Nano-scale dmc catalyst particles
AssigneeDow Global Technologies LLC
InventorsSandeep Dhingra, Karla Mabe, Keith Watson
Life of this patent
Estimating the term…
Abstract
Nano-scale DMC catalyst complexes are highly active alkylene oxide polymerization catalysts. Thy show a greatly improved ability to catalyze the formation of EO-capping onto secondary hydroxyl-terminated polyethers. The catalysts can be prepared by precipitation in the dispersed adequous phase of a water-in-oil emulsion.
Claims20
A process for making a metal cyanide catalyst comprising
- (A) forming an emulsion having a plurality of water droplets dispersed in an immiscible continuous phase, wherein the water droplets contain a transition metal cyanide compound and a metal salt that reacts with the transition metal cyanide compound to form a water-insoluble metal cyanide catalyst, and
- (B) subjecting the emulsion to conditions such that the transition metal cyanide compound and the metal salt react in the water droplets to form the water-soluble metal cyanide catalyst.
A process wherein a poly(propylene oxide) polymer is EO-capped, comprising contacting the poly(propylene oxide) polymer with ethylene oxide under polymerization conditions in the presence of a catalytically effective amount of a metal cyanide catalyst in the form of particles having an average particle. size, as determined by transmission electron spectroscopy, of from about 5 to about 500 nm, prior to being exposed to an alkylene oxide.
A metal cyanide catalyst in the form of particles having an average particle size, as determined by transmission electron spectroscopy, of from about 5 to about 500 nm, prior to contact with an alkylene oxide.
Dependencies are inferred from the claim text.