Cerium paint

Paint Driers and Polymer Additives. Paints based on alkyd resins (qv) dry by the oxidation and cross-linking of unsaturated side chains. Metal catalysts are included in paint formulations to promote this drying. Cerium carboxylates, eg, the naphthenate, are used as through driers, ie, to promote drying in the body of the paint film rather than at the film s surface (44). 

Cobalt in Driers for Paints, Inks, and Varnishes. The cobalt soaps, eg, the oleate, naphthenate, resinate, Hnoleate, ethyUiexanoate, synthetic tertiary neodecanoate, and tall oils, are used to accelerate the natural drying process of unsaturated oils such as linseed oil and soybean oil. These oils are esters of unsaturated fatty acids and contain acids such as oleic, linoleic, and eleostearic. On exposure to air for several days a film of the acids convert from Hquid to soHd form by oxidative polymeri2ation. The incorporation of oil-soluble cobalt salts effects this drying process in hours instead of days. Soaps of manganese, lead, cerium, and vanadium are also used as driers, but none are as effective as cobalt (see Drying). 

Paint dryers, cerium application, 5 688 Paint formulations, 18 60, 61t Painting... 

Metal catalysts, included in paint formulations promote drying. Cerium carboxylates are used as Through driers, i.e. to promote drying in the body of the paint film [20]. 

The secondary and through driers are of a group of metals, including lead, zirconium, calcium and cerium, which assist the drying of the lower layers of the paint film by mechanisms which are not fully understood, but probably involve interactions of the metal with carboxyl (and perhaps hydroxyl) groups in the film-former. Because lead is a cumulative poison, permissible levels of lead in household paints have been reduced so much that paint manufacturers now formulate paints of this type without the use of any added lead at all. 

In stoving paints it is usually satisfactory to include low levels (0.01-0.05% metal on binder) of a single primary drier. Cobalt, manganese, cerium and iron (which only acts as a drier at higher temperatures) are used. Unacceptable discoloration in pale colours can be a hazard, particularly with iron and cerium. 

A paint grade of cerium sulfide has also been developed. The pigment has been evaluated in several coatings formulations such as automotive refinish (acrylic-isocyanate binders), general industrial solvent-based systems (polyester-melamine bin-... 

In comparison to organic pigments, cerium sulfide formulations have a high Per-soz level of hardness, coupled with good direct impact resistance. This produces very good gravel impact resistance. Chemical resistance (acid, base and solvent) has been evaluated in paint by the drop test. No specific problem was detected except for organic acids such as acetic acid. 

Paint grade cerium sulfide pigments exhibit very good durability in both the xenon test and outdoor exposure. In QUV-A testing, however, the humidity conditions of the experiment are too severe to be representative of outdoor exposure. 

Florida exposure has been evaluated (with a refinish acrylic-isocyanate formulation). Paint grade cerium sulfide outperforms cadmium sulfides, and is equivalent to that of lead pigments (Figure 4—14). In comparison with organic pigments, cerium sulfide paint grade also has a good durability. 

Cerium sulfide pigments are also good candidates for automotive paints, due to the IR reflectance properties of Cerium compounds (Figure 4—15). 

Abstract The incorporation of rare earth compounds as corrosion inhibitors in polymeric paint systems is presented. Specifically, uses of cerium salts in an electrolytically deposited coating commonly used in the automotive industry and praseodymium oxide in spray applied epoxy-polyamide primers for aerospace applications are discussed. Special emphasis is placed on the importance of phase of the rare earth material in relation to polymeric matrix as the effectiveness of the corrosion inhibition is strongly link to the starting materials, the formulated paint system and the ambient environment in which the coating operates in practice. 

Using cerium-based inhibitors in eCoat paints... 

Successful incorporation of rare earth corrosion inhibitors irrto a polymeric coating was initially done using cerium oxide, hydrated oxide and nitrate compounds in an electrolytically deposited eCoat paint or primer. Incorporation of less than... 

Developing rare earth-based inhibitors for paint systems may present different issues. As discussed below, there is a developing body of work on rare earth organophosphates, " and the health risks of these compounds depends more on the oiganophosphate anion than the cerium ion. As can be seen in Table 7.2,... 

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