Multilayer film

Patent metadata

Field	Value
Publication number	US-12194713-B2
Application number	US-201917273767-A
Country	US
Kind code	B2
Filing date	Sep 19, 2019
Priority date	Sep 26, 2018
Publication date	Jan 14, 2025
Grant date	Jan 14, 2025

Abstract

Multilayer film of at least three layers, one core layer and at least one sealing layer wherein 5 the sealing layer comprises a linear low density polyethylene having a density in the range of 0.915 to 0.925 g/cm3, and the core layer comprises a propylene 1-hexene copolymer, said copolymer has an 1-hexene content in the range of 4.5 to 8.0 wt.-% and a xylene soluble fraction of more than 10.0 wt.-%.

First claim

The invention claimed is:

1. A multilayer film comprising at least three layers, one 1 st sealing layer (SL1), one core layer (CL) and one outer layer (OL), the stacking order of the at least three layers is (SL1)/(CL)/(OL),
wherein;
(a) the 1 st sealing layer (SL1) comprises at least 90 wt. %, based on the total weight of the 1 st sealing layer (SL1), of a 1 st base polymer composition (BC1), said 1 st base polymer composition (BC1) comprises at least 70 wt. %, based on the total weight of the 1 st base polymer composition (BC1), of a 1 st linear low density polyethylene (LLDPE1), said 1 st linear low density polyethylene (LLDPE1) has a density measured according to ISO 1183-187 in the range of 0.890 to 0.925 g/cm 3 ;
(b) the core layer (CL) comprises at least 90 wt. %, based on the total weight of the core layer (CL), of a 2 nd base polymer composition (BC2), said 2 nd base polymer composition (BC2) comprises at least 90 wt. %, based on the total weight of the 2 nd base polymer composition (BC2), of a propylene 1-hexene copolymer (PHC); and
(c) the outer layer (OL) comprises at least 90 wt. %, based on the total weight of the outer layer (OL), of a 3 rd base polymer composition (BC3), said 3 rd base polymer composition (BC3) comprises at least 90 wt. %, based on the total weight of the 3 rd base polymer composition (BC3), of a polyolefin;
wherein said propylene 1-hexene copolymer (PHC) of the 2 nd base polymer composition (BC2) has:
(i) a 1-hexene content in the range of 4.5 to 8.0 wt. % based on the total weight of the propylene 1-hexene copolymer (PHC); and
(ii) a xylene soluble fraction (XCS) determined at 25° C. according to ISO 16152 of 18.0 to 35.0 wt. % based on the total weight of the propylene 1-hexene copolymer (PHC), wherein the xylene soluble fraction (XCS) of the propylene 1-hexene copolymer (PHC) has a 1-hexene content in the range of 5.0 to 12.0 wt. %, based on the total weight of the propylene 1-hexene copolymer (PHC), and
wherein the propylene 1-hexene copolymer (PHC) comprises a 1 st propylene 1-hexene copolymer (PHC-1) and a second propylene 1-hexene copolymer (PHC-2), wherein
(a′) said 1 st propylene 1-hexene copolymer (PHC-1) has a 1-hexene content in the range of 0.5 to 3.9 wt. % based on the total weight of the 1 st propylene 1-hexene copolymer (PHC-1), and
(b′) said 2 nd propylene 1-hexene copolymer (PHC-2) has a 1-hexene content in the range of 6.0 to 20.0 wt. % based on the total weight of the 2 nd propylene 1-hexene copolymer (PHC-2).

2. The multilayer film according to claim 1 , wherein the propylene 1-hexene copolymer (PHC) has:
(a) a molecular weight distribution (Mw/Mn) in the range of 3.0 to 4.3; and/or
(b) 2,1 erythro regio defects in the range of 0.40 to 0.55 mol. % determined by 13 C NMR spectroscopy and optionally an isotactic triad concentration of higher than 98% determined by 13 C NMR spectroscopy.

3. The multilayer film according to claim 1 , wherein the propylene 1-hexene copolymer (PHC) has:
(a) a melting temperature in the range of 133 to 140° C.; and/or
(b) a melt flow rate MFR 2 (230° C./2.16 kg) measured according to ISO 1133 in the range of 0.5 to 8.0 g/10 min.

4. The multilayer film according to claim 1 , wherein:
(a) the xylene soluble fraction (XCS) of the propylene 1-hexene copolymer (PHC) has a 1-hexene content in the range of 6.0 to 10.0 wt. %, based on the total weight of the xylene soluble fraction (XCS) of the propylene 1-hexene copolymer (PHC); and/or
(b) the propylene 1-hexene copolymer (PHC) has a xylene soluble fraction (XCS) determined at 25° C. according to ISO 16152 in the range of 21.0 to 30.0 wt. % based on the total weight of the 1-hexene copolymer (PHC).

5. The multilayer film according to claim 1 , wherein the
1 st propylene 1-hexene copolymer (PHC-1) has a 1-hexene content in the range of 0.8 to 3.0 wt. % based on the total weight of the 1 st propylene 1-hexene copolymer (PHC-1).

6. The multilayer film according to claim 1 , wherein the propylene 1-hexene copolymer (PHC):
(a) fulfills the inequation (I):

6.00
≤

C
⁢
6
⁢

(

P
⁢

⁢
H
⁢

⁢
C

)

C
⁢
6
⁢

(

P
⁢

⁢
H
⁢

⁢
C

-
1

)

*

[

P
⁢

⁢
H
⁢

⁢
C

-
1

]

[

P
⁢

⁢
H
⁢

⁢
C

]

≤
8.50

wherein:
C6 (PHC-1) is the 1-hexene content of the 1 st propylene 1-hexene copolymer (PHC-1) based on the total weight of the 1 st propylene 1-hexene copolymer (PHC-1) [in wt.];
C6 (PHC) is the 1-hexene content of the propylene 1-hexene copolymer (PHC) based on the total weight of the propylene 1-hexene copolymer (PHC) [in wt. %];
[PHC-1]/[PHC] is the weight ratio between the 1 st propylene 1-hexene copolymer (PHC-1) and the propylene 1-hexene copolymer (PHC) [in g/g]; and
(b) the propylene 1-hexene copolymer (PHC) optionally further fulfills the inequation (II):

0.70
≤

C
⁢
6
⁢

(

P
⁢

Assignees

• Borealis Ag

Inventors

• Wang Jingbo
• Gahleitner Markus
• Bernreitner Klaus
• Leskinen Pauli
• Niedersüss Peter

Classifications

• 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

• C08L2203/16

  used for films · CPC title

• C08L23/142

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

• C08L23/08 Primary

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

• C08J5/18

  Manufacture of films or sheets · CPC title