A large number of light metals, composites and plastics were introduced into the new automobile structure, which resulted in the continuous growth of automobile adhesives and sealants.
The most widely used polyurethane adhesives in automobiles include one-component wet curable polyurethane sealant for windshield assembly, structural adhesives for bonding glass fiber reinforced plastics and sheet moulding composites, two-component polyurethane adhesives for interior parts and waterborne polyurethane adhesives. Automotive interiors are also an area where the amount of adhesives is increasing. In the past quite a long period of time, China's automobile manufacturing industry has been importing polyurethane windshield adhesive from abroad, until the "Eighth Five-Year Plan" period, the development of this adhesive was included in the national key scientific and technological projects. Waterborne polyurethane adhesives widely used in automobiles refer to the adhesives formed by polyurethane dissolved in water or dispersed in water. Most waterborne polyurethanes are linear thermoplastic polyurethanes. Because their coatings are not cross-linked and their molecular weight is low, their water resistance, solvent resistance, film strength and other properties are still poor. It is necessary to modify them to improve their properties. The hybrid dispersions of polyester and acrylic acid are combined with urea diketone and isocyanurate to prepare automobile repairing varnish, which does not need high speed mixing equipment and is easy to mix together and has good adhesion performance.