Method for producing propylene polymeric material

Patent metadata

Field	Value
Publication number	US-9434806-B2
Application number	US-201514837654-A
Country	US
Kind code	B2
Filing date	Aug 27, 2015
Priority date	Aug 29, 2014
Publication date	Sep 6, 2016
Grant date	Sep 6, 2016

Abstract

A method is provided for producing a propylene polymeric material containing a propylene polymer component high in content of α-olefin units. The material can be produced stably without stopping of the operation due to clogging of a pipe. The method is one for producing a propylene polymeric material composed of a propylene polymer component (A) and a propylene polymer component (B) via at least two steps, including a first step of producing the component (A) and a second step of producing the component (B) in a gas phase. The partial pressure of the α-olefin having four or more carbon atoms in the gas phase in the second step reactor is 0.10 MPa or more. A formula, X≦0.0025×Y+0.2850, is satisfied, wherein the partial pressure is X MPa, and the content of the propylene polymer component (A) in the propylene polymeric material is Y % by weight.

First claim

What is claimed is:

1. A method for producing a propylene polymeric material composed of not less than 11% by weight and less than 35% by weight of a propylene polymer component (A) defined below and more than 65% by weight and less than 89% by weight of a propylene polymer component (B) defined below via at least two steps, where the whole amount of the propylene polymeric material is taken as 100% by weight, the method comprising the following first step and second step:
the first step of polymerizing at least propylene and ethylene within a reactor to produce the propylene polymer component (A), and
the second step of polymerizing at least propylene and an α-olefin having 4 or more carbon atoms, in a gas phase contained within a reactor, in the presence of the propylene polymer component (A) under conditions fulfilling the following requirement (a) to produce the propylene polymer component (B),
wherein
the propylene polymer component (A) is: a propylene-ethylene copolymer component (A1) comprising monomer units derived from propylene and monomer units derived from ethylene, wherein the content of the monomer units derived from propylene is not less than 90% by weight and not more than 99% by weight and the content of the monomer units derived from ethylene is not less than 1% by weight and not more than 10% by weight, where the sum total of the content of the monomer units derived from propylene and the content of the monomer units derived from ethylene is taken as 100% by weight, or a propylene-ethylene-α-olefin copolymer component (A2) comprising monomer units derived from propylene, monomer units derived from ethylene, and monomer units derived from an α-olefin having 4 or more carbon atoms, wherein the content of the monomer units derived from propylene is not less than 85% by weight and not more than 98.9% by weight, the content of the monomer units derived from ethylene is not less than 1% by weight and not more than 10% by weight, and the content of the monomer units derived from the α-olefin having 4 or more carbon atoms is not less than 0.1% by weight and not more than 5% by weight, where the sum total of the content of the monomer units derived from propylene, the content of the monomer units derived from ethylene, and the content of the monomer units derived from the α-olefin having 4 or more carbon atoms is taken as 100% by weight,
the propylene polymer component (B) is: a propylene-α-olefin copolymer component (B1) comprising monomer units derived from propylene and monomer units derived from an α-olefin having 4 or more carbon atoms, wherein the content of the monomer units derived from propylene is not less than 50% by weight and not more than 80% by weight and the content of the monomer units derived from the α-olefin having 4 or more carbon atoms is not less than 20% by weight and not more than 50% by weight, where the sum total of the content of the monomer units derived from propylene and the content of the monomer units derived from the α-olefin having 4 or more carbon atoms is taken as 100% by weight, or a propylene-ethylene-α-olefin copolymer component (B2) comprising monomer units derived from propylene, monomer units derived from ethylene, and monomer units derived from an α-olefin having 4 or more carbon atoms, wherein the content of the monomer units derived from propylene is not less than 40% by weight and not more than 79.9% by weigh, the content of the monomer units derived from ethylene is not less than 0.1% by weight and not more than 10% by weight, and the content of the monomer units derived from the α-olefin having 4 or more carbon atoms is not less than 20% by weight and not more than 50% by weight, where the sum total of the content of the monomer units derived from propylene, the content of the monomer units derived from ethylene, and the content of the monomer units derived from the α-olefin having 4 or more carbon atoms is taken as 100% by weight, and
requirement (a) is that the partial pressure of the α-olefin having 4 or more carbon atoms in the gas phase contained within the reactor of the second step is not lower than 0.10 MPa, and the following formula (1) is satisfied: wherein said partial pressure is expressed by X MPa and the content of the propylene polymer component (A) in the propylene polymeric material is expressed by Y % by weight, where the whole amount of the propylene polymeric material is taken as 100% by weight
X≦ 0.0025× Y+ 0.2850  (1).

2. The method for producing a propylene polymeric material according to claim 1 , wherein a saturated hydrocarbon having 6 or more carbon atoms is used and the concentration of said saturated hydrocarbon in the gas phase contained within the reactor of the second step is not more than 1.0 mol %.

Assignees

• Sumitomo Chemical Co

Inventors

• Itoguchi Satoshi

Classifications

• C08L2314/02

  Ziegler natta catalyst · CPC title

• C08L2205/025

  containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure · CPC title

• C08L2308/00

  Chemical blending or stepwise polymerisation process with the same catalyst · CPC title

• C08F293/005 Primary

  using free radical "living" or "controlled" polymerisation, e.g. using a complexing agent · CPC title

• C08L23/142 Primary

  at least partially crystalline copolymers of propene with other olefins · CPC title