasticity. At the same time, the carboxyl group in the acrylic retanning agent has a strong complexing ability with chromium, so it can promote the absorption of chromium an...

AI Technical Summary

Problems solved by technology

[0003] Acrylic retanning agent is mostly carried out by the method of solution polymerization in water medium, the reaction temperature is 70-80 ℃, the molecular weight distribution is wide, and the molecular weight is too large, which is not conducive to the operation of the production and use process

The initiator uses ammonium persulfate or potassium persulfate, the initiation temperature is low and the speed is fast, which is not conducive to the control of molecular weight