A kind of chromium-containing leather retanning filler and preparation method thereof

Abstract

The invention provides a preparation method of a chromium-contained retaining-filling agent. The method comprises the steps that (1), 100 parts of chrome leather scrap hydrolysate, 20 parts to 100 parts of retanning agents, 1 part to 5 parts of masking agents and 3 parts to 5 parts of fatting agents are metered, then, the masking agents and the solid retanning agents are dissolved with water, the fatting agents are diluted and emulsified through water, and acidifying or alkalizing agents are compounded with water to form acidifying or alkalizing agent solutions; (2), the chrome leather scrap hydrolysate is heated to 45 DEG C to 50 DEG C under stirring, then, the chrome leather scrap hydrolysate, the masking agents, and the solid retanning agents or / and liquid-state retanning agents which are at the same temperature and obtained in the step (1) are added into the chrome leather scrap hydrolysate and are evenly mixed, then, the acidifying or alkalizing agent solutions are added to adjust the pH value of mixed liquor to 1.5 to 4.5, undissolved substances are filtered out, and the chromium-contained retaining-filling agent is obtained, wherein the solid content ranges from 40 percent to 45 percent, the content of chromium sesquioxide ranges from 1.5 percent to 5 percent, and the pH value ranges from 1.5 to 4.5. According to the method, chromium and skin collagen protein in chrome leather scrap can be utilized at the same time, the prepared hromium-contained retaining-filling agent is more comprehensive in performance, and problems caused by an existing chemical modification manner can be solved.

Description

technical field [0001] The invention belongs to the field of leather chemical materials, in particular to a chromium-containing leather retanning filler and a preparation method thereof. Background technique [0002] Leather industry is an important light chemical industry, but also a traditional industry that produces serious pollution. A large amount of chrome-containing solid waste such as chromium-containing leather edges and leather scraps will be produced during the tanning process. If these solid chromium-containing wastes are not treated, they will cause serious environmental pollution, but waste chrome leather scraps are also a rich The skin protein resources and chromium resources. Therefore, rational resource utilization of chromium-containing solid waste can not only solve the problem of environmental pollution, but also recycle protein and trivalent chromium which have important economic value. [0003] In the prior art, chromium-containing leather shavings ar...

AI Technical Summary

Problems solved by technology

This method has the following disadvantages: (1) Since this method is to prepare chromium-containing protein filling retanning agent through chemical modification, and chemical modification requires long-term reaction at high temperature, long-term high-temperature reaction will undoubtedly lead to energy consumption and cost In addition, the reaction process also needs to control the dropping rate of monomer and initiator solution, which makes the operation more complicated; (2) because this method only uses acrylic monomers to chemically polymerize the hydrolyzate of chrome tanned leather shavings Modification, thus not only make the performance of the filled retanning agent product obtained single, the range of application of the product is limited, and the prepared finished leather still has the defect of discoloration; When the formic acid has been hydrolyzed, adjust the pH value of the system to about 5.0 and centrifuge to get the supernatant, but the solubility of chromium ions in the environment with a pH value of about 5.0 is limited, so part of the chromium ions will be precipitated and separated by centrifugation. If the operation is removed, on the one hand, the utilization rate of chromium will be reduced, and on the other hand, if the solid waste containing chromium ions cannot be properly disposed of, it will cause environmental pollution problems; The body is completely transformed, and the residual monomer will also cause harm to the environment