Polypropylene composition

Patent metadata

Field	Value
Publication number	US-2020392321-A1
Application number	US-201816633699-A
Country	US
Kind code	A1
Filing date	Aug 14, 2018
Priority date	Aug 21, 2017
Publication date	Dec 17, 2020
Grant date	—

Abstract

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

First claim

1 - 15 . (canceled)

16 . A polypropylene composition comprising
(A) a blend of
(a) 80.0 to 97.0 wt %, based on the blend, of a propylene terpolymer comprising
(i) ethylene-derived comonomer units in an amount of from 0.3 to 4.0 wt % and
(ii) comonomer units derived from a C 4 to C 10 α-olefin in an amount of from 4.0 to 16.0 wt %,

whereby the terpolymer has an MFR2 (230° C., 2.16 kg, ISO1133) in a range of 0.5 to 20.0 g/10 min and
(b) 3.0 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 0.915 g/cm 3 and an MFR2 according to ISO 1133 (190° C.; 2.16 kg) in the range of 5.0 to 50.0 g/10 min, and optionally
(B) one or more additives in a total amount of from 0.0 up to 5.0 wt %, based on the composition, selected from slip agents, anti-block agents, UV stabilizers, alpha and/or beta nucleating agents, antistatic agents, and antioxidants.

17 . The polypropylene composition according to claim 16 , wherein the propylene terpolymer has a melting temperature Tm measured via DSC according to ISO 11357 of equal or higher than 130° C.

18 . The polypropylene composition according to claim 16 , wherein the propylene terpolymer has a xylene cold soluble (XCS) amount, measured according to ISO 16152, 2005, at 25° C., in the range of 3.0 to below 20.0 wt %.

19 . The polypropylene composition according to claim 16 , wherein the ethylene based plastomer has an MFR2 according to ISO 1133 (190° C.; 2.16 kg) in the range of 8.0 to 45.0 g/10 min.

20 . The polypropylene composition according to claim 16 , wherein the composition has a xylene cold soluble (XCS) amount, measured according to ISO 16152, 2005, at 25° C., below 28.0 wt %.

21 . The polypropylene composition according to claim 16 , wherein the MFR2-ratio of the MFR2 of the final polypropylene composition MFR final to the MFR2 of the propylene terpolymer MFR terpolymer is greater than 1.0.

22 . A method of preparing the polypropylene composition according to claim 16 , comprising the steps of
(i) preparing the propylene terpolymer (a) by polymerizing propylene, ethylene, and a C 4 to C 10 α-olefin in the presence of a Ziegler-Natta catalyst, (ii) mixing the propylene terpolymer (a) with the ethylene based plastomer (b), optionally in the presence of one or more additives, to obtain a mixture of components (a) and (b), and (iii) extruding the mixture to obtain the polypropylene composition.

23 .- 24 . (canceled)

25 . An article comprising the polypropylene composition according to claim 16 .

26 . The article according to claim 25 , wherein the article is an unoriented film comprising more than 90% of the polypropylene composition, wherein the film is a cast film or a blown film.

27 . The article according to claim 26 , wherein the film has a sealing initiation temperature in the range of from 90° C. to 110° C.

28 . The article according to claim 26 , wherein the film has a haze according to ASTM D1003-00 determined on 50 μm blown film of below 18.0%.

29 . The article according to claim 26 , wherein the film, has a hot-tack force determined on a 50 μm blown film in the range of from 3.0 to 7.0 N.

30 . (canceled)

Assignees

• Borealis Ag

Inventors

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

Classifications

• C08F210/16

  Copolymers of ethene with alpha-alkenes, e.g. EP rubbers · CPC title

• C08L2203/16

  used for films · CPC title

• C08F2500/26

  Use as polymer for film forming · CPC title

• C08L23/16 Primary

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

• C08F2500/08

  Low density, i.e. < 0.91 g/cm3 · CPC title