James Brian Stowell

US Patent:

51735490, Dec 22, 1992

Filed:

Jul 5, 1990

Appl. No.:

7/548449

Inventors:

David L. Booth - Crystal Lake IL
James K. Stowell - Crystal Lake IL

Assignee:

Morton International, Inc. - Chicago IL

International Classification:

C08F28300
C08F28306

US Classification:

525537

Abstract:

An improved process for reacting a mercaptanterminated aliphatic polysulfide resin with excess epichlorohydrin in the presence of alkali to form an expoxidized polysulfide is disclosed. The reaction takes place in the absence of a solvent such as ethyl alcohol or ether, which will form an inseparable azeotrope with epichlorohydrin and water. The reaction is carried out at a temperature and pressure sufficient to distill away epichlorohydrin and by-product water. The water and epichlorohydrin are separated and the epichlorohydrin is returned to the pot during the reaction. After the reaction is complete, the epichlorohydrin is stripped, leaving an epoxidized polysulfide, by-product sodium chloride, and residual alkali. The epoxidized polysulfide is dissolved in a work-up solvent and filtered to remove sodium chloride and alkali. Then the work-up solvent is stripped, leaving a purified product.