Food packaging material and retort food using same

Abstract

The present invention relates to a food packaging material and a retort food using same. According to an embodiment of the present invention, the food packaging material comprises: a first layer containing a polyamide and having a thickness of 10-30 μm; and a second layer containing polypropylene and having a thickness of 15-60 μm, so that the food packaging material is eco-friendly and has the appropriate quality for sterilization and shrink processes.

Description

Food packaging materials and retort foods using the same

[0001] The present invention relates to a food packaging material having excellent quality, being environmentally friendly and suitable for a sterilization shrinkage process, and to a retort food using the same.

[0002] As the use of packaging materials for food increases due to diverse household types and changing lifestyles, various food packaging methods are being developed. For example, the retort method, which involves filling cooked food into a pouch-shaped packaging material, sealing it, and then heat-sterilizing or sterilizing it, is widely used.

[0003] Polyvinylidene chloride (PVDC) has been used as a raw material for food packaging due to its excellent properties, including barrier properties, heat shrinkage, and moisture permeability. However, suitable recycling technologies for chlorine-based raw materials like PVDC have not been developed, and recyclability is difficult when mixed with other raw materials. Therefore, research is ongoing to develop a food packaging material that can sufficiently replace conventional PVDC raw materials while also being environmentally friendly and exhibiting superior properties, such as barrier properties, heat shrinkage properties, moisture permeability, and oxygen permeability.

[0004] For example, Korean Patent Publication No. 2093102 discloses a vinylidene chloride resin film and a filling packaging body using the same, which can prevent breakage or appearance defects that may occur during retort processing even when sealed at a low current value by including a polyvinylidene chloride resin and an ethylene-vinyl acetate copolymer. However, since polyvinylidene chloride resin is used as the main raw material, environmental problems may arise and recyclability is also low.

[0005] Accordingly, the present invention aims to provide a food packaging material having excellent quality, which is environmentally friendly and has heat shrinkage, moisture permeability and oxygen permeability characteristics suitable for food packaging, and is also suitable for a sterilization shrinkage process, and a retort food using the same.

[0006] A food packaging material according to one embodiment of the present invention comprises a first layer comprising polyamide and having a thickness of 10 μm to 30 μm; and a second layer comprising polypropylene and having a thickness of 15 μm to 60 μm.

[0007] According to one embodiment of the present invention, the food packaging material may have a heat shrinkage rate of 8% to 25% under conditions of 95°C to 130°C and 5 to 30 minutes.

[0008] According to one embodiment of the present invention, the first layer may have a heat shrinkage rate of 8% to 35% under conditions of 95°C to 130°C and 5 minutes to 30 minutes.

[0009] According to one embodiment of the present invention, the first layer may have a difference between a longitudinal (MD) heat shrinkage rate and a transverse (TD) heat shrinkage rate of 3% to 10% under conditions of 95°C to 130°C and 5 minutes to 30 minutes.

[0010] According to one embodiment of the present invention, the first layer may have a thermal shrinkage rate in the transverse direction (TD) that is greater than a thermal shrinkage rate in the longitudinal direction (MD) under conditions of 95°C to 130°C and 5 minutes to 30 minutes, or the thermal shrinkage rate in the longitudinal direction (MD) may be greater than the thermal shrinkage rate in the transverse direction (TD).

[0011] According to one embodiment of the present invention, the second layer may have a tensile strength in the longitudinal direction (MD) of 1.1 to 3 relative to a tensile strength in the transverse direction (TD).

[0012] According to one embodiment of the present invention, the second layer has a tensile strength in the transverse direction (TD) of 1 kgf / mm 2 Up to 10 kgf / mm 2It can be 1.1 kgf / mm in longitudinal direction (MD) tensile strength. 2 Up to 15 kgf / mm 2 It could be.

[0013] According to one embodiment of the present invention, the thickness ratio of the first layer and the second layer may be 1:1.2 to 4.

[0014] According to one embodiment of the present invention, an adhesive layer may be included between the first layer and the second layer.

[0015] According to one embodiment of the present invention, the adhesive layer may include a urethane-based adhesive.

[0016] According to one embodiment of the present invention, the adhesive strength of the first layer and the second layer may be 100 gf to 1,000 gf based on a 15 mm width.

[0017] According to one embodiment of the present invention, the first layer has an oxygen permeability of 1 cc / m 2 ·day·atm to 25 cc / m 2 ·day·atm may be.

[0018] According to one embodiment of the present invention, the food packaging material has a moisture permeability of 25 g / m 2 ·May be less than day, and oxygen permeability is 25 cc / m 2 ·day·atm or less.

[0019] According to one embodiment of the present invention, the food packaging material may further include a third layer comprising polypropylene and having a thickness of 15 μm to 60 μm.

[0020] According to one embodiment of the present invention, the food packaging material may be formed by sequentially stacking the second layer, the first layer, and the third layer.

[0021] According to another embodiment of the present invention, a retort food product comprises: a food; and a food packaging material for sealing the food; wherein the food packaging material comprises a first layer comprising polyamide and having a thickness of 10 μm to 30 μm; and a second layer comprising polypropylene and having a thickness of 15 μm to 60 μm.

[0022] According to another embodiment of the present invention, the retort food may include a sealing portion.

[0023] According to another embodiment of the present invention, the sealing strength of the sealing portion may be 1 kgf to 10 kgf based on a width of 15 mm.

[0024] According to another embodiment of the present invention, the sealing portion may include a central sealing portion and an end sealing portion.

[0025] According to another embodiment of the present invention, the width (Wc) of the central sealing portion may be 5% to 50% of the total width (Wt) of the retort food.

[0026] According to another embodiment of the present invention, the length (Le) of the terminal sealing portion may be 5% to 20% of the total length (Lt) of the retort food.

[0027] According to another embodiment of the present invention, the terminal sealing portion may include a notch portion in a vertical direction.

[0028] According to another embodiment of the present invention, the length (Ln) of the notch portion may be 10% to 50% of the total length (Le) of the terminal sealing portion.

[0029] According to another embodiment of the present invention, the inner side of the terminal sealing portion may include a round shape.

[0030] According to another embodiment of the present invention, the radius of curvature of the round shape may be from 5 mm to 100 mm.

[0031] According to another embodiment of the present invention, the length (Lr) of the inner side of the terminal sealing portion may be 20% to 70% of the total length (Le) of the terminal sealing portion.

[0032] A food packaging material according to one embodiment of the present invention comprises a first layer comprising polyamide and having a thickness of 10 μm to 30 μm; and a second layer comprising polypropylene and having a thickness of 15 μm to 60 μm, thereby being environmentally friendly and having a quality suitable for a sterilization shrinkage process.

[0033] Specifically, the food packaging material includes the structure of the first layer and the second layer, so that even during a sterilization shrinkage process at conditions of 95°C to 130°C and 5 to 30 minutes, the shrinkage shape is uniform, so that no bending or bursting occurs, and thus the appearance is excellent, and a sturdy packaging shape without empty space can be implemented.

[0034] More specifically, the food packaging material satisfies a heat shrinkage rate of 8% to 25% under conditions of 95°C to 130°C and 5 to 30 minutes, so that it does not bend or burst even during a sterilization shrinkage process under conditions of 95°C to 130°C and 5 to 30 minutes, thereby having an excellent appearance.

[0035] In addition, by controlling the properties of the first layer and the second layer, specifically, by controlling the properties of the first layer to secure oxygen barrier properties and heat shrinkage properties, and by controlling the properties of the second layer to secure moisture barrier properties and heat sealability, the food packaging material including the first layer and the second layer is environmentally friendly and has excellent quality that can sufficiently replace polyvinylidene chloride raw materials used in the past.

[0036] In addition, the food packaging material has excellent orientation of the first layer, so that when opening a retort food using the food packaging material, the food can be opened easily and cleanly without damage to the food, thereby providing excellent vertical opening properties and / or horizontal opening properties.

[0037] For example, polyvinylidene chloride (PVDC), which has been conventionally used as a raw material for food packaging, has had difficulty in controlling the orientation in the machine direction (MD), making it difficult to secure vertical opening properties. However, a food packaging material according to one embodiment of the present invention can solve the environmental problems associated with polyvinylidene chloride while ensuring vertical opening properties, thereby providing convenience in use and superior quality.

[0038] More specifically, the first layer has a heat shrinkage rate of 8% to 35% under conditions of 95°C to 130°C and 5 to 30 minutes, and the difference between the heat shrinkage rate in the longitudinal (MD) direction and the heat shrinkage rate in the transverse (TD) direction is controlled to 3% to 10%, so that when a retort food using the food packaging material is opened, the food can be easily and cleanly opened without damage to the contents, thereby providing excellent vertical openability and / or horizontal openability.

[0039] Furthermore, by controlling the physical properties of the second layer, particularly its mechanical properties such as tensile strength, printing can be easily applied to the surface. Therefore, label stickers, etc., currently attached separately to food packaging, can be dispensed with, resulting in excellent processability and recyclability.

[0040] Therefore, when manufacturing a retort food using the above food packaging material, the shrinkage shape is uniform even during the sterilization shrinkage process, so that no bending or bursting occurs, and a retort food having an excellent appearance and excellent quality that can be easily and cleanly opened without damage to the contents can be provided.

[0041] Figure 1 illustrates a food packaging material according to one embodiment of the present invention.

[0042] Figure 2 illustrates a food packaging material according to another embodiment of the present invention.

[0043] Figure 3 illustrates a retort food according to another embodiment of the present invention.

[0044] Figures 4 and 5 illustrate an end sealing portion of a retort food according to another embodiment of the present invention.

[0045] Figure 6 is a photograph of the retort food of Example 2-1 before performing the sterilization shrinkage process.

[0046] Figure 7 is a photograph of the retort food of Example 2-1 after performing the sterilization shrinkage process.

[0047] The present invention is described in detail below. The present invention is not limited to the details disclosed below and may be modified in various ways without altering the spirit of the invention.

[0048] In this specification, when a part is said to "include" a certain component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise specifically stated.

[0049] All numbers and expressions indicating the amounts of components, reaction conditions, etc. described in this specification should be understood to be modified by the term “about” in all cases unless otherwise specified.

[0050] When it is described in this specification that one component is formed on or under another component, it includes both cases where one component is formed directly on or under the other component, or indirectly through the interposition of another component.

[0051] In this specification, the terms "first," "second," "primary," and "secondary" are used to describe various components, and the components are not limited by these terms. These terms are used solely to distinguish one component from another.

[0052]

[0053] food packaging materials

[0054] A food packaging material according to one embodiment of the present invention comprises a first layer comprising polyamide and having a thickness of 10 μm to 30 μm; and a second layer comprising polypropylene and having a thickness of 15 μm to 60 μm.

[0055] According to one embodiment of the present invention, the food packaging material may have a heat shrinkage rate of 8% to 25% under conditions of 95°C to 130°C and 5 minutes to 30 minutes. For example, the heat shrinkage rate of the food packaging material may be 10% to 25%, 12% to 25%, or 15% to 20% under conditions of a temperature of 95°C to 100°C, 105°C to 125°C, 110°C to 125°C, or 115°C to 125°C, and a time of 5 minutes to 10 minutes, 10 minutes to 30 minutes, 15 minutes to 30 minutes, or 20 minutes to 30 minutes (for example, 95°C and 5 minutes, or 121°C and 30 minutes).

[0056] Additionally, the food packaging material may have a heat shrinkage in the transverse direction (TD) that is 1% to 5%, 1.5% to 4%, or 1.5% to 3.5% higher than the heat shrinkage in the longitudinal direction (MD). For example, the food packaging material may have a heat shrinkage in the longitudinal direction (MD) of 9% to 20%, 10% to 18%, or 11% to 15%, and a heat shrinkage in the transverse direction (TD) of 10% to 25%, 12% to 19%, or 14% to 18%.

[0057] Additionally, the food packaging material may have a heat shrinkage in the longitudinal direction (MD) that is 1% to 5%, 1.5% to 4%, or 1.5% to 3.5% higher than the heat shrinkage in the transverse direction (TD). For example, the food packaging material may have a heat shrinkage in the transverse direction (TD) of 9% to 20%, 10% to 18%, or 11% to 15%, and a heat shrinkage in the longitudinal direction (MD) of 10% to 25%, 12% to 19%, or 14% to 18%.

[0058] The above heat shrinkage rate may be calculated according to the following formula A, as measured after sterilizing food packaging materials at a temperature of 121°C and a time of 30 minutes using an A-091 political retro-rotating facility (manufacturer: JBT) and drying them at room temperature for 30 minutes.

[0059] [Formula A]

[0060] Heat shrinkage rate (%) = ((length before shrinkage - length after shrinkage) / length before shrinkage) × 100

[0061] The food packaging material according to one embodiment of the present invention has a heat shrinkage rate controlled within the above range, so that when a sterilization shrinkage process is performed while the inside of a retort food manufactured using the food packaging material is filled with food, no bending or bursting occurs, so that the appearance is excellent and a sturdy packaging form without any empty space can be implemented.

[0062] The food packaging material may have a sealing strength of 1 kgf / 15mm to 10 kgf / 15mm measured in the longitudinal direction (MD). For example, the sealing strength is determined by preparing two sheets of the food packaging material, laminating the second layer of one sheet of the food packaging material and the second layer of the other sheet of the food packaging material face-to-face, heat-sealing them, and then measuring the peel strength thereof. The sealing strength may be 2 kgf / 15mm to 10 kgf / 15mm, 3.5 kgf / 15mm to 8 kgf / 15mm, 4 kgf / 15mm to 6.5 kgf / 15mm, or 4.2 kgf / 15mm to 6.2 kgf / 15mm.

[0063] The above food packaging material has a moisture permeability of 25 g / m 2 ·day or less. For example, the food packaging material has a moisture permeability of 23 g / m 2 ·day or less, 20 g / m 2 ·day or less, 18 g / m 2 ·day or less, 12 g / m 2 ·day or less or 7.5 g / m 2 ·day or less (e.g. 0 g / m 2 ·day to 25 g / m 2 ·day, 1 g / m 2 ·day to 15 g / m 2 ·day or 5 g / m 2 ·day to 8 g / m 2 ·day) may be.

[0064] The above food packaging material has an oxygen permeability of 25 cc / m 2 ·day·atm or less. For example, the food packaging material has an oxygen permeability of 22 cc / m 2 ·day·atm or less, 20 cc / m 2 ·day·atm or less, 18 cc / m 2 ·day·atm or less, 10 cc / m 2 ·day·atm or less, 9 cc / m 2 ·day·atm or less or 6 cc / m 2 ·day·atm or less (e.g. 0 cc / m 2 ·day·atm to 25 cc / m 2 ·day·atm, 3 cc / m 2 ·day·atm to 15 cc / m 2 ·day·atm or 5 cc / m 2 ·day·atm to 9 cc / m 2 ·day·atm) may be.

[0065] Since the sealing strength, moisture permeability and oxygen permeability of the above food packaging material satisfy the above ranges, when manufacturing a retort food using the above food packaging material, it is possible to effectively prevent the packaged food from leaking out or being damaged due to damage to the packaging material during transportation or storage.

[0066] The above food packaging material may be in the form of, but is not limited to, a stick, a tube, a three-way pouch, a two-way stand, a three-way stand, an M-way pouch, a T-way pouch, a box pouch, or a Thompson pouch.

[0067] Fig. 1 illustrates a food packaging material according to one embodiment of the present invention. Specifically, Fig. 1 illustrates a food packaging material (100) in which a second layer (120) is formed on one surface of a first layer (110).

[0068]

[0069] 1st floor

[0070] A food packaging material according to one embodiment of the present invention comprises a first layer comprising polyamide.

[0071] The first layer may include an aromatic polyamide and an aliphatic polyamide. For example, the first layer may be a film manufactured by coextruding an aromatic polyamide and an aliphatic polyamide.

[0072] In addition, the first layer may contain 5 wt% to 70 wt% of aromatic polyamide. For example, the first layer may contain aromatic polyamide and aliphatic polyamide, and the content of the aromatic polyamide may be 5 wt% to 65 wt%, 10 wt% to 60 wt%, or 15 wt% to 60 wt% based on the total weight of the first layer. When the content of the aromatic polyamide satisfies the above range, a barrier property suitable for a food packaging material can be secured. Meanwhile, the content of the aliphatic polyamide may be 30 wt% to 95 wt%, 35 wt% to 95 wt%, 40 wt% to 90 wt%, or 40 wt% to 85 wt% based on the total weight of the first layer.

[0073] The first layer may have a heat shrinkage rate of 8% to 35% under conditions of 95°C to 130°C and 5 minutes to 30 minutes. For example, the heat shrinkage rate of the first layer may be 8% to 30%, 8% to 28%, 12% to 25%, or 15% to 20% under conditions of a temperature of 95°C to 100°C, 105°C to 125°C, 110°C to 125°C, or 115°C to 125°C, and a time of 5 minutes to 10 minutes, 5 minutes to 25 minutes, 5 minutes to 20 minutes, or 10 minutes to 25 minutes (for example, 95°C and 5 minutes).

[0074] In addition, the food packaging material has excellent orientation of the first layer, so that when opening a retort food using the food packaging material, the food can be opened easily and cleanly without damage to the food, thereby providing excellent vertical opening properties and / or horizontal opening properties.

[0075] Specifically, since the heat shrinkage rate of the first layer satisfies the above range, the openability in the vertical or horizontal direction is excellent.

[0076] In addition, the first layer has a thermal shrinkage (S) in the longitudinal direction (MD) under conditions of 95°C to 130°C and 5 to 30 minutes. MD ) and transverse (TD) thermal shrinkage (S TD )'s car (ㅣS MD - S TD ㅣ) can be between 3% and 10%.

[0077] For example, the first layer may have a thermal shrinkage rate in the transverse direction (TD) greater than that in the longitudinal direction (MD) at a temperature of 95°C to 100°C, 105°C to 125°C, 110°C to 125°C, or 115°C to 125°C, and a time of 5 to 10 minutes, 5 to 25 minutes, 5 to 20 minutes, or 10 to 25 minutes (e.g., 95°C and 5 minutes), and the thermal shrinkage rate in the longitudinal direction (MD) (S MD ) and transverse (TD) thermal shrinkage (S TD )'s car (ㅣS MD - S TD ㅣ) can be 3% to 9%, 3.1% to 7%, 3.2% to 6%, or 3.5% to 5.5%.

[0078] In addition, the first layer may have a heat shrinkage ratio in the longitudinal direction (MD) greater than that in the transverse direction (TD) at a temperature of 95°C to 100°C, 105°C to 125°C, 110°C to 125°C, or 115°C to 125°C, and a time of 5 to 10 minutes, 5 to 25 minutes, 5 to 20 minutes, or 10 to 25 minutes (for example, 95°C and 5 minutes), and the heat shrinkage ratio in the longitudinal direction (MD) may be greater than that in the transverse direction (TD), and the heat shrinkage ratio in the longitudinal direction (MD) (S MD ) and transverse (TD) thermal shrinkage (S TD )'s car (ㅣS MD - S TD ㅣ) can be 3% to 9%, 3.1% to 7%, 3.2% to 6%, or 3.5% to 5.5%.

[0079] By controlling the difference between the longitudinal (MD) heat shrinkage rate and the transverse (TD) heat shrinkage rate of the first layer within the above range, the longitudinal (MD) orientation or the transverse (TD) orientation can be improved. For example, by controlling the transverse (TD) heat shrinkage rate of the first layer to be greater than the longitudinal (MD) heat shrinkage rate of the first layer, the longitudinal (MD) orientation can be improved, thereby increasing the vertical openability (longitudinal (MD) openability) of the retort food. In addition, by controlling the longitudinal (MD) heat shrinkage rate of the first layer to be greater than the transverse (TD) heat shrinkage rate of the first layer, the transverse (TD) orientation can be improved, thereby increasing the horizontal openability (transverse (TD) openability) of the retort food.

[0080] More specifically, the first layer has a heat shrinkage rate of 8% to 35% under conditions of 95°C to 130°C and 5 to 30 minutes, and the difference between the heat shrinkage rate in the longitudinal (MD) direction and the heat shrinkage rate in the transverse (TD) direction is controlled to 3% to 10%, so that when opening a retort food using the food packaging material, the food can be opened easily and cleanly without damage to the contents, and thus the vertical openability or horizontal openability is excellent.

[0081] The first layer may have a thermal shrinkage in the transverse direction (TD) of 8% to 35%, 10% to 32%, 18% to 30%, or 22% to 28%, and a thermal shrinkage in the longitudinal direction (MD) of 8% to 30%, 10% to 30%, 12% to 26%, or 14% to 22%.

[0082] Additionally, the first layer may have a heat shrinkage in the longitudinal direction (MD) of 8% to 35%, 10% to 32%, 18% to 30%, or 22% to 28%, and a heat shrinkage in the transverse direction (TD) of 8% to 30%, 10% to 30%, 12% to 26%, or 14% to 22%.

[0083] The above first layer has an oxygen permeability of 1 cc / m2 ·day·atm to 25 cc / m 2 ·day·atm. For example, the first layer may have an oxygen permeability of 1 cc / m 2 ·day·atm to 15 cc / m 2 ·day·atm, 2 cc / m 2 ·day·atm to 12 cc / m 2 ·day·atm, 3 cc / m 2 ·day·atm to 10 cc / m 2 ·day·atm or 5 cc / m 2 ·day·atm to 9 cc / m 2 ·day·atm may be.

[0084] The thickness of the first layer may be 10 μm to 30 μm. For example, the thickness of the first layer may be 10 μm to 25 μm, 12 μm to 20 μm, 13 μm to 18 μm, or 15 μm to 17 μm.

[0085]

[0086] 2nd floor

[0087] A food packaging material according to one embodiment of the present invention comprises a second layer comprising polypropylene.

[0088] Additionally, the second layer may comprise polypropylene in an amount of 80 wt% or more. For example, the content of polypropylene in the second layer may be 85 wt% or more, 90 wt% or more, 95 wt% or more, or 100 wt% based on the total weight of the second layer.

[0089] The second layer may have a tensile strength in the longitudinal direction (MD) of 1.1 to 3 relative to the tensile strength in the transverse direction (TD). For example, the second layer may have a tensile strength in the longitudinal direction (MD) of 1.1 to 2.5, 1.2 to 2, or 1.3 to 2 relative to the tensile strength in the transverse direction (TD). By controlling the tensile strength of the second layer within the above range, the shrinkage shape is uniform even during the sterilization shrinkage process, so that bending or bursting does not occur, resulting in an excellent appearance and a sturdy packaging shape without any empty space.

[0090] In addition, the second layer has a tensile strength in the transverse direction (TD) of 1 kgf / mm. 2 Up to 10 kgf / mm 2 It can be 1.1 kgf / mm in longitudinal direction (MD) tensile strength. 2 Up to 15 kgf / mm 2 may be. For example, the second layer may have a tensile strength in the transverse direction (TD) of 1 kgf / mm. 2 Up to 8 kgf / mm 2 , 1.5 kgf / mm 2 6 kgf / mm 2 or 2 kgf / mm 2 5 kgf / mm 2 It can be 1.1 kgf / mm in longitudinal direction (MD) tensile strength. 2 Up to 13 kgf / mm 2 , 2.5 kgf / mm 2 Up to 10 kgf / mm 2 or 4 kgf / mm 2 Up to 8.5 kgf / mm 2 It could be.

[0091] The thickness of the second layer may be 15 μm to 60 μm. For example, the thickness of the second layer may be 16 μm to 58 μm, 18 μm to 55 μm, 20 μm to 50 μm, or 20 μm to 30 μm.

[0092]

[0093] In addition, the thickness ratio of the first layer and the second layer may be 1:1.2 to 4. For example, the thickness ratio of the first layer and the second layer may be 1:1.2 to 3.8, 1:1.25 to 3.6, or 1:1.3 to 3.5. Since the thicknesses of the first layer and the second layer each satisfy the above range, more specifically, since the thickness ratios of the first layer and the second layer satisfy the above range, the shrinkage shape is uniform even during the sterilization shrinkage process, so that bending or bursting does not occur, and the appearance is excellent, and a sturdy packaging shape without empty space can be implemented.

[0094] According to one embodiment of the present invention, an adhesive layer may be included between the first layer and the second layer.

[0095] Specifically, the first layer and the second layer can be bonded through the adhesive layer, and the adhesive layer can include a urethane-based adhesive, but is not limited thereto.

[0096] Additionally, the adhesive strength of the first layer and the second layer may be 100 gf to 1,000 gf based on a width of 15 mm. For example, the adhesive strength of the first layer and the second layer may be 100 gf to 900 gf, 200 gf to 850 gf, 600 gf to 800 gf, or 400 gf to 800 gf based on a width of 15 mm.

[0097] According to one embodiment of the present invention, the food packaging material may further include a third layer comprising polypropylene and having a thickness of 15 μm to 60 μm. More specifically, the food packaging material may be formed by sequentially laminating the second layer, the first layer, and the third layer.

[0098] Fig. 2 illustrates a food packaging material according to another embodiment of the present invention. Specifically, Fig. 2 illustrates a food packaging material (100) in which a second layer (120) is formed on one surface of a first layer (110) and a third layer (130) is formed on the other surface of the first layer.

[0099] An adhesive layer may be included between the first layer and the third layer. Specifically, the first layer and the third layer may be bonded through the adhesive layer, and the adhesive layer may include a urethane-based adhesive, but is not limited thereto.

[0100] Additionally, the adhesive strength of the first layer and the third layer may be 100 gf to 1,000 gf based on a width of 15 mm. For example, the adhesive strength of the first layer and the third layer may be 100 gf to 900 gf, 200 gf to 850 gf, or 400 gf to 800 gf based on a width of 15 mm.

[0101] The thickness of the third layer may be 15 μm to 60 μm. For example, the thickness of the third layer may be 16 μm to 58 μm, 18 μm to 55 μm, 20 μm to 50 μm, or 20 μm to 30 μm. The thicknesses of the second layer and the third layer may be the same or different.

[0102]

[0103] Method for manufacturing food packaging materials

[0104] A method for manufacturing a food packaging material according to another embodiment of the present invention comprises the steps of manufacturing a first layer (first substrate) comprising polyamide; and the step of laminating a second layer (second substrate) comprising polypropylene to one surface of the first layer to manufacture the food packaging material, wherein the thickness of the first layer may be 10 µm to 30 µm, and the thickness of the second layer may be 15 µm to 60 µm.

[0105] The above bonding can be performed through bonding methods such as, but not limited to, dry lamination, extrusion lamination, non-solvent lamination, and wet lamination.

[0106] Additionally, the bonding can be performed with a strength (adhesive strength) of 100 gf to 1,000 gf based on a 15 mm width. For example, the first layer and the second layer can be bonded with a strength of 100 gf to 1,000 gf, 200 gf to 850 gf, 600 gf to 800 gf, or 400 gf to 800 gf based on a 15 mm width.

[0107] In addition, the laminate may be formed by laminating the first layer and the second layer so that the longitudinal direction (MD) of the first layer and the longitudinal direction (MD) of the second layer, and / or the transverse direction (TD) of the first layer and the transverse direction (TD) of the second layer are aligned.

[0108] Meanwhile, a commonly known uniaxial or biaxial stretching process may be performed during the manufacturing of each of the first layer (first substrate) and the second layer (second substrate).

[0109]

[0110] retort food

[0111] According to another embodiment of the present invention, a retort food product comprises: a food; and a food packaging material for sealing the food; wherein the food packaging material comprises a first layer comprising polyamide and having a thickness of 10 μm to 30 μm; and a second layer comprising polypropylene and having a thickness of 15 μm to 60 μm.

[0112] The food included in the above retort food is not particularly limited as long as it is a commonly known food (e.g., fresh food; or processed food such as fermented food, smoked food, freeze-dried food, instant food, etc.).

[0113] The food packaging material included in the above retort food has substantially the same composition as the food packaging material described above, and a detailed description thereof will be omitted. By including the food packaging material described above, the retort food may have excellent openability (straight-cutting ability) in the vertical and / or horizontal directions.

[0114] According to one embodiment of the present invention, the retort food may include a sealing portion formed by sealing the food packaging material. Specifically, the sealing portion may include a central sealing portion and an end sealing portion. More specifically, the retort food may include a central sealing portion that forms a space capable of filling the interior with food, and an end sealing portion that seals the food.

[0115] Fig. 3 illustrates a retort food according to another embodiment of the present invention. Specifically, Fig. 3 illustrates a cylindrical tube-shaped retort food (200) including a central sealing portion (220) located in the center and terminal sealing portions (210) located at both upper and lower ends.

[0116] The sealing strength of the above sealing portion may be 1 kgf to 10 kgf based on a 15 mm width. For example, the sealing strength of the above sealing portion may be 1 kgf to 9.5 kgf, 1.5 kgf to 8.5 kgf, or 2 kgf to 8 kgf based on a 15 mm width.

[0117] The width (Wc) of the central sealing portion may be 5% to 50% of the total width (Wt) of the retort food (see Fig. 3). For example, the width (Wc) of the central sealing portion may be 6% to 45%, 7% to 35%, or 10% to 30% of the total width (Wt) of the retort food.

[0118] The length (Le) of the terminal sealing portion may be 5% to 20% of the total length (Lt) of the retort food (see Fig. 3). For example, the length (Le) of the terminal sealing portion may be 5% to 18%, 6% to 15%, or 10% to 15% of the total length (Lt) of the retort food.

[0119] Fig. 4 illustrates an end sealing portion of a retort food according to another embodiment of the present invention. Specifically, Fig. 4 illustrates the upper portion of a retort food (200), and exemplifies a retort food (200) having a notch portion (211) formed in a vertical V shape at the outer end of the end sealing portion (210) and a rounded inner surface.

[0120] The above-described terminal sealing portion may include a notch portion in a vertical direction. Specifically, the notch portion may be located at the outer end of the terminal sealing portion, and may be in the shape of, for example, a |, V, or U, but is not limited thereto. A retort food product according to one embodiment of the present invention may further improve vertical opening properties and / or horizontal opening properties by including a notch portion formed at the outer end of the terminal sealing portion.

[0121] The length (Ln) of the notch portion may be 10% to 50% of the total length (Le) of the terminal seal portion (see Fig. 4). For example, the length (Ln) of the notch portion may be 10% to 45% or 15% to 40% of the total length (Le) of the terminal seal portion.

[0122] According to another embodiment of the present invention, the terminal sealing portion may have a rounded inner surface. For example, the inner surface of the terminal sealing portion may have a shape having a L-shape, a semicircle shape, or a rounded shape, but is not limited thereto. The rounded shape may be a normal rounded shape (a) or a reverse rounded shape (b) (see FIG. 5).

[0123] The radius of curvature of the round shape may be from 5 mm to 100 mm. For example, the radius of curvature of the round shape may be from 5 mm to 80 mm, from 10 mm to 70 mm, or from 15 mm to 60 mm.

[0124] The inner length (Lr) of the terminal sealing portion may be 20% to 70% of the total length (Le) of the terminal sealing portion (see Fig. 4). For example, the inner length (Lr) of the terminal sealing portion may be 25% to 70%, 30% to 65%, or 35% to 60% of the total length (Le) of the terminal sealing portion.

[0125]

[0126] Method for manufacturing retort food

[0127] A method for manufacturing a retort food according to another embodiment of the present invention includes a step of sealing a food packaging material.

[0128] The above sealing may be performed by heat sealing or ultrasonic sealing, but is not limited thereto. For example, the sealing may be performed with a sealing strength of 1 kgf to 10 kgf, 1.5 kgf to 10 kgf, 2 kgf to 9 kgf, or 3 kgf to 8 kgf based on a width of 15 mm.

[0129] Additionally, the sealing can be performed with the second layer of the food packaging material facing each other.

[0130] The above sealing step may include a step of forming a central sealing portion and a step of forming an end sealing portion. Specifically, the food packaging material is rolled into a cylindrical shape, the central sealing portion is formed to create a space into which food can be filled, a end sealing portion is formed at one end, food is filled, and then a end sealing portion is formed at the other end, thereby manufacturing a retort food product including sealed food.

[0131] The above contents are explained in more detail with the following examples. However, the following examples are only intended to illustrate the present invention, and the scope of the examples is not limited to these examples.

[0132]

[0133] [Example]

[0134] Manufacturing of food packaging materials

[0135] Example 1-1

[0136] Polyamide film (1st layer, oxygen permeability (OTR): 8 cc / m) 2 ·day·atm, 95℃ and 5 minutes conditions: Heat shrinkage: 25% (transverse direction (TD)), 21% (longitudinal direction (MD)), thickness: 15 ㎛) on one side of polypropylene film (second layer, tensile strength: 3.8 kgf / mm) 2 (longitudinal direction (MD)), 2.4 kgf / mm 2 (Transverse direction (TD)), thickness: 40 ㎛) was placed, and the first and second layers were laminated using a dry lamination method using a urethane adhesive to manufacture a food packaging material (two-layer structure of the first layer / second layer). At this time, the lamination of the first and second layers was performed at a strength of 300 gf to 600 gf based on a width of 15 mm.

[0137]

[0138] Example 1-2

[0139] Polyamide film (1st layer, oxygen permeability (OTR): 8 cc / m) 2 ·day·atm, 95℃ and 5 minutes conditions, heat shrinkage rate: 21% (longitudinal direction (MD)), 25% (transverse direction (TD)), thickness: 15 ㎛) on one side of polypropylene film (second layer, tensile strength: 2.4 kgf / mm) 2 (longitudinal direction (MD)), 1.8 kgf / mm 2 (Transverse direction (TD)), thickness: 20 ㎛) is placed on the other side, and a polypropylene film (third layer, tensile strength: 2.4 kgf / mm) is placed on the other side. 2(longitudinal direction (MD)), 1.8 kgf / mm 2 (Transverse direction (TD)), thickness: 20 ㎛) were placed, and then the first and second layers, and the first and third layers were laminated using a dry lamination method using a urethane adhesive to manufacture a food packaging material (three-layer structure of third layer / first layer / second layer). At this time, the lamination of the first and second layers, and the first and third layers, was performed at a strength of 300 gf to 600 gf based on a width of 15 mm.

[0140]

[0141] Example 1-3

[0142] Second layer: polypropylene film (second layer, tensile strength: 4.5 kgf / mm) 2 (longitudinal direction (MD)), 3.0 kgf / mm 2 A food packaging material (two-layer structure of first layer / second layer) was manufactured in the same manner as in Example 1-1, except that (transverse direction (TD)), thickness: 50 ㎛) was used.

[0143]

[0144] Experimental Example 1: Sealing Strength

[0145] The sealing strength of the food packaging materials manufactured in Examples 1-1 to 1-3 was measured using a universal material testing machine (Model: 34SC-1, Manufacturer: Instron). Specifically, two sheets of the food packaging materials were prepared, and the face-to-face sealing strength between the second layers was measured. At this time, the longitudinal direction (MD) was used as the standard, and the measurement was performed under the conditions of a film width of 15 mm, a gauge distance of 20 mm, a measurement length of 30 mm, and a measurement speed of 50 mm / min.

[0146]

[0147] Experimental Example 2: Moisture Permeability

[0148] For the food packaging materials manufactured in Examples 1-1 to 1-3, moisture permeability was measured using a moisture permeability meter (model name: Permatran-w3 / 34, manufacturer: Mocon). At this time, the measurement was performed under the conditions of a temperature of 37.8±0.5℃ and a relative humidity of 100±2%.

[0149]

[0150] Experimental Example 3: Oxygen Permeability

[0151] For the food packaging materials manufactured in Examples 1-1 to 1-3, oxygen permeability was measured using an oxygen permeability meter (model name: OX2-TRAN 2 / 22, manufacturer: Mocon). At this time, the measurement was performed under the conditions of a temperature of 23±0.5℃ and a relative humidity of 50±2%.

[0152]

[0153] Experimental Example 4: Thermal Shrinkage

[0154] For the food packaging materials manufactured in Examples 1-1 to 1-3, the thermal shrinkage rate was measured using an A-091 static retro-rotating facility (manufacturer: JBT). Specifically, the food packaging materials were cut into 10 cm wide and 10 cm long pieces to manufacture specimens, sterilized under conditions of 121°C and 30 minutes, dried at room temperature for 30 minutes, and then the thermal shrinkage rates in the mechanical direction and the transverse direction were measured, respectively. At this time, the thermal shrinkage rate was calculated according to the following equation A.

[0155] [Formula A]

[0156] Heat shrinkage rate (%) = ((length before shrinkage - length after shrinkage) / length before shrinkage) × 100

[0157]

[0158] Sealing strength (kgf / 15mm)Moisture permeability (g / m) 2 ·day) Oxygen permeability (cc / m) 2·day·atm)Heat shrinkage rate (MD / TD, %)Example 1-15.33757.1797.87814.8 / 17.7Example 1-24.34966.5378.79413.1 / 16.2Example 1-36.06246.1027.63411.3 / 14.2

[0159] As shown in Table 1 above, the food packaging materials of Examples 1-1 to 1-3 had a uniform shrinkage shape during the sterilization process, no bending or bursting occurred, no delamination occurred between layers, and thus had an excellent appearance, and had sealing strength, moisture permeability, and oxygen permeability suitable for food packaging materials.

[0160]

[0161] Manufacturing of retort foods

[0162] Example 2-1

[0163] The food packaging material of Example 1-1 was heat-sealed at a strength of 2 kgf / cm2 using a 10 mm wide sliver to form a central sealing portion, and the lower part of the cylinder was heat-sealed at a strength of 2 kgf / cm2 using a 10 mm wide sliver to form a terminal sealing portion. After filling the inside of the cylinder with meat food, the upper part of the cylinder was sealed at a strength of 2 kgf / cm2 using a 10 mm wide sliver to form a terminal sealing portion, thereby manufacturing a retort food in the form of a stick pouch. Thereafter, a sterilization shrinkage process was performed at 121°C for 20 minutes to ensure that there were no empty spaces inside the retort food filled with meat food.

[0164] Fig. 6 is a photograph of the retort food of Example 2-1 before performing the sterilization shrinkage process, and Fig. 7 is a photograph of the retort food of Example 2-1 after performing the sterilization shrinkage process. As seen in Fig. 7, the shrinkage shape of the retort food (food packaging material) was uniform, so that no bending or bursting occurred, no delamination occurred between layers, and thus the appearance was excellent, and a sturdy packaging shape was implemented without any empty space.

[0165] [Explanation of symbols]

[0166] 100: Food packaging materials

[0167] 110: 1st floor

[0168] 120: Second floor

[0169] 130: Third floor

[0170] 200: Retort food

[0171] 210: Terminal sealing part

[0172] 211: Notch

[0173] 220: Central sealing section

[0174] Le: Total length of the terminal sealing part

[0175] Lt: Total length of retort food

[0176] Ln: Length of the notch

[0177] Lr: Inner length of the end sealing part

[0178] Wc: Width of the central sealing section

[0179] Wt: Total width of retort food

Claims

1. A first layer comprising polyamide and having a thickness of 10 μm to 30 μm; and A food packaging material comprising a second layer comprising polypropylene and having a thickness of 15 μm to 60 μm.

2. In paragraph 1, The above food packaging material is a food packaging material having a heat shrinkage rate of 8% to 25% under conditions of 95°C to 130°C and 5 to 30 minutes.

3. In paragraph 1, A food packaging material wherein the first layer has a heat shrinkage rate of 8% to 35% under conditions of 95°C to 130°C and 5 minutes to 30 minutes.

4. In paragraph 1, A food packaging material wherein the first layer has a difference in thermal shrinkage in the longitudinal direction (MD) and the transverse direction (TD) of 3% to 10% under conditions of 95°C to 130°C and 5 to 30 minutes.

5. In paragraph 1, A food packaging material wherein the first layer has a heat shrinkage rate in the transverse direction (TD) greater than that in the longitudinal direction (MD) under conditions of 95°C to 130°C and 5 to 30 minutes, or a heat shrinkage rate in the longitudinal direction (MD) greater than that in the transverse direction (TD).

6. In paragraph 1, A food packaging material wherein the second layer has a tensile strength in the longitudinal direction (MD) of 1.1 to 3 relative to the tensile strength in the transverse direction (TD).

7. In paragraph 1, The second layer above has a tensile strength in the transverse direction (TD) of 1 kgf / mm 2 Up to 10 kgf / mm 2 and the tensile strength in the longitudinal direction (MD) is 1.1 kgf / mm. 2 Up to 15 kgf / mm 2 People, food packaging materials.

8. In paragraph 1, A food packaging material wherein the thickness ratio of the first layer and the second layer is 1:1.2 to 4.

9. In paragraph 1, An adhesive layer is included between the first layer and the second layer, A food packaging material, wherein the adhesive layer comprises a urethane adhesive.

10. In paragraph 9, A food packaging material wherein the adhesive strength of the first layer and the second layer is 100 gf to 1,000 gf based on a width of 15 mm.

11. In paragraph 1, The above first layer has an oxygen permeability of 1 cc / m 2 ·day·atm to 25 cc / m 2 ·day·atm, The above food packaging material has a moisture permeability of 25 g / m 2 ·day or less, and oxygen permeability is 25 cc / m 2 ·day·atm or less, food packaging materials.

12. In paragraph 1, The above food packaging material further comprises a third layer comprising polypropylene and having a thickness of 15 ㎛ to 60 ㎛, A food packaging material in which the second layer, the first layer, and the third layer are laminated in sequence.

13. Food; and Including a food packaging material that seals the above food, A retort food comprising a first layer comprising polyamide and having a thickness of 10 μm to 30 μm; and a second layer comprising polypropylene and having a thickness of 15 μm to 60 μm.

14. In paragraph 13, The above retort food includes a sealing portion, A retort food product having a sealing strength of 1 kgf to 10 kgf based on a 15 mm width of the sealing portion.

15. In paragraph 13, A retort food product, wherein the sealing portion includes a central sealing portion and an end sealing portion.

16. In paragraph 15, The width (Wc) of the central sealing portion is 5% to 50% of the total width (Wt) of the retort food, A retort food, wherein the length (Le) of the terminal sealing portion is 5% to 20% of the total length (Lt) of the retort food.

17. In paragraph 15, A retort food product, wherein the terminal sealing portion includes a notch portion in a vertical direction.

18. In paragraph 17, A retort food product in which the length (Ln) of the notch portion is 10% to 50% of the total length (Le) of the terminal sealing portion.

19. In paragraph 15, The inner side of the above terminal sealing portion includes a round shape, A retort food having a radius of curvature of the above round shape of 5 mm to 100 mm.

20. In paragraph 15, A retort food product, wherein the inner length (Lr) of the terminal sealing portion is 20% to 70% of the total length (Le) of the terminal sealing portion.

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