Flexible multilayer films with high and low temperature impact strength for medical packaging

Abstract

A heat-sterilizable multilayer film with high and low temperature impact strength for medical packaging, comprising (a) a first polymer layer (A) comprising a polypropylene homopolymer modified with an impact modifier; (b) a second polymer layer (B) comprising B1) 51%-68% by weight of a polypropylene terpolymer; B2) 12%-22% by weight of a styrene block copolymer elastomer; B3) 15%-35% by weight of a propylene-ethylene copolymer; and (c) a central polymer layer (C) comprising C1) 20%-30% by weight of a styrene block copolymer elastomer; C2) 15%-30% by weight of a polyethylene elastomer; and C3) 40%-65% by weight of a propylene-ethylene copolymer.

Description

Technical Field

[0001] This invention relates to heat-sterilizable multilayer films based on aliphatic polyolefins, which have particularly good impact strength at relatively low temperatures, methods for producing said films, and the use of said films in medical packaging. Background Technology

[0002] For many years, multilayer films have had a wide range of applications, not only in the food industry but also in the medical / pharmaceutical industry, such as as primary or secondary packaging materials (overpackaging) for drugs in solution bags, dry concentrates and tablet forms.

[0003] Some multilayer films can be processed into flexible packaging, such as bags suitable for packaging and dispensing pharmaceutical solutions. Pharmaceutical solutions packaged in disposable flexible bags made of polyvinyl chloride (PVC) or non-PVC materials, such as infusion solutions for intravenous administration, are currently considered standard practice in the market.

[0004] The aforementioned bags not only need to be collapsible to ensure complete drainage, but also need to exhibit other performance standards such as transparency, be able to undergo steam sterilization at 121°C, possess sufficient mechanical strength, particularly under dynamic loads in the weld area, have a good water vapor barrier, load-bearing capacity for standard pressure cuff applications, such as pressure infusion, and, from a pharmaceutical perspective, minimize the impact of the packaging on the contents. Multilayer films with a polyolefin-based layered structure have been found to be advantageous in terms of these properties.

[0005] U.S. Patent 5,681,627 describes a multilayer film for medical applications such as medical bags, comprising: a) a first outer layer containing polyurethane (PU); b) a second outer layer (the inner surface of the bag, a sealing layer), preferably composed of a mixture of PP homopolymer or copolymer and elastomer; and c) a central layer composed of a polymeric tackifier, preferably an ethylene / α-olefin copolymer. Preferably, the second outer layer used is a mixture of propylene / ethylene copolymer (80%) and SEBS block copolymer (20%).

[0006] U.S. Patent 5,695,840 describes a five-layer multilayer film for medical applications such as medical bags, comprising: a) a first layer (inner surface of the bag, sealing layer) composed of a mixture of PP homopolymer or copolymer and elastomer; b) a second (center) layer adjacent to a) composed of ethylene / α-olefin copolymer; c) a third (center) layer adjacent to b) (ethylene / α-olefin copolymer); d) a fourth layer adjacent to c) that promotes adhesion (an anhydride-modified copolymer); and e) a fifth layer (outer layer) composed of polyamide or copolyester.

[0007] US Patent 5,783,269 discloses a heat-sterilizable multilayer film for preparing medical bags, comprising an outer layer (2), a support layer (4), and a flexible intermediate layer (3) with or without a heat-sealing layer (5), wherein all layers contain polyolefin homopolymers and / or polyolefin copolymers (softening temperatures: (2) and (4) > 121°C, (3) < 70°C). The four-layer film of the embodiment consists of (2) and (4) PP homopolymers, (3) PE or PP copolymers, and (5) PP copolymers.

[0008] EP-A 0229475 describes a multilayer film for medical containers, preferably a three-layer multilayer film comprising (a) a first (inner) heat-sealing layer composed of (i) polypropylene, (ii) an ethylene copolymer, and (iii) a modifier, such as another ethylene copolymer or an elastomer (e.g., EPDM terpolymer, SBS, SEBS, and SIS copolymer); (b) a second (center) layer composed of (i) polyethylene (PE) (50%-90% by weight) and (ii) a modifier; and (c) a third (outer) layer composed of (i) polypropylene and (ii) a modifier. The outer layer preferably uses a modified PP copolymer.

[0009] EP-A 0199871 describes a flexible multilayer film for medical bags, particularly a three-layer multilayer film comprising (a) an inner sealing layer containing (optionally modified) an ethylene-propylene copolymer (ethylene content: 3.8% by weight); (b) an intermediate layer composed of a flexible polymer material (such as an elastomer copolymer or a terpolymer, such as EPDM); and (c) an outer layer containing an ethylene-propylene copolymer.

[0010] DE-A 10361851 and WO2020 / 127227A1 describe a heat-sterilizable three-layer multilayer film for preparing medical bags, wherein the outer layer consists of a polypropylene homopolymer modified with an impact modifier (at least 70% by weight, 97% by weight in the examples), the middle layer consists of a polypropylene terpolymer modified with an impact modifier, and the (sealable) inner layer consists of a polypropylene terpolymer and / or a polypropylene copolymer modified with an impact modifier. Suitable impact modifiers include styrene-ethylene / butene (SEBS) block copolymers, styrene-ethylene / propylene (SEPS) block copolymers, or ethylene / α-olefin copolymers. The middle layer may contain 20%-80% by weight of a PP terpolymer, 0%-40% by weight of a polyethylene copolymer, and 0%-60% by weight of an SEB block copolymer or a SEP block copolymer. In the embodiments, the central layer of the film consists of 75% by weight of PP terpolymer, 20% by weight of SEBS block copolymer and 5% by weight of PE plastisol (ethylene / octene copolymer), and the inner layer consists of 85% or 75% by weight of PP terpolymer, 15% or 20% by weight of SEB block copolymer and 0% or 5% by weight of PE plastisol.

[0011] DE20320212A1 describes a heat-sterilizable three-layer multilayer film for medical bags, prepared by co-extrusion. The outer layer of the film in this embodiment consists of 97% by weight of polypropylene homopolymer and 3% by weight of SEBS block copolymer; the middle layer consists of 80% by weight of EXCELLEN, a heterogeneous copolymer based on polypropylene and polyethylene, and 20% by weight of SEBS block copolymer; and the inner layer consists of 75% by weight of PP terpolymer, 20% by weight of SEBS block copolymer, and 5% by weight of PE plasmon.

[0012] While existing films have achieved good results in terms of flexibility, heat sterilization capability and transparency, there is still room for improvement, especially in terms of impact strength, particularly at relatively low temperatures, ranging from 4°C to -70°C in many cases, and especially from -18°C to -40°C, and their applicability to medical packaging stored in refrigerators or freezers is limited.

[0013] Materials used in deep-freezing applications on the market are primarily packaging materials (e.g., bags) made of pure polyethylene (e.g., for food) or polyvinyl chloride (e.g., for plasma). PE bags have very good low-temperature impact strength, but a disadvantage is that they are not suitable for the 121°C heat sterilization required for medical films.

[0014] PVC-containing materials are considered harmful to health because they often contain plasticizers that frequently leak, so there has been a constant search for alternative materials to replace PVC. This is especially true for medical packaging and packaging stored in refrigerators or freezers. Summary of the Invention

[0015] Therefore, the object of this invention is to provide a heat-sterilizable multilayer film for medical packaging requiring particularly good low-temperature impact strength, which does not have the aforementioned disadvantages. Furthermore, the multilayer film or packaging made therefrom retains various properties, such as high transparency, the ability to be steam-sterilized at 121°C, sufficient mechanical strength, especially under dynamic loads in the welded areas, a good water vapor barrier, load-bearing capacity for standard pressure cuff applications, such as pressure infusion, and bag collapse resistance.

[0016] Another object of the present invention is to provide a method for preparing the heat-sterilizable multilayer film, and in particular a method for preparing a film sleeve based on the heat-sterilizable multilayer film.

[0017] This invention provides a heat-sterilizable multilayer film, comprising (and composed of):

[0018] a) A first polymer layer (A), comprising (consisting of) at least one, preferably an impact modifier, modified by at least one, preferably an impact modifier, preferably a polypropylene homopolymer;

[0019] b) A second polymer layer (B), comprising (and consisting of):

[0020] B1) Based on (B), at least one polypropylene terpolymer comprising 51%-68% by weight;

[0021] B2) Based on (B), at least one styrene block copolymer (SBC) elastomer in a weight percentage of 12%-22%;

[0022] B3) Based on (B), at least one propylene-ethylene (block) copolymer comprising 15%-35% by weight, wherein, based on (B3), the ethylene structural units comprise ≥9% by weight, typically 9%-15% by weight, preferably ≥10% by weight; and

[0023] c) A central polymer layer (C) located between the first polymer layer (A) and the second polymer layer (B), comprising (and consisting of):

[0024] C1) Based on (C), at least one styrene block copolymer (SBC) elastomer in a weight percentage of 20%-30%;

[0025] C2) Based on (C), at least one polyethylene elastomer comprising 15%-30% by weight, wherein the elastomer is a copolymer of ethylene and an α-olefin containing 4-12 carbon atoms;

[0026] C3) is at least one propylene-ethylene (block) copolymer based on (C), comprising 40%-65% by weight, wherein the ethylene structural unit based on (C3) comprises ≥9% by weight, typically 9%-15% by weight, preferably ≥10% by weight.

[0027] In each case, the percentages expressed as a weight percentage add up to 100% by weight.

[0028] In the context of this invention, the structural units of monomers in (co)polymers should be understood as structural units derived from monomers incorporated through polymerization.

[0029] The term "heat-sterilizable" refers to materials that can be sterilized at high temperatures, preferably by steam sterilization. Sterilization refers to the method of removing live microorganisms from materials and articles. The resulting state of the materials and articles is called "sterile." In the case of steam sterilization of filled or unfilled medical packaging, hot steam is used, and steam sterilization is usually carried out in an autoclave. This involves heating the medical packaging to 121°C at a pressure of 2 bar in steam, preferably for 20 minutes. The air inside the autoclave is completely replaced by steam.

[0030] The term "multilayer film" refers to a film formed by multiple co-extruded polymer layers of thermoplastic material bonded together in the form of a flowing web or sleeve.

[0031] The term "impact modifier" refers to polymeric materials, such as styrene block copolymer elastomers, polyethylene elastomers, and polypropylene elastomers, which, when mixed in the molten state, increase the impact strength of the polymer surrounding the impact modifier.

[0032] The term "impact strength" refers to the ability of a material to withstand dynamic loads. The Izod impact strength of plastics can be determined under specified conditions according to the standard DIN EN ISO 180:2013-08. Detailed Implementation

[0033] First polymer layer (A)

[0034] By definition, the first polymer layer (A) of the multilayer film of the present invention is the polymer layer located on the outside of the packaging when the film is processed into packaging, preferably a bag. Therefore, when the film is further processed into packaging, it comes into direct contact with the surface of the welding tool, and thus a higher melting / softening temperature is preferably required, preferably above 125°C, particularly preferably 127°C-150°C, and very particularly preferably 130°C-145°C.

[0035] The first polymer layer (A) comprises at least one, preferably a polypropylene homopolymer, which is modified by at least one, preferably an impact modifier.

[0036] Preferably, the first polymer layer (A) is composed of at least one, more preferably one, polypropylene homopolymer modified by at least one, more preferably one impact modifier.

[0037] More preferably, the first polymer layer (A) comprises a polypropylene homopolymer modified by an impact modifier.

[0038] The first polymer layer (A) comprises (or consists of) at least one, preferably a polypropylene homopolymer, which is typically modified by at least one impact modifier at a weight percentage of 1%-30%, preferably 2%-20%, particularly preferably 2%-10%, especially 3%-5% to improve (low-temperature) impact strength.

[0039] The preparation of polypropylene homopolymers is known. Furthermore, polypropylene homopolymers can be purchased, for example, from LyondellBasell Corporation in the United States.

[0040] Preferably, the first polymer layer (A) comprises (or consists of) a polypropylene homopolymer modified with at least one impact modifier selected from styrene block copolymers, such as styrene-ethylene-butene-styrene block copolymer (SEBS), styrene-ethylene-propylene-styrene block copolymer (SEPS), styrene-isoprene-styrene block copolymer (SIS), and styrene-butadiene-styrene block copolymer (SBS), preferably SEBS and SEPS, especially SEBS; and / or selected from copolymers of ethylene with at least one α-olefin containing 4-16, preferably 4-12, particularly preferably 4-8 carbon atoms, such as ethylene-butene copolymer and / or ethylene-octene copolymer.

[0041] Particularly preferably, the first polymer layer (A) comprises (or consists of) 90%-98%, particularly 95%-97% by weight, of polypropylene homopolymer and 2%-10%, particularly 3%-5% by weight, of styrene block copolymer and / or copolymer of ethylene with at least one α-olefin containing 4-12, preferably 4-8 carbon atoms.

[0042] In a preferred embodiment, the first polymer layer (A) comprises (or consists of) 95%-97% by weight of polypropylene homopolymer and 3%-5% by weight of styrene-ethylene / butene block copolymer.

[0043] The weight specified for the components of the first polymer layer (A) is based on the total weight of the first polymer layer (A).

[0044] Second polymer layer (B)

[0045] By definition, the second polymer layer (B) is the polymer layer located inside the packaging bag when the multilayer film of the present invention is processed into a package, preferably a bag. This polymer layer can tightly seal the package by heat sealing. The second polymer layer (B) of the film needs to be heat-sealed securely with itself and the properly inserted port elements at the lowest possible temperature and the shortest possible welding time, and can be heat-sterilized at temperatures above 121°C. Low welding temperatures are particularly important for minimizing structural stress on the film structure. Therefore, the melting / softening temperature of the second polymer layer (B) is generally above 121°C, preferably 122°C-135°C, particularly preferably 124°C-130°C, but in any case lower than the melting / softening temperature of the first polymer layer (A).

[0046] The second polymer layer (B) of the multilayer thin film according to the present invention comprises (or consists of) components B1), B2) and B3 in the following proportions (based on (B) in each case):

[0047] B1) 51%-68% by weight, preferably 55%-67% by weight, and particularly preferably 56%-66% by weight;

[0048] B2) 12%-22% by weight, preferably 13%-21% by weight, and particularly preferably 14%-20% by weight;

[0049] B3) 15%-35% by weight, preferably 17%-32% by weight, and particularly preferably 18%-30% by weight.

[0050] Component B1)

[0051] Component B1) is at least one, preferably a polypropylene terpolymer.

[0052] The term "terpolymer" refers to a copolymer made from three different monomers.

[0053] The term "polypropylene terpolymer" refers to a polypropylene molecular chain modified with two other comonomers during the polymerization process. Preferred other comonomers are ethylene and / or at least one C4-C copolymer. 12 α-olefins, preferably ethylene and a C4-C 12 α-olefins, particularly preferably ethylene and a C4-C8 α-olefin, very particularly preferably ethylene and 1-butene.

[0054] Preferably, B1) is propylene, ethylene, and C4-C 12 Terpolymers of α-olefins, in each case based on (B1), wherein the proportion of ethylene is preferably 1%-4% by weight, C4-C 12 The proportion of α-olefins, preferably C4-C8 α-olefins, especially 1-butene, is preferably 9%-12% by weight.

[0055] In each case, the weight percentage is based on the structural units of the monomer incorporated into the terpolymer (B1) through polymerization.

[0056] Very particularly preferred, the polypropylene terpolymer (component B1) is composed of structural units of propylene, ethylene and butene.

[0057] Monomers are generally randomly incorporated into polypropylene terpolymers (= component B1), i.e., polypropylene terpolymer B1 is usually a random polypropylene terpolymer.

[0058] The polypropylene terpolymer B1) was modified with impact modifier components B2) and B3) to improve its impact strength, especially at low temperatures.

[0059] Component B2)

[0060] Component B2) is at least one, preferably a styrene block copolymer (SBC) elastomer.

[0061] The term "styrene block copolymer elastomer" refers to a synthetic thermoplastic elastomer based on styrene block copolymers used for impact modification of polypropylene.

[0062] The at least one styrene block copolymer (SBC) elastomer B2 is preferably selected from: styrene-ethylene-butene-styrene block copolymer (SEBS), styrene-ethylene-ethylene-propylene-styrene block copolymer (SEPS), styrene-ethylene-ethylene-propylene-styrene block copolymer (SEEPS), styrene-isoprene-styrene block copolymer (SIS), and styrene-butadiene-styrene block copolymer (SBS), with SEBS and SEPS being particularly preferred, especially SEBS.

[0063] The styrene block copolymer (SBC) elastomer can also be partially replaced by one or more thermoplastic olefin elastomers (TPE-O) (TPE-O accounts for no more than 45% by weight, preferably 20%-30% by weight).

[0064] Preferably, component B2) is a styrene block copolymer (SBC) elastomer that does not contain any proportion of thermoplastic olefin elastomer.

[0065] Component B3)

[0066] Component B3) is at least one, preferably a propylene-ethylene (block) copolymer, wherein, based on (B3), the weight percentage of the structural units of ethylene is ≥9%, typically 9%-15% by weight, preferably ≥10% by weight, and more preferably 10%-12% by weight.

[0067] Propylene-ethylene copolymer (B3) is also commonly referred to as a "heterogeneous" copolymer. Generally speaking, propylene-ethylene copolymer (B3) is a propylene-ethylene block copolymer with ethylene and propylene polymer blocks, thus forming a heterogeneous phase (morphology).

[0068] Heterogeneous propylene-ethylene (block) copolymer (B3) differs in composition (the proportion of ethylene structural units ≥ 9% by weight) and properties from propylene-ethylene copolymers with two monomers randomly distributed (not used as component B3 according to the present invention), wherein the proportion of ethylene structural units generally does not exceed 8% by weight, and in most cases does not exceed 5% by weight. Such randomly distributed propylene-ethylene copolymers typically form a homogeneous phase (morphology).

[0069] Preferably, the second polymer layer (B) according to the invention comprises (or is composed of): a polypropylene terpolymer composed of structural units of propylene, ethylene and butene (component B1), a styrene-ethylene-butene-styrene block copolymer (SEBS) (component B2), and a propylene-ethylene (block) copolymer (component B3).

[0070] Particularly preferably, the second polymer layer (B) according to the invention comprises (or is composed of):

[0071] B1) 55%-67% by weight, preferably 56%-66% by weight, of a polypropylene terpolymer composed of structural units of propylene, ethylene and butene;

[0072] B2) 13%-21% by weight, preferably 14%-20% by weight, of styrene-ethylene-butene-styrene block copolymer (SEBS); and

[0073] B3) 17%-32% by weight, preferably 18%-30% by weight, of propylene-ethylene (block) copolymer (component B3).

[0074] The weights specified for components B1), B2) and B3) of the second polymer layer (B) are all based on the total weight of the second polymer layer (B).

[0075] Central polymer layer (C)

[0076] The central polymer layer (C) accounts for the largest proportion of the mass of the multilayer film (at least 50% by weight), preferably 60%-95% by weight, particularly preferably 70%-90% by weight, and very particularly preferably 75%-85% by weight of the entire multilayer film, in order to improve the impact strength of the overall structure.

[0077] The central polymer layer (C) of the multilayer thin film according to the invention comprises (or consists of) components C1), C2) and C3) in the following proportions (based on (C) in each case):

[0078] C1) 20%-30% by weight, preferably 21%-30% by weight, and particularly preferably 22%-27% by weight;

[0079] C2) 15%-30% by weight, preferably 15%-25% by weight, and particularly preferably 17%-23% by weight;

[0080] C3) weight percentage 40%-65%, preferably 45%-65%, particularly preferably 50%-60%, very particularly preferably 52%-57%.

[0081] Component C1)

[0082] Component C1) is at least one, preferably a styrene block copolymer (SBC) elastomer.

[0083] Styrene block copolymer (SBC) elastomer C1) is defined as component B2), therefore relevant discussions on component B2) are referenced.

[0084] Component C2)

[0085] Component C2) is at least one, preferably a polyethylene elastomer, which is a copolymer of ethylene and an α-olefin containing 4-12, preferably 4-8, carbon atoms.

[0086] Based on (C2), the proportion of α-olefin structural units is preferably 20%-30% by weight.

[0087] Particularly preferably, the polyethylene elastomer (C2) is an ethylene-butene copolymer and / or an ethylene-1-octene copolymer, especially an ethylene-1-octene copolymer.

[0088] Component C3)

[0089] Component C3) is at least one, preferably a propylene-ethylene (block) copolymer, wherein, based on (C3), the structural units of ethylene account for ≥9% by weight, typically 9%-15% by weight, preferably ≥10% by weight, and more preferably 10%-12% by weight.

[0090] The propylene-ethylene (block) copolymer C3) is defined as component B3), therefore relevant discussions on component B3) are referenced.

[0091] Preferably, the central polymer layer (C) according to the invention comprises (or consists of): styrene-ethylene-butene-styrene block copolymer (SEBS) (component C1), ethylene-1-octene copolymer (component C2) and propylene-ethylene (block) copolymer (component C3).

[0092] Particularly preferably, the central polymer layer (C) according to the invention comprises (or is composed of):

[0093] C1) 21%-30% by weight, preferably 22%-27% of styrene-ethylene-butene-styrene block copolymer (SEBS);

[0094] C2) 15%-25% by weight, preferably 17%-23% by weight, of ethylene-octene copolymer; and

[0095] C3) 45%-65% by weight, preferably 50%-60% by weight of propylene-ethylene (block copolymer (component C3)).

[0096] The weights specified for components C1), C2) and C3) of the central polymer layer (C) are all based on the total weight of the central polymer layer (C).

[0097] Functional Layer (D)

[0098] The heat-sterilizable multilayer film according to the invention may further include an additional functional layer (D) as an outer layer, which is adjacent to the first polymer layer (A) on the outside of (A), that is, on the other side of (A) opposite to the side having the polymer layer (C).

[0099] The functional layer (D) preferably makes the heat-sterilizable multilayer film and the medical bags or film sleeves made therefrom airtight and / or waterproof.

[0100] Functional layer D) comprises (preferably consists of) at least one, preferably one, material selected from: ethylene-vinyl alcohol copolymer, polyvinyl alcohol, polyamide, liquid crystal polymer (LCP), aromatic polyester, preferably polyester terephthalate, particularly preferably polyethylene terephthalate (PET), and silica (SiO2). x ), aluminum oxide (AlO) x ) and acrylate polymers

[0101] Preferably, the functional layer (D) is made of PET / SiO2. x composition.

[0102] The thickness of the functional layer (D) is preferably 5-25 μm, especially 10-20 μm.

[0103] Made of PET / SiO x The functional layer (D) significantly improves the gas barrier properties (e.g., oxygen barrier) of the heat-sterilizable multilayer film of the present invention, thus making the film also very suitable for the storage of oxygen-sensitive components.

[0104] According to the present invention, SiO x The PET functional layer (D) can reduce the oxygen barrier properties, or oxygen transmissibility (OTR), of heat-sterilizable multilayer films by 1000 times to an OTR value of <1cm. 3 / (m 2 × days)(ASTM F1927(23℃, 50% RH)).

[0105] Multilayer thin films

[0106] Preferably, the heat-sterilizable multilayer film according to the present invention is composed of polymer layers (A), (B) and (C).

[0107] In each polymer layer (A), (B), and (C), the multilayer film may contain conventional additives and / or processing aids in conventional amounts suitable for the intended use of the multilayer film.

[0108] The preferred additives are antioxidants and heat stabilizers (phosphoric acid and phenolic stabilizers, such as...). 168, Irgafos P-EPQ 1076 or Irganox 1010), and acid scavengers, such as Synthetic hydrotalcite (SHT) and magnesium oxide (MgO).

[0109] Preferably, the heat-sterilizable multilayer film composed of polymer layers (A), (B) and (C) according to the present invention contains at least one antioxidant, a heat stabilizer and / or an acid scavenger, the total amount of which is preferably <3000 ppm based on the entire multilayer film.

[0110] Preferably, polymer layers (A), (B), and (C) adhere to each other without the use of tackifiers; that is, the multilayer film of the present invention, composed of polymer layers (A), (B), and (C), preferably does not contain tackifiers. Furthermore, preferably, at least the second polymer layer (B) does not contain other additives and / or processing aids (e.g., modifiers or plasticizers, such as mineral oils), and very particularly preferably, polymer layers (A), (B), and (C) do not contain other additives and / or processing aids besides the aforementioned additives. Therefore, during sterilization and storage, the multilayer film of the present invention, as a packaging material, has little or no effect on pharmaceuticals or medical solutions.

[0111] In the case of the multilayer film of the present invention, which consists of polymer layers (A), (B), (C) and functional layer (D), the multilayer film generally contains tackifiers or pressure-sensitive adhesives in addition to the preferred additives described above.

[0112] The thickness of the first polymer layer (A) is generally 5%-15% of the total thickness of the multilayer film of the present invention by weight, preferably 7%-13% by weight, and particularly preferably 7.5%-10% by weight.

[0113] The thickness of the second polymer layer (B) is generally 5%-15% by weight of the total thickness of the multilayer film of the present invention, preferably 7%-13% by weight, and particularly preferably 7.5%-10% by weight.

[0114] The central polymer layer (C) accounts for the largest proportion of the multilayer film of the present invention (preferably at least 70% by weight of the total film thickness) and is used to improve the impact strength of the overall structure.

[0115] In a multilayer film composed of (A), (B), and (C), the thickness of the central polymer layer (C) is generally 70%-85% by weight, preferably 74%-80% by weight.

[0116] If a functional layer (D) is present, the thickness of the optional functional layer (D) is preferably 2.5%-12.5% ​​by weight of the total thickness of the multilayer film of the present invention, and particularly preferably 5%-10% by weight.

[0117] The total thickness of the multilayer thin film of the present invention is preferably 50-500 μm, particularly preferably 100-400 μm, and very particularly preferably 150-300 μm.

[0118] The total thickness of the multilayer film composed of polymer layers (A), (B) and (C) according to the present invention is preferably 50-500 μm, particularly preferably 100-400 μm, and very particularly preferably 150-300 μm.

[0119] Particularly preferably, the multilayer film according to the invention, composed of polymer layers (A), (B), and (C), is characterized in that the total thickness of the multilayer film is 50-500 μm, particularly preferably 100-400 μm, and in each case, based on the total thickness of the multilayer film, the thickness of the first polymer layer (A) is 5%-15% by weight, preferably 7%-13% by weight; the thickness of the second polymer layer (B) is 5%-15% by weight, preferably 7%-13% by weight; and the thickness of the central polymer layer (C) is 70%-85% by weight, preferably 74%-80% by weight; and in each case, the sum of the proportions of (A), (B), and (C) is equal to 100%.

[0120] Methods for preparing multilayer thin films

[0121] The present invention also provides a method for preparing the multilayer film of the present invention, wherein a first polymer layer (A), a central polymer layer (C), and a second polymer layer (B) are co-extruded.

[0122] Co-extrusion involves bringing together the molten plastic of polymer layers (A), (B), and (C) before they leave the extruder's die to form the multilayer film of the present invention.

[0123] In most cases, the extrusion process is a two-stage process. In the first step, the materials for the individual polymer layers are mixed and compacted in an extruder, preferably a parallel twin-screw extruder (compounder), a heated / cooled mixer, or a tablet press. The plastic melt of polymer layers (A), (B), and (C) is then brought together in another extruder, which may be directly coupled or spatially and temporally separated, and then exits through a die to form the multilayer film of the present invention.

[0124] Preferably, the multilayer film obtained according to the method of the present invention is subjected to water impact cooling.

[0125] Co-extrusion can produce the multilayer film of the present invention in the form of a planar film (planar film method, for example, when using a groove die) or a film sleeve (blown film method, for example, filling the interior of the film sleeve with (preferably sterile filtered) air), in the case of a film sleeve, the exterior is composed of a first polymer layer (A) and the interior is composed of a second polymer layer (B).

[0126] In a further method step, an optional functional layer (D) may be applied, for example, by thermal lamination or preferably by lamination, to a multilayer film obtained by the method of the present invention.

[0127] According to a specific embodiment of the method for preparing the laminated multilayer thin film sleeve of the present invention, the method of the present invention includes the following steps:

[0128] (a') A membrane sleeve made of the multilayer film of the present invention is prepared by blown film method, wherein the membrane sleeve is filled with air, preferably sterile filtered air;

[0129] (b') Optionally, the membrane sleeve obtained in step (a') of the method is cooled;

[0130] (c') The optional cooling membrane sleeve is coated with a pressure-sensitive adhesive layer on at least one side (first polymer layer (A));

[0131] (d') Optionally, the membrane sleeve coated with the pressure-sensitive adhesive layer is dried;

[0132] (e') At least one side of the membrane sleeve coated with a pressure-sensitive adhesive layer (first polymer layer (A)) and the functional layer (D), particularly SiO x / PET functional layers are laminated;

[0133] (f) Optionally, the laminated film sleeve is dried and cured.

[0134] According to the above-described embodiment of the method of the present invention, the two parallel inner sides of the film sleeve (= the second polymer layer (B)) are preferably directly adhered to each other on top after the melt extrusion or co-extrusion of the film sleeve, so that the outer surface of the film sleeve (the first polymer layer (A)) can be coated when the inside of the film sleeve is closed. The closed interior, which is inflated when the resulting film sleeve is subsequently used, is therefore substantially free of particles.

[0135] Preferably, in the above-described embodiments of the method according to the invention, the interior of the membrane sheath is filled with sterile filtered air, thereby maintaining a low particulate content in the laminated multilayer membrane sheath and making it particularly suitable for medical use.

[0136] Particularly preferred is the preparation of low-particle laminated multilayer film sleeves by carrying out the above-described method of the present invention in a cleanroom.

[0137] In the above embodiments of the method according to the invention, it is preferable to use a tackifier that allows complete curing at room temperature for about 2 weeks, preferably 1 week. Curing can also be achieved more quickly at high temperatures in a heated chamber, preferably 30°C or higher, and in most cases 40°C-60°C.

[0138] Suitable tackifiers (pressure-sensitive adhesives, adhesives, or laminating adhesives) include, for example, isocyanates, polyurethanes, poly(ethyl acrylate / methacrylate), pure acrylate copolymers, vinyl ester / acrylate copolymers, or inorganic-organic hybrid polymers.

[0139] The preferred tackifier is a two-component system, which can be solvent-based or solvent-free, silane-based or silane-free, and can be selectively used with other "catalysts" to accelerate curing.

[0140] Suitable solvent-based two-component systems include, for example, polyurethane adhesives, including commercially available systems such as...

[0141] -Dow's ADCOTE TM 675A+ADCOTE TM 675C co-reactants;

[0142] -Dow's ADCOTE 811A + ADCOTE 811B co-reactants;

[0143] - Dow's ADCOTE E735A-75+ADCOTE TM E735C2 co-reactant;

[0144] -MORCHEM's PS241AE+CS-97 co-reactant;

[0145] - Henkel's Loctite Liofol LA2798 + Henkel's Loctite Liofol LA7371;

[0146] - Henkel's Loctite HY 4070 2K blended adhesive.

[0147] The above system can be used selectively with a "catalyst", including those such as Dow's 9L10 (polyisocyanate), 9L200, and F Adcote 40-3E, which are commercially available.

[0148] Suitable solvent-free two-component systems are, for example, polyurethane adhesives, including commercially available systems such as...

[0149] - Dow's Mor-FreeTM L 75-720 adhesive + CR 88-720 or CR 88-721 or MOR-FREE TM C79S co-reactants;

[0150] - Dow's Mor-Free TM 203A Adhesive + MOR-FREE TM 200C co-reactants;

[0151] - Dow's Mor-Free TM L705 Adhesive + MOR-FREE TM C 79 or MOR-FREE TM C-102 co-reactant.

[0152] In addition, the tackifier used can be a single-component system, which can be solvent-based or solvent-free, silane-based or silane-free, and can be selectively used with other "catalysts" to accelerate curing.

[0153] Suitable solvent-free single-component systems are, for example, Dow's MOR-FREE. TM ELM 415A (polyurethane adhesive) or WB film lamination adhesive FP NDC 375224 is commercially available.

[0154] Particularly preferably, the selected adhesive should meet the requirements of pharmacopoeia restrictions, such as regarding migration properties, and preferably be free of organic solvents.

[0155] Depending on the processing method or the desired coating, an adhesive layer can be applied to one or both sides of the film sleeve prepared by a co-extrusion process. This can be achieved by methods such as spraying or blade coating. An aqueous solution of the relevant adhesive is also applicable.

[0156] After the adhesive layer is applied, the resulting film sleeve can be selectively dried. For example, if water is used to apply the adhesive, drying can be achieved through the evaporation of the water. The thickness of the pressure-sensitive adhesive layer is preferably 1-10 μm.

[0157] The present invention also provides the use of the multilayer film of the present invention in the preparation of medical packaging, preferably medical bags.

[0158] The present invention also provides the use of the medical packaging of the present invention as a container for at least one drug.

[0159] The medical packaging according to the invention is particularly suitable as a container for at least one drug, and the multilayer film according to the invention is also particularly suitable for packaging and storing medical solutions at temperatures below zero due to the specially modified polymer layer (C).

[0160] In a preferred embodiment, the packaging according to the invention is subdivided into multiple chambers, thereby allowing it to be used simultaneously as a container for multiple drugs. This is necessary, for example, for drug combinations that must be administered together but are unstable over a long period; or for solid drugs administered in solution or suspension form but unstable in solution or suspension over a long period. The components of the final dosage form can be stored individually in separate chambers and mixed together shortly before administration by opening the dividers.

[0161] A method for preparing the medical packaging, preferably a bag, of the present invention includes the following steps:

[0162] a) Provide at least one heat-sterilizable multilayer film according to the invention;

[0163] b) Optionally, one or more port elements and / or flexible tubes may be provided;

[0164] c) A medical package, preferably a bag, is formed from at least one heat-sterilizable multilayer film, such that a second polymer layer (B) forms the medical package, preferably the inner surface of the bag, while a first polymer layer (A) forms the medical package, preferably the outer surface of the bag.

[0165] d) Optionally, the port element and / or flexible tube are located between the inner surfaces of the medical packaging, preferably at the contour of the bag;

[0166] e) Make the inner surfaces contact each other and make the inner surfaces contact the port elements and / or flexible tubes between the inner surfaces optionally located at the outline of the medical packaging, preferably the bag;

[0167] f) Heat-seal the inner surfaces to each other and heat-seal the inner surfaces to the port elements and / or flexible tubes that are optionally located at the outline of the medical packaging, preferably the bag.

[0168] In step a), the multilayer thin film of the present invention is preferably provided in the form of a planar film or a tubular film. Depending on the form of the provided film, the remainder of the method may vary in specific details. The obtained low-particle film sheath can be combined with a functional layer (D), such as SiO2, through other method steps. x / PET functional layers are laminated.

[0169] In the use of medical packaging according to the invention, a bag is preferred, and after the multilayer film of the invention is provided, additional elements such as port elements and / or flexible tubes may optionally be provided in step b) of the method. Providing these elements is useful, for example, if the medical packaging according to the invention is used, the bag is preferably used as a fixing component of a medical device or attached to a medical device. Omitting step b) may be useful, for example, if the medical packaging is used, the bag is preferably used only for storing medicine and is damaged to remove the medicine, for example, by tearing or puncturing with a cannula.

[0170] In step c), the provided multilayer film of the present invention is made into a medical package, preferably a bag. If a tubular film is provided in step a), the forming of the medical package, preferably a bag, may, for example, consist only of cutting the tubular film to the desired length, since the second polymer layer (B) has formed the inner surface of the tubular film and the first polymer layer (A) has formed the outer surface of the tubular film. If a planar film is provided in step a), the medical package, preferably a bag, may be formed from a single multilayer film in step c), for example, by cutting the film sheet into a mirror-symmetrical shape and folding it downward along the mirror axis, such that the edge of the film is uniformly located on top of another layer, with the second polymer layer (B) located inside. Alternatively, the medical package, preferably a bag, of the present invention may be formed from two planar films, for example, by cutting the two planar films mirror-symmetrically to each other and placing them uniformly on top of each other, with the second polymer layer (B) located inside. Rectangular shapes are particularly suitable for cutting because of minimal material loss and the simplest processing. However, other shapes are also possible; for example, medical packages, preferably bags, can be produced with aesthetically appealing shapes that attract children and distract them from actual drug administration.

[0171] Depending on whether additional elements such as port elements and / or flexible tubes are provided in step b), in step d), the elements are positioned between the inner surfaces of the formed medical packaging, preferably the bag, along its contour. In the case of tubular films, this means inserting the additional elements into the openings of the tubular film. Here, the elements are located only on two opposite sides of the medical packaging, preferably the bag. In the case of planar films, the insertion of the additional elements means that they are uniformly placed between the edges of one or more planar films that are on top of each other in step c). Here, the elements can be located at any point along the edges, but are most preferably placed on two opposite edges.

[0172] In step e), the inner surfaces of the formed medical package, preferably the bag, come into contact with each other and with additional elements between the inner surfaces, optionally located at the contour of the bag, so that the inner surfaces can be sealed together by heat and optionally mechanical pressure provided in step f). For heat sealing, the temperature is preferably above the melting / softening point of the second polymer layer (B), but below the melting / softening point of the first polymer layer (A). This makes it possible to ensure that the second polymer layer (B) melts at the contour of the medical package, preferably the bag, thereby permanently and fluidly sealing together, while the first polymer layer (A) retains its shape, thus maintaining the stability of the medical package, preferably the bag.

[0173] An important criterion for using the multilayer film according to the present invention as the primary packaging material for medical solutions is its barrier function to prevent liquid loss. Such liquid loss will cause changes in the concentration of the active ingredient in the solution, and the liquid loss must not exceed a specific value. Liquid loss during storage determines the shelf life of the product. The formulation of the multilayer film of the present invention is selected to provide good moisture barrier properties and good impact strength.

[0174] The heat-sterilizable multilayer film according to the present invention is characterized by its reliable heat-sealing to port elements even by continuous heat welding without the use of plasticizers, minimal impact on medical solutions, and high water vapor barrier properties. Furthermore, the multilayer film according to the present invention exhibits significantly improved low-temperature impact strength even at temperatures below zero degrees Celsius. Multilayer films with an additional functional layer (D), particularly SiO2, are also included. x The PET functional layer has significantly improved gas barrier properties, which makes it possible to store oxygen-sensitive components.

[0175] The invention will now be described in more detail based on embodiments, and the implementation methods are therefore not limited.

[0176] Example 1

[0177] First polymer layer (A):

[0178] - 97% by weight is from Lyondell Basell Corp., USA. HP525J / Polypropylene homopolymer;

[0179] -3% by weight from Asahi Kasei, Japan H1062 / styrene / butene block copolymer.

[0180] The formulation is mixed in a molten state in a separate compounding step and then granulated for further use.

[0181] Second polymer layer (B):

[0182] -65% by weight from Borealis, Austria TD109CF / polypropylene terpolymer;

[0183] -15% by weight from Asahi Kasei, Japan H1062 / styrene / butene block copolymer;

[0184] - 20% by weight from Borealis, Austria SC 820 CF-11 / Heterogeneous propylene copolymer.

[0185] The formulation is mixed in a molten state in a separate compounding step and then granulated for further use.

[0186] Central polymer layer (C):

[0187] -55% by weight from Borealis, Austria SC 820 CF-11 / heterogeneous propylene copolymer;

[0188] -25% by weight from Asahi Kasei, Japan H1062 / styrene / butene block copolymer;

[0189] -20% by weight from Dow Chemical Company, USA 8003 / Ethylene-Octene Polyolefin Elastomer.

[0190] The formulation is mixed in a molten state in a separate compounding step and then granulated for further use.

[0191] The melt of the first polymer layer (A), the central polymer layer (C), and the second polymer layer (B) is co-extruded on a blown film production line and cooled with water using polypropylene with conventional process parameters (temperature of 180℃-230℃) to obtain a multilayer film in the form of a film sleeve, the inside of which is filled with sterile filtered air.

[0192] The total thickness of the film is 200 μm, of which the thickness of the first polymer layer (A) and the second polymer layer (B) is 15 μm each, and the thickness of the central polymer layer (C) is 170 μm.

[0193] The prepared film can be sterilized with hot steam and can be permanently heat-sealed using welding tools adjusted to 125°C.

[0194] Example 2

[0195] The membrane sleeve prepared according to Example 1 is further provided with SiO on both sides. x / The functional layer (D) is composed of PET (Techbarrier T from Mitsubishi) with a layer thickness of 15 μm on each side.

[0196] First, a two-component adhesive (Dow's ADCOTE 811A+ADCOTE 811B co-reactant and Dow catalyst 9L10, available from Dow Chemical Company) is coated on both sides of the flat membrane sleeve. Then, the adhesive-coated membrane sleeve and the functional layer are laminated on both sides.

[0197] The prepared film can be sterilized with hot steam and permanently heat-sealed using welding tools adjusted to 125°C.

[0198] Example 3 (not based on the present invention)

[0199] First polymer layer (A):

[0200] - 97% by weight is from Lyondell Basell Corp., USA. HP525J / Polypropylene homopolymer;

[0201] -3% by weight from Asahi Kasei, Japan H1062 / styrene / butene block copolymer.

[0202] The formulation is mixed in a molten state in a separate compounding step and then granulated for further use.

[0203] Second polymer layer (B):

[0204] -70% by weight from Borealis, Austria TD109CF / polypropylene terpolymer;

[0205] -15% by weight from Asahi Kasei, Japan H1062 / styrene / butene block copolymer;

[0206] - 15% by weight from Borealis, Austria RD804CF-11 / random propylene copolymer.

[0207] The formulation is mixed in a molten state in a separate compounding step and then granulated for further use.

[0208] Central polymer layer (C):

[0209] -55% by weight from Borealis, Austria TD109CF / polypropylene terpolymer;

[0210] -10% by weight from Borealis, Austria SC 820 CF-11 / heterogeneous propylene copolymer;

[0211] -20% by weight from Asahi Kasei, Japan H1062 / styrene / butene block copolymer;

[0212] -15% by weight from Dow Chemical Company, USA 8003 / Ethylene-Octene Polyolefin Elastomer.

[0213] The formulation is mixed in a melt state in a separate compounding step and then granulated for further use.

[0214] The melt of the first polymer layer (A), the central polymer layer (C), and the second polymer layer (B) is co-extruded on a blown film production line and cooled with water using polypropylene with conventional process parameters (temperature of 180℃-230℃) to obtain a multilayer film in the form of a film sleeve, the inside of which is filled with sterile filtered air.

[0215] The total thickness of the film is 200 μm, of which the thickness of the first polymer layer (A) and the second polymer layer (B) is 15 μm each, and the thickness of the central polymer layer (C) is 170 μm.

[0216] The prepared film can be sterilized with hot steam and can be permanently heat-sealed using welding tools adjusted to 125°C.

[0217] Example 4 (Comparative Example (Example 1 according to DE10361851A1))

[0218] First polymer layer (A):

[0219] - 97% by weight is from Lyondell Basell Corp., USA. HP525J / Polypropylene homopolymer;

[0220] -3% by weight from Asahi Kasei, Japan H1062 / styrene / butene block copolymer.

[0221] The formulation is mixed in a molten state in a separate compounding step and then granulated for further use.

[0222] Second polymer layer (B):

[0223] -85% by weight from Borealis, Austria TD109CF / polypropylene terpolymer;

[0224] -15% by weight from Asahi Kasei, Japan H1062 / Styrene / Butene Block Copolymer

[0225] The formulation is mixed in a molten state in a separate compounding step and then granulated for further use.

[0226] Central polymer layer (C):

[0227] -75% by weight from Borealis, Austria TD109CF / polypropylene terpolymer;

[0228] -20% by weight from Asahi Kasei, Japan H1062 / styrene / butene block copolymer;

[0229] -5% by weight from Dow Chemical Company, USA 800 / Ethylene-Octene Polyolefin Elastomer.

[0230] The formulation is mixed in a molten state in a separate compounding step and then granulated for further use.

[0231] The film is co-extruded on the blown film production line and cooled with water using polypropylene with standard process parameters.

[0232] The total thickness of the film is 200 μm, of which the thickness of the first polymer layer (A) and the second polymer layer (B) is 15 μm each, and the thickness of the central polymer layer (C) is 170 μm.

[0233] The prepared film can be sterilized with hot steam and can be permanently heat-sealed using welding tools adjusted to 125°C.

[0234] The impact strength of the obtained film is verified by drop testing in accordance with DIN EN ISO 15747:2019-07.

[0235] illustrate:

[0236] - Prepare several IV bags of the required size, for example, 1000ml;

[0237] - Fill the IV bag with, for example, water and seal it tightly (e.g., with a stopper);

[0238] - Sterilize the IV infusion bags with 121°C hot steam, then they must be completely cooled;

[0239] -10 infusion bags can be stored at 20°C for 24 hours, 10 infusion bags at 4°C for 24 hours, and 10 infusion bags at -18°C for 24 hours.

[0240] -Then each infusion bag is dropped to the ground from the appropriate height (DIN EN ISO 15747:2019-07, Table A.1). A 1000ml bag is placed at a height of 0.75 meters (on the equipment) and then dropped to the ground.

[0241] The test results for 1000ml volumetric bags (contents: water) are shown in Table 1.

[0242]

[0243] Failure rate*: Number of defective bags / Number of test bags

[0244] Drop test results showed that the weight ratio of the impact modifier in the central layer was directly correlated with the low-temperature impact strength at sub-zero temperatures. Only the multilayer films of Examples 1 and 2 passed the drop tests at 4°C and -18°C, which was attributed to the specific amounts of specific impact modifiers in the components of the present invention (each layer (A), (B), and (C)).

Claims

1. A heat-sterilizable multilayer film, comprising: a) A first polymer layer (A) comprising at least one polypropylene homopolymer modified with at least one impact modifier; b) The second polymer layer (B) comprises: (B1) Based on (B), at least one polypropylene terpolymer comprising 51%-68% by weight; (B2) Based on (B), at least one styrene block copolymer (SBC) elastomer comprising 12%-22% by weight; (B3) Based on (B), at least one propylene-ethylene block copolymer comprising 15%-35% by weight, wherein, based on (B3), the proportion of ethylene structural units is ≥9% by weight; and c) A central polymer layer (C) located between the first polymer layer (A) and the second polymer layer (B), comprising: (C1) Based on (C), at least one styrene block copolymer (SBC) elastomer comprising 20%-30% by weight; (C2) Based on (C), at least one polyethylene elastomer comprising 15%-30% by weight, wherein the elastomer is a copolymer of ethylene and an α-olefin containing 4-12 carbon atoms; (C3) is at least one propylene-ethylene block copolymer based on (C), comprising 40%-65% by weight, wherein the proportion of ethylene structural units based on (C3) is ≥9% by weight.

2. The heat-sterilizable multilayer film according to claim 1, characterized in that, The second polymer layer (B) comprises: (B1) Weight percentage 55%-67%; (B2) Weight percentage: 13%-21%; (B3) Weight percentage 17%-32%.

3. The heat-sterilizable multilayer film according to claim 1 or 2, characterized in that, The component (B1 ) is propylene, ethylene and C4-C 12 terpolymers of alpha-olefins.

4. The heat-sterilizable multilayer film according to claim 1 or 2, characterized in that, The styrene block copolymer (SBC) elastomer (B2) and / or (C1) is selected from: styrene-ethylene-butene-styrene block copolymer (SEBS), styrene-ethylene-propylene-styrene block copolymer (SEPS), styrene-ethylene-ethylene-propylene-styrene block copolymer (SEEPS), styrene-isoprene-styrene block copolymer (SIS), and styrene-butadiene-styrene block copolymer (SBS).

5. The heat-sterilizable multilayer film according to claim 1 or 2, characterized in that, The central polymer layer (C) comprises: (C1) Weight percentage 21%-30%; (C2) Weight percentage 15%-25%; (C3) Weight percentage 45%-65%.

6. The heat-sterilizable multilayer film according to claim 1 or 2, characterized in that, The polyethylene elastomer (C2) is an ethylene-butene copolymer and / or an ethylene-octene copolymer.

7. The heat-sterilizable multilayer film according to claim 1 or 2, characterized in that, The first polymer layer (A) comprises 90%-98% by weight of polypropylene homopolymer and 2%-10% by weight of at least one impact modifier, said impact modifier being selected from styrene block copolymers and / or copolymers of ethylene with at least one α-olefin containing 4-12 carbon atoms.

8. The heat-sterilizable multilayer film according to claim 1 or 2, characterized in that, The multilayer film is composed of polymer layers (A), (B) and (C), and the total thickness of the multilayer film is 50-500 μm.

9. A method for preparing the multilayer thin film of claim 1, characterized in that, The first polymer layer (A), the central polymer layer (C), and the second polymer layer (B) are co-extruded.

10. The heat-sterilizable multilayer film according to claim 1, characterized in that, It includes an additional functional layer (D) adjacent to the outside of the first polymer layer (A).

11. A method for preparing a laminated multilayer film sleeve made of the multilayer film of claim 10, comprising the following steps: (a') A film sleeve made of a multilayer film prepared by the method of claim 9 is prepared by a blown film method, wherein the interior of the film sleeve is filled with air; (c') Coat the membrane sleeve with a pressure-sensitive adhesive layer on at least one side of the membrane sleeve; (e') Laminate at least one side of the membrane sleeve coated with the pressure-sensitive adhesive layer to the functional layer (D).

12. A method for preparing medical packaging using the multilayer film of claim 1 or 10.

13. A method for preparing a medical packaging made of the multilayer film of claim 1 or 10, comprising the following steps: a) Provide at least one multilayer thin film prepared by the method according to claim 9 or 11; c) A medical package is formed from at least one or more layers of film, such that a second polymer layer (B) forms the inner surface of the medical package and a first polymer layer (A) forms the outer surface of the medical package; e) Make the inner surfaces contact each other and make the inner surfaces contact the inner surface located at the outline of the medical packaging; f) Heat seal the inner surfaces together and heat seal the inner surfaces to the inner surface located at the outline of the medical packaging.

14. The heat-sterilizable multilayer film according to claim 1 or 2, characterized in that, In the at least one propylene-ethylene copolymer, the proportion of ethylene structural units based on (B3) is 9%-15% by weight.

15. The heat-sterilizable multilayer film according to claim 1, characterized in that, The second polymer layer (B) comprises: (B1) Weight percentage 56%-66%; (B2) Weight percentage 14%-20%; (B3) Weight percentage 18%-30%.

16. The heat-sterilizable multilayer film according to claim 1 or 2, characterized in that, The component (B1) is a terpolymer of propylene, ethylene and butene.

17. The heat-sterilizable multilayer film according to claim 1 or 2, characterized in that, The styrene block copolymer (SBC) elastomer (B2) and / or (C1) is selected from SEBS and SEPS.

18. The heat-sterilizable multilayer film according to claim 1 or 2, characterized in that, The styrene block copolymer (SBC) elastomer (B2) and / or (C1) is SEBS.

19. The heat-sterilizable multilayer film according to claim 1 or 2, characterized in that, The central polymer layer (C) comprises: (C1) weight percentage 22%-27%; (C2) Weight percentage: 17%-23%; (C3) Weight percentage 50%-60%.

20. The heat-sterilizable multilayer film according to claim 1 or 2, characterized in that, The polyethylene elastomer (C2) is an ethylene-octene copolymer.

21. The heat-sterilizable multilayer film according to claim 1 or 2, characterized in that, The first polymer layer (A) comprises 95%-97% by weight of polypropylene homopolymer and 3%-5% by weight of at least one impact modifier selected from styrene block copolymers and / or copolymers of ethylene with at least one α-olefin containing 4-8 carbon atoms.

22. The heat-sterilizable multilayer film according to claim 1 or 2, characterized in that, The multilayer film is composed of polymer layers (A), (B) and (C), and the total thickness of the multilayer film is 100-400 μm.

23. The method for laminating a multilayer film sleeve according to claim 11, characterized in that, The membrane sleeve prepared in step (a') is filled with sterile filtered air.

24. The method for laminating a multilayer film sleeve according to claim 11, characterized in that, The method further includes step (b') cooling the membrane sleeve obtained in step (a').

25. The method for laminating a multilayer film sleeve according to claim 11, characterized in that, The method includes: step (d') drying the film sleeve coated with pressure-sensitive adhesive layer obtained in step (c').

26. The method for laminating a multilayer film sleeve according to claim 11, characterized in that, The method includes step (f') drying and curing the laminated film sleeve.

27. The method for preparing medical bags using multilayer films according to claim 12.

28. The method for preparing medical packaging made of multilayer films according to claim 13, characterized in that, The medical packaging mentioned is a medical bag.

29. The method for preparing medical packaging made of multilayer films according to claim 13, characterized in that, Includes the following steps: a) Provide at least one multilayer thin film prepared by the method according to claim 9 or 11; b) Provide one or more port elements and / or flexible tubing; c) A medical package is formed from at least one or more layers of film, such that a second polymer layer (B) forms the inner surface of the medical package and a first polymer layer (A) forms the outer surface of the medical package; d) Position the port element and / or flexible tube between the inner surfaces of the outline of the medical packaging; e) Make the inner surfaces contact each other and make the inner surfaces contact the port elements and / or flexible tubes located between the inner surfaces at the outline of the medical packaging; f) Heat-seal the inner surfaces to each other and heat-seal the port elements and / or flexible tubes between the inner surfaces and the inner surfaces located at the contour of the medical packaging.

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