Fred J Armellini

US Patent:

58440704, Dec 1, 1998

Filed:

May 16, 1997

Appl. No.:

8/857998

Inventors:

John E. Hayes - Gouvieux, FR
Leah J. Langsdorf - West Chester PA
Bruce H. Isaacs - Media PA
Fred J. Armellini - Willow Grove PA

Assignee:

Arco Chemical Technology, L.P. - Greenville DE

International Classification:

C08F 600
C08G 5968
C08G 6504
C08J 300

US Classification:

528501

Abstract:

A process for activating double metal cyanide catalysts is disclosed. A polyol starter or starter/catalyst mixture is heated under vacuum under conditions effective to achieve improved stripping compared with that which can be achieved through conventional vacuum stripping. Coupling vacuum stripping with inert gas sparging or stripping in the presence of an organic solvent gives a starter/catalyst mixture that activates rapidly in an epoxide polymerization process. Rapid activation makes process start-ups reliable and reduces cycle time. The process gives polyols with lower viscosity, lower polydispersity, and lower unsaturation for better polyurethanes.