| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of producing an alkyd resin in a short period which is transparent and hardly generates foreign matters and hardly has filtration residue by using a regenerated polyester resin which is recovered from wastes. SOLUTION: The method of producing the alkyd resin comprises the steps of dissolving a polyester resin having as a main raw material a regenerated terephthalic acid recovered from the wastes into either a mixture of a fat and oil and an alcoholic component having weight ratio of 0-20 of a polyhydric alcohol having trivalence or less to a polyhydric alcohol having quadrivalence or more, or reactants for transesterification, depolymerizing the polyester resin in the presence of a depolymerization catalyst, and esterifying the depolymerized product by addition of a lipid component and a polybasic acid component, and this method produces the alkyd resin with an oil length of 30-70% by using the polyester resin in an amount of 5-40 wt% based on the total amount of the polyester resin, the alcoholic component, the oil and fat, and the polybasic acid component, and a paint composition containing the alkyd resin obtained by the method.
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