POLYESTER RESIN COMPOSITION, POLYESTER FIBER, POLYESTER RESIN MOLDED ARTICLE, AND PROCESS FOR PRODUCTION OF NUCLEATING AGENT FOR POLYESTER RESIN

摘要

Disclosed is a polyester resin composition which rarely undergoes discoloration even though the composition contains a sulfoneamide compound as a nucleating agent. Specifically disclosed is a polyester resin composition which contains a phosphorus-containing antioxidant agent (A) in an amount of 0.01 to 30 parts by mass and a sulfoneamide compound metal salt (B) in an amount of 0.1 to 30 parts by mass relative to 100 parts by mass of a polyester resin. The polyester resin composition is characterized in that the water content in the sulfoneamide compound metal salt (B) is 0.1% to 20% by mass relative to the mass of the sulfoneamide compound metal salt and is 3% by mass or less by mass relative to the mass of the polyester resin composition.