Лако-красочные материалы — производство

Plasticizers are used to control brittleness of the glue line and to regulate the speed of drying. Commonly used plasticizers act in one of three ways: by forming a solid solution with the dried adhesive, by controlling the moisture in the film, and by lubricating the layers within the dried adhesive. Plasticizers that form a solid solution, such as urea, sodium nitrate, salicylic acid, and formaldehyde, tend to decrease the viscosity of the adhesive preparation. Urea is the most commonly used of these additives, and it may be added at a level of 1-10% based on dry starch. Hygroscopic plasticizers such as glycerol and ethylene glycol are commonly used to decrease the drying rate of the film and ensure that the film does not become brittle. Soaps, polyglycols, and sulfonated oil derivatives are used in small amounts as lubricating adhesives to impart permanent flexibility to the glue line, since they are not affected by changes in humidity.