Patent ID: 7144974

Claim:
A polyester production method comprising: adding to a polyester reaction system for producing a polyester containing primarily ethylene terephthalate units, a titanium compound having a radical selected from a carbonyl group, a carboxyl group, or an ester group, and a phosphorous compound containing a six-membered ring structure or higher which includes a phosphorous atom in said ring and having a structure of Formula (I) in which R 1 represents hydrogen, a hydrocarbon radical comprising 1 to 50 carbon atoms, a hydroxyl group, or a hydrocarbon radical comprising 1 to 50 carbon atoms and including an alkoxy group, of which two or more may be included with regard to the benzene ring; R 2 and R 3 independently represent a hydrocarbon radical comprising 1 to 50 carbon atoms, a hydroxyl group, or a hydrocarbon radical comprising 1 to 50 carbon atoms and including an alkoxy group, and may be an alkoxy group of —OR 2 or —OR 3 as to the phosphorous atom; L, M and N are 1; and R 2 and R 3 form a ring.