| 摘要 |
PURPOSE:To produce a polymer having broad molecular weight distribution and excellent property, and useful as a flocculation agent for the treatment of industrial sewage, a paper-making chemical, a soil-improver, etc., by varying the intensity of light-irradiation in the course of the polymerization process. CONSTITUTION:A monomer is polymerized in the presence of a photo-initiator and/or a photo-sensitizer (e.g. benzoin, anthraquinone derivative, etc.) under the irradiation with light of 300-500nm wavelength emitted preferably from a high-pressure mercury lamp. In the above process, the polymerization stage is divided into two or more stages having different intensity of the light before the polymerization rate reaches 90%. The polymerization rate in each of the stage having weak light intensity (preferably <=10W/m<2> light intensity) and the stage having strong light intensity is set to >=5% and the light intensity in the strong-intensity period is set to >=4 times the intensity in the weak- intensity period. |
