Use of Dithiophosphates not only as Nitrosamine-free Vulcanisation Accelerators but also as Hydro-peroxide Scavengers
Andreas Schr
Today dithiophosphate (DTP) are more and more used in the rubber industry. Due to the chemical structure of DTPs cancirogenic nitrosamines cannot be developed during the vulcanisation process. Therefore EU regulations are met. In addition a more stable sulphur network with a high number of S1 and S2 bridges is formed. DTP vulcanisation systems do not show reversion. The melting point of DTPs is below room temperature. DTPs are liquid and blooming does not occur like for other vulcanisation additives. The diffusion coefficient in rubber is high, resulting in a more homogeneous network structure. In addition to all these advantages the DTPs can also act as hydro-peroxide scavengers. In natural rubber the oxidation induction time (OIT), which can be measured by means of an UV-detector (chemoluminescence) is prolonged significantly