Calcium drier

Chem. Descrip. Calcium drier Uses Drier in org. coatings, inks, polyesters Proper Gardner 4 max. liq. sp.gr. 0.855-0.890 dens. 7.13-7.43 lb/ gal vise. (Gardner) A max. flash pt. 104 F (PMCC) 4.0 0.1% metal Troymax Drier Calcium 5% [Troy]... 

Cobalt Naphthenate Zirconium Drier Manganese Drier Calcium Drier... 

Chem. Descrip. Calcium drier based on sat. branched-chain syn. acid Uses Paint drier promoting pigment wetting... 

Branched-chain acids have a wide variety of industrial uses as paint driers (7), vinyl stabilizers (8), and cosmetic products (9). Cobalt and manganese salts of 2-ethyIhexanoic acid and neodecanoic acid are used as driers for paint, varnishes, and enamels litbium, magnesium, calcium, and aluminum salts of 2-ethyIhexanoic acid are used in the formation of greases and lubricants (see Driers and metallic soaps). Derivatives of isostearic acid have been used as pour point depressants in two-cycle engine oils, as textile lubricants, and in cosmetic formulations. Further industrial appHcations can be found (10). 

A.uxilia driers do not show catalytic activity themselves, but appear to enhance the activity of the active drier metals. It has been suggested that the auxihary metals improve the solubiUty of the active drier metal, can alter the redox potential of the metal, or function through the formation of complexes with the primary drier. Auxihary driers include barium, zirconium, calcium, bismuth, zinc, potassium, strontium, andhthium. 

Cobalt. Without a doubt cobalt 2-ethyIhexanoate [136-52-7] is the most important and most widely used drying metal soap. Cobalt is primarily an oxidation catalyst and as such acts as a surface or top drier. Cobalt is a transition metal which can exist in two valence states. Although it has a red-violet color, when used at the proper concentration it contributes very Httie color to clear varnishes or white pigmented systems. Used alone, it may have a tendency to cause surface wrinkling therefore, to provide uniform drying, cobalt is generally used in combination with other metals, such as manganese, zirconium, lead, calcium, and combinations of these metals. 

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. 

Metal Linoleates and Resinates. The calcium and cobalt salts of Hnoleates and resinates are used chiefly as components of metallic driers used in printing inks. Copper Hnoleate [7721-15-5] is used in antifouling paints for marine use (4). 

The net result is formation of water and a high concentration of free radicals. The cobalt cycles between the two oxidation states. Lead and 2irconium salts cataly2e drying throughout the film and are called through driers. Calcium salts show Httle, if any, activity alone, but may reduce the amount of other driers needed. 

Periodically, the drier is recharged with fresh calcium chloride. 

A paint rarely consists solely of pigment dispersed in a solution of a binder. For one reason or another, small quantities of ancillary materials called additives are included. The oldest and still the most important are the driers which are used in all air-drying and many stoving paints containing drying oils. They are organic salts of certain metals, notably cobalt, calcium, barium, zirconium and manganese, with lead very much in decline. 

E-SOX A flue-gas desulfurization process. The gas is contacted with calcium hydroxide or sodium hydroxide solution in a spray drier, and the resulting particles are trapped in an elec-tostatic precipitator. Developed and piloted by the U.S. Environmental Protection Agency. 

The rates at which nonconjugated drying oils dry are slow. Metal salts (driers) arc known to catalyze the drying rate. The most widely used are the oil-soluble cobalt, manganese, lead, zirconium, and calcium salts of 2-ethylhexanoic acid or naphthenic acids. See also Paints and Coatings. 

Combinations of metal salts arc almost always used. Although mixtures of lead with cobalt and/or manganese are particularly effective, toxicity regulations ban the use of lead driers in consumer paints sold in interstate commerce in the United States, Combinations of cobalt and/or manganese with zirconium, and frequently also with calcium, are commonly used. The amounts of driers needed are very system specific. Their use should be kept to the minimum possible level since they not only catalyze drying but also catalyze the post-drying embrittlement and discoloration reactions. 

Experimental investigations and theoretical computations of SO2 absorption in a spray drier [47] showed that, with an excess of calcium hydroxide absorption is limited only by the gas-phase mass transfer. In addition, the flow in a spray drier could be described by the model of an ideal stirred vessel. Newton et al. [70] considered the subprocesses of mass transfer of SO2 from the gaseous phase to the drop surface, the absorption, the dissociation of SO2, the diffusion of the produced species and the dissolution of calcium hydroxide particles in the drop. 

Typical CAN granulators include drums and pugmills. The calcium carbonate may be mixed with the AN solution before granulation or in the granulator itself. Granules from this process will normally require drying in a fluidized bed or rotary drier.103... 

---