US 12,734,792 B2Granted

Full polyethylene blown film through double bubble process

AssigneeExxonMobil Chemical Patents Inc.

InventorsXiao-Chuan Wang, Zhi-Yi Shen, Chao Liu, Zhi Hui Zhang, Qin Wang

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Abstract

Provided herein are substantially all-poly ethylene films, and in particular blown biaxially oriented all-polyethylene films. The films can be multi-layer, and can be produced using a double bubble process. Particular multi-layer films include at least two skin layers, and al least one core layer disposed directly or indirectly between the at least two skin layers. The film composes: a narrow-composition-distribution metallocene linear low density′ polyethylene (narrow-CD mLLDPE), a long-chain-branched metallocene linear low density′ polyethylene (LCB mLLDPE), and, optionally, either or both of a low density polyethylene (LDPE) and high density polyethylene (HDPE).

Claims13

Dependent claims

A multi-layer film comprising at least two skin layers and at least one core layer disposed directly or indirectly between the at least two skin layers, wherein the multi-layer film comprises:

(a) a narrow-CD metallocene linear low density polyethylene (narrow-CD mLLDPE) comprising 85 to 95 wt % units derived from ethylene and the balance derived from a C3 to C12 α-olefin (said wt % based on total mass of polymer in the narrow-CD mLLDPE), and further having:
Composition Distribution Breadth Index (CDBI) of at least 50%, melt index (I2, determined per ASTM D1238 at 190° C., 2.16 kg load) within the range from 0.1 to 3.0 g/10 min, molecular weight distribution (MWD, Mw/Mn) within the range from 1.5 to 4, peak melting temperature within the range from 105° C. to 120° C., and Vicat softening temperature within the range from 70° C. to 130° C.;
and
(b) a long-chain-branched metallocene linear low density polyethylene (LCB mLLDPE) comprising 80 to 99 wt % units derived from ethylene and the balance derived from a C3 to C12 α-olefin (said wt % based on total mass of polymer in the LCB mLLDPE), and further having:
CDBI of at least 50%, 12 (190° C., 2.16 kg load) within the range from 0.1 to 0.7 g/10 min, g′ (vis) within the range from 0.85 to 0.95, MWD within the range from 2.5 to 5.5;
(c) optionally, either or both of (c-1) a low density homopolyethylene (LDPE) having density within the range from 0.915 to 0.930 g/cm3 and (c-2) a high-density polyethylene (HDPE) having density greater than or equal to 0.935 g/cm3;
and
(d) optionally, a polymer processing additive;
wherein the narrow-CD mLLDPE (a) and the LCB mLLDPE (b) are included in different layers with respect to one another;
wherein the LCB mLLDPE is a first LCB mLLDPE, and the skin layers each comprise the first LCB mLLDPE;
and the core layer comprises (i) the narrow-CD mLLDPE and (ii) a second LCB mLLDPE;
wherein the multi-layer film is biaxially oriented;
and
wherein, of the total polymeric content of the film, at least 95 wt % of such total polymeric content is composed of polyethylenes.

11 more elements

A multi-layer film comprising at least two skin layers and at least one core layer disposed directly or indirectly between the at least two skin layers, wherein the multi-layer film comprises:

(a) a narrow-CD metallocene linear low density polyethylene (narrow-CD mLLDPE) comprising 85 to 95 wt % units derived from ethylene and the balance derived from a C3 to C12 α-olefin (said wt % based on total mass of polymer in the narrow-CD mLLDPE), and further having:
Composition Distribution Breadth Index (CDBI) of at least 50%, melt index (I2, determined per ASTM D1238 at 190° C., 2.16 kg load) within the range from 0.1 to 3.0 g/10 min, molecular weight distribution (MWD, Mw/Mn) within the range from 1.5 to 4, peak melting temperature within the range from 105° C. to 120° C., and Vicat softening temperature within the range from 70° C. to 130° C.;
and
(b) a long-chain-branched metallocene linear low density polyethylene (LCB mLLDPE) comprising 80 to 99 wt % units derived from ethylene and the balance derived from a C3 to C12 α-olefin (said wt % based on total mass of polymer in the LCB mLLDPE), and further having:
CDBI of at least 50%, I2 (190° C., 2.16 kg load) within the range from 0.1 to 0.7 g/10 min, g′(vis) within the range from 0.85 to 0.95, MWD within the range from 2.5 to 5.5;
(c) optionally, either or both of (c-1) a low density homopolyethylene (LDPE) having density within the range from 0.915 to 0.930 g/cm3 and (c-2) a high-density polyethylene (HDPE) having density greater than or equal to 0.935 g/cm3;
and
(e) optionally, a polymer processing additive;
wherein the narrow-CD mLLDPE (a) and the LCB mLLDPE (b) are included in different layers with respect to one another;
wherein the multi-layer film is biaxially oriented;
wherein, of the total polymeric content of the film, at least 95 wt % of such total polymeric content is composed of polyethylenes, and
wherein the LCB mLLDPE is a first LCB mLLDPE, and the core layer comprises the first LCB mLLDPE;
and the skin layers each comprise (i) the narrow-CD mLLDPE and (ii) a second LCB mLLDPE.

10 more elements

A multi-layer film comprising at least two skin layers and at least one core layer disposed directly or indirectly between the at least two skin layers, wherein the multi-layer film comprises:

(a) a narrow-CD metallocene linear low density polyethylene (narrow-CD mLLDPE) comprising 85 to 95 wt % units derived from ethylene and the balance derived from a C3 to C12 α-olefin (said wt % based on total mass of polymer in the narrow-CD mLLDPE), and further having:
Composition Distribution Breadth Index (CDBI) of at least 50%, melt index (I2, determined per ASTM D1238 at 190° C., 2.16 kg load) within the range from 0.1 to 3.0 g/10 min, molecular weight distribution (MWD, Mw/Mn) within the range from 1.5 to 4, peak melting temperature within the range from 105° C. to 120° C., and Vicat softening temperature within the range from 70° C. to 130° C.;
and
(b) a long-chain-branched metallocene linear low density polyethylene (LCB mLLDPE) comprising 80 to 99 wt % units derived from ethylene and the balance derived from a C3 to C12 α-olefin (said wt % based on total mass of polymer in the LCB mLLDPE), and further having:
CDBI of at least 50%, I2 (190° C., 2.16 kg load) within the range from 0.1 to 0.7 g/10 min, g′(vis) within the range from 0.85 to 0.95, MWD within the range from 2.5 to 5.5;
(c) optionally, either or both of (c-1) a low density homopolyethylene (LDPE) having density within the range from 0.915 to 0.930 g/cm3 and (c-2) a high-density polyethylene (HDPE) having density greater than or equal to 0.935 g/cm3;
and
(e) optionally, a polymer processing additive;
wherein the narrow-CD mLLDPE (a) and the LCB mLLDPE (b) are included in different layers with respect to one another;
wherein the multi-layer film is biaxially oriented;
wherein, of the total polymeric content of the film, at least 95 wt % of such total polymeric content is composed of polyethylenes, and
wherein at least one of the at least two skin layer comprises the narrow-CD mLLDPE and the core layer comprises the LCB mLLDPE.

9 more elements

Dependencies are inferred from the claim text.

Facts

Application: 18/564,914Filed 8 Jun 2022 · us provisional application
Priority: 22 Jun 2021
Published: US 2024/0239091 A118 Jul 2024
Granted: 15 Sep 2026
Term ends: Not estimatedThe source records don’t support an estimate.

Classification25 codes

B32B 27/32
Layered products comprising a layer of synthetic resin: comprising polyolefins
B29C 48/0018
Combinations of extrusion moulding with other shaping operations: combined with shaping by orienting, stretching or shrinking, e.g. film blowing
B29C 48/022
Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor:…
B29C 48/08
Flat, e.g. panels: flexible, e.g. films