Study On The Improvement Of DQ Spherical Catalyst

In order to improve the stereospecificity of DQ spherical catalyst, the synthetic process and recipe of the catalyst had been studied. The key influence factor on the performance of DQ spherical catalyst had been described. The synthetic process and recipe, the stereo specificity and the activity of the catalyst had all been improved. The major conclusions are listed as following:1. A new synthetic process and recipe of DQ catalyst had been confirmed:MgCl.n2C2H5OHused as carrier, donor-7 used as internal donor. At the beginning of the reaction, the concentration of TiCl4 is C%, the reaction temperature is -20℃ .Five hours should be taken during the escalation of the reaction temperature from -20 ℃ to 20 ℃.2. The stereospecificity of the improved DQ catalyst is high, and the isotacticity of polypropylene can be controlled easily between 99% and 95%.3. The activity of the improved DQ catalyst is higher more than 60kgPP/gCat-2hours and keeps low decay.4. The polymerization with the improved DQ catalyst is easy to be controlled.5. The stereospecificity of the modified DQ catalyst becomes higher when DCPMS has been used as external donor instead of CHMMS. The response to hydrogen of DQ catalyst becomes higher when DIBS has been used as external donor instead of CHMMS.