Substitution Of Thiurams And Dithiocarbamate Accelerators

- Feb 02, 2019-

The thiuram and dithiocarbamate accelerators have a large effect on vulcanization, and as a second accelerator and a sulfenamide, the curing time can be shortened. Studies have found that thiuram-based and dimethyldithiocarbamate (ZDMC)-based dithio-amino-based vulcanization accelerators of dithiotetramethyl thiuram (TMTD) type N in secondary amines. - nitrosylation reaction. Diphenyl hydrazine and di-o-tolyl hydrazine can be used as temporary substitutes, but since the quinone accelerator itself is also toxic, and the vulcanization rate is slow, the vulcanization set strength is low.

At present, zinc dibutyl dithiophosphate is mainly used abroad to make up for these shortcomings. In recent years, foreign new safe thiura-type accelerators, tetrakilyl sulfuram thiuram (TBZTD) and tetrakis-(2-ethylhexyl) thioacetate (TOT-N) have been introduced. Because TBZTD and TOT-N have large molecular weight, high melting point and difficult to decompose, nitrosamines will not be produced. In particular, TBZTD only has a slightly lower vulcanization rate than TMTD. Other physical properties are almost the same as TMTD, and it has become a promising potential. A new variety of thiuram vulcanization accelerators.