Tribasic lead sulphate

For this reason tribasic lead sulphate, a good heat stabiliser which gives polymer compounds with better electrical insulation properties than lead carbonate, has increased in popularity in recent years at the expense of white lead. Its weight cost is somewhat higher than that of lead carbonate but less than most other stabilisers. This material is used widely in rigid compounds, in electrical insulation compounds and in general purpose formulations. 

Ferro has introduced new calcium-zinc stabilisers, Therm-Chek RC 376P and Therm-Chek RC 377P, to replace tribasic lead sulfate in general purpose wire and cable jacketing applications. The company claims that its new additives outperform lead alternatives and that they can be used at lower dose levels. Electrical insulation resistance is also said to be better than with tribasic lead sulphate. 

PVC lOOphr Corvic S67/111 (PVC resin) 5phr tribasic lead sulphate (stabilizer) 1 phr calcium stearate (lubricant), f ABS lOOphr Cycolac GSM. t FeOOH Bayferrox 3905, hydrated iron(ni) oxide (Bayer UK Ltd). 

Some stabilizers are effective in improving weathering behaviour. Lead compounds are good heat stabilizers basic lead carbonate or tribasic lead sulphate are favoured stabilizers but are toxic. The stearate, palmitate and octoate salts of Cd, Ba, Ca, Zn are increasingly used, but toxicity limits the range of applications for Cd. Organo-tin compounds are also effective stabilizers, especially for transparent products, but may also be somewhat toxic. 

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