Polyethylene composition and thin film prepared from same

Abstract

The invention provides a polyethylene composition and a thin film prepared from the same. The polyethylene composition comprises a component A, a component B, a component C, a nucleating agent and petroleum resin. The component A refers to ethylene / alpha-olefin copolymerized linear low-density polyethylene, and at a temperature of 190 DEG C and with a load of 2.16kg, a melt index MFRA (mass flow rate A) of the linear low-density polyethylene is 0.01-2g / 10min, and a density RhoA is 0.880-0.936g / cm<3>. The component B refers to ethylene / alpha-olefin copolymerized linear low-density polyethylene, and at a temperature of 190 DEG C and with a load of 2.16kg, a melt index MFRB (mass flow rate B) of the linear low-density polyethylene is 2.1-9.9g / 10min, and a density RhoB is 0.910-0.930g / cm<3>. The component C refers to ethylene / alpha-olefin copolymerized linear low-density polyethylene, and at a temperature of 190 DEG C and with a load of 2.16kg, a melt index MFRC (mass flow rate C) of the linear low-density polyethylene is 10-80g / 10min, and a density RhoC is 0.880-0.930g / cm<3>. When the polyethylene composition is applied to prepare a polyethylene thin film by a flat film stretching method, the polyethylene composition is excellent in film-forming property, and the prepared thin film is high in modulus.

Description

technical field

[0001] The present invention relates to a polyethylene composition and its film. Background technique

[0002] Biaxially Oriented Polyethylene (BOPE) film is a film material formed by a polyethylene (PE) resin with a special molecular structure through a biaxial stretching process. In the forming process of BOPE film, after the film is stretched, the PE macromolecular chain and crystal structure are highly oriented, which significantly improves the tensile strength of the film, reduces the tensile elongation at break, and makes the film Lower haze, higher gloss and better clarity. In addition, compared with polyethylene film products prepared by extrusion blow molding process and extrusion casting process in the prior art, BOPE film has high mechanical strength, good puncture resistance and impact resistance, excellent optical properties, energy saving and environmental protection, etc. Advantage. Therefore, BOPE film can be widely used in packaging bags, ...

Examples

Embodiment approach

[0037] According to a preferred embodiment of the present invention, the polyethylene composition is figure 1 Prepared in the shown multi-reactor parallel device, described multi-reactor parallel device comprises first reactor 1, second reactor 2, third reactor 3, solid / liquid (gas) separator 4, homogenizer The silo 5 and the melt granulation system 6, wherein the first reactor 1, the second reactor 2 and the third reactor 3 are connected in parallel, and the number of the solid / liquid (gas) separator 4 is three One, communicated with the first reactor 1, the second reactor 2 and the third reactor 3 respectively, the component A produced by the first reactor 1, the component B produced by the second reactor 2 and the component B produced by the third reactor The component C prepared by the reactor 3 is carried out phase separation in different solid / liquid (gas) separators 4 respectively, and then the component A, component B and component C after the phase separation will be ...

Embodiment 1

[0056] This example is used to illustrate the polyethylene composition and film thereof provided by the present invention.

[0057] (1) Preparation of polyethylene composition:

[0058] The polyethylene composition provided in this example is composed of component A, component B, component C, nucleating agent, petroleum resin, lubricant and antioxidant, wherein component A, component B and component C are all It is the linear low density polyethylene (LLDPE) of ethylene / alpha olefin copolymerization, and component A and component B adopt metallocene catalyst to prepare (the described metallocene catalyst system is the supported metallocene catalyst prepared by CN102453124A embodiment 1 , the same below), component C is prepared by Ziegler-Natta catalyst (the Ziegler-Natta catalyst system is the Ziegler-Natta catalyst system prepared by CN101838351A Example 1, the same below) . Specific steps are as follows:

[0059] Add ethylene, α-olefin, hydrogen and nitrogen (ethylene, α...

Embodiment 2

[0069] This example is used to illustrate the polyethylene composition and film thereof provided by the present invention.

[0070] (1) Preparation of polyethylene composition:

[0071] The polyethylene composition provided in this example is composed of component A, component B, component C, nucleating agent, petroleum resin, lubricant and antioxidant, wherein component A, component B and component C are all It is a linear low density polyethylene (LLDPE) copolymerized with ethylene / alpha olefin, wherein component A and component B are prepared by metallocene catalyst, and component C is prepared by Ziegler-Natta catalyst. Specific steps are as follows:

[0072] Add ethylene, alpha olefin, hydrogen and nitrogen into the fluidized bed gas phase reactor, then add the catalyst system, and then polymerize under the conditions of temperature 84-88°C and pressure 1.8-2.0MPa to obtain components A, Component B and Component C. Among them, the control of the melt index of componen...

technical field

[0001] The present invention relates to a polyethylene composition and its film. Background technique

[0002] Biaxially Oriented Polyethylene (BOPE) film is a film material formed by a polyethylene (PE) resin with a special molecular structure through a biaxial stretching process. In the forming process of BOPE film, after the film is stretched, the PE macromolecular chain and crystal structure are highly oriented, which significantly improves the tensile strength of the film, reduces the tensile elongation at break, and makes the film Lower haze, higher gloss and better clarity. In addition, compared with polyethylene film products prepared by extrusion blow molding process and extrusion casting process in the prior art, BOPE film has high mechanical strength, good puncture resistance and impact resistance, excellent optical properties, energy saving and environmental protection, etc. Advantage. Therefore, BOPE film can be widely used in packaging bags, ...

Examples

Embodiment approach

[0037] According to a preferred embodiment of the present invention, the polyethylene composition is figure 1 Prepared in the shown multi-reactor parallel device, described multi-reactor parallel device comprises first reactor 1, second reactor 2, third reactor 3, solid / liquid (gas) separator 4, homogenizer The silo 5 and the melt granulation system 6, wherein the first reactor 1, the second reactor 2 and the third reactor 3 are connected in parallel, and the number of the solid / liquid (gas) separator 4 is three One, communicated with the first reactor 1, the second reactor 2 and the third reactor 3 respectively, the component A produced by the first reactor 1, the component B produced by the second reactor 2 and the component B produced by the third reactor The component C prepared by the reactor 3 is carried out phase separation in different solid / liquid (gas) separators 4 respectively, and then the component A, component B and component C after the phase separation will be ...

Embodiment 1

[0056] This example is used to illustrate the polyethylene composition and film thereof provided by the present invention.

[0057] (1) Preparation of polyethylene composition:

[0058] The polyethylene composition provided in this example is composed of component A, component B, component C, nucleating agent, petroleum resin, lubricant and antioxidant, wherein component A, component B and component C are all It is the linear low density polyethylene (LLDPE) of ethylene / alpha olefin copolymerization, and component A and component B adopt metallocene catalyst to prepare (the described metallocene catalyst system is the supported metallocene catalyst prepared by CN102453124A embodiment 1 , the same below), component C is prepared by Ziegler-Natta catalyst (the Ziegler-Natta catalyst system is the Ziegler-Natta catalyst system prepared by CN101838351A Example 1, the same below) . Specific steps are as follows:

[0059] Add ethylene, α-olefin, hydrogen and nitrogen (ethylene, α...

Embodiment 2

[0069] This example is used to illustrate the polyethylene composition and film thereof provided by the present invention.

[0070] (1) Preparation of polyethylene composition:

[0071] The polyethylene composition provided in this example is composed of component A, component B, component C, nucleating agent, petroleum resin, lubricant and antioxidant, wherein component A, component B and component C are all It is a linear low density polyethylene (LLDPE) copolymerized with ethylene / alpha olefin, wherein component A and component B are prepared by metallocene catalyst, and component C is prepared by Ziegler-Natta catalyst. Specific steps are as follows:

[0072] Add ethylene, alpha olefin, hydrogen and nitrogen into the fluidized bed gas phase reactor, then add the catalyst system, and then polymerize under the conditions of temperature 84-88°C and pressure 1.8-2.0MPa to obtain components A, Component B and Component C. Among them, the control of the melt index of componen...

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