Paint-grade fluororesin is an organic solvent-soluble or emulsion-type paint made by copolymerizing fluorinated monomers with vinyl or acrylic monomers, creating a coating with excellent weather resistance, heat resistance, and chemical resistance.
1. What is paint-grade fluororesin?
The general image of fluororesin is PTFE, known as Teflon®, often used for coating the inside of frying pans. However, this type of fluororesin has high crystallinity, is insoluble in solvents, and has a high melting point, making it unsuitable for typical paint applications. Instead, resins made by combining fluoromonomers like TFE or CTFE with vinyl monomers or acrylic monomers are commonly used for paints. These resins can have fluoromonomers and other monomers polymerizing either alternately or randomly. Additionally, water-based paints such as emulsion and dispersion types are available, and there are composite emulsions of PVdF and acrylic resins.
One of the key features of fluororesin is the strong C-F bond, which makes it highly resistant to UV rays, heat, and offers excellent durability including weather resistance, heat resistance, and chemical resistance. While standard urethane paint typically lasts around 10 years, fluororesin paint can endure for over 20 years in some cases. Moreover, the C-F bond has a short bond distance and low polarity, resulting in excellent water and oil repellency, and it forms a smooth coating. However, it tends to attract dirt, so it requires attention in applications where stain resistance is essential. Additionally, it can dissolve in organic solvents through copolymerization, and when monomers with hydroxyl or carboxyl groups are copolymerized, cross-linking can occur with curing agents.
Commercial paint-grade fluororesin typically contains hydroxyl groups, and it is combined with other polyol resins to create paint using curing agents such as melamine resin or polyisocyanate. Water-based emulsion-type fluororesins are used similarly to regular acrylic resin emulsions, with the addition of film-forming aids, to create highly weather-resistant paint suitable for exterior architectural applications.