VULCANISABLE COMPOSITIONS BASED ON EPOXY GROUP-CONTAINING NITRILE RUBBERS

摘要

There are provided novel vulcanizable compositions based on optionally fully or partly hydrogenated nitrile rubbers containing epoxy groups, specific acidic crosslinkers and crosslinking accelerators, as a result of which the use of conventional crosslinkers, such as sulphur in particular, is no longer required. The vulcanizates producible therefrom possess very good compression sets at room temperature, 100° C. and 150° C., and additionally exhibit high tensile strength combined with good elongation at break.

主权项

1. Vulcanizable composition comprising
(i) at least one optionally fully or partly hydrogenated nitrile rubber containing epoxy groups and comprising repeat units derived from at least one conjugated diene, at least one α,β-unsaturated nitrile and optionally one or more further copolymerizable monomers, but not from a nonconjugated cyclic polyene, (ii) at least one Lewis and/or Brønsted acid as a crosslinker, and (iii) at least one crosslinking accelerator selected from the group consisting of thiurams, xanthogenates, thioureas, dithiocarbamates and carbamates, where crosslinkers other than those mentioned in (ii) are present in the vulcanizable composition only in an amount of less than 2.5 parts by weight based on 100 parts by weight of the optionally fully or partly hydrogenated nitrile rubber (i) containing epoxy groups, and crosslinking accelerators other than those mentioned in (iii) only in an amount of less than 2.5 parts by weight based on 100 parts by weight of the optionally fully or partly hydrogenated nitrile rubber (i) containing epoxy groups.