TWI742095B - Polyamide-based film and method for producing same - Google Patents

Abstract

Provided are a polyamide-based film having superior thickness uniformity and good slipperiness as well as comparatively little variation in properties in four directions formed of the 0 degree direction, 45 degree direction, 90 degree direction and 135 degree direction, and a method for producing the same. The present invention relates to a polyamide-based film having the following properties (1)- (3): (1) the difference between the maximum value and minimum value of the respective stress at 5% elongation as determined by a uniaxial tensile test is 35 MPa or less in four directions formed of a specific direction from an arbitrary point in the film that is designated as 0 degrees and directions at 45 degrees, 90 degrees and 135 degrees relative to the specific direction in the clockwise direction, (2) the difference between the maximum value and the minimum value of the respective stress at 15% elongation as determined by the uniaxial tensile test in the four directions is 40 MPa or less, and (3) the dynamic friction coefficient is 0.60 or less.

Description

Polyamide-based film and its manufacturing method

Field of invention

The present invention relates to a novel polyamide-based film and its manufacturing method. In addition, the present invention relates to a laminate and a container containing the aforementioned polyamide-based film.

Background of the invention

Various resin films can be processed into various products such as packages. For example, packaging bodies (extrusion packaging) such as pharmaceuticals (tablets) use vinyl chloride films. Another example is the use of polypropylene film when packaging content that requires moisture resistance. In recent years, from the point of view of maintaining the quality of the contents. In order to provide more excellent gas barrier properties or moisture resistance, it is used in a laminate made of a resin film laminated with a metal foil. For example, a laminate composed of a base material layer (resin film)/metal foil layer (aluminum foil)/sealing layer is known.

In the industrial field, the outer packaging material of lithium-ion batteries has been the mainstream since the previous metal can type, but it has been pointed out that it has disadvantages such as low degree of freedom of shape and difficulty in weight reduction. Therefore, it has been proposed to use a laminate consisting of a base layer/metal foil layer/sealing layer or a base layer/base layer/metal foil layer/sealing layer. The laminated body is used as the exterior body. Compared with metal cans, the laminated body is soft and has a higher degree of freedom in shape, can be made thinner and lighter, and can be easily miniaturized and is widely used.

There are various demands for laminates used in the above-mentioned applications, among which a very important element is moisture resistance. However, metal foils such as aluminum foil, which can impart moisture resistance, lack ductility and poor moldability as a single unit. Therefore, the use of a polyamide-based film as a resin film constituting the substrate layer can impart ductility and improve moldability.

The moldability mentioned here particularly refers to the moldability when cold forming (cold working) a film. That is, when a film is formed to produce a product, the molding conditions include: a) thermoforming in which the resin is melted under heating to form, and b) cold forming in which the resin is molded in a solid state without melting the resin, and is used in the above-mentioned applications The above requires the formability of cold forming (especially drawing processing and compression processing). Cold forming is a molding method that has better production speed and economic cost because it has no heating step, and is more advantageous than thermoforming in terms of exhibiting the original characteristics of the resin. Therefore, polyamide-based films have also continued to develop films suitable for cold forming.

As the polyamide-based film, a stretched polyamide-based film is known (for example, Patent Documents 1 to 4). However, these polyamide-based films are produced by stretching using a blown film stretching method. In other words, not only the productivity is low, but the stretched film produced is insufficient in terms of thickness uniformity and dimensional stability. In particular, when the thickness of the film is uneven, when cold forming is used to process the laminate formed by the film and the metal foil, there is a risk of fatal defects such as breakage of the metal foil and generation of holes.

In response to this, a polyamide-based film stretched by the tenter method has been proposed (for example, Patent Documents 5 to 12). The stenter method is more advantageous in terms of productivity and dimensional stability than the blown film stretching method.

Advanced technical literature

Patent literature

Patent Document 1: Japanese Patent No. 5487485

Patent Document 2: Japanese Patent No. 5226942

Patent Document 3: Japanese Patent Application Publication No. 2015-051525

Patent Document 4: Japanese Patent Application Publication No. 2015-051527

Patent Document 5: Japanese Patent No. 5467387

Patent Document 6: Japanese Patent Application Publication No. 2011-162702

Patent Document 7: Japanese Patent Application Publication No. 2011-255931

Patent Document 8: Japanese Patent Application Publication No. 2013-189614

Patent Document 9: Japanese Patent No. 5226941

Patent Document 10: Japanese Patent Application Publication No. 2013-22773

Patent Document 11: International Publication WO2014/084248

Patent Document 12: Japanese Patent No. 3671978

Summary of the invention

However, even the polyamide-based film stretched by the tenter method still has the problem of unevenness (anisotropy) of the physical properties of the film in all directions. Therefore, the moldability during cold forming (especially deep drawing forming) is still hard to be said to have sufficient performance.

The polyamide-based film 14 is manufactured by the steps shown in FIG. 1. head First, the raw material 11 is melted in the melt-kneading step 11a to prepare a melt-kneaded product 12. The melt kneaded product 12 is formed into a sheet shape by the forming step 12a to obtain an unstretched sheet 13. Next, the unstretched sheet 13 is biaxially stretched in the stretching step 13a to obtain a polyamide-based film 14. Then, the stretched polyamide-based film 14 is subjected to, for example, a laminate step 14a of laminating a metal foil layer 15 and a sealing film 16 in order to obtain a laminate 17, and then the laminate 17 is formed in a cold forming step 15a in a secondary process. 17 is processed into a predetermined shape to produce various products 18 (for example, a container, etc.).

For the stretched polyamide-based film 14, it is desirable to reduce the unevenness of physical properties in all directions on the plane, and it is advisable to reduce at least 4 directions every 90 degrees (based on any direction (0 degrees), clockwise relative to this direction (45 degrees, 90 degrees, and 135 degrees total 4 directions) unevenness in physical properties. For example, a biaxially stretched polyamide-based film is shown in Figure 4, with an arbitrary point A as the center and MD (film flow direction) during biaxial stretching as the reference direction (0 degree direction), it is desirable to be able to Decrease (a) the reference direction (0 degree direction), (b) the direction of 45 degrees clockwise relative to MD (hereinafter referred to as "45 degree direction"), (c) the direction of 90 degrees clockwise relative to MD (TD: the direction of film flow) Right-angle direction) (hereinafter referred to as "90 degree direction") and (d) the four directions of 135 degrees clockwise (hereinafter referred to as "135 degree direction") relative to MD have uneven physical properties.

When the laminate 17 containing the stretched polyamide-based film 14 is supplied to the cold forming step 15a, the polyamide-based film 14 will be stretched in all directions. Therefore, when the polyamide-based film 14 is When there is unevenness in physical properties, it is difficult to stretch uniformly in all directions during cold forming. That is, due to the direction that is easy to stretch and the direction that is not suitable for stretching, the metal foil Fracture, delamination or hole. However, when the above-mentioned problem occurs, it is difficult to perform functions such as the package body, and there is a risk that the packaged body (content) may be damaged. Therefore, it is necessary to reduce the unevenness of physical properties in all directions as much as possible.

At this time, one of the physical properties that will affect the moldability during cold forming is the film thickness. When cold-forming a laminate containing a polyamide-based film with uneven film thickness, the thinner part will break to produce holes, or the possibility of delamination will increase. Therefore, the polyamide-based film used for cold forming must control the thickness of the entire film to be uniform.

Here, in terms of the thickness uniformity of the polyamide-based film, although stretching by the tenter method is better than the blown film stretching method, the obtained polyamide-based film can be seen from the above-mentioned Patent Documents 3 to 10 The thickness accuracy is still insufficient. In other words, during cold forming, since it must extend uniformly in four directions, longitudinally and obliquely, as described above, it must have sufficient thickness uniformity to withstand cold forming. In particular, the thinner the film thickness (especially the thickness of 15 μm or less), the more significant the influence of thickness uniformity on moldability.

Generally speaking, the thicker the thickness, the more uniform the thickness of the film can be ensured, so in order to ensure the uniformity of the thickness, it is also designed to be thicker. However, in recent years, polyamide-based films and their laminates used for cold forming have gradually been widely used as exterior materials for lithium-ion batteries. Therefore, with the requirements for higher battery output, miniaturization, and cost reduction Etc., it is desired to reduce the thickness of the polyamide-based film. However, if the thickness is reduced, it is difficult to ensure just the thickness uniformity.

As described above, it is urgently desired to develop a polyamide-based film that is thin but has excellent thickness uniformity and small physical property unevenness in the aforementioned four directions. However, such a film has not yet been developed.

In addition, the physical properties that affect the moldability during cold forming and the smoothness of the film. For example, when cold forming a laminate with a polyamide-based film as the outermost layer, since the polyamide-based film will come into contact with the molding die, if the polyamide-based film is not smooth (that is, the coefficient of friction is large) , The surface of the laminate will have wrinkles when it is pressed into the molding die, or the possibility of delamination of the laminate will increase. Furthermore, since it is difficult to uniformly shape the entire laminate, holes may occur. Especially when cold forming is performed under high humidity, these problems will be more obvious.

Therefore, the main purpose of the present invention is to provide a polyamide-based film that has excellent thickness uniformity, can effectively suppress the aforementioned 4-direction unevenness in physical properties, and is excellent in smoothness, and a method for producing the same.

In view of the problems of the conventional technology, the inventors made active efforts to study, and found that the use of a specific raw material and a film stretched by a special method can achieve the above-mentioned purpose and completed the present invention.

That is, the present invention relates to the following polyamide-based film and its manufacturing method.

1. A polyamide-based film characterized by satisfying all of the following (1) to (3) characteristics: (1) Calculated from any point in the aforementioned film, with a specific direction as 0 degrees and clockwise relative to that direction In the four directions of 45 degrees, 90 degrees and 135 degrees, the difference between the maximum value and the minimum value of each stress when the uniaxial tensile test causes 5% elongation is 35MPa or less; (2) In the aforementioned four directions, perform uniaxial Tensile test causes 15% elongation The difference between the maximum value and the minimum value of each stress for a long time is 40MPa or less; and (3) The dynamic friction coefficient is 0.60 or less.

2. The polyamide-based film of item 1 above, the arithmetic average height Sa is 0.01~0.15μm.

3. The polyamide-based film of item 1 mentioned above, which is calculated from any point in the aforementioned film, with a specific direction of 0 degrees, 45 degrees, 90 degrees, 135 degrees, 180 degrees, 225 degrees clockwise relative to the direction, In the eight directions of 270 degrees and 315 degrees, the standard deviation of the polyamide-based film with respect to the average thickness of the eight directions is 0.200 μm or less.

4. The polyamide-based film of item 1 above, which has an average thickness of 16 μm or less.

5. The polyamide-based film according to item 1 above, wherein the polyamide-based film contains at least one of an organic slip agent and an inorganic slip agent.

6. A coating film comprising the polyamide-based film described in item 1 above and an easy-adhesion coating layer and/or an easy-slip coating layer formed on the film.

7. A laminated body comprising the film of item 1 or 6 above and a metal foil laminated on the film.

8. A container comprising the laminate according to item 7 above.

9. A method for manufacturing a polyamide-based film, which is a method for manufacturing a polyamide-based film, the method is characterized by comprising the following steps: (1) a sheet forming step, which is to form a molten kneaded product into a sheet. An unstretched sheet is prepared, and the melt kneaded material contains polyamide resin and contains at least one of an organic slip agent and an inorganic slip agent; (2) the stretching step is to sequentially or simultaneously transfer the aforementioned unstretched sheet MD and TD are biaxially stretched to prepare stretched films; and (3) satisfy both of the following formulas a) and b):

a) 0.85≦X/Y≦0.95

b)8.5≦X×Y≦9.5

(However, X represents the stretch magnification of the aforementioned MD, and Y represents the stretch magnification of the aforementioned TD).

10. The method for producing a polyamide-based film according to item 9 above, wherein the stretching step is successive biaxial stretching and includes the following steps: (2-1) The first stretching step is at a temperature of 50~120°C Stretching the aforementioned unstretched sheet to MD to obtain a first stretched film; and (2-2) The second stretching step is to stretch the aforementioned first stretched film to TD at a temperature of 70 to 150°C to obtain a first stretched film 2 Stretch film.

11. In the method for producing a polyamide-based film according to item 10 above, the first stretching step is stretching using a roll, and the second stretching step is stretching using a tenter.

12. According to the manufacturing method of the polyamide-based film in item 10 above, the second stretched film is further subjected to relaxation heat treatment at a temperature of 180 to 230°C.

The polyamide-based film of the present invention has excellent thickness uniformity, and out of 4 directions consisting of 0 degree, 45 degree, 90 degree, and 135 degree directions based on any direction, the stress balance during elongation is excellent, and also Can exert excellent smoothness.

Therefore, for example, the laminate formed by laminating the film of the present invention and the metal foil has good ductility in the metal foil, so it is stretched by cold forming During molding (especially deep drawing molding or compression molding), it can effectively suppress or prevent metal foil breakage, wrinkles, delamination, holes, etc., and can produce high-reliability and high-quality products (forms).

In particular, even if the thickness of the polyamide-based film of the present invention is extremely thin, for example, about 15 μm or less, it has excellent thickness uniformity and excellent stress balance when stretched in the aforementioned four directions. Therefore, the laminated body formed by laminating the film and the metal foil can be cold-formed into a product with higher output and miniaturization, and it is also beneficial to economic costs.

In addition, according to the manufacturing method of the present invention, the above-mentioned polyamide-based film with excellent characteristics can be efficiently and reliably manufactured. In particular, it is possible to provide a film having an extremely thin thickness of about 15 μm or less, with excellent thickness uniformity. Moreover, when stretching at a lower temperature, the original characteristics of the resin can be maintained more effectively, and films and laminates that are more suitable for cold forming can be provided.

11: raw materials

11a: Melt-kneading step

12: Melt kneaded material

12a: forming step

13: Unstretched sheet

13’: First stretch film

13a: Extension step

14: The second stretched film; polyamide-based film (the film of the present invention)

14a: Layering steps

15: Metal foil layer

15a: Cold forming step

16: Sealing film

17: Laminated body

18: products

21: Roll

22: Tenter

31: Preheating zone

32: extension area

33: Relaxation heat treatment zone

34: Link device

41: Specimen

51: Film

52: Adhesive layer

52a: Adhesive layer

52b: Adhesive layer

53: metal foil

54: Sealing film

60: Laminated body

70: layered body

A: Center point

a: direction

Fig. 1 is a schematic diagram showing the outline of the manufacturing steps and cold working steps of the polyamide-based film of the present invention.

Fig. 2 is a schematic diagram showing the steps of stretching an unstretched sheet by successive biaxial stretching in the manufacturing method of the present invention.

Fig. 3 is a diagram showing a state in which the stretching step is performed by the tenter as viewed from the direction a in Fig. 2.

The one shown in Figure 4 measures the direction of the stress of the film.

The one shown in Figure 5 is a sample used to measure the stress of the film.

Figure 6 shows a method for measuring the average thickness of the film.

Figure 7 shows the layer structure of the embodiment of the laminate of the present invention.

Figure 8 shows the layer structure of another embodiment of the laminate of the present invention.

The form used to implement the invention

1. Polyamide film

The polyamide-based film of the present invention (the film of the present invention) is characterized in that it satisfies all of the following (1) to (3) characteristics: (1) Calculated from any point in the aforementioned film, with a specific direction as 0 degrees, relative The difference between the maximum value and the minimum value (A value) of each stress when the uniaxial tensile test causes 5% elongation in the four directions of 45 degrees, 90 degrees and 135 degrees clockwise is less than 35 MPa; (2) Among the aforementioned four directions, the difference (B value) between the maximum value and the minimum value of each stress at 15% elongation caused by a uniaxial tensile test is 40 MPa or less; and (3) the dynamic friction coefficient is 0.60 or less.

(A) Material ‧ composition of the film of the invention

(A-1) Polyamide resin

The film of the present invention is a film mainly composed of polyamide resin. Polyamide resin is a polymer formed by multiple monomers bonded by amide, and its representatives can be exemplified by 6-nylon, 6,6-nylon, 6,10-nylon, 11-nylon, and 12-nylon. Nylon, poly(hexamethylene diamide, metaxylylenediamine), etc. It can also be used such as 6-nylon/6,6-nylon, 6-nylon/6,10-nylon, 6-nylon/11-nylon, 6-nylon/12-nylon, etc. Copolymers above yuan. And these mixtures can also be used. Among the above, particularly from the viewpoints of cold formability, strength, economic cost, etc., it is preferable to be a) a homopolymer of 6-nylon, b) a copolymer containing 6-nylon, or c) a mixture of these.

The number average molecular weight of the polyamide resin is not particularly limited, and can be changed according to the type of polyamide resin used, etc., but it is generally about 10,000 to 40,000, and particularly preferably 15,000 to 25,000. The use of polyamide resin in the above range is easy to stretch at lower temperature, so it can more reliably avoid the problems of crystallization and decrease in cold formability caused by stretching at higher temperature.

The content of the polyamide resin in the film of the present invention is generally more than 90% by mass, wherein more than 95% by mass is preferred, and 98-99% by mass is the best.

(A-2) Organic slip agent and inorganic slip agent (also referred to as ``slip agent'')

The film of the present invention preferably contains at least one of an organic slip agent and an inorganic slip agent (especially both organic slip agent and inorganic slip agent). By making the film contain these lubricants, the smoothness can be improved more effectively. In particular, the dynamic friction coefficient and the arithmetic average height can be controlled in the optimal range. Furthermore, in the present invention, in order to further improve the smoothness of the film, it is preferable to include both an organic slip agent and an inorganic slip agent in the polyamide-based film. When both are used in combination, each content is preferably set to each content range shown below.

The method of making the film of the present invention contain the slip agent is not particularly limited. For example, a method of containing it in the polyamide resin as a raw material in advance, a method of directly adding it to an extruder during kneading, etc. can be used. Either method, or two or more methods can be used in combination.

Organic slip agent

The organic slip agent is not particularly limited, for example, in addition to hydrocarbon series, fatty acid series, grease In addition to various organic slip agents such as aliphatic bisamide series and metal soap series, there are also resin-based organic slip agents such as phenol resin, melamine resin, and polymethyl methacrylate resin. In the present invention, it is particularly suitable to use an organic slip agent that can melt by itself during melt kneading with the polyamide resin component (for example, the melting point is below 150° C.), and the organic slip agent can be aliphatic bisamide slip agent and the like.

The carbon number of the bisamide composed of the fatty acid in the aliphatic bisamide lubricant is generally in the range of 8-20, particularly preferably 12-18, and most preferably 16-18. When the carbon number is more than 20, although the smoothness improvement effect can be fully achieved in the high humidity area, the adhesion with the easy-adhesive layer may decrease, or the adhesion with the adhesive may decrease during lamination. When the carbon number is less than 8, sufficient smoothness may not be obtained.

Examples of carboxylic acids that can constitute aliphatic bisamides having the above-mentioned carbon number include saturated fatty acids such as stearic acid and behenic acid, as well as unsaturated fatty acids such as oleic acid and erucic acid.

As for the aliphatic amide derived from these carboxylic acids, a well-known thing or a commercial item can be used. For example, stearyl amide, behenic acid amide, erucamide, ethylene bis-stearyl amide, ethylene bis-oleyl amide, ethylene bis-behenic acid amide, ethylene ethylene Ethylene bis-erucamide, hexamethylene bis-stearyl amide, hexamethylene bis-oleyl amide, hexamethylene bis-behenic acid amide, hexamethylene bis-erucamide, etc. Erucamide and other hexamethylene bisamides. Among them, especially from the viewpoint of excellent compatibility with polyamide resins, a lubricant containing at least one of ethylenebisstearylamide and ethylenebisbehenic acid amide is preferred.

The organic slip agent can be used in powder form under normal temperature and pressure. In the present invention, the organic slip agent will be dissolved during melt kneading, so The particle size is not limited.

The content of the organic slip agent in the polyamide-based film is generally 0.02 to 0.25% by mass, of which 0.03 to 0.15% by mass is preferred. When the content of the organic slip agent is less than 0.02% by mass, the effect of improving the slippage may not be sufficiently obtained. On the other hand, when the content of organic slip agent exceeds 0.25% by mass, too much organic slip agent will flow out of the surface of the film, resulting in a decrease in the adhesion of the adhesive and printing ink, and the adhesion between the adhesive and the printing ink may decrease or printing during lamination. Poor, especially when the adhesive force is reduced, the cold formability may be reduced. Therefore, in the present invention, it is particularly desirable to set the above-mentioned organic slip agent content as the total content of at least one type of aliphatic bisamide slip agent.

Inorganic lubricant

(A) The inorganic slip agent in the present invention can include, for example, silica, clay, talc, mica, calcium carbonate, zinc carbonate, wollastonite, alumina, magnesium oxide, calcium silicate, sodium aluminate, calcium aluminate , Magnesium aluminosilicate, zinc oxide, antimony trioxide, zeolite, kaolinite, hydrotalcite, oxide-based glass, etc. Among them, silicon dioxide is particularly suitable.

Inorganic lubricants are generally in powder form, and their average particle size is generally 0.5~4.0μm. When the average particle size is less than 0.5 μm, the effect of roughening the surface of the film is small, and the effect of improving the smoothness cannot be sufficiently obtained. On the other hand, if the average particle size is larger than 4.0 μm, there is a possibility that transparency may deteriorate.

The particle shape of the inorganic lubricant is not particularly limited. For example, it may be any of spherical, flake-shaped, indefinite shape, balloon shape (hollow shape), and the like. Therefore, the present invention can also use, for example, glass beads, glass balloons, and the like.

In addition, inorganic lubricants with the same average particle size can be used. It is also possible to use two or more types of inorganic slip agents with different average particle diameters.

The content of the inorganic slip agent in the polyamide-based film of the present invention is generally preferably 0.05-5 mass%, preferably 0.1-4 mass%, and particularly preferably 0.1-2 mass%. Therefore, it can be set to 0.05 to 0.25% by mass, for example. In another example, it may be 0.09 to 0.20% by mass. If the content of the inorganic slip agent is less than 0.05% by mass, the effect of improving the slipperiness by adding the inorganic slip agent may not be sufficiently obtained. On the other hand, if the content of the inorganic lubricant exceeds 5% by mass, the surface of the film becomes too rough, so the arithmetic average height described later becomes too large, resulting in decreased ink adhesion or loss of transparency of the film, making it difficult to use printing The situation in which processing imparts ingenuity. In addition, there are also products that are prone to curling during the production of films. In the present invention, the content of the above-mentioned inorganic slip agent is desirably set to be silica, clay, talc, mica, calcium carbonate, zinc carbonate, wollastonite, alumina, magnesium oxide, calcium silicate, sodium aluminate, calcium aluminate, The total content of at least one of magnesium aluminosilicate, glass balloon, zinc oxide, antimony trioxide, zeolite, kaolinite and hydrotalcite.

The ratio of organic slip agent to inorganic slip agent

The ratio of organic slip agent to inorganic slip agent is not particularly limited. It can be set appropriately according to the type of slip agent used. Generally, the weight ratio is organic slip agent: inorganic slip agent=1:0.1~1:70, preferably Set to 1:0.2~1:35, preferably 1:0.2~1:5. Therefore, for example, one can be set as an organic slip agent: inorganic slip agent=1:0.1~1:10. By setting it within the above range, smoothness can be imparted more effectively.

(A-3) Other ingredients

The film of the present invention can also contain Ingredients other than polyamide resin and lubricant. For example, in addition to polyolefins, polyamide elastomers, polyester elastomers and other buckling resistance modifiers, one or more of pigments, antioxidants, ultraviolet absorbers, preservatives, and antistatics can also be added. Various additives such as chemicals, inorganic particles, etc.

In addition, the method of adding various additives may include a method of containing it in the polyamide resin as a raw material, a method of directly adding it to an extruder, and the like. Any of these methods may be used, or two or more methods may be used in combination.

(B) Physical properties of the film of the present invention

The film of the present invention is preferably one whose molecular orientation is biaxially oriented. The film can basically be made by biaxial stretching. It is especially suitable to use rolls and stenters for biaxially stretched films. Furthermore, the film of the present invention is controlled to have the following physical properties.

(B-1) Stress characteristics

The index of the film of the present invention that can exhibit very excellent stress balance during extension during secondary processing must meet the aforementioned A value and B value at the same time. If the aforementioned A value and B value exceed the above range, the stress balance in the entire direction of the polyamide-based film is poor, and it is difficult to obtain uniform moldability. If uniform moldability cannot be obtained, for example, when cold forming a laminate formed by laminating the film of the present invention and metal foil, sufficient ductility cannot be imparted to the metal foil (that is, the polyamide-based film becomes difficult to follow the metal foil). ), so the metal foil will break, or defects such as delamination and holes will occur easily.

The aforementioned A value is generally below 35 MPa, particularly preferably below 30 MPa, preferably below 25 MPa, and most preferably below 20 MPa. In addition, the lower limit of the aforementioned A value is not particularly limited, but is generally about 15 MPa.

The aforementioned B value is generally below 40MPa, especially 38MPa Below, 34MPa or less is better, and 30MPa or less is the best. In addition, the lower limit of the aforementioned B value is not particularly limited, but is generally about 20 MPa.

In addition, the stress in the aforementioned 4 directions at 5% elongation is not particularly limited. From the viewpoint of the cold formability of the laminate, it is preferably in the range of 35 to 130 MPa, and preferably in the range of 40 to 90 MPa. Among them, the best range is 45~75MPa.

The stress in the aforementioned 4 directions at 15% elongation is not particularly limited. From the standpoint of cold formability of the laminate, it is preferably in the range of 55 to 145 MPa, and preferably in the range of 60 to 130 MPa. The best range is 65~115MPa.

If the stress at 5% and 15% elongation in the aforementioned four directions of the film of the present invention does not satisfy the above range, sufficient cold formability may not be obtained.

The stress in the aforementioned four directions of the film of the present invention is measured as follows. First, the polyamide-based film is humidified at 23°C×50%RH for 2 hours. As shown in Fig. 5, take any point A on the film as the center point and arbitrarily specify the reference direction (0° direction) of the film, and Starting from the reference direction (a), take the clockwise 45 degree direction (b), 90 degree direction (c) and 135 degree direction (d) as the measuring direction, and cut out the distance from the center point A. A short strip sample with a direction of 100 mm and a distance of 15 mm in the direction perpendicular to the measurement direction. For example, as shown in FIG. 5, the sample 41 (length 100 mm × width 15 mm) is cut out in the range of 30 mm to 130 mm from the center point A in the 0 degree direction. Samples were also cut in the same direction in other directions. Use a tensile testing machine (manufactured by Shimadzu Corporation) equipped with a 50N measuring load cell and a sample chuck AG-1S), at a tensile speed of 100mm/min, measure the stress of these samples at 5% and 15% elongation, respectively. In addition, when the above-mentioned reference direction can be determined as the MD of the stretching step at the time of film manufacturing, the MD may be the reference direction.

The polyamide-based film of the present invention that satisfies the above-mentioned characteristic values is preferably produced by a biaxial stretching method including a step of stretching using a tenter in at least one of the longitudinal direction and the lateral direction.

Generally, the biaxial stretching method includes a simultaneous biaxial stretching method in which the stretching steps in the longitudinal direction and the transverse direction are simultaneously performed, and the successive biaxial stretching method in which the stretching step in the longitudinal direction is performed and then the stretching step in the lateral direction is performed. In addition, although the foregoing description takes the longitudinal direction as an example of the steps implemented first, the present invention can be implemented regardless of whether the longitudinal direction or the lateral direction is implemented first.

The film of the present invention is preferably prepared by a sequential biaxial stretching method in view of the degree of freedom in setting the stretching conditions. Therefore, the film of the present invention is preferably prepared by successive biaxial stretching in a step of stretching using a tenter in at least one of the longitudinal direction and the lateral direction. The film of the present invention is particularly preferably produced by the production method of the present invention described later.

(B-2) Dynamic friction coefficient (slippage)

The index of the film of the present invention that can exhibit excellent formability (smoothness) during cold forming is to make the coefficient of dynamic friction be 0.60 or less, particularly preferably 0.50 or less. Therefore, for example, it may be 0.48 or less. By controlling the coefficient of dynamic friction below 0.60, even when cold forming is performed in a high humidity (for example, a humidity above 90%), its smoothness is good, and it can effectively suppress or prevent, for example, wrinkles, delamination, Holes and so on. If the dynamic friction coefficient is greater than 0.60, then The smoothness during cold forming is not sufficient, especially when cold forming in a high humidity environment will cause wrinkles or cause delamination. Moreover, it is difficult to uniformly shape the entire laminate, and holes and the like are likely to occur. The lower limit of the coefficient of dynamic friction is not particularly limited, but is generally set to about 0.05. In addition, the coefficient of dynamic friction of the film of the present invention is determined by the following method on at least one surface of the film of the present invention, and only the value meets the above-mentioned range.

The measurement of the coefficient of dynamic friction of the present invention is performed in accordance with JIS K7125. Specifically, a sample of the polyamide-based film was humidity-conditioned at 23° C.×50% RH for 2 hours, and then the measurement was performed under the same temperature and humidity conditions. The dynamic friction coefficient is calculated by taking two samples in each of the four directions specified in the stress characteristic measurement (B-1) described above, measuring 8 points in total, and taking the average value as the average value.

(B-3) Arithmetic average height (surface roughness)

One of the indicators of the film of the present invention that can exhibit excellent formability (smoothness) during cold forming is the arithmetic average height Sa (hereinafter referred to as "Sa") of about 0.01~0.30, and 0.01~0.25 as Good, especially 0.02~0.25 is better, 0.03~0.25 is the best. Therefore, it can also be set to the range of 0.01-0.15, for example. When Sa is less than 0.01, sufficient smoothness cannot be obtained during cold forming, and therefore wrinkles and delamination may occur when pressed into a mold during cold forming. On the other hand, when Sa is greater than 0.30, although the smoothness is good, the strength of the film may decrease.

The Sa measurement of the present invention is performed using an ultra-precision non-contact three-dimensional surface texture measuring machine "Talysurf CCI6000" manufactured by TayLorHobson. Specifically, a sample of a polyamide-based film was humidity-conditioned for 2 hours at 20℃×65%RH, and then the measurement was carried out under the same temperature and humidity conditions. Certainly. In the case of a laminate containing the film of the present invention as the outermost layer, the surface that will become the outermost layer is used as the measurement surface. The sample is cut into a size of 100mm×100mm, and randomly measured at 10 points (n=10) to take the average value.

(B-4) Average thickness and thickness accuracy

The index of the film of the present invention that can exhibit very high thickness accuracy (thickness uniformity) is that the standard deviation relative to the average thickness in the eight directions shown below is generally 0.200 μm or less, particularly preferably 0.180 μm or less, and more preferably 0.160 μm or less . If the standard deviation that can show the above-mentioned thickness accuracy is less than 0.200μm, the film surface thickness unevenness is very small. For example, even if the thickness of the film is less than about 15μm, it is laminated with metal foil to obtain a laminate, which is in deep drawing. After cold forming, there will be no defects such as delamination and holes, and it has good formability. If the standard deviation exceeds 0.200μm, the thickness accuracy will be low, especially when the film thickness is small, when it is laminated with the metal foil, sufficient ductility cannot be given to the metal foil, and delamination or holes will become obvious, which may not be obtained. The case of good formability.

The evaluation method of the above-mentioned thickness accuracy is performed as follows. After adjusting the humidity of the polyamide-based film at 23℃×50%RH for 2 hours, as shown in Figure 6, take any point A on the film as the center point and specify the reference direction (0 degree direction) from the center point From A, toward the reference direction (a), 45 degrees clockwise (b), 90 degrees (c), 135 degrees (d), 180 degrees (e), and 225 degrees (f) clockwise relative to the reference direction. , 270 degree direction (g) and 315 degree direction (h) draw a total of 8 100mm straight lines L1~L8 in 8 directions. Then use the length measuring gauge "HEIDENHAIN-METRO MT1287" (manufactured by HEIDENHAIN) was measured at an interval of 10 mm from the center point (measured at 10 points). Fig. 6 shows an example of the state of the measurement point (10 points) when L2 in the 45-degree direction is obtained. Then, the average value of the 80 points of the data obtained by the measurement is calculated on all straight lines, and this is used as the average thickness, and the standard deviation with respect to the average thickness is calculated. In addition, when the above-mentioned reference direction can be determined as the MD of the stretching step at the time of film production, the MD is used as the reference direction.

In the present invention, the average thickness and standard deviation can be measured based on any point (point A) of the polyamide-based film, especially the desired polyamide-based film rolled on a film roll. Any one of the following 3 points is the average thickness and standard deviation within the above-mentioned range. The 3 points are a) near the center of the roll width and half the volume, b) near the right end of the roll width and half the volume, and c) near the left end of the roll width and near the end of the curl的的位置。 The location.

In addition, the average thickness of the film of the present invention may generally be within the range of 30 μm or less, and preferably within the range of 25 μm or less. More specifically, it is preferably 16 μm or less, particularly preferably 15.2 μm or less, and most preferably 12.2 μm or less.

The film of the present invention is preferably made into a laminate that can be laminated with metal foil, and is suitable for cold forming applications. By performing biaxial stretching using a tenter described below under stretching conditions that meet specific conditions, even thickness With a small film, a biaxially stretched film with excellent thickness accuracy (thickness uniformity) and excellent stress balance during elongation in the aforementioned four directions can be obtained.

If the average thickness of the film exceeds 30μm, the polyamide-based The formability of the film itself is reduced, and it is sometimes difficult to use it as an exterior material for small batteries, and it may also be disadvantageous in terms of economic costs. On the other hand, the lower limit of the film thickness is not particularly limited. When the average thickness is less than 2μm, the ductility imparted to the metal foil is likely to be insufficient when it is bonded to the metal foil, and the moldability is poor, so it is generally set to about 2μm. That's it.

The polyamide-based film of the present invention is laminated with metal foil to form a laminate, which is suitable for cold forming applications, and the use of the polyamide-based film of the present invention that satisfies the above-mentioned characteristics can impart sufficient ductility to the metal foil. With this effect, moldability can be improved during cold forming (among which is drawing forming (especially deep drawing forming)), etc., preventing metal foil from breaking, and preventing or preventing defects such as delamination and holes.

The smaller the thickness of the polyamide-based film, the more difficult it is to impart sufficient ductility to the metal foil. Especially for extremely thin films of 20 μm or less, the stress during elongation will be uneven and the thickness accuracy will decrease. Therefore, the polyamide-based film or metal foil will be significantly broken due to the press-in force during cold forming. In other words, the thinner the film is, the greater the unevenness of the stress will be, and the greater the unevenness of the thickness will be, which requires a higher degree of control.

In this case, the blown film stretching method for general manufacturing of polyamide-based films or the conventional manufacturing method using the tenter method must be manufactured with a thickness of 15 μm or less, and the unevenness of stress during elongation should be small. It is very difficult to have high thickness accuracy. This fact can be clearly seen in any one of Patent Documents 1-10, for example, which only discloses that the polyamide-based films of specific embodiments have a thickness of at least 15 μm.

In contrast to this, the present invention adopts the specific manufacturing shown below The method can successfully provide a polyamide-based film especially having a thickness of about 15 μm or less (especially about 12 μm or less), having excellent stress balance during elongation in the above-mentioned four directions, and having high thickness uniformity. Since the special polyamide-based film can be provided, when a laminate formed with a metal foil is used for, for example, a battery (such as a lithium ion battery) external package, for example, in addition to increasing the number of electrodes and electrolyte In addition to equal capacity, it also contributes to the miniaturization and low economic cost of the battery itself.

(B-5) Haze (transparency)

The haze of the film of the present invention is preferably 60% or less, and for applications requiring transparency, it is preferably 40% or less, particularly preferably 25% or less, and most preferably 10% or less. Therefore, for example, it may be 8% or less. For another example, it may be set to 6% or less. If the haze exceeds 60%, the film will lose transparency, so it may be difficult to impart originality by printing. In addition, the lower limit of the haze is not particularly limited, but it is generally about 1.0%.

The measurement of the haze of the present invention was carried out using a haze meter "NDH4000" manufactured by Nippon Denshoku Industries Co., Ltd. Specifically, a sample of the polyamide-based film was humidity-conditioned at 23° C.×50% RH for 2 hours, and then the measurement was performed under the same temperature and humidity conditions. In the case of a laminate containing the film of the present invention as the outermost layer, the surface that becomes the outermost layer is used as the measurement surface. Measure the number of samples n=10, and take the average value.

(C) Laminated body containing the film of the present invention

The film of the present invention can be used for various applications in the same manner as known or commercially available polyamide-based films. At this time, in addition to directly using the film of the present invention after surface treatment, it can also be laminated with other layers. Body shape for use.

In the form of a laminate, a representative example thereof may include a laminate including the film of the present invention and a metal foil laminated on the film (the laminate of the present invention). At this time, the film of the present invention can be directly contacted with the metal foil to be laminated, or it can be laminated in the state of other layers. In particular, the present invention is preferably a laminate formed by sequentially laminating the film/metal foil/sealing film of the present invention. At this time, the adhesive layer may be interposed between the layers, or the adhesive layer may not be interposed.

For example, as shown in FIG. 7, the laminated body 60 which has the three-layer structure which laminated|stacked the polyamide type film 51/adhesive layer 52/metal foil 53 in order is mentioned. As another example, as shown in FIG. 8, a laminate 70 having a 5-layer structure in which a polyamide-based film 51/adhesive layer 52a/metal foil 53/adhesive layer 52b/sealing film 54 is laminated in this order may be mentioned. In either case, as described later, the intermediate primer layer can be suitably interposed between the layers according to the needs. In addition, if two or more adhesive layers are used, the composition, thickness, etc. may be the same or may be different from each other.

The film of the present invention can be used directly, or a coating layer (especially a wet coating layer) can be formed on the film of the present invention in advance if necessary before laminating the metal foil. As the coating layer, at least one of a) an easy-to-adhesive coating layer (undercoat or anchor coating (AC layer)) and b) an easy-to-slip coating layer can be suitably used. In addition, these coating layers are particularly preferably formed by continuous coating. The physical properties of the coating film formed by forming the coating layer on the film of the present invention are also desirably within the range of physical properties shown in the aforementioned "(B) Physical properties of the film of the present invention". The details of each coating layer will be described later in <Embodiment of Coating Layer>.

Metal foil can include metal foil (including alloy foil) containing various metal elements (aluminum, iron, copper, nickel, etc.), but pure aluminum foil or aluminum alloy is particularly suitable Foil. The aluminum alloy foil preferably contains iron (aluminum-iron-based alloy, etc.), and other components may contain any components as long as they are within the known content range specified by JIS and the like without impairing the formability of the laminate.

The thickness of the metal foil is not particularly limited, but from the viewpoint of moldability and the like, it is preferably 15 to 80 μm, and more preferably 20 to 60 μm.

As the sealing film that can constitute the laminate of the present invention, for example, a thermoplastic resin having heat-sealability such as polyethylene, polypropylene, olefin-based copolymer, and polyvinyl chloride is preferably used. The thickness of the sealing film is not particularly limited. Generally, it is preferably 20 to 80 μm, and particularly preferably 30 to 60 μm.

In addition, the laminate of the present invention can be laminated with one or more other layers depending on the purpose of use, on the exterior side of the film of the present invention constituting the laminate (the side different from the surface where the metal foil is bonded). The other layers are not particularly limited, and for example, a polyester film is preferable. Laminated polyester film not only improves heat resistance, voltage resistance, chemical resistance, etc., but also improves peel strength.

The polyester is not particularly limited. For example, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene-2,6-naphthalate, etc. are suitable. Among these, PET is suitable from the viewpoint of economic cost and effect.

The laminate of the present invention can intervene an adhesive layer between each layer. For example, it is desirable to laminate each layer with an adhesive layer such as a urethane-based adhesive layer, an acrylic adhesive layer, etc. between polyamide-based films/metal foils, between metal foils/sealing films, and the like.

At this time, when the polyamide-based film of the present invention has an easy-adhesive coating layer on at least one side of the film surface, it is suitable to laminate a metal on the easy-adhesive coating layer Foil. Specifically, it is preferable to laminate a metal foil through an adhesive layer such as a urethane-based adhesive layer and an acrylic-based adhesive layer on the easy-adhesive coating layer.

The laminated body of the present invention is particularly suitable for cold-forming drawing forming (especially deep drawing forming or compression forming) in view of those containing the film of the present invention. Here, the stretch molding is a method of basically forming a container with a bottom in the shape of a round tube, a square tube, a cone, etc., from a single layered body. The container generally has the characteristic of being seamless.

(D) Container containing the laminate of the present invention

The present invention also includes a container containing the laminate of the present invention. For example, a container molded using the laminate of the present invention is also included in the present invention. Among them, the container is preferably made by cold forming. It is especially suitable for containers made by cold forming (extension processing) or compression molding (extension processing), and especially suitable for containers made by extension molding.

That is, the container of the present invention can be suitably manufactured using the following container manufacturing method, which is a method of manufacturing a container from the laminate of the present invention, characterized by including the step of cold forming the laminate. Therefore, for example, a seamless container etc. can be manufactured from the laminated body of this invention.

At this time, the cold forming method itself is not limited, and it can be implemented according to a known method. For example, it is possible to adopt a method of directly molding the resin in its solid state without melting the resin contained in the laminate. As long as the above conditions are satisfied, the molding temperature (the temperature of the laminate) can be appropriately set in accordance with the physical properties of the resin used (for example, the glass transition point, etc.). Generally speaking, the molding temperature is preferably set to 50°C or less, and preferably set to 45°C or less. Therefore, for example, the molding temperature may be set to normal temperature (about 20 to 30°C) to perform cold molding. And for example Cold forming is performed at a temperature below the glass transition point of the resin.

More specific forming methods (processing methods) may preferably be used for drawing such as round tube drawing, square tube drawing, special-shaped drawing, cone drawing, pyramid drawing, ball head drawing and other drawing processing. In addition, drawing processing is classified into shallow drawing processing and deep drawing processing, and the layered body of the present invention can also be particularly suitable for deep drawing processing.

Such drawing processing can be carried out using common molds. For example, a press machine equipped with a punch, a die, and a pressing plate can be applied, and the steps including a) arranging the laminate of the present invention between the die and the pressing plate, and b) pressing the punch into the laminate can be used. The method of the step of deforming into a container shape is used for drawing processing.

The container produced in this way can effectively suppress defects such as metal foil breakage, delamination, and holes, so that high reliability can be obtained. Therefore, the container of the present invention can be used not only for packaging materials of various industrial products, but also for various applications. In particular, the molded body obtained by deep drawing molding can be applied to the outer packaging body of lithium ion batteries, and the molded body obtained by compression molding can be applied to extrusion packaging and the like.

<Implementation form of coating layer>

A coating layer (especially a layer formed by applying a coating liquid) that can be formed before the polyamide-based thin-film laminated metal foil of the present invention can be applied to an easy-adhesive coating layer and/or an easy-slip coating layer . These coating layers can take the following embodiments.

Easy Adhesive Coating

It is suitable for the whole or part of at least one side of the film surface of the present invention to have There is an easy-to-bond coating layer (undercoating or anchor coating (AC layer)). When forming the easy-adhesive coating layer, if the adhesive is applied to the surface of the film having the easy-adhesive coating layer and the metal foil is bonded, the adhesion between the polyamide-based film and the metal foil can be further improved. Thereby, more sufficient ductility can be imparted to the metal foil. Therefore, not only does the polyamide-based film or metal foil become less susceptible to breakage, but also prevents delamination or holes from occurring more effectively.

The thickness of the easy-adhesive coating layer is not particularly limited, and is generally preferably 0.01 to 0.10 μm, and particularly preferably 0.02 to 0.09 μm. If the thickness of the easy-adhesive coating layer is less than 0.01 μm, it is difficult to form an easy-adhesive coating layer having a uniform thickness on the thin film. As a result, the effect of improving the adhesion between the polyamide-based film and the metal foil is reduced. On the other hand, if the thickness of the easy-adhesive coating layer is greater than 0.10 μm, the effect of good adhesion between the polyamide-based film and the metal foil will be saturated, which is not conducive to economic costs.

The easy-adhesive coating layer can be a layer containing various synthetic resins such as polyurethane resin and acrylic resin. Especially suitable is an easy-adhesive coating layer containing polyurethane resin. The polyurethane resin preferably contains, for example, an anionic water-dispersible polyurethane resin. The easy-adhesive coating layer containing this resin can be formed by suitably applying an aqueous coating agent containing the aforementioned resin to the surface of a polyamide-based film, for example.

The polyurethane resin is, for example, a polymer obtained by reacting a polyfunctional isocyanate with a hydroxyl-containing compound. Specifically, aromatic polyisocyanates such as toluene diisocyanate, diphenylmethane isocyanate, polymethylene polyphenylene polyisocyanate, or aliphatic polyisocyanates such as hexamethylene isocyanate and xylene isocyanate can be exemplified. Multifunctional isocyanates such as isocyanates Ester, a urethane resin obtained by reacting with polyether polyol, polyester polyol, polyacrylate polyol, polycarbonate polyol and other hydroxyl-containing compounds.

The anionic water-dispersible polyurethane resin used in the present invention has an anionic functional group introduced into the polyurethane resin. Examples of methods for introducing anionic functional groups into polyurethane resins include a) a polyol component using a diol having an anionic functional group, and b) a chain extender using an anionic functional group. The method of dihydric alcohol and so on.

Dihydric alcohols with anionic functional groups such as glyceric acid, dihydroxymaleic acid, dihydroxyfumaric acid, tartaric acid, dimethylolpropionic acid, dimethylolbutanoic acid, 2,2-dimethylolvaleric acid , 2,2-Dihydroxymethylvaleric acid, 4,4-bis(hydroxyphenyl)valeric acid, 4,4-bis(hydroxyphenyl)butyric acid and other aliphatic carboxylic acids, but also 2,6- Aromatic carboxylic acids such as dihydroxybenzoic acid, etc.

When anionic polyurethane resin is to be dispersed in water, it is generally suitable to use a volatile base. The volatile base is not particularly limited, and known ones can be used. More specifically, ammonia, methylamine, ethylamine, dimethylamine, diethylamine, triethylamine, moforin, ethanolamine, etc. can be exemplified. Among them, triethylamine is preferable because the water-dispersible polyurethane resin has good liquid stability and a low boiling point, so that the amount of residue remaining in the easy-to-adhesive coating layer is small.

Commercial products can also be used for the anionic water-dispersible polyurethane resin. For example, "HYDRAN ADS-110", "HYDRAN ADS-120", "HYDRAN ADS-120" manufactured by DIC KU-400SF", "HYDRAN HW-311", "HYDRAN HW-312B", "HYDRAN HW-333", "HYDRAN AP-20", "HYDRAN AP-201", "HYDRAN APX-101H", "HYDRAN AP -60LM", "SUPERFLEX 107M", "SUPERFLEX 150", "SUPERFLEX 150HS", "SUPERFLEX 410", "SUPERFLEX 420NS", "SUPERFLEX 460", "SUPERFLEX 460S", "SUPERFLEX 700" manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd. , "SUPERFLEX 750", "SUPERFLEX 840", "TAKELAC W-6010", "TAKELAC W-6020", "TAKELAC W-511", "TAKELAC WS-6021", "Mitsui Chemical Polyurethane Co., Ltd." "TAKELAC WS-5000", "NeoRe z R9679", "NeoRe z R9637", "NeoRe z R966", "NeoRe z R972", etc. manufactured by DSM.

In the polyamide-based film of the present invention, in order to improve the water resistance and heat resistance of the easy-adhesive coating layer, it is preferable that the easy-adhesive coating layer contains a curing agent such as melamine resin and carbodiimide. The content of the hardener is preferably 1 to 10 parts by mass relative to 100 parts by mass of the anionic water-dispersible polyurethane resin.

The representative of the melamine resin may be tris(alkoxymethyl)melamine. Examples of the alkoxy group include methoxy, ethoxy, propoxy, butoxy and the like. Various melamine resins can be used alone or two or more of them can be used at the same time.

The carbodiimide compound is not particularly limited as long as it has at least two or more carbodiimide groups in the molecule. For example, in addition to p-phenylene-bis (2,6-xylyl carbodiimide), tetramethylene-bis (tertiary butyl carbodiimide), cyclohexane-1,4-bis In addition to compounds having carbodiimide groups such as (methylene-tertiary butyl carbodiimide), polycarbodiimide of polymers having carbodiimide groups can also be cited. One or two or more of these can be used. Among them, polycarbodiimide is preferable from the viewpoint of work convenience.

As the carbodiimide compound, a known or commercially available one can be used. In addition, the production method is not particularly limited. For example, in the case of polycarbodiimide, it can be suitably produced by a condensation reaction accompanying the decarbonization of an isocyanate compound. The isocyanate compound is not particularly limited. For example, it may be any of aliphatic isocyanate, alicyclic isocyanate, aromatic isocyanate, and the like. In addition, the isocyanate compound can be copolymerized with polyfunctional liquid rubber, polyalkylene glycol, and the like as needed. In particular, the commercial products of polycarbodiimide can be applied to the carbodilite series manufactured by Nisshinbo Chemical Inc. Specifically, water-soluble product names "SV-02", "V-02", "V-02-L2", "V-04" (all manufactured by Nisshinbo Chemical Inc.), and organic solutions can be suitably used. Types of product names are "V-01", "V-03", "V-07", "V-09", solvent-free type "V-05" (all manufactured by Nisshinbo Chemical Inc.), etc.

The solid content concentration of the anionic water-dispersible polyurethane resin in the water-based paint containing the anionic water-dispersible polyurethane resin can be appropriately changed using the specifications of the coating device, drying and heating device, etc., but Too thin solution is easy to produce in the drying step and takes a long time The problem. On the other hand, if the solid content concentration is too high, it is difficult to obtain a uniform coating agent, and therefore coating properties are likely to cause problems. From the above viewpoint, the solid content concentration of the anionic water-dispersible polyurethane resin in the water-based paint is preferably in the range of 3 to 30% by mass.

In addition to the anionic water-dispersible polyurethane resin as the main component, the water-based paint may also contain the above-mentioned components. In addition, in order to improve the coating properties when the water-based paint is applied to the film, for example, additives such as defoamers and surfactants may also be added.

By adding a surfactant, it can especially promote the wettability of the water-based paint to the substrate film. The surfactant is not particularly limited, for example, except for polyvinyl alkyl phenyl ether, polyoxyethylene-fatty acid ester, glycerol fatty acid ester, fatty acid metal soap, alkyl sulfate, alkyl sulfonate, alkyl In addition to sulfosuccinate plasma surfactants, nonionic surfactants such as acetylene glycol can also be cited. The surfactant is preferably contained in 0.01 to 1% by mass in the water-based paint. In addition, it is preferably one that can be volatilized by the heat treatment in the production step of the polyamide-based film.

In addition, various additives such as antistatic agents and slip agents can be added to the water-based paint according to the needs without affecting the adhesion.

Slippery coating

It is also possible to form a slippery coating layer on the surface of the film of the present invention where the metal foil is not laminated as needed. In this way, the smoothness (kinetic friction coefficient) of the film of the present invention can be further improved. That is, forming a slippery coating layer on the surface where the metal foil is not formed, and arranging the slippery coating layer as the outermost layer, can provide the same level of slippage as the polyamide-based film of the present invention The coating film.

The thickness of the slippery coating layer is not particularly limited, and is generally preferably 0.01 to 0.10 μm, and particularly preferably 0.02 to 0.09 μm. If the thickness of the slippery coating layer is less than 0.01 μm, it is difficult to form a layer with a uniform thickness on the film. As a result, the friction coefficient of the polyamide-based film of the present invention becomes high, and the smoothness is poor. On the other hand, if the thickness of the coating layer is greater than 0.10 μm, the effect of good smoothness during molding will be saturated, which is not conducive to economic costs.

When the film of the present invention contains an easy-slip coating layer, the dynamic friction coefficient of the surface of the easy-slip coating layer is also preferably 0.60 or less.

As the slippery coating layer, for example, a layer containing various synthetic resins such as polyurethane resin and acrylic resin can be used. Particularly suitable is a coating layer containing a polyurethane resin with a glass transition temperature above 20°C. The polyurethane resin preferably contains, for example, an anionic water-dispersible polyurethane resin. The slippery coating layer containing the resin can be formed by coating the surface of the polyamide-based film with an aqueous coating containing the aforementioned resin.

Commercial products can also be used for the anionic water-dispersible polyurethane resin. For example, "AP-40F" manufactured by DIC, "SUPERFLEX 150HS" manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd., Mitsui Chemicals polyurethane "TAKELAC WS-4022", "TAKELAC WS-5030", "TAKELAC WS- 6010" and so on.

In the polyamide-based film of the present invention, in order to improve the water resistance, heat resistance, etc. of the slippery coating layer, the coating layer preferably contains a curing agent such as melamine resin and carbodiimide. The content of the hardener is preferably 1 to 10 parts by mass relative to 100 parts by mass of the anionic water-dispersible polyurethane resin. Specifically, the melamine resin, carbodiimide compound, and the like can preferably be the same as those described in the easy-adhesive coating layer.

In the present invention, for example, an easy-slip coating layer can be formed by applying an aqueous coating agent containing an anionic water-dispersible polyurethane resin, for example. The solid content of the anionic water-dispersible polyurethane resin in the water-based paint should preferably be in the range of 3-30% by mass as the easy-adhesive coating layer.

In order to improve the smoothness of the slippery coating layer, the slippery coating layer may contain at least one of an inorganic slip agent and an organic slip agent as needed. The inorganic slip agent and/or the organic slip agent can be the same as those contained in the aforementioned polyamide-based film of the present invention. The inorganic slip agent or organic slip agent is preferably contained in the slippery coating layer at about 0.1 to 30.0% by mass.

Moreover, when it is desired to include an inorganic slip agent and/or an organic slip agent in the slippery coating layer, it is preferable to add these slip agents to the water-based coating agent. In the water-based paint, in order to improve the coatability when coating the film, additives such as defoamers and surfactants may also be added.

By adding a surfactant, it can especially promote the wettability of the water-based paint to the substrate film. The surfactant is not particularly limited, and specifically the same as those described in the easy-adhesive coating layer can be used. In addition, it is preferable to use the same amount as when the easy-adhesive coating layer is used.

2. Manufacturing method of the film of the present invention

The manufacturing method of the present invention is a method for manufacturing biaxially oriented polyamide-based film. The method is characterized by including the following steps: (1) a sheet forming step, forming a sheet of molten kneaded material into a sheet. Stretched sheet, the melt-kneaded material contains polyamide resin and contains at least one of an organic slip agent and an inorganic slip agent; (2) the stretching step, the unstretched sheet is biaxially stretched to MD and TD sequentially or simultaneously The stretched film is prepared; and (3) satisfies both the following formulas a) and b):

a) 0.85≦X/Y≦0.95

b)8.5≦X×Y≦9.5

(However, X represents the aforementioned MD stretch magnification, and Y represents the aforementioned TD stretch magnification).

Sheet forming steps

In the sheet forming step, an unstretched sheet is obtained by forming a melt kneaded product containing polyamide resin and containing at least one of an organic slip agent and an inorganic slip agent into a sheet shape.

The aforementioned various materials can be used for the polyamide resin, the organic slip agent and the inorganic slip agent. In addition, various additives may be contained in the melt kneaded material. In the manufacturing method of the present invention, it is particularly desirable to contain both an organic slip agent and an inorganic slip agent in terms of effective control of the dynamic friction coefficient and the like.

The preparation of the melt kneaded product itself may be carried out according to a known method. For example, a raw material containing polyamide resin and at least one of organic slip agent and inorganic slip agent can be fed into an extruder equipped with a heating device, heated to a predetermined temperature and melted, and then extruded with a T-die The kneaded product is melted and cooled and solidified by a casting roll or the like to obtain an unstretched sheet of a sheet-shaped molded body.

The order of addition of polyamide resin, organic slip agent, inorganic slip agent, and the like is not particularly limited. Then, the average thickness of the unstretched sheet is not particularly limited, but it is generally set to about 15 to 250 μm, and particularly preferably set to 50 to 235 μm. By setting in the range, the extension step can be performed more effectively.

Extension step

In the stretching step, the unstretched sheet is biaxially stretched to MD and TD successively or simultaneously to obtain a stretched film.

As mentioned above, it is preferably obtained by successive biaxial stretching including a step of stretching in at least one direction of MD and TD using a tenter. In this way, a more uniform film thickness can be obtained.

The tenter itself has been a device used to stretch the film from before. It is a device that holds the two ends of the unstretched sheet and stretches it in the longitudinal and/or transverse directions. There are two methods of using the stenter: simultaneous biaxial stretching and successive biaxial stretching. Simultaneous biaxial stretching with a tenter is a method of holding the two ends of the unstretched film to extend to MD and simultaneously to TD, and to use the tenter to perform biaxial stretching of MD and TD at the same time. However, using a tenter to carry out sequential biaxial stretching, there are: 1) After the unstretched sheet is stretched through a plurality of rolls with different rotation speeds, the stretched film is stretched to TD with a tenter ; And 2) After the unstretched sheet is stretched to MD with a tenter, the stretched film is stretched to TD with a tenter. However, it is particularly suitable from the viewpoint of the physical properties and productivity of the film obtained This is the method described in 1) above. The method of 1) mentioned above is to perform the steps shown in Fig. 2 to perform successive biaxial stretching of the unstretched film.

First, as shown in FIG. 2, the unstretched sheet 13 is passed through the plurality of rollers 21 to extend in the MD (longitudinal direction). The rotation speeds of the plurality of rollers are different from each other, so the unstretched sheet 13 is stretched toward MD by using the difference in speed. That is, the unstretched sheet is stretched from the low-speed roller group through the high-speed roller group.

In addition, the number of rollers in Fig. 2 is 5, but in fact, it can be a number other than that. In addition, the rolls may be provided with rolls having different functions in the order of a preheating roll, a stretching roll, and a cooling roll, for example. The number of rollers with each of these functions can also be set appropriately. In addition, when a plurality of stretching rollers are installed, they can be installed to perform stretching in multiple stages. For example, if the first stage is set to the stretching magnification E1, and the second stage is set to the stretching magnification E2 to perform two-stage stretching, the MD stretch magnification can be appropriately set within the range of (E1×E2). According to the above, the first stretched film 13' is prepared.

Next, the first stretched film 13' that has passed through the roll 21 is introduced into the tenter 22 and stretched in TD. Specifically, as shown in FIG. 3, the first stretched film 13' that has been introduced into the tenter 22 is held near the entrance by the clamps connected to the link device 34 fixed on the guide rail, and The flow direction passes through the preheating zone 31, the extension zone 32 and the relaxation heat treatment zone 33 in sequence. After the first stretched film 13' is heated to a fixed temperature in the preheating zone 31, it is stretched to TD in the stretching zone 32. Then, in the relaxation heat treatment zone 33, the relaxation treatment is performed at a fixed temperature. According to the above, the second stretched film 14 (the film of the present invention) was produced. After that, the link device 34 fixed to the guide rail is removed from the second stretch film 14 near the exit of the tenter 22 and placed back near the entrance of the tenter 22.

According to the above, the use of a tenter to carry out successive biaxial stretching, the use of rolls to the MD stretching system is advantageous in terms of productivity and equipment, and the use of the tenter to the TD stretching system is advantageous to control the film thickness.

In the manufacturing method of the present invention, the extension step must satisfy both of the following formulas a) and b):

a) 0.85≦X/Y≦0.95

(Suitable for 0.89≦X/Y≦0.93)

b)8.5≦X×Y≦9.5

(Suitable for 8.7≦X×Y≦9.1)

(However, X represents the aforementioned MD stretch magnification, and Y represents the aforementioned TD stretch magnification).

When any one of the above conditions a) and b) is not satisfied, the stress balance of the polyamide-based film produced in the four directions will deteriorate, making it difficult to produce the film of the present invention.

The temperature condition of the stretching step, for example, when performing the aforementioned simultaneous biaxial stretching, it is suitable to perform stretching in a temperature range of 180°C to 220°C. And for example, when performing the aforementioned sequential biaxial stretching, MD stretching should be carried out at a temperature range of 50~120℃ (especially 50~80℃, and 50~70℃, and 50~65℃), and preferably at 70 TD extension is carried out in the temperature range of ~150℃ (especially 70~130℃, and 70~120℃, and 70~110℃). By controlling in the temperature range, the film of the present invention can be manufactured more reliably. These temperatures can be set and controlled, for example, by preheating the roll 21 (roll for preheating) shown in Fig. 2 and the preheating zone 31 of the tenter shown in Fig. 3, etc.

In addition, it is suitable to perform simultaneous biaxial stretching and successive biaxial stretching with a tenter, and to perform relaxation heat treatment after stretching. Relaxation heat treatment It is better to set the relaxation rate to 2~5% under the temperature range of 180~230℃. These temperatures can be set and controlled in the relaxation heat treatment zone 33 of the tenter shown in Figure 3.

The methods used to set the temperature range during stretching to the above-mentioned methods include, for example: 1) a method of blowing hot air on the surface of the film, 2) a method of using a far infrared or near infrared heater, and 3) a method of combining these, etc., The heating method of the present invention preferably includes a method of blowing hot air.

<Implementation form of extension step>

The stretching step in the present invention can suitably adopt a successive biaxial stretching step of stretching to MD using a roll and stretching to TD using a tenter. By adopting this method and satisfying the temperature conditions shown below, not only the thickness uniformity is excellent, but the stress balance in the aforementioned four directions during elongation is also more excellent. In particular, it is possible to more reliably and effectively produce a book with an average thickness of 16μm or less. Invention of film.

MD extension

First of all, the temperature of MD stretching should be carried out in the temperature range of 50~70℃ with rollers, among which 50~65℃ is suitable.

MD extension should be multi-stage extension of more than 2 stages. At this time, the extension ratio should be increased in stages. That is, the elongation ratio of the (n+1)th stage is controlled to be higher than the elongation bridge ratio of the nth stage. In this way, the whole can be extended more uniformly. For example, when stretching in two stages, the stretching magnification of the first stage can be set to 1.1 to 1.2, and the stretching magnification of the second stage can be set to 2.3 to 2.6 for two stages of stretching, and the stretching magnification in the longitudinal direction can be set to 2.53~ Set appropriately within the range of 3.12.

In addition, the temperature gradient should be set for MD extension. Especially in order to increase the temperature along the pulling direction of the film, taking the MD extension as a whole, its The temperature gradient (the temperature difference between the temperature T1 at the starting point (inlet) of the film moving direction and the temperature T2 at the ending point (outlet)) is generally preferably 2°C or more, more preferably 3°C or more. At this time, the film moving time (heating time) between the starting point (inlet) and the ending point (outlet) of the film moving direction is generally 1~5 seconds, especially 2~4 seconds.

TD extension

The TD stretching is performed by using a tenter with the zones shown in FIG. 3 formed. At this time, the temperature of the preheating zone 31 should be set to 60~70°C. Then, it is advisable to set the temperature of the extension zone 32 to a temperature range of 70~130°C, particularly preferably to a temperature range of 75~120°C, and it is best to set a temperature range of 80~110°C.

In addition, it is also advisable to increase the temperature sequentially in the stretching zone 32 along the film's drawing direction. In the stretching zone as a whole, the temperature gradient (the temperature T1 at the starting point (inlet) of the film moving direction and the temperature at the end point (outlet) are The temperature difference between T2) is generally above 5°C, more preferably above 8°C. At this time, the film moving time (heating time) between the starting point (inlet) and the ending point (outlet) of the film moving direction in the extension zone 32 is preferably 1 to 5 seconds, and particularly preferably 2 to 4 seconds.

It is preferable to perform relaxation heat treatment in the relaxation heat treatment zone 33. The heat treatment temperature should be set to the range of 180~230℃, among which the range of 180~220℃ is more suitable, and the best setting is 180~210℃. In addition, the relaxation rate is generally preferably set to about 2 to 5%.

In addition, at least one side of the surface of the polyamide-based film of the present invention is to have a coating layer (especially at least the easy-adhesive coating layer and the easy-slip coating layer) When coating the film of type 1), it is also suitable to use the same stretching method and stretching conditions as the above.

In particular, in order to form a coating layer on the surface of the polyamide-based film, it is preferable to apply an aqueous coating agent to the polyamide-based film that has been stretched to MD in the above-mentioned manufacturing method. Then, the film and the aqueous coating agent (coating film) are stretched to TD (continuous coating) under the same stretching conditions as described above. The coating amount of the water-based coating agent should be adjusted so that the thickness of the coating layer formed on the film surface after stretching becomes 0.01~0.10μm.

In addition, in the manufacturing method of the present invention, it is not recommended to use stretching methods other than the above from the viewpoint of maintaining thickness uniformity in the stretching step. For example, it is expected that the stretching step by the blown film stretching method (inflation method) is not included.

Example

Examples and comparative examples are shown below to further specifically illustrate the features of the present invention. However, the scope of the present invention is not limited to the embodiments.

Example 1

(1) Manufacturing polyamide-based film

First, the ingredients shown in Table 1 were used as the raw materials.

Using the above raw materials, the composition ratio of polyamide resin (polyamide 6 resin)/polyamide resin containing silicon oxide/polyamide resin containing organic slip agent=91.5 parts by mass/2.5 parts by mass/6.0 parts by mass After being melted and kneaded in an extruder, it is supplied to a T-die to form a sheet, and is wound on a metal drum whose temperature has been adjusted to 20°C, cooled and wound to produce an unstretched sheet. At this time, the supply amount of the polyamide resin is adjusted so that the thickness of the polyamide-based film obtained after stretching becomes 12 μm.

Then, the unstretched sheet obtained is subjected to the stretching step by successive biaxial stretching. Specifically, it is implemented by using the device shown in FIG. 2, after stretching with a roll in the MD system, and stretching with a tenter in TD.

First, in the MD stretching system, the aforementioned sheet is passed through a plurality of rollers, and the conventional MD has a total stretching ratio of 2.85 times for stretching. At this time, the stretching is performed in two stages, and the stretching magnification of the first stage is 1.1, the stretching magnification of the second stage is 2.59, and the total stretching magnification (MD1×MD2) is 1.1×2.59=2.85 times. The heating condition is to set a temperature gradient along the film drawing direction with the starting point (T1) of the moving direction at 54°C and the ending point (T2) at 57°C for stretching. At this time, the film moving time (heating time) between the starting point (inlet) and the ending point (outlet) of the film moving direction is about 3 seconds.

Next, TD stretching was implemented using the tenter shown in FIG. 3. First, the temperature of the preheating zone 31 (preheating part) is set to 65° C. for preheating, and the extension zone 32 is extended 3.2 times to TD. At this time, in the extension area 32 (extended portion), it is the starting point of the moving direction along the film pulling direction (T1) is 74°C and the end point (T2) is 96°C. Set the temperature gradient. At this time, the film moving time (heating time) between the starting point (inlet) and the ending point (outlet) of the film moving direction in the stretching zone is about 3 seconds.

The thin film passing through the extension zone is subjected to relaxation heat treatment at a temperature of 202° C. and a relaxation rate of 3% in the relaxation heat treatment zone 33 (heat treatment section). A biaxially stretched polyamide-based film (roll volume 2000m) was prepared by continuously manufacturing 1000m or more as described above. The film is rolled into a roll shape.

(2) Making a laminated body

In the (1) the biaxially stretched polyamide-based film prepared to have the coating amount of 5g / m ² coating two-polyamine-based urethane adhesive (Toyo Morton Co., Ltd. "TM-K55 /CAT-10L”), then dry at 80°C for 10 seconds. A metal foil (aluminum foil with a thickness of 50 μm) was attached to the adhesive application surface. Next, after coating the above-mentioned adhesive on the aluminum foil side of the laminate of the polyamide-based film and aluminum foil under the same conditions, a sealing film (unstretched polypropylene film (GHC manufactured by Mitsui Chemicals Tohcello. Inc.) The thickness is 50 μm)), and the hardening treatment is performed for 72 hours in a 40°C gas environment to produce a laminate (polyamide-based film/aluminum foil/sealing film).

Examples 2-40, Comparative Examples 1-20

In addition to changing the manufacturing conditions and the target thickness of the stretched polyamide-based film as shown in Tables 2 to 4, and changing the composition ratio of the raw materials so that the content of the organic slip agent or inorganic slip agent is as shown in Tables 8 to 10, In the same manner as in Example 1, a polyamide-based film was produced. Using the obtained polyamide-based film, a laminate was produced in the same manner as in Example 1. However, Example 7, Example 17, and Example 38 are specifically modified as follows.

(1) Regarding Example 7

A two-component polyurethane adhesive was applied to the surface of the unlaminated aluminum foil of the polyamide-based film in the laminate prepared in Example 1 with a coating amount of 5g/m ^{2 (Toyo Morton Co., Ltd.} After TM-K55/CAT-10L manufactured by the company, it was dried at 80°C for 10 seconds. A PET film ("EMBLET PET-12" made by UNITIKA, 12 μm in thickness) was bonded to the adhesive coating surface to prepare a laminate (PET film/polyamide-based film/aluminum foil/sealing film).

(2) Regarding Example 17

In addition to using the raw materials shown in Table 1, and changed to polyamide resin (polyamide 6 resin) / polyamide resin (polyamide 66 resin) / polyamide resin containing silicon oxide / polyamide containing organic slip agent The composition ratio of the amide resin=81.8/9.7/2.5/6.0 parts by mass, and the production conditions were changed to those shown in Table 2, and the polyamide-based film was produced in the same manner as in Example 1. Using the obtained polyamide-based film, a laminate was produced in the same manner as in Example 1.

(3) Regarding Example 38

Except for nylon 6 resin (manufactured by UNITIKA Co., Ltd., product name "A1030BRF") with 1% by mass of organic slip agent "Ethylene Didocosan (commercially available)" added as Table 1 In addition to the polyamide resin containing organic slip agents, use the raw materials shown in Table 1 and change to polyamide resin (polyamide 6 resin)/polyamide resin (polyamide 66 resin)/polyamide resin containing silicon oxide The composition ratio of amide resin/polyamide resin containing organic slip agent=81.8/9.7/2.5/6.0 parts by mass, and the production conditions were changed to those shown in Table 3. The polyamide resin was prepared in the same manner as in Example 1. Amide-based film. Using the produced polyamide-based film, a laminate was produced in the same manner as in Example 1.

Test example 1

The physical properties of the polyamide-based films and laminates prepared in Examples 1-40 and Comparative Examples 1-20 were evaluated. The evaluation results are shown in Tables 5-10. In addition, the measurement methods and evaluation methods of various physical properties are performed as follows.

(1) The 4-direction stress of polyamide film at 5% elongation and 15% elongation

The four-direction stress of the polyamide-based film at 5% elongation and 15% elongation is calculated by making the reference direction (0 degree direction) MD, and measuring according to the method described above.

In addition, the sample film used for the measurement was taken near the center of the roll width and at the half of the roll volume among the polyamide-based films wound on the film roll.

(2) Average thickness and standard deviation of polyamide film

The average thickness and standard deviation of the polyamide-based film are respectively measured and calculated in accordance with the aforementioned method. In addition, the following three types of sample films were used for the measurement.

In the polyamide-based film that is wound on the film roll, the one taken a) near the center of the roll width and half of the roll volume is marked as "A", and b) near the right end of the roll width And the one taken at half the volume of the roll is marked as "B", c) the one taken near the left end of the roll width and near the end of the curl is marked as "C".

(3) The coefficient of dynamic friction, haze, and arithmetic average height of the polyamide film Sa

The coefficient of dynamic friction, haze, and arithmetic average height Sa of the polyamide-based film were measured in accordance with the aforementioned method. In addition, the sample film used in the measurement is used The prepared polyamide-based film wound on the film roll is taken near the center of the roll width and at the position of half the roll volume.

In addition, for the coated film, the surface that requires smoothness during cold forming is used as the measurement object. That is, for a coating film having an easy-to-adhesive coating layer formed on a polyamide-based film, the surface on which the coating layer is not formed is used as the measurement target. In addition, for a coating film having a slippery coating layer formed on a polyamide-based film, the surface of the coating layer is used as a measurement target.

(4) Thickness of coating layer (easy adhesion coating layer or easy slip coating layer)

The coating film formed by forming a coating layer on a polyamide-based film is embedded in epoxy resin, and slices with a thickness of 100 nm are taken with a cryomicrotome. The cutting temperature is set to -120°C, and the cutting speed is set to 0.4 mm/min. The collected section was _{vapor-phase stained with RuO 4} solution for 1 hour, and the thickness of the coating layer was measured by transmission measurement at an acceleration voltage of 100 kV using JEM-1230 TEM (manufactured by JEOL Ltd.). At this time, select any 5 points where the thickness of the coating layer is measured, and use the average value of the measured values at 5 points as the thickness.

In addition, the sample film used in the measurement was taken from the coating film wound on the film roll near the center of the roll width and at a position that was half of the roll volume.

(5) Moldability and heat resistance of laminate

1) Formability (extension depth; Erichsen test)

According to JISZ2247, using an Eriksson testing machine (No. 5755, manufactured by Yasuda Seiki Seisakusho Co., Ltd.), a steel ball punch was pressed at a predetermined pressing depth to the resulting laminate to obtain the Eriksson value. The Erickson value is 0.5mm For determination. We judge that the Eriksson value is 5mm or more, and especially that 8mm or more is suitable for deep drawing. In addition, the pressing speed of the steel ball punch was set to 0.20 mm/s, and the measurement environment was set to 23° C.×90% RH.

2) Humidity and heat resistance

In order to evaluate the molding stability under the conditions of high temperature and high humidity, the resulting laminate was processed with a high temperature and high pressure conditioning sterilization device RCS-60SPXTG (manufactured by Hisaka Co., Ltd.) at 120°C, 30 minutes, 1.8 kg/cm ² After the treatment, the same Eriksson test as in 1) above was performed. At this time, if the Eriksson value is 7mm or more, it is expressed as "◎", if the Eriksson value is 6mm or more and less than 7mm, it is expressed as "○", and the Erickson value is 5mm or more and less than 6mm. The hour is marked as "△", and when the Eriksson value is less than 5mm, it is marked as "×".

It can be clearly seen from these results that the stretch ratios of the polyamide-based films in Examples 1-40, especially the polyamide-based films, are within a predetermined range, so the obtained polyamide-based films are satisfactory for the uniaxial tensile test. The difference between the maximum and minimum stress at 5% elongation in the MD, 45-degree, 90-degree (TD), and 135-degree directions is less than 35MPa, and the maximum and minimum stress at 15% elongation The difference is below 40MPa. In addition, the laminated body produced by using these polyamide-based films has a high Eriksson value, and has ductility that can be uniformly stretched in all directions during cold forming. In other words, it can be seen that the polyamide-based film of each example does not have aluminum foil fracture, delamination, holes, etc., and can exhibit excellent moldability.

In addition, the dynamic friction coefficient of the polyamide-based films prepared according to the above-prepared Examples 1-40 is also controlled below 0.60, so it can be seen that the smoothness is particularly excellent, and the cold formability under high humidity is also excellent.

On the other hand, in Comparative Examples 1-16, especially the stretch ratio of the polyamide-based film did not meet the predetermined range, the obtained polyamide-based film was not satisfied with the uniaxial tensile test in the direction of 0 degrees (MD ), 45 degree direction, 90 degree (TD) direction and 135 degree direction the difference between the maximum and minimum stress at 5% elongation is less than 35MPa, and does not meet the difference between the maximum and minimum stress at 15% elongation Below 40MPa. Therefore, it can be confirmed that the laminate obtained by using the polyamide-based films of these comparative examples has a low Eriksson value, does not have ductility that can be uniformly expanded in all directions during cold forming, and has poor moldability. In addition, the polyamide-based films produced in Comparative Examples 17 to 20 also have a high dynamic friction coefficient. Therefore, it can be seen that the friction between the polyamide-based film and the molding mold is large and the smoothness is poor, and the Erickson value is low, and the molding is Poor sex.

Example 41

(1) Manufacture a coating film with an easy-to-adhesive coating layer (primer coating)

First, the ingredients shown in Table 1 were used for the raw material systems. Using the above raw materials, the composition ratio of polyamide resin (polyamide 6 resin)/polyamide resin containing silicon oxide/polyamide resin containing organic slip agent=91.5 parts by mass/2.5 parts by mass/6.0 parts by mass It is melted and kneaded in an extruder, and fed to a T-die to form a sheet, then rolled on a metal drum whose temperature has been adjusted to 20°C, cooled and wound to produce an unstretched sheet. At this time, the supply amount of the polyamide resin is adjusted so that the thickness of the polyamide-based film obtained after stretching can be 15 μm.

Then, the unstretched sheet obtained is subjected to the stretching step by successive biaxial stretching. More specifically, the apparatus shown in FIG. 2 was used to stretch the aforementioned sheet using a roll for MD, and then stretched with a tenter in TD.

First, in the MD stretching system, the aforementioned sheet is passed through a plurality of stretching rollers, and the conventional MD has a total stretching ratio of 2.85 times for stretching. At this time, the stretching is performed in two stages, and the stretching magnification of the first stage is 1.1, the stretching magnification of the second stage is 2.59, and the total stretching magnification (MD1×MD2) is 1.1×2.59=2.85 times. The heating condition is to set a temperature gradient along the film drawing direction with the starting point (T1) of the moving direction at 58°C and the ending point (T2) at 61°C for stretching. At this time, the film moving time (heating time) between the starting point (inlet) and the ending point (outlet) of the film moving direction is about 3 seconds.

After MD stretching, in order to form an easy-to-adhesive coating layer, a gravure coater is used to coat the polyurethane aqueous dispersion on a single surface so that the coating thickness after stretching becomes 0.03 to 0.08 μm. After that, TD extension is performed. The above-mentioned water dispersion system uses 100 parts by mass of anionic water-dispersible polyurethane resin ("HYDRAN KU400SF" manufactured by DIC) and 7 parts by mass of tris (methoxymethyl) melamine resin (manufactured by DIC) "BECKAMINE APM") water-based paint.

Next, TD stretching was implemented using the tenter shown in FIG. 3. First, the temperature of the preheating zone 31 (preheating part) is set to 70° C. for preheating, and the extension zone 32 is extended 3.2 times to TD. At this time, in the stretching zone 32 (extension portion), a temperature gradient is set along the film drawing direction with the starting point (T1) of the moving direction at 78°C and the ending point (T2) at 100°C. At this time, the film moving time (heating time) between the starting point (inlet) and the ending point (outlet) of the film moving direction in the stretching zone is about 3 seconds.

The thin film that has passed through the extension zone is subjected to relaxation heat treatment in the relaxation heat treatment zone 33 (heat treatment part) at a temperature of 202° C. and a relaxation rate of 3%. After the above-mentioned continuous production of 1000m or more, a biaxially stretched polyamide-based film with an easy-to-adhesive coating layer formed on one side of the biaxially stretched polyamide film (roll volume 2000m) was prepared. The film is rolled into a roll shape.

(2) Making a laminated body

Except for using the coating film prepared in (1) above and using a two-component polyurethane-based adhesive laminated aluminum foil on the surface of the easy-to-adhesive coating layer, a laminated body was produced in the same manner as in Example 1 ( Coating film/aluminum foil/sealing film).

Examples 42~84, Comparative Examples 21~44

In addition to changing the manufacturing conditions and the target thickness of the stretched polyamide-based film as shown in Tables 11 to 14, and changing the composition ratio of the raw materials so that the content of the organic slip agent or inorganic slip agent is as shown in Tables 21 to 24, The coated film was prepared in the same manner as in Example 41. Using the obtained coating film, a laminate was produced in the same manner as in Example 41. However, Example 47, Example 55, Example 63, Example 83, and Example 84 are specifically modified as follows.

(1) Regarding Example 47

A two-component polyurethane adhesive (TM-K55 manufactured by Toyo Morton Co., Ltd.) was applied to the surface of the unlaminated aluminum foil coated with the film in the laminate prepared in Example 41 at a coating amount of 5 g/m ² /CAT-10L), then dry at 80°C for 10 seconds. A PET film (EMBLET PET-12 made by UNITIKA, 12 μm in thickness) was bonded to the adhesive coating surface to prepare a laminate (PET film/coating film/aluminum foil/sealing film).

(2) Regarding Example 55

In embodiments the surface coating film is not laminated to the aluminum foil coating amount of 5g / m ² coating two-polyamine-based urethane adhesive (manufactured by Toyo Morton Co. TM-K55 body prepared laminated 48 /CAT-10L), then dry at 80°C for 10 seconds. A PET film (EMBLET PET-12 manufactured by UNITIKA, thickness 12 μm) was bonded to the adhesive coating surface to prepare a laminate (PET film/coating film/aluminum foil/sealing film).

(3) Regarding Example 63

Use the raw materials shown in Table 1, and change to polyamide resin (polyamide 6 resin)/polyamide resin (polyamide 66 resin)/polyamide resin containing silicon oxide Grease/polyamide resin containing organic slip agent = 81.8/9.7/2.5/6.0 parts by mass, and the production conditions were changed to those shown in Table 12. The coating film was prepared in the same manner as in Example 48. . Using the obtained coating film, a laminate was produced in the same manner as in Example 41.

(4) Regarding Example 83

Except that an anionic water-dispersible polyurethane resin (“HYDRAN AP201” manufactured by DIC Corporation) was used for the polyurethane water dispersion used to form the easy-adhesive coating layer, the same method as in Example 41 was used. The coated film is produced. Using the obtained coating film, a laminate was produced in the same manner as in Example 41.

(5) Regarding Example 84

In addition to using anionic water-dispersible polyurethane resin (“HYDRAN AP201” manufactured by DIC Corporation) for the polyurethane water dispersion used to form the easy-to-bond coating layer, the hardener uses carbodiimide series Except for the hardener ("carbodilite V-02-L2" manufactured by Nisshinbo Chemical Inc.), a coating film was prepared in the same manner as in Example 49. Using the obtained coating film, a laminate was produced in the same manner as in Example 41.

Example 85

(1) Manufacturing coating film with slippery coating layer

MD stretching was performed on the unstretched sheet prepared by the same method using the same raw materials as in Example 41. After MD stretching, in order to form a slippery coating layer, a gravure coater was used to coat the polyurethane aqueous dispersion on one side so that the coating thickness after stretching became 0.05 μm. After that, TD extension is performed. The above-mentioned water dispersion system uses self-anionic water-dispersible polyurethane A water-based paint made from ethyl resin (Mitsui Chemicals polyurethane "TAKELAC WS-4022").

Next, the TD stretching and subsequent steps were followed by the same method as in Example 41 to prepare a coated film.

(2) Making a laminated body

Coat the two-component polyurethane adhesive ^{with a coating amount of 5g/m 2} on the surface of the coated film that is not formed with an easy-to-slip coating layer (that is, the surface of the polyamide-based film) ("TM-K55/CAT-10L" manufactured by Toyo Morton Co., Ltd.), and then dried at 80°C for 10 seconds. A metal foil (aluminum foil with a thickness of 50 μm) was attached to the adhesive application surface. Next, after coating the above-mentioned adhesive on the surface of the aluminum foil under the same conditions, a sealing film (unstretched polypropylene film (GHC thickness 50μm manufactured by Mitsui Chemicals Tohcello. Inc.)) was attached to the coated surface, and the gas was heated at 40°C. The hardening treatment was performed for 72 hours under the environment to produce a laminate (coating film/aluminum foil/sealing film).

Examples 86~89

Except that the manufacturing conditions and the target thickness of the stretched polyamide-based film were changed to those shown in Table 15, and the thickness of the slippery coating layer was changed to those shown in Table 20, it was prepared in the same manner as in Example 85. Coating film. Using the obtained coating film, a laminate was produced in the same manner as in Example 85.

Example 90

MD stretching was performed on the unstretched sheet obtained by using the same raw material as in Example 41 and prepared by the same method. After MD stretching, in order to form a slippery coating layer, a gravure coater was used to make the coating thickness after stretching 0.05μm. The polyurethane water dispersion was coated on one side. Then proceed to TD extension. The above-mentioned water dispersion system is used in an anionic water-dispersible polyurethane resin (Mitsui Chemicals polyurethane "TAKELAC WS-4022") with silica as an inorganic slip agent and mixed to prepare a water-based paint. Next, after TD stretching, the same method as in Example 41 was used to prepare a coated film. The prepared coating film contained 0.6% by mass of silicon oxide in the slippery coating layer. And using the obtained coating film, a laminate was produced in the same manner as in Example 85.

Examples 91~94

Except that the manufacturing conditions and the target thickness of the stretched polyamide-based film were changed to those shown in Table 15, and the thickness of the slippery coating layer was changed to those shown in Table 20, it was prepared in the same manner as in Example 90 It has to be coated with a film. Using the obtained coating film, a laminate was produced in the same manner as in Example 90.

Test example 2

The physical properties of the coating films and laminates prepared in Examples 41 to 94 and Comparative Examples 21 to 44 were evaluated. The evaluation results are shown in Tables 16-25. In addition, the measurement methods and evaluation methods of various physical properties were implemented in the same manner as in Test Example 1.

It is obvious from these results that the stretch ratios of the polyamide-based films of Examples 41 to 94 in particular are within a predetermined range, so the obtained coated films are satisfactory in the uniaxial tensile test in the direction of 0 degrees and 45 degrees. The difference between the maximum value and the minimum value of the stress at 5% elongation in the direction, 90 degree direction and the 135 degree direction is 35 MPa or less, and the difference between the maximum and minimum stress value at 15% elongation is 40 MPa or less. In addition, the laminated body obtained by using these coating films has a high Eriksson value, and has ductility that can be uniformly extended in all directions during cold forming. In other words, it can be seen that the coated films of these examples have no aluminum foil breakage, delamination, holes, etc., and have excellent moldability. Moreover, the coating films prepared in Examples 41 to 94 have a dynamic friction coefficient of 0.60 or less, so it can be seen that they are also excellent in smoothness and cold formability under high humidity.

In addition, the coating films prepared in Examples 41 to 84 have an easy-adhesive coating layer containing anionic water-dispersible polyurethane resin on one side, so it can be confirmed that laminates using these coating films are also Has excellent heat and humidity resistance.

In addition, the coated films prepared in Examples 85 to 94 have a slippery coating layer on one side, so the coefficient of kinetic friction is low. It can be seen that the laminated body using the coated film also has excellent smoothness, and can be used under high humidity. The cold formability is also particularly excellent.

In contrast, in Comparative Examples 21 to 40, the stretch ratio of the polyamide-based film did not meet the predetermined range, so the obtained coated film did not satisfy the 0 degree direction and the 45 degree direction in the uniaxial tensile test. The difference between the maximum and minimum stress at 5% elongation in the 90 degree direction and 135 degree direction Below 35MPa, and does not meet the requirement of 15% elongation, the difference between the maximum value and the minimum value of the stress is 40 MPa or less. Therefore, it can be confirmed that the laminated body obtained by using the coating films of these comparative examples has a low Eriksson value, does not have the ductility that can be uniformly expanded in the entire direction during cold forming, and has poor moldability. In addition, the coating films prepared in Comparative Examples 41 to 44 have a high dynamic friction coefficient, so it can be seen that the friction between the coating film and the molding die is large, the smoothness is poor, the Erickson value is low, and the moldability is poor.

51‧‧‧Film

52‧‧‧Adhesive layer

53‧‧‧Metal Foil

60‧‧‧Layered body

Claims (12)

A polyamide-based film characterized by containing polyamide 6 resin or polyamide 66 resin, and the aforementioned film satisfies all the characteristics of the following (1) to (3): (1) any point in the aforementioned film Starting from the calculation, the difference between the maximum and minimum stresses when the uniaxial tensile test causes 5% elongation in the four directions of 0 degrees, 45 degrees, 90 degrees and 135 degrees clockwise relative to the specific direction is 35 MPa Below; (2) In the aforementioned 4 directions, the difference between the maximum value and the minimum value of each stress when 15% elongation is caused by a uniaxial tensile test is 40 MPa or less; and (3) the dynamic friction coefficient is 0.60 or less. For example, the polyamide-based film of claim 1, its arithmetic average height Sa is 0.01~0.15μm. For example, the polyamide-based film of claim 1, which is calculated from any point in the aforementioned film, with a specific direction of 0 degrees, 45 degrees, 90 degrees, 135 degrees, 180 degrees, 225 degrees, 270 degrees clockwise relative to the direction In 8 directions totaling 315 degrees, the standard deviation of the average thickness of the polyamide-based film with respect to the 8 directions is 0.200 μm or less. For example, the polyamide-based film of claim 1 has an average thickness of 16 μm or less. The polyamide-based film of claim 1, wherein the polyamide-based film contains at least one of an organic slip agent and an inorganic slip agent. A coating film comprising the polyamide-based film of claim 1 and an easy-adhesive coating layer and/or an easy-slip coating layer formed on the film. A laminated body comprising a film as claimed in claim 1 or 6 and a metal foil laminated on the film. A container containing a layered body as in claim 7. A method for manufacturing a polyamide-based film is a method for manufacturing a polyamide-based film containing polyamide 6 resin or polyamide 66 resin. The method is characterized by including the following steps: (1) sheet forming step , The melt-kneaded product is formed into a sheet to prepare an unstretched sheet, the melt-kneaded product contains a polyamide resin and contains at least one of an organic slip agent and an inorganic slip agent; (2) the stretching step is to combine the aforementioned The unstretched sheet is biaxially stretched to MD and TD successively or simultaneously to prepare stretched film; and (3) satisfying both of the following formulas a) and b): a) 0.85≦X/Y≦0.95 b) 8.5≦ X×Y≦9.5 (However, X represents the stretch magnification of the aforementioned MD, and Y represents the stretch magnification of the aforementioned TD). Such as the method for manufacturing a polyamide-based film of claim 9, wherein the stretching step is successive biaxial stretching and includes the following steps: (2-1) The first stretching step is to heat the aforementioned The unstretched sheet is stretched to MD to make the first stretched film; and (2-2) The second stretching step is to stretch the aforementioned first stretched film to TD at a temperature of 70 to 150°C to prepare a second stretched film. The method for manufacturing a polyamide-based film according to claim 10, wherein the first stretching step is stretching performed by a roller, and the second stretching step is stretching by a tenter. Such as the manufacturing method of the polyamide-based film of claim 10, wherein the second stretched film is further subjected to relaxation heat treatment at a temperature of 180 to 230°C.

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