Polyurethane resin for high-density shoe leather and preparation method thereof

Abstract

The invention relates to wet-process polyurethane resin for high-density shoe leather. The polyurethane resin is prepared from isocyanate, a polyether polyol mixture, a chain extender and N, N-dimethylformamide serving as an organic solvent. Polyoxytetramethylene-ethylene epoxide copolyether diol and polyoxypropylene diol are taken as macromolecular polylol raw materials for reacting, the raw materials have high hydrolysis resistance and the polyurethane resin can be endowed with high low-temperature flexibility and rebound resilience, so that the prepared high-density shoe leather has finer folds, high durability and high low-temperature adaptability, and recovers quickly. On the aspect of synthesis technology, a special process for stepwise reaction of two polyether polyols is designed,so that a macromolecular structure is more regular, and advantages of the two polyether polyols can be brought into play.

Description

technical field [0001] The present invention relates to a synthetic method of wet-process polyurethane resin for synthetic leather and its production process, in particular to a high-density polyurethane resin for shoe leather with high peeling resistance, hydrolysis resistance, crease resistance and low temperature flex resistance and its preparation method . Background technique [0002] At present, the high-quality shoe leather on the market is made through the wet on wet process, and the shoe leather made by this process is also called high-density shoe leather. [0003] The wet on wet process is to impregnate the non-woven fabric through the impregnation tank, and then directly coat a layer of working slurry on the surface of the non-woven fabric through the coating head without pre-solidification treatment, and then pass the non-woven fabric through the coagulation tank in turn Coagulation treatment and water washing treatment are carried out with the washing tank. A...

AI Technical Summary

Problems solved by technology

However, impregnation materials generally have low solid content and fast solidification speed, and coating slurry with high solid content and slow solidification speed will easily cause differences in solidification speed and cause shelling and other undesirable phenomena.