Abstract: The rubber plasticizer A0709 derived from the 2nd side stream of vacuum distillation of SZ36-1 naphthenic-base crude was prepared by a combined process of hydrodeacidification-solvent refining-clay refining. The process conditions were optimized. The results showed that by the combined technology, the rubber plasticizer A0709 can be produced and reach the GB/T 33322 standard. Under the optimized process conditions, the product yield is up to 74.1% and the CA% is 11.2%.

Key words: 2nd line vacuum distillate, rubber plasticizer, production process