Patent ID: 6815529
Filing Date: 2004-11-09
Classification: C08G

Abstract:
A catalyst for producing aliphatic polycarbonate, comprising a mixture of:(a) a rare-earth coordination compound with the formula: MXnYm wherein, M is a rare earth element selected from the group consisting of Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tu, Yb, Lu, and a mixture of two or more of the rare earth element; X is a carboxylic acid group or sulfonic acid group with Ka values above 10âˆ’3; Y is selected from the group consisting of â€”Cl, â€”NO2, &boxH;O, â€”OH; n and m are independently integers from 0 to 3;(b) an alkyl metal compound, wherein the metal is zinc, magnesium or aluminum, and the alkyl group is selected from the group consisting of CH3â€”, CH3CH2â€”, CH3CH2CH2â€”, (CH2)2CHâ€”, CH3CH2CH2CH2â€”, (CH2)2CHCH2â€”, and CH3CH(CH3)CH2â€”; (c) a polyol selected from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, glycerin and a mixture thereof, and (d) a carbonate selected from the group consisting of ethylene carbonate, propylene carbonate, cyclohexylene carbonate and a mixture thereof, and obtained by stirring or grinding said mixture, and then aging it for 1-24 hours under 0-50 times atmospheric pressure of nitrogen, argon, carbon dioxide or under super critical condition.