It is reported that the environment-friendly water-based adhesive uses water as the solvent, and the hot-melt adhesive uses no solvent as the solid adhesive, which theoretically solves the fundamental problem of "toxicity".
      The solvent-free reactive polyester hot melt adhesive is crosslinked with the help of water or heat to achieve good adhesion strength. As a high-performance environment-friendly adhesive, hot-melt adhesive is a technology developed in the 12th Five-Year Plan.
      Compared with solvent-based polyurethane adhesive, water-based polyurethane adhesive has no odor of solvent, is non-toxic, is easy to clean, has high solid content, and is easy to handle. In the 1990s, the environmental protection laws and regulations of European and American countries became increasingly strict, and waterborne polyurethane adhesive was applied industrially.
      In recent years, the news that is not conducive to China's footwear exports frequently appears. For example, the detection of azo, phthalic acid and other chemical substances implemented by the EU has become a powerful weapon for the EU to resist Chinese footwear products. Europe and the United States and other places not only detect the VOC content of footwear products, but also detect the residue of footwear storage space, objectively becoming a technical barrier for footwear exports.
      Of course, the production of water-based adhesives requires high comprehensive performance, such as solid content of more than 50%, hydrolysis resistance, etc.
      In view of the fact that the environment-friendly water-based adhesive has not become the mainstream at present, Li Ruiyang, deputy general manager of Brilliant Chemical, believes that the cost is not a problem, and the key is the awareness of shoe manufacturers. Li Ruiyang analyzed that 80%~85% of solvent-based glue is solvent, and the effective solid content is not more than 20%, while the solid content of water-based glue is more than 50%, which is three times of that of solvent-based glue. The selling price of water-based adhesive on the market is about 2~2.5 times that of solvent adhesive. In terms of conversion, water-based adhesive is not only inexpensive, but also relatively cheaper.