Low-toxicity high-activity catalyst used for preparing high-density polyethylene, and preparation method thereof
A high-density polyethylene and high-activity catalyst technology, which is applied in the production of bulk chemicals and can solve the problem of low catalyst activity
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
Method used
Image
Examples
Embodiment 1
[0043] Weigh 0.4497 g of 50% chromium acetate solution in a 100 ml dry beaker, add 60 ml of deionized water to form a solution. Weigh 20 grams of Davison 955 silica gel in a 1000ml dry beaker, slowly add the prepared chromium acetate solution into the silica gel under stirring, stir to make the silica gel and chromium acetate solution fully contact, and mix well. Immerse for 4-8 hours, and dry the material at 60-120°C for 12 hours. Move the dried load into a Φ30×500mm quartz tube, pass high-purity nitrogen gas into the bottom, activate at a constant temperature of 200°C for 2 hours, then raise the temperature to 600°C, and switch the activation gas from high-purity nitrogen when the temperature rises to 300°C In dry air, maintain 600°C for 4 hours for activation. After the activation, stop heating and lower the temperature slowly, and switch the activation gas from air to high-purity nitrogen when the temperature drops to 300°C. After the material is lowered to room temperat...
Embodiment 2- Embodiment 5
[0045]The catalyst preparation process of Examples 2-5 is the same as that of Example 1, except that the amount of cocatalyst aluminum alkyl was changed, and chromium-based catalysts with aluminum-chromium ratios of 1.5, 3, 4.5, and 8 were prepared. These five catalysts were polymerized and evaluated on a laboratory 1L gas-phase method polyethylene test device. The polymerization process conditions were as follows: the polymerization pressure was 1.2MPa, and the polymerization reaction temperature was 92°C. A set of experimental data was obtained as shown in Table 1:
[0046] Table 1 Polymerization performance of catalysts with different reducing agent dosages
[0047]
[0048]
Embodiment 6- Embodiment 9
[0050] The preparation process of the catalyst in Examples 6-9 is the same as in Example 1, except that the type of aluminum alkyl is changed, and methylalumoxane, tri-n-hexylaluminum, triethylaluminum, and diethylaluminum chloride are used as cocatalysts respectively , five chromium-based catalysts with a chromium content of 0.25% and an aluminum-chromium ratio of 6 were prepared. These five catalysts were polymerized and evaluated on a laboratory 1L gas-phase method polyethylene test device. The polymerization process conditions were as follows: the polymerization pressure was 1.2MPa, and the polymerization reaction temperature was 92°C. A set of experimental data was obtained as shown in Table 2:
[0051] Table 2 Comparison of polymerization performance of catalysts prepared by different aluminum alkyls
[0052]
PUM
Login to View More Abstract
Description
Claims
Application Information
Login to View More