A kind of leather isolation layer finishing agent and its preparation method and leather

Abstract

The invention discloses a leather isolation layer finishing agent, a preparation method thereof and leather. The preparation method of the leather isolation layer finishing agent comprises: mixing 10-25 parts of isocyanate, 10-20 parts of glycol and 1-3 parts of hydrophilic extender React the chain agent at 70-90°C for 1-4 hours, add 0-5 parts of organic solvent, then cool down to 40-50°C, continue to add 1-3 parts of organic base and 150-200 parts of water, after the dispersion is uniform, then add 1-2.5 parts of amine chain extender to extend the chain, and stir for 1-2 hours to obtain water-based polyurethane containing amino groups in the end group; take 40-70 parts of the water-based polyurethane, add 30-60 parts of water-based epoxy resin, and stir for reaction 3~5h. In the preparation process of the coating agent for leather isolation layer of the present invention, no solvent is added, or only a small amount of organic solvent needs to be added, and there is no irritating taste during spraying, and the environment will not be polluted, and the coating agent is applied in the leather isolation layer, It has good wet scraping performance and heavy pressure off the board, and it does not stick to the board.

Description

technical field [0001] The invention relates to the technical field of leather manufacturing, in particular to a leather isolation layer finishing agent, a preparation method thereof and leather. Background technique [0002] In the current tanning technology, before the leather softening or embossing process, it is necessary to spray the isolation layer finishing agent to prevent the leather from being polluted by oil, dust and other pollutants during the softening process and the slurry layer in the subsequent process. The adhesion of the resin decreases, causing the upper layer of resin to fall off when the leather meets water, which seriously affects the quality and appearance of the leather. Spraying the isolation layer finishing agent can also prevent the coating from sticking and sticking to the board during the high-temperature embossing process of the leather, which will affect the normal operation of the subsequent process and affect the quality of the leather. Cu...

AI Technical Summary

Problems solved by technology

[0002] In the current tanning technology, before the leather softening or embossing process, it is necessary to spray the isolation layer finishing agent to prevent the leather from being polluted by oil, dust and other pollutants during the softening process and the slurry layer in the subsequent process. The adhesiveness of the resin decreases, causing the upper layer of resin to fall off when the leather meets water, which seriously affects the quality and appearance of the leather

Spraying the isolation layer finishing agent can also prevent the coating from sticking and sticking to the board during the high-temperature embossing process of the leather, which will affect the normal operation of the subsequent process and affect the quality of the leather

Currently, the coating agents for leather isolation layers used in the market are almost all nitrocellulose emulsions, and nitrocellulose emulsions are white powders that are insoluble in water. Therefore, nitrocellulose emulsions contain a large amount of organic solvents, and the amount of organic solvents exceeds the total mass of nitrocellulose emulsions. 45%, the nitrocellulose emulsion has a strong pungent smell, resulting in high VOC content (> 450g / L), and such a large amount of organic solvents volatilize into the air, which will have adverse effects on operators and working environment, and also It will cause serious pollution to the natural environment and does not meet the current environmental protection requirements

Images