Primer stain blocking

Uses Styrene-acrylic for maintenance finishes, high gloss enamels, waterproofing masonry coatings, interior stain blocking primers, architectural primers, automotive refinish, metal coatings, concrete curing membranes... 

Uses Acrylic, wet adhesion modifier for water-based stain blocking primers... 

Chem. Descrip. Sec. short oil alkyd emulsion in Dl water Uses Alkyd for air-dry stain blocking or wood penetrating coatings, interior wood primers... 

Primer vehicles based on emulsion polymer technology were introduced in the 1970s and have shown a steady increase in market share over the past 30 years. They are used in a variety of exterior and interior coating applications. Stain blocking primers are one of the most popular types, and are used to prevent discoloration of topcoats by a variety of materials, including tannin stains from wood, children s marker stains, water stains and nicotine stains. Water based primers generally block the transport of stains by two principle mechanisms ... 

While the stain may be visible at the surface of the primer coating after drying, it is effectively locked into the film and does not lead to discoloration of the topcoat. Binders for stain blocking primers are usually based on relatively hydrophobic emulsion polymers with acrylic or styrene acrylic compositions. Primers are expected to have excellent adhesion, and water based primers are formulated to adhere to a variety of substrates including metal, wood, and chalky or aged re-paint surfaces. Since this level of performance may not be needed, or achievable, in many topcoat formulations, the use of specialized primers offers a flexible and cost effective way to meet the performance needs of many different coating apphcations with a limited number of optimized topcoat products. 

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