Cobalt based drying catalysts

In order to come to an economy that is sustainable in all respects it is of utmost importance that biobased materials are able to make an enlarged contribution to products where a long service lifetime is required. The aim of the work described in this paper is to make a contribution to biobased products requiring a long service time. In this paper research and development activities towards phthalate free, isosorbide based plasticisers, high solid alkyd resins and cobalt free drying catalysts are described. 

Although these alternatives can be applied in specific systems, their overall performance does not match up to that of cobalt based driers the paint films usually remain too soft, whereas manganese also has a negative impact on the film colour. At A F a biomimetic approach is being followed to develop alternative cobalt free drying catalysts. 

Cobalt-based catalysts also attracted researehers attention as an aetive metal for dry reforming of methane. Cobalt-supported catalysts (Co/Zr02) modified with different metal additives were recently studied by Ozkara-Aydinoglu et The addition of manganese to Co/Zr02 improved the metal dispersion properties on the surface and had a stabilising effect on the catal3dic activity (80% of its activity was maintained after 6 h. Table 11.2, entry 9) with the suppression of coke formation nevertheless, this effect was not so pronounced as with other promoters. 

Industrial polymerisation processes with the use of titanium-, cobalt- and nickel-based aluminium alkyl-activated Ziegler-Natta catalysts, which are employed for the manufacture of cis- 1,4-poly butadiene, involve a solution polymerisation in low-boiling aromatic hydrocarbons such as toluene or in a mixture of aromatic and aliphatic hydrocarbons such as n-heptane or cyclohexane. The polymerisation is carried out in an anhydrous hydrocarbon solvent system. The proper ratio of butadiene monomer and solvent is blended and then completely dried in the tower, followed by molecular sieves. The alkyla-luminium activator is added, the mixture is agitated and then the transition metal precatalyst is introduced. This blend then passes through a series of reactors in a cascade system in which highly exothermic polymerisation occurs. Therefore, the reaction vessels are cooled to slightly below room temperature. 

Naphthenic acid n, A carboxylic acid derived from petroleum refining and usually one of a mixture of similar compounds. The mixed acids and some of their soaps, e.g., cobalt naphthenate and calcium naphthenate, are useful as catalysts or accelerators in curing polyester resins and as drying agents in paints and varnishes. Commercial naphthenic acids are not pure compounds, but consist of a mixture of acids based on cyclopentane rings. 

The complex of cobalt with Schiff base was dissolved in 24 mmol of APTES, then 48 mmol of TEOS were added to this system. The obtained solution was placed on an ice-bath and 0.26 mol of H2O was added while mixing. After a few minutes, the mixt ire was solidified. It was crushed, allowed to stand at room temperature for two hours, and dried for six hours at 100°C. The solid was washed with water (600ml) and dried at 100°C once more. The obtained catalyst was a light-brown powder. The product yield was 6 g. For the preparation of incorporated Cosalophen complex with Cco=10.8.10 mol/g, 10ml of DMFA was added to the systems. 

---