Resins are typically viscous substances that convert into rigid polymers through a curing process. They are naturally occurring but are now often made synthetically. Some synthetic resins have similar properties to natural plant resins, but many are very different.
Resins have many sources and end uses. From paints and coatings to personal and home care, pharma, rubber, plastics, electrical, jewellery and decorative items and many more.
Resins in paints and coatings
When it comes to paints and coatings resin acts as a binder to hold the pigment particles together and provide adhesion to the surface painted.
Water based paints most often use acrylic emulsion polymers as binders. These come in a wide variety of types and combinations. Common acrylic polymer types are based on monomers such as methyl methacrylate and butyl methacrylate. Traditionally, lower cost paints have been formulated on PVA (Poly Vinyl Acetate) binders.
Solvent-based resins are termed ‘alkyd resins’ and are normally used in enamel paints. Urethane alkyds often used in clear varnishes. Protective coating resins include types such as Epoxy, Urethane, Polysiloxane and Moisture Cured Urethane.
Enamel paint, is generally made from an alkyd resin that is dissolved in a solvent. As the solvent evaporates in the first stage, it forms a tacky lacquer. The resin reacts with the oxygen in the air and forms a hard coating.
Coating paints have two components that are unreactive alone. However, when they are placed together, they undergo a chemical reaction. The reaction may take some time, depending on the room's temperature. The result is a hard, tough coating that has great adhesion.
As new technologies continue to develop, the boundaries between water-based, solvent-based, and reactive coatings are becoming blurry. For instance, some enamels have water-based emulsion resins that produce polymerisation of the dried film. This is similar to what is currently seen in solvent-based enamels.
Advantages of resins
· They can be easily dyed, coloured and mixed with metal powders or fluorescent
pigments.
· They have great precision.
· There is a large variety of resin available with different properties.
· They have a great variety of applications.
· They possess a great water resistance.
· They have high thermal and mechanical properties.
· They have a very high environmental and chemical resistance.
Chemgrit Coatings supplies a variety of constituents used for the manufacture of various types of paints and coatings. These are sourced from leading suppliers around the world. For more information contact Chemgrit Coatings on www.chemgritsa.co.za or athol@chemgritsa.co.za.
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