Alkyds are the dominant binders in commercial oil-based coatings. They are technically polyesters modified with natural oils or fatty acids, which grants them their signature ease of application.
: Alkyds are prized for their versatility and durability. However, they are prone to yellowing in interior settings and may lack long-term gloss retention in exterior environments compared to pure polyesters. 2. Polyester Resins: The "Oil-Free" High-Performers
: They are categorized by their "oil length," which refers to the ratio of oil to dibasic acid: Resins for Surface Coatings. Alkyds & Polyesters
: They offer superior mechanical properties, including high impact and abrasion resistance, alongside excellent aesthetic texture.
: Versatile for both industrial and decorative finishes. Alkyds are the dominant binders in commercial oil-based
Often referred to as , polyester resins are synthetic polymers where monomers are joined by ester bonds without the addition of fatty acids.
: Typically composed of roughly 60% fatty acids (e.g., soybean, linseed, or tung oil), 20% pentaerythritol, and 20% phthalic anhydride. However, they are prone to yellowing in interior
The specialized text is a foundational technical manual in paint technology, detailing the chemistry, production, and application of these two critical resin families. While both are essentially polyesters, they are distinguished by their chemical modification and end-use performance. 1. Alkyd Resins: The Oil-Modified Workhorse