# US 11,440,300 B2 · Multilayer polyproylene film

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- Number: US 11,440,300 B2
- Document ID: US11440300B2
- Status: Granted
- Kind: B2
- Application number: 17/253,872
- Filed: 2019-07-22
- Published: 2021-11-25
- Granted: 2022-09-13
- Earliest claimed: 2018-07-23
- Assignees: Borealis AG
- Applicants: Borealis AG
- Inventors: Markus Gahleitner; Jingbo Wang; Friedrich Berger; Manfred Gruenberger
- Web page: https://patentgrep.com/patent/US11440300B2

## CPC

- B32B 27/08: of synthetic resin
- B32B 25/08: of synthetic resin
- B32B 27/06: as the main or only constituent of a layer, {which is} next to another layer of {the same or of} a {different material (next to a layer of a particular substance B32B9/045; next to a bituminous or tarry layer B32B11/046; next to a water setting substance layer B32B13/12; next to a metal layer B32B15/08; next to a glass layer B32B17/10; next to a layer formed of natural mineral fibres or particles B32B19/045; next to a wood layer B32B21/08; next to a cellulosic plastic layer B32B23/08; next to a natural or synthetic rubber layer B32B25/08)}
- B32B 27/30: comprising vinyl {(co)polymers; comprising acrylic (co)polymers}
- B32B 27/302: {comprising aromatic vinyl (co)polymers, e.g. styrenic (co)polymers}
- B32B 27/32: comprising polyolefins {(comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30)}
- C08F 110/06: Propene
- C08F 210/06: Propene
- B29C 48/022: {characterised by the choice of material}
- B29C 48/08: flexible, e.g. films
- B29C 48/21: the layers being joined at their surfaces
- B29K 2023/14: {Copolymers of polypropylene (B29K2023/16 takes precedence)}
- B29K 2105/0085: {Copolymers}
- B29K 2105/0094: {having particular viscosity}
- B32B 2250/03: 3 layers
- B32B 2250/246: All polymers belonging to those covered by groups B32B27/32 and B32B27/30
- B32B 2270/00: Resin or rubber layer containing a blend of at least two different polymers
- B32B 2274/00: Thermoplastic elastomer material
- B32B 2307/306: Resistant to heat
- B32B 2307/308: Heat stability
- B32B 2307/31: Heat sealable
- B32B 2307/40: having particular optical properties
- B32B 2307/412: Transparent
- B32B 2307/414: Translucent
- B32B 2307/546: Flexural strength; Flexion stiffness
- B32B 2307/732: Dimensional properties
- B32B 2439/00: Containers; Receptacles
- B32B 2439/40: Closed containers
- B32B 2439/80: Medical packaging
- B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00)
- B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS

## Abstract

Multilayer film comprising at least a skin layer, a core layer and an inner layer, the skin layer comprising a homo polypropylene or a random propylene ethylene copolymer including up to 2.5 wt.-% units derived from ethylene, the homopolypropylene or the random propylene ethylene copolymer having a MFR2 (ISO1 133, 230° C.) of 2.0 to 20 g/10 min and a melting temperature (Tm) of above 148° C. measured by DSC according to ISO 11357-3:1999 and a scan rate of 10° C./min; the core layer comprising a mixture obtainable by melt blending 20 to 100 wt.-% of a random heterophasic copolymer and 0 to 80 wt.-% of styrene based TPE, whereby the random heterophasic copolymer has a melting temperature (Tm) of 134° C.-148° C. measured by DSC according to ISO 11357-3:1999 and a scan rate of 10° C./min and includes a propylene ethylene copolymer rubber; and whereby the styrene based TPE has a styrene content of from 5 to 20 wt.-%, and the inner layer comprising a random propylene ethylene copolymer having a melting temperature (Tm) from 132° C. to 144° C. measured by DSC according to ISO 11357-3:1999 and a scan rate of 10° C./min, wherein the multilayer film is free of phthalic acid esters as well as decomposition products thereof.

## Claims

### Claim 1

Multilayer film comprising
at least a skin layer, a core layer and an inner layer,
the skin layer comprising a homo polypropylene or a random propylene ethylene copolymer including up to 2.5 wt. % units derived from ethylene, the homo polypropylene or the random propylene ethylene copolymer having a MFR2 (ISO1133, 230° C.) of 2.0 to 20 g/10 min and a melting temperature (Tm) of above 148° C. measured by DSC according to ISO 11357-3:1999 and a scan rate of 10° C./min;
the core layer comprising a mixture obtainable by melt blending 20 to 100 wt. % of a random heterophasic copolymer and 0 to 80 wt. % of styrene based thermoplastic elastomer (TPE),
whereby the random heterophasic copolymer has a melting temperature (Tm) of 134° C. 148° C. measured by DSC according to ISO 11357-3:1999 and a scan rate of 10° C./min and includes a propylene ethylene copolymer rubber; and
whereby the styrene based TPE has a styrene content of from 5 to 20 wt. %, and
the inner layer comprising a random propylene ethylene copolymer having a melting temperature (Tm) from 132° C. to 144° C. measured by DSC according to ISO 11357-3:1999 and a scan rate of 10° C./min,
wherein the multilayer film is free of phthalic acid esters as well as decomposition products thereof.

### Claim 2 (depends on 1)

Multilayer film according to claim 1, whereby xylene cold soluble fraction (XCS) of the random heterophasic copolymer contributing to the core layer has an intrinsic viscosity of 1.0 to 2.0 dl/g (DIN ISO 1628/1, 10/1999; Decalin, 135° C.).

### Claim 3 (depends on 1)

Multilayer film according to claim 1, in which the random heterophasic copolymer of the core layer is a random heterophasic copolymer of propylene.

### Claim 4 (depends on 1)

Multilayer film according to claim 1, which has a total thickness of 150 to 250 micrometer determined according to ISO4593.

### Claim 5 (depends on 1)

Multilayer film according to claim 1, whereby the core layer has a thickness of 70 to 85% with respect to the thickness of the multilayer film.

### Claim 6 (depends on 1)

Multilayer film according to claim 1, whereby the thicknesses of the skin layer is 10 to 15% with respect to the total thickness of the multilayer film,
and whereby the thicknesses of the inner layer is 10 to 15% with respect to the total thickness of the multilayer film.

### Claim 7 (depends on 1)

Multilayer film according to claim 1, whereby:
the skin layer consists of the homo polypropylene or random propylene ethylene copolymer; and/or
the core layer consists of a mixture obtainable by melt blending 20 to 100 wt. % of a random heterophasic copolymer and 0 to 80 wt. % of styrene based TPE.

### Claim 8 (depends on 1)

Multilayer film according to claim 1, whereby:
the inner layer consists of the random propylene ethylene copolymer,
or
the inner layer consists of
a mixture obtainable by blending the random propylene ethylene copolymer and a propylene ethylene elastomer having an ethylene content of less than 20 wt. %;
or the inner layer consists of
a mixture obtainable by blending the random propylene ethylene copolymer and a styrene ethylene butylene styrene copolymer (SEBS).

### Claim 9 (depends on 1)

Multilayer film according to claim 1,
whereby the propylene homopolymer of the skin layer has an MFR (230° C., 2.16 kg, ISO1133) of 4.0 to 13 g/10 min,
and/or
a melting temperature of above 162° C. measured by DSC according to ISO 11357-3:1999 and a scan rate of 10° C./min,
and/or
a flexural modulus of above 1450 MPa when measured on injection molded specimens (23° C., 50% humidity, ISO 178),
or
the random propylene ethylene copolymer of the skin layer has,
an MFR (230° C., 2.16 kg, ISO1133) of 4.0 to 13 g/10 min,
an ethylene content of 0.5 to 2.2 wt. %
and/or,
a melting temperature of 152 to 155° C. measured by DSC according to ISO 11357-3:1999 and a scan rate of 10° C./min,
and/or,
a flexural modulus of above 975 MPa when measured on injection molded specimens (23° C., 50% humidity, ISO 178).

### Claim 10 (depends on 1)

Multilayer film according to according to claim 1,
whereby the random heterophasic copolymer having a melting temperature (Tm) of 134 to 148° C. measured by DSC according to ISO 11357-3:1999 and a scan rate of 10° C./min contributing to the core layer has,
a MFR2 of 3.0 to 7.0 g/10 min (ISO 1133, 230° C., 2.16 kg)
and/or
a total ethylene content of 7.0 to 14.0 wt. %
and/or
an amount of the xylene cold soluble fraction (XCS) in the range of 18.0 to 25.0 wt. %
and/or
an intrinsic viscosity of 1.0 to 1.6 dl/g (DIN ISO 1628/1, 10/1999; Decalin, 135° C.) of the xylene cold soluble fraction (XCS).

### Claim 11 (depends on 1)

Multilayer film according to claim 1,
whereby the propylene ethylene copolymer of the inner layer having a melting temperature (Tm) from 132° C. to 144° C. measured by DSC according to ISO 11357-3:1999 and a scan rate of 10° C./min
has an ethylene content of 3.5 to 6.0 wt. %
and/or
has a melt flow rate of 6.0 to 13.0 g/10 min (230° C., 2.16 kg, ISO1133),
and/or
a flexural modulus of from 600 to 900 MPa when measured on injection molded specimens (23° C., 50% humidity, ISO 178).

### Claim 12 (depends on 1)

Multilayer film according to claim 1,
whereby the core layer comprises a mixture obtainable by melt blending 40 to 91 wt. % of a random heterophasic copolymer and 9 to 60 wt. % of styrene based TPE.

### Claim 13 (depends on 1)

Multilayer film according to claim 1,
whereby the core layer comprises a mixture obtainable by melt blending 45 to 65 wt. % of a random heterophasic copolymer and 35 to 55 wt. % of styrene based TPE.

### Claim 14 (depends on 1)

Pouches made from the multilayer film as defined in claim 1.

### Claim 15 (depends on 1)

Process for preparing a film according to claim 1, comprising:
extruding on a multilayer cast film line the components forming the skin layer, the core layer and the inner layer of claim 1.