Cobalt naphthenate catalyst

A new crosslinkable polymer was synthesized by the SBP-catalyzed polymerization of cardanol. When HRP was used as catalyst for the cardanol polymerization, the reaction took place in the presence of a redox mediator (phe-nothiazine derivative) to give the polymer. Fe-salen efficiently catalyzed the polymerization of cardanol in organic solvents (Scheme 29). " The polymerization proceeded in 1,4-dioxane to give the soluble polymer with molecular weight of several thousands in good yields. The curing of the polymer took place in the presence of cobalt naphthenate catalyst at room temperature or thermal treatment (150°C for 30 min) to form yellowish transparent films ( artificial urushi ... 

Adipic acid is produced by oxidizing cyclohexane. The two-step process shown in Figure 18—1 is used for almost ail production. Cyclohexane is oxidized with air over a cobalt naphthenate catalyst to give a mixture of... 

Benzoic acid is synthesized by liquid-phase toluene oxidation over a cobalt naphthenate catalyst with air as the oxidizing agent. An older process involving halogenation of toluene to benzotrichloride and its decomposition into benzoic acid is still used available. 

Such a form is more amenable to analysis. Spielman (2) used the data of Ciborowski (3) and assumed the concentration of oxygen in the system remained constant and also that the high temperature and presence of a cobalt naphthenate catalyst caused the hydroperoxide to decompose extremely rapidly so that it does not appear in the kinetic scheme. He then calculated the pseudo first order rate constants of this scheme. Assuming the bulk phase was not saturated with oxygen, these rate constants must be a function of the available interfacial area. 

Oxidation of cyclohexane, usually in two stages, gives adipic acid. In the first stage cyclohexane is oxidized with air in the presence of a cobalt naphthenate catalyst under moderate conditions to give a mixture of cyclohexanol and cyclohexanone (Eq. 19.57, stoichiometry only). 

The first step is performed in liquid phase with air as oxidizing agent under pressures of 3.5-5 atm to maintain liquid conditions. With a cobalt naphthenate-catalyst, temperatures in the range of 120-130 C are adequate, whereas without catalyst the temperatures need to reach 145-150 0. An important feature of the process is the relatively low per-pass conversion of about 15 per cent of the cyclohexane charge. Water formed by the oxidation reaction and impurities in the feedstock such as sulfur-containing compounds and other hydrocarbons are removed azeotropically as reaction proceeds. Unless reaction water is removed, the air-oxidation ceases after about 25-30 per cent conversion. Removal of feed impurities and oxidation by-products results in a clean recycle stream. 

As a possible application of glycerol-based polyesters, new crosshnkable polyesters were synthesized via a lipase CA-catalyzed polymerization of divinyl sebacate and glycerol, in the presence of unsaturated higher fatty acids derived from renewable plant oils [110, 111]. The curing of the polymer obtained from hnoleic or hnolenic acid proceeded via a cobalt naphthenate catalyst or thermal treatment to produce a crosshnked transparent fUm with good biodegradabiHty. 

The first stage in the production of adipic acid is the oxidation of liquid cyclohexane with air using a cobalt naphthenate catalyst at temperatures in the range at 140°-160°C and pressures about 8-12 bar. A mixed ketone/alcohol oil containing cyclohexanol (CeHnOH) and cyclohexanone (CeHioO) (KA oil) is produced at up to 85% selectivity, with the ketone/alcohol ratio of about 1 1. The conversion is only about 10% and unconverted cyclohexane is recycled. The process was improved by Bashkirov by the additions up to 5% boric acid to the cyclohexane and by restricting the oxygen content of the air to about 4%. The overall yield was increased to more than 90% and conversion to more than 12%. The ketone/alcohol ratio was decreased to 1 9. 

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. 

In the other market areas, lead naphthenates are used on a limited basis in extreme pressure additives for lubricating oils and greases. Sodium and potassium naphthenates are used in emulsiftable oils, where they have the advantage over fatty acid soaps of having improved disinfectant properties. Catalyst uses include cobalt naphthenate as a cross-linking catalyst in adhesives (52) and manganese naphthenate as an oxidation catalyst (35). Metal naphthenates are also being used in the hydroconversion of heavy petroleum fractions (53,54) and bitumens (55). 

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. 

The oxidation of cyclohexane to a mixture of cyclohexanol and cyclohexanone, known as KA-od (ketone—alcohol, cyclohexanone—cyclohexanol cmde mixture), is used for most production (1). The earlier technology that used an oxidation catalyst such as cobalt naphthenate at 180—250°C at low conversions (2) has been improved. Cyclohexanol can be obtained through a boric acid-catalyzed cyclohexane oxidation at 140—180°C with up to 10% conversion (3). Unreacted cyclohexane is recycled and the product mixture is separated by vacuum distillation. The hydrogenation of phenol to a mixture of cyclohexanol and cyclohexanone is usually carried out at elevated temperatures and pressure ia either the Hquid (4) or ia the vapor phase (5) catalyzed by nickel. 

A route to phenol has been developed starting from cyclohexane, which is first oxidised to a mixture of cyclohexanol and cyclohexanone. In one process the oxidation is carried out in the liquid phase using cobalt naphthenate as catalyst. The cyclohexanone present may be converted to cyclohexanol, in this case the desired intermediate, by catalytic hydrogenation. The cyclohexanol is converted to phenol by a catalytic process using selenium or with palladium on charcoal. The hydrogen produced in this process may be used in the conversion of cyclohexanone to cyclohexanol. It also may be used in the conversion of benzene to cyclohexane in processes where benzene is used as the precursor of the cyclohexane. 

PEER polymers can be cured with traditional radical initiators such as methyl ethyl ketone (MEK) peroxides and benzoyl peroxide (BPO). Curing can be carried out either at room temperature or at elevated temperature. A PEER polymer containing 30 % maleic anhydride can be cured at room temperature with MEK peroxides in 10 to 60 min, depending on the type of peroxide used (Table 22.2). To cure a PEER resin with MEK peroxides at room temperature, a co-catalyst is needed. The commonly used cobalt naphthenate works very well in this case, while another co-catalyst, dimethyl aniline, is very efficient for the BPO system. 

The present procedure is adapted from that reported by Hartmann and Seiberth4 and Hock and Susemihl.6 Robertson and Waters 6 employed cobalt naphthenate as a catalyst, but this is not required. 

EP-4 developed by ERDL is a very flexible polyester based on polyethylene glycol with molecular weight-200 (PEG-200), isophthalic acid (IPA) and maleic anhydride (MAn). Before its use, it is blended with styrene monomer (1 1) and cured at room temperature using cobalt naphthenate (as an accelerator) and methyl ethyl ketone (MEK) peroxide (as a catalyst). This meets the requirements of the main inhibitor and is used for inhibition of DB and CMDB propellants after the application of a barrier coat (generally a rigid polyester such as PR-3). However, it is observed during manufacture of EP-4 that there is a lot of batch-to-batch variation in properties in spite of the strict quality control measures adopted during its manufacture. 

Hydroformylation, or the oxo process, is the reaction of olefins with CO and hydrogen to make aldehydes. The catalyst base is cobalt naphthenate which transforms to cobalt hydrocarbonyl in place. A rhodium complex that is more stable and functions at a lower temperature also is used. 

Fig. 6. Influence of catalyst systems on cure rate effect of dimethylaniline (DMA) on cure rate of cast polymer resin at 25°C. Initiator system contains cobalt naphthenate (0.5%), MEKP (1.0%), and one of the following A, DMA (0.0%) B, DMA (0.05%) or C, DMA (0.1%).

To provide improved control over the polymerization and additional safety, it is possible to add the catalyst to the concrete mix before curing and to add the promoter to the monomer used for impregnating. Benzoyl peroxide when incorporated in premixed concrete will initiate polymerization of methyl methacrylate at room temperature when cobalt naphthenate is added to the monomer used for impregnation. 

Other Cobalt Compounds. Catalysts prepared from cobalt oleate, octoate, and acetyl acetonate have also been examined. The characteristics of the reactions were the same as with cobalt chloride and naphthenate. The results are shown in Table X. 

It is now well established that many cobalt compounds activated with an alkylaluminum halide may induce polymerization of butadiene to a polymer of over 96% cis-1,4 content (17, 22, 25, 28, 29, 36, 37). To obtain a catalyst of high catalytic activity, it is desirable to use cobalt compounds that are soluble in the polymerization solvent such as cobalt naphthenate or a complex of C0CI2 with A1C13 (37) or pyridine (28). An effective catalyst is also formed by dissolving C0CI2 in ethanol (solubility, 54 grams in 100 ml.) and dispersing this solution in the polymerization solvent (6). 

Benzoyl peroxide, C HsCO-O-O-COCtHg, or methyl ethyl ketone peroxide, CH3C2Hs-C(0-0) CCzH5 CH3 is used as a catalyst. To initiate the reaction at room temperature it is necessary to add another substance ouch as cobalt naphthenate, (Cdimethyl aniline, C H (CH3), to produce an initiator, e.g. free radicals C6H C 00(benzoil radical). 

The effect of several catalysts on the reaction between 80 20-TDI and a ten-molar excess of diethylene glycol adipate was also reported by Bailey et al. [153]. o-Chlorobenzoyl chloride was a slight retarder tertiary amines and cobalt naphthenate were catalytic. 

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