A readily processable high impact polyethylene and its preparation and use

Abstract

The application discloses a kind of easy-to-process high impact polyethylene and its preparation method and application.The weight average molecular weight of the easy-to-process high impact polyethylene is 10×10 4 -45×10 4 G / mol, molecular weight distribution is 20-40, density is 0.940-0.965 g / cm 3 , melt index is 8-15 g / 10 min, branched chain content is 0.2-1.0 C / 1000 C, room temperature simple beam double notch impact strength (23 DEG C) is greater than or equal to 50 kJ / m 2 , low temperature simple beam double notch impact strength (-40 DEG C) is greater than or equal to 28 kJ / m 2 . The easy-to-process high impact polyethylene has the characteristics of wide processing temperature window, easy processing and high impact strength.

Description

TECHNICAL FIELD

[0001] The present application relates to a polyolefin material, in particular, the present application relates to an easy-to-process high impact polyethylene and its preparation method and application. BACKGROUND

[0002] Polyethylene rotational molding material is widely used in rotational molding storage tank, rotational molding water tank, rotational molding inspection well, slide type amusement equipment and other fields. At present, more than 99% of the rotational molding raw materials required for domestic rotational molding production are polyethylene, and 65% of which are linear low density polyethylene LLDPE, 20% are crosslinked polyethylene XLPE, 10% are high density polyethylene HDPE, and 5% are low density polyethylene LDPE. LLDPE is particularly suitable for rotational molding due to its wide processing window and excellent impact performance. However, it has obvious shortcomings in terms of low temperature impact resistance, high temperature resistance, environmental stress cracking resistance and heat expansion resistance. In order to meet the requirements of high temperature resistance, high impact resistance and high environmental stress cracking resistance, rotational molding grade XLPE is currently selected. However, XLPE has the problems of narrow processing window, high scrap rate, high equipment requirement, low processing fluidity and low production efficiency. Therefore, how to balance the processing performance and low temperature impact resistance of polyethylene rotational molding material is the key.

[0003] The copolymerized HDPE has a non-crosslinked structure, and its melt index and processing performance are obviously better than those of XLPE. In addition, the molecular chain of the copolymerized HDPE has a certain amount of long chain branch and / or short chain branch structure, and has certain advantages in impact strength and environmental stress cracking resistance.

[0004] In summary, the present application aims to develop a polyethylene resin with easy processing, wide processing window characteristics and high impact strength, and a preparation method thereof. SUMMARY

[0005] To solve the above technical problems, the present application aims to provide an easy-to-process high impact polyethylene and its preparation method and application. The easy-to-process high impact polyethylene has the characteristics of wide processing temperature window, easy processing and high impact strength.

[0006] According to one object of the present application, the present application provides an easy-to-process high impact polyethylene, wherein the weight average molecular weight of the easy-to-process high impact polyethylene is 10x10 4 -45x10 4 g / mol, the molecular weight distribution is 20-40, the density is 0.940-0.965 g / cm 3 , the melt index is 8-15 g / 10 min, the branch chain content is 0.2-1.0 C / 1000 C, and the room temperature Charpy double-notch impact strength (23℃) is ≥50 kJ / m 2, low temperature Charpy double notch impact strength (-40℃) ≥ 28kJ / m 2 .

[0007] The application further provides a preparation method of the easy-to-process high-impact polyethylene, which comprises the following steps:

[0008] In the first reactor, polymer A is dissolved in solvent B, and then co-catalyst C and catalyst D are added, and α-olefin E and ethylene are introduced to start the polymerization reaction, the polymerization temperature is T1, the polymerization time is t, and the polymerization pressure is P1; after the polymerization reaction is completed, the slurry in the first reactor is introduced into the product collection tank at a flow rate X1 (the flow rate is based on the weight of the solid product); the concentration of polymer A in the first reactor is 0.1-10.0 wt%, and the weight average molecular weight of polymer A is 1000-8000 g / mol;

[0009] Meanwhile, in the second reactor, solvent B is used as the polymerization medium, the polymerization temperature is T2, the polymerization pressure is P2, and co-catalyst F, catalyst G, α-olefin H and ethylene are continuously introduced for continuous production, and the slurry in the second reactor is introduced into the product collection tank at a flow rate X2 (the flow rate is based on the weight of the solid product);

[0010] The first reactor and the second reactor are connected in parallel for production;

[0011] The mixed slurry in the product collection tank is introduced into a solid-liquid separator, the temperature of the solid-liquid separator is T3, the solid-phase product separated from the solid-liquid separator is dried, devolatilized and extruded and granulated to obtain the easy-to-process high-impact polyethylene product, and the liquid-phase product separated from the solid-liquid separator can be further refined to obtain solvent B for use in the first reactor and the second reactor.

[0012] According to a preferred embodiment of the application, polymer A is selected from one or more of polyethylene wax, oxidized polyethylene wax, polypropylene wax, oxidized polypropylene wax, polybutylene, paraffin wax and Fischer-Tropsch wax.

[0013] According to the preferred embodiment of the present application, the concentration of polymer A in the first reactor is 0.1-10.0wt%, the solvent B is selected from one or more of n-butane, isobutane, n-pentane, isopentane, n-hexane, cyclohexane, methylcyclohexane, 2-methylpentane, 3-methylpentane, n-heptane, 2-methylhexane, 3-methylhexane, n-octane, 2-methylheptane, 3-methylheptane, n-nonane, n-decane; the co-catalyst C and the co-catalyst F are selected from one or more of methylaluminoxane, modified methylaluminoxane, ethylaluminoxane, butylaluminoxane, trimethylaluminum, triethylaluminum, triisobutylaluminum, trihexylaluminum, trioctylaluminum, diethylaluminum chloride, ethylaluminum dichloride, triphenylborane, tris(4-fluorophenyl)borane, tris(pentafluorophenyl)borane, tris(3,5-difluorophenyl)borane, tris(2,4,6-trifluorophenyl)borane, and the co-catalyst C and the co-catalyst F can be the same or different; the catalyst D and the catalyst G are selected from one or more of metallocene catalyst, late transition metal catalyst, Ziegler-Natta catalyst, non-metallocene catalyst, FI catalyst, and the catalyst D and the catalyst G can be the same or different;

[0014] The α-olefin E and the α-olefin H are selected from one or more of propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene or 1-decene, and the α-olefin E and the α-olefin H can be the same or different; the amount of the α-olefin E and the α-olefin H added is usually selected in coordination with the catalytic activity of the catalyst to ensure that the branched chain content in the final product is 0.2-1.0C / 1000C.

[0015] The polymerization temperature T1 is 50-90℃, the polymerization time t is 0.5-10h, and the polymerization pressure P1 is 0.5-2.0MPa.

[0016] According to the preferred embodiment of the present application, the content of polymer A in the solid phase product in the slurry in the first reactor is 0.5-8.0wt%, the weight average molecular weight of polymer A is 1000-8000g / mol, the weight average molecular weight of the solid phase product in the slurry in the first reactor is 80-140×10 4 g / mol, the molecular weight distribution is 50-500, the branched chain content is 0.2-1.0C / 1000C, and the initial elastic modulus of the solid phase product excluding polymer A is 0.2-0.5MPa.

[0017] According to the preferred embodiment of the present application, polymer A is widely distributed on the surface and inside the particles of the solid phase product in the slurry in the first reactor, and the surface of the solid phase product presents a scale shape, and polymer A is distributed between the scale-shaped lamellae, and the thickness of the scale-shaped lamellae is 10-300nm.

[0018] According to the preferred embodiment of the present application, the polymerization temperature T2 is 60-100℃, the polymerization pressure P2 is 0.5-2.0 MPa, and the solid-liquid separator temperature T3 is 40-55℃.

[0019] According to the preferred embodiment of the present application, the ratio of the slurry flow rate X1 in the first reactor to the slurry flow rate X2 in the second reactor is 1:(1.5-9.9), and the content of the polymer A in the easy-to-process high-impact polyethylene product is 0.3-2.0 wt%. The weight average molecular weight of the solid-phase product in the slurry in the second reactor is 20×10 4 -45×10 4 g / mol, and the molecular weight distribution is 10-25.

[0020] According to the preferred embodiment of the present application, the high-temperature gel chromatography test spectrum of the easy-to-process high-impact polyethylene product shows a clear bimodal distribution.

[0021] According to the second object of the present application, the present application provides the use of the easy-to-process high-impact polyethylene product prepared by the method in the preparation of impact polyethylene products.

[0022] According to the preferred embodiment of the present application, the easy-to-process high-impact polyethylene is mixed with a plasticizer, a lubricant, a stabilizer, and an antioxidant in a weight ratio of (96.5-99.0):(0.1-1.0):(0.1-1.0):(0.1-1.0):(0.1-1.0), and then subjected to melt blending granulation (granulation temperature 190-230℃, rotation speed 100-250 rpm) to prepare an impact polyethylene product, such as a small, medium, or large hollow product with high impact strength, which can be applied in the fields of high-impact-resistant vehicle urea tanks, air-drop tanks, automobile oil tanks, automobile oil barrels, and chemical container tanks. The plasticizer can be a commonly used plasticizer in the art, such as di(2-ethylhexyl) phthalate, dibutyl phthalate, diisobutyl phthalate, dibutyl sebacate, and di(2-ethylhexyl) sebacate; the lubricant can be a commonly used lubricant in the art, such as calcium stearate, zinc stearate, aluminum stearate, and silicone oil; the stabilizer can be a commonly used stabilizer in the art, such as diphenyl thiourea, α-phenyl indole, melamine, zinc oxide, 2-hydroxy-4-methoxybenzophenone, 2,2-dihydroxy-4-methoxybenzophenone, and 2-hydroxy-4-n-octyloxybenzophenone; and the antioxidant can be a commonly used antioxidant in the art, such as 1010 antioxidant, 1076 antioxidant, 626 antioxidant, and AT-215 antioxidant.

[0023] The present application has the following outstanding advantages:

[0024] (1) The easy-to-process high-impact polyethylene of the present application has a wide molecular weight distribution, the polymer A component can quickly melt and has a very strong molecular chain movement ability, which can promote the movement of high molecular weight polyethylene molecular chains around the polymer A molecular chains, thus the processing temperature required in the melt processing process is lower, and the processing performance and processing economy are better.

[0025] (2) The easy-to-process high-impact polyethylene of the present application is produced by a double-kettle parallel process, the solid-phase product in the first reaction kettle has a molecular weight distribution of 50-500, and the initial elastic modulus of the solid-phase product excluding the polymer A is 0.2-0.5 MPa, which indicates that the solid-phase product in the first reaction kettle has the characteristics of low entanglement. The molecular chain movement ability of the low-entanglement polyethylene is stronger, and the re-entanglement behavior occurs more quickly and fully in the melt processing process, which leads to higher room temperature impact strength and low-temperature impact strength of the polyethylene. In addition, the weight average molecular weight of the solid-phase product in the slurry in the first reaction kettle is 80-140 x 10 4 g / mol, and this low-entanglement polyethylene has the characteristics of high molecular weight. According to the knowledge in the field of polymer physics, the more the molecular chains with high molecular weight are re-entangled, the more the entanglement points formed, and more entanglement points also lead to higher room temperature impact strength and low-temperature impact strength of the polyethylene product.

[0026] (3) The easy-to-process high-impact polyethylene of the present application is a non-crosslinked polyethylene, and has a molecular weight distribution of 20-40 and a melt index of 8-15 g / 10 min, which indicates that its processing performance is better, the range of the processing temperature window is wider, and the range of the influence of the fluctuation of the processing temperature conditions on the product performance is controllable.

[0027] (4) The easy-to-process high-impact polyethylene of the present application is a non-crosslinked polyethylene, and has a branch chain content of 0.2-1.0 C / 1000 C. The insertion of an appropriate amount of branch chains is conducive to improving the environmental stress cracking resistance of the polyethylene product. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is the elastic modulus G'-time t curve of the solid-phase product in the first reaction kettle excluding the polymer A at 160°C.

[0029] Figure 2 is the scanning electron microscope image of the surface of the solid-phase product particles in the first reaction kettle excluding the polymer A. DETAILED DESCRIPTION

[0030] Embodiments of the present application will be described in detail below with reference to Examples, but those skilled in the art will appreciate that the following Examples are intended to be illustrative only and should not be viewed as limiting the scope of the present application. Where specific conditions are not mentioned in the Examples, they are carried out under conventional conditions or conditions recommended by the manufacturer. Where the manufacturer of the reagent or instrument is not mentioned, it is a conventional product that can be obtained commercially.

[0031] The following methods were used to test the structure or properties of the polyolefins produced in the Examples:

[0032] A high temperature gel permeation chromatograph (GPC) was used to test the weight average molecular weight and molecular weight distribution of the polyethylene.

[0033] A gradient density meter was used to test the density of the polyethylene.

[0034] A melt indexer was used to test the melt index of the polyethylene.

[0035] An analytical temperature rising elution fractionation (TREF) was used to test the short chain branch content of the polyethylene.

[0036] An impact testing machine was used to test the room temperature impact strength and low temperature impact strength of the polyethylene.

[0037] The content of Polymer A in the polyethylene product was separated and weighed by xylene temperature rising elution to calculate the mass content.

[0038] A rotational rheometer was used to test the initial elastic modulus of the polyethylene.

[0039] A scanning electron microscope was used to test the surface morphology structure of the polyethylene sample.

[0040] Example 1

[0041] 150 kg of Fischer-Tropsch wax (weight average molecular weight 1200 g / mol) was dissolved in the first reaction kettle (medium: hexane, volume 10 m 3 , 1.1 L of triethylaluminum, 15 g of Ziegler-Natta catalyst, 50 L of 1-hexene were added in sequence, ethylene was introduced to start polymerization, the polymerization temperature was 52°C, the polymerization time (residence time) was 3 h, and the polymerization pressure was 1.1 MPa; the second reaction kettle (volume 40 m 3The polymerization process uses hexane as the polymerization medium, a polymerization temperature of 85℃, and a polymerization pressure of 1.5MPa. Triethylaluminum, Ziegler-Natta catalyst, 1-hexene, and ethylene are continuously introduced for continuous production. The first and second reactors operate in parallel. The slurry from the first reactor is introduced into the product collection tank at a rate of 1 t / h, and the slurry from the second reactor is introduced into the product collection tank at a rate of 6 t / h. The mixed slurry in the product collection tank is introduced into a solid-liquid separator at a temperature of 45℃. The solid product separated by the solid-liquid separator is dried, devolatilized, and extruded into granules to obtain easily processed, high-impact polyethylene product a. The analytical and characterization results of product a are shown in Table 1.

[0042] Example 2

[0043] 125 kg of polyethylene wax (weight average molecular weight 2000 g / mol) was dissolved at a concentration of 2.5 wt% in the first reaction vessel (medium: heptane, volume 10 m³). 3 ), 1.2 L of triisobutylaluminum, 18 g of Ziegler-Natta catalyst, and 60 L of 1-hexene were added sequentially, and ethylene was introduced to start polymerization. The polymerization temperature was 62℃, the polymerization time (residence time) was 3.5 h, and the polymerization pressure was 0.7 MPa; the second reactor (volume 40 m³) 3 The polymerization medium was heptane, the polymerization temperature was 89℃, and the polymerization pressure was 1.9MPa. Triisobutylaluminum, Ziegler-Natta catalyst, 1-hexene, and ethylene were continuously introduced for continuous production. The first and second reactors were operated in parallel. The slurry from the first reactor was introduced into the product collection tank at a rate of 1.1 t / h, and the slurry from the second reactor was introduced into the product collection tank at a rate of 5.5 t / h. The mixed slurry in the product collection tank was introduced into a solid-liquid separator at a temperature of 50℃. The solid product separated by the solid-liquid separator was dried, devolatilized, and extruded and granulated to obtain easily processed high-impact polyethylene product b. The analytical characterization results of product b are shown in Table 1.

[0044] Example 3

[0045] 100 kg of oxidized polyethylene wax (weight average molecular weight 3200 g / mol) was dissolved at a concentration of 2.0 wt% in the first reaction vessel (medium: cyclohexane, volume 10 m³). 3 ), 1.3 L of modified methylaluminoxane, 16 g of supported metallocene catalyst, 30 L1-hexene, and 30 L1-octene were added sequentially, and ethylene was introduced to start polymerization. The polymerization temperature was 71 °C, the polymerization time (residence time) was 2.2 h, and the polymerization pressure was 1.6 MPa; the second reactor (volume 40 m³) 3hexane as the polymerization medium, the polymerization temperature was 80 °C, the polymerization pressure was 1.2 MPa, and the modified methylaluminoxane, the supported metallocene catalyst, 1-hexene and ethylene were continuously introduced to continuously produce; the first reactor and the second reactor were connected in parallel to produce, the slurry in the first reactor was introduced into the product collection tank at a rate of 0.9 t / h, and the slurry in the second reactor was introduced into the product collection tank at a rate of 3.6 t / h. The mixed slurry in the product collection tank was introduced into the solid-liquid separator, the temperature of the solid-liquid separator was 53 °C, and the solid-phase product separated from the solid-liquid separator was dried, devolatilized and extrusion granulated to obtain the easy-to-process high-impact polyethylene product c, and the analysis and characterization results of the product c are shown in Table 1.

[0046] Example 4

[0047] 200 kg of polyethylene wax (weight average molecular weight 6000 g / mol) was dissolved in the first reactor (medium: n-hexane, volume 10 m 3 ), 0.8 L of triethylaluminum, 14 g of Ziegler-Natta catalyst and 70 L of 1-hexene were sequentially added, and the polymerization was started by introducing ethylene, the polymerization temperature was 75 °C, the polymerization time (residence time) was 4 h, and the polymerization pressure was 0.9 MPa; the second reactor (volume 40 m 3 ) was used as the polymerization medium, the polymerization temperature was 85 °C, the polymerization pressure was 1.3 MPa, and the triethylaluminum, the supported metallocene catalyst, 1-hexene and ethylene were continuously introduced to continuously produce; the first reactor and the second reactor were connected in parallel to produce, the slurry in the first reactor was introduced into the product collection tank at a rate of 1.5 t / h, and the slurry in the second reactor was introduced into the product collection tank at a rate of 4.6 t / h. The mixed slurry in the product collection tank was introduced into the solid-liquid separator, the temperature of the solid-liquid separator was 42 °C, and the solid-phase product separated from the solid-liquid separator was dried, devolatilized and extrusion granulated to obtain the easy-to-process high-impact polyethylene product d, and the analysis and characterization results of the product d are shown in Table 1.

[0048] Comparative Example 1

[0049] The first reactor (volume 10 m 3 ) was used as the polymerization medium, 0.9 L of triethylaluminum, 12 g of Ziegler-Natta catalyst and 50 L of 1-hexene were sequentially added, and the polymerization was started by introducing ethylene, the polymerization temperature was 69 °C, the polymerization time (residence time) was 4.5 h, and the polymerization pressure was 0.6 MPa; the second reactor (volume 40 m 3) as the polymerization medium, the polymerization temperature is 88℃, the polymerization pressure is 1.3 MPa, and continuous introduction of triethylaluminum, Ziegler-Natta catalyst, 1-hexene and ethylene is carried out; the first reactor and the second reactor are connected in parallel, the slurry in the first reactor is introduced into the product collection tank at a rate of 1.3 t / h, and the slurry in the second reactor is introduced into the product collection tank at a rate of 4.6 t / h. The mixed slurry in the product collection tank is introduced into a solid-liquid separator, the temperature of the solid-liquid separator is 44℃, and the solid phase product separated by the solid-liquid separator is dried, devolatilized and extruded to obtain polyethylene product e. The analysis and characterization results of the product e are shown in Table 1.

[0050] Table 1: Characterization results of polyethylene a-e

[0051]

[0052]

[0053] As shown in Table 1 above, compared with the polyethylene product e in Comparative Example 1, the polyethylene products a-d in Examples 1-4 have higher melt index, wider molecular weight distribution, higher room temperature impact strength and low temperature impact strength, which indicates that the polyethylene products a-d have better processability and high impact resistance. In addition, the polyethylene products a-d have higher content of polymer A, the initial elastic modulus of the solid phase product in the first reactor removing polymer A is lower (0.25-0.39 MPa, see FIG. 1), and the surface of the solid phase product in the first reactor removing polymer A presents a scale-like structure (see FIG. 2). Figure 1 ), and the surface of the solid phase product in the first reactor removing polymer A presents a scale-like structure (see FIG. 2). Figure 2 The polyethylene product e does not contain polymer A, the initial elastic modulus of the solid phase product in the first reactor is as high as 0.86 MPa, and the surface of the solid phase product does not have obvious scale-like lamellar structure. The above results show that the molecular chains of the polyethylene product e present the characteristics of high entanglement, and due to the influence of the entanglement points, the molecular chains are difficult to open quickly, the molecular chain movement ability is weak, and the re-entanglement behavior is difficult to occur quickly, which leads to lower melt index, greater difficulty in processing, lower economic efficiency in the processing process, and lower room temperature impact strength and low temperature impact strength of the final product of the polyethylene product e.

[0054] The above examples only express several embodiments of the present application, and the description is more specific and detailed, but it cannot be understood as limiting the scope of the patent of the present application. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A readily processable high impact polyethylene, characterized in that, The easily processable high impact polyethylene has a weight average molecular weight of 10 x 10 4 - 45 x 10 4 g / mol, a molecular weight distribution of 20-40, a density of 0.940-0.965 g / cm 3 , a melt index of 8-15 g / 10 min, a branch content of 0.2-1.0 C / 1000 C, a 23 °C room temperature Charpy double notch impact strength of ≥ 50 kJ / m 2 , and a -40 °C low temperature Charpy double notch impact strength of ≥ 28 kJ / m 2 . The easy-to-process high-impact polyethylene is prepared by the following steps: In the first reactor, polymer A is dissolved in solvent B, and then co-catalyst C and catalyst D are added, and α-olefin E and ethylene are introduced to start the polymerization reaction, the polymerization temperature is T1, the polymerization time is t, and the polymerization pressure is P1; after the polymerization reaction is completed, the slurry in the first reactor is introduced into the product collection tank at a flow rate of X1; the concentration of polymer A in the first reactor is 0.1-10.0 wt%, and the weight average molecular weight of polymer A is 1000-8000 g / mol; At the same time, in the second reactor, solvent B is used as the polymerization medium, the polymerization temperature is T2, the polymerization pressure is P2, and co-catalyst F, catalyst G, α-olefin H and ethylene are continuously introduced for continuous production, and the slurry in the second reactor is introduced into the product collection tank at a flow rate of X2; The first reactor and the second reactor are connected in parallel for production; The mixed slurry in the product collection tank is introduced into a solid-liquid separator, the temperature of the solid-liquid separator is T3, and the solid phase product separated by the solid-liquid separator is dried, devolatilized and extruded to obtain the easy-to-process high-impact polyethylene product; Polymer A is selected from one or more of polyethylene wax, oxidized polyethylene wax, polypropylene wax, oxidized polypropylene wax, polybutene, paraffin wax, and Fischer-Tropsch wax; Solvent B is selected from one or more of n-butane, isobutane, n-pentane, isopentane, n-hexane, cyclohexane, methylcyclohexane, 2-methylpentane, 3-methylpentane, n-heptane, 2-methylhexane, 3-methylhexane, n-octane, 2-methylheptane, 3-methylheptane, n-nonane, and n-decane; Co-catalyst C and co-catalyst F are selected from one or more of methylaluminoxane, modified methylaluminoxane, ethylaluminoxane, butylaluminoxane, trimethylaluminum, triethylaluminum, triisobutylaluminum, trihexylaluminum, trioctylaluminum, dichlorodiethylaluminum, dichloroethylaluminum, triphenylborane, tris(4-fluorophenyl)borane, tris(pentafluorophenyl)borane, tris(3,5-difluorophenyl)borane, and tris(2,4,6-trifluorophenyl)borane, and co-catalyst C and co-catalyst F can be the same or different; Catalyst D and catalyst G are selected from one or more of metallocene catalyst, late transition metal catalyst, Ziegler-Natta catalyst, non-metallocene catalyst, and FI catalyst, and catalyst D and catalyst G can be the same or different; α-olefin E and α-olefin H are selected from one or more of propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, and 1-decene, and α-olefin E and α-olefin H can be the same or different; The polymerization temperature T1 is 50-90 ℃, the polymerization time t is 0.5-10 h, and the polymerization pressure P1 is 0.5-2.0 MPa; The polymerization temperature T2 is 60-100 ℃, the polymerization pressure P2 is 0.5-2.0 MPa, and the temperature of the solid-liquid separator T3 is 40-55 ℃. The ratio of the slurry flow X1 in the first reactor to the slurry flow X2 in the second reactor is 1:(1.5-9.9) based on the weight of the solid product, and the content of polymer A in the easily processable high-impact polyethylene product is 0.3-2.0 wt%.

2. The readily processable high-impact polyethylene according to claim 1, characterized in that The content of the polymer A contained in the solid phase product in the slurry in the first reactor is 0.5-8.0 wt%, the weight average molecular weight of the solid phase product in the slurry in the first reactor is 80-140 x 10 4 g / mol, the molecular weight distribution is 50-500, the content of the branch chain is 0.2-1.0 C / 1000 C, and the initial elastic modulus of the solid phase product excluding the polymer A is 0.2-0.5 MPa.

3. The easily processable high-impact polyethylene according to claim 1, characterized in that The polymer A is distributed on the surface and inside the particles of the solid product in the slurry in the first reactor, and the surface of the solid product is scaly, and the polymer A is distributed between the scaly lamellae, and the thickness of the scaly lamellae is 10-300 nm.

4. The easily processable high-impact polyethylene according to claim 1, characterized in that The weight average molecular weight of the solid phase product in the slurry in the second reactor is 20 x 10 4 - 45 x 10 4 g / mol, and the molecular weight distribution is 10-25.

5. Use of the easily processable high-impact polyethylene according to any one of claims 1-4 in the preparation of an impact polyethylene product.

6. Use according to claim 5, characterized in that, The easily processable high-impact polyethylene is mixed with a plasticizer, a lubricant, a stabilizer and an antioxidant in a weight ratio of (96.5-99.0):(0.1-1.0):(0.1-1.0):(0.1-1.0):(0.1-1.0), and then subjected to melt blending and granulation, and then an impact polyethylene product is prepared by using a rotational molding process, with a rotational molding temperature of 180-260 ℃ and a molding time of 4-72 h.

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