AN ORIGINAL ANTI-REVERSION NITROSAMINE-FREE CURING AGENT AS AN ALTERNATIVE TO TMTD

摘要

The development of a new curing system has to answer constraints about safety and environment issues or regulations The use of an activated poly-ter-butylphenol disulfide (TBP) (as Mixland+ TBP 75 GA) is a response to this challenge. This activated TBP is a fully nitrosamine free curing agent and a sulphur donor. TBP has a kinetic similar to that of thiazole accelerators. Moreover, TBP has a strong synergistic effect with various curatives, as mainly sulfenamides (ex: CBS), and, at a least degree, diphenylguanidine (DPG). The survey shows through an experimental design how to replace TMTD in NR compounds by a mix of TBP and CBS and/or DPG. TBP brings an efficient anti-reversion effect, which makes the NR cured at high temperature without degradation, with keeping a good processability for injection moulding, for instance. This synergy efficiently enables TBP to create hybrid bonds. The lower cure rate of the curing system based on the TBP makes this compound more suitable for moulding thick parts than a TMTD based compound. Moreover, tear resistance is kept and the other mechanical properties are equivalent or better. The compression set is improved, without any nitrosamine generation. At last, but not least, this chemical does not generate either blooming or smll.