Copper metal deactivators

When the operating temperature exceeds ca 93°C, the catalytic effects of metals become an important factor in promoting oil oxidation. Inhibitors that reduce this catalytic effect usually react with the surfaces of the metals to form protective coatings (see Metal surface treatments). Typical metal deactivators are the zinc dithiophosphates which also decompose hydroperoxides at temperatures above 93°C. Other metal deactivators include triazole and thiodiazole derivatives. Some copper salts intentionally put into lubricants counteract or reduce the catalytic effect of metals. 

The stabili2ation of polyolefins used to insulate copper conductors requires the use of a long-term antioxidant plus a copper deactivator. Both A[,Ar-bis(3,5-di-/ A-butyl-4-hydroxycinnamoyl)hydra2ine (29) and 2,2 -oxamidobisethyl(3,5-di-/ A-butyl-4-hydroxycinnamate) (30) are bifimctional. They are persistent antioxidants that have built-in metal deactivators. Oxalyl bis(ben2yhdenehydra2ide) (28) is an effective copper deactivator when part of an additive package that includes an antioxidant. 

The catalytic activity of copper as an oxidant can be inhibited by the use of a metal deactivator such as N,1S7-disahcyhdene-l,2-diaminopropane (31) at a concentration of 5—10 ppm. 

Another additive used is a metal deactivator to chemically deactivate any catalytic metals such as copper accidentally dissolved in the fuel from metal surfaces. Uless they are chemically deactivated, dissolved metals cause the loss of good stability quality. 

Retard efficiently oxidation of polymers catalysed by metal impurities. Function by chelation. Effective metal deactivators are complexing agents which have the ability to co-ordinate the vacant orbitals of transition metal ions to their maximum co-ordination number and thus inhibit co-ordination of hydroperoxides to metal ions. Main use of stabilisation against metal-catalysed oxidation is in wire and cable applications where hydrocarbon materials are in contact with metallic compounds, e.g. copper. 

Contact of aqueous ethylene glycol solutions with d.c.-energised silvered copper wires causes ignition of the latter. Bare copper or nickel- or tin-plated wires were inert and silver-plated wire can be made so by adding benzotriazole as a metal deactivator to the coolant solution [1], This problem of electrical connector fires in aircraft has been studied in detail to identify the significant factors [2],... 

Traces as low as parts per million of certain transition metals, notably copper, manganese, cobalt and iron, which may have been introduced as catalysts, are able to propagate oxidation. Metal deactivators serve to reduce these effects. 

Results are presented of studies of the oxidation of cable insulation consisting of a solid PE skin and PE foam in contact with a copper conductor. Measurements were made of the stability of PE containing stabilisers and metal deactivators in the presence of blowing agents and hydrocarbon oils, and interactions between stabilisers and blowing agents were analysed. 

Metal Deactivator - chelates metal ions, primarily copper. Copper catalyzes the oxidation and degradation of jet fuel. Use is not permitted in aviation gasoline. A metal deactivator is permitted in civil and military jet fuels. 

Treat fuel with a copper chelating agent or a metal deactivator. 

Trace levels of soluble metal compounds, particularly copper, catalyze the oxidative degradation of gasoline by promoting the formation of gums and deposits. Metal deactivators overcome this problem by chelating the metal and rendering it inactive. The most widely used metal deactivator is N, N -disalicylidene-l,2-propanediamine, the copper complex of which is shown in Figure 3. 

Figure 3. Structure of the copper complex of the most widely used metal deactivator N, N -disalicylidene-l,2-propanediamine.

Twigg MV, Spencer MS. Deactivation of copper metal catalysts for methanol decomposition, methanol steam reforming and methanol synthesis. Top Catal. 2003 22(3 4) 191-203. 

Deactivation during carbon mononide oxidation carried over alumina supported copper and copper-chromite catalysts has been examined. Prereduction of the oxidic precursor with CO increased catalyst activity, but prereduction with hydrogen led to less activity increase due to copper metal crystallization. 

The main function of metal deactivators (MD) is to retard efficiently metal-catalyzed oxidation of polymers. Polymer contact with metals occur widely, for example, when certain fillers, reinforcements, and pigments are added to polymers, and, more importantly when polymers, such as polyolefins and PVC, are used as insulation materials for copper wires and power cables (copper is a pro-oxidant since it accelerates the decomposition of hydroperoxides to free radicals, which initiate polymer oxidation). The deactivators are normally poly functional chelating compounds with ligands containing atoms like N, O, S, and P (e.g., see Table 1, AOs 33 and 34) that can chelate with metals and decrease their catalytic activity. Depending on their chemical structures, many metal deactivators also function by other antioxidant mechanisms, e.g., AO 33 contains the hindered phenol moiety and would also function as CB-D antioxidants. 

The time to mechanical failure due to thermal oxidation for several nonr-black samples is shown In Figure 3. Here it is seen that the hlgh-denslty polyethylene Is more resistant to thermal oxidation than the low-density material. This can be related to the rate of loss of antioxidant, which Is lost more slowly from the high density polyethylene. Since these are wire insulation samples In contact with copper, the addition of a metal deactivator would further Increase their longevity. 

Metal Deactivators—inhibit oxidation and gum formation catalyzed by ions of copper and other metals... 

Alloys containing copper can catalyse reactions that degrade base oils and benzatriazole and quinizarin are commonly used as yellow metal deactivators to prevent this. 

The rate of degradation increases when polyolefins are used around copper wire. Copper is also undesirable in gasoline. Metal deactivators are used in these cases. 

Metal Deactivator S. [Hart Chem. Ltd.] N,N -Disa]icylidene-1,2-propane diamine copper chelating agent for refinery industry. 

N,N -Disalicylidene-1,2-propane diamine. N,N -Bis(salicylidene)-1,2-diaminopropane Carlisle metal deactivator Copper inhibitor 50 o-Cresol, a,a -(propylenedinitrilo)di- Cuvan 80 ct,a -Dipropyl-enedinitrilodi-o-cresol Disalicylalpropyienediimine N,N -Disalioylidene-1,2-diaminopropane N,N -Disali-cyclidene-1,2-propanediamine N,N -Disalicylidene-1,2-propylenediamine DMD Du Pont metal deactivator EINECS 202-... 

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