US 12,215,208 B2Granted

Polyethylene film for heat sealing

AssigneeSabic Global Technologies B.V.

InventorsPriya Garg, Maria Soliman

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Abstract

The present invention relates to a film comprising at least one sealing layer wherein at least one layer A of the sealing layer(s) comprises a polyethylene comprising moieties derived from ethylene and moieties derived from an α-olefin comprising 4 to 10 carbon atoms, the polyethylene having a density of ≥870 and ≤920 kg/m3 as determined in accordance with ASTM D792 (2013), wherein the polyethylene has: x a fraction of material that is eluted in analytical temperature rising elution fractionation (a-TREF) at a temperature ≤30.0° C. of ≥5.0 wt %, preferably ≥10.0 wt %, with regard to the total weight of the polyethylene; x a shear storage modulus G′ determined at a shear loss modulus G″=5000 Pa of >700 Pa, G′ and G″ being determined in accordance with ISO 6721-10 (2015) at 190° C.; x a melt mass-flow rate, determined at 190° C. under a load of 2.16 kg in accordance with ASTM D1238 (2013) of ≥2.60 and ≤4.90 g/10 min; and x a chemical composition distribution broadness (CCDB) of ≥15.0, preferably ≥20.0. Such film allows for sealing of the film at a reduced temperature, whilst still providing a desirable seal strength, and a desirable hot-tack strength.

Claims15

Dependent claims

A film comprising at least one sealing layer wherein at least one layer A of the at least one sealing layer comprises a polyethylene comprising moieties derived from ethylene and moieties derived from an α-olefin comprising 4 to 10 carbon atoms, the polyethylene having a density of ≥870 and ≤920 kg/m3 as determined in accordance with ASTM D792 (2013),

wherein the polyethylene has:
a fraction of material that is eluted in analytical temperature rising elution fractionation (a-TREF) at a temperature ≤30.0° C. of ≥5.0 wt % with regard to the total weight of the polyethylene;
a shear storage modulus G′ determined at a shear loss modulus G″=5000 Pa of >700 Pa, G′ and G″ being determined in accordance with ISO 6721-10 (2015) at 190° C.;
a melt mass-flow rate, determined at 190° C. under a load of 2.16 kg in accordance with ASTM D1238 (2013) of ≥2.60 and ≤4.90 g/10 min;
and
a chemical composition distribution broadness (CCDB) of ≥15.0,
wherein the CCDB is determined according to formula I:
C
⁢
C
⁢
D
⁢
B
=
T
z
+
2
-
T
n
-
2
T
n
-
2
*
1
⁢
0
⁢
0
formula
⁢
1
wherein
Tn-2 is the moment calculated according to the formula II:
T
n
-
2
=
∑
w
⁡
(
i
)
T
⁡
(
i
)
2
∑
w
⁡
(
i
)
T
⁡
(
i
)
3
formula
⁢
II
and
Tz+2 is the moment calculated according to the formula III:
T
z
+
2
=
∑
w
⁡
(
i
)
·
T
⁡
(
i
)
4
∑
w
⁡
(
i
)
·
T
⁡
(
i
)
3
formula
⁢
III
wherein
w(i) is sampled weight fraction in wt % with regard to a total sample weight in a-TREF analysis of a sample (i) taken at temperature T(i), where T(i)>30° C., an area under an a-TREF curve being normalised to surface area=1 for T(i)>30° C.;
and
T(i) is temperature at which sample (i) is taken in a-TREF analysis, in ° C.

108 more elements

Dependencies are inferred from the claim text.

Facts

Application: 17/423,242Filed 13 Jan 2020
Priority: EP 19152323.217 Jan 2019
Published: US 2022/0064389 A13 Mar 2022
Granted: 4 Feb 2025
Term ends: Not estimatedThe source records don’t support an estimate.

Classification31 codes

B32B 27/06
Layered products comprising a layer of synthetic resin: as the main or only constituent of a layer, which is next to another layer of the same or…
C08J 5/18
Manufacture of articles or shaped materials containing macromolecular substances: manufacture of films or sheets
B29C 65/02
Joining or sealing of preformed parts , e.g. welding of plastics materials; Apparatus therefor: by heating, with or without pressure
B32B 27/18
Layered products comprising a layer of synthetic resin: characterised by the use of special additives