Anticorrosion Coating

Commercial paint Sol-gel epoxysilica Peel-Off (600 hours) Perfect adhesion 

There are hundreds of commercially available trialkoxy-substituted monomers bearing a wide variety of functional groups, which largely 

Good adhesion of the layer is necessary, but not sufficient, to inhibit corrosion. Indeed, all three films show good adhesion to the surface (the films were scratched to visualize the removal effect, and to increase the 

---

Powder Coating. Nylon-11 and nylon-12 are used in powder form for anticorrosion coating of metals. Dip coating and electrostatic and flame spraying are used. Dip coating, which involves immersing a preheated article into fluidi2ed nylon powder, is most suitable for automation. 

Sulfonic acid salts have found widespread use in the area of corrosion inhibition. Lubrizol Corporation produces a wide variety of sulfonic acids, particularly in the form of magnesium salts, for use in lubricant formulations, anticorrosion coatings, greases, and resins (146,147). Petroleum sulfonates are used in epoxy resin elastomers to improve anticorrosion properties of coatings and sealants (qv) (148,149). 

Until the end of World War II, coal tar was the main source of these aromatic chemicals. However, the enormously increased demands by the rapidly expanding plastics and synthetic-fiber industries have greatly outstripped the potential supply from coal carbonization. This situation was exacerbated by the cessation of the manufacture in Europe of town gas from coal in the eady 1970s, a process carried out preponderantly in the continuous vertical retorts (CVRs), which has led to production from petroleum. Over 90% of the world production of aromatic chemicals in the 1990s is derived from the petrochemical industry, whereas coal tar is chiefly a source of anticorrosion coatings, wood preservatives, feedstocks for carbon-black manufacture, and binders for road surfacings and electrodes. 

An extensive survey of accelerated test methods for anticorrosive coating performance which emphasizes the need to develop more meaningful methods of testing has been pubUshed (129). The most powerful tool available is the accumulated material in data banks correlating substrate, composition, apphcation conditions, and specifics of exposure environments with performance. 

Epoxy-silica hybrids are well known for their abrasion resistance and low thermal expansion due to the presence of nanostructured bi-continuous domains. Most recently they have entered the market as anticorrosion coatings in the marine held, for yachts and for large metal vessels, such as oil tankers, and in particular for cargo or ballast tanks and on hulls (Figure 4.9). 

Anticoccidial activity, of polyether antibiotics, 20 135-136 Anticoccidials, 20 135—136 Anticorrosion agents, molybdenum compounds in, 17 39 Anticorrosion coatings, organic titanium compounds in, 25 134 Anti-corrosion metallic coatings, 1 713-714 Anticorrosion pigments, 19 411 Antidegradants... 

OX AZO I, ID I NFS ANI) TETRAMETHYLXYLEN EDIISOCYANATE BASED POLYURETHANES IN LEGISLATION-COMPLIANT ANTICORROSION COATINGS... 

Polyurethanes are frequently used in anticorrosion coatings. The R D drive of most coatings and resin producers is the reduction of the solvent content of the paint and resin systems. One method of achieving the environmental aims demanded by legislation in the PU coatings industry is to use oxazolidines which are suitable as latent hardeners to enable production of single-pack moisture activated PUs. The isocyanate chosen for this research is tetramethylxylene diisocyanate, which has been available commercially only since 1988. 19 refs. 

PVBs are also used as binders for inks, and anticorrosion coatings. 

Benzotriazole has also been used as an additive in anticorrosive coatings for silver layered on plastic film <89JAP8909733). An anticorrosive, electromagnetic wave-shielding coating containing tolyltriazole has been developed for aluminum <91EUP437979). 

The change in the toxicological classification of lead- and chromate-based anticorrosive pigments has resulted in reappraisal of the formulation of anticorrosive coatings. 

Exterior surface corrosion or rusting of pipes occurs by the formation of iron oxides. Painting to an appropriate specification will significantly extend the period to the onset of corrosion, but the durability of the paint finish is largely dependent on the quality of the surface preparation as well as the thickness of the coated film. Improperly installed insulation can provide ideal conditions for corrosion and should be weatherproofed or otherwise protected from moisture and spills to avoid contact of the wet material on equipment surfaces. Application of an impervious coating such as bitumen to the exterior of the pipes is beneficial in some circumstances. Hypalon and neoprene rubber-based anticorrosive coatings admixed with chlorinated rubber are finding use in many installations. 

Figure 4.20. Elementary process flow sheets for molding an internal (a) and an external (b) anticorrosive coatings by the contmuous/subsequent filling method 1 - cylinder (shell) being coated, rotating on supports ...

Fabrics coated with FEP and PFA can be laminated and heat-sealed into protective garments, canopies, etc. FEP-coated polyimide films are used in electronics and as a wire tape. FEP-based anticorrosion coatings are used in the chemical industry and as chemical barriers.18 A thin coating of FEP or PFA can be used as a hot melt adhesive for a variety of substrates, including PTFE-coated fabrics and laminates. 

---