Cobalt salts naphthenate

Oxidation of Cyclohexane. The synthesis of cyclohexanol and cyclohexanone is the first step in the transformation of cyclohexane to adipic acid, an important compound in the manufacture of fibers and plastics. Cyclohexane is oxidized industrially by air in the liquid phase to a mixture of cyclohexanol and cyclohexanone.866 872-877 Cobalt salts (naphthenate, oleate, stearate) produce mainly cyclohexanone at about 100°C and 10 atm. The conversion is limited to about 10% to avoid further oxidation by controlling the oxygen content of the reaction mixture. Combined yields of cyclohexanol and cyclohexanone are about 60-70%. 

This takes place in the liquid phase, around 145 to 175 0. between 0.8 and 1.10 Pa absolute, in the presence of a soluble cobalt salt (naphthenate or ocxoate), as shown in Section 10.1.6.1 concerning phenol synthesis. Once-through conversion is 4 to 6 per cent and the total yield of a cyciohexanol/cydohexanone mixture, adipic add and its esters is about 80 molar per cent (Stamicdrbon process). 

The action of redox metal promoters with MEKP appears to be highly specific. Cobalt salts appear to be a unique component of commercial redox systems, although vanadium appears to provide similar activity with MEKP. Cobalt activity can be supplemented by potassium and 2inc naphthenates in systems requiring low cured resin color lithium and lead naphthenates also act in a similar role. Quaternary ammonium salts (14) and tertiary amines accelerate the reaction rate of redox catalyst systems. The tertiary amines form beneficial complexes with the cobalt promoters, faciUtating the transition to the lower oxidation state. Copper naphthenate exerts a unique influence over cure rate in redox systems and is used widely to delay cure and reduce exotherm development during the cross-linking reaction. 

A number of different cobalt salts have been used in the oxidation of toluene, the most common being cobalt acetate [71-48-7] cobalt naphthenate, and cobalt octoate [1588-79-0],... 

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). 

Cobalt salts are used as activators for catalysts, fuel cells (qv), and batteries. Thermal decomposition of cobalt oxalate is used in the production of cobalt powder. Cobalt compounds have been used as selective absorbers for oxygen, in electrostatographic toners, as fluoridating agents, and in molecular sieves. Cobalt ethyUiexanoate and cobalt naphthenate are used as accelerators with methyl ethyl ketone peroxide for the room temperature cure of polyester resins. 

In the Dupont process, cyclohexane is reacted with air at 150 °C and 10 atm pressure in the presence of a soluble cobalt(II) salt (naphthenate or stearate). The conversion is limited to 8-10% in order to prevent consecutive oxidation of the ol-one mixture. Nonconverted cyclohexane is recycled to the oxidation reactor. Combined yields of ol-one mixture are 70-80%.83,84,555 The ol-one mixture is sent to another oxidation reactor where oxidation by nitric acid is performed at 70-80 °C by nitric acid (45-50%) in the presence of a mixture of Cu(N03)2 and NH4V03 catalysts, which increase the selectivity of the reaction. The reaction is complete in a few minutes and adipic acid precipitates from the reaction medium. The adipic acid yield is about 90%. Nitric acid oxidation produces gaseous products, mainly nitric oxides, which are recycled to a nitric acid synthesis unit. Some nitric acid is lost to products such as N2 and N20 which are not recovered. 

Metal—Carbon Bonds in Cobalt-Catalyzed Polymerization. Concentrations of metal-carbon bonds were determined (using tritium labelled alcohol) with increase in conversions. Experiments were made in two solvents (petrol and benzene) with two cobalt salts (chloride and naphthenate) under conditions giving rise either to liquid mixed structure or to high trans polybutadiene. The data are summarized in Table XI. Table XII and Figure 11 shows optical properties of some cobalt salts and complexes. 

Soluble cobalt salts (acetate or naphthenate) are used as catalysts, most often together with manganese and bromide ions. Particularly in the presence of bromide source (as HBr, sodium bromide, or even organic bromides), the rate of the oxidation of methylbenzenes increases by up to 400 x. None of the other halogens approaches bromide in its promoting activity. The maximum effect is achieved with a 1 1 cobaltrbromine atomic ratio. 

Active catalysts for butadiene polymerization are obtained from aluminium alkyl halides and soluble Co and Co salts and complexes. The structure of the organic grouping attached to the cobalt is not important, but compounds most widely employed are acetylacetonates and carboxylic acid salts such as the octoate and naphthenate. The activity of the catalyst and structure of the polymer are affected by the groupings in the complex. Catalysts from aluminium trialkyls and cobalt salts other than halides are relatively unstable and give syndiotactic 1,2-polybutadiene. If halogens are present, e.g., from CoClj or CoBrj,... 

In the Dupont process, cyclohexane is reacted with air at 150 °C and 10 atm pressure in the presence of a soluble cobalt(ll) salt (naphthenate or stearate). The conversion is limited to 8-10% in order to prevent consecutive oxidation of the ol-one mixture. Nonconverted cyclohexane is... 

At lower temperature the equilibrium is shifted in favor of the allophanate but the rate of equilibrium decreases and at room temperature no reaction occurs in 2 weeks. Metal carboxylates (naphthenates, 2-ethylhexanoates, linoresinates of Pb, Co, Cu, Mn, Fe, Cd, V, Zn) were found to accelerate this reaction very appreciably. Particularly active are the lead and cobalt salts which caused complete conversion at room temperature in a few hours. All the metal salts with the exception of the zinc salts also catalyze the... 

Caswell No. 226 CCRIS 772 Cobalt naphthenate Cobalt naphthenates, powder Cobalt(ll) naphthenate Cobaltous naphthenate EINECS 263-064-0 EPA Pesticide Chemical Code 025101 Naftolite Naphtenate de cobalt Naphthenic acid, cobalt salt UN2001. 

Commercially, mther cobalt powder or soluble cobalt salts of fatty acids or naphthenates are used, depending upon the process. Usually a quantity of catalyst equivalent to about 0.5-5 mole per cent of cobalt is used. 

In the fixed-bed -process, shown schematically in Fig. 11-12, soluble cobalt salts of fatty acids or naphthenates are pumped with the olefin to the top of the first reactor and flow countercurrent to the synthesis gas. One type of fixed-bed catalyst consists of 2 per cent metallic cobalt on a pumice carrier. Part of the cobalt is converted to carbonyl, leaves the reactor with the overhead product, and is replaced by the cobalt salts in the feed. A high recycle of cooled crude product to the converter mds in controlling the reaction temperature. Unreacted synthesis gas leaving the top of the reactor is coo ed, passed through a packed tower countercurrent to the olefin feed to remove cobalt carbonyl, and recycled to the reactor. 

An industrially important example of such a process is the oxidation of cyclohexane to cyclohexanone and cyclohexanol. Cobalt salts are used as multifunctional catalysts. Cyclohexane is generally oxidized in the presence of about 20 ppm of a soluble cobalt salt such as cobalt naphthenate in the liquid phase at 125-165 °C and 8-15 bar up to a conversion of 10-12 %. 

Synonyms Cobalt naphthenate Cobalt naphthenate, powder Cobaltous naphthenate Naphthenic acid cobalt salt Definition Obtained by treating cobaltous hydroxide with naphthenic acid... 

Naphthenic acid, calcium salt. See Calcium naphthenate Naphthenic acid cobalt salt. See Cobalt naphthenate (ous)... 

The autoxidation reactions are promoted by catalysts which are organic salts of polyvalent heavy metals. By far the most powerful of these are cobalt salts, e.g. cobalt octanoate (2-ethylhexanoate, C4H9CH(C2H5)C00H) or cobalt naphthenate, and these are usually accompanied by other organic salts, e.g. of lead, zirconium or calcium. 

Cobalt drier n. One of the many organic cobalt salts (cobalt, naphthenate, cobalt octoate, etc.) which are soluble in paints and varnishes and used to speed the drying and hardening of the oil vehicle. They are also used to accelerate oxidation and polymerization of an ink film. 

Supported Ziegler catalysts are also used [154-156]. High cis contents up to 98% can be obtained with cobalt salts [cobalt octanoate, cobalt naphthenate, tris(2,4-penta-dionato) cobalt] in combination with alumoxanes which are synthesized in situ by hydrolysis of chlorodiethylaluminum or ethylaluminum sesquichloride. Only 0.005 to 0.02 mmol of cobalt salt is needed for the polymerization of 1 mol of 1,3-butadiene [157-159]. At 5 °C the molecular weight varies from 350 000 to 750 000 depending on the alkylaluminum chloride, while at 75 °C the variation is between 20 000 and 200,000. The polymerization rates are fast over a considerable range of chloride content. The 1,4-structure increases with chloride content. The molecular weight increases with the chloride level [160]. 

An important additive to NR compounds used for bonding rubber to brass is a cobalt salt, such as cobalt naphthenate. While this additive improves the stability of the rubber-brass bond, especially in a corrosive environment, it exerts a negative effect on the stability of the rubber network, in that it accelerates reversion phenomena especially in the presence of oxygen and at elevated temperatures. 

Cobalt is important to the rubber industry to promote rubber-to-metal adhesion. The use of cobalt salts, such as cobalt stearate or cobalt naphthenate as compounding additives, will promote better adhesion between cured rubber and brass-coated steel tire cord. 

Cobalt Salts. Barker" studied the effects of cobalt stearate, cobalt naphthenate, and a proprietary boron-containing metal-organic complex on adhesion to brass. He concluded that, with properly optimized compounds, little or no benefit is obtained from the use of cobalt insofar as initial adhesion is concerned. All salts, however, improved steam-aged adhesion to some extent. Other studies tend to support these claims. 

Catalysts and accelerators used in the manufacture of thermosets include peroxides, organic nitrogen compounds and copper and cobalt salts of naphthenic and other organic acids. 

Lead salts of organic acids, the original driers, function as polymerization catalysts throughout the entire paint film depth in contrast, cobalt salts function as surface driers. Hence, until recently, combinations of lead and cobalt driers have been used to achieve a uniform drying rate. Manganese and zirconium salts may be used in place of lead. Many organic acids have been used to form these heavy metal salts, but the most widely used salts are naphthenates, which are based on naphthionic acid, a residue of petroleum resinous. Other acids used to produce driers are octoic, tallic, rosin, and linolenic acids. 

The cobalt catalyst can be introduced into the reactor in any convenient form, such as the hydrocarbon-soluble cobalt naphthenate [61789-51 -3] as it is converted in the reaction to dicobalt octacarbonyl [15226-74-17, Co2(CO)g, the precursor to cobalt hydrocarbonyl [16842-03-8] HCo(CO)4, the active catalyst species. Some of the methods used to recover cobalt values for reuse are (11) conversion to an inorganic salt soluble ia water conversion to an organic salt soluble ia water or an organic solvent treatment with aqueous acid or alkah to recover part or all of the HCo(CO)4 ia the aqueous phase and conversion to metallic cobalt by thermal or chemical means. 

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