The purpose of this blog post is to provide a thorough answer to this basic question, what are water based coatings?
Waterborne coating is a general term used to describe any surface coating or finish that uses water as a solvent to disperse the resin added to it to create the coating.
Composition varies and may include as much as 80% water with small amounts of other solvents such as glycol ethers. High water content makes waterborne coatings both environmentally friendly and easy to apply.
What Makes A Waterborne Coating Different?
Waterborne finishes are very like their solvent based counterparts in terms of curing mechanism, polymer makeup, and film integrity. Chemical composition is also similar as water plays an identical role in the production of waterborne finishes as that played by thinners, such as mineral spirits or toluol, in solvent based finishes.
Waterborne Coating Applications
Waterborne finishes offer a broad variety of application, including automobiles, concrete, furniture, plastic, wood, and even printing inks, and are compatible with both conventional and electrostatic application equipment.
Resin types with waterborne finishes cover a broad range including acrylic, alkyd, epoxy, fluoropolymer, polyester, urethrane, and waterborne powder.
Similarly, they work under a variety of curing chemistries, including air dry thermoplastic, aminoplast, epoxy – polyamide, oxidative, urethrane, and UV cure.
The Primary Categories of Water Based Coatings
There are three primary categories of coatings designated as waterborne: water – soluble or water – reducible, water – dispersible or colloidal, and emulsion or latex.
Water – Soluble
Water – soluble refers to coatings in which individual molecules of resins dissolve completely in water.
Creation of water – soluble coatings takes place in an organic medium through a process of polycondensation or polymerization reaction; accordingly, these typically contain organic co solvents such as alcohol or glycol ethers.
These types of waterborne coatings only 30-40% solid content by weight, and most baked coatings fall under this heading.
Water – Dispersable
Water – dispersable refers to resins first made in solvent and later reduced in water resulting in small particles of insoluble resin dispersed in water. This type of waterborne coating also involves the use of organic solvents as coalescing agents, but these are in small amounts that evaporate on drying.
Colloidal dispersions are used primarily for applications on porous material such as leather or paper.
Emulsions are not dissimilar to water – dispersible coatings. Resin particles in emulsions tend to cluster in larger groups and require the presence of an emulsifier to remain suspended throughout the water base.
Emulsions are more permeable than other waterborne coatings allowing them to “breathe” and reducing the risk for blistering or peeling. Architectural coatings, such as interior and exterior paints, fall under the heading.
So, if you are in need of some help when it comes to water based coatings then make sure you get in touch with CJ Coatings today for more information.