DE102024119437A1 - Recyclable polyethylene film for packaging hygiene products - Google Patents

Abstract

The invention relates to a multilayer polyethylene film comprising, or essentially consisting of, an outer sealing layer (A) comprising an ethylene homo- or copolymer ( _a1 ) and optionally an ethylene homo- or copolymer ( _a2 ); a middle layer (B) comprising an ethylene homo- or copolymer ( _b1 ), an ethylene homo- or copolymer ( _b2 ), and optionally an ethylene homo- or copolymer ( _b3 ); and an outer sealing layer (C) comprising an ethylene homo- or copolymer ( _c1 ) and optionally an ethylene homo- or copolymer ( _c2 ). The polyethylene film has a total layer thickness of at most 50 µm. The middle layer (B) contains, if any, less than 15 wt% propylene homo- or copolymers by weight of the middle layer (B). Optionally, the sealing layer (A) is at least partially coated with a release coating.

Description

The invention relates to a multilayer polyethylene film comprising, or essentially consisting of, an outer sealing layer (A) comprising an ethylene homo- or copolymer ( _a1 ) and optionally an ethylene homo- or copolymer ( _a2 ); a middle layer (B) comprising an ethylene homo- or copolymer ( _b1 ), an ethylene homo- or copolymer ( _b2 ), and optionally an ethylene homo- or copolymer ( _b3 ); and an outer sealing layer (C) comprising an ethylene homo- or copolymer ( _c1 ) and optionally an ethylene homo- or copolymer ( _c2 ). The polyethylene film has a total layer thickness of at most 50 µm. The middle layer (B) contains, if any, less than 15 wt% propylene homo- or copolymers by weight of the middle layer (B). Optionally, the sealing layer (A) is at least partially coated with a release coating.

Polyolefin films are known in various designs as packaging materials for hygiene products.

WO 2017/016660 relates to a multilayer polyolefin film comprising a sequence of layers consisting of a sealable layer (a) based on a polyethylene component with a density in the range of 0.910 to 0.940 g/ ^cm³ and a melting point in the range of 110 °C to 130 °C, a layer (b) based on a polymer mixture of 51–85 wt.% of at least one polyethylene with a density of 0.910 to 0.940 g/ ^cm³ and 15–49 wt.%, each based on the total weight of the polymer mixture, of at least one propylene homopolymer or copolymer, and a sealable layer (c) based on a polyethylene component with a density in the range of 0.910 to 0.940 g/ ^cm³ and a melting point in the range of 110 °C to 130 °C, wherein the melting point of layer (a) or layer (c) is at least 5 °C lower than the melting point of layer (b); the tear resistance of the polyolefin film in the machine direction [MD] is < 5 N and the tear resistance transverse to the machine direction [CD] is at least four times higher than in [MD], in each case measured according to DIN 53356; and the tensile strength, measured according to DIN ISO 527-3, in the machine direction [MD] as well as transverse to the machine direction [CD] is approximately the same > 15 N.

WO 2017/016661 This relates to a packaging film suitable for outer packaging, made of a possibly separable, unstretched, at least single-layer polyolefin film comprising: a) a layer (a) based on a mixture of α) 20-49 wt.% of a polypropylene and/or at least one propylene copolymer and β) 80-51 wt.% of at least one polyethylene or ethylene copolymer, preferably with a melting point of at least 113°C, and optionally γ) customary auxiliaries, preferably processing aids, with a layer thickness of ≤ 20 µm, preferably 6-20 µm, and b) optionally on at least one surface of layer (a) a release coating (b) of hardened polysiloxane, wherein the tensile strength of the polyolefin film in the machine direction is at least 6.5 N/cm, measured according to DIN EN ISO 527-3, and outer packaging produced therefrom.

WO 2022/101299 This relates to a process for producing a release film by coating a carrier film with a release coating, comprising the steps of: (a) providing the carrier film, wherein the carrier film has a first surface side and a second surface side; wherein the carrier film is preferably structured; (b) providing a coating composition comprising a solvent component, preferably comprising ethyl acetate, propyl acetate, butyl acetate and/or n-propanol, and a UV-curable silicone system; (c) coating at least a portion of the first surface side of the carrier film provided in step (a) with the coating composition provided in step (b); (d) evaporating at least a portion of the solvent component; and (e) irradiating at least a portion of the first surface side of the carrier film coated in step (c) with UV radiation to cure the silicone system.

However, the polyolefin films known from the prior art for the packaging of hygiene products are not satisfactory in every respect, and there is therefore a need for improved polyolefin films.

Thus, polyolefin films with low overall thickness known from the prior art are usually not pure and sometimes contain significant amounts of inorganic fillers, such as chalk. Therefore, such polyolefin films can only be recycled to a very limited extent, if at all. Furthermore, polyolefin films with low overall thickness known from the prior art sometimes exhibit poor mechanical properties, are difficult to seal, tend to splinter in the machine direction, and sometimes result in unclean cut or die-cut edges when slicing or punching.

The invention is based on the objective of providing advantageous polyolefin films with a low overall thickness, suitable as packaging for hygiene products. These polyolefin films should exhibit very good mechanical properties with minimal material usage, be easily processed, and be recyclable.

This problem is solved by the subject matter of the patent claims.

It was surprisingly discovered that polyolefin films for packaging hygiene products can be made without propylene homo- and copolymers, and can instead consist exclusively of ethylene homo- and copolymers, without any deterioration in mechanical properties. In fact, some properties are even improved.

By eliminating propylene homo- and copolymers, pure polyethylene films can be produced. Since the polyethylene films according to the invention can also contain only small amounts of inorganic components, they are particularly recyclable overall.

It was surprisingly found that the polyolefin films according to the invention exhibit very good tensile strength in the machine direction (MD) at high modulus of elasticity, which is particularly evident from the force values at 1%, 2% and 5%.

Furthermore, it was surprisingly found that the polyolefin films according to the invention exhibit a significantly improved tear resistance in the machine direction, as shown by the values for the tear force according to DIN53356 (leg) and according to DIN53363 (trapezoid).

Furthermore, it was surprisingly found that the polyolefin films according to the invention exhibit improved sealing properties, as evidenced by a wider temperature range within the processing window in which sealing is possible. This is particularly surprising because this effect is not attributable to the composition of the two outer sealing layers, but rather to the composition of the middle layer, which as such does not even form an outer surface of the polyolefin film.

Furthermore, it was surprisingly found that the polyolefin films according to the invention exhibit improved cutting and punching behavior. The cut and punched edges resulting from cutting and punching are significantly improved.

• - eine äußere Siegelschicht (A) umfassend ein Ethylen-Homo- oder Copolymer (a₁) und optional ein Ethylen-Homo- oder Copolymer (a₂),
• - eine Mittelschicht (B) umfassend ein Ethylen-Homo- oder Copolymer (b₁), ein Ethylen-Homo- oder Copolymer (b₂) und optional ein Ethylen-Homo- oder Copolymer (b₃); und
• - eine äußere Siegelschicht (C) umfassend ein Ethylen-Homo- oder Copolymer (c₁) und optional ein Ethylen-Homo- oder Copolymer (c₂);

umfasst oder im Wesentlichen daraus besteht; wobei

• - die Polyethylenfolie eine Gesamtschichtdicke von höchstens 50 µm aufweist;
• - die Mittelschicht (B), wenn überhaupt, bezogen auf das Gesamtgewicht der Mittelschicht (B) insgesamt weniger als 15 Gew.-% Propylen-Homo- oder Copolymere enthält; und
• - optional die Siegelschicht (A) zumindest teilweise mit einer Releasebeschichtung beschichtet ist.

A first aspect of the invention relates to a multilayer polyethylene film which

• - an outer sealing layer (A) comprising an ethylene homo or copolymer (a ₁ ) and optionally an ethylene homo or copolymer (a ₂ ),
• - a middle layer (B) comprising an ethylene homo or copolymer (b ₁ ), an ethylene homo or copolymer (b ₂ ) and optionally an ethylene homo or copolymer (b ₃ ); and
• - an outer sealing layer (C) comprising an ethylene homo or copolymer (c ₁ ) and optionally an ethylene homo or copolymer (c ₂ );

includes or essentially consists of; wherein

• - the polyethylene film has a total layer thickness of no more than 50 µm;
• - the middle layer (B), if any, contains less than 15 wt% propylene homo- or copolymers in relation to the total weight of the middle layer (B); and
• - optionally, the sealing layer (A) is at least partially coated with a release coating.

The polyolefin film according to the invention necessarily comprises an ethylene homo- or copolymer (a ₁ ) in the sealing layer (A), an ethylene homo- or copolymer (b ₁ ) and an ethylene homo- or copolymer (b ₂ ) in the middle layer (B), and an ethylene homo- or copolymer (c ₁ ) in the sealing layer (C). Additionally, the polyolefin film according to the invention may contain an ethylene homo- or copolymer (a ₂ ) in the sealing layer (A). Additionally, the polyolefin film according to the invention may contain an ethylene homo- or copolymer (b ₃ ) in the middle layer (B). Additionally, the polyolefin film according to the invention may contain an ethylene homo- or copolymer (c ₂ ) in the sealing layer (C).

The ethylene homo or copolymer (a ₁ ) and the ethylene homo or copolymer (a ₂ ) that may be present in the sealing layer (A) differ from each other, but may be identical to ethylene homo or copolymers contained in the middle layer (B) and/or the sealing layer (C) independently of each other.

The ethylene homo or copolymer (b ₁ ), the ethylene homo or copolymer (b ₂ ) and the ethylene homo or copolymer (b ₃ ) that may be present in the middle layer (B) differ from each other, but may be independently identical to ethylene homo or copolymers contained in the sealing layer (A) and/or the sealing layer (C).

The ethylene homo or copolymer (c ₁ ) and the ethylene homo or copolymer (c ₂ ) that may be present in the sealing layer (C) differ from each other, but may be identical to ethylene homo or copolymers contained in the sealing layer (A) and/or the middle layer (B) independently of each other.

In the context of the description, "based on" means that it is the main component, i.e., in a layer based on polyolefin, polyolefin is the main component.

For the purposes of this description, ethylene homopolymers or copolymers are understood to be ethylene homopolymers which are based exclusively on ethylene, and ethylene copolymers which, in addition to ethylene, are based on at least one further α,β-unsaturated olefin with 3 to 10 carbon atoms, preferably with 4 to 10 carbon atoms.

• - Polyethylen geringer Dichte (LDPE), bevorzugt mit einer Dichte von nicht mehr als 0,945 g/cm³, bevorzugt im Bereich von 0,915 bis 0,945 g/cm³, bevorzugt mit stark verzweigten Polymerketten;
• - lineares Polyethylen geringer Dichte (LLDPE), bevorzugt mit einer Dichte von nicht mehr als 0,945 g/cm³, bevorzugt im Bereich 0,915 bis 0,945 g/cm³, bevorzugt mit kurz verzweigten Polymerketten, welche neben Ethylen als Comonomer ein oder mehrere höhere α,β-ungesättigten Olefine wie Buten, Hexen, oder Octen, enthalten können.
• - Polyethylen hoher Dichte (HDPE), bevorzugt mit einer Dichte von mehr als 0,945 g/cm³, bevorzugt im Bereich von mehr als 0,945 bis 0,970 g/cm³, bevorzugt mit schwach verzweigten Polymerketten, welche neben Ethylen als Comonomer ein oder mehrere höhere α,β-ungesättigten Olefine wie Hexen oder Octen enthalten können.

Preferred ethylene homo- or copolymers are

• - Low-density polyethylene (LDPE), preferably with a density of no more than 0.945 g/ ^cm³ , preferably in the range of 0.915 to 0.945 g/ ^cm³ , preferably with highly branched polymer chains;
• - linear low-density polyethylene (LLDPE), preferably with a density of no more than 0.945 g/ ^cm³ , preferably in the range of 0.915 to 0.945 g/ ^cm³ , preferably with short branched polymer chains which, in addition to ethylene as a comonomer, may contain one or more higher α,β-unsaturated olefins such as butene, hexene, or octene.
• - High-density polyethylene (HDPE), preferably with a density of more than 0.945 g/ ^cm³ , preferably in the range of more than 0.945 to 0.970 g/ ^cm³ , preferably with weakly branched polymer chains which, in addition to ethylene as a comonomer, may contain one or more higher α,β-unsaturated olefins such as hexene or octene.

For the purposes of this description, propylene homopolymers or copolymers are understood to be propylene homopolymers based exclusively on propylene, and propylene copolymers based on at least one other α,β-unsaturated olefin with 2 to 10 carbon atoms in addition to propylene. Preferred propylene copolymers are copolymers of propylene and ethylene, wherein the proportion of ethylene is preferably at most 40 wt.%, more preferably at most 20 wt.%, based on the total weight of the propylene copolymer.

• - Polyethylen niedriger Dichte (LDPE, ρ ≤ 0,945 g/cm³),
• - linearem Polyethylen niedriger Dichte (LLDPE, ρ ≤ 0,945 g/cm³), und
• - Polyethylen hoher Dichte (HDPE p > 0,945 g/cm³).

The ethylene homo- or copolymers (a ₁ ), (a ₂ ), (b ₁ ), (b ₂ ), (b ₃ ), (c ₁ ) and (c ₂ ) are preferred, each selected independently from the group consisting of

• - Low-density polyethylene (LDPE, ρ ≤ 0.945 g/cm ³ ),
• - linear low-density polyethylene (LLDPE, ρ ≤ 0.945 g/cm ³ ), and
• - High-density polyethylene (HDPE p > 0.945 g/cm ³ ).

Preferably, the middle layer (B) contains, if any, at most 12.5 wt.% propylene homo- or copolymers based on the total weight of the middle layer (B); preferably at most 10 wt.%, more preferably at most 7.5 wt.%, even more preferably at most 5 wt.%, most preferably at most 2.5 wt.%, and in particular no propylene homo- or copolymers at all.

Preferably, the polyethylene film contains, if any, at most 12.5 wt.% propylene homo- or copolymers based on the total weight of the polyethylene film; preferably at most 10 wt.%, more preferably at most 7.5 wt.%, even more preferably at most 5 wt.%, most preferably at most 2.5 wt.%, and in particular no propylene homo- or copolymers at all.

Preferably, the ethylene homo- or copolymer (a ₁ ) is selected from LDPE and LLDPE; preferably having a density in the range of 0.920 to 0.945 g/cm ³ ; preferred LDPE; more preferably LDPE having a melt flow index (190°C, 2.16 kg, ASTM D1238) of at most 5.0 g/10 min, more preferably at most 4.0 g/10 min, more preferably at most 3.0 g/10 min, most preferably at most 2.0 g/10 min, and particularly at most 1.0 g/10 min.

Preferably, the weight fraction of the ethylene homo- or copolymer (a ₁ ) based on the total weight of the sealing layer (A) is at least 20 wt.%; preferably at least 25 wt.%, more preferably at least 30 wt.%, even more preferably at least 35 wt.%, most preferably at least 40 wt.%, and in particular at least 45 wt.%.

Preferably, the weight fraction of the ethylene homo- or copolymer (a ₁ ) based on the total weight of the sealing layer (A) is at most 80 wt.%; preferably at most 75 wt.%, more preferably at most 70 wt.%, even more preferably at least 65 wt.%, most preferably at most 60 wt.%, and in particular at most 55 wt.%.

Preferably, the ethylene homo- or copolymer (a ₂ ) is selected from LDPE and LLDPE; preferably having a density in the range of 0.920 to 0.945 g/cm ³ ; preferred LLDPE; more preferably LLDPE having a melt flow index (190°C, 2.16 kg, ASTM D1238) of at most 5.0 g/10 min, more preferably at most 4.0 g/10 min, more preferably at most 3.0 g/10 min, most preferably at most 2.0 g/10 min, and particularly at most 1.0 g/10 min.

Preferably, the weight fraction of the ethylene homo- or copolymer (a ₂ ) based on the total weight of the sealing layer (A) is at least 10 wt.%; preferably at least 15 wt.%, more preferably at least 20 wt.%, even more preferably at least 25 wt.%, most preferably at least 30 wt.%, and in particular at least 35 wt.%.

Preferably, the weight fraction of the ethylene homo- or copolymer (a ₂ ) based on the total weight of the sealing layer (A) is at most 70 wt.%; preferably at most 65 wt.%, more preferably at most 60 wt.%, even more preferably at least 55 wt.%, most preferably at most 50 wt.%, and in particular at most 45 wt.%.

Preferably, the ethylene homo- or copolymer (b ₁ ) is selected from LDPE and LLDPE; preferably having a density in the range of 0.920 to 0.945 g/cm ³ ; preferred LDPE; more preferably LDPE having a melt flow index (190°C, 2.16 kg, ASTM D1238) of at most 5.0 g/10 min, more preferably at most 4.0 g/10 min, more preferably at most 3.0 g/10 min, most preferably at most 2.0 g/10 min, and particularly at most 1.0 g/10 min.

Preferably, the weight fraction of the ethylene homo- or copolymer (b ₁ ) based on the total weight of the middle layer (B) is at least 15 wt.%; preferably at least 20 wt.%, more preferably at least 25 wt.%, even more preferably at least 30 wt.%, most preferably at least 35 wt.%, and in particular at least 40 wt.%.

Preferably, the weight fraction of the ethylene homo- or copolymer (b ₁ ) based on the total weight of the middle layer (B) is at most 70 wt.%; preferably at most 65 wt.%, more preferably at most 60 wt.%, even more preferably at least 55 wt.%, most preferably at most 50 wt.%, and in particular at most 45 wt.%.

Preferably, the ethylene homo- or copolymer (b ₂ ) is selected from LDPE and LLDPE; preferably having a density in the range of 0.920 to 0.945 g/cm ³ ; preferred LLDPE; more preferably LLDPE having a melt flow index (190°C, 2.16 kg, ASTM D1238) of at most 5.0 g/10 min, more preferably at most 4.0 g/10 min, more preferably at most 3.0 g/10 min, most preferably at most 2.0 g/10 min, and particularly at most 1.0 g/10 min.

Preferably, the weight fraction of the ethylene homo- or copolymer (b ₂ ) based on the total weight of the middle layer (B) is at least 5 wt.%; preferably at least 7.5 wt.%, more preferably at least 10 wt.%, even more preferably at least 12.5 wt.%, most preferably at least 15 wt.%, and in particular at least 17.5 wt.%.

Preferably, the weight fraction of the ethylene homo- or copolymer (b ₂ ) based on the total weight of the middle layer (B) is at most 35 wt.%; preferably at most 32.5 wt.%, more preferably at most 30 wt.%, even more preferably at least 27.5 wt.%, most preferably at most 25 wt.%, and in particular at most 22.5 wt.%.

Preferably, the ethylene homo- or copolymer (b ₃ ) is selected from HDPE; preferably having a density in the range of 0.950 to 0.965 g/cm ³ ; preferably HDPE having a melt flow index (190°C, 2.16 kg, ASTM D1238) of at most 5.0 g/10 min, more preferably at most 4.0 g/10 min, more preferably at most 3.0 g/10 min, most preferably at most 2.0 g/10 min, and particularly at most 1.0 g/10 min.

Preferably, the weight fraction of the ethylene homo- or copolymer (b ₃ ) based on the total weight of the middle layer (B) is at least 5 wt.%; preferably at least 10 wt.%, more preferably at least 15 wt.%, even more preferably at least 20 wt.%, most preferably at least 25 wt.%, and particularly at least 30 wt.%. Preferably, the weight fraction of the ethylene homo- or copolymer (b ₃ ) based on the total weight of the middle layer (B) is at least 35 wt.%; more preferably at least 40 wt.%.

Preferably, the weight fraction of the ethylene homo- or copolymer (b ₃ ) based on the total weight of the middle layer (B) is at most 60 wt.%; preferably at most 55 wt.%, more preferably at most 50 wt.%, even more preferably at least 45 wt.%, most preferably at most 40 wt.%, and in particular at most 35 wt.%.

Preferably, the ethylene homo- or copolymer (c ₁ ) is selected from LDPE and LLDPE; preferably having a density in the range of 0.920 to 0.945 g/cm ³ ; preferred LDPE; more preferably LDPE having a melt flow index (190°C, 2.16 kg, ASTM D1238) of at most 5.0 g/10 min, more preferably at most 4.0 g/10 min, more preferably at most 3.0 g/10 min, most preferably at most 2.0 g/10 min, and particularly at most 1.0 g/10 min.

Preferably, the weight fraction of the ethylene homo- or copolymer (c ₁ ) based on the total weight of the sealing layer (C) is at least 20 wt.%; preferably at least 25 wt.%, more preferably at least 30 wt.%, even more preferably at least 35 wt.%, most preferably at least 40 wt.%, and in particular at least 45 wt.%.

Preferably, the weight fraction of the ethylene homo- or copolymer (c ₁ ) based on the total weight of the sealing layer (C) is at most 80 wt.%; preferably at most 75 wt.%, more preferably at most 70 wt.%, even more preferably at least 65 wt.%, most preferably at most 60 wt.%, and in particular at most 55 wt.%.

Preferably, the ethylene homo- or copolymer (c ₂ ) is selected from LDPE and LLDPE; preferably having a density in the range of 0.920 to 0.945 g/cm ³ ; preferred LLDPE; more preferably LLDPE having a melt flow index (190°C, 2.16 kg, ASTM D1238) of at most 5.0 g/10 min, more preferably at most 4.0 g/10 min, more preferably at most 3.0 g/10 min, most preferably at most 2.0 g/10 min, and particularly at most 1.0 g/10 min.

Preferably, the weight fraction of the ethylene homo- or copolymer (c ₂ ) based on the total weight of the sealing layer (C) is at least 10 wt.%; preferably at least 15 wt.%, more preferably at least 20 wt.%, even more preferably at least 25 wt.%, most preferably at least 30 wt.%, and in particular at least 35 wt.%.

Preferably, the weight fraction of the ethylene homo- or copolymer (c ₂ ) based on the total weight of the sealing layer (C) is at most 70 wt.%; preferably at most 65 wt.%, more preferably at most 60 wt.%, even more preferably at least 55 wt.%, most preferably at most 50 wt.%, and in particular at most 45 wt.%.

Preferably, the ethylene homo- or copolymers (a ₁ ), (b ₁ ) and (c ₁ ) are each independently selected from LDPE and LLDPE; preferably with a density in the range of 0.920 to 0.945 g/cm ³ ; preferred LDPE; more preferably LDPE with a melt flow index (190°C, 2.16 kg, ASTM D1238) of at most 5.0 g/10 min, more preferably at most 4.0 g/10 min, more preferably at most 3.0 g/10 min, most preferably at most 2.0 g/10 min, and particularly at most 1.0 g/10 min.

Preferably, the ethylene homo- or copolymers (a ₂ ), (b ₂ ) and (c ₂ ) are each independently selected from LDPE and LLDPE; preferably with a density in the range of 0.920 to 0.945 g/cm ³ ; preferred LLDPE; more preferably LLDPE with a melt flow index (190°C, 2.16 kg, ASTM D1238) of at most 5.0 g/10 min, more preferably at most 4.0 g/10 min, more preferably at most 3.0 g/10 min, most preferably at most 2.0 g/10 min, and particularly at most 1.0 g/10 min.

• - als Ethylen-Homo- oder Copolymer (a₁) ein LDPE mit einem Gewichtsanteil bezogen auf das Gesamtgewicht der Siegelschicht (A) im Bereich von 50±17,5 Gew.-%; bevorzugt 50±15 Gew.-%, bevorzugter 50±12,5 Gew.-%, noch bevorzugter 50±10 Gew.-%, am bevorzugtesten 50±7,5 Gew.-% und insbesondere 50±5 Gew.-%, und
• - als Ethylen-Homo- oder Copolymer (a₂) ein LLDPE mit einem Gewichtsanteil bezogen auf das Gesamtgewicht der Siegelschicht (A) im Bereich von 40±17,5 Gew.-%; bevorzugt 40±15 Gew.-%, bevorzugter 40±12,5 Gew.-%, noch bevorzugter 40±10 Gew.-%, am bevorzugtesten 40±7,5 Gew.-% und insbesondere 40±5 Gew.-%.

Preferably the sealing layer (A) contains

• - as an ethylene homo- or copolymer (a ₁ ) an LDPE with a weight fraction based on the total weight of the sealing layer (A) in the range of 50±17.5 wt.%; preferably 50±15 wt.%, more preferably 50±12.5 wt.%, even more preferably 50±10 wt.%, most preferably 50±7.5 wt.% and in particular 50±5 wt.%, and
• - as an ethylene homo- or copolymer (a ₂ ) an LLDPE with a weight fraction based on the total weight of the sealing layer (A) in the range of 40±17.5 wt.%; preferably 40±15 wt.%, more preferably 40±12.5 wt.%, even more preferably 40±10 wt.%, most preferably 40±7.5 wt.% and in particular 40±5 wt.%.

Preferably, the sealing layer (A) contains, if any, a maximum of 12.5 wt.% of polymers that are neither LDPE nor LLDPE, based on the total weight of the sealing layer (A); preferably a maximum of 10 wt.%, more preferably a maximum of 7.5 wt.%, even more preferably a maximum of 5 wt.%, most preferably a maximum of 2.5 wt.%, and in particular no polymers that are neither LDPE nor LLDPE. Preferably, the sealing layer (A) contains, if any, a maximum of 1.5 wt.% of polymers that are neither LDPE nor LLDPE, based on the total weight of the sealing layer (A); preferably a maximum of 1.0 wt.%, more preferably a maximum of 0.75 wt.%, even more preferably a maximum of 0.5 wt.%, most preferably a maximum of 0.25 wt.%, and in particular no polymers that are neither LDPE nor LLDPE.

Preferably, the sealing layer (A) has a thickness in the range of 1.5 to 12.5 µm.

• - als Ethylen-Homo- oder Copolymer (b₁) ein LDPE mit einem Gewichtsanteil bezogen auf das Gesamtgewicht der Mittelschicht (B) im Bereich von 45±17,5 Gew.-%; bevorzugt 45±15 Gew.-%, bevorzugter 45±12,5 Gew.-%, noch bevorzugter 45±10 Gew.-%, am bevorzugtesten 45±7,5 Gew.-% und insbesondere 45±5 Gew.-%,
• - als Ethylen-Homo- oder Copolymer (b₂) ein LLDPE mit einem Gewichtsanteil bezogen auf das Gesamtgewicht der Mittelschicht (B) im Bereich von 20±17,5 Gew.-%; bevorzugt 20±15 Gew.-%, bevorzugter 20±12,5 Gew.-%, noch bevorzugter 20±10 Gew.-%, am bevorzugtesten 20±7,5 Gew.-% und insbesondere 20±5 Gew.-%, und
• - als Ethylen-Homo- oder Copolymer (b₃) ein HDPE mit einem Gewichtsanteil bezogen auf das Gesamtgewicht der Mittelschicht (B) im Bereich von 30±17,5 Gew.-%; bevorzugt 30±15 Gew.-%, bevorzugter 30±12,5 Gew.-%, noch bevorzugter 30±10 Gew.-%, am bevorzugtesten 30±7,5 Gew.-% und insbesondere 30±5 Gew.-%.

Preferably the middle layer (B) contains

• - as an ethylene homo- or copolymer (b ₁ ) an LDPE with a weight fraction based on the total weight of the middle layer (B) in the range of 45±17.5 wt.%; preferably 45±15 wt.%, more preferably 45±12.5 wt.%, even more preferably 45±10 wt.%, most preferably 45±7.5 wt.% and in particular 45±5 wt.%,
• - as an ethylene homo- or copolymer (b ₂ ) an LLDPE with a weight fraction based on the total weight of the middle layer (B) in the range of 20±17.5 wt.%; preferably 20±15 wt.%, more preferably 20±12.5 wt.%, even more preferably 20±10 wt.%, most preferably 20±7.5 wt.% and in particular 20±5 wt.%, and
• - as an ethylene homo- or copolymer (b ₃ ) an HDPE with a weight fraction based on the total weight of the middle layer (B) in the range of 30±17.5 wt.%; preferably 30±15 wt.%, more preferably 30±12.5 wt.%, even more preferably 30±10 wt.%, most preferably 30±7.5 wt.% and in particular 30±5 wt.%.

Preferably, the middle layer (B) contains, if any, a maximum of 12.5 wt.% of polymers that are neither LDPE, LLDPE, nor HDPE, based on the total weight of the middle layer (B); preferably a maximum of 10 wt.%, more preferably a maximum of 7.5 wt.%, even more preferably a maximum of 5 wt.%, most preferably a maximum of 2.5 wt.%, and in particular no polymers that are neither LDPE, LLDPE, nor HDPE. Preferably, the middle layer (B) contains, if any, a maximum of 1.5 wt.% of polymers that are neither LDPE, LLDPE, nor HDPE, based on the total weight of the middle layer (B); preferably a maximum of 1.0 wt.%, more preferably a maximum of 0.75 wt.%, even more preferably a maximum of 0.5 wt.%, most preferably a maximum of 0.25 wt.%, and in particular no polymers that are neither LDPE, LLDPE, nor HDPE.

Preferably the middle layer (B) has a layer thickness in the range of 3 to 25 µm, preferably 5 to 20 µm.

• - als Ethylen-Homo- oder Copolymer (c₁) ein LDPE mit einem Gewichtsanteil bezogen auf das Gesamtgewicht der Siegelschicht (C) im Bereich von 50±17,5 Gew.-%; bevorzugt 50±15 Gew.-%, bevorzugter 50±12,5 Gew.-%, noch bevorzugter 50±10 Gew.-%, am bevorzugtesten 50±7,5 Gew.-% und insbesondere 50±5 Gew.-%, und
• - als Ethylen-Homo- oder Copolymer (c₂) ein LLDPE mit einem Gewichtsanteil bezogen auf das Gesamtgewicht der Siegelschicht (C) im Bereich von 40±17,5 Gew.-%; bevorzugt 40±15 Gew.-%, bevorzugter 40±12,5 Gew.-%, noch bevorzugter 40±10 Gew.-%, am bevorzugtesten 40±7,5 Gew.-% und insbesondere 40±5 Gew.-%.

Preferably the sealing layer contains (C)

• - as an ethylene homo- or copolymer (c ₁ ) an LDPE with a weight fraction based on the total weight of the sealing layer (C) in the range of 50±17.5 wt.%; preferably 50±15 wt.%, more preferably 50±12.5 wt.%, even more preferably 50±10 wt.%, most preferably 50±7.5 wt.% and in particular 50±5 wt.%, and
• - as an ethylene homo- or copolymer (c ₂ ) an LLDPE with a weight fraction based on the total weight of the sealing layer (C) in the range of 40±17.5 wt.%; preferably 40±15 wt.%, more preferably 40±12.5 wt.%, even more preferably 40±10 wt.%, most preferably 40±7.5 wt.% and in particular 40±5 wt.%.

Preferably, the sealing layer (C) contains, if any, a maximum of 12.5 wt.% of polymers that are neither LDPE nor LLDPE, based on the total weight of the sealing layer (C); preferably a maximum of 10 wt.%, more preferably a maximum of 7.5 wt.%, even more preferably a maximum of 5 wt.%, most preferably a maximum of 2.5 wt.%, and in particular no polymers that are neither LDPE nor LLDPE. Preferably, the sealing layer (C) contains, if any, a maximum of 1.5 wt.% of polymers that are neither LDPE nor LLDPE, based on the total weight of the sealing layer (C); preferably a maximum of 1.0 wt.%, more preferably a maximum of 0.75 wt.%, even more preferably a maximum of 0.5 wt.%, most preferably a maximum of 0.25 wt.%, and in particular no polymers that are neither LDPE nor LLDPE.

Preferably, the sealing layer (C) has a thickness in the range of 1.5 to 12.5 µm.

Preferably, the polyethylene film contains, if any, a maximum of 12.5 wt.% of polymers that are neither LDPE, LLDPE, nor HDPE, based on the total weight of the polyethylene film; preferably a maximum of 10 wt.%, more preferably a maximum of 7.5 wt.%, even more preferably a maximum of 5 wt.%, most preferably a maximum of 2.5 wt.%, and in particular no polymers that are neither LDPE, LLDPE, nor HDPE. Preferably, the polyethylene film contains, if any, a maximum of 1.5 wt.% of polymers that are neither LDPE, LLDPE, nor HDPE, based on the total weight of the polyethylene film; preferably a maximum of 1.0 wt.%, more preferably a maximum of 0.75 wt.%, even more preferably a maximum of 0.5 wt.%, most preferably a maximum of 0.25 wt.%, and in particular no polymers that are neither LDPE, LLDPE, nor HDPE.

Preferably, the polyethylene film according to the invention has a symmetrical layer structure with regard to the sealing layer (A), the middle layer (B) and the sealing layer (C).

Preferably, the polyethylene film according to the invention comprises no further layers besides the sealing layer (A) which may be coated with the release coating, the middle layer (B) and the sealing layer (C).

Preferably, the polyethylene film according to the invention has a total layer thickness of at least 10 µm.

Preferably, the polyethylene film according to the invention has a total layer thickness of at most 45 µm, more preferably at most 40 µm, even more preferably at most 35 µm, most preferably at most 30 µm and in particular at most 25 µm.

In preferred embodiments, the polyethylene film according to the invention has a total layer thickness in the range of 10 to 25 µm, preferably 10 to 20 µm. Particularly for use in packaging sanitary napkins, the polyethylene film according to the invention has a total layer thickness of at most 24 µm, more preferably at most 23 µm, even more preferably at most 22 µm, most preferably at most 21 µm, and particularly at most 20 µm. In these preferred embodiments, the sealing layer (A) is preferably at least partially coated with a release coating.

In other preferred embodiments, the polyethylene film according to the invention has a total layer thickness in the range of 25 to 40 µm, preferably 20 to 40 µm. Particularly for use in packaging tampon applicators, the polyethylene film according to the invention has a total layer thickness in the range of 35 to 50 µm. In these preferred embodiments, the polyethylene film according to the invention preferably does not have a release coating.

Preferably, the ratio of the layer thicknesses of the sealing layer (A), the middle layer (B) and the sealing layer (C) is in the range of 1:1.5:1 to 1:3.5:1, preferably about 1:2:1.

Preferably, the sealing layer (A), the middle layer (B) and/or the sealing layer (C) independently contain at least one additive; preferably selected from the group consisting of dyes, fillers such as _CaCO3 ; plasticizers; lubricants; emulsifiers; pigments; rheology additives; catalysts; flow control agents; optical brighteners; light stabilizers; antioxidants; clarifying agents such as substituted or unsubstituted bisbenzylidene sorbates; flame retardants; antistatic agents; UV absorbers such as benzoxazinones; blowing agents; and thiosynergists such as thiodipropionic acid dilauryl esters or thiodipropionic acid distearyl esters.

Preferably, the polyethylene film contains, if any, at most 5.0 wt.% inorganic components based on the total weight of the polyethylene film; preferably at most 4.5 wt.%, more preferably at most 4.0 wt.%, even more preferably at most 3.5 wt.%, most preferably 3.0 wt.% and in particular at most 2.5 wt.%.

In preferred embodiments, the sealing layer (A) and the sealing layer (C) each have a substantially smooth surface.

In other preferred embodiments, the polyethylene film according to the invention is structured, preferably embossed.

Preferably, the polyethylene film according to the invention has a tear force in the machine direction (MD) of at least 2.0 N according to DIN 53356; preferably at least 3.0 N, more preferably at least 4.0 N, even more preferably at least 5.0 N, most preferably at least 6.0 N, and particularly at least 7.0 N. This tear force is preferably achieved with a total layer thickness of the polyethylene film of 20 µm. If the polyethylene film has a different total layer thickness, the numerical minimum tear forces must be recalculated accordingly.

Preferably, the polyethylene film according to the invention has a tear force of at least 2.0 N in the machine direction (MD) according to DIN 53363; preferably at least 3.0 N, more preferably at least 4.0 N, even more preferably at least 5.0 N, most preferably at least 6.0 N, and particularly at least 6.5 N. This tear force is preferably achieved with a total layer thickness of the polyethylene film of 20 µm. If the polyethylene film has a different total layer thickness, the numerical minimum tear forces must be recalculated accordingly.

Optionally, the sealing layer (A) is at least partially coated on its outer surface with a release coating. In preferred embodiments, the release coating covers the entire surface. In preferred embodiments, the release coating covers only part of the surface.

Preferably, the release coating has an areal weight of at most 0.65 g/ ^m² ; preferably at most 0.60 g/ ^m² , more preferably at most 0.55 g/ ^m² , even more preferably at most 0.50 g/ ^m² , most preferably at most 0.45 g/ ^m² , and in particular at most 0.40 g/ ^m² ; preferably at most 0.35 g/ ^m² , more preferably at most 0.30 g/ ^m² , even more preferably at most 0.25 g/ ^m² , most preferably at most 0.20 g/ ^m² .

• - additionsvernetzten, vorzugsweise metallkatalysiert additionsvernetzten, kondensationsvernetzten, radikalisch vernetzten, und/oder kationisch vernetzten Polysiloxanen; vorzugsweise radikalisch vernetzten Polysiloxanen; und/oder
• - Polydialkylsiloxanen, vorzugsweise Polydimethylsiloxanen; und Polyalkylarylsiloxanen, vorzugsweise Polymethylphenylsiloxanen;

bevorzugt chemisch quervernetzten Acrylat-funktionalisierten Polysiloxanen; bevorzugter chemisch quervernetzten Acrylat-funktionalisierten Polydialkylsiloxanen, vorzugsweise chemisch quervernetzten Acrylat-funktionalisierten Polydimethylsiloxanen; oder chemisch quervernetzten Acrylat-funktionalisierten Polyalkylarylsiloxanen, vorzugsweise chemisch quervernetzten Acrylat-funktionalisierten Polymethylphenylsiloxanen.Preferably, the release coating is based on at least one cured polysiloxane selected from the group consisting of

• - addition-crosslinked, preferably metal-catalyzed addition-crosslinked, condensation-crosslinked, radically crosslinked, and/or cationically crosslinked polysiloxanes; preferably radically crosslinked polysiloxanes; and/or
• - Polydialkylsiloxanes, preferably polydimethylsiloxanes; and polyalkylarylsiloxanes, preferably polymethylphenylsiloxanes;

preferably chemically cross-linked acrylate-functionalized polysiloxanes; preferably chemically cross-linked acrylate-functionalized polydialkylsiloxanes, preferably chemically cross-linked acrylate-functionalized polydimethylsiloxanes; or chemically cross-linked acrylate-functionalized polyalkylarylsiloxanes, preferably chemically cross-linked acrylate-functionalized polymethylphenylsiloxanes.

Preferably, the polyethylene film is blown film co-extruded.

In preferred embodiments, the sealing layer (A) is at least partially printed with a printed image on its outer surface. The printed image can cover the sealing layer (A) completely or partially.

If the sealing layer (A) is additionally coated at least partially with a release coating on its outer surface and there are surface sections which are both printed with a printed image and coated with a release coating, the printed image is preferably arranged between the outer surface of the sealing layer (A) and the release coating.

In preferred embodiments, the sealing layer (C) is at least partially printed with a printed image on its outer surface. The printed image can cover the sealing layer (C) completely or partially.

Another aspect of the invention relates to the use of the polyethylene film described above according to the invention for packaging hygiene products; preferably sanitary napkins or tampon applicators.

Another aspect of the invention relates to a packaging comprising a hygiene product as the packaging item, preferably a sanitary napkin or a tampon applicator, and the polyethylene film described above according to the invention as the packaging material.

• Satz 1: Eine mehrschichtige Polyethylenfolie, welche (i) eine äußere Siegelschicht (A) umfassend ein Ethylen-Homo- oder Copolymer (a₁) und optional ein Ethylen-Homo- oder Copolymer (a₂), (ii) eine Mittelschicht (B) umfassend ein Ethylen-Homo- oder Copolymer (b₁), ein Ethylen-Homo- oder Copolymer (b₂) und optional ein Ethylen-Homo- oder Copolymer (b₃); und (iii) eine äußere Siegelschicht (C) umfassend ein Ethylen-Homo- oder Copolymer (c₁) und optional ein Ethylen-Homo- oder Copolymer (c₂); umfasst oder im Wesentlichen daraus besteht; wobei die Polyethylenfolie eine Gesamtschichtdicke von höchstens 50 µm aufweist; wobei die Mittelschicht (B), wenn überhaupt, bezogen auf das Gesamtgewicht der Mittelschicht (B) insgesamt weniger als 15 Gew.-% Propylen-Homo- oder Copolymere enthält; und wobei optional die Siegelschicht (A) zumindest teilweise mit einer Releasebeschichtung beschichtet ist.
• Satz 2: Die Polyethylenfolie nach Satz 1, wobei die Ethylen-Homo- oder Copolymere (a₁), (a₂), (b₁), (b₂), (b₃), (c₁) und (c₂) jeweils unabhängig voneinander ausgewählt sind aus der Gruppe bestehend aus Polyethylen niedriger Dichte (LDPE, ρ ≤ 0,945 g/cm³), linearem Polyethylen niedriger Dichte (LLDPE, ρ ≤ 0,945 g/cm³), und Polyethylen hoher Dichte (HDPE ρ > 0,945 g/cm³).
• Satz 3: Die Polyethylenfolie nach Satz 1 oder 2, wobei die Mittelschicht (B), wenn überhaupt, bezogen auf das Gesamtgewicht der Mittelschicht (B) höchstens insgesamt 12,5 Gew.-% Propylen-Homo- oder Copolymere enthält; bevorzugt höchstens 10 Gew.-%, bevorzugter höchstens 7,5 Gew.-%, noch bevorzugter höchstens 5 Gew.-%, am bevorzugtesten höchstens 2,5 Gew.-%, und insbesondere gar keine Propylen-Homo- oder Copolymere.
• Satz 4: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei die Polyethylenfolie, wenn überhaupt, bezogen auf das Gesamtgewicht der Polyethylenfolie höchstens insgesamt 12,5 Gew.-% Propylen-Homo- oder Copolymere enthält; bevorzugt höchstens 10 Gew.-%, bevorzugter höchstens 7,5 Gew.-%, noch bevorzugter höchstens 5 Gew.-%, am bevorzugtesten höchstens 2,5 Gew.-%, und insbesondere gar keine Propylen-Homo- oder Copolymere.
• Satz 5: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei das Ethylen-Homo- oder Copolymer (a₁) ausgewählt ist aus LDPE und LLDPE; bevorzugt mit einer Dichte im Bereich von 0.920 bis 0,945 g/cm³; bevorzugter LDPE; noch bevorzugter LDPE mit einem Schmelzflussindex (190°C, 2,16 kg, ASTM D1238) von höchstens 5,0 g/10 min, bevorzugter höchstens 4,0 g/10 min, noch bevorzugter höchstens 3,0 g/10 min, am bevorzugtesten höchstens 2,0 g/10 min, und insbesondere höchstens 1,0 g/10 min.
• Satz 6: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei der Gewichtsanteil des Ethylen-Homo- oder Copolymers (a₁) bezogen auf das Gesamtgewicht der Siegelschicht (A) mindestens 20 Gew.-% beträgt; bevorzugt mindestens 25 Gew.-%, bevorzugter mindestens 30 Gew.-%, noch bevorzugter mindestes 35 Gew.-%, am bevorzugten mindestens 40 Gew.-%, und insbesondere mindestens 45 Gew.-%.
• Satz 7: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei der Gewichtsanteil des Ethylen-Homo- oder Copolymers (a₁) bezogen auf das Gesamtgewicht der Siegelschicht (A) höchstens 80 Gew.% beträgt; bevorzugt höchstens 75 Gew.-%, bevorzugter höchstens 70 Gew.-%, noch bevorzugter mindestes 65 Gew.-%, am bevorzugten höchstens 60 Gew.-%, und insbesondere höchstens 55 Gew.-%.
• Satz 8: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei das Ethylen-Homo- oder Copolymer (a₂) ausgewählt ist aus LDPE und LLDPE; bevorzugt mit einer Dichte im Bereich von 0.920 bis 0,945 g/cm³; bevorzugter LLDPE; noch bevorzugter LLDPE mit einem Schmelzflussindex (190°C, 2,16 kg, ASTM D1238) von höchstens 5,0 g/10 min, bevorzugter höchstens 4,0 g/10 min, noch bevorzugter höchstens 3,0 g/10 min, am bevorzugtesten höchstens 2,0 g/10 min, und insbesondere höchstens 1,0 g/10 min.
• Satz 9: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei der Gewichtsanteil des Ethylen-Homo- oder Copolymers (a₂) bezogen auf das Gesamtgewicht der Siegelschicht (A) mindestens 10 Gew.-% beträgt; bevorzugt mindestens 15 Gew.-%, bevorzugter mindestens 20 Gew.-%, noch bevorzugter mindestes 25 Gew.-%, am bevorzugten mindestens 30 Gew.-%, und insbesondere mindestens 35 Gew.-%.
• Satz 10: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei der Gewichtsanteil des Ethylen-Homo- oder Copolymers (a₂) bezogen auf das Gesamtgewicht der Siegelschicht (A) höchstens 70 Gew.-% beträgt; bevorzugt höchstens 65 Gew.-%, bevorzugter höchstens 60 Gew.-%, noch bevorzugter mindestes 55 Gew.-%, am bevorzugten höchstens 50 Gew.-%, und insbesondere höchstens 45 Gew.-%. Satz 11: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei das Ethylen-Homo- oder Copolymer (b₁) ausgewählt ist aus LDPE und LLDPE; bevorzugt mit einer Dichte im Bereich von 0.920 bis 0,945 g/cm³; bevorzugter LDPE; noch bevorzugter LDPE mit einem Schmelzflussindex (190°C, 2,16 kg, ASTM D1238) von höchstens 5,0 g/10 min, bevorzugter höchstens 4,0 g/10 min, noch bevorzugter höchstens 3,0 g/10 min, am bevorzugtesten höchstens 2,0 g/10 min, und insbesondere höchstens 1,0 g/10 min.
• Satz 12: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei der Gewichtsanteil des Ethylen-Homo- oder Copolymers (b₁) bezogen auf das Gesamtgewicht der Mittelschicht (B) mindestens 15 Gew.-% beträgt; bevorzugt mindestens 20 Gew.-%, bevorzugter mindestens 25 Gew.-%, noch bevorzugter mindestes 30 Gew.-%, am bevorzugten mindestens 35 Gew.-%, und insbesondere mindestens 40 Gew.-%.
• Satz 13: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei der Gewichtsanteil des Ethylen-Homo- oder Copolymers (b₁) bezogen auf das Gesamtgewicht der Mittelschicht (B) höchstens 70 Gew.-% beträgt; bevorzugt höchstens 65 Gew.-%, bevorzugter höchstens 60 Gew.-%, noch bevorzugter mindestes 55 Gew.-%, am bevorzugten höchstens 50 Gew.-%, und insbesondere höchstens 45 Gew.-%. Satz 14: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei das Ethylen-Homo- oder Copolymer (b₂) ausgewählt ist aus LDPE und LLDPE; bevorzugt mit einer Dichte im Bereich von 0.920 bis 0,945 g/cm³; bevorzugter LLDPE; noch bevorzugter LLDPE mit einem Schmelzflussindex (190°C, 2,16 kg, ASTM D1238) von höchstens 5,0 g/10 min, bevorzugter höchstens 4,0 g/10 min, noch bevorzugter höchstens 3,0 g/10 min, am bevorzugtesten höchstens 2,0 g/10 min, und insbesondere höchstens 1,0 g/10 min.
• Satz 15: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei der Gewichtsanteil des Ethylen-Homo- oder Copolymers (b₂) bezogen auf das Gesamtgewicht der Mittelschicht (B) mindestens 5 Gew.-% beträgt; bevorzugt mindestens 7,5 Gew.-%, bevorzugter mindestens 10 Gew.-%, noch bevorzugter mindestes 12,5 Gew.-%, am bevorzugten mindestens 15 Gew.-%, und insbesondere mindestens 17,5 Gew.-%.
• Satz 16: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei der Gewichtsanteil des Ethylen-Homo- oder Copolymers (b₂) bezogen auf das Gesamtgewicht der Mittelschicht (B) höchstens 35 Gew.-% beträgt; bevorzugt höchstens 32,5 Gew.-%, bevorzugter höchstens 30 Gew.-%, noch bevorzugter mindestes 27,5 Gew.-%, am bevorzugten höchstens 25 Gew.-%, und insbesondere höchstens 22,5 Gew.-%.
• Satz 17: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei das Ethylen-Homo- oder Copolymer (b₃) ausgewählt ist aus HDPE; bevorzugt mit einer Dichte im Bereich von 0,950 bis 0,965 g/cm³; bevorzugter HDPE mit einem Schmelzflussindex (190°C, 2,16 kg, ASTM D1238) von höchstens 5,0 g/10 min, bevorzugter höchstens 4,0 g/10 min, noch bevorzugter höchstens 3,0 g/10 min, am bevorzugtesten höchstens 2,0 g/10 min, und insbesondere höchstens 1,0 g/10 min.
• Satz 18: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei der Gewichtsanteil des Ethylen-Homo- oder Copolymers (b₃) bezogen auf das Gesamtgewicht der Mittelschicht (B) mindestens 5 Gew.-% beträgt; bevorzugt mindestens 10 Gew.-%, bevorzugter mindestens 15 Gew.-%, noch bevorzugter mindestes 20 Gew.-%, am bevorzugten mindestens 25 Gew.-%, und insbesondere mindestens 30 Gew.-%.
• Satz 19: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei der Gewichtsanteil des Ethylen-Homo- oder Copolymers (b₃) bezogen auf das Gesamtgewicht der Mittelschicht (B) höchstens 60 Gew.-% beträgt; bevorzugt höchstens 55 Gew.-%, bevorzugter höchstens 50 Gew.-%, noch bevorzugter mindestes 45 Gew.-%, am bevorzugten höchstens 40 Gew.-%, und insbesondere höchstens 35 Gew.-%. Satz 20: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei das Ethylen-Homo- oder Copolymer (c₁) ausgewählt ist aus LDPE und LLDPE; bevorzugt mit einer Dichte im Bereich von 0.920 bis 0,945 g/cm³; bevorzugter LDPE; noch bevorzugter LDPE mit einem Schmelzflussindex (190°C, 2,16 kg, ASTM D1238) von höchstens 5,0 g/10 min, bevorzugter höchstens 4,0 g/10 min, noch bevorzugter höchstens 3,0 g/10 min, am bevorzugtesten höchstens 2,0 g/10 min, und insbesondere höchstens 1,0 g/10 min.
• Satz 21: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei der Gewichtsanteil des Ethylen-Homo- oder Copolymers (c₁) bezogen auf das Gesamtgewicht der Siegelschicht (C) mindestens 20 Gew.-% beträgt; bevorzugt mindestens 25 Gew.-%, bevorzugter mindestens 30 Gew.-%, noch bevorzugter mindestes 35 Gew.-%, am bevorzugten mindestens 40 Gew.-%, und insbesondere mindestens 45 Gew.-%.
• Satz 22: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei der Gewichtsanteil des Ethylen-Homo- oder Copolymers (c₁) bezogen auf das Gesamtgewicht der Siegelschicht (C) höchstens 80 Gew.-% beträgt; bevorzugt höchstens 75 Gew.-%, bevorzugter höchstens 70 Gew.-%, noch bevorzugter mindestes 65 Gew.-%, am bevorzugten höchstens 60 Gew.-%, und insbesondere höchstens 55 Gew.-%. Satz 23: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei das Ethylen-Homo- oder Copolymer (c₂) ausgewählt ist aus LDPE und LLDPE; bevorzugt mit einer Dichte im Bereich von 0.920 bis 0,945 g/cm³; bevorzugter LLDPE; noch bevorzugter LLDPE mit einem Schmelzflussindex (190°C, 2,16 kg, ASTM D1238) von höchstens 5,0 g/10 min, bevorzugter höchstens 4,0 g/10 min, noch bevorzugter höchstens 3,0 g/10 min, am bevorzugtesten höchstens 2,0 g/10 min, und insbesondere höchstens 1,0 g/10 min.
• Satz 24: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei der Gewichtsanteil des Ethylen-Homo- oder Copolymers (c₂) bezogen auf das Gesamtgewicht der Siegelschicht (C) mindestens 10 Gew.-% beträgt; bevorzugt mindestens 15 Gew.-%, bevorzugter mindestens 20 Gew.-%, noch bevorzugter mindestes 25 Gew.-%, am bevorzugten mindestens 30 Gew.-%, und insbesondere mindestens 35 Gew.-%.
• Satz 25: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei der Gewichtsanteil des Ethylen-Homo- oder Copolymers (c₂) bezogen auf das Gesamtgewicht der Siegelschicht (C) höchstens 70 Gew.-% beträgt; bevorzugt höchstens 65 Gew.-%, bevorzugter höchstens 60 Gew.-%, noch bevorzugter mindestes 55 Gew.-%, am bevorzugten höchstens 50 Gew.-%, und insbesondere höchstens 45 Gew.-%. Satz 26: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei die Ethylen-Homo- oder Copolymere (a₁), (b₁) und (c₁) jeweils unabhängig voneinander ausgewählt sind aus LDPE und LLDPE; bevorzugt mit einer Dichte im Bereich von 0.920 bis 0,945 g/cm³; bevorzugter LDPE; noch bevorzugter LDPE mit einem Schmelzflussindex (190°C, 2,16 kg, ASTM D1238) von höchstens 5,0 g/10 min, bevorzugter höchstens 4,0 g/10 min, noch bevorzugter höchstens 3,0 g/10 min, am bevorzugtesten höchstens 2,0 g/10 min, und insbesondere höchstens 1,0 g/10 min.
• Satz 27: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei die Ethylen-Homo- oder Copolymere (a₂), (b₂) und (c₂) jeweils unabhängig voneinander ausgewählt sind aus LDPE und LLDPE; bevorzugt mit einer Dichte im Bereich von 0.920 bis 0,945 g/cm³; bevorzugter LLDPE; noch bevorzugter LLDPE mit einem Schmelzflussindex (190°C, 2,16 kg, ASTM D1238) von höchstens 5,0 g/10 min, bevorzugter höchstens 4,0 g/10 min, noch bevorzugter höchstens 3,0 g/10 min, am bevorzugtesten höchstens 2,0 g/10 min, und insbesondere höchstens 1,0 g/10 min.
• Satz 28: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei die Siegelschicht (A) (i) als Ethylen-Homo- oder Copolymer (a₁) ein LDPE mit einem Gewichtsanteil bezogen auf das Gesamtgewicht der Siegelschicht (A) im Bereich von 50±17,5 Gew.-% enthält; bevorzugt 50±15 Gew.-%, bevorzugter 50±12,5 Gew.-%, noch bevorzugter 50±10 Gew.-%, am bevorzugtesten 50±7,5 Gew.-% und insbesondere 50±5 Gew.-%; und (ii) als Ethylen-Homo- oder Copolymer (a₂) ein LLDPE mit einem Gewichtsanteil bezogen auf das Gesamtgewicht der Siegelschicht (A) im Bereich von 40±17,5 Gew.-% enthält; bevorzugt 40±15 Gew.-%, bevorzugter 40±12,5 Gew.-%, noch bevorzugter 40±10 Gew.-%, am bevorzugtesten 40±7,5 Gew.-% und insbesondere 40±5 Gew.-%.
• Satz 29: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei die Siegelschicht (A), wenn überhaupt, bezogen auf das Gesamtgewicht der Siegelschicht (A) höchstens insgesamt 12,5 Gew.-% Polymere enthält, welche weder LDPE noch LLDPE sind; bevorzugt höchstens 10 Gew.-%, bevorzugter höchstens 7,5 Gew.-%, noch bevorzugter höchstens 5 Gew.-%, am bevorzugtesten höchstens 2,5 Gew.%, und insbesondere gar keine Polymere, welche weder LDPE noch LLDPE sind.
• Satz 30: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei die Siegelschicht (A) eine Schichtdicke im Bereich von 1,5 bis 12,5 µm aufweist.
• Satz 31: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei die Mittelschicht (B) (i) als Ethylen-Homo- oder Copolymer (b₁) ein LDPE mit einem Gewichtsanteil bezogen auf das Gesamtgewicht der Mittelschicht (B) im Bereich von 45±17,5 Gew.-% enthält; bevorzugt 45±15 Gew.-%, bevorzugter 45±12,5 Gew.-%, noch bevorzugter 45±10 Gew.-%, am bevorzugtesten 45±7,5 Gew.-% und insbesondere 45±5 Gew.-%; (ii) als Ethylen-Homo- oder Copolymer (b₂) ein LLDPE mit einem Gewichtsanteil bezogen auf das Gesamtgewicht der Mittelschicht (B) im Bereich von 20±17,5 Gew.-% enthält; bevorzugt 20±15 Gew.-%, bevorzugter 20±12,5 Gew.-%, noch bevorzugter 20±10 Gew.-%, am bevorzugtesten 20±7,5 Gew.-% und insbesondere 20±5 Gew.-%; und (iii) als Ethylen-Homo- oder Copolymer (b₃) ein HDPE mit einem Gewichtsanteil bezogen auf das Gesamtgewicht der Mittelschicht (B) im Bereich von 30±17,5 Gew.-% enthält; bevorzugt 30±15 Gew.-%, bevorzugter 30±12,5 Gew.-%, noch bevorzugter 30±10 Gew.-%, am bevorzugtesten 30±7,5 Gew.-% und insbesondere 30±5 Gew.-%.
• Satz 32: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei die Mittelschicht (B), wenn überhaupt, bezogen auf das Gesamtgewicht der Mittelschicht (B) höchstens insgesamt 12,5 Gew.-% Polymere enthält, welche weder LDPE noch LLDPE noch HDPE sind; bevorzugt höchstens 10 Gew.%, bevorzugter höchstens 7,5 Gew.-%, noch bevorzugter höchstens 5 Gew.-%, am bevorzugtesten höchstens 2,5 Gew.-%, und insbesondere gar keine Polymere, welche weder LDPE noch LLDPE noch HDPE sind.
• Satz 33: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei die Mittelschicht (B) eine Schichtdicke im Bereich von 3 bis 25 µm aufweist, bevorzugt 5 bis 20 µm.
• Satz 34: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei die Siegelschicht (C) (i) als Ethylen-Homo- oder Copolymer (c₁) ein LDPE mit einem Gewichtsanteil bezogen auf das Gesamtgewicht der Siegelschicht (C) im Bereich von 50±17,5 Gew.-% enthält; bevorzugt 50±15 Gew.-%, bevorzugter 50±12,5 Gew.-%, noch bevorzugter 50±10 Gew.-%, am bevorzugtesten 50±7,5 Gew.-% und insbesondere 50±5 Gew.-%; und (ii) als Ethylen-Homo- oder Copolymer (c₂) ein LLDPE mit einem Gewichtsanteil bezogen auf das Gesamtgewicht der Siegelschicht (C) im Bereich von 40±17,5 Gew.-% enthält; bevorzugt 40±15 Gew.-%, bevorzugter 40±12,5 Gew.-%, noch bevorzugter 40±10 Gew.-%, am bevorzugtesten 40±7,5 Gew.-% und insbesondere 40±5 Gew.-%.
• Satz 35: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei die Siegelschicht (C), wenn überhaupt, bezogen auf das Gesamtgewicht der Siegelschicht (C) höchstens insgesamt 12,5 Gew.-% Polymere enthält, welche weder LDPE noch LLDPE sind; bevorzugt höchstens 10 Gew.-%, bevorzugter höchstens 7,5 Gew.-%, noch bevorzugter höchstens 5 Gew.-%, am bevorzugtesten höchstens 2,5 Gew.%, und insbesondere gar keine Polymere, welche weder LDPE noch LLDPE sind.
• Satz 36: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei die Siegelschicht (C) eine Schichtdicke im Bereich von 1,5 bis 12,5 µm aufweist.
• Satz 37: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei die Polyethylenfolie, wenn überhaupt, bezogen auf das Gesamtgewicht der Polyethylenfolie höchstens insgesamt 12,5 Gew.-% Polymere enthält, welche weder LDPE noch LLDPE noch HDPE sind; bevorzugt höchstens 10 Gew.%, bevorzugter höchstens 7,5 Gew.-%, noch bevorzugter höchstens 5 Gew.-%, am bevorzugtesten höchstens 2,5 Gew.-%, und insbesondere gar keine Polymere, welche weder LDPE noch LLDPE noch HDPE sind.
• Satz 38: Die Polyethylenfolie nach einem der vorstehenden Sätze, welche im Hinblick auf die Siegelschicht (A), die Mittelschicht (B) und die Siegelschicht (C) einen symmetrischen Schichtaufbau aufweist.
• Satz 39: Die Polyethylenfolie nach einem der vorstehenden Sätze, welche neben der ggf. mit der Releasebeschichtung beschichteten Siegelschicht (A), der Mittelschicht (B) und der Siegelschicht (C) keine weiteren Schichten umfasst.
• Satz 40: Die Polyethylenfolie nach einem der vorstehenden Sätze, welche eine Gesamtschichtdicke von mindestens 10 µm aufweist.
• Satz 41: Die Polyethylenfolie nach einem der vorstehenden Sätze, welche eine Gesamtschichtdicke von höchstens 45 µm aufweist, bevorzugter höchstens 40 µm, noch bevorzugter höchstens 35 µm, am bevorzugtesten höchstens 30 µm und insbesondere höchstens 25 µm.
• Satz 42: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei das Verhältnis der Schichtdicken der Siegelschicht (A), der Mittelschicht (B) und der Siegelschicht (C) im Bereich von 1:1,5:1 bis 1:3,5:1 liegt, bevorzugt etwa 1:2:1.
• Satz 43: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei die Siegelschicht (A), die Mittelschicht (B) und/oder die Siegelschicht (C) unabhängig voneinander mindestens ein Additiv enthält; bevorzugt ausgewählt aus der Gruppe bestehend aus Farbstoffen, Füllstoffen, wie CaCO₃; Weichmachern; Schmiermitteln; Emulgatoren; Pigmenten; Rheologieadditiven; Katalysatoren; Fließsteuerungsmitteln; optischen Aufhellern; Lichtstabilisatoren; Antioxidantien; Klärmitteln, wie substituierten oder unsubstituierten Bisbenzylidensorbiten; Flammverzögerungsmitteln; antistatischen Mitteln; UV-Absorptionsmitteln wie Benzoxazinonen; Treibmitteln; und Thiosynergisten, wie Thiodipropionsäuredilaurylestern oder Thiodipropionsäuredistearylestern.
• Satz 44: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei die Polyethylenfolie, wenn überhaupt, bezogen auf das Gesamtgewicht der Polyethylenfolie höchstens insgesamt 5,0 Gew.-% anorganische Bestandteile enthält; bevorzugt höchstens 4,5 Gew.-%, bevorzugter höchstens 4,0 Gew.-%, noch bevorzugter höchstens 3,5 Gew.-%, am bevorzugtesten 3,0 Gew.-% und insbesondere höchstens 2,5 Gew.-%.
• Satz 45: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei die Siegelschicht (A) und die Siegelschicht (C) jeweils eine im Wesentlichen glatte Oberfläche aufweisen.
• Satz 46: Die Polyethylenfolie nach einem der Sätze 1 bis 44, welche strukturiert ist, bevorzugt geprägt. Satz 47: Die Polyethylenfolie nach einem der vorstehenden Sätze, welche eine Gesamtschichtdicke im Bereich von 10 bis 25 µm aufweist, bevorzugt 10 bis 20 µm.
• Satz 48: Die Polyethylenfolie nach einem der Sätze 1 bis 46, welche eine Gesamtschichtdicke im Bereich von 25 bis 40 µm aufweist, bevorzugt 20 bis 40 µm.
• Satz 49: Die Polyethylenfolie nach einem der vorstehenden Sätze, welche in Maschinenrichtung (MD) eine Weiterreißkraft gemäß DIN53356 von mindestens 2,0 N aufweist; bevorzugt mindestens 3,0 N, bevorzugter mindestens 4,0 N, noch bevorzugter mindestens 5,0 N, am bevorzugtesten mindestens 6,0 N und insbesondere mindestens 7,0 N.
• Satz 50: Die Polyethylenfolie nach einem der vorstehenden Sätze, welche in Maschinenrichtung (MD) eine Weiterreißkraft DIN53363 Weiterreißkraft von mindestens 2,0 N aufweist; bevorzugt mindestens 3,0 N, bevorzugter mindestens 4,0 N, noch bevorzugter mindestens 5,0 N, am bevorzugtesten mindestens 6,0 N und insbesondere mindestens 6,5 N.
• Satz 51: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei die Releasebeschichtung ein Flächengewicht von höchstens 0,65 g/m² aufweist; bevorzugt höchstens 0,60 g/m², bevorzugter höchstens 0,55 g/m², noch bevorzugter höchstens 0,50 g/m², am bevorzugtesten höchstens 0,45 g/m², und insbesondere höchstens 0,40 g/m²; bevorzugt höchstens 0,35 g/m², bevorzugter höchstens 0,30 g/m², noch bevorzugter höchstens 0,25 g/m², am bevorzugtesten höchstens 0,20 g/m².
• Satz 52: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei die Releasebeschichtung auf wenigstens einem ausgehärteten Polysiloxan basiert, welches ausgewählt ist aus der Gruppe bestehend aus (i) additionsvernetzten, vorzugsweise metallkatalysiert additionsvernetzten, kondensationsvernetzten, radikalisch vernetzten, und/oder kationisch vernetzten Polysiloxanen; vorzugsweise radikalisch vernetzten Polysiloxanen; und/oder (ii) Polydialkylsiloxanen, vorzugsweise Polydimethylsiloxanen; und Polyalkylarylsiloxanen, vorzugsweise Polymethylphenylsiloxanen; bevorzugt chemisch quervernetzten Acrylat-funktionalisierten Polysiloxanen; bevorzugter chemisch quervernetzten Acrylat-funktionalisierten Polydialkylsiloxanen, vorzugsweise chemisch quervernetzten Acrylat-funktionalisierten Polydimethylsiloxanen; oder chemisch quervernetzten Acrylat-funktionalisierten Polyalkylarylsiloxanen, vorzugsweise chemisch quervernetzten Acrylat-funktionalisierten Polymethylphenylsiloxanen. Satz 53: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei die Polyethylenfolie blasfoliencoextrudiert ist.
• Satz 54: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei die Siegelschicht (A) auf ihrer Außenseite zumindest teilweise mit einem Druckbild bedruckt ist.
• Satz 55: Die Polyethylenfolie nach Satz 54, wobei die Siegelschicht (A) auf ihrer Außenseite zusätzlich zumindest teilweise mit einer Releasebeschichtung beschichtet ist.
• Satz 56: Die Polyethylenfolie nach Satz 55, wobei es Flächenabschnitte gibt, welche sowohl mit einem Druckbild bedruckt als auch mit einer Releasebeschichtung beschichtet sind, und wobei das Druckbild zwischen der Außenseite der Siegelschicht (A) und der Releasebeschichtung angeordnet ist.
• Satz 57: Die Polyethylenfolie nach einem der vorstehenden Sätze, wobei die Siegelschicht (C) auf ihrer Außenseite zumindest teilweise mit einem Druckbild bedruckt ist.
• Satz 58: Verwendung einer Polyethylenfolie nach einem der vorstehenden Sätze zur Verpackung von Hygieneartikeln; bevorzugt von Damenbinden oder Tampon-Applikatoren.
• Satz 59: Eine Verpackung umfassend einen Hygieneartikel als Verpackungsgut, bevorzugt eine Damenbinde oder einen Tampon-Applikator, und eine Polyethylenfolie nach einem der Sätze 1 bis 57 als Verpackungsmaterial.

Particularly preferred embodiments of the invention are summarized below as sentences:

• Sentence 1: A multilayer polyethylene film comprising (i) an outer sealing layer (A) comprising an ethylene homo- or copolymer (a ₁ ) and optionally an ethylene homo- or copolymer (a ₂ ), (ii) a middle layer (B) comprising an ethylene homo- or copolymer (b ₁ ), an ethylene homo- or copolymer (b ₂ ) and optionally an ethylene homo- or copolymer (b ₃ ); and (iii) an outer sealing layer (C) comprising an ethylene homo- or copolymer (c ₁ ) and optionally an ethylene homo- or copolymer (c ₂ ); wherein the polyethylene film has a total layer thickness of not more than 50 µm; wherein the middle layer (B), if any, contains less than 15 wt% propylene homo- or copolymers on a total basis of the middle layer (B ); and wherein optionally the sealing layer (A) is at least partially coated with a release coating.
• Sentence 2: The polyethylene film according to Sentence 1, wherein the ethylene homo- or copolymers (a ₁ ), (a ₂ ), (b ₁ ), (b ₂ ), (b ₃ ), (c ₁ ) and (c ₂ ) are each independently selected from the group consisting of low-density polyethylene (LDPE, ρ ≤ 0.945 g/cm ³ ), linear low-density polyethylene (LLDPE, ρ ≤ 0.945 g/cm ³ ), and high-density polyethylene (HDPE ρ > 0.945 g/cm ³ ).
• Sentence 3: The polyethylene film according to sentence 1 or 2, wherein the middle layer (B), if any, contains at most 12.5 wt.% propylene homo- or copolymers in total, based on the total weight of the middle layer (B); preferably at most 10 wt.%, more preferably at most 7.5 wt.%, even more preferably at most 5 wt.%, most preferably at most 2.5 wt.%, and in particular no propylene homo- or copolymers at all.
• Sentence 4: The polyethylene film according to one of the preceding sentences, wherein the polyethylene film, if it contains any propylene homo- or copolymers, contains at most 12.5 wt.% propylene by weight; preferably at most 10 wt.%, more preferably at most 7.5 wt.%, even more preferably at most 5 wt.%, most preferably at most 2.5 wt.%, and in particular no propylene homo- or copolymers at all.
• Sentence 5: The polyethylene film according to any of the preceding sentences, wherein the ethylene homo- or copolymer (a ₁ ) is selected from LDPE and LLDPE; preferably having a density in the range of 0.920 to 0.945 g/cm ³ ; preferred LDPE ; more preferably LDPE having a melt flow index (190°C, 2.16 kg, ASTM D1238) of at most 5.0 g/10 min, more preferably at most 4.0 g/10 min, more preferably at most 3.0 g/10 min, most preferably at most 2.0 g/10 min, and particularly at most 1.0 g/10 min.
• Sentence 6: The polyethylene film according to one of the preceding sentences, wherein the weight fraction of the ethylene homo or copolymer (a ₁ ) based on the total weight of the sealing layer (A) is at least 20 wt.%; preferably at least 25 wt.%, more preferably at least 30 wt.%, even more preferably at least 35 wt.%, most preferably at least 40 wt.%, and in particular at least 45 wt.%.
• Sentence 7: The polyethylene film according to one of the preceding sentences, wherein the weight fraction of the ethylene homo or copolymer (a ₁ ) based on the total weight of the sealing layer (A) is at most 80 wt.%; preferably at most 75 wt.%, more preferably at most 70 wt.%, more preferably at least 65 wt.%, most preferably at most 60 wt.%, and in particular at most 55 wt.%.
• Sentence 8: The polyethylene film according to any of the preceding sentences, wherein the ethylene homo- or copolymer (a ₂ ) is selected from LDPE and LLDPE; preferably having a density in the range of 0.920 to 0.945 g/cm ³ ; preferred LLDPE; more preferably LLDPE having a melt flow index (190°C, 2.16 kg, ASTM D1238) of at most 5.0 g/10 min, more preferably at most 4.0 g/10 min, more preferably at most 3.0 g/10 min, most preferably at most 2.0 g/10 min, and particularly at most 1.0 g/10 min.
• Sentence 9: The polyethylene film according to one of the preceding sentences, wherein the weight fraction of the ethylene homo or copolymer (a ₂ ) based on the total weight of the sealing layer (A) is at least 10 wt.%; preferably at least 15 wt.%, more preferably at least 20 wt.%, even more preferably at least 25 wt.%, most preferably at least 30 wt.%, and in particular at least 35 wt.%.
• Sentence 10: The polyethylene film according to any of the preceding sentences, wherein the weight fraction of the ethylene homo- or copolymer (a ₂ ) based on the total weight of the sealing layer (A) is at most 70 wt.%; preferably at most 65 wt.%, more preferably at most 60 wt.%, even more preferably at least 55 wt.%, most preferably at most 50 wt.%, and in particular at most 45 wt.%. Sentence 11: The polyethylene film according to any of the preceding sentences, wherein the ethylene homo- or copolymer (b ₁ ) is selected from LDPE and LLDPE; preferably with a density in the range of 0.920 to 0.945 g/cm ³ ; preferably LDPE; even more preferably LDPE with a melt flow index (190°C, 2.16 kg, ASTM D1238) of not more than 5.0 g/10 min, more preferably not more than 4.0 g/10 min, even more preferably not more than 3.0 g/10 min, most preferably not more than 2.0 g/10 min, and particularly not more than 1.0 g/10 min.
• Sentence 12: The polyethylene film according to one of the preceding sentences, wherein the weight fraction of the ethylene homo or copolymer (b ₁ ) based on the total weight of the middle layer (B) is at least 15 wt.%; preferably at least 20 wt.%, more preferably at least 25 wt.%, more preferably at least 30 wt.%, most preferably at least 35 wt.%, and in particular at least 40 wt.%.
• Sentence 13: The polyethylene film according to any of the preceding sentences, wherein the weight fraction of the ethylene homo- or copolymer ( _b1 ) based on the total weight of the middle layer (B) is at most 70 wt.%; preferably at most 65 wt.%, more preferably at most 60 wt.%, even more preferably at least 55 wt.%, most preferably at most 50 wt.%, and in particular at most 45 wt.%. Sentence 14: The polyethylene film according to any of the preceding sentences, wherein the ethylene homo- or copolymer ( _b2 ) is selected from LDPE and LLDPE; preferably with a density in the range of 0.920 to 0.945 g/ ^cm³ ; preferably LLDPE; even more preferably LLDPE with a melt flow index (190°C, 2.16 kg, ASTM D1238) of not more than 5.0 g/10 min, more preferably not more than 4.0 g/10 min, even more preferably not more than 3.0 g/10 min, most preferably not more than 2.0 g/10 min, and particularly not more than 1.0 g/10 min.
• Sentence 15: The polyethylene film according to one of the preceding sentences, wherein the weight fraction of the ethylene homo or copolymer (b ₂ ) based on the total weight of the middle layer (B) is at least 5 wt.%; preferably at least 7.5 wt.%, more preferably at least 10 wt.%, more preferably at least 12.5 wt.%, most preferably at least 15 wt.%, and in particular at least 17.5 wt.%.
• Sentence 16: The polyethylene film according to one of the preceding sentences, wherein the weight fraction of the ethylene homo or copolymer (b ₂ ) based on the total weight of the middle layer (B) is at most 35 wt.%; preferably at most 32.5 wt.%, more preferably at most 30 wt.%, more preferably at least 27.5 wt.%, most preferably at most 25 wt.%, and in particular at most 22.5 wt.%.
• Sentence 17: The polyethylene film according to any of the preceding sentences, wherein the ethylene homo- or copolymer (b ₃ ) is selected from HDPE; preferably having a density in the range of 0.950 to 0.965 g/cm ³ ; preferably HDPE having a melt flow index (190°C, 2.16 kg, ASTM D1238) of at most 5.0 g/10 min, more preferably at most 4.0 g/10 min, more preferably at most 3.0 g/10 min, most preferably at most 2.0 g/10 min, and particularly at most 1.0 g/10 min.
• Sentence 18: The polyethylene film according to one of the preceding sentences, wherein the weight fraction of the ethylene homo or copolymer (b ₃ ) based on the total weight of the middle layer (B) is at least 5 wt.%; preferably at least 10 wt.%, more preferably at least 15 wt.%, more preferably at least 20 wt.%, most preferably at least 25 wt.%, and in particular at least 30 wt.%.
• Sentence 19: The polyethylene film according to any of the preceding sentences, wherein the weight fraction of the ethylene homo- or copolymer (b ₃ ) based on the total weight of the middle layer (B) is at most 60 wt.%; preferably at most 55 wt.%, more preferably at most 50 wt.%, even more preferably at least 45 wt.%, most preferably at most 40 wt.%, and in particular at most 35 wt.%. Sentence 20: The polyethylene film according to any of the preceding sentences, wherein the ethylene homo- or copolymer (c ₁ ) is selected from LDPE and LLDPE; preferably with a density in the range of 0.920 to 0.945 g/cm ³ ; preferably LDPE; even more preferably LDPE with a melt flow index (190°C, 2.16 kg, ASTM D1238) of not more than 5.0 g/10 min, more preferably not more than 4.0 g/10 min, even more preferably not more than 3.0 g/10 min, most preferably not more than 2.0 g/10 min, and particularly not more than 1.0 g/10 min.
• Sentence 21: The polyethylene film according to one of the preceding sentences, wherein the weight fraction of the ethylene homo or copolymer (c ₁ ) based on the total weight of the sealing layer (C) is at least 20 wt.%; preferably at least 25 wt.%, more preferably at least 30 wt.%, even more preferably at least 35 wt.%, most preferably at least 40 wt.%, and in particular at least 45 wt.%.
• Sentence 22: The polyethylene film according to any of the preceding sentences, wherein the weight fraction of the ethylene homo- or copolymer ( _c1 ) based on the total weight of the sealing layer (C) is at most 80 wt.%; preferably at most 75 wt.%, more preferably at most 70 wt.%, even more preferably at least 65 wt.%, most preferably at most 60 wt.%, and in particular at most 55 wt.%. Sentence 23: The polyethylene film according to any of the preceding sentences, wherein the ethylene homo- or copolymer ( _c2 ) is selected from LDPE and LLDPE; preferably with a density in the range of 0.920 to 0.945 g/ ^cm³ ; preferably LLDPE; even more preferably LLDPE with a melt flow index (190°C, 2.16 kg, ASTM D1238) of not more than 5.0 g/10 min, more preferably not more than 4.0 g/10 min, even more preferably not more than 3.0 g/10 min, most preferably not more than 2.0 g/10 min, and particularly not more than 1.0 g/10 min.
• Sentence 24: The polyethylene film according to one of the preceding sentences, wherein the weight fraction of the ethylene homo- or copolymer (c ₂ ) based on the total weight of the sealing layer (C) is at least 10 wt.%; preferably at least 15 wt.%, more preferably at least 20 wt.%, still more preferably at least 25 wt.%, most preferably at least 30 wt.%, and in particular at least 35 wt.%.
• Sentence 25: The polyethylene film according to any of the preceding sentences, wherein the weight fraction of the ethylene homo- or copolymer (c ₂ ) based on the total weight of the sealing layer (C) is at most 70 wt.%; preferably at most 65 wt.%, more preferably at most 60 wt.%, even more preferably at least 55 wt.%, most preferably at most 50 wt.%, and in particular at most 45 wt.%. Sentence 26: The polyethylene film according to any of the preceding sentences, wherein the ethylene homo- or copolymers (a ₁ ), (b ₁ ) and (c ₁ ) are each independently selected from LDPE and LLDPE; preferably with a density in the range of 0.920 to 0.945 g/cm ³ ; preferably LDPE; even more preferably LDPE with a melt flow index (190°C, 2.16 kg, ASTM D1238) of not more than 5.0 g/10 min, more preferably not more than 4.0 g/10 min, even more preferably not more than 3.0 g/10 min, most preferably not more than 2.0 g/10 min, and particularly not more than 1.0 g/10 min.
• Sentence 27: The polyethylene film according to any of the preceding sentences, wherein the ethylene homo- or copolymers (a ₂ ), (b ₂ ) and (c ₂ ) are each independently selected from LDPE and LLDPE; preferably having a density in the range of 0.920 to 0.945 g/cm ³ ; preferred LLDPE; more preferably LLDPE having a melt flow index (190°C, 2.16 kg, ASTM D1238) of at most 5.0 g/10 min, more preferably at most 4.0 g/10 min, more preferably at most 3.0 g/10 min, most preferably at most 2.0 g/10 min, and particularly at most 1.0 g/10 min.
• Sentence 28: The polyethylene film according to any of the preceding sentences, wherein the sealing layer (A) (i) contains, as an ethylene homo- or copolymer (a ₁ ), an LDPE with a weight fraction based on the total weight of the sealing layer (A) in the range of 50 ± 17.5 wt.%; preferably 50 ± 15 wt.%, more preferably 50 ± 12.5 wt.%, even more preferably 50 ± 10 wt.%, most preferably 50 ± 7.5 wt.% and in particular 50 ± 5 wt.%; and (ii) as an ethylene homo- or copolymer (a ₂ ) an LLDPE with a weight fraction based on the total weight of the sealing layer (A) in the range of 40 ± 17.5 wt.% contains; preferably 40±15 wt.%, more preferably 40±12.5 wt.%, even more preferably 40±10 wt.%, most preferably 40±7.5 wt.% and in particular 40±5 wt.%.
• Sentence 29: The polyethylene film according to one of the preceding sentences, wherein the sealing layer (A), if any, contains at most a total of 12.5 wt.% polymers which are neither LDPE nor LLDPE, based on the total weight of the sealing layer (A); preferably at most 10 wt.%, more preferably at most 7.5 wt.%, even more preferably at most 5 wt.%, most preferably at most 2.5 wt.%, and in particular no polymers at all which are neither LDPE nor LLDPE.
• Sentence 30: The polyethylene film according to any of the preceding sentences, wherein the sealing layer (A) has a thickness in the range of 1.5 to 12.5 µm.
• Sentence 31: The polyethylene film according to any of the preceding sentences, wherein the middle layer (B) (i) contains, as an ethylene homo- or copolymer (b ₁ ), an LDPE with a weight fraction based on the total weight of the middle layer (B) in the range of 45±17.5 wt.%; preferably 45±15 wt.%, more preferably 45±12.5 wt.%, even more preferably 45±10 wt.%, most preferably 45±7.5 wt.% and in particular 45±5 wt.%; (ii) contains, as an ethylene homo- or copolymer (b ₂ ), an LLDPE with a weight fraction based on the total weight of the middle layer (B) in the range of 20±17.5 wt.%; preferably 20±15 wt.%, more preferably 20±12.5 wt.%, even more preferably 20±10 wt.%, most preferably 20±7.5 wt.% and in particular 20±5 wt.%; and (iii) as ethylene homo- or copolymer (b ₃ ) comprising an HDPE with a weight fraction based on the total weight of the middle layer (B) in the range of 30±17.5 wt.%; preferably 30±15 wt.%, more preferably 30±12.5 wt.%, even more preferably 30±10 wt.%, most preferably 30±7.5 wt.% and in particular 30±5 wt.%.
• Sentence 32: The polyethylene film according to one of the preceding sentences, wherein the middle layer (B), if any, contains at most a total of 12.5 wt.% polymers, based on the total weight of the middle layer (B), which are neither LDPE nor LLDPE nor HDPE; preferably at most 10 wt.%, more preferably at most 7.5 wt.%, even more preferably at most 5 wt.%, most preferably at most 2.5 wt.%, and in particular no polymers at all, which are neither LDPE nor LLDPE nor HDPE.
• Sentence 33: The polyethylene film according to one of the preceding sentences, wherein the middle layer (B) has a layer thickness in the range of 3 to 25 µm, preferably 5 to 20 µm.
• Sentence 34: The polyethylene film according to any of the preceding sentences, wherein the sealing layer (C) (i) contains, as an ethylene homo- or copolymer (c ₁ ), an LDPE with a weight fraction based on the total weight of the sealing layer (C) in the range of 50±17.5 wt.%; preferably 50±15 wt.%, more preferably 50±12.5 wt.%, more preferably 50±10 wt.%, most preferably 50±7.5 wt.% and in particular 50±5 wt.%; and (ii) contains, as an ethylene homo- or copolymer (c ₂ ), an LLDPE with a weight fraction based on the total weight of the sealing layer (C) in the range of 40±17.5 wt.%; preferably 40±15 wt.%, more preferably 40±12.5 wt.%, even more preferably 40±10 wt.%, most preferably 40±7.5 wt.% and in particular 40±5 wt.%.
• Sentence 35: The polyethylene film according to one of the preceding sentences, wherein the sealing layer (C), if any, contains at most a total of 12.5 wt.% polymers which are neither LDPE nor LLDPE, based on the total weight of the sealing layer (C); preferably at most 10 wt.%, more preferably at most 7.5 wt.%, even more preferably at most 5 wt.%, most preferably at most 2.5 wt.%, and in particular no polymers at all which are neither LDPE nor LLDPE.
• Sentence 36: The polyethylene film according to any of the preceding sentences, wherein the sealing layer (C) has a thickness in the range of 1.5 to 12.5 µm.
• Sentence 37: The polyethylene film according to one of the preceding sentences, wherein the polyethylene film, if any, contains at most a total of 12.5 wt.% polymers, based on the total weight of the polyethylene film, which are neither LDPE nor LLDPE nor HDPE; preferably at most 10 wt.%, more preferably at most 7.5 wt.%, even more preferably at most 5 wt.%, most preferably at most 2.5 wt.%, and in particular no polymers at all, which are neither LDPE nor LLDPE nor HDPE.
• Sentence 38: The polyethylene film according to one of the preceding sentences, which has a symmetrical layer structure with regard to the sealing layer (A), the middle layer (B) and the sealing layer (C).
• Sentence 39: The polyethylene film according to one of the preceding sentences, which, in addition to the sealing layer (A) possibly coated with the release coating, the middle layer (B) and the sealing layer (C), does not comprise any further layers.
• Sentence 40: The polyethylene film according to one of the preceding sentences, which has a total layer thickness of at least 10 µm.
• Sentence 41: The polyethylene film according to one of the preceding sentences, which has a total layer thickness of at most 45 µm, preferably at most 40 µm, more preferably at most 35 µm, most preferably at most 30 µm and in particular at most 25 µm.
• Sentence 42: The polyethylene film according to one of the preceding sentences, wherein the ratio of the layer thicknesses of the sealing layer (A), the middle layer (B) and the sealing layer (C) is in the range of 1:1.5:1 to 1:3.5:1, preferably about 1:2:1.
• Sentence 43: The polyethylene film according to any of the preceding sentences, wherein the sealing layer (A), the middle layer (B) and/or the sealing layer (C) independently contains at least one additive; preferably selected from the group consisting of dyes, fillers such as _CaCO3 ; plasticizers; lubricants; emulsifiers; pigments; rheology additives; catalysts; flow control agents; optical brighteners; light stabilizers; antioxidants; clarifying agents such as substituted or unsubstituted bisbenzylidene sorbites; flame retardants; antistatic agents; UV absorbers such as benzoxazinones; blowing agents; and thiosynergists such as thiodipropionic acid dilauryl esters or thiodipropionic acid distearyl esters.
• Sentence 44: The polyethylene film according to one of the preceding sentences, wherein the polyethylene film contains, if any, a total of at most 5.0 wt.% inorganic components based on the total weight of the polyethylene film; preferably at most 4.5 wt.%, more preferably at most 4.0 wt.%, even more preferably at most 3.5 wt.%, most preferably 3.0 wt.% and in particular at most 2.5 wt.%.
• Sentence 45: The polyethylene film according to any of the preceding sentences, wherein the sealing layer (A) and the sealing layer (C) each have a substantially smooth surface.
• Sentence 46: The polyethylene film according to any one of sentences 1 to 44, which is structured, preferably embossed. Sentence 47: The polyethylene film according to any one of the preceding sentences, which has a total layer thickness in the range of 10 to 25 µm, preferably 10 to 20 µm.
• Sentence 48: The polyethylene film according to one of sentences 1 to 46, which has a total layer thickness in the range of 25 to 40 µm, preferably 20 to 40 µm.
• Sentence 49: The polyethylene film according to one of the preceding sentences, which has a tear force in the machine direction (MD) according to DIN53356 of at least 2.0 N; preferably at least 3.0 N, more preferably at least 4.0 N, even more preferably at least 5.0 N, most preferably at least 6.0 N and in particular at least 7.0 N.
• Sentence 50: The polyethylene film according to one of the preceding sentences, which has a tear force in the machine direction (MD) of at least 2.0 N; preferably at least 3.0 N, more preferably at least 4.0 N, even more preferably at least 5.0 N, most preferably at least 6.0 N and in particular at least 6.5 N.
• Sentence 51: The polyethylene film according to one of the preceding sentences, wherein the release coating has a basis weight of at most 0.65 g/ ^m² ; preferably at most 0.60 g/ ^m² , more preferably at most 0.55 g/ ^m² , even more preferably at most 0.50 g/ ^m² , most preferably at most 0.45 g/ ^m² , and in particular at most 0.40 g/ ^m² ; preferably at most 0.35 g/ ^m² , more preferably at most 0.30 g/ ^m² , even more preferably at most 0.25 g/ ^m² , most preferably at most 0.20 g/ ^m² .
• Sentence 52: The polyethylene film according to one of the preceding sentences, wherein the release coating is based on at least one cured polysiloxane selected from the group consisting of (i) addition-crosslinked, preferably metal-catalyzed addition-crosslinked, condensation-crosslinked, radically crosslinked, and/or cationically crosslinked polysiloxanes; preferably radically crosslinked polysiloxanes; and/or (ii) polydialkylsiloxanes, preferably polydimethylsiloxanes; and polyalkylarylsiloxanes, preferably polymethylphenylsiloxanes; preferably chemically crosslinked acrylate-functionalized polysiloxanes; preferably chemically crosslinked acrylate-functionalized polydialkylsiloxanes, preferably chemically crosslinked acrylate-functionalized polydimethylsiloxanes; or chemically cross-linked acrylate-functionalized polyalkylarylsiloxanes, preferably chemically cross-linked acrylate-functionalized polymethylphenylsiloxanes. Sentence 53: The polyethylene film according to one of the preceding sentences, wherein the polyethylene film is blown film co-extruded.
• Sentence 54: The polyethylene film according to any of the preceding sentences, wherein the sealing layer (A) is at least partially printed with a printed image on its outer surface.
• Sentence 55: The polyethylene film according to Sentence 54, wherein the sealing layer (A) is additionally coated at least partially with a release coating on its outer surface.
• Sentence 56: The polyethylene film according to Sentence 55, wherein there are surface sections which are both printed with a printed image and coated with a release coating, and wherein the printed image is arranged between the outside of the sealing layer (A) and the release coating.
• Sentence 57: The polyethylene film according to one of the preceding sentences, wherein the sealing layer (C) is at least partially printed with a printed image on its outer surface.
• Sentence 58: Use of a polyethylene film according to one of the preceding sentences for packaging hygiene articles; preferably sanitary napkins or tampon applicators.
• Sentence 59: A package comprising a hygiene article as the packaged item, preferably a sanitary napkin or a tampon applicator, and a polyethylene film according to any of sentences 1 to 57 as the packaging material.

The following examples serve to illustrate the invention, but are not to be interpreted restrictively:

Example B1 according to the invention:

A three-layer polyethylene film B1 according to the invention was produced by blown film coextrusion. The polyethylene film according to the invention had a total density of 0.963 g/ ^cm³ , a layer thickness ratio of 1:2:1, and the following layer structure: # % by weight polymer Density g/ ^cm³ (A) 50.0 (a ₁ ) LDPE 0.923 41.0 (a ₂ ) LLDPE 0.940 7.5 Masterbatch ¹ 1,800 1.5 Masterbatch ² 0.920 (B) 43.3 (b ₁ ) LDPE 0.923 20.0 (b ₂ ) LLDPE 0.940 32.0 (b ₃ ) HDPE 0.955 4.7 Masterbatch ³ 1,980 (C) 50.0 (c ₁ ) LDPE 0.923 41.0 (c ₂ ) LLDPE 0.940 7.5 Masterbatch ¹ 1,800 1.5 Masterbatch ² 0.920 ¹ LDPE, with 70% chalk (prevents clogging, improves whiteness and opacity) ² LDPE with <10% PDMS ³ LDPE with 70% _TiO2 (improves whiteness and opacity)

The polyethylene film B1 contained exclusively LDPE, LLDPE, and HDPE as polymers, i.e., entirely ethylene homo- or copolymers. Furthermore, the polyethylene film contained only a small proportion of inorganic components, making it not only pure in type but also highly recyclable overall.

Comparison example V1:

A three-layer reference film V1 was produced by blown film coextrusion. The reference film had a total density of 0.964 g/ ^cm³ , a layer thickness ratio of 1:2:1, and the following layer structure: # % by weight polymer Density g/ ^cm³ (A) 50.0 (a ₁ ) LDPE 0.923 41.0 (a ₂ ) LLDPE 0.940 7.5 Masterbatch ¹ 1,800 1.5 Masterbatch ² 0.920 (B) 30.0 (b ₂ ) LLDPE 0.940 45.3 (b ₃ ) HDPE 0.955 20.0 PP random copolymer 0.900 4.7 Masterbatch ³ 1,980 (C) 50.0 (c ₁ ) LDPE 0.923 41.0 (c ₂ ) LLDPE 0.940 7.5 Masterbatch ¹ 1,800 1.5 Masterbatch ² 0.920 ¹ LDPE, with 70% chalk (prevents clogging, improves whiteness and opacity) ² LDPE with <10% PDMS ³ LDPE with 70% _TiO2 (improves whiteness and opacity)

The polyolefin film V1 contained significant amounts of polypropylene copolymer in the middle layer (B), which is why it is neither pure nor easily recyclable.

Comparison example V2:

A three-layer reference film V2 was produced by blown film coextrusion. The reference film had a total density of 0.960 g/ ^cm³ , a layer thickness ratio of 1:2:1, and the following layer structure: # % by weight polymer Density g/ ^cm³ (A) 47.0 (a ₁ ) LDPE 0.923 42.0 (a ₂ ) LLDPE 0.940 10.0 Masterbatch ¹ 1,800 1.0 Masterbatch ⁴ 0.940 (B) 43.3 (b ₁ ) LDPE 0.923 20.0 (b ₂ ) LLDPE 0.940 32.0 PP Impact Copolymer 0.897 4.7 Masterbatch ³ 1,980 (C) 47.0 (c ₁ ) LDPE 0.923 42.0 (c ₂ ) LLDPE 0.940 10.0 Masterbatch ¹ 1,800 1.0 Masterbatch ⁴ 0.940 ¹ LDPE, with 70% chalk (prevents clogging, improves whiteness and opacity) ³ LDPE with 70% _TiO2 (improves whiteness and opacity) ⁴ LDPE with 5% PFAS (per- and perfluoroalkyl substances).

The polyolefin film V2 contained significant amounts of polypropylene copolymer in the middle layer (B), which is why it is neither pure nor easily recyclable.

Characteristics:

Numerous properties of the polyethylene film B1 according to the invention, as well as of the two comparison films V1 and V2, were determined. The results are summarized in the following table: V1 V2 B1 DIN527-3 Machine direction (MD) : - E modulus [N/ ^mm² ] 381.4 294 352.1 - Force at 1% elongation [N] 1.7 1.4 1.6 - Force at 2.5% elongation [N] 3.6 3.2 3.6 - Force at 5% elongation [N] 5.1 5.1 5.4 - Force at 10% elongation [N] 6.2 6.9 6.9 - Force at 25% elongation [N] 7.7 10.1 10.1 - Elongation at break [%] 234.9 147.3 114.4 - Breaking force [N] 10.3 13 13.3 - Tensile strength [N/ ^mm² ] 10.3 37.5 40 - Total thickness [µm] 21 23 22 DIN527-3 Transverse direction (CD) : - E modulus [N/ ^mm² ] 522 368.4 454.1 - Force at 1% elongation [N] 2.1 1.6 2 - Force at 2.5% elongation [N] 4 3.1 3.8 - Force at 5% elongation [N] 5 3.9 4.8 - Force at 10% elongation [N] 4.6 4 4.2 - Force at 25% elongation [N] 3.6 3.1 3.3 - Elongation at break [%] 766.9 693 775 - Breaking force [N] 7.3 6 6.5 - Tensile strength [N/ ^mm² ] 25.3 18.1 20 - Total thickness [µm] 19 22 22 DIN53356 Tear force leg : - Machine direction (MD) [N] 0.3 0.1 7.3 - Transverse direction (CD) [N] 5.2 4.2 4.4 DIN53363 Tear strength trapezoid: - Machine direction (MD) [N] 4.2 4.2 6.9 - Transverse direction (CD) [N] 11.1 12.3 11.3 Shrink oil bath 1 min : - Machine direction (MD) at 120°C [%] -13 -13 -16 - Transverse direction (CD) at 120°C [%] +2.5 +2.5 +2.5 - Machine direction (MD) at 130°C [%] -37.5 -22.5 -40 - Transverse direction (CD) at 130°C [%] -3 +1 -3 - Machine direction (MD) at 140°C [%] -67.5 -25 -65 - Transverse direction (CD) at 140°C [%] -10 +2.5 -5 Seal behavior : Process window [°C]: <10 ~5 ~15 Process capability : medium medium very good Punching behavior : Evaluation of cut edges medium/good medium very good

As the experimental data in the table above demonstrate, the polyethylene films according to the invention exhibit very good tensile strength in the machine direction (MD) at high modulus of elasticity, which is particularly evident from the force values at 1%, 2% and 5%.

Furthermore, the polyethylene films according to the invention exhibit a significantly improved tear resistance in the machine direction (MD), as shown by the values for the tear force according to DIN53356 (leg) and according to DIN53363 (trapezoid).

Furthermore, the polyethylene films according to the invention exhibit improved sealing properties, as evidenced by the wider temperature range of the processing window. This is particularly surprising because the composition of the two outer sealing layers (A) and (C) is not the cause, as it has not been changed, but rather the composition of the middle layer (B), which as such does not even form an outer surface of the polyethylene film.

Furthermore, the polyethylene films according to the invention exhibit improved process capability, the evaluation of which cumulatively considers the extrusion performance in kg/h as well as the quality with regard to specks, holes, or embossing defects. The two comparison films are characterized by average process capability, whereby maximum plant performance is not achieved (<85% of the maximum speed in m/min), because specks, holes, and embossing defects occur repeatedly. In contrast, the polyethylene film according to the invention is characterized by very good process capability, whereby maximum plant performance is achieved (>98% to 100% of the maximum speed in m/min), because specks, holes, or embossing defects occur only very rarely, if at all.

Furthermore, the experimental data show that the polyolefin films according to the invention exhibit improved cutting and punching behavior. The cut and punched edges produced during cutting and punching are significantly improved.

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• WO 2017/016660 [0003]
• WO 2017/016661 [0004]
• WO 2022/101299 [0005]

Claims (15)

A multilayer polyethylene film comprising: - an outer sealing layer (A) comprising an ethylene homo- or copolymer (a ₁ ) and optionally an ethylene homo- or copolymer (a ₂ ); - a middle layer (B) comprising an ethylene homo- or copolymer (b ₁ ), an ethylene homo- or copolymer (b ₂ ) and optionally an ethylene homo- or copolymer (b ₃ ); and - an outer sealing layer (C) comprising an ethylene homo- or copolymer (c ₁ ) and optionally an ethylene homo- or copolymer (c ₂ ); wherein - the polyethylene film has a total layer thickness of not more than 50 µm; - the middle layer (B), if any, contains less than 15 wt% propylene homo- or copolymers by weight of the middle layer (B); and - optionally, the sealing layer (A) is at least partially coated with a release coating. The polyethylene film after Claim 1 , wherein the ethylene homo- or copolymers (a ₁ ), (a ₂ ), (b ₁ ), (b ₂ ), (b ₃ ), (c ₁ ) and (c ₂ ) are each independently selected from the group consisting of - low-density polyethylene (LDPE, ρ ≤ 0.945 g/cm ³ ), - linear low-density polyethylene (LLDPE, ρ ≤ 0.945 g/cm ³ ), and - high-density polyethylene (HDPE ρ > 0.945 g/cm ³ ). The polyethylene film according to one of the preceding claims, wherein the sealing layer (A) - as an ethylene homo- or copolymer (a ₁ ) contains an LDPE with a weight fraction based on the total weight of the sealing layer (A) in the range of 50±17.5 wt.%; preferably 50±15 wt.%, more preferably 50±12.5 wt.%, even more preferably 50±10 wt.%, most preferably 50±7.5 wt.% and in particular 50±5 wt.%; and - as an ethylene homo- or copolymer (a ₂ ) contains an LLDPE with a weight fraction based on the total weight of the sealing layer (A) in the range of 40±17.5 wt.%; preferably 40±15 wt.%, more preferably 40±12.5 wt.%, even more preferably 40±10 wt.%, most preferably 40±7.5 wt.% and in particular 40±5 wt.%. The polyethylene film according to one of the preceding claims, wherein the middle layer (B) - as an ethylene homo- or copolymer (b ₁ ) contains an LDPE with a weight fraction based on the total weight of the middle layer (B) in the range of 45±17.5 wt.%; preferably 45±15 wt.%, more preferably 45±12.5 wt.%, even more preferably 45±10 wt.%, most preferably 45±7.5 wt.% and in particular 45±5 wt.%; - as an ethylene homo- or copolymer (b ₂ ) contains an LLDPE with a weight fraction based on the total weight of the middle layer (B) in the range of 20±17.5 wt.%; preferably 20±15 wt.%, more preferably 20±12.5 wt.%, even more preferably 20±10 wt.%, most preferably 20±7.5 wt.% and in particular 20±5 wt.%; and - as ethylene homo- or copolymer (b ₃ ) contains an HDPE with a weight fraction based on the total weight of the middle layer (B) in the range of 30±17.5 wt.%; preferably 30±15 wt.%, more preferably 30±12.5 wt.%, even more preferably 30±10 wt.%, most preferably 30±7.5 wt.% and in particular 30±5 wt.%. The polyethylene film according to one of the preceding claims, wherein the middle layer (B), if any, contains at most 12.5 wt.% polymers based on the total weight of the middle layer (B), which are neither LDPE nor LLDPE nor HDPE; preferably at most 10 wt.%, more preferably at most 7.5 wt.%, even more preferably at most 5 wt.%, most preferably at most 2.5 wt.%, and in particular no polymers at all, which are neither LDPE nor LLDPE nor HDPE. The polyethylene film according to one of the preceding claims, wherein the sealing layer (C) - as an ethylene homo- or copolymer (c ₁ ) contains an LDPE with a weight fraction based on the total weight of the sealing layer (C) in the range of 50±17.5 wt.%; preferably 50±15 wt.%, more preferably 50±12.5 wt.%, even more preferably 50±10 wt.%, most preferably 50±7.5 wt.% and in particular 50±5 wt.%; and - as an ethylene homo- or copolymer (c ₂ ) contains an LLDPE with a weight fraction based on the total weight of the sealing layer (C) in the range of 40±17.5 wt.%; preferably 40±15 wt.%, more preferably 40±12.5 wt.%, even more preferably 40±10 wt.%, most preferably 40±7.5 wt.% and in particular 40±5 wt.%. The polyethylene film according to one of the preceding claims, wherein the polyethylene film contains, if any, at most a total of 12.5 wt.% polymers based on the total weight of the polyethylene film which are neither LDPE nor LLDPE nor HDPE; preferably at most 10 wt.%, more preferably at most 7.5 wt.%, even more preferably at most 5 wt.%, most preferably at most 2.5 wt.%, and in particular no polymers at all which are neither LDPE nor LLDPE nor HDPE. The polyethylene film according to one of the preceding claims, which has a symmetrical layer structure with regard to the sealing layer (A), the middle layer (B) and the sealing layer (C). The polyethylene film according to one of the preceding claims, which, in addition to the sealing layer (A) optionally coated with the release coating, the middle layer (B) and the sealing layer (C), does not comprise any further layers. The polyethylene film according to one of the preceding claims, which has a total layer thickness of at least 10 µm. The polyethylene film according to one of the preceding claims, which has a total layer thickness of at most 45 µm, preferably at most 40 µm, more preferably at most 35 µm, most preferably at most 30 µm and in particular at most 25 µm. The polyethylene film according to one of the preceding claims, wherein the ratio of the layer thicknesses of the sealing layer (A), the middle layer (B) and the sealing layer (C) is in the range of 1:1.5:1 to 1:3.5:1, preferably about 1:2:1. The polyethylene film according to one of the preceding claims, wherein the polyethylene film contains, if any, a maximum of 5.0 wt.% inorganic components based on the total weight of the polyethylene film; preferably a maximum of 4.5 wt.%, more preferably a maximum of 4.0 wt.%, even more preferably a maximum of 3.5 wt.%, most preferably 3.0 wt.% and in particular a maximum of 2.5 wt.%. Use of a polyethylene film according to one of the preceding claims for packaging hygiene articles; preferably sanitary napkins or tampon applicators. A package comprising a hygiene product as the packaged item, preferably a sanitary napkin or a tampon applicator, and a polyethylene film according to one of the Claims 1 until 13 as packaging material.