Bio-based amino resin re-tanning agent and preparation method thereof

Abstract

The invention belongs to the technical field of tanning materials, and particularly discloses a bio-based amino resin re-tanning agent and a preparation method thereof. The bio-based amino resin re-tanning agent is synthesized from the following raw materials in parts by weight: 100 parts of bio-based aldehyde, 5-50 parts of an amino compound and 5-20 parts of a solubilizer. According to the bio-based amino resin re-tanning agent provided by the invention, the adopted bio-based aldehyde basically does not contain free formaldehyde, so that after the bio-based aldehyde reacts with an amino compound, the product quality problem caused by continuous release of the free formaldehyde by an existing amino resin re-tanning agent re-tanned leather blank can be effectively solved, and the bio-based amino resin re-tanning agent meets the manufacturing requirements of ecological leather. According to the preparation method of the bio-based amino resin re-tanning agent, the adopted bio-based aldehyde is not prone to volatilization and free of irritation, meanwhile, the preparation method is simple, convenient, mild in condition, high in operability and convenient to popularize, and therefore the bio-based amino resin re-tanning agent has good operation friendliness and market competitiveness.

Description

technical field [0001] The invention relates to the technical field of tanning materials, in particular to a bio-based amino resin retanning agent and a preparation method thereof. Background technique [0002] The dyeing and finishing of leather is through the combination of retanning agent, fatliquoring agent, dyestuff and other chemicals in leather, endowing leather with good mechanical properties and sensory properties, and improving the use value of leather. The retanning process in dyeing and finishing has long been hailed as the "golden touch" of the tanning industry. It can endow crust leather with various styles and functional properties, and plays a very important role in the tanning process. Amino resin has good selective filling performance, can promote the combination of fatliquor, dye, etc. with leather, and improve its absorption rate, and is one of the most widely used products in the retanning process. Traditional amino resins are mainly heterochain polymer...

AI Technical Summary

Problems solved by technology

If the technical solutions provided by the above two invention patents are used to prepare bio-based amino resins, there will be the following two problems: 1) When bio-based aldehydes and amino compounds react under neutral and alkaline conditions, due to biological Aldehyde will undergo elimination reaction as shown in formula (1) and Cannizzaro reaction as shown in formula (2), resulting in structural transformation, the content of aldehyde group can be reduced by 99.7%, and the addition of amino compound is low, so it will make the final The molecular weight of the product is low, which makes it difficult to show good retanning filling performance; 2) When the bio-based aldehyde reacts with the amino compound under weak acidic conditions, although the aldehyde group can be retained and the two can undergo cross-linking and condensation reactions , to generate macromolecular polycondensation products. However, because the polycondensation products lack enough hydrophilic groups, the polycondensation products obtained under this condition are insoluble in water and further polycondensation reactions will occur during storage, which not only affects product stability. At the same time, due to its poor water solubility, it cannot fully penetrate into the interior of the leather, so it is difficult to play a good role in retanning and filling

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