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AssigneeAkzo Nobel Coatings International B.V.
InventorsMatthew George UNTHANK, Ian Marchant JACKSON, Barry Gordon THOMPSON
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The present invention relates to a process for the manufacture of an epoxy-functional polyester. The process according to the invention comprises the steps of a) providing a polyester having functional groups selected from hydroxyl groups and carboxylic acid groups, or mixtures thereof, b) reacting the functional groups of the polyester with an epihaloalkane to obtain an epoxy-functional polyester dissolved in a liquid phase, c) optionally adding an organic solvent to the liquid phase obtained in step b); d) precipitating the epoxy-functional polyester from the liquid phase obtained in step b) or in step c); and e) isolating the precipitated epoxy-functional polyester from the liquid phase by a solid-liquid separation technique. The thus obtained resin is in particular useful for use in powder coatings. The invention further relates to a solid epoxy-functional polyester obtainable by such process and to a coating composition, in particular a powder coating composition, comprising such solid epoxy-functional polyester.
A process for the manufacture of an epoxy-functional polyester, comprising the steps of:
A process according to any one of the preceding claims, wherein the reaction in step b) is conducted in the presence of an ammonium- or phosphonium-salt catalyst.
A process according to any one of the preceding claims, wherein the reaction in step b) is conducted in the presence of a base.
A process according to any one of the preceding claims, wherein the epoxy-functional polyester is precipitated by cooling to a temperature below 30° C., preferably to a temperature in the range of from −5° C. to 25° C.
A process according to any one of the preceding claims, wherein the liquid phase provided in step c) is subjected to filtration prior to step d).
(canceled)
A process according to any one of the preceding claims, further comprising mixing the solid epoxy-functional polyester obtained with other components to form a coating composition.
Dependencies are inferred from the claim text.