Eco-friendly special purpose film packaging material

Abstract

Provided is an eco-friendly special purpose multilayer film packaging material, and the multilayer film packaging material includes: a polypropylene-based inner layer in contact with a medical infusion bag; a polyolefin-based middle layer on the inner layer; and an outer layer exposed to the outside on the middle layer. The multilayer film for a medical infusion bag according to an exemplary embodiment of the present invention is a film which may be sterilized at a high temperature and satisfies mechanical strength, heat resistance, transparency, impact resistance, and oxygen / humidity blocking properties simultaneously, and may solve problems of a whitening phenomenon and difficulty in recycling, which are shown in the conventional technology.

Description

ECO-FRIENDLY SPECIAL PURPOSE FILM PACKAGING MATERIAL

[0001] The present invention relates to an eco-friendly special purpose film packaging material and an overwrap pouch for a medical infusion bag, and the film packaging material may be used as a multilayer film for a medical infusion bag.

[0002] A conventional medical infusion bag is mainly made of polyvinyl chloride (PVC)-based material and used. PVC provides a low price and excellent processability and has been used for a long time due to the advantages. However, serious problems have arisen from an environmental perspective. A PVC-based infusion bag includes endocrine disrupting chemicals and produces harmful substances such as dioxin upon incineration to cause environmental pollution. Due to the problems, in order to reduce occurrence of environmental hormones and the impact of harmful substances produced after incineration on the environment, development of a non-PVC infusion bag is needed.

[0003] A conventional non-PVC-based infusion bag was designed with a polyolefin-based multilayer structure, but a whitening phenomenon occurs during high-temperature sterilization treatment. In addition, it was difficult to use it in the real medical field due to the lack of flexibility and limitations in moldability. In addition, since it has a high oxygen transmission rate (OTR) and a high water vapor transmission rate (WVTR), oxidation of contents and moisture loss may not be prevented.

[0004] Also, in order to solve the problem of oxidation and moisture loss of contents due to the high oxygen transmission rate and water vapor transmission rate of the polyolefin-based infusion bag, recently, the non-PVC-based infusion bag is being developed in the form of an overwrap pouch (secondary pouch) including a layer of various materials such as ethylene vinyl alcohol, but the material has another problems of causing a waste disposal problem due to a composite material which is difficult to recycle after use and adding to the environmental burden.

[0005] In addition, a metal such as aluminum is coated for oxygen blocking, but it rapidly reduces transparency to cause a fatal problem of making it impossible to check the contents inside. In addition, when a barrier layer such as ethylene vinyl alcohol (EVOH) is included, recycling is difficult, heat resistance is poor, a whitening problem occurs during high-temperature sterilization due to hydrophilicity, and problems of poor appearance and reduced mechanical strength occur. The overwrap pouch formed of the composite material is combined with various materials, so that it is difficult to recycle the pouch, and this exposes a problem of a lack of a solution for reducing an impact on the environment. Conventional technology still has limitations in implementing an eco-friendly infusion bag which is recyclable and is resistant to high-temperature sterilization.

[0006] Therefore, a study of a non-PVC-based film technology which is designed from recyclable materials so that heat resistance to allow a high-temperature sterilization treatment, excellent transparency, impact resistance, oxygen / humidity blocking properties, and the like are simultaneously satisfied is desperately needed.

[0007] An object of the present invention is to provide a multilayer film which has excellent heat resistance, transparency, and impact resistance, has excellent oxygen / humidity blocking properties, and is recyclable.

[0008] Another object of the present invention is to provide an overwrap pouch for a medical infusion bag which is manufactured by including the multilayer film, has excellent heat resistance, transparency, mechanical properties, and barrier properties, and is recyclable.

[0009] In order to achieve the above objects, the present inventors continuously studied in order to manufacture a multilayer film for a medical infusion bag which has excellent heat resistance, transparency, and impact resistance, has oxygen / humidity blocking properties, and is recyclable, and as a result, found that when a polypropylene-based inner layer, a polyolefin-based middle layer satisfying specific conditions, and a polypropylene-based outer layer are used, a multilayer film which has excellent heat resistance, transparency, and impact resistance, has excellent oxygen / humidity blocking properties, and is recyclable, and an overwrap pouch including the film may be manufactured, thereby completing the present invention. Furthermore, when the polyolefin-based middle layer includes a transparent deposition layer, more significant transparency, oxygen / humidity blocking properties, and recyclability may be simultaneously implemented.

[0010] In one general aspect, a multilayer film for a medical infusion bag includes: a polypropylene-based inner layer in contact with the medical infusion bag; a polyolefin-based middle layer on the inner layer; and an outer layer exposed to the outside on the middle layer.

[0011] According to an exemplary embodiment, a transparent deposition layer may be further included on at least one surface of the polyolefin-based middle layer.

[0012] According to an exemplary embodiment, the transparent deposition layer may include SiOxor Al2Ox.

[0013] According to an exemplary embodiment, the outer layer may include a polypropylene resin.

[0014] According to an exemplary embodiment, the outer layer may further include a polyethylene terephthalate resin or a polyamide (nylon) resin.

[0015] According to an exemplary embodiment, the multilayer film may have an oxygen transmission rate (OTR) measured in accordance with ASTM D3985-24 of 1.5 cm3 / m2·day or less and a water vapor transmission rate (WVTR) measured in accordance with ASTM F1249-20 of 1.0 g / m2·day or less.

[0016] In another general aspect, an overwrap pouch includes the multilayer film for a medical infusion bag described above.

[0017] The multilayer film for a medical infusion bag according to an exemplary embodiment of the present invention is a film which may be sterilized at a high temperature and satisfies mechanical strength, heat resistance, transparency, impact resistance, and oxygen / humidity blocking properties simultaneously, and may solve problems of a whitening phenomenon and difficulty in recycling, which are shown in the conventional technology. The multilayer film maintains transparency without deformation even with a high-temperature sterilization treatment and may effectively block oxygen and moisture. In addition, it enhances tensile strength and impact resistance to be resistant to physical shock, is easily recyclable, and may minimize an impact on the environment. When the multilayer film is included, an overwrap pouch for a medical infusion bag having excellent oxygen / humidity blocking properties, eco-friendly and transparency may be manufactured.

[0018] In the present specification, unless otherwise defined, all technical terms and scientific terms have the same meanings as those commonly understood by a person skilled in the art to which the present invention pertains. The terms used herein are only for effectively describing a certain specific example and are not intended to limit the present invention.

[0019] The singular form used in the present specification may be intended to also include a plural form, unless otherwise indicated in the context.

[0020] In addition, the numerical range used in the present specification includes all values within the range including the lower limit and the upper limit, increments logically derived in a form and span of a defined range, all double limited values, and all possible combinations of the upper limit and the lower limit in the numerical range defined in different forms. Unless otherwise defined in the present specification, values which may be outside a numerical range due to experimental error or rounding off of a value are also included in the defined numerical range.

[0021] The term "comprise" in the present specification is an open-ended description having a meaning equivalent to the term such as "is / are provided", "contain", "have", or "is / are characterized", and does not exclude elements, materials, or processes which are not further listed.

[0022] In addition, in the present invention, when a layer is referred to as being "on" another layer, it may include not only the case of being in contact with another layer but also the case in which one or more other layers are interposed between the two layers.

[0023] Hereinafter, a multilayer film for a medical infusion bag according to an exemplary embodiment of the present invention will be described in more detail.

[0024] The present invention provides a multilayer film for a medical infusion bag including: a polypropylene-based inner layer in contact with the medical infusion bag; a polyolefin-based middle layer on the inner layer; and an outer layer exposed to the outside on the middle layer. In addition, an adhesive layer may be further included between the outer layer and the middle layer and between the inner layer and the middle layer, respectively. The adhesive layer may be formed from an adhesive manufactured by mixing an isocyanate-based compound and a polyol at an appropriate ratio to perform a urethane reaction, and also, the adhesive may be applied on the film at an application amount of about 1 to 20 g / m2or 2 to 10 g / m2through a coating roll to bond (combine) the outer layer and the middle layer, and / or the inner layer and the middle layer. In addition, after bonded, the film may be stored in an aging room at about 45°C for 4 or 5 days for aging of the reaction. The multilayer film is a film for an outer pouch for an eco-friendly infusion bag and may implement mechanical properties, transparency, barrier properties (oxygen / moisture blocking properties), and recyclability simultaneously, and it solves the problem with waste disposal due to a difficulty in recycling after using a conventional outer pouch for an infusion bag and is recyclable.

[0025] Polypropylene-based inner layer

[0026] According to an exemplary embodiment of the present invention, the polypropylene-based inner layer may include a polypropylene resin. Specifically, the polypropylene resin may have an isotactic index analyzed by NMR of 90.0% or more or 94.0% or more. In addition, the polypropylene resin may have a melt index measured in accordance with ASTM D1238 of 0.1 to 20 g / 10 min. In addition, the polypropylene resin may have a resulting value from a xylene soluble (XS) method of less than 30 wt%, less than 15 wt%, or less than 10 wt%. The xylene soluble is a value expressed as wt% obtained from the remaining residue after dissolving a resin in boiling xylene. The value may be inversely proportional to the isotactic index.

[0027] According to an exemplary embodiment of the present invention, the polypropylene-based inner layer may have a haze (cloudiness) measured in accordance with JIS 7361 of 25% or less, 20% or less, 15% or less, or more than 0%.

[0028] According to an exemplary embodiment of the present invention, the polypropylene-based inner layer may have a tensile strength measured in accordance with ASTM D 882 of 0.1 kgf / mm2or more, 0.5 kgf / mm2or more, 1 kgf / mm2or more or 1.5 kgf / mm2or more and 20 kgf / mm2or less, 10 kgf / mm2or less, 6 kgf / mm2or less or 5.2 kgf / mm2or less in the machine direction (MD) and 0.1 kgf / mm2or more, 0.5 kgf / mm2or more, 1 kgf / mm2or more, or 1.5 kgf / mm2or more and 20 kgf / mm2or less, 10 kgf / mm2or less, 4 kgf / mm2or less, or 3.7 kgf / mm2or less in the transverse direction (TD).

[0029] According to an exemplary embodiment of the present invention, the polypropylene-based inner layer may have an elongation measured in accordance with ASTM D 882 of 100% or more, 150% or more, 200% or more, or 300% or more and 5000% or less, 2000% or less, 1500% or less, or 1400% or less in the machine direction (MD) and 100% or more, 150% or more, 200% or more, or 300% or more and 5000% or less, 2000% or less, 1500% or less, or 1400% or less in the transverse direction (TD).

[0030] According to an exemplary embodiment of the present invention, the polypropylene-based inner layer may have a thermal adhesive strength of 100 g / 15 mm or more, 500 g / 15 mm or more, 1,000 g / 15 mm or more and 5,000 g / 15 mm or less, 4,000 g / 15 mm or less, 3,000 g / 15 mm or less, as measured under the conditions of 0.2 MPa and 0.5 sec of the ISC method standard and under the temperature conditions of 159°C or 162°C.

[0031] According to an exemplary embodiment of the present invention, the polypropylene-based inner layer may have a thickness of 1 to 200 μm, 5 to 100 μm, 15 to 80 μm, or 30 to 70 μm.

[0032] When the polypropylene-based inner layer satisfying the conditions is used, the medical infusion bag may be sterilized at a high temperature and have improved properties such as heat resistance, transparency, flexibility, impact resistance, thermal adhesive properties, and barrier properties, so that the physical properties to be desired in the present invention may be implemented.

[0033] Polyolefin-based middle layer

[0034] According to an exemplary embodiment of the present invention, the polyolefin-based middle layer may be a polyethylene-based or polypropylene-based middle layer, and specifically, may include a polypropylene resin. Since the description of the polypropylene resin is the same as that of the polypropylene resin of the inner layer above, it will be omitted.

[0035] According to an exemplary embodiment of the present invention, the polyolefin-based middle layer may have the same physical properties as those of the inner layer described above, but is not limited thereto.

[0036] According to an exemplary embodiment of the present invention, a transparent deposition layer may be further included on one surface of the polyolefin-based middle layer. The one surface of the middle layer may be a contact surface between the middle layer and the outer layer, or a contact surface between the middle layer and the inner layer. In another embodiment, a corona treatment may be performed on at least one surface or both surfaces of the polyolefin-based middle layer. In another embodiment, the corona treatment may be performed on at least one surface of the polyolefin-based middle layer, and then the transparent deposition layer may be deposited thereon. In addition, the corona treatment may improve interlayer adhesive intensity between the transparent deposition layer and / or the adhesive layer and the polyolefin-based middle layer.

[0037] According to an exemplary embodiment of the present invention, the transparent deposition layer may include a metal oxide, and as an example, may include SiOxor Al2Ox. The transparent deposition layer may include a metal oxide deposition layer obtained by reacting silicate or aluminum vapor as a metalloid or metal with oxygen to deposit a silicate oxide or an aluminum oxide on one surface of the polyolefin-based middle layer. The metal may include all of metalloids, transition metals, post-transition metal elements.

[0038] According to an exemplary embodiment of the present invention, the polyolefin-based middle layer may have a haze (cloudiness) measured in accordance with JIS 7361 of 25% or less, 15% or less, 10% or less and more than 0%, 0.01% or more, or 0.1% or more.

[0039] According to an exemplary embodiment of the present invention, the polyolefin-based middle layer may have a tensile strength measured in accordance with JIS K7127 of 100 kgf / cm2or more, 300 kgf / cm2or more or 600 kgf / cm2or more and 5,000 kgf / cm2or less, 2,500 kgf / cm2or less, or 1,500 kgf / cm2or less in the machine direction (MD) and 100 kgf / cm2or more, 500 kgf / cm2or more, 1,000 kgf / cm2or more, or 1,100 kgf / cm2or more and 8,000 kgf / cm2or less, 5,000 kgf / cm2or less, or 3,000 kgf / cm2or less in the transverse direction (TD).

[0040] According to an exemplary embodiment of the present invention, the polyolefin-based middle layer may have an elongation (tensile elongation) measured in accordance with JIS K7127 of 100% or more or 150% or more, or 100% or less, 500% or less, or 350% or less in the machine direction (MD) or 5% or more, 10% or more, 15% or more, or 100% or less, 70% or less, or 55% or less in the transverse direction (TD).

[0041] According to an exemplary embodiment of the present invention, the polyolefin-based middle layer may have an elastic modulus (elongation elasticity) measured in accordance with JIS K7127 of 1,000 kgf / cm2or more, 5,000 kgf / cm2or more, or 10,000 kgf / cm2or more or 50,000 kgf / cm2or less, 40,000 kgf / cm2or less, or 30,000 kgf / cm2or less in the machine direction (MD) or 1,000 kgf / cm2or more, 5,000 kgf / cm2or more, or 10,000 kgf / cm2or more or 80,000 kgf / cm2or less, 60,000 kgf / cm2or less, or 50,000 kgf / cm2or less in the transverse direction (TD).

[0042] According to an exemplary embodiment of the present invention, the polyolefin-based middle layer may have a heat shrink measured under the conditions of 120°C and 15 min of 10% or less, 7% or less, or 5% or less or 0.1% or more, 0.5% or more, or 1% or more in the machine direction (MD), or 10% or less, 5% or less, or 4% or less or 0.01% or more, 0.1% or more, or 0.5% or more in the transverse direction (TD).

[0043] According to an exemplary embodiment of the present invention, the polyolefin-based middle layer may have a moisture permeability measured under the conditions of 40°C and 90% RH in accordance with ASTM F1249 of 10g / m2·day or less, 7 g / m2·day or less, or 5 g / m2·day or less or 0.001 g / m2·day or more, 0.01 g / m2·day or more, or 0.1 g / m2·day or more.

[0044] According to an exemplary embodiment of the present invention, the polyolefin-based middle layer may have an oxygen permeability measured under the conditions of 30°C and 70% RH in accordance with ASTM D3985 of 50 ml / m2·day·MPa (10 ml / m2·day·MPa = 1 cc / m2·day·atm) or less, 30 ml / m2·day·MPa or less, or 15 ml / m2·day·MPa or less or 0.01 ml / m2·day·MPa or more, 0.1 ml / m2·day·MPa or more, or 1 ml / m2·day·MPa or more.

[0045] According to an exemplary embodiment of the present invention, the polyolefin-based middle layer may have a thickness of 1 to 100 μm or 5 to 60 μm.

[0046] When the polypropylene-based middle layer satisfying the conditions is used, the medical infusion bag may be sterilized at a high temperature and have improved properties such as heat resistance, transparency, flexibility, impact resistance, thermal adhesive properties, and barrier properties, so that the physical properties to be desired in the present invention may be implemented.

[0047] Outer layer

[0048] According to an exemplary embodiment of the present invention, the outer layer may include a polypropylene resin. Specifically, since the description of the polypropylene resin is the same as that of the polypropylene resin of the inner layer described above, it will be omitted.

[0049] According to an exemplary embodiment of the present invention, the outer layer may further include a non-polypropylene-based resin for improving physical properties. Specifically, the outer layer may further include a polyethylene terephthalate resin and / or a polyamide (nylon) resin, but is not largely limited as long as it is a recyclable non-polypropylene-based resin. The non-polypropylene-based resin may be included at 30 wt% or less, 20 wt% or less and 0 wt% or more with respect to the total weight of the multilayer film. When the range is satisfied, recyclability is allowed, so that the eco-friendliness of the present invention may be implemented.

[0050] Preferably, the outer layer may include a heat resistant polypropylene resin. A heat resistant polypropylene resin which has higher crystallinity than a conventional polypropylene resin by adjusting a catalyst and a cocatalyst and has further improved heat resistance, that is to say, has a higher melting point, preferably by 1 to 10°C or 3 to 8°C than a common polypropylene resin may be included. The heat resistant polypropylene resin may include a homopolypropylene and a random polypropylene, but is not limited thereto.

[0051] According to an exemplary embodiment of the present invention, the outer layer may have a haze (cloudiness) measured in accordance with ASTM 1003 of 15% or less, 10% or less and more than 0%, 0.01% or more, or 0.1% or more.

[0052] According to an exemplary embodiment of the present invention, the outer layer may have a tensile strength measured in accordance with ASTM D882 of 1 kg / mm2or more, 5 kg / mm2or more, or 10 kg / mm2or more and 200 kg / mm2or less, 100 kg / mm2or less, or 50 kg / mm2or less in the machine direction (MD), and 5 kg / mm2or more, 10 kg / mm2or more, or 13 kg / mm2or more and 300 kg / mm2or less, 150 kg / mm2or less, or 80 kg / mm2or less in the transverse direction (TD).

[0053] According to an exemplary embodiment of the present invention, the outer layer may have an elongation measured in accordance with ASTM 882 of 10% or more, 20% or more, 30% or more, or 50% or more and 1000% or less, 500% or less, or 300% or less in the machine direction (MD), and 5% or more, 10% or more, or 25% or more and 500% or less, 300% or less, or 200% or less in the transverse direction (TD).

[0054] According to an exemplary embodiment of the present invention, the outer layer may have a heat shrink measured under the conditions of 150°C and 30 min in accordance with ASTM 1204 of 15% or less, 10% or less, or 5% or less and 0.1% or more, 0.5% or more, or 1% or more in the machine direction (MD) and 10% or less or 7% or less and 0.01% or more, 0.1% or more, or 0.5% or more in the transverse direction (TD).

[0055] According to an exemplary embodiment of the present invention, the outer layer may have a thickness of 1 to 150 μm, 5 to 100 μm, or 10 to 60 μm.

[0056] When the outer layer satisfying the conditions is used, the medical infusion bag may be sterilized at a high temperature and have improved properties such as heat resistance, transparency, flexibility, impact resistance, thermal adhesive properties, and barrier properties, so that the physical properties to be desired in the present invention may be implemented.

[0057] Adhesive layer

[0058] According to an exemplary embodiment of the present invention, the multilayer film may further include at least one adhesive layer. The adhesive layer may be placed between the inner layer and the middle layer or between the middle layer and the outer layer, or between the inner layer and the middle layer and between the middle layer and the outer layer.

[0059] According to an exemplary embodiment of the present invention, the adhesive layer has excellent transparency, and any adhesive composition or adhesive layer used in the art may be used without limitation as long as it is formed from an adhesive composition which may be applied on a film on the inner layer, the middle layer, and the outer layer described above. As an example, a two-component or one-component polyurethane adhesive composition may be used, and the application amount may be easily adjusted within a range which does not impair the physical properties to be desired in the present invention, but as an example, the composition may be applied in the application amount of 0.5 to 30 g / m2or 1 to 10 g / m2, and then two or more films may be combined by a common film combination method, for example, a method such as dry lamination.

[0060] In particular, when the adhesive layer is further included, it serves to reduce light scattering in the interface between films, thereby effectively suppressing diffused reflection. In addition, the adhesive layer mitigates fine roughness on a film surface to improve optical uniformity, resulting in contribution to a decrease in haze.

[0061] Multilayer film

[0062] According to an exemplary embodiment of the present invention, the multilayer film may be a polyolefin-based multilayer film in which the inner layer, the middle layer, and the outer layer are all polyolefin-based, specifically a polyolefin-based made of a polypropylene resin, and specifically, a polypropylene-based multilayer film. In this case, the problem of recycling uneasiness of the conventional technology may be solved. A polyethylene terephthalate film and / or a polyamide film and the like may be further included according to the purpose within the recyclable type or content range, but are not limited thereto.

[0063] According to an exemplary embodiment of the present invention, the multilayer film may have a haze (cloudiness) measured in accordance with ASTM 1003 of 20% or less, 15% or less, 10% or less, or 9% or less and more than 0%, 0.1% or more, or 0.5% or more.

[0064] According to an exemplary embodiment of the present invention, the multilayer film may have a tensile strength measured in accordance with ASTM D882 of 100 kgf / cm2or more, 200 kgf / cm2or more, or 320 kgf / cm2or more and 5,000 kgf / cm2or less, 2,000 kgf / cm2or less, or 1,500 kgf / cm2or less in the machine direction (MD), and 200 kgf / cm2or more, 400 kgf / cm2or more, or 600 kgf / cm2or more and 8,000 kgf / cm2or less, 5,000 kgf / cm2or less, or 2,000 kgf / cm2or less in the transverse direction (TD).

[0065] According to an exemplary embodiment of the present invention, the multilayer film may have an elongation measured in accordance with ASTM D882 of 10% or more, 20% or more, or 40% or more and 500% or less, 200% or less, or 150% or less in the machine direction (MD), and 10% or more in the transverse direction (TD).

[0066] According to an exemplary embodiment of the present invention, the multilayer film may have a tear strength measured in accordance with ASTM D1004 of 5.0 kgf / cm or less, 2.5 kgf / cm or less, or 2.0 kgf / cm or less and 0.01 kgf / cm or more, 0.1 kgf / cm or more, or 0.2 kgf / cm or more in the machine direction (MD), and 7.0 kgf / cm or less, 5.0 kgf / cm or less, or 3.0 kgf / cm or less and 0.01 kgf / cm or more, 0.1 kgf / cm or more, or 0.34 kgf / cm or more in the transverse direction (TD).

[0067] According to an exemplary embodiment of the present invention, the multilayer film may have a thermal adhesive strength measured in accordance with ASTM F88-85 of 1.0 kgf (kgf / 15 mm) or more, 2.0 kgf or more, or 3.5 kgf and 20.0 kgf or less or 10.0 kgf.

[0068] According to an exemplary embodiment of the present invention, the multilayer film may have an oxygen transmission rate (OTR) measured in accordance with ASTM D3985-24 of 5 cm3 / m2·day or less, 3 cm3 / m2·day or less, or 1.5 cm3 / m2·day or less and 0.01 cm3 / m2·day or more, 0.05 cm3 / m2·day or more, or 0.1 cm3 / m2·day or more.

[0069] According to an exemplary embodiment of the present invention, the multilayer film may have a water vapor transmission rate (WVTR) measured in accordance with ASTM F1249-20 of 5 g / m2·day or less, 3 g / m2·day or less, or 1.0 g / m2·day or less and 0.01 g / m2·day or more, 0.05 g / m2·day or more, or 0.1 g / m2·day or more.

[0070] According to an exemplary embodiment of the present invention, the multilayer film may have a thickness of 1 to 1000 μm, 5 to 500 μm, 20 to 300 μm, or 30 to 200 μm.

[0071] According to an exemplary embodiment of the present invention, the multilayer film may not include ethylene-vinyl alcohol (EVOH). The ethylene-vinyl alcohol has transparency and gas barrier properties, but may have a whitening phenomenon due to its hydrophilicity and has poor heat resistance, weak mechanical strength, and poor economic feasibility and processability so that it is difficult to use it universally, and when the outer layer and the inner layer form a multilayer film together, recycling is not allowed, so that the effect to be desired in the present invention may not be achieved.

[0072] An embodiment of the present invention may be a multilayer film including: a polypropylene-based inner layer; a polyolefin-based middle layer on the inner layer; and an outer layer on the middle layer.

[0073] Another embodiment of the present invention may be a multilayer film including: a polypropylene-based inner layer; a polyolefin-based middle layer on the inner layer; a transparent deposition layer on the middle layer; and an outer layer on the transparent deposition layer.

[0074] Another embodiment of the present invention may be a multilayer film including: a polypropylene-based inner layer; a transparent deposition layer on the inner layer; a polyolefin-based middle layer on the transparent deposition layer; and an outer layer on the middle layer.

[0075] Another embodiment of the present invention may be a multilayer film including: a polypropylene-based inner layer; a transparent deposition layer on the inner layer; a polyolefin-based middle layer on the transparent deposition layer; a transparent deposition layer on the middle layer; and an outer layer on the transparent deposition layer.

[0076] Another embodiment of the present invention may be a multilayer film including: a polypropylene-based inner layer; an adhesive layer on the inner layer; a polyolefin-based middle layer on the adhesive layer; an adhesive layer on the middle layer; and an outer layer on the adhesive layer.

[0077] Another embodiment of the present invention may be a multilayer film including: a polypropylene-based inner layer; an adhesive layer on the inner layer; a polyolefin-based middle layer on the adhesive layer; a transparent deposition layer on the middle layer; an adhesive layer on the transparent deposition layer; and an outer layer on the adhesive layer.

[0078] Another embodiment of the present invention may be a multilayer film including: a polypropylene-based inner layer; an adhesive layer on the inner layer; a transparent deposition layer on the adhesive layer; a polyolefin-based middle layer on the transparent deposition layer; an adhesive layer on the middle layer; and an outer layer on the adhesive layer.

[0079] Another embodiment of the present invention may be a multilayer film including: a polypropylene-based inner layer; an adhesive layer on the inner layer; a transparent deposition layer on the adhesive layer; a polyolefin-based middle layer on the transparent deposition layer; a transparent deposition layer on the middle layer; an adhesive layer on the transparent deposition layer; and an outer layer on the adhesive layer.

[0080] Another embodiment of the present invention may be a multilayer film including: a polypropylene-based inner layer; a polyolefin-based middle layer on the inner layer; an outer layer on the middle layer; and an outermost layer including a polyethylene terephthalate film or a polyamide (nylon) film on the outer layer.

[0081] Since the multilayer film according to an embodiment of the present invention includes a polypropylene-based resin in all of the inner layer, the middle layer, and the outer layer, a problem such as whitening does not occur even after a high-temperature sterilization process, and thus, may have excellent heat resistance, transparency, and impact resistance, have excellent oxygen / humidity blocking properties, and have recyclability described later.

[0082] The above embodiments are only an example of the present invention, and are not limited thereto, and may be manufactured in any known order as long as the configuration of the multilayer film described above is included.

[0083] The present invention may provide an overwrap pouch including the multilayer film for a medical infusion bag described above. The overwrap pouch may hold a medical infusion bag and be stored after being sealed, and is transparent when a user uses the pouch, thereby preventing a problem of not seeing the infusion inside well like a conventional overwrap pouch. In addition, the overwrap pouch according to the present invention has heat resistance against high-temperature sterilization treatment and strong barrier properties resistant to stretching and cracks due to vacuum packaging, has excellent impact resistance, transparency, and thermal adhesive properties, and may implement an excellent effect of tearability. The overwrap pouch is manufactured from the multilayer film described above and may be manufactured into any known forms.

[0084] Hereinafter, the examples of the present invention will be described in detail with reference to the attached drawings. However, they are provided so that the present invention may be easily carried out by those skilled in the art, the present invention may be implemented in various forms, and the idea of the present invention is not necessarily limited to the examples.

[0085] [Example 1]

[0086] A heat resistant polypropylene film according to the following standard in Table 1 was prepared as an outer layer.

[0087] ClassificationUnitStandardRemarksAverage thickness㎛30±3%DICTensile strengthKg / mm2MD Min 10.0ASTM 882TD Min 28.0ASTM 882Elongation%MD Max 200ASTM 882TD Max 80ASTM 882Heat Shrinkage%MD Max 4.5ASTM 1204TD Max 1.5ASTM 1204Cloudiness(Haze)%Max 5.0ASTM 1003

[0088] In addition, a polypropylene film of the following standard in Table 2 was prepared as an inner layer.

[0089] Analysis itemUnitTest methodResultsThickness㎛ASTM D 210360.1TreatmentmN / mASTM D 257842Haze%ASTM D 100311.7Elongation at breakMD%ASTM D 8821000TD%ASTM D 8821000Fraction coefficient (C.O.F)Outer surface / Outer surfaceASTM D 18940.19Thermal adhesive strengthg / 15 mmISCMETHOD (0.2 MPa, 0.5 sec)159°C1826162°C2120Tensile strengthMDKgf / mm2ASTM D 882Broken3.8TDKgf / mm2ASTM D 882Broken2.7

[0090] At this time, the polypropylene film of the outer layer and the inner layer satisfied a melt index measured in accordance with ASTM D1238 of 2, an isotacticity among stereoregularities of 95%, and xylene soluble of 3%.In addition, silicate vapor and oxygen were brought into contact in a vacuum state on the same type of polypropylene film as the inner layer to deposit a silicate oxide (SiOx(0<x≤2)) to prepare a middle layer film on which a transparent deposition layer was formed, and the physical properties of the middle layer film are as follow Table 3.

[0091]

[0092] For first combination of the outer layer film and the middle layer film, about 4 g / m2of a polyurethane two-component adhesive was applied, and the outer layer film and the middle layer film were combined by a first dry lamination operation. Subsequently, for second combination of the first combined film and the inner layer film, 4 g / m2of the same adhesive was applied to manufacture a multilayer film having a thickness of about 120 μm on which the outer layer film, the middle layer film on the outer layer film, and the inner layer film on the middle layer film were laminated by a second dry lamination operation.

[0093] The physical properties of the manufactured multilayer film were measured and are shown in the following Table 4. Tensile strength, elongation, tear strength, and thermal adhesive strength were measured using WITHLAB (Model: WL2100C, Load Cell: 20kg), and an oxygen transmission rate and a water vapor transmission rate were measured based on the direction of penetration from the outside to the inside around the film, using ILLINOIS 8003 (SYSTECH, U.S.A.).

[0094] [Example 2]

[0095] The process was performed in the same manner as in Example 1, except when the middle layer film was manufactured, a middle layer film on which a transparent deposition layer was formed was manufactured by depositing an aluminum oxide (Al2Ox(0<x≤3)) using aluminum metal vapor, not silicate vapor.

[0096] [Comparative Example 1]

[0097] The process was performed in the same manner as in Example 1, except that a polyethylene terephthalate film having the same thickness was used as the outer layer and ethylene vinyl alcohol having the same thickness was used as the middle layer.

[0098] Physical propertiesExample 1Comparative Example 1Measurement methodTensile strength [kgf / cm2]MD548574ASTM D882TD1,002746ASTM D882Elongation[%]MD107120ASTM D882TDImmeasurable131ASTM D882Tear strength [kgf / cm]MD0.44-ASTM D1004TD0.58-ASTM D1004Haze (%)712ASTM D1003Thermal adhesive strength [kg]5.263.58120°C, 2bar, 0.5 secOxygen transmission rate [cm3 / m2·day]0.410.38(23±2)°C, ASTM D3985-24Water vapor transmission rate [g / m2·day]0.520.45(38±2)°C, 100% RH, ASTM F1249-20Recyclable or notRecyclableDifficult

[0099] As seen from Table 4, it was confirmed that the multilayer film according to an exemplary embodiment has excellent tensile strength, a low haze value, excellent elongation and thermal adhesive strength, oxygen transmission rate, water vapor transmission rate, and appropriate tear strength, and simultaneously, has recyclability, but when any one of the inner layer, the middle layer, or the outer layer has configurations other than the configuration of the present application, the physical properties were not reached.In addition, the method for evaluating the recyclability may use a common method or a known method, but since a real plastic recycling method varies by recycling companies and is difficult to be specify and complicated, a film made of a single material may be usually required for evaluation of recyclability. That is, a single material such as the multilayer film according to an exemplary embodiment has the best results in the recyclability evaluation, but when the recyclability of the film including two or more materials is evaluated, a total weight of material other than the main material (material included at 50 wt% or more with respect to the total weight) is included at 30 wt% or less, preferably 20 wt% or less with respect to the total weight of the material, it may be evaluated as being recyclable, and when it is out of the range, it may be evaluated as being difficult to be recycled. For example, when a PET / PP laminated film has more than 20 wt% of a PET component, it is difficult to be recycled, and also, a polyurethane film requires much additional costs for recycling and it is difficult to recycle such films in the multilayer film including the polyurethane film.

[0100] Specifically, in Example 1 using the middle layer having a transparent deposition layer formed as the middle layer, dominant resulting values were shown in all of oxygen transmission rate, water vapor transmission rate, and transparency, and heat resistance was excellent without a change in haze even at a high temperature, but the film of Comparative Example 1 had poor heat resistance and caused whitening due to the hydrophilicity of ethylene-vinyl alcohol during high-temperature sterilization to rapidly increase haze and lost transparency, and thus, was difficult to use due to poor appearance. In particular, it was confirmed that the film according to Example 1 was recyclable, but the film of Comparative Example 1 was not able to implement recyclability since it was a heterogeneous material having a content which is difficult to recycle. In addition, a multilayer film including nylon is conventionally often used as the middle layer and / or the outer layer as a pouch for vacuum packaging, and in this case, very poor values of an oxygen transmission rate of about 30 cm3 / m2·day or more and a water vapor transmission rate of about 140 g / m2·day or more were shown, and the barrier properties were not satisfied.

[0101] Therefore, the overwrap pouch for a medical infusion bag including the multilayer film has excellent transparency, is recyclable, has heat resistance to high-temperature sterilization treatment, has strong moisture / oxygen blocking properties against stretching and cracks due to vacuum packaging, and has superior impact resistance and tearability (tear strength). These effects were confirmed to be effects implemented by combining all of the polypropylene-based inner layer; the polyolefin-based middle layer on the inner layer; and the outer layer on the middle layer.

[0102] Hereinabove, although the present invention has been described by specific exemplary embodiments, they have been provided only for assisting in the entire understanding of the present invention. Therefore, the present invention is not limited to the exemplary embodiments. Various modifications and changes may be made by those skilled in the art to which the present invention pertains from this description.

[0103] Therefore, the spirit of the present invention should not be limited to the above-described exemplary embodiments, and the following claims as well as all modifications equal or equivalent to the claims are intended to fall within the scope and spirit of the invention.

Claims

1.A multilayer film for a medical infusion bag comprising: a polypropylene-based inner layer in contact with the medical infusion bag; a polyolefin-based middle layer on the inner layer; and an outer layer exposed to the outside on the middle layer.2.The multilayer film for a medical infusion bag of claim 1, further comprising a transparent deposition layer on at least one surface of the polyolefin-based middle layer.3.The multilayer film for a medical infusion bag of claim 2, wherein the transparent deposition layer includes SiOx(0<x≤2) or Al2Ox(0<x≤3).4.The multilayer film for a medical infusion bag of claim 1, wherein the outer layer includes a polypropylene resin.5.The multilayer film for a medical infusion bag of claim 1, wherein the outer layer further includes a polyethylene terephthalate resin or a polyamide (nylon) resin.6.The multilayer film for a medical infusion bag of claim 1, wherein the multilayer film has an oxygen transmission rate (OTR) measured in accordance with ASTM D3985-24 of 1.5 cm3 / m2·day or less and a water vapor transmission rate (WVTR) measured in accordance with ASTM F1249-20 of 1.0 g / m2·day or less.7.An overwrap pouch comprising the multilayer film for a medical infusion bag of any one of claims 1 to 6.

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