Polyethylene composition and expanded beads, method for producing the same, and expanded bead molding

Abstract

The present invention relates to the field of polymers, and particularly provides a polyethylene composition, a foamed bead and a preparation method thereof, and a foamed bead molding body. The polyethylene composition comprises a component A, a component B, a component C and a cell nucleating agent, wherein the component A is ethylene / alpha-olefin copolymerized linear low-density polyethylene, has the melt index MIA of 0.01-2 g / 10 min, and has the density [rho]A of 0.880-0.936 g / cm<3>, the component B is ethylene / alpha-olefin copolymerized linear low-density polyethylene, has the melt index MIB of 2.1-9.9 g / 10 min, and has the density [rho]B of 0.910-0.930 g / cm<3>, and the component C is ethylene / alpha-olefin copolymerized linear low-density polyethylene, has the melt index MIC of 10-80 g / 10 min, and has the density [rho]C of 0.880-0.930 g / cm<3>. The foamed bead prepared from the polyethylene composition has the uniform and compact cells, and the prepared foamed bead molding body has the high compressive strength.

Description

technical field

[0001] The invention relates to a polyethylene composition, a polyethylene foam bead, a preparation method of the polyethylene foam bead and a molded polyethylene foam bead. Background technique

[0002] Compared with polypropylene foamed beads, polyethylene foamed beads are softer due to their light weight, good mechanical properties including low-temperature impact resistance, higher closed cell ratio, and good resilience. Surface, and can be molded to obtain special shape products and other characteristics. Polyethylene foam beads are a polymer foam material with a wide range of uses. Compared with polystyrene series resin foamed bead molding products, polyethylene foamed bead molded products obtained by molding polyethylene foamed beads have chemical resistance, high toughness, high heat resistance, Good compression resilience and other excellent properties. However, polyethylene resin is a semi-crystalline polymer with a generally linear structure. Wh...

Examples

Embodiment approach

[0035] 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 phase-separated in different solid / liquid (gas) separators 4, and then the phase-separated component A, component B and component C are sent to the homogenizer in proportion si...

Embodiment 1

[0055] This example is used to illustrate the polyethylene composition, expanded beads and expanded bead molded body provided by the present invention and the preparation method thereof.

[0056] (1) Preparation of polyethylene composition:

[0057] The polyethylene composition provided in this embodiment contains component A, component B, component C, cell nucleating agent, lubricant and cell control agent. Wherein, component A, component B and component C are linear low density polyethylene (LLDPE) of ethylene / alpha olefin copolymerization, wherein, component A and component B adopt metallocene catalyst to prepare (the metallocene The catalyst system is the supported metallocene catalyst prepared by CN102453124A embodiment 1, the same below), and component C is prepared by using Ziegler-Natta catalyst (the Ziegler-Natta catalyst system is prepared by CN101838351A embodiment 1 prepared Ziegler-Natta catalyst system, the same below). Specific steps are as follows:

[0058] ...

Embodiment 2

[0076] This example is used to illustrate the polyethylene composition, expanded beads and expanded bead molded body provided by the present invention and the preparation method thereof.

[0077] (1) Preparation of polyethylene composition:

[0078] The polyethylene composition provided in this embodiment contains component A, component B, component C, cell nucleating agent, lubricant and cell control agent. Among them, component A, component B and component C are linear low-density polyethylene (LLDPE) copolymerized with ethylene / α olefin, wherein, component A and component B are prepared by metallocene catalyst, and component C is obtained by using Ziegler-Natta catalysts were prepared. Specific steps are as follows:

[0079] 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 ...

technical field

[0001] The invention relates to a polyethylene composition, a polyethylene foam bead, a preparation method of the polyethylene foam bead and a molded polyethylene foam bead. Background technique

[0002] Compared with polypropylene foamed beads, polyethylene foamed beads are softer due to their light weight, good mechanical properties including low-temperature impact resistance, higher closed cell ratio, and good resilience. Surface, and can be molded to obtain special shape products and other characteristics. Polyethylene foam beads are a polymer foam material with a wide range of uses. Compared with polystyrene series resin foamed bead molding products, polyethylene foamed bead molded products obtained by molding polyethylene foamed beads have chemical resistance, high toughness, high heat resistance, Good compression resilience and other excellent properties. However, polyethylene resin is a semi-crystalline polymer with a generally linear structure. Wh...

Examples

Embodiment approach

[0035] 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 phase-separated in different solid / liquid (gas) separators 4, and then the phase-separated component A, component B and component C are sent to the homogenizer in proportion si...

Embodiment 1

[0055] This example is used to illustrate the polyethylene composition, expanded beads and expanded bead molded body provided by the present invention and the preparation method thereof.

[0056] (1) Preparation of polyethylene composition:

[0057] The polyethylene composition provided in this embodiment contains component A, component B, component C, cell nucleating agent, lubricant and cell control agent. Wherein, component A, component B and component C are linear low density polyethylene (LLDPE) of ethylene / alpha olefin copolymerization, wherein, component A and component B adopt metallocene catalyst to prepare (the metallocene The catalyst system is the supported metallocene catalyst prepared by CN102453124A embodiment 1, the same below), and component C is prepared by using Ziegler-Natta catalyst (the Ziegler-Natta catalyst system is prepared by CN101838351A embodiment 1 prepared Ziegler-Natta catalyst system, the same below). Specific steps are as follows:

[0058] ...

Embodiment 2

[0076] This example is used to illustrate the polyethylene composition, expanded beads and expanded bead molded body provided by the present invention and the preparation method thereof.

[0077] (1) Preparation of polyethylene composition:

[0078] The polyethylene composition provided in this embodiment contains component A, component B, component C, cell nucleating agent, lubricant and cell control agent. Among them, component A, component B and component C are linear low-density polyethylene (LLDPE) copolymerized with ethylene / α olefin, wherein, component A and component B are prepared by metallocene catalyst, and component C is obtained by using Ziegler-Natta catalysts were prepared. Specific steps are as follows:

[0079] 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 ...

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