Rubber Accelerators

Novel Sustainable Accelerator Systems for Natural and Synthetic Polyisoprene Latex without added Zinc oxide

Abstract
Both natural and synthetic latex based products vulcanised with conventional accelerators exhibit Type IV allergic reaction. Conventional sulphur vulcanisation requires the presence of zinc oxide as activator. Leach process water can contain unacceptable levels of zinc ions, which require expensive post treatment to allow safe disposal.

The paper describes the technical performance of Robinson Brothers safer accelerators, zinc diisonyl dithiocarbamate (ZDNC) its activated derivative and diisopropyl xanthogen polysulphide (DIXP) and their benefits in terms of compounding, processing stability of compounded latex and simplicity of use without the addition of a zinc oxide activator.

A risk analysis comparison to conventional accelerators based on exposure (extraction/migration study) coupled with hazard data and toxicological properties in terms of reduction/elimination of Type IV allergy will be discussed. The impact of REACH on existing and newer sustainable accelerators will also be review.

K B Chakraborty and R Couchman, D C Baker and R S Virdi
Robinson Brothers Ltd, West Bromwich B70 0AH