Preparation of polycarbonate products
AssigneeMonsanto Company
InventorsWilliam D. McGhee, Dennis P. Riley
Life of this patent
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Abstract
The present invention provides a process for preparing urethanes and carbonates from an amine or an alcohol, carbon dioxide and a hydrocarbyl halide. The amine or alcohol is reacted with carbon dioxide in a suitable solvent system and in the presence of an amidine or guanidine base, to form the ammonium carbamate or carbonate salt which is then reacted in a polar aprotic solvent with a hydrocarbyl halide. Polymer products can also be prepared utilizing this process or utilizing the resulting urethanes and carbonates under standard polymerization conditions.
Claims14
A process for preparing polycarbonate comprising:
- (a) bringing CO.sub.2 and alcohol into reactive contact in a suitable solvent and in the presence of a sterically hindered amidine or guanidine base to form the corresponding carbonate salt;
- (b) reacting, in a polar aprotic solvent, the salt with a hydrocarbyl halide;
- and
- (c) reacting the product of Step (b) with a polymerization initiator under polymerization conditions.
A process for preparing polycarbonates comprising:
- (a) bringing CO.sub.2 and a diol or polyol into reactive contact in a suitable solvent and in the presence of a strongly basic nitrogenous compound selected from the group consisting of amidine compounds and guanidine compounds to form the corresponding carbonate salt;
- and
- (b) reacting the salt in a polar aprotic solvent with a hydrocarbyl dihalide or hydrocarbyl poly(halide).
Dependencies are inferred from the claim text.