Patent ID: 6399832
Filing Date: 2002-06-04
Classification: C07C

Abstract:
A process for selectively producing organic trisulfides, said process comprises the steps of:(a) contacting a liquid phase mercaptan, elemental sulfur and a catalyst in a reaction vessel to thereby form a liquid reaction solution, wherein said contacting is under reaction conditions which include a first reaction temperature exceeding about 50Â° C. and a first reaction pressure exceeding about one atmosphere and wherein said contacting is for a reaction period sufficient to produce a reaction product comprising an organic polysulfide product and hydrogen sulfide; (b) maintaining during said reaction period a hydrogen sulfide concentration in said liquid reaction solution in the range of from about 0.1 percent to about 10 percent; (c) after said reaction period, subjecting said reaction product to trisulfide enhancing conditions which include maintaining a trisulfide enhancing temperature and a trisulfide enhancing pressure for a trisulfide enhancing period sufficient to provide said organic polysulfide product of a desired distribution of organic polysulfides having a weight percent organic trisulfide greater than about 80 percent, and wherein said trisulfide enhancing temperature is less than about 80Â° C. and said trisulfide enhancing pressure is less than 0 psig; and (d) recovering said organic polysulfide product.