acylation

Although cobalt boron acylate alone can take care of good adhesion in normal conditions as well as under salt aging or steam aging conditions even at elevated temperature, to maintain the physicals as well as adhesion properties in anaerobic aging condition, it is essential to have a suitable network structure which can be achieved by using specialty chemicals like post vulcanization stabilizer (PVS) such as hexamethylene-l,6-bisthio sulfate disodium salt dihydrate (HTSNa) and bis-(3-triethoxy silylpropyl) tetrasulfide (TESPT).

When compared with cobalt boron acylate none of these systems tested gave satisfactory adhesion to zinc coated steel wire (refs.

The stress-strain properties and retention of modulus after aging are best with compounds containing DCBS accelerators, cobalt boron acylate and HTSNa-combination (A2).

After NaCl-salt aging at different salt concentrations (1%, 3% and 5%) at 25[degrees]C temperature, the adhesion values of the compounds containing TESPT drop down drastically in most of the cases, compared to cobalt boron acylate alone or its combination with HTSNa (table 4).