Polyester resin composition

Claim 1

A polyester resin composition for a powder paint, which is obtained by mixing a molten polyester having an average degree of polymerization ranging from about 5 to 50 and a hexaalkoxymethylmelamine or a condensate thereof as a hardener, said polyester being prepared by depolymerizing a highly polymerized polyester having an intrinsic viscosity of not less than 0.4 using a substantially non-volatile alcohol and/or a substantially non-volatile ester, said non-volatile alcohol or ester being non-volatile at about 200°-280°C, said substantially non-volatile alcohol being a polyhydric alcohol having 3 or more hydroxy groups, and said substantially non-volatile ester being the esterification product between said non-volatile polyhydric alcohol and an aliphatic monocarboxylic acid having at least one alcoholic hydroxy group in its molecule, or bis-β-hydroxyethyl terephthalate and/or β-hydroxyethyl p-hydroxyethoxybenzoate, and having as the main acid units, about 40 to 80 mol% of terephthalic acid units, about 20 to 60 mol% of p-hydroxybenzoic acid units and about 0 to 30 mol% of aliphatic dicarboxylic acid units and, as the main alcohol units, ethylene glycol units, and having free hydroxy and/or carboxy groups wherein the amount of said hexaalkoxymethylmelamine or the condensate thereof satisfies the following relationship; ##EQU6## wherein M and H represent, respectively, the alkoxy group equivalents and the hydroxy group equivalents of said polyester resin composition.