Magnesium antimony complex

Other flame retardants and/or smoke suppressants can also be used such as magnesium hydroxide, magnesium carbonate, magnesium-zinc complexes and some tin-zinc compositions. Zinc oxide is a common ingredient in many rubber base formulations used as part of the curing system. At the same time, the action of zinc oxide is similar to that of antimony trioxide, but less effective. 

Notes Blue used in certain pigments and as flame retardant for low lead and arsenic content. Low-cost grade is cost-effective FR with lower tint strength, esp. for wire and cable and general thermoplastics. Antimony/zinc blend is lower cost, can control afterglow. Blends with magnesium/zinc complex combine FR and smoke suppression for PVC also reduce use of pigment ... 

For the polymerization to proceed at a reasonable rate, the use of a transesterification catalyst is needed. Compounds which are usually used as a catalyst for the preparation of polyesters through transesterification can be used here. These include lithium, sodium, zinc, magnesium, calcium, titanium, maganese, cobalt, tin, antimony, etc. in the form of a hydride, hydroxide, oxide, halide, alcoholate, or phenolate or in the form of salts of organic or mineral acids, complex salts, or mixed salts.(10) In this study, tetrabutyl titanate (TBT) in the amount of 1000 ppm was used normally. 

In practice the mass ratio of magnesium to calcium used is between 2 1 and 4 1, and depends on the relative cost of the reagent metals. The process is promoted by the addition of antimony, which can also form intermetallic compounds as a replacement for bismuth, and is necessary to achieve low levels of residual bismuth. It is suggested that the antimony compound is isomorphous with the bismuth compound and a solution of the two causes a lowering of the activity of the bismuth complex (Moodie, 1976). 

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