Vulcanising sulphur vulcanisable rubber mixts - - using a diradical dithiophosphate as accelerator

摘要

A sulphur-vulcanisable rubber mixt. contng. natural and/or synthetic rubbers except ethylene-propylene-diene ternary polymer, sulphur and/or sulphur donor, vulcanisation-accelerator and opt. other additives is heated to vulcanisation temp. The vulcanisation-accelerator is a diradical-dithiophosphate of formula: (where R is same or different straight or branched chain alkyl gp. cycloalkyl with substituent or aryl, Z is polyvalent cation, primary- secondary-. tertiary- or mixed aliphatic mono-, di- or polyamide gp, cyclic aliphatic amine, substd, aromatic or heterocyclic amine, or CO, and x corresponds to the coordination number of Z). together with at least one well-known vulcanisation accelerator typically sulphur, di-caprolactam disulphite dimorpholyl disulphide or their mixt. in amt. of 0.2-1.5 pbw pref. 0.5-1 pbw per 100 pbw rubber using 0.1-5.0 pbw of dithiophosphate and 0.1-2.0 pbw of common additional accelerator per 100 pbw of rubber. The vulcanisation is at 100-250 degrees C, yielding a vulcanisate of improved anti-ageing property.