In lacquers, propylene glycol monomethyl ether acetate (PM acetate) is most useful as a retarder solvent to improve flow and leveling, prevent drying defects, and manage the evaporation rate. It is a slow-evaporating solvent with a mild odor, high solvency, and good compatibility with many lacquer resins. When to use PM acetate in lacquers You should use PM acetate in a lacquer formulation in the following situations:
To prevent blushing. Blushing is a milky film that can form on a lacquer finish, especially in humid conditions, when fast-evaporating solvents cause the surface to cool rapidly. Adding a slow-evaporating retarder like PM acetate helps the coating dry more slowly and evenly, preventing moisture from condensing on the surface.
To improve flow and leveling. Lacquers can sometimes dry too quickly, which results in surface imperfections like brush marks, orange peel, and cratering. The slow evaporation of PM acetate keeps the lacquer wet longer, allowing it to flow out and create a smooth, glossy film.
For enhanced film formation. By controlling the drying time, PM acetate allows the lacquer polymers to align properly as the film forms. This promotes superior film integrity, adhesion, and overall performance. When formulating with specific resins. PM acetate is an excellent solvent for a variety of resins commonly used in lacquers, including cellulose acetate butyrate and nitrocellulose. Its compatibility with these polymers makes it a reliable choice for achieving a stable and well-performing formula.
In combination with fast-evaporating solvents. Lacquers often use a combination of solvents to control the drying process. In these "high-low" systems, PM acetate is the slow-evaporating or "tailing" solvent. It is added in small amounts to fine-tune the evaporation curve and ensure a high-quality finish without slowing the dry time excessively.
