Magnesium modified chromium-based catalyst for vinyl polymerization and preparation method of magnesium modified chromium-based catalyst

A chromium-based catalyst and a technology for ethylene polymerization, which are applied in the field of magnesium-modified chromium-based catalysts for ethylene polymerization and their preparation, can solve the problems of low polymerization activity, long induction period, hydrogen-adjusted sensitivity and poor copolymerization performance, and the like. High polymerization activity, short induction period, hydrogen modulation sensitivity and good copolymerization performance

Active Publication Date: 2019-01-08
吉化集团吉林市天龙催化剂有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] The first object of the present invention is to provide a magnesium-modified chromium-based catalyst for ethylene polymerization, to solve the technical problems of low polymerization activity, long initiation induction period, hydrogen adjustment sensitivity and poor copolymerization performance of existing chromium-based catalysts

Method used

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  • Magnesium modified chromium-based catalyst for vinyl polymerization and preparation method of magnesium modified chromium-based catalyst
  • Magnesium modified chromium-based catalyst for vinyl polymerization and preparation method of magnesium modified chromium-based catalyst
  • Magnesium modified chromium-based catalyst for vinyl polymerization and preparation method of magnesium modified chromium-based catalyst

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Embodiment 1

[0038] A kind of preparation method of magnesium-modified chromium series catalyst for ethylene polymerization, concrete preparation steps are as follows:

[0039] Step S1, preparation of modified carrier: add 5.0 g of magnesium chloride (MgCl2), 0.5 g of chromium nitrate and 150 mL of tetrahydrofuran into a 250 mL three-necked flask fully replaced by N2, stir and react at room temperature for 2 hours, then add 10.0 g of silica gel (WRGrace 955, The specific surface area is 240~375cm 2 / g, the pore diameter is 20~35nm, the pore volume is 1.2~1.8cm 3 / g, particle size is 20~50nm), continue to stir for 6 hours, beating is finished for standby; the mixture after stirring is spray-dried with a spray dryer, spraying conditions: inlet temperature 150°C, outlet temperature 98°C, to obtain granular Composite carrier;

[0040] Step S2, Activation: After activating the modified carrier at 600°C with dry air for 10 hours, cool to 300°C, and pass through dry nitrogen for standby;

[00...

Embodiment 2

[0046] Except that the add-on of chromium nitrate is changed into 1.0g from 0.5g, the preparation method of catalyst component is the same as embodiment 1.

Embodiment 3

[0048] Except that the add-on of chromium nitrate is changed into 2.0g from 0.5g, the preparation method of catalyst component is the same as embodiment 1.

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Abstract

The invention relates to a magnesium modified chromium-based catalyst for vinyl polymerization and a preparation method of the magnesium modified chromium-based catalyst. The catalyst contains a chromium compound, a magnesium modified silica-gel carrier and an alkyl aluminum compound, wherein chromium accounts for 0.01wt%-5.0wt% of total mass of the catalyst, the magnesium modified silica-gel carrier accounts for 70.0wt%-99.9wt% of total mass of the catalyst, the mass ratio of silica gel to a magnesium compound in the carrier is 100-20:1, and aluminum accounts for 0.05wt%-25.0wt% of total massof the catalyst. When the catalyst is applied to industrial production of polyethylene, produced polyethylene particles are good in form, high in bulk density and wide in molecular weight distribution; the preparation method of the catalyst comprises steps as follows: a magnesium salt solution of tetrahydrofuran is taken as a dispersion medium, silica gel is taken as a carrier, the chromium compound is taken as an active component, an organo-aluminum compound is taken as a promoter, modification of carrier silica gel and loading of the active component are realized by spray drying, then drying, high-temperature activation, reduction, reactivation and re-reduction are performed, and the catalyst product is obtained; the technological process of the method is simple and convenient, no chromium-containing wastewater is produced, and industrial implementation is facilitated.

Description

technical field [0001] The invention relates to the technical field of supported catalysts for ethylene polymerization, in particular to a magnesium-modified chromium catalyst for ethylene polymerization and a preparation method thereof. Background technique [0002] The gas-phase fluidized bed polyethylene process is an advanced polyethylene production process. There are many sets of equipment in the world that use the gas-phase process to produce polyethylene. Typical processes include Univation's Uniopl process, BP Amoco's Innovene process, Basell's Spherilene process, Lupotech G process, and Mitsui Chemicals' Evolue process. Its products can range from linear low-density polyethylene to high-density polyethylene. The comonomers used include propylene, 1-butene, 1-hexene and 1-octene, among which 1-hexene and 1-octene As a comonomer, it can significantly improve the transparency, tensile performance, impact resistance and flexibility of the product polyethylene. [0003...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08F4/69C08F210/16C08F210/14
CPCC08F210/16C08F210/14C08F4/69C08F2500/04C08F2500/12Y02P20/52
Inventor 于广臣邓云平陈晓辉丁力于丹丹
Owner 吉化集团吉林市天龙催化剂有限公司
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