| 摘要 |
<p>In the step of producing a polycarbonate, the concentrations of an aromatic dihydroxyl compound and a carbonic diester or the ratio between both is speedily and efficiently determined and controlled to thereby obtain a high-quality consistent polycarbonate. The aromatic dihydroxyl compound/carbonic diester ratio of a molten mixture (A) containing both is determined by near infrared spectroscopy at a wavelength of 1600 to 1900 nm.</p> |
