The assay of 99.5% and 99.9% of Diphenyl Sulfone has been produced by Weifang Ouchem Trade Co.,Ltd since the year of 2016 as GMP standard. Its capacity is 1,000MT/year,and will reach 3,000MT/year in 2020. Diphenyl Sulfone is used mainly for Thermal paper sensitizer, Polysulfone resin, Engineering plastics, etc.,and exported to Japan, USA, Thailand, Brazil,etc.