Propylene polymer compositions

Patent metadata

Field	Value
Publication number	US-10323141-B2
Application number	US-201314385019-A
Country	US
Kind code	B2
Filing date	Mar 12, 2013
Priority date	Mar 13, 2012
Publication date	Jun 18, 2019
Grant date	Jun 18, 2019

Abstract

Propylene polymer compositions comprising:
A) from 70 wt % to 95 wt %, of a random copolymer of propylene with ethylene, containing from 3.5 wt % to 8.5 wt %, of ethylene derived units, having a content of fraction soluble in xylene at 25° C. comprised between 7.1 wt % and 15.2 wt % and having a melting point higher than 142.0° C.; B) from 5 wt % to 35 wt %, of a copolymer of propylene with ethylene, containing from 8.5 wt % to 17.0 wt % of ethylene derived units;

the sum A+B being 100; the melt flow rate, MFR (ISO 1133 (230° C., 2.16 kg).) from 0.6 g/10 min to 20.2 g/10 min.

First claim

What is claimed is:

1. A medical injection molded article comprising a propylene polymer composition comprising:
A) 70-95 wt % of a random copolymer of propylene with ethylene, comprising 3.5-8.5 wt % of ethylene derived units, having a content of fraction soluble in xylene at 25° C. of 7.1-15.2 wt % and having a melting point higher than 142.0° C.;
B) 5-35 wt % of a copolymer of propylene with ethylene comprising 8.8 to 14.7 wt. % of ethylene derived units; and
C) optionally comprising one or more additives:
wherein the sum of A+B+C is 100;
the propylene polymer composition comprises a melt flow rate (MFR: ISO 1133 (230° C., 2.16 kg)) of 0.8-5.0 g/10 min.; and the article comprises a haze value as measured on a 50 μm film of lower than 4.1%.

2. The medical injection molded article of claim 1 , wherein the fraction of the overall composition soluble in xylene at 25° C. ranges from 10.3 wt % to 18.5 wt %.

3. The medical injection molded article of claim 1 , wherein the propylene polymer composition has the intrinsic viscosity [η] of the fraction of the overall composition soluble in xylene at 25° C. ranging from 1-4.5 dl/g.

4. The medical injection molded article of claim 1 , having a flexural modulus higher than 700 MPa.

5. The medical injection molded article of claim 1 , having a flexural modulus of at least 867 MPa.

6. The medical injection molded article of claim 1 , wherein the one or more additives are selected from the group consisting of antioxidants, light stabilizers, heat stabilizers, nucleating agent, colorants and fillers.

7. The medical injection molded article of claim 6 , wherein the fillers comprise one or more of talc, calcium carbonate and mineral fibers.

8. The medical injection molded article of claim 6 , wherein the nucleating agent comprises 0.05-2.0% by weight of the propylene polymer composition.

9. The medical injection molded article of claim 8 , wherein the one or more nucleating agents are selected from p-tert-butyl benzoate, 1,3-dibenzylidenesorbitol and 2,4-dibenzylidenesorbitol.

10. The medical injection molded article of claim 1 , wherein the propylene polymer composition comprises a haze value measured on a 50 μm film of lower than 4.1%.

11. The medical injection molded article of claim 1 , wherein the propylene polymer composition comprises a haze value measured on a 50 μm film of lower than 2.8%.

Assignees

• Basell Poliolefine Italia Srl

Inventors

• Destro Mara
• Ciarafoni Marco
• Massari Paola
• Squarzoni Stefano

Classifications

• C08F2/001

  Multistage polymerisation processes characterised by a change in reactor conditions without deactivating the intermediate polymer (C08F295/00, C08F297/00 take precedence) · 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

• C08F2500/12

  Melt flow index or melt flow ratio · CPC title

• C08L23/14 Primary

  Copolymers of propene (C08L23/16 takes precedence) · CPC title

• C08L2205/02

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