Hi Tech multifunctional additives - high performance with mall dosages
K. Menting, R. Galie-Gutbrecht, H. Umland, M.Hensel. P. Kosczinsky, Schill + Seilacher
The use of processing additives in the various steps of rubber processing has a long traditon. Well known effects like improved filler dispersion, better blending of polymers, fast and smoother extrusion etc. are highly welcome, but there is concern about possible adverse effects in the finished article.
Consequently a series of high performance multifunctional additives has been developed and tested. The goal was to overcome several processing problems with minimum impact on cured properties. Dependping on the polymer/filler/curative system effects like improved filler dispertion, better extrusion and better mould release can be obtained using just one additive.
In "difficult" polymers like FKM it is possible to improve the flow properties and reduce mould fouling with additive dosages lower than 1 phr.
The HT-additives give sigificant improvements of various processing charateristics with less impact on compression set.
For the whole series the infuences on cured properties was carefully evaluated. Generally lower dosages result in less influence on the crosslink density of the rubber matrix. Normally, no fller level correction is required when Hi Tech multifunctional additives are used.
During the investigation an interesting effect in tensile testing was found.
Many promising developments in rubber compounding have been cancelled in the past because of an undesired drop of the modulus in the presence of detergent type processing additives.