TWI668119B - Gas barrier laminated film and packaging bag - Google Patents

Abstract

The object of the present invention is to provide a laminated biaxially stretched polyamide film having an inorganic thin film layer, which is excellent in crack resistance, impact resistance, and bending fatigue resistance, and particularly excellent in bending fatigue resistance in a low-temperature environment, and is used as a food. When packing materials such as packaging, it has excellent effects such as preventing cracks when transporting goods and storage. It can also have high heat-sealing strength and good appearance when filling liquid soups or seasonings at high speed automatically. It is suitable for various Packaging materials such as foods, medical products, and chemicals that require gas barrier properties. The invention also provides a packaging bag.

The solution of the present invention is a gas-barrier laminated film, which is an inorganic thin film layer on one side or two areas of a substrate film, and satisfies the following requirements (1) to (4): (1) keep under dry heat at 160 ° C At 10 minutes, the heat shrinkage rate in the longitudinal direction is 1.5% to 4.0%; (2) the heat shrinkage rate in the horizontal direction is 2.1% to 4.5%; (3) the film thickness is less than 9 μm; (4) the elasticity rate 2.2GPa or less.

Description

Gas barrier laminated film and packaging bag

The present invention relates to a laminated biaxially stretched polyamide film having an inorganic thin film layer, and has excellent bending fatigue resistance in a low-temperature environment. When used as a packaging material for food packaging, the product has the ability to prevent cracks during transportation and storage And other effects, it can fully maintain its strength when the thickness of the film is thin. It can have both high heat seal strength and good appearance when filling liquid soup or seasoning at high speed automatically. It is suitable for all kinds of foods that require gas shielding, Packaging materials such as medical products and chemicals. The present invention relates to a packaging bag.

Conventionally, an unstretched film or stretched film composed of aliphatic polyamines typified by nylon 6 or nylon 66 is excellent in impact resistance or bending fatigue resistance, and has been used alone or as a laminate with other films for various applications. The packaging material is widely used as various packaging material films, for example, by laminating it with various gas shielding resins in order to improve the gas barrier properties of the film. In particular, for applications such as liquid filling and packaging, from the viewpoint of excellent gas barrier properties, bending resistance, and heat resistance, such gas barrier polyamine resin films are widely used.

In the case of liquid filling and packaging such as soups and seasonings, this type of polyamide resin film is widely used in a single layer of aliphatic polyamide to mix various elastomers in order to further improve bending fatigue resistance and impact resistance ( A rubber component) and a more flexible stretched polyamide film for pinhole resistance. The pinhole resistance film is known as a film of an aliphatic polyamide mixed with a polyamide-based elastomer (Patent Document 1). The film has good bending fatigue resistance and impact resistance in a low temperature environment, and pinholes due to bending fatigue are not easily generated even in a low temperature environment.

Moreover, forming a laminated structure of a polyamide film can improve characteristics such as bending fatigue resistance and impact resistance. For example, it has been disclosed that a laminated biaxially stretched polyamide film is composed of an aliphatic polyamide layer containing an aliphatic homopolyamide and a thermoplastic elastomer, and an aliphatic polyamide layer containing a thermoplastic elastomer and inorganic particles. Composition (Patent Document 2). The above-mentioned laminated biaxially stretched polyamide film is characterized by good bending fatigue resistance and impact resistance in a low temperature environment, and pinholes due to bending fatigue are unlikely to be generated even in a low temperature environment. The requirements for fatigue resistance and impact resistance have been further improved. Especially when the film is thinned to have a film thickness of 9 μm or less, the required characteristics such as impact resistance and pinhole resistance have not been fully satisfied.

On the other hand, when the aforementioned polyamide film is used as a packaging bag, if necessary, an adhesive layer is provided on at least one side, and polyethylene, Polypropylene, etc. Into a sealing layer. Next, the bag is formed into a bag shape by a generally known method, and contents such as soup and seasoning are filled from the opening, and then the opening is heat-sealed. In this case, the use of an automatic filling machine for packaging articles is excellent in simplicity and productivity, and is widely used for packaging various articles, including food and beverages.

Regarding these automatic filling machines, in recent years, they have been moving towards higher speed and higher efficiency for the purpose of further improving productivity. However, when automatic filling and bag-making of various articles are performed at high speed, in order to obtain sufficient sealing strength, the heat-sealing temperature must be set to a high temperature. However, heat-sealing at high temperatures will shrink the film and cause wavy wrinkles in the heat-sealed part. problem. If the wavy wrinkles are generated in the heat-sealed portion, the value of the product will not only be reduced in terms of appearance, but also the contents will leak out or crack. On the other hand, if the heat-sealing temperature is lowered in order to prevent wrinkles in the heat-sealed portion, the heat-sealed portion will cause an unfused portion and reduce the sealing strength, causing the problem of leakage of the contents.

In order to solve the foregoing problem, a polyimide film having a set heat shrinkage rate is disclosed (Patent Document 3). However, the invention of the polyimide film does not describe a bending resistance that enhances important characteristics required for use as a packaging material. Fatigue or impact resistance.

As mentioned above, when a gas-shielding polyimide film is used as a liquid packaging bag for soups, seasonings, etc., in addition to bending fatigue resistance and impact resistance, high sealing strength after heat-sealing and heat-sealing parts are also required. Good appearance, However, the conventional film structure cannot meet all these required characteristics.

In addition, as part of countermeasures against environmental problems in recent years, it is required to save resources and reduce waste, and liquid filling packaging materials must also be reduced in capacity.

[Prior technical literature]

[Patent Literature]

Patent Document 1: Japanese Patent Application Laid-Open No. 11-254615.

Patent Document 2: Japanese Patent Application Laid-Open No. 2010-234552.

Patent Document 3: Japanese Patent Application Laid-Open No. 11-277698.

The present invention is made in view of the problems existing in the related art pinhole-resistant polyamine film, and an object thereof is to provide a laminated biaxially stretched polyaminium film having an inorganic thin film layer, which is resistant to bending in a low temperature environment. Excellent fatigue resistance. When used as packaging materials such as food packaging, it has the effect of preventing cracks when transporting goods and storage. It can maintain its strength even when the film thickness is thin, and it can automatically fill liquid soups and seasonings at high speeds. At the same time, it can also have high heat seal strength and good appearance, and is suitable for various packaging materials such as food, medical products, and chemicals that require gas barrier properties. The present invention also provides a packaging bag.

The present inventors considered that the flexural fatigue resistance and the heat-sealing strength and good appearance during auto-filling were good, and the problem was the film thickness of the polyamide film. The amidine film is formed to a specific thickness or less, and the laminated biaxially stretched polyamide film has a layer composed of an aliphatic homopolyamine, an aliphatic copolymer polyamide, and a thermoplastic elastomer, and an aliphatic homopolymer. A layer composed of polyamide and a thermoplastic elastomer, and further forming an inorganic thin film layer, can have both of these characteristics, which were previously unattainable, thus completing the present invention.

That is, the constitution of the present invention is as follows.

1. A gas-barrier laminated film, which is an inorganic thin film layer on one side or two areas of a substrate film, and meets the following requirements: (1) When kept under dry heat at 160 ° C for 10 minutes, the heat shrinkage rate in the longitudinal direction is 1.5% or more and 4.0% or less; (2) Heat shrinkage in the transverse direction is 2.1% or more and 4.5% or less; (3) The film thickness is less than 9 μm; (4) The elastic modulus is 2.2 GPa or less.

2. The gas-barrier laminated film according to 1. above, wherein when the film is kept under dry heat at 160 ° C. for 10 minutes, the value of the heat shrinkage in the transverse direction of the film divided by the heat shrinkage in the longitudinal direction of the film is 1.0 to 1.4.

3. The gas-shielding laminated film according to the above 1. or 2., wherein the base film is composed of 97 to 70% by weight of aliphatic homopolyamide and 3 to 20% by weight of aliphatic copolyamide. At least one side of the A layer composed of a mixed polymer of 0 to 10% by weight of a thermoplastic elastomer, and a layer of a mixed polymer of 99.5 to 90% by weight of an aliphatic homopolyamide and 0.5 to 10.0% by weight of a thermoplastic elastomer The B layer.

4. The gas-shielding laminated film according to any one of 1. to 3., wherein the thickness of the B layer is 1 μm or more.

5. The gas-barrier laminated film according to any one of 1. to 4. above, wherein the punching strength is 0.6 J / 10 μm or more, the number of bending fatigue pinholes at 5 ° C is 5 or less, and the breaking strength is 25 N / 15mm or more.

6. The gas-shielding laminated film according to any one of the foregoing 1. to 5., wherein the inorganic thin film layer includes a mixture of one or more kinds selected from a metal or an inorganic oxide.

7. The gas-shielding laminated film according to any one of 1. to 6., wherein the inorganic thin film layer system includes two metals, two inorganic oxides, or one metal and one inorganic oxide.

8. The gas-barrier laminated film according to any one of 1. to 7., wherein the two inorganic oxide systems include silicon oxide and aluminum oxide.

9. The gas-barrier laminated film according to any one of 1. to 8., wherein the water vapor transmission rate is 6 g / m ² . Less than day, and the oxygen permeability is 30ml / m ² . day. MPa or less.

10. A packaging bag using the gas-barrier laminated film according to any one of 1. to 9. above, and using an inorganic vapor-deposited layer as an outermost layer.

According to the present invention, a polyamide film can be provided, which maintains the strong toughness, pinhole resistance, and bending resistance of the polyamide film. It has high heat seal strength when used in high-speed automatic filling, and has appearance characteristics and gas shielding. Excellent performance and capacity reduction.

Hereinafter, a laminated biaxially stretched polyimide film used as a base film for laminating an inorganic thin film layer will be described in detail. Laminated biaxially stretched polyamide film as the base film (hereinafter referred to as "base film" or "laminated biaxially stretched polyamide film") is on at least one side of the layer A composed of a specific mixed polymer The laminate is composed of a layer B made of a specific mixed polymer.

Layer A of the base film is composed of a mixed polymer of 97% to 70% by weight of aliphatic homopolyamide, 3 to 20% by weight of aliphatic copolyamide, and 0 to 10% by weight of thermoplastic elastomer as needed. . The aforementioned layer A is an aliphatic copolyamide with micro-disperse as a softening agent and a thickener among aliphatic homopolyamides having excellent impact resistance and bending fatigue resistance. It has excellent punching strength and bending fatigue resistance, and is further dispersed with a thermoplastic elastomer as a pinhole resistant material. This structure has excellent bending fatigue resistance, especially in low temperature environments. Here, when the blending amount of the aliphatic copolymer polyamides constituting the A layer is less than 3% by weight, if the blending amount of the thermoplastic elastomer is small, it is impossible to obtain high impact resistance and bending resistance that exceed the current pinhole-resistant polyamide stretch film. Fatigue. Moreover, when the compounding quantity of the aliphatic copolymer polyamide which comprises A layer exceeds 20 weight%, impact strength and bending fatigue resistance will be saturated. Moreover, if the blending amount of the thermoplastic elastomer is increased, the bending fatigue resistance can be improved. When it exceeds 10% by weight, the transparency is deteriorated and the bending fatigue resistance is saturated.

The aliphatic homopolyamine which constitutes the A layer of the base film is not particularly limited as long as it can be used as a film forming material and is suitable for forming the aforementioned structure. For example, aliphatic polyamide homopolymers such as nylon 6, nylon 6/6, nylon 11, nylon 12, nylon 6/10, and the like can be used.

The aliphatic copolyamide blended in layer A is a copolymer in which the copolymerizable monomer in the aforementioned aliphatic homopolyamide is 10% by weight or less, preferably a copolymer in which the copolymerizable monomer is 1 to 10% by weight. For example, aliphatic copolymers such as nylon 6/6/6 copolymer, nylon 6/12 copolymer, nylon 6/6/10 copolymer, nylon 6/6/6/10 copolymer, or the like can be used. ε-caprolactam as a main component and copolymerized with a nylon salt and the like containing a small amount of aromatic polyamine copolymer, and the nylon salt is a nylon salt of hexamethylene diamine and isophthalic acid, or m-xylylene diamine Nylon salt with adipic acid.

The thermoplastic elastomer mixed in layer A is not particularly limited as long as it is a thermoplastic material having a rubber-like elastic substance and is suitable for forming the aforementioned structure. Examples thereof include a polyamide-based elastomer, a polyolefin-based elastomer, a polystyrene-based elastomer, a polyurethane-based elastomer, a polyester-based elastomer, a polyvinyl chloride-based elastomer, and an ionic polymer. In addition, a mixture of such elastomers may be mentioned. The thermoplastic elastomer can be used alone or in combination of two or more.

In the present invention, the thermoplastic elastomer can be modified within a range that does not impair the object of the present invention. For example, it may be a modification of the thermoplastic elastomer exemplified above. Examples of the modification of the thermoplastic elastomer include modification by copolymerization or graft modification, modification by imparting a polar group, and the like. Giving a polar group can be performed by graft modification. Examples of the polar group include an epoxy group, a carboxyl group, an acid anhydride group, a hydroxyl group, an amine group, and a pendant oxygen group. One type of polar group or a combination of plural types of polar groups can be given. Therefore, the modified substance imparting a polar group includes, for example, an epoxy group modified substance of a thermoplastic elastomer, a carboxyl group modified substance, an acid anhydride modified substance, a hydroxyl modified substance, an amine modified substance, and the like.

The thermoplastic elastomer of the present invention is suitably used for a polyamide-based elastomer, a polyolefin-based elastomer, and an ionic polymer.

Examples of the polyamide-based elastomer include a polyamide-based block copolymer including a hard segment composed of a polyamide component and a soft segment composed of a polyoxyalkylene glycol component. The polyamide component of the hard segment can be selected from (1) lactam, (2) omega-amino aliphatic carboxylic acid, (3) aliphatic diamine and aliphatic dicarboxylic acid, or (4) aliphatic A group formed by a diamine and an aromatic dicarboxylic acid, specifically, e.g., ε-caprolactam such as lactam, an aminoheptanoic acid such as an aliphatic diamine, adipic acid or the like Aromatic dicarboxylic acids such as aliphatic dicarboxylic acids and terephthalic acid. Examples of the polyoxyalkylene glycol constituting the soft segment of the polyamido-based block copolymer include polyoxytetramethylene glycol, polyoxyethylene glycol, and polyoxy-1,2-propylene glycol. Wait.

The melting point of the polyamide block copolymer is determined by the type and ratio of the hard segment composed of the polyamide component and the soft segment composed of the polyoxyalkylene glycol component, but 120 ° C to 180 ° C is usually used. Range.

Using a polyamide-based block copolymer as a constituent of a laminated biaxially stretched polyamide film of a base film, thereby improving the bending fatigue resistance of the base film, especially the bending fatigue resistance in a low temperature environment.

The polyolefin-based elastomer is not particularly limited, and examples thereof include block copolymers in which polyolefin is a hard segment and various rubber components are soft segments. Examples of the polyolefin constituting the hard segment include ethylene, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-octene, 1 -Homopolymers or copolymers, such as α-olefins having 2 to 20 carbon atoms, such as decene, 1-dodecene, 1-tetradecene, 1-pentadecene, and 1-octadecene. Polyolefin can be used individually or in combination of 2 or more types. Preferred olefins include ethylene and propylene. Examples of the rubber component constituting the soft segment include ethylene / propylene rubber (EPR), ethylene / propylene / diene rubber (EPDM), polybutadiene, polyisoprene, natural rubber (NR), and nitrile rubber. (NBR; acrylonitrile / butadiene rubber), styrene / butadiene rubber (SBR), neoprene (CR), butyl rubber (IIR), hydrogenated NBR (H-NBR), acrylonitrile / isobutylene Pentadiene rubber (NIR), acrylonitrile / isoprene / butadiene rubber (NBIR), etc. These rubber components also include acid-modified rubbers such as carboxylated rubbers containing unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, and anhydrous maleic acid as comonomers, or other modified rubbers, hydrides, and the like. Wait.所述 胶 成 The rubber into They can be used alone or in combination of two or more.

The ionic polymer is not particularly limited, and examples thereof include polyolefins used as a hard segment, various rubber components subjected to acid modification with an unsaturated carboxylic acid as a soft segment, and intercalation formed by neutralization with metal ions. Block copolymers and so on. Preferred ionic polymers include copolymer resins composed of ethylene and methacrylic acid, or copolymer resins composed of ethylene, methacrylic acid, and acrylate, which are neutralized by metal ions including Na +, K +, and Zn2 +. Into an ionic polymer.

The mixed polymer constituting the layer A may be the aforementioned aliphatic homopolyamide, aliphatic copolyamide, and optionally a thermoplastic elastomer mixed with virgin raw materials, and may be a biaxially stretched polymer added in the layer of the present invention. The non-standard film produced during the production of fluorene film or the cutting material produced by cutting the end material (trimming), and its recycled resin and raw materials are adjusted.

The layer B of the present invention is composed of a mixed polymer of 99.5 to 90% by weight of aliphatic homopolyamide and 0.5 to 10% by weight of thermoplastic elastomer. The aforementioned layer B has excellent resistance to bending pinholes, can withstand the impact of bending applied to the packaging bag, and exhibits crack resistance. When the content of the thermoplastic elastomer is within the aforementioned range, good transparency can be maintained and bending fatigue resistance can be improved.

The aliphatic homopolyamide and thermoplastic elastomer constituting the B layer can be used in the same manner as the aliphatic homopolyamide and thermoplastic elastomer of the A layer described above. Sexual body.

The multilayer biaxially stretched polyamide film used as a base film used in the present invention is formed in this manner. Here, the bending fatigue property of the film is affected by the thickness of the film, and the thicker the film, the lower the bending fatigue property. The reason is that when the film is bent, it will receive tensile stress on the outside of the bend and compressive stress on the inside of the bend, and the thicker the film, the greater these stresses. The polyamide film obtained in the present invention preferably has a thickness of less than 9 μm. When the film thickness is 9 μm or more, the bending fatigue resistance decreases, which is not preferable.

A gas-shielding laminated film is produced by laminating an inorganic thin film layer on the base film produced in the aforementioned manner. The thickness of the gas barrier laminated film will also greatly affect the heat seal strength and film appearance after high-speed automatic filling. The reason is as follows. After the gas barrier laminated film is provided with a sealing layer made of polyethylene, polypropylene, etc. and processed into a bag shape, it is filled with the contents such as seasoning and the sealing layer is used to heat-seal the opening, but the gas barrier property is When the laminated film is thick, heat cannot be sufficiently transmitted to the heat-sealing layer provided inside the gas-barrier laminated film during high-speed automatic filling, thereby reducing heat-sealing strength. On the other hand, if the heat-sealing temperature is set high during high-speed automatic filling, although sufficient strength can be obtained in terms of heat-sealing strength, heating the film at a high temperature will cause wavy wrinkles in the heat-sealed portion, which will reduce the appearance. .

In order to have both heat seal strength and good film appearance during high-speed automatic filling, it is important that the thickness of the gas-shielding laminated film is less than 9 μm. gas When the thickness of the body-shielding laminated film is 9 μm or more, it is difficult to combine these two characteristics, and when the heat-sealing temperature is set low during high-speed automatic filling, the heat-sealing strength is insufficient. On the other hand, if the heat-sealing temperature is set to be high in order to obtain sufficient heat-sealing strength, wrinkles are generated in the heat-sealed portion, and there is a problem that the appearance is not good.

In addition, compared with the conventional polyimide film used in packaging applications, by reducing the thickness of the gas-shielding laminated film to less than 9 μm, capacity reduction can be achieved, and resource saving and waste reduction can be achieved as part of measures against environmental problems. Demand.

As described above, by making the thickness of the gas-shielding laminated film less than 9 μm, both the bending fatigue resistance, heat-sealing strength, and good appearance after heat-sealing can be achieved, and the capacity can be further reduced.

The method of measuring the heat seal strength is described later, but after the gas barrier laminated film of the present invention is provided with a sealing layer made of polyethylene, polypropylene, or the like and processed into a bag shape, the sealing layer is used as the inner side at 140 ° C, 0.5 The conditions for the second are heat-sealed openings, and when the sealing strength is measured in accordance with JISZ1707, the strength is preferably 23 N / 15 mm or more. If it is less than 23N / 15mm, the heat-sealed part will cause unfused parts, which may cause the problem of leakage of the contents, which is not good.

The present invention is formed by laminating at least one side (for example, one side or both sides) of the layer A constituted in the manner described above, and the layer B constituted in the manner described above. The gas-shielding laminated film is an extremely thin film with a total film thickness of less than 9 μm, but can achieve a punching strength of 0.6 J / 10 μm or more, a bending fatigue pinhole number of 5 or less at 5 ° C, and a fracture strength of 25 N / 15 mm the above. The haze of the gas-shielding laminated film of the present invention is preferably 6% or less. If the haze exceeds 6%, the transparency cannot be sufficiently improved, and it is difficult to use it for applications requiring transparency. It is more preferably 5% or less, and still more preferably 4% or less. The smaller the haze value, the better, but it is not a problem even if it is 1% or more. Even 2% or more is a preferable range.

In addition, it is preferable that the heat-shielding rate of the film flow direction (hereinafter referred to as the "longitudinal direction") when the gas-shielding laminated film is kept under dry heat at 160 ° C for 10 minutes is 1.5% to 4.0%, and the film width (hereinafter It is called "horizontal direction") and the heat shrinkage ratio is 2.1 to 4.5%. If the heat shrinkage ratios in the longitudinal direction and the transverse direction exceed 4.0% and 4.5%, respectively, heat history during heat sealing will easily cause shrinkage wrinkles caused by heat shrinkage, which is not good. In addition, in processing steps such as printing or lamination with other substrate films, defects such as deviations in printing gaps and curling caused by thermal shrinkage also occur. On the other hand, if the heat shrinkage in the flow direction is less than 1.5%, when the film is stretched by a heating roller during heat sealing, the film has insufficient tensile strength and is stretched. Therefore, wavy wrinkles are generated in the heat sealed portion, so good.

In order to prevent wavy wrinkles in the heat-sealed portion, it is important to balance the heat shrinkage rate in the longitudinal direction with the heat shrinkage rate in the horizontal direction. For example, the heat shrinkage ratio in the longitudinal direction is 2.5% or more and stretched in the longitudinal direction In the state of exerting tensile resistance, shrinkage occurs in the horizontal direction when performing heat sealing in the horizontal direction, but when the heat shrinkage rate in the horizontal direction is less than 1.5%, the aforementioned shrinkage will not be absorbed, and wavy wrinkles will occur in the heat-sealed portion .

From the above point of view, it is necessary to satisfy the heat shrinkage of the film flow direction (longitudinal direction) of the gas-shielding laminated film in the range of 1.5 to 4.0%, and the heat shrinkage of the wide direction (horizontal direction) to be in the range of 2.1 to 4.5%. In the range, the value of the heat shrinkage in the film width direction divided by the heat shrinkage in the film flow direction when kept at 160 ° C. for 10 minutes is preferably 1.0 to 2.0, and more preferably 1.0 to 1.4. The closer the value is to 1.0, the shrinkage ratio in the film flow direction and the film width direction is equal, it is less likely to cause wrinkles, and the film appearance is good.

The elastic modulus of the gas-shielding laminated film of the present invention is preferably 2.2 GPa or less. Above 2.2 GPa, the flexibility is insufficient, and the bending fatigue resistance is reduced. If it is less than 1.5 GPa, it is too soft, and the balance of pinhole resistance cannot be obtained. More preferably, it is 1.6 GPa or more and 2.1 GPa or less.

Regarding the aforementioned elastic modulus, in order to have other physical properties, it is necessary to optimize the heat fixing temperature and time of the tenter in the film forming step. The heat fixing temperature is preferably 190 ° C to 205 ° C, and more preferably 195 ° C to 203 ° C. The heat fixing time is preferably 5 to 20 seconds, and more preferably 10 to 15 seconds. In particular, if the heat-fixing temperature is lower than 190 ° C, the film will not crystallize, so the structure is unstable and the dimensional stability is poor, and characteristics such as target thermal shrinkage cannot be obtained. In addition, mechanical strength such as impact resistance and pinhole resistance is also insufficient.

On the other hand, when the heat-fixing temperature is higher than 205 ° C, the film is too crystallized to obtain the necessary elastic modulus, which is not preferable. In addition, the film is whitened and devitrified due to the progress of crystallization, and the haze is likely to increase.

In addition, the base film of the present invention preferably contains inorganic fine particles having a pore volume of two or more types in layer B, such as inorganic fine particles having a pore volume of 0.6 to 1.0 ml / g, and 1.1 to 1.6 ml / g. Pore volume of inorganic fine particles. The pore volume range of the inorganic fine particles is preferably 0.5 to 2.0 ml / g, and more preferably 0.8 to 1.5 ml / g. If the pore volume is less than 0.5 ml / g, voids are likely to occur and the transparency of the film is deteriorated. If the pore volume exceeds 2.0 ml / g, the film smoothness is deteriorated, which is not good. By using the above-mentioned inorganic fine particles having a pore volume of two or more types, the transparency can be maintained, and the smoothness can be maintained in a high-humidity environment. It can withstand friction and bending shocks applied to the packaging bag, and can exhibit crack resistance.

The inorganic fine particles can be appropriately selected and used from inorganic lubricants such as silicon dioxide, kaolin, and zeolite; and polymer-based organic lubricants such as acrylic and polystyrene. In terms of transparency and smoothness, it is preferable to use silicon dioxide fine particles.

The average particle diameter of the inorganic fine particles is preferably 0.5 to 5.0 μm, and more preferably 1.0 to 3.0 μm. If the average particle diameter is less than 0.5 μm, it is necessary to add a large amount in order to obtain good smoothness, and if it exceeds 5.0 μm, the surface roughness of the film becomes It is too large to satisfy practical characteristics, so it is not good.

The pore volume refers to the pore volume (ml / g) contained in 1 g of the inorganic fine particles. Such silica particles are generally obtained by pulverizing and classifying synthetic silica, but it is also possible to use porous silica particles obtained directly as spherical fine particles during synthesis. In addition, such silica particles may be aggregates formed by agglomeration of primary particles, and pores may be formed between the primary particles and the primary particles.

The pore volume can be adjusted by changing the synthesis conditions of the inorganic fine particles. The smaller the pore volume, the better the smoothness can be added in a small amount. If inorganic fine particles having a small pore volume are used, the polyamide-based resin doped with particles may form high protrusions on the surface of the film during the stretching step, or may generate more voids and impair the transparency of the film. In contrast, when inorganic fine particles having a large pore volume are used, a large amount can be added while maintaining transparency. However, the height of the formed surface protrusions is relatively low. In order to maintain suitable smoothness under high humidity conditions, a large amount of inorganic fine particles need to be added. Therefore, if the inorganic fine particles of the above two types or more are added to the B layer, transparency can be maintained, and high surface protrusions can coexist with low surface protrusions, and excellent smoothness in a high humidity environment can be obtained. In addition, the transparency of the biaxially stretched film can also be changed by the stretching conditions (temperature or magnification) or a relaxation treatment condition (tempering ratio or temperature) thereafter. Therefore, it is preferable to appropriately control these conditions.

The method of adding inorganic fine particles to the B layer can be achieved by polymerizing the resin It is added at the time of addition, or it is added at the time of melt extrusion with an extruder to form a masterbatch, and it is added to polyamide during the production of a film, and it is performed using a known method such as the aforementioned masterbatch.

The average particle diameter of the inorganic fine particles is a value measured in the following manner. Using a high-speed stirrer, disperse the inorganic fine particles in ion-exchanged water stirred at a fixed rotation speed (about 5000 rpm), add the aforementioned dispersion to AISOTON (physiological saline), and further disperse with an ultrasonic disperser, and then use a Coulomb counter ( The coulter counter) method was used to obtain the particle size distribution, and the particle diameter in 50% of the cumulative weight distribution was calculated as the average particle diameter.

The content of the inorganic fine particles in the layer B is 0.03 to 2.5% by weight, and more preferably 0.08 to 1.5% by weight. If the content of the inorganic fine particles is less than the foregoing range, the smoothness of the biaxially stretched film under high humidity cannot be sufficiently improved. If the content exceeds the foregoing range, the amount of loss in the extraction step is large, and the transparency of the film may be deteriorated Tolerance is not good. In addition, it is preferable that the B layer contains 0.005 to 0.5% by weight of inorganic fine particles having a pore volume of 0.6 to 1.0ml / g, and 0.01 to 2.0% by weight of pore volumes of 1.1 to 1.6ml / g. Of inorganic fine particles.

In addition to the aforementioned essential components, the substrate film of the present invention may contain various other additives such as a lubricant, an anti-caking agent, a heat stabilizer, an antioxidant, an antistatic agent, a light resistance agent, as long as the aforementioned characteristics are not hindered. Shock resistance improver and so on. In particular, if an organic lubricant having a function of reducing surface energy is added to such an extent that adhesion or wettability does not cause a problem, It is preferable because it can impart more excellent smoothness and transparency to the stretched film.

In the present invention, for the purpose of imparting smoothness, the fatty acid amidoamine and / or the fatty acid diamine may be contained in the A layer and / or the B layer. Examples of the fatty acid ammonium and / or the fatty acid diammonium include ammonium sinarate, ammonium stearate, ammonium distearate, and ammonium dioleate.

At this time, the content of the fatty acid amidoamine and / or the fatty acid diamidine in the polyamine is preferably 0.01 to 0.40% by weight, and more preferably 0.05 to 0.2% by weight. If the content of fatty acid amidine and / or fatty acid diamine is less than the aforementioned range, the smoothness is poor and the processing suitability during printing or lamination is not good. If it exceeds the aforementioned range, it may precipitate on the surface of the film over time. Spots appear on the surface, which is not good in terms of quality.

The base material film of the present invention is obtained by adding inorganic fine particles to the B layer as described above, or containing fatty acid amidoamine and / or fatty acid diamidine in the A layer and / or the B layer, thereby achieving a temperature of 23 ° C. and 65% RH. The coefficient of static friction between the slippery surfaces of the film is 0.90 or less. Here, the film slippery surface refers to a layer containing inorganic fine particles, that is, a layer B.

The total thickness of the gas-shielding laminated film of the present invention is usually 100 μm or less when used as a packaging material, and a thickness of 5 to 50 μm is generally used. However, the gas-shielding laminated film of the present invention is characterized in that the above-mentioned effects can be exhibited even in the case of a thin film structure of less than 9 μm.

When the gas-shielding laminated film of the present invention is processed into a packaging bag (bag-making product), the preferred layered structure is the B-layer which becomes the outermost surface of the bag-making product. When the bag-made products are transported, when friction occurs with the transport packaging such as a cardboard box, the friction may scratch the film and rupture, or the contact between the bags may puncture and increase bending fatigue and rupture. In the constitution of the present invention, the layer B with excellent smoothness reduces the cracking factors caused by friction and exhibits high cracking prevention properties.

In this case, when the thickness of the B layer accounts for most of the total thickness of the film, the transparency is greatly reduced, although high smoothness can be ensured. Conversely, when the thickness of the layer A accounts for most of the total thickness of the film, the smoothness cannot be secured although the flexibility, impact strength, and bending fatigue resistance are excellent. Therefore, in the present invention, the thickness of the A layer is 60 to 96%, and preferably 65 to 93%, of the total thickness of the A and B layers. Further, by making the thickness of the B layer at least 1 μm or more, and preferably 3 μm or less, it is possible to effectively achieve both bending fatigue resistance and abrasion resistance.

The method of mixing the various polyamides, thermoplastic elastomers, etc. constituting the A layer and the B layer is not particularly limited, but a method in which a sheet polymer is mixed with a V-type mixer or the like and melt-molded is generally used.

As long as the characteristics are not impaired, other thermoplastic resins, such as polyethylene terephthalate, polyethylene terephthalate, may be contained in the polyamides constituting the A and B layers of the base film of the present invention, if necessary. Polyester polymers such as butyl formate and naphthalate-2,6-ethylene diester; polymer of polyethylene, polypropylene, etc. Olefin-based polymers.

In addition, various additives such as an antistatic agent, an anti-fogging agent, an ultraviolet absorber, a dye, or a pigment may be contained in one or both of the layer A and / or layer B made of polyamide, if necessary.

The base film of the present invention can be produced by a known production method. For example, it is possible to use an extruder to melt the polymers constituting each layer, and then co-extruded from a single die to produce them; the polymers constituting each layer are individually melted and extruded into a film, and then laminated. ; And any known method of combining these methods and the like. For the stretching method, for example, a known method such as a planar sequential biaxial stretching method, a planar simultaneous axis stretching method, and a blown film method can be used, which can be stretched 2 to 5 times in the longitudinal direction and 3 to 6 times in the transverse direction, and heat-fixed. This can improve the transparency, oxygen shielding, or processing suitability of the laminated film.

The gas-barrier laminated film of the present invention is a state in which an inorganic thin film layer is laminated on the base film. That is, the base film of the present invention is used in a gas-shielding laminated film including an inorganic thin film layer, and is in the form of the inorganic thin film laminate.

The inorganic thin film layer is a thin film including a metal or an inorganic oxide. The material for forming the inorganic thin film layer is not particularly limited as long as it can form a thin film. From the viewpoints of processability and gas barrier properties, it is preferable to use a material containing aluminum. Examples of the material containing aluminum include high-purity aluminum (99.9 mol% or more), aluminum oxide containing other additive elements, and inorganic oxides such as aluminum oxide. It may be a plurality of metals, and a combination of a metal and an inorganic oxide or a plurality of inorganic oxides. The combination of materials for forming the inorganic thin film layer is not particularly limited, and examples thereof include high-purity aluminum and aluminum alloys, two types of aluminum alloys (additional elements such as magnesium, silicon, titanium, calcium, and manganese) and aluminum alloys different from each other. And alumina, alumina and titania, silicon oxide and alumina, etc., but from the viewpoint of the flexibility and density of a thin film layer, a composite oxide of silica and alumina is preferred Thing.

Among the foregoing composite oxides, a relatively good mixture of silicon oxide and aluminum oxide is preferably in a range of 20% to 70% in terms of the mass ratio of the metal component. If the Al concentration is less than 20%, the water vapor barrier property may decrease. On the other hand, if the Al concentration is less than 70%, the inorganic thin film layer tends to harden, and the film may break during printing or secondary processing There is a possibility that the shielding property will decrease. Here, silicon oxide refers to various silicon oxides such as SiO or SiO ₂ or a mixture thereof, and aluminum oxide refers to various aluminum oxides such as AlO or Al ₂ O ₃ or a mixture thereof.

The thickness of the inorganic thin film layer is usually 1 nm to 800 nm, and preferably 5 nm to 500 nm. If the thickness of the inorganic thin film layer is less than 1 nm, it is difficult to obtain satisfactory gas barrier properties. On the other hand, if it exceeds 800 nm, even if it is excessively thickened, the corresponding gas barrier improvement effect cannot be obtained, from bending resistance. And manufacturing costs.

The water vapor transmission rate (g / m ² .day) of the laminated film having an inorganic thin film layer is preferably 6 or less, and more preferably 5 or less. When the laminated film has an oxygen permeability of more than 6, sufficient gas barrier properties cannot be obtained.

The oxygen permeability (ml / m ² .day. MPa) of the laminated film having an inorganic thin film layer is preferably 30 or less, and more preferably 25 or less. When the oxygen permeability of the laminated film exceeds 30, sufficient gas barrier properties cannot be obtained.

A method for forming the inorganic thin film layer is not particularly limited, and a known vapor deposition method such as a physical vapor deposition method (PVD method) or a chemical vapor deposition method (CVD method) such as a vacuum vapor deposition method, a sputtering method, or an ion plating method can be suitably used Plating method. Hereinafter, a typical method for forming an inorganic thin film layer will be described using a silicon oxide / alumina film as an example. For example, when a vacuum evaporation method is used, it is preferable to use a mixture of SiO ₂ and Al ₂ O ₃ or a mixture of SiO ₂ and Al as a vapor deposition raw material. These vapor deposition raw materials can use general particles, but at this time, it is preferable that the size of each particle is a size that does not change the pressure degree during vapor deposition, and the particle diameter is preferably 1 mm to 5 mm. Heating can be performed by resistance heating, high-frequency induction heating, electronic wire heating, laser heating, and the like. In addition, oxygen, nitrogen, hydrogen, argon, carbonic acid gas, water vapor, or the like can be introduced as a reaction gas, or reactive evaporation such as ozone or ion-assisted can be used. In addition, a bias voltage may be applied to a body to be vapor-deposited (a laminated film for vapor deposition), a body to be vapor-deposited may be heated or cooled, and the film forming conditions may be arbitrarily changed. When a sputtering method or a CVD method is used, the vapor deposition material, the reaction gas, the bias voltage of the body to be vapor-deposited, and the like can be changed in the same manner.

The gas-shielding laminated film of the present invention described above has an inorganic thin film layer, thereby forming a gas-shielding property excellent in oxygen shielding property and water vapor shielding property. Laminated film (laminated body).

Moreover, in a gas-shielding laminated film having an inorganic thin film layer, at least one or more printed layers or other plastic substrates can be laminated between or outside the inorganic thin film layer or the base film and the heat-sealable resin layer, and / Or paper substrate.

The printing ink forming the printing layer is preferably a water-based or solvent-based resin-containing printing ink. Examples of the resin used in the printing ink include acrylic resins, urethane resins, polyester resins, vinyl chloride resins, vinyl acetate copolymer resins, and mixtures thereof. Printing inks may contain well-known antistatic agents, opacifiers, ultraviolet absorbers, plasticizers, slippers, fillers, colorants, stabilizers, lubricants, defoamers, crosslinking agents, anti-blocking agents, antioxidants, etc. additive. The printing method for providing the printing layer is not particularly limited, and known printing methods such as a lithographic printing method, a gravure printing method, and a screen printing method can be used. For drying of the solvent after printing, a known drying method such as hot air drying, hot roll drying, or infrared drying can be used.

On the other hand, from the viewpoint of obtaining sufficient rigidity and strength of the laminated body, it is preferable to use paper, polyester resin, biodegradable resin, or the like for other plastic substrates or paper substrates. Furthermore, in order to form a film excellent in mechanical strength, a stretched film such as a biaxially stretched polyester film is preferred.

The laminated film of the present invention also includes a state in which the above-mentioned layers are provided in addition to the inorganic thin film layer.

A packaging bag can be formed by using the gas-shielding laminated film of the present invention. A sealing layer is further laminated on the gas-barrier laminated film, and the sealing layers are heat-sealed to each other, thereby forming a packaging bag. The sealing layer is generally provided on the inorganic thin film layer, but may be provided on the outside of the base film (opposite to the surface of the inorganic thin film layer). Generally, a heat-sealable resin layer is formed by an extrusion layer method or a dry layer method. As long as the thermoplastic polymer forming the heat-sealable resin layer exhibits sufficient sealing adhesion, polyethylene resins such as HDPE, LDPE, and LLDPE, polypropylene resins, ethylene / vinyl acetate copolymers, and ethylene / α may be used. -Olefin random copolymers, ionic polymer resins, etc.

The form of the packaging bag of the present invention is not particularly limited, but examples include a three-side sealed open bag, a square bag, a central open bag, a gusset bag, and a rod bag.

(Example)

Hereinafter, the present invention will be further described in detail through examples, but the present invention is not limited to the following examples. The evaluation of the film was performed by the following measurement method.

(1) Impact strength

Using a film impact tester manufactured by Toyo Seiki Seisakusho Co., Ltd., the impact strength of the gas-shielding laminated film was measured under an environment of a temperature of 23 ° C and a relative humidity of 65%.

(2) Number of bending fatigue pinholes

The pinhole resistance tester manufactured by Rigaku Corporation was used to measure the number of bending fatigue pinholes of the laminated film by the following method.

After the polyester-based adhesive was applied to the gas-barrier laminated film produced in the examples, a linear low-density polyethylene film (L-LDPE film: L4102 manufactured by Toyobo Co., Ltd.) was dry-laminated at a temperature of 40 ° C. It was aged for 3 days and used as a laminated film. The obtained laminated film was cut into a 12-inch × 8-inch and formed into a 3.5-inch diameter cylindrical shape. One end of the cylindrical film was fixed to the fixing head side of a Gelvo flex tester and the other end was fixed On the movable head side, the initial clamping interval is 7 inches. The test stroke (stroke) applied a torque of 440 ° for the first 3.5 inches, and then moved linearly and horizontally for 2.5 inches. This was used as a test stroke and gave bending fatigue. After 500 times at a speed of 40 times / minute, the laminated film was calculated. The number of pinholes produced. The measurement was performed under an environment of 5 ° C. With the L-LDPE film side of the test film as the bottom and placed on a filter paper (ADVANTEC, No. 50), the 4 corners were fixed with Cellotape (registered trademark). An ink (PILOT ink (article number INK-350-BLUE) was diluted 5 times with pure water) was applied to the test film, and one side was extended using a rubber roller. After removing excess ink, remove the test film and measure the number of ink dots attached to the filter paper.

(3) Haze

The gas-barrier laminated film was measured using a reading haze meter manufactured by Toyo Seiki Seisakusho Co., Ltd. in accordance with old JIS-K-7105.

Haze (%) = (Td (diffusive transmittance%) / Tt (full light transmission %)) × 100

(4) Static friction coefficient

According to the old JIS-K-7125, the static friction coefficients of the easy-to-slide surfaces of the gas-shielding laminated film were measured under an environment of 23 ° C and 65% RH.

(5) Rupture strength

The gas-barrier laminated film of the measurement object was cut into 180 mm × 15 mm short-cut shapes in the flow direction (MD (vertical) direction) and the width direction (TD (horizontal) direction), and used as test pieces. Using a tensile tester (autograph (trade name) manufactured by Shimadzu Corporation, model name: AG-5000A), tensile cracking in the MD direction and TD direction were measured at a tensile speed of 200 mm / min and a distance of 100 mm between the clamps. Intensity, take the average of MD direction and TD direction as data.

(6) Seal strength

Using the laminated film obtained in (2), the sealing strength was measured in accordance with JISZ1707. The specific sequence is as follows.

For the opposite side of the build-up layer of the inorganic thin film layer in the substrate film, the heat-sealing temperature and heat-sealing time are 140 ° C, 0.1 seconds; 140 ° C, 0.3 seconds; 140 ° C, 0.5 seconds; 140 ° C, 0.7 seconds; 150 ° C, 0.1 second; 150 ° C, 0.3 second; 7 conditions of 150 ° C and 0.5 second were performed as heat-seal conditions. The sealing pressure for all heat-sealing conditions is 0.2 MPa.

In addition, regarding the appearance evaluation after heat sealing, the sample is attached by a heat sealer. The sealing layers were evaluated against each other and the appearance of the heat-sealed portion was evaluated. The appearance evaluation was performed by visually evaluating the state of wavy wrinkles of the heat-sealed portion, the state of no wrinkles was evaluated as ○, and the state of severe wrinkles was evaluated as ×.

The T-shaped peeling strength in the MD (long) direction of the aforementioned heat-sealed sample was measured using a tensile strength tester (manufactured by Toyo Seiki Co., Ltd .: trade name TENSILON UTM). At this time, the tensile speed was 200 mm / min, and the test piece width was 15 mm.

(7) Elasticity

The gas-barrier laminated film of the measurement object was cut into 180 mm × 15 mm short pieces in the flow direction (MD direction) and the width direction (TD direction), and used as test pieces. Using a tensile tester (autograph (trade name), model name: AG-5000A, manufactured by Shimadzu Corporation), the elasticity in the MD and TD directions was measured under conditions of a tensile speed of 200 mm / min and a distance of 100 mm between clips. The average value of the MD direction and the TD direction was taken as the elastic modulus of the film to be measured.

(8) Thermal shrinkage

The gas-barrier laminated film was cut into a short shape of 250 mm × 20 mm in the flow direction (MD direction) and the width direction (TD direction), and used as test pieces. A line of about 150 mm was drawn on the center of the test piece. The aforementioned sample was left for 24 hours under the environment of 23 ° C and 50% RH, and the length of the reference line was measured. The measured length is taken as the length F before the heat treatment. Hang the aforementioned sample After heating in a hot-air drier maintained at 160 ° C for 10 minutes, and further placing it in a 23 ° C, 50% RH environment for 20 minutes, the reference line length was measured and used as the length G after the heat treatment.

The heat shrinkage was calculated as [(F-G) / F] × 100 (%).

Each of the shrinkage rates in the MD direction and the TD direction was measured by the method described above with n = 3 (that is, the number of test samples is 3), and the average value was used as the heat shrinkage rate.

(9) Water vapor permeability of gas-shielding laminated film

For a gas-shielding laminated film having an inorganic thin film layer, a water vapor transmission measuring device ("PERMATRAN-W 3 / 33MG" manufactured by MOCON) was used in accordance with JIS-K7129-B method at a temperature of 40 ° C and a humidity of 100% RH Under normal environment, measure the water vapor transmission rate under normal conditions. The water vapor transmission rate was measured in a direction in which water vapor transmitted from the substrate film side to the inorganic thin film layer side.

(10) Oxygen permeability of gas-barrier laminated film

For a gas-shielding laminated film having an inorganic thin film layer, an oxygen permeability measuring device ("OX-TRAN2 / 20" manufactured by MOCON Corporation) was used at a temperature of 23 in accordance with the electrolytic sensor method (Appendix A) of JIS-K7126-2. Under normal temperature and 65% RH humidity, measure the oxygen permeability under normal conditions. The oxygen transmission rate was measured in a direction in which oxygen was transmitted from the substrate film side to the inorganic thin film layer side.

(Example 1)

Using a co-extrusion T-die equipment to obtain an unstretched thin film sheet. In the configuration of the B layer / A layer, the total thickness of the unstretched sheet was 110 μm, and the ratio of the thickness of the A layer to the total thickness was 88%.

Composition constituting layer A: 87% by weight of nylon 6 (T814 manufactured by Toyobo Co., Ltd.), 10% by weight of aliphatic copolymerized polyamide (7034B manufactured by Ube Kosan Co., Ltd.) composed of nylon 6 and nylon 12; and Nylon 12 is a polyamine based elastomer (PEBAX4033SN01 manufactured by Arkema Co., Ltd.) with a weight fraction of 3.0, and a mixed polymer containing a phenolic antioxidant (Irganox 1010 manufactured by Ciba Specialty Chemicals Co.) at a concentration of 3.0 wt.组合 物。 Composition.

Composition constituting layer B: silicon dioxide composed of nylon 6 (T814 manufactured by Toyo Industries Co., Ltd.) 96.85 weight points, polyamide elastomer (PEBAX4033SN01 manufactured by Arkema Corporation) 3.0 weight points, and a pore volume of 0.6 to 1.0 ml / g of silicon dioxide A polymer composition composed of 0.08 wt.% Of particles, 0.5 wt.% Of silica particles having a pore volume of 1.1 to 1.6 ml / g, and 0.15 wt.% Of fatty acid amidoamine.

The obtained unstretched sheet was stretched 3.4 times in the longitudinal direction, then 4.0 times in the transverse direction, and then heat-treated at 202 ° C for 10 seconds in a heat-fixed area, thereby producing a laminated biaxially-stretched polyurethane film having a thickness of 8 μm. Corona discharge treatment was performed on the surface of layer B on the side of the dry-laminated linear low-density polyethylene film (L-LDPE film: L4102 manufactured by Toyobo Corporation).

(Formation of inorganic thin film layer)

Next, a composite inorganic oxide layer of silicon dioxide and aluminum oxide as an inorganic thin film layer is formed on one side of the obtained biaxially stretched polyamide film by the obtained substrate film by an electron beam evaporation method. As a vapor deposition source, granular SiO ₂ (purity 99.9%) and Al ₂ O ₃ (purity 99.9%) of about 3 mm to 5 mm were used. The composition of the composite oxide layer is SiO ₂ / Al ₂ O ₃ (mass ratio) = 67/33. In addition, in the film (inorganic thin film layer / biaxially stretched polyester film) obtained in the foregoing manner, the film thickness of the inorganic thin film layer (SiO ₂ / Al ₂ O ₃ composite oxide layer) was 15 nm.

The gas-shielding laminated film of the present invention having an inorganic thin film layer on the laminated biaxially stretched polyamide film of the base film is obtained in the above manner. The static friction coefficient, rupture strength, punching strength, bending fatigue pinholes, elastic modulus, thermal shrinkage, oxygen permeability, and water vapor permeability of the obtained gas-barrier laminated film were measured in the aforementioned manner. The results and detailed layer structure are shown in Table 1.

(Making Laminated Film)

After the polyester biaxially stretched polyamide film is coated with a polyester-based adhesive, a linear low-density polyethylene film (L-LDPE film with a thickness of 40 μm) is dry-laminated on the opposite side of the inorganic film layer of the base film. Toyobo Industries Co., Ltd. L4102) was aged at 40 ° C for 3 days and used as a laminated film. The bending fatigue pinholes and sealing strength of the obtained laminated film were measured. The results and detailed layer structure are shown in Table 1. The film is excellent in pinhole resistance and bending resistance. In addition, the heat-sealing temperature and heat-sealing time are respectively 140 ° C, 0.5 seconds, or 150 ° C, 0.1 seconds, so that sufficient heat-sealing strength can be obtained and the appearance after heat-sealing is good, and it is used for high-speed automatic filling. It can also be a film with both high heat seal strength and appearance characteristics.

(Example 2)

An unstretched sheet having the following constitution was obtained using two types of three-layer co-extrusion T-die equipment. In terms of the B layer / A layer / B layer structure, the total thickness of the unstretched sheet is 110 μm, and the ratio of the thickness of the A layer to the total thickness is 75%.

Compositions constituting layer A: 87 weight points of nylon 6 (T814 manufactured by Toyobo Co., Ltd.), 5 weight points of aliphatic copolymer polyamide (7034B manufactured by Ube Kosan Co., Ltd.) composed of nylon 6 and nylon 12, and Nylon 12 as a polyamide component of a polyamide-based elastomer (PEBAX4033SN01 manufactured by Arkema, Inc.) in a weight fraction of 6.0 and a phenol-based antioxidant (Irganox 1010, manufactured by Ciba Specialty Chemicals) in a mixed polymer content of 0.1%组合 物。 Composition.

Composition constituting layer B: Silicon dioxide composed of nylon 6 (T814 manufactured by Toyobo Corporation) 93.85 weight points, polyamide elastomer (PEBAX4033SN01 manufactured by Arkema Corporation) 6.0 weight points, and a pore volume of 0.6 to 1.0 ml / g of silicon dioxide A polymer composition composed of 0.08 wt.% Of particles, 0.5 wt.% Of silica particles having a pore volume of 1.1 to 1.6 ml / g, and 0.15 wt.% Of fatty acid amidoamine.

The obtained unstretched sheet was stretched 3.4 times in the longitudinal direction, then 4.0 times in the transverse direction, and then heat-treated at 202 ° C for 10 seconds in a heat-fixed area, thereby producing a laminated biaxially-stretched polyurethane film having a thickness of 8 μm. Corona discharge treatment was performed on the surface of layer B on the side of the dry-laminated linear low-density polyethylene film (L-LDPE film: L4102 manufactured by Toyobo Corporation).

Thereafter, a composite inorganic oxide layer of silicon dioxide and alumina as an inorganic thin film layer was formed on one side of the obtained laminated biaxially stretched polyamide film by the same method as in Example 1 by an electron beam evaporation method. The static friction coefficient, rupture strength, impact strength, bending fatigue pinholes, elastic modulus, thermal shrinkage, oxygen permeability, and water vapor permeability of the obtained gas-barrier laminated film were measured. The results and detailed layer structure are shown in Table 1. In addition, after the polyester-based adhesive was applied to the gas-barrier laminated film, a linear low-density polyethylene film (L-LDPE film: Toyo L4102) manufactured by Textile Corporation was aged at 40 ° C for 3 days and used as a laminated film. The bending fatigue pinholes and sealing strength of the obtained laminated film were measured. The results and detailed layer structure are shown in Table 1. The film is excellent in pinhole resistance and bending resistance. In addition, the heat-sealing temperature and heat-sealing time were respectively 140 ° C, 0.5 seconds, or 150 ° C, 0.1 seconds, so that sufficient heat-sealing strength was obtained and the appearance after heat-sealing was good. As in Example 1, Films that have both high heat seal strength and appearance characteristics during high-speed automatic filling.

(Comparative example 1)

An unextended sheet configured as follows was obtained using a co-extrusion T-die apparatus. With regard to the structure of the B layer / A layer, the total thickness of the unstretched sheet is 110 μm, and the ratio of the thickness of the A layer to the total thickness is 92%.

Composition constituting layer A: composed of 97 parts by weight of nylon 6 (T814 manufactured by Toyobo Co., Ltd.) and 3.0 parts by weight of polyamide-based elastomer (PEBAX4033SN01 manufactured by Arkema Corporation) using nylon 12 as a polyamide component, Furthermore, it contains a mixed polymer composition made of 0.1% by weight of a phenol-based antioxidant (Irganox 1010 manufactured by Ciba Specialty Chemicals).

Composition constituting layer B: silicon dioxide composed of nylon 6 (T814 manufactured by Toyobo Corporation) 96.85 weight points, polyamine elastomer (PEBAX4033SN01 manufactured by Arkema Corporation) 3.0 weight points, and a pore volume of 1.1 to 1.6 ml / g of silicon dioxide Polymer composition consisting of 0.4 weight part of particles and 0.15 weight part of fatty acid amidoamine.

The obtained unstretched sheet was extended 3.4 times in the longitudinal direction, and then 4.0 times in the transverse direction, and then heat-treated at 215 ° C for 10 seconds in a heat-fixed area, thereby producing a laminated biaxially-stretched polyurethane film having a thickness of 8 μm. Corona discharge treatment was performed on the surface of layer B on the side of the dry-laminated linear low-density polyethylene film (L-LDPE film: L4102 manufactured by Toyobo Corporation).

Thereafter, a composite inorganic oxide layer of silicon dioxide and alumina as an inorganic thin film layer was formed on one side of the obtained laminated biaxially stretched polyamide film by the same method as in Example 1 by an electron beam evaporation method. The static friction coefficient, rupture strength, impact strength, bending fatigue pinholes, elastic modulus, thermal shrinkage, oxygen permeability, and water vapor permeability of the obtained gas-barrier laminated film were measured. The results and detailed layer structure are shown in Table 1. In addition, after the polyester-based adhesive was applied to the gas-barrier laminated film, a linear low-density polyethylene film (L-LDPE film: Toyo L4102) manufactured by Textile Corporation was aged at 40 ° C for 3 days and used as a laminated film. Measurement of the bending of the obtained laminated film Number of fatigue pinholes and seal strength. The results and detailed layer structure are shown in Table 1. Because the temperature of the heat-fixed zone is as high as 215 ° C, the film is excessively crystallized, and as a result, the pinhole of bending fatigue and the film elasticity are poor.

(Comparative example 2)

An unextended sheet configured as follows was obtained using a co-extrusion T-die apparatus. With regard to the structure of the B layer / A layer, the total thickness of the unstretched sheet is 110 μm, and the ratio of the thickness of the A layer to the total thickness is 93%.

Composition constituting layer A: composed of 97 parts by weight of nylon 6 (T814 manufactured by Toyobo Co., Ltd.) and 3.0 parts by weight of polyamide-based elastomer (PEBAX4033SN01 manufactured by Arkema Corporation) with nylon 12 as the polyamide component, and further A mixed polymer composition containing 0.1% by weight of a phenol-based antioxidant (Irganox 1010 manufactured by Ciba Specialty Chemicals).

Composition constituting layer B: silicon dioxide composed of nylon 6 (T814 manufactured by Toyobo Corporation) 96.85 weight points, polyamine elastomer (PEBAX4033SN01 manufactured by Arkema Corporation) 3.0 weight points, and a pore volume of 1.1 to 1.6 ml / g of silicon dioxide Polymer composition consisting of 0.5 weight part of particles and 0.15 weight part of fatty acid amidoamine.

The obtained unstretched sheet was extended 3.4 times in the longitudinal direction, and then 4.0 times in the transverse direction, and then heat-treated at 215 ° C for 10 seconds in a heat-fixed area, thereby producing a laminated biaxially-stretched polyurethane film having a thickness of 8 μm. Corona discharge was applied to the surface of layer B on the side of the dry-laminated linear low-density polyethylene film (L-LDPE film: L4102 manufactured by Toyobo Corporation) deal with.

Thereafter, a composite inorganic oxide layer of silicon dioxide and alumina as an inorganic thin film layer was formed on one side of the obtained laminated biaxially stretched polyamide film by the same method as in Example 1 by an electron beam evaporation method. The static friction coefficient, rupture strength, impact strength, bending fatigue pinholes, elastic modulus, thermal shrinkage, oxygen permeability, and water vapor permeability of the obtained gas-barrier laminated film were measured. The results and detailed layer structure are shown in Table 1. In addition, after the polyester-based adhesive was applied to the gas-barrier laminated film, a linear low-density polyethylene film (L-LDPE film: Toyo L4102) manufactured by Textile Corporation was aged at 40 ° C for 3 days and used as a laminated film. The bending fatigue pinholes and sealing strength of the obtained laminated film were measured. The results and detailed layer structure are shown in Table 1. Since the temperature of the heat-fixed zone was as high as 215 ° C., the film was excessively crystallized. As a result, the fatigue fatigue pinhole property and film elasticity were the same as in Comparative Example 1.

(Comparative example 3)

An unstretched sheet having the following constitution was obtained using two types of three-layer co-extrusion T-die equipment. In terms of the B layer / A layer / B layer structure, the total thickness of the unstretched sheet is 130 μm, and the ratio of the thickness of the A layer to the total thickness is 75%.

Compositions constituting layer A: 87 weight points of nylon 6 (T814 manufactured by Toyobo Co., Ltd.), 5 weight points of aliphatic copolymer polyamide (7034B manufactured by Ube Kosan Co., Ltd.) composed of nylon 6 and nylon 12, and Polyamide based elastomer with nylon 12 as the polyamide component (manufactured by Arkema) PEBAX4033SN01) is a mixed polymer composition composed of 6.0 parts by weight and further containing 0.1 part by weight of a phenol-based antioxidant (Irganox 1010 manufactured by Ciba Specialty Chemicals).

Composition constituting layer B: Silicon dioxide composed of nylon 6 (T814 manufactured by Toyobo Corporation) 93.85 weight points, polyamide elastomer (PEBAX4033SN01 manufactured by Arkema Corporation) 6.0 weight points, and a pore volume of 0.6 to 1.0 ml / g of silicon dioxide A polymer composition composed of 0.08 parts by weight of particles, 0.5 part by weight of silica particles having a pore volume of 1.1 to 1.6 ml / g, and 0.15 part by weight of fatty acid amidoamine.

The obtained unstretched sheet was extended 3.4 times in the longitudinal direction, and then 4.0 times in the transverse direction, and then heat-treated at 202 ° C for 10 seconds in a heat-fixed area, thereby producing a laminated biaxially-stretched polyurethane film with a thickness of 10 μm. Corona discharge treatment was performed on the surface of layer B on the side of the dry-laminated linear low-density polyethylene film (L-LDPE film: L4102 manufactured by Toyobo Corporation). Thereafter, a composite inorganic oxide layer of silicon dioxide and alumina as an inorganic thin film layer was formed on one side of the obtained laminated biaxially stretched polyamide film by the same method as in Example 1 by an electron beam evaporation method. The static friction coefficient, rupture strength, impact strength, bending fatigue pinholes, elastic modulus, thermal shrinkage, oxygen permeability, and water vapor permeability of the obtained gas-barrier laminated film were measured. The results and detailed layer structure are shown in Table 1. In addition, after the polyester-based adhesive was applied to the gas-shielding laminated film, a linear low-density polyethylene film (L-LDPE film: Toyo Textile company L4102), at 40 ° C Aging was carried out for 3 days under ambient conditions, and it was used as a laminated film. The bending fatigue pinholes and sealing strength of the obtained laminated film were measured. Although sufficient heat-sealing strength is obtained, there are no heat-sealing conditions that make the appearance good after heat-sealing. It is a film that cannot have both high heat-sealing strength and appearance characteristics when used for high-speed automatic filling.

The gas-shielding laminated film of the present invention has been described based on a plurality of embodiments, but the present invention is not limited to the structures described in the foregoing embodiments, and the combinations described in the embodiments may be appropriately combined without departing from the scope of the invention. Change its composition as appropriate.

(Industrial availability)

The gas-shielding laminated film of the present invention is excellent in impact resistance and bending fatigue resistance, and is therefore suitable for use in packaging materials such as food packaging. This is particularly useful when thinning is required.

Claims (9)

A gas barrier laminated film is an inorganic thin film layer on one side or two areas of a base film; the aforementioned base film is composed of 97 to 70% by weight of aliphatic homopolyamine and 3 to 20% of aliphatic copolyamide. At least one side of the A layer composed of a mixed polymer of 0% to 10% by weight of a thermoplastic elastomer, and a layer consisting of 99.5 to 90% by weight of aliphatic homopolyamide and 0.5 to 10.0% by weight of a thermoplastic elastomer. Layer B made of mixed polymers; the aforementioned gas-barrier laminated film satisfies the following requirements: (1) when kept under dry heat at 160 ° C for 10 minutes, the thermal shrinkage in the longitudinal direction is 1.5% to 4.0%; (2) ) When kept under dry heat at 160 ° C for 10 minutes, the heat shrinkage in the lateral direction is 2.1% to 4.5%; (3) the film thickness is less than 9 μm; (4) the elastic modulus is 2.2 GPa or less. The gas-shielding laminated film according to claim 1, wherein the value obtained by dividing the heat shrinkage rate in the transverse direction of the film by the heat shrinkage rate in the longitudinal direction of the film is 1.0 to 1.4 when it is held under dry heat at 160 ° C for 10 minutes. The gas-barrier laminated film according to claim 1 or 2, wherein the thickness of the B layer is 1 μm or more. The gas-shielding laminated film according to claim 1 or 2, wherein the impact strength is 0.6 J / 10 μm or more, the number of bending fatigue pinholes at 5 ° C is 5 or less, and the breaking strength is 25 N / 15 mm or more. The gas-shielding laminated film according to claim 1 or 2, wherein the inorganic thin film layer includes a mixture of one or more kinds selected from a metal or an inorganic oxide. The gas-shielding laminated film according to claim 5, wherein the inorganic thin film layer system includes two metals, two inorganic oxides, or one metal and one inorganic oxide. The gas-shielding laminated film according to claim 6, wherein the two inorganic oxides include silicon oxide and aluminum oxide. The gas-barrier laminated film according to claim 1 or 2, wherein the water vapor transmission rate is 6 g / m ² . Less than day, and the oxygen permeability is 30ml / m ² . day. MPa or less. A packaging bag using the gas-barrier laminated film according to any one of claims 1 to 8 and having an inorganic vapor-deposited layer as an outermost layer.