Patent ID: 6867162

Claim:
A double-metal cyanide catalyst having the formula M 1 x ([M 2 x′ (CN) y ] z .[M 3 ]).L 2 .L 1 .M 4 z , wherein M 1 represents at least one metal; [M 2 x′ (CN) y ] represents at least one metal cyanide; M 3 represents at least one transition metal; M 4 represents at least one alkali metal salt, present in an amount within the range of from about 0.4 to about 6 wt. %, based on the total weight of the double metal cyanide catalyst; L 1 represents at least one organic complexing ligand; L 2 is optional and can represent at least one functionalized polymer; and x, x′, y and z are integers chosen such that electroneutrality of the double-metal cyanide catalyst is maintained.