Research on Polyurethane Adhesive for Packaging (I)

With the development of the food industry, flexible packaging has become more and more important. The quality of flexible packaging is closely related to the adhesive used, and polyurethane adhesives, due to their excellent properties, can be used for flexible packaging materials with various properties such as cold resistance, oil resistance, drug resistance, transparency, and abrasion resistance. Therefore, it plays an important role in adhesives for flexible packaging. The status. Polyurethane adhesives are divided into two components and one component. One-component polyurethane adhesives generally consist of an isocyanate-terminated prepolymer or its closure, and are produced by reaction with an active hydrogen-containing component or moisture in the air to cure; a two-component polyurethane adhesive consists of a terminal hydroxyl group ( Polyester or polyether polyols or their polyurethane-type hydroxy-terminated products formed together with diisocyanates, chain extenders, and isocyanate-based components. When the terminal hydroxyl group is a polyester polyol, it has high heat resistance, adhesive strength, oil resistance, and oxidation resistance, but its hydrolysis stability is poor; when the terminal hydroxyl group is a polyether polyol, it is better. The flexibility, low temperature resistance and water resistance, but poor strength and aging resistance.