JP2009274224A - Multilayer oriented polyamide resin film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multilayer oriented polyamide resin film which has a barrier property, interlayer anti-exfoliation strength and a high adhesiveness to a sealant resin and which can be used as a shock absorbing material for packing. <P>SOLUTION: The multilayer oriented polyamide resin film includes a resin layer (X) of aromatic polyamide (c) consisting of a xylylenediamine component and a 4-12C aliphatic dicarboxylic acid component, a mixed polyamide resin layer (Z) containing 99 to 90 mass% of aliphatic polyamide (a) and 1 to 10 mass% of amorphous polyamide (b), and a mixed polyamide resin layer (Y) containing 5 to 90 mass% of the aliphatic polyamide (a) and/or the aromatic polyamide (c) and 95 to 10 mass% of amorphous polyamide (b), and further the multilayer oriented polyamide resin film is formed by laminating five these layers in order of (Z)/(Y)/(X)/(Y)/(Z). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a multilayer stretched polyamide resin film having excellent laminating properties with a polyolefin sealant, gas barrier properties, and excellent delamination strength of a film.

  Conventionally, synthetic resin foams such as expanded polystyrene and expanded polyurethane have been often used as cushioning materials for packing. However, although the synthetic resin foam has a small specific gravity, there is a problem in that it is bulky and takes up space for transportation and storage, resulting in an increase in cost. Moreover, although it is incinerated after use, since a combustion temperature becomes high at the time of incineration and damages a furnace, the buffer material which replaces a synthetic resin foam is desired.

  Therefore, a cushioning material for packing in which the heat seal surface side of two synthetic resin films having heat sealability is set inward, the outer peripheral portion is heated and fused, and an air injection hole is formed to inject air. Has been proposed (Patent Documents 1 and 2).

  Patent Document 1 states that the synthetic resin film used for the buffer material is preferably a multilayer of a heat seal layer and an air barrier layer, an olefin resin as the heat seal layer, and a nylon system as the air barrier layer. Resins, polyvinylidene chloride resins, and ethylene polyvinyl alcohol-based resins are listed, but there is no specific disclosure of what type of multilayer is preferable.

As a candidate for a film constituting the air barrier layer, for example, as in Patent Document 3, a mixed polyamide layer composed of 95 to 50% by weight of an aliphatic polyamide resin and 5 to 50% by weight of an amorphous polyamide resin is used as an outer layer. In addition, a film having an aromatic polyamide layer synthesized from metaxylylenediamine and adipic acid as an inner layer, and an inner layer having a xylylenediamine component and an aliphatic dicarboxylic acid component having 4 to 12 carbon atoms, such as Patent Document 4, And a five-layer film in which the intermediate layer is an aliphatic polyamide and amorphous polyamide resin layer, and the outer layer is an aliphatic polyamide resin layer.
JP-A-4-327158 JP 2003-290447 A Japanese Patent No. 3259595 Japanese Patent No. 3119562

  However, a multilayer film obtained by laminating the laminated film listed in Patent Document 3 and Patent Document 4 as an air barrier layer and a heat seal layer has sufficient mechanical properties and barrier properties as a packaging film. However, when used as a cushioning material for packing, the delamination strength and laminate strength are insufficient, and there is a problem that the cushioning material breaks due to impact during transportation.

  The present invention solves the above-mentioned problems, has a barrier property and delamination strength and can be used as a cushioning material for packaging, and has a high adhesion property to a polyolefin-based sealant. A film is provided.

That is, the gist of the present invention is as follows.
(1) a resin layer (X) of an aromatic polyamide (c) comprising a xylylenediamine component and an aliphatic dicarboxylic acid component having 4 to 12 carbon atoms;
A mixed polyamide resin layer (Z) containing 99 to 90% by weight of aliphatic polyamide (a) and 1 to 10% by weight of amorphous polyamide (b);
Mixed polyamide resin layer (Y) containing aliphatic polyamide (a) and / or aromatic polyamide (c) 5 to 90% by mass and amorphous polyamide (b) 95 to 10% by mass
A multilayer stretched polyamide resin-based film composed of 5 layers, each of which is laminated in the order of (Z) / (Y) / (X) / (Y) / (Z).
(2) The amorphous polyamide is a polymer of isophthalic acid / terephthalic acid / hexamethylenediamine or a polymer of bis (3-methyl-4-aminocyclohexyl) methane / isophthalic acid / terephthalic acid / hexamethylenediamine. (1) The multilayer stretched polyamide resin film according to (1).
(3) The multilayer stretched polyamide resin film according to (1) or (2), wherein the resin layer (Z) has a thickness of 3 μm or more.
(4) The multilayer stretched polyamiamide resin film according to any one of (1) to (3), wherein the interlayer peel strength of each layer of the multilayer stretched polyamide resin film is 2 N / cm or more.
(5) A multilayer film obtained by laminating a polyolefin sealant on the multilayer stretched polyamide resin film according to any one of (1) to (4).
(6) The multilayer film according to (5), wherein the laminate strength between the multilayer stretched polyamide resin film and the polyolefin sealant is 5 N / cm or more.
(7) An air bag obtained by stacking and heat-sealing the sealant layer of the multilayer film according to (5) or (6).
(8) A packing material provided with the air bag according to (7).

  The multilayer stretched polyamide resin-based film of the present invention has a sufficient barrier property and delamination force. Further, the multilayer film of the present invention formed by multilayering a polyolefin-based sealant has a high sealant layer. Laminate strength can be obtained. Therefore, when the multilayer film of the present invention is used as a cushioning material for packaging, it is possible to suppress the occurrence of problems such as breakage of the cushioning material due to impact during transportation, and efficient transportation can be performed. The industrial utility value is very high.

  Hereinafter, the present invention will be described in detail.

  Examples of the aliphatic polyamide (a) in the present invention include nylon 6, nylon 66, nylon 69, nylon 610, nylon 612, nylon 11, nylon 12, nylon 46, nylon 1010 and mixtures thereof, copolymers, composites, and the like. Is mentioned. Among these, nylon 6 is particularly preferable in terms of productivity, performance, and cost performance.

  The aromatic polyamide (c) is a polyamide comprising meta and / or paraxylylenediamine and an aliphatic dicarboxylic acid having 4 to 12 carbon atoms. Examples of the aliphatic dicarboxylic acid having 4 to 12 carbon atoms include adipic acid, succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid. As the aromatic polyamide (c), nylon MXD6 obtained by polycondensation of metaxylylene and adipic acid is particularly preferable.

  In the present invention, the amorphous polyamide (b) refers to a polyamide having a measured heat of crystal fusion of less than 1 cal / g when measured at a rate of temperature increase of 20 ° C./min using a differential thermal analyzer. Say.

  The amorphous polyamide (b) used in the present invention preferably has an alicyclic diamine and / or an aliphatic diamine as a diamine component, and terephthalic acid and / or isophthalic acid as a dicarboxylic acid component.

  Specific examples of the alicyclic diamine include bis (4-aminocyclohexyl) methane, bis (4-aminocyclohexyl) propane, bis (3-methyl-4-aminocyclohexyl) methane, and bis (3-methyl-4-amino). Cyclohexyl) propane, bis (3,5-dimethyl-4-aminocyclohexyl) methane, bis (3,5-dimethyl-4-aminocyclohexyl) propane, bis (3-methyl-4-amino-5-ethylcyclohexyl) methane Bis (3-methyl-4-amino-5-ethylcyclohexyl) propane, bis (3,5-diethyl-4-aminocyclohexyl) methane, bis (3,5-diethyl-4-aminocyclohexyl) propane, bis ( 3-methyl-4-amino-5-isopropylcyclohexyl) methane, bis (3- Til-4-amino-5-isopropylcyclohexyl) propane, bis (3,5-diisopropyl-4-aminocyclohexyl) methane, bis (3,5-diisopropyl-4-aminocyclohexyl) propane, bis (3-ethyl-4 -Cycloaminohexyl) methane, bis (3-ethyl-4-cycloaminohexyl) propane, bis (3-isopropyl-4-aminocyclohexyl) methane, bis (3-isopropyl-4-aminocyclohexyl) propane, etc. Of these, bis (3-methyl-4-aminocyclohexyl) methane is preferred.

  Aliphatic diamines include ethylene diamine, tetramethylene diamine, hexamethylene diamine, undecamethylene diamine, dodecamethylene diamine, 2,2,4 / 2,4,4-trimethylhexamethylene diamine, 5-methylnonamethylene diamine, and the like. Among them, hexamethylenediamine is preferable.

  In the amorphous polyamide (b), as other copolymerization components, lactams such as ε-caprolactam, ω-lauryllactam, 2-pyrrolidone; 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid Amino acids such as 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, bis (aminopropyl) piperazine Alicyclic diamine such as bis (aminoethyl) piperazine and bisaminomethylnorbornene, metaxylylenediamine, paraxylenediamine aromatic diamine; aliphatic dicarboxylic such as adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanoic acid Acid; terephthalate such as naphthalenedicarboxylic acid Aromatic dicarboxylic acids other than phosphoric acid and isophthalic acid may be contained.

  The structural unit molar ratio of alicyclic diamine / aliphatic diamine can be used in the range of 0/100 to 100/0, but is preferably in the range of 0/100 to 20/80.

  The molar ratio of the constituent units of terephthalic acid / isophthalic acid can be used in the range of 0/100 to 100/0, but is preferably in the range of 5/95 to 40/60.

  The glass transition point of the amorphous polyamide (c) is not particularly limited, but can be preferably used within the range of 100 to 270 ° C, and more preferably within the range of 120 to 255 ° C.

  The multilayer stretched polyamide resin-based film of the present invention comprises an aromatic polyamide (c) resin layer (X), an aliphatic polyamide (a) and an amorphous polyamide (b) resin layer (Z), an aliphatic polyamide The resin layer (Y) is composed of polyamide (a) and / or aromatic polyamide (c) and amorphous polyamide (b), and (Z) / (Y) / (X) / (Y) / (Z) It is a polyamide-type film by which the extending | stretching process formed in five layers in this order.

  The resin layer (Z) in this invention consists of mixed polyamide resin containing 99-90 mass% of aliphatic polyamide (a) and 1-10 mass% of amorphous polyamide (b). As for the mixing ratio of the aliphatic polyamide (a) and the amorphous polyamide (b), (a) / (b) is preferably in the range of 95 to 99% by mass / 1 to 5% by mass, more preferably 98.5. It is the range of 96.5 mass% / 1.5-3.5 mass%. When the amorphous polyamide (b) is less than 1% by mass, the laminate strength after laminating with a sealant via an adhesive is less than 5 N / cm, which is not preferable. On the other hand, if the amorphous polyamide (b) exceeds 10% by mass, the polymer extruded from the die becomes melted when melt-extruded by an extruder, and the end of the polymer extruded from the die pulsates. Then, the landing position on the casting drum becomes unstable, and when it is extruded at a high discharge amount, various problems such as winding around the screw are likely to occur, which is not preferable. Such a problem is considered to be caused by a difference in melting characteristics between the aliphatic polyamide (a) and the amorphous polyamide (b). That is, the aliphatic polyamide (a) has a relatively low melting rate and a high crystallization rate, whereas the amorphous polyamide (b) has a very high melting rate and hardly crystallizes. it is conceivable that.

  The resin layer (Y) in the present invention is a layer corresponding to an adhesive layer between the resin layer (X) and the resin layer (Z), and the aliphatic polyamide (a) and / or the aromatic polyamide (c) 5 to 90. It consists of a mixed polyamide containing 95% by mass and 95-10 mass of amorphous polyamide (b). The mixing ratio of the aliphatic polyamide (a) and / or the aromatic polyamide (c) and the amorphous polyamide (b) is such that [(a) + (c)] / (b) is 5 to 49% by mass / 95 to A range of 51% by weight is preferred. When deviating from the above range, that is, when the amorphous polyamide (b) exceeds 95% by mass, and less than 10% by mass, the delamination strength of the film is low, and the film is broken when used as a buffer material. Since it becomes easy to bag, it is not preferable.

  The aliphatic polyamide (a) and the aromatic polyamide (c) in the resin layer (Y) can be used alone or in a mixture of both at an arbitrary ratio.

  The polyamide resin used in the present invention more preferably contains an organic glycidyl ester, a monocarboxylic acid such as dicarboxylic anhydride or benzoic acid, a diamine or the like as a terminal blocking agent in order to suppress monomer formation at the time of melting. .

  The relative viscosity of the polyamide resin used in the present invention is not particularly limited, but the relative viscosity measured using a 96% sulfuric acid as a solvent at a temperature of 25 ° C. and a concentration of 1 g / dl is 1.5 to 5. 0.0 is preferred. More preferably, it is in the range of 2.5 to 4.5, more preferably 3.0 to 4.0. When the relative viscosity is less than 1.5, the mechanical properties of the film are remarkably deteriorated. Moreover, the thing exceeding 5.0 becomes easy to cause trouble in the film forming property of a film.

  One or two kinds of various additives such as pigments, antioxidants, ultraviolet absorbers, preservatives, antistatic agents, inorganic fine particles and the like are added to the polyamide resin as necessary, as long as the effects of the present invention are not impaired. The above may be added.

  Moreover, in order to improve the antiblocking property of a film, 1 type, or 2 or more types of various inorganic type lubricants and organic type lubricants may be mix | blended. These lubricants include clay, talc, mica, calcium carbonate, zinc carbonate, wollastonite, silica, alumina, magnesium oxide, calcium silicate, sodium aluminate, calcium aluminate, magnesium aluminosilicate, glass balloon, zinc oxide, Antimony trioxide, zeolite, kaolinite, hydrotalcite, layered silicate, stearic acid amide, behenic acid amide, erucic acid amide, ethylene bis stearic acid amide, phenol resin, melamine resin, polymethyl methacrylate resin, etc. .

  Various additives as described above may be more effective when blended in the resin layer (Z) layer constituting the outermost layer.

  Although the thickness of the multilayer stretched polyamide resin-type film of this invention is not specifically limited, Preferably it is 5-100 micrometers, More preferably, it is 5-50 micrometers, Most preferably, it is 10-25 micrometers. If the thickness is less than 5 μm, there may be a problem in impact resistance. If the thickness exceeds 100 μm, the film becomes hard and the weight becomes heavy, which is not suitable as a cushioning material for packaging.

  The thickness of the resin layer (Z) is preferably 3 μm or more, more preferably 4 to 35 μm, and most preferably 5 to 20 μm. When the thickness of the resin layer (Z) is less than 3 μm, the lamination strength after laminating the sealant and the polyamide resin film via an adhesive is lowered to less than 5 N / cm, which is not preferable.

  The thickness of the resin layer (Y) is preferably 0.1 to 5 μm, and more preferably 0.3 to 1 μm. When the thickness of the resin layer (Y) is less than 0.1 μm, the delamination strength of the film is low and less than 2 N / cm, which is not preferable. When the thickness exceeds 5 μm, when the polyamide resin of the resin layer (Y) is melt-extruded with an extruder, it is extruded at a high discharge amount, which is not preferable because it is easy to wind around the screw.

  The thickness of the resin layer (X) is preferably 2 μm or more, and more preferably 3 to 20 μm. When the thickness of the resin layer (X) is less than 2 μm, the gas barrier property is inferior, which is not preferable.

  As thickness ratio of resin layer (X) and resin layer (Y), (X) / (Y) = 2-100 is preferable, More preferably, it is 5-50. When (X) / (Y) is less than 2, it is difficult to obtain a film satisfying a sufficient gas barrier property, which is not preferable. When (X) / (Y) exceeds 100, it is difficult to obtain sufficient adhesion between the resin layer (X) and the resin layer (Y).

  The thickness ratio between the resin layer (Z) and the resin layer (Y) is preferably (Z) / (Y) = 2 to 100, and more preferably 5 to 50. When (Z) / (Y) is less than 2, it is difficult to obtain a film satisfying a sufficient laminate strength, which is not preferable. When (Z) / (Y) exceeds 100, it is difficult to obtain sufficient adhesion between the resin layer (Z) and the resin layer (Y).

  The multilayer stretched polyamide resin film of the present invention preferably has a delamination strength of 2 N / cm or more. When the delamination strength of each layer of the multilayer stretched polyamide resin film is less than 2 N / cm, when used as a cushioning material, the bag may be broken by impact and cannot be used. In the multilayer stretched polyamide resin-based film of the present invention, since the (X) layer and the (Z) layer are bonded using the (Y) layer as an adhesive layer, the delamination strength is (X) layer and (Z). The peel strength when the layer was peeled was evaluated.

  The multilayer stretched polyamide resin film of the present invention preferably has a laminate strength of 5 N / cm or more when the sealant layer is laminated. When the laminate strength is less than 5 N / cm, when used as a cushioning material, it cannot be used because it is broken by impact.

  Furthermore, in order to provide sufficient performance as a buffer material, it is particularly preferable that the delamination strength is 2 N / cm or more, and at the same time, the laminate strength is 5 N / cm or more.

The oxygen permeability of the multilayer stretched polyamide resin-based film of the present invention is required to be 100 ml / (m ² · day · MPa) or less, and preferably 70 ml / (m ² · day · MPa) or less. When the oxygen permeability exceeds 100 ml / (m ² · day · MPa), the gas barrier property is inferior, and when used as a buffer material, the air inside escapes and the performance as the buffer material is impaired.

  Next, although an example of the manufacturing method of the multilayer stretched polyamide resin-type film of this invention is demonstrated, it does not limit to this.

  Each resin constituting each layer is melted at a temperature of melting point to melting point + 40 ° C. of each polyamide resin by using a separate extruder, and the melted resins are joined in a feed block or a multi-manifold die. Extruded into a sheet shape with a T-die and brought into close contact with a cooling drum whose temperature has been adjusted to 30 ° C. or lower by a known method such as electrostatic application casting method or air knife method, so that the temperature becomes below the glass transition temperature. Rapid solidification is performed to obtain an unstretched sheet having a desired thickness. Next, a film excellent in mechanical properties and dimensional stability can be obtained by biaxially stretching the obtained unstretched sheet in the longitudinal and lateral directions.

  As the biaxial stretching method, a simultaneous biaxial stretching method in which the tenter type simultaneous biaxial machine simultaneously stretches in the machine direction and the transverse direction, after stretching in the machine direction with a roll type stretching machine, in the transverse direction with a tenter type transverse stretching machine. Although it is possible to use a sequential biaxial stretching method or the like for stretching, when the obtained film is excellent in the balance of mechanical properties in the machine direction and the transverse direction, or when a polyamide resin having a high crystallization speed is sequentially biaxially stretched, A simultaneous biaxial stretching method is preferred because hydrogen bonds are formed during stretching in the machine direction, the molecules are oriented in the stretching direction, and stretching in the transverse direction is difficult.

  Furthermore, when a highly crystalline polyamide resin is stretched, it passes through a water absorption treatment step in which it is immersed in warm water at 45 to 65 ° C. for 60 to 150 seconds at an arbitrary stage of the unstretched sheet before being supplied, and simultaneously. A method using a biaxial stretching machine is preferred.

  The draw ratio is usually 3 times or more, preferably 6 to 20 times in terms of area magnification. When the area magnification is less than 3, it is not preferable because sufficient mechanical properties such as tensile strength and elongation and pinhole strength cannot be obtained.

  The draw ratio is preferably 1.5 to 10 times, more preferably 2 to 5 times in each of the machine direction and the transverse direction, and the ratio of the draw ratio in the transverse direction to the machine direction is TD / MD = 0.5 to 10.

  The multilayer stretched polyamide resin-based film of the present invention is heat-set at a temperature of 150 to 220 ° C. after being stretched, and is 0 to 10% as necessary, preferably 2 to 6% in the longitudinal direction. And it winds up in roll shape through the heat setting process which performs a relaxation process of a horizontal direction, and also through the cooling process of 20-100 degreeC.

  Since the multilayer stretched polyamide resin-based film of the present invention can impart heat sealability by adopting a structure in which the sealant layer is laminated, the multilayer film laminated with the sealant layer in this way is heat-sealed on the sealant layer side. It can be used as a packaging body such as a bag-like body or a lid for tray packaging, and can be used in various bag forms such as a three-side seal bag, a four-side seal bag, a pillow bag, a standing pouch, and a rocket packaging. .

  A bag in which air is sealed inside a bag can be used as a cushioning material for packing by using one or a plurality of the air bags. The plurality of air bags may be connected to each other or may be independent from each other. Moreover, an air injection hole may be provided in any of the air bags.

  For the sealant layer, a resin having good thermal adhesiveness is used. For example, low density polyethylene, medium density polyethylene, high density polyethylene, linear polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ionomer resin, ethylene-acrylic acid / methacrylic acid copolymer, ethylene-acrylic acid / methacrylic acid An ester copolymer, an acid-modified polyethylene / polypropylene resin, a polyvinyl acetate resin, or the like can be used. These may be used alone, may be used by copolymerization or melt-mixing with other resins or components, or may be used after modification. These resin components may be used in a single layer or in multiple layers with at least one or more types of resin components. Particularly preferred are polyolefin resins such as polyethylene, polypropylene, and polyethylene / polypropylene copolymers.

  In order to form a sealant layer, a method of laminating the sealant layer as a film and then laminating it on a multilayer stretched polyamide resin film, a coextrusion method of simultaneously extruding and laminating the multilayer stretched polyamide resin film and the sealant layer, and a sealant layer And a method of coating a multilayer stretched polyamide resin film with a coater. When the sealant layer is once in the form of a film, the film may be unstretched or stretched at a low magnification, but it is practically preferable that it is an unstretched film. The film formation method may be a tenter method in which the film is heated and melted with an extruder, extruded from a T die, and cooled and solidified with a cooling roll, or a tubular method in which it is extruded from a circular die and cooled and solidified by water cooling or air cooling. it can.

  As a method of laminating a sealant layer in the form of a film on a multilayer stretched polyamide resin film, a normal production method can be used. For example, a lamination method such as a dry lamination method, a wet lamination method, a solventless dry lamination method, and an extrusion lamination method can be used. In particular, it is preferable to use an extrusion lamination method.

  A lamination method using an adhesive such as polyurethane can also be used to form the sealant layer. In this case, it is preferable to apply a corona discharge treatment or an easy adhesion treatment to both the multilayer stretched polyamide resin film and the sealant layer and then laminate the treated surfaces with an adhesive.

  An aluminum foil layer, a gas barrier resin layer, another thermoplastic resin layer, another polyamide resin layer, or the like may be laminated between the multilayer stretched polyamide resin film and the sealant layer. The lamination method is not particularly limited, and examples thereof include a dry lamination method, a wet lamination method, a solventless dry lamination method, and an extrusion lamination method.

  In order to impart functionality to the multilayer stretched polyamide resin-based film of the present invention, for example, an easy-adhesive for enhancing adhesion with other films, adhesives, inks, etc., for suppressing the generation of static electricity You may perform in-line coating process of various functional coating agents, such as an antistatic agent and a barrier coating agent for improving barrier property. For this purpose, the in-line coating treatment method is not particularly limited. For example, the gravure roll method, the reverse roll method, the air knife method, the reverse gravure method, the Meyer bar method, or a combination of these, or various spraying methods. A method etc. can be adopted.

The multilayer stretched polyamide resin-based film of the present invention may have a configuration in which a vapor deposition layer is laminated for the purpose of further improving gas barrier properties. A compound made of an inorganic substance or an organic substance is used for the vapor deposition layer. As the inorganic substance, a metal such as aluminum or an inorganic oxide such as aluminum, silicon, magnesium, or titanium is used. Examples of the method for forming the inorganic layer include a vacuum deposition method, a sputtering method, a chemical vapor deposition (CVD) method, and a physical vapor deposition (PVD) method. In particular, the vacuum deposition method is excellent in practicality. When the polyamide resin layer is subjected to vapor deposition processing, in order to improve the adhesion between the polyamide resin layer and the vapor deposition layer, the polyamide resin layer is previously subjected to corona treatment, plasma treatment or coating treatment with an inorganic or organic compound. May be. In the case of vacuum deposition, aluminum (Al), alumina (Al ₂ O ₃ ), silicon (Si), silica (SiO ₂ ), or a combination thereof is used as a deposition raw material.

  The multilayer stretched polyamide resin-based film of the present invention may be configured such that a gas barrier coat layer is further laminated. The gas barrier coat layer is not particularly limited, but a polyvinylidene chloride copolymer (PVDC) is suitable. PVDC is a polymer containing 60% by mass or more, preferably 70 to 97% by mass of vinylidene chloride units, used in the form of latex, and coated on at least one side of the polyamide resin layer. The average particle size of PVDC in the latex is preferably 0.05 to 0.5 μm, and particularly preferably 0.07 to 0.3 μm. Various additives such as an antiblocking agent, a crosslinking agent, a water repellent, and an antistatic agent may be used in combination with the PVDC as long as the effects of the present invention are not impaired.

  An easy-adhesion layer may be further provided on the multilayer stretched polyamide resin film. As the easy adhesion layer, urethane resin or urethane urea resin can be used.

  In order to impart functionality to the multilayer stretched polyamide resin film, for example, an antistatic treatment for suppressing the generation of static electricity may be performed, or application of various functional coating liquids other than the above-described barrier coating liquid May be performed.

  If necessary, the multilayer stretched polyamide resin film may be subjected to physicochemical treatment such as corona discharge treatment, plating treatment, cleaning treatment, and dyeing treatment.

  Next, the present invention will be specifically described with reference to examples. In addition, the evaluation method of the various physical properties in an Example and a comparative example is as follows.

(1) Relative Viscosity Polyamide resin pellets were dissolved in 96% sulfuric acid so as to have a concentration of 1 g / dl, and measured at a temperature of 25 ° C.

(2) Interlaminar peel strength Corona discharge treatment is performed on both sides of a multilayer stretched polyamide resin film, and urethane adhesive (TM329 / CAT-8B two-component type manufactured by Toyo Morton Co., Ltd.) is applied to the corona-treated surface. The film was dried with a hot air drier at 80 ° C. for 10 seconds so that the adhesive coating amount was 3 g / m ² . The adhesive-coated surface and a corona-treated surface of a sealant film (CPP; manufactured by Tosero Co., Ltd., unstretched polypropylene film, GLC general type, thickness 50 μm) were bonded with a nip roll (nip condition 80 ° C.) and wound up. Next, a urethane adhesive (TM329 / CAT-8B two-pack type manufactured by Toyo Morton Co., Ltd.) was applied to the polyamide resin surface of the wound film, and the applied film was dried with a hot air dryer at 80 ° C. for 10 seconds. The amount of adhesive application was 3 g / m ² . The adhesive-coated surface and a corona-treated surface of a sealant film (CPP; manufactured by Tosero Co., Ltd., unstretched polypropylene film, GLC general type, thickness 50 μm) were bonded with a nip roll (nip condition 80 ° C.) and wound up. The laminated film was aged for 72 hours in an atmosphere of 40 ° C. to prepare a laminate film of (CPP // multilayer oriented polyamide // CPP).

  The laminated film was aged for 72 hours in an atmosphere of 40 ° C., and the obtained laminate film was cut into a strip of MD 100 mm × TD 15 mm in an environment of 20 ° C. × 65% RH, and an X layer of a multilayer stretched polyamide resin film A laminate strength test piece was prepared by peeling 30 mm between the Z layer and the Z layer with MD using tweezers. Using a tensile tester (AS-1S manufactured by Shimadzu Corporation) equipped with a 50N measurement load cell and a sample chuck, after fixing each peeled end, the test piece is kept in the “T-type” Then, 50 mm was peeled from MD at a tensile speed of 300 mm / min, and the average value of the strength at that time was read. The measurement was performed on five samples, and the average value thereof was defined as the delamination strength.

(3) Lamination test Corona discharge treatment was performed on both sides of the multilayer stretched polyamide resin film, and a urethane adhesive (TM329 / CAT-8B two-pack type manufactured by Toyo Morton Co., Ltd.) was applied to the corona treatment surface. The film was dried with a hot air dryer at 80 ° C. for 10 seconds so that the adhesive coating amount was 3 g / m ² . The adhesive-coated surface and a corona-treated surface of a sealant film (CPP; manufactured by Tosero Co., Ltd., unstretched polypropylene film, GLC general type, thickness 30 μm) were bonded with a nip roll (nip condition 80 ° C.) and wound up. Next, a urethane adhesive (TM329 / CAT-8B two-pack type manufactured by Toyo Morton Co., Ltd.) was applied to the polyamide resin surface of the wound film, and the applied film was dried for 10 seconds with a hot air dryer at 80 ° C. The amount of adhesive application was 3 g / m ² . The corona-treated surface of the adhesive-coated surface and a sealant film (LLDPE: linear low density polyethylene film HZ thickness 50 μm manufactured by Tosero Co., Ltd.) were bonded together by a nip roll (nip condition 80 ° C.) and wound up. The laminated film was aged for 72 hours in an atmosphere of 40 ° C. to prepare a three-layer laminate film of (CPP // polyamide // LLDPE).

  The obtained laminate film was cut into a strip of MD 100 mm × TD 15 mm in an environment of 20 ° C. × 65% RH, and the biaxially stretched polyamide resin film and the LLDPE sealant were peeled 30 mm from the MD using tweezers. A strong specimen was made. Using a tensile tester (AS-1S manufactured by Shimadzu Corporation) equipped with a 50N measurement load cell and a sample chuck, after fixing each peeled end, the test piece is kept in the “T-type” Then, 50 mm was peeled from MD at a tensile speed of 300 mm / min, and the average value of the strength at that time was read. The measurement was performed on five samples, and the average value thereof was determined as the laminate strength.

(4) Gas barrier property The gas barrier property was evaluated by measuring oxygen permeability.

  The oxygen permeability was evaluated by measuring the oxygen gas permeability in an atmosphere at a temperature of 20 ° C. and a relative humidity of 65% using a Mocon oxygen barrier measuring device (OX-TRAN 2/20).

(Production Example 1: Production of aliphatic polyamide resin A-1)
In a closed reaction vessel equipped with a stirrer, 100 parts by mass of ε-caprolactam, 0.12 parts by mass of benzoic acid (10 mmol / kg with respect to ε-caprolactam), 3 parts by mass of water and inorganic fine particles (thyloid SY-150: Mizusawa) (Chemical Industry Co., Ltd.) 0.15 parts by mass is charged into a polymerization kettle, the temperature is raised, a polycondensation reaction is performed at a control pressure of 0.5 MPa and a temperature of 260 ° C., discharged from the reaction vessel, and then cut into chips. This was scoured and dried to obtain an aliphatic polyamide resin A-1. The relative viscosity of this chip was 3.1.

(Production Example 2: Production of amorphous polyamide resin B-1)
Terephthalic acid / isophthalic acid is 10/90 (molar ratio), bis- (3-methyl-4-aminocyclohexyl) methane / hexamethylenediamine is 16/84 (molar ratio), (isophthalic acid and terephthalic acid) / (bis 10 kg of a raw material having a ratio of 50/50 molar ratio of (3-methyl-4-aminocyclohexyl) methane and hexamethylenediamine) is charged into a reaction tank together with 8 kg of pure water, and the air in the reaction tank is blown several times with nitrogen. Purged. After the temperature was raised to 90 ° C. and reacted for about 5 hours, the reaction temperature was gradually raised to 280 ° C. over 10 hours under pressure (18 bar) with stirring in the tank. Then, after releasing the pressure and reducing the pressure to atmospheric pressure, a polymerization reaction was further performed at the same temperature for 6 hours. After completion of the reaction, it was discharged from the reaction vessel and cut to obtain amorphous polyamide resin B-1 pellets. The relative viscosity of the obtained pellet was 1.80. The glass transition temperature was 157 ° C.

(Production Examples 3 to 6: Production of amorphous polyamide B-2 to B-5)
However, in Production Example 2, the composition of the amorphous polyamide was changed as described in Table 1, and otherwise, amorphous polyamides B-2 to B-5 were produced in the same procedure as in Production Example 2. did.

[Aromatic polyamide resin]
Nylon MXD6 (Mitsubishi Gas Chemical Co., Ltd. MX nylon 6007) was used as C-1.

Example 1
Using a five-layer coextrusion T die, the aromatic polyamide resin C-1 (resin layer X) is 270 ° C. from the extruder (1), and 95.0 parts by mass of the aliphatic polyamide resin A from the extruder (2). -1 and 5 parts by mass of amorphous polyamide resin B-2 (resin layer Z) at 265 ° C, 70 parts by mass of aromatic polyamide resin C-1 and 30 parts by mass of extruder (3) The mixture (resin layer Y) with the amorphous polyamide resin B-1 was melt-extruded at 270 ° C. and superposed in the order of (Z) / (Y) / (X) / (Y) / (Z). The multilayer unstretched sheet was extruded from a die, brought into close contact with a cooling drum having a surface temperature of 18 ° C., and rapidly cooled to obtain an unstretched multilayer sheet having a thickness of 160 μm. The obtained sheet | seat was sent to the 50 degreeC warm water tank, and the water immersion process for 1 minute was performed. The end of this sheet was held with a clip of a tenter type simultaneous biaxial stretching device, and simultaneously biaxially stretched at a stretching ratio of 3.0 times in the machine direction and 3.3 times in the transverse direction under the condition of 180 ° C. Then, the transverse relaxation rate was set to 5%, heat treatment was performed at 210 ° C. for 4 seconds, and the mixture was gradually cooled to room temperature. The thickness was Z / Y / X / Y / Z = 5.0 / 0.5 / A multilayer stretched film of 5.0 / 0.5 / 5.0 (μm) was obtained. The measurement results of the obtained multilayer stretched film are shown in Table 2.

(Examples 2-4, Comparative Examples 1-2)
A multilayer stretched film was obtained in the same manner as in Example 1 except that the mixing ratio of the aliphatic polyamide resin A-1 and the amorphous polyamide resin B-2 in the Z layer was changed to the ratio described in Table 2. The measurement results of the obtained multilayer stretched film are shown in Table 2.

(Example 5)
Other than changing the amorphous polyamide resin used for the Z layer to B-1 and changing the mixing ratio of the aliphatic polyamide resin A-1 and the amorphous polyamide resin B-1 to the ratios shown in Table 2 Obtained a multilayer stretched film in the same manner as in Example 1. The measurement results of the obtained multilayer stretched film are shown in Table 2.

(Examples 6 to 9)
A multilayer stretched film was obtained in the same manner as in Example 1 except that the amorphous polyamide resin used for the Z layer was changed to B-1, B-3, B-4 or B-5. The measurement results of the obtained multilayer stretched film are shown in Table 2.

(Example 10)
A multilayer stretched film was obtained in the same manner as in Example 1 except that the amorphous polyamide resin used for the Y layer was changed to B-1. The measurement results of the obtained multilayer stretched film are shown in Table 2.

(Examples 11-14)
Instead of the aromatic polyamide resin C-1 used for the Y layer, the same procedure as in Example 1 was conducted except that a mixed resin of A-1 or A-1 and C-1 was used as described in Table 2. A multilayer stretched film was obtained. The measurement results of the obtained multilayer stretched film are shown in Table 2.

(Examples 15-17, Comparative Examples 3-4)
A multilayer stretched film was obtained in the same manner as in Example 1 except that the mixing ratio of the aromatic polyamide resin C-1 of the Y layer and the amorphous polyamide resin B-2 was changed to the ratio described in Table 2. The measurement results of the obtained multilayer stretched film are shown in Table 2.

(Examples 18 to 20, Comparative Example 5)
A multilayer stretched film was obtained in the same manner as in Example 1 except that the thickness ratio of the layer of Z / Y / X / Y / Z was changed to the ratio described in Table 2. The measurement results of the obtained multilayer stretched film are shown in Table 2.

(Comparative Example 6)
Using a three-layer coextrusion T-die, the aromatic polyamide resin C-1 (resin layer X) is 270 ° C. from the extruder (1) and 95.0 parts by mass of the aliphatic polyamide resin A from the extruder (2). -1 and a mixture of 5 parts by mass of amorphous polyamide resin B-2 (resin layer Z) were each melt extruded at 265 ° C and superposed in the order of (Z) / (X) / (Z) The unstretched sheet was extruded from a die, brought into close contact with a cooling drum having a surface temperature of 18 ° C., and rapidly cooled to obtain an unstretched multilayer sheet having a thickness of 160 μm. The obtained sheet | seat was sent to the 50 degreeC warm water tank, and the water immersion process for 1 minute was performed. The end of this sheet is held with a clip of a tenter type simultaneous biaxial stretching device, and the stretching ratio is 180.degree. C. and the stretching ratio is 3.0 times in the longitudinal direction and 3.3 times in the transverse direction. After stretching, the heat treatment was performed at 210 ° C. for 4 seconds at a transverse relaxation rate of 5%, and gradually cooled to room temperature. The thickness was Z / X / Z = 5.5 / 5.0 / 5. A multilayer stretched film of .5 (μm) was obtained. The measurement results of the obtained multilayer stretched film are shown in Table 2.

(Comparative Example 7)
A multilayer stretched film was obtained in the same manner as in Comparative Example 6 except that the mixing ratio of the Z-layer aliphatic polyamide resin A-1 and the amorphous polyamide resin B-2 was changed to the ratio described in Table 2. The measurement results of the obtained multilayer stretched film are shown in Table 2.

  Since all of Examples 1 to 20 are excellent in delamination strength, lamination strength, and oxygen barrier properties, if a multilayer stretched film is laminated through a sealant, it can be used as an air bag for packing cushioning materials. It can be said that it is particularly suitable.

  In Comparative Example 1, since the mixing ratio of the amorphous polyamide resin in the Z layer is low, the laminate strength after laminating with the sealant via the adhesive is as low as less than 5 N / cm, and it is peeled off when the T-type is peeled off. Since the interface reaches the sealant layer and delamination occurs, it is not suitable as a cushioning material for packing.

  In Comparative Example 2, since the mixing ratio of the amorphous polyamide in the Z layer exceeded 10% by mass, the polymer extruded from the die when melt-extruded with an extruder became visible as a striped pattern, or was extruded from the die. The end of the polymer pulsates and the landing position on the casting drum becomes unstable.

  In Comparative Example 3, since the mixing ratio of the amorphous polyamide resin in the Y layer exceeds 95% by mass, the delamination strength of the multilayer stretched polyamide is low, and the delamination is not suitable as a cushioning material for packing. It became a thing.

  In Comparative Example 4, since the mixing ratio of the amorphous polyamide resin in the Y layer was less than 10% by mass, the delamination strength of the multilayer stretched polyamide was low, and delamination was not suitable as a cushioning material for packaging. It became a thing.

   In Comparative Example 5, since the thickness of the Z layer is as thin as 3 μm or less, the laminate strength after laminating with the sealant via the adhesive is as low as less than 5 N / cm, and the release interface is the sealant layer at the time of T-type peeling. As a result, it was unsuitable as a cushioning material for packing because of delamination.

  Since Comparative Example 6 lacked the Y layer, the multilayer stretched polyamide had low delamination strength, and was delaminated, making it unsuitable as a packaging cushioning material.

  In Comparative Example 7, since the mixing ratio of the amorphous polyamide resin (B-2) in the Z layer is as high as 30% by mass, the delamination strength of the multilayer stretched polyamide and the laminate after laminating with a sealant via an adhesive Although the strength is satisfactory, the polymer extruded from the die when melt-extruded by an extruder becomes visible as a striped pattern, or the end of the polymer extruded from the die pulsates and the landing position on the casting drum is It becomes unstable and the operability is bad and it cannot be adopted.

Claims (8)

A resin layer (X) of an aromatic polyamide (c) comprising a xylylenediamine component and an aliphatic dicarboxylic acid component having 4 to 12 carbon atoms;
A mixed polyamide resin layer (Z) containing 99 to 90% by weight of aliphatic polyamide (a) and 1 to 10% by weight of amorphous polyamide (b);
Mixed polyamide resin layer (Y) containing aliphatic polyamide (a) and / or aromatic polyamide (c) 5 to 90% by mass and amorphous polyamide (b) 95 to 10% by mass
A multilayer stretched polyamide resin-based film composed of 5 layers, each of which is laminated in the order of (Z) / (Y) / (X) / (Y) / (Z).   The amorphous polyamide is a polymer of isophthalic acid / terephthalic acid / hexamethylenediamine or a polymer of bis (3-methyl-4-aminocyclohexyl) methane / isophthalic acid / terephthalic acid / hexamethylenediamine. The multilayer stretched polyamide resin film according to claim 1.   The multilayer stretched polyamide resin film according to claim 1 or 2, wherein the resin layer (Z) has a thickness of 3 µm or more.   The multilayer stretched polyamiamide resin film according to any one of claims 1 to 3, wherein the interlayer peel strength of the multilayer stretched polyamide resin film is 2 N / cm or more.   The multilayer film formed by laminating | stacking a sealant layer on the multilayer stretched polyamide resin-type film in any one of Claims 1-4.   The multilayer film according to claim 5, wherein the laminate strength between the multilayer stretched polyamide resin film and the sealant layer is 5 N / cm or more.   An air bag obtained by stacking and heat-sealing the sealant layer of the multilayer film according to claim 5 as an inner side. A packing cushioning material comprising the air bag according to claim 7.