Iron driers

Iron. This is a specialty drier that is considered active at temperatures of about 130°C. For this reason iron 2-ethyIhexanoate [19583-54-1] is used in bake coatings that require maximum hardness. The principal drawback of using iron driers is that iron contributes a characteristic brownish red color to the coating and should only be used in dark pigmented systems. It has been reported that iron aids the dispersion of carbon black pigment and reduces the tendency for orange peel film defects (6). 

Iron driers n. Iron salts of naphthenic acid, 2-ethyl hexoic acids or other acids, which actively accelerate polymerization at elevated temperatures, but are only feebly active at room temperature. The presence of the very dark ferric ion makes them applicable in dark or tinted finishes. The British call then iron soaps. Wicks ZN, Jones FN, Pappas SP (1999) Organic coatings science and technology, 2nd edn. Wiley-Interscience, New York. 

Para-chlor-ortho-nitraniline n. Pigment red 6 (12090). The parachlor variety of chlorinated para red is redder (less yellow) in shade and more transparent compared to the ortho-chlor but much superior in lightfastness. It is superior in tint lightfastness to toluidine red. Special precautions are required in drier addition to parachlor red paints since it discolors (dark and dull) with cobalt and/or iron driers. Syn parachlor red. 

Iron and cerium driers effectively catalyze polymerization and through-drying at elevated temperatures and therefore are used in baking enamels. Iron driers have the limitation of dark color, and hence cerium based driers are often preferred where color retention is important. 

Iron driers are used in heat-cured paints where the poor color can be accomodated. Temperatures above 100°C are required for catalytic activity, but high film hardness is obtained. 

Air oxidation of dyestuff waste streams has been accompHshed using cobalt phthalocyanine sulfonate catalysts (176). Aluminum has been colored with copper phthalocyanine sulfonate (177,178). Iron phthalocyanine can be used as a drier in wood oil and linseed oil paints (179). 

A.ctive driers promote oxygen uptake, peroxide formation, and peroxide decomposition. At an elevated temperature several other metals display this catalytic activity but are ineffective at ambient temperature. Active driers include cobalt, manganese, iron, cerium, vanadium, and lead. 

Cerium/Rare Earth. Cerium 2-ethyIhexanoate [56797-01-4] and rare-earth driers promote polymerization and through dry. Like iron they are active at elevated temperature and, since they do not contribute to film discoloration, are recommended for white bake finishes and overprint varnishes where color is critical. Rare earths also find use at the other end of the temperature spectmm in coatings dried at low temperature and high humidity. 

Naphthenates of cobalt, manganese, calcium, copper, iron, zinc, and zirconium are used as driers in printing inks. Their use in coatings is declining as a result of the use of higher metal content synthetic driers and the overall trend to latex paint in architectural coatings. 

A fire, followed by an explosion at Huddersfield in 1900 was also caused by detonation of iron picrate (presumably Fe++). The iron picrate had been formed on the surface of steam pipes located in the Picric Acid drier shop. It ignited when a plumber, unaware of the fact, struck one of the pipes with a hammer. The flame spread along the pipe and set the drying Picric Acid on fire... 

Host microorganisms, for industrial enzyme production, 10 264-265 Host oxide lattice structure, 19 403 Hot air food driers, 12 85 Hot and cold composite curves, 13 222 Hot-box resins, 12 273 Hot briquetted iron (HBI), 14 492-494, 509 21 412... 

The operational safety of this recovery installation is far from perfect. Explosions in driers caused by the impact of steel or even brass tools against iron, by the friction of powder strips against the iron edge of driers or by the electrification of powder strips, are well known. 

A continuous drier of the Petrie type is outlined in Fig. 132. This drier is a sheet-iron box about 4.5 m high, about 6.0 m long, and 1.25 m wide. In this box five or six slatted shelves are constructed. Between the slats a system of movable slats is arranged so as to propell the cotton in one direction, by a series of upward and forward movements. After each forward movement the slats are lowered and return... 

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