Paint types silicone alkyds

Where circumstances suggest the use of a more conventional type of finishing paint with better tolerance of site application conditions than the above, silicone alkyd enamels should be considered. 

Binders, vehicles, or resins may be of several types. AUsyd resins are among the most common and are composed of polymers of alcohols and adds—thus the term alkyd -ale from alcohol, -yd standing for add). Acrylic resins are based on polymers of methacrylate and methyl methacrylate (esters. Figure 11.32) similarly, vinyl resins are derived from vinyl chloride. Urethanes (polyurethanes) and some silicon-based resins are also encountered. Watercol-or paints use gum arabic as a binder. This material is obtained from the sap of the acacia tree and, when dry, forms a dear, water-soluble polymer matrix. 

Paints and coatings can be divided into two categories convertible type which need a chemical reaction, such as oxidation or polymerization, and the non-convertible type which are formed by evaporation of the solvents. The former category includes alkyds, epoxy, esters, polyesters, urethenes, silicon and other resins. 

There are numerous types of paints based on silicone which are combined either with alkyd or acrylic resin. Pure silicone resists temperature up to 600°C and has excellent weathering properties. The copolymer is obtained by reaction between the hydroxyl groups in the alkyd resins with the hydroxyl groups in the silicon intermediates. 

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