JP4824587B2 - Matte polyamide laminated film - Google Patents

Description

  The present invention relates to a mat-like polyamide film used for packaging foods, medical products, medicines and the like.

As films for packaging foods, medical products, medicines, etc., polyamide films having various layer structures formed by using a polyamide resin are used. As one use of a polyamide-based film, there is a demand for a matte-like film in which fine irregularities are provided on the surface of the film so as to improve the design. By adopting such a matte tone, the gloss of the film surface is eliminated, the contents are blurred, and a texture of a Japanese paper style is imparted, whereby a high-quality package is obtained.
Conventionally, as a method of imparting a matte tone to a biaxially stretched polyamide film, (a) a method of eroding the film surface with hard granular sand, acid, alkali, solvent, etc., (b) containing inorganic particles on the film surface. There were a method of coating a coating agent such as a binder resin, and (c) a method of containing inorganic particles, an organic synthetic resin, or the like in the resin constituting the film. In addition, as a film having a matte tone, for example, Patent Document 1 describes a technique that defines a surface uneven state of a polyamide-based rough film.

However, the method of (a) eroding the film surface with hard granular sand, acid, alkali, solvent, etc. is difficult to process and is not sufficient in terms of production efficiency, and may damage the film surface. The film strength was lowered, and the film strength, which is an advantage of the biaxially stretched polyamide film, was sometimes impaired. In addition, (b) the method of coating the film surface with a coating agent such as a binder resin containing inorganic particles generally has a low heat resistance of the coating agent, and heat sealing is performed from the surface side of the biaxially stretched polyamide film by bag making processing or the like. When heated by a bar or the like, the coating agent melts due to heat, stickiness, and may adhere to the heat seal bar side, so that the bag-making speed does not increase and the production efficiency is not sufficient. Furthermore, (c) the method of including inorganic particles or organic synthetic resin in the resin constituting the film is not sufficient for providing surface irregularities, and the haze value does not increase so much that a sufficient matte tone cannot be obtained. There were drawbacks.
Moreover, in the technique described in Patent Document 1, only a film having a low haze value can be obtained, and the surface is smoothed by a process such as biaxial stretching heat setting, so that a sufficient matte tone is difficult to obtain.

JP-A-11-343354

  The present invention provides a polyamide laminated film having a high haze value and an excellent matte tone, and a method for stably producing the polyamide laminated film.

As a result of intensive investigations, the present inventors have reproduced a surface layer by providing a mixed layer containing polyamide 6 having a specific viscosity and polyamide 12 having a specific viscosity in a specific ratio without impairing strength, oxygen barrier properties, and the like. It has been found that a polyamide film having a characteristic matte tone can be obtained.
The present invention
(1) Polyamide 6 having a relative viscosity of 3.8 to 5.8 according to JIS K 6810 (96% sulfuric acid method) on at least one surface of a base material including an aliphatic polyamide film; 3 to 2.1 polyamide 12 in a ratio of 75:25 to 25:75 and having a mixed layer, a mat-like polyamide laminated film, and (2) at least one of a base material including an aliphatic polyamide film On the other hand, polyamide 6 having a relative viscosity of 3.8 to 5.8 according to JIS K 6810 (96% sulfuric acid method) and polyamide 12 having a relative viscosity of 1.3 to 2.1 are 75:25 A method for producing a mat-like polyamide laminated film, comprising a step of providing a mixed layer obtained by mixing at a ratio of 25:75;
About.

  According to the present invention, a polyamide laminated film having a high haze value and an excellent matte tone, and a method for stably producing the polyamide laminated film can be obtained.

Hereinafter, the present invention will be described in detail.
[Matte polyamide laminated film]
In the present invention, the aliphatic polyamide that forms the aliphatic polyamide film constituting the substrate includes a ring-opening polymer of cyclic lactam, a self-polycondensate of aminocarboxylic acid, a polycondensate of dicarboxylic acid and diamine, and the like. Is mentioned. Specifically, a homopolymer of ε-caprolactam called nylon-6 or polyhexamethylene adipamide called nylon-66 can be obtained at a low cost and smoothly perform the stretching operation. This is preferable.

The aliphatic polyamide film constituting the substrate preferably further contains an aromatic polyamide from the viewpoint of stretchability and oxygen barrier properties. The aromatic polyamide that can be used here is a polyamide having an aromatic ring, and the aromatic polyamide used in the aromatic polyamide layer described later can be used in the same manner. The aromatic polyamide is preferably contained in the aliphatic polyamide film in an amount of 0 to 40% by mass, and more preferably 0 to 30% by mass.
The aliphatic polyamide film may be composed of one layer or two or more layers, and the total thickness is preferably in the range of 7 to 29 μm from the viewpoint of strength and economy. More preferably, it exists in the range of 9-24 micrometers.

In addition to the aliphatic polyamide layer, an aromatic polyamide layer and / or a saponified ethylene-vinyl acetate copolymer layer is provided on the substrate of the polyamide laminated film of the present invention in order to further improve the storage stability of foods and the like. It is preferable to have.
Here, the aromatic polyamide constituting the aromatic polyamide layer is a polyamide having an aromatic ring and is not particularly limited. For example, from the viewpoint of gas barrier properties, xylylenediamine and α having 6 to 12 carbon atoms, Those containing a polyamide constituent composed of ω aliphatic dicarboxylic acid in the molecular chain, preferably 70 mol% or more, are suitably used. High gas barrier properties can be obtained by adding 70 mol% or more of the polyamide constituents in the molecular chain in the aromatic polyamide.

  Specific examples of the polyamide component composed of the above xylylenediamine and an α, ω aliphatic dicarboxylic acid having 6 to 12 carbon atoms include polymetaxylylene adipamide, polymetaxylylene pimeramide, polymetaxylylene azelamide, Homopolymers such as polyparaxylylene azelamide, polyparaxylylene decanamide, metaxylylene / paraxylylene adipamide copolymer, metaxylylene / paraxylylene pimeramide copolymer, metaxylylene / paraxylylene azease Examples thereof include a ramid copolymer and a metaxylylene / paraxylylene sebacamide copolymer.

Other polyamide constituents include nylon salts of diamines and dicarboxylic acids, ring-opening polymers of lactams such as ε-caprolactam, self-polycondensates of ω-aminocarboxylic acids such as ε-aminocarboxylic acid, etc. Is mentioned. Specific examples of diamines that form nylon salts include hexamethylene diamine, aliphatic diamines such as 2,2,4-trimethylhexamethylene diamine, piperazine bispropylamine, and allopathies such as neopentylglucose bispropylamine. Examples of the dicarboxylic acids include aliphatic dicarboxylic acids such as adipic acid, azelaic acid and sebacic acid, aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid, and the like. And cycloaliphatic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid.
Among the polyamide constituents, polymetaxylylene adipamide is preferably used in the present invention from the viewpoint of gas barrier properties.

A bending pinhole improving material such as polyolefins, polyamide elastomers and polyester elastomers can be added to the aromatic polyamide layer. Here, the polyolefin contains 50 mass% or more of polyethylene units and polypropylene units in the main chain, and may be graft-modified with maleic anhydride or the like. As structural units other than polyethylene units and polypropylene units, vinyl acetate, partially saponified products thereof, acrylic acid, methacrylic acid, acrylic acid esters, methacrylic acid esters, partial metal neutralized products (ionomers), butene, etc. 1-alkenes, alkadienes, styrene and the like. A plurality of these structural units may be included. These may be added to the aliphatic polyamide layer and the mixed layer of aliphatic polyamide and aromatic polyamide, etc., but adding to a relatively hard aromatic polyamide layer has an effect of improving the resistance to bending pinholes. It is preferable because of improvement.
In the present invention, the thickness of the aromatic polyamide layer is preferably 2 to 10 μm, more preferably 3 to 8 μm, from the viewpoint of gas barrier properties.
In the case of a matte film, the stiffness (rigidity) of the film is often required due to the influence of Japanese paper packaging. However, in the polyamide laminated film of the present invention, an aromatic polyamide layer made of a more aromatic aromatic polyamide is used. By having it, the waist of a favorable film is obtained.

  The saponified ethylene-vinyl acetate copolymer constituting the saponified ethylene-vinyl acetate copolymer resin layer is particularly preferable in terms of ethylene content, from the viewpoints of melt extrudability, coloration prevention, and oxygen gas barrier properties during melt extrusion. Is in the range of 25 to 38 mol%, more preferably in the range of 29 to 35 mol%. From the viewpoint of gas barrier properties, the saponification degree is preferably 95 mol% or more, more preferably 98 mol% or more. Is suitable.

  In addition to the saponified ethylene-vinyl acetate copolymer, the ethylene-vinyl acetate copolymer saponified product includes a small amount of propylene, isobutene, α-octene, α-dodecene, α Α-olefins such as octadecene; unsaturated carboxylic acids, or salts thereof, partial alkyl esters, fully alkyl esters, nitriles, amides, anhydrides; unsaturated sulfonic acids, salts thereof, etc. The saponified ethylene-vinyl acetate copolymer may be obtained by mixing a small amount of a thermoplastic resin such as polyolefin, polyester or polyamide with the above. Among these, the thing which mixed polyolefin from the point of thermal stability is preferable.

In the present invention, the thickness of the ethylene-vinyl acetate copolymer saponified resin layer is preferably 0.5 to 10 μm, more preferably 1 to 8 μm from the viewpoint of coexistence of oxygen permeability and film strength. It is.
In the present invention, the thickness of the base film composed of the above aliphatic polyamide film, aromatic polyamide layer, ethylene-vinyl acetate copolymer saponified layer, etc. is 7 to 7 in terms of both oxygen permeability and film strength. It is preferably in the range of 29 μm, more preferably in the range of 9 to 24 μm.

  In the present invention, polyamide 6 having a relative viscosity of 3.8 to 5.8 according to JIS K 6810 (96% sulfuric acid method) is formed on at least one surface layer of the base material including the aliphatic polyamide film, and the relative viscosity. It is necessary to have a mixed layer (hereinafter, sometimes referred to as “matte tone imparting layer”) containing polyamide 12 having a ratio of 1.3 to 2.1 in a ratio of 75:25 to 25:75. This is because blending polyamide 12 having a viscosity lower than that of polyamide 6 can increase the roughness of the obtained film surface and increase the haze value. In particular, when biaxial stretching heat setting is performed, the original surface roughness may become smooth due to the stretching and heat setting processes, and a sufficient matte tone may not be obtained. An excellent matte polyamide film can be obtained even after axial stretching heat setting.

Here, polyamide 6 refers to a homopolymer of ε-caprolactam, and polyamide 12 refers to a homopolymer of lauryl lactam. Polyamide 6 has a relative viscosity of 3.8 to 5.8, but is preferably 4.0 to 5.5, more preferably 4.2 to 5.3 from the viewpoint that a desired matte tone can be easily obtained. It is. Moreover, although the relative viscosity of the polyamide 12 is 1.3-2.1, it is preferably 1.4-2.0, more preferably 1.5-1. Nine.
Moreover, although the content rate of the polyamide 6 and the polyamide 12 is 75: 25-25: 75, Preferably it is 70: 30-30: 70, More preferably, it is 65: 35-35: 65. When the content ratio of the polyamide 6 and the polyamide 12 is within the above range, the surface unevenness can be sufficiently obtained, a high haze value can be obtained, and the target matte tone can be obtained.

  The haze value can be measured by applying liquid paraffin to the surface (back layer) opposite to the side having the matte tone imparting layer (surface layer) and by the method of JIS K 7361. The reason why the liquid paraffin is applied to the back layer is that a sealant film or the like is usually laminated on the back layer side and its external haze is ignored. That is, even if the back layer has unevenness, the surface unevenness is eliminated by application of a dry laminate adhesive or an anchor coating agent during extrusion lamination, and does not contribute to the haze value necessary for providing a matte tone. In the case of the matte polyamide laminated film of the present invention, the haze value obtained by the above measuring method is 30 to 90%, preferably 35 to 85%, more preferably 40 to 80%. When the haze value is equal to or higher than the lower limit, transparency is lowered and a sufficient matte tone is obtained. When the haze value is equal to or lower than the upper limit, the visibility of the contents is good when the package is formed.

The thickness of the matte tone imparting layer is preferably 0.1 to 10 μm, and the ratio to the thickness of the entire film is preferably 30% or less. If the thickness of the mat tone imparting layer is 0.1 μm or more, the thickness can be easily and uniformly controlled, and a uniform mat tone can be easily obtained in the width direction. Further, if the thickness of the matte tone imparting layer is 10 μm or less, and if it is 30% or less with respect to the thickness of the entire film, the thickness of the polyamide layer other than the matte tone imparting layer can be secured, and sufficient strength is maintained. it can. Since the mat tone imparting layer has a sea-island structure, its strength is lower than that of polyamide 6 alone. Therefore, it is set as thin as possible within a range where a uniform mat tone can be obtained in the entire width direction. It is preferable.
From the above viewpoint, the thickness of the matte imparting layer is more preferably 0.5 to 5 μm, and still more preferably 0.5 to 3 μm. Moreover, the ratio with respect to the thickness of the whole film becomes like this. More preferably, it is 25% or less, More preferably, it is 5-20%.

Although the layer structure of the polyamide laminated film of this invention is not specifically limited, For example, the following structures are mentioned. In addition, each following layer structure is displayed sequentially from the surface layer side, and a back layer side turns into a lamination surface with a sealant film.
(1) Matte tone imparting layer / aliphatic polyamide layer (2) Matte tone imparting layer / aliphatic polyamide layer / matte tone imparting layer (3) Matte tone imparting layer / aliphatic polyamide layer / ethylene-vinyl acetate copolymer Ken Compound resin layer / aliphatic polyamide layer (4) matte tone imparting layer / aliphatic polyamide layer / ethylene-vinyl acetate copolymer saponified resin layer / aliphatic polyamide layer / matte tone imparting layer (5) matte tone imparting layer / (Aliphatic polyamide + aromatic polyamide) layer / aromatic polyamide layer / (aliphatic polyamide + aromatic polyamide) layer (6) matte tone imparting layer / (aliphatic polyamide + aromatic polyamide) layer / aromatic polyamide layer / (Aliphatic polyamide + aromatic polyamide) layer / matte tone imparting layer (7) matte tone imparting layer / aliphatic polyamide layer / (aliphatic polyamide + aromatic polyamide) layer Aromatic polyamide layer / (aliphatic polyamide + aromatic polyamide) layer / aliphatic polyamide layer (8) Matt tone imparting layer / aliphatic polyamide layer / (aliphatic polyamide + aromatic polyamide) layer / aromatic polyamide layer / ( Aliphatic polyamide + aromatic polyamide) layer / aliphatic polyamide layer / matte imparting layer

The polyamide laminated film of the present invention is preferably symmetrical with respect to the thickness, including the thickness, in order to make the film as curled as possible in consideration of handling in post-processing such as printing and laminating described later. However, the matting layer is a mixed layer of polyamide 6 and polyamide 12 and has a weak cohesive force. Therefore, in applications where extremely strong laminate strength is required, such as for air-containing high-temperature boil, the back layer serving as the laminate surface It is preferable to provide a matte tone imparting layer only on the opposite side.
In general, since printing is performed on a laminate surface, when performing extremely sharp printing, it is preferable to have a matte tone imparting layer having a rough surface on a surface other than the printing surface (laminate surface). Therefore, from the above viewpoint, any one of the layer configurations (1), (3), (5) and (7) is more preferable among the layer configurations (1) to (8).

  The polyamide laminated film of the present invention exhibits the effects of the present invention particularly when biaxially stretched and heat-fixed. The stretching is preferably performed at a stretching ratio of 2.5 to 4 times in both the longitudinal direction and the transverse direction from the viewpoint of film strength. The stretching method is not particularly limited, such as a simultaneous biaxial stretching method, a sequential biaxial stretching method, and a tubular stretching method. Moreover, after extending | stretching, it is more preferable to heat-set at 180 to 225 degreeC. A stretching ratio of the biaxial stretching of 2.5 times or more is preferable because stretching is sufficiently performed and there is no stretching unevenness / thickness unevenness and sufficient strength is obtained. Moreover, if a draw ratio is 4 times or less, a fracture | rupture does not occur easily and extending | stretching stability is favorable. From the above points, the draw ratio of the film is more preferably 2.6 to 3.9 times, and still more preferably 2.7 to 3.8 times.

  Further, if the heat setting temperature is 180 ° C. or higher, heat fixing is sufficiently performed, and there is no shift or deformation of the pattern due to shrinkage during printing, laminating, and bag making processing. The orientation of the film is difficult to return and sufficient film strength is obtained. From the above points, the heat setting temperature is preferably 190 ° C to 220 ° C, more preferably 205 ° C to 220 ° C. In particular, it is preferable to set the temperature range from a temperature 20 ° C. lower than the melting point of the main raw material used for the polyamide film to the melting point.

  The total thickness of the polyamide laminated film of the present invention is preferably 10 to 30 μm. If it is 10 μm or more, the toughness that is characteristic of the polyamide film is sufficiently exhibited, and if it is 30 μm or less, it has appropriate rigidity as a laminated film for soft packaging materials, and the hardness of the package is also appropriate. It will be a thing. From the above viewpoint, the thickness of the entire polyamide laminated film of the present invention is more preferably 12 to 25 μm.

The polyamide laminated film of the present invention is preferably used by being laminated with a sealant film. In that case, printing is often performed on the laminate surface side, and after printing is performed on the back surface of the laminated film of the present invention, it is laminated with a sealant film. As a printing method, any method generally used for polyamide films such as gravure printing and flexographic printing can be used and is not particularly limited. The lamination method can also be carried out by a method usually used for polyamide films such as dry lamination and extrusion lamination.
The polyamide laminated film of the present invention can be used for packaging foods, medical products, medicines and the like. In particular, it is preferably used as a film for food packaging, and is often used for automatic filling machines such as bag-processed products and pillow packaging, but the film of the present invention has a matte layer on the surface. It has the advantage that it is easy to use because it is excellent in terms of the ease of accumulation of the bag-making processed products and the slipperiness with the machine in the automatic filling machine.

[Production method of polyamide laminated film]
In the method for producing a polyamide laminated film of the present invention, a polyamide 6 having a relative viscosity of 3.8 to 5.8 according to JIS K 6810 (96% sulfuric acid method) is formed on at least one surface of a substrate including an aliphatic polyamide film. And a step of providing a mixed layer obtained by mixing the polyamide 12 having a relative viscosity of 1.3 to 2.1 in a ratio of 75:25 to 25:75.

An aliphatic polyamide film, a substrate containing the same, polyamide 6 having a relative viscosity of 3.8 to 5.8 according to JIS K 6810 (96% sulfuric acid method), polyamide 12 having a relative viscosity of 1.3 to 2.1, The matte tone imparting layer and the like are as described above.
The matte tone imparting layer may be provided on at least one surface of the base material, but is preferably provided on a surface other than the printing surface from the viewpoint that sharp printing can be performed. In the case where the matte tone imparting layer is provided by mixing polyamide 6 and polyamide 12, the mixing method is not particularly limited, but from the viewpoint of simplicity, a method by dry blending of raw material pellets is preferable. Moreover, there is no restriction | limiting in particular as a method of providing a matte tone provision layer in a base material, From the point of stability of lamination | stacking, it is preferable to depend on methods, such as coextrusion.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following examples. In the following examples, the properties of the used materials were measured and the obtained films were evaluated by the following methods.
1) Relative viscosity of polyamide 6 and polyamide 12:
It was carried out by a method according to JIS K 6810 (96% sulfuric acid method). That is, the concentration in 96% sulfuric acid was 1 g / 100 ml, and the measurement was carried out at a temperature of 25 ° C.
2) Haze value of polyamide laminated film Measured by a method based on JIS K 7361. That is, the liquid paraffin was apply | coated to the base-material surface on the opposite side to the surface which has the mixed layer of the cut-out test film, and it measured using the haze meter (Nippon Denshoku Industries Co., Ltd. make, NDH2000) after that. In addition, the measurement was performed 5 times and the average value was calculated | required.

Example 1
Each polymer was coextruded so as to have the following layer constitution, and the obtained unstretched film was stretched 3.0 times in the longitudinal direction by a roll type longitudinal stretcher under the condition of 60 ° C. Next, the end of this longitudinally stretched film was held with a tenter clip, stretched 3.5 times in the transverse direction under conditions of 130 ° C. in a tenter oven, and then heat-treated at 215 ° C. for 6 seconds.
(Layer structure)
From the surface layer, polyamide 6A and polyamide 12 50:50 blend / polyamide 6B / polyamide 6B and polymetaxylylene adipamide 70:30 blend / polymetaxylylene adipamide / polyamide 6B and polymetaxylylene adipamide 70 : 30 blend / polyamide 6B

Each polymer used was as follows.
Polyamide 6A: Novamid 1040 (relative viscosity: 5.1) manufactured by Mitsubishi Engineering Plastics Co., Ltd.
Polyamide 12: UBE Kosan Co., Ltd. UBESTA3014U (relative viscosity: 1.7)
Polymetaxylylene adipamide: MX nylon 6007 manufactured by Mitsubishi Gas Chemical Company, Inc.
Polyamide 6B: Novamid 1022C6 manufactured by Mitsubishi Engineering Plastics Co., Ltd.
The film after the heat treatment was trimmed at both ends corresponding to the gripping portion of the clip, and the trimmed product film portion was wound into a roll to obtain a biaxially stretched polyamide laminated film having a total thickness of 15 μm. The thickness of each layer was adjusted to 1 μm / 4 μm / 1 μm / 3 μm / 1 μm / 5 μm from the surface layer by adjusting the extrusion amount.

Example 2
In Example 1, a biaxially stretched polyamide film having a total thickness of 15 μm and a thickness of 2 μm / 13 μm from the surface layer was obtained by stretching and heat-treating in the same manner except that the respective polymers were coextruded so as to have the following layer structure.
(Layer structure)
From the surface, polyamide 6A and polyamide 12 50:50 blend / polyamide 6B
Each polymer used was as follows.
Polyamide 6A: Novamid 1040 (relative viscosity: 5.1) manufactured by Mitsubishi Engineering Plastics Co., Ltd.
Polyamide 12: UBE Kosan Co., Ltd. UBESTA3014U (relative viscosity: 1.7)
Polyamide 6B: Novamid 1022C6 manufactured by Mitsubishi Engineering Plastics Co., Ltd.

Example 3
In Example 1, except that each polymer was coextruded so as to have the following layer structure, the film was stretched and heat-treated in the same manner, and the total thickness was 15 μm, and each layer thickness was 1.5 μm / 4.5 μm / 3 μm / 6 μm from the surface layer. A biaxially stretched polyamide film was obtained.
(Layer structure)
From the surface layer, polyamide 6A and polyamide 12 50:50 blend / polyamide 6B / EVOH / polyamide 6B
Each polymer used was as follows.
Polyamide 6A: Novamid 1030 (relative viscosity: 4.2) manufactured by Mitsubishi Engineering Plastics Co., Ltd.
Polyamide 12: UBE Kosan Co., Ltd. UBESTA3014U (relative viscosity: 1.7)
Polyamide 6B: Novamid 1022C6 manufactured by Mitsubishi Engineering Plastics Co., Ltd.
EVOH: manufactured by Nippon Synthetic Chemical Industry Co., Ltd., Soarnol 3203B (ethylene content:
32 mol%)

Example 4
In Example 1, a biaxially stretched polyamide having a total thickness of 15 μm and a thickness of 2 μm / 4 μm / 3 μm / 6 μm from the surface layer was similarly stretched and heat-treated except that the respective polymers were coextruded so as to have the following layer structure. A film was obtained.
(Layer structure)
From the surface, 60:40 blend of polyamide 6A and polyamide 12/80: 20 blend of polyamide 6B and polymetaxylylene adipamide / polymetaxylylene adipamide / 80: 20 blend of polyamide 6B and polymetaxylylene adipamide Each polymer used was as follows.
Polyamide 6A: Novamid 1040 (relative viscosity: 5.1) manufactured by Mitsubishi Engineering Plastics Co., Ltd.
Polyamide 12: UBE Kosan Co., Ltd. UBESTA3014U (relative viscosity: 1.7)
Polymetaxylylene adipamide: MX nylon 6007 manufactured by Mitsubishi Gas Chemical Company, Inc.
Polyamide 6B: Novamid 1022C6 manufactured by Mitsubishi Engineering Plastics Co., Ltd.

Example 5
In Example 1, a biaxially stretched polyamide film having a total thickness of 15 μm and a thickness of 2 μm / 13 μm from the surface layer was obtained by stretching and heat-treating in the same manner except that the respective polymers were coextruded so as to have the following layer structure.
(Layer structure)
From the surface, polyamide 6A and polyamide 12 50:50 blend / polyamide 6B
Each polymer used was as follows.
Polyamide 6A: Novamid 1040 (relative viscosity: 5.1) manufactured by Mitsubishi Engineering Plastics Co., Ltd.
Polyamide 12: manufactured by Ube Industries, UBESTA3020U (relative viscosity: 1.9)
Polyamide 6B: Novamid 1022C6 manufactured by Mitsubishi Engineering Plastics Co., Ltd.

Comparative Example 1
In Example 1, a biaxially stretched polyamide film having a total thickness of 15 μm and each layer thickness of 2 μm / 13 μm from the surface layer was obtained in the same manner except that each polymer was coextruded so as to have the following layer structure. .
(Layer structure)
From the surface, polyamide 6A and polyamide 610 50:50 blend / polyamide 6B
Each polymer used was as follows.
Polyamide 6A: Novamid 1040 (relative viscosity: 5.1) manufactured by Mitsubishi Engineering Plastics Co., Ltd.
Polyamide 610: manufactured by Toray Industries, Inc., Amilan CM2001 (relative viscosity: 2.5)
Polyamide 6B: Novamid 1022C6 manufactured by Mitsubishi Engineering Plastics Co., Ltd.

Comparative Example 2
In Example 1, a biaxially stretched polyamide film having a total thickness of 15 μm and each layer thickness of 2 μm / 13 μm from the surface layer was obtained in the same manner except that each polymer was coextruded so as to have the following layer structure. .
(Layer structure)
From the surface, polyamide 6A and polyamide 12 50:50 blend / polyamide 6B
Each polymer used was as follows.
Polyamide 6A: Novamid 1010 (relative viscosity: 2.3) manufactured by Mitsubishi Engineering Plastics Co., Ltd.
Polyamide 12: manufactured by Ube Industries, UBESTA3035U (relative viscosity: 2.5)
Polyamide 6B: Novamid 1022C6 manufactured by Mitsubishi Engineering Plastics Co., Ltd.

Comparative Example 3
In Example 1, a biaxially stretched polyamide film having a thickness of 15 μm and a thickness of each layer of 2 μm / 13 μm from the surface layer was obtained in the same manner except that each polymer was coextruded so as to have the following layer structure.
(Layer structure)
From the surface, polyamide 6A and polyamide 12 50:50 blend / polyamide 6B
Each polymer used was as follows.
Polyamide 6A: Novamid 1022 (relative viscosity: 3.5) manufactured by Mitsubishi Engineering Plastics Co., Ltd.
Polyamide 12: manufactured by Ube Industries, UBESTA3030XA (relative viscosity: 2.3)
Polyamide 6B: Novamid 1022C6 manufactured by Mitsubishi Engineering Plastics Co., Ltd.

Comparative Example 4
In Example 1, a biaxially stretched polyamide film having a total thickness of 15 μm and each layer thickness of 2 μm / 13 μm from the surface layer was obtained in the same manner except that each polymer was coextruded so as to have the following stratification. .
(Layer structure)
From the surface, polyamide 6A and polyamide 12 77:23 blend / polyamide 6B
Each polymer used was as follows.
Polyamide 6A: Novamid 1040 (relative viscosity: 5.1) manufactured by Mitsubishi Engineering Plastics Co., Ltd.
Polyamide 12: UBE Kosan Co., Ltd. UBESTA3014U (relative viscosity: 1.7)
Polyamide 6B: Novamid 1022C6 manufactured by Mitsubishi Engineering Plastics Co., Ltd.

Comparative Example 5
In Example 1, a biaxially stretched polyamide film having a total thickness of 15 μm and each layer thickness of 2 μm / 13 μm from the surface layer was obtained in the same manner except that each polymer was coextruded so as to have the following layer structure. .
(Layer structure)
From the surface, polyamide 6A and polyamide 12 20:80 blend / polyamide 6B
Each polymer used was as follows.
Polyamide 6A: Novamid 1040 (relative viscosity: 5.1) manufactured by Mitsubishi Engineering Plastics Co., Ltd.
Polyamide 12: UBE Kosan Co., Ltd. UBESTA3014U (relative viscosity: 1.7)
Polyamide 6B: Novamid 1022C6 manufactured by Mitsubishi Engineering Plastics Co., Ltd.

  About each of the film obtained in the said Example and comparative example, the haze value was measured as above-mentioned and the matte evaluation was performed. The results are shown in Table 1.

  The polyamide laminated film of the present invention has a high haze value and an excellent matte tone, so that it has a high design and is suitably used for a polyamide-based film used for packaging foods, medical products, medicines and the like. it can.

Claims (9)

  Polyamide 6 having a relative viscosity of 3.8 to 5.8 according to JIS K 6810 (96% sulfuric acid method) on at least one surface of a base material including an aliphatic polyamide film, and the relative viscosity of 1.3 to 2 1. A mat-like polyamide laminate film having a mixed layer containing 1 polyamide 12 in a ratio of 75:25 to 25:75.   The mat-like polyamide laminated film according to claim 1, wherein liquid paraffin is applied to the surface of the substrate opposite to the surface having the mixed layer, and the haze value measured by JIS K 7361 is 30 to 90%.   The mat-like polyamide laminated film according to claim 1 or 2, wherein the aliphatic polyamide film comprises polyamide 6 as a main component.   The mat-like polyamide laminated film according to any one of claims 1 to 3, which is stretched at a stretch ratio of 2.5 to 4 times in both the longitudinal direction and the transverse direction.   The mat-like polyamide laminated film according to claim 4, which is heat-set at a temperature of 180 ° C to 225 ° C after stretching.   The mat-like polyamide laminated film according to any one of claims 1 to 5, wherein the entire film has a thickness of 10 to 30 µm.   The mat-like polyamide laminated film according to any one of claims 1 to 6, wherein the thickness of the mixed layer is 0.1 to 10 µm, and the ratio of the thickness of the mixed layer to the thickness of the entire film is 30% or less.   The matte finish according to any one of claims 1 to 7, wherein the substrate further comprises an aromatic polyamide resin layer and / or an ethylene-vinyl acetate copolymer saponified resin layer having an ethylene content of 24 to 48 mass%. Polyamide laminated film.   Polyamide 6 having a relative viscosity of 3.8 to 5.8 according to JIS K 6810 (96% sulfuric acid method) on at least one surface of a base material including an aliphatic polyamide film, and the relative viscosity of 1.3 to 2 A process for producing a mat-like polyamide laminated film, comprising a step of providing a mixed layer obtained by mixing the polyamide 12 of .1 in a ratio of 75:25 to 25:75.