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Method for homopolymerizing or copolymerizing ethylene

A technology of copolymerization and ethylene, which is applied in the field of ethylene homopolymerization or copolymerization, can solve the problems of poor particle shape, excessive fine powder, and excessive fine powder of the product, so as to ensure long-term continuous operation and the production of oligomers The effect of less and good particle shape

Inactive Publication Date: 2012-05-16
CHINA PETROLEUM & CHEM CORP +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

For the PZ catalyst, due to its own shortcomings, such as the catalyst activity is not ideal when producing some grades, especially in the production of polyethylene pipe materials, the bulk density is not high, the particle shape is not good, and there are many fine powders, etc. Affect the quality stability of the product
More importantly, due to the unsatisfactory shape of the polymerized polyethylene particles, the produced product has more fine powder, which makes the production device unable to run for a long period, seriously affecting the production capacity of the device
As a new-generation catalyst launched by Mitsui Oil & Chemical, although the RZ catalyst has improved in many properties such as activity and bulk density compared with the PZ catalyst; however, due to the limitation of its preparation technology, it still has not fundamentally solved the problems that affect the long-term operation of the device. The powder problem makes the production device unable to run continuously for a long period, which greatly affects the production capacity of the device

Method used

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  • Method for homopolymerizing or copolymerizing ethylene
  • Method for homopolymerizing or copolymerizing ethylene
  • Method for homopolymerizing or copolymerizing ethylene

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] (1) Synthesis of catalyst

[0032] (1) Preparation of catalyst components: In a reactor fully replaced by high-purity nitrogen, 6.0 g of magnesium dichloride, 90 ml of toluene, 5.0 ml of epichlorohydrin, 9.0 ml of tributyl phosphate, 4-chloro- 3.0ml of 1-butanol and 3.0ml of ethanol were heated to 70°C under stirring, and reacted at 70°C for 1 hour after the solid was completely dissolved to form a uniform solution. Then the system was cooled to -15°C, 60ml of titanium tetrachloride was slowly added dropwise, and then 5.0ml of ethyl orthosilicate was added, and the reaction was carried out for 1 hour. Slowly heat up to 80°C and react for 2 hours. Stop stirring, let it stand, the suspension will quickly separate into layers, remove the upper clear layer, wash twice with toluene, wash four times with hexane, and blow dry with high-purity nitrogen to obtain a solid catalyst component with good fluidity and narrow particle size distribution.

[0033] (2) Ethylene polymeri...

Embodiment 2

[0036] (1) The synthesis of catalyst is the same as in Example 1.

[0037] (2) Ethylene polymerization

[0038] A stainless steel reaction kettle with a volume of 2L, after being fully replaced by high-purity nitrogen, added 1L of hexane, 1.0ml of triethylaluminum with a concentration of 1M, added the hexane solution of the solid catalyst (containing 0.3 mg of titanium) prepared above, and raised the temperature to 80°C, feed hydrogen to make the pressure inside the kettle reach 0.58Mpa, then feed ethylene to make the total pressure inside the kettle reach 0.73Mpa (gauge pressure), polymerize at 80°C for 2 hours, the polymerization results are shown in Table 1 and Table 2.

Embodiment 3

[0040] (1) Synthesis of catalyst

[0041] Example 1 was enlarged 25,000 times to obtain a corresponding amount of catalyst.

[0042] (2) Ethylene polymerization

[0043] Polymerization is carried out on the Mitsui Oil Chemicals (CX) process. In the reactor, hexane is used as the medium, and an appropriate amount of catalyst is added to initiate the polymerization, and the molecular weight of the polymer is adjusted by hydrogen. Both the loads of A kettle and B kettle were 5 tons / h; the polymerization temperature was 80° C.; the comonomers were all propylene, and the addition amount was 0.4wt%. The polymerization pressure of kettle A is 0.32MPa, and that of kettle B is 0.35MPa. The polymerization results are shown in Table 1 and Table 2.

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PUM

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Abstract

The invention discloses a method for homopolymerizing or copolymerizing ethylene. The method comprises the following step of: undergoing a slurry polymerization for homopolymerizing ethylene or copolymerizing with at least one alpha-olefin with 3-10 carbon atoms in a serial or parallel polymerization reactor in the presence of a catalyst and a diluent. The catalyst used in the method has the advantages of high catalytic activity, high hydrogen adjusting performance, high copolymerizing performance, and the like. Meanwhile, polymer particles are in favorable forms and have concentrated particle size distribution and a large stacking density, and long-period continuous running of a production device can be ensured. The polymerizing method disclosed by the invention is particularly suitable for producing trademarks with high requirements on catalyst particle forms, such as special trademarks serving as tube materials or special trademarks serving as ethylene chlorination materials, and the like.

Description

technical field [0001] The invention relates to a method for homopolymerization or copolymerization of ethylene, more specifically, to a method for homopolymerization of ethylene or copolymerization of ethylene and alpha-olefins in parallel or series reactors, and belongs to the field of olefin polymerization. Background technique [0002] As we all know, high-density polyethylene (HDPE) has been widely used in products such as injection molding, blow molding and pipes. As one of the excellent processes for producing high-density polyethylene, the Mitsui Petrochemical slurry polymerization polyethylene process (CX process) has the advantages of simple equipment and process, easy switching of different grades, high production load and easy flash removal of diluents. The polymerizer of the Mitsui CX process reactor consists of two reactors, which can be connected in parallel or in series to produce different grades of high-density polyethylene products as required. When produ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08F110/02C08F210/16C08F4/646C08F4/654C08F4/656C08F4/658
Inventor 周俊领殷大斌郭子方季宝云苟清强徐振明杨红旭陈明华张韬毅王立志
Owner CHINA PETROLEUM & CHEM CORP