Surfactant leaching of acrylic (latex) paints, also known as exudate staining, streak staining, streaking, weeping, exudation, etc., occurs when the freshly painted surface becomes wet and water-soluble components of the paint (

dispersant A dispersant or a dispersing agent is a substance, typically a surfactant, that is added to a suspension of solid or liquid particles in a liquid (such as a colloid or emulsion) to improve the separation of the particles and to prevent their se ...

s, surfactants,

thickener A thickening agent or thickener is a substance which can increase the viscosity of a liquid without substantially changing its other properties. Edible thickeners are commonly used to thicken sauces, soups, and puddings without altering their t ...

glycol A diol is a chemical compound containing two hydroxyl groups ( groups). An aliphatic diol is also called a glycol. This pairing of functional groups is pervasive, and many subcategories have been identified. The most common industrial diol is e ...

s, etc.) leach out of the paint in sticky brown streaks.Handbook of Odors in Plastic Materials
p. 28
/ref> This may happen, e.g., due to rain or dew for exterior surfaces, or water vapor condensation on interior ones. On the external surfaces the streaks will normally weather off in several weeks, and removal of them before that time is impractical, especially because it may damage the paint before it is completely cured. The streaking phenomenon may also be observed for some silicone

sealant Sealant is a substance used to block the passage of fluids through openings in materials, a type of mechanical seal. In building construction ''sealant'' is sometimes synonymous with '' caulking'' and also serve the purposes of blocking dust, so ...

s. The leaching effect should be taken into an account by manufacturers when formulating latex paints. A common approach is replacing water-soluble ingredients with

volatile organic compound Volatile organic compounds (VOCs) are organic compounds that have a high vapour pressure at room temperature. High vapor pressure correlates with a low boiling point, which relates to the number of the sample's molecules in the surrounding air, a ...

s (VOCs), which are not environmentally safe.crylates—Advances in Research and Application: 2013 Edition, Chapter 2: Metacrylates
p. 685
/ref>

References

{{reflist, 2 Paints Solid-solid separation

See also

References