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US 5,856,401 AGranted
Method of preparing condensation polymers by emulsion polymerization
AssigneeSaam Associates
InventorJohn C. Saam
Life of this patent
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Abstract
A method wherein polyesters are prepared under mild conditions by directly condensing hydroxycarboxylic acids or mixtures of polyfunctional alcohols and carboxylic acids in hydrophobic media using heterogeneous catalysts that can form a hydrophilic phase. The systems are inverse emulsions, inverse microemulsions and solid-in-liquid dispersions.
Claims19
A method for preparing a polyester polymer, the method comprising:
- (I) dispersing in a hydrophobic diluent one or more reactive monomers selected from the group consisting essentially of:
- (i) monomers having at least two hydroxyl groups;
- (ii) monomers having at least two carboxyl groups and,
- (iii) monomers having a combination of hydroxyl groups and carboxyl groups, wherein there are present in the diluent, species having at least one hydroxyl group and at least one carboxyl group, each such monomer having at least partial solubility in the diluent;
- (II) adding a strongly acidic catalyst to (I) which will form a separate dispersed phase;
- (III) reacting the monomers and the catalyst at a time and at a temperature sufficient to form by-produced water and, a product which is pre-selected from the group consisting essentially of:
- a. an inverse dispersion;
- b. an inverse emulsion or
- c. an inverse microemulsion,
- with the proviso that during the reaction in (III), any water that is generated during the reaction is adjusted such that the amount of water present in (III) at the end of the reaction is from 1 to 20 weight percent based on the total incipient monomer weight in (I).
7 more elements
Dependencies are inferred from the claim text.