Ethylene polymer and preparation method thereof

Abstract

The invention relates to an ethylene polymer and a preparation method thereof. The ethylene polymer has an average particle size of 50-3000 [mu] m, a bulk density of 0.28-0.55 g / cm < 3 >, a true density of 0.930-0.980 g / cm < 3 >, a melt index of 0.01-2500 g / 10 min under a load of 2.16 Kg at 190 DEG C, a crystallinity of 30-90%, a melting point of 105-147 DEG C, a comonomer molar insertion rate of 0.01-5 mol%, a weight-average molecular weight of 20,000-400,000 g / mol, and a molecular weight distribution of 1.8-10. In the preparation method, an alkane solvent with a boiling point of 5-55 DEG C or a mixed alkane solvent with saturated vapor pressure of 20-150KPa at 20 DEG C is used as a polymerization solvent, and under the condition that the molar ratio of hydrogen to ethylene is (0.01-20): 1, preferably (0.015-10): 1, and the molar ratio of hydrogen to a comonomer is (8-30): 1, preferably (10-25): 1, the polymerization reaction is carried out for 1-2 hours under the existence of a polyethylene catalytic system. A raw material comprising ethylene, hydrogen and a comonomer is subjected to kettle slurry polymerization to produce an ethylene polymer.

Description

technical field

[0001] The invention relates to a high-density ethylene polymer and an ethylene slurry polymerization preparation method for preparing the ethylene polymer. Specifically, the present invention relates to a high-density ethylene copolymer, which uses an alkane solvent with a boiling point of 5-55° C. or a mixed alkane solvent with a saturated vapor pressure of 20-150 KPa at 20° C. as a polymerization solvent. Under the existence of the system, under the condition of ethylene slurry polymerization, the raw material containing ethylene, hydrogen and comonomer is subjected to still-type slurry polymerization to obtain the preparation method of ethylene copolymer. Background technique

[0002] The production methods of polyethylene mainly include high-pressure polymerization, gas phase polymerization, slurry polymerization, solution polymerization and other processes and methods. Among them, ethylene slurry polymerization is one of the main methods to produce pol...

Examples

preparation example Construction

[0032] The present invention also provides a method for preparing ethylene polymers, wherein an alkane solvent with a boiling point of 5-55° C. or a mixed alkane solvent with a saturated vapor pressure of 20-150 KPa at 20° C. is used as a polymerization solvent, in the presence of a polyethylene catalyst system , when the molar ratio of hydrogen to ethylene is 0.01-20:1, preferably 0.015-10:1, the molar ratio of hydrogen to comonomer is 8-30:1, preferably 10-25:1, more preferably 12-23 : Under the condition of 1, the raw material comprising ethylene and comonomer is subjected to tank type slurry polymerization, and the polyethylene catalyst system comprises a polyethylene main catalyst of a Ziegler type catalyst.

[0033] In one embodiment of the present invention, in the preparation method of the ethylene polymer, the ratio of the polyethylene main catalyst to the polymerization solvent is 0.001-0.500 mmol polyethylene main catalyst / L polymerization solvent, preferably 0.005-0...

Embodiment 1

[0158] Ziegler-Natta catalyst CAT-3 (concentration 0.024mmol / L) was used as polyethylene main catalyst, co-catalyst was triethylaluminum (TEAL) in pentane solution (concentration 1.0mol / L), and the polymerization pressure was 1.8MPa, the polymerization temperature is 85°C, the polymerization solvent is n-pentane (boiling point 36.1°C), the dosage is 2.5L, and the comonomer is 1-hexene.

[0159] In the 5L anchor type ethylene slurry polymerization kettle with stirring, at first, 2.5L polymerization solvent is added in the polymerization autoclave at normal temperature, the stirring is started, and the rotation speed is 300rpm, then the polyethylene catalyst and co-catalyst mixture are added at one time, and Add comonomer at one time, then add hydrogen, and finally continue to feed ethylene to keep the polymerization pressure and polymerization temperature constant. After continuous reaction for 2 hours, vent the gas in the kettle to release the polymer in the kettle. Weigh the m...

Embodiment 1-1

[0161] Basically the same as Example 1, but with the following changes:

[0162] The main catalyst concentration of polyethylene is changed to 0.018mmol / L, the cocatalyst is a cyclopentane solution of triethylaluminum (concentration is 1.0mol / L), the polymerization pressure is 1.2MPa, the polymerization temperature is 95°C, and the polymerization solvent is cyclopentane Alkane (boiling point 49.26°C), the dosage is 2.5L, the comonomer is 1-octene, the rotation speed is 240rpm, the polymerization time is 0.5h, the ethylene polymer is marked as PE-1-1, the preparation process and conditions of the ethylene polymer As shown in Table 1-1, the properties of ethylene polymers are shown in Table 1-2.

technical field

[0001] The invention relates to a high-density ethylene polymer and an ethylene slurry polymerization preparation method for preparing the ethylene polymer. Specifically, the present invention relates to a high-density ethylene copolymer, which uses an alkane solvent with a boiling point of 5-55° C. or a mixed alkane solvent with a saturated vapor pressure of 20-150 KPa at 20° C. as a polymerization solvent. Under the existence of the system, under the condition of ethylene slurry polymerization, the raw material containing ethylene, hydrogen and comonomer is subjected to still-type slurry polymerization to obtain the preparation method of ethylene copolymer. Background technique

[0002] The production methods of polyethylene mainly include high-pressure polymerization, gas phase polymerization, slurry polymerization, solution polymerization and other processes and methods. Among them, ethylene slurry polymerization is one of the main methods to produce pol...

Examples

preparation example Construction

[0032] The present invention also provides a method for preparing ethylene polymers, wherein an alkane solvent with a boiling point of 5-55° C. or a mixed alkane solvent with a saturated vapor pressure of 20-150 KPa at 20° C. is used as a polymerization solvent, in the presence of a polyethylene catalyst system , when the molar ratio of hydrogen to ethylene is 0.01-20:1, preferably 0.015-10:1, the molar ratio of hydrogen to comonomer is 8-30:1, preferably 10-25:1, more preferably 12-23 : Under the condition of 1, the raw material comprising ethylene and comonomer is subjected to tank type slurry polymerization, and the polyethylene catalyst system comprises a polyethylene main catalyst of a Ziegler type catalyst.

[0033] In one embodiment of the present invention, in the preparation method of the ethylene polymer, the ratio of the polyethylene main catalyst to the polymerization solvent is 0.001-0.500 mmol polyethylene main catalyst / L polymerization solvent, preferably 0.005-0...

Embodiment 1

[0158] Ziegler-Natta catalyst CAT-3 (concentration 0.024mmol / L) was used as polyethylene main catalyst, co-catalyst was triethylaluminum (TEAL) in pentane solution (concentration 1.0mol / L), and the polymerization pressure was 1.8MPa, the polymerization temperature is 85°C, the polymerization solvent is n-pentane (boiling point 36.1°C), the dosage is 2.5L, and the comonomer is 1-hexene.

[0159] In the 5L anchor type ethylene slurry polymerization kettle with stirring, at first, 2.5L polymerization solvent is added in the polymerization autoclave at normal temperature, the stirring is started, and the rotation speed is 300rpm, then the polyethylene catalyst and co-catalyst mixture are added at one time, and Add comonomer at one time, then add hydrogen, and finally continue to feed ethylene to keep the polymerization pressure and polymerization temperature constant. After continuous reaction for 2 hours, vent the gas in the kettle to release the polymer in the kettle. Weigh the m...

Embodiment 1-1

[0161] Basically the same as Example 1, but with the following changes:

[0162] The main catalyst concentration of polyethylene is changed to 0.018mmol / L, the cocatalyst is a cyclopentane solution of triethylaluminum (concentration is 1.0mol / L), the polymerization pressure is 1.2MPa, the polymerization temperature is 95°C, and the polymerization solvent is cyclopentane Alkane (boiling point 49.26°C), the dosage is 2.5L, the comonomer is 1-octene, the rotation speed is 240rpm, the polymerization time is 0.5h, the ethylene polymer is marked as PE-1-1, the preparation process and conditions of the ethylene polymer As shown in Table 1-1, the properties of ethylene polymers are shown in Table 1-2.

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