Polypropylene composition

Patent metadata

Field	Value
Publication number	US-11993701-B2
Application number	US-202217752243-A
Country	US
Kind code	B2
Filing date	May 24, 2022
Priority date	Sep 20, 2017
Publication date	May 28, 2024
Grant date	May 28, 2024

Abstract

New polypropylene composition which combines low sealing initiation temperature (SIT), high hot-tack, good optical properties, like low haze and its use, and improved stiffness/impact balance.

First claim

The invention claimed is:

1. An unoriented film, wherein the unoriented film is a cast film or a blown film, wherein the unoriented film comprises more than 90% of a polypropylene composition, the polypropylene composition comprising
(A) a blend of
(a) 80.0 to 92.0 wt %, based on the blend, of a propylene terpolymer comprising
(i) ethylene-derived comonomer units in an amount of from 1.0 to 1.6 wt %, and
(ii) comonomer units derived from a C 4 to C 10 α-olefin in an amount of from 6.0 to 10.0 wt %,
whereby the terpolymer has an MFR 2 (230° C., 2.16 kg, ISO 1133) in a range of 1.5 to 5.0 g/10 min and
(b) 8.0 to 20.0 wt %, based on the blend, of an ethylene based plastomer having a density according to ISO 1183 of from 0.850 g/cm 3 to 0.900 g/cm 3 and an MFR 2 according to ISO 1133 (190° C.; 2.16 kg) in the range of 0.3 to 4.0 g/10 min, and
(B) optionally one or more additives in a total amount of from 0.0 up to 5.0 wt %, based on the polypropylene composition, selected from the group consisting of slip agents, anti-block agents, UV stabilizers, alpha and/or beta nucleating agents, antistatic agents, and antioxidants,
wherein the MFR 2 according to ISO 1133 (230° C.; 2.16 kg) of the polypropylene composition is in the range of 1.7 to 4.0 g/10 min,
wherein the unoriented film has a Dart Drop Impact according to ASTM D1709, method A of 500 g to 1500 g, a haze according to ASTM D1003-00 determined on 50 μm blown film of 20.0% to 25.0%, a tensile modulus in machine direction according to ISO 527-3 on blown film with a thickness of 50 μm at a cross head speed of 100 mm/min of 300 to 558 MPa, and a sealing initiation temperature in the range of 100° C. to 108° C.

2. The unoriented film according to claim 1 , wherein the propylene terpolymer has a melting temperature Tm measured via DSC according to ISO 11357 of equal or higher than 130° C.

3. The unoriented film according to claim 1 , wherein the propylene terpolymer has a xylene cold soluble (XCS) amount in the range of 3.0 to below 20.0 wt % (measured according to ISO 16152, 2005, at 25° C.).

4. The unoriented film according to claim 1 , wherein the ethylene based plastomer has an MFR 2 according to ISO 1133 (190° C.; 2.16 kg) in the range of 0.5 to 1.5 g/10 min.

5. The unoriented film according to claim 1 , wherein the polypropylene composition has a xylene cold soluble (XCS) amount below 35.0 wt % (measured according to ISO 16152, 2005, at 25° C.).

6. The unoriented film according to claim 1 , wherein the unoriented film has a hot-tack force determined on 50 μm blown film in the range of from 2.8 to 7.0 N.

7. The unoriented film according to claim 1 , wherein the unoriented film has the Dart Drop Impact according to ASTM D1709, method A of 700 g to 1500 g.

Assignees

• Borealis Ag

Inventors

• Gahleitner Markus
• Wang Jingbo
• Bernreitner Klaus
• Niedersüss Peter
• Berger Friedrich
• Ortner Stefan

Classifications

• B29C49/0005

  characterised by the material · CPC title

• C08L23/14 Primary

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

• B29C39/003

  characterised by the choice of material · CPC title

• C08L23/08

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

• C08L23/16 Primary

  Ethylene-propylene or ethylene-propylene-diene copolymers · CPC title