Polypropylene compositions

Patent metadata

Field	Value
Publication number	US-2016347941-A1
Application number	US-201515117320-A
Country	US
Kind code	A1
Filing date	Feb 4, 2015
Priority date	Feb 6, 2014
Publication date	Dec 1, 2016
Grant date	—

Abstract

The present disclosure relates to a heterophasic polypropylene compositions comprising 78-85% by weight of a propylene homopolymer or copolymer matrix with up to 2.0% by weight of ethylene units, 15-22% by weight of an elastomeric ethylene-propylene copolymer and a clarifying agent. The composition has an intrinsic viscosity of the xylene soluble fraction at room temperature of from 0.5 to 1.5 dl/g and a melt flow rate (230° C., 2.16 kg) of 0.5 to 10 g/10 min. The compositions of the present disclosure can be used to prepare sheets for thermoforming applications.

First claim

What is claimed is:

1 . A polypropylene composition comprising:
(a) 78-85% by weight of a propylene homopolymer or a copolymer of propylene comprising an ethylene content of up to 2.0% by weight; (b) 15-22% weight of a copolymer of ethylene with propylene comprising an ethylene content of from 78 to 90% by weight; and (c) an effective amount of a clarifying agent; wherein the composition has an intrinsic viscosity of the xylene soluble fraction (XSIV) at room temperature of from 0.5 to 1.5 dl/g and a melt flow rate (MFR), measured at 230° C. and 2.16 kg, of from 0.5 to 10 g/10 min.

2 . The propylene polymer composition of claim 1 , wherein the clarifying agent is present in the composition of the present invention in amount of from 0.05 to 1% by weight with respect to the total weight of the composition.

3 . The propylene polymer composition of claim 1 , wherein the clarifying agent is selected among sorbitol derivatives, nonitol derivatives and phosphate derivatives.

4 . The propylene polymer composition of claim 3 , wherein the clarifying agent is selected from 1,3:2,4-bis-(3,4-dimethylbenzylidene) sorbitol and 1,2,3-trideoxy-4,6:5,7-bis-O-[(4-propylphenyl)methylene]-nonitol.

5 . A process for the preparation of the polyolefin composition of claim 1 , comprising at least two sequential polymerization stages, with each subsequent polymerization being conducted in the presence of the polymeric material formed in the immediately preceding polymerization reaction, wherein the polymerization stage of propylene to the polymer component (a) is carried out in at least one stage, and at least one copolymerization stage of mixtures of ethylene with propylene to the elastomeric polymer component (b) is carried out.

6 . The process of claim 5 , wherein the polymerization stages are carried out in the presence of a stereospecific Ziegler-Natta catalyst.

7 . The process of claim 5 , wherein the stereospecific Ziegler-Natta catalyst comprises:
(i) Mg, Ti, a halogen and an internal electron donor; (ii) an alkylaluminum compound and, optionally; (iii) one or more external electron-donor compounds (external donor).

8 . The process of claim 5 , wherein the polymerization of the polymer component (a) is carried out in liquid monomer, while the copolymerization stages of the elastomeric copolymer component (b) is carried out in gas phase.

9 . A sheet obtained from a propylene polymer composition comprising:
(a) 78-85% by weight of a propylene homopolymer or a copolymer of propylene with ethylene, having an ethylene content of up to 2.0% by weight; (b) 15-22% by weight of a copolymer of ethylene with propylene, having an ethylene content of from 78 to 90% by weight; and (c) an effective amount of a clarifying agent; wherein the composition has an intrinsic viscosity of the xylene soluble fraction (XSIV) at room temperature of from 0.5 to 1.5 dl/g and a melt flow rate (MFR), measured at 230° C. and 2.16 kg, of from 0.5 to 10 g/10 min.

10 . A thermoformed article obtained from a propylene polymer composition comprising:
(a) 78-85% by weight of a propylene homopolymer or of a copolymer of propylene with ethylene, having an ethylene content of up to 2.0% by weight; (b) 15-22% by weight of a copolymer of ethylene with propylene having an ethylene content of from 78 to 90% by weight; and (c) an effective amount of a clarifying agent; wherein the composition has an intrinsic viscosity of the xylene soluble fraction (XSIV) at room temperature of from 0.5 to 1.5 dl/g and a melt flow rate (MFR), measured at 230° C. and 2.16 kg, of from 0.5 to 10 g/10 min.

Assignees

• Basell Poliolefine Italia Srl
• Basell Poliolefine Italias R L

Inventors

• Nakajima Takeshi
• Sakai Kazuhiko
• Kuriyama Minoru
• Maruyama Masanori

Classifications

• C08J2423/08

  Copolymers of ethene (C08J2423/16 takes precedence) · CPC title

• C08L23/12 Primary

  Polypropene · CPC title

• C08J5/18

  Manufacture of films or sheets · CPC title

• C08L2314/02

  Ziegler natta catalyst · CPC title

• C08L2205/02

  containing two or more polymers of the same C08L -group · CPC title