BE1025051B1 - Improved five-layer barrier film, use thereof, and method of producing it - Google Patents

Abstract

The present invention relates to a five-layer barrier film for packaging foodstuffs, a use thereof and a method for manufacturing them. The five-layer barrier film comprises an outer layer comprising polyamide; an adhesive layer comprising linear low-density polyethylene and maleic anhydride, an intermediate layer comprising polyethylene, an intermediate layer comprising polyethylene, and a welding layer comprising polyethylene, silica and slip additives.

Description

Priority date:

International Classification: B32B 7/02, B32B 7/12, B32B 27/08, B32B 27/30, B32B 27/32, B32B 27/34

Application number: BE2017 / 5604

Date of submission: 30/08/2017

Holder:

SEGERS & BALCAEN NV

1770, LIEDEKERKE

Belgium

Inventor:

BALCAEN Paul

1770 LIEDERKERKE

Belgium

Improved five-layer barrier film, its use and method of making it

The present invention relates to a five-layer barrier film for food packaging, its use and a method of manufacturing it. The five-layer barrier film includes an outer layer comprising polyamide; an adhesive layer comprising linear low density polyethylene and maleic anhydride, a middle layer comprising polyethylene, an intermediate layer comprising polyethylene, and a seal layer comprising polyethylene, silica and slip additives.

BELGIAN INVENTION PATENT

FPS Economy, K.Μ.O., Self-employed & Energy Publication number: 1025051 Filing number: BE2017 / 5604 Intellectual Property Office International Classification: B32B 7/02 B32B 7/12 B32B 27/08 B32B 27/30 B32B 27/32 B32B 27/34 Date of grant: 05/10/2018

The Minister of Economy,

Having regard to the Paris Convention of 20 March 1883 for the Protection of Industrial Property;

Having regard to the Law of March 28, 1984 on inventive patents, Article 22, for patent applications filed before September 22, 2014;

Having regard to Title 1 Invention Patents of Book XI of the Economic Law Code, Article XI.24, for patent applications filed from September 22, 2014;

Having regard to the Royal Decree of 2 December 1986 on the filing, granting and maintenance of inventive patents, Article 28;

Having regard to the application for an invention patent received by the Intellectual Property Office on 30/08/2017.

Whereas for patent applications that fall within the scope of Title 1, Book XI, of the Code of Economic Law (hereinafter WER), in accordance with Article XI.19, § 4, second paragraph, of the WER, the granted patent will be limited. to the patent claims for which the novelty search report was prepared, when the patent application is the subject of a novelty search report indicating a lack of unity of invention as referred to in paragraph 1, and when the applicant does not limit his filing and does not file a divisional application in accordance with the search report.

Decision:

Article 1

SEGERS & BALCAEN NV, Affligemsestraat 500, 1770 LIEDEKERKE Belgium;

represented by

BRANTS Johan Philippe Emile, Pauline Van Pottelsberghelaan 24, 9051, GHENT;

CRABBE Ellen, Pauline van Pottelsberghelaan 24, 9051, GHENT;

a Belgian invention patent with a term of 20 years, subject to payment of the annual fees as referred to in Article XI.48, § 1 of the Economic Law Code, for: Improved five-layer barrier film, use of it and method for its manufacture.

INVENTOR (S):

BALCAEN Paul, Affligemsestraat 500, 1770, LIEDERKERKE;

PRIORITY :

BREAKDOWN:

Split from basic application:

Filing date of the basic application:

Article 2. - This patent is granted without prior investigation into the patentability of the invention, without warranty of the merit of the invention, nor of the accuracy of its description and at the risk of the applicant (s).

Brussels, 05/10/2018,

With special authorization:

BE2017 / 5604

IMPROVED VI JFLAGI GE BARRI EREFI LM, USES IT AND METHOD OF MANUFACTURING IT

TECHNICAL DOMAIN N

The invention relates to a barrier film comprising an outer layer comprising polyamide, an adhesive layer comprising linear

low density polyethylene comprising polyethylene. (LLDPE) and maleic anhydride, and a welding layer STATE OF THE TECHNI EK US 4 668 571 and US 9 498 937 describe films including a first layer including polyamide, a second layer comprising polyethylene, and a bonding layer adhered to the first and the second layer, where the bonding layer

linear low density polyethylene (LLDPE) and maleic anhydride.

However, the above documents do not describe any means of preventing adhesion of the film to itself.

The present invention aims to solve at least some of the above-mentioned problems.

SUMMARY OF THE INVENTION

In a first aspect, the present invention relates to a five-layer barrier film for food packaging, according to claim 1.

In a second aspect, the present invention relates to a method of manufacturing a five-layer barrier film according to claim 10.

In a third aspect, the present invention relates to a use of a five-layer barrier film according to claim 13.

The present invention is advantageous because the barrier film seal layer is configured to prevent adhesion of the film to itself, while retaining the other properties such as, for example, the seal and barrier properties.

BE2017 / 5604

DETAILED DESCRIPTION

The invention relates to a five-layer barrier film for food packaging, a method of manufacturing it, and a use thereof. The invention has been summarized in the section provided for that purpose. In what follows, the invention is described in detail, preferred embodiments are illustrated, and the invention is illustrated by examples.

Unless otherwise defined, all terms used in the description of the invention, including technical and scientific terms, have the meaning generally understood by those skilled in the art of the invention. For a better assessment of the description of the invention, the following terms are explicitly explained.

“A”, “the” and “it” refer to both singular and plural in this document unless the context clearly assumes otherwise. For example, "a segment" means one or more than a segment.

When "about" or "round" is used in this document with a measurable quantity, a parameter, a duration or moment, and the like, it means variations of +/- 20% or less, preferably +/- 10% or less, more preferably +/- 5% or less, even more preferably +/- 1% or less, and even more preferably +/- 0.1% or less than and of the quoted value, insofar as such variations of are applicable in the described invention. However, this should be understood to mean that the value of the quantity using the term "about" or "round" is itself specifically disclosed.

The terms "include", "include", "consist of", "consist of", "include", "contain", "contain", "include", "include", "contain", "contain" are synonyms and are inclusive or open terms that indicate the presence of what follows, and that do not exclude or prevent the presence of other components, features, elements, members, steps known from or described in the prior art.

Quoting numerical intervals through the endpoints includes all integers, fractions, and / or real numbers between the endpoints, including these endpoints.

BE2017 / 5604

The five-layer barrier film includes an outer layer comprising polyamide (PA); a middle layer comprising polyethylene (PE); an adhesive layer (TIE) comprising linear low density polyethylene (LLDPE) and maleic anhydride, the adhesive layer adhered to the outer layer and the middle layer; a welding layer comprising polyethylene (PE), silica and sliding additives; and an intermediate layer comprising polyethylene (PE), the intermediate layer adhered to the middle layer and the seal layer. The barrier film therefore has the following sequence of layers:

loot and layer / adhesive layer / middle layer / between layer / welding layer, i.e. PA / TIE / PE / PE / PE.

The present invention is advantageous for several reasons. The composition of the adhesive layer (TIE) is especially advantageous to provide good adhesion between the outer layer (PA) and the middle layer (PE). The composition of the weld layer is particularly advantageous to avoid unwanted sticking, while retaining the welding properties. The composition of the outer layer is particularly advantageous to ensure the barrier properties of the film. This makes the five-layer barrier film suitable for packaging a food product, and in particular for packaging a fresh food product.

In a preferred embodiment, the seal layer comprises for a weight percentage of at least 15, preferably at least 18, more preferably at least 21, and most preferably at least 24, such as a weight percentage of about 25, of very low density polyethylene (VLDPE). ), the very low density polyethylene comprising a density (ISO 1183) of at most 0.906 g / cm ³ , preferably at most 0.905 g / cm ³ , more preferably at most 0.904 g / cm ³ , and most preferably at most 0.903 g / cm ³ , such as a density of about 0.902 g / cm ³ . Preferably, the very low density polyethylene is an ethylene-based caprylene plastomer. This is advantageous because it provides a better weld and a better non-stick effect.

In a preferred embodiment, the outer layer comprises crystallized polyamide. Preferably, the outer layer comprises for a weight percentage of at least 5, more preferably at least 10, even more preferably at least 15, and most preferably at least 20, of crystallized polyamide. Preferably, the polyamide in the outer layer is a copolymer comprising polycaprolactam, the copolymer comprising a crystallization rate lower than the crystallization rate of polycaprolactam. Preferably, the five-layer barrier film is fabricated by a method comprising the step of blow co-extruding the outer, adhesive, middle, intermediate and seal layers. Preferably, the method includes the step of temporary

BE2017 / 5604 contacting at least a portion of the five-layer barrier film with a hot water bath for the post-crystallization of the outer layer. Preferably, the hot water bath comprises a temperature of at least 65 ° C and at most 95 ° C, preferably at least 70 ° C and at most 90 ° C, more preferably at least 75 ° C and at most 85 ° C, most preferably at least 78 ° C and at most 82 ° C, such as a temperature of about 80 ° C. Preferably, the film is drawn through the hot water bath at a speed of at least 10 and at most 30 meters / minute, such as a speed of about 20 meters / minute. This is advantageous because the aforementioned features provide good adhesion as well as good barrier action through said post-crystallization.

In a preferred embodiment, the barrier film comprises an average film thickness of at most 100 μm, preferably at most 95 μm, more preferably at most 90 μm, even more preferably at most 85 μm, even more preferably at most 80 μm, at more preferably at most 75 µm, even more preferably at most 70 µm, and most preferably at most 65 µm. This is advantageous because less raw materials are required for thin films.

In a preferred embodiment, the outer layer comprises an outer layer thickness of at least 10 μm and at most 30 μm, preferably an outer layer thickness of at least 12 μm and at most 28 μm, more preferably an outer layer thickness of at least 14 μm and at most 26 μm even more preferably an outer layer thickness of at least 16 µm and at most 24 µm, most preferably an outer layer thickness of at least 18 µm and at most 22 µm, such as an outer layer thickness of about 20 µm. This is advantageous because it optimally balances the barrier effect (the thicker the better) and the cost (PA is more expensive than PE).

In a preferred embodiment, the outer layer comprises an outer layer thickness equal to at least 15% and at most 40% of the average film thickness, preferably at least

18% and at most 38% of the average film thickness, more preferably at least

21% and at most 36% of the average film thickness, most preferably at least

32% and at most 35% of the average film thickness, such as an outer layer thickness of about 33.5% of the average film thickness.

In a preferred embodiment, the adhesive layer comprises an adhesive layer thickness equal to at least 5% and at most 12% of the average film thickness, preferably at least 6% and at most 10.5% of the average film thickness, more preferably at least 7% and at most 9% of the average film thickness, most preferably at least

BE2017 / 5604 at least 7% and at most 8% of the average film thickness, such as an adhesive layer thickness equal to about 7.5% of the average film thickness.

In a preferred embodiment, the middle layer and the intermediate layer comprise a joint thickness of at least 20% and at most 40% of the average film thickness, preferably at least 22% and at most 36% of the average film thickness, more preferably at least 24% and at most 32% of the average film thickness, most preferably at least 25% and at most 27% of the average film thickness, such as a combined thickness of about 26% of the average film thickness.

In a preferred embodiment, the seal layer comprises a seal layer thickness of at least 25% and at most 45% of the average film thickness, preferably at least 30% and at most 40% of the average film thickness, more preferably at least 31% and at most 39 % of the average film thickness, most preferably at least 32% and at most 35% of the average film thickness, such as a seal layer thickness of about 33% of the average film thickness.

In a preferred embodiment, the middle and intermediate layers have essentially the same composition. Preferably, the middle and intermediate layers comprise for a weight percentage of about 100 low density polyethylene (LDPE). Bladder coextrusion is easiest to perform when the central layers are thickest. Because the bonding layer includes expensive additives, it is therefore appropriate to make a multi-layer barrier film instead of a three-layer barrier film PA / TIE / PE (seal layer). In blow co-extruding, the number of layers is typically odd. By working with a five-layer film PA / TlE / PE / PE / PE (welding layer), a film with the desired mechanical properties (such as tensile strength, elongation, tear resistance and puncture resistance) can be obtained at a low raw material and production cost. In addition, layers with essentially the same composition have optimum adhesion.

In a preferred embodiment, the outer layer is printed. The method includes the step of printing the outer layer.

In a preferred embodiment, the five-layer barrier film comprises an oxygen permeability at 23 ° C and 75% relative humidity according to ASTM D-3985 of at most 150 cc / (m ² .24h.atm), preferably at most 120 cc / (m ² .24h .atm), more preferably at most 190 cc / (m ² .24h.atm), and most preferably at most 75 cc / (m ² .24h.atm).

BE2017 / 5604

In a preferred embodiment, the five-layer barrier film comprises a water vapor permeability at 38 ° C and 90% relative humidity according to ASTM F372 of at most 15 g / (m ² .24h.atm), preferably at most 12 g / (m ² .24h.atm ), more preferably at most 9 g / (m ² .24h.atm), and most preferably at most 7 g / (m ² .24h.atm).

In what follows, the invention is described by means of non-limiting examples illustrating the invention, which are not intended or should be interpreted to limit the scope of the invention.

EXAMPLE 1: COMPOSITION

This example concerns an embodiment of a five-layer barrier film according to the present invention, and in particular the composition of the five layers: booty and layer / adhesive layer / middle layer / between layer / seal layer.

Outer layer

The outer layer consists of a copolymer comprising polycaprolactam (PA6), the copolymer having a slower crystallization rate than polycaprolactam. The copolymer has a density (ISO 1183) of about 1.13 g / cm ³ . The copolymer includes a melt viscosity at 260 ° C of about 2250 Pa.s. The copolymer includes a linear thermal expansion coefficient (ISO 11359-1 / -2) of about 0.9 E-4 / ° C. The copolymer has a specific heat capacity of about 1550 J / (kg.K). The copolymer has an average specific heat capacity at 20-150 ° C of about 2250 J / (kg.K). The outer layer includes a transparency of at least 82.5%.

Bonding layer

The adhesive layer comprises for a weight percentage of about 80 to a first material and for a weight percentage of about 20 to a second material.

The first material is LLDPE. Preferably, the first material comprises LLC4. Most preferably, the first material comprises additive-free LLC4. The first material includes a density (23 ° C, ASTM D-792) of about 0.918 g / cm ³ . The first material includes a melt flow index (MFI), 190 ° C / 2.16 kg, ASTM D1238) of about 1.0 g / 10 min. The first material includes a crystalline BE2017 / 5604 melting point of about 122 ° C . The first material includes a Vicat softening point (ASTM D-1525 (A120)) of approximately 100 ° C.

The second material includes linear low density polyethylene (LLDPE) and maleic anhydride. In particular, the second material includes maleic anhydride-modified metallocene LLDPE. The second material includes a density (ASTM D-1505) of about 0.905 g / cm ³ . The second material includes a melt flow index (190 ° C / 2.16 kg, ASTM D-1238) of about 0.9 g / 10 min.

The adhesive layer therefore comprises a weight percentage of at least 80 of LLDPE.

Middle and intermediate layer

The middle and intermediate layers consist of the same third material. The third material includes low density polyethylene (LDPE). The third material comprises a density (ISO 1183) of about 0.924 g / cm ^3. The third material includes a melt flow index (190 ° C / 2.16 kg, ISO 1133) of about 0.8 g / 10 min. The third material includes a melt temperature (ISO 11357) of about 111 ° C and a Vicat temperature (ISO 306) of about 99 ° C. The third material includes a sliding additive, preferably erucamide, and more preferably erucamide at a concentration of about 650 ppm. The third material includes an anti-block additive, preferably talc, and more preferably talc at a concentration of about 500 ppm. Preferably the third material is LDPE FE 8004.

Weld layer

The welding layer includes:

spring a weight percentage of about 10 the third material;

- for a weight percentage of about 1 a non-stick material;

- for a weight percentage of about 25 a fourth material; and

- for a weight percentage of about 64 one fifth material.

The non-stick material includes silica and sliding additives. Preferably, the non-stick material is a dispersion of natural silica and a mixture of sliding additives in polyethylene.

The fourth material is a metallocene very low density polyethylene (mVLDPE). Preferably, the mVLDPE is an ethylene-based caprylene plastomer. The fourth material comprises a density (23 ° C, ISO 1183) of at most 0.904 g / cm ³ , and at BE2017 / 5604 preferably about 0.902 g / cm ³ . The fourth material includes a melt flow index (200 ° C / 2.16 kg, ISO 1133) of about 1.1 g / 10 min. The fourth material includes a melt temperature (ISO 11357-3) of about 95 ° C and a Vicat softening temperature (10 N, ISO 306) of about 80 ° C.

The fifth material is a metallocene LLDPE. Preferably, the fifth material is a metallocene LLDPE with hexene as the comonomer. The fifth material includes sliding additives, preferably at a concentration of about 750 ppm. The fifth material includes anti-block additives, preferably at a concentration of about 2500 ppm. The fifth material has a density (ISO 1183) of about 0.918 g / cm ^3. The fifth material has a melt flow index (190 ° C / 2.16 kg, ISO 1133) of about 1.0 g / 10 min. The fifth material has a melt temperature (ISO 11357) of about 111 ° C. The fifth material has a Vicat temperature (ISO 306) of approximately 105 ° C.

The seal layer has a density of about 0.9155 g / cm ³ .

EXAMPLE 2

This example concerns an embodiment of a five-layer barrier film according to the present invention and according to the composition specified in Example 1. The film has an average film thickness of about 60 µm. The outer layer comprises an outer layer thickness of at least 17.5 μm and at most 22.5 μm, and preferably equal to about 33.5% of the average film thickness. The adhesive layer includes an adhesive layer thickness of at least 3.5 µm and at most 5.5 µm, and preferably equal to about 7.5% of the average film thickness. The middle and intermediate layers have a combined thickness of at least 14.5 μm and at most

16.2 μm, and preferably equal to about 26% of the average film thickness. The seal layer includes a seal layer thickness of at least 18.5 μm and at most 21.1 μm, and preferably equal to about 33% of the average film thickness.

EXAMPLE 3

This example concerns an embodiment of a five-layer barrier film according to the present invention and according to the composition specified in Example 1. The film has an average film thickness of about 70 µm. The outer layer comprises an outer layer thickness of at least 17.5 μm and at most 22.5 μm, and preferably equal to about 28.6% of the average film thickness. The adhesive layer includes a

BE2017 / 5604 adhesion layer thickness of at least 4.6 μm and at most 6.6 μm, and preferably equal to about 8% of the average film thickness. The middle and intermediate layers comprise a joint thickness of at least 18 µm and at most 21 µm, and preferably equal to about 27.9% of the average film thickness. The seal layer includes a seal layer thickness of at least 22.4 µm and at most 27.2 µm, and preferably equal to about 35.4% of the average film thickness.

EXAMPLE 4

This example concerns an embodiment of a five-layer barrier film according to the present invention and according to the composition specified in Example 1. The film has an average film thickness of about 80 µm. The outer layer comprises an outer layer thickness of at least 17.5 μm and at most 22.5 μm, and preferably equal to about 25% of the average film thickness. The adhesive layer includes an adhesive layer thickness of at least 5.8 µm and at most 7.8 µm, and preferably equal to about 8.5% of the average film thickness. The middle and intermediate layers have a combined thickness of at least 22.0 μm and at most

24.8 μm, and preferably equal to about 29.3% of the average film thickness. The seal layer includes a seal layer thickness of at least 27.2 μm and at most 32.2 μm, and preferably equal to about 37.1% of the average film thickness.

EXAMPLE 5

This example concerns an embodiment of a five-layer barrier film according to the present invention and according to the composition specified in Example 1. The film has an average film thickness of about 90 µm. The outer layer comprises an outer layer thickness of at least 17.5 μm and at most 22.5 μm, and preferably equal to about 22.2% of the average film thickness. The adhesive layer includes an adhesive layer thickness of at least 6.8 µm and at most 9.0 µm, and preferably equal to about 8.8% of the average film thickness. The middle and intermediate layers have a combined thickness of at least 26.0 μm and at most

28.6 μm, and preferably equal to about 30.3% of the average film thickness. The seal layer includes a seal layer thickness of at least 32.0 μm and at most 37.0 μm, and preferably equal to about 38.6% of the average film thickness.

EXAMPLE 6

BE2017 / 5604

This example concerns an embodiment of a five-layer barrier film according to the present invention and according to the composition specified in Example 1. The film has an average film thickness of about 100 µm. The outer layer comprises an outer layer thickness of at least 17.5 μm and at most 22.5 μm, and preferably equal to about 20% of the average film thickness. The adhesive layer includes an adhesive layer thickness of at least 8.0 µm and at most 10.0 µm, and preferably equal to about 9% of the average film thickness. The middle layer and the intermediate layer comprise a combined thickness of at least 30.0 µm and at most 32.4 µm, and preferably equal to about 31.2% of the average film thickness. The seal layer comprises a seal layer thickness of at least 37.1 μm and at most 42.1 μm, and preferably equal to about 39.6% of the average film thickness.

EXAMPLE 7

This example concerns an embodiment of a five-layer barrier film according to the present invention and according to the composition specified in Example 1. The film has an average film thickness of about 110 µm. The outer layer comprises an outer layer thickness of at least 17.5 μm and at most 22.5 μm, and preferably equal to about 18.2% of the average film thickness. The adhesive layer includes an adhesive layer thickness of at least 9.1 µm and at most 11.1 µm, and preferably equal to about 9.2% of the average film thickness. The middle and intermediate layers have a combined thickness of at least 33.8 μm and at most

36.4 μm, and preferably equal to about 31.9% of the average film thickness. The seal layer includes a seal layer thickness of at least 42.1 µm and at most 47.1 µm, and preferably equal to about 40.5% of the average film thickness.

EXAMPLE 8

Properties of a film according to example 2 are listed in table 1.

Properties of films according to Examples 4-7 are listed in Table 2.

BE2017 / 5604

Table 1 - Properties of a five-layer barrier film according to Example 2.

Property Example 2 Unit Norm Tensile strength MR 51.3 N / 15 mm NFT 54-102 Tensile strength DR 43.9 N / 15 mm NFT 54-102 Stretch MR 709 % NFT 54-102 Rack DR 618 % NFT 54-102 Tear resistance MR 1127 mN NFT 54-141 Tear resistance DR 3130 mN NFT 54-141 Puncture resistance (dart drop) 900 g ASTM 1709 Friction coefficient welding layer / with. static 0.20 ASTM 1894 Friction coefficient welding layer / with. dynamic 0.15 ASTM 1894 Friction coefficient outer layer / with. static 0.26 ASTM 1894 Friction coefficient outer layer / with. dynamic 0.20 ASTM 1894

BE2017 / 5604

Table 2 - Properties of five-layer barrier films according to Examples 4 to 7.

Property Ex. 4 Ex. 5 Ex. 6 Ex. 7 Unit Norm Tensile strength MR 36.2 43.8 40.9 43.9 N / 1 5 mm ASTM 882 Tensile strength DR 37 40.7 44.5 40.9 N / 1 5 mm ASTM 882 Stretch MR 353 475 484 509 % ASTM 882 Rack DR 508 524 490 538 % ASTM 882 Tear resistance MR 1700 2000 2300 2550 mN ASTM 1922 Tear resistance DR 2900 3250 3500 3950 mN ASTM 1922 Puncture resistance (dart drop) > 900 > 900 > 900 > 900 g ASTM 1709 Friction coefficient welding layer / metal static 0.223 0.210 0.207 0.236 ASTM 1894 Friction coefficient welding layer / metal kinetic 0.196 0.173 0.153 0.190 ASTM 1894 Friction coefficient outer layer / metal static 0.426 0.423 0.410 0.490 ASTM 1894 Friction coefficient outer layer / metal kinetic 0.283 0.273 0.253 0.283 ASTM 1894 O ₂ permeability (0% rel. Moisture.) 62 60 cc / (m ² .24 h.bar) ASTM D3985 O ₂ permeability (75% rel. Moisture.) 81 80 cc / (m ² .24 h.bar) ASTM D3985 H ₂ O permeability (85% rel. Moisture.) 1.8 1.1 g / (m ² .24h .bar) ASTM F372

BE2017 / 5604

Claims (14)

CONCLUSI ES A five-layer barrier film for food packaging, the five-layer barrier film comprising an oxygen permeability at 23 ° C and 75% relative humidity according to ASTM D-3985 of at most 150 cc / (m ² .24h.atm) and a water vapor permeability at 38 ° C and 90% relative humidity according to ASTM F-372 of at most 15 g / (m ² .24h.atm), the five-layer barrier film comprising an average film thickness, the five-layer barrier film further comprising: a. an outer layer comprising polyamide, the outer layer further comprising an outer layer thickness equal to at least 15% and at most 40% of the average film thickness; c. a middle layer comprising polyethylene; b. an adhesive layer adhered to the outer layer and the middle layer, the adhesive layer comprising linear low density polyethylene and maleic anhydride, the adhesive layer further comprising an adhesive layer thickness equal to at least 5% and at most 12% of the average film thickness; e. a seal layer comprising polyethylene, silica and slip additives, the seal layer further comprising a seal layer thickness of at least 25% and at most 45% of the average film thickness; and d. an intermediate layer adhered to the middle layer and the seal layer, the intermediate layer comprising polyethylene, the middle layer and the intermediate layer comprising a joint thickness of at least 20% and at most 40% of the average film thickness. A five-layer barrier film according to the preceding claim 1, wherein the seal layer comprises for a weight percentage of at least 15 of very low density polyethylene, the very low density polyethylene comprising a density according to ISO 1183 of at most 0.906 g / cm ³ . A five-layer barrier film according to any one of the preceding claims, wherein the outer layer comprises crystallized polyamide. Five-layer barrier film according to any of the preceding claims, wherein the polyamide in the outer layer is a copolymer comprising polycaprolactam, BE2017 / 5604 the copolymer comprising a crystallization rate lower than polycaprolactam. A five-layer barrier film according to any one of the preceding claims, wherein the barrier film comprises an average film thickness of at most 100 µm. A five-layer barrier film according to any one of the preceding claims, wherein the outer layer comprises an outer layer thickness of at least 10 µm and at most 30 µm. Five-layer barrier film according to any of the preceding claims, wherein the middle and intermediate layers have essentially the same composition. Five-layer barrier film according to any one of the preceding claims, wherein the film is produced by blow co-extrusion of the outer, adhesive, middle, intermediate and seal layers. A five-layer barrier film according to any one of the preceding claims, wherein the outer layer is printed. The method of manufacturing a five-layer barrier film according to any of the preceding claims 1 to 9, the method comprising the step of blow co-extruding the outer, adhesive, middle, intermediate and seal layers. The method of manufacturing a five-layer barrier film according to the preceding claim 10, wherein the method comprises the step of temporarily contacting the five-layer barrier film with a hot water bath for the post-crystallization of the outer layer. The method of manufacturing a five-layer barrier film according to the preceding claim 11, wherein the hot water bath comprises a temperature of at least 65 ° C and at most 95 ° C. Use of a five-layer barrier film according to any of the preceding claims 1 to 9, as a food packaging. Use of a five-layer barrier film according to the preceding claim 13 for packaging a fresh food product. BE2017 / 5604 IMPROVED VI JFLAGI GE BARRI EREFI LM, USE AND METHOD FOR MANUFACTURING IT