JP2016155928A - Polyamide film for cold molding and laminate and container for cold molding using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyamide film for cold molding and a laminate for cold molding having slipperiness suitable for deep drawing or overhang molding processing, having no effect by temperature conditions during molding processing and capable of maintaining excellent moldability even during molding at high humidity.SOLUTION: There is provided a biaxial oriented polyamide film for cold molding consisting of a polyamide resin composition containing inorganic particles and long chain fatty acid bisamide consisting of fatty acid with C of 20 or more and having the content of long chain fatty acid bisamide of 0.01 to 0.10 mass%. There is provided the biaxial oriented polyamide film for cold molding, where a main component of the polyamide resin is nylon 6 and the long chain fatty acid bisamide is at least one kind of ethylenebisbehenic acid amide or ethylene biserucic acid amide.SELECTED DRAWING: None

Description

  The present invention relates to a polyamide film for cold molding suitable for deep drawing molding and overhang molding processing, and a laminate and a container using the same.

  Conventionally, polyvinyl chloride has been widely used as a material for cold molding when packaging a drug (tablet) or the like (press-through pack) in the case of packaging vinyl chloride, or in the case of packaging contents requiring moisture resistance. . In recent years, for the purpose of imparting better gas barrier properties and moisture proofing from the viewpoint of maintaining the quality of contents, a base material layer / metal foil layer containing a metal foil such as an aluminum foil and using the base material layer as a resin film / A laminate for cold forming composed of a sealant layer is used.

  Also, in the industrial field, the metal ion canisters have been the mainstream for the exterior materials of lithium ion batteries, but have drawbacks such as low degree of freedom in shape and difficulty in weight reduction. On the other hand, a laminate type exterior using a laminate for cold forming consisting of a base material layer / metal foil layer / sealant layer or base material layer / base material layer / metal foil layer / sealant layer having a base material layer as a resin film Since the body is composed of a resin film and metal foil, it is flexible and has a high degree of freedom in shape compared to a metal can, and it can be reduced in weight by making it thinner, and it can be easily reduced in size. Have been widely used.

  Various properties are required for the cold-molded laminate used in the above applications, but moisture resistance is a very important factor. However, a metal foil such as an aluminum foil that imparts moisture resistance is poor in spreadability and inferior in moldability. For this reason, the use of a polyamide film as the resin film constituting the base material layer imparts extensibility and enhances moldability.

As a polyamide film, since it is excellent in strength, impact resistance, pinhole resistance, etc., a biaxially stretched polyamide film is often used (Patent Document 1). For this reason, it has been attempted to improve the slipperiness of the biaxially stretched polyamide film for the purpose of improving the cold moldability.
Patent Documents 2 and 3 propose a polyamide film coated with a component for improving slipperiness, and Patent Documents 4 to 6 provide a polyamide film having excellent slipperiness under high humidity. For the purpose, a polyamide film containing an inorganic lubricant has been proposed.

However, the method of improving the slipperiness by coating requires a coating process, so the productivity is poor, the coating agent component adheres to the processing equipment, and the coating agent component is transferred to the non-coated surface. There were problems such as a decrease in adhesiveness due to the coating agent component.
Even in the method of controlling the slipperiness by blending the inorganic lubricant, the effect of improving the slipperiness is not sufficient, and there is a problem that the slipperiness becomes insufficient particularly at the time of molding under high humidity.

Patent Literature 1: Patent No. 4422171 Patent Literature 2: Patent No. 4940696 Patent Literature 3: Patent No. 4736188 Patent Literature 4: Patent No. 4898017 Patent Literature 5: JP 2011-255931 Patent Literature 6: Patent No. 5487485

  The present invention solves the above-mentioned problems, has slipperiness suitable for deep drawing molding and overhang molding processing, is not affected by humidity conditions during molding processing, and is excellent in molding under high humidity. An object of the present invention is to provide a cold-molding polyamide film and a cold-molding laminate that can maintain the moldability.

  As a result of intensive studies to solve the above-mentioned problems, the present inventor can improve the slipperiness under high humidity by containing a specific amount of inorganic particles and long-chain fatty acid bisamide in the polyamide film. It has been found that the film can be made and the adhesiveness to the metal foil is not lowered, and the present invention has been achieved.

That is, the gist of the present invention is as follows.
(1) A polyamide film comprising a polyamide resin composition containing inorganic particles and a long-chain fatty acid bisamide comprising a C20 or higher fatty acid, wherein the long-chain fatty acid bisamide content is 0.01 to 0.10% by mass. A biaxially stretched polyamide film for cold forming, characterized in that:
(2) The biaxially stretched polyamide film for cold forming according to (1), wherein the long-chain fatty acid bisamide comprising a C20 or higher fatty acid is at least one of ethylene bisbehenic acid amide and ethylene biserucic acid amide.
(3) The inorganic particles include silica (A) having an average particle diameter of 1.0 to 1.4 μm and silica (B) having an average particle diameter of 2.5 to 3.0 μm, and silica (A) and silica ( The total content of B) is 0.1 to 0.3% by mass, and the content of silica (A) is 3.0 or more times the content of silica (B), (1) or (2) Biaxially stretched polyamide film for cold forming as described in 1.
(4) The biaxially stretched polyamide film for cold forming according to any one of (1) to (3), wherein the main component of the polyamide resin is nylon 6.
(5) A biaxially stretched polyamide film for cold forming according to any one of (1) to (4), wherein the base material layer, the metal foil, and the heat bonding layer are sequentially laminated. A laminate for cold forming, characterized in that
(6) A container obtained by deep-drawing or stretch-molding the cold-forming laminate according to (5).

  The biaxially stretched polyamide film for cold forming according to the present invention provides a cold-molded laminate excellent in moldability suitable for deep-drawing molding and overhang molding without being affected by humidity conditions during molding. A container suitable as a press-through pack or a lithium ion battery package can be obtained using this cold-molded laminate.

  Hereinafter, the present invention will be described in detail. As the polyamide resin forming the biaxially stretched polyamide film for cold molding of the present invention, a polyamide resin obtained by polycondensation of a lactam having a three-membered ring or more, ω-amino acid, dibasic acid and diamine can be used. . Specifically, polymers such as ε-caprolactam, aminocaproic acid, enanthractam, 7-aminoheptanoic acid, 11-aminoundecanoic acid, 9-aminononanoic acid, α-pyrrolidone, α-piperidone, hexamethylenediamine, nonamethylene Polycondensation of salts of diamines such as diamine, undecamethylenediamine, dodecamethylenediamine, and metaxylylenediamine with dicarboxylic acids such as terephthalic acid, isophthalic acid, adipic acid, sebacic acid, dodecane dibasic acid, and glutaric acid Or a copolymer thereof, for example, nylon 4, 6, 7, 8, 11, 12, 6, 6, 6, 10, 6, 11, 6, 12, 6T, 6/6, 6 , 6/12, 6 / 6T, 6I / 6T, and the like.

  These may be used in combination of a plurality of types. Among them, nylon 6 is preferable because of its excellent mechanical properties and thermal properties. And it is preferable that the polyamide resin which forms the biaxially-stretched polyamide film for cold forming of this invention has nylon 6 as a main component. Especially, it is preferable that 90 mass% or more of the polyamide resin which forms this polyamide film, and 95 mass% or more are nylon 6.

  The polyamide resin contains inorganic particles and a long-chain fatty acid bisamide composed of a C20 or higher fatty acid. About the inorganic particle used for this invention, arbitrary things can be selected and used from what is conventionally used as a filler of resin. Specifically, silica-alumina clay minerals (hydrous aluminum silicates) typified by clay, kaolin, calcined kaolin, silica-magnesium typified by talc, calcium silicate, silica, alumina, Examples thereof include titanium oxide. Among these, talc, kaolin, calcined kaolin or silica is particularly preferable from the viewpoint of easy dispersibility. Of these, silica is excellent in the design of the resulting film and is particularly preferably used.

The content of inorganic particles in the biaxially stretched polyamide film for cold forming of the present invention is preferably 0.05 to 0.5% by mass, and more preferably 0.1 to 0.3% by mass. preferable.
When the content of the inorganic particles is less than 0.05% by mass, the ability to form surface protrusions of the film is low, and slipperiness is not improved. Moreover, when content of an inorganic particle exceeds 0.5 mass%, although the slipperiness improvement effect will express, the transparency of a film will worsen.

Furthermore, what contains two types of silica (A) and silica (B) as an inorganic particle in this invention is preferable. Silica (A) has an average particle size of 1.0 to 1.4 μm, and silica (B) has an average particle size of 2.5 to 3.0 μm. It is preferable that silica (A) and silica (B) occupy 90% by mass or more, more preferably 95% by mass or more in the inorganic particles.
The total content of silica (A) and silica (B) in the biaxially stretched polyamide film for cold forming of the present invention is preferably 0.1 to 0.3% by mass, and silica (A) The content of is preferably 3.0 times or more of the content of silica (B).

  When silica having an average particle diameter of 1.0 to 1.4 μm is used as the silica (A), it is possible to obtain a film that is excellent in moldability particularly under high humidity and that maintains transparency. If the average particle size is less than 1.0 μm, the ability to form protrusions on the surface of the film is low and the slipping property is lacking, so that it is difficult to obtain the effect of improving moldability. On the other hand, when the average particle diameter exceeds 1.4 μm, the effect of improving moldability is exhibited, but the transparency of the film is deteriorated.

  Furthermore, the moldability under high humidity is improved by including a small amount of silica (B) together with silica (A). The content of silica (B) having an average particle size of 2.5 to 3.0 μm is preferably 1/3 or less with respect to the mass of silica (A). If it exceeds 1/3, transparency and moldability cannot be satisfied at the same time. Moreover, even if silica exceeding an average particle size of 3.0 μm is added, the effect of improving moldability is small and the transparency is deteriorated.

Next, a long-chain fatty acid bisamide composed of C20 or higher fatty acids will be described. C20 or higher fatty acids include saturated fatty acids such as behenic acid (C22) and unsaturated fatty acids such as erucic acid (C22). Specific examples of bisamides composed of these fatty acids are those that are generally commercially available, such as ethylene bisamides such as ethylene bisbehenamide and ethylenebiserucamide, hexamethylene bisbehenamide, and hexamethylene bis. Examples include hexamethylene bisamides such as erucic acid amide. Of these, ethylene bisamide is preferred because it is excellent in the effect of improving slipperiness under high humidity. That is, in the present invention, it is preferable to use at least one of ethylene bisbehenic acid amide and ethylene biserucic acid amide as the long chain fatty acid bisamide composed of C20 or higher fatty acid.
On the other hand, a bisamide composed of a fatty acid of less than C20 has a sufficient moldability improving effect in a low humidity region, but an effect of improving the moldability under high humidity is insufficient.

  The content of the long-chain fatty acid bisamide composed of C20 or higher fatty acid is required to be 0.01 to 0.10% by mass, and more preferably 0.03 to 0.08% by mass. When the content is less than 0.01% by mass, the amount of bleed-out of the long-chain fatty acid bisamide to the film surface is insufficient, so that the slipperiness under high humidity is not improved, and the moldability improving effect is poor. On the other hand, if the content exceeds 0.10% by mass, the slidability under high humidity is improved, but the amount of bleed-out is excessive, so when forming a laminate, other layers (for example, metal foil) and The adhesion between the two layers deteriorates, and floating tends to occur between both layers.

  There is no particular limitation on the method of obtaining a polyamide resin composition by adding inorganic particles and long-chain fatty acid bisamide to the polyamide resin, and it can be prepared according to a commonly used method. For example, a method in which inorganic particles and long-chain fatty acid bisamide are dry blended at a predetermined ratio and melt-kneaded in polyamide resin pellets can be mentioned. As for the inorganic particles, it is preferable to adopt a method in which inorganic particles are blended in the polyamide resin forming raw material and the inorganic particles are dispersed in the polyamide resin in advance during the polymerization of the polyamide resin.

  In the biaxially stretched polyamide film for cold forming of the present invention, various additives and modifiers that are usually blended as necessary, for example, heat stabilizer, ultraviolet absorber, light stabilizer, antioxidant Blending agents, antistatic agents, tackifiers, sealability improvers, antifogging agents, crystal nucleating agents, mold release agents, plasticizers, crosslinking agents, flame retardants and colorants (pigments, dyes, etc.) Also good.

The biaxially stretched polyamide film for cold molding according to the present invention has the characteristics of being excellent in slipperiness under high humidity and excellent in transparency by containing a specific amount of inorganic particles and long-chain fatty acid bisamide. is there.
Regarding slipperiness under high humidity, first, the static friction coefficient and the dynamic friction coefficient can both be 0.45 or less at a humidity of 65% RH, and these values are 0.40 or less. It is preferable that it is preferably 0.38 or less. Further, under high humidity, at a humidity of 90% RH, both the static friction coefficient and the dynamic friction coefficient can be 0.5 or less, and among these values, it is preferable that these values be 0.45 or less. Is preferably 0.43 or less.

  As the transparency, the haze can be 6% or less, preferably 5% or less, and more preferably 4% or less.

  The thickness of the biaxially stretched polyamide film for cold forming of the present invention is preferably 5 to 50 μm, and more preferably 10 to 30 μm.

The biaxially stretched polyamide film for cold forming of the present invention can be produced by the following method.
The biaxially stretched polyamide film for cold forming of the present invention needs to be obtained by a biaxial stretching method from the viewpoint of mechanical properties and thermal dimensional stability. The draw ratio is preferably 1.5 times or more in the longitudinal (MD) direction and the transverse (TD) direction, respectively, and preferably 2.5 to 4.0 times. When the draw ratio is less than 1.5 times, sufficient physical properties may not be obtained even if drawn. On the other hand, when the draw ratio exceeds 4.0 times, drawing may be difficult.

  As a method for producing a film having a single layer structure, any known method can be used. For example, a polyamide resin composition containing inorganic particles and a long-chain fatty acid bisamide composed of C20 or higher fatty acid is heated and melted with an extruder and extruded into a film form from a T-die. An unstretched polyamide film is obtained by cooling and solidifying on a cooling drum whose temperature is adjusted to 30 ° C. or less rotated by a known casting method.

  As a method for producing a film having a multilayer structure, any known method can be used. That is, the resin constituting each layer is melted at a temperature equal to or higher than the melting point by using a separate extruder, and each melted resin is superposed on a multilayer structure in a feed block or a multi-manifold die to form a sheet on the die. Extruded, and then brought into close contact with a cooling drum whose temperature has been adjusted to 30 ° C. or lower by a known method such as an electrostatic application casting method or an air knife method, rapidly cooled, solidified rapidly, and unstretched polyamide having a desired thickness Get a film.

  By simultaneously biaxially stretching the obtained monolayer or multilayer unstretched film in the MD direction and the TD direction with a tenter type simultaneous biaxial stretching machine, a simultaneously biaxially stretched polyamide film is obtained. Can do. Moreover, after extending | stretching the obtained unstretched film to MD direction, a polyamide film can be obtained by the tenter type | formula sequential biaxial stretching which extends | stretches to TD direction next. It is possible to obtain a polyamide film by other methods, for example, a tubular biaxial stretching method, but the polyamide film obtained by the same method may have a problem in thickness accuracy. It is preferable to manufacture by a stretching method. If the unstretched film is oriented, the stretchability may be lowered in a later step. Therefore, it is preferable that the unstretched film is substantially amorphous and non-oriented.

  The biaxially stretched polyamide film for cold forming according to the present invention transfers an unstretched film to a water bath adjusted to a temperature not exceeding 80 ° C., and is subjected to a water immersion treatment within 5 minutes. It is preferable to process.

  The film that has undergone the above stretching step is heat-treated at a temperature of 200 to 250 ° C. in a tenter that has been subjected to the stretching treatment, and is 0 to 10%, preferably 2 to 6% as necessary, in the MD direction and A relaxation process in the TD direction is performed.

  The biaxially stretched polyamide film for cold forming of the present invention preferably has a tensile breaking strength of 150 MPa or more in both MD and TD directions, more preferably 180 MPa or more, and further preferably 230 MPa or more. . When the tensile strength at break is less than 150 MPa, the mechanical strength is not sufficient and the moldability tends to be insufficient. In addition, the tensile elongation at break is preferably 60% or more and more preferably 80% or more in both the MD and TD directions from the same viewpoint as the tensile strength at break.

  The biaxially stretched polyamide film of the present invention may be subjected to a surface treatment such as corona discharge treatment or easy adhesion treatment to the extent that the effects of the present invention are not impaired.

Next, the laminated body of this invention is demonstrated.
The laminate of the present invention is obtained by sequentially laminating a base material layer, a metal foil, and a thermal adhesive layer. As the base material layer, the above-described biaxially stretched polyamide film for cold molding of the present invention is used.
Examples of the metal foil constituting the laminate of the present invention include an aluminum foil, a stainless steel foil, a copper foil, and the like, but an aluminum foil is preferable because it is moldable and lightweight. The material of the aluminum foil may be either a pure aluminum foil or an aluminum alloy foil.

  The thickness of the metal foil is preferably 20 to 80 μm and more preferably 25 to 60 μm in consideration of workability and barrier properties against oxygen, moisture and the like. When the thickness is less than 20 μm, the metal foil may be broken or a pinhole may occur during cold forming. On the other hand, if it exceeds 80 μm, the effect on breakage and pinhole generation at the time of cold forming is saturated, and the mass and rigidity increase, so that it becomes difficult to handle as a laminate or a container.

  For metal foil, in order to improve the adhesion of the base material layer to the polyamide film or to improve the corrosion resistance, undercoat treatment such as silane coupling agent or titanium coupling agent, corona discharge treatment, etc. It is preferable to perform the treatment.

  Next, the thermal adhesive layer constituting the laminate of the present invention is a resin layer for imparting heat sealability and chemical resistance for sealing.

  Examples of the resin used as the heat bonding layer include low density polyethylene, medium density polyethylene, high density polyethylene, linear low density polyethylene, polypropylene, polyethylene / polypropylene copolymer, ethylene-vinyl acetate copolymer, ionomer resin, ethylene- Examples include acrylic acid / methacrylic acid copolymers, ethylene-acrylic acid / methacrylic acid ester copolymers, and polyvinyl acetate resins. These resins may be used alone, or may be copolymerized or melt-mixed with other resins, or may be further acid-modified.

The thermal adhesive layer may have a single layer configuration or a multilayer configuration. The form of the heat bonding layer is not particularly limited, and may be the above-described sealant film or sheet made of a resin or a resin layer. The sealant film or sheet may be in an unstretched state or in a stretched state at a low magnification, but practically it is preferably in an unstretched state.
Among them, from the viewpoint of heat sealability and chemical resistance, it is possible to use unstretched films such as polypropylene, maleic acid-modified polypropylene, ethylene-acrylate copolymer, or ionomer resin or polyvinyl chloride resin as the heat adhesive layer. preferable.

  The thickness of the thermal adhesive layer is preferably 5 to 100 μm, and more preferably 10 to 80 μm.

  In the laminated body of this invention, it is preferable to provide the contact bonding layer 1 when laminating | stacking the biaxially stretched polyamide film for cold forming, and metal foil. For the adhesive layer 1, it is preferable to use a two-component curable polyurethane adhesive obtained by causing a polyisocyanate compound to act as a curing agent in a main component such as polyester polyol, polyether polyol, or acrylic polyol.

  As a method for forming (laminating) the adhesive layer 1, a lamination method such as a dry lamination method, a wet lamination method, a solvent-free dry lamination method, an extrusion lamination method, a co-extrusion method in which two or more resin layers are simultaneously extruded and laminated, Examples thereof include a coating method for forming a film with a coater.

  Furthermore, in the laminated body of this invention, it is preferable to provide the contact bonding layer 2 when laminating | stacking metal foil and a heat bonding layer. As the adhesive layer 2, like the adhesive layer 1, it is preferable to use a two-component curable polyurethane adhesive. Moreover, when using the laminated body of this invention for the exterior material of a lithium ion battery, it is preferable to use the thermoadhesive resin excellent in chemical resistance etc. as the contact bonding layer 2. FIG. As the heat-adhesive resin, it is preferable to use a modified polyolefin resin from the viewpoint of adhesion.

  The modified polyolefin resin is preferably a polyolefin resin modified with an unsaturated dicarboxylic acid or modified by oxidative decomposition of the resin, and more preferably a modified polyolefin modified with an unsaturated dicarboxylic acid. For example, polyolefin resins such as low density polyethylene, medium density polyethylene, high density polyethylene, linear low density polyethylene, polypropylene, polyethylene / polypropylene copolymer, etc. are unsaturated such as acrylic acid, methacrylic acid, maleic anhydride, fumaric acid, etc. A polyolefin resin modified with a dicarboxylic acid is preferred. As the unsaturated dicarboxylic acid, maleic anhydride is particularly preferable, and as the modified polyolefin resin, it is particularly preferable to use a so-called maleic anhydride-modified polyolefin resin.

  As a method for forming (laminating) the adhesive layer 2, the same method as that for the adhesive layer 1 can be employed.

  Since the laminated body of the present invention uses the biaxially stretched polyamide film for cold molding of the present invention, excellent moldability can be maintained even in molding under high humidity. That is, even under high humidity, deep drawing molding and stretch molding can be performed without causing delamination, cracks and pinholes in the laminate. More specifically, when the following Erichsen values are measured under high humidity of 65% RH and 90% RH, it is preferable that the Eriksen value is 3 mm or more.

  The “Ericsen value” in the present invention is measured using an Erichsen tester (No. 5755 manufactured by Yasuda Seiki Seisakusho Co., Ltd.) based on JISZ2247. It is pressed by the indentation depth, and the depth at which the spherical protrusion has entered before delamination, cracks, and pinholes are found in the laminate is obtained. The Erichsen value is measured every 0.5 mm.

The container of the present invention is obtained by cold-molding the laminate of the present invention, and among them, it is preferable that the container is obtained by performing deep drawing molding or overhang molding by cold molding.
Examples of such a container include a lithium ion battery exterior material for deep drawing and a press-through pack for overhang molding.

The present invention will be specifically described with reference to examples. The measurement and evaluation of various characteristic values in the examples were performed as follows.
[Tensile breaking strength / elongation]
The obtained biaxially stretched polyamide film was cut into a strip shape of 100 mm in the measurement direction and 15 mm perpendicular to the measurement direction at 23 ° C. × 50% RH, and a tension attached with a load cell for measuring 1 kN and a sample chuck. MD and TD directions were measured at a tensile speed of 100 mm / min using a testing machine (AG-1S manufactured by Shimadzu Corporation).
〔transparency〕
About the obtained biaxially stretched polyamide film, the haze value was measured according to JISK7136 using the Nippon Denshoku company haze meter (NDH4000).

[Slipperiness]
1. Coefficient of static friction: The coefficient of static friction of the obtained biaxially stretched polyamide film according to JIS K7125 under conditions of 65% relative humidity and 20 ° C. and 90% relative humidity and 20 ° C. Was measured.
2. Coefficient of dynamic friction: The obtained biaxially stretched polyamide film was subjected to a coefficient of dynamic friction with a film / film in accordance with JIS K7125 under conditions of 65% relative humidity and 20 ° C. and 90% relative humidity and 20 ° C. Was measured.
[Moldability]
The Erichsen value of the obtained laminate was determined in the same manner as described above under the conditions of a relative humidity of 65% and a temperature of 20 ° C, and a relative humidity of 90% and a temperature of 20 ° C. Under each condition, an Erichsen value of 3 mm or more was “◯”, 2 mm or more and less than 3 mm was “Δ”, and a value less than 2 mm was “X”.
In both conditions, those with “Δ” or more were judged to have good moldability, and those with “x” in either condition were judged to be inferior in moldability.

The following were used as the inorganic particles (silica) and the long-chain fatty acid bisamide.
[Silica (A)]
-S-1; Silicia 310P (manufactured by Fuji Silysia Chemical Ltd., average particle size 1.4 μm)
S-2: Seahoster KE-P50 (Nippon Shokubai Co., Ltd., average particle size 1.0 μm)
[Silica (B)]
S-3; Mizukasil P73 (manufactured by Mizusawa Science Co., Ltd., average particle size 2.5 μm)
S-4; Mizukasil P78A (manufactured by Mizusawa Science Co., Ltd., average particle size 3.0 μm)
[Long-chain fatty acid bisamide]
A-1; ethylene bislauric acid amide (Nippon Kasei Co., Ltd., SLIPAX L, carbon number 12 of fatty acid)
A-2; ethylene bis-stearic acid amide (Nippon Kasei Co., Ltd., SLIPAX E, carbon number 18 of fatty acid)
A-3: hexamethylene bis-stearic acid amide (Nippon Kasei Co., Ltd., SLIPAX ZHS, carbon number 18 of fatty acid)
A-4; ethylene bisbehenamide (Nippon Kasei Co., Ltd., SLIPAX B, carbon number 22 of fatty acid)
A-5: hexamethylene bisbehenamide (Nippon Kasei Co., Ltd., SLIPAX ZHB, fatty acid carbon number 22)
A-6; ethylenebiserucamide (Nippon Kasei Co., Ltd., SLIPAX R, carbon number 22 of fatty acid)

[Preparation of silica-containing master chip (polyamide resin composition)]
An autoclave having an internal volume of 30 liters was charged with 10 kg of ε-caprolactam, 1 kg of water, and 500 g of silica (S-1), maintained at 100 ° C., and stirred at this temperature until the reaction system became uniform. . Subsequently, the mixture was heated to 260 ° C. with stirring, maintained at a pressure of 1.5 MPa for 1 hour, further released to normal pressure over 1 hour, and further polymerized for 1 hour. When the polymerization was completed, the reaction product was discharged into a strand shape, cooled, solidified, and then cut to obtain polyamide resin composition pellets. Next, the pellets were scoured with hot water at 95 ° C. for 8 hours to remove unreacted monomers and then dried. The relative viscosity of the obtained polyamide resin composition was 2.7.
For silica S-2 to S-4, a pellet of the polyamide resin composition was obtained in the same manner as described above, and a master chip containing silica was prepared.

[Preparation of Master Chip (Polyamide Resin Composition) Containing Long-Chain Fatty Acid-Based Bisamide]
A nylon 6 resin (manufactured by Unitika, trade name: A1030BRF, relative viscosity 2.7) was dry blended with 1% of a long-chain fatty acid bisamide (A-1), and then the inner diameter at a cylinder temperature set to 250 ° C. It was melt-kneaded with a 30 mm twin-screw extruder, extruded into a strand, cooled, solidified, and then cut to obtain polyamide resin composition pellets.
For the long-chain fatty acid-based bisamides A-2 to A-6, a polyamide resin composition pellet was obtained in the same manner as described above, and a master chip containing the long-chain fatty acid-based bisamide was prepared.

Example 1
Master chip containing silica (S-1), master chip containing silica (S-3), and nylon 6 resin (product name: A1030BRF, relative viscosity 2.7, manufactured by Unitika Ltd.) A master chip containing a long chain fatty acid bisamide (A-4) was mixed and adjusted so that the content of silica particles and long chain fatty acid bisamide in the polyamide resin composition was as shown in Table 1. These were supplied to a single-screw extruder having an inner diameter of 90 mm set at a cylinder temperature of 260 ° C., extruded from a T die, and contacted with a cooling roll having a set temperature of 20 ° C. to obtain an unstretched sheet having a thickness of 140 μm. The obtained unstretched sheet was immersed in a warm water layer adjusted to 50 ° C. for 1 minute, and stretched using a simultaneous biaxial stretching machine. At this time, after stretching at 190 ° C., stretching 2.8 times in the MD direction and 3.2 times in the TD direction, performing heat treatment at 210 ° C. for 5 seconds, and further performing a relaxation treatment of 5% in the TD direction. Then, a biaxially stretched polyamide film having a thickness of 15 μm was obtained.

Next, corona discharge treatment was performed on one side of the obtained biaxially stretched polyamide film, and a two-component polyurethane adhesive (TM-K55 / CAT-10L manufactured by Toyo Moment Co., Ltd.) was applied to the treated surface at a rate of 5 g / the coating is m ^2, (to form an adhesive layer 1) was dried for 10 seconds at 80 ° C.. An aluminum foil having a thickness of 50 μm was bonded to the adhesive layer 1.
The same type of adhesive as that of the adhesive layer 1 was applied to the aluminum foil side of the laminate of the biaxially stretched polyamide film and the aluminum foil under the same conditions (adhesive layer 2 was formed). Then, an unstretched polypropylene film (GHC thickness 50 μm, manufactured by Mitsui Chemicals, Inc.) was bonded to the adhesive layer 2 and subjected to an aging treatment for 72 hours in an atmosphere at 40 ° C. to prepare a laminate.

Examples 2-11, Comparative Examples 1-6
Master chip containing silica and master chip containing long chain fatty acid bisamide so that the types and contents of silica particles and long chain fatty acid bisamide in the polyamide resin composition are as shown in Table 1. A biaxially stretched polyamide film was obtained in the same manner as in Example 1 except that the amount was changed and the stretch ratio was changed to that shown in Table 1.
And the laminated body was produced using the biaxially stretched polyamide film obtained by carrying out similarly to Example 1. FIG.

Table 1 shows the characteristic values and evaluations of the biaxially stretched polyamide films and laminates obtained in Examples 1 to 11 and Comparative Examples 1 to 6.

In Examples 1 to 11, since the biaxially stretched polyamide resin film was produced using inorganic particles and long-chain fatty acid-based bisamides based on the conditions described in the claims, the slipperiness was excellent even under high humidity. And moldability.
In particular, in Examples 1 to 7 using two types of silica satisfying a specific average particle diameter and content as inorganic particles, both transparency and moldability were particularly excellent.

On the other hand, in Comparative Examples 1 to 3, since long chain fatty acid bisamides composed of fatty acids of less than C20 were used, the friction coefficient under high humidity was high and the moldability was poor. Moreover, since the comparative example 4 did not contain inorganic particles, any friction coefficient was high and the moldability was poor. In Comparative Example 5, the content of the long-chain fatty acid bisamide was too small, so the friction coefficient under high humidity was high and the moldability was poor. In Comparative Example 6, since the content of the long-chain fatty acid bisamide was too much, the amount of bleed out was excessive, the adhesion with the metal foil was deteriorated, and the moldability was inferior.

Claims (6)

A polyamide film comprising a polyamide resin composition containing inorganic particles and a long-chain fatty acid bisamide composed of C20 or more fatty acid, wherein the long-chain fatty acid bisamide content is 0.01 to 0.10% by mass. A biaxially stretched polyamide film for cold forming, characterized by The biaxially stretched polyamide film for cold forming according to claim 1, wherein the long-chain fatty acid bisamide composed of C20 or higher fatty acid is at least one of ethylene bisbehenamide and ethylenebiserucamide. The inorganic particles include silica (A) having an average particle diameter of 1.0 to 1.4 μm and silica (B) having an average particle diameter of 2.5 to 3.0 μm, and silica (A) and silica (B) The cold content according to claim 1 or 2, wherein the total content is 0.1 to 0.3% by mass, and the content of silica (A) is 3.0 or more times the content of silica (B). Biaxially stretched polyamide film for molding. The biaxially stretched polyamide film for cold forming according to any one of claims 1 to 3, wherein the main component of the polyamide resin is nylon 6. A laminate in which a base material layer, a metal foil, and a thermal adhesive layer are laminated in order, wherein the base material layer is the biaxially stretched polyamide film for cold forming according to any one of claims 1 to 4. A laminate for cold forming. A container obtained by deep drawing or stretch molding the laminate for cold forming according to claim 5.